Patent ID: 8206127

Claim:
A liquid pressure-feed device comprising: a closed vessel, the closed vessel comprising: a working fluid inlet port, a working fluid discharge port, a liquid inlet port, and a liquid discharge port, wherein an intake valve body for opening and closing an intake valve port of the working fluid inlet port and an exhaust valve body for opening and closing an exhaust valve port of the working fluid discharge port are switched over between opening and closing in accordance with the level of liquid accumulated within the closed vessel, wherein, when the exhaust valve port is opened and the intake valve port is closed, liquid is allowed to flow into the closed vessel from the liquid inlet port, and when the exhaust valve port is closed and the intake valve port is opened, the liquid accumulated within the closed vessel is fed from the liquid discharge port under pressure, an inlet-side check valve port of the liquid inlet port is formed within the closed vessel, and an inlet-side check valve body is configured to open the inlet-side check valve port inwards of the closed vessel in the closed vessel, and wherein the closed vessel comprises: an outer opening for opening the working fluid discharge port outwards of the closed vessel, a communication passage for connecting the working fluid discharge port to the liquid inlet port, a ring member that is mounted when connecting the working fluid discharge port to a liquid generation source side through an external pipe connected to the closed vessel outer opening, the ring member providing closure between the working fluid discharge port and the liquid inlet port and communication between the working fluid discharge port and the closed vessel outer opening, and a plug member that is mounted when connecting the working fluid discharge port to the liquid inlet port to close the closed vessel outer opening.