Mirror servo drive with manual override - includes sprung friction rollers on smooth guides

摘要

The servo drive for the external driving mirror has two motors, one for each adjusting axis. The motors drive friction rollers via reduction gears and each pair of rollers (36,38) grip a curved drive guide (48) which is curved about the adjusting axis. The friction drive allows manual control without damaging the gearing. At least one roller of each pair is driven, and the two rollers are held together to clamp the guide by a spring loop (60). The drive is simple and low cost. Low torque motors are used with no damger of damage.