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Expired Canadian patentCanada

Gearless direct drive switched reluctance motor for laundry application

CA 2021106 C · Owner: Erdman, David M. · Inventors: Harms, Harold B.; Erdman, David M.; Wiedemann, Gustave F.

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 drive system for a laundry machine utilizing a switched reluctance motor of three or more phases and with stator/rotor pole ratios selected from the ratios of 6:4 and 8:6 with the actual number of poles being a multiple of 2 or more times those numbers. A stator/rotor gap of 10-20 mils is maintained in large diameter motors and cooling for the coils and electronic components positioned within the motor is provided.

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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 July 12, 1990 and granted December 28, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 12, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 12, 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.
FiledJuly 12, 1990
GrantedDecember 28, 1999
Term endedJuly 12, 2010
Patent numberCA 2021106 C
Classification (IPC)H02K1/10 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJuly 12, 1990Patent grantedDec 28, 1999Term endedJuly 12, 2010

Sources & verification

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