Hydraulic drive and control for elevators

Claim 1

IN A HYDRAULIC ELEVATOR SYSTEM OF THE TYPE HAVING AN ELEVATOR CAR AND HAVING MEANS INCLUDING ROTATABLE MEANS ADAPTED TO BE DRIVEN IN OPPOSITE DIRECTIONS FOR RESPECTIVELY RAISING AND LOWERING SAID ELEVATOR CAR, A HYDRAULIC MOTOR ADAPTED TO BE SELECTIVELY DRIVEN IN ONE OF TWO DIRECTIONS IN RESPONSE TO THE FLOW OF HYDRAULIC FLUID THERETHROUGH AND HAVING A PAIR OF CONNECTIONS FOR RECEIVING AND DISCHARGING SAID FLUID, MEANS COUPLING SAID HYDRAULIC MOTOR TO SAID ROTATABLE MEANS TO SELECTIVELY RAISE AND LOWER SAID ELEVATOR CAR, AND A CONSTANT DISPLACEMENT HYDRAULIC PUMP FOR SUPPLYING SAID FLUID TO SAID MOTOR, THE COMBINATION THEREWITH OF MEANS FOR CONTROLLING THE DELIVERY OF SAID FLUID TO SAID PUMP, COMPRISING MEANS ESTABLISHING AN INLET CHAMBER, CONDUIT MEANS COMMUNICATING SAID PUMP AND SAID INLET CHAMBER TO SUPPLY SAID HYDRAULIC FLUID UNDER PRESSURE TO SAID INLET CHAMBER, MEANS ESTABLISHING AN INTERMEDIATE CHAMBER, SPEED SETTING VALVE MEANS DISPOSED BETWEEN SAID INLET CHAMBER AND SAID INTERMEDIATE CHAMBER FOR SELECTIVELY CONTROLLING THE FLOW OF SAID FLUID FROM SAID INLET CHAMBER TO SAID INTERMEDIATE CHAMBER, A FIRST CONDUIT MEANS CONNECTED TO SAID HYDRAULIC MOTOR AT ONE OF SAID CONNECTIONS THEREOF, A SECOND CONDUIT MEANS CONNECTED TO SAID HYDRAULIC MOTOR AT THE OTHER OF SAID CONNECTIONS THEREOF, MEANS ESTABLISHING A DISCHARGE PASSAGE, REVERSING VALVE MEANS SELECTIVELY MOVABLE BETWEEN A FIRST POSITION AND A SECOND POSITION, WHEN IN SAID FIRST POSITION SAID REVERSING VALVE MEANS COMMUNICATING SAID FIRST CONDUIT MEANS WITH SAID INTERMEDIATE CHAMBER AND SAID SECOND CONDUIT MEANS WITH SAID DISCHARGE PASSAGE FOR DRIVING SAID HYDRAULIC MOTOR IN A FIRST DIRECTION TO RAISE SAID ELEVATOR CAR, WHEN IN SAID SECOND POSITION SAID REVERSING VALVE COMMUNICATING SAID SECOND CONDUIT MEANS WITH SAID INTERMEDIATE CHAMBER AND SAID FIRST CONDUIT MEANS WITH SAID DISCHARGE PASSAGE FOR DRIVING SAID HYDRAULIC MOTOR IN AN OPPOSITE DIRECTION TO LOWER SAID ELEVATOR CAR.