Expired European patentEurope
Digital switching network for telecommunications exchange
EP 0093523 B1 · Applicant: THE PLESSEY COMPANY plc
Overview
The published document from the EPO: abstract, claims, description and drawings. Open it full size
Read the whole patent
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 April 14, 1983 and granted August 6, 1986. A European patent lasts at most 20 years from filing, so its term ended April 14, 2003.
- 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 October 14, 2008.
- 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.
FiledApril 14, 1983
PublishedNovember 9, 1983
GrantedAugust 6, 1986
Term endedApril 14, 2003
Application numberEP 83302093
Classification (CPC)H04Q11/04
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.