A manifold includes multiple first valve mount portions, on each of which three electromagnetic valves are arranged side by side, or a plurality of second valve mount portions, on each of which two electromagnetic valves are arranged side by side, or includes at least one of the first valve mount portions and at least one of the second valve mount portions. Waterproof covers are attached to the valve mount portions of the manifold to each cover the three or two electromagnetic valves mounted on the valve mount portion. Thus, a waterproof manifold electromagnetic valve is formed.

The subject matter of this specification can be embodied in, among other things, a method that includes actuating a closure member at a predetermined first velocity a predetermined first number of cycles between a first configuration and a second configuration, actuating the closure member at a predetermined second velocity a predetermined second number of cycles between the first and the second configuration, actuating the closure member at a predetermined third velocity a predetermined third number of cycles and the second configuration, actuating the closure member at a predetermined fourth velocity a predetermined fourth number of cycles and the second configuration, and actuating the closure member to the second configuration at a predetermined fifth velocity for a predetermined flushing period.

A hydraulic system for controlling bleed down and retraction of a boom within a safety envelope includes a backup battery power supply, and at least a first boom lift hydraulic cylinder configured to raise and lower the boom. The first boom lift hydraulic cylinder includes a solenoid bleed valve electrically connected to the backup battery power supply. The hydraulic system also includes an input device controllable by an operator of the boom. The input device may, for instance, be used by the operator to initiate bleed down and retraction of the boom from an elevated position. To accommodate independent failsafe features of the system, the input device is configured to selectively actuate the solenoid bleed valve using electrical power supplied from the backup battery power supply.

An electrohydraulic poppet valve device control system includes a main body, an extend poppet valve, a retract valve body, a retract poppet valve, and an actuator. The actuator is movable to an extend position, a retract position, and a null position, and moves to, or remains in, the null position when electrical power is not supplied to the actuator. In the extend position, the extend poppet valve is in its open position and the retract poppet valve is in its closed position. In the retract position, the extend poppet valve is in its closed position and the retract poppet valve is in its open position. In the null position, the extend poppet valve is in its closed position and the retract poppet valve is in its closed position.

A hydraulic lockout lever failure detection system preferably includes a first analog sensor, a second analog sensor, at least one electronic control module (ECU) and a solenoid valve. The voltage output level of the first and second analog sensors is monitored by the ECU. The solenoid valve controls the flow of hydraulic fluid to operate an excavator or other equipment. The operation of the solenoid valve is controlled by the ECU. However, a second ECU may be used to control the operation of the solenoid valve. A hydraulic lockout lever causes the first and second analog sensors to output either a low voltage to indicate a closed position, or to indicate an open position to the ECU. If the first and second analog sensors output a voltage that is above a low set value or above a high set value, a fault is detected.

A failsafe vale provides “Hole-In-The-Wall” failsafe functionality for thin-wing aircraft control surface actuation systems having a geared rotary actuator powered by a hydraulic rotary motor. The failsafe valve is associated with the hydraulic rotary motor and mechanically connected to the control surface, and enables the flight control surface to return to an aerodynamically neutral failsafe position if electrical control and/or hydraulic pressure is lost. When the failsafe valve receives a normal command pressure from the hydraulic system, the valve is inactive and the actuation system operates normally. However, if there is a loss of electrical command capacity to control hydraulic valves and/or a loss of hydraulic pressure, the failsafe valve is activated and connects one of the motor hydraulic control lines to the case return line for the motor if the control surface is away from its failsafe position. Consequently, the control surface will be hydraulically powered or aerodynamically ratcheted to its failsafe position in the failure event.

An actuator control arrangement includes a hydraulic actuator having a housing and a piston rod axially moveable within the housing, a stop disposed within the housing to limit the extent of movement of the piston rod into the housing, and a solenoid valve arranged between a pressure source and the actuator. The solenoid valve is switchable between a first mode and a second mode in response to an electric control signal, wherein, in the first mode, the solenoid valve creates a fluid flow path from the pressure source to the actuator so as to locate the stop in its neutral position and in the second mode, the solenoid valve creates a fluid flow path to release pressure from the actuator to permit the stop to move to its retracted position. In the event of electrical failure, the stop will set the actuator to its neutral position.

A power unit with manual override control for a hydraulic system having an initial state and at least one operational state is provided, comprising: a tank for storing hydraulic fluid that moves between a first chamber and a second chamber of a hydraulic cylinder; a pump that routes the hydraulic fluid in and out of the tank; a first relief valve; a first solenoid valve configured to shift between a plurality of positions based on the at least one operational state of the hydraulic system; a first check valve connected to the first solenoid valve; a manual override control unit comprising: a second check valve; and a second solenoid valve configured to shift between a plurality of positions based on activation of a manual override control, wherein the activation of the manual override control returns the hydraulic system from the at least one operational state to the initial state.

An electrohydraulic poppet valve device control system includes an extend valve body, an extend poppet valve, a retract valve body, a retract poppet valve, and an actuator. The actuator is movable to an extend position, a retract position, and a null position, and moves to, or remains in, the null position when electrical power is not supplied to the actuator. In the extend position, the extend poppet valve is in its open position and the retract poppet valve is in its closed position. In the retract position, the extend poppet valve is in its closed position and the retract poppet valve is in its open position. In the null position, the extend poppet valve is in its closed position and the retract poppet valve is in its closed position.

The disclosure relates to an electro-hydraulic control system for directing fluid to at least one hydraulic actuator, the system comprising at least one electronic controller; first and second pilot valves being electrically connected to the at least one electronic controller which is arranged to control the operation of the first and second pilot valves, third and fourth pilot valves being electrically connected to the at least one electronic controller which is arranged to control operation of the third and fourth pilot valves. A pilot operated main valve is configured to control fluid flow to at least one hydraulic actuator. Each of the first and second pilot valves and the third and fourth pilot valves is a fail-safe pilot valve arranged to drain a regulated outlet port to a low pressure reservoir if a spool of the fail-safe pilot valve becomes stuck in an open state.