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Expired Canadian patentCanada

Automatic control for variable displacement pump

CA 1297730 C · Owner: Hagglunds Denison Corporation · Inventors: Thurston, David L.; Deboer, Lee A.; Born, Ellis H.

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

A control for a variable displacement pump in which a displacement control element is made responsive to a load sensing valve and a pilot pressure relief valve. A control fluid is supplied to the pressure relief valve and the load sensing valve and the control pressure fluid controls the working pressure fluid which operates the stroking piston for the pump.

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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 24, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 24, 2009.
  • 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 17, 1989
GrantedMarch 24, 1992
Term endedMarch 24, 2009
Patent numberCA 1297730 C
Classification (IPC)F04B49/08 +1 more

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedMarch 17, 1989Patent grantedMarch 24, 1992Term endedMarch 24, 2009

Sources & verification

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