Road snow melting system using a surface heating element
CA 2069238 C · Owner: Nagai, Yoshinori · Inventors: Nagai, Yoshinori; Watanabe, Koji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention will automatically melt snow that has acculmulated on roads in areas having cold climates, and thus enhance the safety of vehicles and aircraft traveling on such roads and runways. The invention is comprised of a heating unit wherein a surface heating element in sheet form is positioned between metal plates and wrapped in a tar-based moisture-proof sheet. The heating unit is embedded beneath a paved surface. After carefully rolling of the asphalt and concrete base layer so that it is free of irregularities the upper, surface of the base layer is coated with a primer. After installing and wiring the above-mentioned heating unit on top of the base layer, an additional …
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 May 22, 1992 and granted December 29, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 22, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 22, 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.