Patent Publication Number: US-2019193227-A1

Title: Mower reel grinding system using predetermined bracket positions

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Utility Patent Application is a Continuation-in-Part of U.S. patent application Ser. No. 15/723,560, filed Oct. 3, 2017 which is a Continuation of U.S. patent application Ser. No. 14/616,068, filed Feb. 6, 2015, now U.S. Pat. No. 9,776,297, both of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Commercial mowers typically use reel-type mowing units which employ cylindrical cutting reels having a number of helical blades disposed about a central shaft. To ensure optimal cutting performance, the helical blades of the cutting reels must be regularly sharpened. Commercial grinders have been developed to perform such sharpening, which is typically a two part process. First, a spin grinding process is carried out during which the cutting reel is spun counter to a grinding wheel which “squares off” or grinds flat the end of each of the helical blades so as to “true” the reel to its desired cylindrical shape and to form a cutting edge theron. Second, a relief grinding process is carried out where the grinding wheel individually grinds a relief onto the back of each helical blade. 
     Mowing units typically include a frame structure to which the cutting reel, a bedknife, a front roller, and a rear roller are mounted. In order for the grinding process to sharpen the blades of the cutting reel as close as possible to OEM (original equipment manufacturer) specifications, the cutting reel must be properly aligned with the grinding wheel(s) of the grinding system. Conventional grinding systems typically secure to and position the cutting reel of mowing units using the front roller. 
     However, mowing units of different types have different characteristics that often require unique setup requirements. For example, the configuration of the mower unit components may vary between cutting reels of different sizes and between mower units from different manufactures with each configuration requiring a different setup. This is further complicated by the fact that the front roller is often moved to various positions, such as to enable the installation of attachments (e.g. combs, thatchers, groomers, etc.) to the front portion of the frame, thereby making access to the front roller difficult and changing roller positions so that even mowing units of the same manufacturer and model often require different setups for grinding. 
     In view of the above, while conventional mower reel grinding systems are effective at sharpening cutting reels, such grinding systems often require complicated setup procedures to place the cutting reel in a position for optimal grinding results. Such setup procedures are time consuming and can result in inconsistent and inaccurate sharpening of the cutting reel blades. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain principles of embodiments. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
         FIG. 1A  is a perspective view of an example of a reel-type mower unit. 
         FIG. 1B  is a schematic diagram generally illustrating a cross-sectional view of an example of a reel-type mower unit. 
         FIG. 2A  is a schematic diagram generally illustrating a cross-sectional view of an example of a flat-ground helical blade. 
         FIG. 2B  is a schematic diagram generally illustrating a cross-sectional view of an example of a flat-ground helical blade. 
         FIG. 3  is a perspective view illustrating a mower reel grinding system according to one example. 
         FIG. 4A  is a perspective view illustrating a mower reel grinding system, according to one example, with a mower unit mounted thereto. 
         FIG. 4B  is a perspective view illustrating a mower reel grinding system, according to one example, with a mower unit mounted thereto. 
         FIG. 5  is a perspective view illustrating a rear mounting assembly according to one example. 
         FIG. 6A  is a top view illustrating a rear mounting assembly in a first preset position, according to one example. 
         FIG. 6B  is a top view illustrating a rear mounting assembly in a second preset position, according to one example. 
         FIG. 7  is a perspective view illustrating a front mounting assembly according to one example. 
         FIG. 8  is a perspective view illustrating a traverse base assembly and a grinding head assembly, according to one example. 
         FIG. 9  is a perspective view illustrating a grinding head assembly according to one example. 
         FIG. 10A  is a side view illustrating a grinding head assembly, according to one example, in disengaged position. 
         FIG. 10B  is a side view illustrating a grinding head assembly, according to one example, in an engaged position. 
         FIG. 11A  is a side view illustrating an indexguide assembly of a grinding head assembly, according to one example, in a disengaged position. 
         FIG. 11B  is a side view illustrating an indexguide assembly of a grinding head assembly, according to one example, in an engaged position. 
         FIG. 12  is front perspective view of a mower reel grinding system, according to one embodiment, illustrating a mower unit positioned therein. 
         FIG. 13  is a side view of portions of a mower reel grinding system and showing a linear distance gauge positioning, according to one example. 
         FIG. 14  is a side view of portions of a mower reel grinding system and showing a linear distance gauge positioning, according to one example. 
         FIG. 15  is a side view of portions of a mower reel grinding system and showing a linear distance gauge positioning, according to one example. 
         FIG. 16  is a perspective view illustrating a spin drive system according to one example. 
         FIG. 17  is a perspective view illustrating a mower reel mounting assembly according to one example. 
         FIGS. 18A and 18B  generally illustrate a mower reel mounting assembly, according to one example. 
     
    
    
     DETAILED DESCRIPTION 
     In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
     It is to be understood that the features of the various exemplary embodiments described herein may be combined with each other, unless specifically noted otherwise. 
       FIG. 1A  is a bottom perspective view generally illustrating an example of a reel-type mower unit  10 . Reel-type mowing units, such as mower unit  10  typically include a frame structure  12  to which a rear roller  14 , a front roller  16 , a bedknife  18 , and a cylindrical cutting reel  20  are mounted, wherein cutting reel  20  includes a number of helical blades  22  disposed about a shaft  24 . 
       FIG. 1B  is a simplified schematic diagram illustrating a cross-sectional view showing portions of a typical mower unit, such as mower unit  10 . For ease of illustration, frame  12  is not shown in  FIG. 1B . As reel  20  rotates, as indicated by rotational arrow  26 , grass is cut at a sheer point  28  formed between the helical blades  22  and a leading edge of bedknife  18 . A height of cut, d HC , of the mower unit is typically adjusted by adjusting the vertical height (z-axis) of front roller  16  relative to central shaft  24  of cutting reel  20 . A horizontal distance (y-axis) between a centerline of rear roller  14  and a centerline (i.e. axis of rotation) of cutting reel  20  is indicated as d R , and a horizontal distance between a centerline of front roller  16  and the centerline of cutting reel  20  is indicated at d F . 
     As described above, sharpening is typically a two part process, i.e. a spin grinding process followed by a relief grinding process.  FIG. 2A  is a schematic diagram generally illustrating portions of a blade  22  after a spin grinding process, which includes positioning a grinding wheel of the grinding system and the cutting reel relative to one another so that the ends of all blades  22  of reel  20  are ground as cutting reel  20  is spun to “true” cutting reel  20  to a cylindrical shape.  FIG. 2B  is a schematic diagram generally illustrating blade  22  after a relief grinding process, where a grinding wheel is positioned to grind a relief bevel  25  having a relief angle θ onto a backside (or trailing edge) of blade  22  to form a cutting edge  27  that interacts with bedknife  18  to form sheer point  28 . 
     In order to ensure that the grinding process returns reel  20  and blades  22  to OEM specifications, reel  20 , and thus, blades  22 , must be properly positioned and aligned relative to the grinding wheel(s) used in the grinding process. Conventional grinding systems typically secure to the front roller of the mower unit, such as front roller  16  of mower unit  10  illustrated above by  FIGS. 1A and 2A , with some type of support mechanism. The support system and grinding wheel are then adjusted relative to one another to achieve proper positioning of reel  20  relative to the grinding wheel. Such an adjustment process can be difficult, as the distance d F  between the centerline of front roller  16  and the centerline of cutting reel  20  is often different between mower units  10  from different manufactures, and is often different between models of mower units  10  from the same manufacturer. Furthermore, the front roller  16  can be positioned at different horizontal locations for various purposes (e.g. for the installation of accessories such as groomers and brushes) so that distance dF can be different between the same models of cutting units from the same manufacturer. As such, it is often necessary to adjust the positioning to achieve proper alignment each time a different mower unit  10  is to be sharpened, even when mowers units of the same model from the same manufacturer are being consecutively sharpened. Such alignments are time consuming and can result in inconsistent and undesirable grinding results. 
     In contrast to the distance d F  between the centerlines of the front roller  16  and reel  20 , while the vertical position of rear roller  14  may vary, the horizontal distance d R  between the centerlines of the rear roller  14  and cutting reel  20  of a given model of mowing unit is typically at a constant distance, or at least within a tight range of distances. Additionally, attachments and accessories, such as brushes, groomer, and thatchers, for example, are not typically mounted on the rear of the mowing units. 
     According to the present disclosure, as will be described in greater detail below, a mower reel grinding system is provided which includes moveable mounting brackets that releasably secure to the rear roller of a mower unit, such as rear roller  14  of mower unit  10 , or to another predetermined pivot point or rotational axis on the a rear portion of the frame  12  of the mower unit. The mounting brackets are moveable in a horizontal plane to one of a number of predetermined positions along a positioning axis based on characteristics of the mower reel unit  10  (where such characteristics include the manufacturer of mower unit  10  and the size of cutting reel  20 , for example) so as to place the cutting reel  20  at a desired position along the positioning axis for grinding. As described herein, such positioning is referred to as horizontal positioning or horizontal placement of the cutting reel  20 . Moveable mounting brackets according to the present disclosure provide quicker setup and consistent and accurate horizontal placement of the cutting reel  20  relative to conventional grinding systems and, together with other aspects of the present disclosure, enables accurate and consistent grinding of cutting reel  20  to OEM specifications. 
       FIG. 3  is a perspective view illustrating portions of an example of a mower reel grinding system  50  including a cutting reel and grinder alignment system according to the present disclosure. Grinding system  50  includes an enclosure  52  having a shelf  54 , a traverse base assembly  56 , a moveable grinding head assembly  58 , a rear mounting assembly  60  including a horizontally moveable (i.e. y-axis or transverse direction) mounting platform  61 , a front mounting assembly  62  including vertically movable support pedestal  63 , a spin drive system  64 , and a microprocessor controller  66 .  FIGS. 4A and 4B  provide perspective views of the mower reel grinding system  50  of  FIG. 1  illustrating a mower unit  10  having a rear roller  14  releasably secured to rear mounting platform  60  and a front roller  16  releasably secured to front support platform  62  with a cutting reel  20  in position for grinding by grinding head assembly  58 , wherein the mounting and position of mower unit  10  will be described in greater detail below. 
       FIG. 5  is a perspective view illustrating an example of rear mounting assembly  60  including horizontally moving mounting platform  61  according to the present disclosure. In addition to mounting platform  61 , rear mounting assembly  60  includes a base portion  70  (which may be a part of shelf  54  of enclosure  52 ) having a pair of rails  71   a,    71   b  on which mounting platform  61  can move horizontally back and forth in the y-plane along a positioning axis  72 . A pair of v-shaped (although other geometries could be employed) brackets  74   a,    74   a  are positioned on mounting platform  61  proximate to a leading edge  76  and are configured to receive and center rear roller  14  of mowing unit  10  (see  FIG. 4A , for example). A horizontal position indexer  78  disposed on mounting platform  61  and a position selector  80  operate in conjunction with one another to set mounting platform  61  to one of plurality of predetermined positions along positioning axis  72  (see  FIGS. 6A and 6B  below). 
     A base channel  82  having a slot  84  there through, which corresponds to a slot  86  through mounting platform  61 , works with clamp assembly  90  to secure mounting platform  61  to base portion  70  when mounting platform is positioned at a desired location along position axis  72 . Clamp assembly  90  includes a shaft  92 , from which extends a flange  94 , a cam mechanism  96 , a set-arm  97 , a base plate  98 , and a flange element (not shown) extending through slots  84  and  86  and engaging base channel  82 . It is noted that set-arm  97  is shown in a release position where cam mechanism  96  is not set so that clamp assembly  90  is free to move within slots  84  and  86  and mounting platform  61  is able to move along positioning axis  72 . 
       FIGS. 6A and 6B  illustrate top views of rear mounting assembly  60  of  FIG. 5 , with clamp assembly  90  removed and position indexer  78  and position selector  80  illustrated in greater detail. According to one example, position indexer  78  includes a plurality of index markings, such as index markings  100   a,    100   b,  and  100   c,  wherein each index marking corresponds to one or more different types of mower units  10 . For instance, in the example illustrated by  FIG. 6A , index marking  100   a  corresponds to three different types of mower units: a first type by manufacturer “X” having a reel size “A” (e.g. 5-inch diameter) and requiring a relief angle of “θ 1 ” (e.g. 3-degrees); a second type by manufacturer “Y” having a reel size “A” and requiring a relief angle of “θ 2 ” (e.g. 5-degrees); and third type by manufacturer “Z” having a reel size “A” and requiring a relief angle of “θ 2 ”. Similarly, index marking  100   b  corresponds to one type of mower unit by manufacturer “X” having a reel size “A” and requiring a relief angle of “θ 3 ” (e.g. 6-degrees). Finally, index marking  100   c  corresponds to three different types of mower units: a first type by manufacturer “Z” having a reel size “B” (e.g. 7-inch diameter) and requiring a relief angle of “θ 4 ” (e.g. 12-degrees); a second type by manufacturer “Y” having a reel size “B” and requiring a relief angle of “θ 3 ”; and third type by manufacturer “X” having a reel size “B” and requiring a relief angle of “θ 3 ”. 
     It is noted that position indexer  78  can have any number of index markings (e.g. more or fewer than three as illustrated), with each index marking having at least one corresponding type of mower unit  10 . 
     According to one example, position selector  80  is a moveable selector pin  81  which is biased downward toward base portion  70  and extends into one of a number of corresponding openings (not shown) in base portion  70 , each of which corresponds to one of the index markings, such as index markings  100   a - 100   c,  aligning with a pointer element  102  disposed at a fixed position on shelf  54 . 
     In  FIG. 6A , moveable mounting platform  61  is illustrated as being positioned so that pointer element  102  is aligned with index marking  100   c.  At this position, when the rear roller  14  of any one of the three types of corresponding types of mower units  10  is positioned within v-brackets  74   a,    74   b,  the axis of rotation (i.e. shaft  24 ) of cutting reel  10  will be positioned at a desired grinding position along positioning axis  72  for that particular type of mower unit. 
     Similarly, in  FIG. 6B , moveable mounting platform  61  is illustrated as being positioned so that pointer element  102  is aligned with index marking  100   a.  At this position, when the rear roller  14  of any one of the three types of corresponding types of mower units  10  is positioned within v-brackets  74   a,    74   b,  the axis of rotation (i.e. shaft  24 ) of cutting reel  10  will be positioned at a desired grinding position along positioning axis  72  for that particular type of mower unit. 
     To move mounting platform  61  from one position to another, such as from the position illustrated in  FIG. 6A  to the position illustrated in  FIG. 6B , selector pin  81  is lifted upward and mounting platform is moved along positioning axis  72  until pointer element  102  aligns with index marking  100   a.  Selector pin  81  is then released so as to engage the corresponding opening (not shown) in base portion  70  and hold mounting platform  61  in place. After the rear roller  14  of a corresponding type of mower unit  10  is placed in v-brackets  74   a,    74   b,  flange  94  of clamp assembly  90  is slid down shaft  92  onto the rear roller  14 . Set-arm  97  is then rotated and pushed downward to operate cam mechanism  96  which simultaneously forces flange  94  downward and shaft  92  upwards, thereby simultaneously securing the rear roller  14  to v-brackets  74   a,    74   b  and mounting platform  61  to base channel  82  (see  FIG. 4A ). 
     It is noted that suitable clamping mechanisms other than clamping assembly  90  may be employed to secure rear roller  14  to brackets  74   a,    74   b  and to secure mounting platform  61  to base channel  82 . 
     In example, rear mounting assembly  60  further includes ruler marking  110 , a position pointer  112 , and a rotatable locking switch  114  which are employed when a type of mower unit  10 , which is not included among the types of known mower units having corresponding index markings on position indexer  78 , is to be sharpened by grinding system  50 . According to such a scenario, after placing the rear roller  14  of such unknown type of mower unit  10  into brackets  74   a,    74   b,  and after positioning the cutting reel  20  into a desired position for grinding (as will be described in greater detail below), the location of position pointer  112  on ruler marking  110  is noted and used for quick positioning of such type of mower units  10  in the future. Rotatable locking switch  114  provides a function similar to that of moveable selector pin  81 , but is not limited to detaining mounting platform  61  at a finite number of locations where corresponding openings are positioned in base portion  70  as is moveable selector pin  81 . 
       FIG. 7  is a perspective view illustrating front mounting assembly  62  including vertically movable support pedestal  63  according to one example of the present disclosure. Support pedestal  63  includes a planar top surface  120  having a support shaft  122  with a rack gear  124  disposed thereon extending downwardly through a retaining collar  126  that is mounted to a structural element  128  of frame  52 . A front roller clamp assembly  130  extends upwardly from top surface  120  and includes a flange  132  extending horizontally from a shaft  134  and which is free to rotate there about. Shaft  134  is threadably coupled to an upper end of support shaft  122  and includes a screw knob  136  for tightening loosening flange  132  against front roller  16  of a mower unit  10  placed on top surface  120  (see  FIG. 4A , for example). A ratchet  138  is mounted to retaining collar  126  and includes a spur gear (not shown) which operatively engages rack gear  138  to vertically raise and lower support pedestal  63 . 
       FIG. 8  is an enlarged perspective view illustrating traverse base assembly  56  and moveable grinding head assembly  58  according to one example of the present disclosure. Traverse base assembly  56  includes a support beam  140  which is mounted at a first end  141  to a frame element  142  of enclosure  52  via a flexible mounting assembly  144  that enables first end  141  of beam support  140  to pivot about the y- and z-axes. The opposing end  143  of support beam  140  is connected to an adjustable mounting  146  which includes a first wheel  148  for adjusting a horizontal position (i.e. in the x-y plane) of support beam  140  and which is locked in place with a lever  149 , and a second wheel  150  for adjusting a vertical position (i.e. in the x-z plane) of support beam  140  and which is locked in place with a lever  151 . 
     Traverse base assembly  56  further includes a carriage  152  to which grinding head assembly  58  is mounted. Carriage  152  is slideably mounted to a pair of guide rods  154   a,    154   b  via corresponding pair of bearing blocks  156   a,    156   b.  A drive motor  158  drives a continuous belt  160  which is operatively connected to carriage  152  to reciprocally drive carriage  152  and thus grinding head assembly  58 , transversely (i.e. along x-axis) along guide rods  154   a,    154   b.    
     In one example, as illustrated, carriage  152  includes first and second mounting pins  162  and  164  which, as will be described in greater detail below, are used for mounting an electronic linear measuring gauge that is used when adjusting first and second wheels  148  and  150  to align grinding head assembly  58  with shaft  24  of reel  20  of a mower unit  10  mounted in grinding system  50  for sharpening. 
       FIG. 9  is a perspective view illustrating grinding head assembly  58  according to one example of the present disclosure. Grinding head assembly  58  includes a motor  170  that drives a grinding wheel shaft  172  via a belt and pulley system (not shown) enclosed within a housing  174 . For clarity of illustration, a grinding wheel  176  which is mounted on grinding wheel shaft  172  (see  FIGS. 10A / 10 B/ 11 A/ 11 B) is not shown in  FIG. 9 . Grinding head assembly  58  is mounted to carriage  152  via a pivot axis  178  which enables grinding wheel shaft  172  to be rotated toward and away from a cutting reel  20  of a mower unit  10  when mounted to grinding system  50 . 
       FIGS. 10A and 10B  are end views illustrating grinding head assembly  58  and portions of grinding system  50 . In  FIGS. 10A and 10B , a mower unit  10  (with frame  12  not shown for clarity) is illustrated as being mounted to grinding system  50  with rear roller  14  positioned on brackets  74   a,    74   b  of moveable rear mounting platform  61  and front roller  16  positioned on support pedestal  63  of front mounting assembly  62 . Grinding head assembly  58  includes an actuating system  180  including a stepper motor  182  that drives telescoping tubes  184 , the outermost of which is coupled via a pivot  186  to housing  124 , to rotate grinding wheel  176  about pivot access  178  so as vertically position grinding wheel  176  relative to reel  20  of mower unit  10  to perform spin and relief grinding processes.  FIG. 10A  illustrates grinding head assembly  58  in a retracted or disengaged position where grinding wheel  176  is spaced from cutting reel  20 .  FIG. 10B  illustrates grinding head assembly  58  in an extended or engaged position where grinding wheel  176  is positioned so as to contact blades  22  of cutting reel  20  for grinding. 
     Returning to  FIG. 9 , grinding head assembly  58  further includes a relief grinding indexguide assembly  190  including a guide finger  192  and an index stop finger  194  similar to that described by U.S. Pat. No. 6,290,581 entitled “Automatic Mower Reel Grinder”, which is assigned to the same Assignee as the present application, and which is herein incorporated by reference in its entirety. Indexguide assembly  190  further includes a screw knob  196 , a relief angle indexer  198 , and a pointer  199  which, as will be described below, are employed to adjust a position of guide finger  192  relative to grinding wheel  176  in order to adjust a degree of relief angle θ of relief bevel  25  ground onto blades  22  (see  FIG. 2A ) during the relief grinding process. 
       FIGS. 11A and 11B  illustrate side views of grinding head assembly  58 , including indexguide assembly. Indexguide assembly  190  is rotatable about grinding wheel shaft  172  and between an engaged and a disengaged position.  FIG. 11A  shows indexguide assembly  190  in disengaged position where guide finger  192  and index stop finger  194  are positioned down and away from cutting reel  20 , and illustrates a spin grinding process where grinding wheel  176  and cutting reel  20  are each rotated clockwise as grinding wheel  176  grids the ends of blades  22  to restore cutting reel  20  to a cylinder. 
       FIG. 11B  shows indexguide assembly  190  in an engaged position where guide finger  192  is positioned to engage a leading edge of blade  22 , and illustrates a relief grinding process. During a relief grinding process, grinding wheel  176  is rotated clockwise while cutting reel  20  is rotated counter-clockwise such that blade  22  is rotationally biased against guide finger  192  (by spin drive system  64 ), which holds blade  22  in place as grinding wheel  176  grinds relief bevel  25  onto the trailing edge of blade  22 , wherein the relief angle θ of the relief bevel  25  depends on the positioning of guide finger  192  relative to grinding wheel  176 . 
     Referring to  FIG. 9 , according to one example of the present disclosure, relief angle indexer  198  includes a plurality of index markings, including markings which correspond to each of the angle settings θ 1 , θ 2 , θ 3 , and θ 4  as indicated on horizontal position indexer  78  of moveable mounting platform  61  (see  FIGS. 6A, 6B ). To set guide finger  192  to a position which will result in grinding wheel  176  producing a relief bevel  25  having particular relief angle θ, such as θ 1  for instance (e.g. 3-degrees), screw know  196  of indexguide assembly  190  is turned to align pointer  199  with the index marking of relief angle indexer  198  corresponding to angle θ 1 . 
     An example of a process for mounting a mower unit  10  in grinding system  50  in order to perform spin and relief grinding of cutting reel  20  is described below. To begin, moveable mounting platform  61  is moved so that pointer element  102  is aligned with an index marking of position indexer  78  that corresponds to the type of mower unit  10  being mounted. For example, if mower unit  10  is that of manufacturer “Y” having a reel size “A” and requiring a relief angle of θ 2 , mounting platform  61  is moved until pointer element  102  is aligned with index marking  100   a  (see  FIG. 6B ). Rear roller  14  is then positioned in brackets  74   a,    74   b  and front roller  16  is placed on support pedestal  63  of front mounting assembly  62 . 
       FIG. 12  is a front perspective view of grinding system  50  illustrating mower unit  10  with a rear roller  14  positioned on mounting platform  61  and front roller  16  positioned on support pedestal  63  of front mounting assembly  62 . Additionally illustrated are first and second location markers  202  and  204  on frame elements within enclosure  52  and which are respectively positioned at predetermined and known first and second distances along support beam  140  of traverse base assembly  56  from the pivot point of traverse base assembly formed by flexible mounting assembly  144  (see  FIG. 8  above). 
       FIG. 13  is a right side view illustrating portions of grinding system  50  according to one example. After rear roller  14  has been positioned in brackets  74   a,    74   b  and front roller  16  has been positioned on top surface  120  of support pedestal  63  of front mounting assembly  62 , an electronic linear distance gauge  210  is mounted to first mounting pin  162  of carriage  152  of traverse base assembly  56  (see  FIG. 8 ). According to one example, linear distance gauge  210  includes a linearly moveable measuring shaft  212  which is biased so as to extend from an end  214  of a housing  216 . 
     With reference to  FIG. 12 , carriage  152  is then moved so that linear distance gauge  210  aligns with first location marker  202 . Once linear distance gauge  210  has been aligned with first location marker  202 , the distal end of measuring shaft  212  is positioned on an edge of helical cutting blade  22  after cutting reel  20  has been rotated so that helical blade  22  is at the lowest point of cutting reel  20 . 
     Ratchet  138  of front mounting assembly  62  is then employed to move support pedestal  63  vertically up or down until linear distance gauge  210  provides indication that the traverse base is at a predetermined distance (d BR ) from the bottom of cylindrical cutting reel  20 . In one example, indication is provided on linear distance gauge  210  itself. For instance, according to one example, a pin  218  is coupled to measuring shaft  212  and slides within a slot  220  in housing  216  of linear distance gauge  216  as measuring shaft  212  moves updown, with the predetermined distance d BR  being indicated when the pin  218  aligns with an index mark on housing  216 . According to another example, linear distance gauge  216  provides a signal to microcontroller  66  which provides indication of the predetermined distance d BR  being achieved via a graphical user interface (GUI) or other means. 
     It is noted that the predetermined distance d BR  will be the same for all types of mower reels  10 . In other words, the distance d BR  to the outside side edge of cutting reel  10  is adjusted so as to be the same for all cutting reels regardless of size (e.g. 5- and 7-inch reels). 
     With reference to  FIG. 14 , after the predetermined distance d BR  has been achieved, clamp assembly  90  is employed to secure rear roller  14  to mounting platform  61  and to lock mounting platform  61  to shelf  54 , and clamp assembly  130  is employed to secure front roller  16  to support pedestal  63 . 
     Next, with linear distance gauge  210  still aligned with first location marker  202  and still mounted to first mounting pin  162 , cutting reel  20  is rotated so that measuring shaft  212  can be extended to contact shaft  24  of cutting reel  20 . Linear distance gauge  210  then provides a signal to microcontroller  66  indicating a distance (dsi) to the shaft  24  of cutting reel  20  at first location marker  202 . Carriage  152  is then moved so that linear distance gauge  210  aligns with second location marker  204 . Measuring shaft  212  of linear distance gauge  210  is again extended to contact shaft  24  of cutting reel  20 , and linear distance gauge  210  provides a signal to microprocessor controller  66  indicating a distance (d S2 ) to the shaft  24  of cutting reel  20  at second location marker  204 . 
     Based on distances d BR , d S1 , and d S2 , as described above, and knowing the locations (i.e. first and second location markers) at which such distances were measured relative to the pivot point of traverse base assembly  56  formed by mounting assembly  144  (see  FIG. 8 ), microprocessor controller  66  determines the necessary adjustment to support beam  140  of traverse base assembly  56  (i.e. via second wheel  150 , see  FIG. 8 ) so that grinding wheel shaft  172  of grinding head assembly  58  (see  FIG. 9 ) will be vertically paralleled (i.e. in the x-z plane) with the shaft  24  of cutting reel  20 . 
     According to one example, microprocessor controller  66  provides indication of how to adjust second wheel  150  so as to vertically adjust the position of support beam  140 , and thus grinding wheel shaft  172 , and provides indication of when grinding wheel shaft  172  is vertically paralleled (i.e. in the x-z plane) with shaft  24  of cutting reel  20 . In one example, such indication is via a GUI of microprocessor controller  66 . In another example, such indication is via a set of indicating lights  266  disposed on enclosure  52 , with a first light  266   a  indicating that second wheel  150  should be turned clockwise, a second light  266   b  indicating that second wheel  150  should be turned counter-clockwise, and a third light  266   c  indicating when grinding wheel shaft  172  is vertically paralleled with shaft  24  of cutting reel  20 . In one example, the indicating lights are light emitting diodes (LEDs). 
     With reference to  FIG. 15 , after grinding wheel shaft  172  has been vertically paralleled with shaft  24  of cutting reel  20 , linear distance gauge  210  is mounted to second mounting pin  164  on carriage  152 , and carriage  52  is moved so that linear distance gauge  210  is aligned with first location marker  202 . When mounted to second mounting pin  164 , linear distance gauge  210  is disposed at an angle A to vertical. Measuring shaft  212  is extended to contact shaft  24  of cutting reel  20 , and linear distance gauge provides a signal to microprocessor controller  66  indicating a distance (d S3 ) to shaft  24 . The process is repeated with linear distance gauge  210  aligned with second location marker  204  to provide microprocessor controller  66  with a signal indicating a distance (d S4 ) to shaft  24 . 
     Similar to that described above with regard to vertical adjustment of traverse base assembly  56 , based on distances d BR , d S3 , and d S4 , and on angle A, and knowing the locations (i.e. first and second location markers) at which such distances were measured relative to the pivot point of traverse base assembly  56  formed by mounting assembly  144  (see  FIG. 8 ), microprocessor controller  66  determines the necessary adjustment to support beam  140  of traverse base assembly  56  (i.e. via first wheel  148 , see  FIG. 8 ) so that grinding wheel shaft  172  of grinding head assembly  58  (see  FIG. 9 ) will be horizontally paralleled (i.e. in the x-y plane) with the shaft  24  of cutting reel  20 . According to one example, indication of how adjust first wheel  148  is similar to that described above with respect to second wheel  150 . 
     Returning to  FIG. 12 , after grinding wheel shaft  172  has been both vertically and horizontally aligned with shaft  24  of cutting reel  20 , as described above, a spin drive motor  230  of spin drive system  64  is removably coupled to shaft  24  of cutting reel  20  and rotates cutting reel  20  during the spin and relief grinding processes. According to one example, operation spin drive motor  230  is controlled via microprocessor controller  66 . 
       FIG. 16  is a perspective view illustrating spin drive system  64 . According to one example, spin drive motor  230  is mounted to an articulating arm assembly  240  including a first arm segment  242  and a second arm segment  244 . A first end of first arm segment  242  coupled to a frame element of enclosure  52  with a mounting bracket  246  than enables first arm segment  242  to spin around the z-axis and move up and down in the x-z dimension. A first end of second arm segment  244  is coupled to a second end of first arm segment  242  via a hinge that enables second arm segment  244  to be moved up and down in the x-z dimension. A second end of second arm segment  244  is coupled to spin drive motor  230  and enables spin drive motor  230  to be rotated about an axis in the x-y plane and about to be rotated about the said axis in the x-y plane. A shaft  252  of spin drive motor  230  can be fitted with adapters to enable releasable connection of shaft  252  to the shaft  25  of cutting reel  20  of any number of mower unit types. Articulating arm assembly  240  supports spin drive motor  230  and enables movement in any dimension, thereby providing quick and easy connection to cutting reels  20 . 
       FIG. 17  is a perspective view illustrating an example of another implementation of rear mounting assembly  60  for positioning brackets  74   a  and  74   b.  According to such example, in lieu of fixedly mounting brackets  74   a,    74   b  on moveable mounting platform  61 , moveable mounting platform  61  is eliminated and brackets  74   a  and  74   b  themselves are moveable between predetermined locations on shelf  54  of enclosure  52 . Brackets  74   a,    74   b  include a pair of offset mounting pins  75   a,    75   b  (only one pin shown) which are configured to be inserted into corresponding pairs of offset mounting holes  77   a,    77   b  in shelf  54 . In the illustrated example, each of the three pairs of offset mounting holes  77   a,    77   b  corresponds to one of the index markings  100   a,    100   b,  and  100   c  of position indexer  78 , as described above by  FIGS. 5, 6A, and 6B . Similar to that described above, clamp assembly  90  is employed to secure rear roller  14  of mower unit  10  to brackets  75   a,    75   b  and shelf  54 . In one example, a rear edge  79  of bracket  74   a  is configured to align with one of the index markings  100   a,    100   b,  and  100   c  when mounting pins  75   a  are positioned in the corresponding pair of mounting holes  77   a.  In example, in lieu of using two brackets  74   a,    74   b,  a single bracket  74  is employed which extends between the sets of mounting holes  77   a,    77   b.    
     By employing a rear mounting assembly including a mounting brackets which are moveable to predetermined, preset locations for any number of types of mower units, grinding system  50  according to the present disclosure provides fast, accurate, and repeatable horizontal positioning for grinding of cutting reels  20  of any number of different types. Additionally, using a linear measuring gauge  210  and microprocessor controller  66  to determine necessary adjustments to traverse base  56  provides rapid, accurate, and consistent paralleling of grind wheel shaft  172  with shaft  24  of cutting reel  20 . Furthermore, using relief angle indexer  198  and adjustment knob  196  enables simple and rapid adjustment of grinding head assembly  58  to provide consistent and accurate grinding of relief bevels  25  on blades  22 . 
     In one example, as illustrated by  FIGS. 18A and 18B , in lieu of employing moveable mounting brackets, such as moveable mounting brackets  74   a  and  74   b,  according to one example, rear mounting assembly  60  includes a plurality of mounting channels  250 , illustrated as mounting channels  250   a - 250   e,  integral to shelf  54  of housing  52 , where each mounting channel  250  corresponds to one of the predetermined mounting positions relative to grinding wheel shaft  172  (see  FIGS. 9-11B , for example) and each corresponds to at least one type of mower unit. As illustrated, mounting channels  250   a - 250   e  are akin to the positions of mounting brackets  74   a  and  74   b  when mounting platform  61  is positioned at the index markings  100   a - 100   c  of position indexer  78  (see  FIGS. 5-6A , for example). In other words, mounting channels  250   a - 250   e  represent multiple individual fixed brackets at predetermined locations as opposed to a single bracket (or brackets) moveable to multiple predetermined locations. 
     With reference to  FIG. 18B , in one example, each mounting channel  250  comprises a v-shaped channel in shelf  54  which is configured to receive rear roller  14  (or other pivot element) of mower unit  10 , where the v-shape centers the rear roller within the mounting channel. It is noted that other shapes may be employed. In one example, mounting channels extend parallel to one another in a longitudinal direction, where such longitudinal direction is parallel to grinding wheel shaft  172 . In one example, with reference to  FIG. 18A , a slot  252  extends through the plurality of mounting channels  250   a - 250   e  in a direction perpendicular to the longitudinal direction of mounting channels  250   a - 250   e,  where slot  252  is to receive a clamp assembly, such as clamp assembly  90  (see  FIG. 5 , for example). According to one example, clamp assembly  90  is moveable within slot  252  to any one of the mounting channels  250   a - 250   e  and is configured simultaneously clamp a rear roller  14  of a mower unit  10  within a mounting channel  250  and secure clamp assembly to shelf  54 . 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.