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Expired European patentEurope

Stress-compensated quartz resonators

EP 0054447 B1 · Applicant: SCHLUMBERGER LIMITED

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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.

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Why it's free to use

  • Filed November 3, 1981 and granted September 14, 1988. A European patent lasts at most 20 years from filing, so its term ended November 3, 2001.
  • 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 May 3, 2007.
  • 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.
FiledNovember 3, 1981
PublishedJune 23, 1982
GrantedSeptember 14, 1988
Term endedNovember 3, 2001
Application numberEP 81401760
Classification (CPC)H03H9/02023 +1 more

Timeline

Timeline From EPO dates

1982198419861988199019921994199619982000Application filedNov 3, 1981PublishedJune 23, 1982Patent grantedSep 14, 1988Term endedNov 3, 2001

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

Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.