Golf club head with a multi-material striking surface

Abstract

It is necessary to create a putter-type golf club head that balances the golfer's personal preferences and characteristics while considering various impact points. [Solution] Embodiments of a putter-type golf club head 300 are described herein, having a striking surface capable of achieving constant ball velocity across the entire striking surface in order to take into account various ball impact locations. The striking surface 307 has at least two materials 309, 310 with different concentrations away from the geometric center of the striking surface in order to provide this constant velocity. The constant (or uniform) ball velocity is achieved through the striking surface because a portion of the golf ball in contact with the striking surface interacts with at least two materials having different material properties.

Description

[Technical Field]

[0001] This disclosure relates, in general terms, to a golf club head, and more particularly to a putter-type golf club head having a multi-material striking surface. Related application data

[0002] This asserts the interests of U.S. Provisional Patent Application No. 62 / 881,463, filed on 1 August 2019, and U.S. Provisional Patent Application No. 63 / 046,505, filed on 30 June 2020, all of which are incorporated herein in full by reference. [Background technology]

[0003] Because golf clubs are the only instruments that move 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 the design of putter-type club heads, it is known that golfers tend to prioritize personal preference features (i.e., the feel of the club head, the aesthetics of the club head, the sound of the club head, etc.) over performance.

[0004] To putt a golf ball into a hole, a golfer must impact the ball (with the golf club head, more specifically, with a putter-type golf club head) with the correct speed and face angle. This presents a challenge for all golfers, as many struggle to consistently impact the ball in the same spot every time they putt. Impacting the golf ball at different points on a putter-type club head can alter the amount of energy transferred from the putter head to the golf ball during the initial contact, the feel of the impact, the sound of the impact, and / or the direction of the golf ball's movement. In this field, it is necessary to produce putter-type golf club heads that balance the personal preference characteristics of golfers while taking into account various impact locations. [Brief explanation of the drawing]

[0005] [Figure 1] Shows a perspective view of the heel side of a hitting surface having continuous grooves for a non-insert style club head according to one embodiment.

[0006] [Figure 2] Shows the face of the hitting surface diagram of FIG. 1.

[0007] [Figure 3] Shows a close-up face of the hitting surface diagram of FIG. 2.

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

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

[0010] [Figure 6] Shows an exploded view of a hitting surface having continuous grooves for an insert style club head according to one embodiment.

[0011] [Figure 7] Shows a partial assembly view of a hitting surface having continuous grooves of FIG. 6.

[0012] [Figure 8] Shows the face of the hitting surface diagram of FIG. 6.

[0013] [Figure 9] Shows the face of the hitting surface diagram of FIG. 7.

[0014] [Figure 10] Shows a partial assembly view of a hitting surface having separated tablet-shaped voids for an insert style club head according to one embodiment.

[0015] [Figure 11] Figure 10 shows the face of the striking surface.

[0016] [Figure 12] Another face of the striking surface having a separated tablet-shaped void for an insert-style clubhead according to one embodiment is shown in the diagram.

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

[0018] [Figure 14] This diagram shows a partial assembly of a striking surface having a separated hexagonal gap for an insert-style club head according to one embodiment.

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

[0020] [Figure 16] Figure 14 shows the assembly face of the diagram.

[0021] [Figure 17] This shows a perspective view of the heel side of the striking surface having continuous grooves for an insert-style club head according to one embodiment.

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

[0023] [Figure 19] Figure 17 shows the assembly face of the diagram.

[0024] [Figure 20] This shows an exploded view of an insert with separated concentric radiating gaps.

[0025] [Figure 21] Figure 20 shows the assembly face of the insert diagram.

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

[0027] [Figure 23] Figure 22 shows a cross-sectional view.

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

[0029] [Figure 25] The bar graph shows a comparison of ball speed and ball impact location for various exemplary putter embodiments for a 25-foot putt.

[0030] [Figure 26] The bar graph shows a comparison of ball speed and ball impact location for various exemplary putter embodiments for a 25-foot putt. [Modes for carrying out the invention]

[0031] The subject of this specification is a golf club head, and more particularly, a putter-type golf club head having a striking surface capable of achieving constant ball velocity across the entire striking surface to account for various ball impact locations. To provide this constant velocity, the striking surface has at least two materials with different concentrations away from the geometric center (or central region) of the striking surface. The constant (or uniform) ball velocity is achieved through the striking surface because a portion of the golf ball in contact with the striking surface interacts with at least two materials having different material properties (or characteristics).

[0032] Different material properties can be (though this is not an exhaustive list) tensile strength, flexibility modulus, or material hardness. Uniform ball velocity is achieved by a combination of dual-material striking surfaces and by varying the amounts of the first and / or second material away from the geometric center (or central region) of the striking surface. 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 clubhead sweet spot) of the striking surface results in less energy transfer from the clubhead to the golf ball.

[0033] The creation of a central region that is less responsive than the corresponding heel and toe regions can be achieved in several ways. For example, in embodiments where a first soft material is dominant 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 form a larger first material land area in the central region than in the adjacent heel and toe regions.

[0034] As used herein, the term or phrase “lie angle” may be defined as the angle between the golf shaft (not shown) and the playing surface when the sole of the club head is in contact with 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 “integrated” may be defined as two or more elements that are composed of the same piece of material. Two or more elements are “not integrated” if, as defined herein, each element is composed of a different piece of material.

[0036] As used herein, the terms or phrases “connected,” “to be connected,” “to link,” and “connected” may be defined as the mechanical or otherwise binding of two or more elements. A connection (whether mechanical or otherwise) can be of any length of time, for example, permanent, semi-permanent, or only for a moment. Mechanical connection, etc., should be understood broadly and include all types of mechanical connection. The absence of words such as “removably” or “removable” around words such as “to be connected” does not mean that the connection in question is removable or not removable.

[0037] As used herein, the terms or phrases “head weight” or “head mass” may be defined as the total mass or weight of the putter.

[0038] As used herein, the terms or phrases “attachment,” “to be attached,” “to attach,” and “attaching” may be defined as a connection or joint to something. Attachments may be permanent or semi-permanent. Mechanical attachments, etc., should be understood broadly and include all types of mechanical attachments. Integrated attachments should be understood broadly and include all types of integrated attachments that permanently connect two or more objects together.

[0039] As used herein, the term or phrase “loft angle” may be defined as the angle between the striking surface and the golf shaft. In other embodiments, the loft angle may be defined herein as the striking surface comprising a striking surface center point and a loft plane. The striking surface 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 surface of a putter-type golf club head. The golf shaft has a central axis extending along the entire length of the golf shaft. The loft angle is between the central 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 surface and the golf shaft (not shown) when the centerline of the golf shaft is generally perpendicular (i.e., forming an angle of approximately 90° with respect to the playing surface).

[0040] Where terms such as “first,” “second,” “third,” and “fourth” appear in the specification and claims, they are used to distinguish between similar elements and not necessarily to describe a specific sequential or chronological order. It should be understood that such terms are interchangeable under appropriate circumstances so that the embodiments described herein may operate in an order other than, for example, those illustrated or otherwise described herein. Furthermore, the terms “includes” and “have,” and any variations thereof, are intended to include non-exclusive inclusion; therefore, a process, method, system, article, device, or apparatus containing a list of elements is not necessarily limited to those elements and may include other elements not explicitly listed or specific to such process, method, system, article, device, or apparatus.

[0041] Where terms such as “left,” “right,” “front,” “rear,” “top,” “bottom,” “up,” and “down” appear in the specification and claims, they are used for descriptive purposes and not necessarily to describe permanent relative positions. It should be understood that such terms are interchangeable under appropriate circumstances so that embodiments of the apparatus, methods, and / or articles of manufacture described herein may operate in orientations other than those illustrated or otherwise described herein.

[0042] The term “central region” can be defined as the region on the striking surface that contains the geometric center. The central region extends from the upper boundary to the lower boundary of the striking surface and may have a heel-to-touch 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 region on the striking surface (and / or club head) extending from the heel end to the heel-side boundary of the central region. The term "toe region" may be defined as the region on the striking surface (and / or club head) extending from the toe end to the toe-side boundary of the central region.

[0044] The terms “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate that there is at least one item, and that there may be multiple such items unless the context explicitly indicates otherwise. All numerical values ​​of parameters (e.g., of quantity or condition) in this specification, including the appended claims, should be understood in all cases as being 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 inaccuracy (some proximity to the exact value, about, or reasonably close to the value, approximately). Where the inaccuracy provided by “about” is not understood in the art in this ordinary sense in other cases, “about” as used herein indicates at least the variation that may arise from the ordinary methods of measuring and using the parameter. In addition, the disclosure of a range includes the disclosure of all values, and even divided ranges within the whole range. Each value within a range and the endpoints of the range are all disclosed herein as separate embodiments. The terms “comprises,” “comprising,” “including,” and “having” are inclusive and therefore presuppose the existence of the item being described, but do not presuppose the existence 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,” and “third” are used to distinguish different items from one another, these designations are for convenience only and do not limit the items.

[0045] In many instances, 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 velocity, spin direction, etc.) to one or more other values, ranges of values, or parameters, and / or when describing conditions (e.g., with respect to time), such as conditions that remain constant with respect to time. In these instances, the use of the word “about” may mean that a value, range of values, relationship, parameter, or condition is applicable within ±0.5%, ±1.0%, ±2.0%, ±3.0%, ±5.0%, and / or ±10.0% of the related value, range of values, relationship, parameter, or condition.

[0046] Before describing any embodiment of this disclosure in detail, it should be understood that this disclosure is not limited to the structural details and configurations described or shown in the following drawings in its applications. Other embodiments of this disclosure are possible and can be implemented or performed in a variety of ways.

[0047] This specification presents a putter-type golf club head having multiple striking surfaces capable of achieving constant ball velocity across the entire striking surface in order to account for various ball impact locations. In many embodiments, the putter-type golf club head described herein includes a putter body having a dual-material striking surface having a first material and a second material. The first and second materials have varying concentrations away from the geometric center of the striking surface in the heel-toe direction in order to provide constant ball velocity.

[0048] For example, in many embodiments, the proportions (or relationship) of the first and second materials differ to take into account where the ball might impact the striking surface (i.e., towards the toe, heel, or center). Changes in the material relationship of the striking surface directly correlate 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 to 23 show exemplary embodiments of a putter-type golf club head having a multi-material striking surface that allows for control of ball velocity across the entire striking surface, while taking into account the feel and sound of impact at the time of ball impact.

[0050] (2. Loft angle) In many embodiments, a 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 320 to 385 grams. In other embodiments, a putter-type golf club head may be in the range of 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, 3 It could 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 material for a putter-type golf club head can be constructed from any material used to construct conventional club heads. For example, the material for a putter-type golf club head can be any one or a 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 alloys, or any metal or combination of metals used to produce a golf club head. In other embodiments, a putter-type golf club head can be constructed from a non-metallic material such as thermoplastic polyurethane material, thermoplastic elastomer, and / or thermoplastic composite material.

[0053] (1. Composition and mechanism of putter-type golf club heads) In many embodiments, a putter-type golf club head comprises a club head body (which may also be referred to as the “body” or “putter body”). The club head body comprises a toe, a heel, an upper rail, a sole, a striking surface (or part of the striking surface), and a rear section. The striking surface may provide a surface that conforms to the impact with the golf ball. The rear section is spaced rearward from the striking surface. The sole is located between the striking surface and the rear section and is defined as being stationary on the ground (or playing surface) in the address position. The upper rail may be formed on the opposite side of the sole. The striking surface is defined by the sole, the upper rail, the heel, and the toe on the opposite side of the heel.

[0054] As described above, in many embodiments, a putter-type golf club head may be configured to be in the “address position.” Unless otherwise 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 described as (1) the sole of the putter-type golf club head being stationary on the ground it is contacting and 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. Hitting surface) In many embodiments, the striking surface may be defined by at least the toe, heel, upper rail, and sole of the putter body. Furthermore, as previously mentioned, the striking surface may comprise a multi-material striking surface. For example, the striking surface may include at least a first material and a second material that cooperate to make contact with the golf ball when the golf ball impacts the striking surface, having specific material properties for normalizing the ball velocity across the entire 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 may be softer, more flexible, and more deformable than the second material. In other embodiments, the second material may be harder, less flexible, and not deformable than the first material. In many embodiments, the second material may surround, face, and cover the first material.

[0057] (3. Material characteristics of the first material) The first material of the striking surface may vary based on the selection of the second material, since the second material covers the majority of the striking surface. In many embodiments, the first material may be defined by certain material properties, such as (but not limited to) the hardness, tensile strength, bending modulus, or specific gravity of the material.

[0058] The hardness of the first material is generally softer than that of the second material. In many embodiments, the hardness of the first material may have a Shore A value that varies between 30A and 95A. In some embodiments, the hardness of the first material may have a Shore A hardness value between 30-40A, 40A-50A, 50A-60A, 70A-80A, 80A-90A, or 90A-95A. In alternative embodiments, the hardness of the first material may have 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 have a Shore A of 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, 62 It may have a Shore A hardness of A, 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, or 95A.

[0059] The tensile strength of the first material is generally less than that of the second material. The tensile strength of the first material may be between 0.5 MPa and 50 MPa. In many embodiments, the tensile strength of the first material may 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 between 45.5 MPa and 50 MPa. In alternative embodiments, the tensile strength of the first material may 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 may 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 bending ratio of the first material is generally smaller than that of the second material. The bending ratio of the first material can be between 0.5 MPa and 90 MPa. In many embodiments, the bending ratio 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 bending ratio of the first material may 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 specific embodiments, the bending ratio of the first material may 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 may be the same as) that of the second material. The specific gravity of the first material may be between 0.5 and 2. In many embodiments, the specific gravity of the first material may 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 may be less than 2, less than 1.5, or less than 1.0.

[0062] The first material generally consists of a substantially non-metallic material, more preferably a polymer material. For example, in many embodiments, the first material may be formed from elastomers, polyurethanes, thermoplastic elastomers, thermosetting elastomers, thermoplastic polyurethanes, thermosetting polyurethanes, viscoelastic materials, urethanes, other polymers, other polymer materials having metal-doped portions, or combinations thereof. In many embodiments, the first material is selected from one of the categories listed above so as to satisfy one or more of the material characteristics listed above.

[0063] (4. Description of the material properties of the second material) The second material of the striking surface 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 properties, (but not limited to) the hardness, tensile strength, bending coefficient, and specific gravity of the material.

[0064] The hardness of the second material is generally greater than that 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–70D, 70D–80D, 80D–90D, or 90D–100D. In alternative embodiments, the hardness of the second material may have a Shore D hardness between 60D–65D, 65D–70D, 70D–75D, 75D–80D, 80D–85D, 85D–90D, 90D–95D, or 95D–100D. In additional embodiments, the hardness of the second material may have a Shore D hardness 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 that 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 may be approximately 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 may be 141 MPa, 241 MPa, 341 MPa, 441 MPa, 541 MPa, 641 MPa, 741 MPa, 841 MPa, or 941 MPa.

[0066] The bending ratio of the second material is generally higher than that of the first material. The bending ratio of the second material can be between 0.5 MPa and 300 MPa. In many embodiments, the bending ratio 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, and 95 MPa. It may be between 100 MPa and 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 between 290 MPa and 300 MPa. In alternative embodiments, the bending coefficient 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 bending coefficients of the second material are approximately 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, and 110.1 MPa. The pressures are 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) that 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 may 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 consist of substantially non-metallic or metallic materials. For example, in many embodiments, the second material may be formed from non-metallic materials (i.e., elastomers, polyurethanes, thermoplastic elastomers, thermosetting elastomers, thermoplastic polyurethanes, thermosetting polyurethanes, viscoelastic materials, urethanes, other polymers, other polymer materials having metal-doped portions, or combinations thereof). In alternative embodiments, the second material may be constructed from metallic materials. For example, the second material may be constructed from one or a 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 alloys, tungsten, aluminum, aluminum alloys, ADC-12, titanium, or titanium alloys. In many embodiments, the second material is selected from one of the categories listed above so as to satisfy one or more of the material characteristics listed above.

[0069] (5. Arrangement of the first and second materials) In many embodiments, the second material may define a plurality of recesses or voids resembling any shape. The characteristics of the recesses or voids formed by the second material (i.e., outline, shape, dimensions, and spacing) may vary for the desired performance, aesthetic, and tactile properties to be achieved. For example, in many embodiments, the second material may define a plurality of separate voids or recesses that generally define tablet shapes, hexagonal shapes, segmented hexagonal shapes, circular shapes, rectangular shapes, triangular shapes, pentagonal shapes, octagonal shapes, curved shapes, diamond shapes, and / or trapezoidal shapes. In alternative embodiments, the second material may form a sequence of voids or recesses that may generally be defined by one or more consecutive curved grooves, one or more consecutive arched grooves, one or more consecutive arc grooves, one or more consecutive straight grooves, or one or more combinations thereof.

[0070] The first material may be configured to fill, partially fill, be present in, occupy, and / or supplement one or more of the multiple separate 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 above-mentioned multiple voids or recesses. In alternative embodiments, the first material may fill, partially fill, be present in, and / or supplement one or more of the above-mentioned continuous voids or recesses. In embodiments where the first material partially fills the multiple recesses or voids, air may occupy the remaining unfilled portion.

[0071] The first and second materials may be configured to cooperate with each other to generate different material feature regions. 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 more flexible 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. Generating a central region that is more flexible, deformable, softer, and / or less responsive than the adjacent heel and toe regions generates more uniform ball velocity and perceptual feedback features (i.e., impact sound, impact feel, impact feedback, etc.) across the striking surface.

[0072] The creation of a central region that is less responsive than the corresponding heel and toe regions can be achieved in several ways. For example, in embodiments where a first soft material is dominant 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 form 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 to 5 show exemplary embodiments. More specifically, Figures 1 to 3 show an example of a putter-type golf club head 100 having a dual-material striking surface 107 having a first material 109 and a second material 110. The putter-type golf club head comprises a putter body 101 having a toe 102, a heel 103 opposite the toe 102, an upper rail 104, a sole 105 opposite the upper rail 104, a portion of the striking surface 107, and a rear portion 106 opposite the striking surface 107.

[0074] Furthermore, Figures 1 to 3 show the striking surface 107 of the putter body 100, which forms a plurality of consecutive groove recesses 112. These consecutive groove recesses 112 can separate the striking surface 107 into a land area of ​​the second material that forms the ball contact surface and a consecutive groove area that forms the ball non-contact surface (at the time of golf ball impact). Whether the entire surface is arched or through a combination of consecutive recesses having arched sections, the ratio of the ball contact surface to the ball non-contact surface may vary across the striking surface 107, but a constant ball velocity at impact can be generated across the entire striking surface.

[0075] For example, Figure 2 shows one possible arrangement in which each of the arc-shaped portions of the continuous groove recesses 112 is positioned to form a denser, more packed central region. This results in a central region that is less responsive to ball impact than areas (or regions) further away from the central region (i.e., towards the heel or toe) because there are more continuous groove areas (non-ball contact surfaces) than ball contact surfaces. Furthermore, there are overall arc-shaped recesses (also referred to as semicircular recesses) to increase the amount of continuous recesses (non-ball contact surfaces) to create a more densely packed central region toward the upper rail and sole (at the center of the striking face). These semicircular recesses are absent as you move away from the central region and are not present at the heel and toe ends. The arrangement may be progressive from the center of the striking surface to the heel end and / or from the center to the toe end, or it may be asymmetrically arranged.

[0076] As you move away from the center region towards the heel or toe, the distance between adjacent arcuates can gradually increase to introduce a larger ball contact surface. This increase in the amount of ball contact surface (in the heel-toe direction) produces a region with a greater response compared to the center region with a smaller response. Because the response of the striking surface changes, this helps to generate a constant ball velocity across the entire striking surface.

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

[0078] The multiple consecutive groove recesses 112 may resemble many shapes or outlines. For example, in this exemplary embodiment, the multiple consecutive groove recesses 112 may be defined by one or more consecutive curved groove recesses, one or more consecutive arched groove recesses (which may also be referred to as “consecutive arc groove recesses”), one or more consecutive straight groove recesses, and / or combinations thereof. In this specific embodiment, the putter body 101 defines eight consecutive arched groove recesses 113 (or arc grooves), one consecutive straight groove recess 114, and eight consecutive groove recesses 115 that define at least one straight and arched section.

[0079] In an alternative embodiment of a putter-type golf club head having a series of arched grooves 112, the putter body may define one or more series of arched grooves 113, two or more series of arched grooves 113, three or more series of arched grooves 113, four or more series of arched grooves 113, five or more series of arched grooves 113, six or more series of arched grooves 113, seven or more series of arched grooves 113, eight or more series of arched grooves 113, nine or more series of arched grooves 113, ten or more series of arched grooves 113, or eleven or more series of arched grooves 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 and curved section, two or more consecutive groove recesses 115 defining at least one straight and curved section, three or more consecutive groove recesses 115 defining at least one straight and curved section, four or more consecutive groove recesses 115 defining at least one straight and curved section, five or more consecutive groove recesses 115 defining at least one straight and curved section, six or more consecutive groove recesses 115 defining at least one straight and curved section, seven or more consecutive groove recesses 115 defining at least one straight and curved section, eight or more consecutive groove recesses 115 defining at least one straight and curved section, nine or more consecutive groove recesses 115 defining at least one straight and curved section, ten or more consecutive groove recesses 115 defining at least one straight and curved section, or eleven or more consecutive groove recesses 115 defining at least one straight and curved section. In many embodiments, the arched portion of the continuous straight groove recess is located between a first straight section (closer to the heel) and a second straight section (closer to the toe).

[0081] Referring to Figure 2, each of the multiple consecutive groove recesses 112 has (though not required) (1) a first end 116 and a second end 117 that can be connected to the upper boundary 118 of the striking surface 107, (2) a first end 116 and a second end 117 that can be connected to either the heel 103 or the toe 102 of the striking surface, or (3) a first end 116 and a second end 117 that can be connected to the lower boundary 119 of the striking surface 107. This type of groove configuration allows for fine adjustment of the land area (or second material area) between the groove recesses without requiring a change in the width of the consecutive recesses. This helps to achieve a constant ball velocity across the entire striking surface 107.

[0082] In many embodiments, the multiple consecutive groove recesses may be symmetrical with respect to the central axis of an overall continuous straight groove recess 114 extending from the heel 103 to the toe 102. Each of the multiple consecutive groove recesses between the overall continuous straight groove recess 114 and the upper boundary 118 of the striking surface 107 (closer to the upper rail 104 of the putter body 101) may comprise a curved portion and / or a continuous curved groove recess 113 that is concave upward with respect to the upper boundary 118 of the striking surface 107. Similarly, each of the multiple consecutive groove recesses between the overall continuous straight groove recess 114 and the lower boundary 119 of the striking surface 107 (closer to the sole 105 of the putter body 101) may comprise a curved portion and / or a continuous curved groove recess that is concave downward with respect to the lower boundary 119 of the striking surface 107.

[0083] Each of the consecutive grooves may have a certain width measured across the upper rail 104-sole 105 direction. In many embodiments, the width of each consecutive groove may be in the range of 0.02 inches to 0.040 inches. For example, the width of each of the consecutive grooves 112 may 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 arched portions of the multiple consecutive grooved recesses and / or the consecutive arched grooved recesses 113 has a maximum length that is between 1% and 50% of the maximum length of the striking surface 107 (measured in the heel 103-toe 102 direction). For example, each of the arched portions of the multiple consecutive grooved recesses and / or the consecutive arched grooved recesses may have a maximum length 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 multiple consecutive groove recesses or consecutive arc-shaped groove recesses 113 may have a maximum length of 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 arched portions of the multiple consecutive grooved recesses 112 or the consecutive arched grooved recesses 113 may have a maximum length of about 1% to about 50% of the striking surface 107, about 1% to about 45% of the maximum length of the striking surface 107, about 1% to about 40%, about 1% to about 35%, about 1% to about 30%, about 1% to about 25%, or about 1% to about 20%.

[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 arched grooves and / or consecutive arched groove recesses 113 increase from the upper boundary 118 towards the overall consecutive straight groove recesses 114. This can reduce the spacing (or second material area) between the groove recesses in the heel-toe direction and / or the upper rail-sole direction. Similarly, in the same or other embodiments, the diameter and arc length of each of the arched sections and / or consecutive arched groove recesses increase from the lower boundary 119 towards the overall consecutive straight groove recesses 114. This can reduce the spacing (or second material area) between the groove recesses in the heel-toe direction and / or the upper rail-sole direction. The configuration of each groove, which includes an arched section and / or continuous arched grooves that increase in diameter and / or arc length from the upper boundary 118 to the overall continuous straight groove recess 114, and from the lower boundary 119 to the overall continuous straight groove recess 114, allows the groove recess to maintain a constant width while achieving a striking surface 107 that can control the ball velocity across the entire striking surface 107 when the ratio of the first material 109 and the second material 110 changes.

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

[0089] As shown in Figure 3, adjacent consecutive groove recesses 112 are closer to each other along the striking surface virtual vertical axis 120 than 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 the arc shape (i.e., they are packed closer together, resulting in a smaller land area (or second material area) between the groove recesses). Similarly, adjacent consecutive groove recesses are closer to each other along the 0.25-inch vertical reference axis 121 than along the 0.5-inch vertical reference axis 122 (i.e., they are packed closer together, resulting in a smaller land area between the grooves).

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

[0091] Figures 6–9 show a two-piece putter insert 224 comprising a first material 209 (also referred to as the “first part”) and a second material 210 (also referred to as the “second part”). Referring specifically to Figure 6, the second part forms (or defines) a plurality of consecutive groove gaps 212 that separate the striking surface 207 into the second material land area. The first part of the putter insert 224 comprises a plurality of protruding shapes that complement the corresponding consecutive groove gaps 212. By connecting the first part of the insert to the second part of the insert, the plurality of protruding shapes may be flush with (i.e., on the same plane or plane) the second material land area. Thereafter, the plurality of protruding shapes may form the first material land area. The first material land area and the second material land area come into contact with at least a portion of the golf ball upon impact.

[0092] This embodiment shows one possible arrangement in which each of the arc-shaped portions of the continuous groove gaps 212 is arranged to form a denser, more packed central region in order to generate a larger amount of the first material land area than the second material land area. Having a larger amount of the first material land area than the second material land area helps to generate an area 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 may be progressive from the center of the striking surface to the heel end, or from the center to the toe end, or may be arranged asymmetrically.

[0093] As the ball moves away from the central region towards the heel or toe, the separation distance between adjacent arcuates increases, thereby introducing more second material land areas. This separation distance can be symmetrically progressive or asymmetrically progressive. This helps generate areas with gradually greater response as the ball moves away from the central region towards the heel and toe regions. The generation of striking surfaces with different response characteristics helps to control the ball velocity more invariantly across the striking surface.

[0094] Furthermore, there is an overall arc-shaped recess (which may also be called a semicircular groove) that creates a more densely packed central area at the center of the striking face, extending towards the upper rail and sole. This further increases the amount (or degree) of the first material land area, which is absent as you move away from the center and is not present at the heel and toe ends.

[0095] The putter-type golf club heads in Figures 6 to 9 comprise a putter body 201 having a toe 202, a heel 203 opposite the toe 202, an upper rail 204, a sole 205 opposite the upper rail 204, a portion of the striking surface 207, and a rear portion 206 opposite the striking surface 207. The striking surface 207 further defines a striking surface recess 223 defined by the heel 203, toe 202, upper rail 204, sole 205, and rear portion 206 of the putter body 201.

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

[0097] The insert 224 may comprise a front surface 225 that conforms to the impact with a golf ball (not shown) and a rear surface 226 opposite the front surface. The putter insert thickness 227 may be defined as the maximum vertical distance between the front surface 225 and the rear surface 226. For example, Figure 6 shows an insert 224 having a plurality of continuous groove gaps 212 (defined by the second material) that extend through the entire thickness of the second material 210. In many embodiments, the first material, the second material, and / or combinations of the first and second materials may have a constant thickness.

[0098] Furthermore, in many embodiments, the first material 209 covers the entire rear surface 226 of the insert 224. In other words, the rear surface 226 does not have the second material 210. In many embodiments, the first material 209 further completely fills each of the multiple consecutive groove gaps (until it is flush with the front surface 225 of the insert), so that at the front surface 225, the second material 210 surrounds the first material 209, and at the time of golf ball impact, the first material 209 and the second material 210 come into contact with at least a portion of the golf ball.

[0099] The multiple consecutive groove gaps 212 defined by the putter insert 224 may resemble many shapes or outlines. For example, in this exemplary embodiment, the multiple consecutive groove gaps 212 may be defined by one or more consecutive curved groove gaps, one or more consecutive arc-shaped groove gaps (which may also be referred to as “consecutive arc groove gaps”), one or more consecutive straight groove gaps, and / or combinations thereof. In this specific embodiment, the second material 210 defines five consecutive arc-shaped groove gaps 213 (or arc grooves), one consecutive straight groove gap 214, and six consecutive groove gaps 215 that define both straight and arc-shaped sections.

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

[0101] In the same or alternative embodiments, the second material 210 may define one or more consecutive groove gaps defining the straight and arched sections 215, two or more consecutive groove gaps defining the straight and arched sections 215, three or more consecutive groove gaps defining the straight and arched sections 215, four or more consecutive groove gaps defining the straight and arched sections 215, five or more consecutive groove gaps defining the straight and arched sections 215, six or more consecutive groove gaps defining the straight and arched sections 215, seven or more consecutive groove gaps defining the straight and arched sections 215, eight or more consecutive groove gaps defining the straight and arched sections 215, nine or more consecutive groove gaps defining the straight and arched sections 215, ten or more consecutive groove gaps defining the straight and arched sections 215, or eleven or more consecutive groove gaps defining the straight and arched sections 215. Generally, the arc-shaped portion of the continuous groove gap 215 is located between the first straight portion (closer to the heel) and the second straight portion (closer to the toe).

[0102] In many embodiments, each of the multiple consecutive groove gaps comprises (though not required) (1) a first end 216 and a second end 217 that can be connected to the upper boundary 218 of the striking surface 207, (2) a first end 216 and a second end 217 that can be connected to either the heel 203 or the toe 202 of the striking surface, or (3) a first end 216 and a second end 217 that can be connected to the lower boundary 219 of the striking surface 207. This type of groove gap arrangement allows for fine-tuning of the land area (or second material area 210) between the groove gaps without requiring a change in the width or thickness of the consecutive groove gaps. This helps to achieve a constant ball velocity across the entire striking surface 207.

[0103] In some embodiments, the multiple consecutive groove gaps are asymmetrical with respect to the central axis of a generally continuous straight groove gap 214 that extends from the heel 203 to the toe 202. Each of the multiple consecutive groove gaps between the generally continuous straight groove 214 and the upper boundary 218 of the striking surface 207 (closer to the upper rail 204 of the putter body 201) may have a curved portion and / or a continuous curved groove gap 213 that is concave upward with respect to the upper boundary 218 of the striking surface 207. Similarly, each of the multiple consecutive groove gaps between the generally continuous straight groove gap 214 and the lower boundary 219 of the striking surface 207 (closer to the sole 205 of the putter body 201) may have a curved portion and / or a continuous curved groove gap that is concave downward with respect to the lower boundary 219 of the striking surface 207.

[0104] Each of the consecutive groove gaps may have a constant width measured across the upper rail 204-sole 205 direction. In many embodiments, the width of each consecutive groove gap may be in the range of 0.02 inches to 0.040 inches. For example, the width of each consecutive groove gap may 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 multiple consecutive groove gaps and / or consecutive arched groove gaps 213 may have a maximum length between 1% and 50% of the maximum length of the striking surface 207 (measured in the heel 203-toe 202 direction). For example, each of the multiple consecutive groove gaps and / or consecutive arched groove gaps may have a maximum length greater than 1% of the striking surface 207, greater than 5% of the striking surface 207, greater than 10% of the striking surface 207, greater than 15% of the striking surface 207, greater than 20% of the striking surface 207, greater than 25% of the striking surface 207, greater than 30% of the striking surface 207, greater than 35% of the striking surface 207, greater than 40% of the striking surface 207, or greater than 45% of the striking surface 207.

[0106] In the same or alternative embodiments, each of the multiple consecutive groove gaps or consecutive arched groove gaps 213 may have a maximum length of 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 multiple consecutive groove gaps or consecutive arched groove gaps 213 may have a maximum length of about 1% to about 50% of the striking surface 207, about 1% to about 45% of the maximum length of the striking surface 207, about 1% to about 40%, about 1% to about 35%, about 1% to about 30%, about 1% to about 25%, or about 1% to about 20%.

[0108] In many embodiments for controlling the relationship (or ratio) between the first material 209 and the second material 210, the respective diameters and arc lengths of each arched groove and / or continuous arched groove 213 are increased in the central region, from the upper boundary 218 to the overall continuous straight groove 214, to generate a smaller land area (or second material land area) between the continuous groove gaps. In the same or other embodiments, the respective diameters and arc lengths of each arched groove and / or continuous arched groove are increased in the central region, from the lower boundary 219 to the overall continuous straight groove 214, to generate a smaller second material land area between the continuous groove gaps.

[0109] By configuring each continuous groove gap with an arc-shaped section and / or continuous arc-shaped groove gap having an increasing diameter and / or arc length, extending from the upper boundary 218 to the overall continuous straight groove gap 214, and from the lower boundary 219 to the overall continuous straight groove gap 214, the groove gap can have a constant width and depth while achieving a striking surface 207 that can control the ball velocity over the entire striking surface 207.

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

[0111] As further shown in Figure 9, adjacent continuous groove gaps are closer to each other along the striking surface virtual vertical axis 220 than the 0.25-inch vertical reference axis 221 and the 0.5-inch vertical reference axis 222 (i.e., they are packed closer together, creating a smaller land area (or smaller second material land area) between the continuous groove gaps). Similarly, adjacent continuous groove gaps are closer to each other along the 0.25-inch vertical reference axis 221 than along the 0.5-inch vertical reference axis 222 (i.e., they are packed closer together, resulting in a smaller land (or second material) area between the groove gaps).

[0112] In many embodiments of the continuous groove, the proportion 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 proportion 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%. Furthermore, 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 an alternative embodiment, 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 embodiments of the continuous groove, the proportion of the first material (or first material land area) along the 0.25-inch vertical reference axis 221 may be approximately 30% to 50%. For example, the proportion of the first material along the 0.25-inch vertical reference axis 221 may be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Furthermore, 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 an alternative embodiment, 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 embodiments of the continuous groove configuration, the proportion of the first material (or first material land area) along the virtual axis 220 of the striking surface can be approximately 40% to 60%. For example, the proportion of the first material along the virtual axis 220 of the striking surface may be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Furthermore, for example, the proportion of the first material land area along the virtual axis 220 of the striking surface 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 proportion of the first material along the virtual axis 220 of the striking surface 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] Furthermore, 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-sole direction), decreases from the virtual vertical axis 220 of the striking surface to the 0.5-inch vertical reference axis 222. This type of arrangement of the first and second materials helps to provide constant ball velocity across the striking surface because the average ratio along the virtual vertical axis of the striking surface is greater (i.e., softer) than the average ratio along the 0.5-inch vertical reference axis (i.e., stiffer). This cancels out the loss of energy transfer on heel and toe mishits.

[0116] (Separated air gaps (tablet shape)) Figures 10–13 show another exemplary embodiment. More specifically, Figures 10–13 show an example of a putter-type golf club head 300 having a dual-material striking surface 307 comprising a first material 309 and a second material 310. The golf club heads 300 in Figures 10–13 and the golf club heads 200 in Figures 6–9 are similar in many respects, except that the golf club head 300 has separate voids extending in the heel-toe direction rather than continuous voids and / or recesses. The separate voids generally have a greater length near the central region of the striking surface 307 than toward the heel and / or toe. In many embodiments, the separate voids are substantially the same width.

[0117] Figure 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, an upper rail 304, a sole 305 opposite the upper rail 304, a portion of a striking surface 307, and a rear portion 306 opposite the striking surface 307. The striking surface 307 may further define a striking surface recess 323 defined by the heel 303, toe 302, upper rail 304, sole 305, and rear portion 306 of the putter body 301.

[0118] Figures 10–13 show a two-part pattern insert 324 comprising a first material 309 (also referred to as the “first part”) and a second material 310 (also referred to as the “second part”). Referring specifically to Figure 10, the second part 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 come into contact with or touch 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 has multiple protruding tablet-shaped outlines that complement the corresponding isolated tablet-shaped voids 312. By connecting the first and second portions together, the multiple protruding isolated tablet-shaped voids can be flush with the second material land area. Thereafter, the multiple protruding isolated tablet-shaped voids can form the first material land area. The first material land area and the second material land come into contact with at least a portion of the golf ball upon impact. The first material has a lower hardness than the second material.

[0120] This embodiment shows one possible arrangement in which variable-length tablet-shaped voids are arranged to form a denser, more packed central region, generating a larger first material land area than a second material land area. Referring to Figure 12, it can be seen that in any given row, the tablet-shaped void with the longest length is closer to the central region, and the tablet-shaped void with the shortest length is closer to the heel and toe ends. This arrangement generates a central region with a larger amount of first material land area than the second material land area (it generates a central region that is less responsive to ball impact than the area towards the heel or toe end). In the upper rail-sole direction, the first and second material land areas are substantially the same or constant. Thus, the first material land area changes only in the heel-toe direction and not in the upper rail-sole direction.

[0121] As you move along a given row away from the central region towards the heel or toe, the distance between adjacent separated tablet-shaped voids increases (i.e., the length of the separated tablet-shaped voids decreases). This generates more second material land areas, which helps to gradually generate areas with greater response away from the central region towards the heel and toe regions in order to maintain constant ball velocity across the entire striking surface.

[0122] Figures 11–13 show various putter inserts 324 having separated tablet-shaped cavities. In many embodiments, the putter insert 324 can be housed within and complement the striking surface recess 323. However, it should be noted that in alternative embodiments, the putter-type golf club head 300 does not necessarily have to be an insert-style putter.

[0123] Figure 13 shows an exploded view of a putter insert 324 having separated tablet-shaped voids. The insert 324 may comprise a front surface 325 that conforms to the impact with a golf ball (not shown) and a rear surface 326 opposite the front surface. The 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, Figure 13 shows an insert 324 having a plurality of separated tablet-shaped voids 312 (defined by the second material) that extend throughout the thickness (or depth) of a second material 310.

[0124] Furthermore, in many embodiments, the first material 309 may cover the entire rear surface 326 of the insert 324. In other words, the rear surface 326 does not have the second material 310. In many embodiments, the first material 309 may further fill each of the separated tablet-shaped voids 312 of the plurality of separated tablet-shaped voids (until it is flush with the front surface 325 of the insert), so that at the front surface 325, the second material 310 surrounds the first material 309, and when the golf ball impacts, the first material 309 and the second material 310 may come into contact with at least a portion of the golf ball.

[0125] Each of the separated tablet-shaped cavities may have a first end 328 (near the toe) forming an arched shape and a second end 329 (near the heel) forming an arched shape. In many embodiments, the shapes of the first end 328 and the second end 329 may be curved, circular, semicircular, crescent-shaped, arched, curved, or rounded. The first end 328 and the second end 329 may be connected by parallel horizontal segments 330 that extend substantially in the heel-toe direction.

[0126] The maximum length of each of the separated tablet-shaped cavities 312 (measured in the heel-toe direction) can vary in the heel-toe direction. In many embodiments, the maximum length of each of the separated tablet-shaped cavities 312 may be between 0.02 inches and 0.36 inches. For example, the maximum length of each of the gaps 312 in the multiple separated tablet shapes may 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 gaps 312 in the separated tablet shapes may vary between 0.06 inches and 0.180 inches.

[0127] The maximum width of each of the separated tablet-shaped voids 312 (measured in the direction of the upper rail-sole) of the multiple tablet-shaped voids may remain the same or substantially constant. In many embodiments, the maximum width of each of the separated tablet-shaped voids 312 may be between 0.01 inches and 0.3 inches. For example, the maximum width of each of the separated tablet-shaped voids 312 may 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, greater than 0.14 inches. It can be larger than 0.15 inches, larger than 0.16 inches, larger than 0.17 inches, larger than 0.18 inches, larger than 0.19 inches, larger than 0.20 inches, larger than 0.21 inches, larger than 0.22 inches, larger than 0.23 inches, larger than 0.24 inches, larger than 0.25 inches, larger than 0.26 inches, larger than 0.27 inches, larger than 0.28 inches, or larger than 0.29 inches.

[0128] In other embodiments, the maximum width of each of the voids 312 in the separated tablet shape may 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 embodiments of the separated tablet-shaped cavities 312, the multiple separated tablet-shaped cavities 312 may be arranged in substantially horizontal rows and / or substantially vertical columns. In the exemplary embodiment of Figure 11, the multiple separated tablet-shaped cavities are arranged to form 11 rows and 17 columns. In the embodiment of Figure 12, the multiple separated tablet-shaped cavities are arranged to form 13 rows and 17 columns. In alternative embodiments, the multiple separated tablet-shaped cavities 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 multiple separated 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. By arranging the tablet-shaped voids 312 in rows and columns, as further described below, a suitable ratio between the first and second materials along the vertical reference axis is made possible.

[0130] As can be seen in the exemplary embodiments of FIGS. 10 to 13, each of the plurality of separated tablet-shaped voids 312 is spaced apart from each other in both the heel-to-toe direction and the upper rail-to-sole direction. This is different from the embodiments of the continuous grooves or recesses of FIGS. 1 to 9 that are continuously connected in the heel-to-toe direction. Each row or column may have two or more separated tablet-shaped voids, three or more separated tablet-shaped voids, four or more separated tablet-shaped voids, five or more separated tablet-shaped voids, six or more separated tablet-shaped voids, seven or more separated tablet-shaped voids, eight or more separated tablet-shaped voids, nine or more separated tablet-shaped voids, ten or more separated tablet-shaped voids, eleven or more separated tablet-shaped voids, twelve or more separated tablet-shaped voids, thirteen or more separated tablet-shaped voids, fourteen or more separated tablet-shaped voids, fifteen or more separated tablet-shaped voids, sixteen or more separated tablet-shaped voids, seventeen or more separated tablet-shaped voids, eighteen or more separated tablet-shaped voids, nineteen or more separated tablet-shaped voids, or twenty or more separated tablet-shaped voids.

[0131] The volume of the first material 309 filling each of the separated tablet-shaped voids 312 can vary in the heel-to-toe direction. In many embodiments, the first material 309 can fill a volume of 0.0000803 in 3 to 0.00104122 in 3 In some embodiments, the first material 309 can fill a volume of 0.0000803 in 3 to 0.00104122 in 3 0.000176 in 3 to 0.00104122 in 3 0.000272 in 3 to 0.00104122 in 3 0.000368 in 3 to 0.00104122 in 3 0.000464 in 3 to 0.00104122 in 3 0.00056 in 3 to 0.00104122 in 3 0.00065 in 3~0.00104122in 3 , 0.0075in 3 ~0.0010422in 3 , 0.000849in 3 ~0.0010422in 3 , or 0.000945in 3 ~0.00104in 3 It can satisfy the volume. In other embodiments, the first material 309 is 0.000160 in 3 ~0.00052061in 3 The volume can be filled. When the first material 309 fills a separate void of this size, it allows for more precise control of the adjustment solution between the first and second materials to produce a constant ball velocity across the entire striking surface, as well as an improved impact feel and sound.

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

[0133] As further shown in Figures 11 and 12, adjacent separated tablet-shaped gaps 312 are closer to each other along the striking surface virtual vertical axis 320 in both horizontal and vertical directions than the 0.25-inch vertical reference axis 321 and the 0.5-inch vertical reference axis 322 (i.e., they are packed closer together, and the (second material) land area between the separated gaps is smaller). Similarly, adjacent separated tablet-shaped gaps 312 are closer to each other along the 0.25-inch vertical reference axis 321 than the 0.5-inch vertical reference axis 322 (i.e., they are packed closer together, and the land (or second material) area in both horizontal and vertical directions between the separated tablet-shaped gaps 312 is smaller).

[0134] In many embodiments of the separated tablet-shaped voids, the proportion of the first material (or first material land area) along the 0.5-inch vertical reference axis 322 can be approximately 20% to 40%. For example, the proportion 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%. Furthermore, 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 an alternative embodiment, the proportion of the 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 embodiments of the separated tablet-shaped voids, the proportion of the first material 309 along the 0.25-inch vertical reference axis 321 can be approximately 30% to 50%. For example, the proportion of the 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%. Furthermore, for example, the proportion of the 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 an alternative embodiment, the proportion of the 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 embodiments of the separated tablet-shaped voids, the proportion of the first material 309 along the virtual axis 320 of the striking surface can be approximately 40% to 60%. For example, the proportion of the first material along the virtual axis of the striking surface may be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Furthermore, for example, the proportion of the first material 309 along the virtual axis 320 of the striking surface 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 proportion of the first material 309 along the striking surface virtual 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] Furthermore, in many embodiments, the average ratio, defined as the ratio of the surface area of ​​the first material land area 309 to the ratio of the surface area of ​​the second material land area 310 (measured along their respective vertical reference axes), decreases from the striking surface virtual vertical axis 320 to the 0.5-inch vertical reference axis 322. This type of arrangement of the first and second materials helps to provide constant ball velocity across the striking surface because the average ratio along the striking surface virtual vertical axis is greater (i.e., softer) than the average ratio along the 0.5-inch vertical reference axis. This cancels out the loss of energy transfer on heel and toe mishits.

[0138] Furthermore, in this exemplary embodiment, separated voids of variable width, variable thickness, and / or even variable depth are not required to generate a constant ball velocity across the entire striking surface. The separated tablet-shaped voids have varying lengths (in the heel-toe direction) as they generate different first and second material ratios measured along the upper rail-sole direction, thus achieving a constant ball velocity.

[0139] (Separated void (hexagonal shape)) Figures 14–16 show another exemplary embodiment of the invention described herein. More specifically, Figures 14–16 show an example of a putter-type golf club head 400 having a dual-material striking surface 407 comprising a first material 409 and a second material 410. The golf club heads 400 in Figures 14–16 and the golf club heads 300 in Figures 10–13 are similar in many respects, except that the golf club head 400 has a separated cavity that is hexagonal rather than tablet-shaped.

[0140] Figure 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, an upper rail 404, a sole 405 opposite the upper rail 404, a portion of a striking surface 407, and a rear portion 406 opposite the striking surface 407. The striking surface 407 may further define a striking surface recess 423 defined by the heel 403, toe 402, upper rail 404, sole 405, and rear portion 406 of the putter body 401.

[0141] Figure 15 shows a putter insert 424 with two parts, each having a separate hexagonal gap. In many embodiments, the putter insert 424 can be housed within and complement the striking surface recess 423. However, it should be noted that in alternative embodiments, the putter-type golf club head 400 does not necessarily have to be an insert-style putter.

[0142] Figures 14–16 show a putter insert 424 comprising a first material 409 (which may also be referred to as the “first part”) and a second material 410 (which may also be referred to as the “second part”). Referring specifically to Figure 15, the second part 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 any other hexagonal voids. The first material has a lower hardness than the second material.

[0143] The second material surrounds the hexagonal voids to form the second material land area. The first portion of the putter insert 424 has multiple protruding hexagonal outlines that complement the corresponding hexagonal tablet-shaped voids 412. When the first and second portions are joined together, the multiple protruding hexagonal voids can be flush with the second material land area. This allows the multiple protruding, separate hexagonal voids to form the first material land area. The first material land area and the second material land come into contact with at least a portion of the golf ball upon impact.

[0144] This embodiment illustrates one possible arrangement in which the hexagonal voids are arranged to form a denser, more compact central region, generating a larger first material land area than the second material land area. Referring to Figure 16, it can be seen that in any given row, the hexagonal void with the greatest width is closer to the central region, and the hexagonal void with the least width is further away from the central region. This arrangement generates a central region with a larger amount of first material land area than the second material land area. This generates a central region that is less responsive to ball impact with respect to the heel end or toe area. In the upper rail-sole direction, the width of the first material land is substantially the same or constant. Thus, the ratio between the first and second materials also changes as the width of the separated hexagonal voids decreases as they move away from the central region.

[0145] As you move along a given row away from the central region towards the heel or toe, the distance between adjacent isolated hexagonal gaps increases (i.e., the length of the isolated hexagonal gaps decreases). This generates more second material land areas, which helps to gradually generate areas with greater response away from the central region towards the heel and toe regions in order to maintain constant ball velocity across the entire striking surface.

[0146] Continuing with reference to Figure 15, Figure 15 shows an exploded view of a putter insert 424 having separate hexagonal voids. The insert 424 may comprise a front surface 425 that conforms to the impact with a golf ball (not shown) and a rear surface 426 opposite to the front surface. The 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, Figure 15 shows an insert 424 having multiple separate hexagonal voids 412 (defined by the second material) that extend through the entire thickness (i.e., depth) of the second material 410.

[0147] Furthermore, in many embodiments, the first material 409 may cover the entire rear surface 426 of the insert 424. In other words, the rear surface 426 does not have the second material 410. In many embodiments, the first material 409 may further fill each of the separated hexagonal voids 412 of the plurality of separated hexagonal voids (until it is flush with the front surface 425 of the insert), so that at the front surface 425, the second material 410 surrounds the first material 409, and as a result, when the golf ball impacts, the first material 409 and the second material 410 may come into contact with at least a portion of the golf ball.

[0148] Each of the separated hexagonal gaps can be defined as a six-sided polygon having six interior angles and six vertices. Each of the six interior angles may be approximately 120 degrees. The interior angles, in total, are approximately 720 degrees. Each side of the six-sided polygon may be equal in length or substantially equal.

[0149] The maximum length of each of the separated hexagonal gaps 412 (measured in the heel-toe direction) can vary in the heel-toe direction. In many embodiments, the maximum length of each of the separated hexagonal gaps 412 may be between 0.03 inches and 0.40 inches. For example, the maximum length of each of the multiple separate hexagonal gaps 412 may 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 separate hexagonal gaps 412 may vary between 0.074 inches and 0.17 inches.

[0150] In other embodiments, the maximum length of each of the separated hexagonal gaps 412 may 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 separated hexagonal gaps 412 (measured in the direction of the upper rail-sole) can vary. In many embodiments, the maximum width of each separated hexagonal gap 412 can be between 0.03 inches and 0.40 inches. For example, the maximum width of each separated hexagonal gap 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 gaps 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 multiple separated hexagonal voids 412 may be located in substantially horizontal rows and / or substantially vertical columns. In the exemplary embodiment of Figure 16, the multiple separated hexagonal voids are arranged to form five rows and thirteen columns. In alternative embodiments, the multiple 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, the multiple separate 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. By arranging the hexagonal voids 412 in rows and columns, as further described below, a suitable ratio between the first and second materials along the vertical reference axis is made possible.

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

[0154] The volume of the first material 409 filling each of the separated hexagonal voids 412 can vary in the heel-toe direction. In many embodiments, the first material 409 is 0.0000803 in 3 ~0.004in 3 It can satisfy the volume. In some embodiments, the first material 409 is 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 0.000945in 3 ~0.004in 3 It can satisfy the volume. In other embodiments, the first material 409 is 0.00035 in 3 ~0.00187in 3 The volume can be filled. When the first material 409 fills a separate void of this size, it allows for more precise control of the adjustment solution between the first and second materials to produce a constant ball velocity across the entire striking surface, as well as an improved impact feel and sound.

[0155] In many embodiments of the separated hexagonal gap, when the club head is in the address position, the striking surface has a striking surface virtual vertical axis 420 that extends through the geometric center 408 of the striking surface 407 in the upper rail-sole direction (as shown in Figure 16). Furthermore, the corresponding vertical reference axis is offset by 0.25 inches and 0.50 inches in both the heel 403 and toe 402 directions from the striking surface virtual vertical axis.

[0156] As further shown in Figure 16, adjacent separated hexagonal gaps 412 are closer to each other along the striking surface virtual vertical axis 420 in both horizontal and vertical directions than the 0.25-inch vertical reference axis 421 and the 0.5-inch vertical reference axis 422 (i.e., they are packed closer together, and the (second material) land area between the separated gaps is smaller). Similarly, adjacent separated hexagonal gaps 412 are closer to each other along the 0.25-inch vertical reference axis 421 than the 0.5-inch vertical reference axis 422 (i.e., they are packed closer together, and the land (or second material) area in both horizontal and vertical directions between the separated hexagonal gaps 412 is smaller).

[0157] In many embodiments of the separated hexagonal void, the proportion of the first material 409 along the 0.5-inch vertical reference axis 422 can be approximately 20% to 40%. For example, the proportion of the 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%. Furthermore, 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 an alternative embodiment, the proportion of the 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 embodiments of the separated hexagonal void, the proportion of the 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 proportion of the 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%. Furthermore, for example, the proportion of the 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 an alternative embodiment, the proportion of the 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 embodiments of the separated hexagonal void, the proportion of the first material 409 (or first material land area) along the virtual axis 420 of the striking surface can be approximately 40% to 60%. For example, the proportion of the first material 409 along the virtual axis of the striking surface can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Furthermore, for example, the proportion of the first material 409 along the virtual axis 420 of the striking surface 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 an alternative embodiment, the proportion of the first material 409 along the virtual axis 420 of the striking surface 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] Furthermore, in many embodiments, the average ratio, defined as the ratio of the surface area of ​​the first material land area 409 to the ratio of the surface area of ​​the second material land area 410 (measured along their respective vertical reference axes), decreases from the striking surface virtual vertical axis 420 to the 0.5-inch vertical reference axis 422. This type of arrangement of the first and second materials helps to provide constant ball velocity across the striking surface because the average ratio along the striking surface virtual vertical axis is greater (i.e., softer) than the average ratio along the 0.5-inch vertical reference axis. This cancels out the loss of energy transfer on heel and toe mishits.

[0161] Furthermore, in this exemplary embodiment, the separated gaps of variable width (in the upper rail-sole direction along the row) and / or even variable thickness (or depth) are not required to generate constant ball velocity across the entire striking surface. The separated hexagonal gaps have varying lengths (in the heel-toe direction) by generating different first and second material ratios along the vertical direction, thus achieving constant ball velocity.

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

[0163] The putter-type golf club heads in Figures 17 to 19 comprise a putter body 501 having a toe 502, a heel 503 opposite the toe 502, an upper rail 504, a sole 505 opposite the upper rail 504, a portion of the striking surface 507, and a rear portion 506 opposite the striking surface 507. The striking surface 507 further defines a striking surface recess 523 defined by the heel 503, toe 502, upper rail 504, sole 505, and rear portion 506 of the putter body 501.

[0164] Figures 17–19 show a putter insert 524 comprising a first material 509 (which may also be referred to as the “first part”) and a second material 510 (which may also be referred to as the “second part”). Referring specifically to Figure 18, the second part forms (or defines) a plurality of consecutive groove gaps 512, and the second material 510 surrounding the plurality of consecutive groove gaps may be defined as the second material land area. The first part of the putter insert 524 comprises a plurality of protruding outlines that complement the corresponding consecutive groove gaps 512. When the first and second parts of the insert 524 are joined together, the plurality of protruding outlines may be flush with the second material land area. Thus, the plurality of protruding outlines may also form the first material land area. The first material land area and the second material land area may come into contact with at least a portion of the golf ball upon impact.

[0165] This embodiment shows one possible arrangement in which each of the consecutive groove gaps 512 defines an upward curvature point and a downward curvature point. The upward and downward curvature points are centrally located on the striking surface. This allows the maximum width of each of the consecutive groove gaps to be centrally located on the striking surface in the upper rail-sole direction and the heel-toe direction. The first material has a lower hardness than the second material. This creates a denser, more packed central region with a larger amount of first material land area than the second material land area. Having a larger amount of first material land area than the second material land area helps create an area towards the heel or toe end and a central region that is less responsive to ball impact than the heel or toe end.

[0166] As you move away from the central region towards the heel and / or toe, the separation distance between adjacent arcuates increases to introduce more second material land areas. This creates areas with gradually greater response from the central region towards the heel and toe regions, allowing for more invariant control of ball velocity across the entire striking surface.

[0167] Referring to Figure 18, which shows a perspective view of the putter insert 524. In many embodiments, the putter insert 524 can be housed within and complement the striking surface recess 523. The putter insert 524 may comprise a front surface 525 that conforms to the impact with a golf ball (not shown) and a rear surface 526 opposite to the front surface.

[0168] The putter insert thickness 527 can be defined as the maximum vertical distance between the front surface 525 and the rear surface 526. For example, Figure 18 shows an insert 524 having multiple consecutive groove gaps 512 (defined by the second material) that extend through the entire thickness of the second material 510. In many embodiments, the first material, the second material, and / or combinations of the first and second materials may have a constant thickness.

[0169] Furthermore, in many embodiments, as shown herein, the first material 509 covers the entire rear surface 526 of the insert 524. In other words, the rear surface 526 does not have the second material 510. In many embodiments, the first material 509 further completely fills (or completely occupies) each of the multiple consecutive groove gaps (until it is flush with the front surface 525 of the insert), and as a result, at the front surface 525, the second material 510 surrounds the first material 509, and as a result, when the golf ball impacts, the first material 509 and the second material 510 are in contact with at least a portion of the golf ball.

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

[0171] In many embodiments, the upper continuous groove wall 532 decreases continuously from the virtual vertical axis 520 of the striking surface to the first continuous groove vertex 534 and the second continuous groove vertex 535. Alternatively, the upper continuous groove wall 532 defines an upper curvature point along the upper continuous groove wall at the virtual vertical axis 520 of the striking surface, and a lower curvature point along the lower continuous groove wall 533 at the virtual axis 520 of the striking surface. At the first end 516 and the second end 517 of the continuous groove gap 512, the upper continuous groove wall 532 and the lower continuous groove wall 533 intersect to define the first continuous groove vertex 534 and the second continuous groove vertex 535.

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

[0173] Each of the consecutive groove gaps may have a maximum width measured along the virtual vertical axis 520 of the striking surface in the direction of the upper rail 504 and sole 505. In many embodiments, the maximum width of each of the consecutive groove gaps 520 may be in the range of 0.020 inches to 0.060 inches. For example, the maximum widths of each of the consecutive groove gaps 520 may be approximately 0.020 inches, approximately 0.021 inches, approximately 0.022 inches, approximately 0.023 inches, approximately 0.024 inches, approximately 0.025 inches, approximately 0.026 inches, approximately 0.027 inches, approximately 0.028 inches, approximately 0.029 inches, approximately 0.030 inches, approximately 0.031 inches, approximately 0.032 inches, approximately 0.033 inches, approximately 0.034 inches, approximately 0.035 inches, approximately 0.036 inches, approximately 0.037 inches, approximately 0.038 inches, and approximately 0.039 inches. It may be an inch, approximately 0.040 inches, approximately 0.041 inches, approximately 0.042 inches, approximately 0.043 inches, approximately 0.044 inches, approximately 0.045 inches, approximately 0.046 inches, approximately 0.047 inches, approximately 0.048 inches, approximately 0.049 inches, approximately 0.050 inches, approximately 0.051 inches, approximately 0.052 inches, approximately 0.053 inches, approximately 0.054 inches, approximately 0.055 inches, approximately 0.056 inches, approximately 0.057 inches, approximately 0.058 inches, approximately 0.059 inches, or approximately 0.060 inches. The width of the continuous groove gap 520 at the first continuous groove apex and the second continuous groove apex is less than 0.0001 inches, preferably 0 inches.

[0174] In many embodiments, each of the multiple consecutive groove gaps 512 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 surface 507. For example, each of the consecutive groove gaps 512 of the multiple consecutive groove gaps 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, and 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 the consecutive groove voids decreases to virtually zero width from the striking surface virtual vertical axis 520 to the first consecutive groove apex and / or to virtually zero width from the striking surface virtual vertical axis to the second consecutive groove apex. This type of void shape precisely controls the amount of land area (or second material area) between adjacent consecutive groove voids in the vertical direction up to a predetermined first material-second material threshold to be reached.

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

[0177] As further shown in Figure 19, adjacent continuous groove gaps are closer to each other along the striking surface virtual vertical axis 520 than the 0.25-inch vertical reference axis 521 and the 0.5-inch vertical reference axis 522 (i.e., they are packed closer together, resulting in a smaller land area between the grooves). Similarly, adjacent continuous grooves are closer to each other along the 0.25-inch vertical reference axis 521 than along the 0.5-inch vertical reference axis 522 (i.e., they are packed closer together, resulting in a smaller land (or second material) area between the groove gaps).

[0178] In many embodiments of continuous groove voids, the proportion of the first material (or first material land area) along a 0.5-inch vertical reference axis can be approximately 20% to 40%. For example, the proportion of the first material along a 0.5-inch vertical reference axis may be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Furthermore, 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 an alternative embodiment, 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 embodiments of continuous groove voids, the proportion of the first material (or first material land area) along a 0.25-inch vertical reference axis can be approximately 30% to 50%. For example, the proportion of the first material along a 0.25-inch vertical reference axis may be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Furthermore, for example, the percentage of the first material along a 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 an alternative embodiment, 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 embodiments of the continuous groove void, the proportion of the first material (or first material land area) along the virtual axis of the striking surface can be approximately 40% to 60%. For example, the proportion of the first material along the virtual axis of the striking surface may be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Furthermore, for example, the proportion of the first material along the virtual axis of the striking surface 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 proportion of the first material along the virtual axis of the striking surface 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] Furthermore, in many embodiments, the average ratio, defined as the surface area of ​​the proportion of the first material land area to the surface area of ​​the proportion of the second material land area (measured along their respective vertical reference axes), decreases from the virtual vertical axis of the hitting surface to the 0.5-inch vertical reference axis. This type of arrangement of the first and second materials helps to provide constant ball velocity across the hitting surface because the average ratio along the virtual vertical axis of the hitting surface is greater (i.e., softer) than the average ratio along the 0.5-inch vertical reference axis. This cancels out the loss of energy transfer on heel and toe mishits.

[0182] (Separated voids (vertical radiation pattern)) Figures 20–23 show another exemplary embodiment. More specifically, Figures 20–23 show an example of a putter-type golf club head 600 having a dual-material striking surface 607 comprising a first material 609 and a second material 610. The golf club head 600 in Figures 20–23 and the golf club heads 100, 200, 300, 400, and 500 described above are similar in many respects, except that the golf club head 600 has a separate void that extends substantially in the direction of the upper rail-sole.

[0183] The putter-type golf club heads in Figures 20 to 23 may comprise a putter body (similar to the putter body described above), having a toe, a heel opposite the toe, an upper rail, a sole opposite the upper rail, a portion of the striking surface, and a rear portion opposite the striking surface. The striking surface further defines the striking surface recess defined by the heel, toe, upper rail, sole, and rear portion of the putter body.

[0184] Figures 20–23 show a putter insert 624 comprising a first material 609 (which may also be referred to as the “first part”) and a second material 610 (which may also be referred to as the “second part”). Referring specifically to Figure 20, the second part 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 surface geometric center 608.

[0185] The second material substantially surrounds the isolated concentric radiating voids to form the second material land area. The first portion of the putter insert 624 includes a plurality of isolated concentric radiating projections that complement the corresponding isolated concentric radiating voids 612. By connecting the first and second portions together, the plurality of projecting isolated concentric radiating voids can be flush (i.e., in the same plane) with the second material land area. This allows the plurality of projecting isolated concentric radiating voids to form the 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 come into contact with at least a portion of the golf ball upon impact.

[0186] This embodiment shows one possible arrangement in which the separated concentric radial gaps are arranged such that their diameters increase outward from the geometric center 608 of the striking surface. This forms a denser, more packed 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. Thereafter, it produces a central region that is less responsive to ball impact with respect to the heel or toe region. The width of the first material land area is substantially the same or constant in the upper rail-sole direction and the heel-toe direction.

[0187] As you move from the central region toward the heel or toe, the separation distance between adjacent, isolated concentric radial gaps increases. This generates more secondary material land areas, which helps to gradually create areas with greater response toward the heel and toe regions away from the central region in order to maintain constant control of the ball velocity across the entire striking surface.

[0188] Referring to Figure 20, which shows a perspective view of the putter insert 624. In many embodiments, the putter insert 624 can be housed within and complement the striking surface recess. The putter insert 624 may comprise a front surface 625 that conforms to the impact with a golf ball (not shown) and a rear surface 626 opposite to the front surface.

[0189] The putter insert thickness 627 can 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 multiple separate concentric radial voids 612 (defined by the second material) that extend through the entire thickness of the second material 610. In many embodiments, the first material, the second material, and / or combinations of the first and second materials can be of a constant thickness.

[0190] Furthermore, in many embodiments, as shown herein, the first material 609 covers the entire rear surface 626 of the insert 624. In other words, the rear surface 626 does not have the second material 610. In many embodiments, the first material 609 further completely fills (or completely occupies) each of the multiple separate concentric radiating voids (until it is flush with the front surface 625 of the insert), and as a result, at the front surface 625, the second material 610 surrounds the first material 609, and as a result, when the golf ball impacts, the first material 609 and the second material 610 are in contact with at least a portion of the golf ball.

[0191] In many embodiments, most of the isolated concentric radial gaps 612 extend perpendicularly in the direction of the upper rail sole and connect to both the upper boundary 618 and the lower boundary 619 of the striking surface 607. In many embodiments where the isolated concentric radial gaps 612 do not connect to the upper or lower boundary of the striking surface, a support 636 or a series of supports 636 is required to connect it directly or indirectly to the isolated concentric radial gaps that are connected to the upper and lower boundaries of the striking surface.

[0192] In many embodiments, the separated concentric radiating gaps 612 are concentric with respect to the geometric center of the striking surface and can be either circular or arc-shaped. The diameter of the separated concentric radiating gaps increases in the direction from the geometric center of the striking surface towards the toe and from the geometric center of the striking surface towards the heel. Alternatively, in many embodiments, the diameter of the separated concentric radiating gaps increases in the direction from the geometric center of the striking surface towards the upper boundary of the striking surface and from the geometric center of the striking surface towards the lower boundary of the striking surface.

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

[0194] In an alternative embodiment of a putter-type golf club head having separated concentric radial voids 612, the second material 610 has 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, 1 A set of 5 or more separate concentric radiating gaps 612, 16 or more separate concentric radiating gaps 612, 17 or more separate concentric radiating gaps 612, 18 or more separate concentric radiating gaps 612, 19 or more separate concentric radiating gaps 612, 20 or more separate concentric radiating gaps 612, 21 or more separate concentric radiating gaps 612, 22 or more separate concentric radiating gaps 612, 23 or more separate concentric radiating gaps 612, 24 or more separate concentric radiating gaps 612, 25 or more separate concentric radiating gaps 612, 26 or more separate concentric radiating gaps 612, 27 or more separate concentric radiating gaps 612, 28 or more separate concentric radiating gaps 612, 29 or more separate concentric radiating gaps 612, or 30 or more separate concentric radiating gaps 612 can be defined.

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

[0196] In many embodiments of the separated concentric radial gap, as described above, when the club head is in the address position, the striking surface has a striking surface virtual vertical axis 620 that extends through the geometric center 608 of the striking surface 607 in the upper rail-sole direction (as shown in Figure 21). Furthermore, the corresponding vertical reference axis is offset by 0.25 inches and 0.50 inches in both the heel 603 and toe 602 directions from the striking surface virtual vertical axis.

[0197] As further shown in Figure 21, adjacent, separated, concentric radial gaps are closer to each other along the striking surface virtual vertical axis 620 than the 0.25-inch vertical reference axis 621 and the 0.5-inch vertical reference axis 622 (i.e., they are packed closer together, resulting in a smaller land area (or second material area) between the gaps). Similarly, adjacent, separated, concentric radial gaps are closer to each other along the 0.25-inch vertical reference axis 621 than the 0.5-inch vertical reference axis 622 (i.e., they are packed closer together, resulting in a smaller land area (or second material) between the gaps).

[0198] In many embodiments of the separated concentric radiating gap, the proportion of the first material (or first material land area) along a 0.5-inch vertical reference axis can be approximately 20% to 40%. For example, the proportion of the first material along a 0.5-inch vertical reference axis may be 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. Furthermore, 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 an alternative embodiment, 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 embodiments of the separated concentric radiating gap, the proportion of the first material (or first material land area) along the 0.25-inch vertical reference axis can be approximately 30% to 50%. For example, the proportion of the first material along the 0.25-inch vertical reference axis may be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%. Furthermore, for example, the percentage of the first material along a 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 an alternative embodiment, 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 embodiments of the separated concentric radiating gap, the proportion of the first material (or first material land area) along the virtual axis of the striking surface can be approximately 40% to 60%. For example, the proportion of the first material along the virtual axis of the striking surface may be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. Furthermore, for example, the proportion of the first material along the virtual axis of the striking surface 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 proportion of the first material along the virtual axis of the striking surface 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] Furthermore, in many embodiments, the average ratio, defined as the surface area of ​​the proportion of the first material land area to the surface area of ​​the proportion of the second material land area (measured along their respective vertical reference axes), decreases from the virtual vertical axis of the hitting surface to the 0.5-inch vertical reference axis. This type of arrangement of the first and second materials helps to provide constant ball velocity across the hitting surface because the average ratio along the virtual vertical axis of the hitting surface is greater (i.e., softer) than the average ratio along the 0.5-inch vertical reference axis. This cancels out the loss of energy transfer on heel and toe mishits.

[0202] (Example 1) Example 1 demonstrates that both the length of the putt and the proportion of the vertical land area are important factors to consider in order to select a threshold or desired ball speed across the entire striking surface. This example generally corresponds to the continuous groove embodiment shown in Figures 1 to 9.

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

[0204] When a required ball speed of 5.10 mph is needed for a 10-foot putt, the percentage of the second material vertical land area at the vertical reference axis 122, which is 0.5 inches offset from the virtual vertical axis 120 of the striking surface, is approximately 73%. The percentage of the second material vertical land area at the vertical reference axis 121, which is 0.25 inches offset from the virtual vertical axis 120 of the striking surface, is approximately 55%. The percentage of the second material vertical land area at the virtual vertical axis 120 of the striking surface is approximately 50%.

[0205] When a required ball speed of 5.05 mph is needed for a 10-foot putt, the percentage of the second material vertical land area at the vertical reference axis 122, which is 0.5 inches offset from the virtual vertical axis 120 of the striking surface, is approximately 67%. The percentage of the second material vertical land area at the vertical reference axis 121, which is 0.25 inches offset from the virtual vertical axis 120 of the striking surface, is approximately 50%. The percentage of the second material vertical land area at the virtual vertical axis 120 of the striking surface is approximately 46%.

[0206] Furthermore, for example, Figure 5 shows seven other variable gradient maps detailing the required land area needed to achieve a constant ball velocity for a putt of approximately 25 feet in length, for various impact locations. When a required ball velocity of 7.73 mph for a 25-foot putt is needed, the percentage of the second material vertical land area at the vertical reference axis 122, which is 0.5 inches laterally offset from the virtual vertical axis 120 of the striking surface, is approximately 65%. The percentage of the second material vertical land area at the vertical reference axis 121, which is 0.25 inches laterally offset from the virtual vertical axis 120 of the striking surface, is approximately 58%. The percentage of the second material vertical land area at the virtual vertical axis 120 of the striking surface is approximately 55%.

[0207] When a required ball speed of 7.68 mph is needed for a 25-foot putt, the percentage of the second material vertical land area at the vertical reference axis 122, which is 0.5 inches offset laterally from the virtual vertical axis 120 of the striking surface, is approximately 60%. The percentage of the second material vertical land area at the vertical reference axis 121, which is 0.25 inches offset laterally from the virtual vertical axis 120 of the striking surface, is approximately 56%. The percentage of the second material vertical land area at the virtual vertical axis 120 of the striking surface is approximately 53%.

[0208] When a required ball speed of 7.60 mph is needed for a 25-foot putt, the percentage of the second material vertical land area at the vertical reference axis 122, which is 0.5 inches laterally offset from the virtual vertical axis 120 of the striking surface, is approximately 55%. The percentage of the second material vertical land area at the vertical reference axis 121, which is 0.25 inches laterally offset from the virtual vertical axis 120 of the striking surface, is approximately 51%. The percentage of the second material vertical land area at the virtual vertical axis 120 of the striking surface is approximately 48%.

[0209] The seven variable gradient maps in Figures 4 and 5 are based on a second material, generally composed of metal, e.g., 17-4 stainless steel, and a first material, generally composed of air. The ratio or relationship between the first and second materials varies based on the selected material type, but the application of controlling the ratio or relationship between the first and second materials is still applied to achieve an invariant ball velocity.

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

[0211] Exemplary striking surfaces were further benchmarked against a first commercial putter (Putter 1) having polymer-filled grooves but with groove spacing greater in the center, a second commercial putter (Putter 2) having a greater groove density in the center but lacking the second material, and a third commercial putter (Putter 3) having a grooveless striking surface. The results can be seen in Figures 24–26, where the data were plotted as the ratio of ball velocity to its own center for 10ft, 25ft, and 40ft 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 specified location are important factors to consider when uniform ball velocity across the entire striking surface is required. For example, when comparing the features of the separated void (pill shape) Revision 3A and the separated void (pill 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 25ft putt comparison, it can be seen that the ball velocity at heel and toe hits (relative to center impact) in the separated void (pill shape) Revision 3A putter differed by approximately 1.6% more than the ball velocity generated at the center of the striking surface. However, the separated void (pill shape) Revision 3B putter differed by only 0.8% compared to the ball velocity generated at the center of the striking surface. This led to the conclusion that the relationship / difference between the hardness of the first and second materials is an important factor to consider in order to effectively control ball velocity.

[0213] Furthermore, this embodiment led to the conclusion that the proportion of the first material along the vertical reference axis (at a defined location) is important. For example, when comparing a putter with separated void (pill shape) Revision 4A with a putter with separated void (circular shape), the hardness of the first and second materials was substantially the same, but the proportion of the first material along the striking surface differed. At off-center impacts, the separated void (pill shape) Revision 4 putter differed by only 0.4% compared to the ball velocity generated at the center of the striking surface. The separated void (circular shape) differed by approximately 0.8% at off-center impacts compared to the ball velocity generated at the center of the striking surface. Therefore, when controlling the ball velocity generated across the entire striking surface, the proportion of the first material along the vertical reference axis is another important variable that helps produce a uniform heel-toe hitting surface.

Claims

1. It is a putter-type golf club head, Equipped with the main unit, The aforementioned main body is heels, The toe, separated from the aforementioned heel, Upper rail and The sole, which is separated from the aforementioned upper rail, The striking surface that forms a recess defined by the heel, toe, upper rail, and sole of the main body, A virtual vertical axis of the striking surface extending through the geometric center of the striking surface with respect to the heel, the toe, the upper rail, and the sole, The system comprises an insert housed in the recess defined by the striking surface and configured to complement the recess, The insert comprises a first material and a second material forming at least one of a front surface that conforms to the impact with the golf ball, a rear surface opposite to the front surface, and a thickness defined as the distance between the front surface and the rear surface. The insert further defines a plurality of tablet-shaped voids that extend across the entire thickness of the second material pattern insert, Each of the aforementioned plurality of tablet-shaped voids is on the same straight line as the others in the direction of the upper rail sole and the heel-toe direction. A putter-type golf club head in which the volume of the tablet-shaped recess decreases from the virtual vertical axis of the striking surface toward either the heel or the toe of the main body.

2. The putter-type golf club head according to claim 1, wherein the first material of the insert covers the entire rear surface of the insert and fills each of the plurality of tablet-shaped voids.

3. The putter-type golf club head according to claim 2, wherein the maximum length of the gap in each tablet shape, measured in the heel direction, decreases from the virtual axis of the striking surface to either the heel or the toe of the body.

4. The putter-type golf club head according to claim 3, wherein the average ratio, defined as the ratio of the surface area of ​​the land area of ​​the first material to the ratio of the surface area of ​​the second material, decreases from the virtual vertical axis of the striking surface to a second virtual vertical axis offset from the virtual vertical axis of the striking surface.

5. The putter-type golf club head according to claim 4, wherein the second material surrounds the first material on the front surface of the insert such that, upon impact with the golf ball, the first material and the second material come into contact with at least a portion of the golf ball.

6. The first material has a hardness ranging from Shore 30A to Shore 95A, as described in claim 5, for the putter-type golf club head.

7. The first material has a void of 0.0000803 in for each tablet shape. ３ ~0.00104122in ３ A putter-type golf club head according to claim 1, which satisfies the volume of [the specified volume].

8. The putter-type golf club head according to claim 6, wherein the densities of the first material and the second material are substantially the same.

9. The putter-type golf club head according to claim 1, wherein the maximum length of each separated tablet-shaped void, measured in the heel-toe direction, decreases from the virtual vertical axis of the striking surface toward at least one of the heel or the toe, and the length is between approximately 0.01 inches and approximately 0.3 inches.

10. It is a putter-type golf club head, Equipped with the main unit, The aforementioned main body is heels, The toe, separated from the aforementioned heel, Upper rail and The sole, which is separated from the aforementioned upper rail, The striking surface that forms a recess defined by the heel, toe, upper rail, and sole of the main body, A virtual vertical axis of the striking surface extending through the geometric center of the striking surface with respect to the heel, the toe, the upper rail, and the sole, The system comprises an insert housed in the recess defined by the striking surface and configured to complement the recess, The insert comprises a first material and a second material forming at least one of a front surface that conforms to the impact with the golf ball, a rear surface opposite to the front surface, and a thickness defined as the distance between the front surface and the rear surface. The insert further defines a plurality of tablet-shaped voids that extend over a portion of the putter insert thickness, Each of the aforementioned plurality of tablet-shaped voids is on the same straight line as the others in the direction of the upper rail sole and the heel-toe direction. A putter-type golf club head in which the volume of the tablet-shaped recess decreases from the virtual vertical axis of the striking surface toward the heel and toe of the body.

11. The putter-type golf club head according to claim 10, wherein the first material of the insert covers the entire rear surface of the insert and fills each of the plurality of tablet-shaped voids.

12. The putter-type golf club head according to claim 11, wherein the maximum length of the void in each tablet shape, measured in the heel direction, decreases as it moves away from the virtual axis of the striking surface.

13. The putter-type golf club head according to claim 12, wherein the average ratio, defined as the ratio of the surface area of ​​the first material land area to the ratio of the surface area of ​​the hard material land area, decreases from the virtual vertical axis of the striking surface to a second virtual vertical axis offset from the virtual vertical axis of the striking surface.

14. The putter-type golf club head according to claim 13, wherein the second material surrounds the first material on the front surface of the insert such that, upon impact with the golf ball, the first material and the second material come into contact with at least a portion of the golf ball.

15. The first material has a hardness ranging from Shore 30A to Shore 95A, as described in claim 14, for a putter-type golf club head.

16. The first material has a void of 0.0000803 in for each tablet shape. ３ ~0.00104122in ３ A putter-type golf club head according to claim 10, which satisfies the volume of [the specified volume].

17. The putter-type golf club head according to claim 15, wherein the densities of the first material and the second material are substantially the same.

18. The putter-type golf club head according to claim 1, wherein the maximum length of each separated tablet-shaped void, measured in the heel-toe direction, decreases from the virtual vertical axis of the striking surface toward at least one of the heel or the toe, and the length is between 0.01 inches and 0.3 inches.

19. The putter-type golf club head according to claim 10, wherein the putter-type golf club head has a loft angle of less than 5 degrees.

20. The putter-type golf club head according to claim 10, wherein the thickness of the putter insert is substantially constant throughout the entire insert.

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