Abstract: A mirror assembly adapted to be rotatably mounted with respect to a support structure such as a wheeled vehicle of the class that includes trucks, tractors, large recreational vehicles, etc. A rotatable housing carries a mirror and there is a fixed mounting bold for supporting the housing. A motor is connected to the housing so as to rotate it when power is applied to the motor. A clutch is associated with the motor in order to preclude damage if power is applied to the motor but the housing is incapable of moving. The clutch includes two pairs of metallic spring washers which are of the Belleville type and which have concave faces. The two washers of each pair are in contact and are oriented in the same direction, so that there is a substantial area of metal-to-metal contact between the washers of each pair of washers. A lubricant such as graphite is interposed between the pairs of Belleville washers.

Abstract: A mirror assembly for external use on large trucks, tractors, buses, etc. A first reflective surface is pivotably supported with respect to a large, shell-like housing in such a way that the surface is movable at will about two perpendicular axes. A powered hydraulic means is used for selectively rotating the reflective surface to a desired position and normally holding it in a static mode. The hydraulic means includes reservoirs in communication with two hydraulic cylinders, and a plurality of check valves arranged in sets and interposed between the reservoirs and the chambers in the cylinders. The hydraulic fluid is chosen from the group that comprises engine oil, power steering fluid, transmission oil and ethylene glycol.