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Expired Canadian patentCanada

Automatic variable speed transmission

CA 551420 A · Owner: Duffield, William A. · Inventors: Duffield, William A.

CIPO record

Overview

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

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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 January 7, 1958. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 7, 1975.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJanuary 27, 1949
GrantedJanuary 7, 1958
Term endedJanuary 7, 1975
Patent numberCA 551420 A
Classification (IPC)F16H39/00 +1 more

Timeline

Timeline From CIPO dates

195019531956195919621965196819711974Application filedJan 27, 1949Patent grantedJan 7, 1958Term endedJan 7, 1975

Sources & verification

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