Abstract: A control device of the double lever-fulcrum type for controlling the opening and closing of a fluid valve includes a single solid shaft rotatably mounted and connected to a longer or power lever. A notch is formed in the shaft to provide a preferably flat surface, one end edge of which acts on the valve element to close the valve. The fulcrum of the device comprises the longitudinal axis of the shaft, and the shorter or thrust lever of the device comprises a radius of the shaft extending from the longitudinal axis to the one end edge of the surface formed by the notch.