System using a toothed wheel for fragmenting a frangible layer into a particulate form
CA 2013540 C · Owner: Green, Yvonne D. · Inventors: Lattman, William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A layer of material such as pavement or sheet ice coating the surface of a roadway is efficiently removed using apparatus that includes a longitudinal tube in a breaker assembly which is rotatably carried by a control frame beam that depends from an articulate hydraulic lift and tilt mechanism of a road grader. Coaxially attached to the tube and uniformly distributed along its length a number of, retainer rings each carry several radially extended teeth that function to fragment the layer. Each tooth includes a tip portion with a free end that penetrates and punctures the layer and a trailing divergent portion which enters the puncture and translates a linear force applied thereto into a …
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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 March 30, 1990 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 30, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 30, 2012.
- 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.