Adjustable office arm chair structure with articulation for the synchronous movement of the seat and the backrest

摘要

A structure for an office chair with articulation by synchronized movement of the seat and the backrest of the adjustable type includes a swivel type movable base with a height adjustable column supporting a seat surface and a reciprocally hinged backrest. The seat surface is connected frontally by two braces to the corresponding anterior side of a central support body anchored on the top of the adjustable column along the vertical axis. The central support body supports with hinges the lower ends of two arm-rest stanchions provided with a device for the adjustment of the height of the seat and with an locking-unlocking device for the oscillation of the backrest and the chair. The frame of the backrest is hinged along the sides and in correspondence with the posterior part of the seat. A compressed spring is interposed between the central support body and the support frame of the backrest.