Abstract:
A threshing system including a rotor cage with a plurality of slots therein, a first bank of vanes and a second bank of vanes arranged within the cage. An adjustable vane control system is coupled to the rotor cage and the banks of vanes. A first and second member are respectively pivotally coupled the vanes in the first bank and the vanes of the second bank through corresponding slots. Linkages couple an arm to the members. The first and second members each having a range of travel defined by the slots. The members each having a surface facing the outer surface of the rotor cage, the surfaces of the first member and the second member each remain tangent to the outer surface of the rotor cage as the first member and the second member are moved within their range of travel.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to agricultural harvesters such as combines, and, more particularly, to adjustable vane control systems used with a threshing rotor in a crop processing section of the combine. 
     2. Description of the Related Art 
     An agricultural harvester known as a “combine” is historically termed 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. The threshing rotor is provided with rasp bars that interact with the crop matter in order to further separate the grain from the crop matter, and to provide positive crop movement. 
     Once the grain is threshed it falls through perforations in the concaves and is transported to 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. The cleaning system includes a cleaning fan which blows air through oscillating sieves to discharge chaff and other debris toward the rear of the combine. Non-grain crop material such as straw from the threshing section proceeds through a straw chopper and out the rear of 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. 
     More particularly, a rotary threshing or separating system includes one or more threshing rotors which can extend axially (front to rear) or transversely within the body of the combine, and which are partially or fully surrounded by a perforated concave. Again, the one or more threshing rotors are provided with rasp bars that interact with the crop matter to separate grain and to provide positive crop movement. The crop material is threshed and separated by the rotation of the rotor within the concave. Coarser non-grain crop material such as stalks and leaves are transported to the rear of the combine and discharged back to the field. The separated grain, together with some finer non-grain crop material such as chaff, dust, straw, and other crop residue are discharged through the concaves and fall onto the grain pan where they are transported to the cleaning system. Alternatively, the grain and finer non-grain crop material may also fall directly onto the cleaning system itself. 
     The cleaning system further separates the grain from non-grain crop material, and typically includes a fan directing an air flow stream upwardly and rearwardly through vertically arranged sieves which oscillate in a fore and aft manner. The airflow stream lifts and carries the lighter non-grain crop material towards the rear end of the combine for discharge to the field. Clean grain, being heavier, and larger pieces of non-grain crop material, which are not carried away by the air flow stream, fall onto a surface of an upper sieve (also known as a chaffer sieve or sieve assembly) where some or all of the clean grain passes through to a lower sieve (also known as a cleaning sieve). Grain and non-grain crop material remaining on the upper and lower sieves are physically separated by the reciprocating action of the sieves as the material moves rearwardly. Any grain and/or non-grain crop material remaining on the top surface of the upper sieve or sieve assembly are discharged at the rear of the combine. Grain falling through the lower sieve lands on a bottom pan of the cleaning system, where it is conveyed forwardly toward a clean grain auger. The clean grain auger is positioned below the lower sieve, and receives clean grain from each sieve and from the bottom pan of the cleaning system. The clean grain auger then augers the clean grain laterally sideways to a clean grain elevator, which in turn conveys the clean grain to a grain tank onboard the combine. 
     Variable pitch vanes within the rotor cage can bind as the vanes are moved causing them to be less effective than is desired. The binding is generally caused by trapped crop material that wedges beneath the vanes. 
     Accordingly, what is needed in the art is a way to control the pitch of the vanes in a manner that has a non-binding or reduced binding characteristic and is cost effective. 
     SUMMARY OF THE INVENTION 
     The present invention provides a pivoting vane adjustment system in the threshing system of an agricultural harvester. 
     In one form, the invention is directed to a threshing system including a rotor cage with a plurality of slots therein, a first bank of vanes and a second bank of vanes arranged within the cage. An adjustable vane control system is coupled to the rotor cage and the banks of vanes. a first and second member are respectively pivotally coupled the vanes in the first bank and the vanes of the second bank through corresponding slots. Linkages couple an arm to the members. The first and second members each having a range of travel defined by the slots. The members each having a surface facing the outer surface of the rotor cage, the surfaces of the first member and the second member each remain tangent to the outer surface of the rotor cage as the first member and the second member are moved within their range of travel. 
     In another form, the invention is directed to an agricultural harvester including a chassis and a threshing system carried by the chassis, the threshing system for separating grain from Material Other than Grain (MOG). The threshing system has a rotor cage with a plurality of slots therein, the rotor cage having an outer generally cylindrical surface; a plurality of banks of adjustable vanes pivotally coupled to the rotor cage including a first bank of vanes and a second bank of vanes; and an adjustable vane control system coupled to the rotor cage. The adjustable vane control system includes a first member pivotally coupled to each of the vanes in the first bank of vanes through corresponding slots; a second member pivotally coupled to each of the vanes in the second bank of vanes through corresponding slots; a first linkage; a second linkage; and an arm. The arm has an end that is coupled to the first member by way of the first linkage. The arm also has an opposite end that is coupled to the second member by way of the second linkage. The first member and the second member each have a range of travel defined by the slots. The first member and the second member each have a surface facing the outer surface of the rotor cage. The surface of the first member and the surface of the second member each remaining tangent to the outer surface of the rotor cage as the first member and the second member are moved within their range of travel. 
     An advantage of the present invention is that the vanes are efficiently moved by a balanced adjustment system, and the vanes are spaced and provide for some movement in an axial direction relative to the rotor cage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a side view of an agricultural harvester in the form of a combine; 
         FIG. 2  is a plan view of the curved side of a rotor cage of a threshing system having an embodiment of a vane adjustment system of the present invention used in the combine of  FIG. 1 ; 
         FIG. 3  is a plan view of the rotor cage of  FIG. 2  with the adjustment system removed; 
         FIG. 4  is a sectioned end vies of the rotor cage of  FIGS. 2 and 3  with the vane adjustment system seen in profile; 
         FIG. 5  is a view of part of the vane adjustment system of  FIGS. 2 and 4  with some elements removed to illustrate some geometric relationships of elements of the vane adjustment system; and 
         FIG. 6  is a view of an embodiment of one of the vanes of the present invention coupled to the vane adjustment system. 
     
    
    
     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 
     The terms “grain”, “straw” and “tailings” are used principally throughout this specification for convenience but it is to be understood that these terms are 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, which is referred to as non-grain crop material, MOG or straw. Incompletely threshed crop material is referred to as “tailings”. 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. 
     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 conveyance  30 . 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. 
     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 selectively vertically movable using appropriate actuators, such as hydraulic cylinders (not shown). 
     Threshing and separating system  24  is of the axial-flow type, and generally includes a threshing rotor  40  at least partially enclosed by a rotor cage 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 . Threshing and separating system  24  can also be a different type of system, such as a system with a transverse rotor rather than an axial rotor, etc. 
     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 . Cleaning system  26  may include an optional pre-cleaning sieve  46 , an upper sieve  48  (also known as a chaffer sieve or sieve assembly), a lower sieve  50  (also known as a cleaning sieve), and a cleaning fan  52 . Grain on sieves  46 ,  48  and  50  is subjected to a cleaning action by fan  52  which provides an air flow through the sieves to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from straw hood  54  of the residue handling system  70  of combine  10 . Grain pan  44  and pre-cleaning sieve  46  oscillate in a fore-to-aft manner to transport the grain and finer non-grain crop material to the upper surface of upper sieve  48 . Upper sieve  48  and lower sieve  50  are vertically arranged relative to each other, and likewise oscillate in a fore-to-aft manner to spread the grain across sieves  48 ,  50 , while permitting the passage of cleaned grain by gravity through the openings of sieves  48 ,  50 . 
     Clean grain falls to a clean grain auger  56  positioned crosswise below and toward the 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 . Tailings from cleaning system  26  fall to a tailings auger trough  62 . The tailings are transported via tailings auger  64  and return auger  66  to the upstream end of cleaning system  26  for repeated cleaning action. A pair of grain tank augers  68  at the bottom of grain tank  28  convey the clean grain laterally within grain tank  28  to unloading auger  30  for discharge from combine  10 . 
     Now, additionally referring to  FIGS. 2-4  there is shown a partial view of threshing system  24 , more particularly showing vane adjustment system  78  coupled to a rotor cage  80  with vanes  82  positioned along an inner surface of cage  80  in banks  84  and  86  of vanes  82 . A sliding member  88  is pivotally coupled to one end of vanes  82  of bank  84 , and sliding member  90  is pivotally coupled to an end of vanes  82  of bank  86 . An arm  92  is pivotally coupled to cage  80  and is coupled to member  88  by way of a linkage  94  and to member  90  by way of a linkage  96 . 
     Vanes  82  of bank  84  are pivotally attached about axes  98  to rotor cage  80  and vanes  82  of bank  86  are pivotally coupled to rotor cage  80  about axes  100 . Arm  92  is pivotally coupled to rotor cage  80  about an axis  102 . Vanes  82  of bank  84  are pivotally coupled to sliding member  88  though slots  104  about an axes  106 , which are arcuately shaped to correspond to a pivotal range of travel of vanes  82 . In a like manner vanes  82  of bank  86  are pivotally coupled to sliding member  90  though slots  104  about axes  108 , which are arcuately shaped to correspond to a pivotal range of travel of vanes  82  of bank  86 . Slots  144  and  146  are where vanes  82  pivot respectively about axes  98  and  100 . As can be seen in  FIG. 3  slots  144  and  146  are offset from each other as illustrated by the alignment lines  144 A and  146 A that illustrate the general longitudinal axis of the underlying vanes  82  approximately positioned at a midpoint of pivoting in slots  104 . Some offset exists regardless of the pivotal position of vanes  82 . This offset ensures that vanes  82  are always shingled properly as crop material transitions off the trailing end of the vanes  82  in bank  86  and interacts with the leasing end of vanes  82  of bank  84 . Slots  144  and  146  are positioned in such a way that this shingling effect is present regardless of any vane position within curved slots  104 . 
     Members  88  and  90  each have a respective inner surface  110  and  112  that remains tangent to an outer surface  114  of rotor cage  80  over the entire range of movement of members  88  and  90 . As arm  92  is pivoted the pivotal movement of vanes  82  takes place in a coordinated manner with force being transmitted from arm  92  to members  88  and  90  respectively by linkages  94  and  96 . The full range of movement of vanes  82  is subject to slots  104 A, which are a modified version of slots  104 . Slots  104  are generally oversize to allow space so that if any crop material gets into the slots  104  that the full range of motion of vane adjustment system  78  can still take place. However slots  104 A are slightly shortened and have a reduced throat  104 B feature that serves as a hard stop for the motion of adjustment system  78 . 
     Axes  98 ,  100 ,  102 ,  106  and  108  are all substantially normal to surface 114 . Even axes  106  and  108  which move along the curved outer surface  114 , due to the shape and location of slots  104 , remain normal to surface  114  over their range of movement. 
     Now, additionally referring to  FIG. 5  there is shown some further details about adjustment system  78 . Here member  88  or  90  is omitted for the sake of clarity with linkage  94  or  96  shown connected to arm  92  and oriented as if linkage  94 / 96  were coupled to member  88 / 90 . Linkage  94 / 96  has a longitudinal axis  116  that is parallel with a tangent of the movement of the point represented by axis  106  or  108 , which is the pivot point between member  88 / 90  and vanes  82 . Here this relationship is illustrated with longitudinal axis  116  intersecting an axis  106  at the midpoint of travel of axis  106 / 108  within slot  104 . 
     Now, additionally referring to  FIG. 6 , there is shown a closer view of one of vanes  82  with a cross-sectional view of cage  80  where vane  82  is shown spaced a distance  118  from cage  80  when crop material is not pressing against vane  82 . Vane  82  has a flat portion  120  midway between axis  98  and axis  106 . Vane  82  can move distance  118  due to the spacing allowed by shoulder bushings  122  and  124 . Although, the movement of vane  82  is shown as influenced by gravity, it is also contemplated that a biasing feature could be used. The free movement of vane  82  in an axial direction in and out relative to cage  80  allows for crop material to disengage from between vane  82  and cage  80 . Distance  118  is a predefined distance such as 4 mm. 
     The flat portion  120  of vane  82  is there to compensate for the change in curvature geometry between cage  80  and vanes  82 , as vanes  82  are pivoted about axes  98  and  100 . Flat portion  120  allows a needed clearance when members  88  and  90  are slid. 
     The present invention advantageously provides rotor cage  80  slot  104  geometry that constrains vanes  82  to defined pivotal path. Slots  104  provide a greater range of movement tan necessary to ensure that crop material build up never limits the full range of motion. Slots  104 A, which are one of the slots  104  in each bank  84  and  86  is notched at  104 B to provide a hard stop at either end of the desired range of motion. Adjustment arm  92  rotates or pivots about axis  102  providing an equal and opposite motion to vane banks  84  and  86 . Axis  102  is perpendicular to rotor cage  80 . The adjustment of vane banks  84  and  86  occurs on two separate planes which are moved along cage  80  by way of spherical rod ends on linkages  94  and  96 . Positioning of linkages  94  and  96  from arm  92  to vane rails  88  and  90  is such that they are parallel to the motion of axes  106  and  108  in slots  104  at a center of slots  104  to thereby generate an optimal use of the force available to adjust vanes  82 . An actuating system to move arm  92  has been purposely omitted for the sake of clarity in the presentation of the present invention. 
     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.