Brake valve or the like for two separate systems

Claim 1

A RELAY VALVE INCLUDING A VALVE CASING HAVING INLET, DELIVERY AND CONTROL CAVITIES AND PORTS, A NORMALLY CLOSED VALVE ELEMENT BETWEEN THE INLET AND DELIVERY PORTS, AND FLUID PRESSURE RESPONSIVE MEANS FOR CONTROLLING SAID VALVE ELEMENT IN RESPONSE TO OPPOSING PRESSURES IN SAID CONTROL AND DELIVERY CAVITIES, SAID MEANS COMPRISING FIRST AND SECOND COOPERATING PARTS, SAID FIRST PART HAVING A FIST MOTIVE AREA EXPOSED TO THE PRESSURE IN SAID CONTROL CAVITY AND A SECOND OPPOSING ANNULAR MOTIVE AREA EXPOSED TO THE PRESSURE IN SAID DELIVERY CAVITY, A CYLINDRICAL PASSAGE IN THE CENTER OF SAID FIRST PART AND OPEN TO SAID DELIVERY CAVITY, SAID SECOND PART COMPRISING A PISTON SLIDEABLY RECEIVED IN SAID CYLINDRICAL PASSAGE AND HAVING A MOTIVE AREA EXPOSED TO THE PRESSURE IN SAID DELIVERY CAVITY, MEANS CONTROLLED BY SAID PISTON AND ENGAGEABLE WITH SAID VALVE ELEMENT FOR MOVING THE LATTER TO OPEN POSITION WHEN SAID PISTON IS MOVED THERETOWARDS, STOP MEANS IN SAID CYLINDRICAL PASSAGE FOR LIMITING THE MOVEMENT OF SAID PISTON AWAY FROM THE OPEN END OF SAID PASSAGE, RESILIENT MEANS NORMALLY URGING SAID PISTON INTO ENGAGEMENT WITH SAID STOP MEANS WHEREBY BOTH OF SAID PARTS ARE URGED AWAY FROM SAID VALVE ELEMENT, AND A MANUAL MEANS OPERATIVELY CONNECTED TO SAID PISTON FOR EFFECTING MOVEMENT OF THE LATTER TOWARDS SAID VALVE ELEMENT INDEPENDENTLY OF THE FIRST PART OF SAID PRESSURE RESPONSIVE MEANS TO EFFECT OPENING OF SAID VALVE ELEMENT IN THE ABSENCE OF PRESSURE IN SAID CONTROL CAVITY.