Electronically commutated motor having an increased flat top width in its back emf waveform, a rotatable assembly therefor, and methods and methods of their operation
CA 2010138 C · Owner: Forbes, Franklin L. · Inventors: Forbes, Franklin L.; Krefta, Ronald J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electronically commutated motor is disclosed including a stationary assembly having a plurality of winding stages adapted for commutation in at least one preselected sequence and a rotatable assembly having a plurality of permanent magnet elements in magnetic coupling relation with the stationary assembly. The permanent magnet elements are adapted to sequentially apply a magnetic field having a substantially constantly increasing magnetic flux to each respective winding stage during the period that current is supplied to the respective winding stage as the rotatable assembly rotates. The permanent magnet elements are also adapted to sequentially apply a magnetic field having a …
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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 15, 1990 and granted August 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 15, 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.
Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.