Method and apparatus for accurate acoustic distance measurement
CA 2107198 A1 · Owner: Nelson, D. Erle · Inventors: Nelson, D. Erle; Rechner, Eric Francis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus for accurate acoustic distance measurement is disclosed. A transceiver pair comprising two acoustic transceiver units named 'controller' and 'remote' is employed to measure the distance between the transceivers simultaneously in both directions. Thus errors due to wind or fluid currents along the acoustic path are effectively cancelled. Both units can instantaneously communicate with each other via wired or wireless means. The controller initiates measurement by sending an instantaneous trigger signal (a current pulse or electromagnetic pulse) synchronously with an acoustic pulse signal to the remote. At the same instant, a plurality of timers is started. Upon receipt …
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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 September 28, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 28, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 28, 2015.
- 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.