Pneumatischer Stellantrieb mit endmontierter Steuervorrichtung

摘要

This invention features a device for controlling the operation of a pneumatic actuator (1) and a pneumatic actuator having such a control device (20). More particularly, the actuator control device of the instant invention includes a housing (22) mounted to an actuator end cap (2), a solenoid valve (26) disposed within the housing and a gas control valve (24) that controls the pressurized gas admitted to and exhausted from the actuator for valve actuation. The gas control valve is responsive to the solenoid valve and is mounted to the housing. Preferably, the control device includes a position indication mechanism, disposed within the housing, that determines a prespecified position of the valve responsive to the movement of at least one and preferably two moveable actuator probes (14) extending from the actuator end cap into the housing. The gas control valve is a spool valve that is pneumatically controlled by the solenoid valve. The position indication mechanism includes a mechanical switch (28) or an inductive proximity switch, one for each actuator probe that determines the position of an end of each actuator probe that are each actuated by and end of an actuator probe as it moves within the housing responsive to the motion of the actuator.