Method and apparatus for improvement of involute and lead error in powder metal gears
CA 2279730 C · Owner: Amsted Industries Incorporated · Inventors: Graupner, Scott D.; Haye, Steven T.; Engquist, John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Gears, particularly spur gears, are produced by powder metal techniques with minimal lead, line error and eccentricity which gears are preformed from powder metal sintered, hardened and, thereafter have their involute surfaces regenerated by a hard hob with a negative rake on the hob, teeth to provide gears having aligned involute surfaces between adjacent gear teeth and, between, each gear tooth and the gear center line.
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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 August 5, 1999 and granted November 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 5, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 5, 2021.
- 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.