Patent Publication Number: US-2023138956-A1

Title: Milling tool

Description:
BACKGROUND 
     Technical Field 
     The present invention generally relates to milling machinery. 
     Background of the Invention 
     As known to those of ordinary skill and described in U.S. Pat. No. 9,103,079, a milling machine may be used as a soil stabilizer to cut, mix, and pulverize native in-place soils with additives or aggregates to modify and stabilize the soil for a strong base. A milling machine may also be used as a road reclaimer to pulverize a surface layer, such as asphalt, and can mix it with an underlying base to create a new road surface and stabilize deteriorated roadways. 
     Milling tools comprising a base and a sleeve are widely known in the road construction industry. Commonly, these milling tools have a sleeve (also known as a bit holder) that secures press fit into a bore in a base. For example, U.S. Pat. No. 10,598,013 (the &#39;013 patent), the entire contents of which are incorporated herein by reference, teaches a bit holder that is interference or press fit into a base opening. In particular, a slot in the bit holder shank allows the shank to radially compress to fit into the base opening. The bit holder, in turn, secures a diamond, tungsten carbide, or other bit. The system of the &#39;013 patent suffers from several disadvantages, however. For example, the bit holder head may become misaligned with the opening. Further, it may be difficult or unsafe to install the bit holder into the base with this design, and the bit holder may become loose over time. In addition, the side of the head opposite the slot may become plastically deformed. 
     It would be advantageous to provide milling tools that have increased durability, holding power and ease of installation. For example, unlike the sleeve of the &#39;013 patent, the rear ends of the sleeves of the preferred embodiments of the invention include flanges and deflect inward as the sleeves enter the base opening and then relax (radially expand) after they pass rearwardly beyond the rear end of the base opening, which allows the sleeve to lock more firmly into place. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a front top side perspective view of a milling tool of one embodiment of the present invention. 
         FIG.  2    illustrates a top plan view of the milling tool of  FIG.  1   . 
         FIG.  3    illustrates a side elevation view of the milling tool of  FIG.  1   . 
         FIG.  4    illustrates a rear elevation view of the milling tool of  FIG.  1   . 
         FIG.  5    illustrates a side plan view of the milling tool of  FIG.  1   ; in  FIG.  5   , the sleeve is removed from the base. 
         FIG.  6    illustrates a side plan cross sectional view of the milling tool of  FIG.  1   ; in  FIG.  6   , the sleeve is removed from the base. 
         FIG.  7    illustrates a rear top side perspective view of the sleeve of the milling tool of  FIG.  1   . 
         FIG.  8    illustrates a rear bottom side perspective view of the base of the milling tool of  FIG.  1   . 
         FIG.  9    illustrates a top front side perspective view of a milling machine drum equipped with a plurality of the milling tools of  FIG.  1   ; in  FIG.  9   , bits are located in the generally cylindrical shanks of the sleeves. 
         FIG.  10    illustrates a front top side perspective view of a milling tool of one embodiment of the present invention. 
         FIG.  11    illustrates a front elevation view of the milling tool of  FIG.  10   . 
         FIG.  12    illustrates a side plan cross sectional view of the milling tool of  FIG.  10   . 
         FIG.  13    illustrates a side plan view of the milling tool of  FIG.  10   . 
         FIG.  14    illustrates a rear elevation view of the milling tool of  FIG.  10   . 
         FIG.  15    illustrates a bottom plan view of the milling tool of  FIG.  10   . 
         FIG.  16    illustrates a illustrates a front top side perspective view of the milling tool of  FIG.  10   ; in  FIG.  16   , the sleeve is removed from the base. 
         FIG.  17    illustrates a front elevation view of the milling tool of  FIG.  10   ; in  FIG.  17   , the sleeve is removed from the base. 
         FIG.  18    illustrates a side plan cross sectional view of the milling tool of  FIG.  10   ; in  FIG.  18   , the sleeve is removed from the base. 
         FIG.  19    illustrates a rear elevation view of the milling tool of  FIG.  10   ; in  FIG.  19   , the sleeve is removed from the base. 
         FIG.  20    illustrates a front top side perspective view of a milling tool of one embodiment of the present invention. 
         FIG.  21    illustrates a front elevation view of the milling tool of  FIG.  20   . 
         FIG.  22    illustrates a rear elevation view of the milling tool of  FIG.  20   . 
         FIG.  23    illustrates a side plan cross sectional view of the milling tool of  FIG.  20   . 
         FIG.  24 A  illustrates a front bottom side perspective view of a milling tool sleeve of one embodiment of the present invention. 
         FIG.  24 B  illustrates a rear top side perspective view of the milling tool sleeve of  FIG.  24 A . 
         FIG.  24 C  illustrates a side plan view of the milling tool sleeve of  FIG.  24 A . 
         FIG.  24 D  illustrates a front plan view of the milling tool sleeve of  FIG.  24 A . 
         FIG.  24 E  illustrates a rear plan view of the milling tool sleeve of  FIG.  24 A . 
         FIG.  25 A  illustrates a front bottom side perspective view of a milling tool sleeve of one embodiment of the present invention. 
         FIG.  25 B  illustrates a rear top side perspective view of the milling tool sleeve of  FIG.  25 A . 
         FIG.  25 C  illustrates a side plan view of the milling tool sleeve of  FIG.  25 A . 
         FIG.  25 D  illustrates a front plan view of the milling tool sleeve of  FIG.  25 A . 
         FIG.  25 E  illustrates a rear plan view of the milling tool sleeve of  FIG.  25 A . 
         FIG.  26 A  illustrates a front bottom side perspective view of a milling tool sleeve of one embodiment of the present invention. 
         FIG.  26 B  illustrates a rear top side perspective view of the milling tool sleeve of  FIG.  26 A . 
         FIG.  26 C  illustrates a side plan view of the milling tool sleeve of  FIG.  26 A . 
         FIG.  26 D  illustrates a front plan view of the milling tool sleeve of  FIG.  26 A . 
         FIG.  26 E  illustrates a rear plan view of the milling tool sleeve of  FIG.  26 A . 
         FIG.  27 A  illustrates an exploded perspective view of the milling tool of  FIG.  10    and a bit. 
         FIG.  27 B  illustrates an exploded perspective view of the milling tool of  FIG.  10    and a bit. 
         FIG.  28 A  illustrates an exploded perspective view of the base of  FIG.  20    and the sleeve of  FIG.  25 A  and a bit. 
         FIG.  28 B  illustrates an exploded perspective view of the base of  FIG.  20    and the sleeve of  FIG.  25 A  and a bit. 
     
    
    
     SUMMARY OF INVENTION 
     In some embodiments, the present disclosure provides a method for milling a surface that includes one or more of the following steps: a) providing a base that may include i) a base lower portion that may include a front, a rear, a length extending from the front to the rear, and/or a width extending perpendicular to the length; and ii) a base upper portion that may extend from the base lower portion and may include a front comprising a front face, a rear comprising a rear face, a length extending from the front to the rear and parallel to the base lower portion length, a width parallel to the base lower portion width, and/or an interior wall that may form a base upper portion opening extending through the base upper portion from the front face to the rear face, the base upper portion opening optionally comprising a front adjacent the front face, a rear adjacent the rear face, and/or an inner diameter extending across the base upper portion opening; b) providing a sleeve that may include i) a head that may have a front end, a rear end, a length extending from the front end to the rear end, a head diameter, and/or an exterior surface; ii) a shank that may extend rearwardly from the head rear end, the shank optionally comprising a shank front end adjacent to the head rear end, a shank rear end, a length extending from the shank front end to the shank rear end, an outer diameter, an exterior surface, and/or a deflectable rear section located at the shank rear end, the deflectable rear section optionally comprising one or more slots, the one or more slots optionally having a slot front end, a slot rear end located at the shank rear end, and a length extending from the slot front end to the slot rear end; iii) a hole that may pass through the head and shank of the sleeve to form a hollow sleeve interior, the hollow sleeve interior optionally comprising a sleeve interior surface and a sleeve inner diameter; optionally, the sleeve shank is configured to be removably inserted into the base upper portion opening; optionally, the deflectable rear section is configured to deflect inwardly from a relaxed position to a constricted position as the rear end of the sleeve shank is inserted into the front end of the base upper portion opening; optionally, the deflectable rear section is configured to move outwardly and at least partially (i.e., partially or fully) return to the relaxed position after the rear end of the sleeve shank exits the rear end of the base upper portion opening; c) securing the sleeve shank to the base by optionally inserting/passing the rear end of the sleeve shank into the front end of the base upper portion opening and then out the rear end of the base upper portion opening (i.e., moving the rear end of the sleeve shank rearwardly through the base upper portion opening), optionally, the deflectable rear section moves from the relaxed position to the constricted position as the rear end of the sleeve shank is inserted into the front end of the base upper portion opening, and optionally, the deflectable rear section at least partially returns to the relaxed position as the rear end of the sleeve shank exits the rear end of the base upper portion opening; d) securing a milling bit to the sleeve by optionally inserting the milling bit into the sleeve hole; and e) optionally rotating the base (and the sleeve shank and the milling bit secured to the base), on a drum of a milling machine. Optionally, prior to step e), the base has been secured to the exterior surface of the drum by a riser block having a top surface and a bottom surface. More particularly, optionally, the riser block bottom surface has been welded to the exterior surface of the drum, and the lower portion of the base has been welded to the riser block top surface. The method may be performed in any suitable order. For example, optionally, in an exemplary sequence, the riser block bottom surface is welded to the drum exterior surface, then the base lower portion is welded to the riser block top surface, then the sleeve is secured to the base by positioning the shank through the base upper portion opening and then the milling bit is positioned into the sleeve hole. 
     Optionally, the drum is moving along a surface and the milling bit is milling the surface during step e). Optionally, a plurality of milling tools can be secured to the drum by repeating steps a)-d) a plurality of times (so that the drum comprises a plurality of bases, sleeves, and milling bits). 
     Optionally, the deflectable rear section comprises a flange, the flange protruding outwardly as compared to a section of the shank immediately forward of the flange, and further wherein when the deflectable rear section at least partially returns to the relaxed position (i.e., at the conclusion of step c)), the flange is located rearwardly relative to the base upper portion opening. Optionally, the flange extends at least partially around a circumference of the deflectable rear section. Optionally, the plurality of slots interrupts the flange, and, except for where the plurality of slots interrupt the flange, the flange forms a rim and extends completely around a circumference of the deflectable rear section. Optionally, the sleeve shank outer diameter at the flange is greater than the inner diameter of the base upper portion opening at the base upper portion opening rear. Optionally, the flange is configured to engage the base upper portion rear face and inhibits the rear end of the sleeve shank from moving through the base upper portion opening rear. Optionally, the sleeve shank rear end/a rearward portion of the sleeve shank is indented. 
     Optionally, when the deflectable rear section at least partially returns to the relaxed position (i.e., at the conclusion of step c)), the sleeve head is located in front of the base upper portion opening front and there is a space/gap between the sleeve head rear end and the base upper portion front face (i.e., the sleeve head rear end does not abut the base upper portion front face when the sleeve is installed). Optionally, the space/gap is configured to allow the sleeve head rear end to move toward and/or away from the base upper portion front face when the milling tool is milling a surface. Optionally, the sleeve head is conical in shape. 
     Optionally, the at least one slot comprises a plurality of slots, wherein the deflectable rear section comprises a plurality of deflectable slot tails separated by the plurality of slots, and further wherein each slot tail comprises a portion of the flange and further wherein each slot tail has a free rear end. Optionally, the plurality of slots extends from the shank exterior surface to the sleeve interior surface. Optionally, the plurality of slots is arch-shaped. Optionally, the plurality of slots has a width parallel to the outer diameter, and the slot width increases at the rear end of the shank. Optionally, the plurality of slots comprises at least two slots. 
     Optionally, the sleeve head comprises a plurality of indentations spaced about a perimeter of the sleeve head, the plurality of indentations extending from the front face of the sleeve head rearwardly. Optionally, the sleeve is removed from the base upper portion opening by placing a sleeve removal tool (e.g., a wedge-type fork) between the sleeve head and base upper portion front. Optionally, the plurality of indentations is semi-cylindrical in shape. Optionally, the sleeve head diameter is greater than the outer diameter of the portion of the sleeve shank located forwardly relative to the plurality of slots. 
     In some embodiments, the base lower portion bottom comprises a fastener aperture and the base is secured to the drum by placing a fastener through the fastener aperture and into the drum prior to step e). Optionally, the base lower portion bottom is flat. Optionally, the base upper portion front face and head rear face are flat. Optionally, the base upper portion rear face is flat. Optionally, the inner diameter of the base upper portion opening varies in size. Optionally, the inner diameter of the base upper portion opening is largest at the base upper portion front end. Optionally, the base upper portion opening comprises a tapered front section in which the inner diameter of the base upper portion opening tapers in decreasing size rearwardly from the base upper portion opening front. Optionally, the base upper portion opening comprises a tapered rear section in which the inner diameter of the base upper portion opening tapers in decreasing size forwardly from the base upper portion opening rear. Optionally, the base upper portion inner diameter is larger at the tapered front and rear sections than the area between the tapered front and rear sections. 
     In some embodiments, the base upper portion extends upward from the base lower portion top at an angle between 1 and 90 degrees. 
     In some embodiments, the base, sleeve shank, and milling bit are comprised of metal. Optionally, the bit comprises a diamond or tungsten carbide tip. Optionally, the sleeve is comprised of cold-forged steel. 
     In some embodiments, the sleeve shank and opening are cylindrical in shape. 
     In still further embodiments, the present disclosure provides a method for milling a surface that includes one or more of the following steps: a) providing a base that may include a base opening comprising a front adjacent the front face, a rear adjacent the rear face, and an inner diameter extending across the base opening; b) providing a sleeve that may include: i) a head that may have a front end, a rear end, a length extending from the front end to the rear end, a head diameter, and an exterior surface; ii) a shank that may extend rearwardly from the head rear end and may include a shank front end adjacent to the head rear end, a shank rear end, a length extending from the shank front end to the shank rear end, an outer diameter, an exterior surface, and a deflectable rear section that may be located at the shank rear end and may include one or more slots that may have a slot front end, a slot rear end located at the shank rear end, and a length extending from the slot front end to the slot rear end; and/or iii) a hole that may pass through the head and shank of the sleeve to form a hollow sleeve interior that may include a sleeve interior surface and a sleeve inner diameter. Optionally, the sleeve shank is configured to be removably inserted into the base opening. Optionally, the deflectable rear section is configured to deflect inwardly from a relaxed position to a constricted position as the rear end of the sleeve shank is inserted into the front end of the base opening. Optionally, the deflectable rear section is configured to move outwardly and at least partially return to the relaxed position after the rear end of the sleeve shank exits the rear end of the base opening. Optionally, the method further includes c) securing the sleeve shank to the base by inserting/passing the rear end of the sleeve shank into the front end of the opening and then out the rear end of the base opening optionally so that the deflectable rear section moves from the relaxed position to the constricted position as the rear end of the sleeve shank is inserted into the front end of the base opening, and optionally so that the deflectable rear section at least partially returns to the relaxed position as the rear end of the sleeve shank exits the rear end of the base opening. Optionally, the method further includes d) securing a milling bit to the sleeve by inserting the milling bit into the sleeve hole. Optionally, the method further includes e) rotating the base, and the sleeve shank and the milling bit secured to the base, on a drum of a milling machine. In addition, the base, sleeve, milling bit, drum and method may include one or more features and additional steps described above. 
     DETAILED DESCRIPTION 
     With reference to  FIGS.  1 - 28 B , the present invention provides milling tools as described herein.  FIGS.  1 - 28 B  are CAD drawings drawn to scale. However, other dimensions are possible. 
     Referring further to  FIGS.  1 - 28 B , in some embodiments, the present invention relates to bit mounting assemblies  14  that may include a base  16 , a sleeve  70  secured to the base  16 , and a milling bit  132  secured to the sleeve  70 . As shown in  FIG.  9   , the bit mounting assemblies  14  may be mounted to the drums  10  of a milling machine. More particularly, optionally, in use milling a road or soil, as best seen in  FIG.  9   , a plurality of bit mounting assemblies  14  (each with an associated base  16 , sleeve  70  and milling bit  132 ) arranged in a helical pattern may be mounted around the exterior of a drum  10  of a milling machine. The milling machine may roll the drum  10  along a surface (e.g., soil or a road) so that the milling bit  132  mills the surface. 
     The base  16  may include a lower portion  18  comprising a front  20 , a rear  22 , a length  24  extending from the front  20  to the rear  22 , a left side  26 , a right side  28 , a width  30  extending from the left side  26  to the right side  28  and perpendicular to the length  24 , a top  32 , a bottom  34 , and a height  36  extending from the top  32  to the bottom  34  and perpendicular to the length  24  and the width  30 . The base  16  may further include an upper portion  38  that may extend from the base lower portion top  32  at an angle of, for example, between 1 and 90 degrees and may include a front  40  comprising a front face  42  that is generally flat, a rear  44  comprising a rear face  46  that is generally flat, a length  48  extending from the front  40  to the rear  44  and parallel to the base lower portion length  24 , a left side  50 , a right side  52 , a width  54  extending from the left side  50  to the right side  52  and parallel to the base lower portion width  30 , a top  56 , a bottom  58 , and a height  60  extending from the top  56  to the bottom  58  and parallel to the base lower portion height  36 , and an interior wall  62  forming an opening  64  that receives the sleeve  70 . The base upper portion opening  64  may extend through the base upper portion  38  from the front face  42  to the rear face  46 . As noted above and shown in  FIGS.  1 - 28 B , the base upper portion  38  (including the front face  42  and rear face  46  and opening  64 ) may be angled relative to the base lower portion bottom  34   
     As best seen in  FIGS.  6  and  18   , the base upper portion opening  64  may comprise a front end  134  adjacent the front face  42 , a rear end  136  adjacent to the rear face  46 , and a varying inner diameter  66  extending across the base upper portion opening  64 , and the varying inner diameter  66  may be largest at the front end  134 . As best seen in  FIGS.  6  and  18   , the base upper portion opening  64  may further comprise a tapered front section  135  in which the inner diameter  66  of the base upper portion opening  64  tapers in decreasing size rearwardly from the base upper portion opening front end  134 . As best seen in  FIGS.  6  and  18   , the base upper portion opening  64  may also comprise a tapered rear section  137  in which the inner diameter  66  of the base upper portion opening  64  tapers in decreasing size forwardly from the base upper portion rear end  136 . As best seen in  FIGS.  6  and  18   , the base upper portion inner diameter  66  may be larger at the tapered front and rear sections  135  and  137  than the area between the tapered front and rear sections  135  and  137 . 
     The sleeve (also known as a bit holder)  70  may be generally cylindrical and may include a head  72  having a front end  74 , a rear end  76  that may be generally flat, a length  78  extending from the front end  74  to the rear end  76 , a head diameter  80 , and an exterior surface  82 . The sleeve  70  may also include a shank  84  extending rearwardly from the head rear end  76 . The shank  84  may include a shank front end  86  adjacent to the head rear end  76 , a shank rear end  88 , and a length  90  extending from the shank front end  86  to the shank rear end  88 , an outer diameter  92 , and an exterior surface  94 . 
     The sleeve  70  may also include a sleeve hole  100  passing through the sleeve head  72  and sleeve shank  84  to form a hollow sleeve interior  102  that receives the milling bit  132 . The hollow sleeve interior  102  may include a sleeve interior surface  104  and a sleeve inner diameter  106 . The sleeve shank  84  may be configured to be removably inserted into the base upper portion opening  64  and, when inserted, may abut the interior wall  62   
     The shank  84  may also include a deflectable rear section  88 A that may be located at the shank rear end  88  and that may include one or more flanges  96 , and/or deflectable slot tails slots  98 . More particularly, as shown in the embodiments depicted in  FIGS.  1 - 28 B , the deflectable rear section  88 A may comprise a plurality of deflectable slot tails  99  separated by a plurality of slots  98 . Each slot tail  99  may comprise a portion of the flange  96 . 
     To lock the sleeve  70  into the base upper portion opening  64 , the deflectable rear section  88 A may be configured to deflect inwardly from a relaxed position to a constricted position as the sleeve shank rear end  88  is inserted into the front end  134  of the base upper portion opening  64 . The deflectable rear section  88 A may be configured to move outwardly and at least partially return to the relaxed position after the sleeve shank rear end  88  exits the rear end  136  of the base upper portion opening  64 . In other words, the sleeve  70  may be secured to the base  16  by inserting the sleeve shank rear end  88  into the front end  134  of the generally cylindrical base upper portion opening  64  and then out the rear end  136  of the base upper portion opening  64  (i.e., moving the sleeve shank rear end  88  rearwardly through the base upper portion opening  64 ). The deflectable rear section  88 A may move from the relaxed position to the constricted position as the sleeve shank rear end  88  is inserted into the front end  134  of the base upper portion opening  64 . The deflectable rear section  88 A may at least partially return to the relaxed position as the sleeve shank rear end  88  exits the rear end  136  of the base upper portion opening  64 . 
     The flange  96  may protrude outwardly as compared to a section of the shank  84  immediately forward of the flange  94 B. The flange  96  may be located rearwardly relative to the base upper portion opening  64 . The flange  96  may extend at least partially around a circumference of the deflectable rear section  88 A. The plurality of slots  98  may interrupt the flange  96 . Optionally, except for where the plurality of slots  98  interrupt the flange  96 , the flange  96  may form a rim and extend completely around a circumference of the deflectable rear section  88 A. The sleeve shank outer diameter  92  at the flange  96  may be greater than the base upper portion opening inner diameter  66  at the base upper portion opening rear end  136 . The flange  96  may be configured to engage the base upper portion rear face  46  and inhibits the sleeve shank rear end  88  from moving through the base upper portion opening rear end  136 . 
     Each slot tail  99  may have a free rear end. The plurality of slots  98  may extend from the shank exterior surface  94  to the sleeve interior surface  104 . The plurality of slots  98  may be arch-shaped. Each of the plurality of slots  98  may have a width  101  parallel to the outer diameter  92  and the slot width  101  may increase at the rear end of the shank  84 . The one or more slots  98  may have a slot front end  98 A, a slot rear end  98 B located at the shank rear end  88 , and a length  98 C extending from the slot front end  98 A to the slot rear end  98 B. 
     As shown in, for example,  FIGS.  3 ,  12  and  13   , when the deflectable rear section  88 A at least partially returns to the relaxed position, the sleeve head  72  may be located in front of the base upper portion opening front end  134  and there may be a gap/space  128  between the sleeve head rear end  76  and the base upper portion front face  42 . The space  128  may be configured to allow the sleeve head rear end  76  to move toward and/or away from the base upper portion front face  42  when the milling bit  132  is milling a surface. 
     The sleeve head diameter  80  may be greater than the outer diameter of the portion of the sleeve shank  92  located forwardly relative to the plurality of slots  98 . 
     The sleeve head  72  may comprise a plurality of indentations  126  spaced about a perimeter of the sleeve head  72 , and the plurality of indentations  126  may extend from the front of the sleeve head  74  rearwardly. The plurality of indentations  126  may be semi-cylindrical in shape. 
     The sleeve  70  may be removed from the base upper portion opening  64  by placing a sleeve removal tool (e.g., a wedge-type fork) between the sleeve head  72  and the base upper portion front  40 . 
     As shown in  FIGS.  26 A- 26 E , the flange  96  may be indented approximately half of the full length of the slot tails  99 , and the plurality of slots  98  is confined to the full-length slot tails  99 . 
     In some embodiments, the base  16 , sleeve shank  84 , and milling bit  132  are comprised of metal. Alternatively, the sleeve  70  can be comprised of cold forged steel. 
     Optionally, as shown in  FIGS.  5  and  25 A- 26 E , the heads  72  may be conical in shape and may optionally include a nose  114 . 
     Referring to  FIGS.  27 A- 28 B , the milling bit  132  may be secured to the sleeve  70  by inserting the milling bit  132  into the sleeve hole  100 . The sleeve  70  and milling bit  132  may be then secured to the base  16  by inserting the sleeve  70  into the base upper portion opening  64 . In some embodiments, the bit mounting assembly  14  may be then secured to the drum  10  by placing a fastener through the fastener apertures  110  and into the drum  10 . Alternatively, the base lower portion  18  may be welded to a riser block  108  top surface and the riser block bottom surface is welded to the drum  10 . 
     In some embodiments, the milling bit  132  comprises a diamond or tungsten carbide tip. 
     The milling tools described herein may provide several advantages. For example, in some embodiments, the exterior surface  94  of the sleeve shank  84  may be fit for fit, i.e., flush against the interior wall  62  of the base upper portion opening  64  in the base upper portion. Without being bound to any particular theory, this may prevent distortion or misalignment of the sleeve  70  once the sleeve  70  is seated in the base upper portion opening  64 . 
     Further, there may be a small gap  128 , e.g., 6 millimeters, between the sleeve head rear end  76  and the base upper portion front face  42  when the exterior surface  94  of the sleeve shank  84  is flush against the interior wall  62  of the base upper portion opening  64 . When the bit mounting assembly  14  is used on a road, the road may exert a rearward force on the bit  132  and sleeve  70 . The gap  128  may allow the sleeve  70  to be driven deeper into the base upper portion opening  64  by the rearward force exerted by the road. Without being bound to any particular theory, this may have a shock absorbing effect that extends the life of the bit assembly  14 . Additionally, the holding power of the bit assembly  14  may increase as the sleeve  70  is driven deeper into the base upper portion opening  64 . 
     Additionally, the sleeve  70  may be snap fit into the base  16  through the previously described action of the deflectable rear portion  88 A and slot tails  99 . Without being bound to any particular theory, the sleeve  70  being snap fit in the base upper portion opening  64  may serve to initially secure the sleeve  70  into the base  16 . As the sleeve shank  84  and the base upper portion interior wall  62  wear down with use and the sleeve  70  drives deeper into the base upper portion opening  64 , the sleeve shank flange  96  may disengage from the base upper portion rear  44 . At this point the sleeve  70  may transition from being snap-fit in the base upper portion opening  64  to being interference fit in the base upper portion opening  64 . As the sleeve shank  84  and the base upper portion interior wall  62  wear further, the shank flange  84  may reengage the base upper portion rear  44  to prevent the sleeve from ejecting from the base upper portion opening  64  if the interference fit fails. 
     Current tool systems may require several hits with steel hammers to install the sleeve into the base. Hitting the steel hammer against the steel or other metal of the tool system during installation may be unsafe. The design described herein preferably allows a user to install the sleeve into the base of the tool system using a rubber dead blow hammer or similar tool. 
     This discussion is only intended to provide examples of the advantages of the present design. It is not intended to be exclusive of other advantages or limiting on the scope of the claims. 
     
       
         
           
               
             
               
                   
               
               
                 Parts List 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Drum 
                 10 
               
               
                   
                 Drum Exterior Surface 
                 12 
               
               
                   
                 Bit Mounting Assembly 
                 14 
               
               
                   
                 Base 
                 16 
               
               
                   
                 Base Lower Portion 
                 18 
               
               
                   
                 Base Lower Portion Front 
                 20 
               
               
                   
                 Base Lower Portion Rear 
                 22 
               
               
                   
                 Base Lower Portion Length 
                 24 
               
               
                   
                 Base Lower Portion Left Side 
                 26 
               
               
                   
                 Base Lower Portion Right Side 
                 28 
               
               
                   
                 Base Lower Portion Width 
                 30 
               
               
                   
                 Base Lower Portion Top 
                 32 
               
               
                   
                 Base Lower Portion Bottom 
                 34 
               
               
                   
                 Base Lower Portion Height 
                 36 
               
               
                   
                 Base Upper Portion 
                 38 
               
               
                   
                 Base Upper Portion Front 
                 40 
               
               
                   
                 Base Upper Portion Front Face 
                 42 
               
               
                   
                 Base Upper Portion Rear 
                 44 
               
               
                   
                 Base Upper Portion Rear Face 
                 46 
               
               
                   
                 Base Upper Portion Length 
                 48 
               
               
                   
                 Base Upper Portion Left Side 
                 50 
               
               
                   
                 Base Upper Portion Right Side 
                 52 
               
               
                   
                 Base Upper Portion Width 
                 54 
               
               
                   
                 Base Upper Portion Top 
                 56 
               
               
                   
                 Base Upper Portion Bottom 
                 58 
               
               
                   
                 Base Upper Portion Height 
                 60 
               
               
                   
                 Base Upper Portion Interior Wall 
                 62 
               
               
                   
                 Base Upper Portion Opening 
                 64 
               
               
                   
                 Base Upper Portion Opening Inner Diameter 
                 66 
               
               
                   
                 Sleeve 
                 70 
               
               
                   
                 Sleeve Head 
                 72 
               
               
                   
                 Sleeve Head Front End 
                 74 
               
               
                   
                 Sleeve Head Rear End 
                 76 
               
               
                   
                 Sleeve Head Length 
                 78 
               
               
                   
                 Sleeve Head Diameter 
                 80 
               
               
                   
                 Sleeve Head Exterior Surface 
                 82 
               
               
                   
                 Sleeve Shank 
                 84 
               
               
                   
                 Sleeve Shank Front End 
                 86 
               
               
                   
                 Sleeve Shank Rear End 
                 88 
               
               
                   
                 Deflectable Rear Section 
                     88A 
               
               
                   
                 Sleeve Shank Length 
                 90 
               
               
                   
                 Sleeve Shank Outer Diameter 
                 92 
               
               
                   
                 Sleeve Shank Exterior Surface 
                 94 
               
               
                   
                 Sleeve Shank Exterior Surface Forward Section 
                     94A 
               
               
                   
                 Sleeve Shank Exterior Surface Middle Section 
                     94B 
               
               
                   
                 Sleeve Shank Flange 
                 96 
               
               
                   
                 Plurality of Slots 
                 98 
               
               
                   
                 Slot Front End 
                     98A 
               
               
                   
                 Slot Rear End 
                     98B 
               
               
                   
                 Slot Length 
                     98C 
               
               
                   
                 Plurality of Slot Tails 
                 99 
               
               
                   
                 Sleeve Hole 
                 100  
               
               
                   
                 Slot Width 
                 101  
               
               
                   
                 Sleeve Interior 
                 102  
               
               
                   
                 Sleeve Interior Surface 
                 104  
               
               
                   
                 Sleeve Inner Diameter 
                 106  
               
               
                   
                 Riser Block 
                 108  
               
               
                   
                 Fastener Aperture 
                 110  
               
               
                   
                 Sleeve Head Nose 
                 114  
               
               
                   
                 Sleeve Head Nose Front Face 
                 116  
               
               
                   
                 Sleeve Head Nose Outer Diameter 
                 118  
               
               
                   
                 Sleeve Head Base 
                 120  
               
               
                   
                 Sleeve Head Base Diameter 
                 122  
               
               
                   
                 Sleeve Head Base Rear Face 
                 124  
               
               
                   
                 Plurality of Sleeve Head Indentions 
                 126  
               
               
                   
                 Gap between Sleeve and Base 
                 128  
               
               
                   
                 Milling/Cutting Bit 
                 132  
               
               
                   
                 Base Upper Portion Opening Front End 
                 134  
               
               
                   
                 Tapered Front End 
                 135  
               
               
                   
                 Base Upper Portion Opening Rear End 
                 136  
               
               
                   
                 Tapered Rear End 
                 137  
               
               
                   
                   
               
            
           
         
       
     
     Having now described the invention in accordance with the requirements of the patent statutes, those skilled in the art will understand how to make changes and modifications to the disclosed embodiments to meet their specific requirements or conditions. It is understood that use of the singular embraces the plural and vice versa. Changes and modifications may be made without departing from the scope and spirit of the invention. In addition, the steps of any method described herein may be performed in any suitable order and steps may be performed simultaneously if needed. 
     Terms of degree such as “generally”, “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.