Integral valve and seat unit

Claim 1

AN INTEGRAL VALVE AND SEAT UNIT FOR A ROTATABLE PLUG VALVE HAVING A VALVE CHAMBER FORMED THEREIN, SAID UNIT COMPRISING: AN INTEGRAL SEAT MEMBER FORMED OF MOLDABLE RESILIENT PLASTIC MATERIAL HAVING A GENERALLY SPHERICAL CAVITY FORMED THEREIN AND FLOW PASSAGES COMMUNICATING WITH SAID CAVITY, A ROTATABLE VALVE MEMBER HAVING A GENERALLY SPHERICAL EXTERIOR SURFACE POSITIONED WITHIN SAID CAVITY FOR ROTATION THEREIN, SAID VALVE MEMBER HAVING A THROUGH PASSAGE ALIGNABLE WITH SAID FLOW PASSAGES IN THE OPEN POSITION OF SAID VALVE AND MEANS BLOCKING SAID FLOW PASSAGES IN THE CLOSED POSITION OF SAID VALVE, CAM SURFACES FORMED ON SAID PLUG MEMBER AT THE INTERSECTION OF SAID THROUGH PASSAGE WITH SAID SPHERICAL SURFACE, A PAIR OF LIPS DISPOSED ON ABOUT EACH OF SAID FLOW PASSAGES, SAID LIPS BEING INTEGRAL WITH SAID SEAT MEMBER, SAID LIPS HAVING VALVE ENGAGING SURFACES OF THE SAME SHAPE AS THE SHAPE OF SAID CAM SURFACES AND SEALINGLY ENGAGING SAID VALVE AT ALL POSITIONS THEREOF, SAID LIP MEANS ENGAGING SAID VALVE MEMBER WITH GREATER SEALING PRESSURE AT THE CLOSE POSITION OF THE VALVE THAN AT THE OPEN POSITION.