Sheaving arrangement

Claim 1

A crane having a boom with a boom point at the extremity thereof, a load hoist cable, a load hoist, a traveling block and multiple sheave means for said cable, the improvement residing in said sheave means, comprising: first fixed sheave means located with the boom point of said boom over which said cable passes from said load hoist; first movable load sheave means mounted with said traveling block about which said cable passes from said first fixed sheave means; second fixed sheave means located in proximity to said first fixed sheave means with said boom point but outwardly from said first fixed sheave means; said first fixed sheave means mounted adjacent the boom point of said boom in a first plane substantially parallel to the longitudinal axis of said boom; said second fixed sheave means being in a plane substantially perpendicular to said first plane; third fixed sheave means mounted adjacent the boom point substantially in said second plane in substantial radial alignment with and adjacent to said second fixed sheave means and receiving said cable passing from said second fixed sheave means; second movable load sheave means mounted with said traveling block in substantial axial alignment with and adjacent to said first movable load sheave means in a third plane substantially parallel to said first plane and spaced apart therefrom at least substantially the diameters of said second and third fixed sheave means, said second movable load sheave means receiving said cable from said third fixed sheave means; fourth fixed sheave means mounted adjacent to and in substantial axial alignment with said first fixed sheave means in said third plane and receiving said cable from said second movable load sheave means; and, said second and third fixed sheave means, respectively, being laterally spaced from said first and fourth fixed sheave means, respectively, a distance approximately equal to the diameter of said first and second movable load sheave means, respectively, for thereby spacing the cable lengths from said first and second movable load sheave means, respectively, apart such distance to prevent spinning of said traveling block and twisting of said cable when raising and lowering said traveling block.