Device for feeding an extrusion head for plastic material
US4832960A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1987 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Oct 27, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/21
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A device for feeding an extrusion head for plastic material includes a main extruder connected to a main die for extruding a continuous main flow of material, and an auxiliary feed mechanism associated with the main die and selectively controlled to cover the outer exit flow of the main die with a surface layer. The auxiliary feed mechanism continuously conducts two auxiliary flows, a first flow forming the surface layer and the second flow being mixed with the main flow. An invertor valve permits selective exchanging of the two auxiliary flows such that the second flow can cover the main flow and the first flow can be mixed with the main flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.