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Expired Canadian patentCanada

Method and apparatus for monitoring the level of the contents in a container

CA 1296791 C · Owner: Imed Corporation · Inventors: Meijer, Robert S.

CIPO record

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

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Abstract From the Canadian patent

A method and apparatus are disclosed for monitoring the contents of a container in order to detect when the contents are below a predetermined level. An optical metering signal from a light source driven by a multivibrator is projected at a predetermined level across the space within the container. A light sensor on the opposite side of the space within the container detects incident illumination there. The metering signal is incident there only when the contents of the container are below the predetermined level. Otherwise the, contents either block or refract the metering signal from its normal path, and the metering signal goes undetected. A unity gain amplifier of variable sign coupled …

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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.
FiledJuly 11, 1989
GrantedMarch 3, 1992
Term endedMarch 3, 2009
Patent numberCA 1296791 C
Classification (IPC)G01F23/22 +2 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedJuly 11, 1989Patent grantedMarch 3, 1992Term endedMarch 3, 2009

Sources & verification

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