Control devices for motor-driven compressors

Claim 1

A SURGE-FREE MOTOR-DRIVEN COMPRESSOR DEVICE AND DELIVERY CONTROL SYSTEM THEREFOR FOR PROVIDING COMPRESSED AIR FOR USE IN AN AIRCRAFT AND THE LIKE AT SUBSTANTIALLY CONSTANT PRESSURES EVEN WHEN THE DEMAND FOR SAID COMPRESSED AIR IS SUBSTANTIALLY LESS THAN THE CAPACITY OF SAID DEVICE, WHICH COMPRISES IN COMBINATION, A ROTARY MOTOR-DRIVEN AIR COMPRESSOR CONSTRUCTED TO PROVIDE SURGE-FREE CONSTANT DELIVERY AT THE OUTPUT THEREOF, A DELIVERY CONDUIT FOR CONDUCTING COMPRESSED AIR FROM SAID COMPRESSOR AND HAVING A DISCHARGE OUTLET FOR CONNECTION TO SAID USE, PNEUMATICALLY BALANCED EXHAUST VALVE MEANS IN FLOW COMMUNICATION WITH SAID DELIVERY CONDUIT FOR VENTING TO THE ATMOSPHERE PART OR ALL OF SAID COMPRESSED AIR FROM SAID DELIVERY CONDUIT AND INCLUDING VALVE MEMBERS OF THE PRESSURE-BALANCED TYPE MOVEABLE FROM A CLOSED POSITION TO ANY OF A PLURALITY OF OPEN POSITIONS AND DISPOSED IN FLOW COMMUNICATION WITH SAID DELIVERY CONDUIT WHEREBY RESULTANT PRESSURE FORCES ACTING ON SAID VALVE MEMBERS ARE EQUALIZED IN ANY OF SAID POSITIONS THEREOF, ACTUATING MEANS OPERATIVELY CONNECTED TO SAID EXHAUST VALVE MEANS FOR MOVEMENT OF SAID VALVE MEMBERS GRADUALLY FROM SAID CLOSED POSITION TO ANY OF SAID OPEN POSITIONS AND IN FLOW COMMUNICATION WITH AND AND RESPONSIVE TO PRESSURE VARIATIONS IN SAID DELIVERY CONDUIT AT A POINT THEREIN ADJACENT SAID DISCHARGE OUTLET AND BETWEEN SAID EXHAUST VALVE MEANS AND SAID OUTLET, AND MEANS FOR CONTROLLING THE OPERATION OF SAID ACTUATING MEANS FOR SAID GRADUAL MOVEMENT OF SAID EXHAUST VALVE MEANS IN RESPONSE TO THE DEMAND FOR SAID COMPRESSED AIR AT SAID DISCHARGE OUTLET AND WHEREBY UPON SUDDENT CESSATION OF SAID DEMAND SAID EXHAUST VALVE MEANS OPENS SUDDENLY TO VENT THE ENTIRE OUTPUT OF SAID COMPRESSOR.