| 摘要 |
PROBLEM TO BE SOLVED: To provide a telescopic device of a telescopic boom in which operability of the telescopic boom can be improved while reducing a cost, an insertion work can be efficiently performed, and a cross sectional area of the entire telescopic boom can be limited to a minimum required area.SOLUTION: A telescopic mechanism 5 of a telescopic device 3 of a telescopic boom 1 comprises: a rod-like support member 10 whose one end side is fixed to a base end side in a third boom 23 via a connection shaft extending horizontally and which is arranged in a top boom 24; a sheave 61 for extending the third boom; and a wire 62 for extending the third boom. The rod-like support member 10 is formed so as to be built in the top boom 24 while a sheave 71 for extending the top boom is arranged at a tip side thereof. In the wire 62 for extending the third boom, one end is fixed to a base end side of a telescopic cylinder 4, and the other end is fixed to the connection shaft.SELECTED DRAWING: Figure 1 |
