摘要 |
There is provided a telescoping boom system for an excavating apparatus which includes a linkage member having a pivot segment and lever segment pivoted about a rotating fixed boom. A first hydraulic cylinder is coupled from the fixed boom to the pivot segment. A second hydraulic cylinder is coupled from the lever segment to a retractable outer boom. The first hydraulic cylinder extends to rotate the pivot segment away from a proximate end of the fixed boom, thus forcing the lever segment to rotate towards the proximate end of the fixed boom. The second hydraulic cylinder retracts and combines with the extension force of the first hydraulic cylinder across the linkage member to provide a retraction force to the outer boom.
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