WO1993014675A1

WO1993014675A1 - Portable backrest

Info

Publication number: WO1993014675A1
Application number: PCT/GB1993/000140
Authority: WO
Inventors: Kenneth Mcdonald Springer
Original assignee: Kenneth Mcdonald Springer
Priority date: 1992-01-24
Filing date: 1993-01-22
Publication date: 1993-08-05
Also published as: GB2263864A; AU3362493A; GB9201609D0

Abstract

There is described a portable backrest (10) capable of being folded between a collapsed position and an assembled position. The backrest (10) comprises two rectilinear side members (12, 14) that, when in the assembled position, are inclined to the surface on which the backrest (10) is positioned, and at least one web (30, 32) of flexible material that extends transversely and is supported by its ends between the two side members (12, 14). The side members (12, 14) are themselves supported in the inclined position by a respective one of two supporting members (16, 18) hingedly connected thereto. In a preferred embodiment each of the side members (12, 14) is hingedly connected at a lower end thereof to a respective one of two base members (20, 22), each base member (20, 22), when in the assembled position, also being connected to one of the two supporting members (16, 18) so as to provide the backrest (10) with increased rigidity.

Description

PORTABLE BACKREST

The present invention relates to a portable backrest suitable for use in the garden or on the beach.

According to the present invention there is provided a portable backrest capable of being folded between a collapsed and an assembled position, the backrest comprising two rectilinear side members that, when in the assembled position, are inclined to the surface on which the backrest is positioned, and at least one web of flexible material that extends transversely and is supported by its ends between the two side members, each of the side members being themselves supported in the inclined position by a respective one of two supporting members hingedly connected thereto.

Advantageously one or both of the side members may comprise two or more sections that are hingedly interconnected so as to reduce the size of the backrest when in the collapsed position. Preferably one or both of the side members may comprise an upper and a lower section that are hingedly interconnected, the upper section being shorter in length than the lower section so as to be capable of nesting thereagainst when the backrest is in the collapsed position. Alternatively, one or both of the side members may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other. Advantageously one or both of the supporting members may comprise two or more sections that are hingedly interconnected so as to again reduce the size of the backrest when in the collapsed position. Alternatively, one or both of the supporting members may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other. Thus by employing, say, three telescopic sections each supporting member may be secured in any one of three configurations each of a different length depending on which if any of the sections are extended thus enabling the side members to be inclined at any one of three different angles relative to the surface on which the assembled backrest is positioned.

In a preferred embodiment each of the side members is hingedly connected at a lower end thereof to a respective one of two base members, each base member, when in the assembled position, also being connected to one of the two supporting members so as to provide the backrest with an increased rigidity.

Advantageously one or both of the base members may comprise two or more sections that are hingedly interconnected so as to again reduce the size of the backrest when in the collapsed position. Alternatively, one or both of the base members may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

The backrest may also be provided with one or more transverse braces connected between the two side members or between the two base members. The transverse braces serve to hold apart the members to which they are connected as well as contributing to the rigidity of the overall structure. In a particular arrangement each of the transverse braces may be hinged part way along its length and provided with a resilient clip to prevent the accidental folding of the brace when in the assembled, fully open position. Alternatively, each of the transverse braces may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

The backrest may additionally be provided with one or more webbing straps that extend between the two base members to maintain the members substantially parallel to each other and prevent an excessive load being applied to the transverse braces when the backrest is in use.

Preferably, when in the assembled position, one or both of the supporting members are connected to a respective one of the base members by means of a resilient clip adapted to provide a simple snap-fit. Advantageously, one or both of the base members are provided at intervals along their length with one or more formations that define various points at which, when in the assembled position, the base members may be connected to one or other of the two supporting members. By connecting the supporting members to their respective base members in this way, the side members may be inclined at any one of a number of predetermined angles relative to the surface on which the assembled backrest is positioned.

Preferably both of the supporting members are hingedly connected to their respective side members by means of a joint capable of swivelling relative to the side member concerned. In this way each of the supporting members may be arranged to the side of its respective side member when the backrest is in the collapsed position thereby preventing interference with either the corresponding base member or a hinged section of the side member concerned.

In order to increase the rigidity of the backrest the supporting member of one of the side members may be connected to the base member of the other of the side members. In this arrangement the supporting members may be braced together in order to overcome any tendancy for the supporting members to twist when the backrest is in use.

In another embodiment one or both of the supporting members may be provided with a portion that engages the surface on which the assembled backrest is positioned. In this way when a person leans back on the said at least one web that extends transversely and is supported by its ends between the two side members, the backrest is prevented from sliding rearwardly. Similarly, when in the assembled position, one or both of the side members may be provided at a lower end thereof with a portion that engages the surface on which the assembled backrest is positioned. Alternatively, or in addition, one of the webs that extends transversely and is supported by its ends between the two side members may be provided with a portion that, when the backrest is in the assembled position, partially overlies the surface on which the backrest is positioned so that when a person leans on the backrest they also sit on that portion of the web that overlies the surface thereby again preventing the backrest from sliding rearwardly.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 is a perspective view of an assembled backrest in accordance with the present invention;

Figure 2 is a front view of the backrest of Figure 1;

Figure 3 is a rear view of the backrest of Figure 1;

Figure 4 is a side view of the backrest of Figure 1;

Figure 5 is an enlarged cross-sectional view of a catch provided between two coaxial sections capable of relative telescopic movement that comprise a base member of the backrest of Figure 1; and

Figure 6 is an enlarged view of the bracing provided between two supporting members of the backrest of Figure l. Referring initially to Figures 1 to 4, the illustrated backrest 10 can be seen to comprise two side members 12 and 14, two supporting members 16 and 18, and two base members 20 and 22.

The two side members 12 and 14 are substantially identical and comprise an upper section 24 and a lower section 26, the upper section 24 being of shorter length than the lower section 26. The two sections 24 and 26 are hingedly interconnected by means of a joint 23 that permits the sections 24 and 26 to move relative to each other between a collapsed position in which the upper section 24 lies adjacent the lower section 26 and an assembled position in which the upper section 24 is aligned rectilinearly with the lower section 26. When the backrest 10 is assembled, both of the two side members 12 and 14 take up a position inclined to the surface on which the backrest 10 is positioned and are supported in this position by a respective one of the two supporting members 16 and 18 to which they are hingedly connected.

Two webs 30 and 32 of flexible material extend transversely and are supported by their ends between the two side members 12 and 14. The webs 30 and 32 are preferably of nylon or a similar hard-wearing material and are spaced so as to provide support to the back of a user. Each web 30 or 32 is held in position by loops through which the side members 12 and 14 pass and secured by the provision of one or more rivets or similar fixings 34.

At a lower end, each of the side members 12 and 14 are connected to a respective one of the two base members 20 and 22 by means of a hinge 36 that permits each side member to move relative to the base member to which it is connected between a collapsed position in which the side member lies adjacent the base member and an assembled position in which the angle subtended by the members at the hinge 36 is greater than zero.

Each of the side members 12 and 14 are also provided at the lower end with a projecting portion 38 that intersects the plane defined by the two base members 20 and 22. In this way, when the backrest 10 is in use, the two projecting portions 38 are able to engage the surface on which the backrest 10 is positioned and so prevent it from sliding rearwardly.

Like the two side members 12 and 14 , the two base members 20 and 22 are also substantially identical to each other and comprise two coaxial sections 40 and 42 capable of relative telescopic movement between a retracted position and an extended position. A catch 44 is provided between the two sections 40 and 42 to secure the pair against further relative movement when in the extended position. As can be seen in more detail in Figure 5, the catch 44 comprises a radially projecting stud 46 provided at one end of the inner of the two coaxial sections 40 and an opening 48 provided at an end of the outer of the two coaxial sections 42. The stud 46 is biased outwardly by the action of a resilient flange 50 so that when the relative positions of the inner and outer sections 40 and 42 allow, the stud 46 is received within the opening 48 and engages therewith to prevent further relative movement. In order to release the catch 44 the biasing force of the resilient flange 50 must first be overcome and the stud 46 depressed so that the head thereof is substantially flush with the surface of the inner section 40. With the stud 46 depressed in this way the two coaxial sections 40 and 42 are again free to be moved relative to each other.

Referring again to Figures 1 to 4 it will be observed that at an end remote from the stud 46 the inner coaxial section 40 terminates in hinge 36 by means of which the base member is connected to one of the two side members 12 or 14 while toward an end remote from the opening 48 the outer section 42 is provided at intervals along its length with a plurality of formations 52 that define various points at which the base member may be connected to one or other of the two supporting members 16 or 18.

Like the two side members 12 and 14 and the two base members 20 and 22, the two supporting members 16 and 18 are also substantially identical to each other and comprise three coaxial sections 54,56 and 58 capable of relative telescopic movement between a retracted position and an extended position. Both pairs of adjacent sections 54 and 56 and 56 and 58 are provided with a catch (not shown) , each similar to that described with reference to Figure 5, so as to secure the pair against further relative movement when extended relative to each other. As before, each catch comprises a radially projecting stud provided at an end of the inner of the pair of coaxial sections and an opening provided at an end of the outer of the pair of coaxial sections. The stud is again outwardly biased by the action of a resilient flange so that when the sections of the pair are extended relative to each other the stud is received within the opening and engages therewith to prevent further relative movement. Each catch is released by first overcoming the biasing force of the resilient flange and is operable independantly of the other.

In addition to the foregoing, the innermost of the three coaxial sections 54 is provided at one end with a joint 60 by means of which the supporting member is hingedly connected to an elevated end of one of the two side members 12 or 14. The hinge-like action of the joint 60 is such as to permit the supporting member to move relative to the side member between a collapsed position in which the supporting member lies adjacent to the side member and an assembled position in which the angle subtended by the members at the joint 60 is greater than zero. However, unlike joint 28 or hinge 36, the joint 60 is also capable of swivelling relative to the side member to which it is connected thereby enabling the supporting member to occupy a plane different from that of the side member and its associated base member.

At the opposite end of the supporting member, the outermost of the three coaxial sections 58 is provided with a resilient clip 62 capable of a repeated snap-fit engagement with the outer section 42 of either of the base members 20 or 22. However, enabled by the swivelling action of joint 60, the two supporting members 16 and 13 are preferably crossed to provide the assembled backrest 10 with an increased rigidity such that the supporting member of one of the side members is connected by means of its resilient clip 62 to the base member of the other of the side members.

A still further increase in the rigidity of the assembled backrest 10 is provided by the engagement of a push button 64 (shown in Figure 6) located on one of the supporting members 16 or 18 with an opening 66 located on the other. By bracing the two supporting members 16 and 18 together in this way it is possible to overcome any tendancy for them to twist when the backrest 10 is in use.

The assembled backrest 10 is further braced by two transverse braces 68 and 70. The first of these transverse braces 68 is pivotedly connected at either end between the two side members 12 and 14 and located toward the elevated end of each close to the joint 60. In addition, the brace 68 is provided with a central hinge 72 and a resilient clip 74 to prevent the accidental folding of the brace 68 when in an assembled, fully open position. The second transverse brace 70 is pivotedly connected at either end between the two base members 20 and 22 and located close to the hinge 36. Like the first transverse brace 68, the second brace 70 is also provided with a central hinge 76 and a resilient clip 78 to prevent the accidental folding of the brace 70 when in an assembled, fully open position.

Finally, the assembled backrest 10 is provided with a webbing strap 80 that extends between the two base members 20 and 22 and is located at an end of each remote from the hinge 36. The strap 80 is held in position by loops through which the base members 20 and 22 pass and secured by the provision of one or more rivets or similar fixings 82. In order to adjust the angle of inclination of the assembled backrest 10, the resilient clip 62 provided at an end of each of the supporting members 16 and 18 may be disengaged from the base member to which it is connected and reconnected at a different point defined by an alternative pair of formations 52. By moving the resilient clip 62 to a position closer to the hinge 36 the angle of inclination of the backrest 10 is increased while by moving the resilient clip 62 to a position further from the hinge 36 the angle of inclination is reduced.

Alternatively, in order to adjust the angle of inclination of the assembled backrest 10 the lengths of the supporting members 16 and 18 may be altered by causing one or both of the pairs of adjacent coaxial sections 54 and 56 or 56 and 58 to telescope to a retracted position. By decreasing the overall length of the supporting members 16 and 18 in this way the angle of inclination of the backrest 10 may be decreased.

Clearly, by adjusting the position of the resilient clips 62 relative to the base member to which they are connected and the overall length of the supporting members 16 and 18, a wide variety of angles of inclination may be achieved.

In order to fold the backrest 10 from the assembled position shown in Figures l to 4 to a collapsed position push button 64 is first released from engagement with the opening 66 and each of the supporting members 16 and 18 disconnected from the base members 20 and 22 to which, in the assembled position, they were connected by means of the resilient clips 62. The supporting members 16 and 18 are then telescoped to a fully retracted position in which each of the innermost coaxial sections 54 are received within each of the central coaxial sections 56 and each of the central coaxial sections 56 are received within each of the outermost coaxial sections 58. Each supporting member 16 and 18 is then swivelled by means of joint 60 to a position to the side of and in the same plane as the side members 12 and 14. The base members 20 and 22 are similarly telescoped to a fully retracted position in which each of the inner coaxial sections 40 are received within each of the outer coaxial section 42. Each of the upper sections 24 of the two side members 12 and 14 may then be pivoted about joint 28 so as to take up a position adjacent their respective lower sections 26 and the lower sections 26 pivoted about hinge 36 so that each overlies one of the base members 20 or 22 with the corresponding upper section 24 sandwiched in between. Finally the resilient clips 74 and 78 of the two transverse braces 68 and 70 are released to enable the braces 68 and 70 to fold about their respective central hinges 72 and 76 and allow the folded side members 12 and 14 and retracted base members 20 and 22 to take up a compact position adjacent one another.

From the foregoing it will be apparent to those skilled in the art that it is possible to provide a portable backrest in which the base members of the described embodiment are omitted resulting in a simpler and more lightweight structure. It will also be apparent that whereas each of the side members of the described embodiment comprise two hingedly interconnected sections they may, in an alternative embodiment, comprise more than two sections although this may decrease the ease with which the resulting backrest may be folded into a collapsed position. In a different embodiment, the side members may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position in much the same way as the supporting members of the described embodiment. In such an arrangement a catch may be provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

Likewise it will be apparent to those skilled in the art that whereas each of the supporting members of the described embodiment comprise three coaxial sections capable of relative telescopic movement they may, in an alternative embodiment, comprise a different number of coaxial sections with a catch provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other. In a different embodiment, the supporting members may comprise two or more sections that are hingedly interconnected in much the same way as the side members of the described embodiment.

If the backrest is provided with base members, as in the described embodiment, it will be apparent to those skilled in the art that the base members may comprise more than two sections capable of relative telescopic movement either to make the backrest more compact when in a collapsed position or to provide the base members with an increased length that would not only enable the supporting members to be connected in a larger number of positions and so allow the backrest to be inclined at a larger number of angles but would also provide the backrest with an increased resistance to sliding rearwardly when in use. Alternatively, the base members may comprise two or more sections that are hingedly interconnected in much the same way as the side members of the described embodiment.

It will also be apparent to those skilled in the art that the backrest may be provided with a different number of transverse braces and that these braces may be connected between the two side members or between the two base members. Unlike the transverse braces of the described embodiment the braces need not be restricted to a single central hinge but may have a number of hinges disposed at intervals along their length each with a clip to prevent the accidental folding of the brace. In an alternative embodiment, each transverse brace may comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position with a catch provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

Similarly it will also be apparent to those skilled in the art that the backrest may be provided with more than one webbing strap.

Likewise it will also be apparent to those skilled in the art that the formations provided at intervals along the length of the base members need not be in the form of small projections as illustrated in connection with the described embodiment. Instead the formations may comprise a plurality of ridges or grooves with which an appropriately shaped supporting member may engage. Thus under such circumstances the supporting members need not be connected to a respective one of the base members by means of a resilient clip but may, for example, include a portion that is received within a recess of the appropriate base member.

Likewise it will also be apparent to those skilled in the art that the joints by which each of the side members are hingedly connected to a respective one of the two supporting members need not necessarily be capable of swivelling relative to the side member concerned. However, if the joints are not capable of swivelling as described, each supporting member will be constrained to occupy substantially the same plane as the side member and base member to which it is connected and it is thought that this will reduce the rigidity of the construction. Clearly, if the supporting members are crossed in the manner described with the supporting member of one of the side members being connected to the base member of the other, the supporting members may be braced together in any convenient manner.

Likewise it will be apparent to those skilled in the art that in order to prevent the backrest from sliding rearwardly when in use, the backrest need not be limited to the provision of the projecting portions described as located at the lower end of the side members. Instead, or in addition, one or both of the supporting members may be provided with a portion that engages the surface on which the assembled backrest is positioned. This is particularly so if the supporting members are connected to the base members by means of a portion that is received within one of a number of recesses since if the recesses were adapted so as to form a series of through-holes an appropriate portion of each supporting member could not only be received therein but also project therefrom to prevent any sliding of the backrest. In an alternative embodiment, one of the webs that extends transversely between the side members and is supported therebetween by its ends may be provided with a portion that, when the backrest is assembled, partially overlies the surface on which the backrest is positioned. Thus when a person leans back on the backrest they also sit on that portion of the web that partially overlies the surface thereby preventing the backrest from sliding rearwardly.

Claims

1. A portable backrest capable of being folded between a collapsed position and an assembled position, the backrest comprising two rectilinear side members that, when in the assembled position, are inclined to the surface on which the backrest is positioned, and at least one web of flexible material that extends transversely and is supported by its ends between the two side members, each of the side members being themselves supported in the inclined position by a respective one of two supporting members hingedly connected thereto.

2. A portable backrest in accordance with claim 1, wherein one or both of the side members comprise two or more sections that are hingedly interconnected.

3. A portable backrest in accordance with claim 1 or claim 2, wherein one or both of the side members comprise, when in the assembled position, an upper and a lower section that are hingedly interconnected, the upper section being shorter in length than the lower section.

4. A portable backrest in accordance with claim 1, wherein one or both of the side members comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

5. A portable backrest in accordance with any preceding claim, wherein one or both of the supporting members comprise two or more sections that are hingedly interconnected.

6. A portable backrest in accordance with any of claims 1 to 4, wherein one or both of the supporting members comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

7. A portable backrest in accordance with any preceding claim, wherein each of the side members is hingedly connected at a lower end thereof to a respective one of two base members, each base member, when in the assembled position, also being connected to one of the supporting members.

8. A portable backrest in accordance with claim 7 , wherein one or both of the base members comprise two or more sections that are hingedly interconnected.

9. A portable backrest in accordance with claim 7, wherein one or both of the base members comprise two or more sections capable of relative telescopic movement between a retracted position and an extended position, a catch being provided between each of a pair of adjacent sections to secure the pair against further relative movement when extended relative to each other.

10. A portable backrest in accordance with any of claims 7 to 9, wherein one or more transverse braces are provided between the two side members or between the two base members.

11. A portable backrest in accordance with claim 10, wherein each of the one or more transverse braces is hinged part way along its length and provided with a resilient clip to prevent the accidental folding of the brace when in the assembled, fully open position.

12. A portable backrest in accordance with any of claims 7 to 11, wherein one or more webbing straps are provided that extend between the two base members.

13. A portable backrest in accordance with any of claims 7 to 12, wherein one or both of the supporting members are connected to a respective one of the two base members by means of a resilient clip.

14. A portable backrest in accordance with any of claims 7 to 13 , wherein one or both of the base members are provided at intervals along their lengths with one or more formations that define various points at which, when in the assembled position, the base members may be connected to one or other of the two supporting members.

15. A portable backrest in accordance with any preceding claim, wherein both the supporting members are hingedly connected to their respective side members by means of a joint capable of swivelling relative to the side member concerned.

16. A portable backrest in accordance with claim 15, wherein the supporting member of one of the side members is connected to the base member of the other of the side members.

17. A portable backrest in accordance with claim 16, wherein the two supporting members are braced together.

18. A portable backrest in accordance with any preceding claim, wherein one or both of the supporting members are provided with a portion that engages the surface on which the assembled backrest is positioned.

19. A portable backrest in accordance with any preceding claim, wherein one or both of the side members are provided at a lower end thereof with a portion that engages the surface on which the assembled backrest is positioned.

20. A portable backrest in accordance with any preceding claim, wherein one of the webs that extends transversely and is supported by its ends between the two side members is provided with a portion that, when the backrest is in the assembled position, partially overlies the surface on which the backrest is positioned.