The device includes a main valve, first and second auxiliary valves, a valve body and a filter. The main, which has first and second auxiliary valves are mounted on the valve body, which has an air inlet, a cylinder port and an air discharging port. The air inlet is in communication with the main valve through a first air passage, the cylinder port is sequentially in communication with the first and second auxiliary valves, and the main valve through a second air passage. The air discharging port is sequentially in communication with the first and second auxiliary valves and the main valve through a third air passage. The main and the second auxiliary valves are solenoid valves, and the first auxiliary valve is a hand-operated valve. An air outlet of the filter is in communication with the air inlet. The filter is used for filtering out impurities in gas.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

The device includes a main valve, first and second auxiliary valves, a valve body and a filter. The main, which has first and second auxiliary valves are mounted on the valve body, which has an air inlet, a cylinder port and an air discharging port. The air inlet is in communication with the main valve through a first air passage, the cylinder port is sequentially in communication with the first and second auxiliary valves, and the main valve through a second air passage. The air discharging port is sequentially in communication with the first and second auxiliary valves and the main valve through a third air passage. The main and the second auxiliary valves are solenoid valves, and the first auxiliary valve is a hand-operated valve. An air outlet of the filter is in communication with the air inlet. The filter is used for filtering out impurities in gas.

Hydraulic jack assemblies are disclosed herein. The hydraulic jack assemblies may include a hydraulic unit base that includes a plurality of pump pistons to output hydraulic fluids with different characteristics that can be selectively used based on load conditions. The hydraulic jack assemblies may additionally or alternatively include a hydraulic fluid release valve that may be opened by an electrically powered driver.

Arrangements of a flow path to achieve a series circuit, a regeneration circuit and a float/passive regeneration circuit. For example, a valve body having a spool bore, a valve inlet, a plurality of cavities opening into the spool bore and a spool disposed in the spool bore. A first cavity fluidly connected to a tank passage, a second cavity fluidly connected to a first work port, a third cavity fluidly connected to an inlet of another valve, a fourth cavity fluidly connected to a second work port, a fifth cavity fluidly connected to the valve inlet, a sixth cavity fluidly connected to the first work port, a seventh cavity, an eighth cavity fluidly connected to the valve inlet, a ninth cavity fluidly connected to the inlet of the other valve and a tenth cavity fluidly connected to the valve inlet.

Hydraulic jack assemblies are disclosed herein. The hydraulic jack assemblies may include a hydraulic unit base that includes a plurality of pump pistons to output hydraulic fluids with different characteristics that can be selectively used based on load conditions.