| 摘要 |
PURPOSE:To eliminate regulation of a dropping amount by a method wherein through rotation of a cam coupled to a step motor, a seal valve is elevated, and a flow passage opened to an extractor is opened and closed by means of the seal valve to intermittently feed water to the extractor. CONSTITUTION:A water pass device 14 is connected to the bottom part of a tank 13 containing water, and an extractor 27 is mounted below the water pass device 14. In the water pass device 14, through rotation of a cam 32 coupled directly to a step motor 23, a seal valve 20 is elevated. A flow passage 26 having a lower end opened to the extractor 27 is opened and closed by means of the seal valve 20, and water is intermittently fed to the extractor 27. This constitution eliminates regulation of a dropping amount, prevents the decrease if a dropping speed even when an amount of water in the tank is reduced, and effects dropping always at a specified state. |
