| 摘要 |
PURPOSE:To raise the keeping efficiency of closed condition of door as well as safety of door and exact opening and closing operation of door by simplifying the constitution and by reducing the cost for existing doors of outside attachment type. CONSTITUTION:A wire rope 24 engaged to pulleys 11 and 12 supported on both sides of a framework 1 is connected through tension springs 25 and 26 to d ball bearing 2. The pulley 11 is turned to optional directions through a reduction gear mechanism 14 by a motor 13, and the wire rope 24 is moved to move the ball bearing 20, whereby permitting the door to open or close through a link 22. Abrupt change of load is detected by a potensiometer 27 to stop the operation of the motor 13. The ball bearing 20 is always pressed to the direction of closing the door by a constant load spring 30. |
