Patent ID: 7238279

Claim:
An actuator to control the position of a pivoted gate in a curb opening entering into a drainage basin, the opening having a sill, a top and sides, the gate permitting passage while closed only of water flowing at a low flow rate, thereby restraining debris, said gate being pivotable to an open position when water is flowing at a suitably high flow rate thereby to pass both water and accompanying debris, there being a linkage in the basin linked to said gate, said actuator comprising: a rotor having a fixed axis of rotation and a vane receptive of water from said opening flowing at a suitably high rate, said rotor being connected to said linkage in such manner that a sufficient force on said vane from said water at said suitably high flow rate will cause the rotor to rotate in a rotational sense and cause the linkage to rotate the gate to open; and a buoyant float connected as a lever to said rotor relative to said axis of rotation such that a buoyant force on said float will exert a torque on said rotor in the same rotational sense as is exerted by the vane as the consequence of water impact on said vane which opens the gate, whereby to maintain the gate open when the gate has been opened by the rotor, if the rotor then becomes flooded by accumulated water in the basin.