Injection molding apparatus having inter-manifold melt transfer bushings
US5935616A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1997 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Nov 13, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/277
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Injection molding apparatus for multi-layer molding two materials with different injection temperatures having an insulative air space extending between front and rear heated melt distribution manifolds. Heated nozzles extending from the front manifold each have a central melt channel and one or more annular melt channels extending around it. Melt transfer bushings each having a central melt bore extend across the air space to convey melt from the rear manifold to one of the melt channels in each heated nozzle. In one embodiment, each melt transfer bushing has a head portion which provides a spacer between the two manifolds, and an elongated stem portion which extends through a bore through the front manifold to one of the heated nozzles. An air space around the stem portion provides thermal separation between the melt from the rear manifold and the front manifold which is at a higher temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.