Abstract:
Dribble control apparatus including a dribble control door hingedly or pivotally connected to an upper portion of a tube of a grain unloading conveyor. The door has a closed position covering a discharge opening of the tube for preventing grain dribbling, and an open position. The door has a shape which positions a center of gravity of the door for urging the door toward the closed position, including when closed, and which enables the door to support itself in the open position on a stream of grain flowing from the discharge opening with at least a substantial portion of the door spaced above the grain stream, while influencing or controlling an outward extent and direction of the flow of the stream.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 60/933,697, filed Jun. 7, 2007. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a dribble door for the discharge opening of a grain unloader conveyor tube of a combine harvester, and more particularly, a dribble door configured so as to be supportable on a stream of grain discharged through a discharge opening of the conveyor while only minimally contacting the grain stream to influence or control the extent and direction of outflow of at least a portion of the stream, and which is shaped and oriented so as to be urged by its center of gravity toward a closed position covering at least the lower portion of the discharge opening, for preventing dribble. 
       BACKGROUND ART 
       [0003]    U.S. Provisional Application No. 60/933,697, filed Jun. 7, 2007, is hereby incorporated by reference in its entirety. 
         [0004]    During an unload cycle for a combine harvester, the unloader conveyor (typically a helical auger) is operated to move grain from the grain tank of the harvester to another tank or receptacle, such as on a truck or wagon. A well-known problem associated with unloader conveyors of combine harvesters, is that grain that remains in the unloader conveyor tube after an unload cycle, can continue to dribble out of the discharge opening, as the unloader conveyor is swung to its transport position, and with the conveyor in the transport position, particularly as the harvester is moved over rough terrain, up hills, and the like. 
         [0005]    A variety of dribble control doors have been utilized in attempts to reduce the dribble problem. Reference in this regard, Reimer et al. U.S. Pat. No. 6,691,861 issued to Deere &amp; Company, which discloses a dribble door pivotally mounted to a bottom periphery of an unloader conveyor tube, for preventing dribble when in a raised position, and which has a spout like shape to allow unobstructed grain flow when in a lowered position. A spring biases the door toward the raised position. However, an observed shortcoming of dribble doors such as this which are pivotable at the bottom, is that, absent some kind of powered actuator, grain pressure is required to maintain the door in the lowered position, and as the discharged grain flow tapers off, the spring force can prematurely lift the door so as to trap an undesirable amount of grain in the unloader tube. And, if a large quantity of grain remains, and the spring force is low or weak, the door can be opened by jarring and the like, so as to dribble grain. 
         [0006]    Thus, what is sought is a dribble control door which overcomes one or more of the problems, shortcomings, and/or disadvantages, set forth above. 
       SUMMARY OF THE INVENTION 
       [0007]    What is disclosed, is a dribble control door which overcomes one or more of the problems, shortcomings, and/or disadvantages, set forth above. 
         [0008]    According to one preferred aspect of the invention, a grain unloading conveyer for a combine harvester includes a tube having an interior passage containing a helical auger rotatable for conveying grain therethrough, and an outer end portion including a discharge opening in connection with the interior passage and through which the grain is discharged by the auger when rotated. A dribble control door includes an upper door portion and a lower door portion, the upper door portion having an upper peripheral portion pivotally mounted in or adjacent to an upper peripheral portion of the discharge opening. The door is pivotable between a closed position wherein the lower door portion covers at least a lower portion of the discharge opening for preventing dribbling of grain therefrom, and an open position extending outwardly from the opening. 
         [0009]    Additionally, the upper door portion and the lower door portion are angularly related, such that when the door is in the closed position, the upper door portion will extend downwardly and outwardly to about a vertical middle region of the opening and the lower door portion will extend downwardly from the upper door portion and inwardly to contact a lower peripheral portion of the tube to cover the lower portion of the opening. 
         [0010]    As an attendant advantage of the above construction, the center of gravity of the door is positioned such that at least a substantial portion of the weight of the door will act to urge the door toward the closed position, in contrast to the case wherein the door is pivoted at the bottom. This feature is advantageous alone, or in conjunction with a biasing element, for instance, but not limited to, a spring, for automatically closing the door as the adjacent portion of the interior passage of the conveyor tube is emptied, or if the conveyor is turned off while still containing grain as can occur when unloading on the go while harvesting. And, particularly advantageous in this latter instance, the closing force provided by gravity will increase with the tilt of the tube upwardly toward the outer end. 
         [0011]    As another preferred aspect of the invention, a latch, which can be, for instance, a mechanical latch, or magnetic, can be provided for releasably holding the door in the closed position. 
         [0012]    As still another preferred aspect of the invention, the lower door portion includes a lowermost sidewardly extending lip configured for holding the door in the open position on a stream of grain discharged from the discharge opening, mostly away from the stream of grain, while directing at least an outermost portion of the stream downwardly. As another aspect, the lip can include a generally flat surface positioned and oriented to abut the lower peripheral portion of the tube when the door is in the closed position, and configured to ride on a stream of grain discharged from the opening for holding the door in the open position. Further, the flat surface can be straight, so as to impart a flat shape on an outermost periphery of a stream of grain discharged from the discharge opening. Still further, the lip can have a sideward extent greater than a sideward extent of the lower peripheral portion of the tube, so as to extend beyond opposite sides of the tube, which is advantageous and so as to encompass a sideward extent of a stream of grain discharged from the discharge opening, for guiding and directing the stream downwardly across up to its entire sideward extent. 
         [0013]    According to another preferred aspect of the invention, the tube will have middle peripheral portions bounding opposite sides of the opening, respectively, having shapes which bulge outwardly in a direction of grain discharge from the opening. And, the door will have an angular shaped middle portion which at least generally conforms to the shapes of the middle peripheral portions so as to be located in abutting relation thereto when the door is in the closed position, and so as to be located at least substantially above a stream of grain supporting the door in the open position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a rear end view of a combine showing grain unloading from an unloader conveyor into a truck, illustrating a dribble control door of the invention in dotted lines within a grain discharge boot on an outer end of the conveyor; 
           [0015]      FIG. 2  is a fragmentary side view of the conveyor, with a discharge boot and other aspects thereof illustrated in dotted lines, and the dribble control door in a closed position; 
           [0016]      FIG. 3  is another fragmentary side view of the conveyor, with the discharge boot thereof illustrated in dotted lines, and the dribble control door in an open position supported on a stream of grain illustrated being discharged by the conveyor; 
           [0017]      FIG. 4  is an end in view of the conveyor, with the dribble control door in the closed position; 
           [0018]      FIG. 5  is a perspective view of the conveyor with the dribble control door in the closed position; 
           [0019]      FIG. 6  is a perspective view of the conveyor with the dribble control door illustrated in an open position; 
           [0020]      FIG. 7  is a side sectional view of the conveyor tilted at a representative unloading orientation, illustrating a small stream of grain being discharged supporting the dribble control door in a partially open position; 
           [0021]      FIG. 8  is another side sectional view of the conveyor at the Representative unloading orientation, illustrating the dribble control door in the closed position containing a large quantity of grain within an interior passage of the conveyor, representative of conditions after unloading on the go; 
           [0022]      FIG. 9  is another side sectional view of the conveyor, at a representative transport orientation, illustrating the dribble control door in the closed position containing a small quantity of grain within the interior passage of the conveyor; 
           [0023]      FIG. 10  is a fragmentary side view of an unloader conveyor with a discharge boot and other aspects of the conveyor illustrated in dotted lines, and including another embodiment of a dribble control door of the invention in a closed position; and 
           [0024]      FIG. 11  is another fragmentary side view of the conveyor of  FIG. 10 , illustrating the door supported in an open position by a stream of grain being discharged by the conveyor. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Referring now to  FIG. 1 , a combine harvester  20  is illustrated, including an unloader conveyor  22  transversely extending and deployed outwardly in an unloading position as it unloads grain  24  through a discharge boot  26  into a grain truck  28 . This unloading operation can occur as harvester  20  and truck  28  are moving, which is referred to as unloading “on the go”, or stationary. At the end of the unloading operation, unloader conveyor  22  will be pivoted to a rearwardly directed transport position, extending along the adjacent side of harvester  20 . It can be noted here, that truck  28  is located a substantial distance to the side of harvester  20 , which is desired to avoid the possibility of contact with a header  30  mounted on the front of harvester  20 , particularly when unloading on the go. It should also be noted that conveyor  22 , when in the unloading position illustrated, will typically be tilted up toward the outer end thereof, at a greater angle, compared to when in the transport position, as additional height is often required to clear the top of the grain receptacle, here illustrated by truck  28 . Additionally, it should be noted that when unloading grain in a manner such as illustrated, it is desirable to have a capability for at least somewhat controlling the trajectory of the outflowing grain, as it falls toward the receptacle, to limit the possibility of loss and control the location of deposition within the receptacle. Still further, upon cessation of the unloading operation, whether a substantial quantity of grain remains in conveyor  22 , as would often be the instance when unloading on the go, or only a small quantity of grain remains, it is highly desirable and sought, to control inadvertent dribbling of grain from the end of the conveyor, for a variety of reasons, including for reducing grain loss and emergence of volunteer crops. 
         [0026]    Referring also to  FIGS. 2 ,  3 ,  4 ,  5  and  6 , outer end  32  of conveyor  22  is illustrated. Conveyor  22  includes an elongate tube  34  defining and enclosing an interior passage  36  containing an elongate helical auger  38 , supported by bearings for rotation about its longitudinal axis for conveying grain through passage  36 , in a well-known manner. Auger  38  is rotated by a drive on harvester  20 , also in the well known manner. A bearing  40  supporting the outer end of auger  38  is illustrated supported by bearing support structure  42 , which can comprise, for instance, one or more struts, attached to an upper interior portion of tube  34  and extending downwardly into a center region thereof. Tube  34  additionally includes a circumferential periphery  44  extending around and defining an outwardly facing discharge opening  46  on outer end  32 , through which a stream of grain, illustrated by stream  24 , is discharged, as effected by the rotation of auger  38 . Here, it should be noted that in  FIGS. 1 ,  2  and  3 , the grain is illustrated as being discharged through a boot  26 , which is intended to be representative of a wide variety of different boot configurations that can be used on the end of an unloader conveyor, such as conveyor  22 , the boot being absent from  FIGS. 4 ,  5  and  6 , to better show a dribble control door  48  of the invention. 
         [0027]    Referring also to  FIGS. 7 ,  8  and  9 , dribble control door  48  constructed and operable according to the teachings of the present invention, includes an upper door portion  50  and a lower door portion  52 , upper door portion  50  having an upper peripheral portion pivotally mounted in or adjacent to an upper peripheral portion of discharge opening  46 . Door  48  is pivotable between a closed position ( FIGS. 2 ,  4 ,  5 ,  8  and  9 ) wherein lower door portion  52  covers at least a lower portion of discharge opening  46  for preventing dribbling of grain therefrom, and an open position ( FIGS. 1 ,  3 ,  6 , and  7  (partially open)) extending outwardly from opening  46 . A preferred location of the pivotal connection of upper door portion  50  is spaced inwardly of discharge opening  46 , and upper door portion  50  and lower door portion  52  are preferably angularly related at a middle angled region  54 , such that when the door is in the closed position, upper door portion  50  will extend downwardly and outwardly through opening  46  to about a vertical middle region of opening  46 , and lower door portion  52  will extend downwardly from upper door portion  50  and inwardly, but still outwardly of opening  46  and the pivotal connection, to contact a lower portion of periphery  44  of tube  34  to cover the lower portion of opening  46 , to prevent dribbling. 
         [0028]    This configuration is advantageous, as it locates a center of gravity of door  48 , which for this door configuration will be about coincident with angled region  54 , above and outwardly of opening  46 , such that door  48 , at least when open, and preferably also when closed, or nearly closed, will be urged by its weight, denoted by arrow W in  FIG. 7 , in the form of a moment about the pivotal connection to tube  34 , to pivot or rotate toward the closed position, to provide a self or automatic closing capability in the absence of grain being forced thereagainst by the operation of auger  38 . This moment and self-closing capability would be illustrated by counterclockwise pivotal movement of door  48  in the illustrations. This automatic closing capability is also facilitated by the typical more upward and outwardly tilted orientation of conveyor  22  when in the unloading position, as illustrated in  FIGS. 1 ,  2 ,  3 ,  7  and  8 , which places the center of gravity and thus most of the weight of door  48 , more advantageously for urging the door toward the closed position, and which also places the lower portion of circumferential periphery  44  more outwardly relative to the pivotal connection of the door to tube  34 . Further in this regard, this helps to offset the effect on the operation of the door, of a typical beveled configuration of circumferential periphery  44  in regards to closure of the door, which bevel is utilized for facilitating desired grain flow characteristics. Thus, it can be observed that upper door portion  50  is generally located within discharge opening  46 , whereas lower door portion  52  is located outwardly of opening  46 , including when door  48  is closed, and further, lower portion  52  will be in abutment with the lower portion of circumferential periphery  44 , when the door is closed. 
         [0029]    Upper door portion  50  is preferably supported in the above-described position for the above discussed advantageous positioning of door  48  and pivotal movement thereof, by a pivot  56 , which can be, for instance, a hinge or other suitable pinned connection. 
         [0030]    Additionally, pivot  56  can be configured to comprise a self-closing pivot joint utilizing a biasing element  72  ( FIG. 7 ), such as, but not limited to, a spring such as found on a common, commercially available self-closing hinge, for urging door  48  toward its closed position, or, a separate biasing element or other suitable device could be used. 
         [0031]    As an additional feature, a latch  60  is preferably provided adjacent the lower portion of discharge opening  46 , or at other suitable location, for releasably holding door  48  in the closed position. Here, latch  60  is configured as a magnetic latch including two magnets operable for magnetically holding a lowermost portion  58  of lower door portion  52  against the lowermost portion of circumferential periphery  44  of tube  34 , such that lower door portion  52  is held in abutment with the larger lower portion of periphery  44 , to prevent grain dribble. The magnets are selected so as to release door  48  when a force is exerted against the inner surface thereof, by operation of auger  38  to drive grain, represented by grain  66 , against the door. 
         [0032]    Here, it should be noted that upon cessation of operation of auger  38  while unloading on the go, a substantial amount of grain may be present in tube  34  adjacent to opening  46  ( FIG. 8 ), or, virtually no grain may be present ( FIG. 9 ), such as when the grain tank of harvester  20  is emptied by the unloading operation. It should also be noted that any remaining grain, as well as door  48 , may be subject to significant jarring, acceleration forces, etc., due to operation and movements of harvester  20 , and that the orientation (e.g., tilt) of conveyor  22  can vary widely. Thus it should be understood that for satisfactory operation of door  48  under the range of foreseeable conditions, it is desired for door  48  to have a self closing capability sufficient for containing and preventing grain dribbling under the most adverse of those conditions, yet which will allow door  48  to open when appropriate, that is, when operation of auger  38  to force grain against door  48 , is commenced. Here, this capability is provided by the configuration and orientation of door  48 , in combination with the provision of a latch  60  including two magnets selected so as to have sufficient strength for this purpose. 
         [0033]    Referring more particularly to  FIGS. 4 and 5 , as another desirable feature of door  48 , it can be observed that lower door portion  52  preferably has a greater sideward extent, denoted by arrow A, between opposite side portions  62  and  64  thereof, compared to a sideward extent, denoted by arrow B, of the lower portion of opening  46 . This is advantageous, as it facilitates the abutment of lower door portion  52  with the lower portion of circumferential periphery  44  around the lower region of opening  46 . It should also be noted that this greater extent of the lower door portion extends downwardly to lowermost portion  58 . 
         [0034]    Additionally, lowermost portion  58  of door  48  is preferably configured so as to form a generally horizontally extending lip, which is preferably flat and/or straight, but which can have other shapes, as desired or required for a particular application. This is an advantageous feature, as when a stream of grain, such as stream  24  is being discharged through opening  46 , lowermost portion  58  will essentially ride on an upper region of the stream, to support door  48  in the open position, as illustrated in  FIGS. 3 and 7 . As another advantage of this configuration, the weight of door  48 , and any spring force present acting to urge door  48  downwardly, will serve to at least partially influence or direct or guide the outer extent of flow  24  more downwardly, toward a receiving container, such as truck  28  ( FIG. 1 ). This capability can be provided alone, or in combination with a downward directing capability of an accompanying discharge boot, such as boot  26  illustrated. Here, the wider extent of lowermost portion  58  will be advantageous, as it is anticipated under some conditions, that the grain stream will fan out or widen after leaving opening  46 . As another advantage of this in combination with the shape of door  48 , most of door  48  will be spaced above stream  24  of the grain. 
         [0035]    As still another advantage of the angular shape of door  48 , it can be observed in numerous of the figures that this also accommodates and provides a concavity or space for the end of auger  38  and bearing  40 . In this regard, although door  48  has a generally L shape profile when viewed from the side, it should be recognized and understood that other shapes that provide a concave inner surface, as well as other shapes, such as a more flat shape, could likewise be used in the present invention. 
         [0036]    Referring also to  FIGS. 10 and 11  in this regard, conveyor  22  is shown including another dribble control door  68  constructed and operable according to the teachings of the present invention, like parts of door  68  and door  48  being identified by like numerals. Conveyor  22  generally includes an auger  38  rotatable for discharging a stream of grain  24  through discharge opening  46 , in the above described manner. Here, it can be observed that door  68  has a smoother concave C shaped profile when viewed from the side, an upper door portion  50 , a lower door portion  52 , and a middle or angular region  54  therebetween. Upper door portion  50  is pivotally connected, as before, by a pivot  56 , to bearing support  42 . And, a lowermost portion  58  of the door includes or is shaped as a lip, engageable with a latch  60  for holding the door in the closed position, and for supporting the door on a stream  24  of grain being discharged from conveyor  22 , again, as explained above. As another difference, conveyor  22  includes a circumferential periphery  70  extending around and defining a discharge opening  46 , having peripheral side portions  74 , which extend outwardly a greater distance that upper and lower peripheral portions, and so as to at least substantially conform in shape with the C shape of door  68 , to provide adequate abutment and closure between door  68  and periphery  70  to prevent dribbling. Again, the concavity created by the shape of door  68  is advantageous as it accommodates the end of auger  38  and its supporting bearing. Also, lowermost portion  58  will preferably be flat, to provide the above described advantages. 
         [0037]    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 embodiments 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.