Forming of extrusion dies
US4493229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1983 |
| Grant date | Jan 15, 1985 |
| Priority date | — |
| Expiry date | May 25, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23H2200/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of forming an extrusion die comprises forming an extrusion aperture in a die piece, forcing a flowable material partly through the extrusion aperture so that the leading surface of the material becomes deformed in the extrusion direction, and then removing the exposed surface of the extrusion aperture, by chemical or electro-etching, so that the effective axial bearing depth of the extrusion aperture at any location around its periphery corresponds to the deformation of the leading surface of the flowable material at that location. The axial bearing depth of the completed die at any location is thus inversely proportional to the resistance to flow at that location, resulting in substantially uniform flow over the whole of the die aperture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.