Liquid-level gauging
CA 2090697 C · Owner: Sinclair, David · Inventors: Sinclair, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Conventional ultrasonic liquid-level sensors have a transducer mounted at the bottom of a, metal tube that projects upwardly and is filled with liquid to the same height as that outside the, tube. In the present invention the tube has a layer of acoustically-absorbing plastics to damp, the transmission of ultrasonic vibration between the wall of the tube and the liquid within the, tube.
Read the whole patent
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 1, 1993 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 1, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 1, 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.