TENSION ADJUSTMENT MECHANISM FOR A CHAIR

摘要

A tilt control mechanism (18) for an office chair (10) includes a spring assembly (56) therein which controls the tilt tension on the back assembly (24). This tilt control mechanism (18) includes a tension adjustment assembly (50,57) having a cam wedge (82) which supports the legs (79) of a pair of coil springs (77) and a cooperating drive block (83) assembly which cooperates with the cam wedge to drive the cam wedge upwardly and downwardly to vary the tilt tension. The drive assembly includes drive blocks mounted on a threaded shaft which are displaceable sidewardly toward and away from each other to either drive the cam wedge upwardly when the drive blocks (83) move together or downwardly when the drive blocks move away from each other.