| 摘要 |
PROBLEM TO BE SOLVED: To easily open a door which has stopped on closing. SOLUTION: A door 10 is connected to a roller chain 20 which suspends a main weight 25 and a subweight at both respective ends. The door is pulled by the main weight and automatically closed by paying out the roller chain 20 from a driving sprocket 51. When the door stops on the way, the slack of the roller chain 20 is detected by a slack detector 40 and the driving sprocket 51 stops. The door is opened by pushing the door with a larger force than the main weight 25. When the door is completely closed, the main weight is attracted and fixed by a magnetic lock 30. The door 10 is automatically opened, when the magnetic lock 30 is put off and the driving sprocket 51 is reversely rotated to retract the roller chain 20. |
