Abstract:
A vertical spreader of a combine harvester has a reflexing deflector elements hingedly secured to a flow guide element, and the deflectors are reinforced by over-center linkage so as to automatically hinge in response to the positive pressure of an oversized wad of crop residue and/or by loss of impeller speed. The wad is thereby discarded, and the deflector elements thereafter return to the original position held prior to hinging.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates generally to an agricultural combine and to a vertical spreader therefor, which is operable for discharging a flow of straw and/or other crop residue from the combine. More particularly, this invention relates to deflector plates located, generally, intermediately adjacent to counter-rotating impellers within the vertical spreaders. The deflector plates serve to receive and to direct the flow of crop residue from the spreader. 
       BACKGROUND ART 
       [0002]    In the past, combines have typically included, or had associated therewith, crop residue spreaders for discarding (onto the field from which the crop is being harvested) straw, chaff, and other residue separated while harvesting the crop. Some combines have even employed a special spreader solely for spreading chaff residue. Earlier spreaders, in many instances, exhibited uneven distribution of the crop residue resulting in a heavier concentration being distributed at the center of the overall swath, but a lighter concentration being distributed sidewardly. Such uneven distribution resulted in various problems including but not limited to, difficulty in passing tillage tools through residue clumps on the field, uneven insulation of the field (resulting in uneven field warming and thawing), uneven crop emergence during subsequent planting seasons, and increased infestations of rodents and insects inhabiting the uneven crop residuals. Consequently, a variety of devices were developed to enable more desirable flow-patterns from crop residue spreaders, vis-á-vis improved flow guide elements. 
         [0003]    However, until now, there has been no accommodation for handling wads of crop material, caught in the residue spreader, prior to discharge. For example, weeds, cockleburs, corncobs, roots, chunks of bean stalks, which tend to be more supple, are less likely to be chopped up during threshing. Such materials can occasionally agglomerate or wad up, and stall the motor or otherwise cause excessive overloading. This leads to premature damage to impeller tips, excessive wear at the point of discharge, and distorted discharge flow patterns, and stalling from plugging up of the entire spreader with crop residue, beginning at the impellers. Correcting this problem without weakening the structural integrity of the guide elements used for flow distribution, would result in energy savings, e.g., by enabling use of lower horsepower motors, greater fuel efficiency and/or more efficient lubrication protocols. Additional savings, inuring from the improved lifetime of the moving parts, would be a welcomed advancement in combine harvester design. 
         [0004]    Although prior art flow guide elements have been adjustable, the deflector plates which extend from the flow guides have been immovable, during discharge, except by command of the operator, when moving the flow guides and deflectors as a single unit. Uniting the movements of the guide element and deflector elements was believed essential in order to achieve the predetermined flow distribution patterns for the discarded crop residue, even though wads of residue may be entrapped therebetween. 
         [0005]    Accordingly, there has been a longstanding need for a means of dislodging the wadded residue from the crop residue spreader, without adversely distorting the predetermined discharge patterns, and without having to manually dislodge such wads. 
       SUMMARY OF THE INVENTION 
       [0006]    I have herein disclosed, in satisfaction of a longfelt need in my industry, vertical spreaders, having reflexing deflector plates. The plates are united with the guide element and rigidly affixed, except when a predetermined threshold force, of agglomerating, wedged, or wadded residue exerts itself against the surface of the deflector plates. The deflector plates, as a direct consequence of the threshold force, will swing, spring, flex, hinge or move away from the central guide element, increasing the deflector&#39;s clearance or distance from the impeller, discarding the wadded material, and thereafter the deflector plates will immediately return to their original fixed positions integral with the guide element. 
         [0007]    Each deflector plate is preferably hinged at its interface with a flow guide element, and the deflector plates are preferably spring-loaded via over-center linkage elements. The linkage elements inhibit the hinged deflector plates from freely moving downwardly from the flow guide element, except in response to the threshold force of a wad clump or oversized particle of crop residue. As a consequence of the linkage&#39;s construction and spring-like bias, a reflex action, automatically returns the plate to and stops it at, its original position, leaving a sufficient clearance to allow the generally adjacent impeller to rotate unimpededly. The over-center linkages may comprise mechanical springs, hydraulic pistons, or other responsive devices, including, for example, electronic activators and sensors triggering the deflector to hinge away under positive pressure while discarding the wad, but return instantly thereafter in controlled fashion to its original position. The following detailed description, preferred embodiments, and the drawings will illustrate the invention and give rise to contemplated embodiments of the invention, including alternative configurations of components, such as flow guide elements, couplings, connectors, adjustable mechanisms, springs, sensors, stops, deflector plates, leaf springs as substitutes for or in addition to hinges, all of which are within contemplation of this invention. Further and more complete understanding can be derived from or will become apparent from these details and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a simplified fragmentary side view of a representative combine harvester, having a crop residue distribution system including a dual impeller spreader at the bottom of its rear end; 
           [0009]      FIG. 2  is a direct view of the spreader&#39;s dual counter-rotating impellers and intermediate flow guide elements as seen from the rear of the combine harvester; 
           [0010]      FIG. 3  is a direct partial view of the left impeller and an associated flexing deflector element being reinforced against the intermediate flow guide element, by a spring-loaded, piston-type, over-center linkage; 
           [0011]      FIG. 4  is a disassembled view of the spring-loaded piston-type, over-center linkage of  FIG. 3 ; 
           [0012]      FIG. 5  is a direct partial view of the left impeller and an associated flexing deflector element, being reinforced against the flow guide element by a spring-loaded, rocker-type, over-center linkage; 
           [0013]      FIG. 6  is a disassembled perspective view of the rocker-type, over-center linkage of  FIG. 5 ; 
           [0014]      FIG. 7  is a diagram of the flexing deflector element and over-center linkage in  FIG. 5  at the resting or home position; and 
           [0015]      FIG. 8  is a diagram of the flexing deflector element and over-center linkage of  FIG. 5  when in the flexed position in response to the positive pressure of, for example, a wad of crop material to be discarded. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    The preferred embodiments of the present invention are depicted in the drawings, wherein like numerals refer to like items, and wherein prime designations in conjunction with a numeral, for example,  38 ′ and  38 ″, identify variations of the element designated by the numeral. 
         [0017]      FIG. 1  depicts a rear end  20  of a self-propelled combine harvester  10 , including a vertical crop residue spreader  24  operable for spreading straw, stalks, or other refuge, all referred to as crop residue  32  that has been separated from the grain of the crops by a threshing mechanism  30  located forwardly of rear end  20 . The crop residue  32  is propelled rearwardly by rotating beaters  31  as residue  32  exits from the threshing mechanism  30 . In the case of harvesting, for example, wheat, the grain and chaff mixture  33 , unlike crop residue  32 , fall onto the chaffer  38 ′ and the sieve  38 ″ of the cleaning system  38 . The clean grain  34  is sifted from the mixture of grain and chaff  33 , and falls onto the auger  35 , while the lighter material or chaff  36 , which remains after sifting the mixture  33 , is blown by a fan (not shown) back into the spreader  24  along with the heavier straw-type crop residue  32 . 
         [0018]    Referring now to  FIG. 2 , two streams comprising chaff residue  36  and straw-type crop residue  32 , flow into the top of spreader  24  and are propelled by the counter-rotating impellers  25  and  29  into predetermined rotational directions A and B, which rotations also define the circumferential profiles of the impellers  25  and  29  and the attendant circumferential flow paths of the crop residue  32  and  36 . The circumferentially flowing crop residues revolve at rates of speed equal to or greater than the inlet rate of speed of the residues  32  and  36 , but nevertheless may agglomerate into or contain, for example, wad  60 , which may stall or strain, for example, impeller  25  or its attendant motor (not shown). Flow guide element portion  26  of spreader  24  abuts against the back sheet  28 . The flow guide element  26  is preferably constructed of rigid construction material, such as sheet metal, or rigid plastic, suitable for receiving flowing crop material. Laterally extending deflector elements  50  (which may be sheets, plates, ribs, forked-members or the like) project outwardly from the flow guide  26  in arcuate profiles to match the circumferential profiles of the impellers  25  and  29 . Over-center piston-type spring linkages  27  are biased between yoke connections  41  and stop connections  40 , to reinforce the deflector element  50  against freely hinging at yoke  41  or at hinges  90 ′ or  90 ″, absent positive pressure at a threshold level. 
         [0019]    As illustrated in  FIG. 3 , the residue streams  32  and  36 , when propelled by impeller  25  rotating in direction A may gather into or contain a wad  60 . Wad  60 , rather than stalling impeller  25 , creates sufficient pressure to pivot deflector plate  50  downwardly, from hinge  90 , so as to increase the clearance between impeller  25  and plate  50 , and against the bias of spring element  51  on the over-center piston-type linkage  27 . Wad  60  is thereby discharged, after which deflector plate  50  returns back to its original position, by virtue of the spring  57  recoiling and returning piston-type linkage  27  to its original length. 
         [0020]    As may be seen in  FIG. 4 , spring  51  telescopically coils around piston element guide chamber  52  having a hollow bore  57  through its length until it abuts a stop end  53 . Stop end  53  hingedly connects at stop  40  so as to hinge about pin  54 , while being secured by presto pin  55 . Piston  56  provides piston-like action by sliding lengthwise within bore  57  of piston element guide  52 . Rod  56  sliding action is abutted at stop end  53  and its opposite end is hingedly secured at yoke support  41  by yoke  58 . Yoke  58  extends from its hinge at support  41  at one end, to a smaller end, fitting within a central bore in collar  59  which slideably receives piston rod  56 . Roll pin  60  hingedly secures yoke  58  to collar  59 . Pin  61  and presto pin  62  secure rod  56  slideably within collar  59 . 
         [0021]    In  FIGS. 5 ,  6  and  7 , an alternative over-center linkage  27 ′ may be employed which provides more structural support and is more secure than the piston-type over-center linkage  27  shown in  FIG. 4 . The linkage  27 ′ of  FIG. 5  is a two stroke hinged spring, which is under minimal tension. Its assembly can be more readily seen at  FIG. 6  wherein spring  70  is stretched between hinged centrally mounted rocker member  71  and rod  75  which fits through ears  72 . Carriage frame member  73  adds greater strength but also adds additional moving parts. Pin  74  allows rocker  71  and the carriage  73  and spring  70  to all move when plate  50  flexes from the pressure of wad  60  so as to increase the tension on spring  70 . Rocker member  71  is secured at two points including support bracket  76  by virtue of pin  77  and at carriage bracket support arm  78  through spacers  79  and  80  which rotatably receive pin  74 . Carriage frame member  73  is secured to the distributor  26  by bracket support  81  through which pin  75  extends for securing within ears  72 , the support member  81 . Presto pin  82  secures rod  83  enabling spring  70  to securely have tension and bias. 
         [0022]    The threshold pressure, under which the hinging or moving of the deflector plates is initiated, will vary depending upon the conditions of the harvested field and the types of residual clumps which are anticipated. The size of the springs, hinges, cams, rockers, yokes, etc. may also vary and such sizes are integrally coordinated to yield the desired threshold action. For example, a preferred range of threshold pressures is from 33 psi at 300 rpm impeller speed to about 130 psi at 800 rpm; but a range of 41 psi at 300 rpm to 108 psi at 800 rpm is particularly preferred. 
         [0023]    The threshold pressure is that pressure exerted within the spreader, and particularly on the deflector plates, at the point-in-time that wadded crop residue plugs up or stalls the impellers going at a particular speed, but prior to the occurrence of overly excessive damage. The faster the impellers are revolving, the greater the pressure will be at the point-in-time of stalling. For example, Table 1 below charts the ranges of threshold pressures (psi) at particular revolutions per minute (rpm), and provides a preferred threshold pressure within that range. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 Preferred 
                 Range Of Pressures 
                   
               
             
          
           
               
                   
                 Speed 
                 Pressure 
                 Min 
                 Max 
               
               
                   
                 RPM 
                 psi 
                 psi 
                 psi 
               
               
                   
                   
               
             
          
           
               
                   
                 300 
                 41 
                 33 
                 49 
               
               
                   
                 400 
                 54 
                 43 
                 65 
               
               
                   
                 500 
                 68 
                 54 
                 82 
               
               
                   
                 600 
                 81 
                 65 
                 97 
               
               
                   
                 700 
                 95 
                 76 
                 114 
               
               
                   
                 800 
                 108 
                 86 
                 130 
               
               
                   
                   
               
             
          
         
       
     
         [0024]    For hydraulically driven spreaders, the spreader hydraulic circuit is preferably programmed to initiate and control the reflexing by a hydraulic feedback circuit. The deflector plates respond to sensing, for example, the above-described conditions of speed and/or pressure. 
         [0025]    Alternatively, and more simplistic but less preferred, modes of operation are employed on spreaders which sense only impeller speeds. Release mechanisms are employed for activating the reflexing action automatically when impeller speeds drop by a threshold amount, preferably a drop of about 80% of the original speed. One advantage of the speed-type method may be that sensing the speed, to initiate the reflex action, enables use of pre-existing monitors and sensors rather than installing an add-on hydraulic feedback circuit. 
         [0026]    A still further alternative for controlling the threshold reflexing action is to adjust the spring tension, in the over-center linkage, manually, in accordance with whatever impeller speed setting is selected by the operator. 
         [0027]    While the present invention has been described with reference to certain preferred embodiments, one of ordinary skill in the art will recognize that additions, deletions, substitutions, modifications and improvements can be made while remaining within the spirit and scope of the present invention as defined by the appended claims.