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Expired Canadian patentCanada

Digital key telephone system

CA 1322396 C · Owner: Littlewood, Timothy James · Inventors: Maginley, Ronald James; Thomas, Terence Neil; Chapman, Alan Stanley John

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Relocation and/or replacement of terminal apparatus in telecommunications systems including, but not necessarily limited to, key telephone system, usually entails reassignment of administration data; for example, features. When a station or terminal apparatus is moved physically from one port to another within a telecommunications system which comprises a plurality of ports connected to a central processor interface means, operative on initial connection of said terminal apparatus transmits to the central processor an identifier unique to such terminal apparatus within such system. The central processing means has storage for each said identifier together with administration data specific …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted September 21, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 21, 2010.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 9, 1989
GrantedSeptember 21, 1993
Term endedSeptember 21, 2010
Patent numberCA 1322396 C
Classification (IPC)H04M9/00 +1 more

Timeline

Timeline From CIPO dates

1990199319961999200220052008Application filedFeb 9, 1989Patent grantedSep 21, 1993Term endedSep 21, 2010

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.