Golf club head with improved characteristic time

Abstract

An embodiment of a driver-type golf club head includes reduced face height and face thickness, which can increase ball speed while maintaining compliant CT values.

Description

Technical Field

[0001] This case asserts priority to U.S. Provisional Patent Application No. 63 / 371,449, filed August 15, 2022, and U.S. Provisional Patent Application No. 63 / 510,076, filed June 23, 2023, the entire contents of which are incorporated herein by reference.

[0002] This invention relates primarily to golf clubs, and more specifically to the clubhead of a driver-type club. Prior Technology

[0003] Golf club designers aim to maximize ball speed when designing driver heads, as increased ball speed contributes to greater distance and improved scores. This is typically achieved by adjusting various mass characteristics, such as center of gravity, moment of inertia, variable facet configuration, and other features. However, the United States Golf Association (USGA) imposes certain limitations on clubhead performance, one of which is Characteristic Time (CT). The USGA uses the CT test to measure the duration of contact between the steel ball on the pendulum and the clubface, thereby obtaining an assessment of the clubface's stiffness and the amount of energy it receives. While the USGA imposes limitations on clubhead CT, it does not impose limitations on ball speed.

[0004] Throughout the development of golf, the design of driver clubheads has evolved towards increasing surface area and size. Increasing the striking surface has proven to have multiple advantages. The striking surface is analogous to a drumhead or trampoline; a larger area allows for greater deflection / displacement. The same principle applies to golf clubs. Therefore, designers typically aim to enlarge the striking surface to improve clubface flexibility and thus increase ball speed. Furthermore, the thickness of the striking surface also significantly affects ball speed, so designs generally minimize the face thickness as much as possible while adhering to durability and CT (cutoff weight) limits. With the introduction of new high-strength materials, it is now possible to design golf clubheads with a thinner striking surface without sacrificing clubhead durability. A thinner striking surface not only generates higher ball speed at impact but also helps improve the clubhead's CT. The extent to which ball speed is increased at impact with the same force is limited by the clubhead's CT requirements. Therefore, a driver clubhead is needed that can generate higher ball speed while maintaining compliant CT values. Summary of the Invention

[0005] This invention is an embodiment of a driver-type golf club head, which includes reduced face height and face thickness, and can increase ball speed while maintaining compliant CT values. Simple Explanation of the Diagram

[0006] Figure 1 is a front perspective view of a golf club head according to an embodiment of the present invention.

[0007] Figure 2 shows a front view of the golf club head in Figure 1.

[0008] Figure 3 shows a side view of the toe of the golf club in Figure 1.

[0009] Figure 4 shows a top view of the golf club in Figure 1.

[0010] Figure 5 shows the front view of the golf club in Figure 1.

[0011] Figure 6 shows a detailed cross-sectional view of the golf club in Figure 1.

[0012] Figure 7 shows a detailed cross-sectional view of the golf club in Figure 1.

[0013] Figure 8 is a front view of a golf club head according to an embodiment of the present invention.

[0014] Figure 9 shows a front view of the golf club head of Figure 8 without the striking face insert.

[0015] Figure 10 shows a comparison of the internal structure rear view of the embodiment of the present invention and the control rod head.

[0016] Figure 11 shows a cross-sectional view of the rod head in Figure 10.

[0017] Figure 12 shows the relationship between surface height and ball speed.

[0018] Figure 13 shows the relationship between face height and CT.

[0019] Figure 14 shows the relationship between surface thickness and ball speed.

[0020] Figure 15 shows the relationship between surface thickness and CT. Implementation definition

[0021] The terms "first," "second," "third," and "fourth," as used in the following description and claims, are used to distinguish similar elements and do not necessarily describe a specific sequence or order. It should be understood that such terms can be used interchangeably where appropriate, and thus the embodiments described herein can operate in a different order than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; therefore, a procedure, method, system, object, device, or apparatus that comprises a set of elements is not necessarily limited to those elements, but may also include other elements not explicitly listed or included in such procedures, methods, systems, objects, devices, or apparatuses.

[0022] In the following description and claims, terms such as "left," "right," "front," "back," "top," "bottom," "above," and "below," and similar expressions, are for descriptive purposes only and do not necessarily refer to permanent relative positions. It should be understood that such terms can be used interchangeably where appropriate, and thus embodiments of the invention can operate in orientations different from those shown in the figures or described herein.

[0023] "Connection" and similar terms should be understood in a broad sense, referring to the connection of two or more components or signals in an electrical, mechanical and / or other manner.

[0024] The accompanying drawings illustrate various embodiments of golf clubs. A golf club typically includes a clubhead for attaching to the shaft and a grip fixed to the shaft.

[0025] Figures 1 to 9 are schematic diagrams of various embodiments of a driver-type golf club head. Various features are labeled on the club head 100. For ease of explanation, the features shown on the club head 100 are applicable to various embodiments of the club head of the present invention. Any one or more features described in the following embodiments may be used in combination with each other.

[0026] The clubhead 100 may include a striking face 102 and a body 101, which are joined and fixed together to form a substantially closed / hollow internal cavity. The clubhead 100 has a crown 110, a base 112 opposite to the crown 110, a heel 104, a toe opposite the heel 104, a front end 108, and a rear end 111 opposite the front end 108. The body 101 may also have a skirt 114 and / or a rim 109 located between and adjacent to the crown 110 and the base 112. The skirt 114 may extend from near the heel 104 to near the toe 106 of the clubhead 100.

[0027] The term "driver-type golf club head," also known as a driver, as used herein has a specific range of dimensions. Specifically, the driver described in this invention has a high angle of attack, volume, length, depth, and height within the following ranges.

[0028] The "high angle of attack" of the driving club may be less than about 16 degrees, less than about 15 degrees, less than about 14 degrees, less than about 13 degrees, less than about 12 degrees, less than about 11 degrees, or less than about 10 degrees.

[0029] The volume of the teeing club can be greater than approximately 300 cm3, greater than approximately 350 cm3, greater than approximately 400 cm3, greater than approximately 425 cm3, greater than approximately 450 cm3, greater than approximately 475 cm3, greater than approximately 500 cm3, greater than approximately 525 cm3, greater than approximately 550 cm3, greater than approximately 575 cm3, greater than approximately 600 cm3, greater than approximately 625 cm3, greater than approximately 650 cm3, greater than approximately 675 cm3, or greater than approximately 700 cm3.

[0030] The clubhead 100 may comprise one or more body materials, such as steel, stainless steel, tungsten, aluminum, titanium, vanadium, chromium, cobalt, nickel, other metals, or metal alloys. In some embodiments, the body material may comprise a Ti-8Al-1Mo-1V alloy or 17-4 stainless steel. In some embodiments, the body material may be composed of C300, C350, nickel-cobalt-chromium steel alloy, 565 steel, AISI type 304 or AISI type 630 stainless steel, 17-4 stainless steel, titanium alloys (e.g., but not limited to Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti 15-3-3-3, Ti 15-5-3, Ti185, Ti6-6-2, Ti-7s, Ti-9s, Ti-92, or Ti-8-1-1 titanium alloys), amorphous metal alloys, or other similar metals. In some embodiments, one or more portions of the clubhead 100 may comprise non-metallic materials.

[0031] In this document, "ground plane" is defined as a reference plane associated with the surface on which the golf ball is placed. Ground plane 1010 may be a horizontal plane tangent to the bottom when in the aiming position. Ground plane 1010 is shown in Figure 2.

[0032] In this article, the "high-impact plane" of the clubhead refers to a reference plane that is tangent to the geometric center of the impact surface (the "geometric center" is described in detail below). The high-impact plane 1015 is shown in Figure 3.

[0033] The term "high-impact angle" as used herein refers to the angle measured between the high-impact plane 1015 and the XY plane (defined below). The high-impact angle 10 is shown in Figure 3.

[0034] In this document, "base angle" refers to the angle between the sheath shaft 1020 extending through the sheath 105 and the aforementioned ground plane. Base angle 15 is measured from the front view of the pole head, as shown in Figure 2.

[0035] The clubhead 100 has a "hitting aiming position" (also called the "aiming position"), at which the clubhead's orientation results in the designed target height angle 10 and base angle 15. For example, in the hitting aiming position, the high-hitting plane 1015 and the XY plane together constitute the target height angle 10. Similarly, in the hitting aiming position, the sheath shaft 1020 and the ground plane 1010 together constitute the target base angle 15.

[0036] As shown in Figures 2 and 3, the clubhead 100 may have a principal coordinate system centered on the geometric center 116 of the striking face 102. This principal coordinate system may include an X-axis 1040, a Y-axis 1050, and a Z-axis 1060. The X-axis 1040 extends parallel to the ground plane 1010 along the heel-toe direction. The X-axis 1040 is positive towards the heel 104 and negative towards the toe 106. The Y-axis 1050 extends along the crown-toe direction and is orthogonal to both the ground plane 1010 and the X-axis 1040. The Y-axis 1050 is positive towards the crown 110 and negative towards the bottom 112. The Z-axis 1060 extends parallel to the ground plane 1010 along the front-back direction and is orthogonal to both the X-axis 1040 and the Y-axis 1050. The Z-axis 1060 is positive towards the striking face 102 and negative towards the rear end 111.

[0037] In the aforementioned principal coordinate system, the XY plane is a vertical plane extending along the X-axis 1040 and the Y-axis 1050. The XZ plane in the principal coordinate system is a horizontal plane extending along the X-axis 1040 and the Z-axis 1060. The YZ plane in the principal coordinate system is a vertical plane extending along the Y-axis 1050 and the Z-axis 1060. The XY, XZ, and YZ planes are all perpendicular to each other and intersect at the origin of the principal coordinate system, located at the geometric center 116 of the striking face 102. In the above or other embodiments, the forward view of the clubhead 100 is the striking face 102 viewed from a direction perpendicular to the XY plane. Furthermore, in the above or other embodiments, the side view or lateral section view of the clubhead 100 is the heel 104 or toe 106 viewed from a direction perpendicular to the YZ plane.

[0038] The "body depth" or "depth" DB of the clubhead 100 referred to herein refers to the front-to-rear dimension measured across the entire body 101. Referring to Figures 3 and 4, the body depth DB is measured parallel to the Z-axis from the front edge 103 of the body 101 to the nearest rear point 119 of the body 101. In many embodiments, the body depth DB may be measured according to the specifications of golf governing bodies such as the United States Golf Association (USGA).

[0039] The "body height" or "height" HB of clubhead 100 refers to the dimension from crown to bottom, measured across the entire body 101. Referring to Figure 2, the body height HB is the vertical distance (parallel to the Y-axis 1050) between the ground plane 1010 and the highest point of the crown 110. In many embodiments, the body height HB may be measured according to the specifications of golf governing bodies such as the United States Golf Association (USGA).

[0040] The "body width" or "width" WB of the clubhead 100 referred to herein is the heel-to-toe dimension measured across the entire body 101. Referring to Figure 2, the body width WB is measured from the heel apex 117 parallel to the X-axis 1040 to the toe apex 118. The toe apex 118 is the nearest toe point on the body 101. The heel apex 117 is the nearest heel point on the heel 104, located 0.875 mm above the ground plane 1010. In many embodiments, the body width WB may be measured according to the specifications of golf governing bodies such as the United States Golf Association (USGA). The ranges of the body depth DB, body height HB, and body width WB may be set according to USGA specifications.

[0041] The clubhead “center of gravity” or “CG” referred to in this article refers to the point on the clubhead from which the mass is centered. The CG center of gravity 160 is shown in Figures 2 and 3.

[0042] The term "center of gravity position" or "CG position" refers to the location of the clubhead's center of gravity (CG) in the principal coordinate system. The CG position is described by its location on the X-axis (1040), Y-axis (1050), and Z-axis (1060). "CGx" refers to the position of the CG on the X-axis (1040) measured from its geometric center (116). "CG height" refers to the position of the CG on the Y-axis (1050) measured from its geometric center (116). "CGy" is synonymous with CG height. "CG depth" refers to the position of the CG on the Z-axis (1060) measured from its geometric center (116). "CGz" is synonymous with CG depth.

[0043] The golf club head has a secondary coordinate system centered at the center of gravity 160°. As shown in Figures 2 and 3, the secondary coordinate system includes an X' axis 1070, a Y' axis 1080, and a Z' axis 1090. The X' axis 1070 extends in the heel-toe direction. The Y' axis 1080 extends in the crown direction and is orthogonal to both the Z' axis 1090 and the X' axis 1070. The Y' axis 1080 is positive towards the crown 110 and negative towards the bottom 112. The Z' axis 1090 extends forward and backward, parallel to the ground plane 1010, and is orthogonal to both the X' axis 1070 and the Y' axis 1080. The Z' axis 1090 is positive towards the striking face 102 and negative towards the rear end 111.

[0044] The "moment of inertia" (hereinafter referred to as "MOI") is a value obtained using the position of the center of gravity (CG). "MOIxx" or "Ixx" refers to the MOI measured around the X' axis at 107°. "MOIyy" or "Iyy" refers to the MOI measured around the Y' axis at 108°. "MOIzz" or "Izz" refers to the MOI measured around the Z' axis at 109°. The MOI values ​​MOIxx, MOIyy, and MOIzz determine the tolerance that the golf clubhead 100 provides for off-center shots.

[0045] MOI is the measured value of an object's resistance to torsion on a given axis, which can be calculated according to the following formula 1. I = ʃr 2 dm (Eqn.1)

[0046] Equation 1 defines the MOI (Mean Interval) of an object as a whole, about the perpendicular distance (r²) between the MOI measurement axis and the position of the object's mass, denoted as I. If the center of gravity (CG) of an object is known, the object can be considered as a point mass located on that CG. Treating an object as a point mass simplifies Equation 1 to Equation 2.

[0047] Equation 2 states that the moment of inertia I of an object on a given axis is equal to the sum of the masses of the object's particles multiplied by the perpendicular distance between the MOI measurement axis and each particle.

[0048] The term "striking face" as used in this article refers to the front surface of the clubhead used to strike a golf ball. The term "striking face" is used interchangeably with "club face" or "striking face surface."

[0049] The striking face has "horizontal curvature" and "vertical curvature." Horizontal curvature is the curvature of the striking face in the heel-toe direction. Vertical curvature is the curvature of the striking face in the crown-toe direction. Both horizontal and vertical curvatures have "horizontal radius" and "vertical radius," respectively, defining the radii of curvature associated with each. The horizontal and / or vertical curvatures can have one or more radii. The horizontal and vertical radii are designed to improve off-center shots. The horizontal and vertical radii define the boundaries of the striking face and its outer perimeter.

[0050] The term "striking face (SF) periphery" as used in this document refers to the edge of the striking face. The striking face (SF) periphery 120 is located where the horizontal arc radius and vertical arc radius deviate from the horizontal arc curvature and vertical arc curvature, respectively. Referring to Figure 5, the striking face periphery includes the top edge 122, the toe edge 124, the bottom edge 126, and the heel edge 128. The striking face periphery is the outermost boundary of the striking face 102.

[0051] The term "front edge" of the clubhead, as used in this article, refers to the foremost part of the clubhead 100. The front edge 103 is not necessarily part of the striking face 102. The position of the front edge 103 may be below the bottom edge 126 of the striking face. For example, as can be seen in Figure 5, the front edge 103 is located in the transition area between the striking face 102 and the bottom 112 of the clubhead 100.

[0052] The "height of the clubface" or "face height" (HSF) referred to in this document is the distance measured on the YZ plane from the top edge point 123 of the clubface to the bottom edge point 127 of the clubface. The top edge point 123 is defined by the intersection of the top edge 122 of the clubface and the YZ plane. Similarly, the bottom edge point 127 is defined by the intersection of the bottom edge 126 of the clubface and the YZ plane. Referring to Figure 6, the height HSF can be measured on the YZ plane intersecting the geometric center 116 of the clubface, from the top edge point 123 (SF) parallel to the high-impact plane 1015 to the bottom edge point 127 (SF).

[0053] The "face width" (WSF) of the clubhead referred to in this article is the horizontal distance measured across the entire face of the clubhead along the heel-toe direction. Referring to Figure 5, the face width (WSF) is measured from the nearest heel point on the outer perimeter of the face of the clubhead, parallel to the ground plane 1010, to the nearest toe point on the outer perimeter of the face of the clubhead.

[0054] The "top edge height" (HTP) of the clubhead referred to in this article is the distance measured perpendicular to the ground plane between the top edge point 123 and the ground plane 1010, as shown in Figure 7. The top edge point 123 of the striking face is defined by the intersection between the top edge 122 of the striking face and the YZ plane.

[0055] The "bottom edge height" (HBP) of the clubhead referred to in this article is the distance measured perpendicular to the ground plane between the bottom edge point 127 and the ground plane 1010, as shown in Figure 7. The bottom edge point 127 of the striking face is defined by the intersection between the bottom edge of the striking face 126 and the YZ plane.

[0056] The "crown height" (HCA) of the clubhead referred to in this article is the distance measured perpendicularly to the ground plane between the crown apex 130 and the ground plane 1010, as shown in Figure 7. The crown apex 130 is the highest point of the crown 110 on the YZ plane.

[0057] The "crown depth" (DCA) of the clubhead referred to in this article is the distance measured between the apex point 123 and the crown apex 130 on the YZ plane, parallel to the Z-axis 1060.

[0058] The "crown angle" 20 of the clubhead referred to in this article is the angle between the crown apex 130 and the apex point 123. The crown angle 20 is measured between a line parallel to the Z-axis that passes through the crown apex 130 and a line that passes through both the crown apex 130 and the apex point 123.

[0059] The "bottom depth" (DSA) of the clubhead referred to in this article is the distance measured between the bottom edge point 127 and the bottom vertex 132. The bottom vertex 132 is the lowest point of the bottom 112 on the YZ plane, and it is also the point where the bottom 112 is tangent to the ground plane 1010.

[0060] The "bottom-apex angle" 25 of the clubhead referred to in this article is the angle of the bottom vertex 132 relative to the ground plane 1010. The bottom-apex angle 25 is measured between a line passing through the bottom edge point 127 and the bottom vertex 132 and the ground plane 1010.

[0061] The "geometric center" of the striking face referred to in this article is the geometric center point on the outer perimeter of the striking face, as shown in Figures 2 and 5. The position of the geometric center 116 of the striking face 102 is based on the definition proposed by golf governing bodies such as the United States Golf Association (USGA).

[0062] As shown in Figure 7, the striking surface 102 has a center-of-face height HFC. The center-of-face height HFC is measured vertically from the ground plane 1010 to the geometric center 116.

[0063] As shown in Figure 3, the clubhead 100 has a force line 1075 that intersects with the center of gravity 160 and extends perpendicularly to the high-impact plane 1015. The takeoff characteristics of the golf ball depend on the relationship between the force line 1075 and the point of impact on the striking face. The closer the point of impact is to the force line 1075, the greater the energy transfer between the clubhead 100 and the golf ball at impact. Assuming that the point of impact is always at the center of the striking face, adjusting the position of the force line 1075 to deviate from the geometric center 116 of the striking face can change the takeoff characteristics.

[0064] Before learning about the embodiments of the present invention in detail, it should be understood that the application of the present invention is not limited to the structural details and component arrangements described in the following description or drawings. The present invention may have other embodiments and can be implemented in various ways.

[0065] The driver head provided by this invention increases ball speed without exceeding the CT limit through a design that optimizes the ratio of face height to thickness. This driver head is neither a fairway head nor a hybrid head. Specifically, the driver head of this invention has a shallower (i.e., shorter face height) and thinner face than existing driver heads, enabling increased ball speed while maintaining the CT within the limits set by the United States Golf Association (“USGA”). In many embodiments, compared to conventional driver heads with higher and / or thicker face heights, the driver head 100 of this invention, with its shorter and thinner face height, can increase ball speed by at least 1 mph while keeping the CT within the USGA limits. I. Theoretical Discussion

[0066] One aspect of this invention involves minimizing the thickness of the face while maintaining a compliant contact coefficient (CT) and sufficient durability. Face thickness is a decisive factor affecting launch speed. Its importance far surpasses other design parameters, especially for driver heads. Face thickness also affects the CT. With all other structural parameters held constant, simply reducing the face thickness can increase both the CT and launch speed. However, excessive face thinning may exceed USGA limits. This invention clarifies which parameters, in conjunction with face thickness, reduce the CT, thus maintaining it within USGA limits. While adjusting parameters other than face thickness may decrease ball speed, the increase in ball speed from face thinning outweighs the decrease from adjusting other parameters, thus providing a net gain in ball speed.

[0067] One aspect of this invention involves shortening the contact caliber (CT) of a golf clubhead within the USGA's CT limits by reducing or decreasing the height of the contact face. As mentioned above, the contact face height (or size) affects ball speed. In addition to its effect on ball speed, the contact face height also affects the CT value. Compared to the prior art, this invention reduces the CT value by reducing the contact face height (and the total volume of the contact face), thus allowing for a thinner contact face. The ball speed gain achieved by thinning the contact face offsets and exceeds the ball speed loss caused by shortening the contact face height, thus resulting in a net gain in ball speed.

[0068] The shorter, thinner face of the driver-type golf club head described herein also offers advantages in terms of mass characteristics. The shorter, thinner face reduces and lowers the mass of the striking face, thus generating more mass that can be moved to other suitable locations. The mass removed from the striking face can be moved to other parts of the clubhead, such as along the outer perimeter and rearward, to increase MOI and improve center of gravity. For example, the head mass of the driver-type golf club face of this invention is approximately 30g. In other embodiments, the face mass may range between approximately 22g and 32g.

[0069] Besides the height and thickness of the striking face, other structural factors affect the contact tractor (CT) and ball speed. However, many current CT control methods are complex, leading to cost issues and quality concerns. Many front-end structures used for CT control require additional molding processes or materials, resulting in increased weight and cost for the front section of the golf club head. The driver-type golf club head of this invention maintains the CT without using known CT control methods. The driver-type golf club head of this invention does not require any ribs, struts, springs, or extensions to connect the inner surfaces of the bottom, skirt, crown, toe, or heel to the inner surface of the striking face before or during bending at impact, except for the weld lines, weld surfaces, or adhesive surfaces on the outer periphery of the striking face. The driver-type golf club head striking face insert of this invention does not require the use of multiple materials with clearly defined boundaries. The driver-type golf club striking face of this invention does not require any polymer material adhered to the inner surface of the striking face. Except as specifically described herein, the driving club head of the present invention does not require the formation or addition of any other channels, grooves, or fixing structures on the crown, sole, toe, skirt, or heel. Except as specifically described herein, the driving club head of the present invention does not require the provision or addition of any other channels, grooves, or fixing structures at any location on the striking face or tip. The driving club head of the present invention does not require any structure connecting the inner surface of the crown to the inner surface of the sole. The driving club head of the present invention does not require any structure connecting the inner surface of the toe to the inner surface of the heel. The driving club head of the present invention adopts a configuration that increases ball speed while maintaining CT (cutoff velocity). A. Ball speed

[0070] As stated above, when a golf ball is struck with a driver's head, its launch speed is influenced by two characteristics of the face. If the clubhead impact velocity and the face's point of contact remain constant, the launch speed depends on the face height and face thickness. As the face height increases, the launch speed increases, assuming all other characteristics remain constant. Conversely, as the face height decreases, the launch speed decreases, assuming all other characteristics remain constant. This principle holds true within the USGA's limits on driver's head volume. Conversely, as the face thickness decreases, the launch speed decreases. (This principle applies to practical swing speeds between 50 mph and 150 mph).

[0071] This invention relates to a driver-type golf club head that reduces the thickness of the face in a specific manner. USGA rules require the outer surface of the face to be a smooth, curved shape. That is, the outer surface of the face cannot have protrusions or depressions, but should be a smooth surface with fixed horizontal and vertical arc radii across the entire area. The inner surface (or back surface) of the face may have non-smooth or uniform depressions or protrusions. Variable face thickness is achieved by variations in the inner surface of the face. According to the example described herein, the face thickness is reduced by uniformly thinning the outer surface while maintaining variations in the inner surface. In other words, reducing the face thickness can be imagined as uniformly milling the smooth, curved outer surface of the face, so that any specific point on the face is thinned to a fixed degree. The face can still have a variable thickness, but the cross-sectional width at each point is reduced to a fixed degree. The average face thickness is calculated by dividing the face volume by the area of ​​the front surface of the face.

[0072] Referring to Figures 2 and 3, in one embodiment, the launch velocity of the golf ball at impact is linearly related to the height of the striking face. If the clubhead impact velocity and the striking face position remain constant, an increase in the striking face height results in an increase in launch velocity. Conversely, if the clubhead impact velocity and the striking face position remain constant, a decrease in the striking face height results in a decrease in launch velocity. In the embodiment shown in Figure 6, a 0.2-inch reduction in the striking face height results in a launch velocity decrease of approximately 1.5 mph. Conversely, a 0.2-inch increase in the striking face height results in a launch velocity increase of approximately 1.5 mph.

[0073] Referring to Figure 8, in one embodiment, the launch speed of the golf ball at impact is linearly related to the change in the thickness of the striking face, as described above. In the embodiment of Figure 8, the measured launch speed of the golf ball, in miles per hour (mph), is linearly inversely proportional to the thickness of the striking face. This relationship demonstrates that the ball speed decreases as the thickness of the striking face increases, and that the ball speed increases substantially linearly when the thickness of the striking face decreases. B. Contact Time (CT)

[0074] As mentioned above, the contact time (CT) of a golf club's striking face depends on several factors. Among them, the height and thickness of the striking face directly affect the CT of the clubhead. Figure 13 illustrates the relationship between the CT of the striking face and changes in the striking face height. If the clubhead impact velocity and the striking face position remain constant, the CT of the striking face increases with increasing striking face height. Similarly, the CT of the striking face decreases with decreasing striking face height. Increasing the striking face height increases the CT of the striking face. Decreasing the striking face height decreases the CT of the striking face. Increasing the striking face thickness increases the CT of the striking face. Decreasing the striking face thickness decreases the CT of the striking face. In golf club design, while it is desirable to control the CT of the striking face within the USGA limits, a higher CT results in more energy being transferred to the ball at impact. C. Trade-offs between CT control and increased ball velocity

[0075] Referring to Figures 6 to 9, |△CT| caused by changes in face thickness is equal to or less than |△CT| caused by changes in face height. |△BS| caused by changes in face thickness is greater than |△BS| caused by changes in face height. Therefore, when the average face thickness is moderately reduced compared to the comparative driver golf club head, and the face height is moderately reduced compared to the comparative driver golf club head, △CT is 0 or negative, but △BS is positive. In other words, the two functions of face thickness are defined as BS(FT) and CT(FT) shown in Figures 6 to 9. Similarly, the two functions of face height are defined as BS(FH) and CT(FH), respectively, as shown in Figures 6 to 9. The effect of face thickness on launch velocity is proportional to the effect of face thickness on CT, expressed as (△BS(FT)) / (△CT(FT)), in mph / μs. The effect of face height on launch speed is proportional to the effect of face height on total contact (CT), expressed as (△BS(FH)) / (△CT(FH)), in mph / μs. The aforementioned driver-type golf club head can increase launch speed without increasing face height CT, where (△BS(FT)) / (△CT(FT)) > (△BS(FH)) / (△CT(FH)). In other words, adjusting the face thickness results in a higher change in ball speed per unit CT (micrometers) compared to adjusting the face height. D. Performance Goals and Trade-offs

[0076] As mentioned above, one problem faced by golf clubhead designers is the trade-off between increasing the ball's launch speed at impact, the clubhead's durability under repeated impacts, and maintaining the clubhead's contact contact (CT) within the limits of the USGA rules. If the USGA CT limit did not exist, the face thickness should be reduced to its thinnest possible and the face height maximized, within the limits permitted by the durability properties of any face material. However, the USGA CT limit does exist, and existing driver-type golf clubheads have gradually increased their face size within the CT limit to increase ball speed. Therefore, this invention's driver-type golf clubhead takes a different strategy from the prior art. The inventors discovered that instead of seeking to increase the face size, a driver-type golf clubhead with a smaller face size can achieve a greater increase in ball speed than one with a larger face size. The interaction of the following three relationships determines the impact effect: 1) when the face height is reduced and all other factors remain the same, the clubhead CT decreases; 2) when the face thickness is reduced, the ball speed increases; and 3) when the face thickness is reduced, the clubhead CT increases. The key to these three relationships lies in their individual relative effects. Reducing the face height proportionally lowers the CT (Collision Tolerance) more effectively than reducing the face thickness. Therefore, within a certain range, reducing the face height can result in increased ball speed due to a thinner face, without exceeding the USGA's CT limits. All other things being equal, a higher launch speed leads to a greater landing distance. However, trade-offs in other performance aspects of driver-type golf club heads should also be carefully considered.

[0077] When designing the face height, the mass characteristics of the golf clubhead must be considered. Lowering the face height proportionally lowers the geometric center of the face. Therefore, the CG projection of the golf clubhead perpendicular to the high strike plane will proportionally increase relative to the geometric center of the face, reducing the spin rate of the takeoff ball. Without other design adjustments, the extra flight distance achieved by the higher ball speed due to the shorter, thinner face will be reduced by the lower takeoff spin rate. In terms of spin, it has its advantages to have the CG of the golf clubhead below the high strike axis. Based on these trade-offs, designers use increased face height to reduce the takeoff spin rate, thus leading to the industry's continuous increase in golf clubhead face height. (A higher face height raises the geometric center. A higher geometric center raises the high strike axis. A higher high strike axis causes the CG to deviate from the high strike axis, improving takeoff spin.)

[0078] Furthermore, the shortening and thinning of the striking face reduces its mass, which directly affects the mass distribution of the driver-type golf club head 100. To maintain the total mass of the golf club head within an ideal range, the mass removed from the striking face must be redistributed to other parts of the club head body. The moment of inertia (MOI) of the golf club head is also affected by the mass distribution, and therefore needs to be maximized within other constraints. Moreover, the setting of the striking face height and thickness must consider durability; otherwise, if the striking face is too thin, the golf club head will be damaged during use. The driver-type golf club head embodiment described below achieves a high launch speed, thus contributing to increased landing distance, while maintaining ideal durability, mass characteristics that promote player performance, and a CT value that meets USGA requirements. E. Spin ball

[0079] The spin rate of a golf ball at launch is typically measured in revolutions per minute (RPM), and this value affects the distance a shot takes. Generally, a lower RPM results in a "flatter" flight path, thus a longer landing distance. Conversely, a higher RPM results in a higher flight path, thus a shorter landing distance. If the ball speed also increases, the increased landing distance due to the increased launch speed may be offset by the loss of landing distance. This problem is more likely to occur if the height of the clubface is low. Spin is related to the "gear effect" of the golf clubhead. The geometric center of a driver-type golf clubhead is usually the ideal point of impact. The axis perpendicular to the high-hitting plane, extending from the geometric center and into the clubhead, is called the high-hitting normal axis. If the clubhead's CG is at or below the high-hitting normal axis, the launch spin is reduced. If the clubhead's CG is above the high-hitting normal axis, the launch spin is reduced. One way to improve launch spin is to increase the height of the clubface. As the height of the clubface increases, the height of the geometric center increases by 50% of the increase in the height of the clubface. This raises the clubhead's center of gravity (CG) while still providing a more favorable launch spin. The industry often uses a strategy of increasing the height of the hit face to achieve the desired launch spin. However, as the hit face height decreases, the geometric center of the hit face also decreases by 50% of the reduction. With the lower geometric center, the high axis of impact also decreases. As the high axis of impact decreases, the CG position, which must be maintained at or no higher than the high axis of impact (to maintain ideal launch spin), also decreases. To offset the increase in launch spin naturally resulting from the lowered geometric center of impact, the CG must be lowered relative to the high axis of impact.

[0080] The clubhead's mass can be redistributed by moving mass away from the crown and redistributing it to the clubhead body, altering its relative CG position. This redistribution moves mass from the lighter striking face to a lower position on the clubhead body. Alternatively, additional mass can be placed in a removable high-density weight and added to a lower, rearward position on the clubhead body. Furthermore, the shaft connection structure within the hollow interior of the clubhead body can be modified to remove material, and the resulting mass savings can be redistributed to a lower position on the clubhead body. Any of these methods, individually or in combination, can be used to lower the clubhead's CG by adjusting the striking face height and lowering the geometric center of the striking face, thereby improving the golf ball's launch spin.

[0081] Another way to improve the spin on a golf ball's launch is to raise the geometric center of the strike face while reducing its height. Increasing the curvature at the front of the strike face raises the leading edge. Due to this increased curvature, the top of the strike face drops relative to the leading edge, further lifting the entire strike face off the ground. This reduces the vertical length of the strike face (strike face height) while simultaneously raising its geometric center. As the geometric center of the strike face rises due to the increased leading edge, the projection of the center of gravity relative to the strike face center shifts, thus altering the spin and launch characteristics. For example, when the geometric center of the strike face shifts upwards due to the increased leading edge, the projection of the center of gravity relative to the strike face center drops.

[0082] By redistributing mass and increasing curvature, the golf clubhead can be positioned vertically relative to the high-force axis (CG) between 0.1 inches above and 0.5 inches below the high-force axis. The control clubhead's vertical position relative to the high-force axis (CG) is 0.1 inches above and 0.5 inches below the high-force axis. G. Durability

[0083] A potential concern with reducing the thickness of the impact face is that it will reduce clubhead durability. However, by simultaneously reducing both the impact face thickness and the impact face height, a favorable trade-off can be achieved. A thinner impact face results in reduced clubhead durability. A lower impact face height increases impact face durability. II. Discussion of the striking surface

[0084] As described above, by simultaneously reducing the height of the striking face (hereinafter referred to as "SF") HSF and the thickness of the SF TSF, the ball speed of the driver head 100 can be improved while maintaining the CT that meets specifications. As defined above, the "height of the striking face" or "face height" HSF of the clubhead refers to the distance measured in the YZ plane from the top edge point 123 of the striking face to the bottom edge point 127 of the striking face. The top edge point 123 of the striking face is defined by the intersection of the top edge 122 of the striking face and the YZ plane. Similarly, the bottom edge point 127 of the striking face is defined by the intersection of the bottom edge 126 of the striking face and the YZ plane. Referring to Figure 6, the height HSF is measured in the YZ plane intersecting with the geometric center 116 of the striking face from the top edge point 123 of the SF parallel to the high-impact plane 1015 to the bottom edge point 127 of the SF.

[0085] The clubhead SF thickness (TSF) is a measurement of the average face thickness within the outer perimeter 120 of the face (SF). The average thickness is calculated by dividing the face volume by its area. The face volume is the volume of material bounded by the front surface 102, the rear surface 115 of the face 102, and the outer perimeter 120 of the face (SF). The outer perimeter 120 of the face (SF) extends vertically rearward or bulges above the high striking plane until it intersects with the rear surface 115. This bulge defines the outer boundary of the face volume. The face area is the area of ​​the front surface of the face 102 bounded by the outer perimeter 120 of the face (SF).

[0086] In many embodiments, the height of the driver head 100 (HSF) ranges from about 1.40 to 1.80 inches. In some embodiments, the HSF range may be from about 1.40 to 1.45 inches, 1.45 to 1.50 inches, 1.50 to 1.55 inches, 1.55 to 1.60 inches, 1.60 to 1.65 inches, 1.65 to 1.70 inches, 1.70 to 1.75 inches, or 1.75 to 1.80 inches. Furthermore, in some embodiments, the hitting face height HSF may be less than 1.80 inches, less than 1.78 inches, less than 1.76 inches, less than 1.74 inches, less than 1.72 inches, less than 1.70 inches, less than 1.68 inches, less than 1.66 inches, less than 1.64 inches, less than 1.62 inches, less than 1.60 inches, less than 1.58 inches, less than 1.54 inches, less than 1.52 inches, less than 1.50 inches, less than 1.48 inches, less than 1.46 inches, less than 1.44 inches, less than 1.42 inches, or less than 1.40 inches. In some embodiments, the striking face height may be approximately 1.80 inches, 1.79 inches, 1.78 inches, 1.77 inches, 1.76 inches, 1.75 inches, 1.74 inches, 1.72 inches, 1.71 inches, 1.70 inches, 1.69 inches, 1.68 inches, 1.67 inches, 1.66 inches, 1.65 inches, 1.64 inches, 1.63 inches, 1.62 inches, or 1.61 inches. The clubhead heights are 1.60 inches, 1.59 inches, 1.58 inches, 1.57 inches, 1.56 inches, 1.55 inches, 1.54 inches, 1.53 inches, 1.52 inches, 1.51 inches, 1.50 inches, 1.49 inches, 1.48 inches, 1.47 inches, 1.46 inches, 1.45 inches, 1.44 inches, 1.43 inches, 1.42 inches, 1.41 inches, and 1.40 inches. For example, in the illustrated embodiment, the height of the clubhead 100 (HSF) is approximately 1.622 inches. In other embodiments, the HSF can range from 1.733 to 1.622 inches.

[0087] In many embodiments, the face thickness (TSF) of the driver head 100 ranges from approximately 0.085 inches to 0.110 inches. The TSF range can be from 0.085 to 0.090 inches, 0.090 to 0.095 inches, 0.095 to 0.100 inches, 0.100 to 0.105 inches, or 0.105 to 0.110 inches. In other embodiments, the TSF range can be from 0.094 to 0.099 inches, 0.090 to 0.097 inches, or 0.095 to 0.103 inches. The face thickness (TSF) can be less than 0.100 inches, less than 0.099 inches, less than 0.098 inches, less than 0.097 inches, less than 0.096 inches, less than 0.095 inches, less than 0.094 inches, less than 0.093 inches, less than 0.092 inches, less than 0.091 inches, or less than 0.091 inches. For example, in some embodiments, the face thickness (TSF) can be approximately 0.085 inches, 0.086 inches, 0.087 inches, 0.088 inches, 0.089 inches, 0.090 inches, 0.091 inches, 0.092 inches, 0.093 inches, 0.094 inches, 0.095 inches, 0.096 inches, 0.097 inches, 0.098 inches, 0.099 inches, or 0.100 inches. In the illustrated embodiment, the face thickness (TSF) is approximately 0.094 inches. Due to the reduced hit face height (HSF), the TSF of the 100 driver head can also be reduced. The combination of a thinner hit face and a smaller hit face height improves ball speed while maintaining the specified CT value.

[0088] The striking surface may include a maximum thickness value, which is measured from the front surface to the back surface of the striking surface within its outer perimeter. In many embodiments, the maximum thickness may range from about 0.140 to 0.100 inches. For example, the maximum thickness may range from about 0.100 to 0.105 inches, 0.105 to 0.110 inches, 0.110 to 0.115 inches, 0.115 to 0.120 inches, 0.120 to 0.125 inches, 0.125 to 0.130 inches, 0.130 to 0.135 inches, or 0.135 to 0.140 inches. In some embodiments, the maximum thickness is approximately 0.100 inches, 0.102 inches, 0.104 inches, 0.106 inches, 0.108 inches, 0.110 inches, 0.112 inches, 0.114 inches, 0.116 inches, 0.118 inches, 0.120 inches, 0.122 inches, 0.124 inches, 0.126 inches, 0.128 inches, 0.130 inches, 0.132 inches, 0.134 inches, 0.136 inches, 0.138 inches, or 0.140 inches. In the illustrated embodiment, the maximum thickness is approximately 0.122 inches.

[0089] In many embodiments, the SF area can range from about 4.0 to 5.0 in². For example, the SF area can range from 4.0 in² to 4.5 in², 4.1 in² to 4.6 in², 4.2 in² to 4.7 in², 4.3 in² to 4.8 in², 4.4 in² to 4.9 in², or 4.5 in² to 5 in². In one embodiment, the SF area can be 4.02 in², 4.04 in², 4.06 in², 4.08 in², 4.10 in², 4.12 in², 4.14 in², 4.16 in², 4.18 in², 4.20 in², 4.22 in², 4.24 in², 4.26 in², 4.28 in², 4.30 in², 4.32 in², 4.34 in², 4.36 in², 4.38 in², 4.40 in², 4.42 in², 4.44 in², 4.46 in², 4.48 in², 4... The contact area of ​​the driver head 100 is approximately 4.46 in², or 5.00 in². The driver head of this invention, with its shorter and thinner contact area, also has a smaller SF area than existing driver heads. (The provided text also includes a list of contact areas, which are not translated as they are not part of the main text.)

[0090] In many embodiments, the strike face (SF) perimeter 120 may include a length measurement of the strike face (SF) perimeter 120. The strike face perimeter length may range from about 8.15 to 8.90 inches. For example, the strike face perimeter length may range from 8.15 to 8.50 inches, 8.25 to 8.60 inches, 8.35 to 8.70 inches, 8.45 to 8.80 inches, or 8.55 to 8.90 inches. The strike face perimeter length may be 8.15 inches, 8.20 inches, 8.25 inches, 8.30 inches, 8.35 inches, 8.40 inches, 8.45 inches, 8.50 inches, 8.55 inches, 8.60 inches, 8.65 inches, 8.70 inches, 8.75 inches, 8.80 inches, 8.85 inches, or 8.90 inches. For example, in the illustrated embodiment, the length of the outer perimeter of the SF is approximately 8.386 inches.

[0091] The height of the striking face can also be measured using a curve method. The curved striking face height is measured from the top edge point 123 along the front surface of the striking face to the bottom edge point 127, and includes both horizontal and vertical curvature. In many embodiments, the range of the striking face curvature is from approximately 1.40 to 1.80 inches. In some embodiments, the range of the striking face curvature may be from approximately 1.40 to 1.45 inches, 1.45 to 1.50 inches, 1.50 to 1.55 inches, 1.55 to 1.60 inches, 1.60 to 1.65 inches, 1.65 to 1.70 inches, 1.70 to 1.75 inches, or 1.75 to 1.80 inches. Furthermore, in some embodiments, the bending height of the striking surface may be less than 1.80 inches, less than 1.78 inches, less than 1.76 inches, less than 1.74 inches, less than 1.72 inches, less than 1.70 inches, less than 1.68 inches, less than 1.66 inches, less than 1.64 inches, less than 1.62 inches, less than 1.60 inches, less than 1.58 inches, less than 1.54 inches, less than 1.52 inches, less than 1.50 inches, less than 1.48 inches, less than 1.46 inches, less than 1.44 inches, less than 1.42 inches, or less than 1.40 inches. In some embodiments, the bend height of the striking face can be approximately 1.80 inches, 1.79 inches, 1.78 inches, 1.77 inches, 1.76 inches, 1.75 inches, 1.74 inches, 1.72 inches, 1.71 inches, 1.70 inches, 1.69 inches, 1.68 inches, 1.67 inches, 1.66 inches, 1.65 inches, 1.64 inches, 1.63 inches, 1.62 inches, or 1. 61 inches, 1.60 inches, 1.59 inches, 1.58 inches, 1.57 inches, 1.56 inches, 1.55 inches, 1.54 inches, 1.53 inches, 1.52 inches, 1.51 inches, 1.50 inches, 1.49 inches, 1.48 inches, 1.47 inches, 1.46 inches, 1.45 inches, 1.44 inches, 1.43 inches, 1.42 inches, 1.41 inches, 1.40 inches. For example, in the illustrated embodiment, the flex face height of the clubhead 100 is approximately 1.623 inches. In other embodiments, the flex face height may range from 1.735 to 1.624 inches.

[0092] The aforementioned top edge height (HTP) can range between 1.85 inches and 2.20 inches. For example, the range of top edge height (HTP) can be from 1.85 to 2.00 inches, 1.90 to 2.05 inches, 1.95 to 2.10 inches, 2.00 to 2.15 inches, or 2.05 to 2.20 inches. In the illustrated embodiment, the top edge height (HTP) is approximately 1.97 inches. In other embodiments, the range of top edge height (HTP) can be between 1.97 and 2.087 inches.

[0093] The range of the bottom edge height (HBP) can be between 0.350 inches and 0.385 inches. For example, the range of HBP can be between 0.350 and 0.360 inches, 0.355 and 0.365 inches, 0.360 and 0.370 inches, 0.365 and 0.375 inches, or 0.370 and 0.380 inches. In some embodiments, the bottom edge height (HBP) can be approximately 0.350 inches, 0.352 inches, 0.354 inches, 0.356 inches, 0.358 inches, 0.360 inches, 0.362 inches, 0.364 inches, 0.366 inches, 0.368 inches, 0.370 inches, 0.372 inches, 0.374 inches, 0.376 inches, 0.378 inches, or 0.380 inches. In the illustrated embodiment, the bottom edge height HBP is approximately 0.367 inches.

[0094] The range of the center-of-face height (HFC) can be between 1,100 inches and 1,300 inches. For example, the range of HFC can be between 1,100 and 1,200 inches, 1,110 and 1,210 inches, 1,120 and 1,220 inches, 1,130 and 1,230 inches, 1,140 and 1,240 inches, 1,150 and 1,250 inches, 1,160 and 1,260 inches, 1,170 and 1,270 inches, 1,180 and 1,280 inches, 1,190 and 1,290 inches, or 1,200 and 1,300 inches. In the illustrated embodiment, the center-of-face height (HFC) is approximately 1,173 inches.

[0095] A ratio exists between the height of the face (HSF) and the height of the face (HFC) of the driver-type golf club head 100. This ratio is calculated by dividing the HSF by the HFC. In many embodiments, the ratio ranges from 1.20 to 1.60. For example, the ratio may be between 1.20 and 1.35, 1.25 and 1.40, 1.30 and 1.45, 1.35 and 1.50, 1.40 and 1.55, or 1.45 and 1.60. In the illustrated embodiment, the ratio is approximately 1.36.

[0096] When the SF height is reduced, the ball speed lost due to the reduction in SF height can be compensated by thinning the hitting surface, thus mitigating the greater ball speed loss. The reduction in hitting surface thickness is uniform. In some embodiments, the hitting surface thickness is uniformly reduced only within the hitting surface area, thus keeping the thickness of the surrounding transition region unchanged. In other embodiments, the hitting surface thickness is uniformly reduced only within the outer periphery of the hitting surface insert. In this embodiment, even if the hitting surface includes areas outside the outer periphery of the hitting surface insert, only the thickness of the hitting surface insert is reduced.

[0097] The golf club head is a driver type and has a 2D average face thickness. This 2D average thickness is the average thickness of the face measured on the YZ plane. The 2D average face thickness is the cross-sectional area of ​​the face, defined by the projection of the front surface, rear surface, and outer perimeter of the face perpendicular to the high plane of impact. The 2D average face thickness can range from approximately 0.90 inches to 0.120 inches. For example, the 2D average face thickness can range from 0.90 to 0.100 inches, 0.95 to 0.105 inches, 0.100 to 0.110 inches, 0.105 to 0.115 inches, or 0.110 to 0.120 inches. In the illustrated embodiment, the 2D average face thickness is approximately 0.108 inches.

[0098] The hitting face width (WSF), as defined above, can range between 3.0 and 4.5 inches.

[0099] The striking surface also has a striking surface volume. The volume of the striking surface is the material volume calculated by defining the projections of the front and rear surfaces of the striking surface (SF) perpendicular to the high striking plane onto the outer perimeter 120. The striking surface volume can range between 0.410 in³ and 0.500 in³. For example, the striking surface volume can range between 0.410 and 0.460 in³, 0.415 and 0.465 in³, 0.420 and 0.470 in³, 0.425 and 0.475 in³, 0.430 and 0.480 in³, 0.435 and 0.485 in³, 0.440 and 0.490 in³, 0.445 and 0.495 in³, or 0.450 and 0.500 in³. III. Driver Construction

[0100] The material density of the striking surface ranges from 50 g / in³ to 100 g / in³. For example, in some embodiments, the density of the striking surface material ranges from 50 to 60 g / in³, 60 to 70 g / in³, 70 to 80 g / in³, 80 to 90 g / in³, or 90 to 100 g / in³. In the illustrated embodiment, the striking surface density is approximately 72 g / in³.

[0101] As detailed above, reducing both the face height (HSF) and face thickness (TSF) can increase the ball speed of the driver while maintaining the required contact velocity (CT). This practice of simultaneously reducing both face height (HSF) and face thickness (TSF) can be applied to any driver head type, regardless of its construction. However, in some embodiments, face height and face thickness may be expressed in ways different from those defined above. A. Rod face insert

[0102] In some embodiments, the driver head may include a face insert configuration. Figures 8 and 9 depict an embodiment of a driver head 200 including a face insert configuration, wherein the head includes a front opening 202 for receiving an additional face insert 204. The outer periphery 221 of the face insert (FI) may differ from the outer periphery 120 of the face (SF). The outer periphery 221 of the face insert (FI) is the outer peripheral edge of the face insert 204. The front opening 202 has a size and shape capable of receiving the face insert 204. In some embodiments, the front opening 202 has substantially the same size and shape as the face insert 204. In other embodiments, the front opening 202 may have an assembly-friendly configuration, such as a tab, overlap, or other similar structure for placing or mating with a face insert.

[0103] In this embodiment, the face insert has a face insert height HFI and a face insert thickness TFI. The face insert height refers to the distance measured in the YZ plane from the top edge point 223 of the face insert to the bottom edge point 227 of the face insert. The top edge point 223 is defined by the intersection of the top edge 222 of the face insert and the YZ plane. Similarly, the bottom edge point 227 is defined by the intersection of the bottom edge 226 of the face insert and the YZ plane. The height HFI is measured in the YZ plane intersecting the face center 216, from the top edge point 223 of the face insert parallel to the high-impact plane 1015 to the bottom edge point 227 of the face insert.

[0104] The measurement method for clubface insert thickness (TFI) is similar to that for striking face thickness (TSF). The clubface insert thickness is calculated by dividing the volume of the clubface insert by the area of ​​its face. The face area is the area bounded by the outer perimeter (221) of the clubface insert (FI).

[0105] In many embodiments, the face insert height HFI ranges from 1.35 to 1.70 inches. For example, the face insert height HFI may range from 1.35 to 1.45, 1.45 to 1.55, 1.55 to 1.65, or 1.65 to 1.70 inches. In some embodiments, the height of the bar face insert may be approximately 1.35 inches, 1.36 inches, 1.37 inches, 1.38 inches, 1.39 inches, 1.40 inches, 1.41 inches, 1.42 inches, 1.43 inches, 1.44 inches, 1.45 inches, 1.46 inches, 1.47 inches, 1.48 inches, 1.49 inches, 1.50 inches, 1.51 inches, 1.52 inches, 1.53 inches, 1.54 inches, 1.55 inches, 1.56 inches, 1.57 inches, 1.58 inches, 1.59 inches, 1.60 inches, 1.61 inches, 1.62 inches, 1.63 inches, 1.64 inches, 1.65 inches, 1.66 inches, 1.67 inches, 1.68 inches, 1.69 inches, or 1.70 inches. In the illustrated embodiment, the height HFI of the bar face insert is approximately 1.49 inches.

[0106] In many embodiments, the face insert thickness TFI ranges from 0.085 inches to 0.110 inches. The face insert thickness TFI can range from 0.085 to 0.090 inches, 0.090 to 0.095 inches, 0.095 to 0.100 inches, 0.100 to 0.105 inches, or 0.105 to 0.110 inches. In other embodiments, the face insert thickness TFI can range from 0.094 to 0.099 inches, 0.090 to 0.097 inches, or 0.095 to 0.103 inches. The face insert thickness (TFI) can be less than 0.100 inches, less than 0.099 inches, less than 0.098 inches, less than 0.097 inches, less than 0.096 inches, less than 0.095 inches, less than 0.094 inches, less than 0.093 inches, less than 0.092 inches, less than 0.091 inches, or less than 0.091 inches. For example, in some embodiments, the face insert thickness (TFI) can be approximately 0.085 inches, 0.086 inches, 0.087 inches, 0.088 inches, 0.089 inches, 0.090 inches, 0.091 inches, 0.092 inches, 0.093 inches, 0.094 inches, 0.095 inches, 0.096 inches, 0.097 inches, 0.098 inches, 0.099 inches, or 0.100 inches. In the illustrated embodiment, the face insert thickness (TFI) is approximately 0.096 inches.

[0107] As described above, the outer periphery 221 of the face insert (FI) and the outer periphery 120 of the striking face (SF) are separate and distinct. Therefore, in this embodiment, the golf club head 200 may have both the outer periphery 220 of the SF and the outer periphery 221 of the face insert (FI). The outer periphery 220 of the SF is defined by horizontal and vertical arcs, as described above, while the outer periphery 221 of the face insert (FI) is defined by the edge of the striking face insert 204. As shown in FIG8, the outer periphery 220 of the SF is offset outward from the outer periphery 221 of the face insert (FI). Therefore, the striking face insert 204 constitutes only a portion of the total striking surface defined by the outer periphery 220 of the SF. In other embodiments, the striking face insert 204 may constitute the entire total striking surface defined by the outer periphery 220 of the SF.

[0108] In many embodiments, the perimeter of the FI can range from about 7.30 to 8.10 inches. For example, in some embodiments, the perimeter of the face insert can range from 7.30 to 7.40 inches, 7.40 to 7.50 inches, 7.50 to 7.60 inches, 7.60 to 7.70 inches, 7.70 to 7.80 inches, 7.80 to 7.90 inches, 7.90 to 8.00 inches, or 8.00 to 8.10 inches. In the illustrated embodiment, the perimeter of the face insert is about 7.52 inches.

[0109] In some embodiments, the face insert comprises a mass ranging from 15 to 40 grams. For example, in some embodiments, the mass range of the face insert may be from 15 to 20 grams, 20 to 25 grams, 25 to 30 grams, 30 to 35 grams, or 35 to 40 grams. In the illustrated embodiment, the mass of the face insert is approximately 25 grams.

[0110] In some embodiments, the face insert comprises a volume ranging from 0.244 in³ to 0.550 in³. For example, in some embodiments, the face insert may comprise a volume ranging from 0.244 to 0.300 in³, 0.300 to 0.350 in³, 0.350 to 0.400 in³, 0.400 to 0.450 in³, 0.450 to 0.500 in³, or 0.500 to 0.550 in³. In the illustrated embodiment, the volume of the face insert is approximately 0.359 in³. B. Stick Covering

[0111] A driver with a lobe-covered construction has a front section composed of a single element, thus the face and the rearward transition area are integrally formed and contain the same material. In lobe-covered embodiments, the lobe may continue rearward to form the remainder of the body, or the lobe may be fixed to a second rear section of the body. In lobe-covered embodiments, the face height (HSF) and face thickness (TSF) are measured according to the above definitions and as shown in Figures 6 and 7. A driver head with a lobe-covered construction may include the shallow and thin face described in this invention to improve ball speed and maintain a compliant CT value. C.VFT

[0112] As stated above, setting a shorter face height (HSF) for a driver clubhead is not limited by the construction of the driver clubhead. Similarly, setting a thinner face thickness (TSF) for a driver clubhead can be implemented / applied to any VFT profile or construction. In other words, the effect of this invention in increasing ball speed and maintaining CT value is not affected by whether the driver clubhead also has a VFT profile. As stated above, to achieve a thinner face, the face thickness is uniformly reduced across the entire face area. Therefore, the VFT profile configuration does not change or modify due to changes in thickness. Similarly, the VFT profile configuration does not change or modify due to changes in height. Figures 10 and 11 illustrate the consistency of the VFT profile between a driver clubhead with a higher and thicker face and an example driver clubhead with a shorter and thinner face.

[0113] Figure 10 depicts an exemplary clubhead 300 according to the present invention, having a shallow and thin striking face, and a control clubhead 400. The exemplary clubhead 300 includes a VFT profile / configuration on the rear surface 315 of the striking face, while the control clubhead 400 also has a VFT profile on the rear surface 415. The control clubhead has a higher and thicker striking face than the exemplary embodiment. As shown in Figure 10, when the striking face height is reduced, the VFT configuration of the control clubhead and the exemplary clubhead remains unchanged.

[0114] Figure 11 is a cross-sectional comparison of the example clubhead 300 and the control clubhead 400. Figure 11 illustrates the changes in thickness and face height between the control clubhead 400 and the example clubhead 300, but is not drawn to scale. In Figure 11, the face centers 416 and 316 coincide. However, the rear surfaces 415 and 315 are misaligned. Due to the thinner clubface, the rear surface 315 of the example embodiment is closer to the face center 316. Similarly, the top surface is also lower than that of the control clubhead. IV. Structural Features of Golf Club Heads

[0115] The present invention relates to a driver-type golf club head comprising a shallow and thin face as described above. This driver-type golf club head combines the shallow and thin face feature with other features to improve MOI and center of gravity, while providing faster ball speed with the same CT value. The driver-type golf club head has a body width WB, body depth DB, and body height HB as defined above. Reducing the face height and thickness does not affect the body width WB, body depth DB, and body height HB. In other words, the driver-type club head of the present invention achieves a shallow and thin face without significantly altering the body frame, thus achieving a high moment of inertia and improved center of gravity.

[0116] The driver-type golf clubhead 100 includes a body width WB as defined above, ranging from 4.8 to 5 inches. The body width WB provides a larger frame to improve the clubhead's moment of inertia. The body width WB is not affected by simultaneously reducing the height and thickness of the hitting face.

[0117] The 100 driver-type golf clubhead features a body depth (DB) ranging from 4.65 to 4.95 inches. This DB provides a larger frame to improve the clubhead's moment of inertia, and the resulting structure allows for a lower, more rearward center of gravity. The DB is not affected by simultaneously reducing the height and thickness of the face.

[0118] The driver-type golf club head 100 includes a body height HB ranging from 2.35 inches to 2.8 inches. In some embodiments, the body height HB of the club head may remain constant to improve moment of inertia and center of gravity position. In other embodiments, the body height HB may be slightly reduced to accommodate a shortened striking face without significantly altering the crown curvature and sole curvature.

[0119] The crown height (HCA) ranges from 2.15 to 2.45 inches. For example, in some embodiments, the HCA ranges from 2.15 to 2.25 inches, 2.20 to 2.30 inches, 2.25 to 2.35 inches, 2.30 to 2.40 inches, or 2.35 to 2.45 inches. In the illustrated embodiment, the HCA is approximately 2.264 inches.

[0120] The range of the crown depth (DCA) can be from 0.70 to 0.90 inches. For example, in some embodiments, the range of the DCA can be from 0.70 to 0.75 inches, 0.75 to 0.80 inches, 0.80 to 0.85 inches, or 0.85 to 0.90 inches. In the illustrated embodiment, the DCA is approximately 0.871 inches.

[0121] The range of the crown apex angle 20 can be from 18 to 23 degrees. For example, in some embodiments, the range of the crown apex angle 20 can be from 18 to 19 degrees, 19 to 20 degrees, 20 to 21 degrees, 21 to 22 degrees, or 22 to 23 degrees. In the illustrated embodiment, the crown apex angle 20 is approximately 19.6 degrees.

[0122] As described above, in some embodiments, reducing the face height can alter golf ball launch characteristics such as spin and launch angle. In some embodiments, reducing the face height may alter the position of the center of gravity projection point relative to the face center. In some embodiments, the CG projection is raised relative to the geometric center 116 of the face. To maintain a shorter face height and improve the CG projection point, the bottom edge height HBP or bottom-top angle 25 of the driver head can be increased. The geometric center 116 of the face can also be raised by lifting the bottom edge point 127 off the ground plane 1010.

[0123] The range of the bottom edge height (HBP) can be between 0.350 inches and 0.385 inches. For example, the range of HBP can be between 0.350 and 0.360 inches, 0.355 and 0.365 inches, 0.360 and 0.370 inches, 0.365 and 0.375 inches, or 0.370 and 0.380 inches. In some embodiments, the bottom edge height (HBP) can be approximately 0.350 inches, 0.352 inches, 0.354 inches, 0.356 inches, 0.358 inches, 0.360 inches, 0.362 inches, 0.364 inches, 0.366 inches, 0.368 inches, 0.370 inches, 0.372 inches, 0.374 inches, 0.376 inches, 0.378 inches, or 0.380 inches. In the illustrated embodiment, the bottom edge height (HBP) is approximately 0.367 inches. The key to selecting the bottom edge height is to set the geometric center 116 of the hitting face in the ideal position without changing the height of the hitting face (HFC) and the thickness of the hitting face (TSF). This results in the driver head having better ball speed and launch characteristics, while maintaining the CT value that meets the specifications.

[0124] The aforementioned bottom-to-top depth DSA range can be between 0.60 and 0.67 inches. For example, in some embodiments, the bottom-to-top depth DSA range can be between 0.60 and 0.61 inches, between 0.61 and 0.62 inches, between 0.62 and 0.63 inches, between 0.63 and 0.64 inches, between 0.64 and 0.65 inches, between 0.65 and 0.66 inches, or between 0.66 and 0.67 inches. In the illustrated embodiment, the bottom-to-top depth DSA is approximately 0.62 inches.

[0125] The aforementioned apex angle 25 can be between 27 and 32 degrees. For example, the apex angle can be between 27 and 28 degrees, between 28 and 29 degrees, between 29 and 30 degrees, between 30 and 31 degrees, or between 31 and 32 degrees. In the illustrated embodiment, the apex angle 25 is approximately 30.8 degrees.

[0126] The driving club head 100 has a head volume and a head mass. In one embodiment, the head volume is not equal to or less than 400cc. In one embodiment, the head volume is greater than 400cc. In one embodiment, the head volume ranges from 401cc to 500cc. In one embodiment, the head volume can range from 420cc to 460cc. In one embodiment, the head volume can range from 440cc to 460cc. In one embodiment, the head volume can range from 440cc to 480cc. In one embodiment, the head mass is equal to or less than 360 grams. In one embodiment, the head mass is greater than 290 grams. In one embodiment, the head mass can range from 290 grams to 360 grams.

[0127] In some embodiments, the driver-type golf club head 100 may further include a removable and adjustable weight system located at the rear sole and rear skirt. This removable and adjustable weight system includes a weight receiving slot with at least three separate weight attachment points and a removable weight weighing from 5 grams to 50 grams. In other embodiments, the driver-type golf club head 100 may further include a single-position weight, which is attached to a fixed single position on the golf club head as a removable weight. The removable weight may weigh from 15 grams to 50 grams.

[0128] In some embodiments, the driver-type golf club head 100 includes a top opening for receiving a lightweight upper insert. When the lightweight upper insert is inserted into the top opening, it includes a portion of a golf club head crown, a portion of a skirt or sidewall facing the toe, a portion of a skirt or sidewall facing the heel, and a portion of a skirt or sidewall facing rearward. The toe-facing and heel-facing portions of the upper insert may also include portions of the golf club head base. The upper insert may be a monolithic insert composed of multiple pieces, all comprising the same lightweight material. The upper insert may be made of a polymer material, a composite material, or other similar lightweight material.

[0129] In some embodiments, the driver-type golf club head 100 includes an internal sheath structure for engaging the lower end of the golf club shaft or an adjustment system attached to the lower end of the golf club shaft, such that a gap is formed within the internal sheath structure. The internal sheath structure includes an upper internal sheath section adjacent to the upper sheath opening and a lower internal sheath section adjacent to the bottom, which are not connected to each other but form a gap between them. This gap in the internal sheath structure allows the assembled lower end of the golf club shaft or the adjustment system attached to the lower end of the golf club shaft to be partially or entirely exposed within the internal volume of the golf club head 100, but not exposed on the outer surface.

[0130] A driver clubhead may include an Ixx, as defined above, ranging from approximately 3600 g*cm² to 4500 g*cm². For example, in some embodiments, the driver clubhead includes an Ixx greater than 3600 g*cm², greater than 3700 g*cm², greater than 3800 g*cm², greater than 3900 g*cm², greater than 4000 g*cm², greater than 4100 g*cm², or greater than 4200 g*cm².

[0131] A driver clubhead may contain an Iyy, as defined above, ranging from approximately 5000 g*cm² to 6000 g*cm². Iyy can be greater than 5000 g*cm², greater than 5100 g*cm², greater than 5200 g*cm², greater than 5300 g*cm², greater than 5400 g*cm², greater than 5500 g*cm², or greater than 5600 g*cm². The range of Iyy can be between 5000 g*cm² and 5250 g*cm², between 5100 g*cm² and 5350 g*cm², or between 5200 g*cm² and 5450 g*cm².

[0132] A driver clubhead may contain an Izz, as defined above, ranging from approximately 2500 to 2900 g*cm². The range of the Izz may be between 2500 g*cm² and 2600 g*cm², 2600 g*cm² and 2700 g*cm², 2700 g*cm² and 2800 g*cm², or 2800 g*cm² and 2900 g*cm².

[0133] A driver clubhead may include a CGy, as defined above, ranging from -0.30 to 0.00 inches. For example, in some embodiments, the CGy range may be from -0.30 to -0.20 inches, -0.20 to -0.10 inches, or -0.10 to 0.00 inches.

[0134] A driver head may include a CGx, as defined above, ranging from -0.10 to 0.20 inches. For example, the CGx range may be between -0.10 and -0.05 inches, -0.05 and 0.00 inches, 0.00 and 0.10 inches, or 0.10 and 0.20 inches.

[0135] A driver clubhead may include a CGz, as defined above, ranging from -1.5 to -2.0 inches. For example, in some embodiments, the CGz may range from -1.5 to -1.6 inches, -1.6 to -1.7 inches, -1.7 to -1.8 inches, -1.8 to -1.9 inches, or -1.9 to -2.0 inches.

[0136] A driver head may include a YGP, as defined above, ranging from 0.90 to 1 inch. For example, a YGP may be approximately 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, or 1.00 inches. V. Relationships Relationship 1 (Volume of clubface insert versus volume of clubhead) Relationship 2 (Facial insert mass and clubhead mass) Relationship 3 (CGY and bar face insert height) Relationships 4A and 4B (CG position and bar face insert mass) (in / gram) Relationships 5A and 5B (CG position and bar face insert volume) (in-2) Relationship 6 (see Figure 13) CT variation of the driving clubface height y = 92.52x + 264.31 Where y is CT, in microseconds, and x is the surface height Delta (inches). Relationship 7 (Surface Height and Surface Thickness) Relationship 8 - See Figure 15 (Average surface thickness and CT) y = -1319x + 451.6 Where y is the predicted CT in microseconds and x is the surface thickness in inches. Relationship 9 - See Figure 14 (surface thickness and ball speed) y = -134x + 0.002 Where y is the ball speed in mph, and x is the uniform thickness of the entire striking surface. Relationship 10 - See Figure 12 (Changing the surface height and changing the ball speed) (cm / mph) Example VI. Example 1: Relationship between surface thickness and CT and ball velocity

[0137] Example 1 illustrates the relationship between surface thickness and CT and ball velocity. As shown in Figures 14 and 15, the effect of surface thickness on CT is that for every 0.0075" change in surface thickness, CT changes by 9.24 microseconds, and the effect on ball velocity is that for every 0.0075" change in surface thickness, ball velocity changes by 1 mph. VII. Example 2: Relationship between face height and CT and ball velocity

[0138] Example 2 illustrates the relationship between face height and CT and ball velocity. As shown in Figure 13, the effect of face height on CT is that for every 0.100° change in face height, the CT changes by 7.66 microseconds, and the effect on ball velocity is that for every 0.100° change in face height, the ball velocity changes by 0.8 mph. VIII. Example 3: Examples and Comparisons

[0139] Example 3 compares the exemplary driver-type golf club head of this invention with a control club head. This comparative example aims to illustrate the advantages and improvements of the exemplary driver-type golf club head compared to the control club head. The exemplary driver-type golf club head and the control driver-type golf club head are identical except for the following two main features: First, the face height of the exemplary club head is smaller than that of the control club head. Second, the face thickness of the exemplary club head is smaller than that of the control club head. Specifically, the face height of the exemplary club head is 1.733 inches, while the face height of the control club head is approximately 1.820 inches.

[0140] Furthermore, the face thickness of the example driver-type golf club head, measured at the striking face, is 0.080 inches thinner than the face thickness of the control club head at the corresponding location. The example driver-type golf club head contains the exact same VFT configuration / structure as the control driver-type golf club head. The VFT structure has a thickened middle section, with the thickness gradually decreasing towards the thinner outer perimeter. The VFT structures of both example club heads and the control club head are identical except for the thickness. The example driver-type golf club head has the same VFT structure, but the thickness is uniformly reduced by 0.080 inches.

[0141] Data was collected using Finite Element Analysis (FEA) technology with Computer-Aided Design (CAD) software. The collected data included ball speed and contact cross-section (CT). The example driver-type golf clubhead produced a ball speed 0.7 MPH higher than the control clubhead. The CT value of the example clubhead was 270 microseconds, while the CT value of the control clubhead was 269 microseconds. This demonstrates that by reducing the face height and thinning the clubface, the example driver-type clubhead can produce a higher ball speed than the control driver-type clubhead while maintaining the same compliant CT value. IX. Example 4: Face Height and Face Thickness and Standardized Ball Speed

[0142] Example 4 is a comparative example that compares two exemplary driver-type golf club heads according to the present invention with a control driver-type golf club head. This example compares the standardized ball speed of the exemplary embodiment with that of the control club head.

[0143] Table 1 shows the test results. Both exemplary driver clubheads and the control driver clubhead exhibited the same CT value, 237 microseconds. The standardized ball speeds produced by both exemplary driver clubheads were higher than those of the control driver clubhead. The first exemplary driver clubhead, with its thinner and shorter face, exhibited the fastest ball speed. state

[0144] Sample 1: A golf club head of the type of driver, comprising: a club head body, including: a crown, a front end, a rear end opposite to the front end, a toe end, a heel end opposite to the toe end, a bottom end opposite the crown, and a skirt forming a transition surface in the area outside the front end between the crown and the bottom end, each having an inner surface and an outer surface, and a striking face located at the front end and including a geometric center; a body width, a body depth, and a body height; and a body center of gravity; wherein: a high-hitting plane is defined as tangent to the geometric center; a ground plane is defined as tangent to the bottom end when the club head body is in a hitting aiming position; a high-hitting angle is defined by the high-hitting plane and the ground plane; wherein the high-hitting angle ranges from 7.0 degrees to 16 degrees; an x-axis is defined as passing through the geometric center along a direction parallel to the ground plane from the toe to the heel; a y-axis is defined as passing through the geometric center along a direction perpendicular to the x-axis from the crown to the bottom; and a z-axis is defined as passing through the geometric center along a direction perpendicular to the x-axis from the crown to the bottom. The x-axis and y-axis are perpendicular to each other, extending from the front to the rear end through the geometric center; a y' axis is defined as a direction parallel to the y-axis, extending from the crown to the bottom through the center of gravity; Iyy is a measurement of the moment of inertia about the y' axis, and the range of Iyy is from approximately 4900 g*cm² to 5900 g*cm²; the body width is measured parallel to the x-axis between the nearest heel point and the nearest toe point, and the body width is between 4.6 inches and 5 inches; the body depth is... The body depth is measured parallel to the z-axis between the leading edge and the nearest rear point, and is between 4.5 inches and 4.95 inches; the body height is measured between the ground plane and the highest point on the crown, and is between 2.3 inches and 2.8 inches; the volume of the clubhead body is greater than approximately 440 cm³; a YGP is measured from the center of gravity of the clubhead parallel to the y-axis to the ground plane, and is between approximately 0.8 inches and 1.0 inches; A CGz is measured from the geometric center parallel to the z-axis to the center of gravity of the body, and the CGz is between approximately 1.60 and 1.85 inches; the hitting surface is defined by a horizontal curvature and a vertical curvature; the horizontal curvature is the curvature of the hitting surface in the heel-toe direction and the vertical curvature is the curvature of the hitting surface in the crown-toe direction; the horizontal curvature includes a horizontal arc radius and the vertical curvature includes a vertical arc radius; the hitting surface includes a hitting surface perimeter defined by the horizontal arc radius and the vertical arc radius. The vertical arc radius is separated from the horizontal arc curvature and the vertical arc curvature at a point; the outer periphery of the hitting surface includes a top edge, a bottom edge, a toe edge, and a heel edge; the outer periphery of the hitting surface includes a top edge point defined by the intersection of the top edge and a YZ plane, wherein the YZ plane is defined by the y-axis and the z-axis; the outer periphery of the hitting surface includes a bottom edge point defined by the intersection of the bottom edge of the outer periphery of the hitting surface and the YZ plane; the outer periphery of the hitting surface includes a hitting surface length, which is between 8.15 inches and 8.The hitting face includes a height measured between the top and bottom edges of the ball, parallel to the high-hitting plane, and the hitting face height is between approximately 1.40 inches and 1.80 inches; the hitting face includes a volume measured by the projection of the front and rear surfaces of the hitting face perpendicular to the high-hitting plane, and the hitting face volume is between approximately 0.410 in³ and 0.500 in³; the hitting face includes an area measured in the front surface of the hitting face, bounded by the outer perimeter of the hitting face, and the hitting face area is between approximately 4.0 and 5.0 in²; the hitting face includes a thickness measured by the thickness of the hitting face. The thickness of the hitting surface, measured by dividing the volume of the sphere by the area of ​​the hitting surface, is between approximately 0.085 and 0.100 inches. The hitting surface includes a width measured parallel to the x-axis between the nearest heel point and the nearest toe point on the outer periphery of the hitting surface, and this width is between approximately 3.5 and 4.5 inches. The hitting surface includes a top edge height measured parallel to the y-axis between the top edge and the ground plane, and this top edge height is between approximately 1.85 and 2.20 inches. The hitting surface includes a bottom edge height measured parallel to the y-axis between the bottom edge and the ground plane, and this bottom edge height is between approximately 0.3 inches. The clubhead is between 0.50 inches and 0.385 inches; the striking face includes a center height measured parallel to the y-axis between the geometric center and the ground plane, and the center height ranges from 1.10 to 1.30 inches; the clubhead body includes a crown apex located at the highest point on the crown in the YZ plane, the crown apex having a height between approximately 2.15 inches and 2.45 inches, measured parallel to the y-axis between the crown apex and the ground plane; the crown apex includes a depth measured parallel to the z-axis between the apex point and the crown apex, and the crown apex depth is between approximately 0.70 and 0.90 inches; the clubhead includes a crown apex angle, which is located between a first virtual line and a second virtual line. Measured between virtual lines, the first virtual line is parallel to the z-axis and the second virtual line intersects both the crown apex and the apex point, with the crown apex angle ranging between 18 and 23 degrees. The clubhead body includes a bottom apex, which is the lowest point on the bottom of the YZ plane. The bottom apex includes a depth measured from the apex point parallel to the z-axis to the bottom apex, with the bottom apex depth ranging from 0.60 to 0.67 inches. The clubhead body includes a bottom apex angle, measured between a third and a fourth virtual line, the third virtual line being parallel to the z-axis and the fourth virtual line intersecting both the bottom apex and the apex point, with the bottom apex angle ranging between 27 and 32 degrees.

[0145] Replacement of one or more of the claimed requirements constitutes a refactoring rather than a repair. Furthermore, benefits, other advantages, and solutions to problems are described with reference to specific embodiments, but these benefits, advantages, solutions to problems, and any requirement that may cause or highlight such benefits, advantages, or solutions to occur should not be construed as critical, necessary, or essential features or requirements of any or all claims, except where such benefits, advantages, solutions, or requirements are expressly stated in the claim.

[0146] Furthermore, the embodiments and limitations described herein are not contributed to the public based on the principle of contribution if (1) they are not explicitly claimed in the scope of the patent application; and (2) they are or may be equivalents of the performance requirements and / or limitations under the principle of equality.

[0147] 10: High firing angle 15: Bottom corner 20: Crown apex angle 25: Bottom Angle 100: Clubhead 101:Ontology 102: Hitting surface 103: Frontier 104:Heel 105: Insert Sheath 106: Toes 108: Front-end 109: Trailing Edge 110: Crown 111: Backend 112: Bottom 114: Skirt 115: Rear surface 116: Geometric Center 117: Heel apex 118: Toe apex 119: Backside Point 120: Surface of the strike (SF) outer circumference 122: Top Edge 123: Vertex Point 124: Toe edge 126: Bottom edge 127: Bottom edge point 128: Heel Edge 130: Crown Vertex 132: Bottom Vertex 160: Center of gravity 200: Clubhead 202: Front opening 204: Strike surface insert 216: Hit the center of the ball 220:SF peripheral 221: Outer periphery of the face insert (FI) 222: Top Edge 223: Vertex Point 226: Bottom edge 227: Bottom edge point 300: Example clubhead 315: Back surface 316: Hit the center of the ball 400: Comparison with clubhead 415: Back surface 416: Hit the center of the ball 1010: Ground Plane 1015: High-impact plane 1020: Insert sheath shaft 1040: X-axis 1050: Y-axis 1060: Z-axis 1070:X' axis 1075: Line of Force 1080: Y' axis 1090: Z' axis

Claims

1. A golf club head with improved characteristic timing, comprising: a club head body including: a crown, a front end, a rear end opposite the front end, a toe end, a heel end opposite the toe end, a bottom end opposite the crown, and a skirt forming a transition surface in a region between the crown and the bottom end (excluding the front end portion), each having an inner surface and an outer surface; a striking face located at the front end and including a geometric center, defined by a horizontal curvature and a vertical curvature; wherein: A high striking plane is defined as tangent to the geometric center; a ground plane is defined as tangent to the bottom when the clubhead body is in a striking aiming position; an x-axis is defined as passing through the geometric center along a toe-to-heel direction parallel to the ground plane; a y-axis is defined as passing through the geometric center along a crown-to-bottom direction perpendicular to the x-axis; a z-axis is defined as passing through the geometric center along a front-to-rear direction perpendicular to both the x-axis and the y-axis; the horizontal arc curvature is the curvature of the striking face in a heel-to-toe direction and includes a horizontal arc radius; the vertical arc curvature is the curvature of the striking face in a crown-to-bottom direction and includes a vertical arc radius; the striking face includes a striking face (SF) periphery defined where the horizontal arc radius and the vertical arc radius depart from the horizontal arc curvature and the vertical arc curvature, respectively; the striking face (SF) periphery includes a top edge, a bottom edge, a toe edge, and a heel edge; The outer periphery of the strike face (SF) includes a top edge point defined by the intersection of the top edge and a YZ plane, wherein the YZ plane is defined by the y-axis and the z-axis; the outer periphery of the strike face (SF) includes a bottom edge point defined by the intersection of the bottom edge of the outer periphery of the strike face (SF) and the YZ plane; the strike face includes a strike face volume, which is measured by means of the projection of the front surface of the strike face, the back surface of the strike face, and the outer periphery of the strike face (SF) perpendicular to the high-hitting plane; the strike face includes a strike face area, which is measured by means of the front surface of the strike face bounded by the outer periphery of the strike face (SF); the strike face includes a strike face height, which is measured by means of the height between the top edge point and the bottom edge point, parallel to the high-hitting plane; The striking face includes a striking face thickness, which is measured by dividing the volume of the striking face by the area of ​​the striking face; and the driving club head with improved characteristic timing further satisfies the following relationship:

1. Where Hsf is the height of the hitting surface and Tsf is the thickness of the hitting surface.

2. The driving club head with improved characteristic timing as described in claim 1, wherein: The height of the striking face is between approximately 1.40 inches and 1.80 inches; and the thickness of the striking face is between approximately 0.085 inches and 0.100 inches.

3. The driving club head with improved characteristic timing as described in claim 2, wherein: The clubhead body further includes: a body width, a body depth, and a body height; and a body center of gravity; wherein; a y' axis is defined as passing through the body center of gravity along a direction parallel to the y-axis from the crown to the bottom; the striking face includes a striking face volume, which is the volume measured with the front surface of the striking face, the back surface of the striking face, and the projection of the striking face (SF) periphery perpendicular to the high striking plane as the interface.

4. A golf club head with improved characteristic timing as described in claim 3, wherein: A value for the moment of inertia Iyy about the y' axis is a measurement, and the range of Iyy is from about 4900 g*cm2 to 5900 g*cm2; and a high impact angle is defined by the high impact plane and the y-axis, and the range of the high impact angle is from 7.0 degrees to 16 degrees.

5. A golf club head with improved characteristic timing as described in claim 3, wherein: The body width is measured parallel to the x-axis between a nearest heel point and a nearest toe point, and the body width is between 4.6 inches and 5 inches; the body depth is measured parallel to the z-axis between a leading edge and a nearest rear edge point, and the body depth is between 4.5 inches and 4.95 inches; the body height is measured between the ground plane and a highest point on the crown, and the body height is between 2.3 inches and 2.8 inches; the clubhead body includes a lightweight upper insert to form one of the following parts of the golf clubhead: the crown, the skirt at the toe, the skirt at the heel, the rear skirt, and the sole.

6. A golf club head with improved characteristic timing as described in claim 3, wherein: The volume of the clubhead body is greater than approximately 440 cm³; a YGP is measured from the center of gravity of the clubhead parallel to the y-axis to the ground plane, and the YGP is between approximately 0.8 inches and 1.0 inches; a CGz is measured from the geometric center of the clubhead parallel to the z-axis to the center of gravity of the clubhead, and the CGz is between approximately 1.60 inches and 1.85 inches.

7. The driving club head with improved characteristic timing as claimed in claim 3, wherein the striking face includes a striking face width, which is a distance measured from the nearest heel point on the outer periphery of the striking face (SF) in a direction parallel to the x-axis to the nearest toe point on the outer periphery of the striking face (SF), and the striking face width is between approximately 3.5 inches and 4.5 inches.

8. The driving club head with improved characteristic timing as claimed in claim 3, wherein the striking face includes a top edge height measured parallel to the y-axis between the top edge and the ground plane, and the top edge height is between approximately 1.85 inches and 2.20 inches.

9. The driving club head with improved characteristic timing as claimed in claim 3, wherein the striking face includes a bottom edge height measured parallel to the y-axis between the bottom edge and the ground plane, and the bottom edge height is between approximately 0.350 inches and 0.385 inches.

10. The driving club head with improved characteristic timing as claimed in claim 3, wherein the striking face includes a face center height measured parallel to the y-axis between the geometric center and the ground plane, and the face center height ranges from 1.10 inches to 1.30 inches.

11. A golf club head with improved characteristic timing as described in claim 5, wherein: The ratio of the height of the striking surface to the height of the center of the surface is between 1.20 and 1.60; and the striking surface has a density between 60 g / in³ and 70 g / in³.

12. The driving club head with improved characteristic timing as claimed in claim 3, wherein the club head body includes a crown apex located at a highest point on the crown in the YZ plane, the crown apex having a height between approximately 2.15 inches and 2.45 inches, measured parallel to the y-axis between the crown apex and the ground plane.

13. The driving club head with improved characteristic timing as claimed in claim 12, wherein the crown apex includes a crown apex depth measured parallel to the z-axis between the apex point and the crown apex, and the crown apex depth is between approximately 0.70 inches and 0.90 inches.

14. The driving club head with improved characteristic timing as claimed in claim 13, wherein the club head includes a crown apex angle measured between a first virtual line and a second virtual line, the first virtual line being parallel to the z-axis and the second virtual line intersecting both the crown apex and the crown edge, and the crown apex angle being between 18 degrees and 23 degrees.

15. The driving club head with improved characteristic timing as claimed in claim 14, wherein the club head body includes a bottom vertex, which is a lowest point on the bottom in the YZ plane; the bottom vertex includes a depth measured from the bottom edge point parallel to the z-axis to the bottom vertex, and the bottom vertex depth ranges from 0.60 inches to 0.67 inches.

16. The driving club head with improved characteristic timing as claimed in claim 15, wherein the club head body includes a bottom apex angle measured between a third virtual line and a fourth virtual line, the third virtual line being parallel to the z-axis and the fourth virtual line intersecting both the bottom apex and the bottom edge, and the bottom apex angle being between 27 degrees and 32 degrees.

17. The tee-type golf club head with improved characteristic timing as claimed in claim 11, wherein the club head body includes a clubface covering structure including a crown fold and a bottom fold fixed to the lightweight upper insert.

18. The tee-type golf club head with improved characteristic timing as claimed in claim 17, wherein the lightweight upper insert forms a portion of the crown, the base, the skirt at the toe end, and the skirt at the heel end of the golf club head.

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