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:
Oct. 02, 1984
Filed:
Sep. 13, 1982
Applicant:
Inventors:
Lutz Brandt, Maintal, DE;
Karl Kreutzer, Gelnhausen-Meerholz, DE;
Karlheinz Rau, Hanau, DE;
Horst Schmidt, Rodenbach, DE;
Fritz Simmat, Gelnhausen, DE;
Assignee:
Heraeus Quarzschmelze GmbH, Hanau, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C03B / ;
U.S. Cl.
CPC ...
373 27 ; 373122 ; 65136 ;
Abstract
Flat, transparent slabs of vitreous silica of optical quality are produced by melting granular starting material in a vacuum by means of an electrical heating system. The starting material is melted while sustaining a heat flow from the top to the bottom of the crucible. The bottom of the crucible is made permeable to gases. The heat isolation power of the crucible wall increases from the bottom to the top of the crucible.