A device for controlling actuators by pneumatic pulses includes a casing having an inlet for vacuum pulses and an outlet connectable to an actuator. A control wheel is rotatably mounted in the casing and has a plurality of indentations therein. A plunger is disposed in a chamber in the casing and is...http://www.google.co.uk/patents/US4304262?utm_source=gb-gplus-sharePatent US4304262 - Device for controlling actuators by means of pneumatic pulses
