Control circuit for two speed motors
CA 2212972 C · Owner: Therm-O-Disc, Incorporated · Inventors: Bogwicz, Robert R.; Durkee, John E.; Anderson, Jason S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A control circuit for a two speed electric motor includes high and low speed electronic switches. The high speed electronic switch is biased off when the low speed electronic switch is biased on. The low speed run winding of the motor is activatable only through the low speed electronic switch. The high speed run winding of the motor is activatable either directly through a high speed setting of a speed selector switch or through the high speed electronic switch in a low speed setting of the speed selector switch. Upon activation of the motor start winding, the low speed electronic switch is off and the high speed electronic switch is on.
Read the whole patent
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 August 13, 1997 and granted May 9, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 13, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 13, 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.
Timeline
Timeline From CIPO dates
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.