Abstract:
A loader excavator is described that is operable in an excavation mode or in a loader mode. 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.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to a compact utility loader that is convertible to an excavator and vice versa. More particularly, this invention relates to a tracked machine adapted for use in outdoor construction environments.  
       SUMMARY OF THE INVENTION  
       [0002]     A multi-purpose convertible skid loader and excavator is disclosed. An operator can convert the machine from a skid loader to an excavator without leaving the cab, through manipulation of hydraulic controls.  
         [0003]     A loader excavator is described that is operable in an excavation mode or in a loader mode. 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.  
         [0004]     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.  
         [0005]     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.  
         [0006]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a side elevation view of a preferred embodiment of a convertible skid loader and excavator, shown in a loader mode, in phantom in an excavation mode.  
         [0008]      FIG. 2  is a front elevation view of a preferred embodiment of a convertible skid loader and excavator.  
         [0009]      FIG. 3  is a side elevation view of a preferred embodiment of a convertible skid loader and excavator, shown in an excavator mode.  
         [0010]      FIGS. 4   a - c  are top views of a preferred embodiment of operator control configuration.  
         [0011]      FIGS. 5 and 5   a  are detail views of bucket detachment.  
         [0012]      FIG. 6  is a detail views of hydraulic arms. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0013]     Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention that may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.  
         [0014]      FIG. 1  is a side elevation view of a preferred embodiment of a convertible skid loader and excavator  5 , shown in a loader mode with a loader bucket  70 , and in phantom in the loader mode with a dipper boom  20  fully extended.  
         [0015]     The dipper boom  20  is operable through hydraulic controls (described later) to raise and lower the loader bucket  70 . 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  70  is slightly elevated with respect to the remainder of the bottom edge of the loader bucket  70 .  
         [0016]     Loading is generally characterized by the loader bucket  70  facing away the operator, loading of material accomplished by digging or pushing the material away from the operator and then lifted.  
         [0017]     In loader mode, three hydraulic rams are utilized. First, dipper boom hydraulic ram  40 , is operable to manipulate dipper boom  20  toward or away from main boom  10 . Dipper boom hydraulic ram  40  rotates dipper boom  20  when the ram  40  is extended. At full extension of dipper boom hydraulic ram  40 , dipper boom  20  will be in the position shown in phantom.  
         [0018]     Second, bucket ram  50  operates to rotate the loader bucket  70  by extension of a bucket ram  50 , which in turn causes ram joints  55  to pivot about ram pin  53 , resulting in rotation of the bucket  70 .  
         [0019]     Third, dipper extension hydraulic ram  90  is operable to manipulate dipper boom extension  60  toward or away from dipper boom  20 .  
         [0020]     The operator can move the loader/excavator forward or backward using the track sub-assembly  110 , preferably containing an elevated drive sprocket as shown. Further, the operator can rotate the excavator/loader by engagement of a slew ring  130 .  
         [0021]     Main structure and engine compartment  100  houses the engine and other necessary peripherals (not shown) sufficient to drive the slew ring  130 , track sub-assembly  110 , and hydraulic controls operating the booms.  
         [0022]     Referring now to  FIG. 2 , a front elevation view of the convertible skid loader and excavator is shown. In this view, it is apparent that extension of the bucket ram  50  causes pivoting of ram joints  55 . Undercarriage  120  carrying the track sub-assembly  100  is shown. Operators will ordinarily be seated in seat  150 .  
         [0023]     Referring now to  FIG. 3 , a side elevation view of a preferred embodiment of a convertible skid loader and excavator, shown in an excavator mode.  
         [0024]     Excavation is generally characterized by the excavator bucket  80  facing toward the operator, excavation of material accomplished by digging or drawing the material toward the operator and then lifted.  
         [0025]     In the excavation mode, the main boom  10  and the dipper boom  20  are operable through hydraulic controls to raise and lower the excavator bucket  80 . In a preferred embodiment, the main boom  10  and the dipper boom  20  operate in the excavation mode, in contrast to the loader mode, when only the dipper boom  20  is preferably used.  
         [0026]     In order to provide extension of the excavator bucket  80  away from the operator, as emphasized between the phantom and solid views of the dipper boom  20  and main boom  10 , the main boom  10  is hydraulically extended by operation of the main boom hydraulic ram  30 , which in turn causes bucket ram joints  32  to rotate about bucket pins  35 .  
         [0027]     Dipper boom hydraulic ram  40  is extended to rotate the dipper boom  20  as previously described. Additionally, a dipper extension hydraulic ram  90  causes further extension of dipper boom extension  60 , shown in  FIG. 3  in an extended position. Manipulation of the bucket ram  50  causes rotation of the excavator bucket  80  in the same manner as previously described in relation to loader bucket  70 .  
         [0028]     Referring now to  FIGS. 4   a - c , top views of a preferred embodiment of operator control configuration are shown. While preferably seated in seat  150 , an operator can operate a left track and a right track of track sub-assembly  110  by operating one of the forward-reverse actuators shown.  
         [0029]     In order to move the main boom  10  by extension of main boom hydraulic ram  30 , the user moves the Boom  30  Down or Up controls shown in  FIG. 4   b.    
         [0030]     In order to move the dipper boom  20  by extension of dipper boom hydraulic ram  40 , the user moves the Boom  40  Down or Up controls shown in  FIG. 4   c.    
         [0031]     To rotate about slew ring  130 , the operator moves the Slew Left or Right controls shown in  FIG. 4   b.    
         [0032]     To rotate either the excavator bucket  80  or the loader bucket  70 , the operator moves the Bucket down or up control on  FIG. 4   c.    
         [0033]     Last, to extend or retract the dipper extension hydraulic ram  90 , thereby raising or lowering the dipper boom extension  60 , the operator engages the boom extend and retract switch shown on  FIG. 4   c.    
         [0034]      FIGS. 5 and 6  are detail views of hydraulic arms. Referring specifically to  FIG. 5A , it can be seen that a pin  74  is coupled to a cleat ram  72  that can move up or down. A wedge on the pin  74  engages a hole in a tab  76  that is welded on the bucket  70  (or  80 ). This draws the bucket  70  (or  80 ) towards cleat  71  and locks it into place. The cleat  71  is coupled to the dipper boom extension  60  through bucket pin  78 .  
         [0035]     The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.