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Expired Canadian patentCanada

Atm switching system having dual atm switch structure

CA 2019368 C · Owner: Uchida, Yoshihiro · Inventors: Aso, Yasuhiro; Izawa, Naoyuki; Uchida, Yoshihiro

CIPO record

Overview

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

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Abstract From the Canadian patent

An ATM switching system includes two ATM switches which are the same as each other. Each of the ATM switches includes a switch buffer, and a cell counter which indicates the number of cells in the switch buffer. Each of the ATM switches also includes a difference calculator, which calculates the difference between the number of cells in the two switch buffers when one of the ATM switches is changed from an out-of-service state to a slave mode. At this time, the other ATM switch operates in a master mode. Each of the ATM switches further includes a dummy cell generator, which generates a number of dummy cells which corresponds to the difference calculated by the difference calculator. The …

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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

  • Filed June 20, 1990 and granted August 6, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJune 20, 1990
GrantedAugust 6, 1996
Term endedJune 20, 2010
Patent numberCA 2019368 C
Classification (IPC)H04Q3/42 +1 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJune 20, 1990Patent grantedAug 6, 1996Term endedJune 20, 2010

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