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Expired Canadian patentCanada

Hydraulic control valve system with non-shuttle pressure compensator

CA 2250674 C · Owner: Husco International, Inc. · Inventors: Wilke, Raud A.

CIPO record

Overview

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

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Abstract From the Canadian patent

An improved pressure-compensated hydraulic system for feeding hydraulic fluid from a variable displacement pump to multiple hydraulic actuators. A separate valve section controls the fluid flow between the pump and a different actuator. Each valve section has a pressure compensating valve with a valve member and poppet within a bore and biased apart by a spring. The poppet acts as a check valve which prevents fluid flow from the actuator through the valve section to the pump when the back pressure from the load exceeds the pump supply pressure. A pressure differential between the load-dependent pressure and the actuator pressure determines a position of the valve member which controls the …

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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 October 20, 1998 and granted March 18, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 20, 2018.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 20, 2020.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 20, 1998
GrantedMarch 18, 2003
Term endedOctober 20, 2018
Patent numberCA 2250674 C
Classification (IPC)F15B13/04 +2 more

Timeline

Timeline From CIPO dates

1999200120032005200720092011201320152017Application filedOct 20, 1998Patent grantedMarch 18, 2003Term endedOct 20, 2018

Sources & verification

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