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:
Feb. 11, 1997
Filed:
Nov. 14, 1994
Arno Friedrichs, Hamburg, DE;
Konrad Friedrichs KG, Kulmbach, DE;
Gottlieb G uhring KG, Ebingen, DE;
Abstract
An extruder for extrusion manufacturing one of a hard metal and a ceramic rod with at least one helical inner bore and having a smooth outer surface substantially free of elevations and depressions includes a housing and a die connected to the housing. The mechanism for forcing a plasticized mass through the die is provided wherein the mass is shaped in the form of a billet having a cross-section. A spinner is located in the housing upstream of the die for twisting the mass uniformly over the cross-section of the billet, the spinner being surrounded by an axial flow of the mass. A smooth channel is located downstream of the spinner such that the mass emerges from the channel through the die and a mechanism is provided suspending a filament in the mass wherein the filament follows a twisting movement of the twisted mass so as to form a helical inner bore therein. The housing includes an interior coaxial mandrel supporting the spinner, the mandrel being located upstream of the spinner wherein the filament projects from a downstream end of the spinner into the die at eccentrically arranged locations.