Welding accessory
CA 2029664 C · Owner: Yoshida, Mikihiko · Inventors: Yamada, Hiroaki; Yoshida, Mikihiko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A welding accessory which includes an arc shield having outer and inner peripheral surfaces such that a weld can be formed within the inner peripheral surface as the arc shield shields the weld from external air during forming of the weld. The arc shield includes a ceramic material having not less than 40 weight % of boron nitride. The arc shield may be formed of a composite of boron nitride and silicon nitride a composite of, boron nitride and alumina nitride a composite of boron nitride, aluminum and silicon nitride, or a composite of boron nitride and zirconia.
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 9, 1990 and granted May 28, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 9, 2012.
- 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.