| 摘要 |
PROBLEM TO BE SOLVED: To prevent liquid from flowing out even in an open condition by such pressure as gravitational force in the direction of flow and obtain accurate check performance by providing a special semi-spherical check valve in which a hole is opened in the middle thereof. SOLUTION: A pair of check valves 20 are provided at both ends of a bellows pump main body 10, and a soft sealing vessel 30 is provided on a fluid flowing-in side of the check valve 20. The check valve 20 is formed as follows. First, a semi-spherical valve base 21 is provided, and a fringe of a semi-spherical valve 22 of a rubberlike elastic body is fixed on the semi-spherical valve base 21. This semi-spherical valve 22 has such shape that covers a spherical face of the semi-spherical valve base 21 in a close adhesion condition. Furthermore, a thickness of the semi-spherical valve 22 is reduced when approaching its central part, and the vicinity of the center is emptied circularly and has an emptied part 22b. A fluid passing through hole is provided in the middle of the semi-spherical valve base 21 in a condition in which it passes through from its plane part to its semi-spherical face. |
