Method of and an assembly for forming the bell end of a bell and spigot joint

In an assembly for forming an inner circumferential groove in a heated end section of a plastic pipe with a circumferential sealing gasket within said groove, said assembly including an elongated core and a circumferential sealing gasket positioned around and against a circumferential surface portion of said core, whereby the heated end section of said plastic pipe is moved over the core and over the gasket by relative movement between said core and heated end sections so as to form said groove with said gasket therein and whereby said end section with said formed groove and gasket therein is subsequently separated from said core, the improvement comprising:

• means connected with said core and located to one side of said gasket, said means being movable between a first position to form a ramped surface extending upwardly towards said gasket at an angle with the outer periphery of said core whereby said heated end section moves up said ramped surface prior to moving over said gasket and a second position for providing a surface substantially parallel with the axis of said core over which said gasket within said formed groove moves during separation of said end section from said core.