Power pack for controlling the angular position of a vehicle rearview mirror

DETAILED DESCRIPTION The present invention includes a power pack which is to be mounted within a mirror housing.
The mirror housing is shaped to define a cavity.
The power pack is connected to a base plate which holds the mirror within the housing cavity.
A stationary pivot assembly is connected to the power pack to pivotally couple it to the base plate.
A movable pivot assembly is connected to the base plate for pivoting the mirror about the stationary pivot assembly.
A motor is located within the power pack and is rotatably coupled to a drive shaft.
A first portion of the drive shaft has a first set of threads and a second portion of the drive shaft has a second set of threads opposite that of the first portion.
A first arm and second arm are coupled to the first set of threads and the second set of threads, respectively.
Each arm is also connected to the moveable pivot assembly.
As the first arm and second arm travel along the shaft, the moveable pivot assembly moves with respect to the power pack.
The movement provided by the moveable pivot assembly rotates the mirror about the stationary pivot assembly.
In one embodiment of the invention, a second moveable pivot assembly is also mounted within the power pack to provide a full range of movement to the mirror.
For smaller mirrors two adjusters may be mounted in a single power pack.
For larger mirrors, such as in a heavy truck application, first and second pivot assemblies may be separate.
One advantage of the present invention is that an improved movement quality and an improved sound quality has been accomplished.
Three gears have been used for connecting the drive shaft to the output shaft of the motor to reduce load on the motor.
Also any parting lines from forming of the gears are removed prior to assembly.
Each of these reduces the noise from the power pack.
Another advantage of the present invention is that the first arm and the second arm do not have to be centered on the shaft when assembled.
Because the arms are preferably coupled to the shaft by a ratchet, after one full cycle of motion, if the arms are not centered the ratchet movement allows slippage between the shaft and ratchet to allow the arms to become centered on the shaft