| 摘要 |
The protection is fitted to a hoist, in which a cage (5) is moved on a guide rail by an electrically powered cradle (6). The cage is mounted on a vertical ball guide (9), so that it can move with respect to the cradle, and the motion is supported relative to the cage by a spring arrangement, whose spring force exceeds the total weight of the cage and its maximum load.A switch (29) is arranged to disconnect the current supply to the electric motor, following a vertical movement of the cage which results from an overload. The ball guide has ball bearings (13) between two concentric hard steel bushes (11,12), with one bush (12) connected to the cage, and the other connected to the cradle (11).
|
