Flood gate restrained by float controlled brake - braking action directly controlled by level of water behind pivoting gate

摘要

This water level control valve or flood gate, pivoted on its lower edge, is held in the normal closed position by an arm controlled by a brake. The brake itself is actuated by a float on the water surface so that as the water level rises the brake is released and the gate opens. When the gate is open enough to prevent the level rising the braking is reestablished and the gate remains in this position until a subsequently higher water level occurs or until it is reset manually. A band brake is described but other types of brake may be used.