Extension fitting having initial flexible lip seal gasket

Claim 1

IN A PIPE JOINT, A BODY PORTION PROVIDED WITH A FREE END HAVING A CYLINDRICAL BORE AND A CONICAL GASKETENGAGING INNER SURFACE EXTENDING AXIALLY AND RADIALLY OUTWARDLY FROM SAID BORE IN A DIRECTION TOWARD SAID FREE END, AN INNER MEMBER INSERTABLE IN ASSEMBLY AXIALLY INTO SAID BORE AND HAVING A SUBSTANTIALLY CYLINDRICAL PORTION FITTING FREELY INTO SAID BORE, AN ANNULAR FOLLOWER SURROUNDING SAID INNER MEMBER ADJACENT SAID BODY PORTION FREE END AND HAVING A SUBSTANTIALLY RADIAL GASKET-ENGAGING SURFACE, SAID CONICAL SURFACE OF SAID BODY PORTION, SAID RADIAL SURFACE OF SAID FOLLOWER AND AN OUTER SURFACE OF SAID INNER MEMBER TOGETHER DEFINING AN ANNULAR GASKET RECESS CIRCUMFERENTIALLY OF SAID INNER MEMBER, AN ANNULAR GASKET OF ELASTOMER MATERIAL IN SAID RECESS, SAID GASKET SUBSTANTIALLY FILLING SAID RECESS AND HAVING A CONICAL OUTER SURFACE FOR ENGAGING SAID CONICAL SURFACE OF THE BODY PORTION, AN OUTER END FACE ON SAID GASKET COMPRISING AT LEAST A SUBSTANTIALLY RADIAL END SURFACE OF ENGAGING SAID RADIAL SURFACE OF THE FOLLOWER AND A SUBSTANTIALLY CYLINDRICAL INNER SURFACE DEFINING A CYLINDRICAL THROUGH BORE SUBSTANTIALLY COAXIAL WITH SAID BORE OF SAID BODY PORTION AND RECEIVING SAID INNER MEMBER WITH SUFFICIENT PLAY TO PERMIT SAID INNER MEMBER TO SLIDE AXIALLY FREELY IN SAID BORE, SAID GASKET HAVING A CHAMFERED INNER SURFACE EXTENDING AXIALLY AND RADIALLY OUTWARDLY FROM SAID CYLINDRICAL INNER SURFACE AT THE AXIALLY-OUTER END THEREOF TO GUIDE SAID INNER MEMBER INTO SAID JOINT, SAID BODY PORTION HAVING AN ANNULAR SHOULDER EXTENDING RADIALLY OUTWARDLY FROM SAID CONICAL GASKET-ENGAGING SURFACE AND SAID GASKET HAVING AN ANNULAR SHOULDER ENGAGING SURFACE AND SHOULDER OF THE BODY PORTION TO RESTRAIN MOVEMENT OF SAID GASKET IN A DIRECTION AXIALLY INWARDLY OF SAID BODY PORTION, SAID GASKET HAVING IN SAID CYLINDRICAL SURFACE AN OBLIQUE INNER SURFACE DEFINING AN OBLIQUE ANNULAR RECESS HAVING A RADIALLY INNER END INTERMEDIATE THE ENDS OF SAID GASKET AND SUBSTANTIALLY SPACED AXIALLY THEREFROM, AND A SINGLE, FLEXIBLE, INTEGRAL, ANNULAR LIP DISPOSED AXIALLY OUTWARDLY OF AND IMMEDIATELY ADJACENT SAID RECESS, SAID LIP BEING SUBSTANTIALLY SPACED AXIALLY FROM THE ENDS OF SAID GASKET AND IN A FREE CONDITION SAID LIP PROJECTING AXIALLY AND RADIALLY INWARDLY INTO SAID CYLINDRICAL BORE OF SAID GASKET AND TERMINATING IN A THIN TIP PORTION DEFINING A RING WHICH IS SMALLER IN INTERNAL DIAMETER THAN THE OUTER DIAMETER OF SAID CYLINDRICAL PORTION OF SAID INNER MEM-