Patent Publication Number: US-2023158372-A1

Title: Grooves of golf club heads and methods to manufacture grooves of golf club heads

Description:
RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 17/227,207, filed Apr. 9, 2021, which is a continuation of U.S. patent application Ser. No. 16/586,122, filed Sep. 27, 2019, and is issued as U.S. Pat. No. 10,974,104 on Apr. 13, 2021, which is a continuation of U.S. patent application Ser. No. 16/140,759, filed on Sep. 25, 2018, and is issued as U.S. Pat. No. 10,427,011 on Oct. 1, 2019, which is a continuation of U.S. patent application Ser. No. 15/410,521, filed on Jan. 19, 2017, and is issued as U.S. Pat. No. 10,099,091 on Oct. 16, 2018, which is a continuation of U.S. patent application Ser. No. 14/678,622, filed Apr. 3, 2015, and is issued as U.S. Pat. No. 9,561,407 on Feb. 7, 2017, which is a continuation of U.S. patent application Ser. No. 13/628,685, filed on Sep. 27, 2012, and is issued as U.S. Pat. No. 9,108,088 on Aug. 18, 2015, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/697,994, filed on Sep. 7, 2012 and U.S. Provisional Patent Application Ser. No. 61/541,981, filed on Sep. 30, 2011. U.S. patent application Ser. No. 13/628,685 is also a continuation-in-part of U.S. patent application Ser. No. 13/591,620, filed on Aug. 22, 2012, and is issued as U.S. Pat. No. 8,764,578 on Jul. 1, 2014, which is a continuation of U.S. patent application Ser. No. 13/237,293, filed on Sep. 20, 2011, and is issued as U.S. Pat. No. 8,282,505 on Oct. 9, 2012, which is a continuation of U.S. patent application Ser. No. 12/535,868, filed on Aug. 5, 2009, and is issued as U.S. Pat. No. 8,066,586 on Nov. 29, 2011, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/087,158, filed Aug. 7, 2008, all of which are all fully incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates generally to golf equipment, and more particularly, to grooves of golf club heads and methods to manufacture grooves of golf club heads. 
     BACKGROUND 
     Typically, a golf club head may include a club face with a plurality of parallel grooves extending between the toe end and the heel end. In particular, the plurality of grooves in an iron-type club head may clear out water, sand, grass, and/or other debris between a golf ball and the club face. Golf club faces may have grooves with various shapes such as squared or box-shaped grooves, V-shaped grooves, or U-shaped grooves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a putter according to one example. 
         FIG.  2    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  3    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  4    shows a schematic top view of a groove of the ball striking face of  FIG.  3   . 
         FIG.  5    shows a horizontal cross-sectional diagram of the groove of  FIG.  4    taken at section  5 - 5  of  FIG.  3   . 
         FIG.  6    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  3   . 
         FIG.  7    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  3   . 
         FIG.  8    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  9    shows a schematic top view of a groove of the ball striking face of  FIG.  8   . 
         FIG.  10    shows a horizontal cross-sectional diagram of the groove of  FIG.  9    taken at section  10 - 10  of  FIG.  8   . 
         FIG.  11    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  8   . 
         FIG.  12    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  8   . 
         FIG.  13    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  14    shows a schematic top view of a groove of the ball striking face of  FIG.  13   . 
         FIG.  15    shows a horizontal cross-sectional diagram of the groove of  FIG.  14    taken at section  15 - 15  of  FIG.  13   . 
         FIG.  16    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  13   . 
         FIG.  17    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  13   . 
         FIG.  18    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  19    shows a schematic top view of a groove of the ball striking face of  FIG.  18   . 
         FIG.  20    shows a horizontal cross-sectional diagram of the groove of  FIG.  19    taken at section  20 - 20  of  FIG.  18   . 
         FIG.  21    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  18   . 
         FIG.  22    shows a horizontal cross-sectional diagram of another groove of the ball striking face  FIG.  18   . 
         FIG.  23    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIGS.  24 - 26    show different examples of vertical cross sections of grooves of the ball striking face of  FIG.  23    taken at section  24 - 24  of  FIG.  23   . 
         FIG.  27    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  28    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIGS.  29 - 37    show schematic diagrams of exemplary horizontal cross sections of a groove of a ball striking face of a putter. 
         FIGS.  38 - 45    show schematic top views of exemplary grooves of a ball striking face of a putter. 
         FIG.  46    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  47    shows a schematic diagram of a ball striking face of a putter according to one example. 
         FIG.  48    is a horizontal cross-sectional view of a groove of a putter according to one example. 
         FIG.  49    shows a vertical schematic cross-sectional diagram of a putter according to one example. 
         FIG.  50    shows a vertical schematic cross-sectional diagram of a putter according to one example. 
         FIG.  51    shows a putter face according to another example. 
         FIG.  52    shows a putter face according to another example. 
         FIG.  53    shows a method of manufacturing a golf club according to one example. 
     
    
    
     DESCRIPTION 
     In general, grooves of golf club heads and methods to manufacture grooves of golf club heads are described herein. Golf equipment related to the methods, apparatus, and/or articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Further, the figures provided herein are for illustrative purposes, and one or more of the figures may not be depicted to scale. The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     In the examples of  FIG.  1   , a putter  100  is shown. Although grooves for a putter  100  are described herein, the apparatus, methods, and articles of manufacture described herein may be applicable other types of club head (e.g., a driver-type club head, a fairway wood-type club head, a hybrid-type club head, an iron-type club head, etc.). For example, grooves for iron-type club heads are described in detail in U.S. Patent Application Publication US 2010/0035702, filed Aug. 5, 2009, the entire disclosure of which is expressly incorporated by reference. Accordingly, any reference made herein to a putter may include any type of golf club. 
     The putter  100  includes a putter head  102  having a putter face  110 . The putter face  110  may be generally planar. The putter face  110  includes a ball striking face  112  that may be generally on the same plane as the putter face  110  or slightly projected outward from the putter face  110 . The ball striking face  112  may be the same size or smaller (as shown in  FIG.  1   ) than the putter face  110 . The ball striking face  112  may be a region on the putter face  110  that is generally used to strike a golf ball (not shown). However, an individual may also strike a ball with a section of the putter face  110  that is outside the ball striking face  112 . 
     The ball striking face  112  may be a continuous or integral part of the putter face  110  or formed as an insert that is attached to the putter face  110 . Such an insert may be constructed from the same material or different materials as the putter face  110  and then be attached to the putter face  110 . The ball striking face  112  may include one or more grooves, generally shown as grooves  120 , and one or more land portions  170 . For example, the ball striking face 112  is shown to have twelve grooves, generally shown as  122 ,  124 ,  126 ,  128 ,  130 ,  132 ,  134 ,  136 ,  138 ,  140 ,  142 , and  144 . The grooves  120  may be generally referred to with a single reference number such as  120 . However, when specifically describing one of the grooves on the ball striking face  112 , the reference number for that specific groove may be used. 
     Two adjacent grooves may be separated by a land portion  170 . A land portion  170  between each groove  120  and an adjacent groove  120  may have the same or different width as a land portion  170  between another pair of adjacent grooves  120 . The land portions  170  may also define the top surface of the ball striking face  112 . In general, two or more of the grooves  120  may be parallel to each other. For example, the grooves  122  and  124  may be parallel to each other. However, the grooves  120  may be oriented relative to each other in any manner. For example, any of the grooves  120  may be diagonally, vertically and/or horizontally oriented. As shown in the example of  FIG.  2   , one or more of the grooves  120  may be substantially linear and generally parallel to an adjacent groove  120  and extend between a toe end  180  and a heel end  190  of the putter face  110 . 
     As described in detail below, the depth, length, width, a horizontal cross-sectional shape, and/or a vertical cross-sectional shape of the grooves  120  may linearly, nonlinearly, in regular or irregular step-wise intervals, arcuately and/or according to one or more geometric shapes increase, decrease and/or vary from the toe end  180  to the heel end  190  and/or from a top rail  182  to a sole  192  of the putter head  102 . The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     Referring to  FIG.  2   , the ball striking face  112  is shown having grooves  122 - 144 . The ball striking face  112  may be an integral part of the putter face  110  such as to be co-manufactured with the putter face  110 . Alternatively, the ball striking face  112  may be an insert that is attached to the putter face  110 . Each of the grooves  120  may extend from the toe end  180  to the heel end  190  to define a corresponding length  193  (only the length  193  of groove  144  is shown in  FIG.  2   ). The lengths  193  of some or all of the grooves  120  may vary in a direction from the top rail  182  to the sole  192  so that each groove  120  may generally conform to the shape of the perimeter of the ball striking face  112 . For example, the length of the grooves may increase from near the top rail  182  to a center  184  of the ball striking face  112  and decrease from the center  184  to near the sole  192 . The center  184  may be a geometric center of the ball striking face  112 . Alternatively, the center  184  may represent an inertial or weight related center of the ball striking face  112 . However, the center  184  may be generally defined by a region of the ball striking face  112  that typically strikes the ball. As shown in  FIG.  1   , the length  193  of the grooves  120  may be similar. In other examples, such as the example shown in  FIG.  2   , the length  193  of the grooves may decrease from near the top rail  182  to the center  184  and decrease from near the sole  192  to the center  184 . Thus, any groove length arranged on the ball striking face  112  is within the scope of the disclosure. 
     In another example shown in  FIG.  3   , a ball striking face  212  may include grooves  220  (shown specifically as grooves  222 - 244 ). The ball striking face  212  may be an integral part of the putter face  110  or a separate piece that is attached to the putter face  110 . Accordingly, when describing the ball striking face  212 , parts of the putter  100  and the putter head  102  are referred to with the same reference numbers described above. 
       FIG.  4    shows a schematic view of the groove  232  and  FIG.  5    shows a horizontal cross section of the groove  232  taken at section line  5 - 5  of  FIG.  3   . The groove  232  is shown to be divided into horizontally spanning regions, generally shown as regions  271 - 275 , which are visually defined in  FIGS.  3  and  4    by vertical boundary lines. The horizontal regions  271 - 275  may define variations in the horizontal cross-sectional profile of the groove  232  from near the toe end  180  to near the heel end  190  and/or from near the top rail  182  to near the sole  192 . Horizontal cross-sectional profile of a groove may refer to any property of the groove along the length  293  of the groove, such as length of a certain section of the groove, depth, width, cross-sectional shape, and/or construction materials. In the example of  FIGS.  3 - 7   , the grooves  220  include a first vertical wall  250  and a second vertical wall  252  that define the length  293  of the grooves  220 . Each of the grooves  220  has a bottom surface  254  which defines a depth of the groove  220 . The depth of each groove may vary from the first wall  250  to the second wall  252  according to the cross-sectional profile of the groove  220  in the regions  271 - 275 . Each groove  220  also includes a first horizontal wall  256  and a second horizontal wall  258  that define the vertical boundaries of the groove  220 . The distance between the first horizontal wall  256  and the second horizontal wall  258  defines a width  280  of the groove  220 . The width  280  may vary from the first vertical wall  250  to the second vertical wall  252  as shown in the examples of  FIGS.  38 - 45   , where a groove may have a length  590 , a first width  594 , a second width  595  and/or a third width  596 . In the example of  FIGS.  3 - 7   , however, the first horizontal wall  256  and the second horizontal wall  258  are generally parallel to define a generally constant width  280 . 
     Referring to  FIG.  5   , the bottom surface  254  at the region  271  is downwardly sloped or curved to define a first depth  282  at the boundary between regions  271  and  272 . The bottom surface  254  in the region  272  transitions with a steeper downward curve from the first depth  282  to a second depth  284  at the boundary between regions  272  and  273 . If the bottom surface  254  is flat in the region  273 , the second depth  284  may generally define the greatest depth of the groove  232 . However, if the bottom surface  254  is not flat, the greatest depth of the groove  232  may be defined in another part of the region  273 . Any of the grooves  220  may be symmetric about the vertical axis y. Accordingly, the shape of the groove  220  on each side of the y axis may mirror the shape of the groove  232  on the other side of the y axis. However, any of the grooves  220  may be asymmetric. The regions  271  and  275  define shallow portions of the groove  232  and the region  273  defines the deeper center portion of the groove  232 . The deepest part of any of the grooves  220  may be at the center of the groove  220 . The regions  272  and  274  facilitate transition of the bottom surface  254  from the depth  282  to the depth  284 . 
     Referring to  FIGS.  3  and  5   , the general cross-sectional profile of each of the grooves  220  may remain generally similar from the top rail  182  to the sole  190 . However, the cross-sectional profile including lengths, widths and/or depths of the regions  271 - 275  of each of the grooves  220  may progressively vary from the top rail  182  to the sole  192 . In  FIGS.  6  and  7   , the horizontal cross sections of the grooves  238  and  244 , respectively, are shown. For example, the regions  271 - 275  of the groove  238  are smaller in length than the regions  271 - 275  of the groove  232 , respectively. Similarly, the regions  271 - 275  of the groove  244  are smaller in length than the regions  271 - 275  of the groove  238 , respectively. In another example, the regions  271 - 275  of the groove  238  may have smaller depths than the regions  271 - 275  of the groove  232 , respectively. Similarly, the regions  271 - 275  of the groove  244  may have smaller depths than the regions  271 - 275  of the groove  238 , respectively. 
     The progressive increase in the length, depth and/or width of the regions  271 - 275  of the grooves  222 - 232  from the top rail  182  to generally the center of the ball striking face  212  and/or the decrease in the size of the regions  271 - 275  of the grooves  232 - 244  from generally the center of the ball striking face  212  to the sole  192  forms a central strike zone  260  (shown in  FIG.  3   ), which may resemble the shape of a golf ball when viewed by an individual in an address position. The approximate visual representation of a golf ball can assist an individual with lining up the ball striking face  212  with the ball. The regions  273 , which define the deepest parts of the grooves  220  may be larger in length at the center of the ball striking face  212  and progressively reduce in length toward the top rail  182  and the sole  192 . Similarly, the transition regions  272  and  274  may have the greatest length at the center of the ball striking face  212  and progressively reduce in length toward the top rail  182  and the sole  192 . Although the lengths of the regions  271 - 275  may vary depending on the location of the grooves  220  on the ball striking face  212 , the depth of similar regions for each groove  220  may be similar or different. For example, the greatest depth of the groove  232  may be similar to the greatest depth of the groove  244 . Alternatively, the depth of the grooves  222 - 244  may vary based on the location of the groove  220  relative to ball striking face  212 . Alternatively yet, the depths of the grooves  222 - 244  may vary in any manner from the top rail  182  to the sole. Although the above examples may describe a particular number of horizontal regions, the apparatus, methods, and articles of manufacture described herein may include more or less horizontal regions. 
     In another example shown in  FIG.  8   , a ball striking face  312  includes grooves  320  (shown specifically as grooves  322 - 344 ). The ball striking face  312  may be an integral part of the putter face  110  or a separate piece that is attached to the putter face  110 . Accordingly, when describing the ball striking face  312 , parts of the putter  100  and the putter head  102  are referred to with the same reference numbers described above. 
       FIG.  9    shows a schematic view of the groove  332  and  FIG.  10    shows a horizontal cross section of the groove  332  taken at section line  10 - 10  of  FIG.  8   . The groove  332  is shown to be divided into horizontally spanning regions  371 - 375 , which are visually defined in  FIGS.  8  and  9    by vertical boundary lines. The horizontal regions  371 - 375  may define variations in the horizontal cross-sectional profile of the groove  332  from near the toe end  180  to near the heel end  190  and/or from near the top rail  182  to near the sole  192 . Horizontal cross-sectional profile of a groove may refer to any property of the groove along the length  393  of the groove, such as length of a certain section of the groove, depth, width, cross-sectional shape, and/or construction materials. In the example of  FIGS.  8 - 12   , the grooves  320  include a first vertical wall  350  and a second vertical wall  352  that define the length  393  of the grooves  320 . Each of the grooves  320  has a bottom surface  354  which defines a depth of the groove  320 . The depth of each groove may vary from the first wall  350  to the second wall  352  according to the cross-sectional profile of the groove  320  in the regions  371 - 375 . Each groove  320  also includes a first horizontal wall  356  and a second horizontal wall  358  that define the vertical boundaries of the groove  320 . The distance between the first horizontal wall  356  and the second horizontal wall  358  defines a width  380  of the groove  320 . The width  380  may vary from the first vertical wall  350  to the second vertical wall  352  as shown in the examples of  FIGS.  38 - 45   . In the example of  FIGS.  8 - 12   , however, the first horizontal wall  256  and the second horizontal wall  258  are generally parallel to define a generally constant width  380 . 
     Referring to  FIG.  10   , the bottom surface  354  at the region  371  may be generally flat and/or slightly sloped to define a first depth  382  at the boundary between 371 and 372. The bottom surface  354  in the region  372  transitions with a step downward from the first depth  382  to a second depth  384  at the boundary between the regions  372  and  373 . The bottom surface  354  in the region  372  may be generally flat and/or slightly sloped such that the groove  320  has a generally uniform depth  384  in the region  372 . The bottom surface  354  in the region  372  transitions with a step downward from the second depth  384  to a third depth  386 . The bottom surface  354  in the region  373  may be generally flat or slightly sloped such that the groove  320  has a generally uniform depth  386  in the region  373 . Any of the grooves  320  may be symmetric about the vertical axis y. Accordingly, the shape of the groove  320  on each side of the y axis mirrors the shape of the groove  320  on the other side of the y axis. However, any of the grooves  320  may be asymmetric. The depth  386  represents the greatest depth of the grooves  320 . 
     Referring to  FIGS.  10 - 12   , the general cross-sectional profile of the grooves  320  may remain generally similar from the top rail  182  to the sole  190 . However, the cross-sectional profile including the lengths, widths and/or the depths of the regions  371 - 375  of each of the grooves  320  may progressively vary from the top rail  182  to the sole  192 . In  FIGS.  11  and  12   , the horizontal cross sections of the grooves  338  and  344 , respectively, are shown. For example, the regions  371 - 375  of the groove  338  are smaller in length than the regions  371 - 375  of the groove  332 , respectively. Similarly, the regions  371 - 375  of the groove  344  are smaller in length than the regions  371 - 375  of the groove  338 , respectively. In another example, the regions  371 - 375  of the groove  338  may have smaller depths than the regions  371 - 375  of the groove  332 , respectively. Similarly, the regions  371 - 275  of the groove  344  may have smaller depths than the regions  371 - 375  of the groove  338 , respectively. 
     The progressive increase in the length, depth and/or width of the regions  371 - 375  of the grooves  322 - 332  from the top rail  182  to the center of the ball striking face  312  and/or the decrease in the size of the regions  371 - 375  of the grooves  332 - 344  form the center of the ball striking face  312  to the sole  192  forms a central strike zone  360  (shown in  FIG.  8   ), which may discretely resemble the shape of a golf ball when viewed by an individual in an address position. The approximate visual representation of a golf ball can assist an individual with lining up the ball striking face  312  with the ball. The regions  373 , which define the deepest parts of the grooves  360  may be larger in length at the center of the ball striking face  312  and progressively reduce in length toward the top rail  182  and the sole  192 . Similarly, the transition regions  372  and  374  may have the greatest length at the center of the ball striking face  312  and progressively reduce in length toward the top rail  182  and the sole  192 . Although the lengths of the regions  371 - 375  vary depending on the location of the grooves  320  on the ball striking face  312 , the depth of similar regions for each groove  320  may be similar or different. For example, the greatest depth of the groove  344  may be similar to the greatest depth of the groove  332 . Alternatively, the depth of the grooves  322 - 344  may vary based on the location of grooves  320  on the ball striking face  312 . Alternatively yet, the depths of the grooves  322 - 344  may vary in any manner from the top rail  182  to the sole. Although the above examples may describe a particular number of horizontal regions, the apparatus, methods, and articles of manufacture described herein may include more or less horizontal regions. 
     In another example shown in  FIG.  13   , a ball striking face  412  includes grooves  420  (shown specifically as grooves  422 - 444 ). The ball striking face  412  may be an integral part of the putter face  110  or a separate piece that is attached to the putter face  110 . Accordingly, when describing the ball striking face  412 , parts of the putter  100  and the putter head  102  are referred to with the same reference numbers described above. 
       FIG.  14    shows a schematic view of the groove  432  and  FIG.  15    shows a horizontal cross section of the groove  432  taken at section line  15 - 15  of  FIG.  13   . The groove  432  is shown to be divided into horizontally spanning regions  471  and  472 , which are visually defined in  FIGS.  13  and  14    by the boundary lines of the groove  432  and a vertical line at the center of the groove  432 . The horizontal regions  471  and  472  may define variations in the horizontal cross-sectional profiles of the groove  432  from near the toe end  180  to near the heel end  190  and/or from near the top rail  182  to near the sole  192 . Horizontal cross-sectional profile of a groove refers to any property of the groove along the length  493  of the groove, such as length of a certain section of the groove, depth, width, cross-sectional shape, and/or construction materials. In the example of  FIGS.  13 - 17   , the grooves  420  include a first vertical wall  450  and a second vertical wall  452  that define the length  493  of the grooves  420 . Each of the grooves  420  has a bottom surface  454  which defines a depth of the groove  420 . The depth of each groove may vary from the first wall  450  to the second wall  452  according to the cross-sectional profile of the groove  420  in the regions  471  and  472 . Each groove  420  also includes a first horizontal wall  456  and a second horizontal wall  458  that define the vertical boundaries of the groove  420 . The distance between the first horizontal wall  456  and the second horizontal wall  458  defines a width  480  of the groove  420 . The width  480  may vary from the first vertical wall  450  to the second vertical wall  452  as shown in the examples of  FIGS.  38 - 45   . In the example of  FIGS.  13 - 17   , however, the first horizontal wall  456  and the second horizontal wall  458  are generally parallel to define a generally constant width  480 . 
     Referring to  FIG.  15   , the bottom surface  454  at the region  471  has a linear profile and is downwardly sloped. The grooves  450  are symmetric about the center vertical axis y. Accordingly, the bottom surface  454  at the region  472  has a similar linear profile and is similarly downwardly sloped as the bottom surface  454  at the region  471 . Accordingly, the depth of the grooves  420  gradually increase from a depth  482  at the first wall  452  and second wall  454  to a depth  484  at the center of the grooves  420 . The depth  484  represents the deepest part of the grooves  420 , which may be at the center of the groove  420 . 
     Referring to  FIGS.  15 - 17   , the general cross-sectional profile of the grooves  420  may remain generally similar from the top rail  182  to the sole  190 . However, the cross-sectional profile including the lengths and/or the depths of the regions  471  and  472  of each of the grooves  420  may progressively vary from the top rail  182  to the sole  192 . For example, the regions  471  and  472  of the groove  438  are smaller in length than the regions  471  and  472  of the groove  332 , respectively. Similarly, the regions  471  and  471  of the groove  444  are smaller in length than the regions  471  and  472  of the groove  438 , respectively. In another example, the regions  471  and  472  of the groove  438  may have smaller depths than the regions  471  and  472  of the groove  432 , respectively. Similarly, the regions  471  and  472  of the groove  444  may have smaller depths than the regions  471  and  472  of the groove  438 , respectively. 
     The progressive increase in the length, depth and/or width of the regions  471  and  472  of the grooves  422 - 432  from the top rail  182  to the center of the ball striking face  412  and/or the decrease in the size of the regions  471  and  472  of the grooves  432 - 444  form the center of the ball striking face  412  to the sole  192  forms a central strike zone  460  (shown in  FIG.  13   ). The regions  471  and  472  may have the greatest length at the center of the ball striking face  412  and progressively reduce in length toward the top rail  182  and the sole  192 . Although the lengths of the regions  471  and  472  vary depending on the location of the grooves  420  on the ball striking face  412 , the depth of similar regions for each groove  420  may be similar or different. For example, the greatest depth of the groove  444  may be similar to the greatest depth of the groove  432 . Alternatively, the depth of the grooves  422 - 444  may vary based on the location of grooves  420  on the ball striking face  412 . Alternatively yet, the depths of the grooves  422 - 444  may vary in any manner from the top rail  182  to the sole. Although the above examples may describe a particular number of horizontal regions, the apparatus, methods, and articles of manufacture described herein may include more or less horizontal regions. 
     In another example shown in  FIG.  18   , a ball striking face  512  includes grooves  520  (shown specifically as grooves  522 - 544 ). The ball striking face  512  may be an integral part of the putter face  110  or a separate piece that is attached to the putter face  110 . Accordingly, when describing the ball striking face  512 , parts of the putter  100  and the putter head  102  are referred to with the same reference numbers described above. 
       FIG.  19    shows a schematic view of the groove  532  and  FIG.  20    shows a horizontal cross section of the groove  532  taken at section line  20 - 20  of  FIG.  18   . The groove  532  is shown to be divided into horizontally spanning regions  571  and  572 , which are visually defined in  FIGS.  18  and  19    by the boundary lines of the groove  532  and a vertical line at the center of the groove  532 . The horizontal regions  571  and  572  may define variations in the horizontal cross-sectional profiles of the groove  532  from near the toe end  180  to near the heel end  190  and/or from near the top rail  182  to near the sole  192 . Horizontal cross-sectional profile of a groove refers to any property of the groove along the length  593  of the groove, such as a length of a certain section of the groove, depth, width, cross-sectional shape, and/or construction materials. In the example of  FIGS.  18 - 22   , the grooves  520  include a first vertical wall  550  and a second vertical wall  552  that define the length  593  of the grooves  520 . Each of the grooves  520  has a bottom surface  554  which defines a depth of the groove  520 . The depth of each groove may vary from the first wall  550  to the second wall  552  according to the cross-sectional profile of the groove  520  in the regions  571  and  572 . Each groove  520  also includes a first horizontal wall  556  and a second horizontal wall  558  that define the vertical boundaries of the groove  520 . The distance between the first horizontal wall  556  and the second horizontal wall  558  defines a width  580  of the groove  520 . The width  580  may vary from the first vertical wall  550  to the second vertical wall  552  as shown in the examples of  FIGS.  38 - 45   . In the example of  FIGS.  18 - 22   , however, the first horizontal wall  556  and the second horizontal wall  558  are generally parallel to define a generally constant width  580 . 
     Referring to  FIG.  20   , the bottom surface  554  at the region  571  has a linear profile and is downwardly sloped. The bottom surface  554  in the region  572  also has a linear profile and is downwardly sloped. However, because the second wall  552  is longer than the first wall  550 , the bottom surface  554  in the region  572  has a smaller slope than the bottom surface  554  in the region  571 . Accordingly, the grooves  550  of this example are asymmetric about the vertical center axis y. Thus, the grooves  250  have a first depth  582  defined by the first wall  550 , a second depth  584  defined by the second wall  552  and a center depth  586 , which is gradually reached from the depths  582  and  584  according to the downwardly sloped bottom surface  554  of the regions  571  and  572 , respectively. The center depth  586  may be the depth of the deepest part of the groove  520 . 
     Referring to  FIGS.  20 - 22   , the general cross-sectional profile of the grooves  520  may remain generally similar from the top rail  182  to the sole  190 . However, the cross sectional profile including the lengths, widths and/or the depths of the regions  571  and  572  of each of the grooves  520  may progressively vary from the top rail  182  to the sole  192 . In  FIGS.  21  and  22   , the horizontal cross sections of the grooves  538  and  544 , respectively, are shown. For example, the regions  571  and  572  of the groove  538  are smaller in length than the regions  571  and  572  of the groove  532 , respectively. Similarly, the regions  571  and  572  of the groove  544  are smaller in length than the regions  571  and  572  of the groove  538 , respectively. In another example, the regions  571  and  572  of the groove  538  may have smaller depths than the regions  571  and  572  of the groove  532 , respectively. Similarly, the regions  571  and  572  of the groove  544  may have smaller depths than the regions  571  and  572  of the groove  538 , respectively. 
     The progressive increase in the length, depth and/or width of the regions  571  and  572  of the grooves  522 - 532  from the top rail  182  to the center of the ball striking face  512  and/or the decrease in the size of the regions  571  and  572  of the grooves  532 - 544  form the center of the ball striking face  512  to the sole  192  forms a central strike zone  560  (shown in  FIG.  18   ). The regions  571  and  572  may have the greatest length at the center of the ball striking face  512  and progressively reduce in length toward the top rail  182  and the sole  192 . Although the lengths of the regions  571  and  572  vary depending on the location of the grooves  520  on the ball striking face  512 , the depth of similar regions for each groove  520  may be similar or different. For example, the greatest depth of the groove  544  may be similar to the greatest depth of the groove  532 . Alternatively, the depth of the grooves  522 - 544  may vary based on the location of grooves  520  on the ball striking face  512 . Alternatively yet, the depths of the grooves  522 - 544  may vary in any manner from the top rail  182  to the sole. Although the above examples may describe a particular number of horizontal regions, the apparatus, methods, and articles of manufacture described herein may include more or less horizontal regions. 
     The grooves  220 ,  320 ,  420  and  520  described above illustrate four examples of horizontal cross-sectional profile of grooves for use with the putter  100 . Other examples of horizontal cross sectional profiles are shown in  FIGS.  29 - 37   , where each groove may have a length  590 , a first depth  591 , a second depth  592  and/or a third depth  593 . A groove may be defined by any number of horizontal regions, where any one or more regions have similar properties or dissimilar properties. A groove that may be symmetric or asymmetric about the y axis, for example, may have a bottom surface with a complex combination of linear and nonlinear shapes defining similar or various depths from the toe end  180  to the heel end  190 . Such a groove may be described with a large number of horizontal regions, where each region defines one or more of the noted complex shapes. Accordingly, the number, arrangement, sizes and the other properties of the horizontal ranges described above are in no way limiting to the groove cross-sectional profiles according to the disclosure. 
     In the above examples, the grooves on each corresponding ball striking face have similar shapes. However, the grooves on ball striking face may have dissimilar shapes. For example, a ball striking face may include a combination of grooves  220  and  320 . In another example, the ball striking face may include a combination of grooves  420  and  520 . Thus, any combination of groove cross-sectional profiles may be used on a ball striking face to impart a particular ball striking property to the putter. 
     The horizontal cross-sectional profiles of the grooves may progressively and proportionally vary from the top rail  182  to the center of the ball striking face and may progressively vary from the center of the ball striking face to the sole  192 . The noted progressive variation may define a ball strike zone that is larger at the center of the ball striking face than near the top rail  182  and the sole  192 . Furthermore, the progressive noted variation of the grooves&#39; horizontal cross-sectional profiles provides grooves at the center of the ball striking face and around the center of the ball striking face that have longer deep groove sections than grooves near the top rail  182  and the sole  192 . However, the above-described progressive variation of the grooves is exemplary and other progressive variation schemes may be used to impart particular ball striking properties to various portions of the ball striking face. 
     Referring to  FIG.  23   , a ball striking face  612  according to another example is shown having grooves  620 .  FIGS.  24 - 26    show a vertical cross-sectional shape of the grooves  620  as viewed from section line  24 - 24  of  FIG.  23   . In  FIG.  24   , the vertical cross-sectional shape of the groove  620  is box-shaped, rectangular or square. In  FIG.  25   , the vertical cross-sectional shape of the groove  620  is V-shaped. In  FIG.  26   , the vertical cross-sectional shape of the groove  620  is U-shaped. The vertical cross-sectional groove shapes of  FIGS.  24 - 26    are applicable to any groove according to the disclosure. For example, the vertical cross-sectional shape of the grooves  220  may be rectangular or square according to the grooves  620  of  FIG.  24   . In another example, the vertical cross-sectional shape of the grooves  620  may be V-shaped according to the groove  620  of  FIG.  25   . Furthermore, the vertical cross-sectional shape of a groove may vary from the toe end  180  to the heel end  190 . For example, with reference to  FIGS.  4  and  5   , a groove  220  may be have a square or rectangular vertical cross-sectional shape in regions  271  and  275 , U-shaped vertical cross-sectional shape in regions  271  and  274 , and V-shaped vertical cross-sectional shape in region  273 . Additionally, the vertical cross-sectional shapes of the grooves may also vary from the top rail  182  to the sole  190 . For example, grooves near the top rail  182  and the sole  192  may have a square vertical cross-sectional shape, while the grooves at the center of the club face may have a U-shaped vertical cross-sectional shape. 
     The ball striking face of the putter in the above examples is shown to have grooves from the top rail  182  to the sole  192 . However, a ball striking face may have more or less grooves, or have sections that are without grooves. For example, a ball striking face may have several grooves at the center section of the ball strike face and be without grooves at sections near the top rail  182  or the sole  192 . 
     The grooves are not limited to extending horizontally across the ball striking face. The ball striking face may have vertical grooves that vary in depth as described above or a combination of vertical and horizontal grooves with varying horizontal and/or vertical cross-sectional profiles. The orientation of the grooves may be such that a matrix-like ball striking face is provided on the putter. 
     Referring to  FIG.  27   , a ball striking face  712  having grooves  720  may be horizontally separated into three portions, which are the toe portion  780 , a center portion  785  and a heel portion  790 . The ball striking face  712  may be similar to the ball striking face  212  and  312  described above. Accordingly the grooves  720  have regions  271 - 275  and  371 - 375  similar to grooves  220  and  320 , respectively, described above. The three portions described above horizontally separate the ball striking face  712  and span vertically from the top rail  182  to the sole  192 . The toe portion  780  is near the toe end  180 , the heel portion  790  is near the heel end  190 , and the center portion  785  is between the toe portion  780  and the heel portion  790 . According to various examples, the depth of the grooves  720  at the toe portion  780  and the heel portion  790  may not be greater than the depth of the grooves  720  at the center portion  785 . In one example, the shallowest depth of the grooves  720 , which may be nearest to the toe end  180  or nearest to the heel end  190  may be approximately 0.003 inch. At or near the center portion  785 , the depth of the grooves  720  may increase as described above to a depth of approximately 0.017 inch. The variable depth may include a portion with a depth of at least 0.020 inches but less than 0.022 inches. The variable width may include a portion with a width of at least 0.035 inches but less than 0.037 inches. 
     Referring to  FIG.  28   , the ball striking face  712  may be vertically separated into three portions, which are the top rail portion  782 , the mid portion  786  and the sole portion  792 . These portions vertically separate the ball striking face  712  and span horizontally from the toe end  180  to the heel end  190 . The top rail portion  782  is near the top rail  182 , the sole portion  792  is near the sole  192 , and the mid portion  786  is between the top rail portion  782  and the sole portion  792 . The length of the deepest portion of a groove  720  may vary from the top rail portion  782  to the mid portion  786  and from the mid portion  786  to the sole portion  792 . For example, with respect to the examples described above, the length of the deepest portion of a groove may refer to the groove  720  that is proximately centrally located between the top rail portion  782  and the sole portion  792 . As shown in  FIGS.  27  and  28   , the length of the grooves  710  may be greatest at the mid portion  786  and gradually reduce toward the top rail portion  782  and toward the sole portion  792 . 
       FIGS.  29 - 37    show examples of different groove horizontal cross-sectional profiles according to the disclosure. In the above examples, the width of the grooves  220 ,  320 ,  420  and  520  is shown to have a rectangular profile. However, a groove according to the disclosure may have different width profiles as shown by the examples of  FIGS.  38 - 45   . Accordingly, a groove according to the disclosure may have any horizontal cross-sectional profile, vertical cross-sectional profile, width profile and/or depth profile. 
     A cross-sectional profile of a groove including variations in lengths, depth, width and/or cross-sectional shape of the groove may affect ball speed, control, and/or spin. The disclosed variable depth grooves may improve the consistency of the ball speed after being struck by the putter face by about 50% over a plastic putter face insert, and by about 40% over a non-grooved aluminum putter face insert. Striking a ball with a putter having grooves according to the disclosure: (1) may result in lower ball speeds, which may result in decreased ball roll out distance; (2) may result in heel and toe shots to have decreased ball speeds compared to center hits, and also may result in shorter ball roll out distance; (3) allow relatively lower and higher handicap players to strike the ball with different locations on the putter face (higher handicap players tend to hit lower on the ball striking face whereas lower handicap player tend to hit higher on the ball striking face. Also, relatively higher handicap players may have a wider range of hit locations whereas relatively lower handicap players may have a closer range of hit locations; and/or (4) a putter face with grooves in the center of the face may result in reduced ball speed/roll out distance for center shots, which may result in a more consistent ball speed/roll out distances for center/heel/toe shots. 
     Referring to  FIG.  46   , another example of a putter face  810  having grooves of variable cross-sectional profiles is shown. The putter face  810  is shown to have fourteen grooves, which are grouped into grooves  822 - 828  near the toe end  180 , grooves  830 - 840  at the center of the putter face  810 , and grooves  842 - 848  near the heel end  190 . In this example, the more prominent grooves are located at the center of the putter face  810 , and less prominent grooves are on the periphery of the center. A more prominent groove may refer to a groove that has a greater depth and/or width as compared to a less prominent groove. As shown in  FIG.  46   , the grooves  832 - 838  may be more prominent that the remaining grooves on the putter face  810 . Furthermore, portions of the putter face  810  may be without grooves. These portions are referred to with reference number  850 . 
     Referring to  FIG.  47   , another example of a putter face  910  having grooves of variable cross-sectional profile is shown. The putter face  910  is shown to have ten grooves  922 - 940 . The length of each groove progressively increases from the top rail  182  to the sole  190 . Each of the grooves  922 - 940  or groups of the grooves  922 - 940  may have different vertical cross-sectional shapes. For example, grooves  922 - 930  are shown to have box-shaped vertical cross sections, while grooves  932 - 940  are shown to have V-shaped vertical cross sections. 
     Referring to  FIG.  48   , a horizontal cross section of a groove  922  according to another embodiment is shown. A bottom surface  954  of the groove  922  is shown to gradually recede from the edges  950  and  952  of the groove to a greatest depth  951  of the groove  922 . Any of the grooves according to the disclosure may have the same horizontal cross-sectional shape as the groove  922 . Any of the grooves according to the disclosure may have the same depth  951 . However, the depth  951  may be proportionally reduced as the length of the groove is reduced. 
     In another example shown in  FIG.  49   , a ball striking face  1012  may include grooves  1220  (shown specifically as grooves  1222 - 1256 ). The ball striking face  1012  may be for use with the putter  100 . Accordingly, parts of the putter  100  and the putter head  102  are referred to with the same reference numbers presented above. The grooves may have any cross sectional shape, length and width according to the disclosure. 
     Referring to  FIG.  49   , a side cross-sectional view of a ball striking face  1012  having grooves  1220  according to another example is shown. The ball striking face  1012  may be separated into two portions with respect to the grooves  1220 . The ball striking face  1012  may include a top rail portion  1282  and the sole portion  1286 . The top rail portion  1282  and the sole portion  1286  may vertically separate the ball striking face  1012  and span horizontally from the toe end  180  to the heel end  190 . The top rail portion  1282  may extend generally from a center portion of the ball striking face  1012 , which is represented by the center line  1284 , to near the top rail  182  and include the grooves  1222 . The sole portion  1286  may extend generally from near the sole  192  to the center portion  1284  and include the grooves  1224 . The grooves  1224  of the sole portion  1286  may have a greater depth at one or more locations along each groove  1224  than the grooves  1222  of the top rail portion  1282 . By having shallower grooves  1222  at the top rail portion  1282 , the speed by which a golf ball rolls forward after being struck by the putter may increase so as to provide a more consistent and smooth ball roll out. Alternatively, the depth of the grooves  1220  may progressively reduce in one or more groove steps from the center portion  1284  to the top rail  182  (not shown). In another example, the depth of pairs of grooves may progressively reduce from the center portion  1284  to the top rail  182  (not shown). Accordingly, the reduction in groove depth from the sole  192  to the top rail  182  may be for each groove, for pairs of grooves or for various groupings of the grooves. 
     Referring to  FIG.  50   , the grooves  1224  of the sole portion  1286  may have a smaller depth at one or more locations along each groove  1224  than the grooves  1222  of the top rail portion  1282 . Alternatively, the depth of the grooves  1220  may progressively increase in one or more groove steps from the center portion  1284  and/or the sole  192  to the top rail  182  (not shown). In another example, the depth of pairs of grooves may progressively increase from the center portion  1284  and/or the sole  192  to the top rail  182  (not shown). Accordingly, the increase in groove depth from the center portion  1284  and/or the sole  192  to the top rail  182  may be for each groove, for pairs of grooves or for various groupings of the grooves. 
       FIGS.  51  and  52    show other examples according to the disclosure. Referring to  FIG.  51   , a putter head  1300  includes a ball striking face  1312 , which has a plurality of horizontal grooves  1320  and vertical grooves  1322 . Each of the grooves  1320  and  1322  may have a different configuration as compared to another groove, such as variable cross-sectional profiles, depth profiles, width profiles, length profiles and/or other groove characteristics from the toe end  1380  to near the heel end  1390  and/or from a top rail  1382  to a sole  1392 . For example, the depth of the horizontal grooves  1320  may progressively increase in one or more groove steps from the top rail  1382  to the sole  1386 . The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     Referring to  FIG.  52   , a putter head  1400  includes a ball striking face  1412 , which has a plurality of first diagonal grooves  1420  and second diagonal grooves  1422 . The first diagonal grooves  1420  may be generally parallel to each other. Similarly, the second diagonal grooves  1422  may be generally parallel to each other. The first diagonal grooves  1420  and the second diagonal grooves  1422  may be transverse to each other as shown in  FIG.  52   . For example, the first diagonal grooves  1420  may intersect the second diagonal grooves  1422  at an angle of 30°, 45°, 60° or 90°. Each of the grooves  1420  and  1422  may have a different configuration as compared to another groove, such as variable cross-sectional profiles, depth profiles, width profiles, length profiles and/or other groove characteristics from the toe end  1480  to near the heel end  1490  and/or from a top rail  1482  to a sole  1492 . For example, the depth of the first diagonal grooves  1420  may progressively increase in one or more groove steps from the top rail  1482  to the sole  1486 . The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     Referring to  FIG.  52   , a process  2000  of manufacturing a golf club head according to one example is shown. The process  2000  includes forming a golf club face (block  2002 ) defined by a toe end, a heel end, a top rail and a sole. A golf club face may be formed with a golf club head so that the golf club head and the golf club face are a one-piece continuous part. Alternatively, the golf club head and the golf club face may be formed separately. The golf club face may then be attached to the golf club face by using adhesive, tape, welding, soldering, fasteners and/or other suitable methods and devices. The golf club head and/or the golf club face may be manufactured from any material. For example, the golf club head and/or the golf club face may be made from titanium, titanium alloy, other titanium-based materials, steel, aluminum, aluminum alloy, other metals, metal alloys, plastic, wood, composite materials, or other suitable types of materials. The golf club head and/or the golf club face may be formed using various processes such as stamping (i.e., punching using a machine press or a stamping press, blanking, embossing, bending, flanging, or coining, casting), injection molding, forging, machining or a combination thereof, other processes used for manufacturing metal, plastic and/or composite parts, and/or other suitable processes. In one example, when manufacturing a putter head, the material of the putter face and/or the ball striking face may be determined so as to impart a certain ball strike and rolling characteristics to the putter face. In another example, when the ball striking face  212  is separate from the putter face  110  and is inserted and attached into a correspondingly shaped depression on the putter face  110 , the striking face  212  may be constructed from a lighter material than the putter face  110  to generally reduce the overall weight of the putter. 
     According to the process  2000 , grooves are formed on the club face and/or club head between the top rail and the sole such that each groove extends between the toe end and the heel end and depths of the grooves vary in a direction extending between the top rail and the sole and in a direction extending between the heel end and the toe end (block  2004 ). The grooves may be formed using various processes such as casting, forging, machining, spin milled, and/or other suitable processes. The vertical cross-sectional shape of a groove may depend on the method by which a groove is manufactured. For example, the type of cutting bit when machining a groove may determine the vertical cross-sectional shape of the groove. The vertical cross sectional shape of a groove may be symmetric, such as the examples described above, or may be asymmetric (not shown). In one example, the width of a groove can be 0.032 inch, which may be the width of the cutting bit. Accordingly, when machining a groove, the shape and dimensions of the cutting bit may determine the shape and dimension of the groove. 
     The grooves may be manufactured by spin milling the ball strike face, or stamping or forging the grooves into the ball striking face. The grooves may also be manufactured direction on the putter head to create a ball striking face as described above directly on the putter head. A groove may be manufactured by press forming the groove on the putter head. For example, a press can deform and/or displace material on the putter head to create the groove. A groove may be manufacturing by a milling process where the rotating axis of the milling tool is normal to putter face. The rotating axis of the milling tool may be oriented at an angle other than normal to the putter face. A groove may be manufactured by overlaying one material that is cut clean through to form a through groove onto a base or solid material. A groove may be manufactured by laser and/or thermal etching or eroding of the putter face material. A groove may be manufactured by chemically eroding the putter face material using photo masks. A groove may be manufactured by electro/chemically eroding the putter face material using a chemical mask such as wax or a petrochemical substance. A groove may be manufactured by abrading the face material using air or water as the carry medium of the abrasion material such as sand. Any one or a combination of the methods discussed above can be used to manufacture one or more of the grooves on the putter head. Furthermore, other methods used to create depressions in any material may be used to manufacture the grooves. 
     As the rules to golf may change from time to time (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and/or governing bodies), golf equipment related to the methods, apparatus, and/or articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the methods, apparatus, and/or articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The methods, apparatus, and/or articles of manufacture described herein are not limited in this regard. 
     Although a particular order of actions is described above, these actions may be performed in other temporal sequences. For example, two or more actions described above may be performed sequentially, concurrently, or simultaneously. Alternatively, two or more actions may be performed in reversed order. Further, one or more actions described above may not be performed at all. The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     While the invention has been described in connection with various aspects, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptation of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within the known and customary practice within the art to which the invention pertains.