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Expired European patentEurope

Apparatus for transmitting information from a well to the surface during drilling

EP 0172452 B1 · Applicant: Norton Christensen, Inc.

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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 July 27, 1985 and granted January 27, 1988. A European patent lasts at most 20 years from filing, so its term ended July 27, 2005.
  • 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 January 27, 2011.
  • 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.
FiledJuly 27, 1985
PublishedFebruary 26, 1986
GrantedJanuary 27, 1988
Term endedJuly 27, 2005
Application numberEP 85109490
Classification (CPC)E21B4/02 +2 more

Timeline

Timeline From EPO dates

1986198819901992199419961998200020022004Application filedJuly 27, 1985PublishedFeb 26, 1986Patent grantedJan 27, 1988Term endedJuly 27, 2005

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.