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Publication numberUS20070193186 A1
Publication typeApplication
Application numberUS 11/649,524
Publication dateAug 23, 2007
Filing dateJan 3, 2007
Priority dateMar 31, 2003
Also published asUS20040187426
Publication number11649524, 649524, US 2007/0193186 A1, US 2007/193186 A1, US 20070193186 A1, US 20070193186A1, US 2007193186 A1, US 2007193186A1, US-A1-20070193186, US-A1-2007193186, US2007/0193186A1, US2007/193186A1, US20070193186 A1, US20070193186A1, US2007193186 A1, US2007193186A1
InventorsMichael Callahan
Original AssigneeMichael Callahan
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Structures and components thereof
US 20070193186 A1
Abstract
A load-bearing structure, said structure comprising a plurality of single elongated chords, the exterior surface of each said chord defining a cross-section, said cross-section having an interior volume, each said chord having an elongated centerline, said structure further including a plurality of elongated cross-members, each of said cross-members having at least a first and a second end, said elongated cross-members cooperating in maintaining said single elongated chords spaced apart by a dimension substantially greater than said cross-section, at least one of said chords having at least one elongated opening in said exterior surface, through which one of said ends enters said volume interior.
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Claims(28)
1. In a load-bearing structure,
said structure comprising a plurality of single elongated chords, the exterior surface of each said chord defining a cross-section, said cross-section having an interior volume, each said chord having an elongated centerline,
said structure further including a plurality of elongated cross-members, each of said cross-members having at least a first and a second end,
said elongated cross-members cooperating in maintaining said single elongated chords spaced apart by a dimension substantially greater than said cross-section,
at least one of said chords having at least one elongated opening in said exterior surface, through which one of said ends enters said volume interior.
2. The structure according to claim 1, wherein said opening is substantially continuous.
3. The structure according to claim 1, and further including a cover over a portion of said opening.
4. The structure according to claim 1, wherein said at least one chord comprises at least one extrusion.
5. The structure according to claim 1, wherein at least one mechanical fastener is employed in fixing said cross-member with said chord.
6. The structure according to claim 4, wherein at least one mechanical fastener is employed in fixing said cross-member and said chord.
7. The structure according to claim 1, wherein said cross-section has a generally circular cross-section with a diameter not exceeding 2.0 inches.
8. The structure according to claim 1, wherein said exterior surface is substantially without projections.
9. The structure according to claim 1, wherein said exterior surface has at least two opposed flatted surfaces.
10. The structure according to claim 1, wherein said exterior surface defines a generally octagonal cross-section.
11. The structure according to claim 1, wherein said chord further includes at least one internal feature that stiffens said chord.
12. The structure according to claim 1, wherein said chord further includes at least one internal feature cooperating in receiving said end.
13. The structure according to claim 1, wherein said chord accepts internal to said volume at least one local reinforcing element.
14. The structure according to claim 1, wherein said structure further provides for load-bearing end-wise connection of a plurality of said structures to form a load-bearing structure of greater length than that of one of said structures.
15. The structure according to claim 1, wherein said chords of said structure include at least one internal feature cooperating in receiving additional elements used for load-bearing end-wise connection of a plurality of said structures, to form a load-bearing structure of greater length than that of one of said structures.
16. In a load-bearing structure,
said structure comprising a plurality of substantially spaced-apart single chords, each of said chords comprising at least one extrusion and having a cross-section, said cross-section defining a volume interior, said chord further having an elongated centerline,
said structure further including a plurality of elongated cross-members, each of said cross-members having at least a first and a second end,
said elongated cross-members cooperating in maintaining said chords spaced apart by a dimension greater than said cross-section,
said chords further having at least one elongated opening, said opening extending parallel to said elongated centerline, and via which one of said ends enters said volume interior.
17. The structure according to claim 16, wherein a mechanical fastener is employed in fixing said cross-member with said chord.
18. The structure according to claim 16, wherein said chord is substantially circular in cross-section and not more than 2.0 inches in diameter.
19. The structure according to claim 16, wherein said extrusion further includes at least one internal feature that stiffens said chord.
20. The structure according to claim 16, wherein said extrusion further includes at least one internal feature cooperating in receiving said end.
21. The structure according to claim 16, wherein said chord accepts internal to said volume at least one local reinforcing element.
22. The structure according to claim 16, wherein said structure further provides for load-bearing end-wise connection of a plurality of said structures to form a load-bearing structure of greater length than that of one of said structures.
23. The structure according to claim 16, wherein said single structural shape of said structure includes at least one internal feature cooperating in load-bearing end-wise connection of a plurality of said structures.
24. In a truss structure,
said truss structure including at least three, generally parallel, elongated chords, each of said chords having a cross-section and an elongated centerline and each of said chords being spaced apart one from the others by a dimension substantially greater than said cross-section,
said truss structure further including a plurality of elongated cross-members, each of said cross-members having at least a first and a second end,
said elongated cross-members cooperating in maintaining said chords in said spaced apart relationship, each from the other,
said chords each having at least one elongated opening, said opening extending parallel with said elongated centerline, and via which one of said ends enters said volume interior.
25. The structure according to claim 24, wherein said chords each comprise at least one extrusion.
26. The structure according to claim 24, wherein at least one mechanical fastener is employed in fixing said cross-member and said chord.
27. The structure according to claim 24, wherein at least one mechanical fastener is employed in fixing said cross-member and said chord.
28. The structure according to claim 24, wherein said structure further provides for load-bearing end-wise connection of a plurality of said structures to form a load-bearing structure of greater length than one of said structures.
Description
  • [0001]
    This application is a Divisional Application of U.S. application Ser. No. 10/403,651, filed Mar. 31, 2003, the entire disclosure of which is hereby incorporated by reference.
  • FIELD OF THE INVENTION
  • [0002]
    This application relates structures and components thereof such as are used in connection with lighting and other equipment.
  • BRIEF SUMMARY OF THE INVENTION
  • [0003]
    The application discloses a variety of improvements to structures and components thereof such as are used in connection with lighting and other equipment.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0004]
    FIG. 1A is a cross section of the prior art circular pipe and tubing widely employed.
  • [0005]
    FIG. 1B is a cross section of the prior art square tubing as has been employed.
  • [0006]
    FIG. 1C is a cross section of the prior art square tubing with rounded corners that has been employed.
  • [0007]
    FIG. 1D is a cross section of the prior art “unistrut” track that has been employed.
  • [0008]
    FIG. 1E is a cross section of the prior art extruded tubing having an integral “unistrut” track as has been employed.
  • [0009]
    FIG. 1F is a cross section of tubing having a circular external profile but varying wall thickness to increase its strength/stiffness in certain orientations.
  • [0010]
    FIG. 1G is a cross section of tubing having a generally octagonal external profile with rounded corners.
  • [0011]
    FIG. 1H is a cross section of tubing having a similar octagonal profile to that of the tubing of FIG. 1G with the addition of the varying wall thickness of the tubing of FIG. 1F
  • [0012]
    FIG. 1I is a cross section of tubing having an internal web to increase strength/stiffness.
  • [0013]
    FIG. 1J is a cross section of tubing having an internal structure to increase its strength/stiffness.
  • [0014]
    FIG. 1K is a cross section of tubing having an internal web and varying wall thickness to increase its strength/stiffness.
  • [0015]
    FIG. 1L is a cross section of tubing having internal ribs that increase its strength/stiffness.
  • [0016]
    FIG. 1M is a cross section of tubing having both another external profile and having internal ribs.
  • [0017]
    FIG. 1N is a cross section of tubing having internal ribs and illustrating how another element can be inserted in it and fixed in place.
  • [0018]
    FIG. 1O is a cross section of tubing having the internal profile of the tubing of FIG. 1L with a different external profile.
  • [0019]
    FIG. 1P is a cross section of tubing having the internal profile of the tubing of FIG. 1N and the external profile of FIG. 1O illustrating another element inserted in it.
  • [0020]
    FIG. 1Q is a cross section of tubing having alternative external and internal profiles and illustrating another element inserted in it.
  • [0021]
    FIG. 1R is a cross section of tubing having internal ribs and webs for stiffening.
  • [0022]
    FIG. 1S is a cross section of tubing having internal webs for stiffening.
  • [0023]
    FIG. 1T is a cross section of tubing having internal webs for stiffening and showing the insertion of an additional element.
  • [0024]
    FIG. 1U is a cross section of tubing having internal webs for stiffening and providing a “unistrut” type feature.
  • [0025]
    FIG. 1V is a cross section of tubing having a large recess.
  • [0026]
    FIG. 1W is a cross section of tubing having a plurality of recesses that provide for stiffening and accept a “key” that prevents rotation.
  • [0027]
    FIG. 2A is a side elevation of a “cheseboro” type clamp illustrating one possible interior profile that prevents rotation of a tube that employs a suitable exterior profile as illustrated in many of the prior Figures.
  • [0028]
    FIG. 2B is a side elevation of a “cheseboro” type clamp having an interior profile similar to that of the clamp of FIG. 2A illustrating its use with conventional tubing and certain other features.
  • [0029]
    FIG. 2C is a detail of the side elevation of the prior Figures showing one possible interior profile.
  • [0030]
    FIG. 2D is a cross section of a structural shape accepting tubing and having many applications.
  • [0031]
    FIG. 2E is a cross section of a structural shape like that of FIG. 2D but having a continuously open slot at least at the cutting plane.
  • [0032]
    FIG. 2F is a cross section of a structural shape like that of FIGS. 2D and 2E, illustrating the use of a bolt and nut plate for fixing the tubing in place.
  • [0033]
    FIG. 2G is a cross section of a structural shape like that of the prior Figures with the addition of an internal profile similar in principle to that of FIGS. 2A-2C, that both accepts conventional tubing and prevents the rotation of tubing having a suitable exterior profile, here illustrated with a conventional tube.
  • [0034]
    FIG. 2H is a cross section of the structural shape of FIG. 2G, shown with tubing having an anti-rotation feature.
  • [0035]
    FIG. 2I is a cross section of the structural shape of the prior Figures in which the nut plate slot incorporates a “unistrut” type detail.
  • [0036]
    FIG. 2J is a cross section of the structural shape of the prior Figures and incorporating an external flange.
  • [0037]
    FIG. 2K is a cross section of the structural shape of the prior Figures having provisions on its exterior for attachment to other objects.
  • [0038]
    FIG. 2L is a cross section of the structural shape of FIG. 2J showing another structural shape welded to it.
  • [0039]
    FIG. 2M is a cross section of the structural shape of FIG. 2J illustrating the use of an interlocking structural shape.
  • [0040]
    FIG. 2N is a cross section of the structural shape of the prior Figures illustrating flanges large enough to permit bolted and similar mechanical connections.
  • [0041]
    FIG. 2O is a side elevation of a section of the structural shape of FIG. 2N attached to a tube.
  • [0042]
    FIG. 2P is a plan or top view of FIG. 2O.
  • [0043]
    FIG. 2P is a side elevation equivalent to FIG. 2O with the addition of a second such section bolted to the first to form a rigid right-angle fitting.
  • [0044]
    FIG. 2R is a section through an assembly including two structural shapes welded to an intermediate member and used to maintain two tubes in a parallel relationship.
  • [0045]
    FIG. 2S is a side elevation of an assembly as illustrated in the prior Figure.
  • [0046]
    FIG. 2T is a section through an assembly including two structural shapes interconnected by interlocking intermediate structural shapes and used to maintain two tubes in a parallel relationship.
  • [0047]
    FIG. 2U is a side elevation of an assembly as illustrated in the prior Figure.
  • [0048]
    FIG. 2V is a section through an assembly including two structural shapes joined by an intermediate member and used to maintain two tubes in a parallel relationship.
  • [0049]
    FIG. 2W is a side elevation of an assembly as illustrated in the prior Figure.
  • [0050]
    FIG. 3A is a cross section of a paired shape having advantages in the support of fixtures and other loads.
  • [0051]
    FIG. 3B is a top view of the paired shape of FIG. 3A.
  • [0052]
    FIG. 3C is a cross section illustrating one application of the paired shape of FIG. 3A, showing the use of a bolt whose head is accommodated in the profile of the paired shape.
  • [0053]
    FIG. 3D is a top view of the application illustrated in FIG. 3C.
  • [0054]
    FIG. 3E is a cross section illustrating a second application of the paired shape of FIG. 3A, showing the use of a nut accommodated in the profile of the paired shape.
  • [0055]
    FIG. 3F is a top view of the application illustrated in FIG. 3E.
  • [0056]
    FIG. 3G is a cross section illustrating one application of the paired shape of FIG. 3A, showing the use of a bolt whose cap-style head is accommodated in the profile of the paired shapes.
  • [0057]
    FIG. 3H is a top view of the application illustrated in FIG. 3G.
  • [0058]
    FIG. 3I is a cross section illustrating the use of a fastener with a head narrow enough in one dimension to permit its insertion from either side of the paired shapes.
  • [0059]
    FIG. 3J is a top view of the application illustrated in FIG. 3I.
  • [0060]
    FIG. 3K is a cross section illustrating the insertion of a spacer plug between the paired shape illustrated in the prior Figures.
  • [0061]
    FIG. 3L is a top view of the spacer plug illustrated in FIG. 3K.
  • [0062]
    FIG. 3M is a cross section illustrating another embodiment of paired shapes, which accepts an interlocking place.
  • [0063]
    FIG. 3N is a top view of the application of FIG. 3M.
  • [0064]
    FIG. 3O is a cross section illustrating the paired shapes of FIG. 3M in use.
  • [0065]
    FIG. 3Q is a cross section illustrating a plug shape that can be used with the paired shapes of FIG. 3M.
  • [0066]
    FIG. 3QQ is a detail view from the same perspective as FIG. 3Q, showing the plug shape in isolation.
  • [0067]
    FIG. 3R is another embodiment of paired shapes, which accept two interlocking plates.
  • [0068]
    FIG. 3S is a cross section illustrating the paired shapes and interlocking plates of FIG. 3R in use.
  • [0069]
    FIG. 3T is another embodiment of paired shapes.
  • [0070]
    FIG. 3U is a plug shape that can be used with the paired shapes of FIG. 3T.
  • [0071]
    FIG. 3V is a cross section illustrating one method of supporting two paired shapes in the required relationship.
  • [0072]
    FIG. 3W is a bottom view of the arrangement of FIG. 3V.
  • [0073]
    FIG. 3X is a cross section illustrating another method of supporting paired shapes.
  • [0074]
    FIG. 3XX is a detail view from the same perspective as FIG. 3X showing the view of another embodiment of a paired shapes, showing the support in isolation.
  • [0075]
    FIG. 3Y is a cross section illustrating a support useable with the paired shapes illustrated in FIG. 3T.
  • [0076]
    FIG. 4A is an elevation of one end of a typical 12″12″ truss.
  • [0077]
    FIG. 4B is an elevation of one end of a typical “20.5″” truss.
  • [0078]
    FIG. 4C is an elevation of one end of one embodiment of an improved truss in one orientation.
  • [0079]
    FIG. 4D is an elevation of one end of an embodiment of an improved truss in another orientation.
  • [0080]
    FIG. 4E is an elevation of a pair of the embodiment of the prior Figures in one orientation.
  • [0081]
    FIG. 4F is an elevation of a pair of the embodiment of the prior Figures in another orientation.
  • [0082]
    FIG. 4G is an elevation of a trio of the embodiment of the prior Figures in one orientation.
  • [0083]
    FIG. 4H is an elevation of one short side of the embodiment of the prior Figures.
  • [0084]
    FIG. 4I is an elevation of one long side of the embodiment of the prior Figures.
  • [0085]
    FIG. 4J is an elevation of the other short side of the embodiment of the prior Figures.
  • [0086]
    FIG. 4K is an elevation of the other long side of the embodiment of the prior Figures.
  • [0087]
    FIG. 4L is a detail view of one end of the embodiment of the prior Figures from the same perspective as FIG. 4I.
  • [0088]
    FIG. 4M is a cross section through the end of one embodiment of the prior Figures on a cutting plane illustrated in FIG. 4L, looking towards the short side.
  • [0089]
    FIG. 4K is a cross section through the end of one embodiment of the prior Figures on a cutting plane illustrated in FIG. 4L, looking towards the truss section end.
  • [0090]
    FIG. 4O is an elevation of one end of the embodiment of the prior Figures from the perspective identified in FIG. 4L, showing additional detail.
  • [0091]
    FIG. 4P is a section through one major chord of a truss or other structure illustrating the geometry of the intersection of the major chord and a cross brace.
  • [0092]
    FIG. 4Q is an oblique view of the intersection of the major chord and a cross brace as illustrated in FIG. 4P.
  • [0093]
    FIG. 4R is a cross section through the structural shape used for the cross braces of the prior two Figures.
  • [0094]
    FIG. 4S is a section through a structural shape that may be used as one major chord of a truss or other structure illustrating the geometry of its intersection with another structural shape.
  • [0095]
    FIG. 4T is an oblique side view of the intersection of the two structural shapes illustrated in FIG. 4S.
  • [0096]
    FIG. 4U is an oblique top view of the intersection of the two structural shapes illustrated in FIG. 4S.
  • [0097]
    FIG. 4V is a cross section through the another structural shape of the prior three Figures.
  • [0098]
    FIG. 4W is an oblique view of one end of a length of structural shape with internal reinforcement.
  • [0099]
    FIG. 4X is a cross section through the structural shape illustrated in FIG. 4W, showing the reinforcement.
  • [0100]
    FIG. 4Y is a detail of a cross section through the structural shape and reinforcement of the prior Figures at the location of a pass hole.
  • [0101]
    FIG. 4Z is a detail of a cross section like the prior Figures illustrating the use of a stack of thin plates to form the reinforcement.
  • [0102]
    FIG. 5A is a cross section through a pair of truss sections or other structures illustrating the use of a bolted connection between them.
  • [0103]
    FIG. 5B is a similar view to FIG. 5A with the addition of brackets captivating the female threaded fasteners.
  • [0104]
    FIG. 5C is an oblique view of the subject matter of FIG. 5B showing the use of a common bracket to captivate a plurality of threaded female fasteners.
  • [0105]
    FIG. 5D is a similar view to FIG. 5B with the addition of brackets for captivating washers on the bolt side of the connections.
  • [0106]
    FIG. 5E is a similar view to FIG. 5B in which the means to captivate the female threaded fastener is made integral with the truss structure.
  • [0107]
    FIG. 5F is an elevation of a female threaded insert suitable for employment with the captivating method illustrated in FIG. 5E.
  • [0108]
    FIG. 5G is a side elevation of the threaded insert illustrated in FIG. 5F.
  • [0109]
    FIG. 5H is a top view of the threaded insert illustrated in FIGS. 5F and 5G.
  • [0110]
    FIG. 5I is an elevation of the truss structure with the captivating method illustrated in FIG. 5E.
  • [0111]
    FIG. 5J is the same elevation as FIG. 5I with the addition of the threaded insert illustrated in FIGS. 5F-5H.
  • [0112]
    FIG. 5K is a cross section through the truss end in a vertical plane having the same subject matter as FIG. 5J.
  • [0113]
    FIG. 5L is the same elevation of the truss end as FIG. 5J illustrating another method of aligning the threaded insert.
  • [0114]
    FIG. 5M is the same cross section of the truss end as FIG. 5K illustrating the another method of aligning the threaded insert also illustrated in FIG. 5L.
  • [0115]
    FIG. 5N is a cross section similar to FIG. 5E illustrating means to captivate hardware on both sides of a connection.
  • [0116]
    FIG. 5O is an elevation of an insert suitable for use in the previously illustrated truss ends that includes both threaded and unthreaded holes.
  • [0117]
    FIG. 5P is a side elevation of the insert illustrated in FIG. 5O.
  • [0118]
    FIG. 5Q is a top view of the insert illustrated in FIGS. 5O and 5P.
  • [0119]
    FIG. 5R is an oblique view of the subject matter of FIG. 5N illustrating the use of the insert illustrated in FIGS. 5O-5Q in two versions, one including a plurality of both threaded and unthreaded holes.
  • [0120]
    FIG. 5S is a cross section through a vertical plane equivalent in perspective to FIGS. 5K and 5M, but through the structure on both sides of a connection, and showing the insert illustrated in FIGS. 5O-5Q in use.
  • [0121]
    FIG. 5T is a top view of a male and a female clevis fitting as may be employed in joining trusses and other structures.
  • [0122]
    FIG. 5U is a side view of a male and a female clevis fitting as illustrated in the prior Figure, FIG. 5T.
  • [0123]
    FIG. 5V is a side elevation of the ends of two sections of truss, illustrating the male and female clevis fittings of the prior FIGS. 5T and 5U installed in the truss ends.
  • [0124]
    FIG. 5W is a top view of the ends of two truss sections of truss, illustrating a joining “tang” installed on one side of the truss connection.
  • [0125]
    FIG. 5X is a side elevation of the joining tang illustrated in the prior FIG. 5W seen in isolation.
  • [0126]
    FIG. 5Y is an end elevation of the joining tang as illustrated in prior FIGS. 5W and 5X seen in isolation.
  • [0127]
    FIG. 5Z is a side elevation of the subject matter of FIG. 5W.
  • [0128]
    FIG. 6A is an elevation of one side of a unit that may be used to interconnect truss sections and for other purposes.
  • [0129]
    FIG. 6B is a detail of one hole pattern that may be employed in a unit like that illustrated in the prior FIG. 6A.
  • [0130]
    FIG. 6C is a detail of a hole pattern similar to that illustrated in prior FIG. 6B, but having additional holes to permit use with additional truss types.
  • [0131]
    FIG. 6D is a cross section through a unit like that illustrated in FIG. 6A and other Figures.
  • [0132]
    FIG. 6E is a cross section through one of the possible embodiments of a structural shape that can be used at the corners of a unit like that illustrated in the prior FIGS. 6A and 6D.
  • [0133]
    FIG. 6F is a cross section through another embodiment of a structural shape like that in the prior Figures.
  • [0134]
    FIG. 6G is a cross section through another embodiment of a structural shape like that in the prior Figures.
  • [0135]
    FIG. 6H is a side elevation of a unit that may be used to interconnect trusses and for other purposes and including features like casters and a stacking interlock detail.
  • [0136]
    FIG. 6I is a side elevation of a unit that may be used to interconnect trusses and for other purposes and including the features illustrated in the prior FIG. 6H and a handle detail.
  • [0137]
    FIG. 6J is a side elevation illustrating a unit such as illustrated in the prior Figures used to join trusses and suspended by a chain motor.
  • [0138]
    FIG. 6K is a cross section through a structural shape suitable for use at the corners of a unit having sides of different widths.
  • [0139]
    FIG. 6L is a cross section through a unit like that illustrated in FIGS. 6H and 6I, said cross section through a vertical plane and illustrating various features including structural shapes for the top and bottom edges of the unit and the casters and interlocking stacking detail.
  • [0140]
    FIG. 6M is a cross section through one structural shape suitable for uses including the top edge of the unit illustrated in cross section in FIG. 6L.
  • [0141]
    FIG. 6N is a cross section through another structural shape suitable for uses including the top edge of the unit illustrated in cross section in FIG. 6L.
  • [0142]
    FIG. 6O is a cross section through another structural shape suitable for uses including the top edge of the unit illustrated in cross section in FIG. 6L.
  • [0143]
    FIG. 6P is a cross section through one structural shape suitable for uses including the bottom edge of the unit illustrated in cross section in FIG. 6L.
  • [0144]
    FIG. 6Q is a cross section through another structural shape suitable for uses including the bottom edge of the unit illustrated in cross section in FIG. 6L.
  • [0145]
    FIG. 6R is a cross section through one structural shape suitable for uses including the bottom edge of the unit illustrated in cross section in FIG. 6L.
  • [0146]
    FIG. 6S is a cross section illustrating the adjacent top and bottom chords of two stacked truss sections.
  • [0147]
    FIG. 6T is a cross section of a unit having the interlocking stacking detail and caster arrangement illustrated in the prior Figures, including FIG. 6L. stacked atop a truss section.
  • [0148]
    FIG. 6U is a cross section illustrating two units having the features illustrated in the prior Figures including FIG. 6L stacked one atop the other.
  • [0149]
    FIG. 6V is a section through a handle detail such as illustrated in FIG. 6I.
  • [0150]
    FIG. 6W is a section through a handle detail as illustrated in the prior FIG. 6V with an adapter used to permit a threaded structural connection in the area occupied by the handle detail.
  • [0151]
    FIG. 6X is a side elevation illustrating the use of an adapter to permit the use of a unit with a truss section or other element having a larger size.
  • [0152]
    FIG. 7A is a side elevation of a unit equivalent to the view in FIG. 6I with the addition of provisions to insert tubing into the unit.
  • [0153]
    FIG. 7B is a cross section through a structural shape suitable for uses including at the bottom edge of the unit illustrated in the prior FIG. 7A and having provisions to accept and retain tubing.
  • [0154]
    FIG. 7C is a cross section through another structural shape suitable for uses including at the bottom edge of the unit illustrated in the prior FIG. 7A and having provisions to accept a tube and a flange.
  • [0155]
    FIG. 7D is a cross section through another structural shape suitable for uses including at the bottom edge of the unit illustrated in the prior FIG. 7A, having provisions to accept a tube, and illustrating a wire rope loop around its circular portion.
  • [0156]
    FIG. 7E is a cross section through another structural shape suitable for uses including at the bottom edge of the unit illustrated in the prior FIG. 7A, having provisions to accept a tube, and to accommodate various fittings.
  • [0157]
    FIG. 7F is a cross section of the same structural shape illustrated in FIG. 7E with a fitting suitable for fixing the tube in place.
  • [0158]
    FIG. 7G is a side elevation of the fitting illustrated in prior FIG. 7F.
  • [0159]
    FIG. 7H is an end elevation of the fitting seen in the prior two Figures.
  • [0160]
    FIG. 7I is a cross section of the same structural shape illustrated in FIG. 7E with a fitting suitable for use in suspending the unit.
  • [0161]
    FIG. 7J is a cross section of the same structural shape illustrated in FIG. 7E with another fitting suitable for use in suspending the unit.
  • [0162]
    FIG. 7K is a side elevation of the fitting illustrated in prior FIG. 7J.
  • [0163]
    FIG. 7I is a cross section through the fitting seen in the prior two Figures.
  • [0164]
    FIG. 7M is an oblique view of the subject matter of FIG. 7J.
  • [0165]
    FIG. 7N is an end elevation of a bracket that may be used to clamp a tube parallel to a side of the illustrated unit.
  • [0166]
    FIG. 7O is a side elevation of the bracket illustrated in the prior FIG. 7N.
  • [0167]
    FIG. 7P is an end view of the bracket illustrated in the prior two Figures in use.
  • [0168]
    FIG. 7Q is a side view of the bracket illustrated in the prior FIGS. 7N and 7O in use.
  • [0169]
    FIG. 7R is a cross section of a structural shape suitable to clamp a tube to a surface such as a side of the unit illustrated.
  • [0170]
    FIG. 7S is a side elevation of the structural shape illustrated in the prior FIG. 7R in a short length.
  • [0171]
    FIG. 7T is a side elevation of the structural shape illustrated in the prior FIG. 7R in an extended length.
  • [0172]
    FIG. 7U is a cross section of another structural shape suitable to attach a tube to a surface.
  • [0173]
    FIG. 7V is a cross section of another structural shape suitable to attach a tube to a surface.
  • [0174]
    FIG. 7W is an elevation of structural shapes like those illustrated in the prior Figures in use.
  • [0175]
    FIG. 7X is an elevation from another side of structural shapes like those illustrated in the prior Figures in use.
  • [0176]
    FIG. 8A is one elevation of a structure assembled from a plurality of units, tubes, and structural shapes as illustrated in prior Figures, seen from a perspective identified in FIG. 8C.
  • [0177]
    FIG. 8B is another elevation of a structure assembled from a plurality of units, tubes, and structural shapes as illustrated in prior Figures, seen from a perspective identified in FIG. 8C.
  • [0178]
    FIG. 8C is a plan view of a structure assembled from a plurality of units, tubes, and structural shapes as illustrated in prior Figures, elevations of which appear as FIGS. 8A and 8B.
  • [0179]
    FIG. 8D is one elevation of a structure assembled from a plurality of units, truss sections, tubes, and structural shapes as illustrated in prior Figures, seen from a perspective identified in FIG. 8F.
  • [0180]
    FIG. 8E is another elevation of a structure assembled from a plurality of units, truss sections, tubes, and structural shapes as illustrated in prior Figures, seen from a perspective identified in FIG. 8F.
  • [0181]
    FIG. 8F is a plan view of a structure assembled from a plurality of units, truss sections, tubes, and structural shapes as illustrated in prior Figures, elevations of which appear as FIGS. 8D and 8E.
  • [0182]
    FIG. 8G is one elevation of a structure assembled from a plurality of units, truss sections, tubes, and structural shapes as illustrated in prior Figures, and provided with means permitting a plurality of such structures to be stacked.
  • [0183]
    FIG. 8H is another elevation of a structure assembled from a plurality of units, truss sections, tubes, and structural shapes as illustrated in prior Figures, and provided with means permitting a plurality of such structures to be stacked.
  • [0184]
    FIG. 8I is a detailed view of the stacking detail from the same perspective as FIG. 8G.
  • [0185]
    FIG. 8J is a detailed view of the stacking detail from the same perspective as FIG. 8G.
  • [0186]
    FIG. 8K is an elevation showing the use of a planar element to maintain the spacial relationship between a unit and another element.
  • [0187]
    FIG. 8L is a plan view of the subject matter of FIG. 8L.
  • [0188]
    FIG. 8M is an elevation showing the use of elongated structural shapes to maintain the spacial relationship between a unit and another element.
  • [0189]
    FIG. 8N is an elevation illustrating three larger units stacked for storage and/or transport.
  • [0190]
    FIG. 8O is an elevation of the same subject matter as the prior Figure illustrating the attachment of lifting means.
  • [0191]
    FIG. 8P is an elevation of the same subject matter as the prior Figure illustrating the top larger unit being lifted.
  • [0192]
    FIG. 8Q is an elevation of the same subject matter as the prior Figure illustrating all but the bottom larger unit being lifted.
  • [0193]
    FIG. 8R is a side elevation of one design for a unit from which larger units can be assembled.
  • [0194]
    FIG. 8RR is a detailed view from the prior Figure.
  • [0195]
    FIG. 8S is a section through the unit of the prior Figures in a plane parallel to that of the prior Figures.
  • [0196]
    FIG. 8T is a plan or top view of the portion of the unit seen in FIG. 8RR.
  • [0197]
    FIG. 8U is an elevation of the end of the unit.
  • [0198]
    FIG. 8V is a section through the unit at right angles to the section of FIG. 8S
  • [0199]
    FIG. 9A is a side elevation of a wheel bracket.
  • [0200]
    FIG. 9B is a side elevation of a wheel structure in the process of being attached or detached from the chords of a truss.
  • [0201]
    FIG. 9C is a section through a wheel bracket from the same perspective as the prior two Figures.
  • [0202]
    FIG. 9D is a side elevation of the wheel bracket attached to the chords of one truss which is stacked on a second.
  • [0203]
    FIG. 9E is an end elevation of the wheel bracket illustrated in the prior Figures.
  • [0204]
    FIG. 9F is an end elevation of the central member used in the wheel bracket illustrated in the prior Figures.
  • [0205]
    FIG. 9G is an exploded end elevation of one alternative approach to the construction of the central member of the wheel bracket.
  • [0206]
    FIG. 9H is an end elevation of a wheel bracket with the addition of a feature that engages a cross brace in the truss sections with which it is used.
  • [0207]
    FIG. 9I is a detailed view of the latching mechanism used in the embodiment of the wheel bracket illustrated in the previous Figures.
  • [0208]
    FIG. 9J is an embodiment of a wheel bracket whose central member is designed to accommodate “compound” trusses as illustrated in FIG. 4E.
  • [0209]
    FIG. 9K is an embodiment of a wheel bracket that can be adjusted to different chord spacings.
  • [0210]
    FIG. 9L illustrates an embodiment that permits suspending the truss a bracket also serving as a wheel bracket.
  • [0211]
    FIG. 9M is an end elevation of the prior Figure.
  • [0212]
    FIG. 9N is a side elevation of another embodiment of a wheel bracket.
  • [0213]
    FIG. 9O is an end elevation of the embodiment of the prior Figures.
  • [0214]
    FIG. 9P is a side elevation of an embodiment that supports a chain motor inside the truss.
  • [0215]
    FIG. 9Q is an end elevation of the embodiment of the prior Figure.
  • [0216]
    FIG. 9R is a section through a soft structure accommodating a chain motor in a truss.
  • [0217]
    FIG. 9S is plan view of the subject matter of the prior Figure.
  • [0218]
    FIG. 9T is a section through another embodiment of a structure supporting a chain motor inside a truss.
  • [0219]
    FIG. 9U is a top or plan view of the subject matter of the prior Figure.
  • [0220]
    FIG. 9V is a side elevation of the subject matter of the prior Figures.
  • [0221]
    FIG. 9X is a side elevation of a “stacker” in use with two truss sections.
  • [0222]
    FIG. 9XX is a detail view from the same perspective as FIG. 9X.
  • [0223]
    FIG. 9Y is a section through the “stacker” illustrated in the prior two Figures in use.
  • [0224]
    FIG. 9Z is a partial plan view of the “stacker” illustrated in the prior Figures in use.
  • [0225]
    FIG. 10A is a cross section through a unit showing a chain motor “flown” above it.
  • [0226]
    FIG. 10B is a cross section through a unit showing the chain motor engaged to it.
  • [0227]
    FIG. 10C is a side elevation of the subject matter of FIG. 10B.
  • [0228]
    FIG. 10D is a cross section through a unit with a chain motor engaged to it and a truss suspended below it.
  • [0229]
    FIG. 10E is a side elevation of the subject matter of FIG. 10D.
  • [0230]
    FIG. 10F is a cross section through a unit suspended below a chain motor.
  • [0231]
    FIG. 10G is a side elevation of the subject matter of FIG. 10F.
  • [0232]
    FIG. 10H is a cross section through a unit illustrating one embodiment of a bracket to which a chain motor can be attached.
  • [0233]
    FIG. 10I is a cross section through a unit perpendicular to the view of the prior FIG. 10H.
  • [0234]
    FIG. 10J is a section through a unit with a bracket of another design.
  • [0235]
    FIG. 10K is a detail from the same perspective as the view of FIG. 10H of a detail that permits relocating the bracket along an axis perpendicular to the plane of the Figure.
  • [0236]
    FIG. 10L is a cross section of a unit showing a chain motor with a plate attached that can connect the chain motor to the unit and/or a load.
  • [0237]
    FIG. 10M is a cross section through the unit showing the plate attached to the chain motor to the unit by means of brackets attached to the unit.
  • [0238]
    FIG. 10N is a cross section through the unit showing dividers that restrict undesirable motion of the chain motor during shipping of the motor in the unit.
  • [0239]
    FIG. 10O is a cross section through the unit with dividers illustrated in the prior FIG. 10O, in a view perpendicular to the prior Figure.
  • [0240]
    FIG. 10P is a cross section through a unit showing one design for a lid.
  • [0241]
    FIG. 10PP is a detail of the lid of FIG. 10P, seen in isolation.
  • [0242]
    FIG. 10Q is a cross section through a unit showing another design for a lid.
  • [0243]
    FIG. 10R is a cross section through a unit showing another design for a lid.
  • [0244]
    FIG. 11A is a side elevation of an assembly for supporting truss sections with loads hung from them.
  • [0245]
    FIG. 11B is an end elevation of the assembly of the prior Figure.
  • [0246]
    FIG. 11C is the same view as the prior Figure with the wheel assembly retracted for use.
  • [0247]
    FIG. 11D to a plan or top view of the subject matter of the prior Figures.
  • [0248]
    FIG. 11E is a side elevation from the same perspective as FIG. 11A but a wider view.
  • [0249]
    FIG. 11F is a top view of an alternate design for the assembly.
  • [0250]
    FIG. 11G is an end elevation of an alternate approach to caster attachment.
  • [0251]
    FIG. 11H is a top or plan view of another alternate design for the assembly.
  • [0252]
    FIG. 11I is a side elevation of the alternate design of the prior Figure.
  • [0253]
    FIG. 11J is an end elevation of an alternate design that incorporates a stacking feature.
  • [0254]
    FIG. 11K is an end elevation showing the accommodation of such trusses in a truck.
  • [0255]
    FIG. 11L is a section through a truss illustrating an alternative design that permits attachment at other points along the truss.
  • [0256]
    FIG. 11M is a plan or top view of the alternative design of the prior Figure.
  • [0257]
    FIG. 11N is a side elevation of a bracket that supports a chain motor above a truss.
  • [0258]
    FIG. 11O is an end view of the bracket of the prior Figure.
  • [0259]
    FIG. 11P is a side elevation of a bracket that stacks two trusses while allowing space for the chain motor bracket of the prior Figures inbetween.
  • [0260]
    FIG. 11Q is an end elevation of the stacking bracket of the prior Figure.
  • [0261]
    FIG. 11R is a side elevation of the brackets of the prior Figures in use.
  • [0262]
    FIG. 11S is an end elevation showing the brackets of the prior view in use in the truck.
  • [0263]
    FIG. 11T is an end elevation of an alternative design that permits stacking pre-hung trusses.
  • [0264]
    FIG. 11U is an elevation of a spacer plate that supports a second truss above the first.
  • [0265]
    FIG. 11V is a section of an extruded hinge used in a truss having a pivoting side in one position.
  • [0266]
    FIG. 11W is a section of an extruded hinge used in a truss having a pivoting side in a second position.
  • [0267]
    FIG. 11X is a section of an extruded hinge showing a plug shape.
  • [0268]
    FIG. 12A is a side elevation of a stacked rotator assembly.
  • [0269]
    FIG. 12B is a top view of the upper layer of the rotator assembly.
  • [0270]
    FIG. 12C is a top view of the upper portion of the rotator ring.
  • [0271]
    FIG. 12D is a top view of the lifting layer with the arms folded.
  • [0272]
    FIG. 12E is a top view of the lifting layer with the arms extended.
  • [0273]
    FIG. 12F is a side elevation of tilting arms.
  • [0274]
    FIG. 12G is a side elevation of a tilting clamp assembly on a fixture.
  • [0275]
    FIG. 12H is an end view of a tilting clamp assembly on a fixture.
  • [0276]
    FIG. 12I is a top view of a tilting clamp assembly on a fixture.
  • DETAILED DESCRIPTION
  • [0277]
    The application relates to various improvements to elements, structures, and components of structures used to support lighting and other loads, especially in entertainment and display applications.
  • [0278]
    In such applications, a wide variety of larger structures are often assembled from the combination of a relatively limited number of elongated structural shapes and fittings used to interconnect them and/or to attach them to other elements and to attach other elements and loads to them.
  • [0279]
    FIGS. 1A-1E illustrate five of the most commonly used elongated structural shapes.
  • [0280]
    FIG. 1A illustrates what is, by far, the most common shape in use—tubing (including pipe) that is circular in cross section.
  • [0281]
    Such tubing is typically fabricated from one of two different materials.
  • [0282]
    Commercially-available steel pipe is widely-employed, typically in the “1” trade size and “Schedule 40” wall thickness. (The dimension is that of its interior diameter, its “O.D.”, being approximately 1.9″). Such pipe is used as horizontal “battens” in fly systems; assembled into “grids”; and used as the basis of a variety of other structures, such as “booms” and “ladders”. Steel has high strength but also high self-weight.
  • [0283]
    With the need for portable structures, like trusses, having modest self-weight, tubing extruded from aluminum is in wide use, especially in the fabrication of such portable structures. While considerably lighter, aluminum tubing has lower strength and stiffness. Such tubing is typically employed in two diameters—a 2″ O.D. (which some clamps designed for 1″ Schedule 40 steel pipe will not fit) and a 1.9″ O.D..
  • [0284]
    Whether steel or aluminum, the circular cross section has both advantages and disadvantages, some of which will be discussed later. One disadvantage is the need to machine the end of a tube in a relatively complex shape where it intersects another tube in a weld.
  • [0285]
    As a consequence, some structures have been constructed from tubing having a square cross section, as is illustrated in FIG. 1B. The joining of such members is comparatively simple, although the sharp corners can be a hazard in handling, particularly after the aluminum is damaged and burrs are raised in it.
  • [0286]
    As a consequence, a few fabricators have employed square tubing with rounded corners, as illustrated in FIG. 1C.
  • [0287]
    Square tubing, whether rounded or not, has the added advantage that through-holes for fasteners are easier to drill accurately than in round stock—but many of the clamps and other fittings designed to attach loads to round tubing cannot be used with it.
  • [0288]
    Another structural form used is the “unistrut” type track commercially-produced for electrical, plumbing, and HVAC work, as is illustrated in FIG. 1D. In contrast to the other shapes that require the use of either a drilled pass hole and bolt or that require a clamp or other fitting to attach a load to the shape, “unistrut” permits the attachment of a load at any point along its length with only the insertion of a compatible threaded insert, reducing the cost and eliminating the height loss and weight gain of clamp use.
  • [0289]
    More than one company has extruded a shape, illustrated in FIG. 1E, that combines the “unistrut” track feature with a circular cross section similar to 1.9″ or 2″ O.D. tubing, which has the added benefit of greater stiffness over a span; the ability to attach it to structures and loads to it using clamps and other fittings designed for round stock; and a chamber 106C that can accommodate wiring.
  • [0290]
    This application discloses a number of improvements to elongated structural shapes.
  • [0291]
    Such improvements include those having a purpose of increasing the strength/stiffness of a shape of given material relative to prior art profiles, while maintaining an exterior profile that is compatible with the universe of clamps and fittings in present use.
  • [0292]
    Various Figures illustrate techniques by which these advantages may be gained, either alone or in combination with other features having other benefits.
  • [0293]
    Refer now to FIG. 1F, a cross section of tubing 106 having a circular external profile 106E that can be identical to prior art tubing, but varies its wall thickness to increase its strength/stiffness in one axis for only a modest increase in self-weight—in this example, by the use of an elliptical interior profile 106I.
  • [0294]
    In addition to varying wall thickness, the structural shape may employ other internal features to increase strength/stiffness in one or more axes. FIGS. 1I-1U illustrate a number of such features, sometimes in the context of an embodiment that also illustrates other features, including unconventional external profiles.
  • [0295]
    FIG. 1I, for example, illustrates an internal web 109W that serves to substantially stiffen the shape for a modest increase in weight, and without impact on exterior profile. Similarly, FIG. 1J has a more complex internal structure 110W that increases stiffness in multiple axes. Shapes having multiple internal closed voids are more complex to extrude, so other Figures illustrate shapes having features that increase stiffness (and provide other advantages) with simplified extrusion (although the method of fabrication—in one operation or many—should not be understood as limited, except by the claims). FIG. 1K illustrates that the orientation of a stiffening web 111W, combined with an increase in wall thickness 111Y where the web orientation does not significantly contribute, can offer improvements in multiple axes.
  • [0296]
    FIGS. 1L-1Q illustrate embodiments in which variations in wall thickness increase stiffness and provide other advantages. FIG. 1L, as one example, provides four extruded ribs, 112R being one such rib, that stiffen the tube. As illustrated in FIGS. 1N and 1P, these features (or others) also permit the insertion of mating shapes, which are keyed against rotation by their relationship with the feature. In the example of FIG. 1N, an additional element, 124 is inserted in tube 114, being keyed against rotation by ribs like 114R, and retained in a fixed relationship along the elongated axis of the tube 114 by a pin or other element inserted through holes drilled in the additional element (124B) and in the tube (114B).
  • [0297]
    It will also be seen that the additional element (in either FIGS. 1N or 1P) can be readily rotated 90 degrees with respect to the illustrated orientation and fixed there either by a second set of similarly-rotated holes in the additional element or in the tube (e.g. 114BB).
  • [0298]
    FIG. 1Q illustrates another embodiment in which wall thickness is increased to increase stiffness and in which an additional element (here 127) can be accommodated.
  • [0299]
    FIGS. 1R-1W illustrate the use of other internal features that stiffen the shape without unduly complicating the extrusion and that accommodate an additional element, here 130.
  • [0300]
    Illustrated embodiments key the additional element against rotation. Designs can also permit rotation about the elongated axis of the shape without restriction and/or solely as determined by a fixing method, whether by design of the tube profile, the additional element, and/or the fixing method.
  • [0301]
    Another aspect of the invention is improvements to the exterior profile of the tube having additional advantages.
  • [0302]
    Refer now to FIG. 1G, which is an embodiment illustrated with a conventional internal profile but an improved exterior one.
  • [0303]
    The tube illustrated in FIG. 1G employs a generally octagonal exterior profile, whose rounded corners (e.g. 107C) fall within a generally circular diameter, in this case, 1.9″. Thus, the tube illustrated in FIG. 1G has the advantage of being useable with clamps and fittings designed for round tube. The flat surfaces it affords (e.g. 107F) offer several advantages previously limited to square tubing, including the ability to prevent the tube from undesirably rotating in a clamp or bracket and/or a clamp or bracket supporting a load from rotating around it. The facing flat surfaces it affords (e.g. 107F and 107FF) allow rapid and precise drilling of pass holes required for fasteners. As illustrated in FIGS. 4P and 4Q, welded connections made between such tubing and cross-bracing in structures are simplified. And the improved shape can be more resistant to denting from excessive clamp force.
  • [0304]
    FIGS. 1M and 1Q illustrate other embodiments in which four sides are curved and four are substantially flat. Other variations in the number of sides and in the number and sequence of sides that are substantially flat and substantially curved are possible, as are additional features incorporated in the profile.
  • [0305]
    FIG. 1U, for example, includes a “unistrut” feature that provides the capabilities of the prior art shapes of FIGS. 1D and 1E, as well as a recess 121S on both sides that could protect the head of a fastener; a tape label (for example a bar code); or a “velcro” strip used to attach fabric masking. The same or a similar shape could accommodate guide wheels for travelling soft goods or other scenic elements or loads along the elongated axis of the tube.
  • [0306]
    FIG. 1W illustrates a tube having at least one recess 123R. A complementary protruding element on a clamp or fitting extending into recess 123R prevents the tube from rotating in the clamp or fitting. The detail producing recess 123R also serves to stiffen the tube in multiple axes, while it does not prevent the use of the tube with any prior art fitting or clamp usable with conventional round tube.
  • [0307]
    While structural shapes having an improved external profile can be used with most clamps and brackets designed for round stock, they have certain advantages in maintaining the rotational relationship between the shape and the clamp.
  • [0308]
    For example, certain clamps like the theatrical “C-clamp” and the European “J” clamp have flat surfaces, which, when aligned with the flat surfaces on the shape, will assure that the clamp (and its load) is aligned with that surface.
  • [0309]
    Clamps and fittings can also be designed to maintain their rotational relationship with the improved structural shape.
  • [0310]
    As previously described, FIG. 1W illustrates a tube including at least one recess 123R in its exterior profile that does not interfere with its usability with any prior art fitting or clamp, but permits it to be “keyed” to a clamp or fitting having a feature that extends into it.
  • [0311]
    FIG. 2A is a side elevation of one half of a prior art “cheseboro” such as the ProBurger distributed by TMB Associates. This model is produced from two machined extrusions: a base 201, and a cover 202, hinged together on one side (at 203) and held closed by a bolt 206 pivoted at 204, bolt 206 carrying a washer and a wing-nut that bear down on the flange 205 formed in cover 202.
  • [0312]
    It is a problem that without the application of a high clamping force in tightening the clamp (which may damage the wing-nut or bolt), tubing can undesirably rotate in the clamp under load.
  • [0313]
    The clamp of FIG. 2A illustrates in both its base 201 and cover 202, one example of a profile at the clamp/tubing interface having both flat areas (e.g. 201F) and curved areas (e.g. 201C). When a tube 107 having the improved external profile is inserted in the clamp, several of its substantially flat surfaces align with corresponding flat surfaces on the base and cover, restricting the tube from rotation, despite only moderate clamping force.
  • [0314]
    A detailed view of the interface is found in FIG. 2C.
  • [0315]
    FIG. 2C is a composite view, the tubing 107 to the left of the dividing line, illustrating the interface between tubing having an improved profile and the clamp and the tubing 101 to the right of the dividing line illustrating the interface between a tube of conventional cross section.
  • [0316]
    When a tube having a conventional circular profile is inserted in the clamp, its external surfaces contact several areas on the clamp and its cover, including the curved areas.
  • [0317]
    FIG. 2B illustrates such a circular tube in a variant on the clamp of FIG. 2A that illustrates an extruded hinge 203A requiring no machining.
  • [0318]
    When two clamps are joined at their bases by a swivel to form a “cheseboro” they are free to rotate relative to one another about the swivel. Two keyways 209 and 210 are also illustrated, which, with an interlocking shape, e.g. shape 212, and an additional slot milled in the base at right angles to the keyways (indicated in this view by dashed line 211), allow the user to fix the rotational relationship between the two halves of the cheseboro quickly and easily in the field.
  • [0319]
    By insertion of the interlocking shape (e.g. shape 212) into one of the keyways 209 or 210 in one clamp with the extending flange 212F in a keyway of the other clamp, the two clamps and their tubes are locked in a parallel relationship—the choice of keyway used determining whether the two clamps open on the same or opposite sides. If the extending flange is inserted in the milled slot in the other clamp, the two are locked in a right-angle relationship. The interlocking shape can be readily removed to change orientations or restore the “cheseboro” to “swivel” operation. FIG. 2B also illustrates a provision, by way of example, in the form of keyway 213, to insert a component that represents a key that aligns with the recess 123R in shape 123 illustrated in FIG. 1W, preventing the rotation of that shape relative to the clamp.
  • [0320]
    Other variations in design are, of course, are possible. For example, a hole can be machined through base 201 with an additional, blind, hole at other locations. Inserting a length of rod in the first hole that extends into the corresponding hole in the other clamp in a cheseboro will lock the two in a rotational relationship, and multiple holes provide for different possible relationships The rod can be readily moved to change the relationship or removed to restore the cheseboro to swivel operation. However, once a tube is in the clamp the rod cannot escape. Another section of rod (for example) can be inserted in a blind hole to extend into the region occupied by the tubing, serving as the key engaged by a corresponding recess in a tube.
  • [0321]
    Other clamps and brackets are required for clamping round tubes to each other or to other objects. One example is the category of fittings including Speed-Rail and Nu-Rail brands as produced by the Holleander Corporation. These are cast aluminum bodies drilled and tapped to accept set-screws used to fix the tube in the fitting.
  • [0322]
    FIG. 2D is a cross section illustrating one embodiment of an improved structural shape that can be used for many purposes. The embodiment illustrated in FIG. 2D is illustrated as an extrusion 211 having a larger chamber 211L that accepts tubing 200 and a smaller chamber 211S. Referring to FIG. 2F, it will be seen that a purpose of chamber 211S is to accommodate a part 212 with an internal thread that accepts a bolt or set-screw. When the bolt or set-screw is tightened, the threaded part 212, although it might have otherwise been free to move along the elongated axis of the shape 211 in chamber 211S, will be fixed in place relative to the shape, while the tubing 200 is also fixed.
  • [0323]
    To accommodate a bolt or set-screw, passage is required through the shape to the tube, as is illustrated in FIG. 2E. This can be accomplished by providing two continuous openings through the shape (211A and 211B)—which permit locating bolts or set-screws anywhere—or by drilling or otherwise opening pass holes through the shape at locations at which a bolt might be inserted—one technique that retains the bolt or set-screw and the threaded part at that location even when loosened.
  • [0324]
    Many different approaches to forming the threaded part 212 are possible—including a standard hex or other nut; a plate having a tapped hole, or, as illustrated in FIG. 2I, the smaller chamber 211SS can be configured to employ “unistrut” track nuts as the threaded part by incorporating a suitable profile 211U.
  • [0325]
    The interior profile of the shape 211 can be designed to accommodate different sizes and profiles of tube and, as illustrated in FIGS. 2G and 2H, employ a profile that provides for limiting to rotation of tubes having appropriate shapes (here illustrated as the use of a profile similar to that employed in FIGS. 2A-2C).
  • [0326]
    The improved shape illustrated in these Figures has many advantages over prior art fittings. It removes the requirement that the entire shape/fitting be fabricated from a material and by a process that will permit tapped holes with threads of acceptable strength. In fact, the improved shape requires no tapping while it permits the use of materials for the threaded portion that are far harder than those in prior art fittings. Unlike prior art fittings, such threads can also be readily replaced when damaged or worn and changed to suit the application (for example, to vary the diameter of the bolt or set-screw and/or provide either metric or Imperial threads). A simple extrusion replaces the need for cast fittings and can be used in many applications with little or no modification.
  • [0327]
    For example, a length of the illustrated shape can be used to couple two tubes end-wise.
  • [0328]
    FIG. 2J is the first of a series of Figures that illustrate some of the methods by which a fitting like that illustrated can include provisions for attaching it to other objects, including other tubes and/or fittings.
  • [0329]
    FIG. 2J illustrates the addition of a flange 211W, which can be used for attachment to another object, including another section of the same shape.
  • [0330]
    FIG. 2K is a cross section of a shape similar to that of the prior Figures having a flat surface 211B and two flanges (211F and 211FF) that allow attaching the shape to other elements. For example, with flat 211B in contact with a surface, flanges 211F and 211FF can be welded to that surface. FIG. 2L illustrates the shape with another structural shape 215 welded it. FIG. 2M illustrates the use of another shape 216 having features (e.g. 216A) that interlock with structural shape 211, in this example, via flanges 211F and 211FF. The another structural shape 216 may be fixed along the elongated axis of shape 211 by any one or combination of a number of means, here illustrated as a threaded part track 216S similar to that used in shape 211.
  • [0331]
    FIG. 2N is a cross section of a shape similar to that of FIG. 2K whose flanges 211G and 211GG have been elongated relative to the prior Figure to accommodate pass holes (e.g. 211H) for bolts or other fasteners. FIG. 2O is a side elevation of a length of shape 211 forming a fitting 211A on tube 200A and FIG. 2P is a top view of the same arrangement showing the flanges 211G and 211GG, the pass holes in them (e.g. 211H) and the set-screws (e.g. 213S) and threaded parts installed. Such a fitting 211A can be bolted or riveted to an object or structure. FIG. 2P is a side elevation illustrating that two such fittings 211A and 211B can be bolted together (e.g., bolt and nut 214) via their pass holes (e.g. 211H) to form a right-angle fitting joining two tubes 200A and 200B at right angles. The pattern of pass holes like 211H in flanges 211G and 211GG being square, the two fittings can just as readily be bolted together to hold the two tubes in parallel relationship. Additional pass holes and/or other arrangements (including, for example, brackets) will permit other angles and spacial relationships between two or more tubes or a tube and a surface can be accommodated from a minimum number of modular parts.
  • [0332]
    Shapes used for fittings can be designed with details that permit mounting and/or interlocking that are milled or ripped off the basic shape when not required and can be permanently welded, bonded, or otherwise attached to form fittings.
  • [0333]
    Another aspect of the invention resides in improved structural shapes that permit the ready attachment of loads as well as and their own attachment to structures—both at any point along their length.
  • [0334]
    The prior art shapes commonly used for the purpose, the “unistrut” of FIG. 1D and the related shape of FIG. 1E have several disadvantages, most notably the difficulty of reliably inserting and engaging a track nut in the track and the ease with which the most common nut types can be inadvertently disengaged from the track, releasing the load, which typically occurs when loosening or tightening the bolt attaching the load to the track nut, or when attempting to slide the track nut and load to another location.
  • [0335]
    Beginning at FIG. 3A are illustrated improved structural shapes that provide all of the advantages of prior art “unistrut” track with additional advantages and fewer disadvantages.
  • [0336]
    FIG. 3A illustrates one embodiment of a structural shape 301, shown here in paired use. Its profile includes two vertical surfaces 301A and 301C that are offset to define a shoulder 301B. When used in a facing pair the result is an upper area 301D that is wider than a lower area 301E, and that together form a passage from one side of the paired shapes to the other. That passage forms an elongated slot, as seen in the top view of FIG. 3B.
  • [0337]
    FIG. 3C illustrates one use. Vertical surface 301A is located to produce, in this embodiment, a space between such surfaces of a paired set of such shapes a distance slightly greater than the width of the head of a ″ hex nut or bolt 310H across its flats. Vertical surface 301C is located to produce a distance slightly greater than the shank 310S and the thread 310T of such a bolt. The exterior profile of the shape 301 can be of any design, here illustrated as having an improved profile as illustrated in earlier Figures.
  • [0338]
    As illustrated in FIG. 3C in section and in FIG. 3D in top view, a ″ bolt of suitable length is dropped into the passage formed between the pair of shapes, coming to rest with the head 310H resting on shoulder surface 301B and between facing vertical surfaces 301A, substantially within the upper area 301D. The shank 310S and threaded portion 310T of the bolt extend between the facing vertical surfaces 301C of the pair, through the lower area 301E, extending beyond the paired shapes on the side opposite the bolt head 310H. A load, in this example the yoke 312 of a lighting fixture, is attached with the bolt by passing the bolt through a hole in the yoke. Flat washers (e.g. 313) may be provided.
  • [0339]
    It will be seen from FIGS. 3C and 3D that the load is positively attached to the paired shapes. If nut 311 is fully tightened, then the stack of yoke and washers will be pulled tight against the adjacent (lowest) portion of the paired shapes, while the underside of the bolt head 310H will be pulled tight against the shoulder surface 301B, preventing the rotation of both the yoke 312 around the axis of the bolt and movement of the bolt along the slot formed by the paired shapes. On the other hand, partial loosening of nut 311 (as illustrated in FIG. 3O) permits the rotation of the yoke 312 around the axis of the bolt, and the movement of the bolt and its attached load along the elongated axis of the paired shapes—without the possibility that the load might become inadvertently detached. Because the paired shapes offer vertical surfaces 301A spaced only slightly away from the flats of the bolt head 310H, the bolt will essentially not rotate about its axis so long as the bolt head is in the upper area 301D, simplifying the adjustment of nut 311 (for example, requiring only one tool when compared with thru-bolting the prior art shapes of FIGS. 1A-1C). Substantially all of the bolt head is also recessed within the exterior profile of the paired shapes (although in other embodiments—or with the simple expedient of the use of a flat washer under the bolt head—the bolt head may be above the overall profile and/or free to rotate.)
  • [0340]
    FIGS. 3E and 3F illustrate a use with the bolt inverted so that the threaded portion 310T extends above the profile and it is the nut 311 that falls within the upper area 301D.
  • [0341]
    FIGS. 3G and 3H illustrate a use where the ability to rotate a bolt whose head is recessed substantially within the overall profile is required (for example, when engaging a blind threaded insert in the load). In this example a “cap screw” having a cylindrical head 315H that will rotate continuously within the upper area 301D is employed.
  • [0342]
    FIGS. 3I and 3J illustrate a fastener that, like the prior art “unistrut track nut” permits insertion in the structural form from the load-side, including while attached to the load. Fastener 319 (which may be formed integral or assembled from several components including threaded rod or a threaded fastener) has a head 319H, that is rectangular in plan, having one side 319L, that is slightly narrower than the width of the upper area 301D (which is to say, the distance between the surfaces 301A of a pair of shapes), and the other side, slightly narrower that the width of lower area 301E (which is to say, slightly less than the distance between the surfaces 301C of a pair of shapes). The result is that the head 319H may be inserted through 301E from the load side until the lower surface of head 319H (the one that will rest on surface 301B of the paired shapes) is above upper area 301D. Once rotated 90 degrees and lowered towards the paired shapes, head 319H will come to rest in upper area 301D, with head 319H retained and prevented from rotation in the same manner as head 310H in FIG. 3C—but cannot inadvertently fall thru area 301E when loosened for adjustment.
  • [0343]
    FIGS. 3K and 3L illustrate the use of a spacer 316 that substantially fills the upper and lower areas. Extruded, milled, or molded from the same or a different material it has several possible uses. Inserted in the slot formed by the pair shapes where a compression clamp (e.g., a “cheseboro”) will apply considerable force, it prevents the “pinching” of the two shapes together. Attached to the paired shape by bonding, welding, or mechanical fastener(s) (the last indicated by center line 317), it can be used to maintain a fixed relationship between the paired shapes. Attached to the paired shapes, the spacer form may also be attached to another object or a structure, for example, by a fastener inserted through it (indicated by center line 318), attaching the paired shape to that object or structure.
  • [0344]
    FIGS. 3M and 3N illustrate a shape 331 having other features, notably a symmetrical design and a flange and recess in the shoulder area that is engaged by the flanges (e.g. 335F) of a plate 335. As illustrated in FIG. 3O in cross section and in FIG. 3P in top view, plate 335 has a pass hole 335H for the bolt. Downward pressure on the bolt 310 locks the flanges (e.g.335F) of plate 335 into the corresponding detail on the paired shapes, preventing them from splaying outward even if excessive force is applied through the bolt.
  • [0345]
    FIGS. 3Q and 3QQ illustrate a spacer 338 adapted for shape 331, having the same applications as that illustrated in FIGS. 3K and 3L in connection with shape 301.
  • [0346]
    FIGS. 3R and 3S illustrate a shape 341 using plates like 335 both above and below. These plates 345 and 346 include ramped flanges that wedge into corresponding grooves formed in shape 341 by an “ear” 341F. Referring to FIG. 3S, a cross section through an assembly, it will be seen that clamping force on the bolt 310 causes the upper and lower plates 345 and 346 to grip the “ears” tightly, transferring the load to the paired shapes.
  • [0347]
    FIG. 3U is illustrates an external profile including an opening 341G that interlocks (in FIG. 3Y) with corresponding shapes on a mounting bracket 349 that does not extend below the profile of the paired shapes. FIG. 3U is an interlocking internal spacer 342 with similar uses to that of FIG. 3K.
  • [0348]
    FIGS. 3V-3Y illustrate some methods of mounting the paired shapes illustrated in the prior Figures.
  • [0349]
    FIGS. 3V and 3W illustrate a bracket 321 used to attach pair of shapes 301 to a surface represented by 320, while maintaining the relationship between them (the added clearance beyond the diameter of bolt 322 required being produced, in this example, by sleeve 323 slipped over it).
  • [0350]
    FIG. 3X is generally equivalent to FIG. 3V, adapted for the shape illustrated in FIG. 3M, FIG. 3XX being a view of bracket 339 is isolation.
  • [0351]
    FIG. 3Y illustrates a bracket 349 mounting the shapes illustrated first in FIG. 3T, which bracket could be used alone or in combination with spacer 342 of FIG. 3U, and with fasteners as required.
  • [0352]
    Another aspect of the invention relates to improved designs for trusses and similar structures.
  • [0353]
    Long employed in various permanent applications, such as bridges and roofs, over the last thirty years an industry has arisen around the design, manufacture, and provision of relatively lightweight trusses fabricated of aluminum, and intended for use in creating structures, often temporary, for the support of lighting equipment and scenic elements for live performances, special events, and displays (among other applications).
  • [0354]
    Beginning in the early 1970s, companies supplying lighting and other equipment to such applications began designing and building trusses for their own use. Because of the competitive advantages to be gained with a truss of improved design and the relative ease with which new designs could be fabricated, a large number and wide variety of different designs have been produced over the years.
  • [0355]
    By the 1980s, increasing demand for such trusses led to the rise of specialist companies designing and manufacturing them for sale. Examples of firms designing and producing such trusses include: James Thomas Engineering, Tomcat Systems, Total Fabrication, and Slick Systems.
  • [0356]
    Thirty years of intense competition has produced a wide variety of truss designs.
  • [0357]
    Truss designs can differ in a number of parameters including overall form (flat, triangular, rectangular); dimensions; whether they are intended to internally accommodate lighting or scenic equipment; whether they incorporate provisions to displace an internally accommodated load between an enclosed shipping and a more exposed use position and/or incorporate hinged faces to perform the same function and/or to reduce their volume for shipping; in the diameter and profile of structural shapes used for their main chords and/or for cross-bracing; in section length; in the method(s) by which multiple sections can be interconnected to form longer spans; and in whether they incorporate casters—among others.
  • [0358]
    In a typical range of applications, and frequently within the same application, there is a need for more than one truss design. Even if the same overall genus of truss is employed (for example, simple rectangular trusses with no provision to enclose equipment or change profile) there is frequently a requirement for more than one truss design.
  • [0359]
    For example, there may be a need for a truss of sufficient width to accommodate either one or two parallel rows of lighting fixtures or scenic elements and of sufficient height to allow reasonable spans between supporting points. Perhaps the most frequently-used truss design in such applications is the known “20.5″” design, as produced by several manufacturers, an end-wise view of which is presented as FIG. 4B. “20.5″” refers to the overall dimension across the cross section in inches.
  • [0360]
    Such trusses include four, parallel, main chords 401B, 402B, 403B, and 404B that extend along the elongated axis of the truss and define its square cross section.
  • [0361]
    Typically, at the ends, and by perpendicular and/or diagonal cross-bracing at regular, intermediate points, the main chords are connected by lengths of the same and/or another structural shape. In the case of the end view of FIG. 4B, 405B, 406B, 407B, and 408B are the lengths of tubing connecting the main chords in a plane parallel to the illustrated face of the end of the truss section 400B.
  • [0362]
    Several methods have been employed to join multiple sections of truss end-wise to form a longer span. A common method is to provide bolt-plates parallel to the section end with pass holes, such that bolts may be employed to join the section. In the case of the typical “20.5″” truss, sections of right-angle aluminum extrusion are often trimmed to form corner plates 411B, 412B, 413B, and 414B that are welded to the other members and afford pass holes 421B, 422B, 423B, and 424B for bolts used to join sections. Other truss designs or optional enhancements to the same truss design allow the use of other or additional joining methods, such as “spigots” or fittings—such as clevis fittings.
  • [0363]
    In other applications, and frequently within the same application (such as a show, presentation, or display) that employs a truss like the “20.5″” design, there will be a need for a truss of less width—for example, where only a single row of lighting fixtures or a single scenic element need be supported, and the width of a larger truss would be excessive, obstructed by or obstructing other nearby elements. Frequently, in such situations, a “1212” truss, as illustrated in FIG. 4A, is employed—the designation referring to the overall dimensions of the truss in cross section in inches. As will be seen from the end-wise view in FIG. 4A, the “1212” truss employs the same four main chords, similar interconnecting members, and similar end plates (e.g. 413A) affording pass holes 421A, 422A, 423A, and 424A for bolts used to connect multiple sections (or a section to a base plate, corner cube, or other object).
  • [0364]
    While desirably narrower in width (12″ versus the 20.5″), the similarly-reduced height of “1212” results in a reduced load-carrying ability reducing allowable spans between supports, relative to “20.5″”. This undesirably complicates its use.
  • [0365]
    In applications (like events in hotel ballrooms) with limited ceiling heights, the height requirements of a truss like “20.5″” may be deemed to unacceptably reduce the maximum height (or “trim”) of loads supported from it, and specialized “ballroom truss” may be required, which has a similar width, but reduced height.
  • [0366]
    The requirement for multiple truss types complicates inventory, handling, transport, and installation.
  • [0367]
    Refer now to FIG. 4C, a simplified end-wise view of an improved rectangular truss 400C. Like the prior art trusses of the prior Figures, it employs four main chords 401C, 402C, 403C and 404C. In this embodiment, it employs an end-plate detail that is illustrated with pass holes 421C-428C for connection to another section or object.
  • [0368]
    The embodiment illustrated has overall dimensions of nominally 20.5″10.25″—or one-half the cross section of “20.5″” truss.
  • [0369]
    It will be seen that, in the orientation illustrated in FIG. 4C, the improved truss will have an overall width of approximately 10.25″ and a height of 20.5″. In most applications in which “1212” truss is currently employed, the improved truss 400C will offer an even thinner profile while, by virtue of its greater height, supporting greater loads over longer spans—simplifying its support or suspension.
  • [0370]
    In FIG. 4D, the improved truss has been rotated 90 degrees, illustrating that the same truss can be used in “low-profile” or “ballroom” applications—affording two chords at a spacing identical to “20.5″”.
  • [0371]
    Referring now to FIG. 4E, two such improved trusses (400C and 400CC) are illustrated side-by-side, preferably mechanically connected with each other (one possible method to be illustrated in later Figures). The result is a “compound truss” with the same profile as 20.5″ and placing four chords (401C, 402CC, 403CC, and 404C) in the same location (as well as four additional chords along the centerline, e.g. 403C and 404CC). The additional structure of the pair of improved trusses, relative to prior art “20.5″” results in greater load-bearing capacity (and/or alternatively, allows a corresponding reduction in structure to produce parity).
  • [0372]
    Referring to the pattern of pass holes, it will be seen that holes 421C, 422CC, 423CC, and 424C can be made to correspond with holes 421B, 422B, 423B, and 424B of prior art “20.5″” truss, allowing direct interconnection of the two truss types. Further, the additional pass holes of the improved truss can be used to increase the load-bearing capacity of a span of such trusses.
  • [0373]
    FIG. 4F illustrates a coupled pair of improved trusses 400A and 400B rotated 90 degrees relative to the prior Figure, with the benefit of reducing the amount of cross-bracing in the vertical axis, improving access from above to loads hung below the compound truss.
  • [0374]
    In either case, it will also be seen that, in a continuous span, a transition can be made from a coupled pair to a single section, the provision of the additional pass holes 425C-428C permitting such transitions regardless of the relative orientations of the sections at the transition. (It will be understood that only a fifth and sixth such pass hole (e.g. 425C and 426C) are necessary to provide this capability, the seventh and eighth holes (e.g. 427C and 428C) simplifying alignment.
  • [0375]
    FIG. 4G illustrates that “compound” trusses can be assembled with more than two sections for increased dimension and/or strength.
  • [0376]
    It will be apparent that provisions can be made to couple two such trusses along their narrower dimension to produce a taller “compound truss” having substantially greater strength and allowable span due to its increased height—as well as coupling trusses in parallel in both axes.
  • [0377]
    While the illustrated embodiment is based upon the dimensions of “20.5″” truss, it will be apparent that other dimensions can be employed.
  • [0378]
    For example, in the illustrated embodiment, an additional truss design measuring approximately 10.25″10.25″ can be employed—and will intermate with the 10.25″20.5″ in a manner analogous to the relationship between a single section of the 10.25″20.5″ and a compound pair.
  • [0379]
    Another family of trusses could be based around 12″12″, using a 12″24″ section that can be coupled to form a 24″24″.
  • [0380]
    FIGS. 4H-4K are elevations illustrating possible designs for faces of a truss section—those faces parallel with its elongated axis. While generally equivalent to at least some sides of some prior art trusses, the Figures illustrate two features.
  • [0381]
    Members are illustrated as 431-434 (details of which will be seen in later Figures) that provide aligning pass holes (e.g. 431A and 431B) that permit coupling any two such sections in parallel, as illustrated in FIGS. 4E-4G.
  • [0382]
    Further, as a result of handling, a section of truss can be rotated both about its long axis and end-for-end into eight possible relative orientations for a square truss and four for a rectangular one that will appear to align. Trusses incorporate cross-bracing, sometimes similar on all sides, sometimes diagonal on at least the two sides nominally vertical and perpendicular (or “ladder-style”) on the others. Wherever such diagonal bracing is used, structural strength requires that the braces on adjacent truss sections form a continuous pattern, which may not be the case if two sections are in different relative orientations. Without extra care in handling, such different orientations can result.
  • [0383]
    In the illustrated example, a similar cross-bracing method is used on two opposing sides but, when such braces are asymmetrical (as are diagonal braces), are reversed relative to each other. The result, so long as the sections are oriented with the same end-for-end orientation, is, whether square or rectangular, that any relative rotation of two sections about their long axis will still result in a structurally correct result (and end-for-end transpositions are less likely in handling). As a further benefit, if the section joining method has a sexuality (for example, clevis fittings or a threaded insert) all couplings on one end can be made the same sex (or, in the case of rectangular trusses, sex can be reversed between opposite corners) with the assurance that any relative orientation will work. (In the case of the provisions for joining sections in parallel, sexes can be alternated to produce “universal connectivity”.)
  • [0384]
    FIGS. 4L-4O detail improved approaches to truss section end design
  • [0385]
    FIG. 4L is a detail side view of one end of truss as is also illustrated in FIGS. 4I and 4K that shows the cutting planes and perspectives employed by the following Figures.
  • [0386]
    FIG. 4M is a cross section through the end of one embodiment of the prior Figures on a cutting plane illustrated in FIG. 4L, looking towards the short side of either FIGS. 4H or 4J.
  • [0387]
    FIG. 4N is a cross section through the end of one embodiment of the prior Figures on a cutting plane illustrated in FIG. 4L, looking towards the truss end.
  • [0388]
    FIG. 4O is an elevation of one end of the embodiment of the prior Figures, showing additional detail.
  • [0389]
    Referring now to these Figures, several features will be seen.
  • [0390]
    In the illustrated embodiment, unlike those prior art trusses illustrated in FIGS. 4A and 4B, tubing is not used to connect the main chords at the section end. Instead, two extrusions 431 and 433 are each attached to two chords, for example, 401C and 404C in the case of 431. The illustrated extrusion is essentially a right angle, one side of which 431F, parallels the side of the truss section, and provides points, here pass holes 431A and 431B, used to couple two such sections in parallel. A reinforcing flange 431E is illustrated. In the illustrated embodiment, side 431F of the extrusion is milled away at its upper and lower ends to permit contact between it and the tubing forming the main chords along the latter's elongated axis as well as a butt contact to the other face 431G of the same extrusion 431. Welding and/or mechanical fasteners are used to attach them.
  • [0391]
    Two such extrusions 431 and 433, each attached to two main chords (and their inter-connecting cross-braces), are themselves brought into contact with a plate 440 that forms the truss end visible in FIG. 4O. The extrusions 431 and 433 are attached to the end plate 440 by welding and/or other means, for example by welds along their interface at 431Y and 431Z. Aligned pass holes 421-429 for the bolts used to join sections are provided in both the extrusion 431 or 433 and the end plate 440, such that the joining bolts extend through both and that the joining of sections (or a section with a corner, base, or other object) actually reinforces the bond between the extrusions and plate and distributes the load through both. Other designs are certainly possible, the illustrated embodiment having the benefits of requiring one extrusion of relatively modest size and a piece of plate. Different alloys or materials can be used for the two parts (subject to appropriate joining methods) and it will be apparent that same extrusion can be used in different lengths and with plates of different sizes to assemble many different truss designs.
  • [0392]
    In truss design, the location of a joining connection offset significantly within the vertical centers of the main chords may impact the load-bearing capacity at the joint between sections. FIG. 2N and FIG. 2O illustrate pass holes (e.g. 429A and 429B and 430A and 430B) that are substantially aligned with the vertical centers of the main chords.
  • [0393]
    FIG. 4O also illustrates openings (e.g. 440B) in the plate aligned with the main chords whose purpose will be described in connection with later Figures.
  • [0394]
    FIGS. 4R-4Z illustrate other improved methods of truss construction.
  • [0395]
    Trusses (whether flat—also known as “ladder beam”) or dimensional with a polygon cross section, typically rectangular or triangular) require cross-bracing between the main chords. Such cross-bracing requires a structural connection where the shape used for the cross-brace and that used for the main chord meet, which may be at right or other angles.
  • [0396]
    FIGS. 4P-4Q illustrate an intersection between a cross-brace and a main chord 401. By the use of a shape for the main chord having the generally octagonal shape disclosed earlier, the intersection between the cross-brace 409 (here a rounded rectangle as seen in cross section in FIG. 4R) is simplified as seen at interface 409C and 409D—requiring relative simple trimming of the cross-brace end and straight welds.
  • [0397]
    FIGS. 4S-4V illustrate another approach to the cross-brace issue. Here, the shape for the main chord 122, incorporates an opening 122R into which the end of the shape used for the cross-brace (here a rounded rectangle, 409C seen in cross section in FIG. 4V) can be inserted. The two shapes can be fixed relative to each other by mechanical fastening, bonding, and/or welding—for example, straight welds along the interface at 409D. It will be seen that this approach requires only a straight cut across the end 409E of the cross brace 409C with relatively low tolerances, and that any angle of intersection can be accommodated by a change in the angle of cut. This approach offers particular economy in the construction of “flat truss”, which requires cross-bracing in only one plane.
  • [0398]
    FIGS. 4W-4Z illustrate one method by which a shape can be selectively reinforced along its length.
  • [0399]
    Such reinforcement may be desired to better distribute a load applied to the shape locally (for example, at a load-bearing connection) and/or as reinforcement for wear (for example, at a point of repeated insertion of a locking pin).
  • [0400]
    In this embodiment, the structural shape first illustrated in FIG. 1V is shown. In addition to the opening 122P, the shape includes voids (e.g. 122V) formed between its flatted external surface at 122B and internal member 122A. A reinforcing shape 124 is formed (for example, milled) out of the same or different material—in this case, steel. A length of reinforcement 124 is inserted in the void 122V in shape 122 at the required location. Many methods for fixing it in place are possible—in FIG. 4W roll pins 122S and 122T are illustrated as inserted through aligned pass holes in both the reinforcement 124 and the shape 122. In the example, the reinforcement is applied at the location of pass holes 122E and 122F for locking pins as might be used to attach sections together. The reinforcing shape 124 on the opposite side of shape 122 is shown only partially inserted in its void so that the pass holes in it for the locking pins can be seen. FIG. 4Y is a detailed view of a section at the location of pass hole 122E illustrating the pass holes in both members 122A and 122B of shape 122 and in reinforcement 124. Also illustrated is the radiusing of the pass hole on the external side to simplify insertion of the locking pin.
  • [0401]
    Many methods of reinforcing the shape are possible and should not be understood as limited. FIG. 4Z illustrates a reinforcement 125 that is fabricated of a laminated stack of relatively thin stampings. A suitable compound can also be injected into the void.
  • [0402]
    Similarly, reinforcing techniques are not limited to shape 124. It will be seen that many of the improved shapes illustrated in FIGS. 1F-1W (and others not illustrated) can be readily reinforced.
  • [0403]
    FIGS. 5A-5Z illustrate improved methods of joining truss sections with each other and with other objects and structures.
  • [0404]
    For reasons of practicality in shipping and handling and for versatility, most truss sections are fabricated in sections of 10 feet in length or less and typically in a selection of lengths. Sections are provided with at least one mechanical method for coupling multiple sections end-wise to form a longer span of the required length.
  • [0405]
    Many joining methods have been employed over the last three decades, the most common of which remains a bolted connection.
  • [0406]
    As illustrated earlier in FIGS. 4A-4C and others, sections are provided with a structural plate or plates or other forms providing pass holes for bolts that are inserted with their long axes parallel with the long axis of the truss. As illustrated in FIG. 5A (which is a sectional view equivalent to FIG. 4M) two adjoining truss sections have parallel end plates (here 440 and 440D). A bolt 510 is inserted through the pass hole 421D in the end plate 440D of one truss section and through the pass hole 422 in the end plate 440 of the other truss section and a nut 511 threaded to it. When the bolt 510 is tightened, the two end plates 440 and 440D and their trusses are drawn together.
  • [0407]
    The illustrated bolting method has advantages and disadvantages. The connection is relatively cheap and is genderless. The nuts, bolts, and washers are, however, loose parts that require handling and re-assembly each time the sections are joined or separated. Two wrenches are required, one on the bolt head, one on the nut, to prevent the bolt from simply free-spinning. The truss is typically at floor level, requiring the work to be done on hands and knees, and a given application can require dealing with a hundred or more bolts—at a significant cost in time and labor.
  • [0408]
    FIG. 2B illustrates one improvement: the captivation of the nut. Here, nut 511A is illustrated as retained by, in this case, a formed sheet metal bracket 515 that is attached to either shape 432 and/or end plate 440. Only bolt 510 and an associated washer 513 are loose parts. Only one wrench is required as the dimensions of the channel for the bolts formed in bracket 515 can be limited to prevent rotation of the nut. The dimensions of the channel (and the method of retaining the bolt along the length of the channel) can allow sufficient “play” to make the nut self-align with the hole, and, of course, a washer can also be accommodated, if desired.
  • [0409]
    In this example, the bolted connection between truss sections end-wise places a nut on one section end and a bolt on the other, while “compound trusses” are created by similar connections between sections side-to-side. Thus, bracket 515 retains nuts for both end (515A) and side (515B) connections, and bracket 516 for end connections only.
  • [0410]
    In addition to formed sheet metal, brackets can be fabricated from an extrusion, a detail on which can interlock with a compatible detail on the truss structure, reducing or eliminating the requirement for mechanical fasteners to attach the bracket.
  • [0411]
    FIG. 5C is an oblique view of the end of the truss section with shapes 431 and 432 and end plate 440, illustrating how an elongated bracket can accommodate multiple fasteners. Indeed, a single bracket can retain all of the hardware required on one side of the truss, in the example of FIG. 4O, as many as six sets.
  • [0412]
    It will also be apparent in connection with any previous or later embodiment, that the bolts can be made captive as well.
  • [0413]
    FIG. 5D illustrates the addition of a detail that retains the washer associated with the bolt. Bracket 518 is illustrated as accommodating a bolt on its end-side 518A and a washer on its side-side 518B. Similarly, bracket 519 inverts the relationship (and, in a symmetrical design, might be the same bracket used for bracket 518, inverted). Bracket 520 is designed to retain washers on both sides 520A and 520B.
  • [0414]
    It will be apparent that a “washer” bushing or sleeve can also be used on the bolt side that is the same depth as the nut, resulting in a uniform bracket design.
  • [0415]
    FIG. 5E illustrates one embodiment in which the nut or other threaded receptacle is retained by a detail made integral with the truss itself. Corner member 432 is illustrated with two integral rails 432E and 432G that define a track that retains a nut or threaded insert 521.
  • [0416]
    FIGS. 5F-5H illustrate details of one possible insert design. FIGS. 5F and 5G represent two elevations and FIG. 5H a top view of threaded insert 521, which includes a threaded hole 521T and a smaller hole 521S.
  • [0417]
    FIGS. 5I-5K illustrate its installation. FIG. 5I is a reverse elevation of the face of shape 432 interior to the truss section, showing the pass hole 432H for the bolt and an adjacent hole 432S. FIG. 5J is the same view and FIG. 5K a section, both with threaded insert 521 installed, the threaded hole 521T in it in substantial alignment with pass hole 432H (corresponding, for example, to 422 in the earlier Figures) in shape 432 and in end plate 440. (In FIG. 5K, rails 432E and 432G are not shown for clarity).
  • [0418]
    Threaded insert 521 is retained in position, in this example, by the expedient of a part 522 that protrudes into hole 432I in shape 432. One such part may be a fastener mating with threads in either the insert 521 or the hole 432I in shape 432 (or in end plate 440 beyond it). Alternatively, the simple expedient of a plastic plug or wooden dowel press-fit into one of the holes will serve. It will be apparent that the difference in diameter and/or shape between the part 522 and the hole on one part can be used to determine the distance by which the insert will “float” relative to the hole.
  • [0419]
    Another method of retention is a plug or fastener inserted through the shape 432, its rails, or a bracket above and below the nut or threaded insert, which prevents or limits movement of the insert through the track defined by the rails.
  • [0420]
    FIGS. 5L and 5M illustrate another retention method—a spacer shape is inserted in the track formed by the rails 432E and 432G. This method has advantages when multiple nuts or inserts are used in the same track. Several sections of spacer shape (e.g. 523 and 524) with nuts or inserts interspersed can, by the choice of appropriate lengths, determine the spacing between multiple nuts or inserts, and require only a limited number of connections to the truss, either by fixing inserts and/or spacers in place (in the example illustrated in FIGS. 5L and 5M, both methods are illustrated in the form of part 522 and threaded fastener 525).
  • [0421]
    In trusses using a formed track, inserts and spacers can be inserted and changed in a fabricated truss where at least one open end of the rails remains exposed, as in the embodiment illustrated in FIGS. 4N and 4O. In other designs in which the ends are closed by the truss design, the protruding portion of the rails can be machined away for a length sufficient to insert or remove an insert.
  • [0422]
    FIG. 5N illustrates the use of the same rail detail on both sides of the truss-truss connection. A non-threaded insert 526 with a pass hole is inserted in the track on the bolt-side of the connection. As is also illustrated in FIGS. 5F-5H, the shape employed for insert 526 has a flat surface 526F proud of the surface 434F of rails 434E and 434G, such that the clamping load of bolt 510 is transferred to the main body of shape 434D by the insert rather than by the head of bolt 510 bearing on the surfaces of rail 434E and 434G.
  • [0423]
    FIG. 5N also illustrates both threaded (521A) and non-threaded (526A) inserts that can be inserted and removed.
  • [0424]
    There are circumstances in which the user may desire to change a pass hole from threaded to un-threaded or vice versa.
  • [0425]
    FIGS. 5O-5S illustrate one method of achieving the benefits of retained hardware with the ability to rapidly change between threaded and unthreaded holes.
  • [0426]
    FIGS. 5O-5Q are two elevations and a top view equivalent to FIGS. 5F-5H. A profile similar to that of inserts 521 and 526 is used in a greater length and with both a threaded hole 527T and an unthreaded pass hole 527H. FIG. 5R is an oblique detail equivalent to FIG. 5C showing such inserts in the tracks formed by the rails. FIG. 5S is a section showing the adjoining ends of two trusses (the rails, again, suppressed for clarity). The user can manually slide the insert 527 in the track to align the desired hole in the insert with the pass hole in the truss end. Fasteners, pins, or dowels (or another method) are used as stops to limit the movement of the insert in the track. As illustrated, when resting on stop 529 insert 526 aligns threaded hole 526T with the hole through shape 432 and end plate 440. Stop 528 limits the travel of the insert 527 such that the unthreaded pass hole 527H aligns with the same hole. A detent can be used to maintain the insert at one limit or the other. For example, a blind hole 327R in the insert can retain a compression spring 530 that bears against the adjoining face of shape 432. Other methods of resisting inadvertent displacement of the insert can be employed and the detent can engage details (example, holes like 432I) to align the selected threaded or unthreaded hole in the insert with the hole in the truss.
  • [0427]
    FIG. 5R is an oblique view. The track detail in shape 432 illustrates a dual function insert 526. The track detail in shape 434 illustrates an extended section of insert 526B that provides threaded and unthreaded holes for a plurality of bolted connections.
  • [0428]
    Many other approaches are possible and should not be understood as limited, except by the claims.
  • [0429]
    In addition to bolted connections, other methods of joining truss sections are employed.
  • [0430]
    Another form of connection, a “spigot”, refers generally to a fitting that protrudes beyond the nominal end of the truss structure and is provided in male and female versions. A male “spigot” on one truss section is mated with a “female” spigot on another truss section, and the two fixed together using a locking feature such as a pin. Typically, each truss section employs one such spigot at the end of each of its major longitudinally-extending members or “chords”. The most common type uses fork-like “clevis” connections. Such fittings are fabricated separately and attached to the chords of a truss section either permanently (by pinning, welding, or hydraulically swaging the chord tubing around recesses on the fitting) or temporarily with pins. “Spigots” have the advantage of requiring less time to mate than bolted connections; requiring few or no tools; and being easier to inspect (as whether a bolted connection has been fully tightened is not readily visually apparent).
  • [0431]
    “Spigots” may be of one-piece construction, or may be fabricated in two parts: a receiver that is permanently installed in the truss chord, and a fitting that may be inserted in or removed from the receiver—or its orientation changed—to meet current requirements.
  • [0432]
    Over the years, various designs have been employed, both for the fittings themselves and for their method of attachment to their truss section and to the mating fitting.
  • [0433]
    Any of the prior art spigot designs may be employed.
  • [0434]
    FIGS. 5T-5Y illustrate various approaches.
  • [0435]
    FIGS. 5T-5V illustrate the use of conventional male and female clevis fittings (551 and 552 respectively). Both fittings (cast, machined, or otherwise fabricated) have elongated tangs (551E and 552E) that are inserted into the truss chords and retained either temporarily or permanently. In this example, tangs 551E and 552E extend into the truss end and are provided with pass holes 551H and 552H that align with pass holes (e.g. 401H) in the truss chord 401, through which fasteners, whether temporary or permanent, are inserted.
  • [0436]
    Tangs 551E and 552E may be equivalent to the forms 124, 126, 127, or 130 of FIGS. 1N, 1P, 1Q, or 1T.
  • [0437]
    FIGS. 5W-5Y illustrate another approach.
  • [0438]
    In this embodiment, a tang 553 is retained in the truss chord 401 by means of the pass holes 553H and 401H like those illustrated in the prior Figures and of pins 556 and 557. There may be a compatible receiver installed in the chord of the mating truss section (here 400D) or, as illustrated, for example, in FIGS. 1N, 1T, 4P, or 4T, the profile of the tube used for the chord itself may provide such a form, in which the other end of tang 553 is held by locking pins 558 and 559 through pass holes 553G in tang 553.
  • [0439]
    FIG. 5W also illustrates an improvement in which the fitting (in this case, tang 553) can be recessed into the chord of the truss itself when its use is not desired. Compression spring 560 is inserted within the truss chord and retained by a fastener at 561 or other means. To recess the fitting, the user pulls pins 556 and 557 and pushes the fitting tang 553 until the other set of pass holes 553G in tang 553 align with pass holes 401H in the truss chord. Pins 456 and 457 are reinserted, locking the tang 553 in its recessed position. When use of the tang is desired, pins 556 and 557 are pulled and spring 560 serves the function of urging the tang 553 outwards so that the user can grasp it and pull holes 553H into alignment with holes 401H, where the pins 556 and 557 are reinserted, locking the tang 553 in its extended position.
  • [0440]
    In addition to the need to join sections of truss end-wise to create longer spans, there is also a need to join them at right angles when forming larger structures. For this purpose “corner blocks” have long been employed.
  • [0441]
    A “corner block” is typically a cube (if the truss is square in cross section) fabricated of structural shapes that provides for the same joining method as employed by the truss on each of between three and six of the “corner block's” sides. An elevation of a “corner block” for “20.5″” truss, for example, will typically resemble an end view of such truss, e.g. FIG. 4B.
  • [0442]
    Beginning at FIG. 6A are illustrated various possible embodiments and details of a unit that serves the function of a “corner block” and many more.
  • [0443]
    FIG. 6A is an elevation on one side of a unit 600 as adapted for one group of truss types. Prominent is a plate 601, in some respects analogous to plate 440 of prior Figures in that it provides a variety of holes (e.g. 601H) for attachment.
  • [0444]
    As illustrated in FIG. 6A and other Figures, plate 601 includes a number of holes 601H of three shapes.
  • [0445]
    Refer now to FIG. 6B, a detail of the hole pattern illustrated in FIG. 6A. For ease of description, holes are referenced by a column letter (A-E) and by a row letter V-Z) and may be identified by a two-letter designation that specifies their coordinate (for example, the hole 601H in the top right corner of the Figure is hole “EV”).
  • [0446]
    A number of holes and of hole shapes are provided to permit a wide variety of connections between the plate 601 and various truss types.
  • [0447]
    Columns A and E and rows V and Z are on 13.75″ centers, spacing holes AV, AE, AZ, and EZ to correspond with holes 421B, 422B, 423B, and 424B of standard “20.5” truss, as was illustrated in FIG. 4B. Thus plate 601 will mate with known “20.5″” truss.
  • [0448]
    Columns B and C and rows W and Y are spaced on 6.75″ centers. Column C and row X employ elongated holes that include a 6.75″ center relative to both the A and E columns and the V and Z rows. Hole CX is elongated in both axes to produce the 6.75″ center to columns A and E and rows V and Z. 6.75″ is the hole pattern employed by prior art “1212” truss as was illustrated in FIG. 4A. Thus, a section of “1212” truss can be mated with plate 601 in any one of nine possible alignments—in all combinations of left, centered, and right vertically and high, centered, and low horizontally.
  • [0449]
    The “20.510.25” truss earlier described will mate in four possible orientations.
  • [0450]
    FIG. 6C adds additional mounting holes. The four holes on the F and G columns (holes FV, GV, FZ, and GZ) allow “20.510.25” truss to be mated while aligned on the vertical center of unit 600. The five holes on the “U” row allow the mating of known “12″18″” truss in a vertical orientation and a left, centered, or right alignment.
  • [0451]
    It will be apparent that other and/or addition hole patterns can be used.
  • [0452]
    It will be seen that a hole pattern like that illustrated will accept a variety of truss types in a large number of orientations. While illustrated as a plate, it will be apparent that many methods of producing the same or another interface are possible using other fabrication methods. The holes illustrated may be simple pass holes similar in principle to those illustrated in FIG. 5A and/or can employ other or additional features including threads or threaded inserts, other fastener types, and/or “spigots”.
  • [0453]
    FIG. 6D is a section through unit 600 showing one method of construction. Four plates (e.g. 601) are provided on each of four perpendicular faces, and are joined by sections of a structural shape 602 at each of their four adjacent corners.
  • [0454]
    FIGS. 6E-6G are detailed views illustration some of the many possible designs for shape 602.
  • [0455]
    FIG. 6E illustrates the same shape 602 as seen in FIG. 6D, an angle that provides two flanges for attachment to a plate 601 by, for example, welding along their interfaces. Pass holes in shape 602 (here hole 602H) aligned with the holes (here hole 601H) in plate 601 are provided as necessary. A detail is illustrated at the corner, here a shape 603A, which is fabricated, for example, from wood, rubber or plastic, and serves as a protective bumper, which may be bonded or fastened in place.
  • [0456]
    In FIG. 6F, a similar protective bumper 603B is shown as retained by a interlocking tongue-and-groove connection with a corresponding detail 602I on the corner shape 602B, which also includes rails (e.g. 602F) that accept threaded or unthreaded inserts as earlier illustrated.
  • [0457]
    In FIG. 6G, a stiffening rib 602G is illustrated, as well as an extruded corner detail 602J.
  • [0458]
    FIGS. 6H and 6I illustrate another embodiment 600B of the unit with additional features.
  • [0459]
    FIG. 6H is a side view that illustrates the addition of casters (e.g. 604) and a stacking locator detail 605.
  • [0460]
    FIG. 6I is another elevation of a side perpendicular to the side seen in FIG. 6H that differs in two respects: it has an overall width that is 24″ rather than 20.5″ and it includes a handle detail (e.g. 606).
  • [0461]
    (It will be understood that units having the features and improvements described and illustrated in the application—and other equipment—can be produced in many possible embodiments, including sizes and proportions. While an embodiment having faces of different width is illustrated in many of the following Figures, all faces could be of the same width.)
  • [0462]
    FIG. 6J is another elevation from the same perspective as the prior Figure showing the unit illustrated 600B in use. Two sections of truss (400B and 400BB) are attached to unit 600B (and additional trusses could be attached to the side 601S visible and/or the side opposite. The unit 600B is suspended by spansets, cable, or chain bridle 656 from a known chain motor 650, suspending the trusses 400B and 400BB (and any other connected structure).
  • [0463]
    While all sides of the unit can be of equal width, they may also differ and FIG. 6K is a cross section of a corner shape 602K forming an angle with unequal legs that attach to the plates 601E and 601S of two sides of different width.
  • [0464]
    Prior sections have been through a horizontal plane. Beginning at FIG. 6L are a series of cross sections through a vertical plane, illustrating other aspects of possible designs.
  • [0465]
    FIG. 6L is such a cross section and provides a point of reference for the various details seen in detail in the Figures following.
  • [0466]
    FIGS. 6M-6O illustrate several possible approaches to a shape for the top edge of a unit having a substantially open top. All three shapes 611A, 611B, and 611C incorporate a rounded top profile that is equivalent in location and shape to a main chord of “20.5″” truss—which stiffens the top edge of plate 601, provides a comfortable gripping surface, and has other advantages that will be illustrated in later Figures. Any of these shapes can be provided with a detail for retaining inserts, such as rail 611F.
  • [0467]
    FIGS. 6P-6R illustrate several of many possible approaches to a shape for the bottom edge of a unit 601 that has details like those illustrated in the prior Figures. All three shapes 612A, 612B, and 612C are illustrated with a flange (612E, 612F, and 612F respectively) that can be used as a point of attachment to the unit 600 when it is suspended (as was illustrated in FIG. 6J)—as is illustrated by the attachment of a shackle 657 whose bolt is passed through a hole 612H provided in flange 612G. Other illustrated details include a flat lower surface (e.g. 612I) for the attachment of casters, a bottom plate, and/or other items. FIG. 6R elongates this feature to provide an enlarged mounting surface 612J and also illustrates the use of a rail 612K as part of an insert retention detail.
  • [0468]
    FIGS. 6S-6U illustrate how unit 600 can be readily stacked on another such unit or section of truss.
  • [0469]
    Referring to FIGS. 6T and 6U, there is illustrated a bottom edge shape 612 very similar to the shapes illustrated in FIGS. 6P-6R.
  • [0470]
    A bottom plate 607 and casters (e.g. 604) are attached to the bottom edge shape 612, with the casters so located that, as illustrated in FIG. 6T when a unit 600 is stacked atop a section of truss for handling, transport, or storage that they do not interfere (top chord 401BL of the section of truss below is shown). FIGS. 6T and 6U also illustrate an additional part, stacking interlock shape 605 (also seen in prior FIGS. 6H-6J and 6L). As is seen from FIG. 6T, the profile of stacking interlock detail 605 conforms to the external profile of the tubing (here 401BL) used for the main chords of one truss type with which the unit 600 is designed to be used, such that it positively locks the unit to which it is mounted in alignment with the truss section under it. As will be seen by comparison of FIGS. 6S and 6T, the bottom edge of unit 600 is preferably located and stacking interlock detail 605 designed so that a unit 600 stacked on a truss section will have the same overall height as two stacked truss sections. As will be seen from FIG. 6U, the detail used at the top of the unit, here shape 611, is designed with an external profile similar in location and shape to the top chord of a truss so that two such unit can be readily stacked and that the resulting stack will be of the same height as a stacked pair of truss sections. This will have benefits including the ability to ship assembled spans of truss sections that include those with a unit attached.
  • [0471]
    FIG. 6I illustrates a unit whose plate 601 includes a handle detail 606 that can be produced by machining or otherwise forming a suitable hand-hold opening in the plate 601 and in any shape or structure behind it, in this case corner shape 602. The user's comfort and lifting ability are improved by an additional shape 613. While, in FIG. 6I, the handle details replace two mounting holes per side, FIG. 6W illustrates one method by which such mounting holes may be restored. Adapter 614 includes a threaded hole 614T that serves the function. A portion 614A of the adapter 614 that extends into the hand-hole aligns it. Faces 614B and 614C bear against shape 602, transferring the load on the bolt into the structure. Such an adapter could be retained on a hinged connection or other captivating connection.
  • [0472]
    In addition to connecting with truss sections, the unit can connect with tubing by any one or combination of several means.
  • [0473]
    FIGS. 7A-7L illustrate a unit having integral provisions for attaching tubing.
  • [0474]
    FIG. 7A is an elevation showing four recesses 715A-715D, each of which can accept a tube. FIGS. 7B-7M illustrate some of the possible methods of integrating provisions to attach such tubing into the unit structure.
  • [0475]
    FIG. 7B illustrates a shape 712B, here adapted for the lower edge of the unit, that includes a cylindrical opening 712L that receives the tubing and includes a detail 712S like that illustrated beginning at FIG. 2C for accommodating a nut plate to fix the tube in position.
  • [0476]
    FIG. 7C illustrates a shape 722C that incorporates a flange 712F from which the unit can be suspended, here via shackle 657.
  • [0477]
    FIG. 7D illustrates a similar shape 722D, which can be suspended by a wire rope loop 656L wrapped around the tubular member 712P via a hole or slot 7120 opened in the flange connecting the tubular and angled portions of the shape.
  • [0478]
    FIG. 7E illustrates another shape 712E also having an opening 712L that receives the tube and a recess 712SS that can accommodate one or more fitting types. Fitting 722 is a shape that is accommodated within recess 712SS. Seen in an end elevation in FIG. 7H and in side elevation in FIG. 7G, fitting 722 includes threads that receive a bolt 723 or other threaded fastener. In a manner similar to the shape of FIG. 2I and other Figures, tightening bolt 723 against a tube inserted in opening 712L will fix the fitting 722 and the tube in place. To prevent the fitting from moving in the recess 712SS when not tightened on a tube many methods can be employed. Here a pass hole 712P through the shape 712E is illustrated, and a corresponding pass hole 722P through the fitting 722. A fitting may be retained in a given position by insertion of, for example, a known locking pin through both pass holes. If the pass hole 722P in fitting 722 is oversized relative to the diameter of the pin (at least in a dimension perpendicular to the tube's centerline) the fitting will be free to “float” slightly as the fastener 723 is tightened on the tube, assuring that the load is transmitting to the tubing across the interface between the fitting 722 and the shape 712E and not via the pin.
  • [0479]
    It will be apparent that there are many other suitable designs for a detent that will maintain fitting 722 in a selected position.
  • [0480]
    In the Figures, fitting 722 has been fabricated so that the head of fastener 723 is recessed within the profile of the shape 712E.
  • [0481]
    FIGS. 7I and 7J illustrate shape 712E with two other fittings. Fitting 724 and 725 are designed for use in suspending the unit 600 or other unit in which they are employed. Both fittings 724 and 725 have elongated tabs in which a pass hole (724H and 725H) is provided for attachment (of shackle 657 in the case of fitting 725). Pass holes (e.g. 725P) is provided for maintaining the fitting in position.
  • [0482]
    In suspending a load it can be necessary to shift the point of attachment to compensate for variations in the location of the load's true center-of-gravity. FIG. 7M is an oblique view of shape 712E with fitting 725 inserted. A plurality of pass holes 712P are shown in shape 712E, permitting the fitting 725 to be maintained in any one of a range of possible locations to move the point of attachment to the center-of-gravity.
  • [0483]
    There are many methods of providing for a range of attachment points, which should not be understood as limited. In the case of shapes 612A-612C of FIGS. 6P-6R or 712C or 712D of FIGS. 7C and 7C, the flange can be provided with holes or slots in multiple locations. Another method would be to provide teeth or a similar detail at the interface between the fitting and shape 712E (whether integral to the fitting and/or shape or by means of an additional element). A spring might urge the two interlocking details together when not under load. The user could relocate the fitting by pressing the fitting into the shape, overcoming the spring and separating the interlocking details. When released at the new position, the spring would urge the interlocking details together. The interlocking details could not be separated when the fitting was suspending the load.
  • [0484]
    The prior Figures illustrate some of the possible methods by which a tube can be fixed to a unit or other structural element by a shape having other purposes. Various types of clamp or fitting can, of course, be attached to the unit or shape, on a temporary or permanent basis, to perform the one or multiple functions.
  • [0485]
    Beginning at FIG. 7N are illustrated methods of attaching tubes to the exterior of a unit or other structure.
  • [0486]
    Illustrated in FIG. 7N is end elevation and in FIG. 7O in side elevation is an elongated bracket 730 provided with pass holes (e.g. 730H) that align with the hole pattern on the unit 600B. The bracket 730 is dimensioned so that it accommodates a tube (e.g. 200) and that when bolts (e.g. 731B) are tightened down, that the tube is firmly clamped between the bracket 730 and the surface of plate 601, preventing either movement or rotation of the tube. FIGS. 7P and 7Q illustrate two examples of bracket 730 (here brackets 703A and 703B) in use to attach two tubes (here 200A and 200B) to a unit 600B.
  • [0487]
    FIGS. 7R through 7V illustrate other embodiments of fittings used to fix tubes to a unit or structure.
  • [0488]
    FIG. 7R is a cross section through a structural shape 760 (which may or may not be formed by extrusion) that includes a large opening 7600 that can accommodate a tube 200 and, in this embodiment, a smaller opening that can accommodate a threaded insert 762 that accepts a fastener 763, which is used to fix tube 200 in shape 760. Shape 760 also includes an elongated flange 760F that includes one or more pass holes 760H for a bolt (e.g. 731) that can be used to fix shape 760 to a unit or other fitting or structure. As seen from FIGS. 7S and 7T, shape 760 may be fabricated or trimmed to any length including a short version (760S) having a single mounting hole 760H or a longer length (760L) having multiple such holes, in this case on the same centers as the plate 601 of unit 600B.
  • [0489]
    FIGS. 7U and 7T illustrate two variations.
  • [0490]
    In FIG. 7U (and as illustrated side elevation) in FIG. 7T an additional pass hole 760HH is provided in the shape through the centerline of the large opening 7600. When the tube or other shape inserted in the large opening 7600 of shape 760 has aligned pass holes of similar diameter a bolt 731E or a locking pin 732 can be inserted through the pass holes in both shape and tube, fixing the tube in place. The side elevation in FIG. 7T shows both pass holes 760H in the flange 760 and the pass holes 760HH through the large opening.
  • [0491]
    Shape 760U has a flat surface 760I on which bolt heads can bear down.
  • [0492]
    Shape 760V in FIG. 7V omits the extended flange 760F of prior Figures where bolts through hole(s) 760HH will both retain a tube in the shape and the shape to the unit or other structure.
  • [0493]
    FIGS. 7W and 7X illustrate sections of such shapes in use. In the illustrated example, four sections of such shape (760A-D) are used to fix four lengths of tubing (200A-D) to a unit 600B. Note that inversion of the same shape (for example 760A versus 760C) allows offsetting the tubes they attach, such that the tubes will not conflict if extended past one another.
  • [0494]
    Other methods for attaching tubes and other shapes are possible.
  • [0495]
    Beginning at FIG. 8A are illustrated examples of how the components illustrated in the previous Figures can be combined.
  • [0496]
    Among the purposes of such combinations is to create larger structures including “pods” or self-contained structures that can be shipped in essentially their assembled state.
  • [0497]
    FIGS. 8A-8C are three views of a “pod” assembled from four units 600B, tubing or pipe, and various fittings.
  • [0498]
    Referring to FIGS. 8A and 8B, two elevations located in FIG. 8C, sections of shape 760 (e.g. 760M and 760N) are used to attach lengths of tube (e.g. 200A and 200B) to a unit 600B. As seen in FIG. 8C, a plan view, four such units 600B, one at each corner, are used with lengths of tube to assemble a rectangular framework, from which lighting fixtures and/or other loads could be hung, and which, in turn, can support additional structure, such as cross pipe 200I which, in turn, supports cross pipes 200J and 200K, which are attached by cheseboro or other clamp.
  • [0499]
    FIGS. 8D-8F are similar views of a structure assembled from four units 600B and four sections of truss (including 400A and 400AA). That outer truss structure is illustrated as supporting additional internal structure by means of tube attached to the trusses by cheseboros (e.g. tube 200L and clamp 230A).
  • [0500]
    One application for such components and such structures is temporary and touring uses, where important benefits are gained by minimizing the amount of assembly labor required on site to convert the equipment from the configuration in which it is used to the configuration in which it must be shipped.
  • [0501]
    In the case of the structures illustrated and others, so long as a structure or section of it is narrower in one dimension than the width of the truck used to ship it, the structure or section, on the casters 604 afforded by the unit 600B, can be rolled on and off the truck assembled.
  • [0502]
    To further reduce the amount of assembly labor at the point of use, a structure can be shipped with all or part of its “payload” in the form of lighting and/or scenic equipment attached. The height required by such equipment may exceed the “ground clearance” afforded by the height of the unit 600B and, indeed, it may be desirable that a significant portion of the lighting or scenic equipment extend below the plane of the bottom edge of unit 600B to minimize the obstruction it presents.
  • [0503]
    Beginning at FIG. 6A is one method of providing additional “ground clearance” while preserving the ability to roll the structure into place. In the Figures, a section of shape 740, here section 740X is bolted to one side of unit 600B in a vertical orientation. A caster 804 is coupled with a tube 803 that extends into the large opening of shape 740X, and can be maintained at a given distance below the bottom edge of unit 600B by any one of several means, in this example, a bolt 731E that extends through a pass hole in both shape 740X and tube 803. As seen in FIG. 8A, a plurality of such holes (e.g. 803H) can be provided in tube 803 to permit fixing caster 804 at different distances from the bottom edge of unit 600B. By the use of a locking pin, like 732 of FIG. 7U, which can readily be removed, the height of the caster assembly can be changed and the assembly quickly added or removed.
  • [0504]
    In the Figures, the extended caster assembly is also shown with an additional caster 814 that rotates around tube 803, and serves the purpose of a fender that will prevent the structure from dragging against, for example, the sidewall of a truck.
  • [0505]
    Without such an extended caster assembly, structures locating their units 600B in the same places will readily stack, by virtue of their stacking details like those illustrated in detail in FIG. 6U.
  • [0506]
    Beginning at FIG. 8G, it is illustrated that structures employing an extended caster assembly can also be stacked. Illustrated is a caster cup 805 that receives and surrounds the large caster 804 of a structure above it.
  • [0507]
    In the illustrated examples, the method used to increase “ground clearance” while preserving the ability to roll the structure is an extended caster assembly located on an exterior surface.
  • [0508]
    It will be apparent that such a structure could be located on one of the two faces of unit 600B that are interior to the structure, which would permit increasing the size of caster cup 805 (as is illustrated in FIG. 8K) to reduce the tolerances required for capture of the large casters of a structure above it.
  • [0509]
    It will be apparent that other methods of increasing “ground clearance”, such as structures similar to unit 600B of the same, different, or variable height and incorporating a compatible stacking detail can be inserted between the units of a structure and each other and the ground.
  • [0510]
    And it will be apparent that other methods of stacking units and/or structures including them are possible.
  • [0511]
    FIGS. 8K-8L illustrate another method of maintaining units in a relationship—in this case, a plate 660 which includes holes at spacings that hold two or more units 600B in the desired relationship (for example, so as to fit between the side walls of a truck). The plate is bolted in place. Such a plate can, in fact, be accommodated between the plate 601 of a unit 600B and truss sections and/or shapes, adapters, and fittings. And it can be stiffened by forming or adding returns.
  • [0512]
    Alternatively, for example, as illustrated in FIG. 8M, two or more sections of shape 760 or variations, in the appropriate length and with the appropriate hole pattern at either end, will serve the purpose of maintaining two units at the desired distance.
  • [0513]
    In one application, larger structures or units of less than a truck-width and the desired length can be assembled; hung with the desired lighting, scenic, and other elements; largely pre-cabled; and then stacked for shipping as illustrated in FIG. 8N.
  • [0514]
    Upon arrival at the venue a stack is pushed or towed off the truck to a location at which, as illustrated in FIG. 8O, a lifting means, for example chain motors like motor 65, are attached to the top unit. This may be the chain motors used to support that unit in its desired position. As illustrated in FIG. 8P, the top unit (here 60T) is lifted off the stack, and the remaining units are rolled to the desired location for the next unit in the stack, where the process is repeater until all units in the stack have been flown.
  • [0515]
    In an alternative, illustrated in FIG. 8Q, a means is provided for linking the structures, such that lifting the top structure in a stack will also lift those beneath it. In this alternative, the stack is brought to an “unstacking” location where the top structure is attached to a lifting method (such as chain motors). With the bottom structure and the structure immediately above it not linked, lifting the top structure will lift all intermediate ones, including the one above the bottom structure. They are lifted clear of the bottom structure, which can be rolled away. The lifting method then lowers the structure that had been above the bottom structure to the ground, allowing the link between it and the structure above it (here 61 and 61A) to be disconnected. The stack is lifted again, allowing the second structure from the bottom to be rolled away.
  • [0516]
    The process is repeated until all structures have been unstacked.
  • [0517]
    In both alternatives, the process is reversed to stack structures for shipping away from the point of use.
  • [0518]
    Such structures can travel with not only their lighting and/or scenic loads attached, but pre-wired. Indeed, because both lighting equipment and chain motors both require power, heretofore distributed in separate systems, a bulk supply of electrical power can be provided to each structure, which is there distributed for chain motors, un-dimmed power supply, and dimmed power (via dimmers carried on the structure). Cable required to connect equipment on a structure with equipment at another location can travel coiled atop the structure.
  • [0519]
    FIGS. 9R-9U illustrate one embodiment of another unit that simplifies the assembly of such larger structures that may travel largely assembled.
  • [0520]
    In the illustrated embodiment, elongated structural shapes (like members 812 and 813) are used to frame a generally rectangular structure 80 having two ends, one illustrated in FIG. 8U, which can permit the attachment to various trusses and other structures. The length of the structure (and hence the distance between the end plates 815 and 825) can be set at a distance less than the width of a transporting truck—for example at 90″.
  • [0521]
    Like the units of the prior Figures, the unit 80 also provides for attaching trusses and other structures and structural elements and shapes to form a larger, frequently rectangular structure. Referring to FIG. 8RR, holes like 820 are provided in a pattern that permits the use of trusses of varying size and, in the case of smaller trusses, alignment. (The dotted outline 826 is of “20.5″” truss.) In the illustrated embodiment, those holes 820 are provided in either the main chords (e.g. 812 and 813) or in intermediate members like 817 and 818. In the illustrated embodiment, a section of structural angle 816 is used to reinforce the corner and a piece of plate 818 to reinforce the side—the very extensive interfaces between the various structural components resulting in considerable strength.
  • [0522]
    Referring to other views, the unit 80 also includes a pair of structural angles 821 and 822 used to provide a point of attachment for lifting the unit; for a generally circular tube 823 extending under the unit 80 for supporting additional loads; and for structural reinforcement. The unit is casters for handling and ground clearance can be increased by various methods including those illustrated in prior Figures.
  • [0523]
    Prior figures have illustrate methods by which unit 600B and structures can be equipped with casters.
  • [0524]
    FIGS. 9A-9Q illustrate methods by which trusses themselves not provided with integral casters can be provided with casters when desired.
  • [0525]
    Beginning at FIG. 9A is illustrated some of the possible embodiments of a “wheel bracket” that can be attached to a section of truss or similar structure.
  • [0526]
    FIG. 9A is s side elevation of “wheel bracket” 901, showing its side face 903 and casters 904 and 905. FIG. 9C is a cross section from the same perspective, showing the horizontal internal member 902 to which the casters 904 and 905 are mounted, as well as the parts 907 and 908 that engage the truss chords.
  • [0527]
    FIG. 9I is a detailed view of the latch mechanism that retains the wheel bracket on a truss section. A known mechanism, it includes two shapes 908 and 909 that rotate around respective pivots 908P and 909P. In the “engaged” position the concave side of part 908 conforms to the exterior profile of a truss chord. A tab on part 908 resting on a shelf on part 909 prevents rotation of portion 908A of part 908 away from the truss chord, which would release the latter. The curved shoulder 903A and projection 903B of the side face 903 of the bracket in which parts 908 and 909 are mounted prevent the chord from rotating part 908 towards its portion 908B. The bracket is thus retained on the truss chord.
  • [0528]
    The illustrated mechanism is hardly the only method of retention and many alternatives are possible.
  • [0529]
    To release the truss chord the user presses a lever 909L formed in part 909 against spring 919 releasing the pawl mechanism at the interface between parts 908 and 909, permitting the former to rotate, releasing the truss chord and permitting the removal of the bracket from the truss. Part 908 is held in this “open” position by its associated spring 918, with its portion 908B extending into the area occupied by the truss chord in the “engaged” position (as is seen in FIG. 9B. Part 907, which engages the other chord of the truss, can be produced, in this embodiment, by another section of the shape used for part 908, this part fixed in relation to the bracket and truss.
  • [0530]
    As illustrated in FIG. 9B, the user attaches the wheel bracket to a truss section by fitting the fixed side 907 over one chord of the truss, rotating the bracket 901 around that chord until portion 908B of part 908 comes in contact with the upper chord of the other truss chord. Continued rotation of the bracket towards that other chord results in the truss chord pressing against portion 908B of part 908, causing it to rotate about its pivot until this other truss chord is seated against the recess 903A and projection 903B of the bracket's side panel 903, and the latch mechanism between the two parts locks.
  • [0531]
    As seen in FIG. 9A, the side panel 903 of bracket 901 has a recess for the truss chords both above (903A) and below (903C) the projection (903B) such that, as seen in FIG. 9D, one section of truss with a wheel bracket 901 attached to its chords (here 403 and 404) can be stacked on another. Not only do the casters 904 and 905 on the wheel bracket fall within the chords (here 401L and 402L) of the lower truss, but the recess (903C) in the side panel of the wheel bracket locks the two trusses in alignment.
  • [0532]
    FIG. 9E is an end elevation of the wheel bracket seen in the prior Figures from the latch end. FIG. 9F is a detail of an H-shaped member (for example, an extrusion) that can be used for its structure. FIG. 9G illustrates a member created from two U-shared parts (which might be fabricated from sheet metal), in this example, held together using the same bolts used to mount the casters (e.g. 904).
  • [0533]
    FIG. 9J is a variation, bracket 901C, whose structure provides a recess that allows its use with the “compound” truss illustrated in FIG. 4D by avoiding interference with the additional truss chords 403C and 404CC.
  • [0534]
    FIG. 9K is another variant in which separate side panels (e.g. 903D) are illustrated as is a central member that allows changing the width of the bracket, allowing adjustment to different truss chord spacings, and therefore, different truss designs.
  • [0535]
    FIGS. 9L and 9M illustrate another variant that permits suspending the truss a bracket also serving as a wheel bracket. In the illustrated embodiment, the sides 903C are extend upwards and provided with pass holes (920A-920E) for attachment to lifting means.
  • [0536]
    FIG. 9N is a side elevation and FIG. 9O an end elevation of another embodiment of a wheel bracket, in this case assembled from flat plate and generally rectangular tubing.
  • [0537]
    A pair of tubes 911 and 916 are used as a platform to support the truss via the casters 904 and 905 bolted to it. Plates 914 and 915 are used to align the bracket between the lower main chords 403 and 404 of the truss section to which it is attached and, when stacked, with the upper chords 401L and 402L of the truss below it. A third tube 912 is retained between plates 914 and 915 by bolts, locking pins (like 916) or other means, those portions extending over truss chords 403 and 404 retaining the wheel bracket to the truss.
  • [0538]
    When multiple trusses are stacked, the height of the stack relative to its width can make it unstable. The Figures illustrate one method of improving stability—by linking two stacks. Tubular member 913 is a loose fit within member 912 and, as illustrated in FIG. 9N, can be extended beyond the tube 912 of one bracket to be inserted into the tube 912 on an adjacent bracket, where it is retained by locking pins through both, linking the two brackets and therefore their stacks. FIG. 9W illustrates two sets of such paired stacks in a truck.
  • [0539]
    FIGS. 9P and 9Q illustrate another variation that includes a wheel bracket and provisions to lift the truss section with a chain motor that travels internal to the truss.
  • [0540]
    Referring to the Figures the elements in common with the bracket in the prior Figures will be seen. The side panels (e.g. 914A) have been extended upwards and formed with or provided with a right-angle shape affording a horizontal surface upon which a chain motor 650 can sit, cushioned by padding 924. The chain motor's hook extends between the two side panels and a locking pin or other part is inserted through holes (e.g. 920B) in the side panels to form the lifting point for the hook.
  • [0541]
    The motor is contained completely within the truss section for shipping and can be readily “floated” above the truss for use by the simple expedient of removing the pin. It will be recognized that the unit 80 of FIGS. 8R-8V incorporates a similar detail in the form of angles 821 and 822 with their pass holes and the internal members (e.g. 827) that can serve as a shelf to support the chain motor.
  • [0542]
    FIG. 9P is a side elevation and FIG. 9Q an end elevation of another embodiment that supports a chain motor inside the truss.
  • [0543]
    In this case, the embodiment is assembled from webbing and heavy-duty fabric.
  • [0544]
    Referring to the Figures, a “bag” of heavy-duty fabric is fabricated, which may have a reinforcing rim 954 to maintain the shape of its mouth opening. That bag is hung from the upper chords 401 and 402 of a truss by means of webbing straps that wrap the truss chord and can be closed by snap hooks (e.g. 952) to “D”-rings (e.g. 953); by buckles; or other means. The strap detail includes straps (e.g. 955) upon which the chain motor can sit, keeping it from resting on (or being covered by) the motor chain which collects in the bottom 957 of the “bag” below. The motor need not be attached to the “bag”—allowing the motor to rise from a shipping position 650S to a higher “use” position 650E, to permit bridling that increases the stability of the truss and permits the use of horizontal safety lines. Holes (e.g. 958) may be provided for bridles to the lower chords and more typical bridles that wrap both the lower and upper chords can travel attached.
  • [0545]
    A similar approach can be taken using hard materials. FIG. 9T is a section; FIG. 9U a plan view; and 9V a side elevation using substantially rigid materials. The “bag” might be, for example, formed from plastic. The “shelf” supporting the motor in transit 965, might be of the same or a heavier material—for example, from aluminum.
  • [0546]
    When an un-castered truss section is stacked on another, there is typically nothing that prevents one section from moving with respect to the other, with undesirable consequences including collapsing stacks of truss, increased difficulty in packing trusses on a truck or in a storage space, and pinching the hands of those handling the truss sections. Such shifting is common when several trusses are stacked and the stack placed on wheels.
  • [0547]
    The wheel brackets of prior Figures illustrate provisions to prevent trusses from shifting relative to one another.
  • [0548]
    FIGS. 9X-9Z illustrate one design for a simple and inexpensive part for the sole purpose of preventing undesirable movement between stacked trusses.
  • [0549]
    The embodiment illustrated is for those trusses having cross braces between major chords on two opposing faces, those cross braces intersecting the major chord at right angles (“ladder” or “rung” braces).
  • [0550]
    FIG. 9Y is a section through both “rung” cross braces (410 and 410L) of two stacked trusses. “Stacker” 930 is an H-shaped extrusion of metal or plastic (or is formed by another other method of fabrication) that provides a recess for each of the two “rung” cross braces of a pair of trusses stacked. As seen from FIG. 9X a section through the truss stack that is a side elevation of the “stacker” in use (and seen in detail in FIG. 9XX) the vertical sides (e.g. 933) of the “stacker” are cut or formed to the general contour of the main truss chords that the “rung” cross braces intersect. In a manner similar to the “wheel bracket”, the two trusses are prevented from moving laterally with respect to each other.
  • [0551]
    It will be appreciated that, absent other provisions, one truss will remain able to move along the elongated axis of the two, rotating the shape of “stacker” 930 around one of the “rung” cross braces. To prevent this, the horizontal portion 932 of the “stacker” shape 930 extends between the two main chords, the projection tab (e.g. 932A) sandwiched in place by the weight of the upper truss section(s), such that the “stacker” cannot be easily rotated around the “rung” cross brace. This extension is visible in FIG. 9XX and in partial plan view FIG. 9Z.
  • [0552]
    In many applications, structures formed from trusses and from combinations of structural shapes and fitting are “flown” above the ground by lifting methods.
  • [0553]
    One of the most common such methods is the use of a “chain motor”.
  • [0554]
    Generally, the hook attached to the free end of the chain passing through the motor is attached to the building or other structure above. The hoist motor, which is electrically-powered, is run, pulling excess chain through the motor until the motor begins to pull itself up the chain towards the point of attachment. The motor is paused within several feet of the load so that various other components, including known “spansets”, steel wire rope, and shackles can be used to connect the motor body with the load. Once the load has been attached to the motor body, the motor can then be used to lift the load, continuing its climb up the chain. FIG. 6J has illustrated a truss structure supported by chain motor 650 via a “bridle” 656 of steel wire rope.
  • [0555]
    Generally, chain motors are shipped in roadcases, one or two per case. Each time the structure is “flown”, roadcases containing the motors (one hundred or more on a large production) must be maneuvered into the approximate location at which they will be required. A number of operations are required to remove each motor from its roadcase; assemble the required spansets, wire rope, shackles, and other parts; correctly attach them and the motor to the load; “fly” the combination; and store the roadcases for later use.
  • [0556]
    Beginning at FIG. 10A are illustrate various improvements that dramatically reduce the effort required to “fly” a structure.
  • [0557]
    Refer now to FIG. 10A a cross section through a unit 600B with a chain motor 650 visible above. It is apparent from the Figure that there is sufficient space in unit 600B to accommodate chain motor 650 for shipping. As chain motors are frequently used at or near “corner cubes” and similar elements, it is probable that anywhere a unit 600B is employed a chain motor will be required. Shipping a chain motor in the unit 600B eliminates the requirement to provide or handle a separate roadcase for the motor.
  • [0558]
    FIGS. 10A and 10B illustrate provisions in unit 600B to attach chain motor 650 to it. As will be seen in detail in FIGS. 10I and 10J, a bracket 620 that accepts a locking pin 622 that is engaged by the hook 650H of chain motor 650, providing a direct connection between the chain motor 650 and unit 600B. As illustrated in FIG. 10C, the unit 600B can be bolted or otherwise attached in a span of truss sections and/or at their intersection and/or in a structure like that illustrated in FIGS. 8A-8?. A chain motor is shipped in the unit 600B and arrives already attached to it.
  • [0559]
    Installing a unit 600B in a span of truss sections with the chain motor internal is not always practical for two reasons.
  • [0560]
    One is that the “point” at which a chain motor can be located (due, for example, to the design of a building's structure) may not align with the truss or other structure flown from it, such that the chain motor in a unit 600B inserted in that structure will align with it.
  • [0561]
    FIGS. 10D and 10E illustrate an alternative for such situations, in which the chain motor 650 still travels and works attached to the unit 600B, but the truss or other structure is suspended below it, here by bridle legs 656A and 656B attached to the bracket 620 of unit 600B by locking pins 657A and 657B. It will be apparent that there are substantial savings in the time and labor required with complete flexibility of location.
  • [0562]
    Another reason limiting the universal application of the mode illustrated in FIGS. 10B and 10C is that when a truss or structure is supported from “points” all on a common line, there is a tendency for that truss or structure to roll about its long axis, which is magnified when the truss or structure is supported from a point (in this case, motor hook 650H) that is as close to the center-of-gravity as when the motor is contained within the cross section of the truss.
  • [0563]
    The mode of FIGS. 10D and 10E also raises the lifting point sufficiently above the illustrated truss to improve stability. FIGS. 10F and 10G illustrate another mode in which the unit 600B remains in the structure, while the motor and its associated lifting point are raised significantly above it.
  • [0564]
    FIGS. 6H-6J illustrate some of the possible designs for a bracket assembly suited to the illustrated modes.
  • [0565]
    FIG. 10H is a cross section through unit 600B showing the previously illustrated side plate 601, upper edge shape 611, and lower edge shape 612. A structural shape or shapes is used to form a bracket assembly 620 having upper flanges (e.g. 620J) that include pass holes 620A-E that receive parts, for example, locking pin 622 to which hook 650H of chain motor 650 can attach as well as locking pins 657A and 657B that attach the legs of a bridle from a chain motor or other support above. The shape or shapes also include lower flanges (e.g. 620K) that provide pass holes for suspending loads below. The shape or shapes also have horizontal flanges (e.g. 620F) that bear up under lower edge shape 612, transferring the load from the unit 600B to the chain motor 650.
  • [0566]
    Different embodiments of the bracket assembly are illustrated in FIGS. 10I and 10J, differing in the design of the lower flange 620K, which, in the case of the embodiment of FIG. 10J, permits the direct attachment of shackles (e.g. 655A).
  • [0567]
    It can be desirable that the spacial relationship between the chain motor and the load it supports be varied to account for variations in truss center of gravity produced by asymmetrical loading.
  • [0568]
    Various prior Figures provide for such variation by offering multiple points of attachment (as well as the option of bridles with legs of unequal length. FIG. 10K is a detailed sectional view illustrating a provision for shifting the attachment point in a second axis—by employing a “tongue in groove” connection between the attachment flange 620 (and specifically a flange 620F formed from its horizontal portion) and a groove formed in the unit's framework (for example, in the extrusion used at the unit's lower edge.
  • [0569]
    FIGS. 10L, 10M, and 10O illustrate an embodiment in which the chain motor 650A is provided with a lifting plate rather than hook (as is the case with Chainmaster brand). In this case a larger lifting plate 651 can be employed that is captive to the motor, the motor attached to the unit 600B by means of a fastener (e.g. 622 or 622A) that links the lifting plate with the unit via holes like 651B in the lifting plate and 620B in bracket 620J. The lifting plate 651 extends through the bottom of unit 600B, such that loads hung below the unit are attached directly to the lifting plate, and the offset “ears” with holes 651A and 651E allow travelling the motor with an internal bridge attached.
  • [0570]
    There are many methods of supporting the motor within the unit, which should not be understood as limited. FIG. 8S and FIG. 9P illustrate simple “shelves” or internal members on which the motor can ride in transit; soft webbing straps have been illustrated; and FIG. 10N shows a internal divider.
  • [0571]
    It may also be desirable to cover the unit in shipping to prevent dirt, rain, and debris from entering, as well as to permit the unit to be flipped off its wheels or other equipment placed atop it.
  • [0572]
    FIG. 10P shows a simple formed cover 670A that drops or hinges over the unit 600B, which can be provided with latches (e.g. 671) to retain it in place. The top edge extrusion has been modified with a lower lip for the latch to engage.
  • [0573]
    FIG. 10Q shows a flat cover 670B, which again, may be retained by latches. The casters (e.g. 604U) of a unit or roadcase are captivated by the well formed by top edge extrusion 611L.
  • [0574]
    FIG. 10R shows another flat cover 670C, retained on one side by a detail in the top edge extrusion 611K and on the other by latch 671.
  • [0575]
    Beginning at FIG. 11A are other approaches to improving efficiency by permitting trusses to be shipped with loads attached.
  • [0576]
    FIG. 11A is a side elevation of two truss sections 40A and 40B, joined via a leg assembly 860, whose legs (e.g. 864) support the trusses at a distance sufficiently above the ground to permit lighting fixtures (e.g. fixture 50) to be hung. The legs are equipped with casters (e.g. 865) permitting the trusses to be rolled on and off trucks and between the truck and their point of use in a venue.
  • [0577]
    FIGS. 11A-D illustrate the design and operation of this embodiment. Two plates 861 and 861A are spaced apart, here by a structural shape 868, to produce a clearance between their adjoining faces slightly greater than the structural shape used for legs 864 and 864A. Pass holes aligned with the joining holes for the truss sections are provided through both plates 861 and 861A and any structural shape used between them. By the simple expedient of the use of longer bolts (e.g. 510), the pair of plates 861 and 861A are sandwiched between the two truss sections 40A and 40B. The legs, which are connected by brace 866, are fixed by locking pins (e.g. 867) inserted through pass holes in both the plates and the legs. At least two sets of pass holes are provided: one set with the legs in an extended position (as illustrated in FIG. 11B; and another set for a retracted position (shown in FIG. 11C). The truss sections (with their loads attached) are rolled into position, and, once supported by lifts or chain motors and weight is removed from the legs and wheels, the locking pins are removed and the legs are either removed entirely or moved to the retracted position.
  • [0578]
    Leg assemblies can be inserted at any joint between truss sections and at truss ends and, as illustrated in FIG. 11E, trusses can be shipped pre-hung with fixtures and pre-cabled in lengths limited only by the size of truck employed in shipping.
  • [0579]
    FIG. 11F illustrates another embodiment in which a single plate is used and the leg retained in an offset structural shape 862.
  • [0580]
    FIGS. 11G-11I illustrate another embodiment using a single plate 861 and dual legs. A bracket 869 connects the two legs with each other and cross-brace 866 and provides a surface for mounting a caster 865A via a plate rather than a post.
  • [0581]
    FIG. 11J illustrates that an alternative shape 861C for the plate can incorporate a detail that supports and engages a truss above for shipping, and FIG. 11K shows that nine truss sections can be accommodated in a typical truck in this manner.
  • [0582]
    FIGS. 11L and 11M illustrate an alternative method of attachment to a truss—brackets 870 and 870A can be clamped to the main chords of the truss using cheseboros (e.g. 872). U-shaped channel 871 accepts leg 864, which is retained by locking pin 867 in a manner similar to prior embodiments.
  • [0583]
    FIGS. 8N and 8O illustrate a method of shipping a chain motor with a truss that is too large to fit within it.
  • [0584]
    In one embodiment of this “motor saddle” 830, two plates or panels 831 and 832 are held in a parallel, spaced-apart relationship, here by standoffs 833 and 834, their overall dimension being less than the clearance between the structural members on the top side of a truss, here “rungs” 410U and 410UA. As will be seen from FIG. 11O, the external profile of the plates has a lower portion 832C less than the clearance between the two upper main chords 401 and 402 and a central portion 832B wider than that clearance, such that the plate sits atop the upper truss chords 401 and 402. The upper edge of the plate has a recess 832A that accepts a chain motor 650. The embodiment also illustrates a bag or bin 836 for the motor's chain. In this embodiment, the bag or bin is suspended using a readily removeable locking pin 835 so that the motor saddle 830 can be located with side panels 831 and 832 straddling a truss member such as 410U for greater flexibility in location.
  • [0585]
    It will be apparent that such a motor can travel with known “spansets” wrapped around the truss chords and attached to the chain motor, such that no additional operations are required before the motor can lift the truss. It will also be apparent that the motor will readily lift itself out of recess 632A, such that the motor will put the “spansets” under load and can assume a position significantly above its shipping position, increasing the stability of the truss and allowing for a horizontal safety line.
  • [0586]
    In this and other cases, an improved technique can be used to assure that chain from the motor reaches a bag or bin—a rigid or flexible tube or hose through which the chain travels can connect its exit port on the motor housing and the storage bag or bin.
  • [0587]
    With an externally-carried chain motor, an additional suction of truss cannot be readily stacked atop. FIGS. 11P and 11Q illustrate one possible design for a “stacker”. Composed, like the “motor saddle” of the prior Figures, of two plates 841 and 842, maintained in a parallel, spaced-apart relationship by standoffs (e.g. 843) or other means.
  • [0588]
    Like the “motor saddle” 830, stacker 840 has a lower portion that fits between the two top chords of a truss 410L and 402L; an upper portion that fits between the two bottom chords 403U and 404U of a truss above; and a middle portion wider than both. As a result, when inserted in the top of a truss, a second truss can be stacked atop it, with a vertical clearance between the two maintained sufficient for a motor carried in a “saddle” or for other purposes.
  • [0589]
    FIG. 11R is a side elevation illustrating both a “motor saddle” 830 and a stacker 840 in use, FIG. 11S being an end elevation of their use in a truck.
  • [0590]
    Where previous Figures have shown only a single level of trusses using the leg assembly and pre-hung fixtures, multiple levels are possible. In such cases, in one example, the cross-brace 866 of the leg assembly on the upper truss can rest atop the lower truss, the two trusses offset slightly to prevent interference between the wheels of the upper truss and the leg bracket assembly of the lower one. FIG. 11T illustrates a variation in the leg assembly that offsets the wheels outwards to increase stability of the stack and to eliminate interference between the leg assemblies of the two levels.
  • [0591]
    FIG. 11U illustrates a flat plate that may be bolted between truss sections, with or without a leg assembly,that provides a recess for supporting another truss section above it in shipping.
  • [0592]
    FIG. 11V is a section showing an linear extruded hinge such as produced as the “Roton” brand by Hager Hinge used in a truss or other structure design in which portions are moveable between one and another position. Hinge 90 includes two leaf extrusions 90B and 90D that interlock with a third extrusion 90C as a cover.
  • [0593]
    While many designs are possible, the embodiment illustrated provides channels such as 90E in leaf 90B that accepts other structural shapes, such as member 92 in a manner equivalent to the technique illustrated in FIGS. 4S-4V.
  • [0594]
    FIG. 11W illustrates the hinge opened.
  • [0595]
    FIG. 11X illustrates another extrusion 93 used to close the open channel.
  • [0596]
    FIGS. 12G-12I illustrate a method of mounting the clamps used to attach fixtures to trusses in a manner that eliminates the need to attach and remove them from the fixture either when converting between hung and floor use, or to reduce height for accommodation in roadcases.
  • [0597]
    A clamp such as 59 is attached to a bracket or other means which is attached to the fixture so as to permit its rotation between a stowed position parallel to the bottom surface of the fixture enclosure 50E (as illustrated in FIG. 12I) and an extended position in which the clamp is used to hang the fixture (seen in FIGS. 12G and 12H), here illustrated as (but not limited to) a bracket 53, pivotally mounted via pivot 52, to another bracket 51, attached to the fixture enclosure 50E by bolts (e.g. 55). Preferably the clamp 59 is also attached to permit rotation about its central axis 59A—for example, as seen in the difference between FIGS. 12G and 12H to accommodate different relationships between the fixture and the members from which it is hung.
  • [0598]
    FIG. 12I also illustrates a pass hole 51H in the bracket to permit access to the bolt 55 used to mount bracket 51 to the fixture enclosure and feet (e.g. 56) for the floor mode.
  • [0599]
    In these, as in all other cases, variations and other embodiments are possible within the scope of the inventions, which should not be understood as limited except by the claims.
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7779583Dec 5, 2007Aug 24, 2010Newell Operating CompanyMuntin clip
US8881486 *May 22, 2013Nov 11, 2014Bluescope Buildings North America, Inc.Truss saddle apparatus and method
US20100154330 *Mar 5, 2010Jun 24, 2010Newell Operating CompanyMuntin Clip
US20110005154 *Jul 28, 2010Jan 13, 2011Tyler Michael AMuntin Clip
US20130312361 *May 22, 2013Nov 28, 2013Bluescope Buildings North America, Inc.Truss Saddle Apparatus And Method
Classifications
U.S. Classification52/653.1
International ClassificationE04H12/00, E04H12/08, E04C3/04, E04C3/08, E04B1/24
Cooperative ClassificationE04C2003/0491, E04H12/08, E04B2001/2472, E04C3/08, E04B2001/2406
European ClassificationE04C3/08, E04H12/08