Seating furniture i.e. office chair, has lever system formed according to type of toggle lever system, and adjustment unit causing change of mechanical hinge of spring element to lever system without changing deformation of spring unit

摘要

The furniture has a force transmission element (41) i.e. roller, hinged to a seat (2) swivel-movably, and a lever system (4) formed according to the type of a toggle lever system. A spring element (42) e.g. tension spring, is hinged to the lever system in such a manner that the spring element produces a resetting force by deformation during a swivel movement of the seat. An adjustment unit (47) causes a change of the mechanical hinge of the spring element to the lever system without changing the deformation of the spring unit in order to change the resetting force.