Abstract:
A vehicle having a long track or wheel-trail wheel combination on one side and a smaller ground engaging member, such as a short track or wheel on the other. The vehicle has a work attachment on one end of its frame, which is provided clearance on the side of the vehicle with the short track or wheel. A control system is provided to allow an operator to properly control a direction of the vehicle despite the fact that different forces may be required to operate the long track and the short track or wheel.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of provisional patent application Ser. No. 61/864,740, filed on Aug. 12, 2013, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present invention relates generally to the field of skid-steer work vehicles, such as trenchers or vibratory plows. 
       SUMMARY 
       [0003]    A vehicle comprising a frame, a trencher, an auger, a first ground engaging assembly and a second ground engaging assembly. The trencher is connected to the frame and has a rotatable digging chain. The auger defines an auger axis and is connected to the frame. The first ground engaging assembly movably supports the frame and defines a first surface contact area. The second ground engaging member movably supports the frame and defines a second surface contact area. The second surface contact area is smaller than the first surface contact area. The auger axis extends above the first surface contact area but does not extend above the second surface contact area. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a right rear view of the tracked vehicle of the present invention. 
           [0005]      FIG. 2  is a left-front perspective view of the tracked vehicle of  FIG. 1 . 
           [0006]      FIG. 3  is a front view of the tracked vehicle of  FIG. 1  with the trencher digging chain removed. 
           [0007]      FIG. 4  is a side view of a wheeled vehicle in accordance with the present invention. 
       
    
    
     DESCRIPTION 
       [0008]    With reference now to  FIG. 1 , shown therein is a vehicle  10  having a frame  12  and a motive force system  14 . The frame  12  comprises an operator station  16  and a work attachment  18 . The operator station  16  is configured for an operator walking behind the tracked vehicle  10 . Ride-on platform and seated operator station  16  configurations are also contemplated. As shown, the work attachment  18  is a trenching boom, but alternative work attachments such as plows, buckets, excavators, microtrenching blades, and others are anticipated. The motive force system  14  comprises a first ground engaging assembly illustrated as a first track system  20  and a second ground engaging member, which is illustrated as a second track system  22 . Each of the first track system  20  and the second track system  22  comprise an endless track  24  and a corresponding track support structure  26 . The endless track  24  provides a surface-engaging area or contact area between a surface of the ground and the vehicle  10 . 
         [0009]    A first endless track  24 A of the first track system  20  has a larger surface-engaging area between the ground and the endless track than a second endless track  24 B of the second track system  22 . The overall length of the first and second endless tracks  24 A,  24 B may differ, or they may be the same, but the contact surface is adjusted by the geometries of the first track system  20  and second track system  22 . For example, the first track system  20  may provide for a “low track” while the second track system  22  provides a “high track” having a triangular profile. Alternatively, the first and second track systems  20 ,  22  may have similar geometries but different lengths, as shown in  FIG. 1 . The second track system  22  may comprise a surface-engaging area that is 75% or less than the surface-engaging area of the first track system  20 . Additionally, the invention could be utilized where the second ground engaging member comprises one or more wheels (not shown) used in place of the second endless track  24 B. The endless tracks  24 A,  24 B may be adjustable to tension the endless tracks about their corresponding track support structure  26 . 
         [0010]    The track support structure  26  of each track system  20 ,  22  comprises a drive sprocket  28  and a bogey wheel  30 . The drive sprocket  28  is powered by a motor (not shown) to drive the endless track  24 A,  24 B. The drive sprocket  28  of each track system  20 ,  22  may be powered by a separate motor. The bogey wheels  30  provide support and shape for the endless track  24 A,  24 B as it is driven by the sprocket  28 . 
         [0011]    The vehicle  10  further comprises a fuel tank  32  for storing fuel such as gasoline, diesel, and other liquid fuels for operation of the vehicle and its components. The fuel tank  32  comprises a handle  34  for removal of the fuel tank and storage at a location away from the vehicle  10 . A fuel tank tray  36  allows the fuel tank to be removed from the frame  12  for refueling purposes. 
         [0012]    With reference now to  FIG. 2 , the vehicle  10  is shown from the side of the second track system  22 . The work attachment  18  shown comprises a trencher  40  and auger  42 . The trencher  40  comprises a boom  44 , an endless digging chain  46 , and a sprocket  48 . The digging chain  46  comprises a plurality of teeth  50  for digging a trench when the chain is rotated. The sprocket  48  is powered by a motor  52  and causes the digging chain  46  to rotate about the boom  44 . A cylinder  53  is hydraulically powered and controlled at the operator station, and causes the trencher boom  44  to pivot such that the digging chain  46  can engage the ground and create a trench. 
         [0013]    The auger  42  is either independently powered or powered by the same motor  52  as the sprocket  48 . As shown, the auger  42  comprises a blade  54  and a shaft  56  having an auger axis  58 . The blade  54  is attached to the shaft  56  such that rotation of the shaft  56  about the auger axis  58  causes the blade to move spoils from proximate the trencher  40  away from the vehicle  10 . The trencher boom  44  may pivot about the auger axis  58  due to operation of the hydraulic cylinder  53 . Alternatively, the trencher boom  44  may pivot at a different location. The auger axis  58 , when extended in both directions to infinity, will extend above a surface contact area of the first track system  20 , but will not extend above a surface contact area of the second track system  22 , allowing the auger  42  to remove spoils from proximate a trench created by the trencher  40  but outside of the profile of the vehicle  10 . 
         [0014]    As shown in  FIG. 2 , the auger axis  58  and the sprocket  48  are in front of the second endless track  24 B but not in front of the first endless track  24 A. As the second track structure  22  shown is a “low track” system, the sprocket  28  is located proximate the back of the vehicle  10 . One of ordinary skill will appreciate that this sprocket  28  may be placed at any point with a long contact profile with the endless track  24 B, and that a “high track” system may have a sprocket at an apex of a triangular profile (not shown). 
         [0015]    Controls  60  are provided at the operator station  16  for controlling the track systems  20 ,  22  and work attachment  18  of the vehicle  10 . As shown, the controls  60  comprise a first track throttle  62  and a second track throttle  64 . The first track throttle  62  controls the first track system  20 , while the second track throttle  64  controls the speed of the second track system  22 . One of skill in the art will appreciate that for track systems  20 ,  22  of differing lengths to operate at the same speed, a hydraulic control system, gear differential, hydrostatic motors, an electric control system or other means for controlling the throttle (not shown) may be utilized for ease of control of the motive force system  14 . For example, when the first track throttle  62  and second track throttle  64  are fully open, the endless tracks  24 A,  24 B should provide the same motive forces, even if the power required to achieve the force is different for each track. 
         [0016]    Alternatively, the controls  60  may comprise a multi-axis joystick (not shown) for controlling the first track system  20  and second track system  22 . The multi-axis joystick directs the motive force system  14  to cause the vehicle  10  to move in forward, reverse, or turn based on the two-dimensional actuation of the joystick. 
         [0017]    All of the components of the vehicle  10  may be powered by one engine  70  mounted on the frame; however, separate motors may be utilized for each of the work attachment  18 , first track system  20  and second track system  22 . 
         [0018]    With reference now to  FIG. 3 , the vehicle  10  of  FIG. 2  is shown from the front with the digging chain  46  removed so that the auger  42  is clearly shown in front of the second track system  22 . 
         [0019]    With reference to  FIG. 4 , a wheeled embodiment of the vehicle  10  is shown therein. The motive force system  14  comprises a first drive wheel  80 , a second drive wheel  82 , and a roller wheel  84 . The first and second drive wheels  82  provide motive force to the vehicle  10 . As shown, the first and second drive wheels  80 ,  82  are the same size and offset relative to the frame  12 . Alternatively, the first and second drive wheels  80 ,  82  may be of differing sizes. The roller wheel  84  is disposed on the same side of the frame as the first drive wheel  80  and provides stability but no motive force. One of ordinary skill can appreciate that an additional drive wheel could be used in place of roller wheel  84 . As with respect to the first and second track systems  20 ,  22  described above, the drive wheels  80 ,  82  may be powered by separate motors. 
         [0020]    Together, first drive wheel  80  and roller wheel  84  form a first ground engaging assembly with a surface contact area greater than the surface contact area of the second drive wheel  82 . The auger axis  58  ( FIG. 2 ), when extended in both directions to infinity, will extend above a surface contact area defined by the region where the first ground engaging assembly (the first drive wheel  80  and roller wheel  84 ) contacts the ground, but will not extend above a surface contact area of the second drive wheel  82 , allowing the auger  42  to remove spoils from proximate a trench created by the trencher  40  but outside of the profile of the vehicle  10 . 
         [0021]    Various modifications can be made in the design and operation of the present invention without departing from the spirit thereof. For example, the first drive wheel  80  and roller wheel  84  of  FIG. 4  may be used with the second track system  22  of  FIG. 2 . Thus, while the principle preferred construction and modes of operation of the invention have been explained in what is now considered to represent its best embodiments, which have been illustrated and described, it should be understood that the invention may be practiced otherwise than as specifically illustrated and described.