Patent ID: 9441617
Filing Date: 2016-09-13
CPC Classification: F04B

Claim Text:
1. A liquid delivery method for delivering a liquid by reciprocally moving a plunger in a cylinder while a selector valve is shifted in a valve chamber to change over communication of the cylinder and the valve chamber with a channel leading to a liquid tank and communication of the cylinder and the valve chamber with a channel leading to a delivery port from one to the other, the method comprising the steps of: arranging an opening/closing valve in a channel for communicating the liquid tank and the valve chamber with each other, shifting the selector valve to a first position to establish the communication between the cylinder and the channel leading to the liquid tank and opening the opening/closing valve when a liquid is filled in the cylinder, retracting the plunger in the cylinder thereby drawing the liquid into the cylinder from the liquid tank, shifting the selector valve to a second position to establish the communication between the cylinder and the channel leading to the delivery port and closing the opening/closing valve, and advancing the plunger in the cylinder thereby delivering the liquid through the delivery port, wherein the opening/closing valve is automatically opened and closed by employing a check valve disposed in such orientation that the liquid is allowed to flow from the liquid tank to the valve chamber, but the liquid flow from the valve chamber to the liquid tank is blocked.