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:
Jul. 30, 2002
Filed:
Jul. 07, 2000
Masanori Suzuki, Koriyama, JP;
Toshiyuki Kato, Koriyama, JP;
Atsuhi Shimada, Koriyama, JP;
Yutaka Watabe, Koriyama, JP;
Other;
Abstract
A method for producing an optical fiber preform comprising inserting a core glass rod for use in the optical fiber preform into the quartz glass tube for the optical fiber preform and then welding them in a heating furnace to melt weld them together into a monolithic product, wherein the melting is started in such a state that the lower open edge of said quartz glass tube is placed inside the heating furnace and a gas is supplied from the upper edge of the tube, and after the lower edge portion of the quartz glass tube is drawn out from said heating furnace by melt deformation and stretching by the gravitational force, the gas supply is cut off and the pressure is reduced.