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:
Jul. 29, 2014
Filed:
Jan. 09, 2009
Thomas Kayser, Leipzig, DE;
Walter Lehmann, Leipzig, DE;
Hilmar Laudahn, Dessau, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
The invention starts from a method for producing a crucible of quartz glass in that SiOinner layer granules are vitrified in a rotating melting mold, which is covered at least in part by a heat shield, in a light gas-containing atmosphere under the action of a plasma to obtain a transparent inner layer, at least part of the light gas being supplied to the melting mold through a gas inlet of the heat shield. In order to form an inner layer with a particularly low bubble content and with minimal efforts in terms of energy and material, it is proposed that in a layer forming step preceding the vitrifying step a granule layer consisting of the SiOinner layer granules is formed on the inner wall of the crucible, and that the plasma zone and the heat shield are movable together with the gas inlet and are moved laterally in the direction of the granule layer during the vitrifying step taken for vitrifying the granule layer.