Dc resistance welding apparatus
CA 2003245 C · Owner: Saito, Hitoshi · Inventors: Kobayashi, Nobuo; Suzuki, Makoto; Koga, Hidenori
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A DC resistance welding apparatus has a pair of welding electrodes for sandwiching work-pieces to be welded therebetween. A circuit is connected to the welding electrodes for supplying a welding current to the welding electrodes. The circuit includes a plurality of parallelconnected rectifying circuits each having a welding transformer and a rectifier. A plurality of inverters are connected respectively to the rectifying circuits for driving the rectifying circuits. An auxiliary control is connected respectively to the inverters for energizing the inverters. A current detector is provided for generating signals proportional to branch welding currents supplied respectively from the …
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 17, 1989 and granted June 3, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 17, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 17, 2011.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.