Abstract:
A trenching assembly featuring a novel auger arrangement. The arrangement comprises an auger assembly and a digging chain rotatably connected to a trenching boom. The digging chain rotates, driven by a motor, to dislodge soil and creating a trench. The dislodged soil, or spoil, builds up near a projected path of the digging chain. The auger assembly operates to move the spoil from a projected path of the trench. The auger rotates independently from the digging chain and is positioned such that a projected width of the digging chain intersects a threaded length of the auger assembly. The auger may rotate faster than if driven by the digging chain, allowing the auger to have a smaller diameter than conventional augers. Further, the auger can be used in conjunction with a backfill blade to refill cleaned trenches without operation of the digging chain.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of provisional patent application Ser. No. 60/743,816 filed on Mar. 27, 2006, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to the field of work machines, and particularly to a work machine having a trencher and auger attachment. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention is directed to a trenching assembly. The trenching assembly comprises a frame, a trenching boom, a digging chain, and an auger. The trenching boom is pivotally connected to the frame. The digging chain is rotatably connected to the trenching boom, and is characterized by a digging speed. The auger is rotatably supported on the frame, and is characterized by a rotation speed. The rotation speed of the auger may be varied dynamically and without affecting the digging speed of the digging chain. 
         [0004]    In yet another embodiment, the trenching assembly comprises a trencher blade and an auger. The trencher blade comprises a digging chain. The digging chain is rotatably driven about a trenching boom. The auger is rotationally driven such that a rotation rate of the auger is independent of the rotation of the digging chain. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a side view of a work machine having a trenching apparatus built in accordance with the present invention. 
           [0006]      FIG. 2  is side view of an alternative work machine configuration having a trenching apparatus built in accordance with the present invention. 
           [0007]      FIG. 3  is a side cut-away of the trenching apparatus of  FIG. 1 . 
           [0008]      FIG. 4  is a bottom cut-away of the trenching apparatus of  FIG. 1 . 
           [0009]      FIG. 5  is a front cut-away of a trenching apparatus with a trenching blade in a raised position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0010]    With reference now to  FIG. 1 , a trenching machine  10  is shown. The trenching machine  10  comprises a power unit  12  and a trenching assembly  14 . As shown, the trenching assembly  14  is attached to the power unit  12  at an articulation plate  16 . In a preferred embodiment, the articulation plate  16  pivots about a vertical axis giving the trenching machine  10  greater range of motion. The trenching assembly  14  comprises at least one ground supporting member  18 . 
         [0011]    The power unit  12  comprises an engine  20  and at least one ground engaging drive member  22 . The at least one ground engaging drive member  22  is powered by the engine  20  and adapted for translational motion. The engine  20  provides power to various components and motors of the power unit  12  and the trenching assembly  14 . The power unit  12  preferably comprises a platform  24  and a plurality of controls  26 , allowing an operator to control the mobility of the machine  10  and to operate the trenching assembly  14 . 
         [0012]    With continued reference to  FIG. 1 , the trenching assembly  14  comprises a frame  28 , a trenching blade  30 , and an auger assembly  32 . The frame  28  comprises a connection assembly  34  and the at least one ground supporting member  18 . The connection assembly  34  is adapted for connection to the power unit  12  at the articulation plate  16 . Alternatively, the connection assembly  34 , and thus the trenching assembly  14 , may be connected to a tool carrier. Preferably, the connection assembly  34  is adapted to pivotally connect the trenching assembly  14  to the power unit  12  for steering of the machine  10  at the articulation joint  16 . More preferably, the connection assembly  34  is adapted to pivotally connect the trenching assembly  14  to the power unit  12  as disclosed in U.S. patent application Ser. No. 11/610,428, the contents of which are incorporated by reference herein. 
         [0013]    Alternatively, as shown in  FIG. 2 , the trenching assembly  14  having an auger assembly  32  (to be later described) may be integral with a rigid frame trenching machine  10  of either a conventional walk-along or ride-on configuration. As shown, the ground supporting member  18  of the trenching assembly  14  and the ground engaging drive members  22  on the power unit  20  comprise one or more wheels. The ground supporting member  18  and ground engaging drive members  22  may alternatively comprise tracks or a combination of tracks and wheels. The ground supporting member  18  of the trenching assembly  14  may be powered or unpowered. 
         [0014]    Turning now to  FIG. 3 , the trenching assembly  14  is shown in greater detail. Trenching blade  30  of the assembly  14  comprises a trenching boom  35 , a digging chain  36 , and a plurality of cutting teeth  38 . The trenching boom  35  is pivotally connected to the frame  28  and pivots about a headshaft pivot point  40 . The digging chain  36  extends around a periphery of the trenching boom  35 . The digging chain  36  is adapted to rotate around the trenching boom  35 , and is powered by a trenching hydraulic motor  44  (shown in  FIG. 4 ). Preferably, the speed of the digging chain  36  is capable of being dynamically varied by operation of the trencher motor  44 . The plurality of cutting teeth  38  is mounted on the digging chain  36 . The trenching boom  35  is generally moveable between a plurality of positions about the pivot point  40  by a hydraulic cylinder or similar lifting assembly. 
         [0015]    The trenching blade  30  may be in a raised position, in which the cutting teeth  38  do not contact the ground. The trenching blade  30  may alternatively be in a lowered position, in which the cutting teeth engage the ground. In the lowered position, the cutting teeth  38  engage and loosen ground material and move the displaced ground material, or spoils, to the surface, creating a trench as the machine traverses from right to left as shown in  FIGS. 1 and 3 . Preferably, a digging speed of the digging chain  36  may be controlled by the operator to affect a rate at which the trench is created. The trencher boom  35  and trencher motor  44  are controlled by an operator with one or more of the controls  26 . 
         [0016]    In a preferred embodiment, at least one spoils drag  45  is adjustably attached to the trenching boom  35 . The at least one spoils drag  45  slides loosened ground material, or spoil, away from the trench thus reducing the amount of spoils reentering the trench. Preferably, a plurality of spoils drags  45  are used and adjustably attached to each side of the trenching boom  35 . In this embodiment, spoils are loosened by the digging chain  36  and moved away from the open trench. Spoils remaining by the trench are displaced away from an edge of the trench by the spoils drags  45 . 
         [0017]    Referring now to  FIG. 4 , a bottom view of the trenching assembly  14  is shown. The auger assembly  32  is provided to move spoils generated by the trencher blade  30  away from the trench. The auger assembly  32  is mounted on the frame  28 , directly in front of the trenching blade  30  relative to the direction of trenching. The auger assembly  32  preferably comprises an auger motor  46 , a hub  48 , and an auger  50 . 
         [0018]    The auger motor  46 , characterized by an output speed, drives a rotation of the auger  50 . The output speed of the auger motor  46 , and thus the rotation speed of the auger  50 , is preferably dynamically varied by operation of one or more of the controls  26 . Preferably, and because the auger  50  is driven by the motor  46  independent of the trencher motor  44 , the auger rotation speed can be varied independent of the rotation of the digging chain  36  without affecting the speed of the digging chain as controlled by the trencher motor  44 . This aspect of invention provides benefits not found in prior art, for example in varying speed based upon soil conditions. Thus, if operation of the trenching blade  30  causes spoils to accumulate faster than the auger assembly  32  is removing them, the rotation speed of the auger  50  can be increased, increasing the ability of the auger assembly to move spoils away from the trench. 
         [0019]    The hub  48  houses bearings and seals and is secured to the frame  28 . The auger  50  comprises a threaded length  52 . The auger  50  is attached to the hub  48 , and rotated by operation of the auger motor  46 . Preferably, the auger assembly  32  is cantilever mounted and level to the ground. More preferably, the auger  50  is placed proximate the digging chain  36  and low to the ground. Most preferably, the auger  50  is attached to the frame  28  at a point between the rear ground drive members  22  and the pivot point  40  of the trenching boom  35 . In the embodiment shown in  FIG. 1 , the auger  50  is attached to the frame  28  at a point between the articulation plate  16  and the pivot point  40  of the trenching boom  35 . 
         [0020]    The auger  50  is preferably of a smaller diameter than the traditional trencher auger. A shorter flighting pitch of the smaller auger  50  and increased rotation speed breaks the spoils into finer pieces, allowing the spoils to be conveyed to a side of the work machine  10 , resulting in a cleaner trench. Further, this feature makes it easier to return the spoils to the trench. The auger  50  may also be rotated at a higher rate of speed than the digging chain  36 , permitting a smaller diameter auger  50 . A smaller diameter auger  50  allows for a more compact configuration and increased versatility of placement. 
         [0021]    With continued reference to  FIG. 4 , the digging chain  36  defines a projected discharge width  54 . The flighting, or threaded length  52  of the auger  50  is in front of and traverses across the discharge width  54  of the digging chain  36 . This configuration allows spoils to be transferred from one side of the projected discharge width  54  to the other along the threaded length  52  more efficiently Thus, in this configuration, one auger assembly  32  may do the work of a two-auger system. Further, only one pile of spoils is created, reducing the work required in backfilling a trench. 
         [0022]    Alternatively, and now with reference to  FIG. 5 , the auger  50  may be tilted from horizontal. Preferably, in the alternative embodiment, the auger  50  is inclined relative to the ground. The inclined auger  50  allows the auger flighting to be low to the ground near the digging chain  36 , while providing clearance from the ground to an end  56  of the auger remote from the hub  48 . The auger  50  orientation may be tilted by adjustment of the hub  48 . The adjustment may be made by inclining the auger assembly  32  with shims. Alternatively, the adjustment may be made with a pin-slot arrangement. In yet another alternative, the adjustment of the auger assembly  32  may be made dynamically using hydraulics. The vertical distance from the auger  50  to the ground may alternatively be adjusted by mounting the auger in a movable frame with incremental adjustments or dynamically with a hydraulic cylinder. The diameter of the auger  50  can be selected to optimize its mounting location and height from the ground. One skilled in the art will appreciate the beneficial aspects of a tilted auger  50  may also be accomplished with a tapered auger. With a tapered auger  50 , the diameter of the auger or the diameter of the flighting may vary along its length. Further, the auger  50  may be both tilted and tapered. 
         [0023]    With reference again to  FIG. 3 , the trenching assembly  14  further comprises an optionally installed backfill blade  58 . The backfill blade  58  is mounted to the frame  28  and is preferably located between the auger  50  and the power unit  12 . Spoils can be backfilled into an exposed trench without operation of the trenching blade  30  or the auger assembly  32  by pushing the spoils with the backfill blade  58 . In an alternative mode of operation, the backfill blade  58  may be used to guide spoils into the auger assembly  32 , for backfilling into the trench. 
         [0024]    In operation, as the digging chain  36  loosens spoils, the spoils are deposited near the auger assembly  32 . The spoils are then moved from near the digging chain  36  to the end  56  of the auger  50  by rotation of the threaded length  52  of the auger. Thus, a pile of spoils forms at the end  56  of the auger  50 , instead of in the path of the trenching blade  30 . Spoils not removed by the auger assembly  32  are displaced from proximate the newly formed trench by the spoils drag  45 , as described earlier. 
         [0025]    The auger assembly  32  can alternatively be used as a backfill auger. In this configuration, the trencher blade  30  is raised and the trencher motor  44  is not activated. The auger  50  moves collected spoils from the spoils pile to proximate an uncovered trench. Preferably, the machine  10  is translated in a direction opposite a direction of the trenching operation while the auger  50  is rotated in an opposite direction than it rotates when removing spoil from proximate the trench. In this way, use of the backfill blade  58  and the rotation of the auger  50  will cause spoils to be moved back into the trench. 
         [0026]    Various modifications can be made in the design and operation of the present invention without departing from the spirit thereof. Thus, while the principal 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.