US 3485005 A
Description (OCR text may contain errors)
3 Sheets-Sheet 1 Filed Oct. 10, 1966 INVENTOR J4me Ku 7074/ FIG! BY/wl #91, a 31% Dec. 23, 1969 J. H. KUTCHAI 3, 85,00
S TRUC TURAL AS S EMBLY Filed Oct. 10, 1966 3 Sheets-$heet 2 I I 1 4 Y INVENTOR JACOB H. KUTCHAI ATTORNEYS Dec. 23, 1969 J. H. KUTCHAI STRUCTURAL ASSEMBLY Filed Oct. 10, 1966 3 Sheets-Sheet 5 w INVENTOR 44(05 M Kurd/Al United States Patent 3,485,005 STRUCTURAL ASSEMBLY Jacob H. Kutchai, 630 Merrick Ave., Detroit, Mich. 48202 Filed Oct. 10, 1966, Ser. No. 585,426 Int. Cl. E0411 12/10, 12/24 US. Cl. 52-648 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to structural assemblies and more particularly to an improved bracing configuration for a structural framework and including a new connector element adapted for uniting the structural members of the improved bracing.
This invention relates particularly to open structural assemblies such as are typically used for falsework, scaffolding, shoring, towers and the like. Structural assemblies of this type normally comprise a framework made up of a combination of vertical columns and horizontal girts. Secondary or bracing members are normally provided to keep the structure in its original intended shape, except for small elastic deformations. Without bracing, steel frameworks are subjected to collapsing caused by lateral movements initiated by some lateral force. The force might be one such as wind force, horizontal impact forces from cranes or machinery, or the tension of electrical power lines. Thus, in general, bracing is used to plumb up the structural framework during construction, and to keep it in place after construction, to resist computable lateral forces and also forces which defy computation but which might cause lateral movement or buckling of members.
Bracing conventionally takes the form of diagonal braces extending to the ends or the intersections of the members being braced. This is commonly called X-bracing. In order to assist the X-bracing to resist bending moments imposed on the main leg members, it is common practice to provide a series of horizontal girts or braces which are united with the main vertical members at their points of intersection with the diagonal braces.
Structural frameworks which are intended to support vertical loads normally have main members which are subjected to a compression type of load. Normally such members have a great length relative to their least lateral dimension and are therefore considered as columns. The critical load of column members under an axial load is classically considered as a function of the ratio of the unbraced length of the column and the least radius of gyration parallel to which it can bend. It can therefore be seen that an optimum bracing configuration considers means for laterally supporting members subject to column 3,485,005 Patented Dec. 23, 1969 type loads while utilizing a minimum of bracing elements.
It is a broad purpose of the present invention to provide an improved bracing configuration having greater structural stability than conventional bracing. In the preferred embodiment of the present invention, which will be subsequently described in greater detail, a scaffolding structure having upright main leg members is provided with X-bracing in which each set of intersecting diagonal bracing members is united with a pair of horizontal bracing members at their point of intersection with one another rather than with their intersection with the main leg members as is conventional. This pattern provides support for the main load bearing legs at their connection with the diagonal braces and also at a point generally midway between these connections with their coupling with the horizontal braces, Thus by recombining the same number of bracing members in the preferred configuration, greater stability and columnar strength can be obtained. The columnar strength of a typical framework can be increased by 20% over a framework employing the conventional pattern. It is to be understood that the horizontal girts commonly connecting the X-braces at their union with the main vertical members are completely eliminated since they contribute little toward structural stability of the framework and nothing toward the column strength of the framework.
Although the improved bracing configuration is useful in permanent type structures, the present invention is directed toward those type of frameworks which are normally intended to be assembled for a period of time and then dismantled. The emphasis of the present invention is not only to provide a framework requiring a minimum number of elements without sacrificing stability, but in addition on simplicity and economy of manufacture, standardization of components coupled with versatility in use and ease of assembly requiring a minimum of skill and utilizing conventional tools.
To achieve the aforesaid purposes, the preferred embodiment of the present invention contemplates an improved bracing configuration utilizing a novel form of fastening element for connecting the bracing elements one to another and to the main leg members. In connecting a brace member to a main leg member, the improved connecting element takes either of two preferred forms depending upon whether the brace is united with an extreme end of a leg section or an intermediate section.
It is contemplated that each of the structural members, including both bracing and leg members, are formed of circular tubing, preferably of steel. Tubing is chosen because of its relatively high load to weight ratio. The ends of the braces are =swaged or collapsed toward a common side so that a pair of braces may be connected back-toback thus requiring a minimum section at their connection. Each of the collapsed ends is provided with a tapered perforation which is engaged with the improved connecting element. Where the brace is to be connected to the intermediate section of a primary leg member, the fastening element comprises a short sleeve member having an inner diameter slightly larger than the diameter of the leg section and which carries a set screw adapted to engage the leg member. The sleeve normally is provided with a pair of laterally directed stud sections disposed at right angles to one another. Each stud section includes a frustoconical body section having its large end joined to the sleeve member and a small end terminating in a threaded section adapted to receive a nut. The brace members are united with the fastening element by inserting the stud section through their perforated ends so that the tapered Walls of the perforation engage the frusto-conical body section of the stud. The frusto-conical body section has a length chosen to accommodate a plurality of brace members each having a tapered perforation with successively increasing diameters. A lock washer is then received by the threaded section and the nut drawn up so that the tapered perforations are forced against the frusto-conical body section so that relative movement between the members is prevented.
By utilizing a stud having a tapered body section which is mated with a bracing member having a tapered perforation, the problem encountered with conventional stud elements having a cylindrical exterior surface with a diameter which does not correspond to the diameter of the perforation provided in the bracing member and which produces a loose, sloppy connection is eliminated. The
tapered mating members of the preferred embodiment of the present invention can at all times be brought into a snug engagement to provide a rigid connection between the members. This is of particular value in framing structures that are intended to :be assembled and dismantled a number of times and wherein the perforation in conventional braces tend to become enlarged.
Where the end of the diagonal brace member is to be united at the joinder of a pair of axially aligned leg sections, the preferred fastening element takes the form of a stud having a frusto-conical body section and which is fixed to a tubular section having end sections adapted to be inserted in each of the leg sections thus joining the leg sections one to another and also to the bracing members.
The third form of the improved fastening device contemplates the joinder of a plurality of brace members one to the other at the intersection of X-bracing. This form of the fastening device is in the nature of an elongated pin having a body section formed of a pair of frusto-conical sections having their large diameters back-to-back and their small oppositely directed diameters terminating in threaded free ends. Where a plurality of bracing elements are to be joined one to the other, their ends have a length such that the perforations are aligned along a common axis. Half of the bracing elements are engaged with one of the frusto-conical body sections of the pin and the other half are engaged with the opposite frusto-conical body section. This improved tapered stud thus makes possible the joinder of a plurality of brace members to form a rigid non-yielding connection.
Another improvement in structural assemblies contemplated by the present invention takes the form of an additional horizontal bracing member which is utilized between adjacent structural frame sides. This horizontal brace preferably joins the intersections of X-braces associated with each of the frame sides. This lateral horizontal bracing member provides additional rigidity in the improved structural assembly and resists forces which tend to collapse one framework side toward an adjacent framework side.
It is therefore an object of the present invention to improve the stability of structural assemblies comprising a pair of spaced apart primary load bearing members joined one to the other by X-bracing by providing a bracing element joined to the X-braces at their intersection and having its opposite ends joined to the main primary load bearingmembers.
It is another object of the present invention to increase the stability of structural framework adapted to support column type loads and including a pair of frame sides defined by spaced apart leg members provided with X- bracing generally in a plane common with the leg members by providing a lateral brace member having its extreme ends joined with the intersection of the X-bracing of the adjacent sides.
It is a still further object of the present invention to provide an improved connection in structural assemblies between a primary tubular load bearing member and a bracing element by providing a sleeve engageable with the end of the primary bearing member having a stud provided with a frusto-conical body section engageable with a tapered perforation formed in the bracing element.
till another object of the present invention is to provide an improved connection in a structural assembly between a bracing member and a leg assembly comprising a pair of axially aligned leg'sections and which takes the form of an insert engageable'with the opposed ends of the leg sections and having a stud section provided with a frusto-conical body section engageable with a tapered perforation provided in the bracing member.
A still further object of the present invention is to provide an improved connection between a plurality of bracing members by providing a tapered perforation in each of the braces engageable with a pin having a tapered length to accommodate a plurality of braces.
Still further objects and advantages of the present invention will readily occur to those skilled in the art to which the invention pertains upon reference to the accompanying detailed description of preferred embodiments of the invention. The description makes reference to the accompanying drawings in which:
FIGURE 1 is a perspective view of a four-sided selfsupporting structural assembly embodying bracing illustrating the preferred embodiment of the present invention;
FIGURE 2 is an enlarged sectional view taken along line 2-2 of FIGURE 1 and illustrating a coupling embodying a preferred form of the sleeve type fastening device;
FIGURE 3 is an enlarged sectional view taken along line 33 of FIGURE 2;
FIGURE 4 is an enlarged sectional view taken along line 4-4 of FIGURE 1 and illustrating a preferred insert type coupling;
FIGURE 5 is a sectional view taken along line 55 of FIGURE 4;
FIGURE 6 is an enlarged sectional view taken along line 6-6 of FIGURE 1;
FIGURE 7 is a perspective View of a section of a selfsupporting three-sided structural assembly embodying the present invention;
FIGURE 8 is an enlarged view taken along line 88 of FIGURE 7; and
FIGURE 9 is an enlarged sectional view taken along line 99 of FIGURE 7 and illustrating a preferred pin connection.
DESCRIPTION Referring now to the drawings, FIGURE 1 illustrates a self-supporting four-sided structural assembly, comprising four upwardly directed leg sections generally indicated at 10, 12, 14 and 16. The leg sections preferably have upper ends which gradually converge toward one another and are for purpose of description relatively spaced suchthat they form four equal sides 18.
The leg sections 10, 12, 14 and 16 have an identicalconstruction, each comprising a series of axially aligned tubular leg elements 22. Each leg section 22 is united with an adjoining leg section 22 by an insert type coupling 24.
Corresponding leg sections 22 of each of the leg members are interconnected by a plurality of brace members joined to form an X-bracing structure 26. Each X-bracing structure 26 includes four diagonal elements 28 each of which has its outer end connected to the extreme end of a leg section 22 by the insert couplings 24. The inner ends of each of the diagonal brace elements 28 are joined together at an intersection approximately midway between each pair of corresponding elements 22 and may be considered as associated in pairs, each pair substantially axially aligned with one another on an axis which intersects a similar axis formed by the other two diagonal brace elements.
The sides of the preferred structural assembly are interconnected by a series of adjoining X-bracing sections 26. The outer ends of the diagonals associated with each of the X-bracing assemblies 26 are connected to the diagonals of the adjoining X-bracing assemblies by couplings 24.
The inner ends of each of the diagonal brace members 28 are joined or connected by a stud 30 which can best be seen in FIGURE 6. A pair of horizontal brace members 32 are associated with each of the X-bracing assemblies 26 and have their inner ends joined at the inner ends of the diagonal braces 28 by the studs 30-. The outer ends of each of the horizontal brace elements 32 are connected to approximately the midsection of their associated leg elements 22 by a sleeve type of coupling 34.
In conventional structures, the horizontal equivalent of brace elements 32 has its outer end connected to the joindcr of the diagonals with the leg members thus permitting a relatively long unbraced section. Thus it can be seen that in the embodiment illustrated in FIGURE 1, the horizontal braces 32 provide support to the leg sections approximately at their mid-section so that the rearrangement of the same number of bracing elements utilized in conventional bracing produces greater stability and columnar strength. It is to be understood that the horizontal girts conventionally utilized to interconnect the outer ends of diagonal brace elements 28 are eliminated.
In order to provide additional stability in situations where substantial lateral forces Will be imposed on the structural assembly, and as can best be seen in FIGURE 6, a lateral horizontal brace member 36 connects each adjacent side of the structural assembly with one extreme end joined by a stud 30 at the intersection of the X-bracing elements 26 and its opposite extreme end joined by a stud 30 associated with the corresponding X-bracing 26 of the adjacent side of the structural framework.
Each of the leg sections 22, the diagonal braces 28, the horizontal braces 32, and the lateral brace elements 36 are preferably formed of circular tubular sections with the leg sections having a somewhat larger diameter than the bracing element in order to more readily absorb static and dynamic vertical forces imposed on the structural assembly.
Having discussed in detail the bracing structure of the preferred structural assembly, the description will hence forth be directed toward the improved connections between the various structural elements of the structural framework.
As can best be seen in FIGURES 2 and 3, the sleeve type coupling 34 comprises a short tubular sleeve element 38 having an inner diameter slightly greater than the outer diameter of the leg section 22. A boss 40 is joined to the sleeve 38 preferably at its midpoint. A set screw 42 is threadably carried by the boss at an angle perpendicular to the longitudinal axis of the sleeve 38. The set screw 42 functions to lock the sleeve relative to the leg section 22. In order to compensate for the radial spacing required by the inner end of the set screw, three angularly spaced shims 44 are provided between the sleeve 38 and the leg section 22 at opposite ends thereof.
Stud sections 46 are carried by the sleeve 38 preferably with one of the studs diametrically disposed relative to the boss 40 and the other stud section carried at right angles to the first stud section. Each stud section 46 is similar in configuration and comprises a frusto-conical body section 48 having its large diameter fixed to the sleeve 38 and a small diameter terminating with a threaded section 50. The threaded section 50 is formed on an extension of the diameter of the axis of the body section 48, and the axis of each of the studs 46 is formed at right angles to the sleeve 38.
The extreme ends of the horizontal braces 32 which are to be joined in a stress transmitting relationship with back-to-back.
Each of the collapsed ends 52 is provided with a tapered perforation 54. The perforations 54 preferably have a taper corresponding to the slope of the frusto-conical section 48 so that when the collapsed end 52 is engaged with the stud 46 the threaded section 50 can be inserted through the perforation so that the tapered sidewalls of the perforation fit against the tapered sidewalls of the frusto-conical body section. A lock washer 56 is received by the threaded section and a lock nut 58 threadably engaged thereon and tightened such that it imposes a force on the washer 56 sufficient to lock the collapsed end 52 onto the body section 48 so that any relative movement is prevented. It can be seen that by utilizing the tapered perforation which mates with. a frusto-conical body section, that there is no chance for a loose fitting connection. Furthermore, as is common with a conventional straight-sided stud which is utilized with an assembly which is to be dismantled a number of times, the perforations in the braces tend to enlarge. Any such enlargement that might occur in the braces 32 of the present invention will be readily taken up by the tapered body section of the studs 46.
Now referring to FIGURES 4 and 5 for a description of the insert coupling 24, this coupling is utilized to connect the extreme ends of two leg sections 22 to one or more diagonal braces 28. The coupling 24 comprises a tubular insert element 60 having a diameter generally corresponding to the inner diameter of each of the leg sections 22. A second short tubular section 62 is fixed to the mid-section of the tubular insert 60 and generally has a cross-section corresponding to the cross-section of the leg sections 22. Thus, it can be seen that a leg section 22 can be inserted over a free end of the insert 60 and axially slidably received thereon until its extreme end abuts the end of the short tubular section 62.
A pair of stud sections 64 are circumferentially spaced and fixed to the short tubular section 62 and each comprise a frusto-conical body section 66 and a threaded section 68. The stud sections 64 are identical to the stud sections 46 described with reference to the sleeve couplings 34. For purposes of description, FIGURE 4 illustrates one of the studs 64 engaged with a pair of diagonal braces 28 and the other stud 64 illustrated with the braces 28 removed. The diagonal braces 28 are provided with collapsed ends 70 each of which is provided with a tapered perforation 72. The tapered perforation 72, like the tapered perforations 54 associated with the horizontal braces 32, are regularly narrowed at a slope corresponding to the slope of the body section 66, and are formed such that they will fit thereon. The collapsed ends 70 of the braces 28 are jammed on the body section 66 and mounted thereon by a washer 74 and a nut 76 in the same manner that the braces 32 are united with the studs 46 associated with the sleeve coupling 34.
FIGURES 7 and 8 illustrate another embodiment of the present invention which takes the form of a structural framework 78 having a three-sided configuration defined by three upright equiangularly spaced leg members 80. Each of the leg members 80 is formed of a series of tubu lar leg sections 22 connected to one another by diagonal braces 28 and horizontal braces 32. The inner ends of the diagonal braces 28 and the horizontal braces 32 are connected by studs 30. The outer ends of the braces are connected to the leg sections 22 by sleeve couplings 82 and insert couplings 84. The sleeve couplings 82 differ from the sleeve couplings 34 associated with the structural assembly illustrated in FIGURE 1 only in the respect that the studs which engage the brace members are formed at an angle of from one another rather than at a right angle relationship in order to accommodate the threesided configuration. In all other respects the components utilized in the three-sided configuration illustrated in FIGURE 7 are similar to the braces and leg member sections illustrated in FIGURE 1 thus illustrating the versatility and utility of the structural members that form a preferred embodiment of the invention.
With reference to FIGURE 8, lateral braces 36 join the inner connection of the diagonal braces 28 associated with each of the sides, the collapsed ends of the braces 36 permitting the braces to be bent to accommodate the hi angular configuration of the assembly 78.
Now referring to FIGURE 9 for a more detailed description of the stud 30, an elongated member is therein illustrated as comprising a pair of identical frusto-conical body sections 86 formed with a common large diameter and on a common axis and each of which has a small diameter which terminates with a threaded end 8-8 formed on an extension of the axis of the body sections 86. Each of the braces associated with the stud 30 is swaged to present a collapsed end 90 and provided with a tapered perforation 92 having a slope generally corresponding to the taper of the body section 86. Each of the body sections 86 has a length to accommodate a plurality of collapsed brace ends 90 so as to permit them to be stacked one upon the other. A washer 94 and nut 96 cooperate to jam the collapsed ends 90 on the body section 86 thus forming a rigid, non-yielding connection preventing relative movement between each of the brace members.
It is to be understood that although I have described the improved structural bracing and structural connections associated therewith with reference to a column type structural framework, that the invention contemplates that this improved bracing and the connections can be also incorporated with various types of beam type assemblies of the type where main structural members must be braced to transmit secondary loads.
Although I have described several embodiments of my invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention.
Having thus described my invention, I claim:
1. A structural assembly comprising a pair of horizontally spaced upwardly directed leg members,
a plurality of elongated diagonal brace members arranged in pairs,
said members of the pair being axially aligned to transmit lateral stresses imposed on said leg members.
means connecting the outer ends of each of said diagonal brace members to said leg members,
means connecting the inner ends of each of said diagonal brace members at points between said leg members,
and a pair of axially aligned horizontal brace members each having an outer end joined to opposite leg members and an inner end joined to the means connecting the inner ends of said diagonal brace members,
a third upwardly directed leg member horizontally spaced from said first and second leg members,
a second plurality of elongated diagonal brace members arranged to transmit lateral stresses imposed on said leg members in cooperation with the first mentioned plurality of diagonal brace members,
means connecting the outer end of each of said second plurality of diagonal brace members to said second and third leg members,
means connecting the inner ends of said diagonal brace members between said second and third leg members,
a second pair of horizontal brace members each having an outer end joined to said second and third leg members and an inner end joined to the means connecting the inner ends of said second plurality of diagonal brace members,
an inner brace member having one end joined to the means connecting the inner ends of said first mentioned plurality of diagonal brace members and the opposite end joined to the means connecting the inner ends of said second plurality of diagonal braces.
2. A structural assembly as defined in claim 1, wherein said diagonal brace members are associated in pairs and arranged upon pairs of axes substantially intersecting at points intermediate said leg members.
3. A structural assembly comprising:
at least three horizontally spaced upwardly directed leg members;
a plurality of elongated diagonal brace members arranged to transmit lateral stresses imposed on said leg members,
means connecting the outer ends of each of said diagonal brace members to said leg member so that said diagonal brace members intersect in pairs at points intermediate each pair of said leg members;
horizontal brace members having their ends connected with said leg members and intersecting said diagonal brace members at said intersection points;
horizontal braces extending between adjacent intersection points; and
means connecting said diagonal brace members, said horizontal brace members and said horizontal braces together at said intersection points.
4. The structural assembly as defined in claim 3 and including means connecting said diagonal brace members with the ends of said leg members and means connecting said horizontal brace members to said leg members at points intermediate the ends thereof.
5. The structural assembly as defined in claim 3 and in which each of said diagonal brace members has an inner end connected with the inner end of another axially aligned diagonal brace member at said point of intersection.
6. The structural assembly as defined in claim 3 and in which each of said horizontal brace members has an inner end connected with the inner end of another axially aligned horizontal brace member at said point of intersection.
7. A structural assembly comprising:
a pair of horizontally spaced upwardly directed leg members,
a plurality of elongated diagonal brace members ar ranged in pairs,
said members of the pair being axially aligned to transmit lateral stresses imposed on said leg members,
means connecting the outer ends of each of said diagonal brace members to said leg members,
means connecting the inner ends of each of said diagonal brace members at points between said leg members,
a pair of axially aligned horizontal brace members each having an outer end joined to opposite leg members and an inner end joined to the means connecting the inner ends of said diagonal brace members,
a third upwardly directed leg member horizontally spaced from said first and second leg members,
a second plurality of elongated diagonal brace members arranged to transmit lateral stresses imposed on said leg members in cooperation with said first mentioned plurality of diagonal brace members,
means connecting the outer ends of each of said second plurality of diagonal brace members to said second and third leg members,
means connecting the inner ends of said diagonal brace members at points between said second and third leg members,
means connecting the inner ends of each said plurality of diagonal braces comprising: said member having a frustoconical body section and a threaded end form- 9 1O ing an axial extension of said body section, the inner 3,034,812 5/ 1962 Causey 287-5 3.5 ends of each of said diagonal brace members having 1,269,326 6/ 1918 Slater 52-638 a perforation, the length of each of said diagonal 2,465,813 3/1949 Moore 52-638 brace members adapted so that said perforations for 2,665,951 1/ 1954 Bobst 182-178 XR said pluralities of brace members are disposed on 5 2,698,552 1/ 1955 Smith 287-535 common axes, each of said perforations having a tap- 2,830,855 4/1958 Hyre 287-535 ered side Wall engageable with the frusto-conical body section of said stud and a nut element adapted FOREIGN PATENTS to produce an axial force on the perforated ends of 16,099 3/1927 Netherlands said diagonal brace members operative to engage said 10 988,270 4/1965 Great Britain perforated ends with said body section in a locking 1,196,129 5 /1959 France relationship to prevent relative movement between 1,284,691 1/1962 France said body section and said diagonal brace members.
EDWARD C. ALLEN, Primary Examiner References Cited 15 RAYMOND D. KRAUS, Assistant Examiner UNITED STATES PATENTS 2,665,951 1/1954 Bobst 182-178 XR US. Cl. X.R. 2,878,079 3/1959 Hyre 287-535 52633