Forming of materials by extrusion
US4044587A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 1975 |
| Grant date | Aug 30, 1977 |
| Priority date | — |
| Expiry date | Apr 23, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21C23/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In the extrusion of a material, which can be a metal feedstock, through a die means by maintaining frictional engagement of the material with passageway defining surfaces of a member which is moved towards the die means such that frictional drag of the passageway defining surfaces urges the material through the die means, the improvement of providing a change in cross-sectional area and/or shape of the passageway along its length in the direction of movement of the material for extruding to a product having a cross-sectional dimension larger than any cross-sectional dimension of the feed by changing the passageway such that at least one cross-sectional dimension of the passageway at the die end thereof is greater than the corresponding dimension at the inlet end thereof, or, for facilitating multiple extrusion at positions spaced apart in the lengthwise direction of the passageway at the extrusion die end thereof, by changing the passageway such that the cross-sectional area of the passageway diminishes in progressing from one extrusion position to the next, to ensure that the speed of extrusion is substantially the same at each position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.