Expired Canadian patentCanada
Method of preventing hydrogen darkening of optic fibre
CA 2528725 C · Owner: Logan, Robert B. · Inventors: Logan, Robert B.; Chalifoux, Gerald V.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of preventing hydrogen darkening of optic fibre which includes a step of providing a protective barrier of hydrogen free flowing gas around the optic fibre such that the flowing gas sweeps away hydrogen.
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
- Filed November 25, 2005 and granted March 27, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 25, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledNovember 25, 2005
GrantedMarch 27, 2012
Term endedNovember 25, 2025
Patent numberCA 2528725 C
Classification (IPC)G02B6/02 +1 more
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.