Synchronised adaptor for chair seat and backrest with front support and swivel connections

摘要

The front support for the chair seat, in the form of a pendulum joint (10), connects the seat (4) pivotally to a bottom frame (8). A swivel connection (14) is positioned between the backrest and bottom frame, and a swivel connection (16) is positioned between the backrest and seat. The pendulum joint has a lever arm (22) fixed to the seat, and a pivot lever (24) rotarily positioned on the bottom frame and lever arm. The lever arm extends downwards away from the seat. The top end of the pivot lever is rotatrily joined to the bottom frame; the bottom end is connected to the lever arm near its free end.