Abstract: A fan having an air directing grille mounted in the path of air flow includes means for rotating the grille at a speed slower than the speed of rotation of the fan blade. The means for rotation also includes a clutch mechanism having a rotary drive member connected to a drive shaft, a driven member coaxially mounted on the drive shaft in a rotatably free manner, and resilient means in between the drive member and the driven member to engage both and rotate the members together. The resilient means includes a provision to slip the engagement and to permit the rotary drive member to rotate without imparting rotational movement to the driven member when a predetermined restraint of rotation is applied to the driven member.