| 摘要 |
<p>A hydraulic excavator having first and second booms pivoted end to end, plus an arm pivotally connected to a swinging end of the second boom. A bucket is pivotally mounted at the leading end of the arm. A boom operating linkage mechanism including a lever and hydraulic cylinders is mounted on a full-revolving base for swinging the first boom with respect to the base. The arm is adapted to rotate with respect to the second boom and therefore the bucket is capable of providing both back hoe and front loading operations.</p> |
