US Patent 7381128 Operating device of air conditioner for vehicle

A gear portion is provided on the inner peripheral surface of a dial, and a large diameter portion of a main driving gear is mated with the gear portion. A driven gear is mated with a small diameter portion of the main driving gear, and the state of an air conditioner is switched based on the moving operation of a cable through the gear portion, the main driving gear and the driven gear in the rotating operation of the dial. With this structure, it is not necessary to provide a rotary shaft as a member for transmitting an operating force to the central part or the dial. Consequently, it is possible to maintain a space in the central part of the dial. Thus, restrictions can be decreased in the case in which a knob is to be arranged.