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

摘要

A method of forming the bell end of a bell and spigot joint connecting two pipes together is disclosed herein and utilizes a mandrel assembly including an elongated core and a retractable ramp arrangement. A sealing gasket is positioned around the core and to one side of the ramp arrangement. Thereafter, an end section of a heat deformable pipe, heated to its deformable state, is moved concentrically over the core, retractable ramp arrangement and sealing gasket to form an enlarged sleeve or bell having an inner circumferential groove within which the sealing gasket is located. During this movement, as the heated end section approaches the sealing gasket, the ramp arrangement causes the end section to deform outwardly and over the gasket, whereupon the ramp arrangement retracts inwardly for allowing the outwardly deformed end section to shrink back to the core and around the gasket.