Method and apparatus for short arc welding
CA 2260118 C · Owner: Illinois Tool Works Inc. · Inventors: Holverson, Todd; Hutchison, Richard; Uecker, James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A short circuit arc welding system is disclosed. The control scheme uses a current command signal to drive the output current. The command signal is comprised of a long-term current command that sets the long-term current command level and a real-time or short-by-short current command. Arc voltage feedback is used to determine if the desired arc length is present and to adjust the long-term command. The-short-by-short current command is derived from real-time arc current feedback and is used to control the burn-off rate by an instantaneous or short-by-short, adjustment of the current command. A function of the time derivative of arc power less the time derivative of arc current is used to …
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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 19, 1999 and granted July 23, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 19, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 19, 2021.
- 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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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.