Apparatus and method for forming heat treating atmospheres
CA 2199099 C · Owner: Chang, Edward · Inventors: Nayar, Harbhajan S.; Dwyer, John J. Jr.; Chang, Edward
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to a method for forming a heat treating atmosphere in which a nitrogen rich gas containing small amounts of oxygen is preheated. An oxygen-reactive gas such as a hydrocarbon gas, is, combined with the nitrogen rich gas and the mixture is reacted outside of the furnace at temperatures above which substantial sooting does not occur. The resulting heat treating atmosphere is then forwarded to the furnace for conducting the heat treating process.
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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 March 4, 1997 and granted December 19, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2019.
- 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.