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. 23, 1998
Filed:
May. 30, 1996
Kiyoshi Yokokawa, Annaka, JP;
Heraeus Quarzglas GmbH, Hanua, DE;
Abstract
A solid or hollow cylindrical heat-resistant substrate having a tapered shape is rotated about its axis, the degree of tapering being essentially constant along the entire length. The substrate has an outer diameter in the range of 20 mm to 500 mm and a length in the range of 500 mm to 5,000 mm. A mother material body made of porous quartz glass is formed on the outer surface of the substrate by chemical deposition, and vitrified by heating while holding it vertically with the larger outer-diameter side of the heat-resistant substrate positioned downward. Alternatively the heat-resistant substrate is extracted from the mother material body and a heat-resistant tapered body with a taper similar to that of the substrate is inserted into the hole left after extraction in the central region of the mother material body. The mother material body is vitrified starting at the lower end with the larger outer-diameter side positioned downwardly. A large-sized quartz glass rod or a large-sized quartz glass tube can be provided any of which has originally an orderly shape and which therefore can be easily machined.