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Expired Canadian patentCanada

Transformer testing method

CA 2205539 C · Owner: Goedde, Gary L. · Inventors: Kershaw, Stanley S.; Goedde, Gary L.; Veverka, Edward F.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Testing of a transformer in an oil filled housing is done by providing an external arrester insulator/isolator penetrating and making an electrical connection through the housing while preventing leaking of oil from said housing. An arrester inside said housing is electrically coupled between an interior end of arrester isolator and a predetermined potential point within the housing. An exterior end of said arrester isolator is removably and electrically coupled to a ground potential point. The ground coupling is removed from the exterior end of the arrester isolator and the transformer is tested by measuring electrical characteristics on transformer connections emerging from the housing. …

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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 December 1, 1989 and granted February 13, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 1, 2009.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 1, 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.
FiledDecember 1, 1989
GrantedFebruary 13, 2001
Term endedDecember 1, 2009
Patent numberCA 2205539 C
Classification (IPC)G01R31/62 +2 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedDec 1, 1989Patent grantedFeb 13, 2001Term endedDec 1, 2009

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.