Method of controlling welding current and inverter-controlled dc resistance welding apparatus
CA 2227670 C · Owner: Takano, Fumitomo · Inventors: Miyanaga, Kenji; Takano, Fumitomo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Before a deterioration of a secondary current sensor is detected, a controller effects a feedback control process based on a secondary current from the secondary winding of a welding transformer which is energized by an inverter, for thereby controlling a welding current with a high degree of accuracy e.g. an, accuracy level of ~ 1 %. At the same time it is, monitored whether a detected value of a primary current from the primary winding of the welding transformer which is detected by a primary current sensor exceeds a, predetermined allowable range with respect to a reference value of the primary current. If the detected value of the primary current exceeds the predetermined allowable …
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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 January 21, 1998 and granted February 6, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 21, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 21, 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
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.