Linear motor
CA 2374351 A1 · Owner: Fisher & Paykel Limited · Inventors: Boyd, John Henry; Duncan, Gerald David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides an improved design of linear motor as well as an improved control strategy. The design allows for a shorted stator where , the armature magnets are controlled to reciprocate to a greater maximum displacement than for a equivalent conventional linear motor. The control strategy is such that a minimum of external sensors are required. The linear motor is driven at its resonant frequency ensuring optionally efficient operation. A determination of the maximum current is made based on a relationship with the resonant frequency and the evaporating temperature/pressure of the vapour entering the compressor. The current is then limited to control the maximum …
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 June 21, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 21, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 2022.
- 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.