US Patent 7866750 Permanent contact mechanism

A permanent-contact mechanism for an office chair or the like is formed as a comparatively flat permanent-contact mechanism with a seat frame, which can be positioned on a chair upright, with a backrest support, which is arranged on the seat frame such that it can be pivoted about a transverse axis, and with at least one spring-activated or inherently resilient lever element, which interacts with the backrest support such that the backrest support is always pivoted counter to a spring force. The position of the point of rotation of the lever element differs from the position of the transverse axis.