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Expired Canadian patentCanada

Closed granular chemical handling system

CA 2012098 C · Owner: Mccunn, Myron Lee · Inventors: Depauw, Richard Arthur; Hoffman, Jeffrey Alan; Mccunn, Myron Lee

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

A closed granular chemical handling system comprising a dispensing valve and a receiving valve. The dispensing valve and the receiving valve are automatically opened when the valves are coupled together, and are automatically closed when the valves are uncoupled from one another. The valves are configured so that the receiving valve always is the first to open and the last to close. The valves are driven together by a camming structure having a neutral portion that acts as a delay between the opening and closing of both valves so as to allow granular material to flow from between the valves through the receiving valve.

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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 March 13, 1990 and granted November 15, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 13, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 13, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 13, 1990
GrantedNovember 15, 1994
Term endedMarch 13, 2010
Patent numberCA 2012098 C
Classification (IPC)A01C7/06 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedMarch 13, 1990Patent grantedNov 15, 1994Term endedMarch 13, 2010

Sources & verification

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