The invention relates to a device for controlling and regulating a required pressing force from a current collector of a vehicle on an overhead line, a method for using such a device and a vehicle having at least one such device, wherein the device has a base control circuit, an additional control circuit and a working pressure control circuit. The base control circuit has a base control circuit adjustment device for adjusting a base pressure from a provided power pressure and the additional control circuit has a control device for adjusting an additional pressure from a provided power pressure, wherein the base pressure and the additional pressure act together to form a working pressure and to provide the required pressing force.

A downforce control system for an agricultural ground engaging unit provides individual control of each agricultural ground engaging row unit by providing a proportional pressure control valve connected to the retracting chamber of a double acting cylinder which varies the upward force produced by the retracting chamber of the cylinder against a constant counteracting downward force produced by an extending chamber of the cylinder, the valve control based on a comparison of a sensed resultant downward force on the agricultural ground engaging row unit and a predetermined target downward force.

Power machines and control systems used thereon include a lift cylinder, a tilt cylinder, and a slave cylinder mechanically connected to assist the lift cylinder with raising a boom. With a lift control valve controlled to cause extension of the lift cylinder to raise the boom, pressure from a hydraulic source is provided to the slave cylinder to aid in raising the boom. Resulting increased pressure on a side of the slave cylinder opens load holding valves, allowing hydraulic pressure from the tilt cylinder to be communicated to the slave cylinder such that tilt cylinder pressure due to a heavy load on an implement aids in raising the boom.

A hydraulic circuit with a compensation and energy recovery function includes a distribution module having at least one spool defining a main delivery branch and a discharge branch. The hydraulic circuit also includes a supply unit and a three-way compensated adjustment device connected to the spool discharge branch and connected to discharge at a second channel. The three-way compensated adjustment device further includes a first piloting line and a second piloting line configured so that a Maximum Load Sensing piloting signal acts on a first side and a Local Load Sensing piloting signal acts on the second side. An energy recovery device and a selection section are configured to receive a signal at reduced pressure and send it to the first piloting line to activate the three-way compensated adjustment device switching to a position where the fluid coming from the discharge branch is sent to the energy recovery device.

An electric-powered fail-safe actuator for use with a valve, where the actuator stores potential energy for conversion to kinetic energy to close or open the valve to the fail-safe position.

An electric-powered fail-safe actuator for use with a valve, where the actuator stores potential energy for conversion to kinetic energy to close or open the valve to the fail-safe position.

A balancing valve includes four ports. While the pressures at a pair of balancing ports of a hydraulic balancing valve are equal, the valve maintains two other ports in a closed position. Upon a pressure differential between the balancing ports, fluid communication can occur between one of the balancing ports and either of the other ports based upon the direction of the pressure differential. A hydraulic ride control system utilizes the balancing valve together with other control valves to provide ride control functionality.

An aircraft assembly having: a first part; a second part, the second part being movably mounted with respect to the first part; an electro-hydraulic actuator coupled between the second part and a first anchor point, the actuator comprising a cylinder defining a bore and a piston and rod assembly slidably mounted within the bore and an active chamber within which an increase in fluid pressure causes the actuator to change during a first phase between first and second extension states to move the second part relative to the first part. The electro-hydraulic actuator further includes a hydraulic fluid supply circuit comprising a piezo-electric pump operable to supply pressurised fluid to the active chamber to change the actuator between first and second extension states.

Agricultural planting implements, as well as other ground-engaging implements, can utilize supplemental force assemblies to provide up and/or down force at the row or rows of the implements. The force can be used to overcome changing field conditions, obstructions, as well as changing particulate amounts and weights carried by the rows of the implements, and the implement itself. The up force can be set at system pressure, or can include control valves at each of the row units to control the amount of up force provided. The down force can be controlled by control valves at each of the row units, and can be used to overcome the up pressure or provide a designated amount of down force to the row.

A marine hydraulic system and method of use for reducing cyclic loading of the pump(s) and motor(s) and an amount of accumulator storage required in a hydraulic system. A closed loop logic controller comprising at least one control algorithm for each pump/motor pair utilized in a single hydraulic system is utilized to reduce load fluctuations on the motors, allow the use of common pressure compensated, variable displacement (VDH) pumps, reduce the number and/or volume of system accumulators and equalize wear throughout the system.