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Expired Canadian patentCanada

Dual timing circuit for telephone subscriber's instrument

CA 1210173 A · Owner: Gte Business Communication Systems Incorporated · Inventors: James, Miranda L.; Teater, Albert G.

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

A dual timing circuit for use with a subscriber's telephone circuit operated in response to two manual switch operations to simulate the placement of the subscriber's phone in the "on-hook" condition for two different predetermined periods of time. One "on-hook" period being for the operation of transfer circuitry in an asssociated PABX and the other period being for the initiation of a new call.

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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 August 19, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 19, 2003.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 1, 1984
GrantedAugust 19, 1986
Term endedAugust 19, 2003
Patent numberCA 1210173 A
Classification (IPC)H04M7/00 +1 more

Timeline

Timeline From CIPO dates

1985198719891991199319951997199920012003Application filedMay 1, 1984Patent grantedAug 19, 1986Term endedAug 19, 2003

Sources & verification

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