The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 1992
Filed:
Dec. 03, 1990
Rudolf Glatzle, Reutte, AT;
Ronald Huber, Vils, AT;
Thomas Schopf, Breiterwang, AT;
Michael Schretter, Ehrwald, AT;
Schwarzkopf Development Corporation, New York, NY (US);
Abstract
The invention relates to an extrusion process and an extrusion tool for the production of cylindrical metallic or ceramic blanks having one or more internal twisted longitudinal bores. A plasticized, pulverulent starting material, deformable by means of extrusion, is forced through a space formed by a die and a mandrel. One or more twisted central pins of a rigid material are fastened to the mandrel which ends before the inner space of the die. The central pins form the longitudinal bores in the blank. The positioning of the longitudinal bores is extremely symmetrical within the blank and uniformly achieved in the various individual blanks extruded using the same production batch.