Safety control apparatus for operating pressure-actuated devices

Claim 1

A PRESSURE FLUID-OPERATED APPARATUS, COMPRISING A SOURCE OF PRESSURE FLUID, A DEVICE CONSUMING SAID FLUID; TWO MAIN VALVES, EACH HAVING INLET MEANS, OUTLET MEANS, AND OPEN DISCHARGE MEANS, SAID INLET MEANS AND SAID OUTLET MEANS OF ONE OF SAID VALVES RESPECTIVELY COMMUNICATING WITH THE INLET MEANS AND THE OUTLET MEANS OF THE OTHER VALVE, ECH VALVE FURTHER INCLUDING A VALVE MEMBER MOVABLE BETWEEN A FIRST POSITION IN SAID VALVE IN WHICH SAID VALVE CONSTITUTES A FIRST PASSAGE BETWEEN SAID INLET MEANS AND SAID OUTLET MEANS THEREOF, AND A SECOND POSITION IN WHICH SAID VALVE CONSITITUTES A SECOND PASSAGE BETWEEN SAID OUTLET MEANS AND SAID DISCHARGE MEANS THEREOF, THE EFFECTIVE FLOW SECTION OF EACH OF SAID SECOND PASSAGES BEING SUBSTANTIALLY GREATER THAN THE EFFECTIVE FLOW SECTION OF EACH OF SAID FIRST PASSAGES; A FIRST CONDUIT CONNECTING SAID COMMUNICATING INLET MEANS OF SAID VALVES TO SAID SOURCE OF PRESSURE FLUID; AND A SECOND CONDUIT FOR CONNECTING SAID COMMUNICATING OUTLET MEANS OF SAID VALVES TO SAID FLUID CONSUMING DEVICE, WHEREBY SAID FIRST AND SECOND CONDUITS COMMUNICATE WITH ONE OF SAID DISCHARGE MEANS WHEN ONE OF SAID VALVE MEMBERS IS IN THE SECOND POSITION THEREOF.