Adjustable seat construction

Claim 1

An adjustable seat assembly comprising a lower support, a rigid rectangular seat frame, front and rear bell crank levers pivotally connected between said support and the front and rear respectively of said frame, said bell crank levers being pivotal on said frame as a consequence of substantially vertical movement of the adjacent edge of said frame, an elongated longitudinally extending rack plate having a series of openings therein fixed to said frame, elongated longitudinally extending, longitudinally slotted front and rear pawls pivotally connected at one end to corresponding bell crank levers and having teeth at their other ends receivable in the openings in said rack plate, a manually operable control lever having an inwardly extending end pivotal on said frame to provide for pivotal movement of said control lever forwardly and rearwardly from an intermediate position in which both bell cranks are locked against pivotal movement, an operator fixed to said control lever having a lug thereon, front and rear actuators pivoted for independent movement on the inwardly extending end of said control lever engaging said lug, front and rear latch levers pivoted to said frame for independent movement about transverse axes by said actuators, said latch levers having projections thereon receivable in the slots in said pawls and operable to swing the toothed end of the corresponding pawl to disengage its teeth from the openings in said rack plate, the elongated slots in said pawls providing for longitudinal movement thereof on pivotal movement of the associated bell crank levers.