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Expired Canadian patentCanada

Flexible graphite articles with an amorphous carbon phase at the surface

CA 1340440 C · Owner: Greinke, Ronald Alfred · Inventors: Greinke, Ronald Alfred; Howard, Ronald Albert

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

An article, such a seal ring, suitable for reduction of chatter when used in stuffing boxes with reciprocating stems. The article has an amorphous carbon phase at the surface of the article with the amorphous carbon phase extending into the article from the surface.

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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 March 16, 1999. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 16, 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.
FiledMarch 21, 1989
GrantedMarch 16, 1999
Term endedMarch 16, 2016
Patent numberCA 1340440 C
Classification (IPC)F16J15/30 +2 more

Timeline

Timeline From CIPO dates

199019931996199920022005200820112014Application filedMarch 21, 1989Patent grantedMarch 16, 1999Term endedMarch 16, 2016

Sources & verification

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