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Expired Canadian patentCanada

Mixed iron powder for powder metallurgy and method of producing same

CA 2123881 C · Owner: Omura, Takeo · Inventors: Yoshii, Yutaka; Maeda, Yoshiaki; Ohtsubo, Hiroshi

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Abstract From the Canadian patent

This invention is to control the diffusion of C (carbon) from added graphite to particles of iron powder in the sintering to thereby improve the accuracy of dimensional change in the sintered body by using iron powder for powder metallurgy and a mixed powder thereof as a starting material in the production of sintered mechanical parts by adding the iron powder with Cu powder and graphite powder and companying and sintering them, in which 0.008-0.5 wt% in total of at least one element having a value of standard free energy of formation of oxide at 1000°C of not more than -120 kcal/l mol of O2 is included in the iron powder and not less than 20% of the element is rendered into an oxide or, …

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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 17, 1993 and granted December 12, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 17, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 17, 2015.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 17, 1993
GrantedDecember 12, 2000
Term endedSeptember 17, 2013
Patent numberCA 2123881 C
Classification (IPC)B22F1/00 +2 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedSep 17, 1993Patent grantedDec 12, 2000Term endedSep 17, 2013

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.