Abstract: A shaft extends across an air discharge opening and is rotatably mounted therein. A drive means is operatively connected to the shaft for rotating the shaft on its axis. A plurality of planar discs, are eccentrically mounted on the shaft. A pair of adjacent louver blades extending across the air discharge opening are pivotally mounted at their one edge in the air discharge opening. A spring is connected to the louver blades for biasing then into an engaging relationship with the discs such that, as the discs rotate, the louver blades are caused to rotate on their axes to cause a change in the direction of airflow emanating from the discharge opening.

Abstract: A drive motor is located with its axis symmetrically between the parallel shafts on which a pair of louvers are rotatable mounted. A crank pin driven by the motor is connected to the two louver blades by drive arms attached to the upstream ends of the louver blades. A complete rotation of the motor shaft results in the louvers being relatively moved to sweep the air from an upward to a downward direction, while, at times, pinching the air to increase the throw thereof.