Patent ID: 6662705
Filing Date: 2003-12-16
Classification: F15B

Abstract:
A method of controlling an electro-hydraulic valve arrangement disposed in fluid connection between a source of pressurized fluid and an actuator, comprising:receiving a signal to open the electro-hydraulic valve arrangement to provide a flow of fluid from the source of pressurized fluid to the actuator; determining a source pressure representative of the pressure of fluid between the source of pressurized fluid and the electro-hydraulic valve arrangement; determining an actuator pressure representative of the pressure of the fluid between the electro-hydraulic valve arrangement and the actuator modifying the received signal to prevent the electro-hydraulic valve arrangement from opening when the source pressure is less than the actuator pressure to prevent a reverse flow of fluid from the actuator to the source of pressurized fluid; and modifying the received signal to close the electro-hydraulic valve arrangement when the source pressure drops below the actuator pressure.