Golf club head with variable face thickness

Abstract

A variable-thickness ball club head includes a body having a toe portion, a heel portion, a sole portion, and a top portion. A loft angle LA and a mass of the ball club head mh satisfy mh = 2.1 g / degree x LA + a, where 190 g < a < 210 g, and the ball club head has a blade length of less than 80 mm. A ball striking face of the ball club head has a face center and defines a face plane. A virtual center plane extends perpendicularly through the face center and perpendicularly to the face plane. A center of gravity of the ball club head is located no more than 2.0 mm from the virtual center plane; and a moment of inertia about a vertical axis extending through the center of gravity satisfies Izz > mh x 9.3 cm 2 In one aspect, a face insert including the ball striking face has a mass mf such that mf / mh is 0.22 or less.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to the field of golf clubs. More specifically, the present invention relates to a golf club head with variable face thickness. BACKGROUND

[0002] Mass and performance characteristics of a golf club head can affect the quality and consistency of shots when hitting a golf ball. Such mass and performance characteristics are generally related to mass or mass distribution in the golf club head. Examples of such mass and performance characteristics can include the location of the center of gravity (CG) for the head, the coefficient of restitution (COR) or characteristic time (CT) at various locations on the ball striking face of the club head, and the moment of inertia (MOI) about various virtual axes through the CG.

[0003] As an example of a mass characteristic affecting performance, the location of the CG affects, for example, how high a golf ball is hit, the amount of spin on the golf ball, or the forgiveness of the club head in terms of ball speed and straightness for shots that occur at off-center locations away from the "sweet spot" on the striking face. The sweet spot, in the conventional definition, is the point on the striking face from which a normal projection passes through the CG of the club head. For example, lowering the CG from the ball striking face toward the sole and the back of the iron-type club head can effectively increase the height of the shot for more distance, with more backspin on the golf ball for more effective control of the shot. Placing the sweet spot closer to the center of the ball striking face can also better align the sweet spot with the location of the sweet spot intended by the player. Because the shape and mass distribution of conventional iron-type golf club heads are asymmetric, a laterally centered CG location typically requires, for example, inclusion of high-density weights, which can increase cost and negatively affect swing weight.

[0004] As another example of a mass characteristic affecting performance, a higher MOI in the club head means that the club head is more resistant to twisting when a golf ball is hit at off-center locations on the striking face further from the sweet spot. Increasing the MOI of the club head generally makes the club head more stable or more forgiving of off-center shots, so that such off-center shots are straighter and have more speed due to the higher MOI.

[0005] As an example of a performance characteristic, COR is a measure of energy loss or energy transfer between the club face and the golf ball. When the club face impacts the golf ball, a higher measured COR on the club face means less energy loss, or better energy transfer. More energy transfer to the golf ball results in a higher COR, which means faster ball speed, which typically results in a farther shot. COR can be determined by, for example, conventional cannon testing in accordance with the method for determining COR as prescribed by the United States Golf Association (USGA). In this regard, the USGA has moved from using COR to using a different performance characteristic, referred to as characteristic time (CT), to quantify the resiliency of club faces. For all purposes herein, CT refers to the characteristic time described in the USGA's "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 1.0.0, May 1, 2008).

[0006] Improvements in mass and performance characteristics of club heads are balanced against structural requirements for the intended use of the club head (e.g., stress characteristics). Mass and performance characteristics are also balanced against other constraints (e.g., constraints on CT, size, and club head mass as prescribed by regulatory bodies such as the USGA). In addition, players often have implicit expectations for club heads, such as overall appearance relative to size, or overall expected weight of the head for the type of golf club or loft angle of the golf club. SUMMARY

[0007] The present inventors recognized a need for a variable face thickness pattern for golf club heads, particularly iron-type club heads, that would improve the mass and performance characteristics of the club head while maintaining similar stress limits, appearance, and overall club head weight. As discussed in greater detail below, the improved mass and performance characteristics can include, for example, the coefficient of restitution (COR), characteristic time (CT), moment of inertia (MOI), and / or center of gravity (CG) location for the club head. In some example embodiments, a cavity-back or hollow bodied iron-type club head has an improved variable face thickness pattern that allows for discretionary weight to be moved from the ball striking face of the club head to other areas of the club head to improve the mass and / or performance characteristics of the club head. Advantageously, such a club head has improved mass and performance characteristics, such as a higher COR on the ball striking face, a higher MOI and a more laterally centered, deeper and lower CG location, than comparable club heads, while maintaining similar stress limits. Moreover, such a club head does not sacrifice a traditional appearance, size (e.g., blade length, topline thickness), and overall club head weight (e.g., swing weight) that some players can prefer.

[0008] Reducing face weight while maintaining overall club head weight is important for players that can associate a particular loft angle of a golf club head with a particular mass, and can have a preferred golf club swing weight. Generally, the mass of an iron-type club head increases with loft angle when present in a set. For example, the mass of an iron-type club head can conform to the following equation:

[0009] mh = 2.1 g / degree x LA + a Equation 1.

[0010] where mh is the club head mass in grams, LA is the loft angle of the club head when in a reference position, and a is between 190 g and 210 g. In one or more embodiments, a golf club head maintains such a head mass mh while having an improved face thickness pattern. Such a club head can have an improved face thickness pattern where the vertical MOI (Izz) extending through the CG satisfies:

[0011] Izz > mh x 9.0 cm 2 Equation 2.

[0012] In one or more aspects of the application, a golf club head (when in a reference position) includes a golf club head body having a toe, a heel opposite the toe, a sole, and a top opposite the sole. The mass of the club head, mh, satisfies Equation 1. In addition, the blade length of the club head is less than 80 mm. The ball striking face of the club head defines a face plane and has a face center, and a virtual center plane extends normal to the face plane through the face center. As used herein, the face center of the ball striking face is determined according to the procedure set forth in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). The CG of the club head is located no more than 2.0 mm from the virtual center plane, and the MOI (Izz) about a vertical axis extending through the CG satisfies: Izz > mh x 9.3 cm 2 .

[0013] In some aspects, the ball striking face includes: a central region (the central region including the face center), an intermediate region at least partially surrounding the central region, an upper region above the central region, an upper region above the central region, a lower region below the central region, and a toe region toe-ward of the central region. Each of the central region, the upper region, the lower region, and the toe region includes a maximum width and an average thickness, and the intermediate region is disposed between the central region and each of the upper region, the lower region, and the toe region. The average thickness of the intermediate region is greater than the average thickness of each of the central region, the upper region, the lower region, and the toe region. In one or more embodiments, the intermediate region completely surrounds the central region.

[0014] According to some aspects, at least one of the toe region, the upper region, and the lower region includes on a rear surface thereof: an elongated groove or recess having a width of no less than about 2.0 mm. Alternatively or additionally, the upper region, the lower region, and the toe region each include on a rear surface thereof: an upper groove or recess extending generally in a heel-toe direction, a lower groove or recess extending generally in a heel-toe direction, and a toe groove or recess extending generally in a top-sole direction.

[0015] In one or more aspects of the application, a golf club head (when it is in a reference position) includes a golf club head body having a toe portion, a heel portion opposite the toe portion, a sole portion, and a top portion opposite the sole portion. A club face insert of the club head has a mass mf (which is fixedly attached to the golf club head body) and includes a ball striking face that defines a club face plane. The club head has a mass mh that satisfies Equation 1. The club head has a lie angle of less than 80 mm, and an MOI (Izz) about a vertical axis extending through the club head CG that satisfies Izz > mh x 9.3 cm 2 In one or more embodiments, the ratio of mf / mh for an iron-type golf club head is 0.20 or less.

[0016] In some aspects, the ball striking face includes a sweet spot corresponding to a first COR (COR1) and a secondary location corresponding to a second COR (COR2), the secondary location being spaced at least 7.5 mm from the sweet spot, wherein: COR2 > 0.98 x COR1. In some embodiments, the variable thickness of the ball striking face can provide a higher COR near the sweet spot, boost the COR in the area including the sweet spot, and / or provide a larger area of higher COR near the sweet spot. In another aspect, the repositioning of the ball striking face mass can move the CG to correspond the sweet spot with an area of higher COR and / or a striking area of the ball striking face that the player hits more frequently. For example, a mid-portion of the ball striking face can include a heel-side region that is thicker than a toe-side region to improve the COR in the area of the ball striking face that the player hits more frequently.

[0017] The grooves or depressions on the back surface of the ball striking face of the present application not only improve the COR of the ball striking face, but also can improve the weight distribution of the club head to increase the MOI and / or better position the CG of the club head for better performance by repositioning mass from the ball striking face to other areas of the club head. The stress limits on the ball striking face can also be used as a constraint to determine the grooves or depressions, whereby the ball striking face, despite the reduction in mass, is comparable to prior art club heads in testing durability.

[0018] In one or more aspects of the application, a method of manufacturing a golf club head includes forming a golf club head body having a ball striking face, a heel, a toe opposite the heel, a sole, a crown opposite the sole, and a lie angle of no more than 80 mm. A face pattern of the ball striking face is formed by defining at least one of a central region on the ball striking face including a face center, an intermediate region at least partially surrounding the central region, an upper region above the central region, a lower region below the central region, and a toe region toe-ward of the central region. The intermediate region can be disposed between the central region and each or at least one of the upper region, the lower region, and the toe region. The central region is recessed such that a thickness of the central region is less than a thickness of the intermediate region. At least one of the toe region, the upper region, and the lower region is recessed such that a thickness of the recessed region is less than the thickness of the central region. A variable face thickness pattern is formed such that the ball striking face includes a sweet spot corresponding to a first COR (COR1) and an auxiliary location spaced at least 7.5 mm from the sweet spot and corresponding to a second COR (COR2), where COR2 > 0.98 x COR1.

[0019] In one or more aspects of the application, a method of manufacturing a golf club head includes forming a golf club head body having a ball striking face, a heel, a toe opposite the heel, a sole, and a crown opposite the sole. A variable thickness pattern is determined on the ball striking face using a computing device by defining a series of parameterized zones on the ball striking face including a central zone having a face center. Each parameterized zone includes at least one of a variable first parameter and a variable second parameter. A target value is set for at least one of a first constraint, a second constraint, and a third constraint. At least one of the variable first parameter and the variable second parameter varies for each parameterized zone. An impact of the ball striking face with a golf ball is simulated and the resulting values are evaluated for the target value for at least one of the first constraint, the second constraint, and the third constraint. From the evaluation, a determined variable thickness pattern is formed on the ball striking face. In some embodiments, the first constraint is ball striking face mass, the second constraint is mechanical stress on the ball striking face, and the third constraint is a weighted COR representing an overall effective or desired COR for the ball striking face determined based on CORs for different portions of the ball striking face that have been weighted by their desired probability of golf ball impact. Further, in some embodiments, the variable first parameter and the variable second parameter can include a variable maximum width and a variable thickness for a parameterized zone or region.

[0020] In one or more aspects of the application, a method of manufacturing a golf club head includes forming a golf club head body having a ball striking face, a heel, a toe opposite the heel, a sole, and a crown opposite the sole. A variable thickness pattern is determined using a computing device by defining a central region on the ball striking face (the central region including a ball striking face center), an intermediate region at least partially surrounding the central region, an upper region above the central region, a lower region below the central region, and a toe region toe-ward of the central region. Each of the central region, each of the upper regions, each of the lower regions, and each of the toe regions includes a variable width parameter and a variable thickness parameter. The intermediate region is disposed between the central region and each or at least one of the upper regions, the lower regions, and the toe regions. A target value is set for at least one of a first constraint, a second constraint, and a third constraint. Each of the variable first parameters and each of the variable second parameters varies across the respective regions of the ball striking face. A collision of the ball striking face with a golf ball is simulated, and resulting values are evaluated against the target values for the first constraint, the second constraint, and the third constraint. The determined variable thickness pattern is formed on the ball striking face in accordance with the evaluation.

[0021] The various exemplary aspects described above can be used alone or in various combinations. The foregoing features and advantages of the golf club head of the present application will become apparent with further aid of the following description, drawings and claims. BRIEF DESCRIPTION OF DRAWINGS

[0022] Features and benefits of the present embodiments will become apparent from consideration of the following description in conjunction with accompanying drawings. The drawings and corresponding description are only meant to illustrate the embodiments of the present application and are not meant to limit the scope of the application.

[0023] Figure 1 is a front view of an exemplary golf club head according to one or more embodiments.

[0024] Figure 2 is a rear view of an exemplary cavity-back club head according to one or more embodiments.

[0025] Figure 3 is a toe-side view of the cavity-back club head of Figure 2 according to one or more embodiments.

[0026] Figure 4 is a cross-sectional view of the cavity-back club head of Figure 2 according to one or more embodiments.

[0027] Figure 5 is a rear view of an exemplary hollow-back club head according to one or more embodiments.

[0028] Figure 6 is a cross-sectional view of a hollow-type club head according to one or more embodiments. Figure 5 is a cross-sectional view of a hollow-type club head according to one or more embodiments.

[0029] Figure 7 depicts a rear surface of a ball striking face of an exemplary cavity-back club head according to one or more embodiments.

[0030] Figure 8 depicts a rear surface of a ball striking face of an exemplary hollow-type club head according to one or more embodiments.

[0031] Figure 9 depicts a rear surface of a ball striking face of an exemplary club head including a thickness pattern according to one or more embodiments.

[0032] Figure 10 depicts a rear surface of a ball striking face of an exemplary club head including a different thickness pattern according to one or more embodiments.

[0033] Figure 11 is a flowchart of an exemplary thickness pattern formation process for a ball striking face according to one or more embodiments.

[0034] Figure 12 is a flowchart of another exemplary thickness pattern formation process for a ball striking face according to one or more embodiments. DETAILED DESCRIPTION

[0035] The representative examples of the one or more novel and nonobvious aspects and features of the golf club heads and methods of manufacturing such club heads as described below are not intended to be limited in any way. In addition, various aspects and features of the present disclosure can be used alone or in various

[0036] Figure 1 is a front view of an exemplary golf club head 100 according to one or more embodiments. As shown, the club head 100 includes a toe portion 102, a heel portion 104, a top line portion 106, and a sole portion 111. The club head 100 also includes a hosel 110 extending from the heel portion 104. The hosel 110 can include an open end for receiving a golf club shaft (not shown). A hosel axis 120 extends axially through the center of the hosel 110 and lies in a virtual vertical hosel plane (e.g., the virtual vertical hosel plane 21 shown in FIG. 1 1 1). Figure 1 The club head 100 (including the ball striking face 109) can be formed from, for example, a steel material. Figure 3

[0037] Figure 1 ​In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 3 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 2 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005).

[0038] In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005).

[0039] In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 1 As shown in FIG. 1, the ball striking face 109 includes a plurality of grooves or score lines 112 that impart additional spin to a golf ball when it is struck. In some embodiments, the ball striking face 109 can form part of a face insert that is fixedly attached to a main body of the club head 100. In other embodiments, the ball striking face 109 can be integrally formed as part of the main body of the club head 100. Figure 1 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 3 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 1 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). Figure 1 In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005). In some embodiments, the ball striking face 109 includes a face center 14 that lies on a virtual center plane 10 that extends perpendicularly through the face center 14 and is perpendicular to a face plane defined by the ball striking face 109 (e.g., face plane 22 in FIG. 1). As used herein, the "face center" of a ball striking face is determined according to the procedures described in the USGA "Measuring Procedures for the Flexibility of Golf Club Heads" (Revision 2.0, March 25, 2005).

[0040] Figure 1 In the example, the sweet spot 16 is located on the striking surface 109, at a horizontal distance CG from the virtual center plane 10 toward the heel 104. H The sweet spot 16 is located on the virtual vertical CG plane 12, so that the sweet spot 16 is located on the striking face 109, wherein the clubface plane of the striking face 109 (e.g., ...) is perpendicular to the clubface plane of the striking face 109. Figure 3 The virtual line of the normal projection of the clubface plane 22) passes through the CG of the clubhead 100 (e.g. Figure 2 (CG18 in the text). As used herein, the "sweet spot" of a clubhead is defined as the position on the striking face of the clubhead from which a virtual line projecting the normal to the clubface plane of the striking face passes through the CG position of the clubhead.

[0041] As discussed in more detail below, the striking face 109 has a variable thickness formed in different regions or parametric domains to provide improved quality and / or performance characteristics of the clubhead 100. These characteristics may include, for example, a larger coefficient of restitution (COR) and / or a larger characteristic time (CT) over a larger area and / or a more conventional striking area of ​​the striking face 109, a virtual vertical CG axis (e.g., Figure 4 The virtual vertical CG axis 24) around and / or the virtual horizontal CG axis (e.g. Figure 2 This results in a larger moment of inertia (MOI) around the virtual horizontal CG axis 15, and / or an improved CG position for the clubhead 100. These improvements in quality and performance characteristics can be achieved by selectively thinning or thickening different regions or parameterized domains and / or repositioning the free mass of the striking face to other parts of the clubhead. As used herein, the striking face thickness is perpendicular to the plane of the clubface defined by the striking face (e.g., [missing information]). Figure 3 In the rod surface plane 22 and Figure 6 The measurement was taken from the plane of the rod surface (42).

[0042] The total mass of a clubhead can be used as a target total mass that includes structural mass and free mass. Structural mass, as used herein, generally refers to the mass necessary to form the minimum structural integrity required for the clubhead to be operable for its intended use. Free mass, on the other hand, can refer to the remaining mass after the target mass has been given, which is not required to form the minimum structural integrity of the clubhead and can therefore be primarily positioned to adjust the mass and / or performance characteristics of the clubhead.

[0043] For example, the thickness of different regions or parametric domains of the striking face 109 causes mass to be transferred from these regions or parametric domains to other locations within the clubhead 100, providing a higher MOI and improved CG of the clubhead 100 (e.g. Figure 2The position of CG18 in the clubface is adjusted to improve the COR value at a specific location on the striking face. For example, removing mass from a specific area of ​​the striking face can improve the COR of the striking face, and the removed mass can be repositioned in the clubhead, thereby advantageously positioning the CG of the clubhead 100 closer to the virtual center plane 10, closer to the virtual ground plane 13, and further away from the striking face 109. Consequently, the sweet spot 16 can be advantageously positioned closer to the center of the clubface 14 to better correspond to the player's desired sweet spot position and / or the striking area where the striking face is hit more frequently, providing a more forgiving clubhead for better off-center shots in terms of height, straightness, and distance. In this regard, according to the invention, as a result of repositioning mass from the striking face 109, the sweet spot 16 in some embodiments can be horizontally positioned no more than 2.0 mm from the center of the clubface 14. In other words, the CG of the clubhead 100 (e.g., ... Figure 2 In this embodiment, CG18 can be located at a position no more than 2.0 mm away from the virtual center plane 10. In more than one embodiment, the golf club head having this lateral CG position does not contain any high-density material (e.g., tungsten alloy).

[0044] As described above, the variable thickness pattern of the hitting surface, detailed below, can increase the COR (Coefficient of Reduction) on the hitting surface 109 at locations corresponding to more frequent hits or larger areas of the hitting surface, thereby providing better energy transfer for off-center shots or for a statistically larger number of shots. Additionally or alternatively, the disclosed variable thickness pattern for the hitting surface can increase the area of ​​the hitting surface with a relatively high COR. For example, in some embodiments, Figure 1 The striking surface 109 may include: a maximum COR of not less than 0.80 at a first position, and a COR of not less than 98% of the maximum COR at an auxiliary position on the striking surface (which is not less than 7.5 mm from the first position). In such an embodiment, the first position corresponding to the maximum COR may be at or near the sweet spot 16, for example, within 5 mm of the sweet spot 16. Some embodiments of the variable thickness pattern for improving the COR on the striking surface, as described below, include, for example, a central region of the striking surface where the heel-side thickness is greater than the toe-side thickness.

[0045] Figure 2 This is a rear view of an exemplary concave-back golf club head according to one or more embodiments. In this regard, Figure 2 The clubhead 100 includes a rear cavity 114 located at least a portion behind the striking face 109, and a rear muscle 116 near the sole 111. For ease of illustration, Figure 2 Provided Figure 1FIG. 1 illustrates a rear view of a golf club head 100. However, those skilled in the art will appreciate, with the benefit of this disclosure, that the golf club head 100 can include different configurations in other embodiments, such as Figure 6 a hollow body configuration.

[0046] As shown in FIG. 1, the golf club head 100 includes a ball striking face 109, a heel side 110, a toe side 112, a top line 106, a sole 108, and a hosel 114. The ball striking face 109 is a planar surface that is configured to contact a golf ball during a golf swing. The ball striking face 109 is coupled to the heel side 110 and the toe side 112. The top line 106 is a line that extends along the top edge of the ball striking face 109. The sole 108 is a planar surface that is configured to contact the ground during a golf swing. The hosel 114 is a portion of the golf club head 100 that is configured to receive a shaft of a golf club. Figure 2 As shown in FIG. 1, the CG 18 is located on a virtual horizontal CG axis 15. The horizontal MOI (Ixx) of the golf club head 100 is shown around the virtual horizontal CG axis 15, which extends through the CG 18 and is parallel to the ball striking face 109. As described above, a decrease in mass achieved by varying the thickness of the ball striking face 109 can increase Ixx and thereby improve the performance of the golf club head 100 for off-center hits in the vertical direction along the ball striking face 109 (e.g., toward the top line 106 or toward the sole 108).

[0047] Figure 2 FIG. 1 illustrates a blade length (BL) of the golf club head 100, which is measured between the most toe side extent of the golf club head 100 at the virtual vertical toe plane 25 and the intersection of the hosel axis 20 and the ground plane 13, which also defines the lie angle a. In some embodiments, the BL of the golf club head 100 can be less than 80 mm. This blade length may, for example, correspond to a desired BL for an iron-type golf club head. In this regard, the thickness of the ball striking face 109 can be varied without sacrificing the conventional external dimensions of the golf club head 100 (e.g., the BL or the top line thickness of the top line 106 (e.g., the loft angle LA) of the golf club head 100) in some embodiments. Figure 3 TL in FIG. 1 T )) of the golf club head 100. Moreover, the golf club head total mass or golf club head target mass (e.g., swing weight) of the golf club head 100 can correspond to a desired mass for an iron-type golf club head in some embodiments.

[0048] As described above, the mass of an iron-type golf club head typically varies according to the loft angle (LA). When present in a set, the mass of an iron-type golf club head can increase with the loft angle. For example, the mass of an iron-type golf club head can conform to the following equation:

[0049] mh = 2.1 g / degree x LA + a Equation 1.

[0050] where mh is the mass of the golf club head, LA is the loft angle of the golf club head when the golf club head is in a reference position, and a is between 190 g and 210 g. In some embodiments, the golf club head 100 maintains this club head mass mh while having an improved face thickness pattern.

[0051] Figure 3 FIG. 2 illustrates a heel side view of a golf club head 100 according to one or more embodiments. As Figure 3As shown, the LA of the club head 100 is defined between the face plane 22 and the virtual vertical hosel plane 21. As described above, the hosel axis 20 extends axially through the center of the hosel 110 and lies in the virtual vertical hosel plane 21. The face plane 22 is defined such that the ball striking face 109 lies in the face plane 22. Referring to Equation 1 above, the club head mass of the club head 100 can vary with the LA of the club head 100 such that higher numbered clubs having a greater LA angle have a higher club head mass.

[0052] As Figure 3 shown, the distance between the face plane 22 and the back plane 26 defines a top line thickness (TL T ) that corresponds to the thickness of the top line portion 106 shown in Figure 1 . The TL T of the club head 100 is not greater than 6.5 mm. This TL T may correspond to the TL T desired for an iron-type club head. In this regard, the thickness pattern of the ball striking face 109 can be varied without sacrificing the conventional overall dimensions of the club head 100 (e.g., the TL T of the club head 100) that can be preferred by some players.

[0053] Figure 4 is a cross-sectional view of the club head 100 taken along section line 4 in Figure 2 . As Figure 4 shown, the back surface of the ball striking face 109 facing the rear cavity 114 and the rear muscle 116 includes an upper region groove 118, a middle region recess 120, and a lower region groove 122. In embodiments where the ball striking face 109 includes a face insert, the back surface of the face insert can include the upper region groove 118, the middle region recess 120, and the lower region groove 122.

[0054] The back surface of the ball striking face 109 also includes a middle region 108 that at least partially surrounds the middle region including the middle region recess 120. In this regard, the middle region 108 includes an upper middle region 108 U and a lower middle region 108 L that are located above and below the middle region recess 120, respectively. The average thickness of each of the middle region, the upper region, and the lower region (including the middle region recess 120, the upper region groove 118, and the lower region groove 122, respectively) is lower than the average thickness of the middle region 108, which can have a generally uniform thickness. The upper region groove 118 and the lower region groove 122 can generally extend in a heel-to-toe direction, as shown in Figure 7 and 8Examples of the upper region trenches 318 and 418 and the lower region trenches 322 and 422 are shown.

[0055] In some embodiments, at least one of the upper region groove 118 and the lower region groove 122 may be an elongated groove with a width of not less than about 2.0 mm. Furthermore, the thickness of the middle region recess 120 may gradually decrease in some embodiments, such that the heel-side region of the middle recess may be thicker than the toe-side region of the middle recess, for example... Figure 7 An example of a central depression 320 is shown. As another example, the central depression may include a heel-side region with a greater thickness than the toe-side region, such as... Figure 8 Examples of the heel-side region 435 and the toe-side region 433 are shown. In some embodiments, the thickness of the central region may gradually decrease from the heel-side of the central region to the toe-side of the central region.

[0056] Figure 4 In this context, Izz is centered on the virtual vertical CG axis 24. The free mass removed or saved from the striking surface 109 to form the upper region groove 118, the middle region depression 120, and the lower region groove 122 can be repositioned to the heel 104 and toe 102 to enhance Izz. In some embodiments, Izz may satisfy:

[0057] Izz>mh×9.3cm 2 Formula 2

[0058] Where mh is the mass of the clubhead 100. As described above, increasing the MOI around the virtual vertical axis 24 extending through CG18 improves the tolerance of the clubhead 100, thereby resulting in less bending of the clubhead 100 around the virtual vertical axis 24 during horizontally eccentric shots along the striking face 109 (e.g., shots with the sweet spot 16 more toe- or more heel-oriented).

[0059] Furthermore, the variable thickness pattern of the striking surface 109 can increase the COR (Coefficient of Reduction) at locations on the striking surface 109 corresponding to more frequently struck positions or larger striking surfaces, thus providing better energy transfer for off-center shots or for a statistically larger number of shots. The variable thickness pattern of the striking surface 109 (with an upper region groove 118, a middle region depression 120, and a lower region groove 122) can increase the area of ​​the striking surface with a relatively high COR.

[0060] For example, the mass removed from a specific area of ​​the striking face 109 can improve the COR of the striking face 109, and the removed mass can be repositioned in the clubhead 100 so that CG18 can be advantageously positioned closer to the lateral center of the striking face 109, closer to the virtual ground plane 13, and further away from the rear of the striking face 109. In such an example, the mass removed or saved from the striking face 109, for example by machining (e.g., grinding, milling) or by known casting or forging processes, to form the upper region groove 118, the lower region groove 122, and the middle region depression 120, can be repositioned in the back muscle 116 to lower the position of CG18 and move CG18 further away from the rear of the striking face 109. As another example, the mass removed from the striking face 109 can be repositioned from the heel side of the striking face 109 to the toe side of the striking face 109 to move CG18 from the heel 104 to the toe 102.

[0061] Those skilled in the art, upon reviewing this disclosure, will understand that other embodiments may differ. Figure 4 The configuration shown. For example, other embodiments of the concave back clubhead may include a rear cavity 114 or rear muscle 116 of different shapes. As another example variation, the cross-sectional shape of one or more of the upper region groove 118, the middle region recess 120, and the lower region groove 122 may be different in other embodiments. Figure 4 The shapes shown are different. As another example variation, some implementations may not include the central region recess 120 and may only include one or more grooves adjacent to the outer periphery of the rear surface of the striking surface 109, such as the upper region groove 118 and / or the lower region groove 122.

[0062] Figure 5 This is a rear view of an exemplary hollow clubhead 200 according to one or more embodiments. The clubhead 200 (including the striking face 209) may be formed of, for example, steel. Figures 1 to 4 Similar to the clubhead 100, the clubhead 200 includes a sheath 210, a toe 202, and a heel 204. However, instead of having a rear cavity, for example, having a cavity for the clubhead 100... Figure 2 and Figure 4 The posterior cavity 114, Figure 5 and Figure 6 The clubhead 200 includes an inner cavity 224 located at least a portion behind the striking face 209, such as Figure 6 As shown. In some embodiments, the striking face 209 may be formed as part of a face insert fixedly attached to the body of the clubhead 200. In other embodiments, the striking face 209 may be integrally formed as part of the body of the clubhead 200. For ease of explanation, Figure 5 A rear view of the clubhead 200 is provided, which is consistent with... Figure 1The external front appearance of the clubhead 100 is similar to that of the club in the previous embodiment. However, those skilled in the art will understand upon referring to this disclosure that in other embodiments, the clubhead 200 may include... Figure 5 and Figure 6 The different constructions shown.

[0063] like Figure 5 As shown, CG48 is located on the virtual horizontal CG axis 45. Figure 6 The horizontal MOI (Ixx) of the clubhead 200 is shown around a virtual horizontal CG axis 45 (which extends through CG48 and is parallel to the striking face 209). The reduction in mass achieved by varying the thickness of the striking face 209 allows for an increase in Ixx by repositioning mass to other parts of the clubhead 200, thereby improving the performance of the golf clubhead 200 for eccentric shots along the striking face 209 in the vertical direction (e.g., towards the top line 206 or towards the bottom 211).

[0064] Figure 5 The clubhead 200 has a blade length (BL) measured between the toe portion of the clubhead 200 on the virtual vertical toe plane 55 and the intersection of the sheath axis 40 and the ground plane 13, which also defines the neck angle α. In some embodiments, the clubhead 200 may have a BL of less than 80 mm. This blade length may, for example, correspond to the desired BL of an iron clubhead. In this regard, the thickness of the striking face 209 can be varied without sacrificing the conventional external dimensions of the clubhead 200 (e.g., BL or topline thickness of the topline portion 206). Furthermore, in some embodiments, the total clubhead mass or target clubhead mass (e.g., swing weight) of the clubhead 200 may correspond to the desired mass of an iron clubhead.

[0065] As mentioned above, the mass of an iron clubhead typically varies according to its loft angle (LA). Figure 6As shown, the LA of the clubhead 200 is defined between the face plane 42 and the virtual vertical sheath plane 41. The virtual vertical sheath plane 41 includes a sheath axis 40, which extends axially through the center of the sheath 210. The face plane 42 is defined such that the striking face 209 is located within the face plane 42. For the LA, the mass of the clubhead 200 satisfies Equation 1 provided above, while having an improved face thickness pattern. Furthermore, the depth of the clubhead 200 can be less than that of a typical hybrid golf clubhead. For example, the depth of the clubhead 200 can be less than 30 mm, measured from the leading edge to the trailing edge of the bottom 211 of the clubhead 200. As described above, the repositioning of the mass of the striking face 209 can generally allow for improved performance and mass characteristics, such as increased MOI, better CG position, and increased COR or CT, without altering the desired dimensions, footprint, or appearance of a conventional iron golf clubhead.

[0066] Figure 6 It is based on one or more embodiments along Figure 5 The cross-sectional view of the clubhead 200 taken by section line 6 in the figure. Figure 6 As shown, the rear surface of the striking face 209 facing the inner cavity 224 and the buttock muscle 216 includes an upper region groove 218 and a middle region depression 220. In embodiments where the striking face 209 includes a clubface insert, the rear surface of the clubface insert may include an upper region groove 218 and a middle region depression 220.

[0067] The rear surface of the striking surface 209 also includes a central region 208 that at least partially surrounds the central region, the central region including a central region depression 220. In this regard, the central region 208 includes an upper central region 208 located above and below the central region depression 220, respectively. U and the lower middle area 208 L The average thickness of each middle region (including middle region recess 220) and each upper region (including upper region groove or recess 218) is less than the average thickness of the middle region 208. In some embodiments, the middle region 208 may have an approximately uniform thickness. The upper region groove 218 may generally extend in the heel-toe direction, as shown in... Figure 7 and Figure 8 Examples of trenches 318 and 418 in the upper middle region are shown.

[0068] In some embodiments, the upper region groove 218 may have an elongated groove with a width of not less than about 2.0 mm. Furthermore, in some embodiments, the thickness of the middle region depression 220 may gradually decrease so that the heel-side region of the middle depression may be thicker than the toe-side region of the middle depression, such as... Figure 7An example of a central depression 320 is shown. As another example, the central depression may include a heel-side region with a greater thickness than the toe-side region, such as... Figure 8 Examples of the heel-side region 435 and toe-side region 433 are shown in the figure.

[0069] Reference Figures 7 to 10 As discussed in more detail below, this gradual reduction or variation in the thickness or concavity of the central region can generally improve the COR in the central region and / or increase the area of ​​the striking face 209 with a higher COR. Furthermore, the thickness of different regions or parametric domains of the striking face 209 can cause mass to shift from these regions or parametric domains to other locations on the clubhead 200, providing a higher MOI and an improved CG48 position on the clubhead 200, while simultaneously increasing the COR value at specific locations on the striking face.

[0070] For example, the mass removed from a specific area of ​​the striking face 209 can improve the COR of the striking face 209, and the removed mass can be repositioned within the clubhead 200 so that the CG48 can be advantageously located closer to the lateral center of the striking face 209, closer to the virtual ground plane 13, and further away from the rear of the striking face 209. In this example, the mass removed from the striking face 209 to form the upper region groove 218 and the middle region recess 220 (e.g., by machining or by known casting or forging processes) can be repositioned to the buttress 216 to lower the position of the CG48 and move the CG48 further away from the rear of the striking face 209. In some embodiments, the striking face 209 may be formed separately and attached to the body of the clubhead 200 by welding or other known methods. As another example, the mass removed from the striking face 209 can be repositioned from the heel side of the striking face to the toe side of the striking face 209 to move CG48 from the heel 204 to the toe 202.

[0071] As a result, the sweet spot on the striking surface 209 (e.g.) Figure 1 The sweet spot 16 in the clubface can be advantageously located closer to the center of the clubface (e.g., Figure 1 The center of the clubface 200 (14) is positioned to better correspond to the sweet spot position desired by the player or the position on the striking face 209 where the club is struck more frequently. In this regard, in some embodiments, due to the repositioning of the mass of the striking face 209, the sweet spot of the clubhead 200 may be horizontally located no more than 2.0 mm from the center of the clubface.

[0072] As described above, the variable thickness pattern of the hitting face can improve the COR at positions on the hitting face 209 corresponding to more frequently hit positions, thereby providing better energy transfer for a statistically larger number of hits and thus achieving an improved weighted COR for the hitting face. Additionally or alternatively, the disclosed variable thickness pattern for the hitting face can increase the area of ​​the hitting face with a relatively high COR. For example, in some embodiments, the hitting face 209 may include: a maximum COR of not less than 0.80 at a first position, and a COR of not less than 98% of the maximum COR at an auxiliary position on the hitting face not less than 7.5 mm from the first position. In such embodiments, the first position corresponding to the maximum COR may be at or near the sweet spot, for example, within 5 mm of the sweet spot. Some embodiments of the variable thickness pattern described below for improving the COR on the hitting face include, for example, a central region of the hitting face (which has a greater heel-side thickness than the toe-side region).

[0073] Figure 6 In this configuration, Izz is centered on the virtual vertical CG axis 44. The free mass removed or saved from the striking face 209 to form the upper region groove 218 and the middle region recess 220 can be repositioned to the heel 204 and toe 202 to enhance Izz. In some embodiments, Izz may satisfy Equation 2 above. Enhancing the MOI around the virtual vertical axis 44 extending through CG48 improves the tolerance of the clubhead 200, resulting in less bending of the clubhead 200 around the virtual vertical axis 44 during horizontally eccentric shots along the striking face 209 (e.g., shots with the sweet spot more toe- or more heel-oriented).

[0074] Those skilled in the art, upon reviewing this disclosure, will understand that other embodiments may be similar. Figure 5 and Figure 6 The construction shown differs. For example, other embodiments of a hollow clubhead may include an inner cavity 214 or a back muscle 216 of different shapes. As another example variation, the cross-sectional shape of the upper region groove 218 or the middle region recess 220 may differ in other embodiments. Figure 4 The shapes shown are different. In this regard, as discussed above... Figure 4 As shown in the example, other embodiments may also include a lower region groove. In other embodiments, the middle region recess 220 may be omitted so that one or more recesses on the rear surface of the striking surface 209 may only contain one or more grooves or channels adjacent to the periphery of the rear surface, such as the upper region groove 218.

[0075] Figure 7 An exemplary concave back clubhead according to one or more embodiments is depicted (e.g., Figures 2 to 4 The back surface 328 of the striking face 309 of the concave-back clubhead 100. For example...Figure 7 As shown, the posterior surface 328 includes recesses in an upper region, a middle region, a toe region, and a lower region. More specifically, the posterior surface 328 includes an upper region groove or channel 318, a toe region groove or channel 326, and a lower region groove or channel 322, which are adjacent to the periphery of the posterior surface 328. A middle region recess 320 is formed in the middle region between the upper region groove 318, the toe region groove 326, and the lower region groove 322. An intermediate region 308 surrounds the intermediate region recess 320 and is disposed between the intermediate region recess 320 and each of the upper region grooves, each of the toe region grooves 326, and each of the lower region grooves 322. Furthermore, the average thickness of the intermediate region 308 is greater than the average thickness of each of the intermediate region recesses 320, each of the upper region grooves 318, each of the toe region grooves 326, and each of the lower region grooves 322.

[0076] The preferred dimensions of the center recess 320 have a face thickness not exceeding 2.5 mm, preferably decreasing gradually from 2.3 mm on the heel side to 1.9 mm on the toe side. The preferred dimensions of the upper groove 318 have a face thickness not exceeding 1.5 mm and a maximum width not less than 5.0 mm. The preferred dimensions of the toe groove 326 have a face thickness less than the upper groove 318 and a maximum width not less than 2.0 mm. The preferred dimensions of the lower groove 322 have a face thickness not exceeding 1.5 mm (preferably greater than the toe recess 326) and a width not less than 2.5 mm. As described herein, the width of the groove or channel is defined by the maximum vertical distance between the longer opposite sides of the groove or channel. The preferred thickness of the middle region 308 of the depression surrounding the middle region depression 320, the upper region groove 318, the toe region groove 326 and the lower region groove 322 is less than 3 mm and greater than 2.5 mm, preferably about 2.7 mm.

[0077] against Figure 7 Some preferred dimensions of the recess on the middle and rear surface 328 may include those shown in Table 1 below. As used below, thickness refers to the thickness of the striking face 309, width refers to the distance measured perpendicular to the longest opposing side of the recess, and radius refers to the radius of curvature between the bottom of the recess (which has the clubface thickness shown for the recess) and the adjacent walls of the recess.

[0078] Table 1

[0079]

[0080] The aforementioned preferred dimensions for the central region recess 320, upper region groove 318, toe region groove 326, and lower region groove 322 improve the performance and quality-related characteristics of the concave-back clubhead. These performance and quality-related characteristics include, for example, the CG position of the clubhead, the COR or CT at different locations on the strike face, and the MOI around different virtual axes passing through the CG. As described above, the recess on the rear surface 328 not only increases the COR of the strike face 309 (accompanied by a reduction in mass in the strike face 309 at specific locations), but also improves the weight distribution of the clubhead to improve the MOI and / or better position the CG for improved performance. The recess on the rear surface 328 can also be determined using maximum face stress as a constraint, thus ensuring that, despite the reduced mass of the strike face 309, it remains comparable to prior art clubheads when testing durability.

[0081] Those skilled in the art, upon reference to this disclosure, will understand that other embodiments of the rear surface of the striking face of a concave-back clubhead may be similar to... Figure 7 The configurations in the examples differ. For example, other configurations may not include... Figure 7 More than one depression is shown.

[0082] Figure 8 Exemplary hollow clubheads according to one or more embodiments are depicted (e.g., Figure 5 and Figure 6 The hollow clubhead 200 has a striking face 409 and a rear surface 428. For example... Figure 8 As shown, the posterior surface 428 includes depressions in the upper region, middle region, toe region, and lower region. However, compared to... Figure 7 The example of rear surface 328 is different. Figure 8 The rear surface 428 of the middle region contains a different thickness pattern for the central region recess 420. More specifically, the middle portion 437 of the central region recess 420 is thicker than the heel side 435 and the toe side 433. This configuration typically further improves the COR or CT by providing a larger area for the striking surface 409 in the central region.

[0083] Furthermore, the posterior surface 428 includes an upper region groove or channel 418, a toe region groove or channel 426, and a lower region groove or channel 422, which are adjacent to the periphery of the posterior surface 428. A central region recess 420 is formed in the central region between the upper region groove 418, the toe region groove 426, and the lower region groove 422. An intermediate region 408 surrounds the intermediate region recess 420 and is disposed between the intermediate region recess 420 and each of the upper region grooves 418, each of the toe region grooves 426, and each of the lower region grooves 422. Furthermore, the average thickness of the intermediate region 408 is greater than the average thickness of each of the intermediate region recesses 420, each of the upper region grooves 418, each of the toe region grooves 426, and each of the lower region grooves 422.

[0084] Figure 8 Some preferred thicknesses of the recess on the back surface 428 of the impact face 409 include the thicknesses of the following clubheads 1B, 2B, 3B, and 4B as shown in Table 2. The center region thicknesses provided in Table 2 for comparison clubhead B are obtained by measuring the original... Figure 8 The thickness of the striking face is obtained at the location of the central region depressions (i.e., the heel-side central region depression 435, the middle central region depression 437, and the toe-side central region depression 433). In contrast, clubhead B includes continuous peripheral grooves or channels of uniform width and depth along most of the periphery of its striking face rear surface. Table 2 also includes preferred widths for the upper region groove 418, the toe region groove 426, and the lower region groove 422, determined by measuring the vertical distance between the two longest opposing sides of the groove.

[0085] Table 2

[0086]

[0087] The preferred dimensions of the aforementioned central region recess 420 (i.e., the middle central region recess 437, the heel-side central region recess 435, and the toe-side central region recess 433), the upper region groove 418, the toe region groove 426, and the lower region groove 422 improve the performance and quality-related characteristics of the hollow clubhead. These performance and quality-related characteristics include, for example, the clubhead's CG position, the COR or CT at different locations on the strike face, and the MOI around different virtual axes passing through the CG. In this regard, Table 4 below provides measured or computer-simulated values ​​for the mass removed from the strike face 409, the COR at the center of the face 54, the COR at the off-center position 58 (which is 7.5 mm to the toe of the sweet spot 56), and the weighted COR representing the expected COR or total COR for the strike face 409 (calculated by weighting the COR at different locations on the strike face 409 using the probability that the golf ball will be hit at different locations).

[0088] In some embodiments, the striking face 409 may include a maximum COR of not less than 0.80 at a first location (e.g., at the sweet spot 46 or within 5 mm of it) and a COR of not less than 98% of the maximum COR at a second location 48 at a distance of not less than 7.5 mm from the first location. The indentation thickness of the striking face 409 may also be determined to increase the weighted COR. The weighted COR is determined based on the probability of collisions in a binby-bin or location-by-location manner, as discussed in detail in US Patent No. 10,456,643, filed December 28, 2018, entitled "Golf Club Head," the entire contents of which are incorporated herein by reference. The weighted COR, "expected COR," or "total COR" can be considered as a probabilistically adjusted measure of the performance of a golf club head, which is what a typical golfer would actually expect when considering how collisions are distributed around the striking face 409 with experience. Using this type of information, golfers can make more informed decisions about selecting golf clubs based on their weighted COR. Additionally or alternatively, golfers can determine which golf clubs are better suited to their specific handicap or skill level.

[0089] The weighted COR can be determined by overlaying a rectangular virtual evaluation region onto the striking face 409. This rectangular virtual evaluation region includes a first pair of horizontal sides of 35 mm in length, a second pair of vertical sides of 25 mm in length, and a geometric center coinciding with the center of the clubface. The rectangular virtual evaluation region is divided into multiple bins by dividing it into a matrix of five rows (m = 5) with the same height of 5 mm and seven columns (n ​​= 9) with the same width of 5 mm, thus forming multiple bins with coordinates i and j. The average COR is determined (e.g., by measurement or computer simulation) for each bin represented by its coordinates i, j, and the weighted COR can be determined using Equation 3 below. In other embodiments, the COR can be determined for the center position of each bin.

[0090]

[0091] Where p ij It is based on the block collision probability at coordinates i,j in the collision probability matrix, as shown in Table 3 below.

[0092] Table 3

[0093] i＝1 i＝2 i＝3 i＝4 i＝5 i＝6 i＝7 j＝1 0.42％ 0.43％ 0.30％ 0.22％ 0.11％ 0.03％ 0.03％ j＝2 3.58％ 3.64％ 2.96％ 2.23％ 1.20％ 0.76％ 0.31％ j＝3 5.46％ 8.29％ 8.54％ 6.50％ 4.42％ 2.43％ 1.06％ j＝4 3.36％ 5.97％ 6.55％ 6.65％ 5.01％ 2.83％ 1.19％ j＝5 1.52％ 2.43％ 3.31％ 3.18％ 2.49％ 1.80％ 0.81％

[0094] In different implementations, other collision probability matrices may be used to determine the weighted COR. For example, other collision probability matrices used to determine the weighted COR or the desired COR may include those disclosed in US Patent No. 10,456,643, which is incorporated herein by reference above. As another example variation, the location for COR measurement may correspond to a point or a boundary of a shape different from the rectangular blocks described in Table 3 above. In other variations, the location for COR measurement may correspond to mutually spaced regions that are not adjacent to each other. As another example variation, the orientation of the blocks or COR measurement locations may not form a rectangular matrix, but rather an irregular configuration with different constructions, such as a ring or sunburst configuration.

[0095] As described above, the indentation on the rear surface 428 not only improves the Coordination Rate (COR) of the striking face 409 (accompanied by a reduction in mass within the striking face 409 at a specific location), but also improves the weight distribution of the clubhead to enhance the Moment of Intake (MOI) and / or better position the Coordination Rate (CG) for improved performance. The indentation on the rear surface 428 can also be determined using maximum face stress as a constraint, thus ensuring that despite the reduced mass of the striking face 409, it remains comparable to existing clubheads when durability is tested.

[0096] Refer to Table 2 above for the specific targets Figure 8 The dimensions of the recess on the center-back surface 428 are provided in Table 4 below, which provides computer-simulated or measured mass and performance characteristics for the corresponding comparative clubheads B, 1B, 2B, 3B, and 4B. As shown in Table 4, the amount of mass removed or saved from the striking face decreases from clubhead 1B to clubhead 4B as the center face COR, eccentric COR, and weighted COR decrease. However, each of clubheads 1B to 4B provides higher values ​​for the amount of mass removed, center face COR, eccentric COR, and weighted COR compared to the comparative clubhead B.

[0097] Table 4

[0098]

[0099] Those skilled in the art, upon reference to the content of this disclosure, should understand that... Figure 8 Other recess configurations, different from those shown, are also possible. In this regard, as discussed above... Figure 7The removal of mass from the striking face 309 (accompanied by the depression formed on the rear surface 328) can also result in a decrease in the mass of the striking face 309, an increase in the center of the clubface COR, an increase in the COR at the off-center position (7.5mm to the sweet spot), and an increase in the weighted COR. As another example variation, some implementations may not include more than one upper region groove 418, toe region groove 426, lower region groove 422, or middle region depression 420 or any portion thereof, such as heel-side middle region depression 435, middle-middle region depression 437, or toe-side middle region depression 433.

[0100] In this regard, Table 5 below provides preferred striking surface thickness and width for the recesses in a variation of striking surface 409, which do not include the lower region groove 422, but still include the heel-side middle region recess 435, the middle region recess 437, the toe-side middle region recess 433, the upper region groove 418, and the toe-side region groove 426. All recesses in Table 5 may have a radius of 0.4 mm between the recess bottom and the adjacent walls, having the indicated thickness.

[0101] Table 5

[0102]

[0103] Figure 9 The rear surface 528 of an exemplary striking surface 509 according to one or more embodiments is depicted, which includes an example thickness pattern. Figure 9 The thickness pattern includes regions or parameterized domains of variable thickness, as opposed to the grooves discussed above (which are surrounded by an intermediate region with a larger average thickness). The striking surface 509 can be formed of, for example, steel.

[0104] like Figure 9 As shown, the posterior surface 528 includes an upper region 536, a peripheral region 538, a lower region 534, and a middle region 520 (which includes a toe-side middle region portion 533, a mid-middle region portion 537, and a heel-side middle region portion 535). The thickness of these regions can be determined, for example, using an iterative process, as follows: Figure 11 The thickness pattern forming process discussed is used to determine this. The thickness can provide an improved COR (e.g., a larger maximum COR and / or weighted COR) while maintaining the maximum impact surface stress limit or range as a constraint, so that although the mass of the impact surface 509 is reduced, the impact surface 509 is still comparable to the clubheads of the prior art when testing durability.

[0105] In this regard, regarding the 1D clubhead... Figure 9The parameterized domains or regions shown below, as provided in Table 6, have preferred thicknesses with the yield stress limit (i.e., von Mises stress on the striking face), weighted COR, maximum COR, and striking face mass results shown in Table 7. Table 6 also provides the thicknesses of these regions for comparison with the comparison clubhead D, with the stress limit, weighted COR, maximum COR, and striking face mass results provided in Table 7 for comparison. The thickness and width of the peripheral region 538 for both the comparison clubhead D and clubhead 1D can be the same, for example, 2.4 mm thick and 2.5 mm wide. The thicknesses provided below can vary between regions, for example, by gradually decreasing or using a gradual transition. In some embodiments, the thicknesses provided below may represent the average thickness of the region. In other embodiments, the thicknesses provided below may represent the thickness at the center of the region.

[0106] Table 6

[0107] Region Thickness Comparison club head D Club head 1 D Thickness of intermediate mid region 537 2.4 mm 2.8 mm Thickness of heel mid region 535 2.5 mm 2.4 mm Thickness of toe mid region 533 2.3 mm 1.8 mm Thickness of upper region 536 2.2 mm 1.8 mm Thickness of lower region 534 2.3 mm 1.9 mm

[0108] As shown above, the thickness of the striking face across the comparison clubhead D is nearly uniform, with minimal variation in thickness across different regions. Conversely, the central region 537 of clubhead 1D is thicker than other regions, particularly thicker than the toe region 535, upper region 536, and lower region 534. As shown in Table 7 below, this variation in the thickness of the striking face 509, compared to those of the comparison clubhead D, provides an improved weighted COR and an improved maximum COR. Furthermore, the variable thickness pattern of clubhead 1D reduces the mass of the striking face 509 by 6g while maintaining similar or improved stress limits, thereby providing similar or better durability than the comparison clubhead D. The 6g mass removed or saved from the striking face 509 can be redistributed to other parts of the clubhead, such as to the buttock or toe as described above, to improve MOI and / or better position the clubhead's CG and sweet spot.

[0109] Table 7

[0110] Characteristic Comparison club head D Club head 1 D von Mises stress 1405 1472 Weighted COR 0.782 0.788 Maximum COR 0.822 0.825 Ball striking face mass 64g 58g

[0111] Those skilled in the art, upon reference to this disclosure, will understand that other embodiments may include... Figure 9 The examples show regions or parameterized domains of different shapes or configurations. In this regard, Figure 10 Patterns of different thicknesses are provided, with different configurations for each region or parameterized domain.

[0112] Figure 10 The rear surface 628 of the striking face 609 of an exemplary clubhead comprising patterns of varying thicknesses according to one or more embodiments is depicted. Figure 9Similar to the example thickness pattern, Figure 10 The thickness pattern comprises regions or parametric domains of varying thicknesses, as opposed to the grooves described above (which are surrounded by a central region with a larger average thickness). The striking surface 609 may be formed of steel.

[0113] like Figure 10 As shown, the rear surface 628 includes a peripheral region 638, an outer region 630, and a central region 620 (which includes an outer central region 644, a toe-side inner central region 642, and a heel-side inner central region 640). The thickness of these regions can be determined, for example, using an iterative process, as follows: Figure 11 The thickness patterning process is used to determine this. The thickness can provide an improved COR (e.g., a larger maximum COR and / or weighted COR) while maintaining the stress limit or range of the striking surface as a constraint, so that although the mass of the striking surface 609 is reduced, the striking surface 609 is still comparable to the clubheads of the prior art when testing durability.

[0114] In this regard, regarding the clubheads 1E and 2E... Figure 10 The parameterized domains or regions shown below, with preferred thicknesses provided in Table 8, have the yield stress limit (i.e., von Mises stress on the striking face), weighted COR, maximum COR, and striking face quality results shown in Table 9. The thickness and width of the peripheral region 638 of the clubhead can be the same, for example, 2.4 mm thick and 3.5 mm wide. The thicknesses provided below can vary between regions, for example, by gradually decreasing or utilizing a step-by-step transition. In some embodiments, the thicknesses provided below may represent the average thickness of the region. In other embodiments, the thicknesses provided below may represent the thickness at the center of the region.

[0115] Table 8

[0116] Region Thickness Club head 1 E Club head 2 E Thickness of outer region 630 1.7 mm 1.7 mm Thickness of outer mid region 644 2.2 mm 2.3 mm Thickness of toe side inner mid region 642 2.6 mm 2.5 mm Thickness of heel side inner mid region 640 2.6 mm 2.6 mm

[0117] As shown above, the middle region 620 is generally thicker than the outer region 630, with the inner middle region 642 on the toe side and the middle region 640 on the heel side being even thicker than the outer middle region 644. As shown in Table 9 below, this variation in the thickness of the striking face 609 provides an improved weighted COR and an improved maximum COR compared to those of the comparative clubhead D described above with reference to Table 7. Furthermore, the variable thickness patterns of clubheads 1E and 2E reduce the mass of the striking face 609 by 6g and 7g respectively compared to the comparative clubhead D, while maintaining similar stress limits, thereby providing similar durability as the comparative clubhead D. The 6g or 7g mass removed or saved from the striking face 609 can be redistributed to other parts of the clubhead, such as to the buttock or toe as discussed above, to improve MOI and / or better position the clubhead's CG and sweet spot.

[0118] Table 9

[0119] Characteristic Club head 1 E ]]> ​ Club head 2 E ]]> ​ von Mises stress 1448 1484 Weighted COR 0.782 0.788 Maximum COR 0.822 0.825 Ball striking face mass 64g 58g

[0120] Figure 11 This is a flowchart illustrating an exemplary process for forming a thickness pattern on a striking surface according to one or more embodiments. Figure 11 The process can be, for example, the above. Figure 9 and 10 The parameterized domains or regions shown are used together. In some embodiments, computing devices or other electronic processing devices may be used to determine the variable thickness pattern.

[0121] In block 1102, a series of parametric domains or regions are defined for the striking face of the clubhead. The clubhead may be formed from a clubhead body having a striking face, a heel, a toe opposite the heel, a sole, and a top opposite the sole. The clubhead may be formed from, for example, steel and may include hollow clubheads or concave-back clubheads. Each parametric domain or region may have a variable first parameter and a variable second parameter. In some embodiments, the first and second parameters may include the thickness and width, or other dimensions, of the parametric domain or region.

[0122] In block 1104, target values ​​are set for various constraint values ​​of the striking face. In some embodiments, as described above, the first constraint value may be the striking face mass, the second constraint value may be the mechanical stress limit of the striking face, and the third constraint condition may be the weighted COR value of the striking face. The target values ​​for each parameterized domain or region may be set, for example, based on desired improvements to the clubhead (e.g., increasing the amount of free mass redistributed from the striking face, improving or minimizing the durability of the striking face, or improving the weighted COR (which balances against the maximum COR or CT specified by a regulatory body)).

[0123] In block 1106, the parameters of each parameterized domain or region are variable. For example, the maximum width or thickness can be changed as parameters for each middle region, each upper region, each lower region, and each toe region of the striking face. In some implementations, the parameters can be iteratively changed according to the changes in the parameters to generate a set of values ​​for more than one constraint value.

[0124] In block 1108, collisions with a golf ball are optionally simulated for a series of collision locations. In some implementations, blocks 1106 and 1108 can be combined. For example, the collision probability matrix described in Table 3 above can be used with Equation 3 above to generate a weighted COR, based on the variations of the first and second parameters for the parameterized domain or region in block 1106.

[0125] In block 1110, the constraint values ​​obtained from the parameter variations in block 1106 are evaluated relative to the target values ​​for more than one constraint value. For example, the resulting weighted COR value closest to 0.80 can at least partially determine the width and thickness of the parameterized domain or region. As another example, the maximum mass removal or mass saving from the hitting surface can be another factor to consider when determining the size and / or thickness of the parameterized domain or region.

[0126] In block 1112, a variable thickness pattern is formed on the striking face according to the evaluation in block 1110. In some cases, the back surface of the striking face may have material removed by using a cutting tool or other machining to form the variable thickness pattern. In other cases, the variable thickness pattern on the striking face can be formed using casting or forging processes.

[0127] Those skilled in the art, upon reference to the content of this disclosure, should understand that Figure 11 The thickness patterning process may differ in other embodiments. For example, the setting of more than one target for more than one corresponding constraint value in block 1104 may occur before the definition of the parameterized domain or region in block 1102. As another example variation, the change of parameters for each parameterized domain in block 1106 may be combined with the evaluation of the obtained constraint value in block 1110. In some embodiments, block 1108 may be omitted.

[0128] Figure 12 This is a flowchart of another exemplary process for a thickness pattern form of a striking surface according to one or more embodiments. Figure 12 The process can be, for example, the above. Figure 7 and 8 The parameterized domains or regions are used together. In some implementations, computing devices or other electronic processing devices may be used to determine the variable thickness pattern.

[0129] In block 1202, the area defining the striking face of the clubhead includes at least one of a center region, a middle region, and a top region, a bottom region, and a toe region. The clubhead may be formed from a clubhead body having a striking face, a heel, a toe opposite the heel, a bottom, and a top opposite the bottom. The clubhead may be formed from, for example, steel, and may include a hollow clubhead or a concave-back clubhead. The center region includes the center of the striking face, and the middle region at least partially surrounds the center region. The top region may be located above the center region, and the bottom region may be located below the center region. The toe region may be located to the toe of the center region. The middle region may be positioned between the center region and each or at least one of the top, bottom, and toe regions.

[0130] In block 1204, the central region is recessed such that its thickness is less than that of the intermediate region. In this regard, the intermediate region may have a uniform or substantially uniform thickness, for example, at least 2.5 mm and no more than 3.3 mm. The recess in the central region can be formed, for example, by gradually decreasing the thickness of the central region from the toe side to the heel side. In other embodiments, the thickness of the central region can vary with a gradual change in thickness to form the recess. The recess in the central region can be formed, for example, by machining to remove mass from the central region, or by forging or casting at least a portion of the clubhead to save mass from the central region.

[0131] In block 1206, at least one of the toe region, upper region, and lower region is recessed, for example, by means of a groove or channel, such that the thickness of the recessed region is less than the thickness of the middle region. Such a groove may include, for example, an elongated groove with a width of not less than approximately 2.0 mm in at least one of the toe region, upper region, and lower region. The groove may be formed, for example, by machining to remove mass from at least one of the aforementioned regions, or by forging or casting at least a portion of the clubhead to save mass in at least one of the aforementioned regions. In some embodiments, the upper region may include an elongated groove or channel with a width of not less than 6.0 mm.

[0132] The concave central region formed in square 1204 and the concave at least one of the toe region, upper region, and lower region in square 1206 form a striking surface, which includes: a sweet spot corresponding to a first COR (COR1), and an auxiliary position spaced at least 7.5 mm from the sweet spot and corresponding to a second COR (COR2). 辅助The COR2 ≥ 0.98 × COR1. In this respect, the additional or corresponding mass removal or mass saving from the striking surface due to the aforementioned indentation increases the area of ​​the striking surface with a relatively high COR. In some embodiments, as described above, the maximum COR of the striking surface can also be increased or better positioned to correspond to the sweet spot and / or the more frequently hit points on the striking surface, since it can be quantified using a weighted COR.

[0133] Furthermore, removing or saving mass from the striking face allows for a redistribution of mass within the clubhead, such as to the back or toe of the clubhead, thereby improving MOI and / or better positioning of the clubhead CG and the sweet spot. For example, the sweet spot can be located no more than 2.0 mm from the vertical center plane (which is perpendicular to the center of the clubface and extends through the center of the clubface). As another example, the clubhead CG can be located no more than 1.0 mm from the vertical center plane to better position the sweet spot on the clubface where the intended or more frequent striking position is located.

[0134] The description of the exemplary embodiments disclosed above is provided to enable any person skilled in the art to make or use the embodiments of the present invention. Various modifications to these examples will be apparent to those skilled in the art, and the principles disclosed herein can be applied to other examples without departing from the scope of the invention. For example, some alternative embodiments may include different sizes or shapes of the hitting surface area or parameterized domain. Therefore, the described embodiments should be considered exemplary in all respects and not restrictive, and thus the scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations falling within the equivalent meaning and scope of the claims should be included within their scope. The described embodiments should be considered exemplary in all respects and not restrictive. Furthermore, the use of the language in the appended claims in the form of "at least one of A and B" should be understood to mean "only A or only B or both A and B".

Claims

1. A golf club head, wherein, When the golf club head is positioned at the reference position, the golf club head has: A golf club head body, the golf club head body having a toe, a heel opposite the toe, a bottom, and a top opposite the bottom; Loose angle LA; The golf club head mass mh, where: mh = 2.1 g / °C × LA + a; and 190g <a<210g; A blade back length of less than 80mm; A striking face having a center of the clubface, wherein the striking face defines a clubface plane; A virtual center plane that extends vertically through the center of the rod face and is perpendicular to the rod face plane; The center of gravity of the golf club head, wherein the center of gravity is located at a position no more than 2.0 mm away from the virtual center plane; and The moment of inertia Izz extends around a vertical axis passing through the center of gravity, and the moment of inertia Izz satisfies: Izz > mh × 9.3 cm 2 ; The striking surface includes: The central region includes the center of the pole face; An intermediate region, which at least partially surrounds the central region; The upper region is located above the middle region; The lower region; the lower region is located below the middle region; and The toe region, located in the toe direction of the middle region. Each middle region, each upper region, each lower region, and each toe region has a maximum width and an average thickness. The middle region is located between the middle region and each upper region, each lower region, and each toe region. The average thickness of the intermediate region is greater than the average thickness of each middle region, each upper region, each lower region, and each toe region; At least one of the toe region, the upper region, and the lower region includes an elongated groove with a width of not less than 2.0 mm on its posterior surface.

2. The golf club head according to claim 1, wherein, The upper region, the lower region, and the toe region each include, on their posterior surfaces, an upper groove extending in the heel-toe direction, a lower groove extending in the heel-toe direction, and a toe groove extending in the top-bottom direction.

3. The golf club head according to claim 1, wherein, The central region has a heel-side region, the thickness of which is greater than the thickness of the toe-side region.

4. The golf club head according to claim 3, wherein, The thickness of the central region gradually decreases from the heel side region to the toe side region.

5. The golf club head according to claim 1, wherein, The striking surface includes: The sweet spot, which corresponds to the first coefficient of restitution COR1; An auxiliary position, wherein the auxiliary position is at least 7.5 mm away from the sweet spot on the striking surface and corresponds to a second coefficient of restitution COR2, wherein: COR2≥0.98×COR1.

6. The golf club head according to claim 5, wherein, The auxiliary position is at least 7.5 mm away from the sweet spot in the toe direction.

7. The golf club head according to claim 1, wherein, The striking surface includes a weighted COR greater than or equal to 0.

79.

8. The golf club head according to claim 1, wherein, The golf club head also has a topline thickness of no more than 6.5 mm.

9. A golf club head, wherein, When the golf club head is positioned at the reference position, the golf club head has: A golf club head body, the golf club head body having a toe, a heel opposite the toe, a bottom, and a top opposite the bottom; A clubface insert having a mass mf fixedly attached to the body of the golf club head and including a striking surface that defines the clubface plane; Loose angle LA; The golf club head mass mh, where: mh = 2.1 g / °C × LA + a; and 190g <a<210g; A blade back length of less than 80mm; Center of gravity; and The moment of inertia Izz extends around a vertical axis passing through the center of gravity, and the moment of inertia Izz satisfies: Izz > mh × 9.3 cm 2 ; Among them, the ratio of mf / mh is below 0.22; The rod face insert includes: The central region includes the center of the pole face; An intermediate region, which at least partially surrounds the central region; The upper region is located above the middle region; The lower region is located below the middle region; and The toe region, located in the toe direction of the middle region. Each middle region, each upper region, each lower region, and each toe region has a maximum width and an average thickness. The middle region is located between the middle region and each upper region, each lower region, and each toe region. The average thickness of the intermediate region is greater than the average thickness of each middle region, each upper region, each lower region, and each toe region; At least one of the toe region, the upper region, and the lower region includes an elongated groove with a width of not less than 2.0 mm on its posterior surface.

10. The golf club head according to claim 9, wherein, The upper region, the lower region, and the toe region each include, on their posterior surfaces, an upper groove extending in the heel-toe direction, a lower groove extending in the heel-toe direction, and a toe groove extending in the top-bottom direction.

11. The golf club head according to claim 9, wherein, The central region has a heel-side region, the thickness of which is greater than the thickness of the toe-side region.

12. The golf club head according to claim 11, wherein, The thickness of the central region gradually decreases from the heel side region to the toe side region.

13. The golf club head according to claim 9, wherein, The striking surface includes: The sweet spot, which corresponds to the first coefficient of restitution COR1; An auxiliary position, wherein the auxiliary position is at least 7.5 mm away from the sweet spot on the striking surface and corresponds to a second coefficient of restitution COR2, wherein: COR2≥0.98×COR1.

14. The golf club head according to claim 13, wherein, COR2 ≥ 0.99 × COR1.

15. The golf club head according to claim 9, wherein, The striking surface has a weighted COR greater than or equal to 0.

79.

16. The golf club head according to claim 9, wherein, The golf club head also has a topline thickness of no more than 6.5 mm.

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