Patent ID: 7147425

Claim:
A loader-excavator for alternate use with a loader bucket in a loader mode and an excavator bucket in an excavation mode, the loader-excavator comprising: a) a mobile frame powered for forward and rearward movement; b) a main boom connected to the frame at a first pivot for movement between a retracted position and an extended position, the main boom extending rearwardly and inclined upwardly from the first pivot when in its retracted position; c) first and second links connected together at a second pivot rearwardly of the first pivot and generally below the main boom when in its retracted position, the first and second links being further pivotally connected to the frame and the main boom respectively, the first and second links being pivotable from a first position with the main boom in its retracted position to a second position for movement of the main boom to its extended position; d) a main ram connected between the second pivot and the frame rearwardly of the second pivot and at a height generally below the main boom when in its retracted position, the main ram being operable to actuate said links between said first and second positions for movement of the main boom between its retracted and extended positions respectively; e) a dipper boom connected to the main boom at a third pivot for movement between a retracted position and an extended position, the third pivot being located rearwardly of and at a height above the first pivot with the main boom in its retracted position, the dipper boom extending forwardly and inclined downwardly from said third pivot proximately over the main boom when the main boom and dipper boom are in their retracted positions; f) a dipper boom ram connected between the main boom and the dipper boom, the dipper boom ram being operable to pivot the dipper boom between its retracted and extended positions; g) a dipper boom extension connected to the dipper boom at a fourth pivot for movement between a retracted position and an extended position, the fourth pivot being located forwardly of the third pivot when the main boom and dipper boom are in their retracted positions; h) a dipper extension ram connected between the dipper boom and the dipper boom extension, the dipper extension ram being operable to pivot the dipper boom extension between its retracted and extended positions; and i) a lock mechanism for selectively coupling the loader bucket and the excavator bucket to the dipper boom extension.