DEVICE FOR MONITORING CONTROL ELEMENTS

摘要

Device for monitoring the relative position of synchronously moved control elements, especially for monitoring the movement of two valve cases in safety valves controlling a pneumatic or hydraulic drive. The device includes a magnetic member disposed at each of the valve cases and symmetrically arranged with respect to one another, a rotatably mounted magnetic bar having each of the magnetic members arranged proximate to a free end thereof for magnetically influencing the positioning thereof. Spring forces and magnetic forces are effective on the bar so as to provide the bar with a first basic stable position corresponding to synchronous movement of the valve cases and two stable disturbance positions corresponding to asynchronous movement of the valve cases.