| 摘要 |
<p>PROBLEM TO BE SOLVED: To firmly connect a boom head to the tip of an insulating boom. SOLUTION: A hollow cylindrical outer collar 31 is stuck and connected to the tip part of a tip boom 5c made of an insulating material, and a hollow cylindrical inner collar 32 is inserted into the outer collar 31. In the boom head 5d inserted into the hollow space of the tip boom 5c, a bolt insertion hole 24 is formed in the position facing the inner collar 32, and a bolt 34 is inserted into the inner collar 32 from the outside face side via a washer 33. A bolt thread part 34a is screwed to a nut 35 arranged inside the boom head, and consequently, the inner collar 32 and the boom head 5d are fastened and clamped by means of the bolt and the nut via the washer 33. In this case, the outside diameter of the washer 33 is set to be larger than that of the inner collar 32, and the outer collar 31 is clamped between the washer 33 and the boom head 5d. The length of the inner collar 32 is set to be slightly longer than that of the outer collar 31.</p> |
