Abstract A seat assembly includes a seat frame, a back frame defining a back plane pivotally connected to the seat frame at a pivot joint, a back support slideably secured to the back frame, and a back support adjusting mechanism. The back support adjusting mechanism includes a first linking member coupling the back support to the seat frame and pivotable about the pivot axis, and a first slide member slideably supported by the back frame and operatively connected to the first linking member. A second slide member is affixed to the back support and slideably supported by the back frame. A second linking member operatively connects the first and second slide members. Pivoting movement of the back frame from the upright position to the reclined position slides the first slide member away from the pivot axis, causing the second linking member to slide the back support toward the pivot axis.
