Abstract: The device for controlling fluid flow from a rain retention chamber or the like includes an inlet communicating with the chamber, an outlet permitting fluid to flow out of the device, and a shutter disposed between the inlet and the outlet, and supported in the device for linear shifting between a raised position and lowered position. A control element is rotatably mounted in a device for rotation about a central axis and includes a curved controller surface which is non-concentric with the central axis of the central element, such that rotation of the control element varies the radial distance between the central axis and the controller surface. A coupler member operably connects the shutter with the controller surface, such that rotation of the control element shifts the shutter between the raised and lowered positions to achieve a predetermined flow rate of fluid from the chamber.

Abstract: The device for controlling fluid flow from a rain retention chamber or the like includes an inlet communicating with the chamber, an outlet permitting fluid to flow out of the device, and a shutter disposed between the inlet and the outlet, and supported in the device for linear shifting between a raised position and lowered position. A control element is rotatably mounted in a device for rotation about a central axis and includes a curved controller surface which is non-concentric with the central axis of the central element, such that rotation of the control element varies the radial distance between the central axis and the controller surface. A coupler member operably connects the shutter with the controller surface, such that rotation of the control element shifts the shutter between the raised and lowered positions to achieve a predetermined flow rate of fluid from the chamber.