Adjustable back support for a seat assembly

Abstract

A back support includes an anchor plate attachable to a back frame of a wheelchair and a spanning plate securable to the anchor plate in a range of vertical positions to adjust a height of the back support. The spanning plate is secured to the anchor plate by a fastener secured through an aperture in the anchor plate and attached to a laterally extending bar selectively engageable with the spanning plate in a plurality of discrete vertical positions.

We claim: 
     
         1 . A back support comprising:
 an anchor plate attachable to a back frame of a wheelchair; and   a spanning plate securable to the anchor plate in a range of vertical positions to adjust a height of the back support;   wherein the spanning plate is secured to the anchor plate by a fastener secured through an aperture in the anchor plate and attached to a laterally extending bar selectively engageable with the spanning plate in a plurality of discrete vertical positions.   
     
     
         2 . The back support of  claim 1 , wherein first and second end portions of the laterally extending bar are engageable with aligned first and second holes in the spanning plate in each of the plurality of discrete vertical positions. 
     
     
         3 . The back support of  claim 2 , wherein the first and second end portions of the laterally extending bar comprise first and second rear nubs. 
     
     
         4 . The back support of  claim 1 , wherein the fastener is assembled with a threaded rear portion of the laterally extending bar. 
     
     
         5 . The back support of  claim 1 , wherein the fastener is received through a vertically extending slot in the spanning plate. 
     
     
         6 . The back support of  claim 1 , further comprising first and second wing plates securable to first and second lateral sides of the spanning plate in a range of lateral positions to adjust a width of the back support. 
     
     
         7 . The back support of  claim 6 , further comprising third and fourth wing plates securable directly to the anchor plate in a range of lateral positions to adjust a second width of the back support. 
     
     
         8 . The back support of  claim 1 , further comprising first and second wing plates securable directly to the anchor plate in a range of lateral positions to adjust a second width of the back support. 
     
     
         9 . The back support of  claim 1 , further comprising a headrest plate attachable to a headrest and securable to the spanning plate in a range of vertical positions to adjust a height of the headrest on the back support. 
     
     
         10 . A wheelchair seat assembly comprising:
 a seat frame defining a seating area;   a back frame connected to the seat frame;   a back support connected to the back frame, the back support comprising an anchor plate and a spanning plate securable to the anchor plate in a range of vertical positions to adjust a height of the back support, wherein the spanning plate is secured to the anchor plate by a fastener secured through an aperture in the anchor plate and attached to a laterally extending bar selectively engageable with the spanning plate in a plurality of discrete vertical positions.   
     
     
         11 . The seat assembly of  claim 10 , wherein the back frame is pivotally connected to the seat frame at a pivot axis and the back support is slideably secured to the back frame, wherein pivoting movement of the back frame from an upright position to a reclined position causes the back support to slide away from the pivot axis. 
     
     
         12 . The seat assembly of  claim 11 , wherein the anchor plate comprises a plurality of flanged brackets slideably received in recessed tracks in the back frame. 
     
     
         13 . The seat assembly of  claim 10 , wherein first and second end portions of the laterally extending bar are engageable with aligned first and second holes in the spanning plate in each of the plurality of discrete vertical positions. 
     
     
         14 . The seat assembly of  claim 13 , wherein the first and second end portions of the laterally extending bar comprise first and second rear nubs. 
     
     
         15 . The seat assembly of  claim 10 , wherein the fastener is assembled with a threaded rear portion of the laterally extending bar. 
     
     
         16 . The seat assembly of  claim 10 , wherein the fastener is received through a vertically extending slot in the spanning plate. 
     
     
         17 . The seat assembly of  claim 10 , further comprising first and second wing plates securable to first and second lateral sides of the spanning plate in a range of lateral positions to adjust a width of the back support. 
     
     
         18 . The seat assembly of  claim 10 , further comprising third and fourth wing plates securable directly to the anchor plate in a range of lateral positions to adjust a second width of the back support. 
     
     
         19 . The seat assembly of  claim 10 , further comprising first and second wing plates securable directly to the anchor plate in a range of lateral positions to adjust a second width of the back support. 
     
     
         20 . The seat assembly of  claim 10 , further comprising a headrest plate attachable to a headrest and securable to the spanning plate in a range of vertical positions to adjust a height of the headrest on the back support.