Pipe coupling

Claim 1

A PIPE COUPLING, COMPRISING A PAIR OF PIPE SECTIONS DISPOSED IN CONFRONTING END-TO-END RELATION, EACH PIPE SECTION HAVING AN ANNULAR TAPERED EXTERNAL SURFACE LOCATED ADJACENT THE CONFRONTING END, A GENERALLY FLAT ANNULAR SEAL LOCATED BETWEEN THE CONFRONTING ENDS OF THE PIPE SECTIONS WITH THE INNER EDGE OF THE SEAL BEING SUBSTANTIALLY FLUSH WITH THE INTERNAL SURFACES OF THE PIPE SECTIONS AND THE OUTER EDGE OF THE SEAL PROJECTING BEYOND THE OUTER SURFACES OF SAID PIPE SECTIONS, AN EXPANDABLE COUPLING MEMBER DISPOSED AROUND THE PIPE SECTIONS AND HAVING AN INTERNAL GROOVE TO RECEIVE THE PROJECTING OUTER EDGE OF THE SEAL, THE AXIAL WIDTH OF SAID GROOVE BEING SLIGHTLY LARGER THAN THE THICKNESS OF SAID SEAL, SAID COUPLING MEMBER HAVING A PAIR OF ANNULAR EDGE EXTREMITIES STRADDLING THE GROOVE AND DISPOSED IN ENGAGEMENT WITH THE RESPECTIVE TAPERED SURFACES ON SAID PIPE SECTIONS ALONG A SUBSTANTIAL LINE CONTACT, AND CLAMPING MEANS DISPOSED AROUND THE COUPLING MEMBER AND DISPOSED TO CONTACT THE COUPLING MEMBER AND FORCE THE ANNULAR EDGES INWARDLY AGAINST THE TAPERED SURFACES TO THEREBY MOVE THE PIPE SECTIONS AXIALLY TOWARD EACH OTHER TO COMPRESS THE SEAL BETWEEN SAID CONFRONTING END BY A WEDGING ACTION WHEREBY THE OUTER PERIPHERY OF THE SEAL ENGAGES THE BOTTOM OF SAID GROOVE AND CENTERS THE SEAL WITH RESPECT TO THE PIPE SECTIONS.