Patent ID: 7066538

Claim:
A chair comprising a seat frame, a central support member that fixedly supports said seat frame, a seat assembly tiltably mounted to said seat frame, a lock member operatively connected to said seat assembly and in sliding engagement with said seat frame, a lock engagement member operatively secured to said seat frame and in operative relation to said lock member, and an operating lever for operating said lock engagement member between an unlocked condition and a locked condition, said operating lever being movable between a lock position and an unlock position, and a means for connecting said operating lever and said lock engagement member, said connecting means being a biasing means that biases said lock engagement member toward its unlocked position when said operating lever is in its unlock position, and biases said lock engagement member toward its locked position when said operating lever is in the lock position, whereby when said lock engagement member is in an unlocked condition, said seat assembly can move through its range of tilting motion while said lock member slides with respect to said seat frame, and when said lock engagement member is in the locked condition, it engages said lock member such that said lock member does not slide with respect to said seat frame, said seat assembly thereby being restrained from tilting, said operating lever being movable to assert a biasing force through said biasing means to urge said lock engagement member toward said lock member at any tilt position of said seat assembly, said biasing force causing said lock engagement member to move into locking engagement with said lock member when said seat assembly is moved through its range of tilting motion to an untilted position.