| 摘要 |
<p>PURPOSE:To improve safety, durability and workability of a crane vehicle by thinning an extending rope diameter, and contracting a rotary sheave size while decreasing boom sectional width dimension, in a multistage synchronous extending/contracting boom using a telescopic hydraulic cylinder and an extending rope. CONSTITUTION:In an extending mechanism, equalizer sheaves 12, 13 for uniformly generating tension of an extending rope 5 are mounted by each one in the lower right/left of the third boom 3 and by one in a base step boom 1, a tension adjusting member 8 is provided in a side of the base step boom 1, a rotary sheave 11 coaxially two-sheet superposed is arranged in the right/left of the second boom 2, and the extending rope linked right/left with each two is arranged to be used.</p> |
