Chair with adjustable seat

摘要

The chair has an inclinable seat support, and an inclinable backrest supported by a backrest support. A crank contour (14) forms a rectangle with four straight sides which are connected with each other at round corners. A flange (12) of a collar (9) forms an equilateral triangle with the three straight sides that are connected with each other at round corners. The round corners of the collars lie in upper and lower positions of the collar in the front upper and lower corner of the contour. The corners of the flange are supported at the contour during upward and downward movement of the collar.