Apparatus for uniformly distributing gas and/or liquid in an underdrain lateral system
CA 2075564 C · Owner: Weatherford/Lamb, Inc. · Inventors: Maxson, Richard Charles
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Underdrain lateral system, which is especially adapted for use in a gravity filter bed, includes as its preferred, embodiment, scallop-shaped laterals (26 126) having an, upper, wrapped wire, slotted screen surface (28). The screen surface supports and retains the filter media particles (118) directly, without the necessity of an underlying gravel layer, and is itself supported by channelshaped rod members (34) which are welded to the wires (30). The web portions (36) of the channel-shaped rod members perform the function of simultaneously distributing air and water during backwashing, and include a smaller total area of apertures (38) in upper channels and a larger total area of apertures …
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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 7, 1992 and granted April 15, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 7, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 7, 2014.
- 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.