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Expired Canadian patentCanada

Fiber optic hydrophone having rigid mandrel

CA 2199087 C · Owner: Litton Systems, Inc. · Inventors: Frederick, Donald A.; Cappi, John F.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A fiber optic interferometric sensor for use in a hydrophone system at high pressures includes a reference fiber wrapped around a rigid inner cylinder. A solid layer of compliant material is applied over the reference fiber. The sensing arm of the interferometer is wound over the layer of material applied over the reference fiber. The outer material is sufficiently compliant to provide acoustic sensitivity comparable to that of air-backed hydrophones.

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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 March 4, 1997 and granted February 20, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 4, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 4, 2019.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 4, 1997
GrantedFebruary 20, 2001
Term endedMarch 4, 2017
Patent numberCA 2199087 C
Classification (IPC)H04R1/44 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedMarch 4, 1997Patent grantedFeb 20, 2001Term endedMarch 4, 2017

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.