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. 31, 2000
Filed:
Oct. 20, 1998
Tatsuhiko Saito, Yokohama, JP;
Tomomi Moriya, Yokohama, JP;
Sumitomo Electric Industries, Inc., Osaka, JP;
Abstract
In a heating furnace which holds at least one end of a glass rod with a holding portion and elongates the glass rod by softening the glass rod successively from the other end portion thereof with heating while applying a tensile force thereto, the heating furnace comprises a tubular portion through which the glass rod to be elongated is inserted such as to be longitudinally movable; heater, positioned within the tubular portion such as to circumferentially surround the glass rod, for heating the glass rod; a moving portion through which one end of the glass rod is inserted; bellows the ends of which are respectively secured to the moving portion and the tubular portion and which is longitudinally expandable and contractible and composed of at least a double cylinder surrounding the part of the glass rod such as to block an outside air from flowing into the heating furnace; and gas supply line for supplying, for purging, an inert gas into a space within the tubular portion and the inner bellows as well as the space between inner and outer bellows.