Pipe joint seals

Claim 1

A PIPE JOINT SEAL FOR A FIRST PIPE HAVING A LARGE BELL END AND A SECOND PIPE HAVING AN END ADAPTED TO EXTEND INTO SAID BELL END, SAID BELL END HAVING AN ENTRANCE OPENING OUTWARDLY THEREFROM, COMPRISING AN ANNULAR SEAT IN THE BELL END, SAID SEAT BEING BEVELLED FROM AN INNER EDGE OUTWARDLY TOWARDS THE BELL END ENTRANCE TO AN OUTER EDGE, AN ANNULAR COMPRESSIBLE GASKET IN THE BELL END HAVING A BEVELLED SURFACE ADAPTED TO BEAR AGAINST THE BEVELLED SEAT, SAID GASKET WHEN FREE BEING ADAPTED TO FIT LOOSELY AROUND SAID SECOND PIPE END, AN ANNULAR CYLINDRICAL GROOVED SURFACE IN THE BELL END BETWEEN THE SAID ENTRANCE OPENING AND THE BEVELLED SEAT, AN ACTUATING RING MOUNTED IN THE GROOVE FOR ROTATIONAL MOVEMENT ABOUT ITS AXIS BUT CONSTRAINED AGAINST AXIAL MOVEMENT IN THE SAID GROOVE, A THRUST RING ELEMENT MOUNTED BETWEEN THE ACTUATING RING AND THE GASKET AND BEARING AGAINST AN OUTER EDGE OF SAID GASKET FOR AXIAL MOVEMENT AND INCLUDING A RESTRAINING MEANS TO RESTRAIN THE THRUST RING AGAINST ROTATIONAL MOVEMENT, SPACED LUGS EXTENDING RADIALLY FROM THE ACTUATING RING ADAPTED TO FIT INTO THE SAID CYLINDRICAL GROOVE, MEANS FOR APPLYING A CONSTANT FORCE TO THE SAID ACTUATING RING IN A DIRECTION SUBSTANTIALLY PERPENDICULAR TO THE CENTRAL AXIS OF THE RING AND IN A PLANE CONTAINING THE RING TO ROTATE THE SAID RING CIRCUMFERENTIALLY, A PLURALITY OF BEVELLED CAMS MOUNTED ON THE ACTUATING RING AND EXTENDING AXIALLY FROM THE SAID ACTUATING RING TOWARD THE SAID THRUST RING, A PLURALITY OF CAMS ON THE THRUST RING IN OPPOSING RELATIONSHIP TO AND OPERATIVE AGAINST THE CAMS ON THE ACTUATING RING, WHEREBY WHEN THE SAID FORCE IS APPLIED TO THE ACTUATING RING TO ROTATE THE SAME THEN THE SECOND SET OF CAMS AND THE THRUST RING MOVES AXIALLY TOWARDS THE GASKET TO COMPRESS THE GASKET AXIALLY AGAINST THE SAID INNER EDGE OF THE SEAT, AND WHEREIN THE EXPANDING FORCE OF THE GASKET TOWARDS THE OPEN END OF THE BELL ACTING UPON THE THRUST RING IS TRANSFERRED TO THE ACTUATING RING ONLY IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE SAID AXIS THEREOF WHILE SUBSTANTIALLY ALL OF THE TRANSVERSE COMPONENT OF SAID FORCE IS ABSORBED BY THE SAID RESTRAINING MEANS.