US Patent 7396081 Chair height adjustment mechanism

A chair control mechanism has a rotatable shaft with a radially extending member abutting an actuating finger of a gas control cylinder. A slider may push a second radially extending member of the rotatable shaft in order to rotate the shaft. The slider has a tab extending into the mouth of the head of a further shaft which is rotated by a user operated handle. Thus, when the user operates the handle, the head of the further shaft causes the slider to slide.