| 摘要 |
PURPOSE:To widen working range within a stable limit by a method in which a mast part is provided in a rocking manner on the front of an upper rotator, a leader 5 is provided pivotally to the upper part of the mast part, and the mast part and the leader are connected at their lower parts by an oil-pressure cylinder. CONSTITUTION:The lower end of a mast part 10 is attached in a rocking manner to the front frame of an upper rotator 2 by a pin 14, and the upper part of the mast part 10 and the rear of the upper rotator 2 are connected with a supporter 7 with paired oil-pressure cylnders 7a. A leader 5 is pivotally attached to the upper end front of the mast part 10 by a pin 12, and an oil-pressure cylinder 13 is provided between the lower part of the mast part 10 and the leader 5. For slantly driving a pile, the operating amount of the cylinders 7 and 13 are properly adjusted for most stable operation. |
