Apparatus and process for monitoring the cooling properties of liquid quenchants and restoring used quenchants
CA 1292889 C · Owner: Hultgren, David H. · Inventors: Hultgren, David H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus for testing the quench-cooling properties of a liquid quenchant comprising a thermistor adapted to be immersed in the liquid to be tested, means for applying an electric potential across the thermistor comprising means for applying an excitation voltage to electrical bridge circuit which contains the thermistor in one leg thereof, first timing means controlling the duration of time during which said excitation voltage is applied to said bridge circuit and means for determining the electrical resistance the thermistor, such that the quenchant properties of the liquid tested are determinable by comparison of the resistance of the immersed thermistor with at least one reference …
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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
- Granted December 10, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 10, 2008.
- 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.