Abstract:
A straw chopper for an agricultural harvesting machine includes a housing, a rotor carried by the housing, and a stationary knife bank. The rotor includes a plurality of pendulously mounted knife blades. The stationary knife bank includes a plurality of stationary knife blades adjustably movable toward and away from the rotor. The stationary knife bank includes a tension rod extending longitudinally through the stationary knife bank and having a threaded end, and at least one wing nut threadingly engaged with the threaded end.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 60/695,653, entitled “STRAW CHOPPER FOR COMBINE WITH ADJUSTABLE STATIONARY KNIFE BANK”, filed Jun. 30, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to agricultural harvesting machines, such as combines, and, more particularly, to straw choppers for such combines.  
       BACKGROUND OF THE INVENTION  
       [0003]     An agricultural harvesting machine such as a combine includes a head and a feeder housing which remove the crop material from the field, gather the crop material and transport the crop material to a separator. In the case of thinner stemmed crops such as soybeans, wheat, etc. which may be cut with a sickle bar carrying a plurality of knives, the head may also be known as a cutting platform. The separator removes the grain crop material from the non-grain crop material. The grain is cleaned and deposited in a grain tank. When the grain tank becomes full, an unloading auger which is positioned alongside the combine during harvesting is moved to the unloading position in which the auger extends approximately perpendicular to the longitudinal axis of the combine. The combine drives alongside a vehicle into which the grain is to be unloaded, such as a semi-trailer, and the unloading auger is actuated to discharge the grain into the vehicle.  
         [0004]     The non-grain crop material is transported from the separator to the rear of the combine, such as by using straw walkers, etc. If it is desired to maintain the non-grain crop material in windrows, such as when wheat straw is subsequently baled, then the non-grain crop material simply falls to the ground. On the other hand, if it is desired to distribute the non-grain crop material back to the field, then the non-grain crop material is typically transported to a straw chopper, and optionally a downstream blower.  
         [0005]     Straw Choppers are used to reduce the size of crop material, other than grain, that is processed by the harvesting machine. Typically, the straw chopper includes a housing that encloses a rotor. The housing is provided with an inlet for receiving crop material other than grain that has been processed and an outlet for distributing the chopped crop material back to the field. The housing is also provided with a bank of stationary cutter knives. The rotor is provided with a plurality of pendulously mounted straw chopper blades that cooperate with the stationary knives to chop the crop material entering the straw chopper. The rotor typically includes a cylindrical tube having a plurality of mounting locations distributed around the periphery of the rotor. The straw chopper blades are pendulously mounted to the mounting locations.  
         [0006]     It is known to provide a straw chopper with a stationary knife bank which may be adjusted such that the stationary knife blades extend through the housing a desired amount. Making adjustments with a conventional knife bank design requires that hardware be loosened and tightened on both the left and right hand side of the straw chopper. For an operator that changes crops daily, such as a corn and soybean farmer, it is recommended that the knife bank be engaged for beans and not engaged for corn. Adjusting the knife bank requires that two people make the adjustment by loosening the hardward, manually adjusting the knife bank into the desired position and then tightening the hardware to lock the knife bank in place. This conventional design also requires that tools be on hand and used to make the adjustments to the knife bank. The knife bank can bind during adjustment if one end is raised ahead of the other. The knife bank can be freed from binding by an operator laying on the ground on his back and kicking the knife bank. An alternative adjustment procedure, if only one person is available to make the adjustment, is to make several incremental adjustments from side to side. If a major adjustment is needed, such as moving from a fully engaged to a fully disengaged position, or vice versa, it cannot be done all at once or the above mentioned binding of the stationary knife bank can occur.  
         [0007]     What is needed in the art is a straw chopper with a stationary knife bank that can be adjusted quickly, easily and accurately by one person without the use of tools.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention provides a straw chopper on an agricultural combine with a stationary knife bank which can be easily adjusted relative to the rotor blades, without the use of tools.  
         [0009]     The invention comprises, in one form thereof, a straw chopper for an agricultural harvesting machine, including a housing, a rotor carried by the housing, and a stationary knife bank. The rotor includes a plurality of pendulously mounted knife blades. The stationary knife bank includes a plurality of stationary knife blades adjustably movable toward and away from the rotor. The stationary knife bank includes a tension rod extending longitudinally through the stationary knife bank and having a threaded end, and at least one wing nut threadingly engaged with the threaded end.  
         [0010]     The invention comprises, in another form thereof, a method of adjusting a stationary knife bank in a straw chopper of an agricultural harvesting machine, including the steps of: loosening a wing nut coupled with a tension rod extending through the stationary knife bank; moving a positioning handle attached to the stationary knife bank, thereby moving the stationary knife bank; and tightening the wing nut to lock the stationary knife bank in place. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a side, schematic view of an agricultural harvesting machine including an embodiment of a straw chopper of the present invention;  
         [0012]      FIG. 2  is a fragmentary, plan view of the straw chopper shown in  FIG. 1 ;  
         [0013]      FIG. 3  is a fragmentary, perspective view of the straw chopper shown in FIGS.  1  and  2 ;  
         [0014]      FIGS. 4 and 5  are opposite end views of the straw chopper, with the near side shield being removed in  FIG. 5 ;  
         [0015]      FIG. 6  is a perspective view of the bottom pan and stationary knife bank in the straw chopper of  FIGS. 1-5 ; and  
         [0016]      FIG. 7  is a perspective view of the stationary knife bank shown in  FIG. 6 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]     Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an agricultural harvesting machine in the form of a combine  10  including a supporting structure  12  having ground engaging wheels  14  extending from supporting structure  12 . Although combine  10  is illustrated as having wheels  14 , it could also have ground engaging tracks, either full tracks or half tracks. A harvesting platform  16  is used for harvesting a crop and directing it to a feederhouse  18 . The harvested crop is directed by feederhouse  18  to an infeed beater  20 , which directs the crop upwardly through an inlet transition section  22  to an axial crop processing unit  24 .  
         [0018]     Crop processing unit  24  threshes and separates the harvested crop material. Grain and chaff fall through grates on the bottom of unit  24  to cleaning system  26  which removes the chaff and directs the clean grain to a clean grain elevator (not shown). The clean grain elevator deposits the clean grain in grain tank  28 . The clean grain in tank  28  can be unloaded into a grain cart or truck by an unloading auger  30 .  
         [0019]     Threshed and separated straw is discharged from axial crop processing unit  24  through outlet  32  to discharge beater  34 , which in turn propels the harvested crop material other than grain to a straw chopper  40 . The operation of combine  10  is controlled from an operator&#39;s cab  35 .  
         [0020]     The axial crop processing unit comprises a cylindrical rotor housing  36  and a rotor  38  located inside housing  36 . The front part of rotor  38  and rotor housing  36  define the infeed section of crop processing unit  24 . Longitudinally downstream from the infeed section are a threshing section, separating section and discharge section (not separately numbered). Rotor  38  in the infeed section is provided with a conical rotor drum having helical infeed elements for engaging harvested crop material received from the infeed beater  20  and inlet transition section  22 . Immediately downstream from the infeed section is the threshing section of the crop processing unit  24 . In the threshing section, rotor  38  includes a cylindrical rotor drum having a number of threshing elements for threshing the harvested crop material received from the infeed section. Downstream from the threshing section is the separating section where the grain trapped in the threshed crop material is released and falls through a floor grate to cleaning system  26 . The separating section merges into a discharge section where crop material other than grain is expelled from axial crop processing unit  24  to discharge beater  34 . Although the invention is illustrated as being used on a rotary combine, the present invention can be used on other combine types including conventional straw walker combines and hybrid combines having transverse threshing cylinders and rotary separators.  
         [0021]     Referring to  FIGS. 1 and 2 , conjunctively, straw chopper  40  includes a housing  42 , rotor  44 , and a stationary knife bank  46 . Rotor  44  is provided with a plurality of mounting locations  48  for receiving straw chopper blades  50 . Housing  42  is provided with an inlet  52  for receiving previously processed harvested crop material other than grain and an outlet  54  for discharging the chopped crop material back to the field. Housing  42  also carries stationary knife bank  46  that cooperates with the rotating straw chopper blades  50 . In  FIG. 1 , rotor  44  would rotate in a counterclockwise direction.  
         [0022]     As shown in  FIG. 2 , rotor  44  is provided with two types of chopper blades  50 ; namely, paddle blades  56  and straight blades  58 . Straight blades  58  are relatively conventional in design and are provided with sharpened leading and trailing edges and a mounting assembly so they can be pendulously mounted on the mounting locations. Straight blades  58  have cutting edges on both the leading and trailing edges so that they can be reversed if the original leading edge becomes too dull. Paddle blades  56  include a transversely extending paddle. All of the above identified straw chopper blade embodiments are illustrated as having a serrated cutting edge and having a single ground side; however, non-serrated cutting edges could also be used as could be double beveled cutting edges.  
         [0023]     Referring now to  FIGS. 3-7 , stationary knife bank  46  is shown in greater detail. Stationary knife bank  46  includes a frame  60  carrying a plurality of stationary knives  62 . Frame  60  can be thought of as integrally including or separately attached to a pair of end plates  64  at either end of stationary knife bank  46 . End plates  64  extend in a generally downward direction when straw chopper  40  is in an operating orientation as shown in  FIGS. 1 and 3 - 5 . Each end plate  64  includes a slot  65  allowing adjustable movement of stationary knife bank  46 , as will be described hereinafter.  
         [0024]     A positioning handle  66  is pivotally mounted to housing  42  using a pivot rod  68 . Pivot rod  68  extends through a pair of openings on either side of housing  42  and is rigidly attached to positioning handle  66 , such as by welding. Positioning handle  66  has one end forming a positioning grip handle for an operator, and an opposite end rigidly attached to a first linkage linkage  70  of a two-bar linkage, including a second linkage  76  which in turn is coupled with tension rod  72 . Another two-bar linkage including an additional first linkage  70  and second linkage  76  interconnects pivot rod  68  and tension rod  72  on the side opposite positioning handle  66 , as shown in  FIG. 4 . This second two-bar linkage assures that frame  60  moves parallel to rotor  44  upon actuation of positioning handle  66 .  
         [0025]     Positioning handle  66  can also be configured with a generally L-shape, with one leg forming the grip handle for an operator, and the other leg pivotally coupled with second linkage  76 .  
         [0026]     Tension rod  72  extends through opposite end plates  64 , and includes a threaded end which is coupled with wing nut  74 . Wing nut  74  includes a female threaded portion and a pair of oppositely extending, angularly oriented handles for grasping by an operator (not numbered). Wing nut  74  may also include a single handle extending from the female threaded portion if desired.  
         [0027]     During use, wing nut  74  is turned by hand counterclockwise to loosen tension rod  72  extending between opposing end plates  64 . Positioning handle  66  is grasped by an operator and pivoted about the axis of pivot rod  68 . The position of positioning handle  66  determines the extent to which stationary knives  62  extend between rotor blades  50  (including paddle blades  56  and straight blades  58 ). Tension rod  72  slides within slots  65  of each end plate  64  to a desired position. When stationary knife bank  46  is at a desired position, wing nut  74  is tightened by turning in a clockwise direction. In the embodiment shown, positioning handle  66  is most conveniently grasped with the right hand and held in place while wing nut  74  is turned with the left hand to lock stationary knife bank  46  in place.  
         [0028]     In the embodiment of straw chopper  40  shown and described, a single wing nut and handle are attached to either end of tension rod  72 . However, it is also possible to use a pair of wing nuts  74  and/or positioning handles  66  at opposite ends of tension rod  72 , depending on the application.  
         [0029]     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention.