| 摘要 |
PROBLEM TO BE SOLVED: To enhance stability of a toggle link mechanism and reduce consumption current.SOLUTION: An engagement device of a fire door includes: a latch member (a latch plate 130) for engaging a hook (a hook pin 602); a lock member (a lock lever 140) movable to locked and unlocked positions of the latch member; a pair of first and second links (a link lever 160, a connection link 170) linked rotatably with each other for moving the lock member in accordance with an angle between the links; and an unlocking member (an unlocking drive lever 180) for exerting driving force sequentially to different points of application of the pair of links in accordance with the angle, for changing the angle and moving the lock member to the unlocked position.SELECTED DRAWING: Figure 4 |
