| 摘要 |
The door-leaf (1) is movable into an overhead position, having rollers (2) working in guide rails (3). The electrical arrester (15) is incorporated in the rope, and is connected to the leaf-driving motor, which it switches off when the rope goes slack. The mechanical arrester (7) has one half of the leaf, and which engages with a stationary half on the rope going slack. The arresters are interconnected so that the electrical one operates first, followed by the mechanical one. With the rope taut, the spring-loaded leaf half can bear against a catch, which is released on the rope going slack. |
