Plastic molded article or product and method and apparatus for producing the same by injection molding
US6565346B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2001 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Jun 13, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An apparatus for producing a plastic molded article or product for use in an optical device is a mold assembly. The mold assembly includes a pair of molds having an inner mold surface forming a cavity with a preselected volume into which a molten molding material is injected via a gate or sprue to fill the cavity and thereby form a molded product having a sink surface and at least one mirror surface after the molten molding material has cooled. The inner mold surface includes at least one transfer surface portion against which the at least one mirror surface of the molded product is formed, and at least one non-transfer surface portion against which the sink surface portion of the molded product is formed. The mold assembly also includes at least one vent hole, at least one bore in communication with the vent hole so that a preselected air pressure is applied to the molten molding material in the cavity via the bore and the vent hole, and at least one exhaust hole adjacent to, but spaced from the vent hole. Thus, only a part of the molded article or product expected to sink is surely caused to sink while, e.g., a mirror surface is surely transferred to a desired part of the molded …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.