Expired European patentEurope
Telephone apparatus provided with a preamplifier with carrier current, an interrupter for disconnection of the microphone and a device for signalling this disconnection
EP 0052347 B1 · Applicant: HORLOGERIE PHOTOGRAPHIQUE FRANCAISE
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 November 12, 1981 and granted September 5, 1984. A European patent lasts at most 20 years from filing, so its term ended November 12, 2001.
- 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 12, 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.
FiledNovember 12, 1981
PublishedMay 26, 1982
GrantedSeptember 5, 1984
Term endedNovember 12, 2001
Application numberEP 81109647
Classification (CPC)H04M1/6008
Timeline
Timeline From EPO dates
Sources & verification
Official EPO records
Everything on this page comes from the EPO record linked above. EPO data used under CC BY 4.0.