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Expired European patentEurope

Apparatus for detecting ground fault in variable-voltage variable-frequency power system

EP 0122366 B1 · Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed January 17, 1984 and granted April 22, 1987. A European patent lasts at most 20 years from filing, so its term ended January 17, 2004.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by July 17, 2009.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledJanuary 17, 1984
PublishedOctober 24, 1984
GrantedApril 22, 1987
Term endedJanuary 17, 2004
Application numberEP 84100414
Classification (CPC)G01R31/52 +2 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedJan 17, 1984PublishedOct 24, 1984Patent grantedApril 22, 1987Term endedJan 17, 2004

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

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