To avoid complication of a mounting work of a rope on a crane, while simplifying a constitution without using a special rope, and to change a distance between sheave blocks, while maintaining both of the sheave blocks with each other in a substantially parallel state.
The first rope 11 is wound on a boom side sheave 14a selected from every other sheave along an array of boom side sheaves 14a and 14b and a suspended cargo side sheave 15a selected from every other sheave along an array of suspended cargo side sheaves 15a and 15b located on both sides across a vertical line passing a center of gravity part of the suspended cargo part 16 by being alternatively laid between the boom side sheave 14a and the suspended cargo side sheave 15a. The second rope 12 is wound on the boom side sheave 14b and the suspended cargo side sheave 15b located on both sides across the vertical line passing the center of gravity part of the suspended cargo part 16 by being alternatively laid between the boom side sheave 14b and the suspended cargo side sheave 15b laid without the first rope 11.
Takao Ito
Jiro Higuchi
Muramatsu Toshiro