| 摘要 |
PROBLEM TO BE SOLVED: To let sucked water finish flowing out in a short period of time by a method wherein a large diameter drain outlet that serves also as an outside air intake is provided at the center of a bottom plate that has a downward slope toward the center. SOLUTION: A sliding plate 21 is water-tightly fitted in the lower part of the inside of a shell 2a of a container, and when the liquid in the container flows out and decreases, the sliding plate 21 rises to relieve a negative pressure state inside the container. Therefore, a bottom cover 31 having a raised bottom plate 35 is fitted in the lower end of the shell 2a of the container and a large diameter drain hole 38 that serves also as an outside air supply device is provided at the center of the bottom plate 35 that has a downward slope toward the center. Thereby, as the sliding plate 21 raises when the container is put on a floor and a pump is operated, the negative pressure state produced between the sliding late 21 and the bottom cover 31 is relieved by sucking outside air from the drain hole 38. Water entering a gap between the sliding plate 21 and bottom cover 31 flows along the slope and discharge outside through the drain hole 38 in a short period of time. |
