Method of molding plastic workpieces about slender permanent inserts
US4448741A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1982 |
| Grant date | May 15, 1984 |
| Priority date | — |
| Expiry date | Feb 25, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/253
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In injection-molding a plastic workpiece about a prefabricated permanent insert, a first quantity of plastic material is injected into one or more first-shot cavities through which a portion of the insert extends, thereby forming a corresponding number of annular spacers around that portion. After the spacer or spacers have solidified, the spacer-carrying insert is transferred to a second-shot cavity in which each spacer holds the insert separated from the walls of adjoining cavity sections. A second quantity of plastic material is then injected into the second-shot cavity to complete the workpiece by forming a sheath around the insert incorporating the spacer or spacers which are steadying same against lateral movement due to the pressure of the injected second-shot plastic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.