Abstract: A high-pressure fluid is continuously generated with high efficiency without causing pulsation of pressure by reciprocally moving a piston having first, second and third chamber sections under the control of an actuator including an operating pressure source and a directional control valve. With the reciprocating motion of the piston, liquid or fluid such as gas is fed into the first, second and third chamber sections in sequence through check valves and finally discharged outside at high pressure. The actuator is operated hydraulically, mechanically or electrically.

Abstract: A high-pressure fluid is continuously generated with high efficiency without causing pulsation of pressure by reciprocally moving a piston having first, second and third chamber sections under the control of an actuator including an operating pressure source and a directional control valve. With the reciprocating motion of the piston, liquid or fluid such as gas is fed into the first, second and third chamber sections in sequence through check valves and finally discharged outside at high pressure. The actuator is operated hydraulically, mechanically or electrically.

Abstract: An automatic pressurized fluid switching device performs a switching using pressurized fluid rather than electrical elements, and comprises a pressurized-fluid inlet port, plural pressurized-fluid outlet ports, a switching valve for switching between outlet ports, a pilot valve for piloting the valve switching operation, and a reaction member for controlling the pilot valve in response to pressure of the pressurized fluid introduced. The pilot valve includes a first pilot unit controlled only by the reaction member, and a second pilot unit controlled by the reaction member in its initial and final stages and directly by the pressurized fluid in its middle stage, whereby the second pilot unit in the middle stage is reliably controlled even with little pressurized fluid introduced when again operated after an intermediate stoppage.