Method of and apparatus for expanding tobacco
CA 2212652 C · Owner: Stewart, Tony Dean · Inventors: Wilhelm, Douglas Edwin; Poindexter, Dale Bowman; Guy, Keith Rowan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of and an apparatus for expanding tobacco particularly tobacco, impregnated with solid carbon dioxide are disclosed. The apparatus comprises an arcuate, generally C-shaped duct for conveying the tobacco material in a hot gaseous medium to sublimate the solid carbon dioxide and expand the tobacco. The duct has a non-circular cross-section, preferably a rectangular cross-section with a high, width-to-depth ratio and an increasing depth from the inlet to an intermediate portion of the duct then a decreasing depth from the intermediate portion to the outlet of the duct. A winnower device infeeds the tobacco material into the duct adjacent the throat of a venturi section connected to …
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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 August 8, 1997 and granted October 31, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 8, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 8, 2019.
- 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.