| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a telescopic boom, capable of improving resistance to buckling at a lower section of a boom without causing problems in conventional devices such as a larger change ratio of boom cross sectional size when combined in a case of addition of a reinforcement member to the lower section of the boom, and increase in manufacturing manhours or cost due to longer welding required. <P>SOLUTION: The lower section 22 of a boom 20 for each stage for composing a telescopic boom has a cross section in a roughly U-shaped form by use of a continuous plate member. On the part of the roughly U-shaped form of the lower section 22, a small sectional part 27 is formed in a separate form from the roughly U-shaped form. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
