Patent Publication Number: US-10772290-B2

Title: Reversible cutting edge for agricultural cutter

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     CROSS REFERENCE TO RELATED APPLICATION 
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     BACKGROUND OF THE INVENTION 
     The present invention relates generally to machines for preparing feed for ruminant farm animals and the like and in particular to a reversible cutting edge for such that provides improved serviceability. 
     Preparing feed for large animals such as dairy cows can be done through the use of an agricultural mixer, for example, providing a large hopper with a vertically extending augur that rotates to mix feed materials introduced into the hopper. The edge of the augur may support multiple cutting edges having serrated edges that catch and cut fibrous materials such as hay and silage during the mixing process. 
     The cutting edges are subject to damage and accordingly it is known to allow replacement of the entire cutting edges which may be unbolted directly from the auger for replacement or which may be unbolted from a holder plate which attached to the augur. In this latter case, the holder plate may include a pocket serving to support the cutting edge blade against the holder plate and to further restrain the cutting edge against left, right and rearward motion. The pocket serves to block movement of the cutting edge blade in each of four different directions to reduce or eliminate shear forces on the bolts that pass through the holder plate and cutting edge attaching them together. 
     As a general practice, the agricultural mixer may be mounted to a cart or wagon to be moved to different locations of silage or animals being fed. In these locations, unexpected damage to or wear of the blades can be difficult to correct if replacement blades are not brought along or were not previously ordered. Extra blades are inevitably subject to being misplaced or lost. 
     SUMMARY OF THE INVENTION 
     The present invention provides a replaceable cutting edge that may be reversed to bring fresh teeth into exposure to the feed materials allowing field repair without the need for new parts. Each cutting edge carries with it its own replacement to reduce the problem of misplacing or failing to bring cutting edge blades into the field. The cost to replace worn cutting edges is decreased by the ability to use the cutting edges twice, and the ordering of cutting edge edges is simplified by decreasing the number of new blades required. 
     In one embodiment the invention provides an auger cutter for crop materials having a cutting edge plate presenting opposed broad faces bounded by plate edges. The cutting edge plate has a first and second rank of cutting teeth extending from opposed plate edges of the cutting edge plate along a plane of the broad faces of the cutting edge plate. Mounting holes are provided in the cutting edge plate so that it can be attached with respect to an auger flute to draw a first rank of cutting teeth across crop materials with rotation of the auger and to shield the second rank of cutting teeth by a body of the cutting edge plate with rotation of the auger. 
     It is thus a feature of at least one embodiment of the invention to simplify the service of auger cutters in the field and to reduce the cost of these cutters. 
     The first and second rank of cutting teeth maybe rotationally symmetrical at 180 degrees of rotation at a perpendicular to the plane of the broad faces. 
     It is thus a feature of at least one embodiment of the invention to flexibly accommodate a variety of cutting teeth shapes provided they are rotationally symmetric. 
     The mounting points may include a pivot hole and a set of angular fixation holes arranged along a common radius from the pivot hole so that at least two bolts may fit respectively within the pivot hole and one of the angular fixation holes to provide an angular positioning of the mounting plate with respect to an auger flute dependent on a selection of an angular fixation hole to receive a bolt. 
     It is thus a feature of at least one embodiment of the invention to provide a cutting blade that can be affixed to an auger in a variety of different extension orientations. 
     The mounting points may be rotationally symmetrical at 180 degrees about an axis perpendicular to the plane. 
     It is thus a feature of at least one embodiment of the invention to preserve the ability to adjust extension orientation when the cutting blade is rotated to expose a fresh set of teeth. 
     The first and second rank of cutting teeth may each form a chevron whose apex extends outwardly from the cutting edge plate within the plane. 
     It is thus a feature of at least one embodiment of the invention to provide a cutting surface that promotes improved cutting by presenting multiple extension angles while preserving the reversibility to extend cutting edge life. 
     The cutting teeth may each provide a leading edge and a trailing edge, and the cutting teeth cooperate with the mounting holes so that the leading edges of the teeth are oriented to face material passing longitudinally across the cutting teeth away from an axis of rotation of the auger as the cutting edge is mounted, and the leading edges of the teeth are longer and present a face that extends at an acute angle with respect to the plane. 
     It is thus a feature of at least one embodiment of the invention to provide reversibility in a cutting edge plate that exhibits a direction of cutting/sawing action. 
     A broad face of the cutting edge plate adjacent to the leading edge of the teeth may include a cladding material of increased hardness over that of a main body of the cutting edge plate. 
     It is thus a feature of the present invention to provide a self-sharpening feature further extending the life of the cutting teeth. 
     One embodiment may further include a mounting plate attachable to the cutting edge plate using the mounting points of the cutting edge plate, the mounting plate providing auger mounting points adapted to affix a broad surface of the mounting plate to an auger flute, the mounting plate including a ledge surface extending outward with respect to the plane to abut a rearwardly positioned one of the first and second ranks of teeth to support the cutting edge plate against forces of cutting directed along the plane. 
     It is thus a feature of at least one embodiment of the invention to reduce the material that needs to be replaced to refresh the cutting edge by separating mounting and cutting functions. 
     The mounting plate may be constructed of a softer material than surfaces of the first and second ranks of teeth. 
     It is thus a feature of at least one embodiment of the invention to provide shear force protection to the bolts holding the cutting edge to the mounting plate by abutting the unused teeth against a ledge without damage to those teeth. It is another object of the invention to eliminate the need for a pocket to hold the cutting edge by promoting lateral resistance to the engagement of teeth and a softer metal surface. 
     The cutting edge plate may provide a first and second separable portion, and the ledge supports a rearwardly positioned one of the first and second ranks of teeth of each of the first and second portions of the cutting edge plate. 
     It is thus a feature of at least one embodiment of the invention to permit separate reversibility of portions of the cutting edge to accommodate uneven wear or localized damage at reduced cost. 
     The first and second portions of the cutting edge plate may be identical. 
     It is thus a feature of at least one embodiment of the invention to eliminate the need to buy more stock to separate cutting edge portions and/or to allow rotation of the cutting edges in the event of uneven wear as a function of an extension from the auger. 
     These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective fragmentary view of a mixer augur and hopper showing an auger cutter attached to a flute of the augur; 
         FIG. 2  is a perspective view of the auger cutter of  FIG. 1  comprising a holder plate supporting a reversible cutting edge having opposed ranks of teeth; 
         FIG. 3  is a fragmentary perspective view of the holder plate without the cutting edge showing slotted mounting holes for allowing worn teeth of the cutting edge to abut a supporting ledge to remove strain from bolts attaching the cutting edge to the holder plate; 
         FIG. 4  is a top plan view of a first embodiment of one cutting edge providing for two different opposed ranks of cutting teeth on a single blade; 
         FIG. 5  is a figure similar to that of  FIG. 4  showing two cutting edge portions each providing opposed ranks of teeth providing additional options for repair; 
         FIG. 6  is a fragmentary perspective view similar to that of  FIG. 2  showing the cutting edges arranged in an outwardly extending chevron formation with aligned teeth leading edges; 
         FIG. 7  is a top plan detail view of the teeth of each of  FIGS. 2, 4, 5, and 6 , showing the leading and trailing edges of each tooth where the leading edges present a beveled, sharpened surface; 
         FIG. 8  is a cross-sectional view along line  8 - 8  of  FIG. 7  showing a beveling of the leading edges and a cladding material to provide a self-sharpening feature; and 
         FIG. 9  is an alternative embodiment of the cutter eliminating the need for a separate support plate. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , a mixer  10  may provide for a hopper  12  for receiving feed materials through an upper opening. An augur  14  may be positioned within the hopper  12  and provide an augur shaft  16  rotating about a vertical axis  18 . The auger shaft  16  may be attached to a helical flute  20  providing a flute vane  22  extending radially about the axis  18  about the auger shaft  16 . Generally, the augur  14  rotates so that the flute  20  draws materials up from the bottom of the hopper  12  with rotation. 
     Multiple augur cutters  24  may be attached to the outer edge of the flute vane  22  (only one shown) at multiple locations along the flute  20 . Each auger cutter  24  extends generally horizontally from the outer edge of the flute vane  22  to expose a front edge  26  oriented with respect to rotation of the augur  14  so that the rank of cutting teeth  28  on the front edge  26  will be drawn across feed materials held within the hopper  12  during mixing. 
     Referring also to  FIG. 2 , each augur cutter  24  may provide for a support plate  30  attached to the flute vane  22  (as depicted in  FIG. 1 ), for example, by two carriage bolts  32  passing downward through the flute vane  22  to be received by corresponding holes in the support plate  30 . Specifically, the threaded shafts of two bolts  32  may be received respectively in a pivot hole  34  and one of multiple angular fixation holes  36   a - c  each passing through broad faces  37  of the support plate  30  and generally perpendicular to a plane  31  parallel to the broad faces  37  along which the support plate  30  extends. 
     The pivot hole  34  may be located at an edge of the support plate  30  near a front edge  26  of the augur cutter  24  and proximate to the flute vane  22  as attached. The angular fixation holes  36   a - c  may be located toward a center of the support plate  30  at varying distances from the front edge  26  of the support plate  30 , each angular fixation hole  36  angularly separated and positioned along a common radius  33  about the pivot hole  34 . By selecting a particular angular fixation hole  36  to attach the augur cutter  24  to the vane  22 , an angle of the front edge  26  with respect to a line of radius from axis  18  can be varied changing the aggressiveness of the auger cutter  24 . 
     Referring now also to  FIG. 3 , the front edge  26  of the support plate  30  may provide a shelf  40  presenting a generally horizontal supporting surface parallel to the broad faces  37  of the support plate  30  but recessed below the upper broad face  37 . In this way, a rear edge of the shelf  40  abuts a ledge  42  rising upward therefrom extending along a longitudinal axis  41  at the rear edge of the shelf  40  to be generally parallel to the front edge  26 . 
     As shown in  FIG. 2 , a cutting edge plate  44  having a longitudinal dimension approximately equal to that of the shelf  40  may be positioned on the shelf  40  so that its upper broad face  43  is substantially flush with the broad face  37  of the support plate  30  and a lower broad face  43 ′ (not shown) abuts the upper surface of the shelf  40 . The cutting edge plate  44  provides for the cutting teeth  28  arrayed along a first tooth rank  46   a  that extend in cantilevered fashion forward over a front edge the support plate  30   0  to be exposed at the front edge  26  of the augur cutter  24  as depicted in  FIG. 1 . 
     During rotation of the augur  14 , the cutting teeth  28  of the first tooth rank  46   a  will contact material to be cut as brought into contact with the cutting teeth  28  by that rotation. The cutting edge plate  44  also provides a second rank  46   b  of cutting teeth  28  on an opposite edge of the cutting edge plate  44  from the first rank  46   a  that may abut the ledge  42 . As so positioned, force  48  received by the cutting edge plate  44  along a perpendicular  48  to the ledge  42 , caused by the cutting action, is transmitted through the ledge  42  to the support plate  30  and hence to the flute vane  22 . In this way, the cutting edge plate  44  may be attached to the support plate  30  by bolts  50  passing through a corresponding hole  52  in the cutting edge plate  44  and corresponding slots  54  in the shelf  40  of the support plate  30  generally perpendicularly to the plane  31  without sheer damage to those bolts  50  such as may damage their threads or the like. 
     The bolts  50  may have flat heads to be received within counter sinking on the holes  52  to provide contact surfaces outside of the threads of the bolts  50  further reducing damage to the threads. 
     Notably this arrangement of having the second rank  46   b  of teeth engaging the ledge  42  and the countersinking of the bolts  50  eliminates the need to define a pocket in the support plate  30  for retaining the cutting edge plate  44 . 
     The slotted holes  54  in the support plate  30  allow the cutting edge plate  44  to be adjusted rearwardly to ensure that there is always positive engagement between the cutting teeth  28  and the ledge  42  even after the cutting edge plate  44  is reversed (as will be described below) so that worn teeth  28  are adjacent to the ledge  42 . In one embodiment the cutting edge plate  44  may provide for equally spaced holes  52  extending along the longitudinal axis  41  to attach with corresponding bolts to corresponding slots  54  in the shelf  40  of the support plate  30 . 
     The ledge  42  and shelf  40  may be readily constructed by assembling the support plate  30  from two different plates of material stacked on top of each other with the edge of the upper plates forming the ledge  42  and the lower plate forming the shelf  40 . Generally the material of the ledge  42  will be softer than the material forming the outer surface of the teeth  28 , for example, and un-hardened steel, to prevent damage to the unused teeth  28 . 
     Referring now to  FIG. 4 , generally the ranks  46   a  and  46   b  of cutting teeth  28  on the cutting edge plate  44  will be positioned on the cutting edge plate  44  to be rotationally symmetric at 180 degrees about a center point  56  of the cutting edge plate  44 . In this way, rotation of the cutting edge plate  44  about a perpendicular to its upper face through the center point  56  by 180 degrees allows the cutting edge plate  44  to be re-attached to the support plate  30  to provide essentially the same cutting surface at the front edge  26  of the augur cutter  24 . The holes  52  need not be rotationally symmetric at 180 degrees; however, such symmetry will eliminate the need for extra hole drilling. 
     Referring now to  FIG. 5 , in an alternative embodiment the cutting edge plate  44  may be composed of plate portions  60   a  and  60   b  essentially dividing the cutting edge plate  44  of  FIG. 4  into identical halves along its longitudinal length. Each of the plate portions  60   a  and  60   b  will provide rotational symmetry at 180 degrees with respect to its cutting teeth  28  of ranks  46   a  and  46   b  about a respective centerpoint  56   a  and  56   b . In this way, if a few teeth  28  are damaged or prematurely worn, that individual plate portion  60  may be rotated providing additional repair options in the field. In this case, each plate portion  60   a  and  60   b  may provide for at least two holes received by corresponding slots  54  in the support plate  30  (shown in  FIG. 3 ). It will be appreciated that the left plate portion  60   a  and right plate portion  60   b  are also interchangeable allowing, for example, the ability to rotate the positions of the plate portion  60  if there is uneven wear along the longitudinal extent of the cutting edge plate  44 . 
     Referring now to  FIG. 6 , in one embodiment the cutting teeth  28  at the front edge  26  of the augur cutter  24  follow the form of a forwardly extending chevron having a forward most apex  62  on either side of which the cutting teeth  28  sweep backward as one moves away from the apex  62  along the longitudinal axis  18 . A single cutting edge plate  44  may be created in the chevron shape or alternatively the chevron shape may be realized by separate plate portions  60   a  and  60   b  as shown, each conforming to a parallelogram, in this embodiment, to provide for the desired rotational symmetry of the cutting teeth  28  while allowing the longitudinally opposed ends  64  of the plate portions  60   a  and  60   b  to fit together in the chevron shape at different rotations. In this case, the plate portions  60   a  and  60   b  may be interchangeable; however, the invention also contemplates that the teeth  28  may have a leading and trailing edge that differ, as discussed below, in which case the plate portions  60   a  and  60   b  will not be interchangeable without additional rotation by 180 degrees about the longitudinal axis. 
     In all cases of the chevron form, the ledge  42  conforms to the chevron shaped to provide support for the cutting teeth  28  that are not at the front edge  26 . 
     Referring now to  FIG. 7 , as noted above, each of the cutting teeth  28  are generally triangular and may have a trailing edge  66  and a leading edge  70 . The trailing edge extends along a plane having one plane axis that is generally perpendicular to the broad face  43  and one plane axis, perpendicular to the first plane axis, having a trailing angle  68  measured along the plane  31 . Similarly, the leading edge  70  extends in a plane having a first plane axis at a bevel angle  77  with respect to the broad face  43  (shown in  FIG. 8 ) and a second, perpendicular plane axis measured along the plane  31  having a leading angle  72 . In one embodiment, the trailing angle  68  is perpendicular to the leading angle  72 . Generally trailing angle  68  provides an included angle with respect to the longitudinal axis  41  that is larger than the included angle of the leading angle  72 . 
     The teeth  28  may be cut so that the leading edges  70  of each of the teeth in all of these embodiments will be oriented to face inward toward the flute  20  when the augur cutter  24  is attached to the augur  14 . In this way, silage material sliding along the teeth  28  in a radially outward direction from the axis  18  will confront the sharper leading edges  70 . 
     Referring now to  FIG. 8 , a cladding material  74  may be placed on the planar lower broad face  43 ′ of the cutting teeth  28 , this cladding having a higher wear resistance and higher hardness. In this way, erosion of the surface of the teeth  28  indicated by dotted line  76  with use of the augur cutter  24  will tend to provide a self-sharpening effect by preferentially wearing the softer upper material backward into a sharper configuration from the cladding material  74 , the latter of which exhibits reduced where. All surfaces of the teeth  28  may be further hardened, for example, by a case hardening or similar treatment techniques. 
     Referring now to  FIG. 9 , in one embodiment the augur cutter  24  may provide an integrated support plate  30  and cutting edge plate  44  formed from a single metal plate  90 . As with the other designs, this plate  90  may be rotationally symmetric at 180 degrees about a center point  92  perpendicular to the broad faces of the metal plate  90 . In this case the rotational symmetry may be not only with respect to the cutting teeth  28  on opposed ranks  46   a  and  46   b  on opposite edges of the plate  90  but also with respect to pivot holes  34  and  34 ′ and angular holes  36   a - c  and  36 ′ a - c . As before, the cutting edges  70  of the teeth  28  may be oriented to face silage or other material sweeping longitudinally along a longitudinal axis  41  across a rank  46  radially away from the auger axis  18 . 
     Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
     When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.