GB2215752A

GB2215752A - Space frame

Info

Publication number: GB2215752A
Application number: GB8806469A
Authority: GB
Inventors: Sin Fatt Chan; Tong Lian Soh
Original assignee: Pilecon Engineeering Bhd
Current assignee: Pilecon Engineeering Bhd
Priority date: 1988-03-18
Filing date: 1988-03-18
Publication date: 1989-09-27
Also published as: GB8806469D0

Abstract

A space frame comprises an upper grid of a first group of parallel members A and a second group of parallel members B, a lower grid of a third group of parallel members and a fourth group of parallel members, and oblique, intermediate members E with flattened ends H and extending among the nodes of the upper and lower grid. At each node is a connecting device comprised of a connector G in the form of two channels opening away from each other and perpendicular to each other, and nuts-and-bolts I and J attaching the connector respectively to the member A and to the member B and the flattened ends H of the members E. The flattened ends H can be either adjacent and superimposed figure 3A, or adjacent and non-superimposed (see fig 4A). <IMAGE>

Description

"A FRAMEWORK" This invention relates to a framework, in particular a space frame for use in the construction industry.

Space frames exist in many forms where large column-free spaces are desired, the most favoured system being a flat framework consisting of upper and lower grids of elongate members connected by diagonal struts/ties, forming a series of interconnecting square-based pyramids.

According to the present invention, there is provided a framework, comprising a first grid of a first group of elongate members extending substantially parallelly to each other and transversely to a second group of elongate members extending substantially parallelly to each other a second grid of a third group of elongate members extending substantially parallelly to each other and transversely to a fourth group of elongate members extending substantially parallelly to each other, said second grid being spaced from and substantially parallel to said first grid intermediate elongate members extending from nodes of said second grid to nodes of said first grid and connecting means fixedly connecting together the elongate members of the first and second grids and the intermediate elongate members characterized in that at said nodes of said first grid, said first group overlies said second group and, at said nodes of said second grid, said third group overlies said fourth group and in that said connecting means comprises, at said nodes of said first grid and said nodes of said second grid, respective connecting devices each of which interconnects those elongate members present at its associated node.

In order that the invention may be clearly understood and readily carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows a diagrammatic plan view of a space frame for use in the construction industry, Figure 2 shows a diagrammatic side elevation of the space frame, Figure 3A shows a side elevation of a node of an upper grid of the space frame, Figure 3B shows a section taken roughly on the line III-III of Figure 3A, Figure 4A shows a side elevation of a modified version of the node, Figure 4B shows a section taken roughly on the line IV-IV of Figure 4A, Figure SA shows a side elevation of an end of an intermediate strut in a non-bent form, Figure 5B shows a front elevation of that end, in chain lines in a non-bent form and in full lines in a bent form for use in the node shown in Figures 3A and 3B, Figure 6A shows a fragmentary side elevation of a modified version of the intermediate strut in a nonbent form, Figure 6B shows a section taken on line VI-VI of Figure 6A through that version in that non-bent form, Figure 6C shows a similar section through that version in a bent form for use in the node shown in Figures 4A and 4B, Figure 7 shows a top plan view of the node shown in Figures 3A and 3B, Figure 8 shows a top plan view of the node shown in Figures 4A and 4B, Figure 9A shows a perspective view of a connector of the node of Figure 7, Figure 9B shows a developed view of that connector, and Figure 10 shows a developed view of a connector of the node of Figure 8.

Referring to Figures 1 and 2, the space frame includes an upper grid comprised of an upper group of horizontal, elongate members A parallel to each other and a lower group of horizontal elongate members B parallel to each other and perpendicular to the upper group A, and a lower grid comprised of an upper group of horizontal elongate members C parallel to each other and a lower group of horizontal, elongate members D parallel to each other and perpendicular to the upper group C. Nodes F of the upper grid are connected to nodes F of the lower grid by way of diagonal, intermediate, elongate members E which in most constructional applications would act as struts but in some applications would act as ties.

At each node is a connecting device which can be of the form shown in Figures 3A and 3B, in which it consists of a connector G and two nuts - and - bolts I and J.

To make the connector G, a cruciform plate shown in Figure 9B is stamped out of sheet steel, with four holes G' for receiving the nuts - and bolts I and J and with two opposite ends G" of arcuate form. The limbs of the plate are then bent through right - angles to form the connector G shown in Figure 9A, having two channels opening away from each other and perpendicular to each other.

In addition to the connecting device, the node shown in Figures 3A and 3B includes four ends H of four members E present at the node. Each member E consists of a metal tube with each of its ends H flattened as shown in Figures 5A and SB. The flattened end is of a spade form with a central hole H' for receiving a nut and - bolt J and its innermost boundary H" is arcuate, concentric with the hole H', and of slightly greater radius than that of the ends G". The flattened end has three outer edges H"' of which two are parallel to the axis of the member E and the third is perpendicular thereto. As shown in Figure SB, the end H can be bent through an angle. This angle is such that the end H is vertical in the space frame.

In the node shown in Figures 3A and 3B the ends H are adjacent to and superimposed one upon another in two pairs at respective opposite sides of the member B, the members A and B are of timber, and the connector G and its nuts - and - bolts I and J are sized to give sufficient tolerance for variations in the dimensions of the timber members.

Alternatively, the connecting device can be of the form shown in Figures 4A and 4B wherein the ends H are adjacent to, but not superimposed upon, one another in two pairs at the respective opposite sides of the member B, which consists of rectangular steel tube, as does each member A. The connector G is again formed from a cruciform plate shown in Figure 10, but includes two limbs G"' t of a widened form and each provided with a pair of holes G'. These latter holes serve to receive two horizontal parallel nuts - and - bolts J.

As shown in Figures 6A to 6C, the flattened ends H of the members E have straight innermost boundaries H".

The boundaries are horizontal in the space frame.

At each node the member A or C overlies the member B or D, and the end of each member E is interposed between the node connector G and the member B or C.

Preferably, the members A to D are square or oblong rectangular timber sections or square or oblong rectangular steel tube sections; however, any other suitable structural sections may be used.

The space frame system described with reference to the drawings has the following advantages:1) Substantially any desired arrangement of the members can be achieved allowing infinitely varying combinations of grids and space frame depths.

2) Varying member strengths can be employed, to allow the most economic use of material.

3) Readily available standard materials requiring little or no further manufacture can be employed.

4) Any manufactured items can be simple to make using low cost, low energy production equipment and unskilled labour.

5) The space frame can be cheaply assembled with unskilled labour.

6) It can be economical to protect from decay or corrosion.

7) It is capable of being made of a variety of materials to take advantage of the most cost effective materials available.

8) The use of individual fasteners in the horizontal plane allows the space frame to be erected on a ground slab without blocking up clear of the slab for accessing fastener holes.

9) The connection of the members E to the inner members B and C of the grids allows erection of the outer members A and D independently of the members E, simplifying erection by reducing the number of members needing to be connected at one time.

10) Use of solid or closed section members allows direct connection of roofing materials to the top grid, so removing the need for a separate purlin system, hence saving materials and labour.

11) Continuous rectangular section members are more economic than continuous channel or pin jointed tube members, giving higher compression capacity per weight of material.

12) Owing to the positioning of the members A to E relative to each other at their nodes, in other words the node geometry, the surface areas of the members A to D required to allow connection at the nodes are each less than with conventional systems, so that substantially square section members A to D can be employed, as opposed to channel section or oblong rectangular section members of the conventional systems; in this respect it is noteworthy that square section hollow members are stronger than channel section or oblong rectangular section hollow members of equal weight.

In addition, since only the shafts of the bolts J penetrate the members A to D, the holes H' can be closer to the creases at H" in the members E and thus further from the adjacent ends of the members E. The distance from the holes to the adjacent ends of the members E is called the edge distance and has to be a minimum distance for a given bolt hole diameter and our system thus allows a greater edge distance, permitting the use of larger diameter bolts, improving end bearing and shearing capacity of the members E for smaller cross sections.

13) The system allows any combination of span to depth ratio within each module (i.e. each of the square-based pyramids of which the space frame can be imagined to be made up), allowing highly economic use of materials.

14) Less penetrations are required in the members A to D, reducing fabrication costs.

15) The use of closed or solid section members reduces the cost of protective and decorative finishes, by reducing the surface area of coating.

16) No welding is required in manufacture or erection of the system.

17) All materials are available worldwide and are or can be locally produced, hence providing a highly economic solution in varying market conditions.

Any grade of timber or steel can be utilised in manufacture.

Claims

1. A framework, comprising a first grid of a first group of elongate members extending substantially parallelly to each other and transversely to a second group of elongate members extending substantially parallelly to each other a second grid of a third group of elongate members extending substantially parallelly to each other and transversely to a fourth group of elongate members extending substantially parallelly to each other, said second grid being spaced from and substantially parallel to said first grid intermediate elongate members extending from nodes of said second grid to nodes of said first grid and connecting means fixedly connecting together the elongate members of the first and second grids and the intermediate elongate members characterized in that at said nodes of said first grid, said first group overlies said second group and, at said nodes of said second grid, said third group overlies said fourth group and in that said connecting means comprises, at said nodes of said first grid and said nodes of said second grid, respective connecting devices each of which interconnects those elongate members present at its associated node.

2. A framework according to claim 1, wherein each connecting device comprises a connector which extends, in the direction from said first grid to said second grid, over external surfaces of the associated elongate members of the associated group, and a connecting member which extends through the connector, the associated elongate member of the second group or the third group, and the intermediate elongate member(s) present at its associated node.

3. A framework according to claim 2, wherein, at each of said nodes, the end(s) of the intermediate elongate member(s) present at the node are interposed between the connector at the node and the associated elongate member of the second group or the third group.

4. A framework according to claim 2 or 3, wherein, at each of at least some of said nodes, a plurality of the intermediate elongate members are present at the or each side of the associated elongate member of the second group or the third group and their ends at the node are in an adjacent superimposed relationship with each other.

5. A framework according to claim 2 or 3, wherein, at each of at least some of said nodes, a plurality of the intermediate elongate members are present at the or each side of the associated elongate member of the second group or the third group and their ends at the node are in an adjacent, non-superimposed relationship with each other.

6. A framework according to any preceding claim, wherein the elongate members of the first and second grids are each of a rectangular cross-section.

7. A framework according to any preceding claim, wherein each of at least some of said intermediate elongate members has flat ends which lie in respective parallel planes extending in the direction from said first grid to said second grid.

8. A framework according to claim 7, wherein each of said intermediate elongate members with flat ends consists of a hollow tube with its ends flattened and bent into said planes.

9. A framework according to any one of claims 1 to 8, wherein each end of each of at least some of said intermediate elongate members has an edge substantially perpendicular to the axis of its intermediate elongate member and first and second other edges substantially parallel to that axis.

10. A framework according to claim 2, 3, or 4, or any one of claims 5 to 9 as appended to claim 2, wherein each connector has two channels opening away from each other, and having their bases arranged adjacent to each other, the two channels serving to receive the respective elongate members of the grid associated with the connector.

11. A framework according to claim 10, wherein each connector is formed from sheet material.

12. A framework according to claim 2, 3, 4, 10 or 11, or any one of claims 5 to 9 as appended to claim 2, wherein each connecting member extends substantially parallelly to the grids.

13. A framework according to claim 2, 3, 4, 10, 11, or 12, or any one of claims 5 to 9 as appended to claim 2, wherein each connecting means further comprises another connecting member which extends through the connector and through the associated elongate member of the first group or the fourth group, but not through any of the intermediate elongate members.

14. A framework according to any preceding claim, and constituting a space frame for use in the construction industry.

15. A framework, substantially in accordance with any example hereinbefore described with reference to the accompanying drawings.