| 摘要 |
A method of forming a component having a metallic shell 12 and a plastics insert 34. The component is formed by placing the shell 12 inside the mould cavity of a mould assembly 10 which forms part of an injection moulding machine. Prior to injection of plastics material, part of the external surface of the shell 12 is spaced from the opposed surface of the mould cavity. The open end of the shell abuts the adjacent mould cavity end wall so as to form a seal. This end wall is frustoconical in shape so that, during injection of plastics material, as the shell 12 is reformed by polymer pressure into complete engagement with the surface of the mould cavity, longitudinal contraction of the shell in response to this direct lateral strain is compensated for by the frustoconical shape so that the seal is not compromised. <IMAGE> |
