Golf club head with variable thickness face

Abstract

We offer iron-type golf club heads with variable thickness faces. [Solution] With respect to a golf club head, the striking face has a thick central region and a peripheral region where the thickness decreases, thereby improving the performance of the golf club head.

Description

Technical Field

[0001] The present invention generally relates to an iron-type golf club head having a variable-thickness face portion. More specifically, the present invention relates to an iron-type golf club head, wherein the striking face portion has a central region of increased thickness that transitions to a thinner peripheral region. The central region of increased thickness is located near the face center of the striking face portion, and the peripheral region is located radially outward from the central region. The present invention also relates to a specific transition from the central region to the peripheral region.

Background Art

[0002] The design of golf club heads often requires an appropriate balance of the desire to maximize the performance and durability needs of the golf club head.

[0003] One area where these splitting and reaction forces occur is in the design of the striking face of the golf club head. If a club designer wants to maximize the coefficient of restitution of the golf club head, the thickness of the striking face of the golf club head can be reduced, making the striking face more flexible during impact with the club ball, which leads to an increase in further distance. However, as described above, the durability of a striking face portion that is too thin often results in mechanical failures such as plastic deformation of the striking face portion, which is undesirable.

[0004] To address this problem, club designers have invented striking faces with various thicknesses, where the regions experiencing high stress are thicker, and the remaining portions of the striking face portion can have reduced thickness to maximize performance. U.S. Patent No. 6,368,234 to Galloway exemplifies this concept by incorporating concentric elliptical regions of various thicknesses around the center of the striking face of a metal wood type golf club head where the ball is intended to impact the club.

[0005] While maximizing distance is one of the primary objectives in designing metal-wood type golf club heads, as illustrated in Galloway's U.S. Patent No. 6,368,234, designing the striking face of an iron type golf club head can be more complex because maximizing distance is not the primary objective. Although distance is important for iron type golf club heads, the primary objective in designing iron type golf club heads is performance consistency. Furthermore, the challenge in designing an improved face for iron type golf club heads lies in the shape and dimensions of the iron type golf club head, which creates a point of maximum deflection that differs from the typical impact point of the golf club head. This separation of these two high-stress points makes designing an improved striking face more difficult.

[0006] Yoneyama's U.S. Patent No. 6,746,343 describes one method for incorporating a varying face thickness profile into an iron-type golf club head: the use of a thick wall section at the rear of the lower central part of the front plate, and multiple narrow ribs extending radially from the thick wall section toward the upper and outer periphery of the front plate.

[0007] Morales et al.'s U.S. Patent No. 10,258,843 demonstrates one way in which a varying face thickness profile is incorporated into an iron-type golf club head, where the striking face is supported by loop-shaped ribs to create a varying face thickness profile.

[0008] While each of these designs has its own performance advantages, they cannot utilize the inherent shape of iron-type golf club heads, which have an impact point different from the geometric center of the striking face.

[0009] Therefore, it is clear that there is a need in the industry for a new and improved design for the striking face portion of iron-type golf club heads that provides more consistent ball speed across the impact point on the striking face, is more durable, and reduces the overall weight of the striking face. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent No. 6,368,234 [Patent Document 2] U.S. Patent No. 6,746,343 [Patent Document 3] U.S. Patent No. 10,258,843 [Overview of the Initiative]

[0011] In some embodiments, the technology described herein is a golf club head comprising a toe portion, a heel portion opposite to the toe portion, a top line, a sole opposite to the top line, a hosel positioned on the heel side and configured to receive a shaft, and a striking face having a front surface configured to contact a golf ball and a rear surface opposite to the front surface, wherein the front surface of the striking face includes a plurality of scorelines extending from the heel towards the claw, and the rear surface of the striking face portion includes a central region overlapping with at least a portion of the center of the striking face, and a peripheral region formed along the outer circumference of the rear surface of the striking face, and The present invention relates to a golf club head comprising: a first transition region extending from the central region toward the toe portion in the peripheral region; a second transition region extending from the central region toward the heel portion in the peripheral region; a third transition region extending from the central region toward the top line in the peripheral region; and a fourth transition region extending from the central region toward the sole in the peripheral region, wherein the central region has a constant thickness measured from the front surface of the striking face to the rear surface of the striking face, and the thickness of the first, second, third, and fourth transition regions each decreases from the central region toward the peripheral region.

[0012] In some embodiments, the technology described herein is a golf club head comprising a toe portion, a heel portion opposite to the toe portion, a top line, a sole opposite to the top line, a hosel positioned on the heel side and configured to receive a shaft, and a striking face having a front surface configured to contact a golf ball and a rear surface opposite to the front surface, wherein the front surface of the striking face includes a plurality of scorelines extending from the heel towards the claw, and the rear surface of the striking face portion is at least the center of the striking face The present invention relates to a golf club head comprising a central region that overlaps with a portion thereof, a peripheral region formed along the outer circumference of the rear surface of the striking face, a first transition region extending from the central region to the peripheral region toward the toe portion, a second transition region extending from the central region to the peripheral region toward the heel portion, wherein the central region has a constant thickness measured from the front surface of the striking face to the rear surface of the striking face, and the thickness of the first and second transition regions decreases from the central region toward the peripheral region.

[0013] These and other features, embodiments, and advantages of the present invention will be better understood by referring to the following drawings, description, and claims.

[0014] The aforementioned and other features and advantages of the present invention will become apparent from the following description of the invention, as illustrated in the accompanying drawings. The accompanying drawings, incorporated herein and forming part thereof, further serve to illustrate the principles of the present invention and enable those skilled in the art to construct and use the present invention. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 of the attached drawings shows a front perspective view of a golf club head according to an exemplary embodiment of the present invention. [Figure 2] Figure 2 of the attached drawings shows a rear perspective view of a golf club head according to an exemplary embodiment of the present invention. [Figure 3] Figure 3 of the accompanying drawings shows a rear view of the hitting face according to an exemplary embodiment of the present invention. [Figure 4] Figure 4 of the accompanying drawings is a rear perspective view of the hitting face shown in Figure 3. [Figure 5] Figure 5 of the accompanying drawings is a bottom cross-sectional view of a golf club head having the hitting face shown in Figure 3. [Figure 6] Figure 6 of the accompanying drawings shows a heel-side cross-sectional view of a golf club head having the hitting face shown in Figure 3. [Figure 7] Figure 7 of the accompanying drawings is a rear perspective view of a hitting face according to an alternative embodiment of the present invention. [Figure 8] Figure 8 of the accompanying drawings is a rear perspective view of a hitting face according to an alternative embodiment of the present invention. [Figure 9] Figure 9 of the accompanying drawings is a rear perspective view of a hitting face according to an alternative embodiment of the present invention. [Figure 10] Figure 10 of the accompanying drawings is a rear view of a part of the hitting face shown in Figure 9.

Mode for Carrying Out the Invention

[0016] The following detailed description describes the presently contemplated best mode of carrying out the invention. Since the scope of the invention is best defined by the appended claims, the description should not be taken in a limiting sense, but rather is made for the purpose of illustrating the general principles of the invention.

[0017] Figures 1 and 2 of the attached drawings show a front and rear perspective view of a golf club head 100 according to an exemplary embodiment of the present invention. The golf club head 100 includes a toe portion 102, a heel portion 104 opposite the toe portion 102, a top line 106, a sole 108 opposite the top line 106, a hosel 110 located in the heel portion 104 configured to receive a shaft (not shown), and a striking face 112. The striking face 112 has a front surface 113 configured to strike a golf ball and a rear surface 114 opposite to the front surface 113, and the front surface 113 of the striking face 112 includes a plurality of scorelines 117 extending in the direction from heel to toe.

[0018] Figures 3 and 4 of the attached drawings show a rear view and a rear perspective view of the striking face 112 according to one embodiment. In the embodiment shown in Figures 3 and 4, the rear surface 114 of the striking face 112 includes a central region 114a that overlaps with at least a portion of the center of the striking face 112, a peripheral region 116 formed along the outer circumference of the rear surface 114, a first transition region 114b extending from the central region 114a to the peripheral region 116 toward the toe portion 102, a second transition region 114c extending from the central region 114a to the peripheral region 116 toward the heel portion 104, a third transition region 114d extending from the central region 114a to the peripheral region 116 toward the top line 106, and a fourth transition region 114e extending from the central region 114a to the peripheral region 116 toward the sole 108. The central region 114a is bounded by a central region periphery 114a1 that is located entirely radially inward of the peripheral region 116. The central region 114a has a height from the sole to the topline that increases in the toe direction.

[0019] The central region 114a has a constant thickness of less than 2.2 mm, where the thickness is the value measured from the front surface 113 of the striking face 112 to the rear surface 114 of the striking face 112. The central region 114a defines the maximum thickness of the striking face 112. The first transition region 114b has a thickness that decreases from the central region 114a to the peripheral region 116 and has a minimum thickness of less than 1.75 mm. The second transition region 114c has a thickness that decreases from the central region 114a to the peripheral region 116 and has a minimum thickness of less than 1.6 mm. The third transition region 114d has a thickness that decreases from the central region 114a to the peripheral region 116 and has a minimum thickness of less than 1.95 mm. The fourth transition region 114e has a thickness that decreases from the central region 114a to the peripheral region 116 and has a minimum thickness of less than 1.95 mm. The minimum thickness of the first transition region 114b is greater than the minimum thickness of the second transition region 114c. The minimum thickness of the third transition region 114d and the minimum thickness of the fourth transition region 114e are both greater than the minimum thickness of the first transition region 114b. The described thicknesses are important for distributing stress to achieve an increase in ball speed and a more consistent ball speed across the striking face 112 while ensuring high durability.

[0020] The striking face 112 may include a ledge 120 that forms at least a portion of the sole 108. The radiused portion 122 is formed between the rear surface 114 of the striking face 112 and the ledge 120. The radiused portion 122 includes a central radius region 122a, a toe-side radius region 122b located on the toe side of the central radius region 122a, and a heel-side radius region 122c located on the heel side of the central radius region 122a. The central radius region 122a defines a maximum radius of the radiused portion 122 of 1.5 mm to 2.5 mm. The toe-side radius region 122b has a radius that decreases from the central radius region 122a toward the toe portion 102. The toe-side radius region 122b has a minimum radius of less than 1.6 mm. The heel-side radius region 122c has a radius that decreases from the central radius region 122a toward the heel portion 104. The heel-side rounded area 122c has a minimum radius of less than 1.6 mm. The stated radius is important for normalizing the stress passing through the leading edge of the striking face 112 in order to improve performance and durability.

[0021] Figure 5 shows a bottom cross-sectional view of the golf club head 100, showing cross-sections passing through the center of the planes of the central region 114a, the first transition region 114b, and the second transition region 114c. The first transition region 114b has a constant taper from the maximum thickness at the periphery of the central region 114a1 to the minimum thickness at the peripheral region 116 adjacent to the toe portion 102. The constant taper of the first transition region 114b creates a first transition angle θ1 of 0.2° to 0.8° between the front surface 113 and the rear surface 114 of the striking face 112. The second transition region 114c has a constant taper from the maximum thickness at the periphery of the central region 114a1 to the minimum thickness at the peripheral region 116 adjacent to the heel portion 104. The constant taper of the second transition region 114c creates a second transition angle θ2 between the front surface 113 and the rear surface 114 of the striking face 112, which is larger than the first transition angle θ1. The second transition angle θ2 is between 0.6° and 1.2°.

[0022] Figure 6 shows a cross-sectional view of the heel side of the golf club head 100, showing cross-sections passing through the center of the planes of the central region 114a, the third transition region 114d, and the fourth transition region 114e. The third transition region 114d has a constant taper from the maximum thickness at the periphery 114a1 of the central region to the minimum thickness at the periphery 116 adjacent to the top line 106. The constant taper of the third transition region 114d generates a third transition angle θ3 of 3° to 8° between the front 113 and rear 114 of the striking face 112. The fourth transition region 114e has a constant taper from the maximum thickness at the periphery 114a1 of the central region to the minimum thickness at the periphery 116 adjacent to the sole 108. The constant taper of the fourth transition region 114e generates a fourth transition angle θ4 between the front 113 and rear 114 of the striking face 112, which is smaller than the third transition angle θ3. The fourth transition angle θ4 is between 1° and 3°.

[0023] Figure 7 shows a striking face 212 according to another embodiment of the present invention, which can be used with a golf club head 100. The striking face 212 has a front surface (not shown) configured to contact the ball and a rear surface 214 opposite to the front surface. The front surface of the striking face 212 includes a plurality of scorelines (not shown) extending in the direction from heel to toe. In the embodiment shown in Figure 7, the rear surface 214 of the striking face 212 includes a central region 214a that overlaps with at least a portion of the center of the face of the striking face 212. The rear surface 214 of the striking face 212 includes a peripheral region 216 formed along the outer circumference of the rear surface 214. A first transition region 214b extends from the central region 214a to a toe-side constant-thickness region 215b, and the toe-side constant-thickness region 215b extends from the first transition region 214b to the peripheral region 216 in the direction toward the toe portion 102. The second transition region 214c extends from the central region 214a to the heel-side constant thickness region 215c, and the heel-side constant thickness region 215c extends from the second transition region 214c to the peripheral region 216 in the direction toward the heel portion 104. The central region 214a extends from the peripheral region 216 of the sole 108 to the peripheral region 216 of the top line 106.

[0024] The central region 214a has a constant thickness of less than 2.2 mm, and the thickness is measured from the front of the striking face 212 to the rear of the striking face 212. The central region 214a defines the maximum thickness of the striking face 212. The first transition region 214b decreases in thickness from the central region 214a to the toe-side constant thickness region 215b and has a minimum thickness of less than 1.75 mm. The second transition region 214c decreases in thickness from the central region 214a to the heel-side constant thickness region 215c and has a minimum thickness of less than 1.65 mm. The minimum thickness of the first transition region 214b is greater than the minimum thickness of the second transition region 214c. The described thicknesses are important for distributing stress to ensure high durability while achieving increased and more consistent ball velocity across the striking face 212.

[0025] The striking face 212 may include a ledge 220 that forms at least a portion of the sole 108. The rounded portion 222 is formed between the rear surface 214 of the striking face 212 and the ledge 220. The rounded portion 222 includes a central rounded region 222a, a toe-side rounded region 222b located on the toe side of the central rounded region 222a, and a heel-side rounded region 222c located on the heel side of the central rounded region 222a. The central rounded region 222a defines a maximum radius of 1.5 mm to 2.5 mm. The toe-side rounded region 222b has a radius that decreases from the central rounded region 222a toward the toe portion 102. The toe-side rounded region 222b has a minimum radius of less than 1.6 mm. The heel-side rounded region 222c has a radius that decreases from the central rounded region 222a toward the heel portion 104. The heel-side rounded area 222c has a minimum radius of less than 1.6 mm. The stated radius is important for normalizing the stress passing through the leading edge of the striking face 212 in order to improve performance and durability.

[0026] Figure 8 shows a striking face 312 according to another embodiment of the present invention, which can be used with a golf club head 100. The striking face 312 has a front surface (not shown) configured to contact the ball and a rear surface 314 opposite to the front surface. The front surface of the striking face 312 includes a plurality of scorelines (not shown) extending in the direction from heel to toe. In the embodiment shown in Figure 8, the rear surface 314 of the striking face 312 includes a central region 314a that overlaps with at least a portion of the center of the face of the striking face 312. The rear surface 314 of the striking face 312 includes a peripheral region 316 formed along the outer circumference of the rear surface 314. A first transition region 314b extends from the central region 314a to the peripheral region 316 in the direction toward the toe portion 102. A second transition region 314c extends from the central region 314a to the peripheral region 316 in the direction toward the heel portion 104. The third transition region 314d extends from the central region 314a to the peripheral region 316 in the direction toward the sole 108. The central region 314a is bounded by the peripheral region 316 at the top line line 306 and by the U-shaped central region peripheral portion 314a1. The central region peripheral portion 314a1 is located throughout the radially inward portion of the peripheral region 316 in the toe portion 102, the heel portion 104, and the sole 108. The width of the central region 314a in the heel-to-toe direction increases in the top line direction.

[0027] The central region 314a has a constant thickness of less than 1.8 mm, and this thickness is measured from the front surface of the striking face 312 to the rear surface 312 of the striking face 314. The central region 314a defines the maximum thickness of the striking face 312. The first transition region 314b has a decreasing thickness from the central region 314a to the peripheral region 316, with a minimum thickness of less than 1.5 mm. The first transition region 314b may also have a decreasing thickness in the direction from the top line 106 to the sole 108. The second transition region 314c has a decreasing thickness from the central region 214a to the peripheral region 316, with a minimum thickness of less than 1.4 mm. The second transition region 314c may also have a decreasing thickness in the direction from the top line 106 to the sole 108. The third transition region 314d has a decreasing thickness from the central region 314a to the peripheral region 316, with a minimum thickness of less than 1.3 mm. The minimum thickness of the first transition region 314b is greater than the minimum thickness of the second transition region 314c and the minimum thickness of the third transition region 314d. The stated thicknesses are important for distributing stress in a way that ensures high durability while achieving increased and more consistent ball velocity across the striking face 312.

[0028] The striking face 312 may include a ledge 320 that forms at least a portion of the sole 108. The rounded portion 322 is formed between the rear surface 314 of the striking face 312 and the ledge 320. The rounded portion 322 includes a central rounded region 322a, a toe-side rounded region 322b located on the toe side of the central rounded region 322a, and a heel-side rounded region 322c located on the heel side of the central rounded region 322a. The central rounded region 322a defines a maximum radius of 1.5 mm to 2.5 mm. The toe-side rounded region 322b has a radius that decreases from the central rounded region 322a toward the toe portion 102. The toe-side rounded region 322b has a minimum radius of less than 1.6 mm. The heel-side rounded region 322c has a radius that decreases from the central rounded region 322a toward the heel portion 104. The heel-side rounded area 322c has a minimum radius of less than 1.6 mm. The stated radius is important for normalizing the stress passing through the leading edge of the striking face 312 in order to improve performance and durability.

[0029] Figure 9 shows a striking face 412 according to another embodiment of the present invention, which can be used with a golf club head 100. The striking face 412 has a front surface (not shown) configured to contact the ball and a rear surface 414 opposite the front surface. The front surface of the striking face 412 includes a plurality of scorelines (not shown) extending in the direction from heel to toe. In the embodiment shown in Figure 9, the rear surface 414 of the striking face 412 includes a central region 414a that overlaps with at least a portion of the geometric center of the striking face 412, a peripheral region 416 formed along the outer circumference of the rear surface 414, a first transition region 414b extending from the central region 414a to the peripheral region 416 toward the toe portion 102, a second transition region 414c extending from the central region 414a to the peripheral region 416 toward the heel portion 104, a third transition region 414d extending from the central region 414a to the peripheral region 416 toward the apex line 106, and a fourth transition region 414e extending from the central region 414a to the peripheral region 416 toward the sole 108. The central region 414a is bounded by a central region peripheral portion 414a1 located entirely radially inward of the peripheral region 416. The central region periphery 414a1 has a rounded shape.

[0030] The central region 414a has a constant thickness of less than 2.5 mm, and the thickness is measured from the front surface of the striking face 412 to the rear surface 414 of the striking face 412. The central region 414a defines the maximum thickness of the striking face 412. The first transition region 414b has a decreasing thickness from the central region 414a to the peripheral region 416, with a minimum thickness of less than 1.7 mm. The second transition region 414c has a decreasing thickness from the central region 414a to the peripheral region 416, with a minimum thickness of less than 1.7 mm. The third transition region 414d has a decreasing thickness from the central region 414a to the peripheral region 416, with a minimum thickness of less than 1.7 mm. The fourth transition region 414e has a decreasing thickness from the central region 414a to the peripheral region 416, with a minimum thickness of less than 1.7 mm. The peripheral region 416 defines the minimum thickness of the striking face 412. The described thickness is important for distributing stress in a way that ensures high durability while achieving increased and more consistent ball speed across the striking face 412.

[0031] In one embodiment of the striking face 412 shown in Figure 9, the first transition region 414b, the second transition region 414c, the third transition region 414d, and the fourth transition region 414e each have a concave shape relative to the rear surface 414. The concave shape has a greater tangent to the peripheral region 416 and a less tangent closer to the central region 414a. This allows for a greater degree of thinning of the striking face 412 than another linear transition from the central region 414a to the peripheral region 416. Furthermore, the concave shape reduces the mass of the striking face 412, which can then be used as any other mass in the golf club head 100, improving ball velocity performance across the striking face 412 and normalizing stress to improve durability. The scoreline projection 418 is defined as the region immediately surrounding the foremost degree of the scoreline, the furthest degree of the scoreline, the furthest degree of the scoreline, and the uppermost degree of the scoreline projected onto the rear surface 414 of the striking face 412. The peripheral region 416 may be defined as a region radially outward from the scoreline projection 418. In addition to defining the minimum thickness of the striking face 412, the peripheral region 416 may have a certain thickness. This allows the substantial area in front of the scoreline projection 418 to include the minimum thickness, providing further weight reduction while maintaining durability.

[0032] In another embodiment of the striking face 412 shown in Figure 9, the first transition region 414b has a convex shape relative to the rear surface 414, while the second transition region 414c, the third transition region 414d, and the fourth transition region 414e each have a concave shape relative to the rear surface 414. The concave shape has a greater tangent to the peripheral region 416 and a less tangent closer to the central region 414a. This allows for a greater degree of thinning of the striking face 412 than another linear transition from the central region 414a to the peripheral region 416. Furthermore, the concave shape reduces the mass of the striking face 412, which can then be used as arbitrary mass elsewhere on the golf club head 100, improving ball velocity performance across the striking face 412 and normalizing stress to improve durability. The convex shape of the first transition region 414b allows the thickness from the central region 414a to gradually decrease towards the toe portion 102, which helps normalize the stress on the striking face 412.

[0033] The striking face 412 may include a ledge 420 that forms at least a portion of the sole 108. The rounded portion 422 is formed between the rear surface 414 of the striking face 412 and the ledge 420. The rounded portion 422 includes a central rounded region 422a, a toe-side rounded region 422b located on the toe side of the central rounded region 422a, and a heel-side rounded region 422c located on the heel side of the central rounded region 422a. The central rounded region 422a defines a maximum radius of 1.5 mm to 2.5 mm. The toe-side rounded region 422b has a radius that decreases from the central rounded region 422a toward the toe portion 102. The toe-side rounded region 422b has a minimum radius of less than 1.6 mm. The heel-side rounded region 422c has a radius that decreases from the central rounded region 422a toward the heel portion 104. The heel-side rounded area 422c has a minimum radius of less than 1.6 mm. The stated radius is important for normalizing the stress passing through the leading edge of the striking face 412 in order to improve performance and durability.

[0034] Figure 10 shows a rear view of a portion of the impact face 412, focusing on the ledge 420. As shown in Figure 10, the ledge 420 includes a central ledge region 420a, a toe-side ledge region 420b located to the toe of the central ledge region 420a, and a heel-side ledge region 420c located to the heel of the central ledge region 420a. The central ledge region 420a has a height of 1.3 mm to 1.9 mm from the sole to the topline. The toe-side ledge region 420b has a height of 1.0 mm to 1.6 mm from the sole to the topline. The heel-side ledge region 420c has a height of 1.0 mm to 1.6 mm from the sole to the topline. The height of the central ledge region 420a is greater than the heights of the toe-side ledge region 420b and the heel-side ledge region 420c. This allows for stress normalization through the leading edge of the impact surface 412, improving performance and durability.

[0035] Except in the operational examples, or unless otherwise explicitly specified, all numerical ranges, quantities, values, and percentages in the aforementioned parts of this specification, such as quantities of material, moments of inertia, center of gravity, loft, draft, angles, various performance ratios, and others, can be interpreted as being preceded by the term "approximately," even if the word "approximately" is not explicitly indicated in relation to the value, quantity, or range. Therefore, unless explicitly stated otherwise, the numerical parameters described in the above specification and the appended claims are approximations that may vary depending on the desired properties to be obtained by the present invention. At a minimum, and not with the intention of limiting the application of the doctrine of equivalents to the claims, each numerical parameter should be interpreted at least in terms of the reported number of significant figures and by applying common rounding techniques.

[0036] Although the numerical ranges and parameters describing the broad scope of the present invention are approximations, the numerical values ​​described in specific examples are reported as accurately as possible. However, any numerical value inherently contains certain errors that inevitably arise from the standard deviation observed in each test measurement. Furthermore, where numerical ranges of various sizes are described in this disclosure, it is conceivable that any combination of these values, including the values ​​described, may be used.

[0037] Naturally, it should be understood that the foregoing relating to exemplary embodiments of the present invention may be modified without departing from the spirit and scope of the invention as set forth in the following claims.

Claims

1. It is a golf club head, The toe part, The heel portion on the opposite side of the toe portion, Top line and, The sole on the opposite side of the aforementioned top line, A hosel, positioned on the heel portion side and configured to receive the shaft, It comprises a striking face having a front surface configured to contact a golf ball and a rear surface opposite to the front surface, The front surface of the striking face includes a plurality of scorelines extending from the heel towards the toe, The rear surface of the striking face is A central region overlapping with at least a portion of the center of the aforementioned striking face, A peripheral region formed along the outer circumference of the rear surface of the striking face, A first transition region extending from the central region to the peripheral region toward the toe portion, A second transition region extending from the central region to the peripheral region toward the heel portion, A third transition region extending from the central region to the peripheral region in the direction toward the top line, It comprises a fourth transition region extending from the central region toward the sole toward the peripheral region, The central region has a constant thickness measured from the front surface of the striking face to the rear surface of the striking face, A golf club head in which the first, second, third, and fourth transition regions each decrease in thickness from the central region to the peripheral region.

2. The golf club head according to claim 1, wherein the central region has a height from the sole in the direction of the top line, and the height increases in the direction of the toe.

3. The golf club head according to claim 1, wherein the central region has a thickness of less than 2.2 mm.

4. The golf club head according to claim 3, wherein the first transition region has a minimum thickness of less than 1.75 mm, the second transition region has a minimum thickness of less than 1.6 mm, the third transition region has a minimum thickness of less than 1.95 mm, and the fourth transition region has a minimum thickness of less than 1.95 mm.

5. The golf club head according to claim 1, wherein the central region defines the maximum thickness of the striking face.

6. The golf club head according to claim 1, wherein the minimum thickness of the first transition region is greater than the minimum thickness of the second transition region.

7. The golf club head according to claim 6, wherein both the minimum thickness of the third transition region and the minimum thickness of the fourth transition region are greater than the minimum thickness of the first transition region.

8. A golf club head according to claim 1, wherein the first transition region has a constant taper that creates a first transition angle between the front surface of the striking face and the rear surface of the striking face, The second transition region has a constant taper that creates a second transition angle between the front surface of the striking face and the rear surface of the striking face. The third transition region has a constant taper that creates a third transition angle between the front surface of the striking face and the rear surface of the striking face. The fourth transition region has a constant taper that creates a fourth transition angle between the front surface of the striking face and the rear surface of the striking face. The second transition angle is greater than the first transition angle, A golf club head in which the fourth transition angle is smaller than the third transition angle.

9. A golf club head according to claim 8, wherein the first transition angle is 0.2° to 0.8°, The second transition angle is 0.6° to 1.2°, The third transition angle is 3° to 8°, A golf club head having a fourth transition angle of 1° to 3°.

10. A golf club head according to claim 9, wherein the striking face further includes a ledge that forms at least a portion of the sole, A rounded portion is formed between the rear surface of the striking face and the ledge. The aforementioned rounded portion, The central radius machining area and The tow-side radius machining region located on the tow side of the central radius machining region, The central radius machining region includes a heel-side radius machining region located on the heel side, The aforementioned central rounded machining region defines the maximum radius of the rounded portion between 1.5 mm and 2.5 mm. The toe-side radius machining region has a radius that decreases from the central radius machining region toward the toe portion. The heel-side radius machining region has a radius that decreases from the central radius machining region toward the heel portion. The tow-side radius machining region has a minimum radius of less than 1.6 mm. A golf club head having a minimum radius of less than 1.6 mm for the heel-side rounded processing area.

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