AU611878B2 - Space frames - Google Patents

Description

AU-AI-10400/88 PV T WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 88/04345 E04B 1/19 Al International Publication Date: 16 June 1988 (16.06.88) (21) International Application Number: PCT/AU87/004U (8 Desi atelates U, I GB, US.

(22) International Filing Date: 2 December 1987 (02.12.87) Published With international search report.

(31) Priority Application Numbers: PH 9426 79864/87 (32) Priority Dates: 10 December 1986 (10.12.86) 16 October 1987 (16.10.87) J AUG 1988 (33) Priority Country: AU 1 (71) Applicant (for all designated States except US):-PLAS- FAB-PT-Y -LTD[AU/AU]; 12 Gould Road, Herston, QLD 4029 AUS RALIAN (72) Inventor; and 3 0 UN 1988 Inventor/Applicant (for US only) MacKENZIE, Noel, Gordon [AU/AU]; 12 Gould Road, Herston, QLD O IC 4029 i PATN OFFICE Aet ,L f (74) Agent: GR-A-NT~A-DA-MS-&-CGM-PA-N-Y-; 333-Adelaide X 'R -Street-GrP.O-Box-141-3, Brisbane, QLD 4000 C7) 5?4-E- Sfrmu C-mm-r -S us *zCA P-K v. cs u-r e 2, v r (54) Title: SPACE FRAMES (57) Abstract A space frame has upper and lower grids of 1 9 tubular longitudinal and lateral chord members (10, 16 11) with superimposed flattened sections (13, 14) connected at nodes Oblique struts (15, 16) have flattened attachment pads (17) with shoulders (19).

B At each node the ends (18) of the attachment 5 1 pads (17) of the first pair of struts (15) are butted together and are interposed between the attachment 1 pads (17) of the second pair of struts (16) and the flattened section (14) of lateral chord The at- 2 tachment pad (17) of one pair of struts (15, 16) is connected to both attachment pads (17) of the other pair of struts (15, 16) and to the chord members (10, 11) by bolts (21).

13 bi14 L I f "SPACE FRAMES" BACKGROUND OF THE INVENTION This invention relates to space frames.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a space frame where each strut is connected to a node by two bolts, one each through the ends of the respective underlying or overlying struts (and the chords).

It is a further preferred object that all the struts are identical.

Other preferred objects of the present invention will become apparent from the following description.

~With the foregoing and other objects in view, this invention in one aspect resides broadly in a space frame of the type having upper and lower grids of tubular longitudinal and 15 lateral chord menmbers and oblique struts with attachment pads at their ends interconnecting nodes at the intersections of the chord members of the two grids, wherein at each node:the chord members have flattened sections in superimposed relationship; a first pair of flattened strut attachment pads are secured in abutting and substantially co-planar relationship to the superimposed chord sections; S• a second pair of flattened strut attachment pads are secured in abutting and substantially co-planar relationship to the first pair of pads, and four mechanical fasteners interconnect the chord members and the struts so that the attachment pad of each strut is connected to the chord members by a pair of mechanical fasteners.

Preferably, each diagonally opposite one of the mechanical fasteners engage respective co-planar attachment pads of one each of both the first and second pairs of struts.

Preferably, the struts are tubular and are so flattened at their ends to form the attachment pads with a shoulder at the junction of the attachment pads with their struts so arranged that the side edges of the attachment pads of the second pair of struts, bear against the shoulders or abutments of the first pair of struts. The arrangement of the struts as two pairs with their i pu 3 1 respective attachment pads stacked upon one another in superimposed relationship allows for the use of a pair of fasteners to secure each end of each strut. Prior arrangements had only one fastener at each end of each strut, which allowed the struts to pivot about axes normal to the plane of the chord grids.

In an attempt to overcome this short coming, prior teaching was to incorporate the used of load bearing plates relying on frictional engagement between the layers of plates to prevent the pivoting.

With the present invention, a pair of fasteners securing each end of each strut provides mechanical prevention of the pivoting, resulting in a space frame which is stronger and more efficient in use.

The fasteners are preferably suitable threaded connecters such as machine screws with appropriate washers and 15 nuts. The nodes are preferably covered for aesthetic purposes as well as to protect the fasteners from mechanical damage by interposing pairs of mounting plates one of each pair on each side of each node with each mounting plate having a pair of upwardly standing flanges suitable for placing a cover on each mounting plate.

BRIEF DESCRIPTION OF THE DRAWINGS

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In order that this invention may be more easily understood and put into practical effect, reference will now be •made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:- FIG. 1 is a top view of a node of the lower grid of a space frame; SFIG. 2 is an exploded view of the node of FIG. 1, the bolts being omitted for clarity; FIG. 3 is a bottom view of the node showing a removable cover plate; FIG. 4 is a top view of the node showing a removable cover plate, and FIG. 5 is a sectional view through the node taken on line 5-5 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The space frame cimprises upper and lower grids of longitudinal and lateral chord members 10, 11 connected at nodes ;TrI ~c '~II I- i. 3 2ct.

i i 12. Each chord member is tubular and has flattened sections 13, I 14 which are superimposed at the nodes.

SOblique struts interconnect the grids and two pairs of oblique struts 15, 16 are connected to the chord members 10, 11 at each node 12.

As shown in FIG. 2, each strut 15, 16 has an Go

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'iI I tA a~ L, I U I wo 88/04345 PCT/AU87/00407 -3attachment pad 17 which is formed by flattening the end of the struts at an angle to the axis of the strut. The ends 18 of the pads are transverse to the axis of the struts and a shoulder 19 is formed at the junction of the attachment pads 17 with their struts.

The attachment pa ds 17 of the first pair of opposed struts 15 are interposed between the flattened section 14 of the chord member 11 and the attachment pads 17 of the second pair of struts 16. The attachment pad 17 of each first strut 15 underlies one half of each attachment pad 17 of the second struts 16. The side edges 20 of the attachment pads 17 of the second struts engage the adjacent shoulders 19 of the first struts to prevent relative rotation between the struts, the ends 18 of the attachment pads of the first and second struts, respectively, being butted together.

Four bolts 21 secure the chord members 10 and 11 and struts 15 and 16 together. It will be noted that the attachment pad 17 of each strut 15, 16 is connected to each of the the chord members 10, 11 by two bolts and to each of the superimposed, or underlying, attachment pads 17 of the struts 16, 15 respectively, by one bolt.

With this arrangement the chord members and struts are non-rotatably fixed together and any loads applied to the space frame is distributed through the frame.

As hereinbefore described, no load distribution plates are required and the discontinuous struts at the nodes simplify assembly. It will be noted that the struts in each opposed pair are interconnected indirectly at the node.

Referring now to FIGS. 3 to 5, removable covers 30, 31 may be applied to the nodes 12 to cover the bolt heads and nuts for an improved aesthetic appearance.

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WO 88/04345 PCT/AU87/00407 -4- SMounting plates 32, 33 are secured to the node 12 by the bolts 21 and have a pair of upstanding side flanges 34 which are convex in end view. Each cover 31 has an inwardly directed peripheral flange which enables the covers 30, 31 to be releasably "strapped" on to the mounting plates 32, 33.

In a modified embodiment, not shown, members 11 may be C or channel section cold-rolled steel members fixed back-to-back, with the attachment pads 17 of the struts received within the C-or channel section of one of the chord members at each node.

The embodiments illustrated are by way of illustrative examples only and various changes and modifications may be made to the embodiment without departing from the present invention as defined in the appended claim.

Claims (2)

1. 2. A space frame as claimed in claim 1, wherein each diagonally opposite one of said mechanical fasteners engage ooo respective co-planar attachment pads of one each of both said first and second pairs of struts. S* 3. A space frame as claimed in claim 1 or claim 2, wherein the struts are tubular and are so flattened at their ends to form the attachment pads with a shoulder at the junction of the attachment pads with their respective struts, so arranged that the side edges of the attachment pads of the second pair of struts, S superimposed on the attachment pads of the first pair of struts, bear against the shoulders or abutments of the first pair of struts.
2. 4. A space frame as claimed in any one of the preceding claims, wherein a pair of mounting plates are secured to opposite sides of each node by the four fastening means, each mounting plate having a pair of upstanding side flanges which are convex in end view; and respective covers are releasably mountable on the mounting plates, each cover having an inwardly directed peripheral I( C 43 mt~-~ I- i ;i 6 flange engageable with the side flanges on its respective mounting plate. DATED THIS fourteenth DAY OF March, 1991, SPACE STRUCTURES AUSTRALIA PTY. LTD. by PIZZEY COMPANY PATENT ATTORNEYS L;r. Soeo p p p ee t f" ft ft