| 摘要 |
The device is mounted on a supporting frame with a running gear, which can travel on a built-up section of the bridge deck. It comprises a pair of horizontal beams with a counterweight, which are mounted cross-wise with their free ends overlapping the side edge of the bridge deck. A vertical arm, whose top end features a fastened top pulley and bottom end features a fastened bottom pulley, is fixedly connected by its top end to the free end of each horizontal beam. A rope with a hook is guided through both the pulleys, and is wound on a hoisting drum, which is placed on the supporting frame. The vertical arm can by formed by a rolled U section, while an extensible piece of the vertical arm, made of a rolled U section of a smaller cross section, is inserted into the rolled U section and adjustably attached by means of a clamping bolt. The bottom pulley is placed on the bottom end of the extensible piece.<IMAGE>
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