Hydraulic jack synchronizing system

Claim 1

IN A HYDRAULIC JACK SYNCHRONIZING SYSTEM, A LOADSUPPORTING ELEMENT, AT LEAST TWO HYDRAULIC JACKS OPERATIVELY CONNECTED THEREWITH AT SPACED APART POINTS TO MOVE SAID LOAD-SUPPORTING ELEMENT AWAY FROM AND TOWARD A SUPPORT, FLUID PRESSURE SUPPLY MEANS CONNECTED TO BOTH JACKS FOR SUPPLYING FLUID PRESSURE THERETO, MEANS FOR MAINTAINING A PREDETERMINED ANGLE BETWEEN SAID LOAD-SUPPORTING ELEMENT AND THE SUPPORT COMPRISING A SYNCHRONIZING VALVE FOR EACH JACK, ANGLE DEVIATION-SENSING MEANS OPERABLE TO ADJUST SAID VALVES FOR REDUCING THE FLOW OF FLUID PRESSURE FROM SAID SUPPLY MENAS TO ONE OF SAID JACKS WHEN AHEAD OF THE OTHER, EACH OF SAID VALVES COMPRISING A VALVE BODY, OPPOSED VALVE SEATS AND FIRST AND SECOND CAVITIES THEREIN OUTWARD OF SAID VALVE SEATS, A CENTRAL CAVITY BETWEEN SAID SEATS, A STEM EXTENDING THROUGH SAID VALVE SEATS AND CAVITIES AND HAVING A VALVE HEAD BETWEEN THE SEATS OF LESS LENGTH THAN THE DISTANCE BETWEEN THEM, A PUMP INLET TO BOTH OF SAID FIRST AND SECOND CAVITIES, A CHECK VALVE BETWEEN SAID PUMP INLET AND EACH OF SAID FIRST AND SECOND CAVITIES, ONE CHECK VALVE OPEING AWAY FROM SAID FIRST CAVITY AND THE OTHER OPENING TOWARD SAID SECOND CAVITY, SAID ANGLE DEVIATION-SENSING MEANS BEING OPERABLE TO MOVE SAID VALVE HEAD IN THE DIRECTION OF SAID SECOND CAVITY WHEN ITS CORRESPONDING JACK IS AHEAD OF THE OTHER AND IN THE DIRECTION OF SAID FIRST CAVITY WHEN ITS CORRESPONDING JACK IS BEHIND THE OTHER, AND AN OUTLET TO THE JACK FROM SAID CENTRAL CAVITY.