Abstract:
The field of the disclosure relates to anvils for comminuting apparatus such as grinders or chippers. In some embodiments, the anvil is adjustable in length to maintain a clearance between a comminuting drum and a shear edge of the anvil.

Description:
CO-PENDING, CO-OWNED APPLICATIONS INCORPORATED HEREIN 
     The present application incorporates U.S. application Ser. No. 13/872,801, filed Apr. 29, 2013, entitled Cutter Assembly and Adjustable Cutter for use in Comminuting Apparatus and U.S. application Ser. No. 13/872,876, filed Apr. 29, 2013 entitled Mounting Block for Attaching a Reducing Element to a Rotary Drum, herein by reference for all relevant and consistent purposes. 
     FIELD OF THE DISCLOSURE 
     The field of the disclosure relates to anvils for comminuting apparatus such as grinders or chippers and, in particular, to anvils that are adjustable in length to maintain a clearance between the comminuting drum and a shear edge of the anvil. 
     BACKGROUND 
     Comminuting apparatus such as grinders and chippers are used to mechanically grind, chip or shred material to reduce the size of the material. Such apparatus may be used to reduce the size of material such as tree limbs, stumps or brush (i.e., arboraceous material) in land-clearing, municipal waste, composted materials or other vegetation, building materials or recycled material (e.g., car tires and the like). One common type of reducing machine is known as a horizontal grinder. A horizontal grinder may include a power in-feed mechanism that forces larger material (e.g., wood-based material such as tree trunks, tree branches, logs, etc.) into contact with a rotating comminuting drum. The larger material is contacted by reducing elements such as teeth, grinding elements or “knives” carried by the comminuting drum and portions of the material are forced past a fixed shear edge defined by an anvil of the horizontal grinder. 
     Upon passing the shear edge of the anvil, the material enters a chamber in which the material is further reduced by the reducing element carried by the comminuting drum. Once the material within the chamber is reduced in size, the material is discharged. Upon passing through the chamber, the reduced material is typically deposited on a discharge conveyor that carries the reduced material to a collection location. An example of a horizontal grinder is disclosed in U.S. Patent Publication No. 2009/0242677, which is incorporated herein by reference for all relevant and consistent purposes. 
     A continuing need exists for comminuting apparatus that maintain proper clearances between shear edges without replacement of comminuting components. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     SUMMARY 
     One aspect of the present disclosure is directed to an adjustable anvil for a comminuting apparatus. The adjustable anvil includes a first plate having a trailing edge and a second plate having a leading edge. The first plate and second plate form an anvil work surface for bringing material into contact with a comminuting drum. The trailing edge of the first plate is adjacent the leading edge of the second plate. A margin is disposed between the trailing edge of the first plate and leading edge of the second plate. The margin has an adjustable length. 
     Various refinements exist of the features noted in relation to the above-mentioned aspects of the present disclosure. Further features may also be incorporated in the above-mentioned aspects of the present disclosure as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments of the present disclosure may be incorporated into any of the above-described aspects of the present disclosure, alone or in any combination. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an apparatus for reducing the size of material; 
         FIG. 2  is a side view of an in-feed system, anvil, feed roller and comminuting drum of the apparatus of  FIG. 1 ; 
         FIG. 3  is a perspective view of the anvil and comminuting drum; 
         FIG. 4  is a perspective view of the anvil; 
         FIG. 5  is an exploded view of the anvil; 
         FIG. 6  is a top view of a first top plate of the anvil; 
         FIG. 7  is a top view of a second top plate of the anvil; 
         FIG. 8  is a top view of the first top plate and second top plate with the first top plate abutting the second top plate; 
         FIG. 9  is a top view of the first top plate and second top plate with a margin having a length L 2  separating the first top plate and second top plate; 
         FIG. 10  is perspective view of a second embodiment of an anvil with rounded edges; 
         FIG. 11  is a perspective view of the anvil of  FIG. 4  with the second top plate not shown; 
         FIG. 12  is a perspective view of the anvil with the second top plate and support plate not shown; 
         FIG. 13  is a perspective view of the anvil showing the top plate margin and support plate margin; and 
         FIG. 14  is a perspective view of the anvil showing a wider top plate margin and support plate margin relative to  FIG. 13 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     An embodiment of a comminuting apparatus for reducing the size of material is generally referred to as “ 5 ” in  FIG. 1 . The apparatus  5  is depicted as a horizontal grinder having a power in-feed system  13 , a comminuting assembly  20  and a discharge conveyor  40 . While the present disclosure has been described with reference to a horizontal grinder, it should be noted that the principles described herein (e.g., an adjustable length anvil) may also apply to any suitable apparatus for comminuting material such as a wood chipper having a chute for discharging comminuted material. 
     The in-feed system  13  of the comminuting apparatus  5  includes an in-feed conveyor  15  (e.g., chain or belt) to move the material toward a comminuting drum  25  ( FIG. 2 ) in a feed direction indicated by arrow F. As shown in  FIG. 2 , the in-feed system has a first end  37  proximal to an anvil  17 . The anvil  17  is disposed between the conveyor  15  and a comminuting drum  25  to bridge the gap between the conveyor  15  and comminuting drum  25 . A feed roller  30  rotates about an axis in direction R 30  to force material over the anvil  17  and to contact the comminuting drum  25 . The anvil  17  includes a first end  36  adjacent the conveyor  15  and a second end  27  adjacent the drum  25 . 
     The comminuting drum  25  carries a plurality of reducing elements  3  (e.g., teeth, blades, knives, etc. and/or combinations of these elements). During operation, the comminuting drum  25  rotates about an axis of rotation in direction R 25  such that the tips of the reducing elements  3  define a circumferential reducing path. In some embodiments (not shown), the apparatus may include a sizing screen that at least partially surrounds the comminuting drum  25  for forming a reducing chamber defined between the comminuting drum and the sizing screen. The principles of the present disclosure (e.g., use of an adjustable width anvil) may apply to apparatus that do not include such sizing screens such as the comminuting apparatus  5  described herein and may also apply to apparatus that include such sizing screens. 
     Referring now to  FIGS. 3-5 , the anvil  17  includes a first top plate  6  (or simply “first plate) and second top plate  4  (or simply “second plate”). The first top plate  6  ( FIG. 6 ) includes a leading edge  22  (i.e., the edge over which material first passes along feed direction F) and an “undulating” or “serrated” trailing edge  16 . The leading edge  22  of the first top plate  6  may have any suitable profile (e.g., may be essentially straight or serrated). The second top plate  4  ( FIG. 7 ) has a serrated leading edge  14  and a trailing edge  23 . The trailing edge  23  of the second top plate  4  should match the profile of the reducing elements  3  (e.g., essentially straight or serrated depending on the angle (if any) of the reducing elements). 
     The first top plate  6  and second top plate  4  form an anvil work surface  24  ( FIG. 8 ) upon which material travels in feed direction F during operation. In this regard, the anvil work surface  24  may be continuous as shown in  FIG. 8  or may be discontinuous (e.g., separated by a margin  63 ) as shown in  FIG. 9  and discussed further below. 
     The trailing edge  16  of the first top plate  6  ( FIG. 6 ) includes a series of projections  39  and indentations  41  that form a serrated zig-zag pattern along the edge. The leading edge  14  of the second top plate  4  ( FIG. 7 ) also includes a series of projections  29  and indentations  31  that form a serrated “zig-zag” pattern along the edge. The projections  29  ( FIG. 7 ) of the second top plate  4  align with the indentations  41  ( FIG. 6 ) of the first top plate  6  and the projections  39  of the first top plate  6  align with the indentations  31  ( FIG. 7 ) of the second top plate  4  which allows the plates  4 ,  6  to form a continuous anvil work surface  24  when fully adjoined ( FIG. 8 ). Use of a first top plate  6  and second top plate  4  that have aligned projections and indentations (e.g., that from a “zig-zag” pattern) prevents elongated debris (e.g., sticks or twigs) from being trapped within the top plate margin  63  ( FIG. 13 ). The first top plate  6  and/or second top plate  4  may include more or less projections  29 ,  39  and indentations  31 ,  41  than as shown in  FIGS. 6-7  without departing from the scope of the present disclosure. 
     As shown in  FIGS. 6-7 , the projections  29 ,  39  terminate in a point  43 ,  45 . However, the projections  29 ,  39  may also be rounded ( FIG. 10 ) or have other suitable shapes. In embodiments in which the projections  29 ,  39  are rounded, the radius of curvature of the projections and indentations may be less than about 0.5 cm (about 0.2 inches). 
     The anvil  17  includes a shear edge  18  ( FIG. 4 ) for comminuting material as the comminuting drum  25  rotates. The shear edge  18  is formed on an edge member  19 . As the drum  25  rotates, material is gripped between the reducing elements  3  and the shear edge  18  and the rotational force of the drum  25  causes the material to be comminuted. The shear edge  18  is positioned near the second end  27  of the anvil  17 . During use, a radial offset (i.e., clearance) is defined between the reducing elements ( FIG. 2 ) and the shear edge  18 . 
     Referring now to  FIG. 11  (the second top plate and edge member not being shown), the anvil  17  includes a support plate  26  configured for mounting to the second top plate and edge member ( FIG. 4 ) such that the edge member  19  is mounted adjacent the second top plate  4  opposite the leading edge  14  of the second top plate. As shown in  FIG. 11 , the edge member may be mounted by use of threaded bolts  42 . The first top plate  6  is mounted to a base  7  that extends across the trailing edge  16  ( FIG. 6 ) of the first top plate  6  and the leading edge  14  ( FIG. 7 ) of the second top plate  4  and extends beneath the support plate  26 . 
     As shown in  FIG. 12 , the base  7  includes a ledge  9  adjacent the support plate  26  ( FIG. 11 ). The base  7  may be integral (e.g., the ledge and base surfaces may be attached such as by welding) or the anvil  17  may include various separate components that together form the base  7 . The second top plate  4  and support plate  26  are adjustably mounted to the base  7 . The second top plate  4  may be moved relative to the base  7  by use of first row of lengthwise openings or “through-slots”  33  ( FIG. 12 ) and second row of lengthwise through-slots  11  that extend through the base  7  and are generally perpendicular to the shear edge  18  ( FIG. 4 ). In this manner, the support plate  26  and ledge  9  of the base  7  form an adjustable-length support plate margin  61  having a length L 1  ( FIG. 13 ). Alternatively or in addition, the second top plate  4  may include lengthwise through-slots (not shown) that are generally perpendicular to the shear edge for adjusting the relative position of the second top plate  4  and first top plate  6  (i.e., the length of the margin between the first top plate  6  and second top plate  4 ). It should be noted that a series of through-holes may be substituted for the through-slots formed in the anvil  17  for relative adjustment of the anvil components. 
     The second top plate  4  and first top plate  6  form a margin  63  ( FIG. 13 ) having a length L 2 . In embodiments in which projections and indentations extend across the length of the second top plate  4  and first top plate  6 , no portion of the adjustable length margin  63  is parallel to the shear edge  18  and no portion of the adjustable length margin is perpendicular to the shear edge  18 . The margin  61  between the support plate  26  and ledge  9  of the base  7  is offset from the margin  63  between the first top plate  6  and second top plate  4 . 
     As shown in  FIG. 9 , a first top plate serrated area A 6  is defined by the projections  45  and indentations  41  of the first top plate  6  and a second top plate serrated area A 4  is defined by the projections  43  and indentations  31  of the second top plate  4 . Generally, adjustment of the length of the margin between the first plate  6  and second plate  4  is limited such that the area A 6  of the first top plate  6  remains overlapped with the area A 4  of the second top plate  4 . 
     Referring now to  FIG. 12  (second top plate, edge member and support plate not being shown), the base  7  is configured for mounting to the second top plate, edge member and support plate. The first row of lengthwise through-slots  11  and the second row of lengthwise through-slots  33  may be used to adjust the position of the second top plate, edge member and support plate relative to the base  7  and top plate  6 . The support plate  26  ( FIG. 11 ) and elements attached thereto may be adjusted relative to the base  7  by loosening bolts  55 ,  59  that extend through through-slots  11 ,  33  of the base  7 . Bolts  42 ,  55 ,  59  may be fastened to nut bars  56   a ,  56   b ,  56   c  disposed beneath the base  7 . 
     Upon loosening bolts  55 ,  59 , push bolts  44  ( FIG. 11 ) that contact an arm  50  of the support plate  26  on each side of the anvil  17  may be rotated to adjust the position of the support plate, second top plate and edge member relative to the base  7 . For example and as shown in  FIG. 14 , the margins  61 ,  63  may be made relatively wider than the margins  61 ,  63  of  FIG. 13 . Once repositioning to achieve the desired length L 1 , L 2  of margins  61 ,  63  takes place, the bolts  55 ,  59  and push bolts  44  may be retightened to maintain the desired alignment. 
     The apparatus  5  ( FIG. 1 ) is operable to reduce the size of material such as tree limbs, stumps or brush in land-clearing, municipal waste, composted materials or other vegetation, building materials or recycled material (e.g., car tires and the like). Material is conveyed on the in-feed system  13  ( FIG. 2 ) toward the adjustable anvil  17  and is driven over the anvil toward the comminuting drum  25 . As the drum  25  rotates, material is impacted and reduced in size and is forced through a clearance between the reducing elements  3  mounted on the drum and the edge member  19 . 
     Use of the apparatus  5  may cause the shear edge  18  ( FIG. 4 ) of the edge member  19  to become worn causing the clearance between the shear edge and the reducing elements  3  to increase. Such an increase in clearance may cause the product size to be increased to an undesirable amount. When it is desired to decrease the clearance between the shear edge  18  and the reducing elements  3 , the bolts  55 ,  59  ( FIG. 11 ) which secure the second top plate  4  and support plate  26  ( FIG. 4 ) may be loosened and the push bolts  44  ( FIG. 11 ) may be rotated to cause the length L 1 , L 2  of the margins  61 ,  63  ( FIG. 13 ) to increase, thereby increasing the length of the anvil  17 . After the material is reduced in size, the discharge conveyor  40  ( FIG. 1 ) carries the comminuted material to a desired collection location (e.g., a pile, bin, truck bed, etc.). 
     It should be noted that while the length L 2  of the margin  63  between the first top plate  6  and second top plate  4  may be adjusted by manipulating the position of the support plate  26  as described herein, the length of the margin may be adjusted by methods and anvil arrangements other than as described herein without departing from the scope of the present disclosure. In some embodiments (e.g., when an anvil having an unworn edge member is used), the length L 2  of the margin  63  is zero (i.e., the first top plate  4  and second top plate  6  are in an abutting relationship). 
     Compared to conventional apparatus for comminuting material, the apparatus described above has several advantages. For example, use of an anvil  17  ( FIG. 4 ) with a first top plate  6  that may be moved relative to a second top plate  4  allows the length of the anvil to be adjusted such as after the edge member  19  has become worn. Accordingly, a relatively consistent clearance length between the anvil and the comminuting drum may be maintained. This capability allows the shear edge  18  ( FIG. 4 ) of the anvil  17  to be kept in an appropriate cutting zone while preventing a large gap at the leading edge  22  of the first plate  6  (i.e., a large gap with the in-feed conveyor  15  ( FIG. 2 )) where material may otherwise become lodged. That is, an acceptable gap may be formed in the anvil mid-section, rather than forming such a break between the anvil and in-feed conveyor. 
     Further, the use of a second top plate  4  and support plate  26  that are adjustable relative to the first top plate  6  and ledge  9  of the base  7  allows the top-plate margin  63  and support plate margin  61  ( FIG. 13 ) to be non-aligned. Accordingly, debris is prevented from falling within the support-plate margin  61 . Use of a first top plate  6  and second top plate  4  that have aligned projections and indentations (e.g., that form a “zig-zag” pattern) prevents elongated debris (e.g., sticks or twigs) from being trapped within the top plate margin  63  ( FIG. 13 ). In embodiments in which the projections  29 ,  39  ( FIGS. 6 and 7 ) are rounded, using projections  29 ,  39  with a radius of curvature of less than about 0.5 cm (about 0.2 inches) also prevents elongated debris from being trapped within the top plate margin  63  ( FIG. 13 ). 
     As used herein, the terms “about,” “substantially,” “essentially” and “approximately” when used in conjunction with ranges of dimensions, concentrations, temperatures or other physical or chemical properties or characteristics is meant to cover variations that may exist in the upper and/or lower limits of the ranges of the properties or characteristics, including, for example, variations resulting from rounding, measurement methodology or other statistical variation. 
     When introducing elements of the present disclosure or the embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” “containing” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of terms indicating a particular orientation (e.g., “top”, “bottom”, “side”, etc.) is for convenience of description and does not require any particular orientation of the item described, unless otherwise expressly stated to the contrary. 
     As various changes could be made in the above constructions and methods without departing from the scope of the disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawing[s] shall be interpreted as illustrative and not in a limiting sense.