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Expired Canadian patentCanada

Anti-eavesdropping device

CA 2134408 C · Owner: Kury, Charles A. · Inventors: Kury, Charles A.

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

An anti-eavesdropping device is provided which consists of a first structure for containing sound waves produced by a first person. This first structure includes a sound attenuating breathing device. This first structure includes a first mechanism for converting sound waves into electric waves, which are then transferred to a second structure which is for forming an acoustic seal about the ears of a second person. This second structure includes a second mechanism for converting the electric waves back to the sound waves. Because the device enables two or more people to engage in conversation, in such a way that no sound can escape into the environment to be detected in any way by, the human …

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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 October 26, 1994 and granted January 9, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 26, 2014.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 26, 2016.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 26, 1994
GrantedJanuary 9, 2001
Term endedOctober 26, 2014
Patent numberCA 2134408 C
Classification (IPC)H04K1/00 +2 more

Timeline

Timeline From CIPO dates

1995199719992001200320052007200920112013Application filedOct 26, 1994Patent grantedJan 9, 2001Term endedOct 26, 2014

Sources & verification

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