Joint for smooth end or flareless pipe

Claim 1

An improvement in a joint for connecting an end portion of a smooth wall pipe to fittings or other pipes comprising: a hollow body member having a passageway therethrough with an axially extending end portion for receiving the end portion of said pipe, said axially extending end portion of said passageway being defined by a first transversely extending annular shoulder at its inner end and facing outwardly, said first shoulder having an interior diameter less than the outside diameter of the pipe and arranged for initial abutting by the end of the pipe, a first cylindrical bore having a diameter substantially equal to the diameter of the pipe, said first cylindrical bore having its outer end spaced axially outwardly from said first shoulder and terminating in a second transversely extending downwardly facing shoulder, a second cylindrical bore of greater diameter than said first bore and extending outwardly from said second shoulder, and a converging frusto-conical surface extending from the outer end of said second bore and terminating adjacent the outer end of said end portion of said passageway, said frusto-conical surface having a minor diameter at its outer end large enough to receive the end portion of said pipe; a spring-like flexible annular split gripper ring having an axial extent less than the axial extent of said frusto-conical surface, said ring having a frusto-conical exterior surface tapering in the same direction as the frusto-conical surface of said passageway and a cylindrical interior surface provided with pipe gripping means thereon, said gripping means including a plurality of axially spaced teeth extending substantially the entire axial extent of said gripping ring, the teeth at and adjacent to each axial extremity of the gripping means having a diameter slightly less than the diameter of teeth intermediate the same so as to provide an initial bite into the pipe when the pipe is initially inserted into the gripping means with the intermediate teeth being slightly spaced from the pipe, and each of said teeth having an inwardly facing surface extending in a plane substantially normal to the axis of the gripper ring, said ring being positioned within said end portion of said passageway of said body member in an area of said frustoconical surface of said passageway with its larger end inwardly and when relaxed having an interior diameter less than the outside diameter of the pipe; and an annular elastomeric sealing ring member positioned within said end portion of said passageway between said second shoulder and said inner end of said split ring in an area of said second cylindrical bore, said Sealing ring member when relaxed having an inner diameter less than the outer diameter of said pipe and a radial thickness sufficient to cause the sealing ring member to seal against said second cylindrical bore when stretched onto said pipe.