Solenoid controlled valve

Claim 1

IN A VALVE ASSEMBLY, A HOUSING HAVING FLUID INLET, EXHAUST, AND MOTOR CHAMBER, A VALVE ELEMENT MOVABLE TO A FIRST OPERATING POSITION IN WHICH IT CONNECTS THE MOTOR CHAMBER TO THE INLET CHAMBER AND MOVABLE TO A SECOND OPERATING POSITION IN WHICH IT CONNECTS THE MOTOR CHAMBER TO THE EXHAUST CHAMBER, SAID VALVE ELEMENT HAVING A FIRST PISTON PORTION EXPOSED TO A FIRST PISTON CHAMBER AND A SECOND PISTON PORTION A SMALLER AREA THAN THE FIRST PISTON PORTION EXPOSED TO A SECOND PISTON CHAMBER, PASSAGE MEANS CONNECTING THE INLET CHAMBER TO BOTH SAID PISTON CHAMBERS, CHECK VALVE MEANS CLOSING COMMUNICATION BETWEEN SAID PASSAGE MEANS AND SAID INLET CHAMBER WHEN THE PRESSURE OF FLUID IN SAID INLET CHAMBER IS LESS THAN THE PRESSURE OF FLUID IN SAID PASSAGE MEANS, A VENT PORT, PILOT VALVE MEANS OPERABLE TO A FIRST POSITION IN WHICH IS CONNECTS THE FIRST PISTON CHAMBER TO THE VENT PORT AND CLOSES COMMUNICATION BETWEEN THE FIRST PISTON CHAMBER AND SAID PASSAGE MEANS WHEREBY FLUID IN THE SECOND PISTON CHAMBER MOVES THE VALVE ELEMENT TO ONE OF ITS OPERATING POSITIONS, SAID PILOT VALVE ALSO BEING OPERABLE TO A SECOND POSITION IN WHICH IT CLOSES COMMUNICATION BETWEEN THE FIRST PISTON CHAMBER AND THE VENT PORT AND OPENS COMMUNICATION BETWEEN THE FIRST PISTON CHAMBER AND THE PASSAGE MEANS WHEREBY FLUID UNDER PRESSURE IN SAID FIRST PISTON CHAMBER MOVES THE VALVE ELEMENT TO ITS OTHER OPERATING POSITION, SAID SECOND PISTON CHAMBER BEING OF A SIZE TO CONTAIN A SUFFICIENT AMOUNT OF FLUID UNDER PRESSURE WHEREBY WHEN THE CHECK VALVE MEANS IS CLOSED AND THE PILOT VALVE MEANS IS OPERATED FOR CONNECTING THE PASSAGE MEANS TO THE FIRST PISTON CHAMBER FLUID WILL FLOW FROM SAID SECOND PISTON CHAMBER TO THE FIRST PISTON CHAMBER VIA SAID PASSAGE MEANS FOR MOVING SAID VALVE ELEMENT AS AFORESAID, AND MEANS TO OPERATE SAID PILOT VALVE MEANS.