Patent attributes
A floating flap gate to prevent water from overflowing into underground spaces, with ease in raising or lowering the door body when water level changes. The floating flap gate comprises a door body with a forward end which swings upwards or downwards in a same direction following a rise or a drop in water level, wherein an opposite end serves as a fulcrum. A rod is attached to the forward end of the door body. One end of a wire rope is attached to the rod, and the other end is attached to a counterweight via fixed pulleys. The fixed pulleys are arranged so that the counterweight is at its lowest point when the angle of inclination of the door body with respect to a horizontal plane reaches within a range from 10° to 80° during raising or lowering of the door body.
