Abstract:
A chopper knife assembly for use by an agricultural harvester. The chopper knife assembly includes a mounting lug with a fulcrum, wedge, and counterwedge; and at least one bladed knife attached to the mounting lug between the wedge and counterwedge; the assembly is held in place by an attachment means. The bladed knives are able to pivot on the fulcrum of the mounting lug during use, thereby forcing the knife blades onto the counterwedges to provide a more secure retention means.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to agricultural vehicles such as combines, and, more particularly, to chopper knife assemblies used in straw choppers on such vehicles. 
         [0003]    2. Description of the Related Art 
         [0004]    An agricultural vehicle 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. Once the grain is threshed it falls through perforations in the concaves onto 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. 
         [0005]    More particularly, a rotary threshing or separating system includes one or more 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. 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. 
         [0006]    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 air flow 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) 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 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. 
         [0007]    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. 
         [0008]    The non-desirable crop material, known as “material other than grain” (MOG), can be processed prior to being discharged from the harvester. Typically, this processing involves cutting or “chopping” the MOG into small pieces that are easily handled and distributed. The MOG processing is often accomplished in a “straw chopper”, where the MOG is cut up or chopped by multiple knife assemblies mounted on a rapidly-turning rotary shaft. The smaller pieces are then discharged from the harvester and spread onto an agricultural field. 
         [0009]    Over time, as the knives encounter the MOG during use, the working edge becomes dull. The knife is then typically removed from its mounting base, “flipped” 180 degrees, and re-secured. Thus, an unused and sharp working edge can be utilized until it, too becomes dull. The entire knife must then be replaced. 
         [0010]    In order to achieve a finer and finer size of the MOG, more and more knives are used to process the material. It can be seen that there is therefore a considerable amount of time and labor needed to flip or change the knives. 
         [0011]    Additionally, the large amount of torque needed for the bolts typically used to secure the knife to its base does not lend itself to easy installation or removal when service is needed. 
         [0012]    The knives also encounter high centrifugal forces from being mounted to a rapidly-turning rotary shaft, as well as large shear and impact forces from contact with the MOG, or unintentional foreign material which may be entrained in the MOG. 
         [0013]    What is needed in the art is a way to mount chopper knives in a manner that lends itself to quicker and easier assembly and disassembly, while at the same time providing the adequate strength needed to protect the knives from external forces. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention provides an agricultural harvester including a chopper knife assembly, with features that enable the chopper knives to be easily removable and adequately strong. 
         [0015]    The invention in one form is directed to an agricultural harvester, including a straw chopper with multiple chopper knife assemblies mounted to a rotating shaft. The chopper knife assemblies individually include a mounting lug, at least one bladed knife component, a counterwedge, and a fastener. The mounting lug includes a fulcrum opposite the surface where it is mounted to the rotating shaft, and a wedge. At least one bladed knife component is placed upon the mounting lug with its base in contact with the fulcrum, and one of its beveled edges in contact with the wedge. A counterwedge is placed against the opposite beveled edge of the bladed knife component, and a fastener is used to secure the assembly. 
         [0016]    The invention in another form is directed to an agricultural harvester, including a straw chopper with multiple chopper knife assemblies mounted to a rotating shaft. The chopper knife assemblies individually include a mounting lug, at least one bladed knife component, a counterwedge, and a fastener. The mounting lug includes at least one boss, and a wedge. At least one bladed knife component is placed upon the mounting lug with the at least one boss directed through at least one through-hole of the at least one bladed knife component. The at least one knife blade component is then rotated until one of its beveled edges is in contact with the wedge. A counterwedge is placed against the opposite side of the bladed knife component, and a fastener is used to secure the assembly. 
         [0017]    The invention in still another form is directed to an agricultural harvester, including a straw chopper with multiple chopper knife assemblies mounted to a rotating shaft. The chopper knife assemblies individually include a mounting lug, at least one bladed knife component, a wedge, a counterwedge, and a fastener. The mounting lug includes at least one boss. At least one bladed knife component is placed upon the mounting lug with the at least one boss directed through at least one through-hole of the at least one bladed knife component. A wedge is placed upon one side of the bladed knife component, and a counterwedge is placed against the opposite side. A fastener is used to secure the assembly. 
         [0018]    An advantage of the present invention is to reduce the time needed for the bladed knife components to be flipped or replaced. 
         [0019]    Another advantage of the present invention is to allow the operator to disassemble the chopper knife assembly without encountering unnecessarily large torque forces. 
         [0020]    Another advantage of the present invention is that the crop load will pivot the bladed knife component about the fulcrum during use, effectively creating a tighter assembly. 
         [0021]    Still another advantage of the present invention is the assembly provides structural support to resist centrifugal forces. 
         [0022]    Yet another advantage of the present invention is the assembly provides structural support to resist shear and impact forces. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    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: 
           [0024]      FIG. 1  is a side view of an embodiment of an agricultural vehicle in the form of a combine, which may include an embodiment of a chopper knife assembly as disclosed herein; 
           [0025]      FIG. 2  is a perspective view of a portion of the internal components of the combine shown in  FIG. 1 , including a straw chopper with multiple chopper knife assemblies; 
           [0026]      FIG. 3  is an exploded view of a chopper knife assembly shown in  FIG. 2 ; 
           [0027]      FIG. 4  is a perspective view of the mounting lug of the chopper knife assembly shown in  FIG. 3 ; 
           [0028]      FIG. 5  is a side view of the chopper knife assembly shown in  FIG. 3 ; 
           [0029]      FIG. 6  is a perspective view of a second embodiment of a chopper knife assembly; 
           [0030]      FIG. 7  is an exploded view of the chopper knife assembly shown in  FIG. 6 ; 
           [0031]      FIG. 8  is a perspective view of a third embodiment of a chopper knife assembly; and 
           [0032]      FIG. 9  is an exploded view of the chopper knife assembly shown in  FIG. 8 . 
       
    
    
       [0033]    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 
       [0034]    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. 
         [0035]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an agricultural vehicle 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 auger  30 . 
         [0036]    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. 
         [0037]    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). 
         [0038]    Threshing and separating system  24  is of the axial-flow type, and generally includes a rotor  40  at least partially enclosed by 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. 
         [0039]    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), 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 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 . 
         [0040]    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 . 
         [0041]    According to an aspect of the present invention, and referring now to  FIGS. 2-5 , there is shown a portion of a straw chopper assembly  70  which cooperates with other components inside the harvester to process the MOG into small pieces to be eventually discharged from the rear of combine  10 . 
         [0042]    In a typical operation, rotating shaft  72  rotates rapidly in a horizontal configuration in the flowpath of the MOG. Attached to rotating shaft  72 , in multiple locations along its periphery, are chopper knife assemblies  74 . The rotating chopper knife assemblies  74  cooperate with fixed blades or other mechanisms (not shown) to reduce the MOG to small pieces which are then discharged from the rear of combine  10 . 
         [0043]    Each chopper knife assembly  74  preferentially includes bladed knife components  76  and  77 , which are connectively attached to mounting lug  78  and secured with counterwedge  80  and fastener  82 . 
         [0044]    Mounting lug  78  includes but is not limited to a base  84 , sides  86  and  88 , thru-holes  87  and  89 , fulcrums  90  and  92 , integral wedges  94  and  96 , and counterwedge/fastener reception feature  98 . 
         [0045]    Base  84  on mounting lug  78  is generally concave in shape, permitting temporary or permanent attachment to the convex outer surface of rotating shaft  72 . A typical method of securing mounting lug  78  to rotating shaft  72  is by welding, but other means of attachment may be used. 
         [0046]    Sides  86  and  88  are arranged in parallel to each other and perpendicular to base  84 . For descriptive purposes, side  86  will be described in detail; associated features of side  88  are mirror images of their respective counterparts. Integral to and extending outward from side  86  of mounting lug  78  is fulcrum  90 . Fulcrum  90  includes protrusion  100  and contact surface  102 , used to retain a portion of bladed knife component  76 . Contact surface  102  has a generally convex shape. 
         [0047]    Integral to and extending outward from side  86  at the rear of mounting lug  78  is integral wedge  94 , which includes one wedge opening  104  with radiused notch  106  for receiving a beveled edge of bladed knife component  76 , described in detail elsewhere in this specification. 
         [0048]    Now looking at the front of mounting lug  78  (the side opposite the integral wedges), features are included for receiving and securing the counterwedge  80  and fastener  82 . Particularly, counterwedge/fastener reception feature  98  includes top surface  108 , bottom surface  110 , counterbore  112 , and threads  114 . Counterwedge/fastener reception feature  98  is communicably mated with counterwedge  80  and fastener  82  after assembly and is described in detail elsewhere in this specification. 
         [0049]    The material of mounting lug  78  is typically cast or forged metal. However, any suitable metal may be used; and mounting lug  78  may be machined or produced by any other suitable manufacturing method. 
         [0050]    Counterwedge  80  includes top surface  118 , bottom surface  120 , thru-hole  122 , countersink  124 , counterwedge openings  126  and  128 , and radiused notches  130  and  132 . Counterwedge  80  is communicably mated with counterwedge/fastener reception feature  98  and fastener  82  after assembly and is described in detail elsewhere in this specification. The material of counterwedge  80  is typically cast, forged, or machined metal; and can be the same as or different from materials used in manufacturing the mounting lug  78 . 
         [0051]    Bladed knife components  76  and  77  are described herein. For descriptive purposes, bladed knife component  76  will be described in detail; associated features of bladed knife component  77  are mirror images of their respective counterparts. Bladed knife component  76  includes base  134 , beveled edges  136  and  138 , sides  140  and  142 , and at least one thru-hole  144 . The material of the bladed knife components  76  and  77  is typically metal but can be any material known to withstand external forces and maintain a sharp edge. 
         [0052]    Fastener  82  includes a head  146  and shaft  148 . The head  146  of the fastener  82  may include a hexagonal countersink  150  for contact with a corresponding insertion instrument. The shaft  148  of fastener  82  may be partially or fully threaded with threads  152 . 
         [0053]    The material of fastener  82  is typically metal, but can be any material known to have adequate strength for connecting components. The material of fastener  82  can be the same as or different from materials used in manufacturing the counterwedge  80  or mounting lug  78 . 
         [0054]    The assembly of chopper knife assembly  74  is now discussed in detail. With mounting lug  78  securely attached to rotating shaft  72 , bladed knife component  76  is placed with beveled edge  136  into integral wedge  94  in intimate contact with the sides of wedge opening  104  and radiused notch  106 , while concurrently base  134  is located on fulcrum  90  between protrusion  100  and side  86 , and in contact with contact area  102 . After bladed knife component  77  is placed on mounting lug  78  in a similar manner opposite bladed knife component  76 , counterwedge  80  is placed into mounting lug  78  so that counterwedge openings  126  and  128  and radiused notches  130  and  132  are in intimate contact with beveled edges  138  and  139 , respectively. Finally, fastener  82  is passed through counterwedge  80  and threaded into counterbore  112  of mounting lug  78  and tightened securely. 
         [0055]    Radiused notches  106 ,  107 ,  130  and  132  are dimensionally larger than beveled edges  136 ,  137 ,  138 , and  139 , respectively. This allows for some “play” during operation of the straw chopper assembly  70 ; that is, the radiused notches permit some movement of the beveled edges and will therefore not “edge load” the bladed knife components, which could result in loosening. The sides of integral wedge openings  104  and  105  and counterwedge openings  126  and  128 , however, are tapered in the same manner as the sides of the bladed knife components, resulting in a secure contact between the mounting lug and the bladed knife components. 
         [0056]    The secure contact may actually increase as the centrifugal forces and MOG load act upon the beveled edges  138  and  139  and force beveled edges  136  and  137  into the wedge openings  104  and  105 , respectively. This is a result of the convexity of fulcrum bases  90  and  92 ; bladed knife components  76  and  77  can slidably or rotatably move on their bases  130  and  135 , respectively, when in operation. 
         [0057]    Counterwedge  80  has features which advantageously secure bladed knife components  76  and  77  to mounting lug  78 . In particular, surfaces  118  and  120  of counterwedge  80  are dimensioned appropriately for line-to-line contact with corresponding faces  108  and  110  of counterwedge/fastener reception feature  98  when assembled. In this manner, shear and other forces are adequately resisted. In addition, the dimensions of the thru-hole  122  and countersink  124  of counterwedge  80  are dimensioned appropriately such that fastener  82  will not “bottom out” in the counterbore  112  of mounting lug  78 ; that is, the assembly can be tightened until it is secure. 
         [0058]    A longitudinal axis A-A runs through fastener  82 . When chopper knife assembly  74  is completely assembled, longitudinal axis A-A of fastener  82  can be at any angle, but is preferably perpendicular to beveled edges  138  and  139 . The desired angle is chosen in order to change reaction forces to optimize the connection or minimize harmful external forces. 
         [0059]    Chopper knife assembly  74  allows secure assembly using one fastener, unlike typical assemblies which require two or more high-torque fasteners. However, thru-holes  87  and  88  in mounting lug  78  and thru-holes  144  of bladed knife components  76  and  77  can be utilized with a fastener or fasteners to provide primary or redundant locking 
         [0060]    With this and other described embodiments, as the working beveled edges become dull, the chopper knife assembly can be disassembled and the bladed knife components can be “flipped” or rotated 180 degrees so sharp beveled edges can then be utilized. After both beveled edges of the bladed knife components become dull, the chopper knife assembly can be disassembled and new bladed knife components installed. 
         [0061]    Referring now to  FIGS. 6-7 , with continued reference to  FIGS. 2-5 , an alternative embodiment of chopper knife assembly  74  is described. Chopper knife assembly  74 ′ includes counterwedge  80 , fastener  82 , and bladed knife components  76  and  77 , all identical as previously described. 
         [0062]    Mounting lug  154  of chopper knife assembly  74 ′ is similar in every feature to mounting lug  78  previously described, with two exceptions: mounting lug  154  does not include fulcrums  90  and  92 ; and unlike thru-hole  87  of mounting lug  78 , mounting lug  154  includes bosses  156  and  158 . Bosses  156  and  158  are each at least longer than the thickness of bladed knife components  76  and  77 , respectively, and are of a diameter slightly less than the diameter of thru-holes  144  of bladed knife components  76  and  77 . 
         [0063]    The assembly of chopper knife assembly  74 ′ is now discussed in detail. With mounting lug  154  securely attached to rotating shaft  72 , bladed knife component  76  is placed with beveled edge  136  into integral wedge  94  in intimate contact with the sides of wedge opening  104  and radiused notch  106 , while simultaneously thru-hole  144  is located over boss  156 . After bladed knife component  77  is placed on mounting lug  154  in a similar manner opposite bladed knife component  76 , counterwedge  80  is placed into mounting lug  154  so that counterwedge openings  126  and  128  and radiused notches  130  and  132  are in intimate contact with beveled edges  138  and  139 , respectively. Finally, fastener  82  is passed through counterwedge  80  and threaded into mounting lug  154  and tightened securely. 
         [0064]    Radiused notches  106 ,  107 ,  130  and  132  are dimensionally larger than beveled edges  136 ,  137 ,  138 , and  139 , respectively. This allows for some “play” during operation of the straw chopper assembly  70 ; that is, the radiused notches permit some movement of the beveled edges and will therefore not “edge load” the bladed knife components, which could result in loosening. The sides of integral wedge openings  104  and  105  and counterwedge openings  126  and  128 , however, are tapered in the same manner as the sides of the bladed knife components, resulting in a secure contact between the mounting lug and the bladed knife components. 
         [0065]    The secure contact may actually increase as the centrifugal forces and MOG load act upon the beveled edges  138  and  139  and force beveled edges  136  and  137  into the wedge openings  104  and  105 , respectively. This is a result of the single bosses  156  on each side of mounting lug  154 ; bladed knife components  76  and  77  are able to pivot on through holes  144  when in operation. 
         [0066]    A longitudinal axis A-A runs through fastener  82 . Similar to the assembly of chopper knife assembly  74  (see  FIG. 5 ), when chopper knife assembly  74 ′ is completely assembled, longitudinal axis A-A of fastener  82  can be at any angle, but is preferably perpendicular to beveled edges  138  and  139 . The desired angle is chosen in order to change reaction forces to optimize the connection or minimize harmful external forces. 
         [0067]    Chopper knife assembly  74 ′ allows secure assembly using one fastener, unlike typical assemblies which require two or more high-torque fasteners. 
         [0068]    Referring now to  FIGS. 8-9 , with continued reference to  FIGS. 2-5 , another alternative embodiment of chopper knife assembly  74  is described. Chopper knife assembly  74 ″ includes bladed knife components  76  and  77 , identical as previously described. Chopper knife assembly  74 ″ also includes mounting lug  160 , wedge  162 , counterwedge  212 , and fastener  164 . 
         [0069]    Mounting lug  160  includes but is not limited to a base  166 , sides  168  and  170 , bosses  172 , wedge/fastener reception feature  174 , and counterwedge/fastener reception feature  176 . 
         [0070]    Base  166  on mounting lug  160  is generally concave in shape, permitting temporary or permanent attachment to the convex outer surface of rotating shaft  72 . A typical method of securing mounting lug  160  to rotating shaft  72  is by welding, but other means of attachment may be used. 
         [0071]    Sides  168  and  170  are arranged in parallel to each other and perpendicular to base  166 . Integral to and extending outward from side  168  of mounting lug  160  are at least two bosses  172 , used to retain a bladed knife component  76  by thru-holes  144 . Similarly, integral to and extending outward from side  170  of mounting lug  160  are at least two bosses  172 , used to retain a bladed knife component  77  by thru-holes  144 . Bosses  172  are each at least longer than the thickness of bladed knife components  76  and  77 , respectively, and are of a diameter slightly less than the diameter of thru-holes  144  of bladed knife components  76  and  77 . 
         [0072]    Wedge  162  includes top surface  180 , bottom surface  182 , threaded thru-hole  184 , wedge openings  186  and  188 , and radiused notches  190  and  192 . Wedge  162  is communicably mated with wedge/fastener reception feature  174  and fastener  164  after assembly and is described in detail elsewhere in this specification. The material of wedge  162  is typically cast, forged, or machined metal; and can be the same as or different from materials used in manufacturing the mounting lug  160 . 
         [0073]    Counterwedge  212  includes top surface  214 , bottom surface  216 , thru-hole  218 , countersink  220 , counterwedge openings  222  and  224 , and radiused notches  226  and  228 . Counterwedge  212  is communicably mated with counterwedge/fastener reception feature  176  and fastener  164  after assembly and is described in detail elsewhere in this specification. The material of counterwedge  212  is typically cast, forged, or machined metal; and can be the same as or different from materials used in manufacturing the mounting lug  160 . 
         [0074]    Fastener  164  includes a head  194  and shaft  196 . The head  194  of fastener  164  may include a hexagonal countersink  198  for contact with a corresponding insertion instrument. The shaft  196  of the fastener  164  may be partially or fully threaded with threads  200 . 
         [0075]    The material of fastener  164  is typically metal, but can be any material known to have adequate strength for connecting components. The material of fastener  164  can be the same as or different from materials used in manufacturing the wedge  162 , counterwedge  212  or mounting lug  160 . 
         [0076]    The assembly of chopper knife assembly  74 ″ is now discussed in detail. With mounting lug  160  securely attached to rotating shaft  72 , bladed knife component  76  is placed with thru-holes  144  located over bosses  172  on side  168 , and bladed knife component  77  is placed with thru-holes  144  located over bosses  172  on side  170 . Wedge  162  is then placed into mounting lug  160  with sides of wedge opening  186  and radiused notch  190  in intimate contact with beveled edge  136 , and sides of wedge opening  188  and radiused notch  192  in intimate contact with beveled edge  137 . Counterwedge  212  is then placed into mounting lug  160  with sides of counterwedge opening  222  and radiused notch  226  in intimate contact with beveled edges  138 , and sides of counterwedge opening  224  and radiused notch  228  in intimate contact with beveled edge  139 . Finally, fastener  164  is passed through counterwedge  212  and threaded into wedge  162  and tightened securely. 
         [0077]    Radiused notches  190 ,  192 ,  226  and  228  are dimensionally larger than beveled edges  136 ,  137 ,  138 , and  139 , respectively. This allows for some “play” during operation of the straw chopper assembly  70 ; that is, the radiused notches permit some movement of the beveled edges and will therefore not “edge load” the bladed knife components, which could result in loosening. The sides of wedge openings  186  and  188  and counterwedge openings  222  and  224 , however, are tapered in the same manner as the bladed knife components, resulting in a secure contact between the mounting lug and the bladed knife components. 
         [0078]    Wedge  162  and counterwedge  212  have features which advantageously secure bladed knife components  76  and  77  to mounting lug  160 . In particular, surfaces  180  and  182  of wedge  162  are dimensioned appropriately for line-to-line contact with corresponding faces  202  and  204  (not shown) of wedge/fastener reception feature  174  when assembled. Similarly, surfaces  214  and  216  of counterwedge  212  are dimensioned appropriately for line-to-line contact with corresponding faces  206  and  208  (not shown) of counterwedge/fastener reception feature  176 . In this manner, shear and other forces are adequately resisted. In addition, the dimensions of the thru-hole  218  and countersink  220  of counterwedge  212  are dimensioned appropriately such that fastener  164  will not “bottom out” in the threaded thru-hole  182  of mounting lug  160 ; that is, the assembly can be tightened until it is secure. 
         [0079]    A longitudinal axis C-C runs through fastener  164  and a longitudinal axis D-D runs through wedge  162 . Similar to the assembly of chopper knife assembly  74  (see  FIG. 5 ), when chopper knife assembly  74 ″ is completely assembled, longitudinal axes C-C and D-D of fastener  164  and wedge  162 , respectively, can be at any angle, but are preferably perpendicular to beveled edges  138  and  139 . The desired angle is chosen in order to change reaction forces to optimize the connection or minimize harmful external forces. 
         [0080]    Chopper knife assembly  74 ″ allows secure assembly using one fastener, unlike typical assemblies which require two or more high-torque fasteners. 
         [0081]    While a chopper knife assembly 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.