Process and apparatus for semi-sequential transmission using several radiofrequencies simultaneously and used to link an earthquake-detecting device to a central control and recording laboratory

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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

• Granted March 3, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 3, 2009.
• We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.