Body support structure

Abstract

A body support structure includes a base, a seat and a backrest, with the backrest connected to the base with a torsion leaf spring. The torsion leaf spring may be configured with a plurality of fingers, and/or one or more flex regions. One or more struts may be connected between the seat or backrest and the base. In another aspect, the seat and/or backrest may be supported with one or more links that provide a counter-intuitive motion. In another aspect, a link may be coupled to a support with a flexible blade.

1 - 93 . (canceled) 
     
     
         94 . A backrest comprising:
 a frame comprising a pair of uprights;   a lateral support extending between and fixedly coupled to the pair of uprights, wherein the lateral support is twistable between at least first and second configurations;   a lumbar support vertically spaced from the lateral support, wherein the lumbar support is moveable between at least first and second configurations; and   a strut extending between the lateral support and the lumbar support, wherein the strut twists the lateral support between the first and second configurations as the lumbar support is moved between the first and second configurations.   
     
     
         95 . The backrest of  claim 94  wherein the lumbar support comprises opposite ends supported by the uprights. 
     
     
         96 . The backrest of  claim 95  wherein each of the ends is moveably supported by one of the uprights. 
     
     
         97 . The backrest of  claim 96  wherein the each of the ends is slideably supported by one of the uprights. 
     
     
         98 . The backrest of  claim 94  wherein the strut is disposed between the pair of uprights. 
     
     
         99 . The backrest of  claim 98  wherein the strut is centrally located between the pair of uprights. 
     
     
         100 - 103 . (canceled) 
     
     
         104 . A backrest comprising:
 a base;   a strut pivotably supported by the base, wherein the strut is pivotable about a laterally extending axis; and   a lumbar support coupled to the strut, wherein the lumbar support is vertically spaced from the axis, wherein the lumbar support is moveable in response to the strut pivoting about the axis.   
     
     
         105 . The backrest of  claim 104  further comprising a biasing member applying a biasing force to the strut in response to the strut pivoting about the axis. 
     
     
         106 . The backrest of  claim 105  further comprising a lateral support member defining the axis. 
     
     
         107 . The backrest of  claim 106  wherein the lateral support member is non-rotatably fixed at opposite ends thereof, wherein the lateral support member is twisted when the strut is pivoted about the axis. 
     
     
         108 . The backrest of  claim 107  wherein the biasing member comprises a torsion biasing member defined by the lateral support member. 
     
     
         109 . The backrest of  claim 107  wherein the base comprises a pair of laterally spaced uprights, wherein the opposite ends of the lateral support member are non-rotatably fixed to the uprights. 
     
     
         110 . The backrest of  claim 104  further comprises a body support member having a front substrate covering a front surface of the lumbar support. 
     
     
         111 . The backrest of  claim 110  wherein the body support member comprises a rear substrate covering a rear surface of the lumbar support. 
     
     
         112 . A method of supporting the body of a user with a backrest comprising:
 leaning rearwardly against the backrest;   applying a force to a lumbar support connected to a strut;   pivoting the strut about a laterally extending axis spaced vertically from the lumbar support; and   applying a biasing force to the strut to resist the pivoting of the strut about the axis.   
     
     
         113 . The method of  claim 112  further comprising a lateral support member defining the axis. 
     
     
         114 . The method of  claim 113  wherein applying the biasing force to the strut comprises twisting the lateral support about the axis. 
     
     
         115 . The backrest of  claim 114  wherein the base comprises a pair of laterally spaced uprights, wherein the opposite ends of the lateral support member are non-rotatably fixed to the uprights. 
     
     
         116 . The backrest of  claim 112  wherein the backrest further comprises a body support member having a front substrate covering a front surface of the lumbar support. 
     
     
         117 . The backrest of  claim 116  wherein the body support member further comprises a rear substrate covering a rear surface of the lumbar support.