Abstract:
An agricultural combine including an agricultural harvester, a crop tank for harvested material, and an unloading auger assembly for unloading and discharging crop material. The auger assembly has inner and outer auger tubes pivotally connected to one another. The auger tubes pivot between a first position in which the auger tubes extend transversely and are coaxial and a second position in which the auger tubes form an angle. The auger tubes contain augers having first and second couplings at cooperating ends. The first coupling has two projections extending to cooperate with a single radial projection on the second coupling to provide improved engagement.

Description:
[0001]    This application is the US National Stage filing of International Application Serial No. PCT/US2013/042469 filed on May 23, 2013 which claims priority to U.S. Provisional Application No. 61/689,069 filed May 29, 2012, each of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to agricultural harvesters such as combines, and, more particularly, to auger assemblies used in such combines. 
         [0004]    2. Description of the Related Art 
         [0005]    An agricultural harvester known as a “combine” is historically termed as such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating and cleaning. A combine includes a header which removes the crop from a field, and a feeder housing which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves and performs a threshing operation on the crop to remove the grain. Once the grain is threshed it falls through perforations in the concaves onto a grain pan. From the grain pan the grain is cleaned using a cleaning system, and is then transported to a grain tank onboard the combine. When the grain tank becomes full, the combine is positioned adjacent a vehicle into which the grain is to be unloaded, such as a semi-trailer, gravity box, straight truck, or the like; and an unloading system on the combine is actuated to transfer the grain into the vehicle. 
         [0006]    Typical unloading systems for combines involve unloading augers that are formed from inner and outer tubes (relative to the chassis of the combine) with rotatable augers inside that can be actuated to move grain longitudinally through the tubes. The tubes are pivoted to the combine so that they may be displaced laterally relative to the movement of the combine to an unload position in which grain is deposited in a wagon or other vehicle for transport. When the unloading function is completed, the auger tubes are retracted to a fold position in which the inner auger tube is generally parallel to the longitudinal axis of the combine and the outer auger tube is bent to an angle in a horizontal plane so that its free end is maintained within the overall configuration of the combine. 
         [0007]    The auger tubes each have longitudinally extending augers within them that are mounted for rotation so that crop material is moved longitudinally through the augers. Because the auger tubes are pivoted between the unload and fold position, it is necessary to provide a mechanical coupler between the drive auger in the inner auger tube and the driven auger in the outer auger tube that delivers crop material to a transport vehicle. In the past, the coupling between the two augers has been provided by single projections at the end of each auger that interact and abut to cause the outer auger to be driven. With prior auger designs, the initial coupling of the auger tubes in the driving position causes, under certain circumstances, a movement of the projection into place and subsequent rotational displacement that can be close to a complete circle. The rotational displacement causes an opportunity for accelerated impact between the two projections, thus having an effect on long term wear. 
         [0008]    Accordingly, what is needed in the art is an auger coupling mechanism that minimizes acceleration forces upon engagement. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides an auger coupling mechanism for auger tube assemblies that reduces engagement forces. 
         [0010]    The invention in one form is an unloading auger tube assembly for an agricultural harvester having first and second tubes, each having a longitudinal axis and pivotally connected to one another. First and second augers are positioned longitudinally in the tubes for rotating to move crop material longitudinally upon rotation of the augers. First and second couplers selectively couple the first and second augers when the auger tubes are pivoted to be coaxial with the first coupler including at least two projections extending toward the second coupler with the second coupler having a single projection for interacting with one of said at least two projections. 
         [0011]    The invention in another form is an agricultural combine with an agricultural harvester in a crop tank for harvested material. An unloading auger is provided for unloading and discharging crop material with the auger assembly including inner and outer auger tubes, each having a longitudinal axis and pivotally connected to one another with the auger tubes pivotal between a first position in which the auger tubes are coaxial and a second position in which the auger tubes form an angle. Inner and outer augers are positioned longitudinally in the inner and outer tubes respectively for rotation to move crop material longitudinally upon rotation of the augers. First and second couplers selectively couple the inner and outer augers respectively when the auger tubes are pivoted to be coaxial. The first coupler includes at least two projections extending toward the second coupler with the second coupler having a single projection for interacting with one of the at least two projections. 
         [0012]    An advantage of the present invention is that the coupling is designed to increase coupling life. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a side view of an embodiment of an agricultural harvester in the form of a combine which may include a folding auger assembly coupler of the present invention; 
           [0015]      FIG. 2  is a fragmentary enlarged view of the agricultural harvester of  FIG. 1  showing the folding auger assembly in a first position. 
           [0016]      FIG. 3  is a fragmentary enlarged view of the agricultural harvester of  FIG. 1  showing the folding auger assembly in a second position. 
           [0017]      FIG. 4  is a greatly enlarged perspective view of one of the components of  FIGS. 2 and 3 . 
           [0018]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The term “grain” is used principally throughout this specification for convenience but it is to be understood that this term is not intended to be limiting. Thus “grain” refers to that part of the crop material which is threshed and separated from the discardable part of the crop material. Also, the terms “forward”, “rearward”, “left” and “right”, when used in connection with the agricultural harvester and/or components thereof are usually determined with reference to the direction of forward operative travel of the harvester, but again, they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the agricultural harvester and are equally not to be construed as limiting. 
         [0020]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an agricultural harvester in the form of a combine  10 , which generally includes a chassis  12 , ground engaging wheels  14  and  16 , header  18 , feeder housing  20 , operator cab  22 , threshing and separating system  24 , cleaning system  26 , grain tank  28 , and unloading auger assembly  30 . 
         [0021]    Front wheels  14  are larger flotation type wheels, and rear wheels  16  are smaller steerable wheels. Motive force is selectively applied to front wheels  14  through a power plant in the form of a diesel engine  32  and a transmission (not shown). Although combine  10  is shown as including wheels, is also to be understood that combine  10  may include tracks, such as full tracks or half tracks. 
         [0022]    Header  18  is mounted to the front of combine  10  and includes a cutter bar  34  for severing crops from a field during forward motion of combine  10 . A rotatable reel  36  feeds the crop into header  18 , and a double auger  38  feeds the severed crop laterally inwardly from each side toward feeder housing  20 . Feeder housing  20  conveys the cut crop to threshing and separating system  24 , and is s selectively vertically movable using appropriate actuators, such as hydraulic cylinders (not shown). 
         [0023]    Threshing and separating system  24  is of the axial-flow type, and generally includes a rotor  40  at least partially enclosed by and rotatable within a corresponding perforated concave  42 . The cut crops are threshed and separated by the rotation of rotor  40  within concave  42 , and larger elements, such as stalks, leaves and the like are discharged from the rear of combine  10 . Smaller elements of crop material including grain and non-grain crop material, including particles lighter than grain, such as chaff, dust and straw, are discharged through perforations of concave  42 . 
         [0024]    Grain which has been separated by the threshing and separating assembly  24  falls onto a grain pan  44  and is conveyed toward cleaning system  26  including sieves  46 ,  48  and  50 . Clean grain falls to a clean grain auger  56  positioned crosswise below and in front of lower sieve  50 . Clean grain auger  56  receives clean grain from each sieve  48 ,  50  and from bottom pan  58  of cleaning system  26 . Clean grain auger  56  conveys the clean grain laterally to a generally vertically arranged grain elevator  60  for transport to grain tank  28 . A pair of grain tank augers  68  at the bottom of grain tank  28  conveys the clean grain laterally within grain tank  28  to unloading auger assembly  30  for discharge from combine  10 . 
         [0025]    Referring to  FIGS. 1 ,  2  and  3 , unloading auger assembly  30  is formed from a first (or inner) auger tube  70  pivotally connected to combine  10  to receive grain from grain tank  28 . Auger tube  70  has a longitudinally extending auger  74 . A second (or outer) auger tube  72  has an auger  76 , both shown in  FIG. 2  to convey crop material along the axis of tubes  70  and  72 . Auger tube  70  is pivotally connected to second auger tube  72  by an appropriate pivotal interconnection (not shown). The arrangement of first and second auger tubes  70  and  72  in  FIG. 1  shows the auger assembly  30  in a position in between the load position and the fold position in which first auger tube  70  extends along side the combine  10  and second auger tube  72  is folded to be maintained within the width of the combine  10 . As shown in  FIG. 1 , the angle made between the first and second auger tubes  70  and  72  is 95°, but other angles may be employed. 
         [0026]    The auger tubes  70 ,  72  are in the fold position, except when crop material is being discharged, in which case the auger tubes  70  and  72  are pivoted to be coaxial in the load position for discharging grain and the auger assembly is pivoted to a position generally laterally from the combine  10 . 
         [0027]    In accordance with the present invention, an improved coupler assembly  78  shown in  FIGS. 2-4  reduces the engagement loads when the auger tubes  70  and  72  are pivoted to coaxial or load position. Specifically referring to  FIGS. 2 and 3 , a first (or inner) auger  74  includes a central tubular element  80  having attached thereto flighting  82  which is helical in form and has the effect of moving crop material along the axis of tubular element  80  when it is rotated. Tubular element  80  has an end shaft  84  retained within a bearing assembly  86  fixed to the walls of tube  70 . End shaft  84  has a splined section  88  and leading to a nose section  90  with a conical end portion  92 . 
         [0028]    A first coupling  110 , as illustrated, is formed from a unitary material and includes a central section  112  having internal splines  114 , shown in  FIG. 4  to be received over splines  88  on end shaft  84 . Coupling  110  also has axially extending first and second projections  116  and  118  extending beyond the axial end face  120  of coupling  110 . First and second projections  118  have side faces  122  and  124  respectively that are each formed in a plane extending through the central axis of shaft  84  so that they are essentially a radially extending surface. Projections  116  and  118  have tapered nose sections  126  and  128 , herein shown as conical shapes. It should be noted however that the end faces  126  and  128  may also have a wedge shape. 
         [0029]    A second (or outer) auger  76  includes a central tubular element  94  with flighting  96  similarly attached so that crop material moves axially upon rotation of tubular element  94 . Auger  76  has a second coupling  98  including a cylindrical outer section  100  having a radial projection  102  with a tapered nose section  104 . Second coupling  98  also has a central bore  106  extending to a tapered end section  108 . 
         [0030]    The position of the augers  74  and  76  in  FIG. 2  is a position between the fold position of  FIG. 1  and the unload position of  FIG. 3  in which the augers  74  and  76  are coaxial. As the augers  74  and  76  are displaced to be engaged, the conical end piece on end shaft  90  cooperates with the tapered section  108  on second coupling  98  to form a pilot for auger tube  76  and to cause auger  76  to be supported for rotation by bearing assembly  86  that supports auger  74 . As the augers  74  and  76  are displaced to the position of  FIG. 3 , the projections  116  and  118  on the first coupling  110  move over the outer cylindrical surface  100  of coupling  98  to a point where the axial end face  120  of coupling  110  abuts the end face of second coupling  98 . In this position, shown specifically in  FIGS. 3 , the rotation of auger  74  causes the projections  116  and  118  to rotate so that one of the two projections abuts the side face of single projection  102 . It is to be noted that the tapered end sections  126  and  28  on first coupling  110  and the tapered section  104  on single projection  102  of second coupling  98  allow the projections and single projections to be moved to the side for engagement when the elements are lined up. When the projections  116  or  118  abut the single projection  102  the auger  76  then is driven by auger  74 . 
         [0031]    By providing at least two projections  116  and  118 , the arc for free movement before engagement of single projection  102  by projections  116  or  118  is reduced by about half. Accordingly, the opportunity for acceleration of the projections before impact is reduced significantly, thus increasing longevity. It has been found that the alignment of the flighting  82  and  96  can either be in a position in which it is aligned or the other position in which it is 180 degrees out of phase. Experimentation has shown that this does not significantly affect flow of grain material through the auger assembly. Furthermore, an additional number of projections may be provided to further reduce free movement upon initial engagement. 
         [0032]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.