| 摘要 |
<P>PROBLEM TO BE SOLVED: To automatically and effectively prevent intrusion of water into an opening even when such a large amount of water as to cause the submersion of the whole opening under the water surges. <P>SOLUTION: A shutter includes: a lifting plate lower in specific gravity than water; a storage part that houses the lifting plate; a frame part that ascendably/descendably guides the lifting plate above the storage part; and a seal part that seals a contact surface between the frame part and the lifting plate. Characteristically, the lifting plate moves upward/downward between the storage part and the frame part depending on fluctuations in water level of water flowing into the storage part. <P>COPYRIGHT: (C)2013,JPO&INPIT |
