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Expired European patentEurope

Receiver for push-button PCM-encoded multifrequency signals

EP 0028404 B1 · Applicant: CSELT Centro Studi e Laboratori Telecomunicazioni S.p.A.

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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 October 31, 1980 and granted October 19, 1983. A European patent lasts at most 20 years from filing, so its term ended October 31, 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 May 1, 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.
FiledOctober 31, 1980
PublishedMay 13, 1981
GrantedOctober 19, 1983
Term endedOctober 31, 2000
Application numberEP 80106678
Classification (CPC)H04Q1/4575

Timeline

Timeline From EPO dates

1981198319851987198919911993199519971999Application filedOct 31, 1980PublishedMay 13, 1981Patent grantedOct 19, 1983Term endedOct 31, 2000

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.