GB2054694A

GB2054694A - Structural frame

Info

Publication number: GB2054694A
Application number: GB8018488A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-06-08
Filing date: 1980-06-05
Publication date: 1981-02-18
Also published as: GB2054694B

Abstract

The frame, known as a "space frame" comprises upper and lower planar grids 11, 12 interconnected by substantially orthogonal spacing members 14. Most of the frame is made of main modules 20 and there are edge modules 26 and corner modules 25 to form straight edges to each grid. Each main module comprises a spacing member 14 and a cruciform arrangement of four arms 23 at each end of the member 14. Each arm is connected in alignment with an arm of another module, so that the two cruciform arrangements form parts of the respective grids. <IMAGE>

Description

SPECIFICATION Structural frame This invention relates to a structural frame which may be of the type known as a "space frame". Such frames are often used where it is desired to roof a large space without interruption of the space by upright supports, such as in exhibition hails and factories.

One such known frame is made up of a multiplicity of pyramidal portions, with the result that it is difficult to mount services (e.g. electrical and water services) in the frame. Further, there is a large number of structural members in the frame, so that there are high labour costs in constructing the frame. These costs are made higher by the problems inherent in connecting together these members at relatively oblique angles. Special connectors have been developed to reduce this problem, but this results in higher costs in fabricating the members of the frame and in addition, such connectors cause projections beyond the otherwise planar face of the frame, which would define a ceiling in use. As a result, cladding of the frame is rendered more difficult.

Another problem of the pyramidal construction of the frame is that the grid at the top face is offset from that of the bottom face. Since it is common to mount partitioning by jacking it between the floor and the frame, it is necessary to adapt and strengthen the frame at the locations where partitioning is to be mounted. Apart from the problems inherent in doing this, it is not possible to move the partitioning to alternative locations to meet changing requirements.

The present invention provides a structural frame which avoids these problems.

The invention is also applicable to structural frames for forming bridges and gantries.

In accordance with this invention, a structural frame comprises first and second planar grids interconnected by substantially orthogonal spacing members, the frame comprising a multiplicity of modules joined together in the grids, each module comprising at least one of said spacing members and portions of both grids.

Preferably, most of the frame comprises main modules, each of which comprises a single one of said spacing members extending between and fixed at the centres of a pair of cruciform arrangements, each arm of each cruciform arrangement being secured substantially in alignment with a corresponding arm of an adjacent module to define said grids.

Also preferably, corner and edge modules are provided each incorporating a spacing member fixed to arm arrangements forming parts of the grids, the arm arrangements of the corner modules having two arms orthogonally arranged and the arm arrangements of the edge modules having three arms orthogonally arranged, these corner and edge modules being positioned at the perimeter of the frame to define straight edges of the grids.

The spacing members of the edge modules may be parallel to the spacing members of the main modules having the cruciform arrangements or may be inclined thereto.

The invention may reside in a structural module for constructing a space frame, the module comprising a pair of cruciform arrangements of orthogonally arranged arms secured together by a spacing member secured at the centres of said arrangements and substantially orthogonally positioned relative to the arms of both arrangements.

Reference is now made to the accompanying drawings, wherein.

Figure 1 is an isometric view of a structural frame according to the invention; Figure 2 is an enlarged exploded isometric view of a part of the frame, showing main, edge and corner modules of the frame; Figure 3 is an isometric view of an alternative construction of a corner module; Figure 4 is an isometric view of an alternative construction of an edge module; Figure 5 is an isometric view of an alternative construction of a main module; and Figure 6 is an exploded isometric view of part of a modified frame.

The frame shown in Figure 1 comprises two rectangular grids 11, 12, arranged one above the other. The frame members of each grid meet at nodal points, such as 13, and at each nodal point a spacing member 14 is secured, extending between the two grids. The frame members of each of the grids are orthogonally arranged and directly overlie corresponding frame members of the other grid, the spacing members being orthogonally arranged relative to the members of the two grids. The portion such as 16, of each frame member, extending between two adjacent nodal points, comprises two initially separate parts 1 6a, 1 6b secured together, as by bolting, for example. Each of these parts is rigidly secured at a respective nodal point 1 3.

It is apparent that the frame is composed of modules and some of these are better illustrated in Figure 2. Most of the frame is made up of main modules 20, each of which comprises two cruciform arrangements 21, 22 whose centres are nodal points 13 separated by a spacing member 14. Each cruciform arrangement has four orthogonally arranged arms 23, each arm forming one of the grid member parts. Each arm is formed in its width with a rebated end portion 24 arranged to interlock with a corresponding rebated end portion of an arm of another module. The rebated end portions are bolted together to form the only inter-connections between the modules.

In addition to main modules 20, there are provided corner modules 25, having only two arms, and T-form edge modules 26, having only three arms. These corner and edge modules are mounted, as shown, to define straight edges of the grids.

Each spacing member 14 comprises a hollow square-section tube formed at each end with a longitudinal slot 1 9 in each side of the tube. Each arm 23 comprises two angle-section pieces 23a, 23b secured back-to-back, with one extending beyond the other to define the rebate 24. Each arm 23 is slotted into a corresponding slot 19 and welded in place. In the case of each main module 20, two of the arms 23, which are aligned, are integral.

An alternative construction is shown in Figure 3. Only a corner module is shown, but other modules could be similarly constructed. In this case, in one grid, each arm 30 comprises two channel-shaped pieces 30a, 30b secured back-toback. One piece extends beyond the other to define a rebate 32. The spacing member 31 is of hoilow circular section. The arms 23, in the other grid, one of the same construction as described with respect to Figure 2, but could be made of channel shaped pieces.

A further alternative is shown in Figure 4. The arms 33, as well as the spacing member 34 are all composed of square-section tubes, the rebates 35, being cut into the arms.

Another construction is shown in Figure 5. In this construction, the spacing member 40 is again of square-section tube, but each arm 41 is of Isection. No rebates are provided, but, instead, the connecting web 42 of each I-section arm is joined to the next arm by means of a plate 43 bolted to both arms.

It will be appreciated that the frame can very easily be constructed by bolting together the modules and the modules are of simple construction and can be easily and cheaply transported. The connecting points between the modules are located half-way between the adjacent nodal points in each grid and this arrangement facilitates calculation of the required strength of parts of the frame.

There are, in effect, corridors defined between the spacing members in the frame, which facilitate laying of services, both horizontally and vertically, and use of the space for other purposes. In addition, partitioning may be jacked against any of the members of the lower grid in any desired position, so that re-arrangement of the partitioning can be made without difficulty.

Fire-stop or sound insulation panels can readily be mounted on the spacing members within the frame.

If desired, the upper grid may have a camber instead of being exactly parallel with the iower grid and both grids may still be parallel having the same camber relative to the spacing members, which remain vertical. This facilitates drainage.

This camber will be small it is envisaged, for example, about 50, so that the frame members of the grids are still substantially orthogonal to the spacing members.

The spacing members of the corner and edge modules need not be parallel to the rest of the spacing members, but may slope to provide sloping edges to the frame. The great majority of the spacing members will, however, be parallel to each other and substantially orthogonal to the grids.

In Figure 6, an alternative construction is shown e.g. for forming a frame for a bridge or gantry or for a vertical support frame. The frame is made up primarily of T-form modules 26 to form an elongate frame. At each end of the frame, corner modules 25 are provided.

Claims

1. A structural frame comprising first and second planar grids interconnected by substantially orthogonal spacing members, the frame comprising a multiplicity of modules joined together in the grids, each module comprising at least one of said spacing members and portions of both grids.

2. A structural frame according to Claim 1, wherein most of the frame comprises main modules, each of which comprises a single one of said spacing members extending between and fixed at the centres of a pair of cruciform arrangements, each arm of each cruciform arrangement being secured substantially in alignment with a corresponding arm of an adjacent module to define said grids.

3. A structural frame according to Claim 2, including corner and edge modules in addition to said main modules and each incorporating a spacing member fixed to arm arrangements forming parts of the grids, the arm arrangements of the corner modules having two arms orthogonally arranged and the arm arrangements of the edge modules having three arms orthogonally arranged, the corrier and edge modules being positioned at the perimeter of the frame to define straight edges of the grids.

4. A structural frame according to Claim 3, wherein the spacing members of the edge modules are inclined to the spacing members of the main modules.

5. A structural frame according to Claim 2, 3 or 4 in which each arm has a rebated portion at its free end complementary to a corresponding rebated portion of the arm to which it is secured, the rebated portions being inter-engaged and secured together.

6. A structural frame according to Claim 2, 3 or 4, wherein each two mutually secured arms are butted end-to-end and secured by members bridging the interface between the butted ends.

7. A structural frame according to any preceding claim, wherein at least one of the grids is slightly cambered from strictly orthogonal relationship to the spacing members.

8. A structural frame according to Claim 7, wherein said slight camber is 5 .

9. A structural frame according to Claim 1, wherein most of the frame comprises modules each of which comprises a single one of said spacing members extending between and fixed at the centres of a pair of T-form arrangements, each arm of each arrangement being secured substantially in alignment with a corresponding arm of an adjacent module to define said grids.

10. A structural module for use in constructing a space frame, the module comprising a pair of spaced arrangements of orthogonally arranged arms the arrangements being secured together by a spacing member secured at the centres of said arrangements and substantially orthogonally positioned relative to the arms of both arrangements.

11. A structural module according to Claim 10, wherein each arrangement comprises three said arms in a T-like formation.

12. A structural module according to Claim 10, wherein each arrangement comprises four said arms in a cruciform formation.

13. A set of main modules, edge modules and corner modules for constructing a space frame and constructed substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings.

14. A structural frame constructed substantially as herein described with respect to Figure 1, wherein modules of which the frame is constructed are modified substantially as herein described with respect to Figure 3, Figure 4, or Figure 5 of the accompanying drawings.