Control valve

Claim 1

A CONTROL VALVE COMPRISING A HOUSING HAVING A PAIR OF PORTS THEREIN, A STEPPED PISTON MEANS INCLUDING A LARGER PORTION MOVABLE IN SAID HOUSING BETWEEN SAID PORTS, OPPOSED DIFFERENTIAL AREAS ON SAID LARGER PORTION RESPECTIVELY SUBJECTED TO FLUID PRESSURE AT SAID PORTS, AND A SMALLER PORTION MOVABLE IN SAID HOUSING EXTENDING FROM SAID LARGER PORTION AND HAVING A FREE END DEFINING WITH SAID HOUSING AN ATMOSPHERIC CHAMBER, RESILIENT MEANS URGING SAID PISTON MEANS TOWARD ONE OF SAID PORTS, OTHER MEANS MOVABLE IN SAID STEPPED PISTON MEANS FOR CONTROLLING PRESSURE FLUID COMMUNICATION BETWEEN SAID PORTS, OTHER RESILIENT MEANS NORMALLY URGING SAID OTHER MEANS TOWARD SAID ONE PORT AND TOWARD A POSITION ESTABLISHING PRESSURE FLUID COMMUNICATION BETWEEN SAID PORTS, AND OPPOSED EFFECTIVE AREAS ON SAID OTHER MEANS RESPECTIVELY SUBJECTED TO FLUID PRESSURE AT SAID ONE PORT AND TO THE ATMOSPHERE IN SAID ATMOSPHERIC CHAMBER, SAID STEPPED PISTON MEANS BEING MOVABLE TOWARD THE OTHER OF SAID PORTS AGAINST SAID FIRST NAMED RESILIENT MEANS TO STORE THE ENERGY THEREOF IN RESPONSE TO FLUID PRESSURE LESS THAN A PREDETERMINED VALUE OF SAID PORTS RESPECTIVELY ACTING ON SAID OPPOSED DIFFERENTIAL AREAS, SAID OTHER MEANS BEING MOVABLE AGAINST SAID OTHER RESILIENT MEANS AND THE ATMOSPHERIC PRESSURE IN SAID ATMOSPHERIC CHAMBER ACTING ON ONE OF SAID OPPOSED EFFECTIVE AREAS TOWARD SAID OTHER PORT AND A POSITION INTERRUPTING PRESSURE FLUID COMMUNICATION BETWEEN SAID PORTS WHEN THE FLUID PRESSURE AT SAID ONE PORT ACTING ON THE OTHER OF SAID OPPOSED EFFECTIVE AREAS ATTAINS THE PREDETERMINED VALVE, AND SAID STEPPED PISTON MEANS AND OTHER MEANS BEING THEREAFTER FURTHER MOVABLE TOWARD SAID ONE PORT IN RESPONSE TO FURTHER INCREASES IN THE FLUID PRESSURE AT SAID OTHER PORT IN EXCESS OF THE PREDETERMINED VALUE ACTING ON ONE OF SAID OPPOSED DIFFERENTIAL AREA AND ASSISTED BY THE STORED ENERGY OF SAID FIRST NAMED RESILIENT MEANS TO EFFECT AN INCREASE IN THE FLUID PRESSURE AT SAID ONE PORT IN EXCESS OF THE PREDETERMINED VALUE ACTING ON THE OTHER OF SAID OPPOSED DIFFERENTIAL AREAS AND SAID OTHER OPPOSED EFFECTIVE AREA IN A PREDETERMINED RATIO WITH THE INCREASED FLUID PRESSURE IN EXCESS OF THE PREDETERMINED VALUE AT SAID OTHER PORT.