NOYAU DE MOULE DEMONTABLE, NOTAMMENT POUR MATIERES PLASTIQUES

摘要

A core collapsible from a cylindrical expanded state to facilitate release of a moulded article comprises a frustoconical central member (24) having alternate guide ridges (36) and grooves (35) extending along its sloping outer surface. Longitudinally slidable along the ridges are a first set of outer mould segments (30) Each segment has a curved outer surface (44) and undercut sloping side surfaces (46). Longitudinally slidable along the grooves are a second set of smaller segments (32). Each segment has a narrow curved outer surface (56) and a diverging side surface (52) adapted to engage and slide over the undercut side surfaces of the segments of the first set. The core is of use in injection moulding cylindrical articles such as buckets having undercuts preventing them for being slipped from non collapsible cores.