Side-hole cane waveguide sensor
CA 2897288 C · Owner: Weatherford Technology Holdings, Llc · Inventors: Kersey, Alan D.; Maida, John L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor …
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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 February 20, 2004 and granted November 15, 2016. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 20, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 2026.
- 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.