| 摘要 |
PURPOSE:To ensure a proper expanding/contracting operation of an antenna with a clutch mechanism without producing noises, by setting a clutch torque which is slightly larger than the expanding/contracting torque of a normal antenna. CONSTITUTION:A press contacting torque between a clutch plate 3 and a drum 2, i.e. the sum of press-contacting friction torques based on a spring 6 between an engaging projected part 37 and the rear surface of the drum 2 as well as between an engaging projected part 27 and the rear surface of the clutch plate 3, is set slightly larger than the expanding/contracting torque of a normal antenna at a time point when a switch is turned off. The antenna can be expanded completely and contracted owing to the rotational inertia of a motor 10, the drum 2 and a worm wheel 1 respectively even though the conduction of electricity is turned off to the motor 10. |
