| 摘要 |
PURPOSE: To prevent breakage or malfunction of an automatic door opening/ closing unit, by providing a means absorbing excessive opening forces when an excessive force larger than a preset limit is exerted on the door from the external side of a telephone booth, between a power transmission means and an opening/closing drive source. CONSTITUTION: When an excessive opening force larger than a preset limit is exerted on a folding door 17 from the outside of a telephone booth 1, the force is absorbed by a coupling with a clutch installed between a motor 31, a reducer 32, and a rotary shaft coupling 34. In this way, damage and malfunction of the motor unit 30 can be prevented. |
