Device for controlling actuators by means of pneumatic pulses

A device for controlling actuators by pneumatic pulses, comprising:

• a casing having an inlet for vacuum pulses, an outlet connectable to an actuator and a ganging connection;
• a chamber in the casing having a single connection for the supply of the vacuum pulses;
• a control wheel rotatably mounted in the casing and having a plurality of indentations therein;
• a plunger disposed in the chamber of the casing;
• means sealingly guiding the plunger in the chamber for movement from a normal rest position wherein the plunger is engaged with one of the indentations to a retracted position when the chamber is evacuated wherein the plunger is engaged with a successive indentation and effecting rotation of the control wheel when the plunger returns to the rest position;
• means providing fluid communication between the inlet and outlet and between the inlet and the chamber through the control wheel to control the supply of the vacuum pulses to the outlet and to the chamber in dependence on the angular position of the control wheel comprising passages in the end faces of the control wheel, throughbores connecting the end faces of the control wheel and fluid passages connected to the inlet and ganging connection and terminating at one end face of the control wheel and wherein the control wheel has said one end face configured to connect the inlet and ganged connection when the control wheel is in a given angular position;
• wherein the casing comprises front and rear cover plates between which the control wheel is rotatably mounted and wherein the inlet and ganging connection are disposed on the rear cover plate.

In an apparatus for the control of actuators for execution of a presettable number of successive identical work cycles by means of pneumatic pulses, wherein the pneumatic pulses are fed to a chamber which is contained in the housing of the apparatus and in which a plunger guided sealingly with respect to the chamber is disposed, said plunger operating an adjustable control wheel which is provided with a plurality of indentations at its periphery, is disposed between a front cover plate and a rear cover plate, and is provided with bores which when aligned with apertures in the two cover plates establish an air channel between a source providing a pressure differential relative to atmospheric pressure and means for initiating the work cycles, the improvement wherein:

• a. the plunger is guided by means mounting same for movement between a rest position and a retracted position against a spring bias and the source for providing a pressure differential comprises a vacuum source producing a pulsating vacuum which is simultaneously fed to the chamber to move the plunger into the retracted position;
• b. the two cover plates comprise members covering the entire control wheel;
• c. means forming a zero pulse actuation position for the control wheel wherein the bores and indentations are located in the control wheel to establish said air channel except when the control wheel is in the zero position and the control wheel comprises a sealing surface and venting aperture wherein, in the zero position of the control wheel, the feed to the aperture in one of the cover plates is shut off by the sealing surface of the control wheel and the vacuum pulses are vented through the venting aperture in the control wheel to the outer atmosphere.