Abstract:
A chopper assembly for harvesting equipment including a rotary chopper device with a plurality of knives and a cylindrical chopper grate assembly spaced from the rotary chopper to form a passageway for crop residue. The chopper grate assembly includes a plurality of slots extending in the direction of crop residue flow. A knife bank assembly includes a plurality of knife elements aligned with and insertable in the slots with the knife bank assembly being displaceable toward and between a position where the bank knife elements are fully inserted through the slots into the passageway and a position where they are substantially clear of the passageway. A deflector is provided for covering the slots and the deflector is displaceable with the knife elements to uncover the slots as the knife elements are displaced through the slots and into the passageway.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/818,102, entitled “COUNTER KNIFE BANK DEBRIS DEFLECTOR”, filed May 1, 2013, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present application relates to chopper assemblies for a combine and more specifically to a system in which debris is deflected from the counter knife bank assemblies used in such combines. 
     DESCRIPTION OF THE RELATED ART 
     Harvesting equipment such as agricultural combines frequently use integral chopper assemblies or systems to transport material away from the threshing system and also to treat the material by further cutting. It is frequently necessary to employ a residue chopper assembly that has a rotary chopper apparatus disposed within the combine housing and extending generally transverse across the path of the crop residue. A chopper grate assembly extends along the rotary chopper apparatus and has a plurality of slots through which knives attached to a counter knife bank apparatus adjustably project. The interaction between the rotary chopper and the counter knife bank apparatus cuts and reduces the size of the crop residue. In order to accommodate variable field and/or crop conditions it is necessary to provide a variation in the degree to which the knives of the counter knife bar apparatus extend through the slots in the chopper grate. The knives, when fully inserted through the slots in the chopper grate, produce a fine consistency to the chopped crop residue whereas the retraction of the knives from the slots produces a coarser consistency. 
     The harvesting and threshing process produces a great deal of crop residue which is accelerated through the combine and propelled rearward by the crop processing system (rotor) used in the processing of the crop material. Since the rotary chopper assembly is at the downstream end of the path of the crop residue, it is fully impacted by the debris carried around in the flow path through the combine. It has been found that the debris particularly collects adjacent the slots on the chopper grate and can span the space adjacent the leading edge of the knife elements used in the counter knife bar apparatus. The accumulation of the debris across the slots prevents free movement of the counter knife bar apparatus and requires frequent cleaning of the mechanism. Depending upon the configuration of the combine the cleaning process can be particularly complicated. 
     What is needed in the art therefore, is a chopper assembly in which debris is prevented from accumulating in the area between the chopper grate and the counter knife bar apparatus. 
     SUMMARY OF THE INVENTION 
     The invention seeks to provide a mechanism for preventing debris from accumulating between the chopper grate and the counter knife bar assemblies. 
     The invention, in one form, is a chopper assembly for harvesting equipment including a rotary chopper device and a chopper grate assembly spaced from the rotary chopper device to form a passage way for crop residue. The chopper grate assembly includes a plurality of slots extending in the direction of crop residue flow through the passageway. A knife bank assembly includes a plurality of knife elements aligned with and insertable in the slots. The knife bank assembly is displaceable toward a position where the knife elements are fully inserted through the slots into the passageway and a position where they are substantially clear of the passageway. A deflector is provided for covering the slots with the deflector being displaceable with the knife elements to uncover the slots as the knife elements are displaced through the slots and into the passageway. 
     The invention, in another form, is an agricultural combine with a crop processing apparatus to separate desired crop material from residue and a chopper assembly for receiving crop residue. The chopper assembly includes a rotary chopper device and a chopper grate assembly spaced from the rotary chopper device to form a passageway for crop residue. The chopper grate assembly includes a plurality of slots extending in the direction of crop residue flow through the passageway. A knife bank assembly includes a plurality of knife elements aligned with and insertable in the slots. The knife bank assembly is displaceable toward a position where the knife elements are fully inserted through the slots into the passageway and a position where they are substantially clear of the passageway. A deflector is provided for covering the slots with the deflector being displaceable with the knife elements to uncover the slots as the knife elements are displaced through the slots and into the passageway. 
     The invention, in yet another form, is a chopper assembly for harvesting equipment including a blower for processing crop residue and a rotary chopper device with a chopper grate assembly spaced from the rotary chopper device to form a passageway for crop residue. The chopper grate assembly includes a plurality of slots extending in the direction of crop residue flow through the passageway. A knife bank assembly includes a plurality of knife elements aligned with and insertable in the slots. The knife bank assembly is displaceable toward a position where the knife elements are fully inserted through the slots into the passageway and a position where there are substantially clear of the passageway. A deflector is positioned to direct flow of air from the blower to the vicinity of the slots and the knife elements extending through the slots. 
    
    
     
       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 embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side view of a combine incorporating a chopper assembly embodying the present invention; 
         FIG. 2  is a fragmentary perspective view of the chopper assembly of  FIG. 1 ; 
         FIG. 3  is a side view of the chopper assembly of  FIG. 1  in a first position; 
         FIG. 4  is a side view of the chopper assembly of  FIG. 1  in a second position; and 
         FIG. 5  is a side view of a chopper assembly incorporating an alternate embodiment of the present invention. 
         FIG. 6  is a side view of a chopper assembly incorporating another embodiment of the present invention 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows an agricultural combine  20  which includes the usual harvesting apparatus (not all of which is shown to facilitate an understanding of the invention). An axially oriented crop processing system  22  receives harvested crop and a crop residue treatment and distribution system  24  with a crop residue spreader  26  is positioned at the aft end of combine  20 . The crop processing system includes a cylindrical threshing rotor  28  that conveys a flow of crop material in a helical flow path. As the crop material is moved through the processing apparatus  22 , the desired crop such as grain or other material is loosened and separated from crop residue such as husk and pods in a cleaning system located beneath the threshing rotor  28 . The crop processing system  22  includes a blower  34 , schematically depicted to aid in the separation of the desired crop from the crop residue. The blower  34  has a duct  35  extending aft in the combine  20  towards the cleaning system and the crop residue treatment and distribution system  24 . 
     Existing crop residue systems provide the ability to variably chop the crop residue but encounter the problems of crop residue plugging the adjustable apparatus. In accordance with the present invention, the crop residue treatment system  24  shown in  FIGS. 2-4  minimizes, if not eliminates, plugging by crop residue material. 
     As specifically shown in  FIG. 2 , crop residue treatment system  24  includes a rotary chopper device  50  which includes a central rotor extending transverse to the flow of crop material and which supports a plurality of knives  52 , only two of which are shown. Details of such a rotary chopper device may be found in U.S. Pat. No. 8,141,805, of common assignment with the present invention, which is hereby incorporated in its entirety. Rotary chopper device  50  has adjacent thereto a chopper grate assembly  56  which is formed from sheet material extending substantially the same length as that the axial length of the rotary chopper device  50 . The chopper grate assembly  56  is generally cylindrical in form and defines, with the rotary chopper assembly  50 , a flow path  58  for crop residue material flowing in direction A. Chopper grate  56  has a plurality of slots  60  arranged in side-by-side relation across the width of the crop residue treatment system  24 . Slots  60  extend in a direction that is generally parallel to the direction of flow A for the crop residue material. 
     A knife bank assembly  62  is positioned adjacent the chopper grate  56  and includes a plurality of knife elements  64 , only a portion of which are shown that are positioned to be inserted through slots  60  and into flow path  58  in between the knives  52  of rotary chopper device  50 . Individual knife elements  64  are fixed to mounting frames  66  by removable fasteners  68 . Knife mounting frames  66  are all fastened to a main cross frame  70  extending across the length of the crop residue treatment system. Cross frame  70  includes a first section  72  providing a support for knife supports  66  and an integral second section  74  bent with respect to the plane of section  72 . Section  72  has brackets  76  affixed thereto that have holes through which bolt assemblies  78  extend to provide a pivotal mounting for knife bank assembly about axis B. Knife bank assembly  62  is pivotally displaced by a crank arm  80  shown in dashed lines that has an inner end and arranged to be pivotal about axis B and an outer end receiving an actuating arm  82  also shown in dashed lines. The translation of actuating rod  82  manually or by an actuator causes crank arm  80  to pivot the knife bank assembly  62  from the positions shown in  FIGS. 2 and 3  to the position shown in  FIG. 4  in which the knife elements  64  fully extend into flow path  58  through slots  60 . 
     In existing crop residue treatment systems, debris accumulates in the generally triangular area between the leading edge of knife elements  64  and the outer face of grate assembly  56 . In accordance with the present invention, a deflector  84  shown in  FIGS. 2-4  is employed to minimize, if not eliminate, accumulation of crop residue in the above-mentioned space. Deflector  84  is formed from flexible sheet material with sufficient stiffness to provide a resilient abutment on the outside of chopper grate  56 . Although one material may be stainless spring steel, it should be apparent to those skilled in the art that other materials may also be employed. Deflector  84  extends across the width of the crop residue treatment system  24  and has a first section  86  affixed to section  74  of cross frame  70 . Section  86  is secured with removable fasteners to enable replacement and fabrication although these fasteners are not shown to simplify the understanding of the present invention. Section  86  of deflector  84  continues to a second section  88  and a bend into a further section  90  and finally through an additional bend to a final section  92  that in its free state is generally contoured to fit the approximately cylindrical outer contour of chopper grate  56 . As illustrated in  FIG. 2 , the trailing edge  94  of section  92  abuts the leading edge of knife elements  64  so that when the knife elements  64  are in the position shown in  FIGS. 2 and 3 , the slots  60  are substantially covered. By covering the slots  60  in this position, the accumulation of crop residue debris through and around the slots is substantially minimized. It should be noted that the trailing edge  94  of section  92  may extend beyond the leading edge of knife elements  64  by providing a notch for even further coverage. 
     As the knife bank assembly  62  is rotated to cause the knife elements  64  to be inserted through slots  60  and into the flow area  58 , the trailing edge  94  of the deflector  84  moves with the leading edge of knife elements  64  to maintain a cover or deflector over the slots  60  to the extent that the slots  60  are not receiving a portion of the knifes  64 . Because deflector element  84  is resilient sheet material, it will bend and conform to the shape of the chopper grate  56  throughout the pivoting displacement of the knife bank assembly  62 . By placing the bend between the sections  88  and  90  in deflector  84 , the trailing edge  94  of deflector  84  is circumferentially displaced along the exterior of chopper grate  56 . This allows a smoother transition between the positions shown in  FIG. 2  and the one in  FIG. 4 . The deflector  84  may be formed in a plurality of sections abutting one another extending along the width of the crop residue processing system  24  or it may be formed in a single unit so long as the slots  60  are covered and uncovered as stated above. 
     As specifically shown in  FIG. 3 , a plurality of hook elements  96 , only one of which is shown in dashed line, may be employed adjacent the trailing edge  94  of deflector  84  to drag with them any material that may have accumulated in adjacent the leading edge of knife elements  64  to further enhance the process of eliminating debris. 
     By providing the deflector  84 , the accumulation of any debris that impedes the pivoting movement of the knife elements through the slots and into the flow path  58  is substantially minimized. This enables freer operator movement to adjust the crop residue processing system  24  to accommodate varying crops and field conditions. Furthermore, it makes operation more efficient in that it minimizes down time for cleaning 
       FIG. 5  shows an alternate embodiment of the present invention in which the same basic crop processing elements are present (using the same reference characters as in  FIGS. 2-4 ) but without the deflector  84 .  FIG. 5  shows the knife elements  64  in position out of the flow path  58  during which debris can accumulate. In accordance with this aspect of the present invention, there is provided a deflector  98  consisting of a sheet metal deflector bringing air flow C from blower  34  and duct  35  into the region  100  between the leading edge of knife elements  64  and the outer circumference of grate assembly  56 . The accelerated flow of air into the region  100  by virtue of deflector  98  causes any debris that resides in the area to be blown away. Since the blower  34  is operated continuously, the cleaning process takes place continually. 
       FIG. 6  shows yet another embodiment of the invention. In this view, a grate assembly  102  has the plurality of slots as in the previous embodiments through which a plurality of knife elements  104  (only one is shown) extend. The rotary chopper assembly shown in  FIGS. 2-5  is omitted to enable a clearer understanding of this aspect of the present invention. The passage for crop residue is adjacent the upper face of the grate assembly  102 . 
     Knife elements  104  are releasably fastened to blade supports  106  which are in turn fastened to a cross frame  108 . Frame  108  is pivotally mounted to grate assembly  102  at  110 . A crank arm  112  receives displacement inputs from a rod  114  to pivot frame  108  and blade elements  104  to variably extend through the slots in grate assembly  102 . As shown in  FIG. 6 , the knife elements  104  are pivoted to be out of the crop residue passage. The blade elements  104  may be pivoted to a position where they are totally extended through the slots in grate assembly  102  and into the passageway adjacent its upper face. 
     In accordance with another aspect of the present invention, a deflector  116  is employed to minimize, if not eliminate the buildup of debris between the slot in the grate assembly  102  and the leading edge of the blade elements  104 . Deflector  116  includes a continuous sheet  120  having an arc contour and which is fixed to frame  108  at  118 . Sheet  120  curves around to abut the bottom face of grate assembly  102  and has slots  122  for embracing opposite faces of the blade elements  104 . Sheet  120  ends in trailing edge hook elements  124  that variably extend across the faces of blade elements  104  as they are pivoted into the passageway. 
     A curved guide  126  is fastened to a flange  128  integral with grate assembly  102  by fasteners  130 . The curved guide  126  directs sheet  120  in a path that facilitates following the outer contour of grate assembly  102 . Guide  126  also provides a barrier against debris entering the space between the slots in guide assembly  102  and the leading edge of blade elements  104 . 
     In operation, the sheet  120  covers slots in the grate assembly  102  and moves with the pivoting the cross frame  108  to keep debris away. In addition, hook elements  124  provide a cleaning away of debris as the knife elements  104  are pivoted into the slots in grate assembly  104 . 
     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.