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. 15, 2004
Filed:
Apr. 26, 2001
Yukio Kohmura, Chiyoda-ku, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A porous preform vitrification apparatus of the present invention, provided with a means for forcibly feeding nitrogen etc. from a furnace core tube to a discharge gas pipe so as to balance a pressure between a furnace core tube accommodating a porous preform and a heating furnace body surrounding this and so as to suppress pressure fluctuation in the furnace core tube to a minimum level, controlling the gas feed rate and discharge rate to the furnace core tube and the heating furnace body, and controlling the feed rate of the nitrogen from the furnace core tube to the discharge gas pipe based on a differential pressure signal of a pressure in the furnace core tube and a pressure in the heating furnace body.