Apparatus for multi-cavity injection molding
US5149547A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1991 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Jun 12, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/7613
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Apparatus and methods suitable for controlling and metering thermoplastic material or resin to multiple cavities in a multi-cavity injection molding tool are described, whereby the amount of resin injected into each cavity can be individually controlled. This system minimize overfilling or underfilling of individual article cavities in such a multiple cavity tool and, therefore, allows for the production of more uniform plastic articles from a multiple cavity mold or tool. In practice, a spindle, which is designed to rotate in a reproducible manner as resin flows past it, is inserted into the resin stream feeding each cavity. The amount of resin fed to a particular cavity is determined by measuring the rotation of the spindle. When the amount of resin fed to a particular cavity is equal to the amount appropriate for that cavity (the target amount), the shut-off valve associated with that cavity is activated, thereby terminating the resin flow to that cavity without affecting resin flow to the other cavities. Resin flow is continued until all cavities are filled with their respective target amounts of resin. The apparatus and methods of this invention are especially adapted for use …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.