Title: Forming of materials by extrusion

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.

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Inventors: Green, Derek (Cumbria, EN)
Pardoe, John Alan (Lytham St. Annes, EN)
Etherington, Clifford (Blackpool, EN)

Application Number: 570753
Filing Date: 1975-04-23
Publication_date: 1977-08-30
Assignee: United Kingdom Atomic Energy Authority (London, EN)
Primary Class(es): 72/261 72/262, 72/271, 425/374
Other Classes:
US Patent Ref:

2892212	Jun, 1959	Rhodes	425/374.
3142091	Jul, 1964	Curtiss	425/374.
3765216	Oct, 1973	Green	72/263.
3871810	Mar, 1975	Geyer	425/374.
3872703	Mar, 1975	Green	72/273.
3934446	Jan, 1976	Avitur	72/262.

Other Refs:
Primary Examiner: Lanham, C.W.
Assistant Examiner: Gurley, D. M.
Attorney: Larson, Taylor and Hinds