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Expired Canadian patentCanada

Microcomputer controlled locking system

CA 1252854 A · Owner: Computerized Security Systems, Incorporated · Inventors: Fraser, Stephen G.

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

A locking system is disclosed which comprises a microcomputer controlled lock with multiple level keying, i.e. multiple keys having different functions in the locking system. A key reader, for example punch card or magnetic type, reads key code into the microcomputer. A read/write memory has a predetermined number of assigned key codes stored therein and a read-only memory has a control program stored therein for control of the microcomputer. An electrically controlled actuator for the locking means is coupled with an unlocking output of the microcomputer. The control program comprises a main program and a plurality of subroutines each stored at a different location in the read-only memory. …

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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 April 18, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 18, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledAugust 16, 1985
GrantedApril 18, 1989
Term endedApril 18, 2006
Patent numberCA 1252854 A
Classification (IPC)H04Q1/39 +2 more

Timeline

Timeline From CIPO dates

1986198919921995199820012004Application filedAug 16, 1985Patent grantedApril 18, 1989Term endedApril 18, 2006

Sources & verification

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