METHOD OF MOULDING PLASTICS ARTICLES AND ARTICLES PRODUCED THEREBY

摘要

A method of injection moulding an undercut formation (26) on a circular body (20) wherein said formation is moulded in a series of arcuate sections (28) alternating with spaces (29), and wherein the moulding core (24) which produces the formation is extracted by firstly relatively rotating said body (20) and said core (24) so that the body is expanded radially and then ejecting the body off the core. The method is applicable to the manufacture of novel closure members and coupling elements.