| 摘要 |
<p>The pulley (1) comprises a wheel (4) around which a cable (5) is wound. The wheel (4) is retained by a locking device (6). When the locking device (6) is released, the cable is unwound since a weight (14) is suspended at its ends (15). The cable (5) is so arranged that both its ends (15) are situated on one side of the wheel (4) when the cable is wound while they hang on either side of the wheel (4) when the cable (5) is unwound.</p> |
