Retractable gas injection pin for an injection mold
US5282730A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1991 |
| Grant date | Feb 1, 1994 |
| Priority date | — |
| Expiry date | Jun 12, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/401
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved injection molding system having gas injected through an injection pin associated with an ejector pin. The injection pin is movable between a retracted position at which it is sealed from the mold cavity, to an extended position where it delivers gas into the cavity. In a first embodiment, the injection pin is powered by a cylinder to move between the extended and retracted positions. In a second embodiment, the injection pin is actuated by the pressurized gas. The improved system injects gas into a mold cavity without the requirement of a separate injection aperture. Further, the inventive injection pins have outlet ports sealed from the flow of plastic until the injection pin is extended to deliver the gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.