Fluid system and valve assembly therefor

Claim 1

IN COMBINATION, A DIRECTIONAL CONTROL VALVE AND A FLOW CONTROL VALVE, SAID DIRECTIONAL CONTROL VALVE COMPRISING A HOUSING HAVING AN INLET PORT FOR COMMUNICATION WITH A FLUID PRESSURE SOURCE, A RETURN PORT, A PAIR OF BORES, AND A PAIR OF MOTOR PORTS ASSOCIATED WITH EACH BORE, SAID BORES BEING INTERSECTED AXIALLY THEREALONG BY PASSAGES COMMUNICATING WITH SRAID INLET, RETURN, AND MOTOR PORTS, A VALVE SPOOL IN EACH BORE MOVABLE TO OPERATING POSITIONS WHEREAT COMMUNICATION IS ESTABLISHED SELECTIVELY BETWEEN SAID INLET PASSAGE AND ONE OF ITS ASSOCIATED MOTOR PORTS WHILE THE OTHER ASSOCIATED MOTOR PORT IS COMMUNICATED WITH SAID RETURN PASSAGE, AND MEAN INCLUDING A CHECK VALVE OPERATIVE TO PERMIT FLOW OF FLUID FROM SAID RETURN PASSAGE TO SAID INLET PORT WHEN THE PRESSURE IN SAID INLET PORT IS LOWER THAN THE PRESSURE IN SAID RETURN PASSAGE TO SUPPLEMENT THE FLUID IN SAID INLET PORT WHICH IS ALREADY BEING SUPPLIED BY SAID FLUID PRESSURE SOURCE; SAID FLOW CONTROL VALVE COMPRISING A VALVE MEANS LOCATED IN SAID RETURN PASSAGE DOWNSTREAM OF BOTH OF SAID VALVE SPOOLS OPERATIVE TO BLOCK RETURN FLOW FROM SAID MOTOR PORTS THROUGH SAID RETURN PASSAGE TO SAID RETURN PORT WHEN THE PRESSURE IN SAID INLET PORT DROPS BELOW A PREDETERMINED VALE TO CAUSE A BUILDUP OF THE PRESSURE IN SAID RETURN PASSAGE, WHEREBY THE DISCHARGE FROM ALL OF SAID MOTOR PORTS WILL BE DIRECTED TO SAID INLET PORT TO PROVIDE MAKEP FLOW FROM SAID DIRECTIONAL CONTROL VALVE WHEN THE PRESSURE IN SAID INLET PASSAGE DROPS BELOW SUCH PREDETERMINED VALUE.