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Expired European patentEurope

Circuit for polling terminals in a data transmission system

EP 0009551 B1 · Applicant: International Business Machines 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 July 16, 1979 and granted September 8, 1982. A European patent lasts at most 20 years from filing, so its term ended July 16, 1999.
  • 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 16, 2005.
  • 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 16, 1979
PublishedApril 16, 1980
GrantedSeptember 8, 1982
Term endedJuly 16, 1999
Application numberEP 79102451
Classification (CPC)H04L12/423 +2 more

Timeline

Timeline From EPO dates

1980198219841986198819901992199419961998Application filedJuly 16, 1979PublishedApril 16, 1980Patent grantedSep 8, 1982Term endedJuly 16, 1999

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.