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Expired European patentEurope

Device for avoiding sustained disturbing oscillations in a closed-loop system and loud-speaking telephone apparatus utilising this device

EP 0065335 B1 · Applicant: TELECOMMUNICATIONS RADIOELECTRIQUES ET TELEPHONIQUES T.R.T.

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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 May 6, 1982 and granted December 27, 1984. A European patent lasts at most 20 years from filing, so its term ended May 6, 2002.
  • 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 November 6, 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.
FiledMay 6, 1982
PublishedNovember 24, 1982
GrantedDecember 27, 1984
Term endedMay 6, 2002
Application numberEP 82200544
Classification (CPC)H04M9/08

Timeline

Timeline From EPO dates

1983198519871989199119931995199719992001Application filedMay 6, 1982PublishedNov 24, 1982Patent grantedDec 27, 1984Term endedMay 6, 2002

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

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