Hydraulically-actuated operating mechanism for an electric circuit breaker

Claim 1

IN A HYDRAULICALLY-CONTROLLED OPERATING SYSTEM FOR AN ELECTRIC CIRCUIT BREAKER, A FLUID MOTOR COMPRISING A MOVABLE PISTON ADAPTED TO MOVE IN A CLOSING DIRECTION TO CLOSE SAID CIRCUIT BREAKER AND ADAPTED TO MOVE IN A REVERSE DIRECTION DURING OPENING OF SAID CIRCUIT BREAKER, AN ACCUMULATOR FOR SUPPLYING PRESSURIZED OPERATING LIQUID TO SAID MOTOR, A DUMP PORT INTERCONNECTING SAID MOTOR AND A LOW PRESSURE REGION, CONTROL VALVE MEANS LOCATED HYDRAULICALLY BETWEEN SAID ACCUMULATOR AND SAID MOTOR FOR CONTROLLING THE FLOW OF PRESSURIZED LIQUID TO AND FROM SAID MOTOR, SAID CONTROL VALVE MEANS BEING EFFECTIVE IN A FIRST CONDITION TO AFFORD COMMUNICATION BETWEEN SAID ACCUMULATOR AND SAID MOTOR AND TO CLOSE SAID DUMP PORT AND BEING EFFECTIVE IN A SECOND CONDITION TO BLOCK COMMUNICATION BETWEEN SAID MOTOR AND SAID ACCUMULATOR AND TO AFFORD COMMUNICATION BETWEEN SAID MOTOR AND SAID LOW PRESSURE REGION THROUGH SAID DUMP PORT, MEANS FOR OPERATING SAID CONTROL VALVE MEANS INTO SAID FIRST CONDITION TO PRODUCE MOVEMENT OF SAID PISTON IN SAID CLOSING DIRECTION AND FOR OPERATING SAID CONTROL VALVE MEANS INTO SAID SECOND CONDITION TO PERMIT MOVEMENT OF SAID PISTON IN SAID REVERSE DIRECTION, MEANS FOR RESTORING SAID CONTROL VALVE MEANS TO SAID FIRST CONDITION DURING MOVEMENT OF SAID PISTON IN SAID REVERSE DIRECTION TO INITIATE A CIRCUITBREAKER-RECLOSING OPERATION, DECELERATING MEANS FOR PRODUCING AHEAD OF SAID PISTON DURING MOVEMENT IN SAID REVERSE DIRECTION OCCURING AFTER SAID CONTROL VALVE MEANS HAS BEEN RESTORED TO SAID FIRST CONDITION A SUBSTANTIALLY HIGHER BACK PRESSURE THAN THE PRESSURE THEN PRESENT IN SAID ACCUMULATOR AND FOR MAINTAINING SAID BACK PRESSURE ABOVE THE ACCUMULATOR PRESSURE DURING SUBSTANTIALLY THE ENTIRE INTERVAL EXTENDING FROM THE INSTANT THAT SAID BACK PRESSURE FIRST EXCEEDS SAID ACCUMULATOR PRESSURE UNTIL MOVEMENT OF SAID PISTON IN SAID REVERSE DIRECTION IS TERMINATED, SAID DECELERATING MEANS COMPRISING A CHECK VALVE LOCATED HYDRAULICALLY BETWEEN SAID CONTROL VALVE MEANS AND SAID ACCUMULATOR FOR RESTRICTING THE FLOW OF LIQUID INTO SAID ACCUMULATOR FROM SAID FLUID MOTOR DURING MOVEMENT OF SAID PISTON IN SAID REVERSE DIRECTION, SAID CHECK VALVE OFFERING A SUBSTANTIALLY GREATER RESISTANCE TO FLOW FROM SAID MOTOR TOWARD SAID ACCUMULATOR THAN TO FLOW FROM SAID ACCUMULATOR TOWARD SAID MOTOR, SAID HYDRAULIC SYSTEM BEING SO CONSTRUCTED THAT SAID ACCUMULATOR AND OTHER SYSTEM COMPONENTS CAN SAFELY WITHSTAND THE MAXIMUM PRESSURES DEVELOPED IN SAID SYSTEM EVEN IN THE ABSENCE OF SAID CHECK VALVE.