Injection device for molding machines
US3960201A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 13, 1974 |
| Grant date | Jun 1, 1976 |
| Priority date | — |
| Expiry date | Dec 13, 1994 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22D17/203
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention concerns an improved injection device for molding machines with a cooling chamber for casting of non-ferrous metals and alloys. It is characterized by a two-part piston, one part of which slides freely and coaxially inside the other, forming a chamber in which a gas, neutral with respect to the metal to be cast, is compressed by the forward movement of the piston by virtue of a stop-pin, then liberated and expanded at the end of injection in a container of liquid metal where it causes a balancing force effect and improves the filling of the mold. This device makes it possible to eliminate the "ramroddings" which occur in single-piston machines at the end of injection and to obtain cast products which are free of defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.