Abstract:
The present invention relates to grinding tools and, more particularly, to outdoor grinding tools, and also more particularly to rotating disc assemblies (including a disc, bit subassembly, and cutting bit shield/guard assembly). The rotating disc assembly can be used for grinding tree stumps, among other things.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Patent Application Ser. No. 62/078,931 filed Nov. 12, 2014, the entirety of which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to grinding tools and, more particularly, to outdoor grinding tools, and also more particularly to rotating disc assemblies (including a disc, bit subassembly, and cutting bit shield/guard assembly). 
         [0004]    2. Description of the Related Art 
         [0005]    Stump cutting tools conventionally include a rotating disc assembly that includes a rotating disc and multiple bit sub-assemblies located at regular angular intervals on the peripheral edge of the rotating disc. For example.  FIGS. 1 and 2  of U.S. Pat. No. 8,789,566 show a simplified conventional rotating disc assembly  100  including disc  102 ; and bit sub-assembly  104 . Bit sub-assembly includes: bit holder  108 ; and bit  112 . Conventional bit holder  108  provides a substantially rigid mechanical connection between the bit sub-assembly and the rotating disc so that there is substantially no relative motion between the bit sub-assembly and the rotating disc. Angular direction R shows the direction of rotation of the disc in operation. 
         [0006]    Further, in  FIG. 1  of U.S. Pat. No. 8,789,566, the bit sub-assembly  104  and its pocket  106  are centered at a twelve o&#39;clock position over the center  107  of the disc. In  FIG. 2  U.S. Pat. No. 8.789,566, at dotted area  112   a,  shows the view taken tangent to the top of the disc when the disc is in this twelve o&#39;clock position of  FIG. 1 . It is this view that defines the “footprint” of the bit. This concept of a “footprint” will be important for understanding certain aspects of embodiments of present invention in the example of  FIG. 1  and  FIG. 2  of U.S. Pat. No. 8,789,366, the front face of the bit is substantially perpendicular to the viewing vector that defines the foot print of bit  112 , but this is not necessarily always true in the prior art. or in embodiments of the present invention. Both the angular length (that is, angular length in direction R) of the bit sub-assembly and/of a non-orthogonal geometry for the bit itself can cause the front face of the bit to be non-perpendicular to the foot-print defining viewing vector. When the footprint of the bit is substantially perpendicular to the viewing vector, its footprint area will generally be at least approximately equal to the surface area of the front face of the bit. However, when the front face of the bit is not perpendicular to the viewing vector, then its footprint area will be less than the surface area of the front face of the bit. 
         [0007]    In conventional usage, this idea of inclining the front face of the bit, forward or backward or not at all, relative to the footprint-defining viewing vector is called a “rake angle.”Conventionally, rake angle is adjusted by the grinder designer depending on factors such as soil type and/or rotational speed. 
         [0008]    For present purposes, the important thing to note is that the footprint of the bit—that is, dotted area  112   a  taken perpendicular to the viewing vector—is entirely exposed as the disc rotates in direction R during operation of the grinder. More specifically: (i) no portion of disc  102  is interposed in front of the footprint when viewed from the viewing vector; and (ii) no portion of bit holder  108  or any other element positioned on the rotating disc is interposed in front of the footprint of the bit as its footprint is viewed from the viewing vector. Further, the bit only cuts in the “R” direction. 
         [0009]    Description of the Related An Section Disclaimer: To the extent that specific patents/publications/products are discussed above in this Description of the Related Art Section or elsewhere in this Application, these discussions should not be taken as an admission that the discussed patents/publications/products are prior art for patent law purposes. For example, some or all of the discussed patents/publications/products may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific patents/publications/products are discussed above in this Description of the Related Art Section and/or throughout the application, the descriptions/disclosures of which are all hereby incorporated by reference into this document in their respective entirety(ies). 
       SUMMARY OF THE INVENTION 
       [0010]    The disclosure is directed to inventive rotating disc assemblies for use on a stump grinder. An embodiment can include, but is not limited to. a rotating disc assembly for use on a stump grinder including a rotating disc defining a peripheral edge; a first bit holder that is mechanically connected to the peripheral edge of the rotating disc; a first cutting bit that is mechanically connected to and positioned in front of the first bit holder, wherein the first cutting bit is structured, positioned and configured to cut in three directions; and a first shield assembly mechanically connected to a first shoulder formed on the peripheral edge of the rotating disc in front of the first cutting bit so that a footprint of the first cutting bit is at least partially shielded by a corresponding footprint of the first shield assembly. 
         [0011]    Another embodiment can include, but is not limited to a rotating disc assembly for use on a stamp grinder including: a rotating disc defining a peripheral edge, a first bit holder that is mechanically connected to the peripheral edge of the rotating disc; a first cutting bit that is mechanically connected to and positioned in front of the first bit holder, wherein the first cutting bit is structured, positioned and configured to cut in three directions; and a first shield assembly mechanically connected to the peripheral edge of the rotating disc in front of the first cutting bit so that a footprint of the first cutting bit is at least partially shielded by a corresponding footprint of the first shield assembly, and wherein the first shield assembly comprises a layer of shock absorbing material comprising a lower relative hardness value than surrounding layers of the first shield assembly. 
         [0012]    Column 2, line 64-column 13, line 42 and FIGS. 3-86 of U.S. Pat. No. 8,789,566, the disclosure of which is hereby incorporated by references in its entirety, provides some background on particular stump cutting tools and may serve as support for certain aspects of one or more embodiments described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
           [0014]      FIGS. 1 and 2  are perspective views of a rotating disc assembly, according to a first embodiment. 
           [0015]      FIGS. 3-4  are perspective views of a rotating disc assembly, according to a second embodiment. 
           [0016]      FIG. 5  is a side view of a cutting bit shield/guard assembly , according to an embodiment. 
           [0017]      FIG. 6  is a perspective view of the cutting bit shield/guard assembly shown in  FIG. 5 , according to an embodiment. 
           [0018]      FIG. 7  is a front view schematic representation of a cutting bit shield/guard assembly, according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The present invention will be more folly understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, wherein like reference numerals refer to like components. 
         [0020]    Turning to  FIGS. 1-2 , perspective views of a rotating disc assembly  100  are illustrated, according to a first embodiment of the present invention. The rotating disc assembly  100  includes a rotating disc  7  which rotates to the left in the “R” direction as one looks at either  FIG. 1-2 , when the rotating disc assembly  100  is in operation. Rotating disc  7  is shown with a bit subassembly comprising a bit holder  5  securely attached to the perimeter or peripheral edge of the rotating disc  7 , a cutting bit  15  positioned in front of the bit holder  5 , and a bolt  3  securing the cutting bit  15  to the bit holder  5  together and the bit to the perimeter of the rotating disc  7 . The cutting bit  15  is shown fitting within a recess of the bit holder  5 , where a portion of the bit holder  5  is positioned behind, underneath and in front of the cutting bit  15 . The cutting bit  15  is configured, structured, and or attached to the rotating disc  7  to cut in three directions—to the left in the R direction as one looks at  FIG. 1  (i.e., in a forward direction perspective to the user of the rotating disc assembly  100 ) and inside and outside of the page as one looks at  FIG. 1  (i.e., in a side to side direction perspective to the user of the rotating disc assembly  100 ). In an exemplary embodiment, cutting bit  15  includes a cutting surface which can be sharper and/or more pointed than the rest of the cutting bit  15  around the perimeter P of the front of cutting bit  15 . A cutting bit shield/guard assembly  10  is also shown attached to the rotating disc  7  preferably separate from (but not necessarily) and in front of the cutting bit  15  in  FIG. 1 . and shown detached from the rotating disc  7  in  FIG. 2 . 
         [0021]    A purpose of the cutting bit shield/guard assembly  10  is to block a portion of the cutting bit  15  as it cuts in the forward direction (R direction) and in the side to side direction (essentially perpendicular to the R direction). In other words, the footprint of the cutting bit  15  can be shielded by the corresponding footprint of the cutting bit shield/guard assembly  10 . The footprint of the cutting bit shield/guard assembly  10  can be configured, structured, and/or attached to the rotating disc  7  to shield at least 50% of the corresponding footprint of the cutting bit  15 , and preferably at least 90% of the corresponding footprint of the cutting bit  15 . 
         [0022]      FIG. 2  shows the cutting bit shield/guard assembly  10  detached from the perimeter of the rotating disc  7 . A shoulder configuration  9  (e.g., an “L” shaped “cutaway” area on the perimeter of the rotating disc  7 , which can be any shaped cutaway or recess) is shown on the perimeter of the rotating disc  7  where the cutting bit shield-guard assembly  10  attaches near the bit subassembly. This shoulder configuration  9  assists with enabling the cutting bit shield/guard assembly  10  to maintain its secured position on the perimeter of the rotating disc  7  during operation. A plurality of these bit subassemblies and cutting bit shield-guard assemblies  10  can be placed around the perimeter of the rotating disc  7 . The bit subassemblies and cutting bit shield/guard assemblies can be evenly spaced or randomly spaced around the perimeter of the rotating disc  7 . The cutting bit shield/guard assembly  10 , as shown, can be wider at the front and narrower towards the back (closer to the cutting bit  15 ). 
         [0023]    Turning to  FIGS. 3-4 , perspective views of a rotating disc assembly  200  are illustrated, according to a second embodiment of the present invention. The rotating disc assembly  200  rotates to the left in the “R” direction as one looks at either  FIG. 3-4 , when the rotating disc assembly  200  is in operation. Rotating disc  7 ′ is shown with a bit subassembly comprising a bit holder  5 ′ securely attached to the perimeter or peripheral edge of the rotating disc  7 ′, a cutting bit  15 ′ positioned in front of the bit holder  5 ′, and a bolt  3 ′ securing the cutting bit  15 ′ to the bit holder  5 ′ together and the bit to the perimeter of the rotating disc  7 ′. The cutting bit  15 ′ is configured, structured, and/or attached to the rotating disc  7 ′ to cut in three directions—to the left and in the R direction as one looks at  FIG. 3  (i.e., in a forward direction perspective to the user of the rotating disc assembly  200 )—and inside and outside of the page as one looks at  FIG. 3  (i.e., in a side to side direction perspective to the user of the rotating disc assembly  200 ). In an exemplary embodiment, cutting bit  15 ′ includes a cutting surface which can be sharper and/or more pointed than the rest of the cutting bit  15 ′ around the perimeter P′ of the front of cutting bit  15 ′. A cutting bit shield/guard assembly  10 ′ is also shown attached to the rotating disc  7 ′ preferably separately from (but not necessarily) and in front of the cutting bit  15 ′in  FIG. 3 , and shown detached from the rotating disc  7 ′ in  FIG. 4   
         [0024]    A purpose of the cutting bit shield/guard assembly  10 ′ is to block a portion of the culling bit  15 ′ as it cuts in the forward direction (R direction) and in the side to side direction (essentially perpendicular to the R direction). In other words, the footprint of the cutting bit  15 ′ can be shielded by the corresponding footprint of the cutting bit shield/guard assembly  10 ′. The footprint of the cutting bit shield/guard assembly  10 ′ can be configured, structured, and/or attached to the rotating disc  7 ′ to shield at least 50% of the corresponding footprint of the cutting bit  15 ′, and preferably at least 90% of the corresponding footprint of the cutting bit  15 ′. 
         [0025]      FIG. 4  shows the cutting bit shield/guard assembly  10 ′ detached from the perimeter of the rotating disc  7 ′. A shoulder configuration  9 ′ (e.g., a “stepped” configuration “cutaway” on the perimeter of the rotating disc  7 , which can be any shaped cutaway or recess) is shown on the perimeter of the rotating disc  7 ′ where the cutting bit shield/guard assembly  10 ′ attaches near the bit subassembly. The shoulder configuration  9  can also include a section of the perimeter  19  that is positioned in front of the shield/guard assembly, which can extend almost to the same height of the cutting bit shield/guard assembly  10 ′ (if not higher) when the cutting bit shield guard assembly  10 ′ is positioned on the rotating disc  7 ′. However, cutting bit shield/guard assembly  10 ′ is preferably thicker than the rotating disc, at least at the front portion of the cutting bit shield/guard assembly  10 ′. This shoulder configuration  9 ′ assists with enabling the cutting bit shield/guard assembly  10 ′ to maintain its secured position on the perimeter of the rotating disc  7 ′ during operation. A plurality of these bit subassemblies and cutting bit shield/guard assemblies  10 ′ can be placed around the perimeter of the rotating disc  7 ′. The bit subassemblies and cutting bit shield/guard assemblies can be evenly spaced or randomly spaced. The cutting bit shield/guard assembly 10% as shown, can be wider at the front and narrower towards the back (closer to the cutting bit  15 ′). In an exemplary embodiment, it can be somewhat shaped like an arrow facing in the direction of rotation, as shown in  FIGS. 1-2 . 
         [0026]    Referring to  FIGS. 5-6 , a side view and a perspective view, respectively, of a cutting bit shield/guard assembly  10 ″ is shown. The cutting bit shield/guard assembly  10 ″ includes at least one layer of a shock absorbing material  20 . This material contains a material with a lower relative hardness value (i.e., softer) than the surrounding top portion  24  of the cutting bit shield/guard assembly  10 ′ and of the bottom portion  22  of the cutting bit shield/guard assembly  10 ″, which is the portion that attaches to the perimeter of a rotating disc  7 ,  7 ′. When a rotating disc  7 ,  7 ′ is spinning while in use, the shock absorbing material  20  can help absorb, spread out and/or dissipate the rotational energy when impacted by rocks, wood, or other debris. 
         [0027]    Ideally, the inclusion of shock absorbing material  20  provides some very minor additional movement of the cutting bit shield/guard assembly  10 ″ from the point of the shock absorbing material  20  upon impact to preserve the useful life of the cutting bit shield guard assembly  10 ″ (prevent fracture, chipping or other damage), while at the same time maintaining the protection of the cutting bit  15  via the cutting bit shield/guard assembly&#39;s  10 ″ positioning, shape, configuration and associated functionality (as discussed above and shown in the previous Figures). 
         [0028]    For example, upon a lateral impact, the shock absorbing material  20  is structured, configured, and positioned to allow at least a portion of the cutting bit shield/guard assembly  10 ″ to move in the direction of the lateral force m amount equal to 5% to 20% of its total width (while at the same time being in position to protect the cutting bit with which it is associated), and then to maw back to its original position. Similarly, for example, upon impact from the front of the cutting bit shield/guard assembly  10 ″, the shock absorbing material  20  is structured, configured, and positioned to allow at least a portion of the cutting bit shield/guard assembly  10 ″ to move in the direction of the head-on force opposite the rotational force of the rotating disc  7 ,  7 ′ in an amount equal to 5% to 20% of its total length, height or combination thereof (while at the same time being in position to protect the cutting bit with which it is associated) and then to move back to its original position. Such movement can be a compressive movement, a movement away from the center of the rotating disc  7 ,  7 ′ or a combination thereof. Any of the movement discussed herein is preferably more movement than the cutting bit shield/guard assembly  10 ″ would have without being damaged if no shock absorbing material  20  was part of the cutting bit shield/guard assembly  10 ″. 
         [0029]    The shock absorbing material can exist in an infinite number of various planar layers within the three dimensional cutting bit shield/guard assembly, in addition to the horizontal planar layers that are shown in  FIGS. 5-6 . For example, the shock absorbing material planar layers (which include a thickness, a length, and a width and can extend in a particular planar layer in order to sufficiently meet the purpose and functionality of the shock absorbing layer (including to absorb etc. part of a particular force coming from a particular direction) described herein), can exist in a planar vertical layer  20 ′ and a planer angled layer  20 ″ (which can be angled from the horizontal or from the vertical) as shown in  FIG. 7  (which is a front schematic view of a cutting bit shield/guard assembly  10 ′″, showing various shock absorbing material layers). Further, the shock absorbing material layers can exist together in a single cutting bit shield/guard assembly and can overlap, but do not have to  FIG. 7  does not take into account depth, so shock absorbing material layer  20 ″, for example, can start from about the front of the cutting bit shield/guard assembly  10 ′″ and extend to the back of the cutting bit shield/guard assembly  10 ′″. Further, the horizontal shock absorbing material  20  layer docs not have to extend from front to back of the cutting bit shield/guard assembly  10 ″′, and the vertical shock absorbing material  20 ′ layer does not have to extend from top to bottom of the cutting bit shield/guard assembly  10 ″′. With such an infinite number of shock absorbing material layers, upon particular impacts, portions of a particular cutting bit shield/guard assembly can move in different directions as a result of the functionality of the shock absorbing material layers upon such impacts. For example, if there is a shock absorbing material vertical layer placed in the middle of a cutting bit shield/guard assembly, the part of the cutting bit shield/guard assembly in front of the shock absorbing material vertical layer could move to the left upon a right side impact while the rear portion of the cutting bit shield/guard assembly behind the shock absorbing material vertical layer could stay stationary 
         [0030]    As shown, the shock absorbing material  20  has a particular shape fraction where, for example, the at least one layer of the shock absorbing material  20  extends in a plane with a particular thickness that is not as wide as its length or width. 
         [0031]    In an exemplary embodiment, the cutting bits may be made of a carbide material. In additional exemplary embodiment, the shock absorbing material may be made from a rubber with a durometer of about between 80 and 100 (shore A). In an alternative embodiment, the shock absorbing material may be made of a woven metal mesh material, which can be weaved and compressed, and can have the same properties of the shock absorbing material  20  made from the rubber with a particular high durometer. These particular exemplarily compositional configurations are preferably sufficient to meet the particular purposes/functionalities of the shock absorbing material discussed above (i.e., the durometer value and/or the weave and metal wire size of the woven mesh material can change, and long as the purposes/functionalities are met and maintained). 
         [0032]    While several embodiments of the invention have been discussed, it will be appreciated by those skilled in the art that various modifications and variations of the present invention are possible. Such modifications do not depart from the spirit and scope of the present invention.