| 摘要 |
PURPOSE:To automatically absorb the permanent elongation of a wire, by using a driving or driven unit comprising a first and a second pulleys provided with ratchet teeth on their facing sides. CONSTITUTION:A lever 5 is rotated in a direction (b) to move a part 42 of a wire 4 to wind it around a first pulley 6 in the same direction. If the wire 4 is elongated, it sags so that another part 41 of the wire 4 having passed through the pulley 7 of a driven unit 2 is not immediately pulled in a direction (f). For that reason, a second pulley 12 on which the wire 4 is engaged is not rotated in the direction (b) but remains standstill. In that case, ratchets 6a, 12a race but only the first pulley 6 is rotated in the direction (b) to wind the wire 4 to complete the absorption of its elongation. At the time of the completion, the wire 4 is tightened enough to pull the second pulley 12 in the direction (b). As a result, the first and the second pulleys 6, 12 resume rotating together in the same direction because of the pushing of an elastic member 13. |
