Golf club head with multi-material striking surface

Abstract

To create a putter-type golf club head that balances golfers' personal preference characteristics while considering various impact locations.SOLUTION: A striking surface 307 has at least two materials that differ in concentration away from the geometric center of the striking surface to provide this consistency. Consistent (or uniform) ball speed is achieved throughout the striking surface as the portion of the golf ball that contacts the striking surface interacts with at least two materials differing in a material characteristic.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates generally to golf club heads, and more particularly to putter-type golf club heads having a multi-material striking face. Related application data

[0002] This claims the benefit of U.S. Provisional Patent Application No. 62 / 881,463, filed August 1, 2019, and U.S. Provisional Patent Application No. 63 / 046,505, filed June 30, 2020, the entire contents of which are incorporated herein by reference in their entireties. [Background technology]

[0003] Because the golf club is the only equipment that moves the golf ball during play, the golf industry has seen improvements in putter and golf club head design in recent years. However, when it comes to designing putter-type club heads, it is known that golfers tend to prioritize personal preference features (i.e., club head feel, club head aesthetics, club head sound, etc.) over performance.

[0004] To putt a golf ball into the hole, a golfer must successfully impact the golf ball (with a golf club head, more specifically, a putter-type golf club head) with the proper velocity and face angle. This presents a challenge to all golfers, as many struggle to consistently impact the golf ball in the same location every putt. Striking the golf ball at various locations on a putter-type club head can change the amount of energy transferred from the putter head to the golf ball during initial contact, the feel of the impact, the sound of the impact, and / or the direction of travel of the golf ball. There is a need in the art to produce a putter-type golf club head that balances the personal preference characteristics of a golfer while taking into account various impact locations. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 illustrates a perspective view of the heel side of a striking face having continuous grooves for a non-insert style club head, according to one embodiment.

[0006] [Figure 2] 2 shows the face of the striking surface diagram of FIG. 1.

[0007] [Figure 3] 3 shows a close-up of the face of the striking surface view of FIG. 2.

[0008] [Figure 4] Shown are seven variable gradient maps comparing ball speed, impact location, and land area percentage for a 10-foot long putt.

[0009] [Figure 5] Shown are seven variable gradient maps comparing ball speed, impact location, and land area percentage for a 25-foot long putt.

[0010] [Figure 6] 1 illustrates an exploded view of a striking face with continuous grooves for an insert-style club head, according to one embodiment.

[0011] [Figure 7] 7 shows a partial assembly view of the striking face having continuous grooves of FIG. 6.

[0012] [Figure 8] 7 shows the face of the striking surface diagram of FIG. 6.

[0013] [Figure 9] 8 shows the face of the striking surface diagram of FIG. 7.

[0014] [Figure 10] FIG. 10 illustrates a partial assembly view of a striking face with separate pill-shaped voids for an insert-style club head, according to one embodiment.

[0015] [Figure 11] 11 shows the face of the striking surface diagram of FIG.

[0016] [Figure 12] 10 shows another face of a view of a striking face having separate pill-shaped voids for an insert-style club head, according to one embodiment.

[0017] [Figure 13] 13 shows an exploded view of the striking surface of FIG. 12.

[0018] [Figure 14] FIG. 10 illustrates a partial assembly view of a striking face with separated hexagonal voids for an insert-style club head, according to one embodiment.

[0019] [Figure 15] 15 shows an exploded view of the insert with the separated hexagonal voids of FIG. 14.

[0020] [Figure 16] 15 shows the assembly face of the view of FIG. 14.

[0021] [Figure 17] FIG. 1 illustrates a perspective view of a heel side of a striking face having continuous grooves for an insert-style club head, according to one embodiment.

[0022] [Figure 18] 18 shows an exploded view of the insert of FIG. 17.

[0023] [Figure 19] 18 shows the assembled face of the view of FIG. 17.

[0024] [Figure 20] 1 shows an exploded view of an insert with separate concentric radial voids.

[0025] [Figure 21] 21 shows the assembled face of the insert view of FIG. 20.

[0026] [Figure 22] 21 shows the unassembled face of the second material view of FIG. 20.

[0027] [Figure 23] A cross-sectional view of FIG. 22 is shown.

[0028] [Figure 24] 1 shows a bar graph comparing ball speed and ball impact location for various exemplary putter embodiments for a 10-foot long putt.

[0029] [Figure 25] 1 shows a bar graph comparing ball speed and ball impact location for various exemplary putter embodiments for a 25-foot long putt.

[0030] [Figure 26] 1 shows a bar graph comparing ball speed and ball impact location for various exemplary putter embodiments for a 25-foot long putt. DETAILED DESCRIPTION OF THE INVENTION

[0031] The subject matter of this specification is golf club heads, and in particular putter-type golf club heads with a striking face capable of achieving consistent ball velocity across the striking face to account for various ball impact locations. The striking face has at least two materials with different concentrations away from the geometric center (or central region) of the striking face to provide this consistency. The consistent (or uniform) ball velocity is achieved throughout the striking face because the portion of the golf ball contacting the striking face interacts with at least two materials having different material properties (or characteristics).

[0032] The different material properties can be (but are not an exhaustive list) tensile strength, flexure modulus, or material hardness. Uniform ball velocity is achieved by combining a dual-material striking face and varying the amount of the first material and / or second material away from the geometric center (or central region) of the striking face. In many embodiments, the first and second materials cooperate to form a softer, more flexible central region, and opposite the central region in either the heel or toe direction, the first and second materials cooperate to form a harder, stiffer, less flexible region. This is because contact outside the geometric center (or club head sweet spot) of the striking face results in less energy transfer from the club head to the golf ball.

[0033] Creating a central region that is less responsive than the corresponding heel and toe regions can be achieved in a number of ways. For example, in embodiments where a first soft material dominates over a second, less soft material, a less responsive central region can be formed. In other embodiments, a less responsive central region can be formed by controlling the void and / or recess pattern to create a larger first material land area in the central region than in the adjacent heel and toe regions.

[0034] The term or phrase "lie angle" as used herein may be defined as the angle between a golf shaft (not shown) and the playing surface when the sole contacts the playing surface. The lie angle of a golf club head may also be referred to as the angle formed by the intersection of the centerline of the golf shaft and the playing surface when the sole of the golf club head is at rest on the playing surface.

[0035] As used herein, the term or phrase "unitary" may be defined as two or more elements when they are constructed from the same piece of material. As defined herein, two or more elements are "non-unitary" when each element is constructed from a different piece of material.

[0036] As used herein, the terms or phrases "coupled," "coupled," "couple," and "connecting" may be defined as connecting two or more elements mechanically or otherwise. A connection (whether mechanical or otherwise) may be for any length of time, for example, permanent or semi-permanent, or only for a moment. A mechanical connection or the like should be understood broadly and includes all types of mechanical connections. The absence of words such as "removably," "removable," etc. around a word such as "coupled" does not mean that the connection in question is or is not removable.

[0037] The term or phrase "head weight" or "head mass" as used herein may be defined as the overall mass or weight of the putter.

[0038] The words or phrases "attach," "attached," "attach," and "attaching," as used herein, may be defined as connecting or joining to something. Attachment may be permanent or semi-permanent. Mechanical attachment, etc., should be understood broadly and include all types of mechanical attachment means. Integral attachment means should be understood broadly and include all types of integral attachment means that permanently connect two or more objects together.

[0039] The term or phrase "loft angle" as used herein may be defined as the angle between the striking face and the golf shaft. In other embodiments, the loft angle may be defined herein as the striking face comprising a striking face center point and a loft plane. The striking face center point is (1) equidistant from the lower and upper ends of the striking face, and (2) equidistant from the heel and toe ends of the striking face. The loft plane is tangent to the striking face of a putter-type golf club head. The golf shaft has a centerline axis that extends the entire length of the golf shaft. The loft angle is between the centerline axis of the golf shaft and the loft plane of the putter. The loft angle of a putter-type golf club head may also be defined herein as the angle between the striking face and the golf shaft (not shown) when the centerline of the golf shaft is generally vertical (i.e., forms a generally 90° angle with the playing surface).

[0040] Terms such as "first," "second," "third," and "fourth," where present in the specification and claims, are used to distinguish between similar elements and do not necessarily describe a particular sequential or chronological order. Terms so used should be understood to be interchangeable under appropriate circumstances, such that the embodiments described herein are capable of operating in orders other than those illustrated or otherwise described herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to include non-exclusive inclusions, such that a process, method, system, article, device, or apparatus that includes a list of elements is not necessarily limited to those elements and may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

[0041] Terms such as "left," "right," "front," "rear," "top," "bottom," "above," "below," and the like, when used in the specification and claims, are used for descriptive purposes and do not necessarily describe permanent relative positions. Terms so used should be understood to be interchangeable under appropriate circumstances, such that embodiments of the apparatus, methods, and / or articles of manufacture described herein are operable, for example, in orientations other than those illustrated or otherwise described herein.

[0042] The term "central region" can be defined as the area on the striking face that contains the geometric center. The central region extends from the upper boundary of the striking face to the lower boundary of the striking face and can have a heel-to-toe span of approximately 0.1 inches, 0.2 inches, 0.3 inches, 0.4 inches, 0.5 inches, 0.6 inches, 0.7 inches, 0.8 inches, 0.9 inches, 1.0 inches, 1.1 inches, 1.2 inches, 1.3 inches, 1.4 inches, 1.5 inches, 1.6 inches, 1.7 inches, 1.8 inches, 1.9 inches, or 2.0 inches.

[0043] The term "heel region" may be defined as the area on the striking face extending from the heel end of the striking face (and / or club head) to the heel-side boundary of the center region. The term "toe region" may be defined as the area on the striking face extending from the toe end of the striking face (and / or club head) to the toe-side boundary of the center region.

[0044] 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 dictates otherwise, a plurality of such items may be present. All numerical 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 numerical value. "About" indicates that the stated numerical value allows for some slight imprecision (some proximity to the exact value, about or reasonably close to the value, approximately). Where the imprecision provided by "about" is not otherwise 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 the parameter in question. Additionally, the disclosure of a range includes the disclosure of all values, as well as subranges within that entire range. Each value within a range and the endpoints of a 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.

[0045] In many examples, as used herein, the term "about" may be used when comparing one or more values, ranges of values, relationships (e.g., position, orientation, etc.), or parameters (e.g., velocity, acceleration, mass, temperature, spin rate, spin direction, etc.) to one or more other values, ranges of values, or parameters, respectively, and / or to describe a condition (e.g., with respect to time), such as, for example, a condition that remains constant with respect to time. In these examples, use of the word "about" may mean that the value, range of values, relationship, parameter, or condition is within ±0.5%, ±1.0%, ±2.0%, ±3.0%, ±5.0%, and / or ±10.0%, as applicable, of the associated value, range of values, relationship, parameter, or condition.

[0046] Before describing any embodiments of the present disclosure in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0047] Presented herein are putter-type golf club heads with multiple striking surfaces capable of achieving consistent ball speeds across the striking surface to account for various ball impact locations. In many embodiments, the putter-type golf club heads described herein include a putter body with a dual-material striking surface having a first material and a second material. The first and second materials vary in density away from the geometric center of the striking surface in a heel-to-toe direction to provide consistent ball speeds.

[0048] For example, in many embodiments, the proportions (or relationship) of the first and second materials are different to account for where the ball may impact the striking face (i.e., toward the toe, toward the heel, or toward the center). The alteration of the material relationship of the striking face directly correlates to the impact efficiency or ball velocity generated between the golf club head and the golf ball at impact.

[0049] (1. Putter-type golf club head) In many of the embodiments described herein, the golf club head is a putter-type golf club head. Figures 1-23 show an exemplary embodiment of a putter-type golf club head having a multi-material striking face that is capable of controlling ball velocity across the striking face while allowing for impact feel and sound upon ball impact.

[0050] (2. Loft angle) In many embodiments, the putter-type golf club head may have a loft angle of less than 10 degrees. In many embodiments, the loft angle of the golf club head may be between 0 and 5 degrees, between 0 and 6 degrees, between 0 and 7 degrees, or between 0 and 8 degrees. For example, the loft angle of the golf club head may be less than 10 degrees, less than 9 degrees, less than 8 degrees, less than 7 degrees, less than 6 degrees, less than 5 degrees, less than 4 degrees, less than 3 degrees, or less than 2 degrees. In further examples, the loft angle of the golf club head may be 0 degrees, 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, or 10 degrees.

[0051] (3. Weight) In many embodiments, a putter-type golf club head may have a weight in the range of between 320 and 385 grams. In other embodiments, a putter-type golf club head may range between 320-325 grams, 325-330 grams, 330-335 grams, 335-340 grams, 340-345 grams, 345-350 grams, 350-355 grams, 355-360 grams, 360-365 grams, 365-370 grams, 370-375 grams, 375-380 grams, or 380-385 grams. In some embodiments, the weight of the putter-type golf club head is 320 grams, 321 grams, 322 grams, 323 grams, 324 grams, 325 grams, 326 grams, 327 grams, 328 grams, 329 grams, 330 grams, 331 grams, 332 grams, 333 grams, 334 grams, 335 grams, 336 grams, 337 grams, 338 grams, 339 grams, 340 grams, 341 grams, 342 grams, 343 grams, 344 grams, 345 grams, 346 grams, 347 grams, 348 grams, 349 grams, 350 grams, 351 grams, 352 grams, 353 grams, 354 grams, 355 grams, 356 grams, 357 grams, 358 grams, 359 grams, 360 grams, 361 grams, 362 grams, 363 grams, 364 grams, 365 grams, 366 grams, 367 grams, 368 grams, 369 grams, 370 grams, 371 grams, 372 grams, 373 grams, 374 grams, 375 grams, 376 grams, 377 grams, 378 grams, 379 grams, 380 grams, 381 grams, 382 grams, 383 grams, 384 grams, 385 grams, 386 grams, 387 grams, 388 grams, 389 grams, 390 grams, 391 grams, 392 grams, 393 grams, 394 grams, 395 grams, 396 grams, 397 grams, 398 grams, 399 grams, 400 grams, 401 grams, 40 It can be 51 grams, 352 grams, 353 grams, 354 grams, 355 grams, 356 grams, 357 grams, 358 grams, 359 grams, 360 grams, 361 grams, 362 grams, 363 grams, 364 grams, 365 grams, 366 grams, 367 grams, 368 grams, 369 grams, 370 grams, 371 grams, 372 grams, 373 grams, 374 grams, 375 grams, 376 grams, 377 grams, 378 grams, 379 grams, 380 grams, 381 grams, 382 grams, 383 grams, 384 grams, or 385 grams.

[0052] (4.Materials) The putter-type golf club head may be constructed from any material used to construct a conventional club head. For example, the putter-type golf club head may be constructed from any one or combination of the following: 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 1380 stainless steel, 303 stainless steel, stainless steel alloy, or any metal or combination of metals for producing a golf club head. In other embodiments, the putter-type golf club head may be constructed from a non-metallic material, such as a thermoplastic polyurethane material, a thermoplastic elastomer, and / or a thermoplastic composite material.

[0053] (1. Composition and Mechanism of Putter-Type Golf Club Head) In many embodiments, a putter-type golf club head includes a club head body (which may also be referred to as a "body" or "putter body"). The club head body includes a toe, a heel, a top rail, a sole, a striking face (or a portion of the striking face), and a rear section. The striking face may provide a surface adapted for impact with a golf ball. The rear section is spaced rearward from the striking face. The sole is defined as being between the striking face and the rear section and resting on the ground (or playing surface) at address. The top rail may be formed opposite the sole. The striking face is defined by the sole, the top rail, the heel, and the toe opposite the heel.

[0054] As noted above, in many embodiments, a putter-type golf club head may be configured to be in an "address position." Unless otherwise noted or stated, the putter-type golf club head is in the address position for all reference measurements, ratios, and / or descriptive parameters. The address position may be referred to as (1) the sole of the putter-type golf club head resting on the ground it contacts and being parallel to the playing surface and / or the ground, and (2) the striking surface being substantially perpendicular to the ground and / or the playing surface.

[0055] (2. Striking surface) In many embodiments, the striking face may be defined by at least the toe, heel, top rail, and sole of the putter body. Additionally, as previously described, the striking face may comprise a multi-material striking face. For example, the striking face may include at least a first material and a second material that cooperate to contact the golf ball when it impacts the striking face with two or more materials (i.e., a first material, a second material, etc.) having unique material characteristics for normalizing ball velocity throughout the club head while enhancing a wide range of individual, personal preference characteristics (i.e., impact sound and / or impact feel).

[0056] In many embodiments, the first material can be softer, more flexible, or more deformable than the second material. In other embodiments, the second material can be harder, less flexible, or less deformable than the first material. In many embodiments, the second material can surround, face, or cover the first material.

[0057] (3. Material characteristics of the first material) The first material of the striking face can vary based on the selection of the second material, since the second material comprises the majority of the striking face. In many embodiments, the first material can be defined by a predetermined material characteristic, such as (but not limited to) the hardness, tensile strength, flexural modulus, or specific gravity of the material.

[0058] The hardness of the first material is generally softer than the hardness of the second material. In many embodiments, the hardness of the first material can have a Shore A value that varies between 30A and 95A. In some embodiments, the hardness of the first material can have a Shore A hardness value between 30A-40A, 40A-50A, 50A-60A, 70A-80A, 80A-90A, or 90A-95A. In alternative embodiments, the hardness of the first material can be a Shore A hardness value between 30A-35A, 35A-40A, 40A-45A, 45A-50A, 50A-55A, 55A-60A, 60A-65A, 65A-70A, 70A-75A, 75A-80A, 80A-85A, 85A-90A, or 90A-95A. In additional embodiments, the hardness of the first material may have a Shore A of less than 95A, less than 90A, less than 85A, less than 80A, less than 75A, less than 70A, less than 65A, less than 60A, less than 55A, less than 50A, less than 45A, less than 40A, or less than 35A. In other embodiments, the hardness of the first material may be less than 30A, 31A, 32A, 33A, 34A, 35A, 36A, 37A, 38A, 39A, 40A, 41A, 42A, 43A, 44A, 45A, 46A, 47A, 48A, 49A, 50A, 51A, 52A, 53A, 54A, 55A, 56A, 57A, 58A, 59A, 60A, 61A, 62A, 63A, 64A, 65A, 66A, 67A, 68A, 69A, 70A, 71A, 72A, 73A, 74A, 75A, 76A, 77A, 78A, 79A, 80A, 81A, 82A, 83A, 84A, 85A, 86A, 87A, 88A, 89A, 90A, 91A, 92A, 93A, 94A, 95A, 96A, 97A, 98A, 99A, 100A, 101A, 102A, 103A, 104A, 105A, 8A, 90A, 91A, 92A, 93A, 94A, or 95A Shore A hardness.

[0059] The tensile strength of the first material is generally less than the tensile strength of the second material. The tensile strength of the first material can be between 0.5 MPa and 50 MPa. In many embodiments, the tensile strength of the first material can be between 0.5 MPa and 5.5 MPa, 5.5 MPa and 10.5 MPa, 10.5 MPa and 15.5 MPa, 15.5 MPa and 20.5 MPa, 20.5 MPa and 25.5 MPa, 25.5 MPa and 30.5 MPa, 30.5 MPa and 35.5 MPa, 35.5 MPa and 40.5 MPa, 40.5 MPa and 45.5 MPa, or 45.5 MPa and 50 MPa. In alternative embodiments, the tensile strength of the first material can be less than 50 MPa, less than 45 MPa, less than 40 MPa, less than 35 MPa, less than 30 MPa, less than 25 MPa, less than 20 MPa, less than 15 MPa, less than 10 MPa, or less than 5 MPa. In certain embodiments, the tensile strength of the first material can be about 0.5 MPa, about 5 MPa, about 10 MPa, about 15 MPa, about 20 MPa, about 25 MPa, about 30 MPa, about 35 MPa, about 40 MPa, about 45 MPa, or about 50 MPa.

[0060] The flexural modulus of the first material is generally less than the flexural modulus of the second material. The flexural modulus of the first material can be between 0.5 MPa and 90 MPa. In many embodiments, the flexural modulus of the first material can be between 0.5 MPa and 5.5 MPa, 5.5 MPa and 10.5 MPa, 10.5 MPa and 15.5 MPa, 15.5 MPa and 20.5 MPa, 20.5 MPa and 25.5 MPa, 25.5 MPa and 30.5 MPa, 30.5 MPa and 35.5 MPa, 35.5 MPa and 40 MPa, 40 MPa and 45.5 MPa, 45.5 MPa and 50 MPa, 50 MPa and 55 MPa, 55 MPa and 60 MPa, 60 MPa and 65 MPa, 65 MPa and 70 MPa, 70 MPa and 75 MPa, 75 MPa and 80 MPa, 80 MPa and 85 MPa, or 85 MPa and 90 MPa. In alternative embodiments, the flexural modulus of the first material can be less than 90 MPa, less than 85 MPa, less than 80 MPa, less than 75 MPa, less than 70 MPa, less than 65 MPa, less than 60 MPa, less than 55 MPa, less than 50 MPa, less than 45 MPa, less than 40 MPa, less than 35 MPa, less than 30 MPa, less than 25 MPa, less than 20 MPa, less than 15 MPa, less than 10 MPa, or less than 5 MPa. In certain embodiments, the flexural modulus of the first material can be about 0.5 MPa, about 5 MPa, about 10 MPa, about 15 MPa, about 20 MPa, about 25 MPa, about 30 MPa, about 35 MPa, about 40 MPa, about 45 MPa, about 50 MPa, about 55 MPa, about 60 MPa, about 65 MPa, about 70 MPa, about 75 MPa, about 80 MPa, about 85 MPa, or about 90 MPa.

[0061] The specific gravity of the first material is generally less than (or can be the same as) the specific gravity of the second material. The specific gravity of the first material can be between 0.5 and 2. In many embodiments, the specific gravity of the first material can be between 0.5 and 0.75, 0.75 and 1, 1 and 1.25, 1.25 and 1.5, 1.5 and 1.75, or 1.75 and 2.0. In alternative embodiments, the specific gravity of the first material can be less than 2, less than 1.5, or less than 1.0.

[0062] The first material is generally comprised of a substantially non-metallic material, more preferably a polymeric material. For example, in many embodiments, the first material may be formed from an elastomer, polyurethane, thermoplastic elastomer, thermoset elastomer, thermoplastic polyurethane, thermoset polyurethane, viscoelastic material, urethane, other polymer, other polymeric material with metal doping, or combinations thereof. In many embodiments, the first material is selected from one of the categories listed above to satisfy one or more of the material characteristics listed above.

[0063] (4. Description of material characteristics of the second material) The second material of the striking face may vary based on the selection of the first material, as the first material provides specific ball impact characteristics. In many embodiments, the second material may be defined by predetermined material characteristics, including but not limited to, the material's hardness, tensile strength, flexural modulus, and specific gravity.

[0064] The hardness of the second material is generally harder than the hardness of the first material. In many embodiments, the hardness of the second material may have a Shore D value that varies between 60D and 100D. In some embodiments, the hardness of the second material may have a Shore D hardness value between 60D and 70D, 70D and 80D, 80D and 90D, or 90D and 100D. In alternative embodiments, the hardness of the second material may have a Shore D hardness value between 60D and 65D, 65D and 70D, 70D and 75D, 75D and 80D, 80D and 85D, 85D and 90D, 90D and 95D, or 95D and 100D. In additional embodiments, the hardness of the second material may have a Shore D hardness of greater than 60D, greater than 65D, greater than 70D, greater than 75D, greater than 80D, greater than 85D, greater than 90D, greater than 95D, or greater than 100D. In other embodiments, the hardness of the second material may have a Shore D hardness of 60D, 61D, 62D, 63D, 64D, 65D, 66D, 67D, 68D, 69D, 70D, 71D, 72D, 73D, 74D, 75D, 76D, 77D, 78D, 79D, 80D, 81D, 82D, 83D, 84D, 85D, 86D, 87D, 88D, 89D, 90D, 91D, 92D, 93D, 94D, 95D, 96D, 97D, 98D, 98D, or 100D.

[0065] The tensile strength of the second material is generally greater than the tensile strength of the first material. The tensile strength of the second material may be between 40 MPa and 1040 MPa. The tensile strength of the second material may be between 40 MPa and 140 MPa, 140 MPa and 240 MPa, 240 MPa and 340 MPa, 340 MPa and 440 MPa, 440 MPa and 540 MPa, 540 MPa and 640 MPa, 640 MPa and 740 MPa, 740 MPa and 840 MPa, 840 MPa and 940 MPa, or 940 MPa and 1040 MPa. In alternative embodiments, the tensile strength of the second material may be greater than 40 MPa, greater than 140 MPa, greater than 240 MPa, greater than 340 MPa, greater than 440 MPa, greater than 540 MPa, greater than 640 MPa, greater than 740 MPa, greater than 840 MPa, greater than 940 MPa, or greater than 1040 MPa. In certain embodiments, the tensile strength of the second material can be about 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47 MPa, 48 MPa, 49 MPa, 50 MPa, 51 MPa, 52 MPa, 53 MPa, 54 MPa, 55 MPa, 56 MPa, 57 MPa, 58 MPa, 59 MPa, 60 MPa, 61 MPa, 62 MPa, 63 MPa, 64 MPa, 65 MPa, 66 MPa, 67 MPa, 68 MPa, 69 MPa, or 70 MPa. In alternative embodiments, the tensile strength of the second material can be 141 MPa, 241 MPa, 341 MPa, 441 MPa, 541 MPa, 641 MPa, 741 MPa, 841 MPa, or 941 MPa.

[0066] The flexural modulus of the second material is generally higher than the flexural modulus of the first material. The flexural modulus of the second material can be between 0.5 MPa and 300 MPa. In many embodiments, the flexural modulus of the second material is between 0.5 MPa and 5.5 MPa, 5.5 MPa and 10.5 MPa, 10.5 MPa and 15.5 MPa, 15.5 MPa and 20.5 MPa, 20.5 MPa and 25.5 MPa, 25.5 MPa and 30.5 MPa, 30.5 MPa and 35.5 MPa, 35.5 MPa and 40 MPa, 40 MPa and 45.5 MPa, 45.5 MPa and 50 MPa, 50 MPa and 55 MPa, 55 MPa and 60 MPa, 60 MPa and 65 MPa, 65 MPa and 70 MPa, 70 MPa and 75 MPa, 75 MPa and 80 MPa, 80 MPa and 85 MPa, 85 MPa and 90 MPa, 90 MPa and 95 MPa, to 100 MPa, 100 MPa to 110 MPa, 110 MPa to 120 MPa, 120 MPa to 130 MPa, 130 MPa to 140 MPa, 140 MPa to 150 MPa, 150 MPa to 160 MPa, 160 MPa to 170 MPa, 170 MPa to 180 MPa, 180 MPa to 190 MPa, 190 MPa to 200 MPa, 200 MPa to 210 MPa, 210 MPa to 220 MPa, 220 MPa to 230 MPa, 230 MPa to 240 MPa, 240 MPa to 250 MPa, 250 MPa to 260 MPa, 270 MPa to 280 MPa, 280 MPa to 290 MPa, or 290 MPa to 300 MPa. In alternative embodiments, the flexural modulus of the second material may be less than 300 MPa, less than 275 MPa, less than 250 MPa, less than 225 MPa, less than 200 MPa, less than 175 MPa, less than 150 MPa, less than 125 MPa, less than 100 MPa, less than 75 MPa, less than 50 MPa, or less than 25 MPa.In certain embodiments, the flexural modulus of the second material is about 0.6 MPa, 5.6 MPa, 10.6 MPa, 15.6 MPa, 20.6 MPa, 25.6 MPa, 30.6 MPa, 35.6 MPa, 40.1 MPa, 45.6 MPa, 55.1 MPa, 60.1 MPa, 70.1 MPa, 75.1 MPa, 80.1 MPa, 85.1 MPa, 90.1 MPa, 100.1 MPa, 110.1 MPa, 120.1 MPa, 130.1 MPa, 140.1 MPa, 150.1 MPa, 160.1 MPa, 170.1 MPa, 180.1 MPa, 190.1 MPa, 200.1 MPa, 210.1 MPa, 220.1 MPa, 230.1 MPa, 240.1 MPa, 250.1 MPa, 260.1 MPa, 270.1 MPa, 280.1 MPa, 290.1 ​​MPa, 300.1 MPa, 310.1 MPa, 320.1 MPa, 330.1 MPa, 340.1 MPa, 350.1 MPa, 360.1 MPa, 370.1 MPa, 380.1 MPa, 390.1 MPa, 410.1 MPa, 420.1 MPa, 430.1 MPa, 440.1 MPa, 450.1 MPa, 460.1 MPa, 470.1 MPa, 480.1 MPa, 490.1 MPa, 500.1 MPa, Pa, 120.1 MPa, 130.1 MPa, 140.1 MPa, 150.1 MPa, 160.1 MPa, 170.1 MPa, 180.1 MPa, 190.1 MPa, 200.1 MPa, 210.1 MPa, 220.1 MPa, 230.1 MPa, 240.1 MPa, 250.1 MPa, 260.1 MPa, 270.1 MPa, 280.1 MPa, or 290.1 ​​MPa.

[0067] The specific gravity of the second material is generally greater than (or the same as) the specific gravity of the first material. The specific gravity of the second material can be between 0.5 and 13.5. In many embodiments, the specific gravity of the second material can be between 0.5 and 1.5, 1.5 and 2.5, 2.5 and 3.5, 3.5 and 4.5, 4.5 and 5.5, 5.5 and 6.5, 6.5 and 7.5, 7.5 and 8.5, 8.5 and 9.5, 9.5 and 10.5, 10.5 and 11.5, 11.5 and 12.5, or 12.5 and 13.5. In alternative embodiments, the specific gravity of the second material can be about 0.5, about 1.5, about 2.5, about 3.5, about 4.5, about 5.5, about 6.5, about 7.5, about 8.5, about 9.5, about 10.5, about 11.5, about 12.5, or about 13.5.

[0068] The second material may generally be comprised of a substantially non-metallic or metallic material. For example, in many embodiments, the second material may be formed from a non-metallic material (i.e., elastomer, polyurethane, thermoplastic elastomer, thermoset elastomer, thermoplastic polyurethane, thermoset polyurethane, viscoelastic material, urethane, other polymer, other polymeric material with metal doping, or combinations thereof). In alternative embodiments, the second material may be constructed from a metallic material. For example, the second material may be constructed from any one or combination of the following: 8620 alloy steel, S25C steel, carbon steel, maraging steel, 17-4 stainless steel, 1380 stainless steel, 303 stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, ADC-12, titanium, or titanium alloy. In many embodiments, the second material is selected from one of the above-listed categories to satisfy one or more of the above-listed material characteristics.

[0069] (5. First and second material arrangements) In many embodiments, the second material may define a plurality of recesses or voids resembling any shape. The characteristics (i.e., contour, shape, dimensions, and spacing) of the recesses or voids formed by the second material may vary to achieve desired performance, aesthetic, and tactile properties. For example, in many embodiments, the second material may define a plurality of separate voids or recesses that generally define a tablet shape, a hexagonal shape, a split hexagonal shape, a circular shape, a rectangular shape, a triangular shape, a pentagonal shape, an octagonal shape, a curved shape, a diamond shape, and / or a trapezoidal shape. In alternative embodiments, the second material may form a continuous void or recess that may generally be defined by one or more continuous curved grooves, one or more continuous arcuate grooves, one or more continuous arcuate grooves, one or more continuous linear grooves, or one or more combinations thereof.

[0070] The first material may be configured to fill, partially fill, reside in, occupy, and / or compensate for one or more of the plurality of discrete recesses or voids defined by the second material. For example, in many embodiments, the first material may partially or completely fill one or more of the plurality of voids or recesses described above. In alternative embodiments, the first material may fill, partially fill, reside in, and / or compensate for one or more of the contiguous voids or recesses described above. In embodiments in which the first material partially fills the plurality of recesses or voids, air may occupy the remaining unfilled portions.

[0071] The first and second materials may be configured to cooperate with one another to create regions of different material characteristics. In many embodiments, the central region of the striking surface may be softer than the adjacent heel and toe regions. In alternative embodiments, the central region of the striking surface may be softer than the adjacent heel and toe regions. In other embodiments, the central region of the striking surface may be more deformable than the adjacent heel and toe regions. Creating a central region that is more flexible, deformable, softer, and / or less responsive than the adjacent heel and toe regions creates more uniform ball speed and sensory feedback characteristics (i.e., impact sound, impact feel, impact feedback, etc.) across the striking surface.

[0072] Creating a central region that is less responsive than the corresponding heel and toe regions can be achieved in a number of ways. For example, in embodiments where a first soft material dominates over a second, less soft material, a less responsive central region is formed. In other embodiments, a less responsive central region can be formed by controlling the void and / or recess pattern to create a larger first material land area in the central region than in the adjacent heel and toe regions.

[0073] (I. EMBODIMENTS) (Continuous grooves (non-insert style putter)) Figures 1-5 illustrate an exemplary embodiment. More specifically, Figures 1-3 illustrate an example of a putter-type golf club head 100 with a dual-material striking face 107 having a first material 109 and a second material 110. The putter-type golf club head includes a putter body 101 having a toe 102, a heel 103 opposite the toe 102, a top rail 104, a sole 105 opposite the top rail 104, a portion of the striking face 107, and a rear portion 106 opposite the striking face 107.

[0074] 1-3 further illustrate the striking face 107 of the putter body 100 forming a plurality of continuous groove recesses 112. These continuous groove recesses 112 may separate the striking face 107 into a land area of ​​a second material that forms the ball-contacting surface, and continuous groove areas that form the non-ball-contacting surface (upon golf ball impact). Through a combination of continuous recesses that are generally arcuate or have arcuate portions, the proportion of ball-contacting surface to ball-non-contacting surface may vary across the striking face 107, yet may produce a consistent ball velocity at impact across the striking face.

[0075] For example, FIG. 2 shows one possible arrangement in which each arcuate portion of successive groove recesses 112 is positioned to form a denser, more compact central region. This results in the central region being less responsive to ball impact than the area (or areas) away from the central region (i.e., toward the heel or toe) because there is more continuous groove area (non-ball contacting surface) than the ball contacting surface. Additionally, to create a more densely packed central region toward the top rail and sole (at the center of the striking face), there are generally arcuate recesses (also referred to as semicircular recesses) to increase the amount of continuous recesses (non-ball contacting surface). These semicircular recesses are absent as you move away from the central region and are absent at the heel and toe ends. The arrangement can be gradual or asymmetrical from the center to the heel end of the striking face and / or from the center to the toe end.

[0076] Moving away from the center region toward the heel or toe, the separation distance between adjacent arcuate sections can be gradually increased to introduce more ball contact surface. Increasing the amount of ball contact surface (in the heel-toe direction) creates a more responsive area compared to the less responsive center region. This helps produce consistent ball speed across the striking face, as the response of the striking face changes.

[0077] Additionally, as previously mentioned, the golf club head 100 may be configured to be in an "address position." The address position is the reference orientation of the golf club head for all reference measurements, ratios, and descriptive parameters described below. Specifically, FIG. 1 illustrates a putter-type golf club head 100 with a plurality of continuous groove recesses 112 defined by a putter body 101. In other words, the putter-type golf club head 100 is a non-insert style club head.

[0078] The plurality of continuous groove recesses 112 may resemble many shapes or configurations. For example, in this exemplary embodiment, the plurality of continuous groove recesses 112 may be defined by one or more continuous curved groove recesses, one or more continuous arcuate groove recesses (which may also be referred to as "continuous arcuate groove recesses"), one or more continuous straight groove recesses, and / or combinations thereof. In this particular embodiment, the putter body 101 defines eight continuous arcuate groove recesses 113 (or arcuate grooves), one continuous straight groove recess 114, and eight continuous groove recesses 115 that define at least one straight and one arcuate portion.

[0079] In alternative embodiments of a putter-type golf club head having continuous groove recesses 112, the putter body may define one or more continuous arcuate groove recesses 113, two or more continuous arcuate groove recesses 113, three or more continuous arcuate groove recesses 113, four or more continuous arcuate groove recesses 113, five or more continuous arcuate groove recesses 113, six or more continuous arcuate groove recesses 113, seven or more continuous arcuate groove recesses 113, eight or more continuous arcuate groove recesses 113, nine or more continuous arcuate groove recesses 113, ten or more continuous arcuate groove recesses 113, or eleven or more continuous arcuate groove recesses 113.

[0080] In the same or alternative embodiments, a putter-type golf club head may define one or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, two or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, three or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, four or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, five or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, six or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, seven or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, eight or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, nine or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, ten or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion, or eleven or more consecutive groove recesses 115 defining at least one straight portion and an arcuate portion. In many embodiments, the arcuate portion of the continuous linear groove recess is located between a first linear portion (near the heel) and a second linear portion (near the toe).

[0081] 2 , each successive groove recess 112 of the plurality of successive groove recesses includes (but is not required to include) either (1) a first end 116 and a second end 117 that may be connected to an upper boundary 118 of the striking face 107, (2) a first end 116 and a second end 117 that may be connected to either the heel 103 or the toe 102 of the striking face, or (3) a first end 116 and a second end 117 that may be connected to a lower boundary 119 of the striking face 107. This type of groove configuration allows the land area (or second material area) between the groove recesses to be finely tuned without having to vary the width of successive recesses. This helps achieve consistent ball speed across the striking face 107.

[0082] In many embodiments, the plurality of continuous groove recesses may be symmetrical about a centerline axis of the generally continuous straight groove recess 114 that extends from the heel 103 to the toe 102. Each of the plurality of continuous groove recesses between the generally continuous straight groove recess 114 and an upper boundary 118 of the striking face 107 (near the top rail 104 of the putter body 101) may include an arcuate portion and / or a continuous arcuate groove recess 113 that is concave upward relative to the upper boundary 118 of the striking face 107. Similarly, each of the plurality of continuous groove recesses between the generally continuous straight groove recess 114 and a lower boundary 119 of the striking face 107 (near the sole 105 of the putter body 101) may include an arcuate portion and / or a continuous arcuate groove recess that is concave downward relative to the lower boundary 119 of the striking face 107.

[0083] Each successive groove recess can have a constant width measured across the top rail 104-sole 105 direction. In many embodiments, the width of each successive groove recess can range from 0.02 inches to 0.040 inches. For example, the width of each successive groove recess 112 can be about 0.020 inches, about 0.021 inches, about 0.022 inches, about 0.023 inches, about 0.024 inches, about 0.025 inches, about 0.026 inches, about 0.027 inches, about 0.028 inches, about 0.029 inches, about 0.030 inches, about 0.031 inches, about 0.032 inches, about 0.033 inches, about 0.034 inches, about 0.035 inches, about 0.036 inches, about 0.037 inches, about 0.038 inches, about 0.039 inches, or about 0.040 inches.

[0084] In many embodiments, each of the plurality of consecutive groove recess arcuate portions and / or consecutive arcuate groove recesses 113 has a maximum length (measured in the heel 103-toe 102 direction) that is between 1% and 50% of the maximum length of the striking surface 107. For example, each of the plurality of consecutive groove recess arcuate portions and / or consecutive arcuate groove recesses can have a maximum length that is greater than 1% of the striking surface 107, greater than 5% of the striking surface 107, greater than 10% of the striking surface 107, greater than 15% of the striking surface 107, greater than 20% of the striking surface 107, greater than 25% of the striking surface 107, greater than 30% of the striking surface 107, greater than 35% of the striking surface 107, greater than 40% of the striking surface 107, or greater than 45% of the striking surface 107.

[0085] In the same or alternative embodiments, each of the arcuate portions of the multiple consecutive groove recesses or consecutive arcuate groove recesses 113 may have a maximum length that is less than 50% of the striking surface 107, less than 45% of the striking surface 107, less than 40% of the striking surface 107, less than 35% of the striking surface 107, less than 30% of the striking surface 107, less than 25% of the striking surface 107, less than 20% of the striking surface 107, less than 15% of the striking surface 107, or less than 10% of the striking surface 107.

[0086] In other embodiments, each of the arcuate portions of the plurality of consecutive groove recesses 112 or consecutive arcuate groove recesses 113 may have a maximum length that is between about 1% and about 50% of the striking surface 107, between about 1% and about 45%, between about 1% and about 40%, between about 1% and about 35%, between about 1% and about 30%, between about 1% and about 25%, or between about 1% and about 20% of the maximum length of the striking surface 107.

[0087] In many embodiments for controlling the relationship (or ratio) between the first material 109 and the second material 110, the diameter and arc length of each of the arcuate groove portions and / or each successive arcuate groove recess 113 increases in the direction from the upper boundary 118 to the generally successive linear groove recess 114. This may reduce the spacing (or second material area) between the groove recesses in the heel-toe and / or upper rail-sole directions. Similarly, in the same or other embodiments, the diameter and arc length of each of the arcuate portions and / or each successive arcuate groove recess 113 increases in the direction from the lower boundary 119 to the generally successive linear groove recess 114. This may reduce the spacing (or second material area) between the groove recesses in the heel-toe and / or upper rail-sole directions. The configuration of each groove with arcuate portions and / or continuous arcuate grooves that increase in diameter and / or arc length from the upper boundary 118 to the generally continuous linear groove recess 114 and from the lower boundary 119 to the generally continuous linear groove recess 114 allows the groove recess to maintain a constant width as the ratio of the first material 109 and the second material 110 is varied while achieving a striking surface 107 that can control ball velocity across the striking surface 107.

[0088] In many of the continuous groove recess embodiments, when the club head is in the address position, the striking face 107 has a striking face imaginary vertical axis 120 that extends through the geometric center 108 of the striking face 107 in the upper rail-to-sole direction (as shown in FIG. 2). Additionally, a total of five other vertical axes are shown in FIG. 3: the striking face imaginary vertical reference axis 120, the heel and toe vertical axes 121 0.25 inches from the center, and the heel and toe vertical axes 122 0.5 inches from the center. These vertical axes 121, 122 are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 103 and toe 102 directions.

[0089] 3, adjacent consecutive groove recesses 112 are closer to each other (i.e., closer packed and have smaller land (or second material area) between groove recesses) along the striking face imaginary vertical axis 120 than they are along the 0.25 inch vertical reference axis 121 and the 0.5 inch vertical reference axis 122 (in the heel-toe direction) due to the groove recess spacing and arcuate portion. Similarly, adjacent consecutive groove recesses are closer to each other (i.e., closer packed and have smaller land area between groove recesses) along the 0.25 inch vertical reference axis 121 than they are along the 0.5 inch vertical reference axis 122.

[0090] (Continuous grooves (insert style putter)) Figures 6-9 illustrate another exemplary embodiment. More specifically, Figures 6-9 illustrate an example of a putter-type golf club head 200 with a dual-material striking face 207 having a first material 209 and a second material 210. The golf club head 200 of Figures 6-9 and the golf club head 100 of Figures 1-3 are similar in many respects, except that the golf club head 200 is an insert-style putter.

[0091] 6-9 illustrate a two-piece putter insert 224 comprising a first material 209 (also referred to as the "first portion") and a second material 210 (also referred to as the "second portion"). With specific reference to FIG. 6, the second portion forms (or defines) a plurality of continuous groove voids 212 that separate the striking face 207 into second material land areas. The first portion of the putter insert 224 comprises a plurality of protruding contours that complement the corresponding continuous groove voids 212. By connecting the first portion of the insert to the second portion of the insert, the plurality of protruding contours may be flush with (i.e., on the same plane or plane as) the second material land areas. The plurality of protruding contours may thereby form the first material land areas. The first material land areas and the second material land areas contact at least a portion of a golf ball upon golf ball impact.

[0092] This embodiment illustrates one possible arrangement in which each arcuate portion of the successive groove voids 212 is arranged to create a denser, more compact central region to create more of the first material land area than the second material land area. Having a greater amount of first material land area than the second material land area helps create areas toward the heel or toe end and a central region that is less responsive to ball impact than the heel or toe end. This arrangement can be gradual or asymmetrically arranged from the center of the striking face to the heel end or from the center to the toe end.

[0093] Moving away from the center region toward the heel or toe, the separation distance between adjacent arcuate sections can increase, thereby introducing more secondary material land area. This separation distance can be symmetrically progressive or asymmetrically progressive. This helps create areas of progressively greater response away from the center region toward the heel and toe regions. Creating a striking surface with different response characteristics helps control ball speed more consistently across the striking surface.

[0094] Additionally, there is a generally arcuate recess (which may also be referred to as a semicircular groove) to create a more densely packed central region at the center of the striking face toward the top rail and sole, which further increases the amount (or degree) of first material land area that is absent moving away from the center and is absent at the heel and toe ends.

[0095] 6-9 includes a putter body 201 having a toe 202, a heel 203 opposite the toe 202, a top rail 204, a sole 205 opposite the top rail 204, a portion of a striking face 207, and a rear portion 206 opposite the striking face 207. The striking face 207 further defines a striking face recess 223 defined by the heel 203, the toe 202, the top rail 204, the sole 205, and the rear portion 206 of the putter body 201.

[0096] Referring to Figure 7, Figure 7 shows a perspective view of putter insert 224. In many embodiments, putter insert 224 may be received within and complement striking face recess 223. Unlike the embodiment of Figures 1-3, in which putter body 201 defines second material 210, second material 210 and first material 209 are part of putter insert 224 (i.e., separate from putter body 201).

[0097] The insert 224 may include a front surface 225 adapted for impact with a golf ball (not shown) and a rear surface 226 opposite the front. A putter insert thickness 227 may be defined as the maximum vertical distance between the front surface 225 and the rear surface 226. For example, FIG. 6 shows an insert 224 having a plurality of continuous groove voids 212 (defined by the second material) extending through the entire thickness of the second material 210. In many embodiments, the first material, the second material, and / or the combination of the first and second materials may be of a constant thickness.

[0098] Additionally, in many embodiments, first material 209 covers the entire rear face 226 of insert 224. In other words, rear face 226 is free of second material 210. In many embodiments, first material 209 further completely fills each consecutive groove void of the plurality of consecutive groove voids (to the point where it is flush with front face 225 of the insert), such that at front face 225, second material 210 surrounds first material 209, and upon golf ball impact, first material 209 and second material 210 contact at least a portion of the golf ball.

[0099] The plurality of continuous groove voids 212 defined by the putter insert 224 may resemble many shapes or configurations. For example, in this exemplary embodiment, the plurality of continuous groove voids 212 may be defined by one or more continuous curved groove voids, one or more continuous arcuate groove voids (which may also be referred to as "continuous arcuate groove voids"), one or more continuous straight groove voids, and / or combinations thereof. In this specific embodiment, the second material 210 defines five continuous arcuate groove voids 213 (or arcuate grooves), one continuous straight groove void 214, and six continuous groove voids 215 that define both straight and arcuate portions.

[0100] In alternative embodiments of a putter-type golf club head having continuous arcuate groove voids 213, the second material 210 may define (or form) one or more continuous arcuate groove voids 213, two or more continuous arcuate groove voids 213, three or more continuous arcuate groove voids 213, four or more continuous arcuate groove voids 213, five or more continuous arcuate groove voids 213, six or more continuous arcuate groove voids 213, seven or more continuous arcuate groove voids 213, eight or more continuous arcuate groove voids 213, nine or more continuous arcuate groove voids 213, ten or more continuous arcuate groove voids 213, or eleven or more continuous arcuate groove voids 213.

[0101] In the same or alternative embodiments, the second material 210 may define one or more consecutive groove voids defining straight and arcuate portions 215, two or more consecutive groove voids defining straight and arcuate portions 215, three or more consecutive groove voids defining straight and arcuate portions 215, four or more consecutive groove voids defining straight and arcuate portions 215, five or more consecutive groove voids defining straight and arcuate portions 215, six or more consecutive groove voids defining straight and arcuate portions 215, seven or more consecutive groove voids defining straight and arcuate portions 215, eight or more consecutive groove voids defining straight and arcuate portions 215, nine or more consecutive groove voids defining straight and arcuate portions 215, ten or more consecutive groove voids defining straight and arcuate portions 215, or eleven or more consecutive groove voids defining straight and arcuate portions 215. Generally, the arcuate portion of the continuous groove void 215 is located between a first linear portion (near the heel) and a second linear portion (near the toe).

[0102] In many embodiments, each successive groove void of the plurality of successive groove voids comprises (but is not required to have) either (1) a first end 216 and a second end 217 that may be connected to an upper boundary 218 of the striking face 207, (2) a first end 216 and a second end 217 that may be connected to either the heel 203 or the toe 202 of the striking face, or (3) a first end 216 and a second end 217 that may be connected to a lower boundary 219 of the striking face 207. This type of groove void arrangement allows the land area (or second material area 210) between the groove voids to be finely tuned without having to vary the width or thickness of successive groove voids. This helps achieve consistent ball speed across the striking face 207.

[0103] In some embodiments, the plurality of continuous groove voids are asymmetrical about a centerline axis of the generally continuous straight groove void 214 that extends from the heel 203 to the toe 202. Each of the plurality of continuous groove voids between the generally continuous straight groove 214 and an upper boundary 218 of the striking face 207 (near the top rail 204 of the putter body 201) may include an arcuate portion and / or a continuous arcuate groove void 213 that is concave upward relative to the upper boundary 218 of the striking face 207. Similarly, each of the plurality of continuous groove voids between the generally continuous straight groove void 214 and a lower boundary 219 of the striking face 207 (near the sole 205 of the putter body 201) may include an arcuate portion and / or a continuous arcuate groove void that is concave downward relative to the lower boundary 219 of the striking face 207.

[0104] Each successive groove void can have a constant width measured across the top rail 204-sole 205 direction. In many embodiments, the width of each successive groove void can range from 0.02 inches to 0.040 inches. For example, the width of each successive groove void can be about 0.020 inches, about 0.021 inches, about 0.022 inches, about 0.023 inches, about 0.024 inches, about 0.025 inches, about 0.026 inches, about 0.027 inches, about 0.028 inches, about 0.029 inches, about 0.030 inches, about 0.031 inches, about 0.032 inches, about 0.033 inches, about 0.034 inches, about 0.035 inches, about 0.036 inches, about 0.037 inches, about 0.038 inches, about 0.039 inches, or about 0.040 inches.

[0105] In many embodiments, each of the plurality of consecutive arcuate groove voids and / or consecutive arcuate groove voids 213 can have a maximum length (measured in the heel-to-toe direction) that is between 1% and 50% of the maximum length of the striking face 207. For example, each of the plurality of consecutive arcuate groove voids and / or consecutive arcuate groove voids can have a maximum length that is greater than 1% of the striking face 207, greater than 5% of the striking face 207, greater than 10% of the striking face 207, greater than 15% of the striking face 207, greater than 20% of the striking face 207, greater than 25% of the striking face 207, greater than 30% of the striking face 207, greater than 35% of the striking face 207, greater than 40% of the striking face 207, or greater than 45% of the striking face 207.

[0106] In the same or alternative embodiments, each of the arcuate portions of the plurality of consecutive groove voids or consecutive arcuate groove voids 213 may have a maximum length that is less than 50% of the striking surface 207, less than 45% of the striking surface 207, less than 40% of the striking surface 207, less than 35% of the striking surface 207, less than 30% of the striking surface 207, less than 25% of the striking surface 207, less than 20% of the striking surface 207, less than 15% of the striking surface 207, or less than 10% of the striking surface 207.

[0107] In other embodiments, each of the arcuate portions of the plurality of consecutive groove voids or consecutive arcuate groove voids 213 may have a maximum length that is between about 1% and about 50% of the striking surface 207, between about 1% and about 45%, between about 1% and about 40%, between about 1% and about 35%, between about 1% and about 30%, between about 1% and about 25%, or between about 1% and about 20% of the maximum length of the striking surface 207.

[0108] In many embodiments for controlling the relationship (or ratio) between the first material 209 and the second material 210, the diameter and arc length of each of the arcuate groove portions and / or each successive arcuate groove 213 increases in the direction from the upper boundary 218 to the generally successive linear groove 214 to create less land area (or second material land area) between successive groove voids in the central region. In the same or other embodiments, the diameter and arc length of each of the arcuate portions and / or each successive arcuate groove increases in the direction from the lower boundary 219 to the generally successive linear groove 214 to create less second material land area between successive groove voids in the central region.

[0109] The configuration of each successive groove void with arcuate sections and / or successive arcuate groove voids that increase in diameter and / or arc length from the upper boundary 218 to the generally continuous linear groove void 214 and from the lower boundary 219 to the generally continuous linear groove void 214 allows the groove voids to have a consistent width and depth while achieving a striking surface 207 that can control ball velocity across the striking surface 207.

[0110] In many of the continuous groove void embodiments, when the club head is in the address position, the striking face has a striking face imaginary vertical axis 220 that extends through the geometric center 208 of the striking face 207 in the upper rail-to-sole direction (as shown in FIG. 9). Additionally, corresponding vertical reference axes are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 203 and toe 202 directions.

[0111] 9, adjacent consecutive groove voids are closer to each other (i.e., closer packed, creating a smaller land area (or smaller second material land area) between consecutive groove voids) along the striking face imaginary vertical axis 220 than they are along the 0.25 inch vertical reference axis 221 and the 0.5 inch vertical reference axis 222. Similarly, adjacent consecutive groove voids are closer to each other (i.e., closer packed, creating a smaller land (or second material) area between consecutive groove voids) along the 0.25 inch vertical reference axis 221 than they are along the 0.5 inch vertical reference axis 222.

[0112] In many of the continuous groove embodiments, the percentage of the first material (or first material land area) along the 0.5 inch vertical reference axis 222 can be approximately 20% to 40%. For example, the percentage of the first material land area along the 0.5 inch vertical reference axis 222 can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Further, for example, the percentage of the first material land area along the 0.5 inch vertical reference axis 222 may be greater than 20%, greater than 21%, greater than 22%, greater than 23%, greater than 24%, greater than 25%, greater than 26%, greater than 27%, greater than 28%, greater than 29%, greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, or greater than 39%. In alternative embodiments, the percentage of the first material land area along the 0.5 inch vertical reference axis 222 may be less than 21%, less than 22%, less than 23%, less than 24%, less than 25%, less than 26%, less than 27%, less than 28%, less than 29%, less than 30%, less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, or less than 40%.

[0113] In many of the continuous groove embodiments, the percentage of first material (or first material land area) along the 0.25 inch vertical reference axis 221 can be approximately 30% to 50%. For example, the percentage of first material along the 0.25 inch vertical reference axis 221 can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Further, for example, the percentage of the first material land area along the 0.25 inch vertical reference axis 221 may be greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, greater than 39%, greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, or greater than 49%. In alternative embodiments, the percentage of the first material land area along the 0.25 inch vertical reference axis 221 may be less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, less than 40%, less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, or less than 50%.

[0114] In many of the continuous groove embodiments, the percentage of the first material (or first material land area) along the striking face imaginary axis 220 can be approximately 40% to 60%. For example, the percentage of the first material along the striking face imaginary axis 220 can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Further, for example, the percentage of the first material land area along the striking face imaginary axis 220 may be greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, greater than 49%, greater than 50%, greater than 51%, greater than 52%, greater than 53%, greater than 54%, greater than 55%, greater than 56%, greater than 57%, greater than 58%, or greater than 59%. In alternative embodiments, the percentage of the first material along the striking face imaginary axis 220 may be less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, less than 50%, less than 51%, less than 52%, less than 53%, less than 54%, less than 55%, less than 56%, less than 57%, less than 58%, less than 59%, or less than 60%.

[0115] Additionally, in many embodiments, the average ratio, defined as the surface area of ​​the first material land area to the surface area of ​​the second material land area (measured in the upper rail-to-sole direction), decreases from the striking face imaginary vertical axis 220 to the 0.5 inch vertical reference axis 222. This type of arrangement of the first and second materials helps provide consistent ball speed across the striking face because the average ratio along the striking face imaginary vertical axis is greater (i.e., softer) than the average ratio along the 0.5 inch vertical reference axis (i.e., harder). This counteracts energy transfer losses on heel and toe mishits.

[0116] (Separate voids (tablet shape)) Figures 10-13 illustrate another exemplary embodiment. More specifically, Figures 10-13 illustrate an example of a putter-type golf club head 300 with a dual-material striking face 307 comprising a first material 309 and a second material 310. The golf club head 300 of Figures 10-13 is similar in many respects to the golf club head 200 of Figures 6-9, except that the golf club head 300 includes separate voids extending in a heel-to-toe direction rather than a continuous void and / or recess. The separate voids generally have a greater length near the central region of the striking face 307 than toward the heel and / or toe. In many embodiments, the separate voids are substantially the same width.

[0117] 10 shows a putter-type golf club head 300 comprising a putter body 301 having a toe 302, a heel 303 opposite the toe 302, a top rail 304, a sole 305 opposite the top rail 304, a portion of a striking face 307, and a rear portion 306 opposite the striking face 307. The striking face 307 may further define a striking face recess 323 defined by the heel 303, the toe 302, the top rail 304, the sole 305, and the rear portion 306 of the putter body 301.

[0118] 10-13 illustrate a two-part putter insert 324 comprising a first material 309 (also referred to as the "first portion") and a second material 310 (also referred to as the "second portion"). With specific reference to FIG. 10, the second portion forms (or defines) a plurality of separate tablet-shaped voids 312. These separate tablet-shaped voids are arranged in rows and columns and do not touch or otherwise contact another tablet-shaped void.

[0119] The second portion surrounds the tablet-shaped voids to form a second material land area. The first portion of the putter insert 324 includes a plurality of protruding tablet-shaped contours that complement the corresponding discrete tablet-shaped voids 312. By connecting the first and second portions together, the plurality of protruding discrete tablet-shaped voids can be flush with the second material land area. The plurality of protruding discrete tablet-shaped voids can thereby form a first material land area. The first material land area and the second material land contact at least a portion of the golf ball upon golf ball impact. The first material has a lower hardness than the second material.

[0120] This embodiment illustrates one possible arrangement in which tablet-shaped voids of varying lengths are arranged to form a denser, more compact central region that produces more first material land area than second material land area. Referring to FIG. 12, it can be seen that in any given row, the tablet-shaped voids with the greatest length are closer to the central region, and the tablet-shaped voids with the smallest length are closer to the heel and toe ends. This arrangement produces a central region with a greater amount of first material land area than second material land area (which produces an area toward the heel or toe end and a central region that is less responsive to ball impact than the heel or toe ends). In the upper rail-to-sole direction, the first material land area and the second material land area are substantially the same or constant. Therefore, the first material land area only varies in the heel-to-toe direction, not in the upper rail-to-sole direction.

[0121] Moving away from the center region toward the heel or toe along a given row, the separation distance between adjacent discrete tablet-shaped voids increases (i.e., the length of the discrete tablet-shaped voids decreases). This creates more secondary material land area, which helps to create progressively more responsive regions away from the center region toward the heel and toe regions for consistent ball speed control across the striking face.

[0122] 11-13 illustrate various putter inserts 324 with separate pill-shaped voids. In many embodiments, the putter insert 324 may be received within and complement the striking face recess 323. However, it should be noted that in alternative embodiments, the putter-type golf club head 300 need not be an insert-style putter.

[0123] FIG. 13 shows an exploded view of a putter insert 324 with discrete, tablet-shaped voids. The insert 324 may include a front surface 325 adapted for impact with a golf ball (not shown) and a rear surface 326 opposite the front. A putter insert thickness (or depth) 327 may be defined as the maximum vertical distance between the front surface 325 and the rear surface 326. For example, FIG. 13 shows an insert 324 having a plurality of discrete, tablet-shaped voids 312 (defined by the second material) extending entirely through the thickness (or depth) of the second material 310.

[0124] Additionally, in many embodiments, first material 309 may cover the entire rear surface 326 of insert 324. In other words, rear surface 326 is free of second material 310. In many embodiments, first material 309 further fills each of the discrete tablet-shaped voids 312 of the plurality of discrete tablet-shaped voids (until flush with front surface 325 of the insert), such that at front surface 325, second material 310 surrounds first material 309, and upon golf ball impact, first material 309 and second material 310 may contact at least a portion of the golf ball.

[0125] Each of the separate tablet-shaped voids may have a first end 328 (near the toe) that forms an arcuate profile and a second end 329 (near the heel) that forms an arcuate profile. In many embodiments, the profiles of the first end 328 and second end 329 may be curvilinear, circular, semicircular, crescent-shaped, arcuate, curved, or rounded. The first end 328 and second end 329 may be connected by parallel horizontal segments 330 that extend substantially in a heel-to-toe direction.

[0126] The maximum length of each of the discrete tablet-shaped voids 312 (measured in the heel-toe direction) can vary in the heel-toe direction. In many embodiments, the maximum length of each of the discrete tablet-shaped voids 312 can be between 0.02 inches and 0.36 inches. For example, the maximum length of each of the plurality of discrete tablet-shaped voids 312 can be between 0.02 inches and 0.36 inches, 0.04 inches and 0.36 inches, 0.06 inches and 0.36 inches, 0.08 inches and 0.36 inches, 0.10 inches and 0.36 inches, 0.12 inches and 0.36 inches, 0.14 inches and 0.36 inches, 0.16 inches and 0.36 inches, 0.18 inches and 0.36 inches, 0.20 inches and 0.36 inches, 0.22 inches and 0.36 inches, 0.24 inches and 0.36 inches, 0.26 inches and 0.36 inches, or 0.28 inches and 0.36 inches. In other embodiments, the maximum length of each of the discrete tablet-shaped voids 312 can vary between 0.06 inches and 0.180 inches.

[0127] The maximum width of each of the discrete tablet-shaped voids 312 of the plurality of tablet-shaped voids (measured in the top rail-to-sole direction) can remain the same or approximately constant. In many embodiments, the maximum width of each of the discrete tablet-shaped voids 312 can be between 0.01 inches and 0.3 inches. For example, the maximum width of each of the discrete tablet-shaped voids 312 can be greater than 0.01 inches, greater than 0.02 inches, greater than 0.03 inches, greater than 0.04 inches, greater than 0.05 inches, greater than 0.06 inches, greater than 0.07 inches, greater than 0.08 inches, greater than 0.09 inches, greater than 0.10 inches, greater than 0.11 inches, greater than 0.12 inches, greater than 0.13 inches, or greater than 0.14 inches. It may be greater than 0.15 inches, greater than 0.16 inches, greater than 0.17 inches, greater than 0.18 inches, greater than 0.19 inches, greater than 0.20 inches, greater than 0.21 inches, greater than 0.22 inches, greater than 0.23 inches, greater than 0.24 inches, greater than 0.25 inches, greater than 0.26 inches, greater than 0.27 inches, greater than 0.28 inches, or greater than 0.29 inches.

[0128] In other embodiments, the maximum width of each of the discrete tablet-shaped voids 312 can be less than 0.30 inches, less than 0.29 inches, less than 0.28 inches, less than 0.27 inches, less than 0.26 inches, less than 0.25 inches, less than 0.24 inches, less than 0.23 inches, less than 0.22 inches, less than 0.21 inches, less than 0.20 inches, less than 0.19 inches, less than 0.18 inches, less than 0.17 inches, less than 0.16 inches, less than 0.15 inches, less than 0.14 inches, less than 0.13 inches, less than 0.12 inches, less than 0.11 inches, less than 0.10 inches, less than 0.09 inches, less than 0.08 inches, less than 0.07 inches, less than 0.06 inches, less than 0.05 inches, less than 0.04 inches, less than 0.03 inches, or less than 0.02 inches.

[0129] In the same or other discrete tablet-shaped voids 312 embodiments, the multiple discrete tablet-shaped voids 312 may be located in substantially horizontal rows and / or substantially vertical columns. In the exemplary embodiment of FIG. 11, the multiple discrete tablet-shaped voids are arranged to form 11 rows and 17 columns. In the embodiment of FIG. 12, the multiple discrete tablet-shaped voids are arranged to form 13 rows and 17 columns. In alternative embodiments, the multiple discrete tablet-shaped voids may be arranged to form two or more rows, three or more rows, four or more rows, five or more rows, six or more rows, seven or more rows, eight or more rows, nine or more rows, ten or more rows, eleven or more rows, twelve or more rows, thirteen or more rows, fourteen or more rows, fifteen or more rows, sixteen or more rows, seventeen or more rows, eighteen or more rows, nineteen or more rows, or twenty or more rows. In the same or alternative embodiments, the plurality of discrete tablet-shaped voids may be arranged to form two or more rows, three or more rows, four or more rows, five or more rows, six or more rows, seven or more rows, eight or more rows, nine or more rows, ten or more rows, eleven or more rows, twelve or more rows, thirteen or more rows, fourteen or more rows, fifteen or more rows, sixteen or more rows, seventeen or more rows, eighteen or more rows, nineteen or more rows, or twenty or more rows. As described further below, arranging the tablet-shaped voids 312 in rows and columns allows for the appropriate ratio between the first and second materials along the vertical reference axis.

[0130] As can be seen in the exemplary embodiment of Figures 10-13, each of the plurality of discrete tablet-shaped voids 312 are spaced apart from one another in both the heel-toe direction and the upper rail-to-sole direction, as opposed to the continuous groove or recess embodiment of Figures 1-9, which are continuously connected in the heel-toe direction. Each row or column can have two or more separate tablet-shaped voids, three or more separate tablet-shaped voids, four or more separate tablet-shaped voids, five or more separate tablet-shaped voids, six or more separate tablet-shaped voids, seven or more separate tablet-shaped voids, eight or more separate tablet-shaped voids, nine or more separate tablet-shaped voids, ten or more separate tablet-shaped voids, eleven or more separate tablet-shaped voids, twelve or more separate tablet-shaped voids, thirteen or more separate tablet-shaped voids, fourteen or more separate tablet-shaped voids, fifteen or more separate tablet-shaped voids, sixteen or more separate tablet-shaped voids, seventeen or more separate tablet-shaped voids, eighteen or more separate tablet-shaped voids, nineteen or more separate tablet-shaped voids, or twenty or more separate tablet-shaped voids.

[0131] The volume of first material 309 filling each of the discrete tablet-shaped voids 312 may vary in the heel-to-toe direction. In many embodiments, the volume of first material 309 is greater than or equal to 0.0000803 in. 3 ~0.00104122in 3 In some embodiments, the first material 309 may fill a volume of 0.0000803 in 3 ~0.00104122in 3 , 0.000176in 3 ~0.00104122in 3 , 0.000272in 3 ~0.00104122in 3 , 0.000368in 3 ~0.00104122in 3 , 0.000464in 3 ~0.00104122in 3 , 0.00056in 3 ~0.00104122in 3 , 0.00065in 3~0.00104122in 3 , 0.0075in 3 ~0.0010422in 3 , 0.000849in 3 ~0.0010422in 3 , or 0.000945 in 3 ~0.00104in 3 In other embodiments, the first material 309 may fill a volume of 0.000160 in 3 ~0.00052061in 3 When the first material 309 fills discrete voids of this size, it provides more precise control over the coordination between the first and second materials to produce consistent ball speeds across the striking face and improved impact feel and sound.

[0132] In many of the split pill-shaped void embodiments, when the club head is in the address position, the striking face has a striking face imaginary vertical axis 320 that extends through the geometric center 308 of the striking face 307 in the upper rail-to-sole direction (as shown in FIGS. 11 and 12). Additionally, corresponding vertical reference axes 321, 322 are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 303 and toe 302 directions.

[0133] 11 and 12, adjacent separate tablet-shaped voids 312 are closer to each other (i.e., closer packed and have smaller (second material) land areas between the separate tablet-shaped voids) in both horizontal and vertical directions along the strike face imaginary vertical axis 320 than they are along the 0.25 inch vertical reference axis 321 and the 0.5 inch vertical reference axis 322. Similarly, adjacent separate tablet-shaped voids 312 are closer to each other (i.e., closer packed and have smaller land (or second material) areas between the separate tablet-shaped voids 312) along the 0.25 inch vertical reference axis 321 than they are along the 0.5 inch vertical reference axis 322.

[0134] In many of the discrete tablet-shaped void embodiments, the percentage of the first material (or first material land area) along the 0.5 inch vertical reference axis 322 can be about 20% to 40%. For example, the percentage of the first material land area along the 0.5 inch vertical reference axis 322 can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Further, for example, the percentage of the first material along the 0.5 inch vertical reference axis 322 may be greater than 20%, greater than 21%, greater than 22%, greater than 23%, greater than 24%, greater than 25%, greater than 26%, greater than 27%, greater than 28%, greater than 29%, greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, or greater than 39%. In alternative embodiments, the percentage of first material 309 along the 0.5 inch vertical reference axis 322 may be less than 21%, less than 22%, less than 23%, less than 24%, less than 25%, less than 26%, less than 27%, less than 28%, less than 29%, less than 30%, less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, or less than 40%.

[0135] In many of the discrete tablet-shaped void embodiments, the percentage of first material 309 along the 0.25 inch vertical reference axis 321 can be approximately 30% to 50%. For example, the percentage of first material 309 along the 0.25 inch vertical reference axis 321 can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Further, for example, the percentage of first material 309 along the 0.25 inch vertical reference axis 321 may be greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, greater than 39%, greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, or greater than 49%. In alternative embodiments, the percentage of first material 309 along the 0.25 inch vertical reference axis 321 may be less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, less than 40%, less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, or less than 50%.

[0136] In many of the discrete tablet-shaped void embodiments, the percentage of first material 309 along the striking surface imaginary axis 320 can be approximately 40% to 60%. For example, the percentage of first material along the striking surface imaginary axis can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Further, for example, the percentage of the first material 309 along the striking face imaginary axis 320 may be greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, greater than 49%, greater than 50%, greater than 51%, greater than 52%, greater than 53%, greater than 54%, greater than 55%, greater than 56%, greater than 57%, greater than 58%, or greater than 59%. In alternative embodiments, the percentage of first material 309 along striking face imaginary axis 320 may be less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, less than 50%, less than 51%, less than 52%, less than 53%, less than 54%, less than 55%, less than 56%, less than 57%, less than 58%, less than 59%, or less than 60%.

[0137] Additionally, in many embodiments, the average ratio, defined as the percentage surface area of ​​the first material land area 309 to the percentage surface area of ​​the second material land area 310 (measured along the respective vertical reference axes), decreases from the striking face imaginary vertical axis 320 to the 0.5 inch vertical reference axis 322. This type of arrangement of the first and second materials helps provide consistent ball speeds across the striking face because the average ratio along the striking face imaginary vertical axis is greater (i.e., softer) than the average ratio along the 0.5 inch vertical reference axis. This counteracts energy transfer losses on heel and toe mishits.

[0138] Furthermore, in this exemplary embodiment, discrete voids of variable width, variable thickness, and / or even variable depth are not required to produce consistent ball speeds across the striking surface. Consistent ball speeds are achieved because discrete, tablet-shaped voids vary in length (heel-to-toe) to produce different first and second material ratios measured along the upper rail-to-sole direction.

[0139] (separate voids (hexagonal shape)) Figures 14-16 show another exemplary embodiment in accordance with the invention described herein. More specifically, Figures 14-16 show an example of a putter-type golf club head 400 with a dual-material striking face 407 comprising a first material 409 and a second material 410. The golf club head 400 of Figures 14-16 and the golf club head 300 of Figures 10-13 are similar in many respects, except that the golf club head 400 includes separated voids that are hexagonal in shape rather than tablet-shaped.

[0140] 14 shows a putter-type golf club head 400 comprising a putter body 401 having a toe 402, a heel 403 opposite the toe 402, a top rail 404, a sole 405 opposite the top rail 404, a portion of a striking face 407, and a rear portion 406 opposite the striking face 407. The striking face 407 may further define a striking face recess 423 defined by the heel 403, the toe 402, the top rail 404, the sole 405, and the rear portion 406 of the putter body 401.

[0141] 15 shows a two-part putter insert 424 with a separated hexagonal void. In many embodiments, the putter insert 424 may be received within and complement the striking face recess 423. However, it should be noted that in alternative embodiments, the putter-type golf club head 400 need not be an insert-style putter.

[0142] 14-16 illustrate a putter insert 424 comprising a first material 409 (which may also be referred to as a "first portion") and a second material 410 (which may also be referred to as a "second portion"). With specific reference to FIG. 15, the second portion forms (or defines) a plurality of separate hexagonal voids 412. These separate hexagonal voids are arranged in rows and columns and do not contact or touch another hexagonal void. The first material has a lower hardness than the second material.

[0143] The second material surrounds the hexagonal voids to form second material land areas. The first portion of the putter insert 424 includes a plurality of protruding hexagonal contours that complement the corresponding hexagonal tablet-shaped voids 412. When the first and second portions are coupled together, the plurality of protruding hexagonal voids can be flush with the second material land areas, thereby allowing the plurality of protruding discrete hexagonal voids to form the first material land areas. The first material land areas and the second material lands contact at least a portion of the golf ball upon golf ball impact.

[0144] This embodiment illustrates one possible arrangement in which the hexagonal voids are arranged to form a denser, more compact central region, producing more first material land area than second material land area. Referring to FIG. 16, it can be seen that in any given row, the hexagonal voids with the largest widths are closer to the central region, while the hexagonal voids with the smallest widths are further from the central region. This arrangement produces a central region with a greater amount of first material land area than second material land area. This produces a central region that is less responsive to ball impacts than the heel or toe region. In the upper rail-sole direction, the width of the first material land remains substantially the same or constant. Therefore, as the width of the discrete hexagonal voids decreases away from the central region, the ratio between the first and second materials also changes.

[0145] Moving away from the center region toward the heel or toe along a given row, the separation distance between adjacent discrete hexagonal voids increases (i.e., the length of the discrete hexagonal voids decreases). This creates more secondary material land area, which helps to create progressively more responsive regions away from the center region toward the heel and toe regions for consistent ball speed control across the striking face.

[0146] Continuing with reference to FIG. 15, FIG. 15 shows an exploded view of a putter insert 424 with discrete hexagonal voids. The insert 424 may include a front surface 425 adapted for impact with a golf ball (not shown) and a rear surface 426 opposite the front. A putter insert thickness (i.e., depth) 427 may be defined as the maximum vertical distance between the front surface 425 and the rear surface 426. For example, FIG. 15 shows an insert 424 with a plurality of discrete hexagonal voids 412 (defined by the second material) extending through the entire thickness (i.e., depth) of the second material 410.

[0147] Additionally, in many embodiments, first material 409 may cover the entire rear surface 426 of insert 424. In other words, rear surface 426 is free of second material 410. In many embodiments, first material 409 further fills each of the separated hexagonal voids 412 of the plurality of separated hexagonal voids (until flush with front surface 425 of the insert), such that at front surface 425, second material 410 surrounds first material 409, such that upon golf ball impact, first material 409 and second material 410 may contact at least a portion of the golf ball.

[0148] Each of the discrete hexagonal voids may be defined as a six-sided polygon having six interior angles and six vertices. Each of the six interior angles 431 may be approximately 120 degrees. The interior angles add up to approximately 720 degrees. Each side of the six-sided polygon may be equal or substantially equal in length.

[0149] The maximum length (measured in the heel-toe direction) of each of the separate hexagonal voids 412 may vary in the heel-toe direction. In many embodiments, the maximum length of each of the separate hexagonal voids 412 may be between 0.03 inches and 0.40 inches. For example, the maximum length of each of the plurality of discrete hexagonal voids 412 can be between 0.03 inches and 0.40 inches, 0.04 inches and 0.40 inches, 0.05 inches and 0.40 inches, 0.06 inches and 0.40 inches, 0.07 inches and 0.40 inches, 0.08 inches and 0.40 inches, 0.09 inches and 0.40 inches, 0.10 inches and 0.40 inches, 0.11 inches and 0.40 inches, 0.12 inches and 0.40 inches, 0.13 inches and 0.40 inches, 0.14 inches and 0.40 inches, or 0.15 inches and 0.40 inches. In other embodiments, the maximum length of each of the discrete hexagonal voids 412 can vary between 0.074 inches and 0.17 inches.

[0150] In other embodiments, the maximum length of each of the discrete hexagonal voids 412 can be less than 0.30 inches, less than 0.29 inches, less than 0.28 inches, less than 0.27 inches, less than 0.26 inches, less than 0.25 inches, less than 0.24 inches, less than 0.23 inches, less than 0.22 inches, less than 0.21 inches, less than 0.20 inches, less than 0.19 inches, less than 0.18 inches, less than 0.17 inches, less than 0.16 inches, less than 0.15 inches, less than 0.14 inches, less than 0.13 inches, less than 0.12 inches, less than 0.11 inches, less than 0.10 inches, less than 0.09 inches, less than 0.08 inches, less than 0.07 inches, less than 0.06 inches, less than 0.05 inches, or less than 0.04 inches.

[0151] The maximum width of each of the separate hexagonal voids 412 of the plurality of hexagonal voids (measured in the upper rail-to-sole direction) can vary. In many embodiments, the maximum width of each of the separate hexagonal voids 412 can be between 0.03 inches and 0.40 inches. For example, the maximum width of each of the separate hexagonal voids 412 can be greater than 0.03 inches, greater than 0.04 inches, greater than 0.05 inches, greater than 0.06 inches, greater than 0.07 inches, greater than 0.08 inches, greater than 0.09 inches, greater than 0.10 inches, greater than 0.11 inches, greater than 0.12 inches, greater than 0.13 inches, greater than 0.14 inches, greater than 0.15 inches, greater than 0.16 inches, greater than 0.17 inches, greater than 0.18 inches, greater than 0.19 inches, or greater than 0.20 inches. In other embodiments, the maximum width of each of the separated hexagonal voids 412 may be less than 0.20 inches, less than 0.19 inches, less than 0.18 inches, less than 0.17 inches, less than 0.16 inches, less than 0.15 inches, less than 0.14 inches, less than 0.13 inches, less than 0.12 inches, less than 0.11 inches, or less than 0.10 inches.

[0152] In the same or other embodiments of the separated hexagonal voids 412, the plurality of separated hexagonal voids 412 may be located in substantially horizontal rows and / or substantially vertical columns. In the exemplary embodiment of Figure 16, the plurality of separated hexagonal voids are arranged to form five rows and thirteen columns. In alternative embodiments, the plurality of separated hexagonal voids may be arranged to form two or more rows, three or more rows, four or more rows, five or more rows, six or more rows, seven or more rows, eight or more rows, nine or more rows, ten or more rows, eleven or more rows, twelve or more rows, thirteen or more rows, fourteen or more rows, fifteen or more rows, sixteen or more rows, seventeen or more rows, eighteen or more rows, nineteen or more rows, or twenty or more rows. In the same or alternative embodiments, a plurality of discrete hexagonal voids may be arranged to form two or more rows, three or more rows, four or more rows, five or more rows, six or more rows, seven or more rows, eight or more rows, nine or more rows, ten or more rows, eleven or more rows, twelve or more rows, thirteen or more rows, fourteen or more rows, fifteen or more rows, sixteen or more rows, seventeen or more rows, eighteen or more rows, nineteen or more rows, or twenty or more rows. As described further below, arranging the hexagonal voids 412 in rows and columns allows for an appropriate ratio between the first and second materials along the vertical reference axis.

[0153] As can be seen in the exemplary embodiment of Figures 14-16, each of the plurality of discrete hexagonal voids 412 are spaced apart from one another in both the heel-toe direction and the upper rail-to-sole direction, as opposed to the continuous groove or recess embodiment of Figures 1-9, which are continuously connected in the heel-toe direction. Each row or column can have two or more separate hexagonal voids, three or more separate hexagonal voids, four or more separate hexagonal voids, five or more separate hexagonal voids, six or more separate hexagonal voids, seven or more separate hexagonal voids, eight or more separate hexagonal voids, nine or more separate hexagonal voids, ten or more separate hexagonal voids, eleven or more separate hexagonal voids, twelve or more separate hexagonal voids, thirteen or more separate hexagonal voids, fourteen or more separate hexagonal voids, fifteen or more separate hexagonal voids, sixteen or more separate hexagonal voids, seventeen or more separate hexagonal voids, eighteen or more separate hexagonal voids, nineteen or more separate hexagonal voids, or twenty or more separate hexagonal voids.

[0154] The volume of first material 409 filling each of the discrete hexagonal voids 412 may vary in the heel-to-toe direction. In many embodiments, the volume of first material 409 is greater than or equal to 0.0000803 in. 3 ~0.004in 3 In some embodiments, the first material 409 may fill a volume of 0.0000803 in 3 ~0.004in 3 , 0.000176in 3 ~0.004in 3 , 0.000272in 3 ~0.004in 3 , 0.000368in 3 ~0.004in 3 , 0.000464in 3 ~0.004in 3 , 0.00056in 3 ~0.004in 3 , 0.00065in 3 ~0.004in 3 , 0.0075in3 ~0.004in 3 , 0.000849in 3 ~0.004in 3 , or 0.000945 in 3 ~0.004in 3 In other embodiments, the first material 409 may fill a volume of 0.00035 in 3 ~0.00187in 3 When the first material 409 fills discrete voids of this size, it provides more precise control over the coordination between the first and second materials to produce consistent ball speeds across the striking face and improved impact feel and sound.

[0155] In many of the split hexagonal cavity embodiments, when the club head is in the address position, the striking face has a striking face imaginary vertical axis 420 that extends through the geometric center 408 of the striking face 407 in the upper rail-to-sole direction (as shown in FIG. 16 ). Additionally, corresponding vertical reference axes are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 403 and toe 402 directions.

[0156] 16, adjacent separated hexagonal voids 412 are closer to each other (i.e., closer packed and have smaller (second material) land areas between the separated voids) in both the horizontal and vertical directions along the striking face imaginary vertical axis 420 than they are along the 0.25 inch vertical reference axis 421 and the 0.5 inch vertical reference axis 422. Similarly, adjacent separated hexagonal voids 412 are closer to each other (i.e., closer packed and have smaller land (or second material) areas between the separated hexagonal voids 412 in both the horizontal and vertical directions) along the 0.25 inch vertical reference axis 421 than they are along the 0.5 inch vertical reference axis 422.

[0157] In many of the discrete hexagonal void embodiments, the percentage of first material 409 along the 0.5 inch vertical reference axis 422 can be approximately 20% to 40%. For example, the percentage of first material 409 along the 0.5 inch vertical reference axis 422 can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Further, for example, the percentage of the first material along the 0.5 inch vertical reference axis 422 may be greater than 20%, greater than 21%, greater than 22%, greater than 23%, greater than 24%, greater than 25%, greater than 26%, greater than 27%, greater than 28%, greater than 29%, greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, or greater than 39%. In alternative embodiments, the percentage of first material 409 along the 0.5 inch vertical reference axis 422 may be less than 21%, less than 22%, less than 23%, less than 24%, less than 25%, less than 26%, less than 27%, less than 28%, less than 29%, less than 30%, less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, or less than 40%.

[0158] In many of the isolated hexagonal void embodiments, the percentage of first material 409 (or first material land area) along the 0.25 inch vertical reference axis 421 can be approximately 30% to 50%. For example, the percentage of first material 409 along the 0.25 inch vertical reference axis 421 can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Further, for example, the percentage of first material 309 along the 0.25 inch vertical reference axis 421 may be greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, greater than 39%, greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, or greater than 49%. In alternative embodiments, the percentage of first material 409 along the 0.25 inch vertical reference axis 421 may be less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, less than 40%, less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, or less than 50%.

[0159] In many of the discrete hexagonal void embodiments, the percentage of the first material 409 (or first material land area) along the striking face imaginary axis 420 can be approximately 40% to 60%. For example, the percentage of the first material 409 along the striking face imaginary axis can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Further, for example, the percentage of first material 409 along striking face imaginary axis 420 may be greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, greater than 49%, greater than 50%, greater than 51%, greater than 52%, greater than 53%, greater than 54%, greater than 55%, greater than 56%, greater than 57%, greater than 58%, or greater than 59%. In alternative embodiments, the percentage of first material 409 along striking face imaginary axis 420 may be less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, less than 50%, less than 51%, less than 52%, less than 53%, less than 54%, less than 55%, less than 56%, less than 57%, less than 58%, less than 59%, or less than 60%.

[0160] Additionally, in many embodiments, the average ratio, defined as the percentage surface area of ​​the first material land area 409 to the percentage surface area of ​​the second material land area 410 (measured along the respective vertical reference axes), decreases from the striking face imaginary vertical axis 420 to the 0.5 inch vertical reference axis 422. This type of arrangement of the first and second materials helps provide consistent ball speeds across the striking face because the average ratio along the striking face imaginary vertical axis is greater (i.e., softer) than the average ratio along the 0.5 inch vertical reference axis. This counteracts energy transfer losses on heel and toe mishits.

[0161] Furthermore, in this exemplary embodiment, discrete voids of variable width (in the upper rail-to-sole direction along the row) and / or even variable thickness (or depth) are not required to produce consistent ball speeds across the striking surface. Consistent ball speeds are achieved because the discrete hexagonal voids vary in length (in the heel-to-toe direction) to produce different first and second material ratios along the vertical direction.

[0162] (Continuous grooves (insert style putter)) Figures 17-19 illustrate another exemplary embodiment. More specifically, Figures 17-19 illustrate an example of a putter-type golf club head 500 with a dual-material striking face 507 comprising a first material 509 and a second material 510. The golf club head 500 of Figures 17-19 is similar in many respects to the previously described embodiments.

[0163] 17-19 includes a putter body 501 having a toe 502, a heel 503 opposite the toe 502, a top rail 504, a sole 505 opposite the top rail 504, a portion of a striking face 507, and a rear portion 506 opposite the striking face 507. The striking face 507 further defines a striking face recess 523 defined by the heel 503, the toe 502, the top rail 504, the sole 505, and the rear portion 506 of the putter body 501.

[0164] 17-19 illustrate a putter insert 524 comprising a first material 509 (which may also be referred to as a "first portion") and a second material 510 (which may also be referred to as a "second portion"). With specific reference to FIG. 18, the second portion forms (or defines) a plurality of continuous groove voids 512, and the second material 510 surrounding the plurality of continuous groove voids may be defined as a second material land area. The first portion of the putter insert 524 comprises a plurality of protruding contours that complement the corresponding continuous groove voids 512. When the first and second portions of the insert 524 are coupled together, the plurality of protruding contours may be flush with the second material land area. Thus, the plurality of protruding contours may also form a first material land area. The first material land area and the second material land area may contact at least a portion of a golf ball upon golf ball impact.

[0165] This embodiment illustrates one possible arrangement, where each successive groove void 512 defines an upper curvature point and a lower curvature point. The upper and lower curvature points are centered on the striking face. This allows the maximum width of each successive groove void to be centered on the striking face in the upper rail-to-sole and heel-to-toe directions. The first material has a lower hardness than the second material. This creates a denser, more compact central region with more first material land area than second material land area. Having a larger amount of first material land area than second material land area helps create areas toward the heel or toe end and a central region that is less responsive to ball impact than the heel or toe end.

[0166] Moving away from the center region toward the heel and / or toe, the spacing between adjacent arcuate sections increases to introduce more secondary material land area, creating areas of progressively greater response from the center region toward the heel and toe regions for more consistent ball speed control across the striking face.

[0167] 18, which shows a perspective view of putter insert 524. In many embodiments, putter insert 524 may be received within and complement striking face recess 523. Putter insert 524 may include a front surface 525 adapted for impact with a golf ball (not shown) and a rear surface 526 opposite the front surface.

[0168] The putter insert thickness 527 may be defined as the maximum vertical distance between the front face 525 and the rear face 526. For example, Figure 18 shows an insert 524 having a plurality of continuous groove voids 512 (defined by the second material) extending through the entire thickness of the second material 510. In many embodiments, the first material, the second material, and / or the combination of the first and second materials may be of a constant thickness.

[0169] Further, in many embodiments, as shown herein, first material 509 covers the entire rear surface 526 of insert 524. In other words, rear surface 526 is free of second material 510. In many embodiments, first material 509 further completely fills (or completely occupies) each consecutive groove void of the plurality of consecutive groove voids (to the point where it is flush with front surface 525 of the insert), such that at front surface 525, second material 510 surrounds first material 509, such that upon golf ball impact, first material 509 and second material 510 contact at least a portion of the golf ball.

[0170] The plurality of continuous groove voids 512 defined by the putter insert 524 may resemble many shapes or configurations. For example, in the exemplary embodiment shown herein, the continuous groove voids 512 extend substantially horizontally in a heel-to-toe direction. Each continuous groove 512 of the plurality of continuous grooves 512 defines an upper continuous groove wall 532 near an upper boundary 518 of the striking face, a lower continuous groove wall 533 near a lower boundary 519 of the striking face, a first continuous groove apex 534 near the toe, and a second continuous groove apex 535 near the heel.

[0171] In many embodiments, the upper continuous groove walls 532 continuously decrease from the striking face imaginary vertical axis 520 to a first continuous groove apex 534 and a second continuous groove apex 535. Stated another way, the upper continuous groove walls 532 define an upward curvature point along the upper continuous groove walls at the striking face imaginary vertical axis 520 and a downward curvature point along the lower continuous groove walls 533 at the striking face imaginary vertical axis 520. At the first end 516 and the second end 517 of the continuous groove void 512, the upper continuous groove walls 532 and the lower continuous groove walls 533 intersect to define a first continuous groove apex 534 and a second continuous groove apex 535.

[0172] In alternative embodiments of a putter-type golf club head having continuous groove voids 512, the second material 510 may define one or more continuous groove voids 512, two or more continuous groove voids 512, three or more continuous groove voids 512, four or more continuous groove voids 512, five or more continuous groove voids 512, six or more continuous groove voids 512, seven or more continuous groove voids 512, eight or more continuous groove voids 512, nine or more continuous groove voids 512, ten or more continuous groove voids 512, or eleven or more continuous groove voids 512.

[0173] Each successive groove void can have a maximum width measured on the striking face imaginary vertical axis 520 in the direction of the top rail 504 and the sole 505. In many embodiments, the maximum width of each successive groove void 520 can be in the range of between 0.020 inches and 0.060 inches. For example, the maximum width of each successive groove void 520 can be about 0.020 inches, about 0.021 inches, about 0.022 inches, about 0.023 inches, about 0.024 inches, about 0.025 inches, about 0.026 inches, about 0.027 inches, about 0.028 inches, about 0.029 inches, about 0.030 inches, about 0.031 inches, about 0.032 inches, about 0.033 inches, about 0.034 inches, about 0.035 inches, about 0.036 inches, about 0.037 inches, about 0.038 inches, about 0.039 inches, about 0.040 inches, about 0.041 inches, about 0.042 inches, about 0.043 inches, about 0.044 inches, about 0.045 inches, about 0.046 inches, about 0.047 inches, about 0.048 inches, about 0.049 inches, about 0.050 inches, about 0.051 inches, about 0.052 inches, about 0.053 inches, about 0.054 inches, about 0.055 inches, about 0.056 inches, about 0.057 inches, about 0.058 inches, about 0.059 inches, about 0.060 inches, about 0.061 inches, about 0.062 inches, about 0.063 inches, about 0.064 inches, about inch, about 0.040 inch, about 0.041 inch, about 0.042 inch, about 0.043 inch, about 0.044 inch, about 0.045 inch, about 0.046 inch, about 0.047 inch, about 0.048 inch, about 0.049 inch, about 0.050 inch, about 0.051 inch, about 0.052 inch, about 0.053 inch, about 0.054 inch, about 0.055 inch, about 0.056 inch, about 0.057 inch, about 0.058 inch, about 0.059 inch, or about 0.060 inch. The width of the continuous groove gap 520 at the first consecutive groove apex and the second consecutive groove apex is less than 0.0001 inch, and preferably 0 inch.

[0174] In many embodiments, each of the consecutive groove voids 512 of the plurality of consecutive groove voids may have a maximum length (measured in the heel 503-toe 502 direction) that is between 30% and 100% of the maximum length of the striking face 507. For example, each of the consecutive groove voids 512 may have a maximum length greater than 30% of the striking surface 507, greater than 35% of the striking surface 507, greater than 40% of the striking surface 507, greater than 45% of the striking surface 507, greater than 50% of the striking surface 507, greater than 55% of the striking surface 507, greater than 60% of the striking surface 507, greater than 65% of the striking surface 507, greater than 70% of the striking surface 507, greater than 75% of the striking surface 507, greater than 80% of the striking surface 507, greater than 85% of the striking surface 507, greater than 90% of the striking surface 507, or greater than 95% of the striking surface 507.

[0175] In many embodiments for controlling the relationship (or ratio) between the first material 509 and the second material 510, the width of successive groove voids decreases from the striking face imaginary vertical axis 520 to a width of effectively zero at a first successive groove apex, and / or decreases from the striking face imaginary vertical axis to a width of effectively zero at a second successive groove apex. This type of void configuration precisely controls the amount of land area (or second material area) between adjacent successive groove voids in the vertical direction, up to a predetermined first material-second material threshold.

[0176] In many of the continuous groove void embodiments, as described above, when the club head is in the address position, the striking face has a striking face imaginary vertical axis 520 that extends through the geometric center 508 of the striking face 507 in the upper rail-to-sole direction (as shown in FIG. 19). Additionally, corresponding vertical reference axes are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 503 and toe 502 directions.

[0177] 19, adjacent consecutive groove voids are closer to each other (i.e., closer packed and have smaller land areas between grooves) along striking face imaginary vertical axis 520 than they are along 0.25 inch vertical reference axis 521 and 0.5 inch vertical reference axis 522. Similarly, adjacent consecutive grooves are closer to each other (i.e., closer packed and have smaller land (or second material) areas between groove voids) along 0.25 inch vertical reference axis 521 than they are along 0.5 inch vertical reference axis 522.

[0178] In many of the continuous groove void embodiments, the percentage of the first material (or first material land area) along the 0.5 inch vertical reference axis can be about 20% to 40%. For example, the percentage of the first material along the 0.5 inch vertical reference axis can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Further, for example, the percentage of the first material along a 0.5 inch vertical reference axis may be greater than 20%, greater than 21%, greater than 22%, greater than 23%, greater than 24%, greater than 25%, greater than 26%, greater than 27%, greater than 28%, greater than 29%, greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, or greater than 39%. In alternative embodiments, the percentage of the first material along the 0.5 inch vertical reference axis may be less than 21%, less than 22%, less than 23%, less than 24%, less than 25%, less than 26%, less than 27%, less than 28%, less than 29%, less than 30%, less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, or less than 40%.

[0179] In many of the continuous groove void embodiments, the percentage of the first material (or first material land area) along the 0.25 inch vertical reference axis can be about 30% to 50%. For example, the percentage of the first material along the 0.25 inch vertical reference axis can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Further, for example, the percentage of the first material along the 0.25 inch vertical reference axis may be greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, greater than 39%, greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, or greater than 49%. In alternative embodiments, the percentage of the first material along the 0.25 inch vertical reference axis may be less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, less than 40%, less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, or less than 50%.

[0180] In many of the continuous groove void embodiments, the percentage of the first material (or first material land area) along the striking face imaginary axis can be between about 40% and 60%. For example, the percentage of the first material along the striking face imaginary axis can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Further, for example, the percentage of the first material along the striking face imaginary axis may be greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, greater than 49%, greater than 50%, greater than 51%, greater than 52%, greater than 53%, greater than 54%, greater than 55%, greater than 56%, greater than 57%, greater than 58%, or greater than 59%. In alternative embodiments, the percentage of the first material along the striking face imaginary axis may be less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, less than 50%, less than 51%, less than 52%, less than 53%, less than 54%, less than 55%, less than 56%, less than 57%, less than 58%, less than 59%, or less than 60%.

[0181] Additionally, in many embodiments, the average ratio, defined as the percentage surface area of ​​the first material land area to the percentage surface area of ​​the second material land area (measured along each vertical reference axis), decreases from the striking face imaginary vertical axis to the 0.5 inch vertical reference axis. This type of arrangement of the first and second materials helps provide consistent ball speeds across the striking face because the average ratio along the striking face imaginary vertical axis is greater (i.e., softer) than the average ratio along the 0.5 inch vertical reference axis. This counteracts energy transfer losses on heel and toe mishits.

[0182] (Separate air gap (vertical radiation pattern)) Figures 20-23 illustrate another exemplary embodiment. More specifically, Figures 20-23 illustrate an example of a putter-type golf club head 600 having a dual-material striking face 607 comprising a first material 609 and a second material 610. The golf club head 600 of Figures 20-23 is similar in many respects to the golf club heads 100, 200, 300, 400, and 500 described above, except that the golf club head 600 includes a separated void extending substantially in the upper rail-to-sole direction.

[0183] 20-23 may include a putter body (similar to the putter bodies described above) having a toe, a heel opposite the toe, a top rail, a sole opposite the top rail, a portion of a striking face, and a rear portion opposite the striking face portion. The striking face portion further defines a striking face recess defined by the heel, toe, top rail, sole, and rear portion of the putter body.

[0184] 20-23 illustrate a putter insert 624 comprising a first material 609 (which may also be referred to as a "first portion") and a second material 610 (which may also be referred to as a "second portion"). With specific reference to FIG. 20, the second portion forms (or defines) a plurality of separate concentric radial voids 612. Each of the separate concentric radial voids has a common center at the striking face geometric center 608.

[0185] The second material substantially surrounds the discrete concentric radial voids to form a second material land area. The first portion of the putter insert 624 includes a plurality of discrete concentric radial protrusions that complement the corresponding discrete concentric radial voids 612. By connecting the first and second portions together, the multiple protruding discrete concentric radial voids can be flush (i.e., coplanar) with the second material land area. This allows the multiple protruding discrete concentric radial voids to form a first material land area. The first material has a lower hardness than the second material. The first material land area and the second material land contact at least a portion of the golf ball upon golf ball impact.

[0186] This embodiment illustrates one possible arrangement in which the separate concentric radial voids are arranged such that their diameters increase outward from the striking face geometric center 608. This creates a denser, more compact central region that produces more of the first material land area than the second material land area. This arrangement produces a central region with a greater amount of the first material land area than the second material land area, thereby producing a central region that is less responsive to ball impacts relative to the heel or toe regions. The widths of the first material land areas in the upper rail-to-sole and heel-toe directions are substantially the same or constant.

[0187] Moving from the center region toward the heel or toe, the spacing between adjacent discrete concentric radial voids increases, creating more secondary material land area, which helps create progressively more responsive regions away from the center region toward the heel and toe regions for consistent ball speed control across the striking face.

[0188] 20, which shows a perspective view of a putter insert 624. In many embodiments, the putter insert 624 may be received within and complement the striking face recess. The putter insert 624 may include a front surface 625 adapted for impact with a golf ball (not shown) and a rear surface 626 opposite the front surface.

[0189] The putter insert thickness 627 may be defined as the maximum vertical distance between the front surface 625 and the rear surface 626. For example, Figure 20 shows an insert 624 having a plurality of discrete concentric radial voids 612 (defined by the second material) extending through the entire thickness of the second material 610. In many embodiments, the first material, the second material, and / or the combination of the first and second materials may be of a constant thickness.

[0190] Further, in many embodiments, as shown herein, first material 609 covers the entire rear surface 626 of insert 624. In other words, rear surface 626 is free of second material 610. In many embodiments, first material 609 further completely fills (or completely occupies) each discrete concentric radial void of the plurality of discrete concentric radial voids (to the point where it is flush with front surface 625 of the insert), such that at front surface 625, second material 610 surrounds first material 609, such that upon golf ball impact, first material 609 and second material 610 contact at least a portion of the golf ball.

[0191] In many embodiments, most of the separate concentric radial voids 612 extend perpendicular to the upper rail-to-sole direction and connect to both an upper boundary 618 of the striking face 607 and a lower boundary 619 of the striking face 607. In many embodiments where the separate concentric radial voids 612 are not connected to the upper or lower boundaries of the striking face, a support post 636 or a series of support posts 636 are required to directly or indirectly connect the separate concentric radial voids connected to the upper and lower boundaries of the striking face.

[0192] In many embodiments, the separate concentric radial voids 612 are concentric about the geometric center of the striking face and can be either circular or arc-shaped. The diameters of the separate concentric radial voids increase from the geometric center of the striking face to the toe and from the geometric center of the striking face to the heel. Stated another way, in many embodiments, the diameters of the separate concentric radial voids increase from the geometric center of the striking face to the upper boundary of the striking face and from the geometric center of the striking face to the lower boundary of the striking face.

[0193] As can be seen in Figures 20-23, not all of the separate concentric voids are directly connected to the upper and lower boundaries of the striking surface. One or more support posts 636 are required to ensure that the first material fills the separate concentric voids during the manufacturing process (i.e., molding), the separate concentric voids that are not directly connected to the upper and lower boundaries of the striking surface. As can be seen in combination with Figures 22 and 23, multiple support posts are recessed inward from the front surface 625 of the striking face 607. These support posts allow the separate concentric voids that are not connected to the upper and lower boundaries of the striking surface to be indirectly connected to one or more separate concentric voids that are connected to the upper and lower boundaries of the striking surface.

[0194] In alternative embodiments of the putter-type golf club head having separated concentric radial voids 612, the second material 610 may include one or more separated concentric radial voids 612, two or more separated concentric radial voids 612, three or more separated concentric radial voids 612, four or more separated concentric radial voids 612, five or more separated concentric radial voids 612, six or more separated concentric radial voids 612, seven or more separated concentric radial voids 612, eight or more separated concentric radial voids 612, nine or more separated concentric radial voids 612, ten or more separated concentric radial voids 612, eleven or more separated concentric radial voids 612, twelve or more separated concentric radial voids 612, thirteen or more separated concentric radial voids 612, fourteen or more separated concentric radial voids 612, or one or more separated concentric radial voids 612. Five or more separate concentric radial voids 612, sixteen or more separate concentric radial voids 612, seventeen or more separate concentric radial voids 612, eighteen or more separate concentric radial voids 612, nineteen or more separate concentric radial voids 612, twenty or more separate concentric radial voids 612, twenty-one or more separate concentric radial voids 612, twenty-two or more separate concentric radial voids 612, twenty-three or more separate concentric radial voids 612, twenty-four or more separate concentric radial voids 612, twenty-five or more separate concentric radial voids 612, twenty-six or more separate concentric radial voids 612, twenty-seven or more separate concentric radial voids 612, twenty-eight or more separate concentric radial voids 612, twenty-nine or more separate concentric radial voids 612, or thirty or more separate concentric radial voids 612 may be defined.

[0195] Each of the separate concentric radial voids 612 can have a constant width measured across the heel-toe direction. In many embodiments, the width of the plurality of separate concentric radial voids can range from 0.020 inches to 0.060 inches. For example, the width of the plurality of separate concentric radial voids can be about 0.020 inches, about 0.021 inches, about 0.022 inches, about 0.023 inches, about 0.024 inches, about 0.025 inches, about 0.026 inches, about 0.027 inches, about 0.028 inches, about 0.029 inches, about 0.030 inches, about 0.031 inches, about 0.032 inches, about 0.033 inches, about 0.034 inches, about 0.035 inches, about 0.036 inches, about 0.037 inches, about 0.038 inches, or about 0.039 inches. The width of the striking face 607 may be about 0.040 inch, about 0.041 inch, about 0.042 inch, about 0.043 inch, about 0.044 inch, about 0.045 inch, about 0.046 inch, about 0.047 inch, about 0.048 inch, about 0.049 inch, about 0.050 inch, about 0.051 inch, about 0.052 inch, about 0.053 inch, about 0.054 inch, about 0.055 inch, about 0.056 inch, about 0.057 inch, about 0.058 inch, about 0.059 inch, or about 0.060 inch. As further explained in the Examples section, variable width, variable depth, and / or variable thickness voids are not required to achieve consistent ball velocity across the striking face 607.

[0196] In many of the split concentric radial void embodiments, as described above, when the club head is in the address position, the striking face has a striking face imaginary vertical axis 620 that extends through the geometric center 608 of the striking face 607 in the upper rail-to-sole direction (as shown in FIG. 21 ). Additionally, corresponding vertical reference axes are offset from the striking face imaginary vertical axis by 0.25 inches and 0.50 inches in both the heel 603 and toe 602 directions.

[0197] As further shown in FIG. 21 , adjacent, separated concentric radial voids are closer to each other (i.e., closer packed and have smaller land (or second material) areas between the voids) along the striking face imaginary vertical axis 620 than they are along the 0.25 inch vertical reference axis 621 and the 0.5 inch vertical reference axis 622. Similarly, adjacent, separated concentric radial voids are closer to each other (i.e., closer packed and have smaller land (or second material) areas between the voids) along the 0.25 inch vertical reference axis 621 than they are along the 0.5 inch vertical reference axis 622.

[0198] In many of the embodiments of the separated concentric radial voids, the percentage of the first material (or first material land area) along the 0.5 inch vertical reference axis can be about 20% to 40%. For example, the percentage of the first material along the 0.5 inch vertical reference axis can be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Further, for example, the percentage of the first material along a 0.5 inch vertical reference axis may be greater than 20%, greater than 21%, greater than 22%, greater than 23%, greater than 24%, greater than 25%, greater than 26%, greater than 27%, greater than 28%, greater than 29%, greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, or greater than 39%. In alternative embodiments, the percentage of the first material along the 0.5 inch vertical reference axis may be less than 21%, less than 22%, less than 23%, less than 24%, less than 25%, less than 26%, less than 27%, less than 28%, less than 29%, less than 30%, less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, or less than 40%.

[0199] In many of the embodiments of the separated concentric radial voids, the percentage of the first material (or first material land area) along the 0.25 inch vertical reference axis can be about 30% to 50%. For example, the percentage of the first material along the 0.25 inch vertical reference axis can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Further, for example, the percentage of the first material along the 0.25 inch vertical reference axis may be greater than 30%, greater than 31%, greater than 32%, greater than 33%, greater than 34%, greater than 35%, greater than 36%, greater than 37%, greater than 38%, greater than 39%, greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, or greater than 49%. In alternative embodiments, the percentage of the first material along the 0.25 inch vertical reference axis may be less than 31%, less than 32%, less than 33%, less than 34%, less than 35%, less than 36%, less than 37%, less than 38%, less than 39%, less than 40%, less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, or less than 50%.

[0200] In many of the separate concentric radial void embodiments, the percentage of the first material (or first material land area) along the striking surface imaginary axis can be approximately 40% to 60%. For example, the percentage of the first material along the striking surface imaginary axis can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Further, for example, the percentage of the first material along the striking face imaginary axis may be greater than 40%, greater than 41%, greater than 42%, greater than 43%, greater than 44%, greater than 45%, greater than 46%, greater than 47%, greater than 48%, greater than 49%, greater than 50%, greater than 51%, greater than 52%, greater than 53%, greater than 54%, greater than 55%, greater than 56%, greater than 57%, greater than 58%, or greater than 59%. In alternative embodiments, the percentage of the first material along the striking face imaginary axis may be less than 41%, less than 42%, less than 43%, less than 44%, less than 45%, less than 46%, less than 47%, less than 48%, less than 49%, less than 50%, less than 51%, less than 52%, less than 53%, less than 54%, less than 55%, less than 56%, less than 57%, less than 58%, less than 59%, or less than 60%.

[0201] Additionally, in many embodiments, the average ratio, defined as the percentage surface area of ​​the first material land area to the percentage surface area of ​​the second material land area (measured along each vertical reference axis), decreases from the striking face imaginary vertical axis to the 0.5 inch vertical reference axis. This type of arrangement of the first and second materials helps provide consistent ball speeds across the striking face because the average ratio along the striking face imaginary vertical axis is greater (i.e., softer) than the average ratio along the 0.5 inch vertical reference axis. This counteracts energy transfer losses on heel and toe mishits.

[0202] Example 1 Example 1 shows that both the length of the putt and the percentage of vertical land area are important factors to consider in selecting a threshold or desired ball speed across the striking face. This example generally corresponds to the continuous groove embodiment of Figures 1-9.

[0203] 4 shows a seven-variable gradient map detailing the vertical required land area percentage (or second material percentage) required for various impact locations to achieve a consistent ball speed for a putt approximately 10 feet in length. For example, if a required ball speed for a 10-foot putt of 5.15 mph is required, the second material vertical land area percentage at a vertical reference axis 122 offset 0.5 inches from the striking face imaginary vertical axis 120 is approximately 76%. The second material vertical land area percentage at a vertical reference axis 121 offset 0.25 inches from the striking face imaginary vertical axis 122 is approximately 58%. The second material vertical land area percentage at the striking face imaginary vertical axis 120 is approximately 53%.

[0204] If a required ball speed for a 10 ft putt of 5.10 mph is required, the percentage of the second material vertical land area at a vertical reference axis 122 offset by 0.5 inches from the striking face imaginary vertical axis 120 is approximately 73%. The percentage of the second material vertical land area at a vertical reference axis 121 offset by 0.25 inches from the striking face imaginary vertical axis 120 is approximately 55%. The percentage of the second material vertical land area at the striking face imaginary vertical axis 120 is approximately 50%.

[0205] If a required ball speed for a 10 ft putt of 5.05 mph is required, the percentage of the second material vertical land area at a vertical reference axis 122 offset by 0.5 inches from the striking face imaginary vertical axis 120 is approximately 67%. The percentage of the second material vertical land area at a vertical reference axis 121 offset by 0.25 inches from the striking face imaginary vertical axis 120 is approximately 50%. The percentage of the second material vertical land area at the striking face imaginary vertical axis 120 is approximately 46%.

[0206] Further, for example, Figure 5 shows another seven-variable gradient map detailing the required land area needed to achieve a consistent ball speed for a putt approximately 25 feet in length for various impact locations. If a required ball speed for a 25-foot putt of 7.73 mph is required, the second material vertical land area percentage at a vertical reference axis 122 offset 0.5 inches laterally from the striking face imaginary vertical axis 120 is approximately 65%. The second material vertical land area percentage at a vertical reference axis 121 offset 0.25 inches laterally from the striking face imaginary vertical axis 120 is approximately 58%. The second material vertical land area percentage at the striking face imaginary vertical axis 120 is approximately 55%.

[0207] If a required ball speed for a 25 ft putt of 7.68 mph is required, the percentage of the second material vertical land area at a vertical reference axis 122 that is 0.5 inches laterally offset from the striking face imaginary vertical axis 120 is approximately 60%. The percentage of the second material vertical land area at a vertical reference axis 121 that is 0.25 inches laterally offset from the striking face imaginary vertical axis 120 is approximately 56%. The percentage of the second material vertical land area at the striking face imaginary vertical axis 120 is approximately 53%.

[0208] If a required ball speed for a 25 ft putt of 7.60 mph is required, the percentage of the second material vertical land area at a vertical reference axis 122 that is 0.5 inches laterally offset from the striking face imaginary vertical axis 120 is approximately 55%. The percentage of the second material vertical land area at a vertical reference axis 121 that is 0.25 inches laterally offset from the striking face imaginary vertical axis 120 is approximately 51%. The percentage of the second material vertical land area at the striking face imaginary vertical axis 120 is approximately 48%.

[0209] The seven variable gradient maps of Figures 4 and 5 are based on a first material generally comprised of air and a second material generally comprised of a metal, such as 17-4 stainless steel. The ratio or relationship between the first material and the second material varies based on the type of material selected, but the application of controlling the ratio or relationship between the first material and the second material is still applied to achieve a consistent ball speed.

[0210] Example 2 For many of the above-described embodiments, the hardness of the first material and the percentage characteristics of the first material land area were varied to fully understand the effect these variables have on ball speed. Specifically, putter pendulum testing was performed to measure ball speed for 10 putters. The table below shows the material characteristics of exemplary striking surfaces tested. Ball speed data was taken at the striking surface imaginary vertical axis, a 0.5 inch heel vertical reference axis, and a 0.5 inch toe vertical reference axis.

[0211] The exemplary striking face was further benchmarked against a first commercially available putter (Putter 1) with polymer-filled grooves but with grooves that were not less spaced in the center, a second commercially available putter (Putter 2) with a greater groove concentration in the center but without the second material, and a third commercially available putter (Putter 3) with a striking face without grooves. The results can be seen in Figures 24-26, where the data was plotted as a percentage of ball speed relative to its center for 10-foot, 25-foot, and 40-foot putts. [Table 1]

[0212] The results indicate that the hardness of the first material, the hardness of the second material, and the proportion of the first material along the vertical reference axis at a defined location are important factors to consider when uniform ball velocity across the entire striking face is required. For example, when comparing the characteristics of the Separate Void (Tablet Shape) Revision 3A and Separate Void (Tablet Shape) Revision 3B putters, it can be seen that the putters were constructed identically except for the difference in the hardness of the first material. In a 25-foot putting comparison, it can be seen that the ball velocity at heel and toe hits (relative to center impact) for the Separate Void (Tablet Shape) Revision 3A putter varied approximately 1.6% more than the ball velocity generated at the center of the striking face. However, the Separate Void (Tablet Shape) Revision 3B putter varied only 0.8% more than the ball velocity generated at the center of the striking face. This led to the conclusion that the relationship / difference between the hardness of the first and second materials is an important factor to consider when effectively controlling ball velocity.

[0213] Furthermore, this example led to the conclusion that the percentage of the first material along the vertical reference axis (at a defined location) is important. For example, when comparing the Separate Void (Tablet Shape) Revision 4A putter with the Separate Void (Circular Shape) putter, the hardness of the first and second materials was substantially the same, but the percentage of the first material along the striking face varied. During off-center impacts, the Separate Void (Tablet Shape) Revision 4 putter generated only 0.4% more ball velocity than the ball velocity generated at the center of the striking face. The Separate Void (Circular Shape) changed approximately 0.8% more ball velocity during off-center impacts compared to the ball velocity generated at the center of the striking face. Therefore, when controlling the ball velocity generated across the striking face, the percentage of the first material along the vertical reference axis is another important variable that helps create a uniform heel-toe hitting face.

Claims

1. A putter-type golf club head, It has a main body, The body includes: Heels and a toe opposite the heel; The upper rail and a sole opposite the upper rail; a striking face having a striking surface adapted for impact with a golf ball; a striking face first imaginary vertical axis extending through a geometric center of the striking face in an upper rail-sole direction; a striking surface second imaginary vertical axis and a striking surface third imaginary vertical axis extending in the upper rail-sole direction and offset from the geometric center by 0.5 inches in the heel-toe direction, the striking face defines a first plurality of continuous groove recesses extending between the heel and the toe and forming a non-ball contacting area of ​​the striking surface; each successive groove recess of the first plurality of successive groove recesses includes an arcuate portion extending transverse to the striking face first imaginary vertical axis; each successive groove recess of the first plurality of successive groove recesses includes a first linear portion proximate the heel and a second linear portion proximate the toe; a width of each consecutive groove recess of the first plurality of consecutive groove recesses measured in the upper rail-sole direction is constant across the striking face in the heel-toe direction; a spacing between adjacent groove recesses of the first plurality of consecutive groove recesses measured in the upper rail-sole direction increases in a direction from the striking face first imaginary vertical axis toward at least one of the heel and the toe; the striking face further includes a second plurality of consecutive groove recesses and a third plurality of consecutive groove recesses that are arcuate consecutive groove recesses extending transverse to the striking face first imaginary vertical axis, each consecutive groove recess of the second and third pluralities of consecutive groove recesses being arcuate and having a first end and a second end; the first and second ends of each consecutive groove recess of the second plurality of consecutive groove recesses are connected to a striking face upper boundary; the first and second ends of each consecutive groove recess of the third plurality of consecutive groove recesses connect to a striking face lower boundary; there are more contiguous groove recesses within the area bounded by the second and third imaginary perpendicular axes than outside the area bounded by the second and third imaginary perpendicular axes; the striking face comprises a first material having a first hardness and a second material having a second hardness; A putter-type golf club head, wherein the first material at least partially fills each consecutive groove recess of the first, second and third pluralities of consecutive groove recesses.

2. the first material comprises a polymer; The putter-type golf club head of claim 1 , wherein the second material comprises a metal.

3. The putter-type golf club head according to claim 1 or 2, wherein the putter-type golf club head has a loft angle of less than 7 degrees.

4. 4. The putter-type golf club head according to claim 1, wherein the spacing between adjacent groove recesses of the first plurality of consecutive groove recesses is smallest at the striking face first imaginary vertical axis.

5. 5. The putter-type golf club head of claim 4, wherein the spacing between adjacent groove recesses of the first plurality of consecutive groove recesses is greater at the striking face second imaginary vertical axis than at the striking face first imaginary vertical axis.

6. A putter-type golf club head, It has a main body, The body includes: Heels and a toe opposite the heel; The upper rail and a sole opposite the upper rail; a striking face having a striking surface adapted for impact with a golf ball; a striking face first imaginary vertical axis extending through a geometric center of the striking face in an upper rail-sole direction; a striking surface second imaginary vertical axis and a striking surface third imaginary vertical axis extending in the upper rail-sole direction and offset from the geometric center by 0.5 inches in the heel-toe direction, the striking face defines a first plurality of continuous groove recesses extending between the heel and the toe and forming a non-ball contacting area of ​​the striking surface; each successive groove recess of the first plurality of successive groove recesses includes an arcuate portion extending transverse to the striking face first imaginary vertical axis; each successive groove recess of the first plurality of successive groove recesses includes a first linear portion proximate the heel and a second linear portion proximate the toe; a width of each consecutive groove recess of the first plurality of consecutive groove recesses measured in the upper rail-sole direction is constant across the striking face in the heel-toe direction; a spacing between adjacent groove recesses of the first plurality of consecutive groove recesses measured in the upper rail-sole direction increases in a direction from the striking face first imaginary vertical axis toward at least one of the heel and the toe; there are more contiguous groove recesses within the area bounded by the second and third imaginary perpendicular axes than outside the area bounded by the second and third imaginary perpendicular axes; the striking face comprising a first material and a second material; the first material comprises a polymer that at least partially fills each consecutive groove recess of the first plurality of consecutive groove recesses; The putter-type golf club head, wherein the second material comprises a metal.

7. 7. The putter-type golf club head of claim 6, wherein the first material has a first hardness and the second material has a second hardness.

8. 8. The putter-type golf club head according to claim 6, wherein the putter-type golf club head has a loft angle of less than 7 degrees.

9. 9. The putter-type golf club head of claim 6, wherein the striking face further comprises a second plurality of consecutive groove recesses and a third plurality of consecutive groove recesses extending transverse to the striking face first imaginary vertical axis, and each consecutive groove recess of the second and third pluralities of consecutive groove recesses is arcuate.

10. 10. The putter-type golf club head of claim 9, wherein the spacing between adjacent groove recesses of the first plurality of consecutive groove recesses is greater on the striking face second imaginary vertical axis and the striking face third imaginary vertical axis than on the striking face first imaginary vertical axis.

11. A putter-type golf club head, It has a main body, The body includes: Heels and a toe opposite the heel; The upper rail and a sole opposite the upper rail; a striking face having a striking surface adapted for impact with a golf ball; a striking face first imaginary vertical axis extending through a geometric center of the striking face in an upper rail-sole direction; a striking surface second imaginary vertical axis and a striking surface third imaginary vertical axis extending in the upper rail-sole direction and offset from the geometric center by 0.5 inches in the heel-toe direction, the striking face defines a first plurality of continuous groove recesses extending between the heel and the toe and forming a non-ball contacting area of ​​the striking surface; each successive groove recess of the first plurality of successive groove recesses includes an arcuate portion extending transverse to the striking face first imaginary vertical axis; each successive groove recess of the first plurality of successive groove recesses includes a first linear portion proximate the heel and a second linear portion proximate the toe; the arcuate portion of each successive groove recess of the first plurality of successive groove recesses is disposed between the first linear portion and the second linear portion; a width of each consecutive groove recess of the first plurality of consecutive groove recesses measured in the upper rail-sole direction is constant across the striking face in the heel-toe direction; a spacing between adjacent groove recesses of the first plurality of consecutive groove recesses measured in the upper rail-sole direction increases in a direction from the striking face first imaginary vertical axis toward at least one of the heel and the toe; the striking face further includes a second plurality of consecutive groove recesses and a third plurality of consecutive groove recesses extending transverse to the striking face first imaginary vertical axis, each consecutive groove recess of the second and third pluralities of consecutive groove recesses being arcuate and including a first end and a second end; the first and second ends of each consecutive groove recess of the second plurality of consecutive groove recesses are connected to a striking face upper boundary; the first and second ends of each consecutive groove recess of the third plurality of consecutive groove recesses connect to a striking face lower boundary; The putter-type golf club head, wherein the striking face comprises a polymeric material at least partially filling each consecutive groove recess of the first, second and third pluralities of consecutive groove recesses, and a metallic material.

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