Sealed pipe coupling

Claim 1

A SEALED PIPE COUPLING ASSEMBLY COMPRISING A COUPLING SLEEVE HAVING INTERNAL THREADS AT ITS ENDS, A MONOLITHIC COLLAR OF YIELDING MATERIAL SEALING LODGED WITHIN SAID SLEEVE BETWEEN SAID END THREADS, SAID COLLAR HAVING INITIALLY UNTHREADED TUBULAR END PORTIONS AND A CENTRAL INTERNAL RIDGE WITH INCLINED EDGE WALLS FORMING ANNULAR V-GROOVES, AND A PAIR OF PIPE MEMBERS WITH INCLINED END WALLS OF V-SECTION COMPLEMENTARY TO SAID EDGE GROOVES IN SAID COLLAR AND CIRCUMFERENTIALLY CONTINUOUS INTERNAL SYNTHETIC RESINOUS LININGS OVERLYING SAID END WALLS, SAID LININGS HAVING A COEFFICIENT OF FRICTION RELATIVE TO SAID COLLAR SUFFICIENTLY LOW TO PERMIT ROTARY CONTACT WITH SCRUBBING, SAID PIPE M EMBERS HAVING EXTERNAL END THREADS FOR MATING WITH SAID INTERNAL THREADS IN SAID SLEEVE, FOR CUTTING THREADS IN SAID END PORTIONS OF SAID COLLAR, AND FOR CAUSING SAID LINED PIPE END WALLS TO SEALINGLY ABUT SAID COMPLEMENTARY RIDGE GROOVES, SAID COLLAR BEING OF SUFFICIENT HARDNESS TO FACILITATE FORMATION OF STABLE THREADS THEREIN DURING ASSEMBLY OF SAID PIPE MEMBERS THEREWITH AND BEING ADAPTED TO ACCOMMODATE FRICTIONAL ENGAGEMENT BETWEEN SAID LINED ENDS AND SAID V-GROOVES.