Method and apparatus for surface austempering of cast iron parts
CA 2031361 C · Owner: Pramstaller, Douglas M. · Inventors: Keough, John R.; Pramstaller, Douglas M.; Kovacs, Bela V.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a selectively surface hardened cast iron part includes uniformly heating the surface of the part by immersion into a molten metallic bath until a desired thickness of surface austenite is produced and, thereafter quenching the heated cast iron part in a liquid quenching bath which is maintained at a temperature of between about 450 to about 800°F for about 10 minutes to about 4 hours. The resultant selectively surface hardened cast iron part is surface hardened with the bulk of the body of the part remaining untempered. An apparatus for performing this process includes a molten metal bath chamber for containing the molten metal and a molten salt bath quenching chamber …
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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 December 3, 1990 and granted January 19, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 3, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 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
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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.