Valves for hydraulic systems

Claim 1

IN COMBINATION A PLURALITY OF HYDRAULIC CYLINDERPISTON UNITS EACH OF WHOSE CYLINDERS HAS FIRST AND SECOND CONDUITS IN COMMUNICATION WITH OPPOSITE SIDES OF ITS PISTON, AND A VALVE FOR CONTROLLING THE DELIVERY OF LIQUID UNDER PRESSURE TO SAID UNITS, SAID VALVE COMPRISING A BODY HAVING A CYLINDRICAL CHAMBER AND A VALVE ELEMENT ROTATABLE THEREIN, SAID BODY HAVING A PUMP DELIVERY PORT ADJACENT ONE END OF ITS CHAMBER, A PUMP RETURN PORT ADJACENT THE OTHER END THEREOF, AND INTERMEDIATE PAIRS OF DIAMETRICALLY ALINED CYLINDER PORTS, EACH PAIR OF CYLINDER PORTS BEING FOR A RESPECTIVE ONE OF SAID UNITS AND EACH CYLINDER PORT OF THAT PAIR BEING FOR AN APPROPRIATE ONE OF THE CYLINDER CONDUITS OF THE UNIT, CORRESPONDING CYLINDER PORTS OF THE PAIRS ARRANGED SIDE-BY-SIDE, AND SAID VALVE ELEMENT HAVING ANGULARLY SPACED PAIRS OF TRANSVERSELY ALINED CHANNELS ARRANGED AT RIGHT ANGLES TO ITS AXIS, EACH PAIR BEING FOR ONE OF SAID PAIRS OF CYLINDER PORTS AND REGISTERABLE THEREWITH AS SAID ELEMENT ROTATES AND SPACED 90* FROM THE CHANNELS OF THE OTHER PAIR, SAID VALVE ELEMENT ALSO HAVING ANNULAR GROOVES, ONE FOR EACH MAIN PORT AND IN COMMUNICATION THEREWITH, AND CONNECTING PASSAGES BETWEEN EACH ANNULAR GROOVE AND A CORRESPONDING CHANNEL OF EACH OF THE ANGULARLY SPACED PAIRS THEREOF.