Ball valve seat

Claim 1

A BALL VALVE COMPRISING A CASING HAVING A VALVE CHAMBER AND INLET AND OUTLET OPENINGS COMMUNICATING THEREWITH, SAID CHAMBER HAVING AN END WALL IN WHICH SAID OUTLET OPENING IS DISPOSED, A BALL MOUNTED IN SAID CHAMBER AND HAVING A FLUID PASSAGE,MEANS FOR TURNING SAID BALL BETWEEN AN OPEN POSITION IN WHICH SAID PASSAGE IS IN COMMUNICATION WITH SAID OPENINGS AND A CLOSED POSITION IN WHICH SAID PASSAGE IS OUT OF COMMUNICATION WITH SAID OPENINGS, AND A UNITARY SEAT RING DISPOSED AGAINST SAID WALL AROUND SAID OUTLET OPENING, SAID RING INCLUDING A CORE OF RIGID MATERIAL AND A SLEEVE OF MATERIAL MORE ELASTIC THAN THAT OF SAID CORE, SAID SLEEVE HAVING AN AXIALLY FLEXIBLE LIP ENGAGING SAID BALL TO FORM A SEAL THEREWITH, SAID BALL BEING MOVABLE TOWARD SAID WALL, AND SAID LIP BEING BENDABLE TO PERMIT SUCH MOVEMENT, AND SAID CORE HAVING A FIRST PORTION ENGAGING SAID WALL AND A SECOND PORTION DISPOSED BETWEEN SAID BALL AND SAID WALL AND ALL AROUND SAID OPENING AND INITIALLY SPACED FROM SAID BALL BUT ADAPTED TO LIMIT THE BALL MOVEMENT TOWARD SAID WALL, AND SAID CORE AND SLEEVE HAVING INTERLOCKING PORTIONS ADAPTED TO PREVENT RELATIVE ROTATION THERE BETWEEN DUE TO AXIAL LOAD ON SAID LIP.