Mould for shaping an integral beaded sleeve and plastics pipe - incorporates aligned core, composite forming ring and bushing, to avoid re-softening and final deformation prod. after removal from tool

摘要

In a device for mfg. thermoplastics tubes or pipes with beaded sleeve, the shaping of the initial, plain pipe whose (intended) sleeve section near the end gradually passes into a cylindrical section of relatively greater dia., is effected by heating at least the leading section and radial constriction of the pipe. The injection-mould used incorporates a bushing upon the mould core, and a shaping ring which is divided into segments and has the outer contours of the constriction. Both the bushing and the ring are coaxial with the mould and radially movable w.r.t. the core. They are displaced after injection of the moulding cpd. by moving the bushing axially away from the moulding, the ring segments radially towards the core and shaping ring axially towards the moulding. Shaping of the constriction is effected inside the mould whilst the moulding is still hot, thus dispensing with reheating and re-shaping after removal from the mould.