Spring mechanism for weight adjustment for office chair, has auxiliary element exerting force on spring element, where force transmission takes place in displacement-free manner, during adjustment of pre-stressing of spring element

摘要

The mechanism has a spring element e.g. torsion rod (10) and leg spring, designed for transmission of a resetting force to a chair i.e. office chair, part i.e. backrest (2). An auxiliary spring element (22) exerts a force on the spring element in a pre-stressing direction. The force transmission to the spring element takes place in a relative displacement-free manner, during an adjustment of pre-stressing of the spring element manually using an adjusting mechanism. The auxiliary spring element acts together with the spring element over a lever arm (12).