Abstract:
A positive operating combine unloading discharge door which operates independent of the presence of grain in the unloading tube and is attached to the unloading tube to minimize opposition and obstruction to grain flow and completely cover the open end of the unloading tube when the unloading cycle is complete to minimize or eliminate grain loss due to grain dribble.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates generally to an agricultural harvesting machine unloading discharge system, and more particularly, to an unloading discharge door arrangement which is positively controlled for opening and closing independent of grain presence or unloading auger operation, and which can be configured to provide a cohesive discharge stream of grain which is less susceptible to wind drift and other problems. 
       BACKGROUND ART 
       [0002]    The unloading tube on a combine harvester is comprised of a cylindrical housing, which encloses an auger. This tube is pivotally attached to the combine so as to allow it to swing out to a deployed operational position substantially normal to the direction of travel and extending upwardly for unloading, and swing into a more level, stowed position supported by its saddle, so as to extend rearwardly substantially parallel to the direction of travel the remainder of the time. The enclosed auger has helical flighting that when the auger is rotated causes grain to move generally longitudinally through the unloading tube. The discharge end of the tube is fitted with a discharge spout. As grain exits the spout, it falls to a separate vehicle for transport. 
         [0003]    Typically the unloading tube has a discharge outlet in connection with the discharge spout and an associated dribble door biased toward a closed position partially covering the discharge outlet. During operation of the auger, if present in sufficient quantity, the grain will be pushed by the auger against the dribble door to push the door open. However, when only a small amount of grain is present, which is inadequate to force the door open, this grain will only press against the closed door. 
         [0004]    A problem that can arise with usage of a spring loaded dribble door is that this grain remaining in the unloading tube is susceptible to discharge and loss at inappropriate times. For instance, the grain can slosh out over the top of the door, or it can force the door open, such as when the unloading tube is in the more level stowed position even with the auger not operating. This can occur, for instance as a result of a sudden acceleration of the combine or when traversing rough terrain, ditches and the like, and can leave a quantity or strip of grain on the ground. 
         [0005]    Another problem that can occur when using a spring loaded dribble door is that, by design, the spring will oppose the opening of the door and the discharge of grain. When smaller or irregular amounts of grain are conveyed by the auger towards the door, the door may only partially open or possibly open by varying amounts as the amount of grain varies. The resulting discharge stream may be irregular and/or varied as influenced by the quantity of grain present making it susceptible to wind drift, which can be generally defined as sideward movement of elements of the downward flow of grain resulting from forces exerted by wind thereagainst. Even small amounts of wind drift can be significant because the grain is often unloaded while the combine is moving while the receiving vehicle is being driven or towed in parallel with the combine over rough terrain or furrows making steering difficult. In instances such as environments such as the plains region of North America, winds can be quite strong and gusty. Often the operator of the receiving vehicle may attempt to position one side or the other of the receiving vehicle more beneath the spout such that, with wind drift, the stream of grain will be directed more to the center of the receiving vehicle. This is facilitated by a tighter, more cohesive discharge stream of grain. 
         [0006]    Reference in this regard, Reimer et al., U.S. Pat. No. 6,691,861, which discloses an auger discharge chute with a spring loaded dribble door that has been observed to suffer from at least some of the above problems. The Reimer discharge chute has a dribble door attached to the unloading tube discharge end by a hinge with a spring that biases the door to the upward or closed position. The force of the grain pushes and holds the door open during discharge operations. However, if the amount of grain being conveyed is varied or reduced, for instance, as the grain tank of the combine nears empty, the force generated by the grain against the door may be insufficient to hold the door fully open. This may result in the situation discussed above, such that the grain flow stream is influenced by the position of the door as well as the amount of grain present. Here, using a spring having sufficient force to reduce the amount of grain dribbling out when the auger is not operating, is disadvantageous. To counter the negative effects of the spring loaded door varying in position as a function of the spring force and the amount of grain present, the Reimer door is illustrated to be shortened and shaped as a spout which will likely facilitate grain flow thereover, but the variable position of the door will still have an influence on the flow path of the stream of grain, and additionally the shortened door means that the discharge outlet is not fully covered when the door is in a closed position, such that small amounts of grain can remain in the discharge outlet region of the tube and can urge the door open at inappropriate times as discussed above. Thus, when fully open, the Reimer dribble door may mating engage the chute and be removed from the flow of grain, but in any other position, the door may remain within the grain flow an influences the position, flow path, and other characteristics of the stream of grain. 
         [0007]    In addition, it appears from  FIGS. 1 and 4  of the Reimer patent that when the unloading door is open, it creates a V shaped groove in which grain can become lodged which may prevent the door from closing properly risking unintentional grain loss. 
         [0008]    As another observed shortcoming of some known unloading tube constructions, they may include support ribs or struts which extend through the internal passage of the unloading tube from the wall of the unloading tube transversely through the grain flow region to the endmost bearing supporting the auger, which ribs or struts may be positioned, oriented, and/or of sufficiently large sectional extent perpendicular to the direction of grain flow so as to have the effect of obstructing, splitting or dividing the grain flow to such an extent as to disrupt or split the stream of grain exiting from the discharge outlet, so as to be less cohesive, and thus more susceptible to wind drift and other problems. 
         [0009]    Therefore what is sought is a discharge door arrangement for an unloading tube that overcomes one or more of the problems set forth above, including more positive operation to facilitate emptying of grain from the tube, and holding the door closed when the unloading tube is not in use. The arrangement can further include struts supporting the endmost auger bearing oriented to be only minimally obstructive such that a more cohesive stream of grain can be directed to the transport vehicle. 
       SUMMARY OF THE INVENTION 
       [0010]    What is disclosed is an unloading tube discharge system for a combine which overcomes one or more of the problems set forth above including more positive operation to facilitate emptying of grain from the tube, and holding the door closed when the unloading tube is not in use. The arrangement can further include struts supporting the endmost auger bearing oriented to be only minimally obstructive such that a more cohesive stream of grain is achieved. 
         [0011]    According to a preferred aspect of the invention, the unloading tube discharge system is used with a cylindrical shaped unloading tube defining an internal passage in connection with a discharge outlet at an end of the tube, a helical auger operable for conveying grain through the internal passage of the tube and discharging the grain through the discharge outlet as a stream of grain along a flow path. The invention includes a door sized and shaped, most preferably, for covering the unloading tube discharge outlet, the door being pivotally attached to the unloading tube adjacent the discharge outlet, so as to be pivotally movable between a closed position covering the discharge outlet preventing grain loss through inadvertent or unintentional opening and an open position uncovering the discharge outlet. A discharge spout is preferably connected to the tube adjacent to the discharge outlet of the unloading tube. The invention include an actuator in connection with the door and selectively operable for positively moving the door to the open position and to the closed position independent of presence of grain within the internal passage of the tube. 
         [0012]    In another preferred aspect of the invention the door is attached to the unloading tube in a manner such that, when moved to the open position the door is located beneath the grain flow path so as not to obstruct, interfere with, influence, or oppose the flow of the stream of grain. An advantage is that the grain stream is not effected by a varying door position resulting in a more cohesive and predictable grain flow. Even when only small amounts of grain are being discharged, such as when the grain tank is nearly empty, smaller amounts of grain that fall onto the door will be carried by the door to its outermost edge, which is more outwardly from the discharge outlet compared to a shorter dribble type door. 
         [0013]    As a further aspect of the invention, the cylindrical unloading tube includes a circumferential edge bounding the discharge outlet, the edge including an upper portion and a lower portion, the upper portion extending longitudinally outwardly of the lower portion. 
         [0014]    According to yet another a preferred aspect of the invention, the helical auger includes a helical flight extending around an auger shaft supported for rotation about a central longitudinal axis, the flight having an auger surface oriented at an acute angle to the auger shaft, and a bearing supporting the shaft adjacent to the discharge outlet, the bearing being supported by one or more support arms having a thinnest sectional extent in a direction substantially parallel to the auger surface so as to aligned with the direction of grain for to minimize splitting or division of the stream of grain. 
         [0015]    Preferred apparatus of the system include, but are not limited to, fluid controlled actuators and electrically powered actuators. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a simplified rear view of a combine unloading grain to a transport vehicle; 
           [0017]      FIG. 2  is a simplified perspective view illustrating a discharge end of an unloading tube of the combine of  FIG. 1  with a discharge spout positioned for installation thereon and a discharge door of the present invention; 
           [0018]      FIG. 3A  is a simplified side view of the unloading tube, with discharge door arrangement of the invention installed thereon and illustrated in a positively closed position, with a helical auger within the tube shown in dotted lines along with a discharge spout installed on the discharge tube; 
           [0019]      FIG. 3B  is a simplified side view of the unloading tube, with discharge door arrangement of the invention illustrated in a positively open position, with the auger and discharge spout illustrated in dotted lines, and a stream of grain being discharged from the discharge outlet and through the spout along a flow path above the open door; 
           [0020]      FIG. 4  is a perspective view of the discharge end of the tube looking upwardly through a discharge end of the spout with the discharge door of the invention open to reveal an auger within the unloading tube; 
           [0021]      FIG. 5  is a simplified schematic top view of the unloading tube with the top portion thereof removed to show the auger and elements supporting the end of the auger in the tube; 
           [0022]      FIG. 6A  is a simplified schematic top view of an auger of the unloading tube supported by a prior art strut, illustrating the disruption to a flow of grain conveyed by the auger resulting from the orientation of the strut; and 
           [0023]      FIG. 6B  is a simplified schematic top view of the auger of the unloading tube supported by a strut, illustrating a reduction in the disruption to a flow of grain conveyed by the auger resulting from the orientation of the strut according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    The invention will be described with reference to  FIGS. 1 ,  2 ,  3 A,  3 B,  4 ,  5 ,  6 A, and  6 B wherein like numbers refer to like parts,  FIG. 1  shows a rear view of a combine  10  unloading grain to a transport vehicle  12  through a cylindrical shaped unloading tube  14  and a spout  16 . Grain is moved from combine  10  through unloading tube  14  by an auger  18  (see  FIGS. 3A and 3B ) in a well known manner. 
         [0025]    According to the invention, a discharge door  20  sized and shaped to cover discharge outlet  22 , is pivotally attached adjacent discharge outlet  22 , so as to be pivotally movable from a closed position covering discharge outlet  22  to an open position uncovering discharge outlet  22  as shown in  FIGS. 2 ,  3 A,  3 B, and  4 . Discharge spout  16  may connect to tube  14  adjacent to discharge outlet  22  accommodating door  20  and its attachment to tube  14  as shown in  FIG. 2 . Spout  16  may be held in place with one or more hose clamps  26  or the like. In a preferred embodiment of the invention, door  20  is mounted for pivotal movement relative to discharge outlet  22  between a closed position ( FIG. 3A ) and an open position ( FIG. 3B ), with a hinge  24 , or the like, and is positively controlled to the closed and open positions. Preferred apparatus for positively controlling movements of door  20  include, but are not limited to, an electrically powered actuator  28  as shown in  FIG. 2  or fluid controlled actuator  30  as shown in  FIGS. 3A and 3B . It is important to note that, because of positive control, door  20  may be opened independent of the presence of grain in tube  14 . That is, the present invention does not require the force of grain acting against the door to effect opening thereof, or the absence of grain to effect closing thereof. 
         [0026]    As seen in  FIGS. 2 and 3B , door  20  may be attached on the periphery of unloading tube  14  near discharge outlet  22 , so that opening door  20  may create a separation  21  between door  20  and tube  14  at discharge outlet  22 . As door  20  closes, grain that may remain on door  20  will discharge through spout  16  or be carried back into tube  14 . Because no ledge is created by a connection point between door  20  and tube  14  near discharge outlet  22 , it is unlikely that grain will lodge in separation  21  to inhibit the closing of door  20 . 
         [0027]    When door  20  is in the closed position, it is positively held in that position by actuator  28   30  as shown in  FIGS. 2 and 3A , and substantially covers discharge outlet  22  virtually eliminating the possibility of grain dribble or slosh from tube  14 . When positively controlled to be in its open position, as shown in  FIG. 3B , door  20  uncovers discharge outlet  22  and is positioned outside of a discharging stream of grain  25  along a flow path  31 . Also, when door  20  is positively held in its open position, the force created when auger  18  moves grain through unloading tube  14  is not required in any way to open door  20  and therefore is not dissipated by pushing and holding open a spring biased door, as is required in the prior art discussed above. As a result, the grain is allowed to flow unopposed, as if no door was present, such that it is discharged in a cohesive, predictable stream  25  along flow path  31 . Although shown attached to tube  14  near outlet  22 , it is contemplated according to the invention that door  20  could alternatively be mounted within spout  16  and perform in essentially the same manner. 
         [0028]    Another aspect of the invention related to discharge outlet  22  can be seen in  FIG. 2 . A circumferential edge bounding discharge outlet  22  may be slanted diagonally so that an upper portion  27  of unloading tube  14  extends longitudinally outwardly of a lower portion  29  of tube  14 . This arrangement may facilitate attachment of door  20  in the above described manner. In addition, as illustrated in  FIG. 1 , this arrangement may extend the reach of unloading tube  14  by a distance  49  as upper portion  27  extends further into spout  16  than lower portion  29 . 
         [0029]    Another feature of the invention that reduces obstruction to grain flow can be seen in a simplified schematic top view of the unloading tube  14  as shown in  FIG. 5 . Helical auger  18  includes a helical flight  40  having an auger surface  41  extending around an auger shaft  42  which is supported adjacent to discharge outlet  22  for rotation by a bearing (not shown) about a central longitudinal axis  43 . The bearing is supported by at least one strut  32 ,  34 ,  36  having a thinnest sectional extent  44  in a direction substantially parallel to auger surface  41 , which is parallel to the grain flow as shown in  FIGS. 5 and 6B  for reducing division of grain stream  25 . 
         [0030]    This effect can be understood with reference to  FIGS. 6A and 6B .  FIG. 6A  shows a typical prior art attaching member  32   a  situated parallel to longitudinal axis  43  of auger shaft  42 . When grain is urged forward by auger surface  41 , it approaches a prior art strut  32   a  at an angle. Discharging grain impacts sectional extents  44  and  46  of strut  32   a  causing a separation  50  in grain stream  25  which is relatively wide.  FIG. 6B  shows strut  32  of the present invention situated so that only its thinnest extent  44  is parallel to auger surface  41 . In this case, when the grain is urged forward by auger surface  41 , strut  32  is generally parallel to grain stream  25  minimizing separation to no more that extent  44  which is smaller than separation  50 . Notice also in  FIG. 6B , that strut  32  may be narrowed at a leading end  48  to gradually interrupt the discharging grain, possibly resulting in even less separation in grain stream  25 . Struts  34 ,  36  may also be aligned with grain stream  25  in a similar manner. Thus when grain discharges past at least one strut  32 ,  34 ,  36 , attached in an orientation so as to reduce separation, through discharge outlet  22  without resistance or interference from positively controlled door  20 , discharge grain stream  25  may be tighter, stronger and less susceptible to loss due to wind. 
         [0031]    Referring to  FIGS. 2 ,  3 B and  4 , it should be noted that the bottom region of spout  16  can be shaped to accommodate and receive door  20  when in the open position so as to be located beneath flow path  31 , and will have a suitable opening for passage of actuator  28 ,  30  to door  20 . Another advantage of this arrangement, at times when only a minimal amount of grain is being discharged and fall onto door  20 , it will be allowed to smoothly transition onto the bottom outer surface of spout  16  and easily exit. 
         [0032]    It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.