Lightweight cement blocks and method of producing same
CA 2133366 C · Owner: Enviro Products Ltd. · Inventors: Le Blanc, Frank X.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A lightweight cement block and a method of producing the lightweight cement block comprising the steps of mixing three parts by volume sawdust with water to form a first mixture having a relative moisture content in the range of 40% to 44%; adding one part by volume sand to the first mixture to form a second mixture; mixing the second mixture with water until the relative mixture content of the second mixture is in the range of 40% to 44%; adding one part by volume cement to the second mixture to form a third mixture; mixing the third mixture with water until the relative moisture content is in the range of 40% to 44%; forming the third mixture into a block. The resultant block comprises …
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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 30, 1994 and granted April 22, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 30, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 30, 2016.
- 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.