Landfill liner
CA 2047591 C · Owner: Lewis, Stanley M. · Inventors: Lewis, Stanley M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A landfill liner is provided for protecting soil from contaminated waste. The landfill liner includes a unitarily extruded sheet having a flexible central support defining opposed substantially parallel top and bottom surfaces. A plurality of soil gripping protrusions project unitarily from the bottom surface of the central support. The soil gripping protrusions are pointed to grippingly engage the soil being protected and are disposed in, a staggered array to prevent furrowing of the soil to which the liner is applied. A plurality of supporting protrusions project unitarily from the top surface of the central support. The supporting protrusions include substantially blunted or planar top …
Read the whole patent
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 July 23, 1991 and granted July 29, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 23, 2013.
- 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.