Back rest adjustment for seat - controls height and position and consists of rotary element in two parts receiving sliding arm which supports backrest

摘要

The link between the back-rest and seat of a chair, esp. a working chair, enables the position and height of the back-rest to be adjusted by the sitter while seated. The link consists of a sliding arm supporting the back-rest, with a spring, and rotary element. A control (40) locks the arm (13) holding the back-rest in the reouired position and height. The rotary piece is formed in two separate parts (10,10') between two mobile side-plates (3,3'). A recess (12) between the separate parts received the second end of the arm which is slide mounted in it.