Extruder for extrusion manufacturing

US5904939A · kind A · utility

Assignees

• Konrad Friedrichs KG · DE
• Guehring OHG · DE

Inventor

• Arno Friedrichs · Kulmbach, DE

Key dates

• Filing date: Jul 24, 1997
• Grant date: May 18, 1999
• Expiry date: Jul 24, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T408/455
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

An apparatus for manufacturing a rod of hard metal or ceramic with at least one helical inner bore. A plasticized mass of hard metal or ceramic is simultaneously forced through a die and twisted. Either the mass is twisted uniformly over the cross-section of the billet by a spinner immersed in the mass or the spinner is rotated by the mass. The mass emerges either subject to torsion or entirely or mostly without torsion from a smooth downstream channel through the die. A filament-shaped material extends or is injected into the mass to produce the inner bore or bores.