Patent · US Expired

Pressure molding apparatus for molten resin

US5545023A · kind A · utility

2Cited by
21References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 5, 1995
Grant dateAug 13, 1996
Priority date
Expiry dateJun 5, 2015

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C45/2806
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A pressure molding apparatus for molten resin in which an oil-pressurized cylinder internally holding an end of gate pin can freely move in compatibility with thermal elongation or contraction of a manifold pipe. In addition, a limit switch to be activated by the descending movement of this cylinder in correspondence with the descending movement of the gate pin is interlinked to a molten-resin supply source. By provision of these mechanisms, molten resin can smoothly be delivered to the interior of a molding unit without obstruction. Since substantial space is provided around this cylinder, pipes can easily be installed. Furthermore the inner later surface of the gate aperture on the side of the gate pin is provided with an obtuse angle wider than the tip angle of the gate pin, and a tapered hole having an adequate length and tapered diameter expanding itself from the gate aperture to the inner surface of the molding unit is provided. By provision of the above structure, the gate aperture is prevented from being choked by residual resin and a concave indentation cannot be generated in the molded resin product at the portion corresponding to the gate aperture.

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