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. 08, 1990
Filed:
Feb. 17, 1989
Applicant:
Inventors:
Helmut Leber, Hanau, DE;
Nigel R Whippey, Seligenstadt, DE;
Assignee:
Heraeus Quarschmelze GmbH, Hanau, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03B / ; C03B / ;
U.S. Cl.
CPC ...
65 86 ; 65 325 ; 65 61 ; 65111 ; 65DI / ; 65DI / ;
Abstract
A method for the continuous production of a tube or rod of vitreous fused silica. Silicon dioxide in particle form is heated in a crucible to the softening temperature and is withdrawn contiuously downward from a bottom outlet opening in which a shaping tool is disposed. In the annular space between the shaping tool and the bottom outlet opening the softened silicon dioxide is subjected to an electrical field. In the closed crucible, a hydrogen-containing atmosphere with a hydrogen content of at least 80% is sustained above the silicon dioxide and in the space underneath the crucible that adjoins the shaping region.