Closed fluid system for sealing valve closure elements

Claim 1

IN A VALVE INCLUDING A BODY HAVING A TRAVERSE BORE FOR FLUID FLOW THERETHROUGH AND HAVING A LATERAL BORE INTERSECTING THE TRANSVERSE BORE FOR RECEIVING THEREIN A GATE ELEMENT FOR CLOSING AND OPENING THE TRANSVERSE BORE TO FLUID FLOW AND A MOVABLE VALVE STEM EXTENDING INTO THE BODY AND CONNECTED TO THE ELEMENT FOR OPENING AND CLOSING THE TRANSVERSE BORE TO FLUID FLOW ON RELATIVE MOVEMENT OF THE ELEMENT IN THE LATERAL BORE, THE IMPROVEMENT COMPRISING: (A) SEAL RECEIVING MEANS RECEIVED IN AN ENLARGEMENT IN THE BODY ENCIRCLING THE TRANSVERSE BORE AND SPACED FROM THE LATERAL BORE; (B) SLIDABLE SEAL MEANS COOPERATING BETWEEN SAID SEAL RECEIVING MEANS AND THE BODY FOR SEALING THEREBETWEEN AS SAID SEAL RECEIVING MEANS SLIDES RELATIVE TO THE LATERAL BORE AND ELEMENT THEREIN; (C) A SEAL MEMBER CARRIED IN SAID SEAL RECEIVING MEANS; (D) FLUID PASSAGE MEANS COMMUNICATING WITH SAID SEAL MEMBER THROUGH SAID SEAL RECEIVING MEANS; (E) SHOULDER AREA MEANS FORMED ON SAID SEAL RECEIVING MEANS AND FACING FROM THE LATERAL OPENING, SAID MEANS BEING COMMUNICATED WITH SAID FLUID PASSAGE MEANS; (F) PISTON MEANS RECEIVED IN ONE END OF SAID FLUID PASSAGE MEANS TO CLOSE OFF SAME AND FORM A CLOSED FLUID RECEIVING AND RETAINING SYSTEM, SAID SYSTEM RECEIVING AND RETAINING FLUID THEREIN FOR COMPRESSION BY SAID PISTON MEANS; (G) MEANS CARRIED ON THE STEM FOR ACTUATING AND MOVING SAID PISTON MEANS ON MOVING THE ELEMENT IN THE LATERAL BORE TOWARD A CLOSED POSITION, SAID PISTON MEANS COMPRESSING FLUID IN SAID CLOSED FLUID RECEIVING AND RETAINING SYSTEM TO ACT ON SAID SHOULDER AREA MEANS AND MOVE SAID SEAL RECEIVING MEANS INTO CONTACT WITH THE ELEMENT IN THE CLOSED POSITION; AND (H) SAID PISTON MEANS ALSO COMPRESSING FLUID IN SAID CLOSED FLUID RECEIVING AND RETAINING SYSTEM TO ACT ON SAID SEAL MEMBER AND SEALINGLY URGE SAME INTO CONTACT WITH THE ELEMENT TO CLOSE THE VALVE.