Means and method for measuring inductance
CA 2005123 C · Owner: Finger, Eugene P. · Inventors: Penkalski, Thomas A.; Jalbert, Bernard W.; Finger, Eugene P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A proximity switch including an inductor having an actuator rod movable in proximity thereto to affect the inductance thereof. An electrical pulse of relatively short duration is applied to the inductor and the current from the inductor is measured at a selected time interval after the initiation of the pulse. When a selected value of the current is exceeded, the switch is triggered. A plurality of inductors may be sequentially interrogated by one electronic circuit, thus requiring low power and affording smooth operation. Calibration of the trigger point is accomplished electronically after mechanical installation, thus inherently compensating for mechanical tolerances and proximity …
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 December 11, 1989 and granted August 3, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 11, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 11, 2011.
- 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.