Pulse arc welding apparatus
CA 2233172 C · Owner: Sato, Eiji · Inventors: Ogasawara, Takaaki; Homma, Masahiro; Sato, Eiji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An pulse arc welding apparatus feeds a consumable electrode with a constant rate, and arc-welds by applying a welding current constituted of a pulse current of a constant voltage characteristic and a base current of a constant current characteristic between the consumable electrode and a workpiece. A pulse current control circuit outputs a pulse current command value based on, a difference signal between a pulse voltage detector and a pulse voltage setting device. A pulse frequency control circuit outputs a pulse frequency command value based on, a difference signal between a pulse current detector and a pulse current setting device. Setting devices which output a pulse current upper limit …
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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 26, 1998 and granted March 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 26, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 26, 2020.
- 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.