US Patent 10456936 Adjustable spacing comb, adjustment drive and hair cutting appliance

An adjustment drive for an adjustable spacing comb for a hair cutting appliance that may be fitted with an adjustable spacing comb. The adjustment drive comprises an actuator for actuating a movable comb portion of the adjustable spacing comb with respect to a blade set of the hair cutting appliance, a manually operable rotation element, and a rotary encoder, that is configured to detect rotary movement of the rotation element and to output a respective user input signal, wherein the actuator is operated in response to the user input signal.