Servo mechanism having cylinder with elastically-deformable wall - provides signals from double-acting chamber to logic circuit via bellows and electrode

摘要

A servo system has a cylinder made with an elastically-deformable front wall. It determines when the piston has reached the end position. The cylinder is double acting and the two chambers are linked to a pressure pipe and a feed pipe. The piston (16) is made with an actuator prong on one side. The actuator prong (28) operates in conjunction with a spring-loaded bellows (30) made from stainless steel and incorporated in the front wall of the cylinder. It actuates a proximity microswitch (34) supplying a signal to a logic circuit (50). The other chamber has a spring-loaded bellow protruding from the end wall with an air orifice (54) and an electrode (56). A signal is supplied to another logic circuit (60).