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Expired Canadian patentCanada

Energy storage flywheel apparatus and methods

CA 2245557 C · Owner: Active Power, Inc. · Inventors: Little, Scott R.; Clifton, David B.; Pinkerton, Joseph F.

CIPO record

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Abstract From the Canadian patent

A flywheel energy conversion device (10) provides highly efficient conversion between kinetic and electrical energy. The flywheel (10) produces increased output by providing armature coils (44) in an air gap (46) formed about the flywheel (both radial and axial embodiments are described). In preferred embodiments, field coils (30, 32) of a magnetic circuit are energized with DC drive current that creates homopolar flux within a rotating solid rotor (12) having teeth (14) cut from a flat disk. The total reluctance of the magnetic circuit and total flux remain substantially constant as the rotor rotates. The flux may travel radially outward and exit the flat disk through the teeth …

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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 February 5, 1997 and granted July 9, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 5, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 5, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 5, 1997
GrantedJuly 9, 2002
Term endedFebruary 5, 2017
Patent numberCA 2245557 C
Classification (IPC)H02K7/02 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedFeb 5, 1997Patent grantedJuly 9, 2002Term endedFeb 5, 2017

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