Method and apparatus for manufacturing a female connection plastic material for the pipe, of the type a sleeve comprising an annular groove enclosed

摘要

A resin pipe joint is formed having a groove on the internal surface thereof adapted for receiving a seal. The mold for forming the pipe joint includes an external split mold and an internal mold core and sleeve with parts slidable relative to one another so that the elements form a space therebetween for injecting resin therein. Subsequently, while the injected resin is still in an unhardened state, the movable parts are moved to a second position relative to one another thereby providing an annular opening surrounding the resin body formed during the resin injecting step. A pressurized fluid is jetted through a passageway towards the internal periphery of the resin body to cause said resin body to bulge into the annular space thereby creating the internal groove or exteranl bulge in the resin body.