Flush valves

Claim 1

AN OPERATING SYSTEM FOR VALVES OF THE TYPE HAVING A MAIN VALVE MEMBER DIVIDING A VALVE OPERATING SPACE INTO AN INLET CHAMBER AND A SECOND CHAMBER OPPOSED THERETO AND HAVING MEANS FOR ADMITTING PRESSURE FROM THE INLET CHAMBER TO SAID SECOND CHAMBER WHEREBY THE PRESSURE IN SAID SECOND CHAMBER MAY HOLD SAID VALVE CLOSED UPON ITS SEAT, INCLUDING AN OPERATING MEMBER ADAPTED TO UNSEAT A PILOT VALVE FOR SAID MAIN VALVE SO AS TO RELIEVE THE PRESSURE IN THE SECOND CHAMBER OF THE MAIN VALVE AND ALLOW OPENING OF SAID MAIN VALVE, SAID OPERATING MEMBER BEING MOUNTED FOR MOVEMENT TOWARD AND AWAY FROM PILOT VALVE OPENING POSITION, MEANS FOR BIASING SAID MEMBER AWAY FROM PILOT VALVE OPENING POSITION, A LINKAGE HAVING AN ACTUATING STEM ASSOCIATED WITH SAID OPERATING MEMBER AND ADAPTED UPON MOVEMENT IN ONE DIRECTION TO CAUSE MOVEMENT OF SAID OPERATING MEMBER TOWARD PILOT VALVE OPENING POSITION, A PRESSURE CHAMBER ADAPTED TO BE SUBJECTED TO THE PRESSURE IN THE INLET CHAMBER OF SAID MAIN VALVE AND HAVING A MOVABLE PRESSURE RESPONSIVE MEMBER THEREIN ADAPTED FOR MOVEMENT IN ONE DIRECTION IN RESPONSE TO A BUILDUP OF PRESSURE IN SAID CHAMBER, SAID LINKAGE BEING INTERCONNECTED WITH SAID PRESSURE RESPONSIVE MEMBER TO CAUSE MOVEMENT OF SAID STEM AWAY FROM PILOT VALVE OPENING POSITION IN RESPONSE TO A BUILDUP OF PRESSURE, MEANS BIASING SAID ACTUATING STEM TOWARD PILOT VALVE OPENING POSITION, SAID LINKAGE HAVING A RELEASABLE CONNECTION WITH SAID PRESSURE RESPONSIVE MEMBER CONSTRUCTED AND ARRANGED SO THAT MOVEMENT OF SAID PRESSURE RESPONSIVE MEMBER IN SAID ONE DIRECTION PRODUCES MOVEMENT OF SAID ACTUATING MEMBER OPPOSITE TO THE PILOT VALVE OPENING DIRECTION WHILE, UPON RELEASE OF SAID CONNECTION, SAID LINKAGE PRODUCES REVERSE MOVEMENT OF SAID ACTUATING MEMBER UNDER THE BIAS OF SAID MEANS AND IN THE PILOT VALVE OPENING DIRECTION, AND MEANS RETARDING MOVEMENT OF THE ACTUATING MEMBER AND SAID LINKAGE.