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Expired Canadian patentCanada

Piston spring seal

CA 1134875 A · Owner: Greene, Tweed & Co. Inc. · Inventors: Burke, John A.; Gross, James B.

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

Abstract of the Disclosure A sealing ring firmly grips a movable piston performs the, normal sealing function, and when pressure is released on the piston the sealing ring pulls back on the piston so as to retract the piston. The sealing ring is designed so as to fit in a conventional seal or "O" ring groove without any modification of the groove.

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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 November 2, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 2, 1999.
  • 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 28, 1980
GrantedNovember 2, 1982
Term endedNovember 2, 1999
Patent numberCA 1134875 A
Classification (IPC)F16J15/00 +2 more

Timeline

Timeline From CIPO dates

1981198319851987198919911993199519971999Application filedMarch 28, 1980Patent grantedNov 2, 1982Term endedNov 2, 1999

Sources & verification

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