| 摘要 |
Disclosed is a multi-stage extension boom structure of a crane capable of effectively using power by installing a power providing unit for raising an extension boom on the uppermost portion or a center portion of the extension boom instead of the bottommost portion of the extension boom by being installed in the inner side as a multi-stage extension boom used for the crane, a tower wagon, a high place work platform, etc. As a structure capable of being used in the extension boom comprising a boom more than three-stages capable of being drawn, the present invention installs one or more power providing units for providing the drawing power to the boom on any one among residual booms of the extension boom except for the bottommost portion connected to a vehicle. |
