US 3701553 A
A frame structure comprising hollow members of polygonal cross-section, hollow members forming different frame portions being interconnected by means of spreadable coupling units comprising loosely assembled parts held in predetermined positions within said hollow members and adapted to be braced in at least two directions in pairs against the inside surfaces of said hollow members.
Description (OCR text may contain errors)
[ OCL3I, 1972 vUnited States Patent Vogt I 6 nAxk 1 644 w am w 27 87 -28 8 W2 8 "u "m2 nu ma n m m m.. a r w m m lnu wn e e i HFKYCG nflmmmw 999999 111111 773252 1 8 5 wwzfilafi WOO-5.247 997 4 23 233 m hm m e vC m n w .mu 0 u M M e W 1 C mm U m m w m M l v S m m m A e .3 .R m s F l A l n T M 7 7 Berne, Switzerland Nov. 30, 1970 FOREIGN PATENTS OR APPLICATIONS  Filed:
 Appl. No.: 93,686
608,407 Italy..................287/l89.36 H 438,848 Switzerland .............287/54 A  Foreign Application Priority Data Primary Examiner-David J. Williamowsky Assistant Examiner-Wayne L. Shedd Attorney-Imitie & Smiley Dec. 5, 1969 Switzerland.............l8160/69 g dify means ABSTRACT A frame structure comprising hollow members of polygonal cross-section, hollow members formin ferent frame portions being interconnected b of spreadable coupling units comprising loosely assem- References Cited bled parts held in predetermined positions within said UNITED STATES PATENTS hollow members and adapted to be braced in at least two directions in pairs against the inside surfaces of said hollow members.
3,437,362 4/1969 Ofi'enbroich.......287/l27 R X 1 9 Claims, 14 Drawing Figures V il/Ill;
PATENTEMMI 1 3.701.553
' SHEET 1 OF 3 INVENTOR WILHELM VOGT costly.
Proposals for connecting the frame members by braced coupling units were unsatisfactory for various reasons. It was found, more especially, that in practice the dimensional tolerances of the hollow frame members were so wide that sufficient rigidity of standardised coupling units in the frames could not be attained simultaneously with adequate accuracy of joining.
It is an object of the present invention to provide a hollow frame member structure having internal expanding coupling units, which fulfil all normal and practical requirements and are cheaper than known structures.
According to the present invention there is provided a frame structure made of hollow members of polygonal cross-section, and having at least one coupling unit expanded into an end ofa frame member, wherein the coupling unit has loosely interconnected flats braced in at least two directions in pairs against the inside surfaces of the frame member.
It has been found that certain hollow frame members marketed which normally are of rectangular or square cross-section have dimensions which diverge to a minimal extent from standard in a diagonal direction, but the dimensions of the flat inside surfaces may vary considerably. In order, therefore, in all cases to obtain an accurate position of the coupling units in such hollow members and hence a flush alignment of abutting section ends, it is preferable to ensure that the coupling units are located by supporting them from the corners of the hollow members. In a preferred embodiment of the invention, the flat parts of a coupling are positioned by elements supported from the corners of the interior ofa hollow frame member.
The invention is now explained in detail by way of some examples which are shown in the accompanying drawings.
FIG. I shows a perspective view of a connecting point of a structure, with one hollow frame members removed from one side,
FIG. 2 shows a crosssection through a connecting point, v
FIG. 3 shows a coupling unit in section FIG. 4 shows the parts of a coupling unit in expanded form FIG. 5 shows an alternative coupling unit in section FIG. 6 shows a section on the line IV-IV in FIG. 5,
FIG. 7 shows an enlarged sectional view of part of FIG. 6,
FIG. 8 shows a three-dimensional connecting point in spatial view,
FIG. 9, l0 and 12 show further alternative embodiments in section,
FIG. 11 shows a part of FIG. in an alternative section, partly in elevation, and
FIG. 13 and 14 show two coupling embodiments in top view.
FIG. 1 4 shows a corner connection of a hollow 7 frame structure. The hollow metal frame members I, of
which one is shown in FIG. 1, have a rectangular crosssection as shown in FIG. 2. A large selection of such hollow-members of varying outer shape and with standardised internal dimensions are available. The hollow member 1 is mitre cut and is to be butt connected with a corresponding mitre-cut hollow member of identical cross-section, not shown in FIG. 1
For this purpose an L-shaped coupling unit is used, a part of which is shown in FIG. 1. As shown more clearly in FIG. 4, this unit comprises four L-shaped flat sections, namely an outer flat angle iron 2, an inner flat angle iron 3, a lower flat angle iron 4 and an upper flat angle iron 5. The angles 4 and 5 each consist of two short angularly disposed limbs 6 formed from stampings and welded together so that the outer surfaces thereof are located on a common plane. The limbs of the angles 4 and 5 are provided at'their free ends with two holes 7 each. In these holes 7 bent-over ends of wires 8 are inserted. When the unit is in position as shown in FIG. 1, each wire is supported against the two edge surfaces of abutting flat surfaces of the angle irons 2 to 5. Connected to the inside surfaces of the two lateral angle irons 2 and 3 are plate holders 9, the projecting shanks of which are provided with embossed grooves 10. Ribs 11 (FIG. 3) engage in the grooves 10 to locate spreaders 12, so that these spreaders are secured to the shanks of the angle irons 2 and 3 and are displaceably mounted. As shown in FIG. 2, one spreader 12 is provided with a tapped bore to receive a spreader bolt 13, the tip of which engages in a recess in the other spreader 12. Between the semicylindrical outer surfaces of the spreaders l2 and between the angle formed by each two abutting flats 2 5 a spreading cylinder 14 is loosely inserted. As indicated in FIG. 1, the two halves of the assembled coupling unit are initially held together by means of a self-adhesive tape wrapping 5.
A corner connection as shown in FIG. 1 is produced by mitre-cutting the hollow frame ends, whereupon a hole 16 to receive the spreader bolt 13 is bored by means of a jig on one side of each hollow frame member 1. The flat 2 is provided with a corresponding hole 16'. The unit assembled in accordance with FIGS. 1 and 2 respectively, is now inserted into one frame end. Then the bolt 13 is inserted and tightened. This forces the two central spreaders apart and the spreading cylinders 14 are pressed outwardly into the corners.
, This locates one leg of the unit firmly in an end ofa frame member. The positioning of all flats 2 5 is effected by abutment of the wires 8 against the most accurate parts of i.e. hollow frame i.e., the corners. The flats 2 5 and wires 8 are so dimensioned that these parts when mounted in a frame engage in the hollow parts substantially without clearance, and the flats are of the correct size to be accurately located. At the same time a considerable spreading movement of each flat is possible. Unevenesses of the flat inside surfaces of the hollow members therefore do not affect the location of the'coupling unit in the framework. After firmly locat ing one leg of the coupling unit in a hollow member 1, the other hollow member may be slipped over the other leg and located on the coupling in the manner described. It is, of course, also possible first to slip the two hollow members on to the coupling unit and then to insert the two spreader bolts and tighten them.
Besides the L-shape shown, other shapes such as T or cruciform are possible for the coupling unit. The latter shape is suitable for use with special fittings such as hollow section members provided with fittings such as locks or strips.
The use of the parts 4 and as shown in FIGS. 1 4 has the advantage that all angles can be made of flat iron strip. In mass production it may be preferable to stamp the parts 4 and 5 from one sheet to avoid having to weld them together.
Corresponding parts in FIGS. 5 to 7 are given the same designations asin FIGS. 1 4. The coupling unit in this embodiment does not connect two abutting mitred ends, but is fastened to one frame member and connects it with another member 1 at right angles thereto. The two oppositely disposed flats 2' and 3' are joined together by a yoke 20 to form a U-shaped stirrup, which by means of self-tapping screws 21 is fastened to the frame member 22. The remaining parts correspond to the elements with similar designations in FIGS'. 1 4, except that in place of the semi-cylindrical spreaders l2, flat bars 12' with bevelled edges are provided. Between the spreading cylinders 14 and the flats 2' and 3' there are thin retaining plates 23. As shown in FIG. 7, these effect exact location positioning of the parts 8 and 14 when these are connected to form a unitary structure by means of one of the loose flat bars 4 and 5 respectively, and are held together by adhesive tape at one or two points. The coupling action corresponds to that shown in FIGS. 1 4 and requires no detailed description. During assembly the stirrup 2', 20, 3 is first screwed in position, then two prepared units as shown in FIG. 7 are inserted from the side, then the member 1 is mounted and finally the screw 13 introduced.
FIG. 8 shows one use of coupling units in accordance with FIGS. 5 7, six such units being screwed to the surfaces ofa cube to connect six frame members.
F IG. 9 shows an alternative embodiment for particularly narrow frame members. In place of the usual two spreaders only one spreader 12 is provided which acts on two spreading cylinders 14. These brace the flat bars 4 and 5 and at the same time exert a pressure against the flat 3, whilst screw 13 presses the flat 2 against the inner wallof the frame member.
FIGS. 10 and 11 show an alternative embodiment, also for particularly narrow frames which differs from the remaining embodiments in the method of action of the spreader. It concerns a corner connection, in which as in FIGS. 1 4 four flats 2, 3, 4 and 5' are provided, each of which form an angle as indicated in FIG. 11. A flat angle iron 24 is inserted between the flats 4 and 5', said angle iron 24 having ribs 25 engaging in slots 26 in the flats 4' and 5, respectively. The angle iron 24 has thin joints 27 at its ends and is provided with a slot 28 over the remainder of its length. Each spreader screw 13' has a conical shoulder 29 and a tip 30. When the coupling is braced, the conical shoulder engages in a round enlargement 31 of the slot 38 and spreads apart the lower part of the flat bar 24 and hence the flats 4' and 5'. Flats 2 and 3 are spread simultaneously by the screw 13.
Further embodiments also are possible. Instead of positioning elements inthe form of loose-wires joined to the parts 4 and 5, they may, if necessary, form an integral whole therewith. Thus flats 2 5 may have outer edges which, like the wires 8, engage without clearance in the corners of the hollow members 1. This is possible only if the edges are serrated, or the like, so that only individual positioning teeth remain, the positioning teeth of the flats 2 and 3 engaging in gaps between the positioning teeth of the flats 4 and 5. v
The hollow frame members may have cross-sections which are polygonal, e. g. triangular or hexagonal.
The parts 8, l2 and 14 may be displaceably held together in cages instead of by means of adhesive tape, so as to facilitate assembly. These parts may also have different cross-sections from those shown. It is also possible to combine two spreading cylinders 14 by a resilient inwardly curved bridge, the spreading force of the screw 13 acting on the apex of this bridge. In this case the two parts corresponding to the cylinders 14 and the bridge connecting them may be formed integrally as an extended section or stamping.
As shown in FIG. 12, the frame structure may also comprise an inner carrying hollow member I for instance of steel and outer hollow covering members 32 for instance of aluminum or plastics material slid thereon. The inner hollow member 1 and coupling unit correspond to those shown in FIG. 6. Preferably, the inner hollow member has longitudinal slots 33, for instance in the corners of its profile within reach of the spreading cylinders 14, the inner member being thus slightly spread when the bolt 13 of the coupling unit is tightened. The inner hollow member 1 is thereby pressed against the outer profile 32 for securing the same in the desired position. The outer hollow member 32 has holes 34 for inserting and tightening the screws 13. This modification of the frame structure also allows simple and cheap manufacture in that hollow members may be shifted into each other and interconnected by means of coupling units.
FIGS. 13 and 14 are top views of l-shaped and cross shaped embodiments of the coupling unit. In these embodiments the upper flat bars 5a and 5b and their .opposite members, not shown in FIGS. 13 and 14, are of T-shape or cross-shape and stamped in one piece or welded together as shown in FIG. 4. The flat angle irons 2 and 3 are as shown in FIG. 4 except for a plane flat iron at the left in the coupling of FIG. 13.
1. A frame structure comprising hollow members of polygonal cross-section, including at least one coupling unit expanded into an end of a frame member, said coupling unit comprising a plurality of flats loosely interconnected together, means for bracing said flats in at least two directions in pairs against the inside surfaces of said frame member, and elements positioning all said flats in said hollow frame member, said elements resting in the corners of the inside of said hollow frame member.
2. A structure as recited in claim 1, comprising means for connecting said elements to said flats to form an integral whole.
- 3. A structure as recited in claim 1, wherein said flats have a rectangular cross-section and said elements each have a circular cross-section said elements being loosely arranged between adjacent edges of two flats.
4. A structure as recited in claim 1 wherein said flats are provided at the ends of the unit with flanges defining holes, said elements having the bent-over ends entering said holes.
5. A structure as recited in claim '3 comprising cylindrical spreaders located in corners formed between adjacent flats, and central bracing members braced apart to support said Spreaders.
6. A structure as recited in claim 5, wherein said central bracing members are mounted in holders located on oppositely situated flat.
7. A structure as recited in claim 1 comprising a U shaped yoke connecting opposite flats of a pair, with means for fixing said yoke to the outside surface of a frame member.
8. A structure as recited in claim 1, wherein said coupling unit comprises a flat part, two cylindrical spreaders, a central bracing member and two positioning elements, all held together by means of adhesive tape and inserted between two of said flats.
9. A structure according to claim 1, comprising a slotted spreadable rib between two opposite flats, a conical spreading shoulder defined by said flats, and at least one spreader screw passing through said shoulder and directly spreading two other flats.