| 摘要 |
PURPOSE:To displace the first and the second diaphragm means vertically by the pressure difference between fluids introduced into the first and the second chamber by switch valves and the like for obtaining automatic pumping work only by giving fluid pressures. CONSTITUTION:When a rod 27 is displaced upwards, a valve means 22 is pushed anticlockwise by a shoulder part 29, and a valve part 26 is separated from a seat 25 to be seated on a seat 24. Consequently, the first signal chamber 20 and a signal pressure chamber 61 of a switching unit 50 are connected to the source of the open air. A negative pressure is introduced into the second signal chamber 21 of an air- pump unit 10 through ports 55 and 56. By the pressure difference between fluids in two chambers 20 and 21, the first and the second diaphragm parts 19 and 36 are displaced downward. Thus, the capacity of the second pump chamber 35 is reduced, and that of the first pump chamber 34 is increased for sucking in air. Subsequently, compression work is given by the downward displacement of the rod 27 for making smooth pumping work automatically. |
