Resources Contact Us Home
Hydraulic unloading valves

Image Number 3 for United States Patent #4766926.

An hydraulic unloading valve for unloading hydraulic fluid from a circuit pressurized by a diesel engine powered pump under cold climate conditions to assist starting of the engine. The valve has an inlet through which fluid enters the valve, an outlet through which fluid may leave the valve, an outlet valve seat, a valve member movable towards and away from the valve seat and carrying a valve surface for closing off the seat valve, a first orifice sensitive to viscosity which in response to the flow of fluid through the inlet generates a first pressure drop arranged to tend to move the valve member away from the valve seat, and second orifice which is not sensitive to viscosity and which in response to said flow generates a second pressure drop arranged to tend to move the valve towards the valve seat to bring the valve seat and surface into contact to close-off through the valve outlet when the second pressure drop is greater than the first pressure drop. The pressure drop characteristics of the two orifices can be arranged so that at lower fluid temperatures of say below -10 degrees C. the valve is held open up to higher fluid flow rates, thus relieving load on the engine and assisting cold starting.

  Recently Added Patents
Pyrrolidine derivatives, pharmaceutical compositions containing the same, and methods of using the same
Non-volatile memory and method having efficient on-chip block-copying with controlled error rate
Sealed, waterproof digital electronic camera system and method of fabricating same
Modified and stabilized GDF propeptides and uses thereof
Radio frequency splitter
Method of fabricating solid electrolytic capacitor and solid electrolytic capacitor
PMI feedback with codebook interpolation
  Randomly Featured Patents
Method and apparatus for recognizing preceding vehicle with determination of curved traffic lane
Torque limited drawout mechanism for circuit device
System and method for deflecting an aerodynamic control surface
Minimized corrosion fuel cell device and a method of making the same
Hole saw plug ejector
Method of manufacturing a MOSFET structure
CCR2 receptor antagonists and uses thereof
Extracorporeal pumping methods
Air control valve assembly for fuel evaporative emission storage canister
Programmable PPM detector