Multi-stage telescopic boom having a polygonal cross-section

摘要

(57) [summary] improves the receiving member in accordance with each boom of [purpose] polygonal section, while reliably prevent lateral movement of the intermediate boom at the time of extension of the multi-stage telescopic boom, sliding the line-like material possible it is easier to dispose it on. [Configuration] cross-sectional polygonal shape each boom 1 to 3 which is formed on and configure freely tighten sequentially fitted let expansion and contraction, the tip inside the bottom of the base boom 1, the lower inclined surface 2a of the upright the lower and the upper intermediate boom 2 and arranging a pair of receiving member 11 provided with a first receiving component 12 formed to be inclined outwardly so as to be opposed to and integrally formed with respective receiving member 11 through the spacer 15. The inclined surfaces 12b at the upper portion of the first receiving portion constituting members 12 and pads 16 for slidably supporting the lower inclined surface 2a of the intermediate boom 2 which corresponds to the inclined surface 12b And is attached to, the inclined surface 12a below the empty space of the first receiving component 12 (the lower space), a group boom 1 Slidably wearing a cable 7 through between the intermediate boom 2.