Wellhead apparatus

Claim 1

AN UNDERWATER WELLHEAD ASSEMBLY MOUNTED ON A WELL CASING EXTENDING DOWNWARDLY INTO AN EARTH FORMATION COVERED BY A BODY OF WATER SAID WELLHEAD ASSEMBLY INCLUDING A WELLHEAD CONNECTOR DEVICE HAVING A HOUSING REMOVABLY SECURED TO SAID ASSEMBLY, CHAMBER MEANS IN SAID HOUSING, SUBSTANTIALLY FLUIDTIGHT MOVABLE BARRIER MEANS MOUNTED IN SAID CHAMBER MEANS, MOVABLE MEANS CARRIED BY SAID HOUSING AND OPERATIVELY-ENGAGING SAID MOVABLE BARRIER MEANS, PRESSURE-FLUID CONDUITS THROUGH SAID HOUSING TO OPPOSITE SIDES OF SAID MOVABLE BARRIER MEANS, EACH OF SAID CONDUITS BEING IN COMMUNICATION WITH THE DISCHARGE PORT OF ONE OF A PAIR OF PUMPS MOUNTED ON SAID HOUSING, REVERSIBLE ELECTRIC MOTOR MEANS HAVING A SHAFT CONNECTED TO SAID TWO PUMPS AND MOUNTED ON SAID HOUSING ADJACENT SAID PUMPS, A PRESSURE-FLUID RESERVOIR MOUNTED ON SAID HOUSING, SUPPLY CONDUIT MEANS IN COMMUNICATION BETWEEN SAID RESERVOIR AND INTAKE PORTS OF SAID PUMPS, FLOW CONTROL VALVE MEANS IN SAID CONDUIT MEANS BETWEEN SAID PUMPS AND SAID MOVABLE BARRIER MEANS AND SAID RESERVOIR, SAID VALVE MEANS BEING ARRANGED TO PUT SELECTIVELY ONE PUMP AND THE RESERVOIR IN COMMUNICATION WITH THE CONDUITS TO OPPOSITE SIDES OF THE MOVABLE BARRIER MEANS AND THEN THE OTHER PUMP AND THE RESERVOIR IN COMMUNICATION WITH OPPOSITE AND DIFFERENT SIDES OF SAID MOVABLE BARRIER MEANS, CHECK VALVES IN SAID CONDUITS FROM SAID PUMPS, HYDRAULICALLY-OPERATED VALVE ACTUATOR MEANS IN PRESSURE COMMUNICATION WITH BOTH OF SAID PUMPS AND BEING OPERATIVELY CONNECTED TO SAID FLOW CONTROL VALVE MEANS, POWER LEADS TO SAID MOTOR MEANS EXTENDING TO ABOVE THE SURFACE OF THE BODY OF WATER, AND REVERSING SWITCHING MEANS IN SAID POWER LEADS AT A POINT ABOVE SAID BODY OF WATER.