Flexible gasket for high and low pressure pipe joints

Claim 1

A PIPE JOINT COMPRISING A FIRST PIPE HAVING AN ENLARGED HUB PORTION AT ITS END, A SECOND PIPE TELESCOPICALLY RECEIVED IN THE HUB PORTION OF THE FIRST PIPE, THE HUB PORTION HAVING A CIRCUMFERENTIAL RECESS FOR RECEIVING AN ANNULAR SEALING GASKET, AND A GASKET HAVING A RESILIENT RINGLIKE BODY SUBSTANTIALLY COMPLETELY FILLING THE RECESS AND INCLUDING A HOLLOW ANNULAR CENTRAL CAVITY, THE WALLS OF WHICH ARE FORMED BY THE GASKET BODY, THE END OF THE RADIALLY INNER WALL OF THE CAVITY NEAREST THE END OF THE SECOND PIPE BEING REMOVED TO FORM AN ANNULAR OPENING PERMITTING ACCESS TO THE CENTRAL CAVITY AND DEFINING THEREBY A C SHAPED CROSS-SECTION FOR THE GASKET, THE RADIALLY OUTER WALL OF THE CENTRAL CAVITY BEING EXTENDED RADIALLY INWARD TO FORM A FLEXIBLE CURVING TIP PORTION WEDGED TIGHTLY BETWEEN THE HUB PORTION AND THE SECOND PIPE WITH ITS CAVITY SURFACE IN CONTACT WITH THE SECOND PIPE, THE UNCONFINED INSIDE DIAMETER OF THE GASKET BEING LESS THAN THE OUTSIDE DIAMETER OF THE SECOND PIPE, WHEREBY THE RADIALLY INNER WALL OF THE CAVITY IS DISPLACED WHEN THE JOINT IS ASSEMBLED, THE RADIALLY INWARD REACTION FORCE CAUSED BY SUCH DISPLACEMENT SERVING TO TIGHTLY ENGAGE THE GASKET AND THE SECOND PIPE TO PREVENT THE FLOW OF FLUID THEREBETWEEN, THE ANNULAR OPENING SERVING TO PERMIT THE ENTRY OF HIGH PRESSURE FLUID INTO THE CENTRAL CAVITY TO EXPAND THE SEALING GASKET THEREBY INCREASING ITS SEALING EFFECTIVENESS, THE CURVED TIP PORTION BEING TIGHTLY ENGAGED BETWEEN THE HUB AND THE SECOND PIPE TO ENHANCE THE SEALING PROPERTIES OF THE GASKET WHEN THE INTERNAL PRESSURE IS BELOW THAT ON THE OUTSIDE OF THE PIPE.