Method and apparatus for molding clay pigeons and the like
US4276015A · kind A · utility
Inventor
Key dates
| Filing date | Jul 19, 1978 |
| Grant date | Jun 30, 1981 |
| Priority date | — |
| Expiry date | Jul 19, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/2868
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection molding machine includes complementary mold members which cooperate to present a mold cavity in the shape of a clay pigeon or other articles. An injection passage leading to the mold cavity receives a slidable pin of smaller diameter than the passage. The pin has a tapered tip which, when the pin is extended by a power cylinder, seats in an outlet opening of the passage to block the opening in a manner to prevent the formation of a sprue on the part. The pin is heated along with a surrounding sleeve to maintain the material in the passage in a molten state and to assure proper release of the part from the mold. When the pin is retracted, molding material is able to flow around it, through the injection passage, and into the mold cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.