Multiple disc valve

Claim 1

A VALVE COMPRISING A CIRCULAR HOUSING HAVING SPACED INWARDLY PROJECTING RIBS, AN INLET CONDUIT FORMED ON SAID HOUSING, ANNULAR FLUID FLOW CONTROLLING MEANS HAVING RESILIENT ELEMENTS INTERPOSED BETWEEN RIGID ELEMENTS AND ARRANGED IN A STACK SPACED FROM THE INNER SURFACE OF SAID HOUSING BY SAID RIBS, THE CONTACTING SURFACES OF CERTAIN OF SAID RESILIENT ELEMENTS BEING CORRUGATED TO PROVIDE AT TIMES PASSAGES FOR THE FLOW OF FLUID THROUGH THE SPACES BETWEEN THE STACK OF ELEMENTS AND THE HOUSING AND THE SPACE WITHIN SAID STACK OF ANNULAR ELEMENTS, A PRESSURE HEAD ABUTTING AGAINST THE END OF SAID STACK OPPOSITE TO SAID INLET CONDUIT, A STEM ENGAGING WITH SAID PRESSURE HEAD AND EXTENDING AXIALLY OUTWARD OF SAID HOUSING, A FLUID SEALING MEANS BETWEEN THE HOUSING AND SAID STEM, ADJUSTABLE RESILIENT MEANS MOUNTED ON SAID HOUSING AND BEARING AGAINST SAID STEM TO MOVE THE PRESSURE HEAD IN A DIRECTION TENDING TO CLOSE SAID ANNULAR ELEMENTS ON ONE ANOTHER, SAID INLET CONDUIT BEING IN FLOW COMMUNICATION WITH THE SPACE WITHIN SAID STACK OF ANNULAR ELEMENTS, AN OUTLET CONDUIT IN FLOW COMMUNICATION WITH THE SPACES BETWEEN THE STACK OF ANNULAR ELEMENTS AND THE HOUSING, AND FLUID FLOW TO THE SPACES BETWEEN SAID STACK OF ANNULAR ELEMENTS AND SAID HOUSING FROM THE SPACE WITHIN SAID STACK OF ANNULAR ELEMENTS BEING PREVENTED EXCEPT WHEN THE PRESSURE OF FLUID EFFECTIVELY ACTING AGAINST THE BIASING ACTION OF SAID ADJUSTABLE RESILIENT MEANS IS SUFFICIENT TO CAUSE THE PRESSURE HEAD TO BE MOVED IN A DIRECTION OPPOSED TO THE BIASING ACTION OF SAID ADJUSTABLE RESILIENT MEANS FOR FORMING PASSAGES BETWEEN ADJACENT ANNULAR ELEMENTS OF SAID STACK OF ANNULAR ELEMENTS.