| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a sheave device for a crane, which can allow a driving visual field, when a hook is housed, to be excellent when a boom is housed forward and which can allow the loading height of a load to be made higher when the boom is housed backward in such a state that a hook part is abutted on the undersurface of the tip of the boom. <P>SOLUTION: The sheave device 25 or 35 for the crane includes: a support 21 or 38; and a circular-arc orbit part 26 or 36 having a plurality of rotating wheels arranged on the support 21 or 38 and an orbital belt for surrounding the whole of the plurality of rotating wheels. The plurality of rotating wheels comprise load-applied rotating wheels, around each of which a wire rope of the crane is wound and to each of which a load is applied, and supporting rotating wheels each of which exists on the load-unapplied side and supports the orbital belt. Centers of the load-applied rotating wheels form a line along one circular arc. The wire rope 12 is wound along the outer circumference of the orbital belt for surrounding the load-applied rotating wheels. The ratio of the diameter of a center circle of the wire rope 12 wound around the circular-arc orbit part 26 to that of the wire rope is firmly kept equal to or higher than a fixed value. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
