Mechanism e.g. synchronous mechanism, for office chair, has adjuster for changing movement characteristic of mechanism to change pivoting resistance of backrest of office chair, and electric motor and spindle actuating adjuster

摘要

The mechanism (1) has an adjuster (6) for changing a movement characteristic of the mechanism to change a pivoting resistance of a backrest of an office chair. An electric motor (7) and a spindle actuate the adjuster. The spindle is directly or indirectly connected with the electric motor, and driven by the electric motor. The adjuster includes a spring arrangement with a pressure spring (9), where the spring arrangement is actively connected with a backrest support (4) of the office chair. The spindle changes a tension of the spring and a spring rate of the spring arrangement.