Flexible pipe connection having line pressure actuated sealing means

Claim 1

A PIPE CONNECTION STRUCTURE COMPRISING A CYLINDRICAL PIPE OD SYNTHETIC RESIN HAVING SUBSTANTIALLY THE PHYSICAL PROPERTIES OF POLYETHYLENE AND HAVING AN ANNULAR END SURFACE, A FITTING FORMED OF RIGID MATERIAL AND HAVING INSIDE SURFACES DEFINING AN OPEN-ENDED PASSAGE EXTENDING THROUGH THE FITTING THE FITTING COMPRISING A TUBULAR BODY PORTION AND AN ANNULAR NUT PORTION IN AXIAL ALIGNMENT WITH THE BODY PORTION, THE FITTING PASSAGE EXTENDING THROUGH SAID BODY AND NUT PORTIONS, COUPLING MEANS ON THE BODY AND NUT PORTIONS FOR INTERCONNECTING SAID PORTIONS, THE FITTING HAVING AN ANNULAR RECESS FORMED THEREIN OPEN TO AND CONCENTRIC WITH SAID PASSAGE AND SPACED AXIALLY INWARD FROM ONE END OF THE PASSAGE, SAID RECESS BEING DEFINED BY AN ANNULAR SHOULDER SURFACE ON SAID NUT PORTION, A STOP SURFACE AND AN ANNULAR RADICALLY INWARD FACING SURFACE BETWEEN SAID SHOULDER AND STOP SURFACES, SAID SHOULDER SURFACE FACING IN A DIRECTION AXIALLY INWARD OF THE FITTING WITH RESPECT TO SAID ONE END OF THE FITTING PASSAGE, SAID STOP SURFACE FACING TOWARD SAID SHOULDER SURFACE, A SEPARATE EXPANDER MEMBER IN THE PIPE ADJACENT SSAID END SURFACE OF THE PIPE, WHEREBY THE END PORTION OF THE PIPE IS EXPANDED AND FLARED RADICALLY OUTWARD TO EXTEND INTO SAID RECESS, THE EXPANDED AND FLARED END PORTION OF THE PIPE HAVING A PORTION OF A GREATER RADICAL EXTEND THAN THE RADIAL EXTENT OF SAID ANNULAR SHOULDER SURFACE AND SAID GREATER RADICAL PORTION BEING OF AN AXIAL EXTENT LESS THAN THE AXIAL DISTANCE BETWEEN SAID STOP SHOULDER AND SAID ANNULAR SHOULDER SURFACE, THE PIPE BEING MOVABLE AXIALLY INWARD OF THE FITTING PASSSAGE TO AN ABUTMENT POSITION IN WHICH AT LEAST ONE OF SAID EXPANDER