| 摘要 |
PROBLEM TO BE SOLVED: To provide an earth drill having a constitution, by which, when an earth drill is used not only for excavation but also as a crane, the earth drill retains a proper slue torque to enable crane works, so that the crane works using the earth drill can be executed effectively and earth drill works can be also performed safely. SOLUTION: The boom-type earth drill capable of the crane works is provided with relief valves 24, 25 for changing the slue torque by a sluing gear, and the like.
|
