Balanced hydraulic valve assembly

Claim 1

A HYDRAULIC VALVE ASSEMBLY COMPRISING IN COMBINATION: A CASING HAVING A PAIR OF SPACED, AXIALLY EXTENDING, PARALLEL, CYLINDER BORES THEREIN AND AN AXIALLY SLIDABLE CYLINDER SLEEVE UNIT MOUNTED IN EACH OF SAID BORES; EACH OF SAID CYLINDER SLEEVE UNITS COMPRISING A PLURALITY OF AXIALLY ALIGNED PARTS HAVING A BORE THEREIN; FIRST FLUID DUCT CONNECTIONS FROM A COMMON FLUID SOURCE CONNECTING THE ENDS OF ONE OF SAID SLEEVE RECEIVING BORES, AND SECOND FLUID DUCT CONNECTIONS FROM A COMMON FLUID SOURCE CONNECTING THE ENDS OF SAID OTHER SLEEVE RECEIVING BORE; PORTS NEAR EACH END OF EACH OF AID SLEEVES AND SPACED INWARDLY OF SAID FLUID DUCT CONNECTIONS; AN AXIALLY EXTENDING VALVE PISTON POSITIONED IN EACH OF SAID BORES OF SAID SLEEVES, SAID PISTONS HAVING AN AXIAL LENGTH LESS THAN THE DISTANCE BETWEEN ASSOCIATED DUCT CONNECTIONS WHEREBY AT ALL TIMES ONLY THE OPPOSITE ENDS OF SAID PISTONS ARE EXPOSED TO FLUID FROM THEIR ASSOCIATED DUCT CONNECTIONS THEREBY PROVIDING HYDRAULICALLY BALANCED PISTONS IN ALL POSITIONS; MEANS INTERCONNECTING SAID VALVE PISTONS TO RECIPROCATE SAID PISTONS, SAID PISTONS COOPERATING WITH SAID PORTS TO CONTROL THE FLOW FO FLUID THROUGH SAID PORTS; AND MEANS POSITIONED IN SAID BORE AT EITHER END OF SAID SLEEVE UNITS ENGAGING THE ENDS THEREOF TO ADJUST SAID CYLINDER SLEEVE UNIT PARTS RELATIVE TO SAID CASING AND SAID PISTON.