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Expired Canadian patentCanada

Valve seat materials for internal combustion engines

CA 988331 A · Owner: Sumitomo Electric Industries, Ltd. · Inventors: Osawa, Makoto; Hagiwara, Yoshitoshi; Kawakita, Takao

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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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

  • Granted May 4, 1976. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 4, 1993.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedMay 4, 1976
Term endedMay 4, 1993
Patent numberCA 988331 A
Classification (IPC)F01L3/02 +2 more

Timeline

Timeline From CIPO dates

197719791981198319851987198919911993Patent grantedMay 4, 1976Term endedMay 4, 1993

Sources & verification

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