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:
Jun. 11, 2019
Filed:
Jul. 12, 2017
Heraeus Quarzglas Gmbh & Co. KG, Hanau, DE;
Boris Gromann, Aschaffenburg, DE;
Nigel Whippey, Seligenstadt, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
A method for forming a hollow cylinder, in a single step, into a quartz glass tube with a large outer diameter and high dimensional stability is provided. To produce the tube, the cylinder, while rotating, is softened in portions in a heating zone which is moved at a relative feed rate Va and the softened portion is radially expanded by a centrifugal force and/or internal overpressure applied in the hollow cylinder bore so as to form a deformation zone. The radial expansion of the softened portion is carried out at a location-dependent radial expansion rate Vr, the profile of which along the deformation zone has a maximum value Vr,max which is smaller than 20 cm/min. The temperature in a rear heating portion of the heating zone, assigned to the end of the deformation zone, is lower than in a front heating portion assigned to the beginning of the deformation zone.