GB2208100A - Support structure - Google Patents

Abstract

A collapsible support structure comprising, in its erect condition, spaced-apart mutually opposed end members 1,2 inter-connected by at least two resilient members 3,7 arranged to provide a resilient restoring force against compressive loads applied between the end members 1,2, wherein the end members 1,2 and resilient members 3,7 are hingedly interconnected to one another for pivotal movement about respective parallel axes the arrangement of which permits the structure to be collapsed by relative lateral movement of the end members 1,2 and pivoting of the resilient members 3,7 into a generally flat condition with all the members 1,2,3,7 lying in the same general plane. The invention is particularly suited to forming part of the structure of a collapsible stool. <IMAGE>

Description

SUPPORT STRUCTURE This invention relates to a support structure, and in particular to such a structure adapted to provide resilient support between two end members.

The invention is particularly, but not exclusively, concerned with such a support which may constitute or form part of a chair or stool.

Viewed from one aspect the invention provides a collapsible support structure comprising, in its erect condition, spaced-apart mutually opposed end members inter-connected by at least two resilient members arranged to provide a resilient restoring force against compressive loads applied between the end members, wherein the end members and resilient members are hingedly inter-connected to one another for pivotal movement about respective parallel axes the arrangement of which permits the structure to be collapsed by relative lateral movement of the end members and pivoting of the side members into a generally flat condition with all the members lying in the same general plane for transportation or storage of the structure if desired.

Such a structure may have many applications where a resilient support is required, an important advantage over known supports being that the structure may be readily collapsed into a generally flat condition if desired. A structure in accordance with the invention is particularly suitable for use as a stool or part of a chair, in which case one of the end members constitutes or supports a seat of the chair or stool whilst the other end member forms the base thereof. Such a chair or stool may thus be sold, stored or supplied in the collapsed condition, and readily erected for use when required. The upper member may be suitably slatted, sprung, or cushioned to provide a more comfortable seat, the resilient members being chosen to provide a suitable resilient restoring force agains the weight of a person sitting on the structure.

The structure in accordance with the invention may however have any number of other uses; for example it could be suitably scaled up or scaled down for use in any application where a resilient support is required such as a vehicle suspension system, furniture generally e.g. matresses etc.

In its simplest form a support structure in accordance with the invention may include a single pair of spaced resilient members providing resilient support between the end members and hingedly connected thereto about respective parallel axes.

In a preferred embodiment, however, additional resilient members may be provided, which are also hingedly connected to the end members about further, parallel axes, so that all such members pivot generally in parallel to one another upon lateral movement of one end member relative to the other when the structure is collapsed.

In a particularly preferred embodiment the resilient members constitute panels or struts formed of resilient material such as plastic or metal sheet, such members being arranged to be inwardly or outwardly bowed with respect to one another when the structure is erect, and becoming substantially flat when the structure is collapsed.

It is envisaged that in one such embodiment of the invention two or more resilient members may be bowed inwardly towards one another by means of a suitable tie member or members adapted to be manually engaged between the central parts of the members when the structure is erect, and released to permit the members to straighten when it is desired to collapse the structure. Such a tie member should restrain the central parts of the resilient members from moving apart, thus maintaining the members resiliently bowed towards one another, but should permit the central parts to move closer together when a load is applied between the end members so that increased bowing of the resilient members can provide the desired resilient restoring force.A simple form of tie member may comprise a flexible bracing member or cord, or alternatively a compressible piston/cylinder arrangement might be provided the maximum extension of which corresponds to the desired maximum spacing of the central parts of the inwardly bowed members. The use of such a tie member provides the additional advantage that once the tie member is secured between the central parts of the inwardly bowed resilient members collapsing of the structure by relative lateral movement of the end members is prevented and the structure is stable until such time as the tie member is removed.

In addition to or instead of a tie member for maintaining opposed resilient members inwardly bowed with respect to one another, a particularly advantageous embodiment further includes outwardly bowed resilient members arranged in the erect structure in back-to-back relation with the respective inwardly bowed members, and coupled thereto in such a way that their central regions are displaced towards one another, the coupling arrangement permitting relative sliding movement between the members when the structure is collapsed whereby the members are permitted to flatten in the collapsed condition.

In such an arrangement the respective inwardly and outwardly bowed resilient members are of equal length, and are hingedly connected to the end members about spaced axes, the coupling of their central regions thus causing the inwardly and outwardly bowed configurations thereof automatically as the structure is erected without the need manually to urge the members inwardly or outwardly to engage a tie member. A further advantage of the additional, outwardly bowed members is that they provide increased resilient support between the end members.

In a preferred such embodiment the inwardly bowed members define a general H shape and thus comprise two resilient outer limbs connected by a cross-piece adjacent their central regions.

The outwardly bowed members are, in this embodiment, threaded around the cross-piece of the H shape, the respective pivot axes about which such members are hingedly attached to the end members being so spaced that the resilient members are inwardly and outwardly bowed as desired when the structure is erected, the sliding connection of the outwardly bowed member around the cross-piece of the H permitting the resilient members gradually to straighten as one end member is moved laterally with respect to the other. In such an arrangement, one or more tie member(s) as discussed above may be manually engaged between the central parts of the inwardly bowed members when the structure is erect to permit unwanted collapse of the structure. It is envisaged a respective such tie member might be associated with each outer limb of the H shaped members, or alternatively a single tie member could extend between the cross-piece thereof.

In a preferred embodiment in addition to the respective pairs of inwardly and outwardly bowed resilient members coupled together adjacent their central parts as discussed above, additional outwardly bowed members may be arranged in back to back relation with the inwardly bowed ones for improved appearance and/or strength of the structure.

The hinge means whereby the resilient members and end members are pivotally inter-connected may take any convenient form depending on the size of the structure and the material from which it is fabricated. Suitable hinge means might constitute fabric tapes or traditional door type hinges.

A preferred embodiment of the invention which constitutes a stool or chair base provides an attractive and comfortable item of furniture which has the additional advantage of collapsibility.

Viewed from a second aspect the invention provides a collapsible chair, stool or other item of furniture comprising or consisting of a support structure as discussed above.

A preferred embodiment of the invention will now be described, by way of example, only with reference to the accompanying drawings, wherein: Figure 1 is a schematic perspective view of a support structure in accordance with the invention; Figure 2 is a diagramatic side elevation of the support structure of Figure 1; Figure 3 is a diagramatic end elevation of the structure; Figure 4 is a top plan view of the structure; and Figure 5 is a side elevation on an enlarged scale illustrating the support structure in a partly collapsed condition thereof.

Referring to the drawings, the support structure comprises end members 1,2 in the form of upper and lower panels, inter-connected by a plurality of resilient members. In the preferred embodiment, all the members of the structure are in fact formed of like resilient sheet material, as will be discussed in more detail below.

The resilient members in the erect condition of the structure comprise inwardly bowed members 3 each of which has side limbs 4 inter-connected by a cross-piece 5 thus defining an H shape, as shown most clearly in Figure 1. The limbs 4 of the inwardly bowed resilient members 3 are of equal length and are hingedly connected to the end members so as to be pivotal about respective parallel axes A.

Threaded around the cross-pieces 5 of the inwardly bowed resilient members 3 are respective outwardly bowed resilient members 6 which are of equal length to the limbs 4 of the inwardly bowed members but which are hingedly connected to the upper and lower members about axes B which are parallel to and midway between the parallel axes A.

As shown in Figure 1, the lengths of the resilient members 3,6 and the spacing between the axes A and B are chosen such that the members 3,6 pull each other into respective inwardly and outwardly bowed configurations, thus providing a sprung support between the upper and lower members 1,2. The preferred embodiment illustrated also comprises additional, outwardly bowed resilient members 7 hingedly connected to the upper and lower members 1,2 so as to be pivotal about the axes A, such members -7 increasing the resilient force between the upper and lower members 1,2 and also improving the balanced appearance of the structure.

As shown in Figure 5, the arrangement of the parallel axes A,B and of the respective resilient members 3,6,7 of equal lengths is that the entire structure may be collapsed by relative lateral movement of the end members 1,2 which causes pivotal movement of the resilient members. By virtue of the sliding connection between the respective inwardly and outwardly bowed members 3,6 the members are straightened as the tension/compression therein is released during collapse of the structure.

Figure 5 shows the partly collapsed structure, and it will be appreciated that when collapse is complete all of the members lie in the same general plane with the resilient members allowed to flatten.

Conversely, when it is desired to erect the structure, reverse relative lateral and pivotal movement of the members is performed, whereby the inwardly and outwardly bowed members are automatically placed in bending compression/tension by virtue of the sliding coupling between the inwardly and outwardly bowed members 3,6. By virtue of the restraint thereby placed on the maximum spacing between the end members 1 and 2 this also results in the resilient members 7 adopting an outwardly bowed configuration.

As shown in broken lines in Figure 2, when the load e.g. of a person sitting on the structure is applied between the end members 1 and 2 the resilient members are further inwardly/outwardly bowed so as to provide a suitable resilient restoring force. It will be appreciated that the displacement of the outwardly bowed members 6 is permitted between the limbs 4 of the inwardly bowed H shaped members 3.

As shown schematically in Figures 2, 3 and 4, the preferred embodiment includes tie members 8 arranged to be manually connected between the central regions of the inwardly bowed resilient members 3. Such tie members are arranged to permit inward displacement of such central regions consequent upon a load being applied between the end members 1,2, but to prevent the central regions moving further away from one another. Accordingly with such tie members in place the structure is stabilised and collapsing movement as shown in Figure 5 is prevented. The tie members 8 could constitute simple flexible straps or cords, although in a preferred embodiment it is envisaged that such members may comprise compressible piston/cylinder fittings to improve stability and/or appearance.

The tie members can be detachably secured to the resilient members 3 by any suitable means, such as bolts which engage in apertures in the members 3.

The hinge means whereby the members are pivotally inter-connected about the axes A,B could take any convenient form, and in the preferred embodiment comprise door type hinges which may be plastic or brass for the sake of appearance. A protecting cushion or the like is preferably provided adjacent the hinges on the opposite sides thereof to avoid the possibility of the user being pinched by the abutting end edges of the members as they are closed together during erection of the structure.

A preferred embodiment suitable for use e.g.

as a chair or stool comprises end members which are approximately 38cm square, the resilient members being approximately 60cm long providing a structure whose height, i.e. the vertical spacing between the end members 1,2 in the erect condition, is 55cm. Typically such height will be compressed to the order of 50cm under the load of a person.

In such an embodiment the members may be fabricated from a resilient polypropylene sheet material such as that sold under the trade mark "PROPYLEX" by Kappa Plastics, Horsham, West Sussex. For the dimensions of seat discussed above, the thickness of the sheet material may be in the order of 4.5mm.

Claims (19)

CLAIMS:

1. A collapsible support sructure comprising, in its erect condition, spaced-apart mutually opposed end members inter-connected by at least two resilient members arranged to provide a resilient restoring force against compressive loads applied between said end members, wherein said end members and resilient members are hingedly inter-connected to one another for pivotal movement about respective parallel axes the arrangement of which permits said structure to be collapsed by relative lateral movement of said end members and pivoting of said resilient members into a generally flat condition with all said members lying in the same general plane.

2. A collapsible support structure as claimed in claim 1, wherein said resilient members comprise panels formed of resilient material.

3. A collapsible support structure as claimed in claim 1, wherein said resilient members comprise struts formed of resilient material.

4. A collapsible support structure as claimed in claim 2 or 3, wherein said resilient material comprises plastic.

5. A collapsible support structure as claimed in claim 2 or 3, wherein said resilient material comprises metal.

6. A collapsible support structure as claimed in any preceding claim, wherein said resilient members are arranged to be inwardly bowed with respect to one another when said structure is erect.

7. A collapsible support structure as claimed in any of claims 1 to 5, wherein said resilient members are arranged to be outwardly bowed with respect to one another when said structure is erect.

8. A collapsible support structure as claimed in claim 6, wherein said resilient members are bowed inwardly towards one another by one or more tie members adapted to be manually engaged between the central parts of said resilient members when said structure is erect.

9. A collapsible support structure as claimed in claim 8, wherein said tie member(s) include a compressible piston/cylinder arrangement.

10. A collapsible support structure as claimed in any of claims 6, 8 or 9, including outwardly bowed resilient members arranged, in the erect structure, in back-to-back relation with the respective inwardly bowed resilient members, and coupled thereto in such a way that their central regions are displaced towards one another, the coupling arrangement permitting relative sliding movement between said resilient members when said structure is collapsed whereby said resilient members are permitted to flatten in the collapsed condition.

11. A collapsible support structure as claimed in claim 10, wherein the respective inwardly and outwardly bowed resilient members are of equal length, and are hingedly connected to said end members about spaced axes, the coupling of their central regions thus causing the inwardly and outwardly bowed configurations thereof automatically as said structure is erected.

12. A collapsible support structure as claimed in claim 11, wherein said inwardly bowed resilient members comprise two resilient outer limbs connected by a cross-piece adjacent their central regions, said outwardly bowed resilient members being threaded around said cross-piece, the respective pivot axes about which such resilient members are hingedly attached to said end members being so spaced that said resilient members are inwardly and outwardly bowed as desired when the structure is erected, the sliding connection of the outwardly bowed resilient member around said cross-piece permitting said resilient members gradually to straighten as one end member is moved laterally with respect to the other.

13. A collapsible support structure as claimed in claim 12 and in claim 8 or 9, wherein a tie member is associated with each outer limb.

14. A collapsible support structure as claimed in claim 12 and in claim 8 or 9, wherein a tie member is associated with said cross-piece.

15. A collapsible support structure as claimed in any of claims 12 to 14, including additional outwardly bowed resilient members arranged in back to back relation with said inwardly resilient bowed member.

16. A collapsible item of furniture including a collapsible support structure as claimed in any preceding claim.

17. A collapsible item of furniture as claimed in claim 16, wherein said item of furniture is a stool.

18. A collapsible item of furniture as claimed in claim 16, wherein said item of furniture is a chair base.

19. A collapsible support structure substantially as hereinbefore described with reference to the accompanying drawings.