Double chamber sliding backpurge device for gas shielded arc welding
CA 2079836 A1 · Owner: Hunt, James F. · Inventors: Hunt, James F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sliding backpurge device for supplying shielding gas to an arc welding process comprises a concave primary gas chamber surrounded by inner and outer seals which define a pressurized secondary gas chamber therebetween. Pressurized secondary gas is supplied to the secondary gas chamber and primary gas is supplied to the primary chamber. Any leaks which do form, minimize impact on the shield gas within the primary chamber despite sliding engagement of the inner and outer seals over the surface to be welded since secondary gas rather than atmospheric gas leaks into the primary chamber.
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 October 5, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 5, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 2014.
- 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.