Sprue bar assembly for use in a stack mold
US5968562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1998 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Aug 28, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/322
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A sprue bar assembly for a melt transfer system for stack molds comprises a sprue bar and a sprue bar sleeve, a sprue bar and drool restrictor and sleeve or a sprue bar and drool restrictor. For the assemblies with the sleeve, when the stack mold is opened, the sprue bar slides inside the sprue bar sleeve which captures any leakage therefrom. When the mold is closed, the sprue bar sweeps captured leakage out of the sleeve to an area outside the mold. As the busing at the end of the sprue bar can contact the nozzle of the injection machine at a point very close to the edge of the fixed platen, the resulting minimum length of the sprue bar is reduced, reducing pressure losses through the sprue bar and reducing the cost of the sprue bar. The sprue bar sleeve can be fabricated from an insulating material to enhance the thermal characteristics of the sprue bar assembly and a scraper can be provided on the sprue bar to improve removal of captured material from the sprue bar sleeve. If a drool restrictor is provided within the bushing, the amount of drool from the sprue bar when the bushing is not in engagement with the nozzle of the injection machine can also be reduced and, in some circ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.