Abstract: A mechanism for adjusting the height of a back part (3) of a typist's chair uses a sleeve-shaped slider (13) on the back part which slides along a rigid bar (8), and an interengageable pawl (37) and rack (22 or 23) are used to retain the back part (3) in an adjusted position. The sleeve (13) is accurately guided on the bar by engagement of projections (42, 43) such as lengths of cord, with grooves (40, 41). This guide arrangement can also be used for guiding movement of separate parts on furniture or in other applications.

Abstract: An office chair has a seat (1) mounted on a base (2) so that its inclination can be adjusted with a mechanism (4). The mechanism has a spring (28) mounted in compression between the seat and base, and a manual control (20) acts to adjust the extent of compression of the spring and also the direction of application of the spring force so that a generally linear resistance characteristic can be obtained. The spring (28) preferably has a lower support (12) which engages a positionally adjustable fulcrum (15, 18), and an upper support (11) pivotally connected to the lower support (12). The upper support (11) may be rigidly connected via a rigid bar to a chair back (3). A spring and ratchet arrangement (33, 34) may be provided for locking the seat in position relative to the base.

Abstract: An arrangement providing a backrest support pillar, particularly, though not exclusively, for an office chair whereby the height of a backrest can be selected by the user in a simple and ready manner using one hand. More particularly an arrangement is contemplated wherein the pillar is adjustable from a maximum length to a minimum length without resistance and is adjustable incrementally from that minimum length and automatically maintainable at a selected length. The invention also provides a seat/back synchronous tilt mechanism for a chair which eliminates the "shirt-lifting" effect of known chairs.