A mechanism for the backrest of a chair

Abstract

The invention is a flexible hinge for a chair having a seat and backrest formed or otherwise moulded as a single. The flexible hinge provides a means of facilitating the movement of the backrest, and in particular the controlled movement of the upper portion of the backrest relative to the lower portion of the backrest. This may help improve comfort of the person using the chair, particularly when reclining, and may also minimise excessive flexure of the backrest which, over time, may otherwise lead to fatigue and potential failure of the backrest.

Description

[0001] James & Wells ref: 506607PCT

[0002] A Mechanism for the Backrest of a Chair

[0003] Statement of Corresponding Applications

[0004] This application is based on the provisional specification filed in relation to Australian Patent Application No. 2024903351, the entire contents of which are incorporated herein by reference.

[0005] Technical field

[0006] The present invention generally relates to chairs having a seat and backrest formed or otherwise moulded as a single shell from plastics material. The invention has particular application to a mechanism to control the relative flexibility of the backrest of a chair.

[0007] Background Art

[0008] Chairs having a seat and backrest formed or otherwise integrally moulded as a shell from plastics material are widely used in commercial and educational sectors. Although a frame of metal which includes legs may be provided to the seat portion of such a chair, thereby allowing transfer of the weight of the sitter through to the legs, these chairs are usually manufactured without a metal frame being provided to the backrest portion of the shell. As such, these chairs can be relatively economic to produce.

[0009] Comfort and ergonomics are important considerations for chairs. For the person using the chair, support is provided by the seat and backrest and this should be achieved without undue pressure on the parts of the body in contact with the chair.

[0010] A contoured plastic shell, without a metal reinforcing frame for the backrest, provides some comfort as it has sufficient flexibility to allow some reclining of the backrest through the weight of a person leaning backwards while seated. Providing some flexure or "give" to the backrest helps with comfort for the sitter.

[0011] However, the extent of the flexure is dependent upon the shape of the shell and plastics materials used in the construction of same. James & Wells ref: 506607PCT

[0012] Furthermore, the plastics material can become fatigued through repeated flexure and or application of a force to the backrest, particularly the upper portion of the backrest, that is in excess of its range of flexibility. Such forces can be applied when a person sitting in the chair reclines backwards or alternatively, when a person standing behind the chair with their hands of the backrest leans forward. Over time, this could lead to eventual breakage at the point of flexure of the backrest. Furthermore, an excessive recline of the backrest may not be conducive to good posture for the sitter.

[0013] Some chairs include arrangements to control the extent of the flexibility of the backrest of the chair, one example being Australian Patent No. 581064. However, these arrangements are relatively complicated structures which can be difficult to cost-effectively produce and assemble. Furthermore, they also require user adjustment to operate.

[0014] Object of the Invention

[0015] It is an object of the invention to provide a flexible hinge mechanism for facilitating the movement of the backrest portion, relative to the seat portion, of a moulded plastic chair.

[0016] It is an object of the invention to provide a flexible hinge mechanism for facilitating the movement of the backrest portion, relative to the seat portion, of a moulded plastic chair without requiring active user operation.

[0017] Alternatively, it is an object to provide a flexible hinge mechanism for facilitating the movement of the backrest portion, relative to the seat portion, of a moulded plastic chair which is cost effective to manufacture and assemble.

[0018] Alternatively, it is an object to provide a flexible hinge mechanism for facilitating the movement of the backrest portion, relative to the seat portion, of a moulded plastic chair to avoid material fatigue arising from excessive flexure of the backrest portion.

[0019] Alternatively, it is an object of the invention to at least provide the public with a useful choice. James & Wells ref: 506607PCT

[0020] Summary of the Invention

[0021] According to a first aspect of the invention, there is provided a chair moulded from plastic material and including a seat, backrest and at least a portion of a flexible hinge, and wherein the backrest includes a first, upper portion, and a second, lower portion, wherein the first portion of the backrest is movable relative to the second portion of the backrest in a first direction and an opposing second direction through the action of the flexible hinge, wherein the flexible hinge includes: a first strut associated with the first portion of the backrest, wherein the first strut includes a first biasing surface; a second strut associated with the second portion of the backrest, wherein the second strut includes a second biasing surface opposing the first biasing surface; a compression member located between the first and second biasing surfaces; a linking member connecting the first and second struts; and wherein movement of the first portion of the backrest in the first direction is limited by the compression member and movement of the first portion of the backrest in the opposing second direction is limited by the linking member.

[0022] Preferably, the chair is formed or otherwise moulded with the backrest, at least a portion of the flexible hinge, and the seat as an integral one-piece component. However, in some alternative examples, at least a portion of the flexible hinge may be provided one or more separate components to be attached to the relevant portion of the chair.

[0023] Preferably the flexible hinge is located in the area of the backrest substantially corresponding to the lumbar region of the chair. In use, the lumbar region of the chair corresponds to the lower lumbar region of a person's back and supports this area of the body.

[0024] The first strut is a substantially vertical post-like structure associated with the first portion of the backrest. Preferably the first strut is integrally formed, for example moulded, with the first portion of the backrest. James & Wells ref: 506607PCT

[0025] However, in some alternative examples, the first strut may be a separate component which is secured to a suitably configured area of the first portion of the backrest through the use of one or more fasteners or another securing technique such as adhesive.

[0026] Preferably the first strut of the flexible hinge extends / depends downward from the first portion of the backrest.

[0027] The second strut is a substantially vertical post-like structure associated with the second portion of the backrest. Preferably the second strut is integrally formed, for example moulded, with the second portion of the backrest. However, in some alternative examples, the second strut may be a separate component which is secured to a suitably configured area of the second portion of the backrest through the use of one or more fasteners or another securing technique such as adhesive.

[0028] Preferably the second strut of the flexible hinge extends upward from the second portion of the backrest.

[0029] Preferably each of the first and second struts are configured with an end having a flat surface, the flat surfaces opposing each other.

[0030] Preferably the flat surface of each of the first and second struts is the biasing surface of the respective struts.

[0031] Preferably, each of the first and second struts are configured with a recess configured to receive or otherwise engage with the linking member. Alternatively, each of the first and second struts may be configured with a lip or hook-like structure configured to receive or otherwise engage with the linking member.

[0032] Preferably, the compression member is a block of elastomeric material, such as rubber or the like. However, this is not meant to be limiting and alternative embodiments are envisaged in which the compression member may be, for example, a compression spring.

[0033] Preferably, the compression member has a top surface and a bottom surface, i.e. a top and bottom respectively.

[0034] Preferably the top and bottom of the compression member contacts the biasing surfaces of the first and second struts. James & Wells ref: 506607PCT

[0035] As noted previously, in preferred embodiments of the invention, the biasing surfaces of the respective first and second struts are substantially flat. However, in some embodiments, these surfaces may be contoured orthe like. In such embodiments, this may allow the compression member, configured with complementary contoured surfaces, to key in with the respective surfaces of the first and second struts.

[0036] Preferably, the linking member is a length of rigid material that is configured to engage with the first and second struts.

[0037] In particularly preferred embodiments, the linking member is a one-piece component with a first section having one or more pegs or similar protrusions extending therefrom, and a second section having one or more pegs or similar protrusions extending therefrom. The one or more pegs of the first section engage with the recesses provided to the first strut and the one or more pegs of the second section engage with the recesses provided to the second strut.

[0038] In a particularly preferred embodiment, the linking member is configured as a cover for the flexible hinge, the cover having an exterior surface configured to substantially blend in with the backrest of the chair and an interior surface configured with the pegs or protrusions. In this embodiment, the interior surface may also be configured to be complementary to a surface of the compression member. Even more preferably, the interior surface may be configured with pegs or similar structures to key into complementary surfaces provided to the compression member.

[0039] However, in alternative embodiments, the linking member is a loop of metal with a first section engaging with an appropriate structure, such as a lip or hook or recess, provided to the first strut and a second section engaging with a structure, such as a lip or hook or recess, provided to the second strut.

[0040] In this embodiment, a portion of the loop of metal is profiled to be complementary to a protrusion or recess provided to the sides of the compression member.

[0041] In this embodiment, a separate cover is provided for the flexible hinge, the cover having an exterior surface configured to substantially blend in with the backrest of the chair and an interior surface with sufficient clearance for the linking member and compression member. James & Wells ref: 506607PCT

[0042] However, this is not meant to be limiting and alternative embodiments of the linking member are envisaged.

[0043] For example, the linking member may be a length of composites material or the like.

[0044] Preferably, the seat is provided with a plurality of legs. In some embodiments, the plurality of legs may be integral to a frame structure which is engaged with the seat. In other embodiments, the seat may be configured with means that engage with individual or paired legs.

[0045] The invention provides a means of facilitating the movement of the backrest, and in particular the movement of the upper portion of the backrest relative to the lower portion of the backrest. This helps improve comfort of the person using the chair, particularly when reclining, and also minimises excessive flexure of the backrest which, overtime, may otherwise lead to fatigue and potential failure of the backrest.

[0046] Further aspects of the invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading of the following description which provides at least one example of a practical application of the invention.

[0047] Brief Description of the Drawings

[0048] One or more embodiments of the invention will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which:

[0049] Figure 1 is a perspective side view of a chair incorporating one embodiment of the invention;

[0050] Figure 2 is a perspective exploded view of one embodiment of the invention;

[0051] Figure 3 is a perspective view of the embodiment of Figure 2 when partially assembled;

[0052] Figure 4a is a perspective view of a chair, incorporating the embodiment of Figures 2 and 3, when a force is applied in a first direction;

[0053] Figure 4b is a perspective view of a chair, incorporating the embodiment of Figures 2 and 3, when a force is applied in a second direction;

[0054] Figure 5 is a perspective exploded view of another embodiment of the invention; and

[0055] Figure 6 is a further perspective exploded view of the embodiment of Figure 5. James & Wells ref: 506607PCT

[0056] Best Modes for Carrying out the Invention

[0057] In Figure 1, an example of a moulded plastics chair, generally indicated by arrow 100 and with which the present invention may be used, is illustrated. It should be appreciated that the chair shown is simply by way of example and the invention may be readily used with chairs having a different appearance with minimal or no modification.

[0058] The chair 100 has a seat 102 and backrest 104 which preferably is injection or rotationally moulded, from a suitable plastics material as will be apparent to a skilled addressee, as a single, unitary shell-like structure. However, as noted below, select parts of the chair may be formed separately if desired.

[0059] On the underside of the illustrated example, the seat 102 is moulded with sockets 106 which receive tubular metal legs 108, four in total. It will be appreciated that in other embodiments of the chair, not shown here, the legs may be paired and the seat configured appropriately to receive the legs as a pair. In further embodiments, the legs may be lined via a frame which is received by the seat.

[0060] The backrest 104, close to the intersection with the seat 102, includes the invention, a flexible hinge 110, in the circled area 112. The position of the hinge 110 approximately corresponds to the lumbar portion of the back of the person sitting in the chair 100.

[0061] The portion 104a of the backrest 104 above the hinge 110 should be understood to be the first or upper portion of the backrest. The portion 104b of the backrest below the hinge, which leads into the seat of the chair, should be understood to the second or lower portion of the backrest.

[0062] The upper portion 104a of the backrest 104 provides a slightly more reclined surface relative to the second portion 104b of the backrest, below the hinge 110. This helps with user comfort when seated. The user's comfort is enhanced through the use of the hinge, which provides a means of controlling the extent of the movement of the upper portion of the backrest.

[0063] One embodiment of the hinge 1 10 of the present invention is illustrated in Figure 2 in an exploded view and in Figure 3 is a partially assembled view. James & Wells ref: 506607PCT

[0064] The outer or exterior side of the backrest 104 is moulded with a profile 1 14 about its perimeter which is generally designed for rigidity. This does away with the need for a metal frame or reinforcing structures such as ribs or strengthening materials, as may be found in conventional chairs, for the backrest.

[0065] The profile 114 includes a flexible region 1 16 at the lumbar region of the backrest. This flexible region is configured as a recess or cut through which reduces the amount of plastics material relative to the rest of the backrest and confers a degree of flexibility in the lumbar region of the backrest. The flexible region joins the upper portion 104a of the backrest 104 to the lower portion 104b and forms part of the hinge.

[0066] In the illustrated example, the flexible region 116 is an integral part of the plastic shell (the combination of 102 and 104 of Figure 1 ) of the chair. However, in alternative embodiments of the invention not shown here, the backrest and seat may be moulded as separate components, with the flexible region provided to one or the other of the backrest or seat. For example, the flexible region may be a protrusion or pair of protrusions extending downwards from the backrest, the tips of which engage in sockets provided to the seat. In yet another example not shown here, the flexible region may be a separate component altogether, which interlocks or is otherwise fixed to the upper backrest and lower backrest (which may or may not be integrally formed with the seat).

[0067] In Figures 2 and 3, the hinge 1 10 has a first strut or post-like structure 1 18, descending from the upper side of the cut through 116, that is associated with the first portion 104a of the backrest 104. Here, the first strut is moulded integrally with the first but in an example not shown, the first strut may be a separate component, moulded or otherwise, secured to the first portion though the use of fasteners or the like. The hinge also has a second strut or post-like structure 120, this one being associated with the second portion 104b of the backrest and ascending from the lower side of the cut out. In the illustrated example, the second strut is moulded integrally with the second portion but could alternatively be provided as a separate component that is secured in place with appropriate fastening mechanisms. The respective ends 118a, 120a of the struts, which oppose each other, form biasing surfaces. James & Wells ref: 506607PCT

[0068] Positioned in between the biasing surfaces 1 18a, 120a is located a compression member 122. The compression member serves to limit the extent of the recline of the upper portion 104a of the backrest relative to the lower portion 104b.

[0069] In the illustrated example, the compression member 122 is in the form of an elastomeric block of urethane or similar polymeric material with a degree of resiliency. The selected material is not meant to be limiting; for example, the compression member may be a block of rubber.

[0070] Preferably, the height of the compression member 122 substantially corresponds to the distance between the biasing surfaces 118a, 120a of the respective first and second struts 118, 120. This makes it easy for the compression member to remain in place through a friction fit.

[0071] In the illustrated example, the biasing surfaces 1 18a, 120a are substantially flat and the surfaces of the compression member 122 that contacts these are similarly flat. It will be seen that these are the top and bottom surfaces respectively of the compression member. However, in alternative embodiments, the biasing surfaces of the first and second struts 1 18, 120 may be profiled with recesses or flanges that help with locating and restraining the compression member.

[0072] As will be appreciated, the compression member 122 is compressed under the application of a force which urges the first strut 118 towards the second strut 120. The durometer of the elastomeric block may vary depending on the degree of compression that is required. For example, if the chair to which the resilient hinge 110 is mounted is to be used by adults, a higher durometer may be preferred to allow for a greater resistance to the range of movement for the upper portion of the backrest. However, if small children are to use the chair, a lower durometer may be preferred since the likely force applied to the backrest may be less.

[0073] In alternative embodiments of the invention not shown here, the compression member may be in the form of a compression spring or the like. To maintain placement of the spring, its ends may engage or otherwise be connected to the biasing surfaces. Depending on the compressive qualities of the spring, it may be possible to provide the ability to customise the chair to particular users or age groups. James & Wells ref: 506607PCT

[0074] Returning to the illustrated embodiment, the hinge 110 also includes a linking member 124 which in use serves to connect the first and second struts 1 18, 120. As can be seen, the struts are configured with a lip 1 18b, 120b extending laterally towards the flexible region. The respective lips are profiled to receive the linking member.

[0075] Additionally, the linking member 124 is profiled with a protrusion 124a which in use engages with a recess 122a provided on the sides of the compression member 122. In this embodiment, this helps maintain the compression block in place even as it is deformed in response to the application of a force urging the first strut 1 18 towards to the second strut 120.

[0076] In this embodiment, the linking member 124 is a closed loop of steel or similar metal. However, it should be appreciated that it could be of any form and / or material that has sufficient strength properties is able to be placed in tension and maintain structural integrity when it is loaded.

[0077] For example, in an embodiment not shown here, the linking member may be in the form of a C-shaped length of metal; the ends of the C-shape profile may be inserted into grooves provided to the first and / or second struts. Alternatively, the linking member may be in the form of a I -shaped profile; one end of the profile may be fixed to one strut, while the other is positioned within a slot provided to the opposing strut. The length of the slot determines the range of movement allowed by the linking member. Persons skilled in the art will readily envisage other configurations for the linking member.

[0078] A cover or panel 128, seen in place on the opposing side of the chair in Figures 2 and 3, is provided to cover the mechanism of the hinge 1 10. This is desirable, and in many jurisdictions is a safety requirement, since it limits the possibility that users may place their fingers into the hinge and injure themselves. The cover also improves the overall aesthetic appearance of the chair.

[0079] As can be seen on the nearer cover 128 in Figure 3, its reverse side is configured with clips 128a which, in this embodiment, key in or otherwise engage with the linking member 124. However, it will be appreciated that one or both of the struts 1 18, 120 may be configured with recesses for the clips, so long as they allow James & Wells ref: 506607PCT for the relative movement of the hinge 1 10. Other arrangements for interlocking the cover with the back rest 104 will be readily envisaged by a person skilled in the art.

[0080] Turning now to Figures 4a and 4b, the manner in which movement of the backrest 104 of the chair 100 is controlled by the hinge 110 shall be made apparent. When the upper portion of the backrest is moved, as indicated by the large arrow A in Figure 4a, in the first direction, i.e. a rearward load is applied, the respective biasing surfaces (not labelled for sake of clarity) of the hinge are urged towards each other, thereby compressing the compression block 122 located therebetween. This serves to control the extent of the movement of the upper portion 104a of the backrest. Often this movement is as a result of the person using the chair reclining backwards.

[0081] Conversely, when the upper portion 104a of the backrest 104 is moved in the second direction, as indicated by the large arrow B in Figure 4b, the linking member (not labelled for sake of clarity) acts to control the extent of the movement of the upper portion of the backrest. This reduces the risk of damage to the chair 100 in the event excessive force or forward load, coming from the second direction, is applied to the upper portion of the backrest. This movement often arises from a person standing behind the chair leaning forwards while gripping the upper portion of the backrest, but may be any other scenario when the backrest is pushed or pulled forward relative to the seat of the chair. In some examples, not shown here, the cover (128 in Figure 3), may be configured with stops on its internal surfaces which act as stops or otherwise limit the extent of the compression of the compression block 122.

[0082] Another embodiment of the hinge 110 of the present invention is illustrated in Figures 5 and 6 in which like features from the previous embodiment described have the same reference numbers. In this embodiment, the cover 128 fulfils the function of the linking member, thus doing away with the separate metal closed loop structure of the embodiment of Figures 2 and 3. This is also advantageous from a manufacturing and inventory perspective, since fewer parts are required.

[0083] In this example, the cover 128 is injection or rotationally moulded, from a suitable plastics material, preferably the same plastics material used for the remainder of the backrest / seat shell of the chair with which it is to be used. This allows for continuity of the design aesthetic, particularly in texture and feel. James & Wells ref: 506607PCT

[0084] However, in some examples, the cover may be deliberately formed from plastics material of a greater strength / rigidity than that used for the remainder of the shell of the chair, bearing in mind the stresses that may be applied to the cover when it performs in its function as a linking member.

[0085] Referring to Figure 5, it will be seen that the first strut 118 is configured with an open recess 200, facing the flexible region 116 of the backrest 104 and forming a channel spanning the inner side of the strut. Similarly, the second strut 120 is also configured with an open recess 202. In use, the compression member 122 is disposed between the respective struts and concealed from view with the cover 128, the exterior side of which being configured to substantially match the profile of the chair surrounding the flexible hinge 1 10.

[0086] In Figure 6, it will be seen the interior side of the cover 128 is configured with a pair of protrusions 204, 206 which corresponding to the open recesses 200, 202 of the first strut 118 and second strut 120 respectively. When the cover is fitted is fitted in place such that the respective protrusions engage with their respective recesses, this serves to link the first and second struts. It should be noted that the dimensions of the respective protrusions and recesses are optimised to maximise surface area, i.e. contact area, for the overall functionality and longevity of the hinge 1 10.

[0087] It will be apparent in these views that the surfaces 118a, 120a of the first strut 1 18 and second strut 120 that contact the protrusions 204, 206 of the cover 128 are tapered, becoming wider towards the respective open recesses 200, 202. Similarly, the surfaces of the protrusions that contact the tapered surfaces of the first strut and second strut have a substantially complementary taper. In use, these features combine to serve as a ramp-like structure that positively guides the protrusions towards the recesses of the first strut and second strut as the cover is being applied.

[0088] As will be appreciated, when a rearward load is applied to the upper portion 104a of the backrest 104, this serves to urge the first 1 18 and second struts 120 together, bearing down upon the compression member 122 disposed between them. When a forward load is applied to the upper portion of the backrest, the protrusions 204, 206 of the cover 128, being engaged with their respective struts, serve to limit the movement of the upper portion of the backrest. James & Wells ref: 506607PCT

[0089] The cover 128 also includes a rib-like structure 208; this keys in with the recess 122a provided to the compression member 122. This may help with assembly and act to limit the movement of the compression, particularly when a forward load is applied to the upper portion 104a of the backrest that is sufficient for the upper side of the compression member to lose contact with the first strut 118. However in some examples not shown here, the compression member and the cover may be configured as an integral structure; in such examples, the compression member could be overmoulded to the interior surface of the cover. This has the advantage of a reduced part count.

[0090] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of "including, but not limited to".

[0091] Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

[0092] The invention may also be said broadly to consist in the parts, elements, characteristics and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements, characteristics or features.

[0093] The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference. Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world.

[0094] Aspects of the present invention have been described by way of example only. It should be noted that changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims, and without diminishing its attendant advantages.

Claims

James & Wells ref: 506607PCTClaims1. A chair moulded from plastic material and including a seat, backrest and at least a portion of a flexible hinge, and wherein the backrest includes a first, upper portion, and a second, lower portion, wherein the first portion of the backrest is movable relative to the second portion of the backrest in a first direction and an opposing second direction through the action of the flexible hinge, wherein the flexible hinge includes: a first strut associated with the first portion of the backrest, wherein the first strut includes a first biasing surface; a second strut associated with the second portion of the backrest, wherein the second strut includes a second biasing surface opposing the first biasing surface; a compression member located between the first and second biasing surfaces; a linking member connecting the first and second struts; and wherein movement of the first portion of the backrest in the first direction is limited by the compression member and movement of the first portion of the backrest in the opposing second direction is limited by the linking member.

2. The chair as claimed in claim 1, wherein the backrest, at least a portion of the flexible hinge, and the seat is configured as an integral one-piece component.

3. The chair as claimed in claim 1 , wherein a portion of the flexible hinge is provided as a separate component configured to be attached to the chair.

4. The chair as claimed in any one of claims 1 to 3, wherein the flexible hinge is located in the area of the backrest substantially corresponding to a lumbar region of the chair.

5. The chair as claimed in any one of claims 1 to 4, wherein the first strut is a substantially vertical post-like structure associated with the first portion of the backrest.James & Wells ref: 506607PCT6. The chair as claimed in claim 5, wherein the first strut is integrally formed with the first portion of the backrest.

7. The chair as claimed in claim 5, wherein the first strut is a separate component which is arranged to be secured to a suitably configured area of the first portion of the backrest.

8. The chair as claimed in any one of claims 5 to 7, wherein the first strut depends downward from the first portion of the backrest.

9. The chair as claimed in any one of claims 1 to 8, wherein the second strut is a substantially vertical post-like structure associated with the second portion of the backrest.

10. The chair as claimed in claim 9, wherein the second strut is integrally formed with the second portion of the backrest.1 1 . The chair as claimed in claim 9, wherein the second strut is a separate component which is arranged to be secured to a suitably configured area of the second portion of the backrest.

12. The chair as claimed in any one of claims 9 to 11 , wherein the second strut extends upward from the second portion of the backrest.

13. The chair as claimed in any one of claims 1 to 12, wherein each of the first and second struts are configured with an end having a flat surface, the flat surfaces opposing each other.

14. The chair as claimed in claim 13, wherein the flat surface of each of the first and second struts is the biasing surface of the respective struts.

15. The chair as claimed in any one of claims 1 to 14, wherein each of the first and second struts are configured with a recess configured to receive or otherwise engage with the linking member.

16. The chair as claimed in any one of claims 1 to 14, wherein each of the first and second struts is configured with a lip or hook-like structure configured to receive or otherwise engage with the linking member.James & Wells ref: 506607PCT17. The chair as claimed in any one of claims 1 to 16, wherein the compression member is a block of elastomeric material.

18. The chair as claimed in any one of claims 1 to 16, wherein the compression member is a compression spring.

19. The chair as claimed in any one of claims 1 to 18, wherein the compression member has a top side and a bottom side and wherein the top side and bottom side respectively of the compression member contacts the biasing surfaces of the first and second struts.

19. The chair as claimed in claim 19, wherein the biasing surfaces of the respective first and second struts are contoured, and wherein the compression member is configured with a complementary contoured surface.

20. The chair as claimed in any one of claims 1 to 19, wherein the linking member is a length of rigid material that is configured to engage with the first and second struts.21 . The chair as claimed in claim 20, wherein the linking member is a one-piece component with a first section having one or more pegs or similar protrusions extending therefrom, and a second section having one or more pegs or similar protrusions extending therefrom.

22. The chair as claimed in claim 21, wherein the one or more pegs of the first section engage with one or more recesses provided to the first strut and the one or more pegs of the second section engage with one or more recesses provided to the second strut.

23. The chair as claimed in either claim 21 or claim 22, wherein the linking member is configured as a cover for the flexible hinge, the cover having an exterior surface configured to substantially blend in with the backrest of the chair and an interior surface configured with the pegs or protrusions.

24. The chair as claimed in claim 23, wherein the interior surface of the cover is configured to be complementary to a surface of the compression member.James & Wells ref: 506607PCT25. The chair as claimed in either claim 23 or claim 24, wherein the interior surface of the cover is configured with one or more pegs or similar structures to key into one or more complementary surfaces provided to the compression member.

26. The chair as claimed in claim 20, wherein the linking member is a loop of metal with a first section engaging with an appropriate structure provided to the first strut and a second section engaging with a structure provided to the second strut.

27. The chair as claimed in claim 26, wherein a portion of the loop of metal is profiled to be complementary to a protrusion or recess provided to one or more sides of the compression member.

28. The chair as claimed in claim 27 or 26, wherein the chair includes a separate cover for the flexible hinge.

29. The chair as claimed in any one of claims 1 to 28, wherein the seat is provided with a plurality of legs.

30. The chair as claimed in claim 29, wherein the plurality of legs are integrally formed with a frame structure which is engaged with the seat.

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