Furnace for heating glass preform for optical fiber and method for producing glass preform
CA 1323193 C · Owner: Ishiguro, Yoichi · Inventors: Ishiguro, Yoichi; Tsuchiya, Ichiro; Kyoto, Michihisa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract:, A furnace for heating a porous preform of fine particles of quartz base glass for making an optical fiber in an atmosphere containing fluorine to add fluorine to the preform and to vitrify the preform to produce the glass preform. The furnace has a heater and a muffle tube positioned inside the heater to separate the heating atmosphere from the heater. The invention is characterized in that at least an inner layer of the muffle tube consists of highly pure carbon. As a result the life of the muffle tube is significantly lengthened.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted October 19, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 19, 2010.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.