US Patent 9091033 Floating flap gate

The present invention provides a floating flap gap which has a door body with a forward end which is able to swing upwards, in a direction in which the water flows into an opening or at an access way, around a base end thereof serving as a fulcrum. The door body is attached to one end of a wire rope, and an auxiliary force generating means is attached to the other end thereof. This structure makes it possible to prevent an overflow during the initial influx of water and to enhance the ability of the door body to follow the water level when the door body begins to lower. This structure additionally makes it possible to mitigate a shock which occurs when raising of the door body is completed and when lowering of the door body is completed.