Locally milled golf club face

Abstract

To provide a metal wood golf club having a milled ball striking surface, and a set of golf clubs having milled faces.SOLUTION: A wood-style golf club head includes a strike face and a body that cooperate to define a hollow internal club head volume. The strike face is formed from a strike plate having an outer perimeter, and a frame surrounding the strike plate. The strike plate is affixed to the frame across the entire outer perimeter. The strike plate and the frame define a continuous ball striking surface that has a surface texture characteristic of milling that extends continuously across both the strike plate and the frame.SELECTED DRAWING: None

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority from U.S. Provisional Patent Application No. 62 / 435,944, filed December 19, 2016, which is hereby incorporated by reference in its entirety.

[0002] SUMMARY OF THE DISCLOSURE The present disclosure relates generally to metal wood golf clubs having milled ball-striking surfaces and sets of golf clubs having milled faces. [Background technology]

[0003] A conventional metal wood golf club head includes a face and a body extending rearward from the face. In some embodiments, the face may have a slightly rounded shape to impart a straighter and / or longer trajectory to the golf ball, even when the ball is struck away from the center of the face. This rounded shape may be defined in terms of a bulge profile (curvature from the toe end to the heel end) and a roll profile (curvature from the crown end to the sole end).

[0004] A typical metal wood golf club head can be formed by coining and / or machining a striking plate to have a predetermined bulge and roll curvature, welding the striking plate into an opening in a front frame, grinding away any weld beads exposed after the welding process, and applying a uniform polished surface finish across the frame and striking plate. However, such processes can result in rather large tolerances in the final product due to variations in the coining, welding, grinding, and finishing processes. Therefore, there is a need in the art to create a golf club with a face profile that can achieve much tighter bulge / roll tolerances to reduce variation across multiple club heads of the same design. There is also a need for a low-loft club head that reduces spin imparted to a golf ball to increase carry distance and help improve golf ball trajectory. Summary of the Invention

[0005] Aspects of the present invention will become apparent by consideration of the detailed description and accompanying drawings. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic perspective view of a golf club head.

[0007] [Figure 2] 2 is a schematic, partially exploded perspective view of the golf club head of FIG. 1. FIG.

[0008] [Figure 3] 1A-1C are schematic diagrams of a method of forming a golf club head.

[0009] [Figure 4] 1A-1C are schematic diagrams of a method of forming a golf club head.

[0010] [Figure 5A]FIG. 1 is a schematic front view of a golf club head having a linear vertical milling pattern.

[0011] [Figure 5B] FIG. 1 is a schematic front view of a golf club head having a linear horizontal milling pattern.

[0012] [Figure 5C] FIG. 1 is a schematic front view of a striking face having a circular central portion with a linear horizontal milling pattern and a peripheral portion with a milling pattern extending radially outward from the central portion.

[0013] [Figure 5D] FIG. 1 is a schematic front view of a striking face having a circular central portion with a milling pattern extending radially outward from the center and a peripheral portion with a linear horizontal milling pattern.

[0014] [Figure 5E] FIG. 1 is a schematic front view of a striking face having a circular central portion with a milling pattern extending radially outward from the center and a peripheral portion with a milling pattern having overlapping, intersecting linear milling marks.

[0015] [Figure 5F] FIG. 1 is a schematic front view of a striking face having a circular central portion with a milling pattern extending radially outward from the center and a peripheral portion with a milling pattern having overlapping, intersecting curvilinear milling marks.

[0016] [Figure 5G] FIG. 1 is a schematic front view of a striking face having a circular central portion with a concentric milling pattern extending radially outward from the center and a peripheral portion with a concentric milling pattern extending radially outward from the central portion.

[0017] [Figure 5H] FIG. 1 is a schematic front view of a striking face having a curved polygonal central portion with a linear horizontal milling pattern and a peripheral portion with multiple regions each having a linear milling pattern of a different orientation.

[0018] [Figure 5I] FIG. 1 is a schematic front view of a striking face having a curved polygonal central portion with a concentric milling pattern extending radially inward from an outer periphery and a peripheral portion with multiple regions each having a linear milling pattern of a different orientation.

[0019] [Figure 5J] FIG. 1 is a schematic front view of a striking face having a curved polygonal central portion with a linear horizontal milling pattern and a peripheral portion with multiple regions each having a linear milling pattern of a different orientation.

[0020] [Figure 6] 10 is a graph showing a schematic diagram of the calculation of the surface parameter WVoid.

[0021] [Figure 7] 10 is a graph that schematically illustrates the calculation of the surface parameter WVDCL.

[0022] [Figure 8] FIG. 2 is a schematic perspective view of a golf club head showing a coordinate system with the face center positioned at the geometric face center. DETAILED DESCRIPTION OF THE INVENTION

[0023] The embodiments detailed below are generally directed to golf club heads, methods of making golf club heads, and / or tailored sets of golf club heads having a surface texture milled across the forward, ball-striking face for the purpose of influencing the spin imparted to a golf ball impacted by the club head.

[0024] Milling a golf club face has been shown to provide a more controlled and / or more controllable surface profile, contour, and texture compared to other golf club finishing techniques. When properly executed, the milled surface texture can impart a greater amount of contact friction during impact with a golf ball than other finishing techniques, such as polishing. Unfortunately, milling is highly variable and can alter the existing surface roughness (e.g., average roughness (R A ) measurement cannot adequately account for the differences between various milling patterns. Therefore, the present disclosure is further directed to milled ball-striking surfaces characterized by a newly developed surface parameter that correlates closely with the amount of spin imparted to a golf ball by a low-loft club, such as a driver (i.e., reduced spin in a low-loft club may indicate increased contact friction at impact). Using these techniques, the milled faces of the present disclosure are characterized by a surface roughness (R) that is approximately equal to or slightly reduced. A ), they found a reduction in imparted spin. This technique for characterizing milled golf club faces may further be used to create faces suitable for different design objectives (high backspin, low backspin, customized side spin profiles (e.g., to increase the bulge profile of a driver), milling patterns in zones to affect off-center impacts, varying the spin profile as a function of loft, etc.).

[0025] The terms "a," "an," "the," "at least one," and "one or more" are used interchangeably to indicate the presence of at least one item; unless the context clearly indicates otherwise, a plurality of such items may be present. All values ​​of parameters (e.g., amounts or conditions) in this specification, including the appended claims, should be understood in all instances to be modified by the term "about," regardless of whether "about" actually precedes the value. "About" indicates that the stated numerical value allows for some imprecision (some proximity to the precision of the value, relative to a value, approximately or reasonably close to a value, approximation). Where the imprecision conferred by "about" is not understood in this ordinary sense in the art, as used herein, "about" indicates at least the variation that can result from ordinary methods of measuring and using such parameters. Furthermore, the disclosure of a range includes the disclosure of all values, as well as sub-divided ranges within the entire range. Each value within a range and the endpoints of the range are all disclosed herein as separate embodiments. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated items but do not exclude the presence of other items. As used herein, the term "or" includes any and all combinations of one or more of the listed items. When terms such as first, second, third, etc. are used to distinguish various items from one another, these designations are merely for convenience and do not limit the items.

[0026] As used herein, the terms "loft" or "loft angle" of a golf club refer to the angle formed between the club face and the shaft as measured by any suitable loft and lie machine. The geometric center of the face or "face center" is defined in accordance with convention and accepted wisdom for identifying the geometric center of the face. As is well understood, the face center is a location equidistant between the heel edge of the face and the toe edge of the face, and is a location equidistant between the top edge of the face and the bottom edge of the face.

[0027] Terms such as "first," "second," "third," and "fourth" in the specification and claims, when used, are used to distinguish between like elements and not necessarily to describe a particular sequential or chronological order. It should be understood that terms so used are interchangeable under appropriate circumstances, such that the embodiments described herein can, for example, operate in sequences other than those illustrated or described herein. Furthermore, the terms "comprise" and "have," and any conjugations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that includes listed elements is not necessarily limited to those elements and may include other elements not expressly listed or other elements inherent to such process, method, system, article, device, or apparatus.

[0028] Terms such as "left," "right," "front," "back," "upper," "lower," "above," and "below" in the specification and claims, when present, are used for descriptive purposes with a golf club held in an address position on a level ground and at a predetermined loft and lie angle as a general reference, and are not necessarily intended to describe permanent relative positions. Terms so used are interchangeable under appropriate circumstances, and it should be understood that the apparatus, method, and / or article embodiments described herein can operate, for example, in orientations other than those shown or described herein.

[0029] The terms "coupled," "coupled," "couple," "connecting," and the like should be understood broadly and refer to the connection of two or more elements, mechanically or otherwise. The connection (whether mechanical or otherwise) may be for any length of time, for example, permanently, semi-permanently, or merely momentarily.

[0030] Other features and aspects will become apparent by consideration of the following detailed description and the accompanying drawings. Before any embodiment of the present disclosure is described in detail, it should be understood that the disclosure is not limited in its application to the details or the construction and arrangement of components as set forth in the following description or illustrated in the drawings. The present disclosure is capable of supporting other embodiments and can be practiced or carried out in various ways. It should be understood that the description of a particular embodiment is not intended to limit the disclosure, since it covers all modifications, equivalents, and alternatives within the spirit and scope of the disclosure. It should also be understood that the phraseology and terminology used herein is for the purpose of description and should not be construed as limiting.

[0031] Referring to the drawings, wherein like reference numerals are used to identify similar or identical components in the various views, FIG. 1 generally illustrates a perspective view of a wood-type golf club head 10 including a striking face 12 and a body 14 that cooperate to define a hollow interior club head volume 16 (shown in FIG. 2). As shown, golf club head 10 further includes a toe portion 20, a heel portion 22, a rear portion 24, a crown 26, and a sole 28. While the present disclosure is generally directed to wood-type club heads, such as drivers, fairway woods, or hybrid irons, it should be understood that aspects of the present disclosure may be equally applicable to iron-type golf clubs, such as controlling face texture to affect contact friction and spin.

[0032] As generally shown in Figures 1-2, in some embodiments, the striking face 12 may include a striking plate 30 and a frame 32 that cooperate to define a continuous ball-striking surface 34 (i.e., the portion of the club head 10 intended to directly impact a golf ball). In embodiments, the striking plate 30 and the frame 32 may be integrally formed from a single piece of material. In some variations of this design, the frame 32 may flow rearwardly away from the ball-striking surface 34 to form a "cup face" portion of the club head.

[0033] In another embodiment, instead of being integrally formed, the striking plate 30 may be generally secured within an opening 36 in the frame 32. For example, in some embodiments, the frame 32 may include a lip 38 or recessed ledge that extends around at least a portion of the perimeter of the opening 36. When assembled, the striking plate 30 may nest within the opening 36 such that the rear surface of the striking plate 30 abuts the lip 38 and such that the front surface of the striking plate 30 is approximately flush with the front surface of the frame 32. Once positioned within the opening 36, the striking plate 30 may be secured to the frame 32 around the entire perimeter / seam through an integral attachment technique, such as welding.

[0034] In embodiments in which the striking plate 30 is formed separately from the frame 32, the striking plate 30 may be coined before being secured within the opening 36. This coining may impart a bulge and / or roll curvature to the ball striking face 34 to provide room for correction on off-center impacts through a dynamic response commonly referred to as the "gear effect."

[0035] During coining, a large force is applied to the strike plate 30, causing the material to plastically deform into a predetermined curvature (characterized by the bulge radius and the roll radius). In many embodiments, the bulge radius and the roll radius may be the same. In other embodiments, the bulge radius and the roll radius may be different. In the illustrated embodiment, both the bulge and the roll have a radius of 12 inches (approximately 304.8 mm). In other embodiments, the bulge may have any radius of curvature. For example, in some embodiments, the bulge may have a radius of 4 inches, 5 inches, 6 inches, 7 inches, 8 inches, 9 inches, 10 inches, 11 inches, 12 inches, 13 inches, 14 inches, 15 inches, 16 inches, 17 inches, 18 inches, 19 inches, 20 inches, 21 inches, 22 inches, 23 inches, 24 inches, 25 inches, 26 inches, 27 inches, or 28 inches (approximately 100 mm to approximately 720 mm). In the same or other embodiments, the roll may have any radius of curvature. For example, in some embodiments, the roll may have a radius of 4 inches, 5 inches, 6 inches, 7 inches, 8 inches, 9 inches, 10 inches, 11 inches, 12 inches, 13 inches, 14 inches, 15 inches, 16 inches, 17 inches, 18 inches, 19 inches, 20 inches, 21 inches, 22 inches, 23 inches, 24 inches, 25 inches, 26 inches, 27 inches, or 28 inches (about 100 mm to about 720 mm).

[0036] The frame 32 and / or the striking plate 30 may be formed from the same or different materials, so long as they are both constructed with sufficient strength to withstand the repeated impact stresses that occur when the club head 10 strikes a golf ball. Examples of suitable materials for the frame 32 and / or striking plate 30 include stainless steel or alloy steel (e.g., C300, C350, Ni (nickel)-Co (cobalt)-Cr (chromium)-alloy steel, 565 steel, AISI type 304, or AISI type 630 stainless steel), titanium alloy (e.g., Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti-15-3-3-3, Ti-15-5-3, Ti-185, Ti-6-6-2, Ti-7s, Ti-92, or Ti-8-1-1 titanium alloy), amorphous metal alloy, aluminum alloy, or one or more high-strength composite materials including, for example, plastic polymers and copolymers, carbon fiber, glass fiber, or metal fiber.

[0037] The club head body 14 may be formed from the same or a different material as the frame 32 and / or striking plate 30. In some embodiments, the material of the body 14, along with the design of the body structure, may provide a controlled dynamic impact response that may affect launch angle, spin, and ball speed. In some embodiments, the body 14 may be formed from stainless steel, titanium, aluminum, alloy steel, titanium alloy, carbon fiber composite, molded filled or unfilled engineering plastic / polymer, or a combination thereof.

[0038] 3 illustrates a first method 100 for forming the golf club head assembly 10. The first method 100 includes a first step 102 of forming the striking plate 30 and the club head body 14. The striking plate 30 and / or the club head body 14 may be formed using machining, casting, stamping, injection molding (metal and / or polymer), direct laser sintering, powder metal forming, or other suitable processes known to those skilled in the art.

[0039] Once formed into the general shape, the striking plate blank may then be coined in step 104. As previously described, coining is a form of precision stamping in which the striking plate 30 is subjected to a large force that causes it to plastically deform. The coining process is used to create the bulge and roll radius described above.

[0040] The striking plate 30 may then be milled or machined to provide a precise contour and surface texture in step 106. Machining is generally performed using a rotary cutter to remove material from the striking plate 30 and a CNC system to control the processing.

[0041] Once machined, the striking plate 30 may then be welded to the opening 36 in the frame 32 in step 108. The striking plate 30 is aligned with the opening 36 in the frame 32 and abuts the lip 38. The striking plate 30 is secured to the frame 32 by welding along the perimeter of the opening 36 to form the golf club head 10. In some embodiments, the welding step may utilize a pulsed plasma or laser welding process.

[0042] Following the welding process in step 108, the weld line and any protruding weld beads may be removed through a grinding process in step 110. The grinding process involves a rotary grinding wheel being used to remove material along the weld line. The grinding process may also ensure that the bulge and roll radii of the frame 32 match the bulge and roll radii of the striking plate 30 created during the coining step 104 and machining step 106. The golf club head assembly 10 formed from the method 100 shown in FIG. 3 will include a striking face 12 having at least two different surface finishes (i.e., the original and / or polished finish of the frame 32 and the machined / milled finish of the striking plate 30).

[0043] Figure 4 generally illustrates a second method 200 for forming the golf club head 10. The method 200 illustrated in Figure 4 is similar in many respects to the first method 100 illustrated in Figure 3, except that the machining / milling of step 106 is performed after the striking plate 30 is welded to the frame 32 in step 108. In doing so, the polishing of step 110 may optionally be omitted, and the surface texture of the striking plate 30 may optionally be extended across the frame 32 in a continuous manner.

[0044] The second method 200 generally begins by forming the striking plate 30 and golf club head body 14 in step 202, such as by machining, casting, stamping, injection molding (metal and / or polymer), direct laser sintering, powder metal forming, or other suitable process known to those skilled in the art. The striking plate 30 may then be coined in step 204, as described above in step 104 of FIG.

[0045] The stamped striking plate 30 may then be welded into the opening 36 in the frame 32 in step 206. Any remaining weld beads / weld lines may optionally be removed via a grinding process 208 (shown in phantom to indicate that this is not a strictly required step). Finally, the entire ball striking face 34 may be machined / milled in step 210. In some embodiments, this machining step 210 may be operable to remove any weld beads not removed via optional step 208.

[0046] By machining / milling throughout the entire ball striking face 34, the manufacturing method 200 may create little or no surface texture at specific locations around the weld line / perimeter of the striking plate 30. For example, the surface texture may be uniform and continuous across both the striking plate 30 and the frame 32, may vary continuously as a function of distance from the face center, or may take on any other pattern deemed desirable. Most importantly, these milling patterns need not be constrained by the size and location of the striking plate perimeter.

[0047] Milling or machining the entire striking face 12, such as through the second method 200 of Figure 4, provides the added benefit of tighter / reduced profile / curvature tolerances (i.e., to provide more precise curvatures) for the bulge and roll radii. Having a textured surface throughout the striking face 12 while maintaining tighter tolerances for the bulge and roll radii can produce a higher performing club head assembly 10 that provides greater distance, spin control, and forgiveness.

[0048] Surface Texture In a general sense, the milled striking plate 30 has a surface texture that may be characterized by one or more directional cutting patterns and a direction-dependent surface texture. Typical milling processes utilize a rotating cutting tool to remove material from the striking plate 30. This process may be automated using a computer numerically controlled (CNC) system to provide increased precision, consistency, and repeatability across multiple club heads. Furthermore, CNC machining can ensure that the primary pattern direction, surface texture, and overall face contour precisely match predetermined specifications. This level of increased precision is desirable because it has been found that the primary pattern direction and surface texture on the striking plate 30 can significantly affect the spin characteristics of a golf ball after impact. Therefore, given the level of manufacturing control and repeatability afforded by CNC milling, it is possible to customize the textured surface on the striking plate 30 to an individual's swing type, which results in a longer, straighter ball flight pattern.

[0049] Typical milling patterns may simulate a plurality of concentric or linear grooves cut into the outer surface. These patterns may more specifically comprise a plurality of major peaks and valleys, each extending along a linear or curved path. In some embodiments where the milling paths overlap, each major peak may include a plurality of minor valleys arranged in a regular pattern along at least a portion of the peak's length, and each major valley may include a plurality of minor peaks arranged in a regular pattern along at least a portion of the valley's length. In some embodiments of the present design, depending on the direction along the striking plate surface being measured, the peaks and valleys (measured from the mid-plane of the peaks and valleys) may range from -100 μin to 100 μin (about -2.54 μm to about 2.54 μm), -140 μin to 140 μin (about -3.56 μm to about 3.56 μm), -200 μin to 200 μin (about -5.08 μm to about 5.08 μm), or The thickness may range from -500 μin to 500 μin (about -12.7 μm to about 12.7 μm), -700 μin to 700 μin (about -17.78 μm to about 17.78 μm), -1000 μin to 1000 μin (about -25.4 μm to about 25.4 μm), -1400 μin to 1400 μin (about -35.56 μm to about 35.56 μm), or more.

[0050] In some embodiments, the surface texture across the ball striking surface 34 may be uniform across the entire striking plate 30, while in other embodiments, the ball striking surface 34 may have a surface texture that varies functionally across the striking face 12. For example, in embodiments, the surface texture may vary from a central region of the striking plate 30 toward the periphery of the striking plate 30. In some embodiments, the surface roughness may vary across the striking plate 30 from near the toe portion 20 of the club head 10 to near the heel portion 22 of the club head 10. In other embodiments, the surface roughness may vary across the striking plate 30 from near the sole 28 of the club head 10 to near the crown 26 of the club head 10. In yet other embodiments, the surface roughness may vary in any combination of the foregoing examples. In yet other embodiments, the surface roughness may be uniform in certain areas of the striking plate 30 and vary in other areas of the striking plate 30. In embodiments, the textured surface of the striking plate 30 may have a uniform roughness of approximately 148 μin (approximately 3.76 μm). In other embodiments, the textured surface may have a surface roughness of between about 50 μinch and about 300 μinch (between about 1.27 μm and about 7.62 μm). In some embodiments, the textured surface may have a surface roughness of between 25-350, 25-50, 50-75, 75-100, 100-125, 125-150, 150-175, 175-200, 200-225, 225-250, 250-275, 275-300, 300-325, 25-150, 150-350, 75-250, 25-125, 125-225, 225-350, 75-150, 150-225, or 225-300 μinch. In other embodiments, the roughness may be 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, or 350 μinch. In still other embodiments, the surface roughness may be between about 140 μinch and about 300 μinch (between about 3.56 μm and about 7.62 μm).

[0051] As generally shown in FIGS. 5A-5J , the primary pattern direction of the textured surface in any particular region may comprise one or more linear, curved, or intersecting patterns to form milling pattern 250. In some embodiments, these patterns may extend somewhat uniformly across striking face 12. However, in other embodiments, these patterns may be banded or may vary across the face due to their curved and concentric nature. In some embodiments, milling pattern 250 may comprise a central portion 252 surrounded by a peripheral portion 254, as shown in FIGS. 5C-5J . The milling profiles shown in FIGS. 5A-5J are examples of different milling patterns 250 that may be used to meet different design objectives, as described in more detail below. It should be understood that additional designs may be developed in combination with each figure, and that all combinations of patterns and shapes for central portion 252 and peripheral portion 254, even if not shown, are considered separate embodiments.

[0052] As shown generally in FIG. 5A , in embodiments, milling pattern 250 may include a plurality of peaks and valleys oriented in a linear manner between crown 26 and sole 28. FIG. 5B illustrates an embodiment in which this pattern is rotated 90 degrees to extend between heel portion 22 and toe portion 20. FIGS. 5A-5B further illustrate grooves 256 that may be disposed around the periphery of milling pattern 250 to provide a more defined transition between milling pattern 250 and the remainder of club 10. As further shown in FIGS. 5A-5B , in some embodiments, an end portion 258 of the forward-most surface (i.e., ball-striking face 34) may not include a milling texture. Such a surface may instead be polished or sandblasted to more easily blend with the body.

[0053] 5C-5J more clearly illustrate examples of milling patterns 250 having different aspects of the central portion 252 and peripheral portion 254. As shown in FIGS. 5C-5G, in some embodiments, the central portion 252 may be rounded. In other embodiments, as shown in FIGS. 5H-5J, the central portion 252 may have a rounded polygonal design, such as a rounded triangle or a rounded square (or a rounded pentagon, hexagon, heptagon, octagon, etc.). As further shown in FIGS. 5C-5J, the milling patterns 250 within the central portion 252 may comprise linear patterns ( FIGS. 5C, 5H, and 5J ), concentric patterns that begin, for example, at the outer periphery of the central portion 252 ( FIGS. 5G and 5I ), or radial patterns arising from points, lines, or regions ( FIGS. 5D-5F ).

[0054] The peripheral portion 254 may include one or more regions 260 between which the direction / orientation of the milling pattern changes, the type changes, or the milling pattern begins anew. For example, FIGS. 5H-5J show three peripheral designs including multiple regions 260 in which the linear pattern is rotated between each region 260. FIG. 5C shows a diverging ray pattern (i.e., milling lines diverge linearly from a central point or region). FIG. 5D shows linear arrangements across the peripheral portion 254. FIG. 5E shows intersecting linear arrangements (i.e., a first linear arrangement is cut, then a second linear arrangement is cut on top of the first linear arrangement in a second orientation). Figure 5F shows intersecting curved patterns (i.e., a first curved pattern is cut from toe to heel and a second from heel to toe. Similar patterns may be formed by cutting from crown to sole and sole to crown or from various corners.) Figure 5G shows concentric patterns emanating from a central point or central region.

[0055] In some embodiments, the striking face 12 of the golf club head assembly may include two or more different surface finishes / textures. For example, as described above with respect to FIG. 3 , the striking plate 30 may be milled or machined to create a first surface finish before being welded to the opening 36 in the frame 32. The remainder of the striking face 12, which is not milled, may have a second surface finish, such as a smooth or sandblasted surface finish. Having different textured surfaces on the striking face 12 can provide a visual alignment aid to the player to help position the golf ball on the center of the striking face 12. In other embodiments, the entire ball-striking surface 34 (including the frame 32 and striking plate 30) can include a textured surface from milling or machining.

[0056] While milled faces are beneficial in that they provide more controlled face curvature, the surface texture and milling pattern created by the tool can result in a significant amount of variation in the resulting spin and launch characteristics of an impacted ball. For example, two clubs with milling patterns oriented 90 degrees apart can produce significantly different ball launch characteristics. Furthermore, even when the patterns are similarly oriented, differences in the feed rate, cutting depth, tool diameter, end profile, and tool spindle speed used to create the patterns can result in variations in the surface texture that affect ball flight.

[0057] Through testing, it was found that traditional measurements of surface roughness do not appear to adequately characterize the effects of different surface textures and / or milling patterns. For example, Table 1 shows four identical driver designs (i.e., similar volume, mass distribution, construction, and loft), one with a conventional polished surface finish across the striking face 12 (i.e., the control club) and three with different milled surface finishes across the striking face 12. For each club, the average surface roughness (R A ) is measured along a vertical line extending through the geometric center of the face (i.e., from the sole 28 to the crown 26).

[0058] [Table 1]

[0059] In this analysis, the first milled face (Milling 1) attempted to match the average roughness of a polished surface finish as closely as possible. Despite the close average roughness, the milled face generated approximately 10.7% less spin than the polished face. This reduction in spin was an unexpected result. Milled faces 2 and 3 were then constructed with increasing average roughness, due to the conventional wisdom that increasing average roughness reduces the spin imparted by a driver. However, both milled faces 2 and 3 resulted in approximately 5% more spin than the less rough milled face (Milling 1). From this analysis, it was determined that average surface roughness may not be adequate to fully characterize the spin effect caused by the surface texture of a driver face (which is contrary to common understanding).

[0060] Following additional research, a new approach to characterizing the surface texture of a striking face was developed to more effectively predict the resulting spin imparted by the striking face to a golf ball. Furthermore, embodiments of the present design utilize this new characterization to provide a golf club with a face that is optimized to meet one or more spin-based design objectives.

[0061] To more accurately characterize how the surface texture of a golf face can affect the spin of an impacted golf ball, two new surface parameters were discovered. These parameters are: (1) W Void R for the surface porosity parameter called (explained later) A and (2) W VDCL and the value of the surface contact parameter called R A To eliminate ambiguity, W Void and W VDCL is defined as follows:

[0062] R A - as known in the art, R A represents the arithmetic mean of the absolute surface deviation relative to the mean centerline. In practice, the deviation and mean centerline are calculated following application of a high-pass filter with a cutoff selected to eliminate surface waviness. In this design, the stable cutoff wavelength may be approximately 0.03 inches (approximately 0.762 mm).

[0063] W Void As shown generally in FIG. Voidis a parameter developed to represent the average profile void depth 300 relative to a reference surface 302 created by applying a morphological closing filter to the actual surface profile 304. Morphological closing is an image processing technique that can generally be best analogized as a (two-dimensional) disk 306 or (three-dimensional) sphere of a given radius 308 (i.e., radius of curvature) theoretically rolling over the actual surface profile 304. The lower envelope formed by the rolling disk thus creates a "closed" reference surface 302. In a two-dimensional situation, such as that shown in FIG. 5, W Void may be calculated by summing the area 310 of the entire gap between the closed reference surface 302 and the actual surface profile 304 and dividing that total area by the length of the surface (i.e., the length of the average centerline 312).

[0064] W VDCL - As shown generally in Figure 7, W VDCL is (W Void 5) and the actual surface profile 304 to the (two-dimensional) length or (three-dimensional) area of ​​the surface itself (i.e., measured along the centerline 312). VDCL is equal to 1.0, and for wavy surfaces (e.g., when the radius of curvature of the disk / sphere 308 is smaller than any outer radius of curvature of the surface), W VDCL can be greater than 1.0, and for surfaces with rather fine texture (e.g., when the radius of curvature 308 of the disk / sphere is greater than the outer radius of curvature for a portion of the surface), W VDCL may be less than 1.0.

[0065] R A , W Void , and W VDCLWhen calculating , each parameter may be calculated in a manner that is dependent on several directions. More specifically, the surface profile shown in Figures 6 and 7 may be assumed to be obtained from a two-dimensional cutting plane through the striking face 12, similar to the striking face 12 shown in Figure 1. If this cutting plane is oriented perpendicular to the primary milling flutes, all three surface parameters may differ from measurements when the cutting plane is oriented parallel to the milling flutes, which may still differ from three-dimensional calculations where any closed reference surface is generated by a theoretical sphere.

[0066] For purposes of this disclosure, a face-centered coordinate system 400 may be utilized to better explain how the parameters are derived, as shown in FIG. 8 . As shown in FIG. 8 , the face-centered coordinate system 400 may have an origin coincident with the geometric face center, an X-axis 402 and a Y-axis 404, each tangent to the ball-striking surface 34 at the face center, and a Z-axis 406 perpendicular to the ball-striking surface 34 at the face center. The X-axis 402 may further be parallel to the ground 408 and may extend generally between the heel and toe when the club is held at address according to a predetermined loft and lie angle. The Y-axis 404 is perpendicular to the X-axis 402 and is generally a projection of a vertical reference line 410 onto the ball-striking surface 34 when the club is held at address.

[0067] When calculating the various parameters, each may be calculated along a two-dimensional line (e.g., calculated within a single two-dimensional slice taken from the YZ plane), averaged over multiple two-dimensional lines (e.g., averaged over multiple two-dimensional slices taken from adjacent YZ planes), or may be calculated in three dimensions across the entire face (i.e., directionality independent).

[0068] R A / W Void and W VDCLIt is believed that both R and R provide slightly different approximations of the amount of surface area that a golf ball may come into direct contact with (at a microscopic level) during impact (i.e., provide a more accurate approximation of the actual contact friction experienced between the ball and the face during impact). More specifically, the "closed" reference surface 302 may approximate a flexible object (i.e., a polymeric compressible golf ball) that is forced into contact with the surface texture and deforms around the peaks. Based on this assumption, the flexible object (golf ball) does not contact any particular portion of the voids / valleys, and therefore the depth and / or size of the non-contact portions are not significantly related to the effective force transmission and contact friction between the ball and the striking face 12. Despite these voids not being significantly related, they can significantly affect traditional measurements of surface roughness. Under these assumptions, R A / W Void and W VDCL As ρ increases, contact friction also increases, which naturally reduces imparted spin for low loft clubs such as drivers. Empirical test data supports this understanding, as shown through the comparative examples below.

[0069] W Void R A Percentage of: To create the reference surface 302, an R of approximately 0.03 inches (approximately 0.762 mm) A high-pass filter and a W of approximately 0.005 inches (approximately 0.127 mm) Void Using the radius of curvature of and , W Void R A It has been found that the ratio of R to R is correlated with the amount of spin imparted to a golf ball impacted by a low loft golf club, such as a driver. More specifically, as generally shown in Table 2, A / W Void As σ increases, imparted spin decreases. The numbers in Table 2 are all calculated in the YZ cutting plane through the face center for drivers with similar overall geometry, construction, and mass properties.

[0070] [Table 2]

[0071] As shown in Table 2, the R between the polished face and the face of "Milling 1" A Although the values ​​are nearly equal, the R A / W Void The ratios are quite different and more predictive of the spin imparted.

[0072] W VDCL To create the reference surface 302, a W of approximately 0.02 inches (approximately 0.508 mm) VDCL Using the radius of curvature of W VDCL It has been found that the value of W correlates with the amount of spin imparted to a golf ball impacted by a low loft golf club, such as a driver. More specifically, as generally shown in Table 3, VDCL As σ increases, imparted spin decreases. The numbers in Table 3 are all calculated in the YZ cutting plane through the face center for drivers with similar overall geometry, construction, and mass properties.

[0073] [Table 3]

[0074] Club Face Design The above-mentioned features of the surface texture may be utilized to characterize the spin effect of surface textures formed by various techniques (e.g., polishing, milling, sandblasting, etc.), but milling may provide the best control of the resulting texture in three dimensions across the face. In this manner, the golf club head 10 may be customized to fit specific design objectives. Void R A Ratio of W VDCLFor all examples described below, all numerical values ​​are inclusive of an R A A 0.03 inch (approximately 0.762 mm) high-pass cutoff filter and W Void A radius of curvature of 0.005 inches (approximately 0.127 mm) to create a reference surface for W VDCL Note that we are assuming a radius of curvature of 0.02 inches (approximately 0.508 mm) to create a reference surface for .

[0075] The first embodiment is a method for enabling a low loft club, such as a low loft driver (i.e., having a loft angle of about 8 to about 14 degrees, or about 8 to about 12 degrees, or about 8 to about 10 degrees), to have a W of greater than about 4, greater than about 5, greater than about 6, greater than about 7, greater than about 8, greater than about 9, or greater than about 10, measured in a YZ plane passing through the face center. Void R A In some embodiments, the W may be specifically designed to have a low backspin tendency by having a milled striking face with a surface texture characterized by a ratio of W Void R A The ratio may be in the range of 4 to 12, 4 to 8, 8 to 12, 6 to 10, 4 to 6, 36 to 8, 8 to 10, or 10 to 12. For example, Void R A may be 4, 6, 8, 10, or 12. Additionally or alternatively, this low spin driver face surface texture has a W of greater than about 18%, or greater than about 20%, or greater than about 22%, or greater than about 24%, or greater than about 26%, or greater than about 28%, or greater than about 30%, measured in a YZ plane passing through the face center. VDCL In some embodiments, the W VDCL The value may range from 18% to 33%, from 18% to 24%, from 24% to 36%, from 24% to 30%, from 30% to 36%, or from 27% to 33%. VDCL The value may be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, or 36%.

[0076] A second embodiment is a metal wood intended to induce a greater amount of loft (i.e., having a loft angle of about 12 to about 28 degrees or about 14 to about 24 degrees), with a W of less than about 4, less than about 3, less than about 2, or within the range of about 1 to about 4, or about 2 to about 4, as measured in the YZ plane through the face center. Void R A Additionally or alternatively, this higher spin face surface texture may have a W of less than about 24%, or less than about 22%, or less than about 20%, or less than about 18%, or within the range of about 20% to about 24%, measured in the YZ plane through the face center. VDCL It may be characterized by a value.

[0077] In any of these embodiments, instead of just a single read, W Void R A The ratio of W VDCL The values ​​may be averages of values ​​across multiple YZ slices. For example, these values ​​may be averaged over a central band, region, or portion of face 12. For example, these values ​​may be averaged over a 1.68-inch (42.67 mm) impact area, measured along the X-axis, and centered at the face center. Similarly, in some variations, these small or large backspin surface textures may be localized within a central portion 252 of the face, such as within a 1.68-inch diameter circle centered at the face center. Alternatively, these values ​​may be averaged along the X-axis or over a narrower central portion of the impact area, which may measure approximately 0.375 inches (9.53 mm) in diameter.

[0078] In embodiments, in an attempt to maximize contact friction in the heel-toe direction, the striking face 12 has a W measured in the XZ plane through the face center that is greater than about 4, greater than about 5, greater than about 6, greater than about 7, greater than about 8, greater than about 9, or greater than about 10. Void R A Additionally or alternatively, the surface texture with directionally increased contact friction may have a milled surface texture characterized by a W ratio measured in an XZ plane passing through the face center that is greater than about 18%, greater than about 20%, greater than about 22%, greater than about 24%, greater than about 26%, greater than about 28%, or greater than about 30%. VDCL In some embodiments, W VDCL The value may range from 18% to 33%, from 18% to 24%, from 24% to 36%, from 24% to 30%, from 30% to 36%, or from 27% to 33%. VDCL The value may be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, or 36%.

[0079] Alternatively, to minimize contact friction in the heel-toe direction, striking face 12 may have a W of less than about 4, less than about 3, less than about 2, or within the range of about 1 to about 4, or about 2 to about 4, as measured in the XZ plane passing through the face center. Void R A Additionally or alternatively, the surface texture with directionally reduced contact friction may have a W measured in an XZ plane passing through the face center that is less than about 24%, less than about 22%, less than about 20%, less than about 18%, or in the range of about 20% to about 24%. VDCL It may be characterized by a value.

[0080] While the above-described embodiments detail increasing contact friction at / about the center of the striking face 12 (which reduces backspin in drivers), in other embodiments, contact friction may be promoted or inhibited in other locations or regions around the striking face 12 through variations in surface texture. For example, the surface texture in the peripheral region (or peripheral portion 254) of the striking face 12 (e.g., outside the central region or narrower central portion 252) may be controlled to provide improved forgiveness, alter the spin profile, and / or offset other design parameters of the club head 10.

[0081] In one embodiment, the contact friction is greater than about 4, greater than about 5, greater than about 6, greater than about 7, greater than about 8, greater than about 9, or greater than about 10, measured in the YZ plane and / or in the XZ plane and averaged over at least a portion of the peripheral region. Void R A Additionally or alternatively, this increased friction in the peripheral region may be greater than about 18%, greater than about 20%, greater than about 22%, greater than about 24%, greater than about 26%, greater than about 28%, or greater than about 30%, measured in the YZ plane and / or in the XZ plane and averaged over at least a portion of the peripheral region. VDCL In some embodiments, the surface texture may be characterized by a W VDCL The value may range from 18% to 33%, from 18% to 24%, from 24% to 36%, from 24% to 30%, from 30% to 36%, or from 27% to 33%. VDCL The value may be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, or 36%. The peripheral area of ​​increased friction may specifically include one or more of an increased friction portion abutting the sole 28, an increased friction portion abutting the toe portion 20, an increased friction portion abutting the crown 26, and / or an increased friction portion abutting the heel portion 22.

[0082] In some embodiments, increased contact friction in the peripheral region may be used to provide additional design flexibility, for example, when changing the radius of curvature of the bulge and / or roll of the striking face 12, when changing the center of gravity of the club head 10, or when increasing forgiveness for particular impacts.

[0083] In embodiments, the contact friction is less than about 4, less than about 3, less than about 2, or in the range of about 1 to about 4, or about 2 to about 4, measured in the YZ plane and / or the XZ plane and averaged over at least a portion of the peripheral area. Void R A Additionally or alternatively, this reduced friction peripheral region may be reduced by providing a W of less than about 24%, less than about 22%, less than about 20%, less than about 18%, or in the range of about 20% to about 24%, measured in the YZ plane and / or in the XZ plane and averaged over at least a portion of the peripheral region. VDCL The peripheral region of reduced friction may specifically include one or more of a reduced friction portion abutting the sole 28, a reduced friction portion abutting the toe portion 20, a reduced friction portion abutting the crown 26, and / or a reduced friction portion abutting the heel portion 22.

[0084] In some embodiments, the W from within the central region or narrower central portion 252 of the striking face 12 Void R A Average percentage of W VDCL The value is the W from within a portion of the peripheral area of ​​the striking face 12. Void R A Average percentage of W VDCL In another embodiment, W Void R A Ratio of W VDCL The value may vary as a function of increasing distance from the geometric center of the striking face 12. In an embodiment, W (measured in one or both of the YZ and XZ planes)Void R with respect to A the average ratio and / or W VDCL values may be greater closer to the toe portion 20 and / or the heel portion 22 than at the center of the hitting face 12.

[0085] In fact, for a particular face, the R Void to W A ratio and W VDCL values may be customized during milling by varying one or more tools (e.g., ball end mill, square end mill, or corner round end mill), the angle of the tool with respect to the face (e.g., from greater than about 0 degrees to about 90 degrees with respect to the face), cutting speed (e.g., about 60 to about 300 inches per minute for titanium, or about 300 to about 1000 inches per minute for steel), step over (e.g., about 0.005 inches to about 0.125 inches), and feed rate (e.g., about 0.005 inches to about 0.010 inches per minute).

[0086] W Void R with respect to A the ratio and W VDCL both being well correlated with the spin imparted to the impacted golf ball, it may also be desirable to provide an adjusted golf club set that varies W Void R with respect to A the ratio and W VDCL (taken in the Y-Z plane through the face center). For example, with a low loft club, spin may be less desirable than in a relatively higher loft club. Thus, the milling pattern / surface texture provided on the face may be specifically controlled to support the design objectives of the club head.<00​​​​​Void The ratio of (i.e., here (R A / W Void )1>(R A / W Void )2>(R A / W Void )3) and / or a gradually decreasing W VDCL value (i.e., W VDCL1 >W VDCL2 >W VDCL3 ). In one embodiment, at least a first club of the three clubs (designated in the above relationship with a subscript "1") may be a wood-type club and a driver having a loft of between about 8 degrees and about 12 degrees. In an embodiment, at least a third golf club of the set (designated in the above relationship with a subscript "3") may be an iron-type golf club. In an embodiment, L3 may be about 24 degrees or less. Finally, in an embodiment, all three clubs in the set may be wood-type golf clubs, or all three may be iron-type golf clubs.

[0088] Spin and W Void R A The ratio of W VDCL It should further be noted that the inverse correlation between W and W generally only applies to smaller lofted club heads (i.e., loft angles between about 8 degrees and about 24 degrees). For larger lofted club heads (i.e., loft angles greater than about 30 degrees), the opposite effect may exist. More specifically, for larger lofted club heads, W Void R A The ratio of W VDCL Spin may increase with a corresponding increase in both loft angle and impact angle. This transition is believed to occur due to the change in the magnitude of the shear impact forces as loft angle and impact angle increase (i.e., the driver imparts primarily a compression force to the golf ball, while the wedge imparts a much larger net shear force).

[0089] Thus, in embodiments, a large loft iron (i.e., having a loft angle of about 30 to about 64 degrees, about 34 to about 64 degrees, or about 39 to about 64 degrees) may be specifically designed to have a tendency for large backspin by comprising a milled striking face with a surface texture characterized by a ratio of R Void to W A that is greater than about 4, greater than about 5, greater than about 6, greater than about 7, greater than about 8, greater than about 9, or greater than about 10 as measured in the Y-Z plane passing through the face center. In some embodiments, the ratio of R Void to W A may be in the range of 4 to 12, 4 to 8, 8 to 12, 6 to 10, 4 to 6, 36 to 8, 8 to 10, or 10 to 12. For example, the ratio of R Void to W A may be 4, 6, 8, 10, or 12. Additionally or alternatively, this large spin iron face surface texture may be characterized by a W VDCL value that is greater than about 18%, greater than about 20%, greater than about 22%, greater than about 24%, greater than about 26%, greater than about 28%, or greater than about 30% as measured in the Y-Z plane passing through the face center. In some embodiments, the W VDCL value may be in the range of 18% to 33%, 18% to 24%, 24% to 36%, 24% to 30%, 30% to 36%, or 27% to 33%. For example, the W VDCL value may be 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, or 36%.

[0090] Similarly, in embodiments, a golf club set may comprise three golf clubs each having a different loft angle (L) where L1 < L2 < L3. In this set, each golf club may have a ratio of R A / W Void )1 > (R A / W Void )2 and (R A / W Void )3 > (R A / W​​​​​​VDCL1 >W VDCL2 and W VDCL3 >W VDCL2 W VDCL In an embodiment, at least the first of the three clubs (designated in the above relationship by the subscript "1") may be a wood-type club and a driver having a loft of about 8 degrees to about 12 degrees, and the third of the three clubs (designated in the above relationship by the subscript "3") is an iron-type club having a loft of about 30 degrees to about 64 degrees, about 34 degrees to about 64 degrees, or about 39 degrees to about 64 degrees.

[0091] The substitution of one or more claim elements constitutes a rearrangement, not a repair. Additionally, benefits, other advantages, and solutions to problems have been described in connection with particular embodiments. However, the benefits, advantages, solutions to problems, and any one or more elements that provide or make more pronounced any benefit, advantage, or solution should not be construed as a critical, necessary, or essential feature or element of any or all of the claims unless such benefit, advantage, solution, or element is explicitly recited in the claim.

[0092] Because the Rules of Golf may change from time to time (e.g., new Rules may be adopted, or old Rules may be repealed or modified, by golf standards organizations and / or governing bodies such as the United States Golf Association (USGA) or the Royal and Ancient Golf Club of St. Andrews (R&A)), golf equipment relating to the apparatus, methods, and products described herein may or may not conform to the Rules of Golf at any particular time. Accordingly, golf equipment relating to the apparatus, methods, and products described herein may be advertised, offered for sale, and / or sold as conforming or non-conforming golf equipment. The apparatus, methods, and products described herein are not limited in this respect.

[0093] Although the above examples may be described in the context of iron-type golf clubs, the devices, methods, and products described herein may be applicable to other types of golf clubs, such as driver wood-type golf clubs, fairway wood-type golf clubs, hybrid-type golf clubs, iron-type golf clubs, wedge-type golf clubs, or putter-type golf clubs. Alternatively, the devices, methods, and products described herein may be applicable to other types of sports equipment, such as hockey sticks, tennis rackets, fishing rods, ski poles, etc.

[0094] Furthermore, embodiments and limitations disclosed herein are not made available to the public under the doctrine of public domain if the embodiment and / or limitation (1) is not explicitly claimed in the claims and (2) is an equivalent or potential equivalent of an explicit element and / or limitation in the claims under the doctrine of equivalents.

[0095] Various features and advantages and characteristics of the present disclosure are further described in the following paragraphs.

[0096] Clause 1: A wood-type golf club head, comprising: a toe portion, a heel portion, a crown, a sole, a striking face and a body cooperating to define a hollow interior club-head volume, the striking face further comprising a ball-striking surface having a milled surface texture characteristic, the surface texture comprising a plurality of peaks and a plurality of valleys and a reference mid-plane extending between the plurality of peaks and the plurality of valleys, wherein a negative distance below the reference mid-plane and a positive distance above the reference mid-plane, the plurality of peaks and the plurality of valleys extending an average maximum distance from the mid-plane of at least -200 microinches (-5.08 micrometers) to at least 200 microinches (5.08 micrometers), and the surface texture has an average surface roughness (R ) representing an arithmetic mean of absolute surface deviations from a mean centerline. A), and a surface void parameter (W ) representing the average depth of the valleys relative to a closed reference surface created using a morphological closing filter applied to the surface texture. Void ), and a surface contact parameter (W VDCL ) and the surface texture measured in at least one of a vertical cutting plane and a second cutting plane is at least one of the following: W Void R A The ratio of W to W is greater than about 4, or VDCL parameter is greater than about 24%, and the second cutting plane is perpendicular to both the vertical cutting plane and the ball striking surface.

[0097] Clause 2: The above R A is measured using a high-pass filter with a cutoff of 0.762 mm, and Void The parameter is measured using a 0.127 mm radius closing filter, and the W VDCL 10. The golf club head of clause 1, wherein the parameters are measured using a 0.508 mm radius closing filter and the striking face is positioned at a loft angle of from about 8 degrees to about 14 degrees.

[0098] Clause 3: The golf club head of clause 1 or 2, wherein at least one of the vertical cutting plane and the second cutting plane extends through a geometric center of the striking face.

[0099] Clause 4: The surface texture is at least one of the following: Void R A the ratio of W to W is greater than about 8; or VDCL The golf club head of any one of clauses 1 to 3, further characterized by the parameter being greater than about 28%.

[0100] Clause 5: The golf club head of any one of clauses 1 to 4, wherein the plurality of peaks comprises a plurality of smaller valleys, and the plurality of valleys comprises a plurality of smaller peaks.

[0101] Clause 6: The golf club head of any one of clauses 1 to 5, wherein the surface texture varies as a function of distance from a geometric center of the face.

[0102] Clause 7: The striking face further includes a central portion surrounded by a peripheral portion, and the surface texture is W. Void R A The ratio of or the W VDCL 7. The golf club head of any one of clauses 1 to 6, further characterized by at least one of the parameters being greater in the peripheral portion than in the central portion.

[0103] Clause 8: A golf club head described in any one of clauses 1 to 7, wherein the striking face comprises a striking plate and a frame surrounding the striking plate, the striking plate being secured within an opening in the frame such that the striking plate and the frame cooperate to define the ball striking surface.

[0104] Clause 9: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is at least one of the following: W Void R A the ratio of W to W is less than about 4; VDCL 9. The golf club head of any one of clauses 1 to 8, characterized by the parameter being less than about 24%.

[0105] Clause 10: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is W Void R A is measured in the vertical cutting plane that intersects the geometric center Void R Aor the W VDCL The parameter W is measured in the plane intersecting the geometric center. VDCL 10. The golf club head of any one of clauses 1 to 9, characterized by:

[0106] Clause 11: The surface texture measured in the vertical cutting plane extending through the geometric center of the face is R A 11. The golf club head of any one of clauses 1-10, further characterized by:

[0107] Clause 12: The ball striking surface comprises a first region having a first surface texture and a second region having a second surface texture, and has at least one of the following: W measured in a vertical cutting plane; Void R A The average ratio of W measured in the vertical cutting plane is different between the first region and the second region. VDCL 12. The golf club head according to any one of clauses 1 to 11, wherein a parameter is different between the first region and the second region.

[0108] Clause 13: The golf club head of clause 12, wherein the second region surrounds the first region.

[0109] Clause 14: A golf club head comprising: a striking face having a ball-striking surface operative to impact a golf ball, said ball-striking surface being disposed at a loft angle of about 8 degrees to about 24 degrees; said ball-striking surface having a milled surface texture including a plurality of peaks and valleys each extending in a linear or curved direction; said surface texture having an average surface roughness (R ) measured using a high-pass filter with a cutoff of 0.762 mm; A ) and the surface void parameter (W) measured using a 0.127 mm radius closing filter. Void) and the surface contact parameter (W) measured using a 0.508 mm radius closing filter. VDCL ) and the surface texture measured in a vertical cutting plane extending through the geometric center of the face has at least one of the following: W Void R A The ratio of W to W is greater than about 4, or VDCL The golf club head is characterized by a parameter being greater than about 24%.

[0110] Clause 15: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is at least one of the following: W Void R A The ratio of W to W is less than about 4, or VDCL 15. The golf club head of clause 14, characterized by the parameter being less than about 24%.

[0111] Clause 16: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is W Void R A is measured in a plane intersecting the geometric center. Void R A or W VDCL The parameter W is measured in a plane intersecting the geometric center. VDCL 16. The golf club head of clause 14 or 15, characterized by:

[0112] Clause 17: The surface texture measured in a vertical cutting plane extending through the geometric center of the face is R A 17. The golf club head of any one of clauses 14-16, further characterized by:

[0113] Clause 18: The golf club head of any one of Clauses 14 to 17, wherein the loft angle is from about 8 degrees to about 14 degrees.

[0114] Clause 19: The ball striking surface comprises a first region having a first surface texture and a second region having a second surface texture, and has at least one of the following: W measured in a vertical cutting plane; Void R A The average ratio of W measured in the vertical cutting plane is different between the first region and the second region. VDCL 19. The golf club head of any one of clauses 14 to 18, wherein a parameter is different between the first region and the second region.

[0115] Clause 20: The golf club head of clause 19, wherein the second region surrounds the first region.

[0116] Clause 21: The golf club head of any one of Clauses 14 to 20, wherein the surface texture varies as a function of distance from the geometric center of the face.

[0117] Clause 22: The surface texture is at least one of the following: Void R A The ratio of W to W is greater than about 8, or VDCL 22. The golf club head of any one of clauses 14 to 21, further characterized by the parameter being greater than about 28%.

[0118] Clause 23: The golf club head of any one of Clauses 14 to 22, further comprising a body extending rearwardly from the ball striking face, the body and the striking face defining a hollow interior volume.

[0119] Clause 24: A golf club head described in any one of clauses 14 to 23, wherein the striking face comprises a striking plate having an outer periphery and a frame surrounding the striking plate, the striking plate being welded to the frame around the entire outer periphery, and the ball striking surface and the surface texture extending continuously across both the striking plate and the frame.

[0120] Clause 25: A golf club head as described in any one of clauses 14 to 24, further comprising a reference mid-plane extending between the plurality of peaks and the plurality of valleys, wherein a negative distance below the reference mid-plane and a positive distance above the reference mid-plane, the plurality of peaks and the plurality of valleys extending an average maximum distance from the mid-plane of at least -200 microinches (-5.08 micrometers) to at least 200 microinches (5.08 micrometers).

[0121] Clause 26: A method of forming a golf club head, comprising: welding a striking plate within an opening in a frame to provide an outer ball striking surface extending across the striking plate and a frame; and milling the ball striking surface to create a surface texture that extends continuously across both the striking plate and the frame, wherein the surface texture comprises a plurality of peaks and a plurality of valleys and a reference mid-plane extending between the plurality of peaks and the plurality of valleys, wherein a distance below the reference mid-plane is a negative distance and a distance above the reference mid-plane is a positive distance, the plurality of peaks and the plurality of valleys extend an average maximum distance from the mid-plane of at least -200 microinches (-5.08 micrometers) to at least 200 microinches (5.08 micrometers), and the surface texture has an average surface roughness (R ) that represents an arithmetic average of absolute surface deviations from a mean centerline. A ), and a surface void parameter (W ) representing the average depth of the valleys relative to a closed reference surface created using a morphological closing filter applied to the surface texture. Void ), and a surface contact parameter (W VDCL ) and further comprising: A is measured using a high-pass filter with a cutoff of 0.762 mm, and Void The parameter is measured using a 0.127 mm radius closing filter, and the W VDCLWhen the parameters are measured using a 0.508 mm radius closing filter, the surface texture measured within at least one of a vertical cutting plane and a second cutting plane is at least one of the following: W Void R A The ratio of W to W is greater than about 4, or VDCL parameter is greater than about 24%, and the second cutting plane is perpendicular to both the vertical cutting plane and the ball striking surface.

[0122] Clause 27: The method of clause 26, wherein the welding step forms a weld bead around the outer periphery of the striking plate, and the method further includes the step of grinding the weld bead before milling so that the frame and the striking plate form a continuous outer surface.

[0123] Clause 28: The method of clause 26, wherein the striking face is positioned at a loft angle of about 8 degrees to about 14 degrees.

[0124] Clause 29: The method of any one of clauses 26 to 28, wherein at least one of the vertical cutting plane and the second cutting plane extends through a geometric center of the striking face.

[0125] Clause 30: The surface texture is at least one of the following: Void R A The ratio of W to W is greater than about 8, or VDCL 30. The method of any one of clauses 26 to 29, further characterized by the parameter being greater than about 28%.

[0126] Clause 31: The method of any one of clauses 26 to 30, wherein the plurality of peaks comprises a plurality of smaller valleys, and the plurality of valleys comprises a plurality of smaller peaks.

[0127] Clause 32: The method of any one of clauses 26 to 31, wherein the surface texture varies as a function of distance from a geometric center of the face.

[0128] Clause 33: The surface texture is W Void R A Ratio or W VDCL 33. The method of any one of clauses 26-32, further characterized by at least one of the parameters being greater within a peripheral portion of the ball striking surface than within a central portion of the ball striking surface.

[0129] Clause 34: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is at least one of the following: W Void R A The ratio of W to W is less than about 4, or VDCL 34. The method of any one of clauses 26 to 33, characterized by the parameter being less than about 24%.

[0130] Clause 35: The surface texture measured in a vertical cutting plane offset from the geometric center of the face is W Void R A The ratio of W measured in a vertical cutting plane intersecting the geometric center Void R A or W VDCL The parameter W is measured in a plane intersecting the geometric center. VDCL 35. The method of any one of clauses 26 to 34, characterized by:

[0131] Clause 36: The surface texture, as measured in a vertical cutting plane extending through the geometric center of the face, has an R of between about 3.56 μm and about 7.62 μm. A 36. The method of any one of clauses 26 to 35, further characterized by:

[0132] Clause 37: The method further comprising milling a first surface texture into a first region of the ball striking surface and milling a second surface texture into a second region of the ball striking surface, wherein at least one of the following is true: W measured in a vertical cutting plane; Void R A The average ratio of W measured in the vertical cutting plane is different between the first region and the second region. VDCL 37. The method of any one of clauses 26 to 36, wherein a parameter is different between the first region and the second region.

[0133] Clause 38: The method of clause 36, wherein the second region surrounds the first region.

[0134] Clause 39: A golf club set comprising: a first golf club head having a first face disposed at a first loft angle (L1), the first face having a ball striking surface with a first surface texture; a second golf club head having a second face disposed at a second loft angle (L2), the second face having a ball striking surface with a second surface texture; and a third golf club head having a third face disposed at a third loft angle (L3), the third face having a ball striking surface with a third surface texture, Each of the first surface texture, the second surface texture, and the third surface texture comprises a plurality of peaks and a plurality of valleys, and a reference mid-plane extending between the plurality of peaks and the plurality of valleys, wherein a negative distance below the reference mid-plane and a positive distance above the reference mid-plane, the plurality of peaks and the plurality of valleys extend an average maximum distance from the mid-plane of at least -200 microinches (-5.08 micrometers) to at least 200 microinches (5.08 micrometers), and each of the first surface texture, the second surface texture, and the third surface texture has an average surface roughness (R ) representing an arithmetic mean of absolute surface deviations from a mean centerline. A1 , R A2 , R A3 ), and a surface void parameter (W ) representing the average depth of the valleys relative to a closed reference surface created using a morphological closing filter applied to the surface texture. Void1 , W Void2 , W Void3 ), and a surface contact parameter (W VDCL1 , W VDCL2 , W VDCL3), wherein the average surface roughness for each of the first, second, and third golf club heads is measured using a high pass filter having a cutoff of 0.762 mm, the surface void parameter for each of the first, second, and third golf club heads is measured using a radius closing filter of 0.127 mm, and the surface contact parameter for each of the first, second, and third golf club heads is measured using a radius closing filter of 0.508 mm, and L1 <L2<L3であり、(R A1 / W Void1 )>(R A2 / W Void2 ) or W VDCL1 >W VDCL2 A golf club set that is at least one of the above.

[0135] Article 40:(R A2 / W Void2 )>(R A3 / W Void3 ) or W VDCL2 >W VDCL3 39. The set of golf clubs of clause 39, wherein at least one of

[0136] Article 41:(R A2 / W Void2 )<(R A3 / W Void3 ) or W VDCL2 <W VDCL3 39. The set of golf clubs of clause 39, wherein at least one of

[0137] Clause 42: The first golf club head is a wood-type club head having a closed internal volume, L1 is about 8 degrees to about 14 degrees, and R A is between about 3.56 μm and about 7.62 μm, and the first surface texture is at least one of the following: R A1 / W Void1 is greater than about 4, or W VDCL1 42. The set of golf clubs of any one of clauses 39 to 41, characterized by:

Claims

1. A wood-type golf club head, A toe portion, a heel portion, a crown, a sole, a striking face and a body that cooperate to define a hollow interior club head volume, the striking face further comprising a ball striking surface having a milled surface texture characteristic; Equipped with the striking face is positioned at a loft angle of between 8 and 14 degrees; the surface texture is uniform across the striking face when measured in any one direction and comprises a plurality of first peaks, a plurality of first valleys, and a reference mid-plane extending between the plurality of first peaks and the plurality of first valleys, wherein a negative distance below the reference mid-plane and a positive distance above the reference mid-plane, the plurality of first peaks and the plurality of first valleys extending an average maximum distance measured from the reference mid-plane of at least −200 microinches (−5.08 micrometers) to at least 200 microinches (5.08 micrometers); the surface texture further comprising a central portion surrounded by a peripheral portion; the central portion having a concentric milling pattern extending radially inward from an outer periphery; the peripheral portion has a linear milling pattern; The surface texture is expressed as the average surface roughness (R Ａ ), and a surface void parameter (W) representing the average depth of all of the plurality of first valleys relative to a closed reference surface created using a morphological closing filter applied to the surface texture. Ｖｏｉｄ ), and a surface contact parameter (W ＶＤＣＬ ) and further comprising: The surface texture measured in at least one of the vertical cutting plane and the second cutting plane may be at least one of the following: The W Ｖｏｉｄ The R Ａ The ratio is greater than 4, or The W ＶＤＣＬ is greater than 24%; is characterized by the second cutting plane is perpendicular to both the vertical cutting plane and the ball striking surface; at least one of the vertical cutting plane and the second cutting plane extends through a geometric center of the striking face; The R Ａ is measured using a high-pass filter with a cutoff of 0.762 mm, and Ｖｏｉｄ is measured using a 0.127 mm radius closing filter, and the W ＶＤＣＬ is measured using a 0.508 mm radius closing filter, The W Ｖｏｉｄ The R Ａ or the ratio of W ＶＤＣＬ At least one of the above is different in the central portion and the peripheral portion. Golf club head.

2. The surface texture may be at least one of the following: The W Ｖｏｉｄ The R Ａ or The W ＶＤＣＬ is greater than 28%; The golf club head of claim 1 further characterized by:

3. The golf club head of claim 1 , wherein the plurality of first peaks comprises a plurality of second valleys, and the plurality of first valleys comprises a plurality of second peaks.

4. The surface texture is Ｖｏｉｄ The R Ａ The ratio of or the W ＶＤＣＬ The golf club head of claim 1 , further characterized by at least one of:

5. 2. The golf club head of claim 1, wherein the striking face comprises a striking plate and a frame surrounding the striking plate, the striking plate secured within an opening in the frame such that the striking plate and the frame cooperate to define the ball striking surface.

6. A wood-type golf club head, A toe portion, a heel portion, a crown, a sole, a striking face and a body that cooperate to define a hollow interior club head volume, the striking face further comprising a ball striking surface having a milled surface texture characteristic; Equipped with the striking face is positioned at a loft angle of between 8 and 14 degrees; the surface texture is uniform across the striking face when measured in any one direction and comprises a plurality of peaks, a plurality of valleys, and a reference mid-plane extending between the plurality of peaks and the plurality of valleys, wherein a negative distance is below the reference mid-plane and a positive distance is above the reference mid-plane, the plurality of peaks and the plurality of valleys extending an average maximum distance measured from the reference mid-plane of at least −200 microinches (−5.08 micrometers) to at least 200 microinches (5.08 micrometers); the surface texture further comprising a central portion surrounded by a peripheral portion; the central portion is circular and has a concentric milling pattern; the peripheral portion has a linear milling pattern; The surface texture is expressed as the average surface roughness (R Ａ ), and a surface void parameter (W) representing the average depth of the valleys relative to a closed reference surface created using a morphological closing filter applied to the surface texture. Ｖｏｉｄ ), and a surface contact parameter (W ＶＤＣＬ ) and further comprising: The surface texture measured in at least one of the vertical cutting plane and the second cutting plane may be at least one of the following: The W Ｖｏｉｄ The R Ａ The ratio is less than 4, or The W ＶＤＣＬ is less than 24%; is characterized by the second cutting plane is perpendicular to both the vertical cutting plane and the ball striking surface; at least one of the vertical cutting plane and the second cutting plane extends through a geometric center of the striking face; The R Ａ is measured using a high-pass filter with a cutoff of 0.762 mm, and Ｖｏｉｄ is measured using a 0.127 mm radius closing filter, and the W ＶＤＣＬ is measured using a 0.508 mm radius closing filter, The W Ｖｏｉｄ The R Ａ or the ratio of W ＶＤＣＬ At least one of the above is different in the central portion and the peripheral portion. Golf club head.

7. The surface texture measured in a vertical cutting plane offset from the geometric center of the striking face is at least one of the following: The W Ｖｏｉｄ The R Ａ The ratio is less than 4, or The W ＶＤＣＬ is less than 24%; The golf club head of claim 6 , characterized by:

8. The surface texture measured in a vertical cutting plane offset from the geometric center of the striking face comprises: The W Ｖｏｉｄ The R Ａ The ratio of the W measured in the vertical cutting plane intersecting the geometric center Ｖｏｉｄ The R Ａ or The W ＶＤＣＬ is the W measured in the vertical cutting plane that intersects the geometric center ＶＤＣＬ Something bigger, The golf club head of claim 6 , characterized by:

9. The surface texture measured within the vertical cutting plane extending through the geometric center of the striking face comprises: R Ａ between 140 microinches (3.56 μm) and 300 microinches (7.62 μm); The golf club head of claim 6 further characterized by:

10. the ball striking surface comprising a first region having a first surface texture and a second region having a second surface texture; At least one of the following: W measured in the vertical cutting plane Ｖｏｉｄ R against Ａ the average percentage of the first region is different from the average percentage of the second region; or Average W measured in the vertical cutting plane ＶＤＣＬ is different between the first region and the second region; The golf club head according to claim 6 , wherein the above formula (1) is satisfied.

11. The golf club head of claim 10 , wherein the second region surrounds the first region.

12. a body extending rearward from the ball striking surface; The golf club head of claim 11 , wherein the body and the striking face define a hollow interior volume.

13. The striking face comprises: a striking plate having an outer periphery; a frame surrounding the striking plate; the striking plate is welded to the frame around the outer periphery; The golf club head of claim 6 , wherein the ball striking surface and the surface texture extend continuously across the striking plate and the frame.

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