Coin diameter measurement
CA 2244102 A1 · Owner: Mars Incorporated · Inventors: Furneaux, David Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A coin diameter measuring circuit uses a pair of coils coupled in the feedback path of an oscillator so that the oscillator frequency is dependent upon the inductances of the coils and the mutual inductance therebetween. The coils are switched between aiding and opposing configuration during the time that a coin passes therebetween, the oscillator frequency in each configuration is measured, and the difference therebetween determined to provide an indication of the mutual inductance of the coils, and thence the diameter of the coin. Preferably, the diameter is determined by the difference between the measured mutual inductance with the coin present and with the coin absent.
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 January 24, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 24, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 24, 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.