| 摘要 |
PROBLEM TO BE SOLVED: To provide a telescopic boom for providing high bending strength even if it is light, good manufacturability of the boom and a pad, and superior shim adjustability. SOLUTION: An arc part 23 of which the outer circumference face internally contacts with a virtual arc 22 that is semicircle or smaller and has an opening width smaller than an outer width of each boom, and of which the outer width coincides with the opening width of the virtual arc 22 is formed at a lower half portion on the side of a ventral of a section face cut in a direction orthogonally crossing with a longitudinal direction of each boom comprising the telescopic boom, and an end part side of a side plate 21a where the right and left of an upper half portion on the side of a back of each boom are parallel is continued to an opening side of the arc part 23 through a side portion inclination plane part 24. COPYRIGHT: (C)2010,JPO&INPIT |
