FIELD OF INVENTION:

An innovative design of the loader-excavator (named as Exca-loader or Excaloader) is described, wherein the said attachment is operable in an excavation mode or in a loader mode as per the user preference. The Exca-loader comprises of a main boom, and a dipper boom, such that the loader bucket or an excavator bucket can be selectively attached and Excaloader can be operated as an excaloader or loader depending upon the preference.

BACKGROUND OF THE INVENTION
This invention relates to a compact utility skid steer loader which can be operated as a loader or as an excavator as per the requirements. More particularly, this invention relates to a skid steer machine with application in the outdoor construction environments.

SUMMARY OF THE INVENTION:
An Excaloader which is a multi-utility and convertible skid loader-cum-excavator is disclosed here. The mechanical linkages and the hydraulic controls allow the operator to change the machine from a skid loader to an excavator. The loader excavator comprises a main boom and a dipper boom, wherein a loader bucket or an excavator bucket can be selectively utilized in accordance with user preference. In the excavation mode, a main boom and a dipper boom are operable through hydraulic controls to raise and lower the excavator bucket. Excavation is generally characterized by the excavator bucket facing toward the operator, excavation of material accomplished by digging or drawing the material toward the operator and then lifted. In a loader mode, the dipper boom is operable through hydraulic controls to raise and lower the loader bucket. Loading is generally characterized by the loader bucket facing away the operator, loading of material accomplished by digging or pushing the material away from the operator and then lifted. The main boom operable in an excavation mode when said dipper boom is coupled with the excavator bucket; the dipper boom is operable in the excavation mode and a loader mode when said dipper boom is coupled with the loader bucket.

DESCRIPTION OF THE PREFERRED EMBODIMENT
While the preferred embodiment is being described, the details may be changed without departing from the invention.
Figure 1 is a side elevation view of a preferred embodiment of a convertible skid loader and excavator, shown in a loader mode with a loader bucket, and in phantom in the loader mode with a dipper boom fully extended. The dipper boom is operable through hydraulic controls (described later) to raise and lower the loader bucket. The loader bucket is also rotatable from a digging position (not shown) to a carrying position as shown, in which the front edge of the loader bucket is slightly elevated with respect to the remainder of the bottom edge of the loader bucket. Loading is generally characterized by the loader bucket facing away the operator, loading of material accomplished by digging or pushing the material away from the operator and then lifted.
In loader mode, three hydraulic rams are utilized. First, dipper boom hydraulic ram, is operable to manipulate dipper boom toward or away from main boom. Dipper boom hydraulic ram rotates dipper boom when the ram is extended. At full extension of dipper boom hydraulic ram, dipper boom will be in the position shown in phantom. Second, bucket ram operates to rotate the loader bucket by extension of a bucket ram, which in turn causes ram links to pivot about ram pin, resulting in rotation of the bucket. Third, dipper extension hydraulic ram is operable to manipulate dipper boom extension toward or away from dipper boom. The operator can move the loader/excavator forward or backward using the track sub-assembly, preferably containing an elevated drive sprocket as shown. Further, the operator can rotate the excavator/loader by engagement of a slew ring. Main structure and engine compartment houses the engine and other necessary peripherals (not shown) sufficient to drive the slew ring, track subassembly, and hydraulic controls operating the booms. it is apparent that extension of the bucket ram causes pivoting of bucket ram links. Undercarriage carrying the track subassembly is shown. Operators will ordinarily be seated in seat. Excavation is generally characterized by the excavator bucket facing toward the operator, excavation of material accomplished by digging or drawing the material toward the operator and then lifted.

CLAIMS:

1. A loader-excavator for alternate use with a loader bucket in a loader mode and an excavator bucket in 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
i) a lock mechanism for selectively coupling the loader bucket and the excavator bucket to the dipper boom extension.
2. The loader-excavator as defined in claim 1 further comprising an operator's seat carried by the frame, and in which the main boom and dipper boom extend alongside the operator's seat when in their retracted positions.
3. The loader-excavator as defined in claim 1 in which the dipper boom extension extends generally downwardly from said fourth pivot to approximately past said first pivot forwardly thereof when the main boom and dipper boom and dipper boom extension are all in their retracted positions.