Method and apparatus for detecting mechanical overload of a hoist
CA 2008685 C · Owner: Pratt, Richard L. · Inventors: Pratt, Richard L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A control method and apparatus for detecting mechanical overload in a hoist driven by an alternating current motor is disclosed. The level of the current of the power supplied to the motor which is indicative of a mechanical overload condition of the hoist is determined. Current measuring means coupled to the power supply measures the actual level of the current supplied to the motor and produces a signal indicative of the measured current level. An overload reference means provides a reference signal representative of the motor current level indicative of the mechanical overload condition. Comparison means compares the current signal representative of the motor current level and the …
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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 January 26, 1990 and granted December 6, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 26, 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.