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Expired Canadian patentCanada

Password controlled switching system

CA 1320554 C · Owner: American Telephone And Telegraph Company · Inventors: Geers, Thomas Joseph, Jr.; Belfield, William Rohrman; Handy, Stephen Wade

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

Abstract, A password controlled switching system and method of operation for enrolling and storing passwords identifying lines and trunks of the switching system denied access thereto by other lines and trunks and which is operable upon a match of a calling party command with an enrolled and stored password for selectively interconnecting the calling party via a line with ones of the restricted lines and trunks.

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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 July 20, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 20, 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.
FiledSeptember 26, 1989
GrantedJuly 20, 1993
Term endedJuly 20, 2010
Patent numberCA 1320554 C
Classification (IPC)H04M3/38 +2 more

Timeline

Timeline From CIPO dates

1990199319961999200220052008Application filedSep 26, 1989Patent grantedJuly 20, 1993Term endedJuly 20, 2010

Sources & verification

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