Sealing and retaining bushing for injection molding
US4740151A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1986 |
| Grant date | Apr 26, 1988 |
| Priority date | — |
| Expiry date | Oct 20, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/277
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to sealing and support bushings which are located between the manifold and the mold back plate to encircle each valve pin in a multi-cavity valve gated injection molding system. Each bushing is bolted through the manifold to a respective heated nozzle with central bores in alignment to receive the valve pin therethrough. The bushing has an outer flanged portion which extends to contact the mold back plate and forms a leakage containment chamber between them. Thus, the bushings retain the manifold in place, seal against substantial melt leakage around the reciprocating valve pins and collect any melt which does escape to prevent it entering the insulative air space between the hot manifold and the cooled mold back plate. Location of the bushing between the manifold and the mold back plate also enables the use of a standard manifold having longitudinal and transverse bores without requiring diagonal bores.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.