Underwater blowout preventer

Claim 1

A BLOWOUT PREVENTER FOR USE ON AN UNDERWATER DRILLING WELLHEAD ASSEMBLY COMPRISING A SUBSTANTIALLY CYLINDRICAL UNITARY HOUSING, UPPER AND LOWER CLOSURE PLATE MEMBERS CLOSING THE TOP AND BOTTOM OF SAID HOUSING, ONE OF SAID PLATE MEMBERS BEING REMOVABLE FROM SAID HOUSING TO OPEN THE ASSOCIATED END, A TRANSVERSE WALL MEMBER REMOVABLY SECURED WITHIN SAID HOUSING INTERMEDIATE THE END THEREOF AND REMOVABLE THROUGH SAID OPENABLE END OF SAID HOUSING, CONNECTOR MEANS OPERATIVELY SECURING SAID TRANSVERSE WALL MEMBER TO SAID HOUSING, SAID PLATE MEMBERS AND SAID TRANSVERSE WALL MEMBER HAVING CENTRALLY-POSITIONED AND COAXIALLY ALIGNED OPENINGS THERETHROUGH FOR PASSAGE OF A WELL MEMBER THEREIN, SAID TRANSVERSE WALL MEMBER DIVIDING THE INTERIOR OF SAID HOUSING INTO FIRST AND SECOND AXIALLY-SPACED ANNULAR CHAMBERS WHILE FORMING THE BOTTOM OF SAID FIRST CHAMBER AND THE TOP OF SAID SECOND CHAMBER, EACH OF SAID CHAMBERS BEING OF A SIZE SUFFICIENT TO CONTAIN A RADIALLY-CONTRACTIBLE RESILIENT PACKING MEMBER AND A PACKING ACTUATION MEANS THEREFOR, FIRST AND SECOND ANNULAR RESILIENT PACKING MEMBERS CARRIED WITHIN SAID FIRST AND SECOND CHAMBERS ADJACENT THE TOPS THEREOF, EACH OF SAID PACKING MEMBERS HAVING A BORE THERETHROUGH SUBSTANTIALLY THE SIZE OF THE ALIGNED OPENINGS IN SAID CLOSURE PLATE MEMBERS, COAXIALLYLOCATED POSITIONING MEANS CARRIED IN EACH OF SIAD CHAMBERS FOR POSITIONING SAID PACKING MEMBERS IN THE UPPER ENDS THEREOF AGAINST VERTICAL DISPLACEMENT, AN ANNULAR PISTON-TYPE PACKING-ACTUATING MEMBER CARRIED WITHIN EACH OF SAID CHAMBERS AND HAVING A DOWNWARDLY AND INWARDLY TAPERING FACE AT LEAST A PORTION OF WHICH IS ARRANGED ADJACENT AND IN CONTACT WITH THE OUTER PERIPHERAL FACE OF ONE OF SAID PACKING MEMBERS FOR APPLYING A RADIALLY INWARDLY DIRECTED PRESSURE THERETO, AN ANNULAR PISTON FORMED ON EACH OF SAID PACKING-ACTUATING MEMBERS AS A PART THEREOF, AND INLET AND OUTLET PRESSURE FLUID PORT MEANS EXTENDING SEPARATELY THROUGH SAID HOUSING TO EXPANSIBLE SPACES ON EITHER SIDE OF EACH OF SAID PISTONS WITHIN SAID CHAMBERS FOR INTRODUCING A PRESSURE FLUID, INDEPENDENTLY TO ONE SIDE OF EACH OF SAID PISTONS TO FORCE SELECTIVELY EACH OF SAID PACKING MEMBERS RADIALLY INWARDLY.