Improvements in or relating to the control of linear motors
CA 2024666 C · Owner: Kelly, Hugh-Peter Granville · Inventors: Kelly, Hugh-Peter Granville
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A linear motor comprises a stator and an armature provided, respectively, with a set of spaced apart permanent magnets and a set of drive coils (not shown). The permanent magnets produce a radial magnetic field whose strength varies periodically along the length of the stator . The field strength is to derive speed and position signals by means of detectors constituted by field coils and Hall Effect sensors. The periodic variation of the field strength is compensated for in the case of the field coils by staggering their phases along the length of the armature and selectively combining their outputs; in the case of the Hall Effect sensors, the periodical variation is used to derive …
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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 September 5, 1990 and granted May 30, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 5, 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
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.