Independence of multi-stage nested type boom structure and/or kiyariyatoratsuku system null for synchronous operation

摘要

PROBLEM TO BE SOLVED: To prevent damage of a flexible hydraulic hose and an electric cable by adjusting the movement of the flexible hydraulic hose and the electric cable by first and second carrier tracks during telescopic movement of respective sections of a boom. ;SOLUTION: A rod-type hydraulic cylinder 9 is connected among stages 1a, 1b and 1c of a boom, and respective sections of the boom are extended and retracted in the independent and synchronous state. Respective hydraulic hoses and the electric cables are housed in a air of flexible carrier tracks 10, 11 to prevent the hoses and the cables from being damaged in the telescopic movement of respective sections. One end of the first carrier track 10 is connected to the inner end of the mid section 1b at the position 10a, and the other end is connected to the lower end wall of the lower section 1a. One end of the second carrier track 11 longitudinally extends in the position 11a and connected to the outer end of a hose and cable support tube to be fixed to the inner end of the mid section 1b at the position 12a. The other end of the carrier track 11 is connected to the lower end wall of the upper section 1c at the position 11b.;COPYRIGHT: (C)1996,JPO