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:
May. 19, 1992
Filed:
Mar. 22, 1991
Applicant:
Inventors:
Ichiro Tsuchiya, Yokohama, JP;
Shinji Ishikawa, Yokohama, JP;
Masahide Saitoh, Yokohama, JP;
Yoichi Ishiguro, Yokohama, JP;
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C03B / ; C03B / ; C03B / ;
U.S. Cl.
CPC ...
432206 ; 432208 ; 432239 ; 432244 ; 65157 ; 65 13 ;
Abstract
A heating furnace for heating a porous preform made of fine particles of highly pure quartz glass for an optical fiber, which furnace comprises a cylindrical furnace body, a heater installed in said furnace body and a muffle tube installed inside said heater to separate a heating atmosphere from said heater, wherein said muffle tube is made of highly pure carbon and coated with a gas impermeable carbon, which furnace prevents contamination of the preform with impurities and has long life.