Coupling for joining pipe sections of differing diameter

Claim 1

A PIPE COUPLING JOINING A FIRST SECTION OF PIPE WITH A SECOND SECTION OF PIPE HAVING AN OUTER DIAMETER SMALLER THAN THE INNER DIAMETER OF SAID FIRST SECTION, SAID COUPLING COMPRISING A BAND ENCIRCLING THE ENDS OF SAID SECTIONS, SAID BAND HAVING INWARDLY TAPERED EDGE PORTIONS, AND BETWEEN SAID BAND AND SAID PIPE SECTIONS A GASKET COMPRISING AN INNER GASKET PORTION HAVING AN INNER SURFACE BEARING AGAINST THE OUTER SURFACE OF SAID SECOND PIPE SECTION AND SEPARATE OUTER GASKET PORTION HAVING AN OUTER SURFACE BEARING AGAINST SAID BAND AND AN INNER SURFACE BEARING AGAINST THE OUTER SURFACE OF SAID INNER GASKET PORTION AND AGAINST THE OUTER SURFACE OF SAID FIRST PIPE SECTION, SAID TAPERED EDGE PORTIONS OF SAID BAND COMPRESSING EDGE PORTIONS OF SAID OUTER GASKET PORTION, SAID INNER SURFACE OF SAID GASKET OUTER PORTION HAVING A CENTRALLY LOCATED INWARDLY PROJECTING ANNULAR RIB AND SAID FIRST PIPE SECTION HAVING A BEAD AT ITS END, SAID RIB PROJECTING FROM SAID INNER SURFACE OF SAID GASKET OUTER PORTION BY A DISTANCE SUBSTANTIALLY EQUAL TO THE THICKNESS OF SAID BEAD, SAID GASKET BEING SEPARATED FROM THE INTERIORS OF SAID PIPE SECTION BY A CORROSION-RESISTANT LINER, SAID LINER BEING HELD AGAINST SAID HEAD OF SAID FIRST PIPE SECTION BY SAID GASKET OUTER PORTION AND BY SAID RIB ON SAID GASKET OUTER PORTION AND BEING HELD AGAINST THE OUTER SURFACE OF SAID SECOND PIPE SECTION BY SAID GASKET INNER PORTION.