| 摘要 |
PURPOSE:To make the work of letting air out effective by providing a passage which makes the mutual connection of a space from a pump discharge portion to the supply valve of a booster device, and a space from the supply valve to a pump suction portion, and providing at the passage a changeover valve which is usually closed and is opened by means of an outside operation. CONSTITUTION:A passage 82 bypassing a check valve 80 is provided at the main body 73 of a pump 70. The passage 82 is made up of two longitudinal passages 82a, 82b meeting at right angles with the axis of a cylinder 76, and a large diametered lateral passage 82c of a stepped shape making the connection of these passages, and a changeover valve 100 is provided at the lateral passage 82c. The ball 101 of the changeover valve 100 is usually seated at a valve seat 102a by means of a spring 103 and a closing condition is realized, but at the time of letting air out, the valve is opened as an operation rod 105 is pushed from the outside. Accordingly, letting air out of two closed piping systems 71, 72 is simultaneously accomplished by one action. |
