Golf club head with slits and flexure inserts

Abstract

A golf club head having a slit and a cantilever arm extending forward into the slit from the inner surface of the sole. The cantilever arm has a fixed end connected to the inner surface of the sole behind the slit and a tip on the opposite side of the fixed end. The cantilever arm extends in an arc from the fixed end over the rear wall, with the tip positioned between the front and rear walls, and is configured to contact the front wall of the slit upon impact with the golf ball.

Description

[Technical Field]

[0001] (Cross-reference priority) This application claims the interests of U.S. Provisional Application No. 63 / 618,184 filed on 5 January 2024 and U.S. Provisional Application No. 63 / 512,261 filed on 6 July 2023, and is a continuation of U.S. Application No. 18 / 153,829 filed on 12 January 2023, which claims the interests of U.S. Provisional Application No. 63 / 371,613 filed on 16 August 2022 and U.S. Provisional Application No. 63 / 266,722 filed on 12 January 2022, the contents of which these applications are incorporated herein by reference in their entirety.

[0002] The present invention generally relates to golf equipment, and more specifically to a golf club head having slits and flexure inserts for the purpose of increasing the flex of the striking face in order to control the loft of the club head, ball speed, and ball spin. [Background technology]

[0003] Many golf club heads (especially wood-type club heads, i.e., drivers, fairway woods, and hybrids) have features designed to control the flex of the striking face at impact. Generally, increasing the flex of the striking face improves club head performance by increasing ball speed and reducing spin, thereby increasing ball distance. Many conventional club heads attempt to increase the flex of the striking face by providing an elongated slit (also referred to herein as a "slot") near the striking face that has an opening that penetrates part of the club head body and extends into the internal cavity. The slit is usually filled with a lightweight, flexible insert that closes the opening and seals the internal cavity. The insert is usually made of a uniform viscoelastic material that absorbs and dissipates energy when compressed, thus reducing the overall energy transfer between the club head and the golf ball. Reduced energy transfer results in a decrease in ball speed, negatively impacting the performance of the club head. Furthermore, conventional inserts have the limitation that, due to their material and uniform structure, they only exhibit a constant response across the entire slit. [Brief explanation of the drawing]

[0004] [Figure 1] An upward perspective view of a wood-type clubhead with slits and a flexure insert is shown.

[0005] [Figure 2] Figure 1 shows a wood-type club head viewed from the front.

[0006] [Figure 3] Figure 1 shows a wood-type club head viewed from the heel side.

[0007] [Figure 4] Figure 1 shows a wood-type club head viewed from the sole side; the flex insert is not shown.

[0008] [Figure 5] Figure 1 shows a wood-type club head viewed from the sole side.

[0009] [Figure 6] A detailed cross-sectional view of a wood-type club head equipped with a slit and flexure insert according to the first embodiment is shown.

[0010] [Figure 7] Figure 6 shows a detailed cross-sectional view of a wood-type club head equipped with a slit and flexure insert according to the first embodiment.

[0011] [Figure 8] Figure 6 shows a top view of the internal cavity of the slit and flexure insert.

[0012] [Figure 9] Figure 6 shows a perspective view of the internal cavity of the slit, and the Flexier insert is not shown.

[0013] [Figure 10] A detailed cross-sectional view of a wood-type club head equipped with a slit and flexure insert according to the second embodiment is shown.

[0014] [Figure 11] Figure 10 shows a top cross-sectional view of the spring component of the flexure insert.

[0015] [Figure 12] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the third embodiment is shown.

[0016] [Figure 13] Figure 12 shows a detailed cross-sectional view of the slit and flexure insert.

[0017] [Figure 14] Figure 12 shows an internal top view of the slit and flexure insert.

[0018] [Figure 15] A detailed cross-sectional view of a wood-type club head equipped with a slit and flexure insert according to the fourth embodiment is shown.

[0019] [Figure 16] Figure 15 shows a detailed cross-sectional view of the slit and flexure insert.

[0020] [Figure 17] Figure 15 shows an internal top view of the slit and flexure insert.

[0021] [Figure 18] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the fifth embodiment is shown.

[0022] [Figure 19] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the sixth embodiment is shown.

[0023] [Figure 20] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the seventh embodiment is shown.

[0024] [Figure 21] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the eighth embodiment is shown.

[0025] [Figure 22] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the ninth embodiment is shown.

[0026] [Figure 23]A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the 10th embodiment is shown.

[0027] [Figure 24] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the 11th embodiment is shown.

[0028] [Figure 25] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the 12th embodiment is shown.

[0029] [Figure 26] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the 13th embodiment is shown.

[0030] [Figure 27] A cross-sectional view of a wood-type club head equipped with a slit and a flexure insert according to the 14th embodiment is shown.

[0031] [Figure 28] This diagram shows a wood-type club head with a slit extending in the heel-toe direction, viewed from the sole side.

[0032] [Figure 29] Figure 28 shows a cross-sectional view of a golf club head, according to the first embodiment, which has a slit formed by a plurality of retaining walls.

[0033] [Figure 30] The diagram shows a cross-sectional view of a golf club head having a slit formed by a plurality of retaining walls according to the second embodiment.

[0034] [Figure 31] An overhead perspective view of a golf club head, comprising a slit, a flexure insert, and a crown flip on the striking face, according to one embodiment, is shown.

[0035] [Figure 32] Figure 31 shows a cross-sectional view of a golf club head with a slit, a flexure insert, and a crown flip on the striking face.

[0036] [Figure 33A] A perspective view of a flexure insert according to one embodiment is shown.

[0037] [Figure 33B] A perspective view of a flexure insert according to one embodiment is shown.

[0038] [Figure 34] This shows a top cross-sectional view of a club equipped with a flexure insert according to one embodiment.

[0039] [Figure 35A] A perspective view of a flexure insert according to one embodiment is shown.

[0040] [Figure 35B] Figure 35A shows an exploded assembly diagram of the flexure insert.

[0041] [Figure 36A] A cross-sectional view of a flexure insert according to one embodiment is shown.

[0042] [Figure 36B] Figure 36A shows a top view of the spring component of the flexure insert.

[0043] [Figure 36C] A cross-sectional view of a flexure insert according to one embodiment is shown.

[0044] [Figure 36D] A cross-sectional view of a flexure insert according to one embodiment is shown.

[0045] [Figure 37] A cross-sectional view of a flexure insert according to one embodiment is shown.

[0046] [Figure 38] A cross-sectional view of a flexure insert according to one embodiment is shown.

[0047] [Figure 39] A bottom view of a golf club head according to one embodiment is shown.

[0048] [Figure 40] Figure 39 shows a top view of the golf club head.

[0049] [Figure 41] Figure 39 shows an internal perspective view of the golf club head.

[0050] [Figure 42] This shows a plot of the resultant force exerted by the bumper on the front wall of the slit.

[0051] This specification describes various embodiments of wood-type club heads (e.g., drivers, fairway woods, or hybrids) that feature slits and flexure inserts for the purpose of strategically increasing the deflection of the striking face. The flexure insert may be designed to have varying stiffness and bending properties so that it can locally reinforce high-stress areas of the slit and locally maximize deflection in low-stress areas of the slit. The club head includes a flexure insert that is tuned to achieve a desired amount of deflection of the striking face. The flexure insert has advantages over conventional uniform inserts that have uniform stiffness and bending properties throughout the slit. In some embodiments, the flexure insert may include a cantilever arm that extends forward from the inner surface of the sole into the slit and contacts and reinforces the front wall of the slit. In other embodiments, the flexure insert may have a multi-material construction and include a cap and a spring component. The flexure insert is always composed of two or more materials. The flexure insert offers advantages over slit inserts composed of a single material. Spring components are positioned in specific areas of the slit to achieve the desired stiffness profile of the flexure insert. Furthermore, the spring components provide a spring effect that increases energy transfer between the club head and the golf ball. Because the flexure insert allows for varying stiffness and flexibility at different points in the slit, the deflection of the impact face can be controlled more precisely. Club heads with multi-material flexure inserts offer performance advantages compared to conventional inserts, which are typically made of uniform shape and material and do not vary the stiffness and flexibility profiles of the slit.

[0052] Furthermore, the embodiments of the flexure insert described herein can increase energy transfer between the club head and the golf ball. The spring component may be made of a material having linear elastic properties. The spring component efficiently stores internal energy when the flexure insert is compressed during impact and releases that internal energy when it expands. Due to the linear elastic properties of the spring component, it can hold more internal energy than conventional viscoelastic inserts and release it to the striking face. In conventional pure viscoelastic inserts, a larger amount of energy is dissipated. A club head equipped with a flexure insert having a spring component will have increased ball speed and other performance improvements compared to a club head with an insert made of pure viscoelastic material.

[0053] The club heads equipped with the slit and multi-material flexure insert described herein can significantly improve face deflection and launch conditions compared to conventional single-material viscoelastic inserts. In particular, the flexure insert equipped with slits and spring components can increase ball speed by 0.5 mph to 4.5 mph and increase internal energy by 3 lbf·in to 20 lbf·in, which can correspond to an increase in carry distance of 2 to 10 yards. Furthermore, the flexure insert equipped with slits and spring components can also result in other performance improvements such as increased face displacement, increased dynamic loft, and reduced ball spin.

[0054] In the wood-type golf club heads described herein, the slit and flexure insert may be combined with other performance-enhancing features of the club head. In some embodiments, the club head may utilize a multi-material design to increase the MOI. In some embodiments, the club head may have a large mass pad positioned behind the slit to achieve a desired CG position, increase ball speed and ball distance, and improve launch conditions. Any one or any combination of the above features may be combined with the slit and flexure insert to realize a high-performance club head. definition

[0055] The terms “first,” “second,” “third,” “fourth,” etc., as used herein are for distinguishing similar elements and do not necessarily represent a specific order or chronological order. It should be understood that such terms are interchangeable under appropriate circumstances, for example, when the embodiments described herein can operate in an order other than that shown herein or otherwise described. Furthermore, the terms “includes” and “has,” and their variations, are intended to cover non-exclusive inclusion, and a process, method, system, article, device, or apparatus comprising a list of elements is not necessarily limited to those elements and may include elements not explicitly enumerated, or other elements inherent to such process, method, system, article, device, or apparatus.

[0056] The terms “left,” “right,” “front,” “back,” “up,” “down,” “above,” and “below” used herein are for illustrative purposes only and do not necessarily describe permanent relative positions. It should be understood that these terms are interchangeable in appropriate circumstances where the embodiments of the invention described herein are capable of operating in orientations other than those illustrated or otherwise described herein.

[0057] As used herein, the term "striking face" refers to the front of the club head configured to strike a golf ball. The term "striking face" is interchangeable with the term "face."

[0058] As used herein, the term “periphery of the striking face” may refer to the edge of the striking face. The periphery of the striking face may be located along the outer edge of the striking face where the curvature deviates from the bulge and / or roll of the striking face.

[0059] As used herein, the terms “geometric center point” or “geometric center” may refer to the geometric center point of the outer perimeter of the striking face, which is located at the midpoint of the face height of the striking face. In the same or other examples, the geometric center point may be located at the center of the design impact zone defined by the groove area on the striking face. Alternatively, the geometric center point of the striking face may be located according to the definition of a golf governing body such as the United States Golf Association (USGA).

[0060] As used herein, the term “ground surface” may refer to a reference surface relating to the surface on which the golf ball is placed. The ground surface may be a horizontal plane in contact with the sole of the club at the address position.

[0061] As used herein, the term "loft plane" may refer to a reference plane tangent to the geometric center point of the striking face.

[0062] As used herein, the term "loft angle" may refer to the angle measured between the loft plane and the XY plane (defined below in relation to the XYZ coordinate system).

[0063] As used herein, the term "face height" may refer to the distance measured parallel to the loft plane between the upper edge and the lower edge of the outer perimeter of the striking face.

[0064] As used herein, the term “lie angle” may refer to the angle between the hosel axis, which extends through the hosel, and the ground plane. The lie angle is measured in the front view.

[0065] In this specification, the "depth" of a golf club head can be defined as the dimension of the golf club head in the front-to-back direction.

[0066] In this specification, the “height” of a golf club head can be defined as the crown-to-sole dimension of the golf club head. In many embodiments, the height of the club head may be measured according to the standards of a golf governing body such as the United States Golf Association (USGA).

[0067] In this specification, the “length” of a golf club head can be defined as the heel-to-toe dimension of the golf club head. In many embodiments, the length of the club head may be measured according to the regulations of a golf governing body such as the United States Golf Association (USGA).

[0068] In this specification, the "face height" of a golf club head can be defined as the height measured parallel to the loft plane between the upper edge of the outer perimeter of the striking face near the crown and the lower edge of the outer perimeter of the striking face near the sole.

[0069] In this specification, the "geometric center height" of a fairway-type golf club head is the height measured vertically from the ground surface to the geometric center point of the golf club head.

[0070] In this specification, the "leading edge" of the club head may be the part of the outer perimeter of the striking face that is closest to the sole.

[0071] As shown in Figures 2 and 3, the "XYZ" coordinate system of the golf club head 100 described herein is based on the geometric center 120 of the striking face 102. The dimensions of the golf club head 100 described herein may be measured based on the coordinate system described below. The geometric center 120 of the striking face 102 defines a coordinate system having an origin located at the geometric center 120 of the striking face 102. This coordinate system defines an X-axis 3040, a Y-axis 3050, and a Z-axis 3060. The X-axis 3040 extends through the geometric center 120 of the striking face 102 in the direction from the heel 104 to the toe 106 of the club head 100. The Y-axis 3050 extends through the geometric center 120 of the striking face 102 in the direction from the crown 110 to the sole 112 of the golf club head 100. The Y-axis 3050 is perpendicular to the X-axis 3040. The Z-axis 3060 extends from the front end 108 to the rear end 111 of the golf club head 100, passing through the geometric center 120 of the striking face 102. The Z-axis 3060 is perpendicular to both the X-axis 3040 and the Y-axis 3050.

[0072] The term "center of gravity" or "CG position" may refer to the position of the club head's center of gravity (CG) 199 relative to the XYZ coordinate system, where the CG position is represented by a position along the X-axis 3040, a position along the Y-axis 3050, and a position along the Z-axis 3060. The term "CGx" may refer to the CG position along the X-axis measured from the origin 120. The term "CG height" may refer to the CG position along the Y-axis measured from the origin 120. The term "CGy" may be synonymous with CG height. The term "CG depth" may refer to the CG position along the Z-axis measured from the origin 120. The term "CGz" may be synonymous with CG depth.

[0073] The XYZ coordinate system for the golf club head described herein defines an XY plane passing through the X-axis 3040 and the Y-axis 3050. This coordinate system defines an XZ plane passing through the X-axis 3040 and the Z-axis 3060. This coordinate system further defines a YZ plane passing through the Y-axis 3050 and the Z-axis 3060. The XY plane, XZ plane, and YZ plane are all orthogonal to each other and intersect at the coordinate system origin located at the geometric center 120 of the striking face 102. In these embodiments or other embodiments, the golf club head 100 is viewed from the front when the striking face 102 is viewed perpendicular to the XY plane. Furthermore, in these embodiments or other embodiments, the golf club head 100 is viewed from the side or in cross-section when the heel 104 is viewed perpendicular to the YZ plane.

[0074] As shown in Figures 2 and 3, the golf club head 100 further comprises a coordinate system centered on the center of gravity 199. This coordinate system comprises an X' axis 3070, a Y' axis 3080, and a Z' axis 3090. The X' axis 3070 extends in the heel-toe direction. The X' axis 3070 is positive toward the heel 104 and negative toward the toe 106. The Y' axis 3080 extends in the sole-crown direction and is perpendicular to both the Z' axis 3090 and the X' axis 3070. The Y' axis 3080 is positive toward the crown 110 and negative toward the sole 112. The Z' axis 3090 extends in the front-to-back direction, is parallel to the ground plane, and is perpendicular to both the X' axis 3070 and the Y' axis 3080. The Z' axis 3090 is positive toward the striking face 102 and negative toward the rear 111.

[0075] The term "moment of inertia" (hereinafter "MOI") may refer to a value measured around the center of gravity 199. The term "MOIxx" may refer to the MOI measured in the heel-toe direction around the X' axis 3070. The term "MOIyy" may refer to the MOI measured in the sole-crown direction around the Y' axis 3080. The term "MOIzz" may refer to the MOI measured in the front-to-back direction around the Z' axis 3090. The values ​​of MOIxx, MOIyy, and MOIzz determine the degree of forgiveness of the clubhead 100 for off-center shots with the golf ball.

[0076] The loft angle of the “driver” or “driver-type” club head as used herein is less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees. Furthermore, in many embodiments, the volume of the “driver golf club head” as used herein is more than approximately 400cc, more than approximately 425cc, more than approximately 445cc, more than approximately 450cc, more than approximately 455cc, more than approximately 460cc, more than approximately 475cc, more than approximately 500cc, more than approximately 525cc, more than approximately 550cc, more than approximately 575cc, more than approximately 600cc, more than approximately 625cc, more than approximately 650cc, more than approximately 675cc, or more than approximately 700cc. In some embodiments, the volume of the driver may be approximately 400cc to 600cc, 425cc to 500cc, approximately 500cc to 600cc, approximately 500cc to 650cc, approximately 550cc to 700cc, approximately 600cc to 650cc, approximately 600cc to 700cc, or approximately 600cc to 800cc.

[0077] In this specification, the loft angle of a “fairway wood” or “fairway wood type” club head is less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Furthermore, in some embodiments, the loft angle of a fairway wood club head may be greater than approximately 12 degrees, greater than approximately 13 degrees, greater than approximately 14 degrees, greater than approximately 15 degrees, greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, or greater than approximately 20 degrees. For example, in other embodiments, the loft angle of a fairway wood may be between 12 and 35 degrees, between 15 and 35 degrees, between 20 and 35 degrees, or between 12 and 30 degrees.

[0078] Furthermore, the volume of the club head of a “fairway wood” or “fairway wood type” as described herein may be less than approximately 400cc, less than approximately 375cc, less than approximately 350cc, less than approximately 325cc, less than approximately 300cc, less than approximately 275cc, less than approximately 250cc, less than approximately 225cc, or less than approximately 200cc. In some embodiments, the volume of the fairway wood may be approximately 100cc to 200cc, approximately 150cc to 250cc, approximately 150cc to 300cc, approximately 150cc to 350cc, approximately 150cc to 400cc, approximately 300cc to 400cc, approximately 325cc to 400cc, approximately 350cc to 400cc, approximately 250cc to 400cc, approximately 250cc to 350cc, or approximately 275cc to 375cc.

[0079] The loft angles of the clubheads referred to herein as “hybrid” or “hybrid type” are less than approximately 40 degrees, less than approximately 39 degrees, less than approximately 38 degrees, less than approximately 37 degrees, less than approximately 36 degrees, less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. Furthermore, in many embodiments, the loft angle of the hybrid may be greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

[0080] Furthermore, the volume of “hybrid” or “hybrid type” as used herein is less than about 200 cc, less than about 175 cc, less than about 150 cc, less than about 125 cc, less than about 100 cc, or less than about 75 cc. In some embodiments, the volume of the hybrid may be about 100 cc to 150 cc, about 75 cc to 100 cc, about 100 cc to 125 cc, or about 75 cc to 125 cc.

[0081] The golf club heads described in this disclosure may be formed from metals, metal alloys, composite materials, or combinations of metals and composite materials. For example, a golf club head may be formed from steel, steel alloys, stainless steel alloys, nickel, nickel alloys, cobalt, cobalt alloys, titanium alloys, amorphous metal alloys, or other similar materials, but is not limited to these materials. In another example, a golf club head may be formed from C300 steel, C350 steel, 17-4 stainless steel, or T9s+ titanium, but is not limited to these materials.

[0082] Other features and embodiments will become apparent upon review of the following detailed description and accompanying drawings. Before describing the embodiments of this disclosure in detail, it should be understood that this disclosure is not limited to the details, embodiments, structures, and component arrangements shown in the following description and drawings. This disclosure can also support other embodiments and is implementable or executable in various ways. It should be understood that descriptions relating to specific embodiments do not exclude all variations, equivalents, and substitutes that fall within the spirit and scope of this disclosure. It should also be understood that the words and terms used herein are for illustrative purposes only and should not be construed as limiting. Detailed explanation I. Overview of Golf Club Heads

[0083] In the drawings, similar or identical parts are given the same reference number, and Figures 1 to 3 show schematic diagrams of a wood-type golf club head 100 from various viewpoints. Specifically, Figure 1 shows a front perspective view of a wood-type club head 100. Here, the features are described in relation to a fairway wood, but any of the features, including the slit and flexure insert, are also applicable to driver and hybrid-type club heads. The club head 100 may comprise a striking face 102 and a body 101, which are fixed to each other and define a nearly closed / hollow internal cavity 107. The club head 100 comprises a crown 110, a sole 112 opposite the crown 110, a heel 104, a toe 106 opposite the heel 104, a front section 108, and a rear section 111 opposite the front section 108. The body 101 may further include a skirt 114 positioned between the crown 110 and the sole 112 and in contact with them, the skirt 114 extending from near the heel 104 to near the toe 106 of the club head 100.

[0084] The striking face 102 and the body 101 may define the internal cavity 107 of the club head 100 (shown in the following figures). The body 101 may extend across the crown 110, sole 112, heel 104, toe 106, rear 111, and front 108. In these embodiments, the striking face 102 may be located only in the front 108 of the club head 100. In another embodiment, the striking face 102 may extend beyond the outer circumference of the front 108 and form at least one of the front portions of the crown 110, sole 112, heel 104, and toe 106. In such embodiments, the club head 100 may resemble a “cup face” or “face wrap” design. The striking face 102 comprises a striking surface 113 configured to strike a golf ball and a back surface (described in a later embodiment) opposite the striking surface 113.

[0085] As shown in Figures 1 to 3, the club head 100 includes a hosel structure 105. The hosel structure 105 can receive a golf shaft (not shown). In many embodiments, the hosel structure 105 may further include a hosel sleeve 116, which can be connected to the end of the golf shaft. In such embodiments, the hosel sleeve 116 can be connected to the hosel structure 105 in various configurations, so that the golf shaft can be fixed to the hosel structure 105 at various angles. In such embodiments, the hosel sleeve 116 makes it possible to adjust the loft angle and / or lie angle of the club head 100.

[0086] In many embodiments, the club head 100 may have a multi-material design. The striking face 102 may be formed of a metallic material, and the body 101 may be formed of one or more metallic or non-metallic materials. In such embodiments, the body 101 may comprise a first metallic component 118 and a second non-metallic component 119. As shown in Figure 1, the club head 100 may have a non-metallic wrap-around design in which the second component 119 forms part of the crown 110, part of the skirt 114, part of the heel 104, part of the toe 106, and part of the sole 112. In another embodiment, the club head 100 may have any other multi-material design in which the non-metallic second component 119 forms any part of the striking face 102, crown 110, skirt 114, heel 104, toe 106, and / or sole 112. By using a multi-material design for the club head 100, the discretionary mass that can be redistributed to the club head 100 can be increased in order to improve mass properties such as MOI and the position of CG199. In another embodiment, the club head 100 may have a single-material design in which the entire body 101 is formed of the same or similar material. II. Overview of Slits

[0087] Referring to Figures 4 and 5, the club head 100 includes a slit 130 configured to receive a flexure insert 150. The slit 130 may be a through-slit 130 communicating the outside of the club head 100 with the internal cavity 107. In many embodiments, the slit 130 is located in the sole 112, but in other embodiments, the club head 100 may have one or more slits in the sole 112, heel 104, toe 106, skirt 114, crown 110, or any combination thereof. Referring to the exemplary embodiment in Figure 4, the slit 130 may be an opening extending in the heel-toe direction in a portion of the sole 112. The slit 130 strategically weakens the sole 112, making it more flexible than a sole without the slit 130. Thus, the slit 130 promotes flexing of the club head body 101. The slit 130 may have a front edge 132 adjacent to the striking face 102 and a rear edge 134 opposite to the front edge 132, the front edge 132 and the rear edge 134 defining the boundary of the slit 130. The slit 130 further has a heel end 129 and a toe end 131 opposite to the heel end 129. The front edge 132 and the rear edge 134 may extend between the heel end 129 and the toe end 131.

[0088] In many embodiments, the slit 130 may be located near the striking face 102 and separated from the leading edge 103 by the sole front portion 117. The proximity of the slit 130 to the striking face 102 can increase the flex of the striking face 102 at impact. Furthermore, the proximity of the slit 130 to the striking face 102 can increase the dynamic loft and / or reduce spin. Details regarding the position, shape, and arrangement of the slit 130 will be described later.

[0089] This specification describes various embodiments of a golf club head having a slit 130 to improve the flexibility of the striking face 120. The sole 112 defines the slit 130. The slit 130 is configured to hold a flexure insert 150. The dimensions, characteristics, and features of the slit 130 are described in relation to the club head 100, but any of the slits 130, 230, 330, 430, 530, 630, 730, 930, 1030, 1130, 1230, 1330, 1430, 1530, 1630, 1730, and 1830 described herein may be combined with any embodiment of the club head described herein. For example, any of the flexure inserts 150, 250, 350, 450, 550, 650, 750, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, and 1850 described in the following embodiments are applicable to any slit shape described herein. Any of the above embodiments of the flexure insert may be applied to a basic slit 130 that does not have retaining walls or complex shapes. In other embodiments, any of the above embodiments of the flexure insert may be applied to a slit 130 having one or more retaining walls or other features described in the following embodiments. In some embodiments, one or more retaining walls or other configurations of the slit 130 can complement the flexure insert 150 by further controlling the deflection of the striking face 102 or by making it easier to retain the flexure insert 150 within the slit 130.

[0090] As described above, Figures 4 and 5 show that the sole 112 of the club head 100 defines a slit 130. The slit 130 is a through slit, providing an opening between the outside of the club head 100 and the internal cavity 107. In many embodiments, the slit 130 is located near the striking face 102. The slit 130 has a front edge 132 adjacent to the striking face 102 and a rear edge 134 opposite the front edge 132. In many embodiments, the slit 130 is located in the front part of the sole 112, closer to the front end 108 than to the rear part 111. Referring to Figure 4, the slit 130 is separated from the leading edge 103 of the striking face 102 by the front part 117 of the sole. The slit 130 extends in the heel-toe direction in the sole 112.

[0091] The slit 130 strategically weakens the sole 112 near the striking face 102, allowing the striking face 102 to bend at impact. Therefore, the slit 130 improves the bending dynamics of the striking face 102, resulting in beneficial golf ball performance characteristics such as increased ball speed, a higher launch angle, and reduced spin. As will be described in detail below, the sole 112 may define slits 130 in various embodiments to improve the flex of the striking face 102.

[0092] The configuration and dimensions of the slit 130 are important in determining the flexibility of the striking face 102 at impact. The size, shape, and position of the slit 130 as viewed from the sole side, as shown in Figure 4, are defined as the "profile" of the slit 130. The profile of the slit 130 affects not only the overall amount of flex of the striking face 102, but also the relative degree of flex of each part on the striking face 102 (i.e., whether the part of the striking face 102 closer to the geometric center 120 flexes more than the part closer to the outer periphery of the striking face 102).

[0093] Referring to Figure 28, the slit profile may be represented by a slit offset distance 141 measured from the leading edge 103 of the club head 100 to the leading edge 132 of the slit. The slit offset distance 141 is measured from the leading edge 103 of the club head to the leading edge 132 of the slit. In many embodiments, the slit offset distance 141 may be less than 20 mm. In some embodiments, the slit offset distance 141 may be less than 15 mm, less than 10 mm, or less than 5 mm. In some embodiments, the slit offset distance 141 may be about 20 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, or 5 mm.

[0094] The profile of the slit 130 may further be represented by the slit width and slit length. The slit width may be measured as the short-side width between the leading and trailing edges. In many embodiments, the slit width may be 3.5 mm to 10 mm. In some embodiments, the slit width may be about 3.5 mm, 3.8 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, or 10 mm. The slit length may be the distance between the heel-side point and the toe-side point of the slit 130, measured parallel to the X-axis 3040. In many embodiments, the length of the slit 130 may be 70 mm to 90 mm. In some embodiments, the slit length may be about 70 mm, 75 mm, 80 mm, 85 mm, or 90 mm.

[0095] The profile of the slit 130 may further be represented by the shape of the slit 130. The slit 130 may be an elongated slit 130 extending in the heel-toe direction in the sole 112. Figure 28 shows an embodiment of the elongated slit 130. The slit 130 may have a heel end 219 and a toe end 131. The heel end 219 and the toe end 131 may have rounded ends.

[0096] In some embodiments, the heel end 129 and toe end 131 of the slit 130 may be inclined with respect to the center of the slit 130. The heel end 129 and toe end 131 of the slit 130 may be inclined rearward toward the rear 111 of the club head 100. The inclination of the heel end 129 and toe end 131 of the slit 130 increases the length Ls of the slit 130 in the heel-toe direction. The heel end 129 and toe end 131 of the slit 130 may extend behind the striking face 102. In other words, a portion of the leading edge 132 of the slit 130 may be parallel to the striking face 102, while the rest of the leading edge 132 of the slit may not be parallel. The orientation of the leading edge 132 of the slit can lengthen the slit 130, thereby increasing the deflection of the sole 112. A longer length Ls of the slit 130 increases the deflection of the sole 112. The inclination of the heel end 129 and the toe end 131 also makes it easier to secure the flexure insert within the slit 130.

[0097] Furthermore, if the heel end 129 and toe end 131 are inclined, the total stress on the slit 130 is more easily reduced. Due to the elongated slit 130 configuration, stress concentrates at the ends 129 and 131 in the club head 100 upon impact with the golf ball. At impact, the leading edge 132 of the slit 130 flexes more backward than the central part. When the slit 130 flexes, stress concentrates at the heel end 129 and toe end 131. Because the heel end 129 and toe end 131 are inclined, more mass is distributed around the ends of the slit 130, allowing it to withstand stress concentration.

[0098] In other embodiments, the profile of the slit 130 may have a different shape or configuration to increase the flexibility and durability of the slit 130. For example, the angles of the heel end 129 and the toe end 131 may be larger. The central part of the slit 130 may also be inclined or curved relative to the leading edge. The width of the heel end 129 and the toe end 131 may be wider, or the heel end 129 and the toe end 131 may have more rounded ends, such as a dumbbell shape. III. Flexure Inserts

[0099] As described above and shown in Figure 5, the club head 100 further includes a flexure insert 150 configured to be inserted into the slit 130. The flexure insert 150 performs several functions. The flexure insert 150 fills the opening formed by the slit 130, sealing the internal cavity 107. The flexure insert 150 provides resistance against excessive bending of the slit 130 at impact. The amount of bending of the slit 130 at impact may be related to the stiffness of the flexure insert 150. The higher the stiffness of the flexure insert 150, the less the slit 130 will deflect at impact. The flexure insert 150 may be designed to maximize the amount of bending of the slit 130 as much as possible without causing excessive bending and breakage of the slit 130. The flexure insert 150 improves the durability of the slit 130, allowing the walls surrounding the slit 130 to be made thinner. The flexure insert 150 also allows for a thinner striking face. In some embodiments, the stiffness of the flexure insert 150 may vary at various positions along the slit 130. In such embodiments, the flexure insert 150 allows for more precise control of the deflection of the striking face 102.

[0100] The flexure insert 150 may have various configurations to adjust the overall stiffness of the slit 130 so that the slit 130 flexes and is supported as desired. In some embodiments, the stiffness of the flexure insert 150 may be higher near the center of the slit 130 than near the heel end 129 or the toe end 131. In other embodiments, the stiffness of the flexure insert 150 may be higher near the heel end 129 or the toe end 131 as needed. Furthermore, the degree of stiffness of the flexure insert 150 may be adjusted so that the slit 130 flexes and is supported as desired. Thus, by customizing or specially designing the flexure insert 150, the overall performance of the slit 130 may be adjusted to achieve the desired flex and support by increasing the stiffness in specific areas of the slit 130 or by adjusting the stiffness of the flexure insert 150 itself.

[0101] The stiffness of the flexure insert 150 may be adjusted by using at least two materials in the flexure insert 150. The flexure insert described herein is composed of at least two materials. The first material may have a first stiffness value, and the second material may have a second stiffness value different from the first stiffness value. The first and second materials may be arranged as desired so that the stiffness profile of the slit described above is obtained.

[0102] In many embodiments, the flexure insert 150 may include a spring component 160 and a cap 180, as described below. The flexure insert 150 is a separate component formed from a different material than the striking face 102 and body 101. The flexure insert 150 is not integrated with the club head 100 (i.e., it is not formed from the same material as the sole 112). The spring component 160 functions as a reinforcing member or support structure that prevents the slit 130 from flexing excessively to the point of breakage. The spring component 160 also plays a role in increasing the internal energy of the club head 100 upon impact with the golf ball. The spring component 160 improves the overall performance of the slit 130 by storing energy when compressed upon impact and releasing energy when expanded. The improvement comes from the spring component 160 returning more energy to the club head than conventionally used inserts. The spring component functions linearly elastically, while conventionally used inserts (such as polymer inserts) function viscoelastically. Viscoelastic compression results in greater energy loss than linear elastic compression. In viscoelastic compression, energy is absorbed and dissipated, so the energy is not returned to the system, leading to significant energy loss. The spring component 160 may be made of plastic, composite material, spring steel, titanium, or other material that provides sufficient linear elastic compression. In linear elastic compression, most, though not all, of the energy is returned to the system and the club head, thus increasing the energy. The cap 180 seals the internal cavity 107 of the club head 100. The cap 180 may be formed from a polymer material. The cap 180 fills the remaining space of the slit 130, blocking communication between the outside of the club head 100 and the internal cavity 107.

[0103] Upon impact with the golf ball, the slit 130 allows the club head body 101 to flex more than the sole of a club head without the slit 130. However, excessive flexing of the slit 130 can lead to cracking or breakage. To prevent excessive flexing, the flexure insert 150 reinforces or supports the slit 130 as the sole 112 flexes upon impact with the golf ball. The flexure insert 150 improves the durability of the club head by preventing excessive flexing of the sole 112 upon impact with the ball. Improved club head durability allows the striking face 102 in the club head 100 to flex as desired, resulting in better ball speed, spin, and / or distance. In some embodiments, the presence of the flexure insert 150 eliminates the need for a sole wall to be erected around the slit 130. If an extra wall is provided, the weight of the front part of the sole will increase unnecessarily, negatively affecting the MOI characteristics and CG position. Furthermore, since the sole wall directly surrounding the slit can be made thinner, not only will flex and ball speed increase, but discretionary mass can also be increased. The slit 130 and flexure insert 150 of the present invention maximize the flex of the striking face 102 and sole 112, improving golf ball performance (e.g., ball speed, spin, distance).

[0104] The Flexure insert 150, equipped with a spring component 160, offers performance advantages compared to conventional inserts without a spring component. Conventional inserts are made of a uniform viscoelastic material, which dissipates energy upon impact and does not return energy to the striking face 102. On the other hand, the Flexure insert 150 is equipped with a linearly elastic spring component 160 that efficiently stores and returns internal energy upon impact, thereby increasing ball speed and the total internal energy of the club head.

[0105] In many embodiments, a flexure insert 150 with a spring component 160 can increase the internal energy at impact by 3 lbf·in to 25 lbf·in compared to a club head with an insert that does not have a spring component. In many embodiments, the increase in internal energy at impact may be 3 to 5 lbf·in, 5 to 10 lbf·in, 10 to 15 lbf·in, 15 to 20 lbf·in, or 20 to 25 lbf·in. In many embodiments, the increase in internal energy at impact may be about 3 lbf·in, about 4 lbf·in, about 5 lbf·in, about 6 lbf·in, about 7 lbf·in, about 8 lbf·in, about 9 lbf·in, about 10 lbf·in, about 11 lbf·in, about 12 lbf·in, about 13 lbf·in, about 14 lbf·in, about 15 lbf·in, about 16 lbf·in, about 17 lbf·in, about 18 lbf·in, about 19 lbf·in, about 20 lbf·in, about 21 lbf·in, about 22 lbf·in, about 23 lbf·in, about 24 lbf·in, or about 25 lbf·in.

[0106] Similarly, in many embodiments, a flexure insert 150 with a spring component 160 can increase the ball velocity at impact (measured at a clubhead velocity of 100 mph) by 0.5 mph to 4.5 mph compared to a clubhead with an insert that does not have a spring component. In many embodiments, the increase in ball velocity at impact may be 0.5 mph to 1.0 mph, 1.0 mph to 1.5 mph, 1.5 mph to 2.0 mph, 2.0 mph to 2.5 mph, 2.5 mph to 3.0 mph, 3.0 mph to 3.5 mph, 3.5 mph to 4.0 mph, or 4.0 mph to 4.5 mph. In some embodiments, the increase in ball velocity at impact is approximately 0.5 mph, 0.6 mph, 0.7 mph, 0.8 mph, 0.9 mph, 1.0 mph, 1.1 mph, 1.2 mph, 1.3 mph, 1.4 mph, 1.5 mph, 1.6 mph, 1.7 mph, 1.8 mph, 1.9 mph, 2.0 mph, 2.1 mph, 2.2 mph, 2.3 mph, and approximately It may be 2.4 mph, approximately 2.5 mph, approximately 2.6 mph, approximately 2.7 mph, approximately 2.8 mph, approximately 2.9 mph, approximately 3.0 mph, approximately 3.1 mph, approximately 3.2 mph, approximately 3.3 mph, approximately 3.4 mph, approximately 3.5 mph, approximately 3.6 mph, approximately 3.7 mph, approximately 3.8 mph, approximately 3.9 mph, approximately 4.0 mph, approximately 4.1 mph, approximately 4.2 mph, approximately 4.3 mph, approximately 4.4 mph, or approximately 4.5 mph. IV. Overview of Multi-Material Flexure Inserts

[0107] As detailed below, the club head 100 includes a flexure insert 150 configured to be inserted into a slit 130. In one embodiment, the flexure insert 150 may include a spring component 160 and a cap 180. The spring component 160 is configured to increase the internal energy of the club head 100 while limiting the deflection of the slit 130 upon impact with the golf ball. The cap 180 is configured to seal the internal cavity 107 of the club head 100. The spring component 160 may be formed from a polymer, plastic, composite material, spring steel, or titanium. The cap 180 may be formed from a polymer or plastic material.

[0108] In many embodiments, the spring component 160 is located in the center of the slit 130. In other embodiments, the spring component 160 may be located near the heel end 129 of the slit 130, near the center of the slit 130, near the toe end 131 of the slit 130, or any combination thereof. Typically, the center of the sole 112 near the striking face 102 flexes more than the portions of the sole 112 near the heel 104 or toe 106. In many embodiments, the spring component 160 is located near the center of the slit 130 where the sole 112 flexes the most.

[0109] The flexure insert 150 may have one spring component 160. In other embodiments, the flexure insert may have one, two, or three spring components 160. In an embodiment with two spring components (not shown), the first spring component may be located near the center of the slit 130, and the second spring component may be located near the heel end 129 or the toe end 131 of the slit 130. In an embodiment with three spring components, the first spring component may be located near the center of the slit 130, the second spring component may be located near the heel end 129 of the slit 130, and the third spring component may be located near the toe end 131 of the slit 130.

[0110] The spring component 160, like a spring, stores energy when compressed linearly elastically. The spring component 160 of the flexure insert 150 is compressed upon impact with the golf ball. Upon impact, the flexure insert 150 is compressed as the leading edge 132 of the slit 130 bends or displaces backward. The spring component 160 prevents breakage by limiting the amount of displacement or bending of the leading edge 132 of the slit 130, and further increases the energy returned to the slit 130 upon recovery. In other words, the spring component 160 limits the bending of the slit 130, but improves performance and durability by pushing the slit 130 back to its original shape. This results in better structural integrity and increased internal energy compared to inserts made of viscoelastic polymers.

[0111] The spring component 160 is made of a first material. The first material may be selected from the group consisting of plastic, thermosetting composite material, steel, stainless steel, spring steel, titanium, and aluminum.

[0112] The spring component 160 further has a first modulus value. In some embodiments, the first modulus value may be about 20 to 210 GPa. For example, the first modulus value may be 20 to 70 GPa, 70 to 120 GPa, 120 to 170 GPa, or 170 to 210 GPa.

[0113] As described above, the Flexure insert 150 includes a cap 180 that seals the internal cavity 107 of the club head. The cap 180 may extend along the entire profile of the slit 130 from the heel end 129 to the toe end 131, and from the front edge 132 to the rear edge 134 of the slit 130. The cap 180 closes the slit 130 and isolates the internal cavity 107 from the outside of the club head 100. The cap 180 may include an outer cap surface 187 that forms part of the sole 112 in the slit 130. The cap 180 prevents water and dust from entering the hollow internal cavity 107 and may also contribute to structurally supporting the slit 130 and suppressing excessive flexing of the slit 130.

[0114] As described above, the flexure insert 150 includes not only the spring component 160 but also a cap 180. The cap 180 is made of a second material. The second material may be an injection-molded polymer such as TPE or TPU, silicone, butyl rubber, foamed metal, or other suitable material, or a combination thereof.

[0115] The cap 180 further has a second modulus value. In some embodiments, the second modulus value may be about 0.1 GPa to 30 GPa. For example, the second modulus value may be about 0.1 to 1 GPa, 1 to 5 GPa, 5 to 10 GPa, 10 to 20 GPa, or 20 to 30 GPa. In another embodiment, the modulus of the spring component may be at least 30 GPa, at least 31 GPa, at least 32 GPa, at least 33 GPa, at least 34 GPa, at least 35 GPa, at least 40 GPa, at least 45 GPa, at least 50 GPa, at least 60 GPa, at least 70 GPa, at least 80 GPa, at least 90 GPa, or at least 100 GPa. The spring component 160 has a larger modulus value than the cap 180, and its first modulus value is greater than its second modulus value.

[0116] In many embodiments, as shown in the embodiments of Figures 6 to 27, the spring component 160 and the cap 180 are combined to form a single flexure insert 150. In many embodiments, the spring component 160 may be partially or entirely embedded in the cap 180. In many embodiments, the lower part of the spring component 160 may be embedded in the cap 180. In such embodiments, the cap 180 covers the entire lower part of the spring component 160 so that no part of the spring component 160 is exposed to the outside of the club head 100. In another embodiment, the lower part of the spring component 160 may not be completely embedded in the cap 180, in which case at least a portion of the spring component 160 is exposed to the outside of the club head 100. In many embodiments, only the lower part of the spring component 160 may be embedded in the cap 180, and the upper part of the spring component 160 is exposed to the hollow internal cavity 107. In many embodiments detailed below, the spring component 160 is completely embedded in the cap 180, and no part of the spring component 160 is exposed to the outside of the club head 100, nor to the hollow internal cavity 107.

[0117] As described above, the Flexure insert 150 offers several advantages. The Flexure insert 150 seals the internal cavity 107, reinforces the slit 130, and prevents excessive deflection of the slit 130. Specifically, the multi-material Flexure insert 150, which includes a spring component 160 and a cap 180, can offer performance advantages compared to conventional inserts. The spring component 160 improves golf ball performance (i.e., ball speed, spin, and distance) by creating a spring effect that increases the internal energy transmitted between the club head 100 and the golf ball. Flexure insert with U-shaped spring component

[0118] Figures 6 to 9 show one embodiment of a golf club head equipped with a slit 130 and a flexure insert 150, the flexure insert 150 comprising a U-shaped spring component 160. The U-shaped spring component comprises a front wall 162, a rear wall 164, and an upper wall 166. The upper wall 166 connects the front wall 162 and the rear wall 164. The upper wall 166 curves inward toward the inside of the club head, thereby giving it a U-shaped appearance.

[0119] The front wall 162 and the rear wall 164 are configured to contact the front and rear surfaces of the slit 130, respectively. In other embodiments, the front wall 162 and the rear wall 164 may be offset from the front and rear surfaces of the slit. The front wall 162 and the rear wall 164 of the spring component 160 each have a front projection 167 extending forward and a rear projection 168 extending backward. The front projection 167 and the rear projection 168 are configured to be inserted into the front recess 140 and the rear recess 142, respectively. The projections 167 and 168 allow the spring component 160 to be fixed in the slit 130. In other embodiments, the spring component 160 may have any number of other projections. For example, the spring component 160 may have no projections, may have one projection, or may have three or more projections.

[0120] As shown in Figure 8, the spring component 160 is located in the central part 190 of the slit 130, and there are no spring components 160 in the heel and toe sections. As mentioned above, the central part 190 of the slit 130 flexes the most when impacted by the golf ball, so the spring component 160 is positioned for the central part 190 of the slit 130.

[0121] Upon impact with the golf ball, the front of the slit 130 flexes backward, pushing the front wall 162 of the spring component 160 toward the rear wall 164. The upper wall 166 of the spring component 160 bends due to its curved shape, placing a load on the spring component 160 and accumulating internal energy. When the compression and bending of the spring component 160 reach its maximum, the front wall 162 returns to its forward position, returning the front of the slit 130 to its position before impact.

[0122] The spring component 160 has a length Lsc, which is the distance from the heel-side point of the spring component 160 to the toe-side point of the spring component 160. In this embodiment, the length Lsc of the spring component is approximately 0.20 inches. In other embodiments, the length Lsc of the spring component may be approximately 0.10 inches to 1.50 inches. The length Lsc of the spring component can also be expressed as a ratio to the total length of the slit Ls. In the illustrated embodiment, the length Lsc of the spring component is approximately 32% of the total length of the slit Ls. In other embodiments, the length Lsc of the spring component may be approximately 10% to 50% of the total length of the slit Ls.

[0123] The flexure insert 150 further comprises a cap 180. In this embodiment, the cap 180 covers the entire slit 130 and the spring component 160 so that the spring component 160 cannot be seen from outside the club. The spring component 160 is partially embedded in the cap 180, and a portion of the spring component 160 can be seen from inside the club head. The cap 180 comprises a heel portion 182, a center portion 184, and a toe portion 186. The cap 180 may further have a thickness tc measured from the outer surface 187 to the inner surface 188 of the cap 180. In many embodiments, the thickness tc of the cap 180 is greater in the heel and toe portions than in the center portion.

[0124] The Flexure Insert 150 improves the durability of the slit by reinforcing the center of the slit. In addition, the U-shaped spring component 160 receives load and stores energy when the slit flexes. When the flex is at its maximum, the U-shaped spring component 160 returns energy to the club head, thereby increasing ball speed, spin, and distance. The U-shaped spring component 160 also prevents slit breakage by preventing the slit from flexing to the point of cracking.

[0125] In this embodiment, the spring component 160 has a U-shape. In other embodiments, the spring component 160 may have other shapes, such as a V-shape or a W-shape. In each of these embodiments, a portion of the spring component extends into the cavity and is not embedded in the cap, so that a portion of the spring component can be seen from inside the club head. In each of these embodiments, the spring component 160 is in contact with both the front and rear walls of the slit.

[0126] The illustrated configuration of the slit 130 should not be interpreted restrictively, but is shown as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 130 may be adjusted as needed. Furthermore, the configuration of the flexure insert 150 may also be adjusted to complement the walls of the slit 130. b. Flexure insert with floating spring component

[0127] Figures 10 and 11 show a second embodiment of a club head having a slit 230 and a flexure insert 250. The flexure insert 250 includes a spring component 260. In this embodiment, the spring component 260 is entirely embedded in the cap 280. In other words, the spring component may be suspended in mid-air within the cap 280. In the embodiments of Figures 10 to 12, the spring component 260 is spaced apart from the edge of the slit 230 and does not contact either the front 233 or the rear 235 of the slit 230. In this embodiment, the spring component 260 is not connected to the wall of the slit 230. The spring component 260 is suspended in mid-air within the cap 280 and functions as a “floating spring” that does not contact the wall of the slit 230. As described above, the spring component 260 may be located anywhere within the cap 280.

[0128] As shown in Figures 10 and 11, the spring component 260 may be elliptical. The ellipse has a major axis 270 and a minor axis 272. The major axis 270 of the ellipse may coincide with the heel-toe direction within the slit 230, and the minor axis 272 of the ellipse may coincide with the front-to-back direction. Thus, the elliptical spring component 260 is longer in the heel-toe direction than in the front-to-back direction. Furthermore, as shown in Figures 10 and 11, the flexure insert 250 may comprise a series of elliptical spring components 260 located within the slit 230. The elliptical shape of the spring component 260 allows it to flex upon impact. The spring component 260 flexes along the minor axis 272 so that the minor axis distance is reduced. In another embodiment, the club head may comprise a floating spring component 260 whose shape is not necessarily elliptical. In other embodiments, the shape of the floating spring component may be circular, triangular, rectangular, capsule-shaped, or any other suitable shape. In each of these embodiments, the spring component does not come into contact with either the front or rear surface of the slit, and another material is interposed between the spring component and the wall of the slit.

[0129] As shown in Figures 10 and 11, the cap 280 may completely fill the slit 230. The cap 280 may have a cap thickness tc. The cap thickness tc may be the same as the thickness of the sole at the leading edge of the slit 230. The cap thickness tc may be the same as the thickness of the sole at the trailing edge of the slit 230. The elliptical spring component is positioned within the cap 280 such that the cap 280 completely encloses the spring component 260.

[0130] In this embodiment, the outer circumference of the spring component 260 is continuous. The continuity of the outer circumference allows the spring component 260 to bend and restore its shape. The spring component may be formed in any shape with a continuous outer circumference. Since the spring component is not firmly fixed to the wall of the slit, if the outer circumference of the embedded spring component is not continuous, it will negatively affect the spring component's ability to store energy and restore its shape.

[0131] The configuration of the slit 230 shown in the figure should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 230 may be adjusted as needed. Furthermore, the configuration of the flexure insert 250 may also be adjusted to complement the walls of the slit 230. Flexure insert with cN-shaped spring component

[0132] Figures 12 to 14 show a third embodiment of a golf club head equipped with a slit 330 and a flexure insert 350. The flexure insert 350 is equipped with an "N-shaped" spring component 360. The N-shaped spring component 360 comprises a front arm 361, a rear arm 363, and a cross arm 365 connecting the front arm 361 and the rear arm 363. The N-shaped spring component 360 is configured to flex within the slit 330 in response to the force of impact with the golf ball, as well as to provide resistance against excessive flexing of the slit 330. The "N-shaped" spring component 360 can also be considered as a "Z-shape," which is a "Z" turned on its side.

[0133] The front arm 361 comprises an upper end 371 and a lower end 373 opposite the upper end 371. The front arm 361 forms a spring front wall 362 that extends vertically between the upper end 371 and the lower end 373. The spring front wall 362 forms the frontmost surface of the flexure insert 350 and is configured to interlock with the front surface of the slit 330.

[0134] Similarly, the rear arm 363 comprises an upper rear arm end 375 and a lower rear arm end 377 opposite the upper rear arm end 375. The rear arm 363 forms a spring rear wall that extends vertically between the upper rear arm end 375 and the lower rear arm end 377. The spring rear wall 363 forms the rearmost surface of the flexure insert 350 and is configured to interlock with the rear surface of the slit 330.

[0135] The cross arm 365 extends between the front arm 361 and the rear arm 363. In many embodiments, the cross arm 365 extends diagonally from the upper end 371 of the front arm to the lower end 377 of the rear arm. This orientation forms an "N" shape when viewed in cross-section (see Figures 12 and 13). In other embodiments (not shown), the cross arm 365 may extend diagonally in the opposite direction from the lower end 373 of the front arm to the upper end 375 of the rear arm. The diagonal orientation of the cross arm 365 allows the N-shaped spring component 360 to be compressed upon impact with the golf ball.

[0136] The N-shaped spring component 360 forms a front joint 378 located at the connection point between the cross arm 365 and the front arm 361, and a rear joint 379 located at the connection point between the cross arm 365 and the rear arm 363. The front joint 378 and the rear joint 379 strategically create weak points in the N-shaped spring component 360, allowing the spring component to be compressed in the longitudinal direction. The N-shaped spring component 360 further forms a front joint angle, defined as an acute angle between the front arm 361 and the cross arm 365. Similarly, the N-shaped spring component 360 forms a rear joint angle, defined as an acute angle between the rear arm 363 and the cross arm 365. In many embodiments, the front joint angle and the rear joint angle may be approximately the same. In other embodiments, the front joint angle and the rear joint angle may be different. In many embodiments, the front joint angle and / or rear joint angle may be about 25 to 65 degrees. For example, the front joint angle and / or rear joint angle may be 25-35 degrees, 35-45 degrees, 45-55 degrees, or 55-65 degrees. Each of the front and rear joint angles is measured with the spring component in a "stationary" position where the club head is not subjected to any impact force.

[0137] The N-shaped spring component 360, together with the cap 380, forms the flexure insert 350. In some embodiments, both the lower end 373 of the front arm and the lower end 377 of the rear arm may be embedded in the cap 380, in which case no portion of the N-shaped spring component 360 is exposed to the outside of the club head. In some embodiments, the upper end 371 of the front arm and the lower end 373 of the front arm may not be embedded in the cap 380, in which case the upper end 371 and the lower end 373 of the front arm are exposed to the hollow internal cavity. In another embodiment, the N-shaped spring component 360 may be completely embedded in the cap 380, in which case the N-shaped spring component 360 is not exposed to the outside of the club head or to the hollow internal cavity.

[0138] The N-shaped spring component 360 is not only designed to flex when a load is applied during impact with the golf ball, but is also configured to structurally support the edges and surfaces of the slit 330, preventing excessive flexing of the slit 330. When the club head and the golf ball collide, the presence of the front joint 378 and rear joint 379 allows the N-shaped spring component 360 to be compressed in accordance with the load applied to the front arm 361 and rear arm 363 by the edges of the slit 330. The more the N-shaped spring component 360 is compressed, the greater the resistance it exerts on the edges of the slit 330. In this way, the N-shaped spring component 360 can flex in a way that prevents excessive flexing of the slit 330.

[0139] The N-shaped spring component 360 is configured to be positioned in the central portion 390 of the slit 330, and the spring component 360 is not positioned in the heel and toe portions of the slit 330. The spring component 360 reinforces the central portion 390 of the slit and prevents excessive bending. In other embodiments, the spring component 360 may be configured to abut against the heel or toe portion of the slit 330.

[0140] The illustrated configuration of the slit 330 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 330 may be adjusted as needed. Furthermore, the configuration of the flexure insert 350 may also be adjusted to complement the walls of the slit 330. d. Flexure insert with hook-shaped spring component

[0141] Figures 15 to 17 show a fourth embodiment of a club head comprising a slit 430 and a flexure insert 450. In this embodiment, the flexure insert 450 comprises a "hook-shaped" spring component 460. The hook-shaped spring component 460 comprises a bumper 474 configured to work in conjunction with the front surface 433 of the slit 430, and an anchor 463 separated rearward from the bumper 474 by a shank portion 461. The hook-shaped spring component 460 is configured to not only flex within the slit 430 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 430. The hook-shaped spring component 460 may be asymmetrical and may have varying thicknesses.

[0142] The bumper 474 is located at the front end of the hook-shaped spring component 460 and is close to the front surface 433 of the slit 430. The bumper 474 forms a bumper surface 476 configured to contact the front surface 433 of the slit when the slit 430 flexes upon impact with the golf ball. The bumper 474 may extend downward from the shank portion 461 into the interior of the slit 430. In some embodiments, the bumper surface 476 may be substantially flat so as to be coplanar with the front surface 433 of the slit 430. In other embodiments, the bumper surface 476 may be curved, as shown in Figures 15 and 16. In some embodiments, the bumper surface 476 may be configured to contact the front surface 433 of the slit 430 when the club head is in a stationary position (when the club head is not subjected to any impact force). In another embodiment, there may be a gap between the bumper surface 476 and the front surface 433 of the slit 430 when the club head is in a stationary position. In embodiments with such a gap, the slit 430 flexes upon impact with the golf ball, eliminating the gap, and the front surface 433 of the slit moves in conjunction with the bumper surface 476. Therefore, in such embodiments, the hook-shaped spring component 460 contacts only the front surface 433 of the slit 430 upon impact with the golf ball.

[0143] The anchor 463 is located at the rear end of the hook-shaped spring component 460 and is attached to an inner recess 470 provided in the sole behind the slit 430. As shown in Figures 15 to 17, the club head has a recess 470 on the inner surface of the sole configured to receive the anchor 463. The recess 470 may be set back from the rear edge 434 of the slit 430. The recess 470 may extend approximately parallel to the rear edge 434 of the slit 430 and generally in the heel-toe direction. The anchor 463 may be approximately vertical and extends into the recess 470 toward the sole. When impacted with the golf ball, the anchor 463 is pressed against the rear wall of the recess, making it easier for the hook-shaped spring component 460 to be compressed.

[0144] In many embodiments, the recess 470 may be provided in a position corresponding to the heel-toe direction of the hook-shaped spring component 460 of a particular embodiment. For example, in many embodiments where the hook-shaped spring component 460 is located in the center of the slit 430, the recess 470 may be provided in the center of the sole 490, which is behind the center 490 of the slit 430.

[0145] As described above, the bumper portion 474 and anchor 463 of the hook-shaped spring component 460 are connected by a shank portion 461. The shank portion 461 extends generally in the front-rear direction. The shank portion 461 may be partially located within the slit 430 and partially located within a hollow internal cavity. Since the bumper 474 is located within the slit 430 and the anchor 463 is housed in a recess 470 spaced rearward from the slit 430, the shank portion 461 may extend from the slit 430 through the internal cavity to the recess 470. In many embodiments, as shown in Figures 15 to 17, the shank portion 461 straddles a portion of the sole between the trailing edge 434 of the slit and the recess 470.

[0146] The hook-shaped spring component 460 is not only designed to flex when a load is applied during impact with the golf ball, but is also configured to structurally support the edges and surfaces of the slit 430, preventing excessive flexing of the slit 430. The hook-shaped spring component 460 may be compressed in the front-rear direction during impact with the golf ball. When the slit 430 flexes, the hook-shaped spring component 460 is compressed between the front surface of the slit, which applies a rearward force to the bumper 474, and the rear wall of the recess, which applies a forward force to the anchor, pushing the bumper downward and bending the entire spring component 460. The more the hook-shaped spring is compressed, the greater the resistance that the spring provides to the edges of the slit. In this way, the hook-shaped spring can be flexed in a way that prevents excessive flexing of the slit.

[0147] The illustrated configuration of the slit 430 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 430 may be adjusted as needed. Furthermore, the configuration of the flexure insert 450 may also be adjusted to complement the walls of the slit 430. e. Flexure insert with an elongated U-shaped spring component

[0148] Figure 18 shows another embodiment of a golf club head having a slit 930 and a flexure insert 950. The flexure insert 950 comprises a cap 980 and a spring component 960. In this embodiment, the spring component 960 is configured to abut the front 933 and rear 935 of the slit 930. The front 933 and rear 935 of the slit 930 extend inward toward the inside of the club head, providing sufficient surface area for the flexure insert 950 to adhere. The rear 935 of the slit has a recess 937 that facilitates securing the spring component 960 to the slit 930. The recess 937 is located at the upper end of the rear 935.

[0149] The spring component 960 comprises a front wall 962, a rear wall 964, and an upper wall 966, and has an elongated U-shape. The rear wall 964 has a projection 969 at its upper part that extends rearward from the rear wall 964. The projection 969 is configured to be inserted into a recess 937 provided on the rear surface 935 of the slit 930.

[0150] Upon impact with the golf ball, the front surface 933 of the slit 930 is displaced forward, thereby compressing the spring component 960. The front wall 962 of the insert is also displaced forward, thereby reducing the distance between the front wall 962 and the rear wall 964. The front wall 962 and the rear wall 964 bend around the upper wall 966.

[0151] The illustrated configuration of the slit 930 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 930 may be adjusted as needed. Furthermore, the configuration of the flexure insert 950 may also be adjusted to complement the walls of the slit 930. f. Flexure embodiment with cross arms

[0152] Figure 19 shows another embodiment of a golf club head having a slit 1030 and a flexure insert 1050. The flexure insert 1050 comprises a cap 1080 and a spring component 1060. In this embodiment, the slit 1030 has a front surface 1033, a rear surface 1035, and a top surface. The spring component 1060 may be configured to abut the front surface 1033, the rear surface 1035, and the top surface of the slit 1030. The front surface 1033 and the rear surface 1035 of the slit 1030 extend inward toward the inside of the club head, providing sufficient surface area for the flexure insert 1050 to adhere. The top surface 1037 extends from the rear surface 1035 toward the front surface 1033. The upper surface 1037 is provided with a projection 1039 that extends away from the inside of the club head, and the projection 1039 facilitates the fixing of the spring component 1060 in the slit 1030.

[0153] The spring component 1060 may be similar in many respects to the "N"-shaped spring component 360 described above. The spring component 1060 comprises a front arm 1062, a rear arm 1064, and a cross arm 1066 connecting the front arm 1061 and the rear arm 1064. The spring component 1060 is configured not only to flex within the slit 1030 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1030. The front arm 1061, the rear arm 1064, and the cross arm 1065 are connected and function similarly to the front arm 361, the rear arm 363, and the cross arm 365 of the "N"-shaped spring component 360. The upper projection 1039 may abut against both the cross arm 1065 and the rear arm 1064 of the spring component 1060. As shown in Figure 19, the protrusion 1039 may have a shape corresponding to the shapes of the cross arm 1065 and the rear arm 1064. The upper surface 1037 of the slit 1030 may be in contact with one end of the rear arm 1064 and may be located on the inside of the club head relative to the spring component 1060.

[0154] Upon impact with the golf ball, the front surface 1033 of the slit 1030 is displaced forward, thereby compressing the spring component 1060. The front arm 1062 is also displaced backward, thereby reducing the distance between the front arm 1062 and the cross arm 1066.

[0155] The illustrated configuration of the slit 1030 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1030 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1050 may also be adjusted to complement the walls of the slit 1030. g. Flexure insert with a spring component having a wall that converges in a concave shape.

[0156] Figure 20 shows another embodiment of a golf club head having a slit 1130 and a flexure insert 1100. The flexure insert 1100 comprises a cap 1180 and a spring component 1160. In this embodiment, the slit 1130 comprises a front surface 1133, a rear surface 1135, and a recess 1137 provided in the front surface 1133. The recess 1137 facilitates positioning and securing the insert in the slit 1130. The spring component 1160 may be configured to abut against the front surface 1133 and the rear surface 1135. The front surface 1133 and the rear surface 1135 of the slit 1130 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1100 to adhere. Furthermore, the front surface 1133 and the rear surface 1135 extend curvilinearly toward the interior of the club head, with the upper ends of the front surface 1133 and the rear surface 1135 being closer together than their lower ends. In other words, the front surface 1133 and rear surface 1135 of the slit 1130 are concave. In other embodiments, the front surface 1133 and / or rear surface 1135 may be convex or not curved.

[0157] The spring component 1160 may be similar in many respects to the "U"-shaped spring component 160 described above. The spring component 1160 comprises a front wall 1162, a rear wall 1164, and an upper wall 1166 connecting the front wall 1162 and the rear wall 1164. The spring component 1160 is configured not only to flex within the slit 1130 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1130. The front wall 1162, rear wall 1164, and upper wall 1166 are connected and function similarly to the front wall 162, rear wall 164, and upper wall 166 of the "U"-shaped spring component 160. The front wall 1162 of the spring component 1160 has a projection 1169 configured to be inserted into the recess 1137.

[0158] Upon impact with the golf ball, the front surface 1133 of the slit 1130 is displaced forward, thereby compressing the spring component 1160. The front wall 1162 of the insert is also displaced forward, thereby reducing the distance between the front wall 1162 and the rear wall 1164. The front wall 1162 and the rear wall 1164 bend around the upper wall 1166.

[0159] The illustrated configuration of the slit 1130 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1130 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1150 may also be adjusted to complement the walls of the slit 1130. Flexure insert with hV-shaped spring component

[0160] Figure 21 shows another embodiment of a golf club head comprising a slit 1230 and a flexure insert 1250. The flexure insert 1250 comprises a cap 1280 and a spring component 1260. In this embodiment, the slit 1230 comprises a front surface 1233 and a rear surface 1235. The spring component 1260 may be configured to abut the front surface 1233 and the rear surface 1235. The front surface 1233 and the rear surface 1235 of the slit 1230 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1250 to adhere. Furthermore, the front surface 1233 and the rear surface 1235 extend curvilinearly toward the interior of the club head. The front surface 1233 is concave, and the rear surface 1235 is convex.

[0161] The "V" shaped spring component 1260 may be similar in many respects to the "U" shaped spring component 160 described above. The spring component 1260 comprises a front wall 1262, a rear wall 1264, and an upper wall 1266 connecting the front wall 1262 and the rear wall 1264. The spring component 1260 is configured not only to flex within the slit 1230 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1230. The front wall 1262, rear wall 1264, and cross wall 1266 are connected and function similarly to the front wall 162, rear wall 164, and upper wall 166 of the "U" shaped spring component 160.

[0162] Upon impact with the golf ball, the front surface 1233 of the slit 1230 is displaced forward, thereby compressing the spring component 1260. The front wall 1262 of the insert is also displaced forward, thereby reducing the distance between the front wall 1262 and the rear wall 1264. The front wall 1262 and the rear wall 1264 bend around the upper wall 1266.

[0163] The illustrated configuration of the slit 1230 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1230 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1250 may also be adjusted to complement the walls of the slit 1230. i. Flexure insert with a U-shaped spring component having a curved rear wall.

[0164] Figure 22 shows another embodiment of a golf club head comprising a slit 1330 and a flexure insert 1350. The flexure insert 1350 comprises a cap 1380 and a spring component 1360. In this embodiment, the slit 1330 comprises a front surface 1333 and a rear surface 1335. The spring component 1360 may be configured to abut the front surface 1333 and the rear surface 1335. The front surface 1333 and the rear surface 1335 of the slit 1330 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1350 to adhere. Furthermore, the front surface 1333 is a generally flat surface, while the rear surface 1335 is curved. The rear surface 1335 is concave. The curvature of the rear surface 1335 facilitates securing the insert 1350 in place.

[0165] The spring component 1360 may be similar in many respects to the "U"-shaped spring component 160 described above. The spring component 1360 comprises a front wall 1362, a rear wall 1364, and an upper wall 1366 connecting the front wall 1362 and the rear wall 1364. The spring component 1360 is configured not only to flex within the slit 1330 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1330. The front wall 1362, rear wall 1364, and upper wall 1366 are connected and function similarly to the front wall 162, rear wall 164, and upper wall 166 of the "U"-shaped spring component 160. The rear wall 1364 has a shape that complements the curved rear surface 1335 of the slit 1330.

[0166] Upon impact with the golf ball, the front surface 1333 of the slit 1330 is displaced forward, thereby compressing the spring component 1360. The front wall 1362 of the insert is also displaced forward, thereby reducing the distance between the front wall 1362 and the rear wall 1364. The front wall 1362 and the rear wall 1364 bend around the upper wall 1366.

[0167] The illustrated configuration of the slit 1330 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1330 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1350 may also be adjusted to complement the walls of the slit 1330. Flexure insert with U-shaped spring component and curved surface

[0168] Figure 23 shows another embodiment of a golf club head comprising a slit 1430 and a flexure insert 1450. The flexure insert 1450 comprises a cap 1480 and a spring component 1460. In this embodiment, the slit 1430 comprises a front surface 1433 and a rear surface 1435. The spring component 1460 may be configured to abut the front surface 1433 and the rear surface 1435. The front surface 1433 and the rear surface 1435 of the slit 1430 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1450 to adhere. Furthermore, the front surface 1433 is a generally flat surface, while the rear surface 1435 is curved. The rear surface 1435 is concave. The curvature of the rear surface 1435 facilitates securing the insert 1450 in place.

[0169] The spring component 1460 may be similar in many respects to the "U"-shaped spring component 160 described above. The spring component 1460 comprises a front wall 1462, a rear wall 1464, and a lower wall 1466 connecting the front wall 1462 and the rear wall 1464. The spring component 1460 is configured not only to flex within the slit 1430 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1430. The front wall 1462, rear wall 1464, and lower wall 1466 are connected and function similarly to the front wall 162, rear wall 164, and upper wall 166 of the "U"-shaped spring component 160. The rear wall 1464 has a shape that complements the curved rear surface 1435 of the slit 1430.

[0170] Upon impact with the golf ball, the front surface 1433 of the slit 1430 is displaced forward, thereby compressing the spring component 1460. The front wall 1462 of the insert is also displaced forward, thereby reducing the distance between the front wall 1462 and the rear wall 1464. The front wall 1462 and the rear wall 1464 bend around the upper wall 1466.

[0171] The illustrated configuration of the slit 1430 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1430 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1450 may also be adjusted so that the flexure insert 1450 complements the walls of the slit 1430. k. Flexure insert with two cross arms

[0172] Figure 24 shows another embodiment of a golf club head having a slit 1530 and a flexure insert 1550. The flexure insert 1550 comprises a cap 1580 and a spring component 1560. The spring component 1560 may be configured to abut the front surface 1533 and the rear surface 1535. The front surface 1533 and the rear surface 1535 of the slit 1530 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1550 to adhere. Furthermore, the front surface 1533 and the rear surface 1535 extend roughly perpendicularly toward the interior of the club head, and the distance between the upper end of the front surface 1533 and the upper end of the rear surface 1535 is approximately equal to the distance between the lower end of the front surface 1533 and the lower end of the rear surface 1535.

[0173] The spring component 1560 may be similar in many respects to the "N" shaped spring component 360 described above. The spring component 1560 comprises a front arm 1562, a rear arm 1564, a first cross arm 1566 connecting the front arm 1562 and the rear arm 1564, and a second cross arm 1568 connecting the front arm 1562 and the rear arm 1564. The first cross arm 1566 may be located closer to the internal cavity of the club head. The second cross arm 1568 may be located closer to the sole of the golf club. The first cross arm 1566 and the second cross arm 1568 are located apart from each other. The spring component 1560 is configured not only to flex within the slit 1530 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1530. The front arm 1562, rear arm 1564, and cross arm 1566 are connected and function similarly to the front arm 361, rear arm 363, and cross arm 365 of the "N" shaped spring component 360. The upper projection 1539 may contact both the cross arm 1566 and the rear arm 1564 of the spring component 1560. As shown in Figure 19, the projection 1539 may have a shape corresponding to the shapes of the cross arm 1566 and the rear arm 1564. The upper surface 1537 of the slit 1530 may contact one end of the rear arm 1564 and be located on the inside of the club head relative to the spring component 1560.

[0174] Upon impact with the golf ball, the front surface 1533 of the slit 1530 is displaced forward, thereby compressing the spring component 1560. The front arm 1562 of the insert is also displaced forward, reducing the distance between the front arm 1562 and the rear arm 1564. Due to the orientation and angle of the first cross arm 1566 and the second cross arm 1568, the compression of the spring component 1560 causes the front arm 1562 to move slightly towards the inside of the club head.

[0175] The illustrated configuration of the slit 1530 should not be interpreted as limiting, but rather as an illustrative embodiment. For example, the width, length, profile, and walls of the slit 1530 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1550 may also be adjusted so that the flexure insert 1550 complements the walls of the slit 1530. Flexure insert with IZ-shaped spring component

[0176] Figure 25 shows another embodiment of a golf club head having a slit 1630 and a flexure insert 1650. The flexure insert 1650 comprises a cap 1680 and a spring component 1660. In this embodiment, the slit 1630 comprises a front wall 1631 and a rear wall 1641. The front wall 1631 comprises an upper surface 1632, an inclined surface 1633, and a lower surface 1635. The rear wall 1641 comprises an upper horizontal surface 1642, an upper vertical surface 1643, an inclined surface 1644, a lower horizontal surface 1645, and a lower vertical surface 1646. The surfaces of the front wall 1631 and the rear wall 1641 extend inward toward the internal cavity of the club head, providing sufficient surface area for the flexure insert 1650 to adhere. In another embodiment, the front wall 1631 and the rear wall 1641 may have other surface combinations or configurations to improve the manufacturability and durability of the slit 1630.

[0177] The spring component 1660 may have a "Z-shaped" configuration and comprises an upper arm 1662, a cross arm 1664, and a lower arm 1666. The spring component 1660 has a shape that complements the front wall 1631 and rear wall 1641 surfaces of the slit 1630. The Z-shaped configuration makes it easier to hold the insert 1650 within the slit 1630.

[0178] The configuration of the illustrated slit 1630 should not be construed as limiting and is shown as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1630 may be adjusted as necessary. Further, the configuration of the flexure insert 1650 may also be adjusted such that the flexure insert 1650 complements the walls of the slit 1530. m. A flexure insert having an inverted U-shaped spring part and a protrusion

[0179] FIG. 26 shows another embodiment of a golf club head having a slit 1730 and a flexure insert 1750. The flexure insert 1750 includes a cap 1780 and a spring part 1760. In this embodiment, the slit 1730 includes a front surface 1733, a rear surface 1735, a first recess 1737 provided in the front surface 1733, and a second recess 1738 provided in the rear surface 1735. The first recess 1737 and the second recess 1738 facilitate positioning and fixing the flexure insert 1750 in the slit 1730. The spring part 1760 may be configured to abut against the front surface 1733 and the rear surface 1735. The front surface 1733 and the rear surface 1735 of the slit 1730 extend inwardly toward the internal cavity of the club head and provide a sufficient surface area for the flexure insert 1750 to adhere. Further, the front surface 1733 and the rear surface 1735 extend generally perpendicular to the internal cavity of the club head, and the distance between the upper ends of the front surface 1733 and the rear surface 1735 is substantially equal to the distance between the lower ends of the front surface 1733 and the rear surface 1735.

[0180] The spring component 1760 may be similar to the above-described U-shaped spring component 160 in many respects. The spring component 1760 includes a front wall 1762, a rear wall 1764, and an upper wall 1766 that connects the front wall 1762 and the rear wall 1764. The spring component 1760 is configured not only to bend within the slit 1730 in response to the force during the impact with the golf ball, but also to provide resistance against excessive bending of the slit 1730. The front wall 1762, the rear wall 1764, and the upper wall 1766 are connected and function in the same manner as the front wall 162, the rear wall 164, and the upper wall 166 of the U-shaped spring component 160. In the present embodiment, the upper wall 1766 is located on the inner cavity side of the golf club head. The front wall 1762 of the spring component 1760 includes a first protrusion 1769 and a second protrusion 1770 that are configured to be inserted into the first recess 1737 and the second recess 1738.

[0181] During the impact with the golf ball, the front surface 1733 of the slit 1730 is displaced forward, whereby the spring component 1760 is compressed. The front wall 1762 of the insert is also displaced forward, and the distance between the front wall 1762 and the rear wall 1764 is reduced. The front wall 1762 and the rear wall 1764 bend around the upper wall 1766.

[0182] The configuration of the illustrated slit 1730 should not be construed as limiting, and is shown as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1730 may be adjusted as needed. Further, the configuration of the flexure insert 1750 may also be adjusted such that the flexure insert 1750 complements the walls of the slit 1730. n. A flexure insert comprising an elongated U-shaped spring component having protrusions

[0183] Figure 27 shows another embodiment of a golf club head having a slit 1830 and a flexure insert 1850. The flexure insert 1850 comprises a cap 1880 and a spring component 1860. In this embodiment, the slit 1830 comprises a front surface 1833, a rear surface 1835, and a recess 1837 provided in the front surface 1833. The recess 1837 facilitates positioning and securing the insert in the slit 1830. The spring component 1860 may be configured to abut the front surface 1833 and the rear surface 1835. The front surface 1833 and the rear surface 1835 of the slit 1830 extend inward toward the interior of the club head, providing sufficient surface area for the flexure insert 1850 to adhere. The front 1833 and rear 1835 extend roughly vertically toward the internal cavity of the club head, and the distance between the upper end of the front 1833 and the upper end of the rear 1835 is approximately equal to the distance between the lower end of the front 1833 and the lower end of the rear 1835.

[0184] The spring component 1860 may be similar in many respects to the "U"-shaped spring component 160 described above. The spring component 1860 comprises a front wall 1862, a rear wall 1864, and a lower wall 1866 connecting the front wall 1862 and the rear wall 1864. The spring component 1860 is configured not only to flex within the slit 1830 in response to the force of impact with the golf ball, but also to provide resistance against excessive flexing of the slit 1830. The front wall 1862, rear wall 1864, and lower wall 1866 connect and function in the same way as the front wall 162, rear wall 164, and upper wall 166 of the "U"-shaped spring component 160. In this embodiment, the lower wall 1866 is located on the sole side of the golf club head. The front wall 1862 of the spring component 1860 includes a first projection 1869 and a second projection 1870, which are configured to be inserted into a first recess 1837 and a second recess 1838.

[0185] Upon impact with the golf ball, the front surface 1833 of the slit 1830 is displaced forward, thereby compressing the spring component 1860. The front wall 1862 of the insert is also displaced forward, and the distance between the front wall 1862 and the rear wall 1864 decreases. The front wall 1862 and the rear wall 1864 bend around the bottom wall 1866.

[0186] The illustrated configuration of the slit 1830 should not be interpreted as limiting, but rather as an exemplary embodiment. For example, the width, length, profile, and walls of the slit 1830 may be adjusted as needed. Furthermore, the configuration of the flexure insert 1850 may also be adjusted so that the flexure insert 1850 complements the walls of the slit 1830. o. Enclosing cap and exposed spring component

[0187] Figures 35A and 35B show another embodiment of the flexure insert 2250. The flexure insert 2250 comprises a cap 2280 and a spring component 2260. In this embodiment, the spring component 2260 is enclosed within the cap 2280, forming a multi-material insert that increases energy retention and transmission. The cap 2280 comprises a front wall 2282, a rear wall 2284, a heel side wall 2286, a toe side wall 2288, and a bottom wall 2290. Together, the front wall 2282, rear wall 2284, heel side wall 2286, toe side wall 2288, and bottom wall 2290 form an opening for receiving the spring component 2260. In this embodiment, the spring component 2260 is exposed through an opening formed in the upper part of the flexure insert 2250, so that when the flexure insert 2250 is assembled to the golf club head, the spring component 2260 can only be seen from inside the club head. The opening is defined by a front wall 2282, a rear wall 2284, a toe side wall 2288, and a heel side wall 2286. Furthermore, in this embodiment, the spring component 2260 is not configured to contact the front and rear walls of the slit. Instead, the front wall 2282, rear wall 2284, heel side wall 2286, and toe side wall 2288 of the cap abut against the walls of the slit. Since the cap seals the slit, dust and other debris cannot enter the internal cavity of the club head.

[0188] In this embodiment, the spring component 2260 is a solid sheet metal or leaf spring. The spring component 2260 extends from the heel sidewall 2286 to the toe sidewall 2288 of the cap 2280. As shown in Figure 35B, the cap 2280 and the spring component 2260 form an arc-shaped or curved shape. The shape of the cap 2280 and the spring component 2260 corresponds to the general shape of the slit into which the flexure insert 2250 is housed.

[0189] The overall deflection characteristics of the slit may be altered by adjusting the thickness of the spring component 2260. The thickness of the spring component 2260 may vary along its length. For example, in some embodiments, the thickness of the spring component 2260 is greater in the center than at the heel and toe ends. In other embodiments, the thickness of the spring component 2260 is constant along its entire length. The thickness of the spring component, measured from the front to the rear, may be between 0.050 inches and 0.50 inches. In some embodiments, this thickness may be between 0.050 and 0.10 inches, 0.10 and 0.20 inches, 0.20 and 0.30 inches, 0.30 and 0.40 inches, or 0.40 and 0.50 inches.

[0190] In the illustrated embodiment, the length of the spring component 2260 is greater than 85% of the length of the cap 2280. In other embodiments, the length of the spring component 2260 may be less than 85% of the length of the cap 2280. For example, in some embodiments, the length of the spring component 2260 is at least 85%, 90%, or 95% of the length of the cap 2280. In another example, the length of the spring component 2260 may be less than 85%, less than 75%, less than 65%, or less than 60% of the length of the cap.

[0191] In this embodiment, the spring component 2260 is made of a first material having a first modulus of elasticity. The material of the spring component 2260 may be a polymer, plastic, composite material, spring steel, titanium, or aluminum. In the illustrated embodiment, the spring component 2260 is made of aluminum. The cap 2280 is made of a second material having a second modulus of elasticity. The second modulus of elasticity is smaller than the first modulus of elasticity. Thus, the flexibility and rigidity of the slit are determined by the modulus of elasticity of the spring component 2260. U-shaped cap and stepped spring component

[0192] Figures 36A to 36C show another embodiment of the flexure insert 2350. The flexure insert 2350 comprises a cap 2380 and a spring component 2360. The cap 2380 has a U-shaped cross-section and includes a front wall 2382, a bottom wall, and a rear wall 2384. The spring component 2360 is positioned between the front wall 2382 and the rear wall 2384. The spring component 2360 includes a central portion 2364 that abuts the front wall 2382, toe ends 2366 and heel ends 2368 located on either side of the central portion 2364 and in contact with the rear wall 2384 of the cap at the heel and toe ends, and a stepped portion 2362 which is a transition between the central portion 2364 and the toe ends 2366 and heel ends 2368. The stepped portion 2362 of the spring component 2360 reinforces the central part of the front wall 2382, where the deflection of the slit is greatest upon impact with the golf ball. In this embodiment, the spring component 2360 is exposed inside the club head and can be seen from the inside.

[0193] Figure 36A shows a first embodiment of a spring component 2360 having a stepped portion 2362. In this embodiment, the front wall 2382 of the cap has a smooth, flat surface against which the spring component abuts. The smooth surface of the front wall 2382 allows the spring component 2360 to slide in the crown-sole direction when it flexes.

[0194] Figure 36C shows a second embodiment of the spring component 2360 having a stepped portion 2362. The embodiment in Figure 36C is similar to the embodiment in Figure 36A in that the spring component has a stepped portion 2362 that contacts the front wall 2382 of the cap 2380. The embodiment in Figure 36C differs from the embodiment in Figure 36A in that the front wall 2382 has a recess 2361 that receives the central portion 2364 of the spring component 2360. The recess 2361 guides the spring component 2360 to a desired position and prevents the spring component from sliding or moving along the front wall 2382. q. Embedded spring parts

[0195] Figure 36D shows another embodiment of the flexure insert 2450, comprising a cap 2480 and a spring component 2460. In this embodiment, the spring component 2460 is embedded within the cap 2480 and completely covered by the cap 2480, so that the spring component 2460 cannot be seen from any viewpoint of the flexure insert 2450. Thus, the cap 2480 has a solid structure, extending from the front wall 2433 to the rear wall 2435 of the slit, and is formed so that there are no gaps or channels around the entire spring component 2460.

[0196] In the embodiment shown in Figure 36D, the spring component 2460 is similar to the spring component 2360 in Figures 36A-36C in that it has a stepped portion between the central part and the end of the spring component 2460. As described above, the stepped portion allows the threaded component 2460 to reinforce the central part of the front wall 2433 where the deflection of the slit is greatest upon impact with the golf ball. In other embodiments, the spring component 2460 may have a different shape or configuration to reinforce any desired region of the front wall 2433 of the slit. For example, the spring component 2460 may give the slit the desired stiffness by reinforcing the heel portion, the toe portion, or both. In some embodiments, the flexure insert 2450 may selectively reinforce multiple desired regions of the slit by comprising two or more spring components 2360. rU-shaped cap and cantilever spring component

[0197] Figure 37 shows another embodiment of the Flexure insert. In this embodiment, the golf club head includes a cantilever arm 2550 having a fixed end 2554 connected to the inner surface of the sole behind the slit 2530. The cantilever arm 2550 further includes a tip 2552, which is positioned between the front wall 2533 and the rear wall 2535 of the slit 2530. The cantilever arm 2550 extends in an arc between the tip 2552 and the fixed end 2554. The cantilever arm 2550 further includes a bumper 2560 connected to the tip 2552, which is configured to contact the front wall 2533 of the slit upon impact with the golf ball. The cantilever arm 2550 bends because the fixed end 2554 is firmly bonded to the inner surface of the sole, but the tip 2552 is free to flex. Upon impact with the golf ball, the front wall 2533 flexes backward and contacts the bumper 2560, applying force and causing the cantilever arm 2550 to bend. The curved, arc-shaped cantilever arm 2550 functions like a leaf spring, storing energy when it bends. Subsequently, the cantilever arm 2550 and bumper 2533 push back the front wall 2533 of the slit 2530, returning energy to the ball, resulting in increased ball speed and carry distance compared to a clubhead with a slit that does not have a cantilever arm.

[0198] As described above, the bumper 2560 contacts the front wall 2533 of the slit during large deflections (i.e., upon contact with the ball at normal / average swing speeds with a wood type club head). The bumper 2560 is made of a material different from that of the cantilever arm 2550 and is attached as a separate body to the tip 2552. The bumper 2560 may be made of a non-metallic material so as not to wear when contacting the front wall 2533. The bumper 2560 may be made of a non-metallic material that allows the bumper 2560 to slide sufficiently without restriction with minimal friction against the front wall 2533. For example, in some embodiments, the bumper 2560 is made of Delrin material or an acetal resin such as polyoxymethylene (POM). In other embodiments, the bumper 2560 may be made of other thermoplastic resins, thermosetting resins, ceramics, or composite materials.

[0199] The cantilever arm 2550 may be integrally formed with the inner surface of the sole or may be attached as a separate body. In some embodiments, the cantilever arm 2550 is connected to a mass pad inside the sole of the golf club head. The mass pad is a region that is thicker than the peripheral wall of the club head. For example, the thickness of the mass pad may be at least 1 mm, 2 mm, 3 mm, or 4 mm greater than that of the peripheral wall. The cantilever arm 2560 may be made of the same material as the body of the club head or may be made of other materials such as spring steel or the material of the spring component described above. By selecting the material of the cantilever arm 2550, the energy storage characteristics can be adjusted to obtain the desired rigidity and / or bending characteristics.

[0200] Furthermore, the thickness and length of the cantilever arm may be adjusted to obtain the desired stiffness and bending characteristics. Thickness is directly proportional to stiffness. Stiffness may be reduced by decreasing the thickness, or increased by increasing the thickness. In some embodiments, the thickness of the cantilever arm may be 0.030 to 0.50 inches. For example, in some embodiments, the thickness may be 0.030 to 0.10 inches, 0.10 to 0.20 inches, 0.20 to 0.30 inches, 0.30 to 0.40 inches, or 0.40 to 0.50 inches.

[0201] The length of the cantilever arm (also known as the rear offset distance 2565, shown in Figure 38) may be adjusted to obtain the desired stiffness. The rear offset distance 2565 is measured from the rear surface 2535 of the slit to the base of the fixed end 2554 of the cantilever arm 2550. The base is the transition point from the inner surface of the sole to the underside of the cantilever arm. The rear offset distance may be between 0.10 and 1.5 inches. For example, in some embodiments, the rear offset distance may be between 0.10 and 0.25 inches, 0.25 and 0.50 inches, 0.50 and 0.75 inches, 0.75 and 1.0 inches, 1.0 and 1.25 inches, or 1.25 and 1.50 inches. The rear offset distance 2565 may be shortened to increase stiffness, or lengthened to decrease stiffness.

[0202] The radius of curvature of the cantilever arm 2550 may be adjusted to obtain the desired stiffness. The stiffness may be reduced by decreasing the radius of curvature, or increased by increasing the radius of curvature. The radius of curvature of the cantilever arm 2550 does not have to be constant between the tip and the fixed end. For example, in some embodiments, the radius of curvature may vary between 0.25 to 1 inch, 1 to 2 inches, 2 to 3 inches, 3 to 4 inches, or 4 to 5 inches.

[0203] As shown in Figure 39, the cantilever arm 2550 has a width 2567 measured in the heel-toe direction. The width 2567 may be adjusted to reinforce a desired portion of the slit. For example, the width 2567 may be narrowed to reinforce a localized area, or widened to reinforce a wider area of ​​the slit. The width 2567 may be between 0.10 inches and 1 inch. For example, the width may be between 0.10 and 0.25 inches, 0.25 and 0.50 inches, 0.50 and 0.75 inches, or 0.75 and 1 inch.

[0204] In the illustrated embodiment, the bumper 2560 and the cantilever arm 2550 are located approximately in the center of the slit. In another embodiment, the bumper 2560 and the cantilever arm 2550 may be located closer to the toe or heel. The cantilever arm 2550 may be positioned to achieve desired performance characteristics by reinforcing a desired region in the heel-toe direction. In some embodiments, the club head may have two or more cantilever arms to reinforce two or more desired regions. In another embodiment, the cantilever arm may have two or more ends and only one fixed end. For example, the cantilever arm may have a Y-shape with two ends. In this embodiment, each end is individually equipped with a bumper. The Y-shaped cantilever arm strategically reinforces two separate regions of the slit.

[0205] In some embodiments, as shown in Figure 37, the rear wall 2535 of the slit may have a rear wall recess 2540. The rear wall recess forms a clearance for the cantilever arm 2550 to extend into the slit 2530. The width of the rear wall recess 2540 is greater than the width 2567 of the cantilever arm 2550.

[0206] As shown in Figures 40 and 41, the cap 2580 has a U-shaped cross-section. The height of the cap 2580, measured vertically, varies along the length of the slit. Specifically, the height of the cap 2580 in the center or middle of the slit is lower than the height of the cap in the heel and toe portions, thereby forming a notch 2586. The presence of the notch 2586 in the center of the cap allows the bumper 2560 to contact the front wall 2533 of the slit directly, rather than the cap 2580. Direct contact with the front wall 2533 of the slit allows the bumper 2560 and the cantilever arm 2550 to reinforce the slit during rebound and handle the energy returned to the slit. In another embodiment, the height of the cap may be constant along the length of the slit.

[0207] As described above, the cantilever arm 2550 flexes and bends upon impact with the golf ball. Therefore, the cantilever arm 2550 has both unloaded and loaded states. The unloaded state may be defined as the bumper being at a distance greater than 0 inches from the front wall of the slot. The loaded state may be defined as the bumper being in contact with the front wall. In the loaded state, the amount of bending and displacement will vary depending on the speed of the club head and the position on the face where the golf ball strikes. The bumper should be positioned close enough to the front wall so that the front wall can remain in contact with the bumper throughout the contact with the golf ball. For example, the bumper should be positioned at a distance of less than 0.025 inches from the front wall. V-shaped lattice structure single-material flexure insert

[0208] In many embodiments, the club head may have a flexure insert 2050 made of a single material having varying effective densities, as shown in Figures 33A and 33B. By varying the effective density of the flexure insert 2050 along the slit 2030, the flexibility of a given location or area of ​​the slit 2030, the striking face 2002, or the sole 2012 can be controlled. Having varying effective densities in a single-material flexure insert 2050 is an alternative to controlling or customizing the flexibility of the slit 2030 using an insert 2050 made of multiple materials having different properties. In some embodiments, the effective density of the flexure insert 2050 may be higher in areas of the slit 2030 where high rigidity or reinforcement is desired. Conversely, the effective density of the flexure insert 2050 may be lower in areas of the slit 2030 where high flexibility is desired but high rigidity or reinforcement is not required.

[0209] Figure 33A shows one embodiment of a club head 2000 having a flexure insert 2050 with varying effective densities. The flexure insert 2050 is not formed of a solid material and has a lattice structure having interconnected walls 2051 defining a plurality of voids 2052. The size and density of the voids 2052 in a portion of the flexure insert 2050 determines the effective density in that portion. The effective density of the flexure insert 2050 may be defined as the mass of any portion of the flexure insert 2050 divided by the unit volume occupied by that portion. Therefore, the effective density of the flexure insert 2050 is independent of the density of the material forming the flexure insert 2050 (i.e., "material density").

[0210] The flexure insert 2050 may be composed of a polymeric material such as a polymer matrix composite material. The polymer matrix composite material may be a glass-filled elastomer, a stainless steel-filled elastomer, a tungsten-filled elastomer, a thermoplastic polyurethane (TPU) composite material, a thermoplastic elastomer (TPE) composite material, other elastomer matrix composite materials, Kevlar® (aramid) fiber reinforced polymer, carbon fiber reinforced polymer, rubber, ethylene vinyl acetate foam, polymer foam, any combination of a suitable resin and a suitable reinforcing fiber, or any combination of the materials described above.

[0211] In many embodiments, the material density of the flexure insert 2050 may be from 0.75 to 2.0 g / cm 3 In many embodiments, the material density of the flexure insert 2050 may be from 0.75 to 1.0 g / cm 3 1.0 to 1.25 g / cm 3 1.25 to 1.5 g / cm 3 1.5 to 1.75 g / cm 3 or 1.75 to 2.0 g / cm 3 In many embodiments, the material durometer hardness of the flexure insert 2050 may be from Shore 30A to Shore 90D. In some embodiments, the material hardness of the flexure insert 2050 may be from Shore 30A to Shore 50A, from Shore 50A to Shore 70A, from Shore 70A to Shore 90A, from Shore 10D to Shore 30D, from Shore 30D to Shore 50D, from Shore 50D to Shore 70D, or from Shore 70D to Shore 90D.

[0212] In many embodiments, the effective density of the flexure insert 2050 may be from 0.35 to 1.0 g / cm

[0213] In many embodiments, at least a portion of the effective density of the flexure insert 2050 may be from 0.35 to 0.50 g / cm 3 In many embodiments, at least a portion of the effective density of the flexure insert 2050 may be from 0.35 to 0.50 g / cm 3 0.40 to 0.55 g / cm 3 0.45 to 0.60 g / cm3 , 0.50~0.65 g / cm³ 3 , 0.55~0.70 g / cm³ 3 , 0.60~0.75 g / cm³ 3 , 0.65~0.80 g / cm³ 3 , 0.70~0.85 g / cm³ 3 , 0.75~0.90 g / cm³ 3 0.80~0.95 g / cm³ 3 , or 0.85~1.0 g / cm³ 3 This may be the case. Other parts of the flexure insert 2050 may have different effective densities so that the rigidity and modulus of the slit are desirable.

[0214] In many embodiments, the flexure insert 2050 has a high effective density in the portion of the slit 2030 that requires reinforcement (i.e., the high-stress region). In many embodiments, the flexure insert 2050 has a low effective density in the portion of the slit 2030 that does not require reinforcement (i.e., the low-stress region), so that the portion can be significantly deflected without compromising the durability of the slit 2050.

[0215] In the embodiment shown in Figure 33A, the flexure insert 2050 may comprise a central portion 2084 occupying the center of the slit, a heel portion 2082 adjacent to the heel end 2029 of the slit, and a toe portion 2086 adjacent to the toe end 2031 of the slit. The effective density of the flexure insert 2050 may differ among the central portion 2084, the heel portion 2082, and the toe portion 2086.

[0216] The flexure insert 2050 shown in Figure 33A has varying effective densities. The effective density of the flexure insert 2050 is higher in the center portion 2084 than in the heel portion 2082 and the toe portion 2086. As shown in Figure 33A, the density of voids 2052 in the flexure insert 2050 is higher in the heel portion 2082 and the toe portion 2086 than in the center portion 2084. In some embodiments, the center portion 2084 may be substantially solid and have no voids.

[0217] The central portion 2084 may have the maximum effective density of the flexure insert 2050. In many embodiments, the maximum effective density of the flexure insert 2050 may be 0.75 to 1.0 g / cm³. Furthermore, the heel portion 2082 and / or the toe portion 2086 may have the minimum effective density of the flexure insert 2050. The minimum effective density of the flexure insert 2050 may be 0.35 to 0.5 g / cm³.

[0218] By increasing the effective density in the central portion 2084 of the flexure insert 2050 and decreasing the effective density in the heel portion 2082 and toe portion 2086, the center of the slit 2030 can be locally reinforced while allowing the slit 2030 to flex to its maximum extent near the heel end 2029 and toe end 2031. This embodiment is useful when the slit 2030 is subjected to large stresses near its center.

[0219] Furthermore, as shown in Figure 33A, the flexure insert 2050 may include a base layer 2085 located along the bottom of the flexure insert 2050. The base layer 2085 may be integrally formed with the rest of the flexure insert 2050 and does not contain the void 2052. Since the base layer 2085 forms a solid layer along the entire bottom of the flexure insert 2050, the void 2052 is not exposed to the outside of the club head 2000 even when inserted into the slit. By concealing the void 2052 from the outside of the club head 2000, the internal cavity 2007 is sealed, preventing mud and dust from entering the flexure insert 2050 and the internal cavity 2007.

[0220] Figure 33B shows a second embodiment of the flexure insert 2150 having varying effective densities, similar to the flexure insert 2150. In the embodiment of Figure 33B, the effective density of the flexure insert 2150 is greater in the heel portion 2182 and toe portion 2186 than in the central portion 2184. As shown in Figure 33B, the density of voids 2152 in the flexure insert 2150 is higher in the central portion 2184 than in the heel portion or toe portion. In some embodiments, the heel portion 2182 and toe portion 2186 may be substantially solid and have no voids.

[0221] The heel portion 2182 and / or the toe portion 2186 may have the maximum effective density of the flexure insert 2150. In many embodiments, the maximum effective density of the flexure insert 2150 may be 0.75 to 1.0 g / cm³. Furthermore, the central portion 2184 may have the minimum effective density of the flexure insert 2150. In many embodiments, the minimum effective density of the flexure insert 2150 may be 0.35 to 0.5 g / cm³.

[0222] By increasing the effective density in the heel portion 2182 and toe portion 2186 of the flexure insert 2150 and decreasing the effective density in the central portion 2184, the heel end 2129 and toe end 2131 of the slit 2130 can be locally reinforced while allowing the slit 2130 to flex to its maximum extent near the center. This embodiment is useful when the slit 2130 is subjected to high stress near the heel end 2129 and toe end 2131. The flexure insert 2150 may further include a base layer 2185 similar to the base layer 2085, thereby sealing the internal cavity 2107 and preventing mud and dust from entering the flexure insert 2150 and the internal cavity 2107. VI. Slit-holding wall structure

[0223] The performance of the slit 130 (i.e., the amount of deflection of the striking face 102 caused by the slit) may depend on the structure of the slit 130. The structure of the slit 130 refers to the structure around the through-opening formed by the slit 130, and may include the various walls of the slit 130 and the features of the club head 100 adjacent to the slit 130. The structure of the slit 130 affects not only how the slit 130 bends, but also how the flexure insert 150 is held within the slit 130. The structure of the slit 130 also affects the durability of the slit 130 and may help prevent damage to the sole 112. In many embodiments, it is desirable to minimize the complexity of the structure of the slit 130 in order to simplify manufacturing. In many embodiments, the structure of the slit 130 may include features such as a mass pad (detailed below) that can modify the mass properties of the club head 100 to compensate for the addition of the slit 130.

[0224] As described above, in many embodiments, the slit 130 is a simple opening that penetrates the sole 112. In such embodiments, the structure of the slit 130 is not formed by retaining walls or rising structures around the slit 130, and the walls or surface of the slit 130 are formed solely by the thickness of the sole 112. In many such embodiments, the thickness of the sole 112 at the leading edge 132 of the slit 130 may be close to or the same as the thickness of the sole 112 at the trailing edge 134 of the slit 130.

[0225] In many embodiments, the club head 100 may have a slit 130 that is not a simple slit 130, but rather a slit 130 having a structure that includes one or more retaining walls or other rising features surrounding the slit 130. As described above, the structure of the slit 130 improves not only the durability and flexibility of the slit 130, but also the ability of the slit 130 to retain the flexure insert 150.

[0226] Figure 29 shows a club head 500 having a slit 530 defined by a plurality of retaining walls 592. The retaining walls 592 are formed by the sole 112 and form the edges 532, 534 of the slit 530. The retaining walls 592 may be features of the sole 512 extending upward from the inner surface 521 of the sole 512 toward the interior of the internal cavity 507. The retaining walls 592 are configured to hold the flexure insert 550 in place so that the flexure insert 550 abuts against the retaining walls 592 and fills the slit 530. The plurality of retaining walls 592 include front retaining walls 592a located at the front edge 532 of the slit 530 and rear retaining walls 592b located at the rear edge 534 of the slit 530.

[0227] In the embodiment shown in Figure 29, the front retaining wall 592a may be a vertical wall and may extend substantially perpendicular to the inner surface 521 of the sole 512. The front retaining wall 592a further comprises a front surface 594a facing the rear surface 525 and a rear surface 594b facing the slit 530 and configured to contact the flexure insert 550. The front retaining wall 592a comprises a base 596a located at the joint between the front retaining wall 592a and the sole 512 and a free upper end 597a facing the base 596a.

[0228] Similarly, the rear retaining wall 592b may be a vertical wall extending substantially perpendicular to the inner surface 521 of the sole 512. The rear retaining wall 592b further comprises a front surface 594a facing the slit 530 and configured to contact the flexure insert 550, and a rear surface 595b facing the rear 511 of the club head 500. Similar to the front retaining wall 592a, the rear retaining wall 592b comprises a base 596b located at the junction between the rear retaining wall 592b and the sole 512, and a free upper end 597b facing the base 596b. In many embodiments, the front retaining wall 592a and the rear retaining wall 592b may be substantially parallel to each other. In other embodiments, one or both of the retaining walls 592 may be inclined relative to the other.

[0229] The front retaining wall 592a and the rear retaining wall 592b are located at the front edge 532 and rear edge 534 of the slit 530, respectively, and are spaced apart from each other in the front-rear direction, forming a through-opening from the outside of the club head 500 into the internal cavity 507. The slit 530 forms an external opening 538 between the base 596a of the front retaining wall and the base 596b of the rear retaining wall. The external opening 538 forms an entrance from the outside of the club head 500 into the slit 530. The slit 530 further forms an internal opening 536 between the upper end 597a of the front retaining wall and the upper end 597b of the rear retaining wall. The internal opening 536 forms an exit from the slit 530 to the internal cavity 507.

[0230] The retaining wall 592 shown in Figure 29 offers several advantages. The surfaces with which the flexure insert 550 abuts (i.e., the rear surface 595a of the front retaining wall 592a and the front surface 594b of the rear retaining wall 592b) increase the surface area to which the flexure insert 550 is attached or connected. This increased surface area enhances the slit 530's ability to hold the flexure insert 550. Furthermore, the retaining wall 592 adds mass to the edges 532, 534 of the slit 530, reinforcing the slit 530 and increasing its durability. The vertical retaining wall 592 shown in Figure 29 has a simple shape that is not difficult to cast. Therefore, the presence of the retaining wall 592 does not complicate the manufacturing process.

[0231] Figure 30 shows a second embodiment of a club head 600 having multiple retaining walls 692. Each of the retaining walls 692 (i.e., the front retaining wall 692a and the rear retaining wall 692b) may have a transition section 693 and an upper section 698. The presence of a transition section 693 in each retaining wall 692 creates a size difference between the outer opening 638 and the inner opening 636 of the slit 630. This size difference between the outer opening 638 and the inner opening 636 forms a mechanical stopper that securely holds the flexure insert 650 within the slit 630.

[0232] Referring to Figure 30, the front retaining wall 692a may have a front wall transition section 693a extending from the base 696a of the front retaining wall 692a into the internal cavity 607. The front wall transition section 693a may be inclined with respect to the inner surface 621 of the sole. In many embodiments, the front surface 694a of the front wall transition section 693a may be inclined with respect to the inner surface 621 by 30 to 60 degrees. In some embodiments, the angle between the front surface 694a of the front wall transition section 693a and the inner surface 621 of the sole may be 30 to 40 degrees, 35 to 45 degrees, 40 to 50 degrees, 45 to 55 degrees, or 50 to 60 degrees. In some embodiments, the angle between the front surface 694a of the front wall transition portion 693a and the inner surface 621 of the sole may be about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, or about 60 degrees. The inclination of the front wall transition portion 693a causes a gradual change in shape between the sole 612 and the front retaining wall 692a.

[0233] Furthermore, the front retaining wall 692a includes an upper front wall 698a that extends further into the internal cavity 607 from the end of the front transition portion 693a opposite to the base portion 696a. The upper front wall 698a may be substantially vertical and is approximately perpendicular to the inner surface 621 of the sole. The gradual change in shape described above minimizes stress concentration around the front retaining wall 692a, thereby improving durability.

[0234] Similar to the front retaining wall 692a, the rear retaining wall 692b may include a rear wall transition 693b extending from the base 696b of the rear retaining wall 692b into the internal cavity 607. The rear wall transition 693b may be inclined with respect to the inner surface 621 of the sole. In many embodiments, the rear surface 695b of the rear wall transition 693b may be inclined with respect to the inner surface 621 by 30 to 60 degrees. In some embodiments, the angle between the rear surface 695b of the rear wall transition 693b and the inner surface 621 of the sole may be 30 to 40 degrees, 35 to 45 degrees, 40 to 50 degrees, 45 to 55 degrees, or 50 to 60 degrees. In some embodiments, the angle between the rear surface 695b of the rear wall transition 693b and the inner surface 621 of the sole may be about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, or about 60 degrees. The inclination of the rear wall transition 693b causes a gradual change in shape between the sole 612 and the rear retaining wall 692b. This gradual change in shape minimizes stress concentration around the rear retaining wall 692b, resulting in improved durability.

[0235] Furthermore, the rear retaining wall 692b includes a rear wall upper 698b that extends further into the internal cavity 607 from the end of the rear transition 698b located opposite the base 696b. The rear wall upper 698b may be substantially vertical and approximately perpendicular to the sole surface 621. In many embodiments, the rear wall upper 698b may be parallel to the front wall upper 698a.

[0236] In the embodiment shown in Figure 30, the retaining wall 692 is provided with a flat transition portion 693, but in other embodiments, the transition portion 693 may be curved or concave (when viewed in cross-section) relative to the internal cavity 607. Such a curved transition portion 693 can further smooth the transition between the sole 612 and the retaining wall 692.

[0237] As shown in Figure 30, the front wall transition 693a and the rear wall transition 693b move closer to each other as they extend deeper into the internal cavity. As the transitions 693 move closer to each other, the slit width Ws changes. The slit 630 has an external slit width Wse at the external opening 638 and an internal slit width Wsi at the internal opening 636. In many embodiments, the external slit width Wse is greater than the internal slit width Wsi. The difference in width Ws of the slit 630 forms a mechanical stopper that holds the flexure insert 650 in place. The flexure insert 650 has a shape that complementarily fills the profile of the slit 630 formed by the retaining wall 692, and may be flush with the rear surface 695a of the front retaining wall 692a and the front surface 694 of the rear retaining wall 692b. The different slit widths Ws allow the flexure insert 650 to be inserted through the larger external opening 638, preventing it from falling out into the internal cavity 607 through the smaller internal opening 636.

[0238] As shown in Figure 30, in some embodiments, the flexure insert 650 may further include a stopper 655 configured to fix the flexure insert 650 within the slit 630. The stopper 655 may be located at the end of the flexure insert 650 that is exposed to the internal cavity 607. The stopper 655 may be a portion of the flexure insert 650 having a front-to-back width slightly larger than the internal slit width Wsi. When the flexure insert 650 is assembled into the slit 650, the stopper 655 may overlap the upper end 697 of the retaining wall 692. The stopper provides resistance against the upper end 697 of the retaining wall 692, preventing the flexure insert 650 from slipping out of the slit 630 through the external opening 638. Because the flexure insert 650 is made of a flexible material, the stopper 655 can be compressed when the flexure insert 650 is pressed into the slit 630. The stopper 655 expands and returns to its original shape after passing through the internal opening 636, thereby securely locking the flexure insert 650 in place. VII. Clubhead with slit and face crown flip

[0239] The club heads described herein may have various other features that work (directly or indirectly) with the slits to produce a high-performance club head. Any of the other features described below may be combined with any of the slits 130, 230, 330, 430, 530, 630, 730, 930, 1030, 1130, 1230, 1330, 1430, 1530, 1630, 1730, 1830 and Flexure inserts 150, 250, 350, 450, 550, 650, 750, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, 1850 described herein.

[0240] Figures 31 and 32 show a club head 700 comprising a striking face 702 having a slit 730 and a crown flip 727. As shown in Figure 31, the striking face 702 forms a striking surface 728 located at the front end 708 of the club head 700 and a crown flip 727 extending rearward from the upper part of the striking surface 728. The crown flip 728 may extend rearward to form at least the front portion of the crown 710. The striking face 702 may comprise an upper outer perimeter 737 and a lower outer perimeter 739, each of which constitutes a boundary between the striking face 702 and the body 701. For example, the upper outer perimeter 737 is located along the rear edge of the crown flip 727 and forms a boundary between the striking face 702 and the crown 710. In the embodiments shown in Figures 31 and 32, the lower outer periphery 739 of the striking face is located at the front end 708, while the upper outer periphery 737 of the striking face is located on the crown 715 and is spaced rearward from the front end 708.

[0241] In many embodiments, as shown in Figure 32, the crown return 727 may have a return depth Dcr measured in the front-to-back direction from the geometric center 720 to the upper outer periphery 737. In many embodiments, the return depth Dcr may be 0.25 to 1.5 inches. In many embodiments, the return depth Dcr may be 0.25 to 0.50 inches, 0.50 to 0.75 inches, 0.75 to 1.0 inches, 1.0 to 1.25 inches, or 1.25 to 1.5 inches. In many embodiments, the return depth Dcr may be greater than 0.50 inches, greater than 0.60 inches, greater than 0.70 inches, greater than 0.80 inches, greater than 0.90 inches, greater than 1.0 inches, greater than 1.1 inches, greater than 1.2 inches, greater than 1.3 inches, greater than 1.4 inches, or greater than 1.5 inches.

[0242] In many embodiments, the striking face 702 and the body 701 are formed of different materials. In many embodiments, the striking face 702 is made of a higher-strength material than the body 701. By forming a portion of the crown 710 with a crown rib 727, a high-strength material can be placed along the transition from the front end 708 to the crown 710. In this way, the crown rib 727 increases the durability of such areas that are normally at high risk of breakage during impact.

[0243] By providing the crown rib 727, the high-strength material of the striking face 702 is positioned in the front portion of the crown 710, allowing the front portion of the crown 710 to be thinned without compromising durability. Thinning this portion of the crown 710 increases the deflection of the striking face 702, which, combined with the internal energy increment from the slit 730, maximizes the ball speed. In many embodiments, the thickness of the crown rib 727 (measured from the outer surface to the inner surface of the crown rib 727) may be less than 0.040 inches. In many embodiments, the thickness of the crown rib 727 may be less than 0.038 inches, less than 0.036 inches, less than 0.034 inches, less than 0.032 inches, less than 0.030 inches, less than 0.028 inches, less than 0.026 inches, less than 0.024 inches, less than 0.022 inches, or less than 0.020 inches.

[0244] Typically, the striking face 702 can be formed by punching, pressing, or forging, rather than by casting. Therefore, it is difficult to make the striking face 702 have a complex shape. In many embodiments of the club head 700 having a slit 730, particularly in the embodiments described above with respect to one or more retaining walls, the shape of the slit 730 must be formed by casting it into the sole 712. In many embodiments, if the slit 730 is close to the front end 708, it is disadvantageous for the striking face 702 to form part of the sole 712. Therefore, the striking face 702 does not need to have a sole flip. In such embodiments, the striking face 702 may form part of the crown 710 by a crown flip 727, but not any part of the sole 712.

[0245] In other embodiments (not shown), particularly in embodiments where the slit 730 has a simpler configuration, the striking face 702 may have a sole rib extending rearward from the striking surface 728 along the sole 712. In such embodiments, the sole rib may have one or more edges forming one or more edges of the slit 730. The striking face 702 with the crown rib 727 may be combined with any of the various slits described herein and any of the various flexure inserts 150, 250, 350, 450, 550, 650, 750, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, 1850 described herein. VIII. Clubhead with slits and mass pad

[0246] In many embodiments, the club head is equipped with an internal mass pad to position the CG (center of gravity) to a desired location, thereby further improving the golf ball performance characteristics. Referring to Figure 32, the club head 700 is equipped with a combination of a slit 730 and an internal mass pad 745. In many embodiments, the mass pad 745 is integrally formed with the inner surface 721 of the sole. The mass pad 745 is a mass concentration area with a thickness greater than the material thickness of the sole 712. The mass pad 745 may be located between the slit 730 and the rear end 711. However, in many embodiments, the mass pad 745 may be located closer to the striking face 702 than the rear end 711 so that the position of the CG 799 of the club head 700 is relatively forward, thereby reducing undesirable golf ball spin. The mass pad 745 may be combined with any of the various slits described herein, any of the various flexure inserts 150, 250, 350, 450, 550, 650, 750, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, 1850 described herein, or any of the other features described herein.

[0247] In many embodiments, as shown in Figure 32, the mass pad 745 is spaced rearward from the slit 730. In such embodiments, the mass pad 745 does not form any portion of the slit 730 and does not form any portion of the retaining wall 792. In such embodiments, the mass pad 745 is separated from the slit 730 by a portion of the sole 712. In such embodiments, the mass pad 745 does not form the rear edge 734 of the slit 730 and is separated from the retaining wall 792. By separating the mass pad 745 from the slit 730, the amount of deflection of the slit can be maximized. Because the mass pad 745 has a greater thickness (i.e., lower flexibility) than the rest of the sole 712, by spaced the mass pad 745 rearward from the slit 730, the sole 712 and the striking face 702 can be deflected more. Furthermore, by spaced the mass pad 745 rearward from the slit 730, the position of the CG 799 can be moved further rearward, resulting in a club head 700 with a large MOI.

[0248] In other embodiments (not shown), it may be desirable to position the mass pad 745 immediately next to the slit 730 such that the mass pad 745 forms part of the slit 730. In such embodiments, the mass pad 745 may form at least part of the trailing edge 734 of the slit. By positioning the mass pad 745 immediately next to the slit 730, the position of CG799 can be moved more aggressively forward, which can improve the launch characteristics of the golf ball (i.e., reduce the spin rate).

[0249] In many embodiments, the mass of the mass pad 745 may be 25 to 40 grams. In some embodiments, the mass of the mass pad 745 may be 25 to 30 grams, 30 to 35 grams, or 35 to 40 grams. As described above, in many embodiments, the mass pad 745 is integrally formed with the sole 712. In another embodiment, the mass pad 745 may be formed separately and attached to the sole 712 (from the inside or the outside) by adhesive and / or mechanical mounting means. IX. Center of Gravity and Moment of Inertia Characteristics

[0250] The club heads described herein provide advantageous golf ball characteristics such as increased ball speed, high launch angle, and low spin by improving the flexion dynamics of the striking face. As described above, the slit 130 is located close to the striking face 102 and affects the flexion characteristics of the striking face 102. The mass characteristics shown below apply to any combination of the various slits 130, 230, 330, 430, 530, 630, 730, 930, 1030, 1130, 1230, 1330, 1430, 1530, 1630, 1730, and 1830 described herein and the various flexure inserts 150, 250, 350, 450, 550, 650, 750, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, and 1850 described herein.

[0251] Adding a slit often reduces the mass of the front portion of the club head, which can negatively affect the center of gravity (CG) and moment of inertia (MOI) characteristics. However, the club heads described herein have an improved center of gravity position, resulting in better MOI characteristics. Specifically, the club heads with slits described herein have a lower, rearward-positioned CG, resulting in a larger moment of inertia. A club head with a larger moment of inertia is more forgiving of off-center shots. Therefore, the various configurations of the club heads with slits described herein improve feel, increase forgiveness, and enhance competitiveness.

[0252] To improve the CG position and achieve high MOI characteristics, the club head may further incorporate structures that affect the mass characteristics of the club head, such as removable weights, mass pads, thin crowns, weighted inserts, and / or lightweight crowns formed from non-metallic materials. These structures allow for adjustment of the mass characteristics so that high MOI characteristics are obtained by positioning the CG lower and further back. Below, we describe an improved CG position that increases the moment of inertia and club head forgiveness by positioning the CG lower and further back.

[0253] In various embodiments of a driver-type club head, the position of CGx may be -2mm to 6mm. In some embodiments, the position of CGx in a driver-type club head is -2mm to 2mm, or 2mm to 6mm. In some embodiments, the position of CGx in a driver-type club head is approximately -2mm, -1.5mm, -1mm, 0mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, or 6mm.

[0254] In various embodiments of fairway wood-type club heads, the position of CGx may be -7mm to 1mm. In some embodiments, the position of CGx in a fairway wood-type club head is -7mm to -3mm, or -3mm to 1mm. In some embodiments, the position of CGx in a fairway wood-type club head is approximately -7mm, -6mm, -5mm, -4mm, -3mm, -2mm, -1mm, 0mm, 0.5mm, or 1mm.

[0255] In various embodiments of the hybrid club head, the position of CGx may be -5mm to 2mm. In some embodiments, the position of CGx in the hybrid club head is -5mm to -1mm, or -1mm to 2mm. In some embodiments, the position of CGx in the hybrid club head is -4mm to 0mm, -3mm to 1mm, or -2mm to 2mm. In some embodiments, the position of CGx in the hybrid club head is approximately -5mm, -4mm, -3mm, -2.5mm, -2mm, -1.5mm, -1mm, -0.5mm, 0mm, 0.5mm, 1mm, 1.5mm, or 2mm.

[0256] In various embodiments of driver-type club heads, the position of CGy is -4mm to -10mm. In some embodiments, the position of CGy in a driver-type club head is -4 to -7mm, or -7mm to -10mm. In some embodiments, the position of CGy in a driver-type club head is approximately -4mm, -5mm, -6mm, -7mm, -8mm, -9mm, or -10mm.

[0257] In various embodiments of fairway wood-type club heads, the position of CGy is -3mm to -12mm. In some embodiments, the position of CGy in a fairway wood-type club head is -3mm to -7mm, or -7mm to -12mm. In some embodiments, the position of CGy in a fairway wood-type club head is approximately -3mm, -4mm, -5mm, -6mm, -7mm, -8mm, -9mm, -10mm, -11mm, or -12mm.

[0258] In various embodiments of the hybrid club head, the position of CGy may be -3mm to -12mm. In some embodiments, the position of CGy of the hybrid club head is -3mm to -8mm, or -8mm to -12mm. In some embodiments, the position of CGy of the hybrid club head is -4mm to -8mm, -5mm to -9mm, -6mm to -10mm, -7mm to -11mm, or -8mm to -12mm. In some embodiments, the position of CGy of the hybrid club head is approximately -3mm, -4mm, -5mm, -6mm, -7mm, -8mm, -9mm, -10mm, -11mm, or -12mm.

[0259] In various embodiments of driver-type club heads, the position of CGz is greater than 38mm, greater than 40mm, greater than 42mm, greater than 45mm, or greater than 48mm. In some embodiments, the position of CGz in a driver-type club head is between 38mm and 55mm. In some embodiments, the position of CGz in a driver-type club head is between 38mm and 45mm, or between 45mm and 55mm. In some embodiments, the position of CGz in a driver-type club head is approximately 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, or 55mm.

[0260] In various embodiments of fairway wood type golf club heads, the position of CGz may be greater than 25 mm, greater than 28 mm, or greater than 30 mm. In some embodiments, the position of CGz in a fairway wood type golf club head is between 25 mm and 40 mm. In some embodiments, the position of CGz in a fairway wood type golf club head is between 25 mm and 32 mm, or between 32 mm and 40 mm. In some embodiments, the position of CGz in a fairway wood type golf club head is approximately 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, or 40 mm.

[0261] In various embodiments of the hybrid club head, the position of CGz may be greater than 15mm, greater than 18mm, greater than 20mm, greater than 22mm, or greater than 24mm. In some embodiments, the position of CGz in the hybrid club head is between 15mm and 30mm. In some embodiments, the position of CGz in the hybrid club head is between 15mm and 25mm, or between 25mm and 30mm. In some embodiments, the position of CGz in the hybrid club head is between 16mm and 26mm, 17mm and 27mm, 18mm and 28mm, 19mm and 29mm, or between 20mm and 30mm. In some embodiments, the position of CGz in the hybrid club head is approximately 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, or 30mm.

[0262] As described above with reference to Figures 2-4, the center of gravity (CG) defines the origin of a coordinate system having the CGx, CGy, and CGz axes. The CGx axis is parallel to the x axis, the CGy axis is parallel to the y axis, and the CGz axis is parallel to the z axis. Furthermore, the club head has a moment of inertia Ixx about the CGx axis (i.e., the moment of inertia in the crown-sole direction) and a moment of inertia Iyy about the CGy axis (i.e., the moment of inertia in the heel-toe direction). In many embodiments, the crown-sole moment of inertia Ixx and the heel-toe moment of inertia Iyy are made large or maximized based on the amount of discretionary mass available to the club head designer. The moment of inertia represents the ability of the golf club head to resist twisting. A larger moment of inertia about the x axis results in greater forgiveness for off-center shots in the vertical direction. The larger the moment of inertia around the y-axis, the more forgiving the club is for off-center shots in the heel-toe direction.

[0263] In various embodiments of driver-type club heads, in many embodiments, the moment of inertia Ixx in the crown-sole direction is approximately 3000 g·cm². 2 Over 3250g·cm 2 Over 3500g·cm 2 Over 3750g·cm 2 Over 4000g·cm 2 Over 4250g·cm 2 Over 4500g·cm 2 Over 4750g·cm 2 Over, or approximately 5000g·cm 2 It may exceed this value. In various embodiments of driver-type club heads, in many embodiments, the moment of inertia Ixx in the crown-sole direction is 3000 g·cm. 2 ~5000g·cm 2 This may be the case. In other embodiments, the moment of inertia Ixx in the crown-sole direction is 3000 g·cm² to 4000 g·cm². 2 , or 4000g·cm 2 ~5000g·cm 2It may be such. For example, the moment of inertia Ixx in the crown-sole direction is 3000 g·cm. 2 3100g·cm 2 3200g·cm 2 3300g·cm 2 2,3400g·cm 2 3500g·cm 2 3600g·cm 2 3700g·cm 2 3800g·cm 2 3900g·cm 2 , 4000g·cm2, 4100g·cm2, 4200g·cm2, 4300g·cm2, 4400g·cm2, 4500g·cm2 2 4600g·cm 2 4700g·cm 2 4800g·cm 2 4900g·cm 2 , or 5000g·cm 2 That's fine.

[0264] In various embodiments of fairway wood-type club heads, in many embodiments, the moment of inertia Ixx in the crown-sole direction is approximately 1200 g·cm². 2 Over 1300g·cm 2 Over 1400g·cm 2 Over 1500g·cm 2 Over 1600g·cm 2 Over 1700g·cm 2 Over 1800g·cmv 2 Over, or approximately 1900g·cm 2 It may exceed this value. In other embodiments, the moment of inertia Ixx in the crown-sole direction is 1200 g·cm. 2 ~2200g·cm 2 It may be. In other embodiments, the moment of inertia Ixx in the crown-sole direction is 1200 g·cm 2 ~1700g·cm 2 , or 1700g·cm 2 ~2200g·cm 2It may be. For example, the moment of inertia Ixx in the crown - sole direction is 1200 g·cm 2 , 1300 g·cm 2 , 1400 g·cm 2 , 1500 g·cm 2 , 1600 g·cm 2 , 1700 g·cm 2 , 1800 g·cm 2 , 1900 g·cm 2 , 2000 g·cm 2 , 2100 g·cm 2 , or 2200 g·cm 2 and may be.

[0265] In various embodiments of the hybrid - type club head, in many embodiments, the moment of inertia Ixx in the crown - sole direction is greater than about 880 g·cm 2 , greater than about 890 g·cm 2 , greater than about 900 g·cm 2 , greater than about 910 g·cm 2 , greater than about 920 g·cm 2 , greater than about 930 g·cm 2 , greater than about 940 g·cm 2 , greater than about 950 g·cm 2 , greater than or greater than about 960 g·cm 2 and may be. In other embodiments, the moment of inertia Ixx in the crown - sole direction may be 880 g·cm 2 ~1500 g·cm 2 and may be. In other embodiments, the moment of inertia Ixx in the crown - sole direction may be 880 g·cm 2 ~1200 g·cm 2 , or 1200 g·cm 2 ~1500 g·cm 2 and may be. In still other embodiments, the moment of inertia Ixx in the crown - sole direction may be 900 g·cm 2 ~1300 g·cm 2 , 1000 g·cm 2 ~1400 g·cm 2 , or 1100 g·cm 2 ~1500 g·cm 2It may be. For example, the moment of inertia Ixx in the crown - sole direction is 880 g·cm 2 , 900 g·cm 2 , 920 g·cm 2 , 930 g·cm 2 , 940 g·cm 2 , 950 g·cm 2 , 960 g·cm 2 , 970 g·cm 2 , 980 g·cm 2 , 990 g·cm 2 , 1000 g·cm 2 , 1020 g·cm 2 , 1100 g·cm 2 , 1200 g·cm 2 , 1300 g·cm 2 , 1400 g·cm 2 , or 1500 g·cm 2 It may be.

[0266] In various embodiments of the driver - type club head, in many embodiments, the moment of inertia Iyy in the heel - toe direction is greater than about 4500 g·cm 2 greater than about 4800 g·cm 2 greater than about 5000 g·cm 2 greater than about 5150 g·cm 2 greater than about 5250 g·cm 2 greater than about 5500 g·cm 2 greater than about 5750 g·cm 2 greater than or greater than about 600 g·cm 2 It may be. In other embodiments, the moment of inertia Iyy in the heel - toe direction is 4500 g·cm 2 ~6000 g·cm 2 It may be. In other embodiments, the moment of inertia Iyy in the heel - toe direction is 450 g·cm 2 ~5200 g·cm 2 , or 5200 g·cm 2 ~6000 g·cm 2 It may be. For example, the moment of inertia Iyy in the heel - toe direction is 4500 g·cm 2 , 4600 g·cm 2 , 4700 g·cm2 4800g·cm 2 4900g·cm 2 5000g·cm 2 5100g·cm 2 5200g·cm 2 5300g·cm 2 5400g·cm 2 5500g·cm 2 5600g·cm 2 5700g·cm 2 5800g·cm 2 5900g·cm 2 , or 6000g·cm 2 That's fine.

[0267] In various embodiments of fairway wood-type club heads, in many embodiments, the moment of inertia Iyy in the heel-toe direction is approximately 2700 g·cm². 2 Over 2800g·cm 2 Over 2900g·cm 2 Over 3000g·cm 2 Over 3100g·cm 2 Over 3200g·cm 2 Over, or approximately 3300g·cm 2 It may exceed this value. In other embodiments, the heel-toe moment of inertia Iyy is 2700 g·cm 2 ~3500g·cm 2 This may be the case. In other embodiments, the heel-toe moment of inertia Iyy is 2700 g·cm 2 ~3100g·cm 2 , or 3100g·cm 2 ~3500g·cm 2 It may be. In yet another embodiment, the moment of inertia Iyy in the heel-toe direction is 2700 g·cm 2 ~3200g·cm 2 , or 3200g·cm 2 ~3500g·cm 2 It may be. For example, the moment of inertia Iyy in the heel-toe direction is 2700 g·cm. 2 2800g·cm 22900g·cm 2 , 3000g·cm 2 3100g·cm 2 3200g·cm 2 3300g·cm 2 3400g·cm 2 , or 3500g·cm 2 That's fine.

[0268] In various embodiments of hybrid-type club heads, in many embodiments, the moment of inertia Iyy in the heel-toe direction is approximately 2400 g·cm². 2 Over 2500g·cm 2 Over 2600g·cm 2 Over 2700g·cm 2 Over 2800g·cm 2 Over 2900g·cm 2 Over, or approximately 3000g·cm 2 It may exceed this value. In other embodiments, the heel-toe moment of inertia Iyy is 2400 g·cm. 2 ~3200g·cm 2 It may be. In other embodiments, the moment of inertia Iyy in the heel-toe direction is 2400 g·cm 2 ~2700g·cm 2 , or 2700g·cm 2 ~3200g·cm 2 It may be. In yet another embodiment, the moment of inertia Iyy in the heel-toe direction is 2400 g·cm 2 ~2900g·cm 2 , 2500g·cm 2 ~3000g·cm 2 , 2600g·cm 2 ~3100g·cm 2 , or 2700g·cm 2 ~3200g·cm 2 It may be. For example, the moment of inertia Iyy in the heel-toe direction is 2400 g·cm. 2 , 2500g·cm 2 , 2600g·cm 2 2700g·cm 2 2750g·cm2 2800g·cm 2 2850g·cm 2 2900g·cm 2 2950g·cm 2 , 3000g·cm 2 3100g·cm 2 , or 3200g·cm 2 That's fine.

[0269] In various embodiments of driver-type club heads, the total moment of inertia (i.e., the sum of the moment of inertia Ixx in the crown-sole direction and the moment of inertia Iyy in the heel-toe direction) is 8000 g·cm². 2 Over 8500g·cm 2 Over 9000g·cm 2 Over 9500g·cm 2 Exceeding 10,000 g·cm 2 Over 11,000g·cm 2 Over 12,000 g·cm 2 It's okay to exceed the limit.

[0270] In various embodiments of fairway wood-type club heads, the total moment of inertia (i.e., the sum of the moment of inertia Ixx in the crown-sole direction and the moment of inertia Iyy in the heel-toe direction) is 4000 g·cm². 2 Over 4100g·cm 2 Over 4200g·cm 2 Over 4300g·cm 2 Over 4400g·cm 2 Over 4500g·cm 2 Over 4600g·cm 2 Over 4700g·cm 2 Over 4800g·cm 2 It's okay to exceed the limit.

[0271] In various embodiments of hybrid club heads, the total moment of inertia (i.e., the sum of the moment of inertia Ixx in the crown-sole direction and the moment of inertia Iyy in the heel-toe direction) is 3500 g·cm². 2 Over 3600g·cm2 Over 3700g·cm 2 Over 3800g·cm 2 Over 3900g·cm 2 Over 4000g·cm 2 Over 4100g·cm 2 Over 4200g·cm 2 It's okay to exceed the limit. example A. Example 1 - Club head with slit and crown flip

[0272] As a comparative example, a control club head was compared with an exemplary embodiment according to an aspect of the present invention. The exemplary embodiment was similar to the club head shown in Figure 32. The exemplary embodiment includes a slit and a crown flip on the striking face. The crown flip on the striking face is formed from the same high-strength material as the striking face. The crown flip on the striking face extends from the top of the striking surface to the front portion of the crown. The thickness of the crown flip on the striking face of the exemplary embodiment is approximately 0.025 inches. The control club head includes a slit and a face insert, and the crown flip is formed from a different material than the striking face. The crown flip on the control club head was approximately 0.035 inches. The slit in the control club head and the exemplary embodiment have the same shape and characteristics.

[0273] Data was collected using finite element analysis (FEA). The FEA simulation assumed a scenario where a golf ball collides with the center of the clubface at approximately 100 MPH. The FEA simulation results showed that, in an exemplary embodiment, the ball velocity increased by 0.67 MPH compared to a control clubhead. Therefore, the crown flip of the striking face, which is made of the same material as the striking face, increased the ball velocity compared to a control clubhead without a crown flip. The presence of a crown flip on the striking face allows for a thinner crown, which in turn allows the crown to flex more upon impact with the golf ball, thus increasing the ball velocity. B. Example 2 - Comparison of Flexure Inserts and Control Inserts (FEA)

[0274] As a comparative example, the energy storage characteristics and reaction forces of club heads equipped with slits and inserts were investigated using finite element analysis (FEA). In the FEA test, the performance of an exemplary club head equipped with a flexure insert according to one embodiment of the present invention was compared with a control club head equipped with a single-material insert. The exemplary flexure insert used in the test was similar to the cantilever arm shown in Figure 37. The flexure insert is equipped with a cantilever arm having a tip and a fixed end, the fixed end protruding forward from the inner surface of the sole. The tip is equipped with a bumper made of Delrin material. The control club head is equipped with a slit made of a single viscoelastic material. The slit shape and other club head features of the control club head and the exemplary club head are substantially identical.

[0275] FEA testing revealed that the example clubhead exhibited a 0.7 MPH increase in ball speed compared to the control clubhead, while maintaining similar stress values ​​within the durability limit. The cantilever arm with a bumper strategically reinforces the slit at its maximum displacement while returning more energy to the slit upon rebound, thus increasing internal energy and ball speed compared to a slit with a single-material insert and no spring component. The cantilever arm's reinforcing properties allow for a thinner face, thereby improving the durability of the clubhead body. The minimum thickness of the faceplate in the example clubhead was 0.067 inches, and the maximum thickness was 0.071 inches.

[0276] Furthermore, FEA testing revealed the resultant force exerted by the bumper on the front wall of the slit upon impact with the golf ball, as shown in the graph in Figure 42. Point 2590 indicates the point on the graph where the slit displacement reached its peak. At the peak of displacement, the bumper was expected to exhibit the largest resultant force or local maximum at point 2590. However, in reality, the bumper exhibited a local minimum resultant force at point 2590, with the force increasing after the displacement peak. This increase in force after the displacement peak allows more energy to be returned to the slit and the ball. In contrast, a uniform, single-material insert would exhibit the maximum force at point 2590, with the force decreasing after the displacement peak. The bumper and cantilever arm increase the resultant force on the front wall of the slit under both loaded and unloaded conditions, allowing more energy to be returned to the golf ball and increasing ball velocity.

[0277] Item 1: A golf club head comprising: a striking face having a striking surface for striking a golf ball; a body joined to the striking face and enclosing a hollow internal cavity, the body having a crown, a sole, a heel, a toe, and a rear end, the sole including a front wall and a rear wall located near the striking face and spaced apart to define a slit opening to a hollow internal cavity; a cantilever arm, the cantilever arm having a fixed end connected to the inner surface of the sole behind the rear wall and a tip opposite the fixed end, the cantilever arm extending in an arc from the fixed end over the rear wall such that the tip is positioned between the front wall and the rear wall; and a bumper connected to the tip.

[0278] Item 2: The cantilever arm is made of spring steel, as described in Item 1, for the golf club head.

[0279] Item 3: The golf club head as described in Item 1, wherein the cap is configured to be inserted into a slit to seal a hollow internal cavity.

[0280] Item 4: The golf club head as described in Item 2, wherein the cap has a central notch, and the front wall of the slit is exposed through the central notch to a hollow internal cavity.

[0281] Item 5: The fixed end of the cantilever arm is connected to the inner surface of the sole, located 0.1 to 0.5 inches behind the rear wall, as described in Item 1 of the golf club head.

[0282] Item 6: The fixed end of the cantilever arm is connected to the mass pad, the golf club head as described in Item 1.

[0283] Item 7: The golf club head as described in Item 1, wherein the bumper is configured to contact the central portion of the front wall of the slit.

[0284] Item 8: The golf club head as described in Item 1, wherein the cantilever arm has a loaded position and an unloaded position, the loaded position defined by the bumper being in contact with the front wall, and the unloaded position defined by the bumper being away from the rear of the front wall and not in contact with the front wall.

[0285] Item 9: The bumper is formed of polyoxymethylene material, as described in Item 1, for the golf club head.

[0286] Item 10: A golf club head comprising: a striking face having a striking surface for striking a golf ball; a body joined to the striking face and surrounding a hollow internal cavity, the body having a crown, a sole, a heel, a toe, and a rear end, the sole including a front wall and a rear wall located near the striking face and spaced apart to define a slit opening to a hollow internal cavity; and an insert positioned in the slit, the insert comprising: a first lattice zone located in the toe portion and having a first plurality of interconnected walls forming a first lattice structure having voids; a second lattice zone located in the heel portion and having a second plurality of interconnected walls forming a second lattice structure having voids; and a solid central zone located between the first lattice zone and the second lattice zone.

[0287] Item 11: The insert is made of polymer material, as described in Item 10.

[0288] Item 12: The golf club head described in Item 10, wherein the effective density of the first and second grid zones, respectively, is 0.75 to 2.0 g / cm³.

[0289] Item 13: The golf club head according to item 10, further comprising a solid base layer having a size such that it engages with the front and rear walls to seal the slit.

[0290] Item 14: A golf club head comprising: a striking face having a striking surface for striking a golf ball; a body joined to the striking face and enclosing a hollow internal cavity, the body having a crown, a sole, a heel, a toe, and a rear end, the sole including a front wall and a rear wall located near the striking face and spaced apart to define a slit opening to a hollow internal cavity; and an insert positioned in the slit, the insert comprising a cap having a bottom wall, a front wall, a rear wall, a heel side wall, and a toe side wall together to form an opening, the cap being made of a first material having a first modulus of elasticity; and a spring component having a size such that it is inserted into the opening and extending between the front wall, the rear wall, the heel side wall, and the toe side wall of the cap, the spring component being made of a second material having a second modulus of elasticity greater than the first modulus of elasticity.

[0291] Item 15: The second material is aluminum, as described in Item 14, for the golf club head.

[0292] Item 16: The thickness of the spring component is 0.10 to 0.30 inches, as described in Item 15 for the golf club head.

[0293] Item 17: The spring component is embedded in the cap of the golf club head as described in Item 14.

[0294] Item 18: The golf club head according to item 14, wherein the spring component comprises a central portion that contacts the front wall, a toe end that contacts the rear wall and is joined to the central portion by a first step, and a heel end that contacts the rear wall and is joined to the central portion by a second step.

[0295] Item 19: The golf club head according to item 18, wherein the front wall of the cap defines a recess having a size for receiving the central portion of a spring component.

Claims

1. It is a golf club head, A striking face equipped with a striking surface for hitting a golf ball, A body joined to the striking face and surrounding a hollow internal cavity, the body having a crown, a sole, a heel, a toe, and a rear end, the sole being located near the striking face and including a front wall and a rear wall spaced apart to define a slit opening to the hollow internal cavity, A cantilever arm comprising a fixed end connected to the inner surface of the sole behind the rear wall, and a tip on the opposite side of the fixed end, wherein the cantilever arm extends arc-shaped beyond the rear wall from the fixed end so that the tip is positioned between the front wall and the rear wall, The bumper connected to the tip, Golf club head.

2. The cantilever arm comprises spring steel, The golf club head according to claim 1.

3. The cap is configured to be inserted into the slit to seal the hollow internal cavity. The golf club head according to claim 1.

4. The aforementioned cap has a central notch, The front wall of the slit is exposed to the hollow internal cavity through the central notch. The golf club head according to claim 2.

5. The fixed end of the cantilever arm is connected to the inner surface of the sole at a position 0.1 to 0.5 inches rearward from the rear wall. The golf club head according to claim 1.

6. The fixed end of the cantilever arm is connected to a mass pad. The golf club head according to claim 1.

7. The bumper is configured to contact the central part of the front wall of the slit. The golf club head according to claim 1.

8. The cantilever arm has a loaded position and an unloaded position, The load position is defined by the bumper being in contact with the front wall. The no-load position is defined by the bumper being away from the front wall and not in contact with the front wall. The golf club head according to claim 1.

9. The bumper is made of polyoxymethylene material. The golf club head according to claim 1.

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