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Expired European patentEurope

A spark plug for use in internal combustion engine

EP 0479506 B1 · Applicant: NGK SPARK PLUG CO., LTD

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Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

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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.

Why it's free to use

  • Filed September 27, 1991 and granted August 23, 1995. A European patent lasts at most 20 years from filing, so its term ended September 27, 2011.
  • 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 March 27, 2017.
  • 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.
FiledSeptember 27, 1991
PublishedApril 8, 1992
GrantedAugust 23, 1995
Term endedSeptember 27, 2011
Application numberEP 91308877
Classification (CPC)H01T13/14

Timeline

Timeline From EPO dates

1992199419961998200020022004200620082010Application filedSep 27, 1991PublishedApril 8, 1992Patent grantedAug 23, 1995Term endedSep 27, 2011

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