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Expired European patentEurope

Circuit arrangement for the synchronization of a subordinate device, in particular a digital subscriber station, by a higher order device, in particular a digital switching exchange of a PCM telecommunication network

EP 0023331 B1 · Applicant: SIEMENS AKTIENGESELLSCHAFT

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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.

Why it's free to use

  • Filed July 18, 1980 and granted July 20, 1983. A European patent lasts at most 20 years from filing, so its term ended July 18, 2000.
  • 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 18, 2006.
  • 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 18, 1980
PublishedFebruary 4, 1981
GrantedJuly 20, 1983
Term endedJuly 18, 2000
Application numberEP 80104259
Classification (CPC)H04Q11/04 +2 more

Timeline

Timeline From EPO dates

1981198319851987198919911993199519971999Application filedJuly 18, 1980PublishedFeb 4, 1981Patent grantedJuly 20, 1983Term endedJuly 18, 2000

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