Abstract: Support and adjusting mechanism for the seat and backrest of a work chair having a pedestal with feet and a vertical support column comprises a support part fixed on the upper end of the support column and having laterally spaced, parallel upwardly extending support flanges. A seat support has laterally spaced, parallel downwardly extending flanges which partially overlap and are pivotally connected with the flanges of the support part. A backrest support has laterally spaced, parallel, forwardly extending flanges partially overlapping and pivotally connected with the flanges of the support part and also the flanges of the seat support. A coupling lever has spaced, parallel flanges which partially overlap and are pivotally with the flanges of the support part, the seat support and the backrest support. An air spring acts between a lower region of the support part and a lower region of the backrest support.

Abstract: A work chair (10) has a seat (15) divided into a forward seat part (15.1) and a rear seat part (15.3) of which the forward seat frame part (17.1) and rear seat and back frame part (17.2) are connected with one another by a hinge joint with a hinge axis (18). The frame parts are supported on a pedestal (11) by seat frame supports (20,21). On the column (13) of the pedestal there is provided a column support part (25) which carries the pivot axis (23) and a swivel support part (28). On the pivot axis (23) seat frame supports (21) are mounted. The swivel support part (28) is tiltable by means of an inclination adjusting device with an actuating handle (6) for tilting the plane (E). The swivel support part (28) has forwardly an elongated bearing opening in which the sliding axis (22) is slidable against the force of an adjustable spring. The sliding axis (22) carries the seat frame support (20).

Abstract: Adjusting mechanism for the step-wise height adjustment of the backrest of a work chair comprises two U-form guide bars embracing side edges of a rectangular support arm extending up from the seat of the chair. A C-form slide, on which the backrest is mounted, embraces and is slidable on the guide bars. One of the guide bars has a wider flange in which locking recess are formed. A locking lever pivotally mounted on the slide has a nose portion engageable in the locking recesses to hold the slide and hence the backrest in selected fixed position. The locking lever is spring biased to locking position and is releasable by a handle at the side of the slide so that the locking lever can be released and the slide, with the backrest, moved up or down with one hand.