| 摘要 |
The present invention relates to a boom rotating device which enables an extended boom extended from a main boom to be axially rotated up and down at 180 degrees or more around a coupling portion with the main boom, so that working radius of high place work can increased, an efficient and stable high place work in a difficult work place is available, and the extended boom is pushed to the inner side when not working, thereby reducing a storage space. The boom rotating device comprises a base boom and an extended boom directly connected through a first rotary shaft; a bent link connected to the front end of the base boom through a second rotary shaft, and bent around a central shaft; and a linear link having one side connected to the bent link through a hinge shaft, and having the other side connected to the extended boom through a third rotary shaft, wherein a relief cylinder installed on the base boom transfers linear movement to the central shaft of the bent link, and the bent link is rotated upon the corresponding linear movement transfer, so the extended boom is axially rotated around the first rotary shaft for the base boom. |
