Magnetic field analysis method for determining stress characteristics
CA 2085048 C · Owner: Downs, Robert W. · Inventors: Simek, James C.; Downs, Robert W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The apparatus of the invention is a segmented pig body having an electrical instrumentation subassembly mounted thereto. The subassembly consists of a plurality sensors for electromagnetically coupling to the inner surface of the pipeline, each of which generates a signal that varies as the localized relative permeability of the pipeline metal; an odometer assembly for generating correlating data; and an instrument for recording the signal and data for later analysis. The method of the invention comprises passing the pig through the pipeline while it is electromagnetically coupled by the sensors to the inner surface of the pipeline. During the pass signals varying with the localized …
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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 December 10, 1992 and granted April 15, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 10, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 10, 2014.
- 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.