Variable conductivity trafficked surface for permafrost regions
CA 2051024 A1 · Owner: Goodrich, Laurel E. · Inventors: Goodrich, Laurel E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Road and the like construction on permafrost is improved by the inclusion of a variable heat conductivity (K) layer between the permafrost and the trafficked surface. The result is a lowering of the mean temperature of the permafrost itself over several years until a lower equilibrium temperature is reached then with the use of merely an insulating layer as in conventional construction.
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 September 10, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 10, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 10, 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.