| 摘要 |
A movable structure for supporting a current-collector bow is pivotally mounted on a frame and lifted by means of a spring attached to the structure and to the frame. Upper members of the bow support structure permit displacement of the bow independently of the structure. Hook-engagement means or valve units are provided for neutralizing the lifting spring and transmission means are provided for connecting the bow-displacement means to the spring-neutralizing means. A load limiter inhibits the bow-displacement means below a predetermined load threshold value and releases the bow above this value. |
