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. 25, 2004
Filed:
Sep. 07, 2001
Dagobert Knieling, Hanau, DE;
Rainer Schleich, Hanau, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
In a known method of producing a quartz glass tube ( ), a cylinder ( ) of quartz glass which rotates about a rotational axis ( ) is continuously fed to a heating zone ( ), softened therein in portions starting from one end, and the softened portion ( ) is drawn over a drill head ( ) of a drill body arranged to be coaxial to the rotational axis and is thereby formed into the quartz glass tube ( ). Starting therefrom, in order to indicate a method for forming a cylinder of quartz glass into a hollow cylinder of quartz glass having an inner bore that is as flawless as possible and straight and dimensionally stable, it is suggested according to the invention that a drill body should be used with a drill head ( ) having a contact surface ( ) of a convex curvature facing the cylinder ( ), preferably a spherically shaped contact surface ( ). The drill body according to the invention is characterized by a drill head ( ) which has a contact surface ( ) of a convex curvature ( ).