Patent · US Expired

Sprue ejector in automatic injection molding machines

US4787841A · kind A · utility

19Cited by
6References
12Claims
0Family size

Inventor

Key dates

Filing dateNov 25, 1987
Grant dateNov 29, 1988
Priority date
Expiry dateNov 25, 2007

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C45/1759
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

An apparatus for removing the sprue from an injection mold, having a cylinder and an associated piston rod, in which the piston rod extends between the two halves of the mold into the runner when the injection mold is closed. Molding material is molded around the forward end of the piston rod during the injection. Upon opening of the mold the sprue fixedly carried by the forward end is removed by movement of the piston rod into the cylinder.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.