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Expired European patentEurope

Directory assistance call processing and non-supervisory signal monitoring arrangements

EP 0321498 B1 · Applicant: AT&T Corp.

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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 June 17, 1987 and granted March 25, 1992. A European patent lasts at most 20 years from filing, so its term ended June 17, 2007.
  • 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 December 17, 2012.
  • 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.
FiledJune 17, 1987
PublishedJune 28, 1989
GrantedMarch 25, 1992
Term endedJune 17, 2007
Application numberEP 87906322
Classification (CPC)H04M3/4931

Timeline

Timeline From EPO dates

1988199019921994199619982000200220042006Application filedJune 17, 1987PublishedJune 28, 1989Patent grantedMarch 25, 1992Term endedJune 17, 2007

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.