Patent Publication Number: US-9901176-B2

Title: Chair and supports

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 14/348,874, filed Mar. 31, 2014, which is a nationalization of PCT Application No. PCT/NZ2012/000179, filed Oct. 4, 2012, which claims priority to U.S. Provisional Application No. 61/543,088, filed Oct. 4, 2011, which are incorporated herewith. 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to chairs and supports for use in chairs. More particularly, although not exclusively, the invention relates to reclining and rocking chairs suitable for domestic lounge use. 
     BACKGROUND TO THE INVENTION 
     Traditional reclining and/or rocking chairs are often large, heavy chairs that take up significant room. They also often have large housings that extend substantially to the floor to hide bulky mechanisms that provide the rocking and/or reclining action of the chairs. Such chairs often have extendible leg rests or supports which have bulky mechanisms, which again must be hidden in the large housings of the chair for aesthetic purposes and to hide potential pinch points from users. 
     In more recent times, lighter weight reclining lounge chairs have become available that do not have the large housings. Such chairs are generally mounted on pedestals. However, those chairs often have basic mechanisms that only provide limited functionality in the chair. Those reclining chairs have a less than optimal relationship between the seat and back. When the back of the chair is reclined, the relationship between the seat and back will generally be such that the user will not be comfortable in the chair, particularly over long periods. Such chairs also do not have built in extendible leg rests or supports, due to the lack of housing to hide the mechanisms of such supports. A purchaser generally needs to buy a separate stool or ottoman, if they want a leg support to match their chair. 
     Typical recliner mechanisms move the seat predominantly forward, so require a tension adjustment of the recline mechanism or a user activated recline lever to suit different user body sizes. 
     Some chairs have head rests or supports that are adjustable in position to suit a user. Most head rests can be raised or lowered in height relative to a chair back. Some can also be adjusted horizontally. Traditional head rests require the use of two separate actuators to initially adjust the vertical position of the head rest and then adjust the horizontal position of the head rest. This means the head rest adjustment is a two step process, and reduces the likelihood of the headrest position being adjusted. As a result, people may be inclined to use the head rests in a less than optimal position. Often, the user will not be able to adjust the head rest whilst seated due to high friction mechanisms and twin action adjusters, which means the user cannot switch between different head rest positions as needed when moving the chair between upright and reclined positions or when changing between tasks such as watching television and working on a laptop computer. 
     Some chairs have adjustable foot or leg rest arrangements. However, those arrangements typically only provide two or three discrete adjustment positions. A user may not be provided with optimal comfort with that restricted number of adjustment positions. 
     It is an object of at least preferred embodiments of the present invention to provide a chair or support that addresses at least one of the disadvantages outlined above, or that at least provides the public with a useful choice. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, there is provided a chair comprising: a supporting frame; a seat portion for supporting an occupant; a back portion for supporting the back of a seated occupant that has an upper end, a lower end, and is pivotally mounted to the supporting frame at a position above its lower end; and a recline mechanism configured to lift and move the seat portion forward upon a reclining action of the back portion, the recline mechanism comprising an operative connection between the seat portion and the supporting frame, and a drag link pivotally connected to the seat portion and pivotally connected to the back portion at a position below the pivotal mounting of the back portion to the supporting frame, the recline mechanism configured such that as the back portion of the chair is reclined, the lower end of the back portion moves forward and the drag link pulls the seat portion upward and forward relative to the supporting frame. 
     In an embodiment, the chair comprises a front operative connection between a relatively forward portion of the seat portion and the supporting frame. In an embodiment, the front operative connection comprises a slide arrangement comprising a track on one of the seat portion and the supporting frame, and a follower on the other of the seat portion and the supporting frame, with the follower arranged to travel in the track as the seat portion is moved upward upon recline of the back portion. In an embodiment, the chair comprises two front operative connections, one at or adjacent each side of the seat portion, and wherein each front operative connection comprises a slide arrangement comprising a track on one of the seat portion and the supporting frame, and a follower on the other of the seat portion and the supporting frame, with the follower arranged to travel in the track as the seat portion is moved upward upon recline of the back portion. 
     In an embodiment, the chair comprises a rear operative connection between a relatively rearward portion of the seat portion and the supporting frame. In an embodiment, the rear operative connection comprises a forward link that is pivotally connected to the supporting frame, a rearward link that is pivotally connected to the supporting frame, and a carrier link that is pivotally connected to the forward link and to the rearward link, wherein the carrier link is pivotally connected to the seat portion. In an embodiment, when the back portion is in an upright configuration, the forward link hangs downwardly and rearwardly from its pivot connection to the supporting frame, and the rearward link hangs downwardly and forwardly from its pivot connection to the supporting frame, and when the back portion is fully reclined, the forward link hangs generally downwardly from its pivot connection to the supporting frame, and the rearward link extends generally forwardly from its pivot connection to the supporting frame. 
     In an embodiment, the pivot connection of the carrier link to the seat portion is positioned rearwardly of the pivot connections of the forward link and rearward link to the carrier link. 
     In an embodiment, the pivot connection of the drag link to the seat portion is positioned generally above and generally behind the pivot connection of carrier link and the seat portion, when the back portion of the chair is not reclined. In an embodiment, the pivot connection of the drag link to the seat portion is positioned upwardly and rearwardly of the pivot connection of the carrier link and the seat portion, when the back portion of the chair is fully reclined. 
     In an embodiment, the chair comprises two rear operative connections, one at or adjacent each side of the seat portion, and wherein each rear operative connection comprises a forward link that is pivotally connected to the supporting frame, a rearward link that is pivotally connected to the supporting frame, and a carrier link that is pivotally connected to the forward link and to the rearward link, and that is pivotally connected to the seat portion. 
     In an embodiment, the operative connection(s) between the seat portion and the supporting frame is/are arranged such that the relatively forward and relatively rearward portions of the seat portion move upward and forward with a substantially linear movement as the back portion is reclined, with the amount of movement of the relatively rearward portion being greater than the amount of movement of the relatively forward portion, to provide a forward tilt of the seat portion as the back portion is reclined. The seat portion may have a rearward tilt angle when the back portion is upright, and the seat portion may have a smaller rearward tilt angle when the back portion is fully reclined. 
     In an embodiment, the upward movement of the relatively rearward portion of the seat portion may be greater than that of the relatively forward portion of the seat portion. 
     In an embodiment, the back portion comprises a central spine, and a compliant support surface supported by the spine for supporting the back of a seated occupant, wherein a lower portion of the spine is pivotally connected to the supporting frame, with a bottom portion of the spine pivotally connected to the drag link. The compliant support surface may comprise a resiliently flexible shell supported by the spine and a cushion supported by the shell. In an embodiment, the spine is resiliently flexible such that an upper end of the spine can be flexed rearwardly relative to a portion of the spine adjacent the pivot connection of the spine to the supporting frame. 
     In an embodiment, the spine is resiliently flexible so it can twist with a torsional action around a longitudinal axis of the spine, upon application of a suitable force by a seated occupant to the compliant support surface. 
     In an embodiment, the supporting frame comprises an intermediate support with a generally horizontally extending portion and a pair of rearward uprights, with the lower portion of the spine positioned between and pivotally connected to the uprights. In an embodiment, the seat portion comprises a seat frame and a support surface mounted to the seat frame for supporting a seated occupant, wherein the operative connection(s) between the seat portion and the supporting frame are connected between the intermediate support and the seat frame. 
     In an embodiment, the supporting frame comprises a main transom, an intermediate support, and a rocker mechanism that operatively connects the main transom and the intermediate support to provide a rocking motion therebetween, wherein the front and rear operative connections between the seat portion and the supporting frame are connected to the intermediate support. In an embodiment, the intermediate support, and thereby the seat portion, can be rocked between a rearwardly angled rearward rocked position and a forward rocked position. In an embodiment, the rocker mechanism comprises a front rocker arm pivotally connected to the main transom and to the intermediate support, and a rear rocker arm pivotally connected to the main transom and to the intermediate support. The front rocker arm and the rear rocker arm may hang downwardly, from their pivot connections to the main transom, at least when the rocker mechanism is in a neutral position. In an embodiment, when the intermediate support is in the rearward rocked position, the front rocker arm extends generally rearwardly from its pivot connection to the main transom, and the rear rocker arm extends generally downwardly from its pivot connection to the main transom, and when the intermediate support is in the forward rocked position, the front rocker arm extends generally downwardly from its pivot connection to the main transom, and the rear rocker am extends downwardly and forwardly from its pivot connection to the main transom. 
     In an embodiment, the front rocker arm is longer than the rear rocker arm. The pivot connection of the front rocker arm to the main transom may be positioned vertically higher than the pivot connection of the rear rocker arm to the main transom. 
     In an embodiment, the rocker mechanism comprises two front rocker arms and two rear rocker arms, positioned at or adjacent respective sides of the seat portion. 
     In an embodiment, the chair further comprises: an extendable foot or leg support assembly pivotally connected to the seat portion; and a rocking inhibitor arrangement to inhibit forward rocking of the intermediate support relative to the main transom when the foot or leg support assembly is extended. 
     In an embodiment, the rocking inhibitor arrangement is configured to automatically engage to inhibit forward rocking of the intermediate support when the foot or leg support assembly is extended, and to automatically disengage to allow forward rocking of the intermediate support when the foot or leg support assembly is retracted. 
     In an embodiment, the main transom or the intermediate support comprises one or more resiliently compressible stop(s) and the other of the main transom or intermediate support comprises one or more respective abutment surface(s) configured such that when the intermediate support is rocked sufficiently forward and/or rearward, the stop(s) are compressed against the respective abutment surface(s) to damp and limit the forward and/or rearward rock of the support. 
     In accordance with a second aspect of the present invention, there is provided a chair comprising: a supporting frame; a seat portion for supporting an occupant; a back portion for supporting the back of a seated occupant and that is reclinable from an upright position to a reclined position; a recline mechanism configured to lift the seat portion upon a reclining action of the back portion; and a pair of arm assemblies positioned one on either side of the seat portion, each arm assembly comprising an arm rest support that is mounted to the seat portion to move with the seat portion as the seat portion is moved by the recline mechanism, and an arm rest that is slidably mounted to the arm rest support, wherein the arm rests are operatively connected to the back portion such that as the back portion is reclined, the arm rests slide rearwardly on the arm rest supports. 
     In an embodiment, the back portion comprises a central spine, and a support surface supported by the spine for supporting the back of a seated occupant. 
     In an embodiment, the recline mechanism is configured to lift and move the seat portion forward upon a reclining action of the back portion. 
     In an embodiment, the supporting frame comprises a main transom, an intermediate support that operatively supports the seat portion and the back portion, and a rocker mechanism that operatively connects the main transom and an intermediate support to provide a rocking motion therebetween, wherein the arm rest supports are mounted to the seat portion to move as the seat portion is rocked by the rocker mechanism. The arm assemblies may alternatively be provided in a reclining chair that does not have a rocker mechanism. 
     In an embodiment, the seat portion comprises a seat frame and a support surface supported by the seat frame for supporting a seated occupant, and the arm rest supports are mounted to the seat frame. 
     In an embodiment, the arm rest supports are mounted to the seat portion so that the orientations of the arm rest supports relative to the seat portion are fixed. 
     In an embodiment, lower portions of the arm rest supports are pivotally connected to the seat portion, the arm rest supports configured such that the orientations of the arm rest supports relative to the seat portion change for at least part of the reclining action of the back portion. 
     In an embodiment, in each arm assembly, either the arm rest or the arm rest support comprises one or more bearing members, and the other of the arm rest or arm rest support comprises one or more complementary elongate slots for receiving the bearing member(s), the one or more elongate slot(s) extending in the direction of movement of the arm rest on the arm rest support. 
     In an embodiment, the back portion comprises a resiliently flexible shell to support an occupant&#39;s back, with upper body contacting surfaces of the arm rests being resiliently flexible and formed by, or connected to, part of the resiliently flexible shell. In an embodiment, the resiliently flexible shell comprises a central main back supporting portion, and elongate arm rest portions, one on either side of the central main back supporting portion, wherein rear ends of the elongate arm rest portions are connected to the central main back supporting portion and forward ends of the elongate arm rest portions form the upper body contacting surfaces of the arm rests. In an embodiment, rear portions of the elongate arm rest portions are arcuate when the back portion of the chair is in an upright position, and are substantially flat when the back portion of the chair is reclined. 
     In accordance with a third aspect of the present invention, there is provided a head or neck support assembly for a chair, the head or neck support assembly comprising: a base for mounting the head or neck support assembly to a chair; a first member that is rotatable relative to the base about a first axis; a second member that is rotatable relative to the base about a second axis that is substantially parallel to the first axis; a first linkage arrangement comprising a first pair of generally parallel arms that have first ends that are pivotally connected to the first member about axes that are substantially perpendicular to the first axis and that have second ends; a second linkage arrangement comprising a second pair of generally parallel arms that have first ends that are pivotally connected to the second member about axes that are substantially perpendicular to the second axis and that have second ends; and a head or neck support that is operatively supported by the second ends of the generally parallel arms of the first and second linkage arrangements, wherein the head or neck support is moveable relative to the base with two substantially perpendicular degrees of freedom. 
     In an embodiment, the second ends of the first pair of generally parallel arms are moveable toward and away from the second ends of the second pair of generally parallel arms, upon movement of the head or neck support relative to the base. 
     In an embodiment, the second ends of the first pair of generally parallel arms are pivotally connected to a first support link about axes that are substantially parallel to the pivot axes between the parallel arms and the first member, and the second ends of the second pair of generally parallel arms are pivotally connected to a second support link about axes that are substantially parallel to the pivot axes between the parallel arms and the second member, and wherein the first and second support links being rotatable relative to the head or neck support, with the rotation axes of the first and second support links relative to the head or neck support being substantially parallel to the rotation axes of the first and second members relative to the base. In an embodiment, the first and second members are operatively coupled such that as the first member is rotated in one direction relative to the base, the second member rotates a corresponding amount in an opposite direction relative to the base, and wherein the rotating of the first and second members causes corresponding movement of the first and second linkage arrangements about the first and second axes relative to the base and rotation of the first and second support links relative to the head or neck support, with corresponding movement of the first and second support links toward or away from one another. In an embodiment, the head or neck support comprises a housing containing a first toothed rack that is coupled to the first support link, a second toothed rack that is coupled to the second support link, and a pinion gear that is rotatably mounted to the housing and engaged with the first and second toothed racks, wherein movement of the first and second support links toward and away from one another moves the toothed racks, with the racks and pinion gear linking the movement of the first and second support links. 
     In an embodiment, the head or neck support assembly comprises a locking mechanism to selectively inhibit movement of the first and second members and the first and second linkage arrangements and thereby maintain the head or neck support in a desired position. In an embodiment, the head or neck support assembly comprises a locking member that selectively inhibits pivoting of the first pair of generally parallel arms relative to the first member and that selectively inhibits rotation of the first member relative to the base. In an embodiment, the first pair of generally parallel arms are pivotally connected to a first support link, wherein the locking member is carried by the first support link and is engageable with one of the first pair of generally parallel arms to inhibit pivoting of the first pair of generally parallel arms relative to the first support link and thereby inhibit pivoting of the first pair of generally parallel arms relative to the first member. In an embodiment, an engagement surface is provided on one of the first pair of generally parallel arms, and the locking member comprises a complementary engagement surface for engaging with the engagement surface on one of the first pair of generally parallel arms. 
     In an embodiment, the head or neck support comprises a housing containing a first toothed rack that is rotatably connected to the first support link, and wherein the locking member is engageable with the first toothed rack to inhibit rotation of the first support link relative to the first toothed rack, thereby inhibiting rotation of the first member relative to the base. In an embodiment, the toothed rack comprises a body having an aperture and an engagement surface, and the locking member extends through the aperture in the body of the toothed rack and through an aperture in the first support link and is moveable only axially relative to the first support link, and wherein the locking member comprises a complementary engagement surface for engaging with the engagement surface on the toothed rack to inhibit rotation therebetween. 
     In an embodiment, the locking member is configured such that when moving the locking member from an unlocked position to a locked position, the locking member initially inhibits pivoting of the first pair of generally parallel arms relative to the first member and then inhibits rotation of the first member relative to the base. In an embodiment, the locking member comprises a first locking member portion for inhibiting pivoting of the first pair of generally parallel arms relative to the first member, a second locking member portion for inhibiting rotation of the first member relative to the base, and a biasing device between the first locking member portion and the second locking member portion. 
     In an embodiment, the head or neck support assembly comprises a second locking member that selectively inhibits pivoting of the second pair of generally parallel arms relative to the second member and that selectively inhibits rotation of the second member relative to the base. In an embodiment, the head or neck support comprises an unlock plate with a pair of slots in which the locking members are slidably mounted such that the first and second support links can move toward and away from one another, and at least one actuation lever for actuating by a user, wherein actuation of the actuation lever moves the unlock plate and disengages the locking members to enable the position of the head or neck support to be adjusted. In an embodiment, the head or neck support assembly comprises a biasing device to bias the lever and thereby the unlock plate into a position in which the locking members are engaged to inhibit movement of the head or neck support. 
     In an embodiment, the head or neck support assembly comprises two actuation levers for actuating by a user, wherein actuation of either or both actuation levers moves the unlock plate and disengages the locking members to enable the position of the head or neck support to be adjusted. In an embodiment, it is sufficient to actuate one of the actuation levers to disengage the locking members to enable the position of the head or neck support to be adjusted. In an alternative embodiment, it is necessary to actuate both of the actuation levers to disengage the locking members to enable the position of the head or neck support to be adjusted. The actuation levers may be positioned adjacent respective sides of the head or neck support. In an embodiment, the actuation levers are arranged for actuation from a rear of the head or neck support. In an alternative embodiment, the actuation levers are arranged for actuation from a front of the head or neck support. 
     In an embodiment, the head or neck support assembly is mounted to a chair having a back portion with a central spine, wherein the base and the central spine are integral. Alternatively, the base may be separately formed from the central spine, and may be mounted to the back portion by being connected to the spine. Alternatively, the base may be connectable to, or integrally formed, with a part of the back portion other than the spine, for example a frame member or shell of the back portion. 
     In accordance with a fourth aspect of the present invention, there is provided an adjustable support arrangement for a chair comprising: a flexible mounting assembly comprising an elongate flexible closure and tension members for movably attaching the support arrangement to a frame or relatively rigid member; a slider arrangement comprising a first slider portion and a second slider portion in fixed relation, the slider portions being slidable together along the closure to open and close a portion of the closure; and a support member operatively connected to the slider arrangement; wherein the support member is adjustable to a plurality of positions between first and second end positions by sliding the slider portions along the closure. 
     In an embodiment, the first slider portion and the second slider portion are integrally formed. Alternatively, the first slider portion and the second slider portion may be separately formed, but configured to move together with movement of the support member. 
     In an embodiment, the closure comprises two opposite, engagable sides that engage to close or partially close the respective closure. 
     In an embodiment, the opposing sides of each closure each comprise a plurality of engagable teeth. The closure may comprise a zipper with first and second slider portions. Alternatively, the opposing sides of the closure may comprise a cooperating projection and recess. 
     In an embodiment, portions of the closure externally of the first and second slider portions are closed. A portion of the closure between the first and second slider portions may form an opening. 
     The support arrangement may comprise a second elongate closure that is substantially parallel to the first elongate closure, and wherein the slider arrangement comprises third and fourth slider portions that are slidable together along the further second closure. The second elongate closure may have any one or more of the features outlined in relation to the first closure. The first and second closures could be the same, or could differ. 
     In an embodiment, the support arrangement further comprises a carriage wherein the slider portions are fixed to the carriage and the support member is operatively connected attached to the support carriage. In an embodiment, the slider portions are connected to the carriage by way of a snap connection. 
     In an embodiment, the support member is removably attached to the carriage. The support member may, for example, be connected to the carriage by way of a snap connection. 
     In an embodiment, the mounting assembly comprises a flexible load dispersion panel for attachment to the front surface of a cushioned support. 
     In an embodiment, the support member is a head or neck support and the support member is height adjustable relative to the mounting assembly. In an alternative embodiment, the support member is a lumbar support and the support member is height adjustable relative to the mounting assembly. 
     In accordance with a fifth aspect of the present invention, there is provided a chair comprising: a seat portion for supporting an occupant; a back portion for supporting the back of a seated occupant; and an adjustable support arrangement as outlined in relation to the fourth aspect above; wherein the mounting assembly is attached to the back portion. 
     In an embodiment, the back portion is upholstered and the upholstery comprises an elongate aperture substantially parallel to the closure(s), and wherein the slider arrangement comprises a carriage with a forwardly protruding connector portion that protrudes through the aperture for connection to the support member. 
     In accordance with a sixth aspect of the present invention, there is provided an adjustable support arrangement for a chair back portion comprising a cushioned portion and an upholstery layer, the adjustable support arrangement comprising: a flexible mounting assembly, the mounting assembly comprising a flexible support rail and a flexible load dispersion panel arranged to be positioned between the front surface of the cushioned portion and a back surface of the upholstery layer; a slider arrangement being slidable along the support rail; and a support member operatively connected to the slider arrangement; wherein the support member is adjustable to a plurality of positions between first and second end positions by sliding the slider arrangement along the support rail, and wherein the flexible load dispersion panel is arranged to disperse a user&#39;s load from the support member across the cushioned portion. 
     In an embodiment, the flexible support rail comprises an elongate closure. 
     In an embodiment, the load dispersion panel is configured for attachment to the front surface of the cushioned portion. In an embodiment, the load dispersion panel comprises a woven or non-woven fabric. 
     In an embodiment, the back attachment assembly further comprises tension members for movably attaching the support arrangement to the relatively rigid portion. 
     In an embodiment, the support member is a head or neck support and the support member is height adjustable relative to the mounting assembly. In an alternative embodiment, the support member is a lumbar support and the support member is height adjustable relative to the mounting assembly. 
     The support arrangement may have any one or more of the features outlined in relation to the fourth aspect above. 
     In accordance with a seventh aspect of the present invention, there is provided a chair comprising: a seat portion for supporting an occupant; a back portion for supporting the back of a seated occupant; and an adjustable support arrangement as outlined in relation to the sixth aspect above, wherein the back portion comprises a rear relatively rigid portion and a cushioned portion and the mounting assembly is attached to a front surface of the cushioned portion. 
     In an embodiment, the flexible load dispersion panel is attached to the front surface of the cushioned portion by an adhesive, and is positioned behind an upholstery layer. 
     In an embodiment, the mounting assembly comprises tension members that extend through apertures in the cushioned portion and attach to the relatively rigid portion of the back portion. 
     This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features. 
     The term “comprising” as used in this specification means “consisting at least in part of”. When interpreting each statement in this specification that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner. 
     As used herein the term “and/or” means “and” or “or”, or both. 
     As used herein “(s)” following a noun means the plural and/or singular forms of the noun. 
     It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. 
     The invention consists in the foregoing and also envisages constructions of which the following gives examples only. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more fully understood, some embodiments will now be described by way of example with reference to the accompanying figures in which: 
         FIG. 1  is a side view of a chair in accordance with a preferred form of the present invention, in a neutral rock, no recline position with the leg or foot support assembly retracted and when that chair is unoccupied; 
         FIG. 2  is a side view similar to  FIG. 1 , but once the chair is occupied; 
         FIG. 3  is a side view similar to  FIG. 2 , but with the chair in a forward rocked position; 
         FIG. 4  is side view similar to  FIG. 3 , but with the chair in a rearward rocked position; 
         FIG. 5  is a side view of the chair of  FIG. 1  in a neutral rock, half reclined and occupied position, with the leg or foot support assembly extended; 
         FIG. 6  is a side view similar to  FIG. 5 , but with the chair in a fully reclined position; 
         FIG. 7  is a side view similar to  FIG. 6 , but with the chair in a rearward rocked position; 
         FIG. 8  is a side view similar to  FIG. 7 , but with the foot or leg support assembly retracted; 
         FIG. 9  is a side view of the skeleton of the chair, in a position similar to  FIG. 1 , but with the chair in a forward rocked position; 
         FIG. 10  is a perspective view corresponding to  FIG. 9 ; 
         FIG. 11  is a side view of the skeleton of the chair, in a position corresponding to  FIG. 5 ; 
         FIG. 12  is a side view of the skeleton of the chair, in a position corresponding to  FIG. 7 ; 
         FIG. 13  is a perspective view corresponding to  FIG. 12 ; 
         FIG. 14  is a side view of the cantilevered support frame of the chair, in a position corresponding to the chair being unoccupied; 
         FIG. 15  is a side view similar to  FIG. 14 , but in a position corresponding to the chair being occupied; 
         FIGS. 16A to 16C  show examples of possible configurations of the resilient member of cantilevered support frame; 
         FIG. 17  is an exploded perspective view of the swivel of the cantilevered support frame of  FIGS. 14 and 15 , showing part of the cantilevered support; 
         FIG. 18  is a sectional view through the swivel of the cantilevered support frame of  FIGS. 14 and 15 ; 
         FIG. 19  is a side view of part of the recline mechanism of the chair, when the back portion is in an upright position; 
         FIG. 20  is a part sectional view corresponding to  FIG. 19 ; 
         FIG. 21  is a side view similar to  FIG. 19 , but when the back portion is partly reclined; 
         FIG. 22  is a part sectional view corresponding to  FIG. 21 ; 
         FIG. 23  is a side view similar to  FIG. 19 , but when the back portion is fully reclined; 
         FIG. 24  is a part sectional view corresponding to  FIG. 23 ; 
         FIG. 25  is a side view of part of the rocker mechanism of the chair, when the intermediate support is in a neutral rock position; 
         FIG. 26  is a side view similar to  FIG. 25 , but when the intermediate support is in a forward rocked position; 
         FIG. 27  is a side view similar to  FIG. 25 , but when the intermediate support is in a rearward rocked position; 
         FIGS. 28A to 28C  are partial sectional views through the cantilevered support frame showing the rocker mechanism connecting the intermediate support frame, and a rock stop arrangement for limiting forward and rearward rock of the intermediate support frame, with FIG.  28 A showing the intermediate frame rocked rearward and the front intermediate frame stop compressed,  FIG. 28B  showing the intermediate frame in a neutral rock position, and  FIG. 28C  showing the intermediate frame rocked forward and the rear intermediate frame stop compressed; 
         FIG. 29  is a side view of the chair when the back portion is in a neutral rock, upright position, showing the forward sliding position of the arm rests; 
         FIG. 30  is a side view corresponding to  FIG. 29 , with the chair rocked rearward and the back portion is reclined, with a corresponding rearward slide of the arm rests; 
         FIG. 31  is a sectional view through one of the arm rest assemblies; 
         FIG. 32  is an exploded perspective view of one of the arm rest assemblies; 
         FIG. 33  is an underside view of one of the arm rest assemblies; 
         FIG. 34  is a side view of one of the arm rest assemblies; 
         FIG. 35  is an overhead view of the back portion of the chair, schematically showing the twisting action of the back portion; 
         FIG. 36  is a side view of the chair, schematically showing the rearward flexing of the upper end of the back portion, with the rearward flexed position shown in broken lines; 
         FIG. 37  is a left side view of the foot or leg support assembly of the chair when the foot or leg support member is retracted; 
         FIG. 38  is a left side view of the foot or leg support assembly of  FIG. 37  when the foot or leg support member is partially extended; 
         FIG. 39  is a left side view of the foot or leg support assembly of  FIG. 37  when the foot or leg support member is extended; 
         FIG. 40  is an underside perspective view of the underside of the foot or leg support assembly of  FIG. 37  in an extended position; 
         FIG. 41  is an elevation view normal to the support frame of part of the foot or leg support assembly of  FIG. 37  in an un-extended position; 
         FIG. 42  is a view normal to the support frame of part of the foot or leg support assembly of  FIG. 37  in a fully extended position; 
         FIG. 43  is a chart showing the relationship between the gas spring extension required for various angular displacements of the foot or leg support frame for the foot or leg support assembly of  FIGS. 37 to 42 ; 
         FIG. 44  is a section view taken through a centreline of the foot or leg support assembly when the foot or leg support member rest is retracted 
         FIG. 45  is similar view to  FIG. 44 , but with the foot or leg support member in a substantially vertical position when the chair is upright; 
         FIG. 46  is similar view to  FIGS. 44 and 45 , but with the foot or leg support member fully extended; 
         FIG. 47  is an overhead front perspective view of a rocking inhibitor arrangement comprising an anti-rock ratchet assembly to inhibit forward rocking of the intermediate support when the foot or leg support is extended and a lock assembly to selectively lock the rock of the seat independent of the position of the foot or leg support, in a configuration where the foot or leg support is extended and forward rocking is prevented; 
         FIG. 48  is a perspective view corresponding to  FIG. 47  of the underside of the rocking inhibitor arrangement of  FIG. 47 ; 
         FIG. 49  is a partially exploded perspective view of the rock inhibitor arrangement of  FIG. 47 , showing the central slide member removed; 
         FIG. 50  is an overhead exploded perspective view of the anti-rock ratchet assembly of the rock inhibitor arrangement of  FIG. 47 ; 
         FIG. 51  is an underside exploded perspective view of the anti-rock ratchet assembly of  FIG. 50 ; 
         FIG. 52A  is a bottom view of the anti-rock ratchet assembly of the rocking inhibitor arrangement of  FIG. 47 , in a configuration where the foot or leg support is retracted and forward rocking is enabled; 
         FIG. 52B  is a view corresponding to  FIG. 52A , but in a configuration where the foot or leg support is extended and forward rocking is prevented; 
         FIG. 53A  is an enlarged plan view of the engagement teeth of the anti-rock ratchet assembly of  FIG. 47  when the foot or leg support has been extended but the teeth on the pawl and ratchet are not aligned and engagement of the teeth is delayed by a biasing device; 
         FIG. 53B  is a view corresponding to  53 A but with the seat portion rocked slightly forward of the position of  FIG. 53A , with the ratchet and pawl teeth partly engaged; 
         FIG. 53C  is a view corresponding to  53 B but with the seat portion rocked slightly forward of the position of  FIG. 53B , with the ratchet and pawl teeth fully engaged to prevent forward rocking; 
         FIG. 54  is an overhead exploded perspective view of the lock assembly of the rock inhibitor arrangement of  FIG. 47 ; 
         FIGS. 55A  and B are top and bottom perspective views respectively of the rock lock detent pawl; 
         FIGS. 56A to 56G  are partial overhead views showing the operation of the rock lock assembly, with  FIG. 56A  showing the rock lock in a released configuration with the seat portion free to rock,  FIG. 56B  showing the rock lock during actuation with locking delayed due to misaligned engagement teeth on the central slide member,  FIG. 56C  corresponding to  FIG. 56B  but when the user has released the actuator and the detent pin is in a locked position,  FIG. 56D  showing the seat portion rocked slightly forward from its position in  FIGS. 56B  and C and the lock biased into engagement with the teeth on the central slide member,  FIG. 56E  showing the detent pin moved into the unlocked position during actuation by user to unlock the rock lock,  FIG. 56F  showing the detent pin returned to the unlocked position but retraction of the lock pawl delayed due to frictional force, and  FIG. 56G  showing the lock pawl retracted and the rock lock in the released configuration with the seat portion free to rock; 
         FIG. 57  shows the rocking inhibitor arrangement of  FIG. 47  positioned in the transom of the chair; 
         FIG. 58  is a rear perspective view of a first preferred form head or neck support assembly of the chair; 
         FIGS. 59A  to F show some of the possible adjustment positions of the head or neck support assembly; 
         FIG. 60  is a rear perspective view similar to  FIG. 58 , but with some of the components removed for clarity; 
         FIG. 61A  is a front view of some of the components of the head or neck support assembly, when in a raised position, and  FIG. 61B  is a front view, when in a lowered position; 
         FIG. 62A  is a view corresponding to  FIG. 61A  but from behind, and  FIG. 62B  is a view corresponding to  FIG. 61B  but from behind; 
         FIG. 63A  is an overhead section view of some of the components of the head or neck assembly, when in a forward position, and  FIG. 63B  is an overhead section view, when in a rearward position; 
         FIG. 64  is an overhead exploded view of some of the components of the head or neck support; 
         FIG. 65  is a rear view of the head or neck support assembly, with the head or neck support housing removed showing section line H-H; 
         FIG. 66  is a horizontal cross-section view taken through line H-H of  FIG. 65 , with the locking members in an unlocked position; 
         FIG. 67  is a view similar to  FIG. 66 , but with the locking members in an initial locking position in which they inhibit forward or rearward movement of the support member; 
         FIG. 68  is a view similar to  FIG. 67 , but with the locking members in a fully locking position in which they inhibit both forward or rearward, and up or down, movement of the support member; 
         FIG. 69A  is a section view similar to the sectional view of  FIG. 68 , but with the head or neck support assembly in a forward position and showing the head or neck support housing; 
         FIG. 69B  is a sectional perspective view similar to the sectional view of  FIG. 69A ; 
         FIGS. 70A to 70C  are enlarged detail section views of one of the locking mechanisms shown in  FIGS. 66 to 68 ;  FIG. 70A  corresponds the un-locked position of  FIG. 66 ,  FIG. 70B  corresponds the locking position of  FIG. 67 ,  FIG. 70C  corresponds the locking position of  FIG. 68 ; 
         FIG. 71  is a perspective view of one of the linkage arrangements of the head or neck support assembly; 
         FIG. 72  is a front perspective view of the head or neck support assembly with some parts removed for clarity; 
         FIG. 73  is an exploded view of the assembly shown in  FIG. 72 ; 
         FIG. 74  is front exploded view of part of the head or neck support assembly; 
         FIG. 75  is view corresponding to  FIG. 74  but from the rear; 
         FIG. 76  is a top view of the lever assembly for the neck or head support assembly; 
         FIG. 77  is a front exploded view corresponding to  FIG. 76 ; 
         FIG. 78  is a horizontal cross-section view through a second preferred form head or neck support assembly, with the locking members in an unlocked position; 
         FIG. 79  is rear exploded view of part of the head or neck support assembly of  FIG. 78 ; 
         FIG. 80  is a top view of the lever assembly for the neck or head support assembly of  FIGS. 78 and 79 ; 
         FIG. 81  is a front exploded view corresponding to  FIG. 80 ; 
         FIGS. 82A to 82C  are top views of the levers of the lever assembly of  FIGS. 78 to 81 , with  FIG. 82A  showing the lever position when the head or neck support assembly is locked,  FIG. 82B  showing the lever position when the head or neck support assembly is partially locked; and  FIG. 82C  showing the lever position when the head or neck support assembly is unlocked and free to be repositioned; 
         FIG. 83  is a perspective view of a second preferred form chair incorporating a height adjustable head or neck support assembly; 
         FIG. 84  is a side view of the chair of  FIG. 83 ; 
         FIG. 85  is a left side section view through the chair of  FIGS. 83 and 84 ; 
         FIG. 86  is a perspective view of a preferred form height adjustable head or neck support assembly for attaching to a high back chair such as that shown in  FIGS. 83 and 84 , showing the head or neck support member in its highest position; 
         FIG. 87  is a perspective view of the head or neck support assembly shown in  FIG. 86 , showing the head or neck support member in its lowest position; 
         FIG. 88  is a section view of the head or neck support assembly of  FIGS. 86 and 87 , taken through a vertical centreline of  FIG. 86 ; 
         FIG. 89  is an exploded perspective view of the mounting assembly and slider arrangement of the head or neck support assembly of  FIGS. 86 to 88 ; 
         FIG. 90  is a front view of the double zipper member and attached sliders of the mounting assembly of  FIGS. 86 to 89 ; 
         FIG. 91  is a front view of a double zipper member and attached sliders for a mounting assembly according to an alternative embodiment; 
         FIG. 92A  is a perspective view of the slider carriage of the support assembly of  FIGS. 86 to 88 , with two sliders unattached; 
         FIG. 92B  is a plan view of the slider carriage arrangement in  FIG. 92A ; 
         FIG. 92C  is a section view taken along A-A of  FIG. 92B ; 
         FIG. 93A  is a perspective view of the slider carriage of  FIGS. 92A to 92C , with the two sliders being pressed into place during assembly; 
         FIG. 93B  is a plan view of the slider carriage arrangement in  FIG. 93A ; 
         FIG. 93C  is a section view taken along B-B of  FIG. 93B ; 
         FIG. 94A  is a perspective view of the slider carriage of  FIGS. 92A to 93C , with the sliders attached to the carriage; 
         FIG. 94B  is a plan view of the slider carriage arrangement in  FIG. 94A ; 
         FIG. 94C  is a section view taken along C-C of  FIG. 94B ; 
         FIG. 95A  is a front view of the head or neck support of  FIGS. 86 to 88 ; 
         FIG. 95B  is a rear view of the head or neck support of  FIG. 95A ; 
         FIG. 96A  is the view of  FIG. 95B , indicating section line D-D; 
         FIG. 96B  is section view taken along D-D of  FIG. 96A ; 
         FIG. 96C  is an enlargement of the detail B in  FIG. 96B ; 
         FIG. 97  is a front view of the mounting assembly of  FIG. 86 to 89 , illustrating assembly and stitching of the load dispersion panel, double zipper member and trim strip; 
         FIG. 98A  is a rear perspective view of the back attachment assembly shown in  FIGS. 86 to 89 ; 
         FIG. 98B  is an exploded perspective view of the back attachment assembly of  FIG. 98A ; 
         FIG. 99A  is a front elevation of the back attachment assembly of  FIG. 98A ; 
         FIG. 99B  is a front perspective view of the back attachment assembly of  FIG. 98A ; 
         FIG. 99C  is a side elevation of the back attachment assembly of  FIG. 98A ; 
         FIG. 99D  is a rear elevation of the back attachment assembly of  FIG. 98A ; 
         FIG. 100  is an exploded perspective view showing assembly of the head or neck support assembly of  FIGS. 86 to 89  to the back portion of the high-back chair of  FIGS. 83 and 84 ; 
         FIG. 101  is a rear perspective view showing the ends of the straps on the back attachment assembly of  FIGS. 98A to 99D  protruding through the back cushion for attaching to the chair back shell; 
         FIG. 102  is a partial front perspective view showing attachment of the load dispersion panel to the back cushion; 
         FIG. 103  is a partial front perspective view of the upholstery on the chair back portion assembled over the mounting assembly of  FIG. 97 , with the support connecting portion of the slider carriage exposed by a slot in the upholstery; 
         FIG. 104A  is a partial exploded view showing attachment of the head or neck support to the upholstery covered mounting assembly of  FIG. 103 ; and 
         FIG. 104B  is a front perspective view showing the head or neck support attached to the upholstery covered mounting assembly of  FIGS. 103 and 104A , showing the head or neck support adjusted to an upper position. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED FORMS 
       FIGS. 1 to 8  show a reclining domestic lounger chair according to a preferred embodiment of the present invention. The chair comprises a supporting frame  1  including a base assembly  3 , a seat portion  101  for supporting a seated occupant, a back portion  201  for supporting the back of a seated occupant, arm rests  301  for supporting the arms of a seated occupant, an adjustable head or neck rest or support assembly  401  and an extendable and retractable foot or leg rest or support assembly  501 . 
     The chair additionally has a recline mechanism configured to lift the seat portion  101  relative to an intermediate support of the supporting frame  1  upon a reclining action of the back portion  201 , and a rocker mechanism that operatively connects a main transom of the supporting frame and the intermediate support of the supporting frame, to provide a rocking motion therebetween. These features will be described in further detail below. 
     The mechanisms and features operate together to provide a large number of possible occupant supporting configurations of the chair, some of which are shown in  FIGS. 1 to 13 . The rocker mechanism enables the body supporting surfaces of the chair (including the seat portion, back portion, foot or leg support, head or neck support, and arm rests) to rock forward and rearward relative to the base assembly  3 , for example between a forward rocked position shown in  FIG. 3 , a neutral rock position shown in  FIG. 2 , and a full rearward rocked position shown in  FIG. 4 . The recline mechanism enables the back portion  201  of the chair to be reclined from an upright position shown in  FIG. 2 , through a partly reclined position shown in  FIG. 5 , to a fully reclined position shown in  FIG. 6 . The rocker mechanism is configured such that the chair can be rocked by a seated occupant whether the back portion is in the upright, partly reclined, or fully reclined position. The foot or leg support can be extended or retracted in any position of the back portion. Similarly, the head or neck support can be adjusted in position in any rocked or reclined position of the chair. Therefore, the configurations shown in  FIGS. 1 to 13  are only some of the possible occupant supporting configurations of the chair, and other configurations are possible. 
     Since the figures illustrate the preferred form chairs from various different angles as convenient to explain certain parts, an arrow marked “F” has been inserted into the figures where appropriate to indicate a forward direction of the chair. Accordingly the terms forward, rearward, left side, and right side (or similar) should be construed with reference to the forward direction F of the chair, not necessarily with reference to the orientation shown in the particular figure. 
     The features of the preferred form chairs are described and shown herein to give a full understanding of the components and operation of the preferred form chair. It will be appreciated that not all of the features described herein need be provided in every chair. 
     Base 
     The lower part of the supporting frame  1  comprises a base  3  for supporting the chair on a support surface. Referring to  FIGS. 10 to 18 , the base has a plurality of radially extending legs  5  that intersect at a hub  7 . The base can have any suitable number of legs, but preferably has at least three legs to provide the required level of support and balance to the chair on the support surface. In the preferred form shown, the base has four equally angularly spaced legs, but the base could have five or more legs. A base upright  9  extends at a non-perpendicular angle upwardly and forwardly from the hub  7 , and at its upper end has a support  11  that extends forwardly at a flatter angle than the majority of the upright  9  of the base. A pivot connection  13  is provided on each side of the support at a forward end thereof, and a main transom  15  is connected to the support  11  at the pivot connections  13 , with the main transom cantilevered rearwardly from its connection to the support  11 . The seat portion, back portion, recline mechanism, and rocker mechanism are supported either directly or indirectly on the main transom. 
     The main transom  15  may be supported from the base by at least one resilient member  17  that is arranged to deform and allow generally downward movement of the main transom to absorb initial impact as an occupant sits on the seat portion. This provides a ‘plonk’ feature, and avoids the hard impact that would generally be experienced when an occupant initially sits on a conventional chair. In the form shown, the supporting frame has two elastomeric blocks  17  that are provided between the main transom  15  and the support  11 , one elastomeric block positioned at or toward each side of the support  11 . The elastomeric blocks are positioned between the main transom and the base at a position spaced from the pivot connections  13 . The elastomeric blocks are compressed between engagement surfaces  11   a  on the support and engagement surfaces  15   a  on the main transom, as an occupant sits on the seat portion  101 . The elastomeric block(s) or other resilient member(s) may have cut-outs, apertures, or weakened areas to change the amount of deformation force with respect to deformation. 
       FIG. 14  shows the position of the main transom  15  relative to the support  11  before an occupant sits on the seat portion, with the main transom being substantially horizontal (i.e. typically at an angle of about zero degrees).  FIG. 15  shows the position of the main transom  15  relative to the support  11  after an occupant sits in the seat portion, with the main transom pivoted downwardly and rearwardly about the pivot connections  13  to be rearwardly tilted from horizontal at an angle of about 8 degrees. The elastomeric blocks provide an increasing resistance to the pivoting of the main transom as it moves, to provide a soft landing as the occupant sits down on the seat portion. As shown in  FIG. 15 , a spacing is preferably provided between the sides of the support  11 , so that part of the main transom  15  can pass between the sides of the support  11  as the occupant sits on the seat portion. 
     The elastomeric blocks  17  or other resilient members could be solid with sufficient compressibility to give the required plonk, or could be shaped in such a way as to give the required deflection using less material. Such shapes might include cylindrical cross sections which deform in the radial direction or honeycomb matrixes where the honeycombs collapse.  FIGS. 16A to 16C  show three example configurations of the elastomeric blocks  17 .  FIG. 16A  shows a ‘ FIG. 8 ’ configuration having two adjacent hollow cylinders  17   a  with respective apertures  17   b , and an interconnecting region  17   c .  FIG. 16B  shows a tapered arrangement having a polygonal exterior shape  17   d  with at least one internal web  17   e , and a plurality of apertures  17   f .  FIG. 16C  shows a cellular matrix form having a plurality of polygonal cells  17   g , and in the form shown square cells, defining respective apertures  17   h.    
     Alternatively, rather than being pivotally connected, the transom  15  may be rigidly fixed to the base upright  9 . In one embodiment, the transom  15  and the upright  9  may be integral. 
     Base Swivel 
     The base  3  of the supporting frame  1  is preferably configured so that the upright  9  and thereby the main transom  15  and the components supported by the main transom  15  are rotatable about a substantially vertical axis relative to the support surface engaging portion of the base. The hub  7  may be configured as shown in  FIGS. 17 and 18 . 
       FIGS. 17 and 18  show a preferred swivel arrangement that pivots the cantilevered upright  9  to the base  3 . The base  3  has a central recess  3   a  for receiving the hub  7  of the upright  9 . In an alternative configuration, the recess could be formed by a through aperture. An annular bearing plate  31  having an aperture  31   a  with a smaller diameter than the base recess  3   a  is fixed to the base  3  and arranged to be concentric with the base aperture, such that the bearing plate protrudes into the base providing upper and lower bearing surfaces  32   a  and  32   b.    
     Base recess  3   a  and bearing plate aperture  31   a  together form a stepped recess in the base. An underside of the hub  7  of the upright  9  has a complementary stepped profile with surfaces that are spaced from the surfaces of the base  3  and bearing plate  31   a  when the hub is mounted to the base. An upper, top hat washer  33  having a central cylindrical portion  33 ′ and an annular flange  33 ″ at one end thereof is positioned in the stepped recess, between the hub  7  of the upright and an upper planar annular bearing surface  32   a , to provide a planar annular bearing surface  34   a  that bears against surface  32   a  as the upright rotates relative to the base. A sandwich member  37  is provided on the opposite side of the bearing plate  31  to the hub  7  of the upright, and fixed to the hub  7  at a central portion, for example using bolts  41 . A lower washer  35  is positioned between an upper side  37   a  of the sandwich member and a lower planar annular bearing surface  32   b , to provide a planar annular bearing surface  36   a  to bear against surface  32   b  as the upright rotates relative to the base. The lower washer  35  has an aperture  35   a  corresponding in size to an aperture  33   a  in the upper washer. An o-ring  42  may be positioned between the lower washer  35  and the sandwich member  37 . The o-ring  42  is compliant to minimise non-rotational movement of the upright  9  and to reduce the need for fine tolerances on the base swivel components. 
     The upright  9 , washers  33 ,  35 , and sandwich member  37  are rotatable in tandem relative to the base  3  and bearing plate  31  to swivel the chair. As the upright  9 , washers  33 ,  35 , and sandwich member  37  are rotated, the bearing surfaces  34   a  and  36   a  slide against the respective bearing surface on the bearing plate  31 . 
     The upper and lower washers  33 ,  35  preferably comprise a low friction material such as acetal. The bearing plate  31  comprises a hard bearing material, and may be a metallic material, for example hardened chrome steel or anodised aluminium. The hub  7 , legs  5 , and sandwich member  37  are all suitably a metallic material. The use of low friction materials in the bearing surfaces provides a smooth low friction swivel with a large surface area for the bearing surfaces suitable for accommodating offset loadings and moment loads such as those produced by the cantilevered upright  9 . 
       FIGS. 17 and 18  show only one preferred embodiment of the base swivel, however other embodiments are possible. For example, in an alternative embodiment, the underside of the hub  7  of the upright  9  could be a flat surface and the stepped recess could be provided on the sandwich member  37  such that a central portion of the sandwich member  37  extends through the aperture  31   a  in the bearing plate. Similarly, the upper washer  33  could be a plain washer, and the lower washer  35  a ‘top hat’ washer. In a further embodiment, the respective sides of the hub  7  of the upright  9  and the sandwich member  37  that are adjacent the respective washers  33 ,  35  could comprise a flat surface and be spaced apart. In such an arrangement, a spacer may optionally be provided between the two members. 
     In the embodiment shown, the bearing plate  31 , upper washer  33  and lower washer  35  are all separate members. Alternatively one or more of these members may be integral with another component, for example the bearing plate  31  may be integral with the base  3 , the upper washer  33  may be integral with the hub of the upright  7 , and/or the lower washer  35  may be integral with the sandwich member  37 . As a further example, rather than having one or both of the washers  33 ,  35 , the bearing surfaces  34   a ,  36   a  may be provided by a coating of a suitable bearing material on the respective upright and/or the sandwich member, and/or the bearing surfaces  32   a ,  32   b  may be provided by a coating of suitable bearing material on the upper and lower surfaces of the bearing plate  31 . 
     In place of the swivel described in relation to  FIGS. 17 and 18 , an alternative off-the-shelf component could be used which may be of similar construction or use an alternative bearing mechanism such as ball or roller bearings. 
     In an alternative configuration, the main transom could be provided on a more conventional pedestal base. However, such a base would not provide the benefit of the ‘plonk’ feature described above. 
     Recline Mechanism 
     Referring to  FIGS. 19 to 24 , the chair comprises a recline mechanism  601  that is configured to lift the seat portion  101  upon a reclining action of the back portion  201 . The recline mechanism comprises at least one operative connection between the seat portion  101  and the supporting frame  1 . 
     Reverting to  FIG. 9  for example, it can be seen that the back portion  201  for supporting the back of a seated occupant that has an upper end  203 , a lower end  205 , and is pivotally mounted at pivot  207  relative to the supporting frame  1 . Pivot  207  is positioned above the lower end  205  of the back portion  201 . As shown in  FIGS. 35 and 36 , the back portion of the chair comprises a central spine  209 , and a compliant support surface  211  supported by the spine for supporting the back of a seated occupant. An upper portion of the spine will preferably have connection feature  212  for connecting the compliant support surface to the spine. A lower portion of the spine  209  is pivotally connected to the supporting frame at pivot  207 , with a bottom portion of the spine  205  pivotally connected to a drag link  602 . The compliant support surface  211  may be any suitable type. For example, the compliant support surface may comprise a resiliently flexible shell supported by the spine  209  and a cushion supported by the shell. Alternatively, the cushion may not be provided, and instead the compliance in the support surface may be provided by slots, apertures, or regions of enhanced flexibility in the shell. 
     As shown in  FIG. 36 , the spine  209  is resiliently flexible such that an upper end of the spine can be flexed rearwardly relative to a portion of the spine adjacent the pivot connection  207  of the spine to the supporting frame. Additionally, as shown in  FIG. 35   
     the spine  209  may be resiliently flexible so it can twist with a torsional action around a longitudinal axis of the spine, upon application of a suitable force by a seated occupant to the compliant support surface  211 . These features, and the compliant support surface, enable an occupant to sit in unusual positions and be supported by the chair, thereby increasing the comfort level offered by the chair. Additionally, the configuration encourages healthy blood flow through micro-movements and allows freedom of movement with continuous support of the user. 
     Similarly, the seat portion comprises a seat frame  103  and a support surface  107  mounted to the seat frame for supporting a seated occupant. The support surface  107  of the seat portion may be compliant or rigid and of any of the types outlined in relation to the back portion. 
     Referring to  FIGS. 19 to 24 , a drag link  602  is pivotally connected at pivot  602   a  to the seat portion  101 . A fixed extension  105  extends rearwardly from a seat frame  103  of the seat portion  101 , and the drag link  602  is pivotally connected at pivot  602   a  to that fixed extension  105 . The drag link is also pivotally connected at pivot  602   b  to the back portion  201  at a position below the pivotal mounting  207  of the back portion relative to the supporting frame. The recline mechanism  601  is configured such that as the back portion  201  of the chair is reclined, the lower end  205  of the back portion moves forward and the drag link  602  pulls the seat portion  101  upward relative to the supporting frame  1 . The drag link acts in tension during that pulling action. The drag link  602  preferably moves from a generally vertical orientation when the back portion of the chair is in the upright configuration, to a forwardly inclined orientation when the back portion of the chair is reclined (when the chair is in a neutral rock configuration). 
     In the form shown, the chair comprises a rocker mechanism  701  as will be described below. The rocker mechanism  701 , shown in  FIGS. 25 to 28C , operatively connects the main transom  15  and an intermediate support  21  to provide a rocking motion therebetween. Therefore, rather than being connected to the main transom  15 , the recline mechanism  701  supports the seat portion from the intermediate support  21  of the supporting frame. The back portion  201  is also supported by the intermediate support  21 . This means that the seat portion  101  and back portion  201  will rock with the intermediate support  21 . In an alternative configuration of the chair without a rocker mechanism, the recline mechanism could instead support the seat portion from the main transom  15  of the supporting frame, and the back portion could be supported by the main transom. 
     As shown in  FIGS. 12 and 19-24 , the intermediate support  21  has a generally horizontally extending portion  23  and a pair of rearward uprights  25 , with the lower portion  205  of the spine positioned between and pivotally connected to the uprights  25  at pivot  207 . As shown in  FIGS. 10 and 13 , a portion of the spine below the pivot connection  207  may have one or more stops  213  connected thereto, which engage against uprights  25  to define the maximum rearward movement of the lower portion of the spine relative to the uprights  25 . Alternatively the stops  213  may comprise inwardly protruding tabs or ledges on the uprights  25  that are configured to engage a rear surface of the lower portion  205  of the spine to limit its rearward movement. 
     Reverting to  FIGS. 19-24 , the recline mechanism comprises at least one operative connection between the seat portion  101  and the intermediate support  21 . In the preferred form shown, the recline mechanism  601  comprises a front operative connection  603  between a relatively forward portion of the seat portion and the supporting frame. The front operative connection  603  guides movement of the relatively forward portion of the seat portion as the back portion is reclined or returned to upright. The front operative connection  603  comprises a slide arrangement comprising a track  605  on the seat portion  101  and a follower  607  on the intermediate support  21  of the supporting frame, with the follower  607  arranged to travel in the track  605  as the seat portion is moved upward upon recline of the back portion. Alternatively, the track  605  could be provided on the intermediate support  21  and the follower provided on the seat portion  101 . The track  605  is angled upwardly and forwardly, to cause the forward part of the seat portion  101  to move upwardly and forward as the seat portion  101  is lifted by the drag link  602  of the recline mechanism. Preferably, the recline mechanism comprises two of these front operative connections, one at or adjacent each side of the seat portion  101 . 
     In the preferred form shown, the recline mechanism also comprises a rear operative connection  611  between a relatively rearward portion of the seat portion  101  and the intermediate support  21  of the supporting frame. The rear operative connection  611  guides movement of the relatively rearward portion of the seat portion as the back portion is reclined or returned to upright. The rear operative connection  611  comprises a forward link  613  that is pivotally connected at pivot  613   a  to the intermediate support  21 , a rearward link  615  that is pivotally connected at pivot  615   a  to the intermediate support  21 , and a carrier link  619  that is pivotally connected at pivots  613   b ,  615   b  to the forward link and to the rearward link respectively. The carrier link  619  is pivotally connected at pivot  619   a  to the seat portion  101 . The pivot connection  619   a  of the carrier link  619  to the seat portion  101  is positioned rearwardly of the pivot connections  613   b ,  615   b  of the forward link  613  and rearward link  615  to the carrier link  619 . The pivot connection  602   a  ( FIGS. 20, 22, 24 ) of the drag link  602  to the seat portion  101  is positioned generally above and generally behind the pivot connection  619   a  of carrier link  619  and the seat portion  101 , when the back portion  201  of the chair is not reclined, and is positioned generally above the pivot connection  619   a  of the carrier link  619  and the seat portion  101 , when the back portion of the chair is reclined. 
     When the back portion  201  is in an upright configuration ( FIG. 19 ), the forward link  613  hangs downwardly and rearwardly from its pivot connection  613   a  to the intermediate support  21 , and the rearward link  615  hangs downwardly and forwardly from its pivot connection  615   a  to the intermediate support. When the back portion is fully reclined ( FIG. 23 ), the forward link  613  hangs generally downwardly from its pivot connection  613   a  to the intermediate support  21 , and the rearward link  615  extends generally forwardly from its pivot connection  615   a  to the intermediate support  21 . The pivot connection  602   a  of the drag link  602  to the seat portion  101  is positioned upwardly and rearwardly of the pivot connection  619   a  of the carrier link  619  and the seat portion  101 , when the back portion  201  of the chair is fully reclined. Preferably, the recline mechanism comprises two of these rear operative connections, one at or adjacent each side of the seat portion  101 . 
     The operative connections  603 ,  611  between the seat portion  101  and the intermediate support  21  are arranged such that the relatively forward and relatively rearward portions of the seat portion move upward and forward with a substantially linear movement as the back portion is reclined, with the amount of movement of the relatively rearward portion being greater than the amount of movement of the relatively forward portion, to provide a forward tilt of the seat portion  101  as the back portion is reclined. That forward tilt reduces force against the underside of the occupant&#39;s thighs as the back portion is reclined, and also reduces ‘shirt pull’. Preferably, the seat portion  101  has a rearward tilt angle when the back portion  201  is upright, and the seat portion  101  has a smaller rearward tilt angle when the back portion  201  is fully reclined. Preferably, the upward movement of the relatively rearward portion of the seat portion is greater than that of the relatively forward portion of the seat portion. 
     In an alternative configuration, the rear operative connections could instead comprise track and follower arrangements of the type described for the front operative connections. In another configuration, the front operative connections could instead comprise pivot and link arrangements of the type described for the rear operative connections. 
     Because the recline mechanism  601  lifts the seat portion  101  upon recline of the back portion  201 , the recline mechanism is a weight compensating mechanism. That is, the occupant&#39;s body weight influences the force that must be applied to the back portion to cause it to recline. A lighter weight occupant who would generally be less strong does not need to apply as much force to the back portion, as a heavier occupant who would generally have greater strength. A lighter occupant is also typically shorter and therefore applies force to the back portion at shorter distance above the back pivot  207 , achieving less leverage than a taller occupant. The present recline mechanism, has the advantage that for the same force applied to the back portion, less leverage is required (i.e. the force can be applied closer to the back pivot) to lift a lighter occupant than a heavier occupant. These benefits mean that tension adjustment and/or a user activated recline lever are not required. 
     The use of the drag link  602  and a pivot of the back portion to the supporting frame above the bottom of the back portion enables the lower portion of the back portion and the seat portion to travel on independent paths, reducing the amount of ‘shirt pull’ that would occur if the back portion was pivoted directly to the seat portion. The position of the pivot  207  of the back portion to the supporting frame also provides optimal lumbar rotation as the back portion is reclined, and reduces the spacing that is required between the back of the chair and a wall to enable the chair to be reclined, despite the back portion of the preferred embodiment chair being reclinable to an angle of about 37 degrees. Additionally, the drag link  602  provides variable gearing through the travel of the back portion  201  and the seat portion  101 , due to the changing link angle relative to the back angle. That varies the weight compensation rate inversely to the recline angle of back portion. As the back portion  201  reclines rearward, more of the occupant&#39;s weight is on the back portion  201 , increasing the weight compensation requirement of the seat portion  101  to keep the rate of change of angle of the back portion recline controlled. The drag link angle change increases the amount of seat lift per degree of back angle, and therefore the effort required to recline, as the back angle increases 
     Having a recline mechanism that moves the seat portion  101  forward and upward upon recline of the back portion  201  means that the occupant&#39;s centre of gravity will be moved a minimal amount upon recline of the back portion. This minimises any undesired rocking of the chair that may otherwise occur due to recline of the back portion. 
     Rocker Mechanism 
     As discussed above, the supporting frame  1  comprises a main transom  15 , an intermediate support  21 , and a rocker mechanism  701  that operatively connects the main transom and the intermediate support to provide a rocking motion therebetween. Referring to  FIGS. 25 to 28C , the rocker mechanism  701  comprises a front rocker arm  703  pivotally connected to the main transom  15  at pivot  703   a  and to the intermediate support  21  at pivot  703   b , and a rear rocker arm  705  pivotally connected to the main transom at pivot  705   a  and to the intermediate support  21  at pivot  705   b.    
     The front rocker arm  703  and the rear rocker  705  arm hang generally downwardly from their pivot  703   a ,  705   a  connections to the main transom  15 , at least when the rocker mechanism is in a neutral position as shown in  FIG. 25 . As shown in  FIG. 27 , when the intermediate support  21  is in the rearward rocked position, the front rocker arm  703  extends generally rearwardly from its pivot connection  703   a  to the main transom, and the rear rocker arm  705  extends generally downwardly from its pivot connection  705   a  to the main transom. When the intermediate support is in the forward rocked position as shown in  FIG. 26 , the front rocker arm  703  extends generally downwardly from its pivot connection  703   a  to the main transom, and the rear rocker arm  705  extends downwardly and forwardly from its pivot connection  705   a  to the main transom. 
     The arms  703 ,  705  are configured such that their action simulates rocking motion of a traditional rocking chair utilising a curved piece of wood in contact with the support surface. A traditional rocking chair motion is a combination of rotation and translation. The intermediate support  21 , and thereby the seat portion  101  and the back portion  201 , can be rocked between a rearwardly angled rearward rocked position as shown in  FIG. 27  and a forwardly angled forward rocked position as shown  FIG. 26 . 
     Preferably, the front rocker arm  703  is longer than the rear rocker arm  705 . Preferably, the pivot connection  703   a  of the front rocker arm  703  to the main transom  15  is positioned vertically higher than the pivot connection  705   a  of the rear rocker arm  705  to the main transom, as shown in  FIG. 25 . ‘Plonk’ of the chair as a user sits down will affect the pivot positions. This configuration provides a compact package size for the rocker mechanism, while providing the same motion that would be provided if equal length arms were used with their pivots to the main transom positioned the same height from the floor. 
     Preferably, the rocker mechanism comprises two of said front rocker arms and two of said rear rocker arms, positioned at or adjacent respective sides of the seat portion. 
     Preferably, the rocker mechanism comprises one or more stops (not shown) to limit forward and/or rearward rock of the intermediate support relative to the transom  15 .  FIGS. 28A to 28C  illustrate an embodiment having compressible forward  709  and rearward  711  stops fixed to the intermediate support. The forward stop  709  is fixed to a rearward portion of the intermediate support  21  and limits forward rocking of the intermediate support relative to the transom  15 . The rearward stop  711  is fixed to a portion of the intermediate support  21  forward of the forward stop  709  and limits rearward rocking of the intermediate support relative to the transom  15 . The transom  15  comprises a fixed stop  707  having first and second abutment surfaces  708   a ,  708   b . The forward and rearward stops  709 ,  711  provided on the intermediate support comprise compressible elastomeric members. The elastomeric members are tapered from their base and comprise apertures  710 ,  712  to increase their compressibility. The fixed stop  707  of the transom is substantially non-compressible. 
     As the intermediate frame  21  rocks rearward relative to the transom  15 , as shown in  FIG. 28A , the rearward compressible stop  711  comes into contact with the first abutment surface  708   a  on the fixed stop  707 . As the intermediate frame  21  continues to rock rearward, the forward compressible stop  711  is forced into the first abutment surface  708   a , compressing the rearward stop  711  and slowing the velocity of the rearward rock. As the rearward stop  711  is compressed further, the velocity of the rock slows further until the stop is fully compressed, limiting the rearward rock of the intermediate member  21 . As the intermediate member  21  is rocked forward towards the neutral rock position, the rearward stop  711  expands until it is out of contact with the fixed stop  707  and in its non-compressed configuration as shown in  FIG. 28B . 
     Similarly, as the intermediate frame  21  rocks forward relative to the transom  15 , the forward compressible stop  709  comes into contact with the second abutment surface  708   b  on the fixed stop  707 . As the intermediate frame  21  continues to rock forward, the forward compressible stop  709  is forced into the second abutment surface  708   b , compressing the forward stop  709  and slowing the velocity of the forward rock. As the forward stop  709  is compressed further, the velocity of the rock slows further until the stop is fully compressed, limiting the forward rock of the intermediate member  21 . As the intermediate member  21  is rocked rearward towards the neutral rock position, the forward stop  709  expands until it is out of contact with the fixed stop  707  and in its non-compressed configuration. 
     In an alternative embodiment, the compressible stops could be provided on the transom, and the abutment surfaces may be provided on the intermediate member. In a further embodiment, rather than compressible stops, the intermediate support  21  and/or the transom  15  may comprise front and/or rear hard limit stops to limit the front and rear rock of the seat portion. 
     The rocker mechanism will function irrespective of whether the back portion is upright or reclined. However, in an embodiment having a foot or leg support assembly as described below, the chair is preferably provided with a rocking inhibitor arrangement to counter the effect of weight change when the foot or leg support is extended. 
     Arm Assemblies 
     The chair has a pair of arm assemblies  301  positioned one on either side of the seat portion  101 . As shown in  FIGS. 29 to 34 , each arm assembly comprises an upright arm rest support  303  and an arm rest  305  that is slidably mounted to the arm rest support at an upper end thereof. The arm rests  305  are operatively connected to the back portion  201  such that as the back portion  201  is reclined, the arm rests  305  slide rearwardly on the arm rest supports  303 . When the back portion is returned to the upright position, the arm rests  305  slide forward on the arm rest supports to return to their forward positions.  FIG. 29  shows the arm rests in their forward positions when the back portion  201  is upright, and  FIG. 30  shows the arm rests in their rearward positions when the back portion  201  is fully reclined. 
     Because the chair comprises a recline mechanism  601  configured to lift the seat portion  101  upon a reclining action of the back portion  201 , to maintain a desired position between the seat portion and the arm rest supports  303 , the arm rest supports  303  are mounted to the seat portion  101  to move with the seat portion as the seat portion is moved by the recline mechanism. Similarly, because the chair comprises a rocker mechanism that operatively connects the main transom  15  and the intermediate support  21  to provide a rocking motion therebetween, by mounting the arm rest supports  303  to the seat portion  101 , the arm rest supports  303  will move with the seat portion  101  as the seat portion is rocked by the rocker mechanism. 
     In the form shown, the arm rest supports  303  are mounted to the seat frame of the seat portion  101 , so that the orientations of the arm rest supports  303  relative to the seat portion  101  are fixed. In an alternative configuration, lower portions  303   a  of the arm rest supports  303  are pivotally connected to the seat portion (e.g. to the seat frame  103 ), with the arm rest supports  303  configured such that the orientations of the arm rest supports relative to the seat portion  101  change for at least part of the reclining action of the back portion. This could occur, for example, by the arm rests  305  initially sliding on the arm rest supports and, at a certain point of the rearward movement of the arm rests  305 , the arm rests could catch and cause the arm rest supports to pivot rearwardly. 
     Referring to  FIGS. 31 to 33 , in each arm assembly, either the arm rest  305  or the arm rest support  303  comprises a pair of spaced apart guiding members  307   a , and the other of the arm rest  305  or arm rest support  303  comprises a pair of complementary elongate slots  309   a  that receive the guiding members. The guiding members  307   a  are spaced apart in a direction transverse to the forward and rearward movement direction of the arm rest on the arm rest support. In the form shown in  FIG. 32 , each arm assembly includes a support  303  with a post plate  303   a , an optional slide support  306  mounted to the post plate  303   a , and a guide structure  307  mounted to the slide support. The guide structure  307  includes the spaced apart guiding members  307   a . The arm rest  305  has slide structure  309  that includes the spaced apart slots  309   a , an optional slide top plate  310 , and an upper body contacting surface  311 . Alternatively the guide structure  307  may directly connect to the post plate  303   a  and/or the upper body contacting surface  311  may directly connect to the slide structure  309 . At least part of the guiding members  307   a  are generally T-shaped in vertical cross-section, with the upright portion  307   a ′ of the T-shape extending between two inwardly-directed base flanges  309   a ′ of the slide structure  309 . 
     Either the arm rest  305  or the arm rest support  303  of each assembly may further comprise a central guide member  307   b , and the other of the arm rest  305  or arm rest support  303  may comprise a complementary central elongate slot  309   b  that receives the central guide member. When the arm rest  305  is slid forward or rearward relative to the support  303 , the surfaces of the central guide member  307   b  bear against the surfaces of the central slot  309   b . The tolerances between the central guide member  307   b , and the central slot  309   b  are finer than the tolerances between the T-shaped guide members  307   a  and their respective slots  309   a  so that the central guide member  307   b , and the central slot  309   b  prevent side-to-side movement and twisting of the arm rest support. The T-shaped guide members  307   a  and their respective slots  309   a  primarily act to prevent the arm rest  305  being lifted off the arm rest support. 
     As discussed above, the back portion may comprise a resiliently flexible shell  211 . Upper body contacting surfaces  311  of the arm rests may be integrally formed by part of the resiliently flexible shell. The resiliently flexible shell  211  preferably comprises a central main back supporting portion  211   a , and elongate arm rest portions  211   b , one on either side of the central main back supporting portion. Rear ends of the elongate arm rest portions are connected to the central main back supporting portion and forward ends of the elongate arm rest portions form the upper body contacting surfaces  311  of the arm rests. The elongate arm rest portions  211   b  may be integrally formed with the resiliently flexible back shell  211  or may be separate members that are connected to the back shell  211 , for example by clipping an upper portion  211   c  of the arm rest to the back shell  211 . 
     The arm rest portions could also be tension members, with biasing members such as springs to return the slides to their forward positions. 
     Preferably, rear portions  211   c  of the elongate arm rest portions  211   b  are arcuate when the back portion  201  of the chair is in an upright position (as shown in  FIG. 29 ), and are substantially flat when the back portion  201  of the chair is reclined ( FIG. 30 ). 
     By providing the sliding arm rests with part of the arm rests  305  formed by, or connected to, the back portion of the chair  201 , the gap that would otherwise open between the back portion  201  and the arm rest  305  is eliminated. Additionally, because the arm rests  305  slide forward and rearward on the arm rest supports  305  with movement of the back portion, the occupant&#39;s arm will not slide excessively on the surfaces of the arm rests, reducing wear on the occupant&#39;s clothing and on any upholstery on the arm assemblies. Additionally, the flattening of the rear portions of the arm rests  305  upon recline of the back portion follows the natural straightening of the occupant&#39;s arms as the occupant reclines the back portion of the chair. 
     Cushioning surfaces could be provided on or in the arm rests. For example, cushioning could be provided on or under the surfaces  311 . The cushioning may be integral with the cushioning of the back portion  201  of the chair. 
       FIGS. 33 and 34  also show a first user actuator  321  mounted to the underside of one of the arm rests  305  for use by a chair occupant to actuate the foot or leg support assembly described below. A corresponding second user actuator may be mounted to the underside of the other one of the arm rests  305  for use by a chair occupant to actuate the rock lock assembly described below. The user actuators each comprise a paddle for gripping by an occupant&#39;s fingers, which is operatively connected to a respective cable, the cables being operatively connected to the foot or leg support assembly or to the rock lock assembly respectively. For the foot or leg support assembly, when the paddle is released, the foot or leg support assembly is not actuated. The user actuator  321  could be any other suitable type, such as a lever or button for example. In an alternative configuration, the actuator could activate an electrically driven foot or leg support via a motor. 
     The arm assemblies could be incorporated into other types of chairs with reclining back portions which may or may not have recline mechanisms to move the seat portions upon movement of the back portion, and which may or may not have rocker mechanisms. 
     Foot or Leg Support Assembly 
     The chair comprises a foot or leg support assembly  501  as described below. The assembly can be used to support an occupant&#39;s feet, legs, or both, depending on the configuration of the assembly and the size of the occupant. References to a foot or leg support assembly should be understood to cover any of: a support assembly that is suitable for supporting an occupant&#39;s feet, a support assembly that is suitable for supporting an occupant&#39;s legs, or a support assembly that is suitable for supporting an occupant&#39;s feet and legs. 
     The foot or leg support assembly  501  is movable between a deployed and extended position shown in  FIG. 39  for supporting an occupant&#39;s feet or legs, and a retracted position shown in  FIG. 37 .  FIG. 38  shows an intermediate position of the foot or leg support assembly  501  between the deployed and retracted positions. The foot or leg support assembly is mounted to the seat portion  101  of the chair via a mounting bracket  503  so that the foot or leg support assembly moves with the seat portion  101  when the seat is rocked and/or moved during recline of the back portion in embodiments having rocker or recline mechanisms as described above. 
     The foot or leg support assembly comprises a frame  505 , an extension mechanism  509 , an actuator  511  and a movable support portion  513  for receiving and supporting an occupant&#39;s feet or legs. The frame  505  is pivoted at a first end  505   a  to the mounting bracket  503  or directly to the seat portion  101  and configured to be pivoted about its first end by the actuator  511  which is preferably a gas spring. In the retracted position, the frame  505  is preferably angled rearwardly so that the angle to between the mounting bracket  503  and the frame  505  is about 60 degrees. That corresponds to a rearward angle of the frame  505  of about 30 degrees when the chair is upright and in its neutral rock position. As the frame  505  is pivoted outward toward the deployed position, the extension mechanism  509  is configured to move the moveable support portion  513  in a direction away from the first frame end, increasing the angle to, to the extended position shown in  FIG. 39 . Preferably in the extended position, the angle to between the mounting bracket  503  and the frame  505  is about 170 degrees. That corresponds to an angle of about 10 degrees below horizontal when the chair is upright and in its neutral rock position. The footrest extended to a position slightly below horizontal provides a more comfortable seating position than it would if it extended the entire way to horizontal. 
     As best seen in  FIGS. 37 to 40 and 44 to 46 , the gas spring  511  is operably connected at a first end  511   a  to the mounting bracket  503  via a linkage  520  and pivotally connected at a second end  511   b  to the frame  505 . The foot or leg support may have a single linkage  520  having the components described below. Alternatively, there could be two spaced apart linkages  520 , each having the components described below. The linkage  520  comprises three links  521 ,  523 ,  525  forming a four-bar linkage with the mounting bracket  503 . A first link  521  is pivotally connected to the mounting bracket  503  at a pivot  521   a  that is co-linear with the frame  505  pivot  505   a , a second link  523  is pivotally connected to the mounting bracket  503  at a pivot  523   a  spaced rearwardly from the first link pivot  521   a . A third link  525  is pivotally attached to the first link  521  at a first pivot  525   a  and to the second link  523  at a second pivot  525   b . The gas spring  511  is pivotally attached to the linkage at the pivot  525   a  between the first and third links  521 ,  525 . A restrictor link  527  ( FIG. 40 ) is pivotally attached at one end to the pivot  525   b  between the second and third links  523 ,  525  and pivotally attached at its opposite end to the frame  505 . The frame  505  is pivotable outwardly about its first end  505   a  between the retracted position and the deployed position upon extension of the gas spring  511 , and pivotable inwardly about its first end  505   a  between the deployed position and the retracted position upon compression of the gas spring  511 . The restrictor link  527  pulls the linkage forward as the frame  505  pivots outwards, moving the pivoted end of the gas spring  511   a  forward. 
     The gas spring  511  may be selectively actuated at any frame  505  position via the user actuator  321 . When the frame  505  is in the retracted position, actuation of the user actuator enables the foot or leg support assembly  501  to move from the retracted position to the deployed position. 
     The gas spring  511  is selectively released by an occupant using a user actuator  321  which is coupled to a gas spring release by a cable.  FIGS. 37 and 39  show the frame  505  in the retracted and extended positions with the user actuator  321  released so there is no movement of the frame  505  relative to the seating portion. The frame can be stopped and positioned at any intermediate position between the transition position and the deployed position by an occupant releasing the user actuator  321 . 
     To retract the foot or leg support assembly  501  from any position, a chair occupant must actuate the user actuator  321  and apply an inward force to the foot or leg support member, for example with their legs or feet. The linkage  520  controls the position of the first end  511   a  of the gas spring  511  so that the position of the first end  511   a  is a function of the position of the frame  505 . Moving the position of the first end  511   a  of the gas spring  511  changes the ratio between the required gas spring extension or retraction to angularly displace the frame  505  a given amount. 
       FIG. 43  shows the displacement of the gas spring  511  against the angular displacement of the frame  505 . When the frame is substantially vertical (at 30 degrees forward of the fully retracted position), the magnitude of the gas spring  511  extension required to pivot the frame  505  outwards 5 degrees is less than the spring extension required to pivot the frame  505  outwards 5 degrees when the frame is 60 degrees forward of the retracted position, for example. This means that, when the foot or leg support  501  is being deployed, the user experiences a rising force rate as the foot or leg support rotates outwards, to assist the user in lifting their legs. The converse is also true. When the frame is substantially vertical, the amount the gas spring  511  must be compressed to pivot the frame  505  inwards 5 degrees is less than the amount the gas spring  511  must be compressed to pivot the frame  505  inwards 5 degrees when the frame is 60 degrees forward of the retracted position, for example. This means that as the foot or leg support assembly is moved back to the retracted position, the user needs to apply less force the closer the footrest is to the retracted position. 
     The moveable foot or leg support member  513  of the foot or leg support assembly  501  is arranged to slide relative to the frame  505  such that the foot or leg support assembly  501  is extendable from an initial length L 1  to an extended length L 2 . The extension mechanism  509  is configured to slide the moveable support member in a direction away from the first frame end  505   a , to an extended position as the frame is moved from the retracted position to the deployed position by the gas spring  511 . This sliding of the support member causes the support member to follow an arc similar to the arc through which an occupant&#39;s lower legs or feet move as the occupant moves them outward. This results in less ‘trouser pull’ which is the result of relative movement between a support portion and an occupant&#39;s legs or feet as a foot or leg support is deployed. 
     Referring to  FIGS. 40 to 42 , the extension mechanism  509  comprises two drag links  531 , a support portion frame  533  that forms part of the movable support member  513 , and a linkage arrangement operatively connected between the drag links  531  and the support portion frame  533 . The drag links  531  are pivotable about respective first pivots  531   a  spaced below and rearward of the frame pivot  505   a , and each have an end  531   b  that is slidable relative to the frame  505 . The linkage arrangement further comprises two driving links  535  pivoted to the frame  505  at a fixed pivot  537  spaced from the first frame end  505   a  (and preferably at or towards the opposite end of the frame  505  as shown), two drag connecting links  539  each having a first end  539   a  pivotally connected to a respective driving link  535  and a second end  539   b  that is pivotable relative to the slidable end  531   b  of a respective drag link  531  and arranged to slide relative to the frame  505  with the slidable end of the respective drag link  531 , and a scissor linkage. The scissor linkage comprises two support connector links  543  each pivotally connected to the movable support portion frame  533 , and two main links  541 . The main links  541  each comprise a first end  541   a  pivoted to a respective driving link  535  and a second end  541   b  pivoted to a respective support connector link  543 . The two main links  541  are pivotally connected to each other at a pivot  542  intermediate their first and second ends  541   a ,  541   b . The pivot  542  is movable relative to both the frame  505  and the support portion  513 . 
     In a preferred embodiment, the slidable end  531   b  of each drag link  531  is pivotally connected to a sliding block  545 . Slots  544  are positioned on opposite sides of the centre of the frame  505 , and the sliding blocks  545  are each configured to slide longitudinally in a respective slot  544 . The second end  539   b  of each frame connector link  539  is pivotally connected to a respective sliding block  545  about a pivot that is transverse to the pivots between the drag links  531  and sliding blocks  545 , such that each pivot slides relative to the frame  505  with the slidable end of the respective drag link  531  and sliding block  545 . 
       FIG. 41  shows the foot or leg support assembly  501  and extension mechanism  509  in an unextended position. This position corresponds to a substantially vertical frame position when the chair is in an upright and neutral rock position. When the frame  505  is pivoted by the gas spring  511  from the position shown in  FIG. 37  toward the deployed position shown in  FIG. 39 , the slidable ends  531   b  of the drag links  531  move toward the first end of the frame  505   a  and the support portion frame  533  moves toward the extended position, as shown in  FIG. 42 . 
     In the embodiment shown in  FIGS. 40 to 42  the moveable support member  513  is slidably mounted to the frame  505 . In the form shown, the support member  513  is mounted to the frame  505  via a slide assembly  551 . The slide assembly comprises a first part  551   a  fixed to the frame  505 , a second part  551   b  fixed to the support member  513 , and a floating part  551   c  slidably attached to both the first and second parts  551   a ,  551   b . In an alternative embodiment, the foot or leg support assembly may comprise two slidable extension members, slidably attached to the frame, with the movable support portion  513  slidably mounted to the extension members. The extension members could be slidable via slots in the frame sides, and guide features on the extension members, or via slots or channels on the extension members and corresponding guide features on the frame  505 , for example. In such an embodiment, the slidable extension members would be pulled outwardly along to the frame  505  as the moveable support member  513  is moved to the extended position. The support member  513  or support member frame  533  may have features on its underside to catch the extension members to slide them outward as the support member  513  is extended, allowing the support member  513  to be supported beyond the end of the frame  505  in the extended position. Springs acting between the frame  505  and the extension members may be used to retract the slides as the support member  513  retracts. 
     The single user actuator  321  controls all of the outward pivoting of the frame  505 , inward pivoting of the frame  505 , and extension and retraction of the support member  513  relative to the frame  505 . 
     Other than the drag links  531 , the components of the extension mechanism  509  all move in a plane substantially corresponding to that of the frame  505 . That configuration enables a low profile support assembly to be provided. The sliding of the support member  513  as the frame  505  is pivoted outwardly and inwardly means that the support member  513  can stay in an approximately fixed position relative to an occupant&#39;s feet or legs, improving comfort and reducing wear on clothing. 
     The above describes only one preferred form extension mechanism  509 . Alternative linkage arrangements may be used to push or pull the movable support member  513  relative to the frame  505  as the frame  505  is pivoted inwards or outwards. In an alternative embodiment, the actuator  511  could be provided in a foot or leg support assembly that doesn&#39;t have an extension mechanism. In another alternative embodiment, rather than a gas spring, an alternative actuator, for example a powered actuator, could be used to deploy and retract the foot or leg support assembly  501 . 
     The foot or leg support assembly could be incorporated into other types of chairs that may or may not have recline mechanisms or rocking mechanisms. In embodiments that do not have rocking mechanisms, the frame  505  may instead be pivotally mounted to a main transom rather than to the seat portion. 
     Because the foot or leg support member  513  of the preferred embodiment can retract to a rearwardly angled position beneath the seat portion of a chair, an occupant can more easily egress the chair than would be the case if the foot or leg support only retracted to a vertical position. An occupant can place their feet flat on the ground partly beneath the seat portion to stand up. In an alternative embodiment, the foot or leg support may comprise a switch and gas spring arrangement that avoids the need of the occupant applying rearward force to fully retract the support member past the vertical position. 
       FIGS. 44 to 46  show an arrangement  533 ,  535  coupling the movement of the foot of leg support assembly  501  to a rocking inhibitor arrangement to prevent forward rocking of the chair when the foot or leg support is deployed. This arrangement is discussed further below in relation to the rocking inhibitor. 
     Rocking Inhibitor 
     Referring to  FIGS. 47 to 57 , the chair comprises a rocking inhibitor arrangement  801  to inhibit forward rocking of the intermediate support  21  relative to the main transom  15  when the foot or leg support assembly  501  is extended and to selectively lock forward and rear rocking of the intermediate support  21  independent of the position of the foot or leg support assembly  501 . The rocking inhibitor arrangement  801  comprises a mounting member  827  for mounting to the transom  15 , an optional anti-rock ratchet assembly  803 , a rock lock assembly  805 , and a slide assembly  806  connected to the intermediate support  21  and comprising a slide member  811  slidably mounted to the main transom. 
     Referring to  FIGS. 50 and 51 , the anti-rock ratchet assembly  803  comprises a carriage  809  transversely slidable relative to the mounting member  827 , a ratchet pawl  807  carried by the carriage  809  and slidable relative to the carriage  809  and transversely slidable relative to the mounting member  827  and slide member  811 . A series of ratchet teeth  813  are formed on the slidable member  811  of the slide assembly  806 , for engaging with teeth on the ratchet pawl  807 . The ratchet pawl  807  is slidable transversely relative to the slidable member  811  between an outward disengaged position and an engaged position. The anti-rock ratchet assembly  803  is configured to automatically engage to inhibit forward rocking of the intermediate support  21  when the foot or leg support assembly  501  is extended, and to automatically disengage to allow forward rocking of the intermediate support when the foot or leg support assembly is retracted. 
     The central slide member  811  of the slide assembly  806  is slidably mounted to the mounting member  827  via a guide channel  829  in the mounting member. Guide features  831  in the form of inwardly protruding tabs retain the slide member  811  in the channel  829 . A connecting member  833  is attached to the central slide member  811  and connected to the intermediate support  21  which rocks relative to the transom and mounting member  827  as the chair is rocked. The connecting member  833  may be integral with the central slide member  811 , or alternatively, the central slide member  811  may be directly connected to the intermediate support  21 , such as via a pivot connection. 
     The anti-rock ratchet assembly  803  comprises an actuation assembly  810 , shown in exploded form in  FIG. 51 , operatively connected to the foot or leg support  501 . The actuation assembly  803  comprises a first actuation link  815  having a first end  815   a  pivotally connected to the mounting member  827  at pivot  827   a  towards one side of the mounting member  827 , and a second actuation link  817  having a first end  817   a  pivotally connected to the carriage  809  at a pivot  809   a  towards the opposite side of the mounting member  827 . A second end  815   b  of the first link  815  is pivotally attached to the second end  817   b  of the second actuation link  817  at a central pivot  819 . A biasing member  821  in the form of a torsion spring is positioned between the mounting member  827  and the pivot  809   a  between the carriage  809  and second actuation link  817  to bias the first end  817   a  of the actuation link outwards and the carriage  809  and pawl  807  inwards towards the slide member  811  and therefore the pawl  807  into engagement with the ratchet teeth  813 . 
     A cable  823  is operatively connected to the actuation links  815 ,  817  at the central pivot  819 . As shown in  FIG. 52A , pulling the cable pulls the central pivot  819  forward, moving the first end  817   a  of second actuation link  817  inwards and the carriage  809  and ratchet pawl  807  outwards and out of engagement with the ratchet teeth  813 . As shown in  FIG. 52B , releasing the cable tension reverses this action, allowing the first end  817   a  of second actuation link  817  to move outwards under the bias of biasing member  821  and the carriage  809  and ratchet pawl  807  to move inwards, and back into engagement with the ratchet teeth  813 . The cable  823  is operatively attached to the foot or leg support  501 . 
       FIG. 52A  shows the actuation assembly  810  in a first, disengaged mode of the anti-rock ratchet assembly  803  in which the foot or leg support assembly  501  is retracted and the chair is free to rock. In the first mode, the anti-rock ratchet pawl  807  is in its disengaged position. The retracted foot or leg support  501  tensions the cable, pulling the actuator into the disengaged position shown. The slide assembly  806  is free to move with the seat portion of the chair as it rocks. 
       FIG. 52B  shows the actuation assembly  810  in a second, engaged mode of the anti-rock ratchet assembly  803  in which the foot or leg support assembly has been at least partially deployed. As the foot or leg support is moved outward from its retracted position, a member that is operatively connected to the foot or leg support acts on the cable  823 . That reduces the tension in the cables  823 , so that the first biasing spring  821  causes the carriage  809  to move inwards, allowing the actuation arrangement  810  to move into the second, engaged mode shown. Preferably, the actuator arrangement  810  is moved into the second mode when the foot or leg support  501  reaches an approximately vertical position or is moved slightly forward of vertical, and teeth on the ratchet pawl  807 , are biased into engagement with teeth  813  on the slide member  811 . 
     As can be seen from  FIGS. 50 and 51 , a second biasing member  808  in the form of a compression spring is positioned between the pawl  807  and the carriage  809  and biases the ratchet pawl  807  inwards relative to the carriage  809 , towards the slidable member  811  and teeth  813 . When the carriage  809  is in the engaged position of the second mode, the ratchet pawl  807  is biased into engagement with the ratchet teeth  813 . When the anti-rock ratchet assembly is configured to the second mode, if the teeth of the ratchet pawl  807  and the teeth  813  of the slide member  811  and misaligned as shown in  FIG. 53A , the ratchet pawl is not forced into engagement but is biased towards the teeth by biasing member  808 . The ratchet pawl  807  will then move to engage the teeth  813  of the slide member  811  upon slight forward or rearward sliding of the slide member  811  aligning the teeth as shown in  FIGS. 53B  and C. In the second mode, the ratchet pawl  807  can slide outwards relative to the carriage to allow the slide assembly  806  to slide only rearward relative to the transom. Forward rocking of the chair while the foot or leg support  501  is forward of the seat is disabled, preventing the chair from tipping forward due to the weight of the foot or leg support, but still allowing the seat to be rocked rearwardly. 
     When the foot or leg support is being retracted, the actuator arrangement and anti-rock ratchet assembly  803  is returned to the first mode when the foot or leg support  501  is moved to slightly forward of vertical or a vertical position as it is being retracted. 
     Referring to  FIGS. 44 to 46 , the anti-rock ratchet actuating cable  823  is operatively connected to the foot or leg support assembly  501  by a cable connector arrangement. The cable connector arrangement comprises a moulded housing  535  fixed to the mounting bracket  503  or an underside of the seat portion and a cable connector  533  fixed to the second link  523  of the linkage  520  supporting the gas spring  511 . The housing  535  contains a channel, slot or cavity  537  with an aperture at its rearmost end. An end  823   a  of the cable  823  extends through the aperture and is free to slide in the channel, slot or cavity  537  as the foot or leg support frame  505  pivots. A cable connector  533  attaches the sheath of the anti-rock ratchet cable  823  to the second link  523  of the linkage  520 . When the foot or leg support  501  is in an extended position as shown in  FIG. 46 , the second link  523  and therefore the cable connector  533  is close to the moulded housing  535  allowing the cable end  823   a  to slide forward in the housing  535 , such that no tension is being applied to the cable  823  and therefore, the anti-rock ratchet assembly is biased into its locked position. 
     When the foot or leg support  501  is retracted, the second link  523  and therefore the cable connector  533 , is moved away from the moulded housing  535 . That pulls the cable end  823   a  rearward in the housing  535 . When the foot or leg support  501  reaches a vertical orientation, as shown in  FIG. 45 , the end of the cable  823   a  is positioned at the rearmost position in the channel, slot or cavity  537 . 
     As the foot or leg support  501  is retracted further, towards the position shown in  FIG. 44 , the second link  523  and therefore the cable connector  533  continues to be moved away from the moulded housing  535 . An enlarged portion or pin on the end of the cable end  823   a  prevents the cable from being pulled through the aperture and out of the housing  535 , instead tensioning the cable  823 , pulling the central pivot  819  in the anti-rock ratchet assembly forward to unlock the forward rock. The foot or leg support assembly maintains the anti-rock ratchet assembly  501  in this unlocked configuration as long as it is retracted behind the generally vertical orientation (when the chair is upright). 
     The rock lock assembly  805  is shown in exploded form in  FIG. 54 . The rock lock  805  comprises a detent assembly  846  which is operatively connected to and actuates a locking assembly  848 . The locking assembly comprises a lock carriage  845  transversely slidable in a channel  830  in the mounting member  827 , a lock member  841  carried by the lock carriage  845  and which is slidable relative to the lock carriage  845 , and the slide member  811 . One side of the slide member  811  comprises square lock teeth  840 . The lock member  841  comprises complementary square lock teeth  841   a  that are engageable with the slide member square lock teeth  840  to prevent forward and rearward sliding of the slide member  811  and rocking of the chair. Alternatively, the teeth  840 ,  841   a  could be different shapes. 
     In the locking assembly,  848 , a lock biasing member  843  is positioned between the lock carriage  845  and the lock member  841 , biasing the lock member  841  towards the slide member  811 . The lock carriage  845  is biased outwards, away from the slide member  811  by a carriage biasing member  847  positioned between a projection on the lock carriage  845  and a projection on the mounting member  827 . 
     The detent assembly  846  comprises a detent pawl  851  pivotally mounted on the mounting member  827 , a slidable pin carrier  855  slidably mounted on the mounting member  827 , and a detent pin  857  protruding downwardly from the pin carrier. A biasing member comprising a spring  861  is positioned between the pin carrier  855  and a protrusion  862  on the mounting member  827  to bias the pin carrier rearwardly. A cable  863  is operatively connected to a front end of the pin carrier  855  and to a paddle (not shown) or lever for actuation by a user to lock and unlock the rocking of the chair. 
     The detent pawl  851  is shown in  FIGS. 55A  and B. The detent pawl  851  is pivotally attached to the mounting member  827  through an aperture  849  in the mounting member about an off-centre pivot  852 . A heart-shaped groove  853   a  on the top surface of the pawl  851  receives the detent pin  857 . The groove  853   a  has a central projection  853   b  and a stepped surface to guide the pin  857  in the groove  853   a . A resilient member  859  ( FIG. 54 ) movably connects the detent pin  857  to the pin carrier  855  to enable some up and down movement of the pin  857 , biasing the pin downwardly towards the surface of the groove so that the pin contacts the stepped surface of the groove  853   a  at every position in the groove  853   a . The off-centre pivot  852  of the pawl  851  enables the pawl to pivot towards the left or right in response to movement of the pin carrier  855  and pin  857  in the groove  853   a.    
     An underside of the pin carrier  855  comprises a cam  856 . The lock carriage  845  of the locking assembly comprises a camming surface  845   a  with two parallel end portions and a rearwardly inwardly angled intermediate portion ( FIG. 56A ). The cam  856  contacts the camming surface  845   a  to operate the lock. 
     Operation of the lock assembly will now be described with reference to  FIGS. 56A to 56G . In a first stage shown in  FIG. 56A , the rock lock is released and the seat portion is free to rock. In this configuration, the user has released the actuation paddle and the pin carrier  855  and pin is biased rearwardly by spring  861  to a first stop position in the detent pawl  851 . The cam  856  on the underside of the pin carrier  855  is therefore also in its rearmost position. The lock carriage  845  and camming surface  845   a  are biased outwardly by spring  847 , into contact with the cam  856 . The extent of the outward movement of the lock carriage  845  is limited by the position of the cam  856 . In this stage, the cam is in its rearmost position to allow maximum outward movement of the lock carriage  845  and lock member  841 , so that the teeth  840 ,  841   a  on the slide member and lock member  811 ,  841  are disengaged. 
     In a second stage shown in  FIG. 56B  the user is actuating the actuation paddle or lever to lock the chair rock. This tensions the cable  863  and pulls the pin carrier  855 , pin  857 , and cam  856  forward to their forward-most position. The movement of the cam  856  along the lock carriage camming surface  845   a  pushes the lock carriage  845  and lock member  841  inwards. In the configuration shown, the user has actuated the lock assembly when the teeth  840  on the central slide  811  and the teeth  841   a  on the lock member  841  are misaligned. This means that when the lock carriage  845  is moved inwards, the lock member  841  moves outwards relative to the lock carriage  845 , compressing biasing member  843 , to delay locking until the slide member  811  is moved to align the teeth. 
       FIG. 56C  shows a third stage where the user has released the actuation paddle or lever, releasing tension in the cable  863 . The spring  861  causes the pin carriage  855  to again move rearwardly, and the pin  857  to move rearwardly in the detented groove  853   a . The stepped, angled surfaces within the groove  853   a  prevent the pin from returning to the first stop position of stage one, and instead direct the pin  857  to a second stop position between the pin positions of stages one and two, as shown. The cam  856  moves rearwardly with the pin carriage  855  but remains forward of the angled portion of the camming surface  845   a  and holds the lock carriage  845  in the position of stage two. 
     The fourth stage shown in  FIG. 56D  corresponds to the third stage where the actuation paddle is released, but the seat has been rocked slightly forward from its position in  FIGS. 56B  and C. The forward rocking slides the slide member teeth  840  to a position where they are aligned with the teeth  841   a  on the lock member  841 . The lock member  841  biased inwardly on the lock carrier  845  by spring  843 , is then forced into engagement with the slide member teeth  840  to lock forward and rearward rock of the chair relative to the transom. 
       FIG. 56E  shows a fifth stage where the user is actuating the actuation paddle or lever to release the lock. The cable  863  is tensioned pulling the pin carriage  855 , pin  857 , and cam  856  forward to their forward most position. The pin  857  travels forward in the detent pawl groove  853   a , but to a different side of the pawl than in stage two. The movement of the cam  856  forward along the lock carriage camming surface  845   a  retains the lock carriage  845  and lock member  841  in their engaged positions. 
     In a sixth stage, shown in  FIG. 56F , the user has once again released the actuation paddle or lever, releasing tension in the cable  863 . The spring  861  causes the pin carriage  855  to again move rearwardly, causing the pin  857  to move rearwardly in the detented groove  853   a . The stepped, angled surfaces within the groove  853   a  direct the pin  857  back to the first stop position of the first stage. The cam  856  moves rearward with the pin carrier  855 . Friction between the lock member teeth  841   a  and the slide member teeth  840  may prevent the lock member  841  and carriage  845  sliding outwards, out of engagement, meaning the camming surface  845   a  is no longer in contact with cam  856 , as shown, delaying unlocking of the rock. 
       FIG. 56G  shows a final stage, corresponding to the sixth stage of  FIG. 56F  but where the pressure on the seat portion has been shifted, releasing the frictional forces between the lock member teeth  841   a  and the slide member teeth  840 . This allows the lock  841  and lock carriage  845  to move out of engagement with the slide member  811 , into the configuration of the first stage so that the chair is free to rock relative to the transom. 
     The lock assembly  805  enables a user to selectively lock forward and rearward rocking of the intermediate support  21 , independent of the position of the foot or leg support assembly  501 . A first ‘click’ of the actuation paddle or lever moves the assembly to a locking configuration (stages three and four) and a second ‘click’ moves the lock assembly to a release configuration (stages one, six and seven). 
     In the embodiment shown, the slide member  811  forms part of both the anti-rock ratchet assembly  803  and the lock assembly  805 . Angled teeth  813  are provided on one side of the slide member to interact with the ratchet pawl  807 , and square teeth  840  are provided on the opposite side of the slide member  811  to interact with the lock member  841 . Alternatively, separate slidable members could be provided for each of the anti-rock ratchet assembly  803  and the lock assembly  805 . Alternative embodiments of the chair may comprise only one of the anti-rock ratchet assembly  803  or the lock assembly  805 . Embodiments of the chair having no foot or leg support would not include the anti-rock ratchet assembly. 
     Preferably, the components in the rocking inhibitor arrangement  801  are designed to be thin so that the arrangement is compact for packaging under the seat.  FIG. 57  shows the mounting member  827  carrying the rocking inhibitor arrangement  801  positioned in the transom  15 . Alternatively, the rocking inhibitor arrangement  801  may be arranged in a vertical plane. 
     First Preferred Form Support Assembly 
     The chair may comprise a head or neck support assembly  401  as described below. The assembly can be used to support an occupant&#39;s head, neck, or both, depending on the configuration of the assembly and the size of the occupant. References to a head or neck support assembly should be understood to cover any of: a support assembly that is suitable for supporting an occupant&#39;s head, a support assembly that is suitable for supporting an occupant&#39;s neck, or a support assembly that is suitable for supporting an occupant&#39;s head and neck. 
     Referring to  FIGS. 58 to 77 , the head or neck rest assembly  401  comprises a base  403  (only shown in some views, for clarity) for mounting the assembly  401  to the chair. In the form shown, the base  403  is a mounting plate, with a lower part  403   a  of the plate being connected to the spine  209  at the upper end  203  thereof. The base  403  could alternatively be any suitable shape to provide a desired aesthetic. The connection of the lower part  403   a  of the plate to the spine  209  can be any suitable type, such as a fastener(s) or clip(s) for example. The connection of the plate to the spine may be permanent or may be reversible, so a user can reconfigure the chair with or without the support assembly. Alternatively, the base  403  may be integral with the spine  209 . The remainder of the support assembly is mounted to the upper part of the plate. 
     The upper part  403   b  of the plate has two forwardly-directed spigots  405   a ,  405   b . A first member  407   a  is rotatably connected to the base by being rotatably mounted on the first spigot  407   a . A second member  407   b  is rotatably connected to the base by being rotatably mounted on the second spigot  407   b . The first axis  405   a ′ of the first member  407   a  on the first spigot  405   a  is substantially parallel to the second axis  405   b ′ of the second member  407   b  on the second spigot  405   b.    
     The first and second members  407   a ,  407   b  are preferably operatively coupled by gear surfaces  407   a ′,  407   b ′ ( FIGS. 61A to 62B ) such that as the first member  407   a  is rotated in one direction relative to the base  403 , the second member  407   b  rotates a corresponding amount in an opposite direction relative to the base. It will be appreciated from the geometry and arrangement of components that the first and second members  407   a ,  407   b  can only be rotated by substantially less than 360 degrees. 
     The first member  407   a  carries a first linkage arrangement  409   a  comprising a first pair of generally parallel arms  411   a ,  413   a  that have first ends that are pivotally connected to the first member about axes  411   a ′,  413   a ′ that are substantially perpendicular to the first axis  405   a ′. The second member  407   b  carries a second linkage arrangement  409   b  comprising a second pair of generally parallel arms  411   b ,  413   b  that have first ends that are pivotally connected to the second member about axes  411   b ′,  413   b ′ that are substantially perpendicular to the second axis  405   b ′. As first and second members  407   a ,  407   b  are rotated relative to the base about axes  405   a ′,  405   b ′, the first and second linkage arrangements pivot with the first and second members. This movement is controlled by the gearing at  407   a ′,  407   b ′, to control movement of the head or neck support as the first and second members  407   a ,  407   b  are rotated relative to the base. In the form shown, the arms  411   a ,  413   a  on the first base member  407   a  and the arms  411   b ,  413   b  on the second base member  407   b  extend outwardly away from each other. Alternatively the two sets of arms  411   a ,  413   a  and  411   b ,  413   b  could extend in the same direction, so that the arm  411   a  is substantially parallel to arm  411   b , and so that the arm  413   a  is substantially parallel to the arm  413   b.    
     Arms  413   a ,  413   b  act as protective covers over the parallel arms  411   a ,  411   b . Alternatively separate protective covers could cover the first and second pairs of parallel arms. The arms  411   a ,  411   b  will typically be identical to each other, but could differ. It will be appreciated from reviewing the FIGS. that the arms  411   a ,  413   a , and  411   b ,  4113   b  need not be truly parallel, and can instead be any suitable shape that provides a four bar linkage of the type shown with substantially parallel pivot axes on members  407   a ,  407   b  and on support mounting links  415   a ,  415   b  described below. Indeed, in the form shown, arms  411   a  and  413   a , and arms  411   b ,  413   b  are different shapes, with arms  413   a ,  413   b  at least partly encapsulating arms  411   a ,  411   b  within recesses in the arms. In the form shown, the arms  413   a ,  413   b  are each two-part members comprising two halves, with connectors  412   a ,  412   b  joining the two halves together to partly encapsulate the respective parallel arm  411   a ,  411   b . By using generally parallel arms, the head or neck support  417  will stay substantially parallel to the base  403 , rather than possibly becoming skewed during adjustment. 
     A head or neck support  417  is operatively supported by the second ends of the generally parallel arms  411   a ,  413   a ,  411   b ,  413   b  of the first and second linkage arrangements. In the form shown, the second ends of the first pair of generally parallel arms  411   a ,  413   a  are pivotally connected to a first support link  415   a  about axes  411   a ″,  413   a ″ that are substantially parallel to the pivot axes  411   a ′,  413   a ′ between the parallel arms  411   a ,  413   a  and the first member  407   a . The second ends of the second pair of generally parallel arms  411   b ,  413   b  are pivotally connected to a second support link  415   b  about axes  411   b ″,  413   b ″ that are substantially parallel to the pivot axes  411   b ′,  413   b ′ between the parallel arms  411   b ,  413   b  and the second member  407   b . The first and second support links  415   a ,  415   b  are pivotable relative to the head or neck support  417 , with the pivot axes  415   a ′,  415   b ′ of the first and second support links  415   a ,  415   b  relative to the support  417  being substantially parallel to the pivot axes  405   a ′,  405   b ′ of the first and second members  407   a ,  407   b  relative to the base. 
     The second ends of the first pair of generally parallel arms  411   a ,  413   a  are moveable toward and away from the second ends of the second pair of generally parallel arms  411   b ,  413   b  (in a widthwise direction of the chair), upon movement of the head or neck support  417  relative to the base  403 . The movement toward and away from each other of the second ends of the first and second pairs of generally parallel arms, causes a corresponding movement toward and away from each other of the first and second support links  415   a ,  415   b.    
     The head or neck support  417  comprises a housing having a front part  417   a  and a back part  417   b . The housing  417  houses a unlock plate  419  containing a first toothed rack  421   a  that is coupled to the first support link  415   a , a second toothed rack  421   b  that is coupled to the second support link  415   b , and a pinion gear  423  that is rotatably mounted to unlock plate  419  and engaged with the first and second toothed racks  421   a ,  421   b , wherein movement of the first and second support links  415   a ,  415   b  toward and away from one another moves the toothed racks  421   a ,  421   b , with the racks and pinion gear linking the movement of the first and second support links  415   a ,  415   b  and thereby movement of the second ends of the first and second generally parallel arms. This arrangement also prevents the head or neck support  417  from moving to an off-centred position to one side relative to the base  403 . 
     The head or neck rest assembly also comprises a locking mechanism  431   a ,  431   b  to selectively inhibit movement of the first and second support links  415   a ,  415   b , the first and second linkage arrangements  409   a ,  409   b , and indirectly, the first and second members  407   a ,  407   b , to thereby maintain the head or neck support  417  in a desired adjusted position. As shown in  FIGS. 64 to 71 and 75 to 77 , the locking mechanism  431   a ,  431   b  comprises at least one locking member  433   a  that selectively inhibits pivoting of the first pair of generally parallel arms  411   a ,  413   a  relative to the first support link  415   a  and thereby inhibits pivoting of the first pair of generally parallel arms relative to first member  407   a , and that selectively inhibits rotation of the first support link  415   a  and thereby inhibits rotation of first member  407   a  relative to the base  403 . Preferably, the locking mechanism also comprises a second locking member  433   b  that selectively inhibits pivoting of the second pair of generally parallel arms  411   b ,  413   b  relative to the second support link  415   b  and thereby inhibits pivoting of the second pair of generally parallel arms relative to the second member  407   b , and that selectively inhibits rotation of the second support link  415   b  and thereby inhibits rotation of the second member  407   b  relative to the base  403 . However, in an alternative embodiment, a single locking member could be provided to lock movement on one side of the head or neck support assembly. As a result of the linking of movement of members  415   a  and  415   b , and the interactions of the racks  421   a ,  421   b  and pinion gear  423 , locking movement on one side of the assembly would lock movement of the assembly overall. 
     Member  417   b  comprises a rear plate  451  made of stainless steel for example and comprising two spaced apart transversely extending elongate slots  451   a ,  451   b  within which first and second support links  415   a ,  415   b  are slidably mounted. 
     With reference to the right hand side of the head or neck support assembly, the first locking member  433   b  is carried by the first support link  415   b  and is engageable with one of the first pair of generally parallel arms  411   b ,  413   b  to inhibit pivoting of the first pair of generally parallel arms relative to the first support link  415   b  and thereby inhibit pivoting of the first pair of generally parallel  411   b ,  413   b  arms relative to the first member  407   b . An engagement surface  435   b  ( FIGS. 65 to 70C ) is provided on one of the first pair of generally parallel arms, and in form shown is provided on arm  413   b . The locking member  433   b  comprises a complementary engagement surface  437   b  for engaging with the engagement surface  435   b . The engagement surface  435   b  is an arcuate gear surface with a plurality of teeth, and the engagement surface  437   b  has complementary teeth to engage with the teeth of the arcuate gear surface. The teeth on the gear surface  435   b  are concentric with the pivot  413   b ″ of the arm  413   b  to the first support link  415   b . The pivot axis  413   b ″ passes through the shank of the locking member  433   b  which extends through the first support link  415   b.    
     The first locking member  433   b  is engageable with the first toothed rack  421   b  to inhibit pivoting of the first support link  415   b  relative to the first toothed rack  421   b  about axis  415   b ′, thereby inhibiting pivoting of the first member  407   a  relative to the base  403 . The first toothed rack  421   b  comprises a body  439   b  having an aperture  441   b  and an engagement surface  443   b , and the locking member  433   b  extends through the aperture  441   b  in the body of the toothed rack and through an aperture  416   b  in the first support link  415   b . The cross-section of the aperture  416   b  in the first support link  415   b  is non-circular, as is the cross-section of the shank of the locking member, so that the locking member  433   b  is moveable only axially relative to the first support link  415   b  along axis  415   b ′ but is rotatable relative to the toothed rack  421   b  in aperture  441   b  as the link  415   b  rotates relative to the rack. The locking member has a complementary engagement surface  445   b  for engaging with the engagement surface  443   b  on the toothed rack to inhibit pivoting therebetween. Preferably, the engagement surface on the toothed rack comprises an arcuate or semi-arcuate gear surface surrounding the aperture  441   b , and the locking member has a head with a complementary gear feature on its underside. 
       FIG. 73  shows how the rack  421   b , the second support link  415   b  and the pinion  423  are assembled in the rear portion of the housing  417   b . The support link  415   b  has a rearwardly projecting spigot  477  with a groove. The rack  421   b  comprises a removable portion  473   b  that can be removed to insert the spigot  477  into the aperture  441   b  in the rack  421   b  so that the rack holds the support link  415   b  at its grooved part preventing the support link  415   b  from moving normal to the rack  421   b . The removable portion is then held in place by way of a snap fit. Alternatively the removable portion could be held in place by a key, for example as in the embodiment shown in  FIGS. 78 to 82 .  FIG. 73  also shows an additional plate  460  that is a finger trap guard that covers the slot  420   b . Two such plates will be provided. 
     The locking members  433   a ,  433   b  are configured such that when moving the locking member  433   b  from an unlocked position as shown in  FIG. 66 , to a locked position as shown in  FIG. 68 , the locking member initially inhibits pivoting of the first pair of generally parallel arms  411   a ,  411   b  relative to the first member  407   b  and then inhibits pivoting of the first member  407   b  relative to the base  403 . The locking member  433   b  comprises a first locking member portion  433   b ′ for inhibiting pivoting of the first pair of generally parallel arms relative to the first member and which carries the engagement surface  437   b , a second locking member portion  433   b ″ for inhibiting pivoting of the first member relative to the base and which carries the engagement surface  445   b , and a biasing device  433   d  between the first locking member portion and the second locking member portion to bias the first locking member portion  433   b ′ away from the second locking member portion  433   b ″. The biasing device can be any suitable type, such as an elastomeric block or a compression spring for example. As shown in  FIG. 67 , axial movement of the locking member  433   b  initially causes the engagement surface  437   b  to engage with engagement surface  435   b . Engagement surfaces  443   b ,  445   b  are still disengaged. As shown in  FIG. 68 , further axial movement of the locking member  433   b  causes engagement surfaces  443   b ,  445   b  to engage. This arrangement prevents fouling of one of the sets of teeth, which could otherwise occur and prevent the locking mechanism from working. 
     In embodiments having two locking members  433   a ,  433   b , the features and functioning of the left locking member  433   a  and interaction of the left locking member  433   a  with other components is the same as described above for the right locking member  433   b . Like reference numerals indicate like parts, with suffix ‘a’ rather than ‘b’. 
     The locking members  433   a ,  433   b  are slidably mounted in slots  419   a ,  419   b  in unlock plate  419  such that the first and second support links  415   a ,  415   b  can move toward and away from one another. The heads of the locking members  433   a ,  433   b  are configured with recesses that interact with the unlock plate, so that the heads of the locking members can only move relative to unlock plate  419  toward and away from each other or rotate relative to the rack  421 , and not in any other direction. 
     As shown in  FIG. 77 , the unlock plate  419  is operatively connected to at least one actuation lever  469   a ,  469   b ,  469   a ′,  469   b ′ each connected at one end to a paddle  461   a ,  461   b  for actuating by a user. Unlock plate  419  has grooves at or toward opposite ends thereof for pivotally receiving the ends of the levers  469   a ,  469   b ,  469   a ′,  469   b ′. In one embodiment, a single actuation lever  469   a  could be provided on each side; however, it is preferred that two levers are provided. The levers comprise pivot pins  455   a ,  455   b  that are received in respective grooves  462   a ′,  462   b ′ in pivot supports  462   a ,  462   b  ( FIG. 75 ), to connect the levers to the member  451 . The pivot supports  462   a ,  462   b  attach to the inner surface of the front housing portion  417   a  and the grooves  462   a ′,  462   b ′ provide a fulcrum for the levers to pivot about. The levers  469   a  and  469   a ′ could be one and the same part as the paddle  461   a , or separate and coupled to the paddle; with the same configuration on the other side. 
     The outer parts of the levers are attached to paddles  461   a ,  461   b  for use by a chair occupant to release the locking mechanism to enable the head or neck support to be moved to a desired position. The levers  469   a ,  469   b ,  469   a ′,  469   b ′ are normally biased forward, which corresponds to the unlock plate  419  and the locking members  433   a ,  433   b  being biased rearwardly so the head or neck support is locked in position. The biasing could be provided by any suitable biasing device such as one or more springs acting on the levers or the unlock plate for example. Preferably, the biasing device biases the levers  461   a ,  461   b  and thereby the unlock plate  419  into a position in which the locking members are engaged to inhibit movement of the head or neck support. 
     The front portion of the housing  417   a  comprises two movable portions  418   a ,  418   b  positioned on either side of the front portion of the housing  417   a , in front of the paddles  461   a ,  461   b . The movable portions of the housing are hinged at respective resilient hinges  418   c ,  418   d . Actuation of the actuation levers  469   a ,  469   b ,  469   a ′,  469   b ′ by pushing both movable housing portions  418   a ,  418   b  and thereby both paddles  461   a ,  461   b  rearwardly relative to the rear housing member  417   b  moves unlock plate  419  and disengages the locking members  433   a ,  433   b  to enable the position of the head or neck support  417  to be adjusted. Rearward pressure must be applied to both movable portions  418   a ,  418   b  to adjust the head or neck support  417 . This prevents inadvertent disengaging of the locking members  433   a ,  433   b  if a user leans their head against one of the movable portions. 
       FIGS. 78 to 82  show an alternative embodiment mechanism of the head or neck support  401 . Unless described below, the features and functioning should be considered to be the same as described above. This embodiment comprises an alternative actuation arrangement with paddles  481   a ,  481   b  that are actuated by pushing the paddles forward from the rear. The embodiment comprises an unlock plate  485  with a pair of slots  485   c ,  485   d  and attached pins  485   a ,  485   b . Actuation levers  483   a ,  483   b ,  483   a ′,  483   b ′ connected to paddles  481   a ,  481   b  comprise respective slots  484   a ,  484   b ,  484   a ′,  484   b ′ that receive the pins  485   a ,  485   b.    
     Inner ends of the actuation levers  483   a ,  483   b ,  483   a ′,  483   b ′ are geared to each other at  487  and  487 ′ respectively, so that movement of one lever will also cause movement of the other lever to which it is geared. 
     The paddles project from a rear surface of the head or neck support housing  491  adjacent respective sides thereof through openings  491   a ,  491   b . The levers  483   a ,  483   b ,  483   a ′,  483   b ′ are normally biased rearwardly, which corresponds to the unlock plate  485  and the locking members  433   a ,  433   b  being biased rearwardly so the head or neck support is locked in position. Actuation of the actuation levers  483   a ,  483   b ,  483   a ′,  483   b ′ by pushing or pulling the paddles  481   a ,  481   b  forward relative to the head or neck support moves the unlock plate  485  and disengages the locking members  433   a ,  433   b  to enable the position of the head or neck support  417  to be adjusted. Because the actuation levers  483   a ,  483   b ,  483   a ′,  483   b ′ are geared together, forward movement of either or both paddles moves the unlock plate  485  and disengages the locking members  433   a ,  433   b  to enable the position of the head or neck support  417  to be adjusted. 
     The head or neck support  417  is moveable relative to the base  403  with two substantially perpendicular degrees of freedom. That is, the support  417  can be moved up and down, and forward and rearward relative to the base  403 , in any combination of movements simultaneously, when the actuation lever(s) are actuated by a user. The support  417  can be simultaneously vertically and horizontally adjusted, such as by moving the head or neck support in a diagonal movement relative to the base. The head or neck support can then be maintained in the desired adjusted position by simply releasing the actuation lever(s) so the locking member(s) engage.  FIGS. 59A to 59F  show a selection some of the possible adjusted positions of the head or neck support. 
     The orientation of the head rest mechanism could be varied. While in the form shown the pivoting of the generally parallel arms relative to the first members and support links causes forward and rearward movement of the head or neck support relative to the base  403 , and the pivoting of members  407   a ,  407   b  relative to the base causes height adjustment of the head or neck support relative to the base, the mechanism could be mounted in a different orientation depending on the specific application and space considerations. 
     Second Preferred Form Support Assembly 
       FIGS. 83 and 84  show a second preferred form chair. Unless described below, the features and functioning of the chair are the same as described above, and like reference numerals indicate like parts with the addition of a prime (′). 
     This chair differs in that it is a high backed chair, with the upper end  203 ′ of the back portion  201 ′ extending upwardly beyond the upper end of the spine  209 ′. A preferred embodiment adjustable head support arrangement  901  is supported by the back portion  201 ′. 
       FIGS. 86 to 104B  show preferred embodiments of the adjustable support arrangement  901 . The adjustable support arrangements  901  comprise a mounting assembly  903  with first and second parallel closures defining slits  912 , a slider arrangement  904  slidable relative to the mounting assembly  903 , and a support member  905  operatively connected to the slider arrangement  904 . The mounting assembly  903  is configured for attachment to the back portion  201 ′ of the chair. The support member  905  is preferably a head support, but alternatively could be a neck support, and is slidable substantially vertically relative to the mounting assembly  903  and chair back portion  201 ′ when the back portion is generally upright, between an upper position shown in  FIG. 86  and a lower position shown in  FIG. 87 , to adjust the height of the head or neck support member  905 . 
     First and second parallel elongate closures each comprise two opposed, engagable sides  912   a ,  912   b  that engage to close or partially close the respective slit  912  in the closure. The slider arrangement  904  comprises two pairs of sliders  923  and a carriage  925 . The sliders  923  act to open or close the respective slit  912  as they slide along the slits  912 . The closures provide compliant flexible support rails upon which the support member  905  is supported. 
     One pair of the sliders  923  is arranged on each of the first and second slits  912 , as shown in  FIG. 90 , with the two sliders in each pair oppositely oriented. The carriage  925  attaches to each of the sliders  923  to fix the sliders relative to each other. As the carriage  925  is moved up and down relative to the mounting arrangement  903 , all four sliders slide along the respective slits to the same extent. The head or neck support member  905  in turn is connectable to the carriage  925 . As the sliders  923  in each pair are oppositely opposed, as the carriage is moved the leading slider in the direction of movement opens the slit  912  of the closure, and the trailing slider in the direction of movement closes the slit  912  of the closure. 
     In the embodiment of  FIG. 90 , the closures and sliders  923  each comprise a flexible zipper with the opposed sides  912   a ,  912   b  of the zipper having engagable teeth. The upper zipper slider  923  in each pair of sliders is arranged so that the zipper  912  is closed above the slider and open immediately below the slider. The lower slider  923  in each pair is oppositely arranged so that the slit  912  is open immediately above the slider  923  and closed below the slider  923 . By that configuration, the only portion of each zipper slit  912  that is open is the portion between the sliders  923 . That portion will be hidden in use by the support panel  905 , when viewed from the front of the chair. 
     Preferably, the teeth of the zippers have 10 mm width when engaged, and the closures are preferably about 230 mm long to provide about 170 mm range of adjustable travel of the support member  905 . The zippers are positioned a suitable distance apart, such as about 60 mm between slits  912  for example. Alternative sizes and configurations could be used. 
     In an alternative embodiment shown in  FIG. 91  the two elongate parallel closures each comprise slits  912 ′ and sliders  935  in a flexible zip-lock type arrangement. The two opposed, engagable sides  912   a ′,  912   b ′ of the closures comprise complementary elongate projections and recesses running along the length of the slits. A two-part slider  935  comprising and upper portion  935   a  and a lower portion  935   b  is arranged on each slit. Each upper portion  935   a  causes engagement of the complementary projections to close the respective slit  912 ′ above the slider as the slider is lowered, and parts the two sides  912   a ′,  912   b ′ immediately below the portion  935   a  as the slider is raised. Conversely, each lower portion  935   b  causes engagement of the complementary projections to close the slit below the slider as the slider is raised, and parts the two sides  912   a ′,  912   b ′ immediately above the portion  935   b  as the slider is lowered. With this arrangement, the slits  912 ′ are closed above and below the slider arrangement for any position of the slider arrangement intermediate the two ends. The upper and lower portions  935   a ,  935   b  of each slider  935  may be separate parts or may be integral. 
     In further alternative embodiments, the sliders  923 ,  935  may be oppositely oriented so that the slits  912 ,  912 ′ are open above and below the slider arrangement  904  and closed between sliders  923  or slider portions  935   a ,  935   b  on the same slit. The orientation of the sliders on the first slit may be different to the orientation of the sliders on the second slit. For example, the first slit and the respective slider(s) may be arranged so that the first slit is open above and below the slider arrangement  904 ; and the second slit and the respective slider(s) may be arranged so that the second slit is closed above and below the slider arrangement  904  as the slider arrangement is moved up and down. 
     While the following description relates to the zipper embodiment, it will be appreciated that the features and functioning for the zip-lock type embodiment will be the same. 
     The support member  905  is adjustable to a plurality of intermediate positions between the upper and lower positions of  FIGS. 86 and 87  by sliding the sliders along the respective closures. The engagement between the opposing sides of each slit  912 ,  912 ′ holds the sliders and the support  905  in place in the absence of an applied force. To adjust the height of the support  905 , an upward or downward force must be applied that is sufficient to slide the sliders along the closures  912 ,  912 ′ closing and opening respective portions of the slits. 
       FIGS. 92A to 94C  show the carriage  925  of  FIGS. 86 to 89 , and attachment of the zipper sliders  923  to the carriage  925 . An underside of the carriage  925  comprises four recesses  928  shaped to receive a top portion of the zipper sliders  923 . An upper portion of each recess  928  comprises an aperture, a boss  926 , and a resilient flap  927 . To attach the sliders  923  to the carriage, the sliders  923  are pressed into the carriage recesses. Each zipper slider  923  comprises a crown  924 , which in conventional zippers is for attaching a pull tab. The crowns  924  on the sliders push the flaps  927  upwards, as shown in  FIGS. 93A to 93C . The slider  923  can then be slid sideways onto the respective boss  926  so that the boss  926  is positioned between the slider crown  924  and the slider body. The respective flap  927  then snaps downwards to lock the slider  923  on the boss  926  to fixing it to the carriage  925 , as shown in  FIGS. 94A to 94C . 
     In an alternative embodiment, the carriage and the sliders  923  or  935  may be integral. 
     The carriage  925  comprises a centrally positioned support connector  929  protruding from an opposite surface of the carriage  925  from the sliders, for attaching the head or neck support  905  to the carriage and thereby to the mounting assembly  903 . The support connector  929  comprises four hollow compartments  930  which are open at a front end, for receiving portions of complementary connector(s) on the support  905 . The two middle compartments each comprise at least one side aperture  931  at their base. 
       FIGS. 95A to 96C  show the head or neck support member  905 . The head or neck support member  905  comprises a support panel  915 . A back side of the support panel  915  comprises a ribbed portion  916 . The ribbed portion  916  provides additional strength to the support  905  and preferably allows some flexing of the support panel  915 . In the embodiment shown, the ribbing in the ribbed portion is in the form of a lattice, but alternatively other ribbing patterns may be used. The back side of the support panel  915  comprises a non-ribbed surface  915   a  around the periphery of the ribbed portion  916 , for attaching upholstery. 
     The head or neck support member  905  may further comprise one or more layers of cushioning, and covering upholstery. The support member  905  shown in  FIG. 88  comprises three foam cushioning layers  905   a ,  905   b ,  905   c  of different densities. The first foam layer  905   a  adjacent the support panel  915  has the highest hardness and density, the middle foam layer  905   b  is less dense than the first layer  905   a , and the outer layer  905   c  has the lowest density and is the softest layer to provide maximum compliance to a user&#39;s head or neck. Alternatively, the cushioning may comprise a single moulded foam member. 
     The support panel  915  comprises a rearwardly projecting carriage connector  933  for connecting the support to the carriage  925 . Alternatively, the connector  933  may be a separate member attached to the support panel  915 . 
     The carriage connector  933  comprises a plurality of projections protruding from the main support panel  915  configured to fit into the compartments on the support connector  929  on the carriage  925 . Two of the projections  934  for receipt by the two central compartments on the support connector  929  each comprise a lateral lip or catch  934   a . Apertures  937  in the main support panel  915  adjacent to those two projections  934  enable those projections to be resiliently moved relative to the main support panel  915 . The carriage connector  933  and the support connector  929  are connectable by way of a snap-fit. As the support connector  929  and the carriage connector are moved into engagement, the central projections  934  deflect resiliently inwards. When the lips or catches  934   a  reach the base of the respective compartment, the lips or catches move into the apertures  931  at the base of the support connector  929  to engage the support connector  929 . 
     In an alternative embodiment, the head or neck support  905  and the carriage  925  may be integral and/or the carriage  925  and the sliders  923  may be integral. 
       FIG. 97  shows a front view of the mounting assembly  903 . The mounting assembly  903  comprises a double zipper member  911 , which comprises the two parallel slits  912 , a load dispersion panel  909 , and a back attachment assembly  906 . The double zipper member  911  and load dispersion panel  909  are both preferably compliant flexible members and the double zipper member  911  is stitched to a front surface of the load dispersion panel  909 . The bold lines  932  in  FIG. 97  indicate where the double zipper member is stitched. 
     With reference to  FIGS. 98A to 99D , the back attachment assembly  906  comprises a main back attaching member  907  and a retainer  908 . The main back attaching member  907  comprises a substantially planar, generally rectangular body with two straps  919   a ,  919   b  for attaching the member  907  to the back portion  201 ′ of a chair. A first one of the two straps  919   a  extends upwardly and rearwardly from a central upper portion of the body. A second one of the two straps  919   b  extends downwardly and rearwardly from a central lower portion of the body. Similarly the retainer  908  comprises a generally rectangular body with two straps  920   a ,  920   b  for attaching the retainer  908  to the back portion  201 ′ of a chair. A first one of the two retainer straps  920   a  extends upwardly and rearwardly from a central upper portion of the retainer body. A second one of the two straps  920   b  extends downwardly and rearwardly from a central lower portion of the retainer body. The upper straps  919   a ,  920   a  on the retainer  908  and the back attaching member  907  each comprise an enlarged portion  919   c ,  920   c  that allow the two upper straps  919   a ,  920   a  to be attached to the back portion with sufficient strength using the same fasteners. The straps act in tension, but are compressible to enable the dispersion panel  909 , zippers, carriage, and support member to be moved rearwardly under load. In alternative embodiments, rather than rearwardly extending straps, the back attachment member may comprise any other suitable tension member for example cords or fabric members to attach the back attachment member to the back portion of the chair. 
     A central portion of the back attaching member  907  comprises two apertures  907   a ,  907   c  for receiving the retainer straps  920   a ,  920   b . The lower aperture  907   c  is substantially rectangular to receive the lower strap  920   b . The upper aperture  907   a  is the same width as the lower aperture but comprises an enlarged upper portion to enable the enlarged end  920   c  of the upper retainer strap  920   a  to pass through the aperture  907   a . When assembled, the main body of the retainer  908  sits against the front surface of the back attachment member  907 , and the retainer straps extend through the apertures  907   a    907   c  and rearward from the back attachment member  907 . The retainer body comprises projections  908   a  that are received by complementary locating apertures  907   b  on the back attachment member  907  to correctly position the retainer  908  on the back attachment member  907  and prevent the retainer moving relative to the back attachment member  907 . 
     The back attaching member  907  is flexible about a horizontal axis to allow the assembly  906  to flex rearward upon contact with a user&#39;s back, for example when the head or neck support is in its highest position. Preferably, the rectangular portion  907  is thicker at its upper end than at its lower end, so that the flexibility of the back attaching member  907  transitions from relatively stiff at its upper end to relatively flexible at its lower end. The stiffness of the upper end provides stability of the head or neck support while the flexibility of the lower end provides a compliant contact surface for a taller occupant&#39;s back when the support member  905  is in the highest position. Preferably the back attaching assembly  906  is less flexible about a substantially vertical axis, to minimise side-to-side rotation of the head or neck support during use. In the embodiment shown, the back attaching assembly  906  is forwardly concave to match the curvature of the chair, for comfort. Alternatively the back attaching assembly  906  could be flat. 
     The retainer  908  and the back attaching member  907  preferably comprise polypropylene, or an elastomer such as Hytrel from DuPont, and are preferably made of the same materials. Rather than being two separate members, the retainer  908  and the back attaching member  907  may instead be integral. 
     Referring to  FIG. 100 , the back portion  201 ′ of a chair according to one embodiment comprises a relatively rigid portion comprising a back shell or frame  253 , a compliant cushion layer  255 , and an upholstery layer  257 . The upholstery could be any suitable type, such as natural or synthetic leather, fabric, or a polymeric material for example. As discussed above in relation to the preferred form chair, the back shell may be resiliently flexible, but will still be more rigid than the compliant cushion layer  255 . The slider arrangement  904  and the mounting assembly  903  are substantially positioned between a front surface of the cushion  255  and a back surface of the upholstery  257 . The load dispersion panel  909  is attached to the front surface of the cushion  255  by an adhesive, as shown in  FIG. 102 . Alternatively, the load dispersion panel  909  may not be fixed to the cushion  255 . The load dispersion panel  909  provides a larger area than the double zipper member  911  for transferring the load from the head or neck support  905  to the cushion  255 . By dispersing the user&#39;s load across the cushion, the load dispersion panel  909  also helps to mask the edge of the retainer  908  from the user&#39;s back, improving comfort. Preferably the load dispersion panel comprises a non-woven fabric, for example microsuede, but woven fabrics may also be used. 
     The cushion  255  comprises four central apertures  256 . The back attachment assembly straps  919   a ,  919   b ,  920   a ,  920   b  extend through these apertures to a rear side of the cushion  255 , as shown in  FIG. 101 . The straps  919   a ,  919   b ,  920   a ,  920   b  comprise apertures  921   a ,  921   b ,  922   a ,  922   b  at their ends. Fasteners  917  such as screws, push fasteners, or the like are placed through these apertures  921   a ,  921   b ,  922   a ,  922   b  and fasten to apertures  259  in the back shell  253  to secure the head or neck support assembly  901  to the back shell  253 . Due to limited space on the back portion above the back attaching member  907 , the upper strap  919   a  on the back attaching member is shorter than the other straps  919   b ,  920   a ,  920   b , and attaches to the back portion at the same point as the upper strap  920   a  on the retainer  908 . To reinforce the connection, the upper strap  920   a  on the retainer  908  folds over the top and in front of the upper strap  919   a  of the back attaching member  907 , so the enlarged portion of the upper strap  919   a  on the back attaching member  907  is positioned nearest the back portion and the apertures  921   a  and  922   a  are aligned. 
     Two fasteners  917  pass through the two aligned apertures  922   a ,  921   a  on the upper retainer strap  920   a  and the upper back attaching member strap  919   a , to provide a stronger connection to the back portion than if only one fastener were used. In an alternative embodiment where the back portion has sufficient height above the back attaching member  907 , the upper straps  920   a ,  919   a  may each comprise only one aperture and connect to the back portion independently in the same manner as the lower straps  920   b ,  919   b . The direct attachment of the back attachment assembly  906  to the back shell  253  minimises undesirable rotation of the support about a horizontal axis. 
     Because the straps  919   a ,  919   b ,  920   a ,  920   b  are flexible, the mounting assembly can move rearward or be tilted or twisted in response to rearward force on the head or neck support and compression of the cushion member  255 . 
     The upholstery  257  comprises an elongate aperture  258  that is substantially parallel to the two slits  912  and is preferably positioned between the two slits  912 . The aperture may be an elongate rectangular slot, or alternatively may be a slit in the upholstery. In a preferred embodiment, a polypropylene reinforcement member  959  with a central slot is optionally provided on a back side of the upholstery. The upholstery is wrapped around the slot and stitched to the polypropylene member  959  to reinforce and stiffen the elongate aperture  258 . In alternative embodiments, there may be no separate reinforcement member, or the reinforcement member may comprise any suitable material other than polypropylene. The support connector  929  protrudes forwardly through the upholstery aperture  258 , as shown in  FIG. 103 , and the head or neck support  905  attaches to the support connector  929 , as shown in  FIGS. 104A and 104B . The head or neck support and the sliders  923  are positioned on opposite sides of the upholstery layer  257 . The support connector  929  slides in the upholstery aperture  258  during height adjustment of the head or neck support  905 . 
     In a preferred embodiment, the mounting assembly  903  further comprises a trim strip  913  that is made from the same material as the upholstery, or from another fabric or material similar in colour and appearance to the upholstery. The trim strip  913  is positioned between the two slits  912  in the double zipper member and is preferably stitched to the load dispersion panel  909  as illustrated in  FIG. 97 . The trim strip  913  covers the only part of the mounting assembly  903  that would be visible through the aperture  258  in the upholstery  257  to minimise the visibility of the aperture. 
     The support assembly has been described above and is shown in the drawings with reference to a height adjustable head or neck support for a chair. Alternatively, the support assembly may be a height adjustable lumbar support, or alternatively a support that is adjustable side-to-side. In an assembly with a side-to-side adjustable support  905 , the slits  912  would be oriented substantially horizontally. 
     Rather than having two spaced-apart elongate closures, a single elongate closure could be provided, with the slider(s) supporting the support panel  905  from the single closure. However, the spaced-apart closures are preferred, as they minimise undesirable rotation of the support panel about a horizontal axis extending forward/rearward through the back portion and twisting about a vertical axis. For the zipper embodiment, rather than having separate sliders  923  that are configured to move together during adjustment of the support member, the sliders in the pair that engage one closure could be integrally formed. Equally, for the zip-lock type embodiment, the sliders  935  could be separately formed and configured to move together during movement of the support member  905 . The opposed pairs of sliders (or integrally formed effective opposed pairs) provide four points of stability for the carriage  925  and thereby the support member  905 , to thereby minimise undesirable rotation about a horizontal axis extending forward/rearward through the back portion of the chair. 
     The above describes preferred forms of the present invention, and modifications can be made thereto without departing from the scope of the present invention. 
     For example, the preferred form features are described and shown with reference to a domestic lounger chair. However, it will be appreciated that many of the features can readily be incorporated into different types of chairs, such as office chairs, vehicle chairs (e.g. aircraft, marine, or motor vehicle chairs), cinema, or theatre chairs for example. The supporting frame could be modified accordingly, so as to be fixed to the ground or a wall panel for example for a cinema or theatre chair. References herein to a chair should be construed sufficiently broadly to encompass these alternative applications. 
     Additionally, a number of the features described herein can be incorporated into chairs having different features. They need not all be incorporated into the same chair. 
     To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.