Granular spreader
CA 2129688 C · Owner: Whitell, David · Inventors: Whitell, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A spreader for granular material such as sand comprises a trailer adapted to be pulled behind a vehicle such as a tractor or other utility vehicle. A frustoconical bin forms a hopper for a granular material to be dispensed and directs the material into a spreader housing where the material is impelled outwardly through a discharge opening by a rotating impeller. The impeller and an orbital rotating bin sweep arm are driven by coaxial drive shafts via a belt and pulley mechanism. A frictional tire engages the upper rim of the bin and propels the sweep arm in an orbital path. The material discharge rate and discharge pattern are controllable by a slide gate and interchangeable cover plates …
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 August 2, 1994 and granted May 11, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 2, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 2, 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.