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Expired European patentEurope

Improved unrestricted frequency changer system and adjustable frequency AC motor drive using such a system

EP 0127306 B1 · Applicant: WESTINGHOUSE ELECTRIC CORPORATION

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Overview

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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 April 24, 1984 and granted January 20, 1988. A European patent lasts at most 20 years from filing, so its term ended April 24, 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 October 24, 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.
FiledApril 24, 1984
PublishedDecember 5, 1984
GrantedJanuary 20, 1988
Term endedApril 24, 2004
Application numberEP 84302728
Classification (CPC)H02P27/16 +1 more

Timeline

Timeline From EPO dates

1985198719891991199319951997199920012003Application filedApril 24, 1984PublishedDec 5, 1984Patent grantedJan 20, 1988Term endedApril 24, 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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