Corrosion protection employing alternating voltage
CA 2176161 C · Owner: Frankenthal, Robert Peter · Inventors: Sinclair, James Douglas; Frankenthal, Robert Peter; Fiorino, Mary Elaine
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of protecting metals from corrosion by applying an alternating voltage to them thereby, reversing the metal's polarity with respect to its surroundings. Particular applications are for metals which are buried in soil or are exposed to an electrolyte. Amphoteric metals which are subject to cathodic corrosion are protected. Steels which are, subject to hydrogen embrittlement when made cathodic are also protected by polarity reversal.
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 May 9, 1996 and granted January 16, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 9, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 9, 2018.
- 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.