Shuttle valve with integrated detent means

Claim 1

IN A SAFETLY VALVE OF THE TYPE HAVING A PAIR OF INLET PRESSURE FLUID CHAMBERS AND A BASE PROVIDED WITH A PRESSURE FLUID SUPPLY CHAMBER AND A SHUTTLE VALVE HOUSING HAVING A SHUTTLE VALVE BORE IN WHICH IS OPERADTIVEY MOUNTED A SHUTTLE VALVE INCLUDING A SPOOL PROVIDED WITH A CENTRALLY MOLUNTED VALVE HEAD AND A PISTON OF EQUAL AREA AT EACH END FOR ENGAGEMENT BY FLIUD UNDER PRESSURE PROVIDED BY SAID FLUID CHAMBERS, TO MAINTAIN THE SHUTTLE VALVE IN A CENTRAL OPERATIVE BALANCED POSITION, SAID VALVE INCLUDING AN OUTLET CLOSABLE BY SAID VALVE HEAD WHEN IT IS MOVED FROM SAID BALANCED CENTRAL POSITION, A VARIABLE PRESSURE DETENT MEANS COMPRISING, A DETENT PISTON MOUNTED IN SAID SHUTTLE VALVE HOUSING FOR MOVEMENT TRANSVERSE TO THE LONGITUDINAL AXIS OF THE SHUTTLE VALVE; ONE OF SAID SHUTTLE VALVE PISTONS HAVING A V-SHAPED GROOVE FORMED ON THE PERIPHERY THEREOF; SAID DETENT PISTON HAVING A POINTED INNER END EXTENDABLE INTO SAID SHUTTLE VALVE BORE AND INTO RELEASABLE ENGAGEMENT WITH SAID V-SHAPED GROOVE ON SAID ONE OF SAID SHUTTLEE VALVE PISTONS AND PASSAGE MEANS THROUGH SAID BASE AND SHUTTLE VALVE HOUSING INTERCONNECTING SAID PRESSURE FLUID SUPPLY CHAMBER AND SAID DETENT PISTON FOR NORMALLY MOVING SAID DETENT PISTON POINTED INNER END INTO OPERATIVE ENGAGEMENT WITH SAID V-SHAPED GROOVE ON SAID SHUTTLE VALVE PISTON, SAID DETENT PISTON BEING AUTOMATICALLY ADJUSTABLY TO VARIATIONS IN THE OPERATING PRESSURE OF SAID SAFETY VALVE WHERBY THE INWARDLY DIRECTED TRANSVERSE FORCE EXERTED ON SAID DETENT PISTON IS DIRECTLY PROPORTIONED TO THE PRESSURE OF THE OPERATING FLUID, SO THAT AS THE OPERATING PRESSURE IN SAID PRESSURE FLUID SUPPLY CHAMBER VARIES THE FORCE EXERTED ON SAID DETENT PISTON VARIES AND THEREFORE THE FORCE IT EXERTS ON SAID SHUTTLE VALVE PISTON VARIES.