An improved underdrain system
CA 2538121 C · Owner: R.G. Delaware, Inc. · Inventors: Addison, Mark Kevin; Roberts, R. Lee
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An underdrain system having a bottom formed of concrete. The concrete bottom includes a plurality of generally cone shaped depressions formed therein. A porous plate is operably associated with at least one of the generally cone shaped depressions. The underdrain system further includes an insert having at least one distribution orifice for distributing the flow. The insert is positioned beneath the porous plate and at least partially within the at least one generally cone shaped depression. The insert insures thorough distribution of any fluid passing through the porous plate i.e. the fluid is evenly distributed over the entire surface area of the porous plate. In an alternative embodiment …
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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 5, 2002 and granted May 21, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 5, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 5, 2024.
- 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.