Patent Publication Number: US-7896274-B2

Title: Machine with snag anvil

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to machines that grind, shred, and/or chip various types of material. More particularly, this disclosure relates to components for use on machines having a conveying system that convey various types of material to a grinding, shredding, and/or chipping chamber. 
     BACKGROUND 
     Machines, such as grinders and chippers, are used both commercially and non-commercially for shredding, grinding, and/or chipping a variety of materials. Grinders, for example, typically include a grinding chamber having a grinding drum, and a conveying system that transports the various materials to the grinding chamber. Many conventional grinders have an anvil positioned adjacent to the conveying system at a location just prior to where the material enters the grinding chamber. The anvil provides a solid surface that accommodates impact forces, produced by tips or hammers of the grinding drum, and transferred through the material being ground. 
     In use, material is fed into the grinding chamber of conventional machines at a feed rate generally dictated by the speed of the conveying system. The speed of the conveying system is set to correspond to the machine&#39;s grinding capacity. In some circumstances, the rotational motion of the grinding drum and the hammers can cause the hammers or tips to grip and pull the conveyed material into the grinding chamber at a rate that exceeds the machine&#39;s grinding capacity. When the incoming material is pulled into the grinding chamber at too great a rate, the machine can plug, reducing the grinding efficiency of the machine, and even causing the machine to stall. 
     The conveying system of some conventional grinders includes a lower feed conveyor and an upper roller. The upper roller, in cooperation with the lower feed conveyor, functions to transport the material to the grinding chamber. The upper roller is often partly enclosed by a shroud or shoot having sidewalls. On some occasions, material is forced between the roller and the shroud sidewalls, and collects within a volume located at the open ends of the roller. The material becomes trapped within open ends of the roller due to the proximity of the roller ends to shroud sidewalls. As material collects within the open ends of the roller, the increasing volume of material within the roller begins to drag or scrape against the sidewalls, and can sometimes jam between the roller and the sidewall. The collected, trapped material creates an undesirable drag on the conveying system, and can even subsequently stall the conveying system. 
     The region adjacent to the conveying system and just prior to where the material enters the grinding chamber is often referred to as a transition region. In some conventional arrangements, the transition region includes a transition plate located adjacent to the lower feed conveyor. A gap or opening exists between the transition plate and the lower feed conveyor of conventional machines. During operation, chips and other small pieces of material often fall through the opening. The pile of material that builds up underneath the machine requires a user to expend extra time and effort in clean up and maintenance of a work site. 
     In general, improvement has been sought with respect to such conventional grinder machines, generally to address the problems previously described. 
     SUMMARY 
     One feature of the present disclosure relates to a snag anvil, a machine that incorporates the snag anvil, and associated methods. In one aspect, the snag anvil includes first and second longitudinal edges positioned along opposite sides of a recessed impact plane. In another aspect, the anvil is a reversible anvil. In yet another aspect, the longitudinal edges of the anvil are located a distance above the recessed impact plane, and flush with a conveying plane of a grinding machine. 
     Another feature of the present disclosure relates to an upper feed roller of a conveying system. The upper feed roller includes large openings that allow material to pass through the roller, and prevent the collection of material within an interior region of the roller. 
     Still another feature of the present disclosure relates to a sealing arrangement that can be used to prevent chips and material from falling to the ground between a grinding machine&#39;s conveying system and grinding chamber. 
     A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only, and are not restrictive of the claimed invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of a grinding machine incorporating the features presently disclosed; 
         FIG. 2  is a partial side view of the grinding machine of  FIG. 1 , illustrating one embodiment of an anvil, an upper feed roller, and a sealing arrangement, in accordance with the principles disclosed; 
         FIG. 3  is an enlarged, detailed view of the grinding machine of  FIG. 2 , taken from circled detail X; 
         FIG. 4  is a perspective view of the anvil shown in  FIG. 3 ; 
         FIG. 5  is a side elevation view of the anvil of  FIG. 4 ; 
         FIG. 6  is partial side elevation view of the grinding machine of  FIG. 1 , having an alternative embodiment of an anvil in accordance with the principles disclosed; 
         FIG. 7  is a perspective view of the anvil of  FIG. 6 ; 
         FIG. 8  is a perspective view of the upper feed roller shown in  FIG. 2 ; 
         FIG. 9  is a front elevation view of the upper feed roller of  FIG. 8 ; 
         FIG. 10  is an enlarged, detailed view of the grinding machine of  FIG. 2 , taken from circled detail Y; 
         FIG. 11  is a perspective view of a chip control seal shown in  FIG. 10 ; and 
         FIG. 12  is a perspective view of one embodiment of a chipper machine incorporating an anvil, in accordance with the principles disclosed. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various features of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 1  illustrates one embodiment of a grinding machine  10  having features that are examples of how inventive aspects in accordance with the principles of the present disclosure may be practiced. Although the present disclosure is described in relation to a grinding machine, it is to be understood that the term “grinding” machine is used for explanatory purposes only. Applying the present principles to machines having different nomenclature, yet having similar theories of operation, such as chipper machines for example, is within the scope of the present disclosure. 
     The grinding machine  10  of  FIG. 1  generally includes a material conveying system  12  that transports or conveys various materials toward a grinding chamber  14  of the machine. Preferred features of the grinding machine  10  are adapted for preventing an undesired rapid feed rate of material into the grinding chamber  14 ; preventing an undesirable operating condition and/or subsequent stalling of the conveying system  12 ; and eliminating undesired chip or material buildup underneath the grinding machine  10 . 
     Referring to  FIG. 2 , the grinding chamber  14  of the grinding machine  10  is partially enclosed by a housing or shroud  16 . A grinding drum  18  is located within the partially enclosed grinding chamber  14 . A plurality of hammers  20  extends radially outward from the drum  18 . During operation, the drum  18  rotates about a central axis A ( FIG. 3 ) while material is transported by the conveying system  12  toward the rotating hammers  20  of the drum. The impact from the rotating hammers  20  on the material shreds, chips, and/or grinds the transported material. The ground material exits the grinding chamber  14  through a screen  22 , and can then be conveyed away from the grinding machine for disposal or other use. 
     I. Snag Anvil 
     Referring now to  FIGS. 2 and 3 , one feature of the present grinding machine  10  relates to a snag anvil  30  that is adapted to prevent an undesired rapid feed rate of material into the grinding chamber  14  of the grinding machine  10 . The snag anvil  30  is located in a transition region  24  of the grinding machine, i.e., the region  24  between the conveyor system  12  and the grinding chamber  14 . The transition region  24  includes a stationary transition plate  26  and the anvil  30 . The anvil  30  is positioned adjacent to the drum  18  to accommodate impact forces produced by the hammers  20  and transferred through the material. 
     The snag anvil  30  of the present disclosure is constructed to reduce the occurrence of exceeding a desired incoming material feed rate. The desired incoming material feed rate, or material intake rate, can be exceed when grinding tips of a drum catch and pull material into the grinding chamber at a rate too fast for the grinding chamber to handle. The present anvil  30  prevents excessive material intake rates by snagging or slowing material at a point just prior to entry into the grinding chamber  14 . This provides a more controlled and uniform flow of material into the grinding chamber  14  so that the hammers can effectively operate without clogging or plugging. 
     Referring to  FIGS. 4 and 5 , the snag anvil  30  includes a base  32  having a top surface  34  and a bottom surface  36 . The top and bottom surfaces  34 ,  36  extend between a first end  38  and a second end  40  of the anvil  30 . The top surface  34  of the base  32  defines a recessed impact plane or impact surface. The impact plane  34  is the primary plane or surface onto which impact forces from the hammers  20  are transferred. Mounting holes  42  are formed in the base  32 . The mounting holes  42  are sized to receive fasteners for mounting the anvil  30  to a support member  44  ( FIG. 3 ) located in the transition region  24 . 
     As shown in  FIG. 4 , the anvil  30  includes first and second longitudinal edges  46 ,  48 . The longitudinal edges  46 ,  48  extend between the first and second ends  38 ,  40  of the anvil  30 . Each of the longitudinal edges  46 ,  48  are defined by the respective union or conjunction of ramped surfaces  50 ,  52  and side surfaces  54 ,  56 . The side surfaces  54 ,  56  extend generally perpendicular to the impact plane  34  of the anvil. The ramped surfaces  50 ,  52  angle upward and away from the impact plane  34 . Accordingly, the longitudinal edges  46 ,  48  of the anvil are located a distance d ( FIG. 5 ) above the impact plane  34 . 
     Referring back to  FIG. 3 , the ramped surfaces  50 ,  52  (as shown with regards to the second ramped surface  52 ) are angled upward from the impact plane  34  at an angle B projects outward below the central axis A of the drum  18 . That is, when the anvil  30  is mounted relative to the drum  18 , the central axis A of the drum is at an angle of about 40 degrees relative to an intersection E ( FIG. 5 ) of the impact plane  34  and the ramped surface  52 ; the angle B of the ramped surface  52  is between about 40 degrees and 20 degrees; more preferably between about 40 degrees and 35 degrees. The angle B causes material passing over the anvil  30  at an excessive rate to snag, which in turn creates a more uniform and controlled material intake flow. 
     The illustrated embodiment of the anvil  30  having a particular ramped surface angle B of between about 40 and 35 degrees provides a particular snagging or retarding effect, i.e., a particular level or characteristic of material intake control. It is contemplated that the angle B of the ramped surfaces  50 ,  52  can be configured to provide less aggressive or more aggressive snagging or retarding effect to accommodate a particular machine or application in which the anvil will be used. 
     For example, when using hammers with particularly aggressive grinding tips, the ramped surfaces  50 ,  52  of the anvil  30  can be more aggressively angled (e.g., greater than 20 to 40 degrees) to cancel or balance the aggressive gripping of the hammers and provide a more controlled material intake. Likewise, when using hammers with less aggressive grinding tips, the ramped surfaces  50 ,  52  of the anvil  30  can be less aggressively angled (e.g., less than 20 to 40 degrees) to accommodate or balance the less aggressive gripping of the hammers. Accordingly, the angle B of the ramped surface  52  can be less than 20 degrees, for example, so long as a sufficient retarding or snagging effect can be achieved to prevent excessive material intake rates; yet in other embodiments, the angle B may be greater than the 40 degrees, so long as the hammers can adequately compensate for the more aggressive snagging characteristic. 
     Referring again to  FIG. 5 , the ramped surfaces  50 ,  52  and the side surfaces  54 ,  56  of the snag anvil  30  define triangular shaped portions  58 ,  60  that are integral with the base  32  of the anvil; the base  32  of the anvil  30  having a base portion  62  that is generally rectangular in shape. The triangular shaped portions  58 ,  60  are preferably integrally formed with the base  32  (i.e. a solid or monolithic construction) for purposes of structural strength. In an alternative embodiment, however, the triangular shaped portions or longitudinal edges of the anvil can be manufactured as separate pieces that are joined to the base  32  by fasteners or weldments, for example. 
     The triangular portions  58 ,  60  of the anvil  30  define an anvil tray or depression  64  (i.e., the recessed impact plane  34 ). The depression  64  is centrally located between the edges  46 ,  48 , and extends between the first and second ends  38 ,  40  of the base  32 . As shown in  FIG. 3 , the depression  64  in the anvil  30  is below a conveying plane C (see also  FIG. 2 ) of the conveyor system  12  and the transition plate  26 . 
     In particular, the anvil  30  is positioned in the transition region  24  of the grinding machine  10  such that the longitudinal edges  46 ,  48  of the anvil are at or flush with the conveying plane C of the conveying system  12  and transition plate  26 ; accordingly, the depression  64  or recessed impact plane  34  of the anvil  30  is located below the conveying plane C of the machine. Positioning the anvil  30  such that the depression  64  is below the conveying plane C accommodates the provision of the projecting longitudinal edge (e.g.,  52 ) that snags material, without creating an obstacle in the conveying plane C that could inhibit transport of material to the grinding chamber  14 . That is, the projecting longitudinal edges  46 ,  48  are preferably at or below the conveying plane C over which material passes so as to not impede the normal intake of material at a desired intake rate, while at the same time provide a snagging effect that prevents excessive material intake. 
     Referring again to  FIGS. 4 and 5 , the depression  64  of the anvil  30  is symmetrically located along a central longitudinal axis D of the anvil. The longitudinal edges  46 ,  48  are also symmetrically located in relation to the longitudinal axis D of the anvil  30 . This arrangement permits a user to reverse the anvil  30  when one of the longitudinal edges becomes worn. That is, the anvil  30  can be reversibly mounted to the grinding machine in either of both of a first orientation and a second orientation (the first longitudinal edge  46  being oriented toward the grinding chamber  14  in the first orientation, and the second longitudinal edge  48  being oriented toward the grinding chamber  14  in the second orientation). To accommodate the reversible feature the present anvil, the mounting holes  42  of the anvil are also symmetrically located in the base  32  of the anvil so that the anvil  30  can be mounted in either one of both of the first and second orientations. 
     As can be understood, the longitudinal edges  46 ,  48  are relatively sharp and non-chamfered, as provided by the structural intersection of the ramped surfaces  50 ,  52  and the side surfaces  54 ,  56  of the anvil. The longitudinal edges  46 ,  48  of the disclosed anvil  30  are preferably of a sufficient sharpness to aid in preventing material from entering the grinding chamber  14  at a rate too great for the machine&#39;s grinding capacity. It is contemplated that the edges of the anvil can be manufactured to a particular sharpness, such as by machining, for example. In some embodiments, the combination of the angle B of the ramped surfaces  50 ,  52 , and the sharpness of the longitudinal edges  46 ,  48  can be provided in collaboration with one another to control the material intake rate. 
     For example, the ramped surfaces  50 ,  52  of the anvil  30  can be provided with a less aggressive angle B, in combination with sharper, longitudinal edges  46 ,  48  to produce a particular degree of material intake control. Yet, the ramped surfaces  50 ,  52  of the anvil  30  can also be provided with a more aggressive angle B, in combination with less sharp, longitudinal edges  46 ,  48  to produce the same particular degree of material intake control. Modifying either the angle B of the surfaces  50 ,  52 , or the sharpness of the edges  46 ,  48 , will create an accordingly more or less aggressive intake control characteristic. The snag anvil  30  can thereby be adapted to effectively control material intake in a variety of chipping/grinding applications. 
     Conventional anvil arrangements do not resist rapid material intake rates. Chamfered corners on conventional anvils, for example, provide no resistance to rapid movement of material into a grinding chamber. The present anvil  30  snags and retards the movement of material that is pulled across the anvil when the movement becomes too rapid. Material plugging and subsequent engine stall are thereby avoided. 
     As can be understood, wear on the longitudinal edges  46 ,  48  of the present anvil can reduce the effectiveness of the control of material intake. The reversibility of the present snag anvil  30  provides a user with longer productive use of the anvil. To further enhance the life of the anvil  30 , the longitudinal edges  46 ,  48  can be manufactured to provide protection from wear. Such protection can include heat treating the entire anvil  30 , case hardening the snag edges  46 ,  48 , providing a hard-face weld overlay of various materials, and/or involve a tungsten carbide impregnating process, for example. 
     Referring back to  FIGS. 2 and 3 , in use, the reversible anvil  30  is mounted in a horizontal orientation. In particular, the anvil  30  is selectively oriented in one of either the first horizontal orientation or the second horizontal orientation previously described. In  FIG. 3 , the anvil  30  is mounted in the second orientation, i.e., with the second longitudinal edge  48  positioned toward the grinding chamber  14 ; although the feature of the anvil being selectively oriented means that the first longitudinal edge  46  could also be operatively positioned toward the grinding chamber  14  to provide controlled material intake. When the anvil  30  has been selectively oriented, the reversible anvil is then secured or mounted to the support member  44 . If the anvil becomes worn, the anvil can be detached from the support member  44 , reversed, and re-mounted in the other of the first and second orientations for continued use. 
     Referring now to  FIGS. 6 and 7 , an alternative embodiment of an anvil  30 ′ incorporating the principles presently disclosed is illustrated. In this embodiment, the anvil  30 ′ is mounted to a support member  44 ′ in a vertical orientation, as opposed to a horizontal orientation. In contrast to the previous embodiment, the anvil  30 ′ does not include a depression  64 ′. The depression  64 ′ is instead defined by the support member  44 ′ in a transition region  24 ′ of the grinding machine. The depression could also be similarly formed in an extension of the transition plate (e.g.,  26 ′), for example. Similar to the previous embodiment, the depression  64 ′ in the transition region  24 ′ functions as a recessed impact plane  34 ′. The recessed impact plane  34 ′ is provided below the conveying plane C′ of the grinding machine. 
     Referring to  FIG. 7 , the anvil  30 ′ includes opposing first and second longitudinal edges  46 ′,  48 ′. The longitudinal edges  46 ′,  48 ′ are defined by angled side surfaces  54 ′,  56 ′. When mounted in the transition region  24 ′, the longitudinal edge (e.g.,  46 ′) extends upward and away from the depression  64 ′. Accordingly, the longitudinal edge  46 ′ of the anvil  30 ′ is located a distance d′ ( FIG. 6 ) above the impact plane  34 ′, and is also preferably located at or below the conveying plane C′ of the machine. 
     The angle side surfaces  54 ′,  56 ′ can be similarly configured as described with respect to the angle B of the ramped surfaces of the previous embodiment to produce a snagging effect on material passing over the anvil  30 ′. It is to be understood that the principles and features of the recessed impact plane  34 , the angular configurations of the anvil, and sharpness and location of the longitudinal edges with respect to the conveying plane C ( FIG. 2 ) of the grinding machine, as described with respect to the previous embodiment similarly apply to the embodiment shown in  FIGS. 6 and 7 . For example, in keeping with the principles disclosed, the vertically mounted anvil  30 ′ is a reversible anvil including symmetrically arranged mounting holes  42 ′ that permit a user to reverse the anvil when the first longitudinal edge  46 ′, for example, becomes worn. 
     II. Open Feed Roller 
     Another of the features of the present grinding machine  10  relates to an upper feed roller  72  ( FIG. 2 ) that prevents an undesirable operating condition and/or stalling of the conveying system  12 . Referring back to  FIGS. 1 and 2 , the conveying system  12  of the present grinding machine  10  includes a lower feed conveyor  70  ( FIG. 1 ) and the upper feed roller  72  ( FIG. 2 ). The upper feed roller  72  is partly enclosed by a portion of the housing  16 , e.g., a shoot or shroud  28 . 
     The shoot  28  of the housing  16  has sidewalls  92  (see also  FIG. 9 ) that contain and direct the incoming material being transported by the conveying system  12 . The upper feed roller  72  is located between the sidewalls  92  of the shoot  28 . Clearance gaps G ( FIG. 9 ) are provided between the sidewalls  92  and each of a first open end  66  and a second open end  68  (see  FIG. 8 ) of the roller  72 . 
     During operation, material can sometimes pass through the gaps G and enter into the open ends  66 ,  68  of the roller  72 . In conventional arrangements, such wayward material would otherwise be trapped within the end of the roller due to the proximity of the ends  66 ,  68  to the shoot sidewalls  92 . As the trapped material collects, the increasing volume of material within the roller  72  begins to drag or scrape against the sidewalls  92  and/or other internal structure or components. The scraping and frictional drag impedes the efficient operation of the conveying system. Sometimes material can even jam between the roller  72  and the sidewall  92 , possibly causing the conveying system to stall. The upper feed roller  72  of the present grinding machine  10  has an open construction that provides a path of escape for wayward material that would otherwise impede operation of the conveying system. 
     In particular, as shown in  FIG. 8 , the upper feed roller  72  of the present disclosure has a cylindrical wall  74  that defines a number of large openings  76 . The cylindrical wall  74  extends between the first open end  66  of the roller  72  and the second open end  68 . The large openings  76  of the upper feed roller  72  permit material to pass through the openings so that wayward material does not become trapped within the upper feed roller  72 . In the illustrated embodiment, the large openings  76  include two large-sized openings  76 , specifically first large-sized openings  84  and second large-sized openings  86 . What is meant by large openings or large-sized openings is that the openings each have a cross-sectional area  78  of at least 6.0 square inches; more preferably at least 9.0 square inches. 
     Referring now to  FIG. 9 , in the illustrated embodiment, the first large-sized openings  84  have a height H, and a first width W 1 . The first width W 1  of the first large-sized openings  84  is preferably between about 2.5 and 4.0 inches; more preferably between about 3.0 and 3.5 inches. The height H of the first large-sized openings  84  is preferably between about 3.0 and 4.0 inches. The cross-sectional area  78  of each of the first large-sized opening  84  is preferably at least 6.0 square inches; more preferably at least 9.0 square inches, as previously described. 
     Similarly, the second large-sized openings  86  have a height H, and a second width W 2 . The second width W 2  of the second large-sized openings  86  is preferably between about 5.5 and 7.0 inches; more preferably between about 6.0 and 6.5 inches. The height H of the second large-sized openings  84  is essentially the same as the first large-sized opening, i.e., preferably between about 3.0 and 4.0 inches. The cross-sectional area  78  of each of the second large-sized opening  86  is preferably at least 16 square inches; more preferably at least 20 square inches. 
     The large openings  76  are located between alternating rows of gripping knives  80 . The gripping knives  80  have sharp edges  82  that grip material for conveyance of the material into the grinding chamber  14 . Each of the first large-sized openings  84  is located in a circumferential column adjacent to the first end  66  of the roller  72 . Each of the second large-sized openings  86  is located in a circumferential column adjacent to the second end  68  of the roller  72 . In the illustrated embodiment, the upper feed roller  72  includes six, first large-sized openings  84  and six, second large-sized openings  82 , for a total of twelve large openings  76 . 
     The circumference of the cylindrical wall  74  of the illustrated roller  72  is approximately 18 inches in diameter. The length L 1  of the roller, defined between the first end  66  and the second end  68 , is approximately 16.5 inches. In one embodiment, the total cross-sectional area of the twelve large openings  76  is between about 15 and 20 percent of the overall circumferential surface area of the cylindrical wall  74  of the roller; the percentage of open area being defined by only the twelve large openings  76 . 
     The widths W 1 , W 2  of each of the large openings  76  generally corresponds to the depth of an interior region  94  ( FIG. 8 ) located at each of the open ends  66 ,  68  of the roller  72 . The depth of the interior region  94  of the second open end  68 , for example, is determined by the location of an inner roller drive plate  88 . The depth of the interior region  94  of the first open end  66  is similarly determined by the location of another inner roller drive plate (not shown). Referring to  FIG. 2 , the inner roller drive plates  88  of the upper feed roller  72  are interconnected to an arm  90  of the conveyor system  12 , which rotational drives the upper feed roller  72  and positions the roller in relation to the lower feed conveyor  70 . The height H of the large openings  76  generally corresponds to the placement of the gripping knives  80 . As can be understood, in alternative embodiments, the large openings can be of different sizes depending upon the structural design of the roller. That is, the openings  76  can be made smaller or larger depending upon the number, size, and placement of gripping knives  80  and the provision and/or location of the inner roller drive plates  88 , for example. Likewise, the number of openings  76  can also be varied. Preferably, however, the size and number of openings provided allows material to pass through the roller  72  to prevent the collection of material within the interior region of the open ends of the roller. 
     III. Chip Control Seal 
     Still another feature of the present grinding machine  10  relates to a sealing arrangement  100  ( FIG. 10 ) that eliminates undesired chip or material buildup underneath the grinding machine  10  during operation. Referring to  FIG. 10 , the sealing arrangement  100  is located between the grinding chamber  14  and the conveying system  12  of the machine  10 . In particular, the sealing arrangement  100  is located in the transition region  24  adjacent to the lower feed conveyor  70  of the conveying system  12 . The sealing arrangement  100  includes a seal  102  that prevents material from falling between the lower feed conveyor  70  and the transition plate  26 . The seal  102  eliminates material build up and chip piles under the machine that can occur without such a sealing arrangement  100 . 
     As shown in  FIG. 11 , the seal  102  has a length L 2  that spans across the width of the lower feed conveyor  70 . Preferably, the seal  102  is made of a material that is rigid enough to prevent material from passing through the space between the transition plate  26  and the lower feed conveyor  70 , yet flexible enough to allow a belt joint (not shown) of the lower feed conveyor  70  to pass by the seal  102 . In the illustrated embodiment, the seal  102  is made of a rubber material; although other types of material can be used. 
     The seal  102  includes guide holes  106  ( FIG. 11 ) sized to receive fasteners  104  ( FIG. 10 ). The fasteners  104  secure the transition plate  26  to the support member  44 . The seal  102  is clamped between the transition plate  26  and the support member  44 , the fasteners  104  extending through the guide holes  106  of the seal  102  to further secure the seal in relation to the lower feed conveyor  70 . Other mounting arrangements can be used to secure the seal  102  in relation to the lower feed conveyor  70 . 
     In the illustrated embodiment of  FIG. 10 , the support member  44  has an extended portion  108  that supports a majority of a width W 3  ( FIG. 11 ) of the seal  102 . In particular, the extended portion  108  supports the seal  102  from a clamped end  110  to a point proximate a free end  112 . Supporting the rubber seal  102  proximate the free end  112  provides added sealing strength and rigidity to prevent material from passing between the lower feed roller and grinding chamber  14 . 
     IV. Alternative Machine Embodiments 
     Referring now to  FIG. 12 , another embodiment of a machine  210  having features in accordance with the principles of the present disclosure is illustrated. The machine  210  is a chipper machine having similar theories of operation to that of the previously described grinding machine  10 . It is to be understood that the features previously described with respect to the grinding machine  10 , similarly apply to the chipper machine  210 . 
     For example, the present chipper machine  210  includes a snag anvil  230  that is adapted to prevent an undesired rapid feed rate of material into a chipping chamber  214  of the chipper machine  210 . The snag anvil  230  is located between the chipping chamber  214  and a region  229  where material is input into the chamber  214 . Material can be manually input into the region  229  via a shoot, for example, (as shown in  FIG. 12 ); or automatically input into the region  229  via a conveying system. 
     The anvil  230  is positioned adjacent to a drum  218  in the chipping chamber  214 . The drum includes chipping knives  220 . The anvil  230  accommodates impact forces produced by the chipping knives  220  and transferred through the material. Preferably, the anvil  230  is constructed and arranged as previously described with regards to the anvil  30  of  FIGS. 3-5 . The anvil  230  thereby reduces the occurrence of exceeding a desired incoming material feed rate of the chipper machine  210 , and provides a more controlled and uniform flow of material into the chipping chamber  214  so that the knives  220  can effectively operate without clogging or plugging. In operation, the drum  218  rotates; the impact from the rotating knives  220  on the material shreds, chips, and/or grinds the incoming material. The ground material exits the chipping chamber  214  through shoot  231 . 
     The chipping machine  210  can also include a feed roller  272  designed with large openings, which provide a path of escape for wayward material that would otherwise create an undesirable operating condition. That is, the roller  272  can be constructed and arranged, as previously described with regards to the roller  72  of  FIGS. 8 and 9 . In addition, although not shown, the chipper machine  210  can also include a sealing arrangement, as previously described, that eliminates undesired chip or material buildup underneath the chipper machine  210 . 
     The above specification provides a complete description of the present invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, certain aspects of the invention reside in the claims hereinafter appended.