| 摘要 |
PURPOSE: A door release device for a fire door is provided to stably maintain the fire door regardless of an external impact by preventing the fire door from being released due to the external impact. CONSTITUTION: A hook holder(20) is rotatably installed to cross the movement direction of a hook on a fire door and includes a driven gear on one side. The hook holder locks and unlocks the hook of the fire door by forward or reverse rotation. A gearing shaft(30) has a drive gear engaged with a driven gear(23) of the hooker holder A release motor(40) releases the hook holder according to an external fire sensing signal and includes a reducer. An output shaft(47) of the reducer is combined with the gearing shaft and restricts the rotation of the hook holder. A one-way clutch unit(50) is installed in a transmission path between the hook holder and the reducer and makes the release motor and the reducer rotate to one direction regardless of the forward or reverse rotation of the hook holder. |
