GOLF CLUB HEAD WITH VARIABLE THICKNESS FACE

Description

FIELD OF THE INVENTION

The present invention relates generally to an iron type golf club head having a striking face portion that has variable thickness. 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 which transitions to a thinner perimeter region. The central region of increased thickness is located near a face center of the striking face portion, and the perimeter region is located radially outward from the central region. The present invention also relates to the particular transition from the central region to the perimeter region.

BACKGROUND OF THE INVENTION

The design of golf club heads often requires the proper balance of the desire to maximize the performance of a golf club head together with the durability needs of a golf club head.

One of the areas where these diverging and counter acting forces manifest itself is in the design of the striking face of a golf club head. If a golf club designer wishes to maximize the coefficient of restitution of a golf club head, it would be easy for him or her to reduce the thickness of the striking face of that golf club head, leading to more flexibility of the striking face upon impact with a golf ball leading to further distance gains. However, as indicated earlier, the durability of a striking face that is too thin can often result in mechanical failures such as plastic deformation of the striking face, which is undesirable.

In order to address this issue, golf club designers have invented striking faces with variable thickness wherein the regions experiencing high stresses are thickened while the remainder of the striking face can have a reduced thickness to maximize performance. U.S. Pat. No. 6,368,234 to Galloway illustrates this concept by incorporating concentric elliptical regions of varying thickness into a striking plate of a metalwood type golf club head, located around a geometric center of the striking face where the golf ball is intended to impact the golf club.

Although maximizing distance is one of the main goals of designing for a metalwood type golf club head as illustrated in U.S. Pat. No. 6,368,234 to Galloway, the design of striking faces of iron type golf club heads can be more complicated because maximizing distance is not the main objective. Although distance in iron type golf club head is important, the main objective in designing an iron type golf club head is consistency of performance. Additionally, the challenge in designing an improved face design for an iron type golf club head resides in the shape and dimension of an iron type golf club head that creates a location of max deflection that is different from the general impact location of a golf club head. This separation of these two high stress points makes designing an improved striking face more difficult.

U.S. Pat. No. 6,746,343 to Yoneyama illustrates the utilization of a thick-walled portion in the back of the lower central part of the front face plate and multiple narrow ribs to radially extend from the thick-walled portion towards the upper and lateral peripheral parts of the front face plate as one way to incorporate a variable face thickness profile in an iron type golf club head.

U.S. Pat. No. 10,258,843 to Morales et al. illustrates one of the ways that a variable face thickness profile has in incorporated into an iron type golf club head wherein the striking face is supported by a looped rib to create a variable thickness profile.

These designs, although each having their own performance benefits, fail to take advantage of the unique shape of an iron type golf club head that has an impact location that is different from the geometric center of the striking face.

Hence it can be seen that there is a need in the industry for a new and improved design for the striking face portion of an iron type golf club head that provides more consistent ball speeds at impact locations across the striking face, is durable, and reduces overall weight of the striking face.

BRIEF SUMMARY OF THE INVENTION

In some aspects, the techniques described herein relate to a golf club head including: a toe portion; a heel portion opposite the toe portion; a topline; a sole opposite the topline; a hosel located at the heel portion configured to receive a shaft; and a striking face having a front surface configured to contact a golf ball and a rear surface opposite the front surface, wherein the front surface of the striking face includes a plurality of scorelines extending in a heel-to-toe direction, wherein the rear surface of the striking face includes: a central region overlapping at least a portion of a face center of the striking face; a perimeter region formed along an outer perimeter of the rear surface of the striking face; a first transition region extending from the central region to the perimeter region in a direction towards the toe portion; a second transition region extending from the central region to the perimeter region in a direction towards the heel portion; a third transition region extending from the central region to the perimeter region in a direction towards the topline; and a fourth transition region extending from the central region to the perimeter region in a direction towards the sole, 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 wherein the first transition region, the second transition region, the third transition region, and the fourth transition region each decrease in thickness from the central region towards the perimeter region.

In some aspects, the techniques described herein relate to a golf club head including: a toe portion; a heel portion opposite the toe portion; a topline; a sole opposite the topline; a hosel located at the heel portion configured to receive a shaft; and a striking face having a front surface configured to contact a golf ball and a rear surface opposite the front surface, wherein the front surface of the striking face includes a plurality of scorelines extending in a heel-to-toe direction, wherein the rear surface of the striking face includes: a central region overlapping at least a portion of a face center of the striking face; a perimeter region formed along an outer perimeter of the rear surface of the striking face; a first transition region extending from the central region to the perimeter region in a direction towards the toe portion; and a second transition region extending from the central region to the perimeter region in a direction towards 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 wherein the first transition region and the second transition region each decrease in thickness from the central region towards the perimeter region.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will be apparent from the following description of the invention as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.

FIG. 1 of the accompanying drawings shows a front perspective view of a golf club head in accordance with an exemplary embodiment of the present invention.

FIG. 2 of the accompanying drawings shows an rear perspective view of a golf club head in accordance with an exemplary embodiment of the present invention.

FIG. 3 of the accompanying drawings shows a rear view of a striking face in accordance with an exemplary embodiment of the present invention.

FIG. 4 of the accompanying drawings shows a rear perspective view of the striking face shown in FIG. 3.

FIG. 5 of the accompanying drawings shows a bottom cross-sectional view of a golf club head having the striking face shown in FIG. 3.

FIG. 6 of the accompanying drawings shows a heel side cross-sectional view of a golf club head having the striking face shown in FIG. 3.

FIG. 7 of the accompanying drawings shows a rear perspective view of a striking face in accordance with an alternative embodiment of the present invention.

FIG. 8 of the accompanying drawings shows a rear perspective view of a striking face in accordance with an alternative embodiment of the present invention.

FIG. 9 of the accompanying drawings shows a rear perspective view of a striking face in accordance with an alternative embodiment of the present invention.

FIG. 10 of the accompanying drawings shows a rear view of a portion of the striking face shown in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description describes the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

FIGS. 1 and 2 of the accompanying drawings show front perspective and rear perspective views of a golf club head 100 in accordance with 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 topline 106, a sole 108 opposite the topline 106, a hosel 110 located at 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 contact a golf ball and a rear surface 114 opposite the front surface 113. The front surface 113 of the striking face 112 includes a plurality of scorelines 117 extending in a heel-to-toe direction.

FIGS. 3 and 4 of the accompanying drawings show rear and rear perspective views of the striking face 112 in accordance with one embodiment. In the embodiment shown in FIGS. 3 and 4, the rear surface 114 of the striking face 112 includes a central region 114a which overlaps at least a portion of a face center of the striking face 112, a perimeter region 116 formed along an outer perimeter of the rear surface 114, a first transition region 114b extending from the central region 114a to the perimeter region 116 in a direction towards the toe portion 102, a second transition region 114c extending from the central region 114a to the perimeter region 116 in a direction towards the heel portion 104, a third transition region 114d extending from the central region 114a to the perimeter region 116 in a direction towards the topline 106, and a fourth transition region 114e extending from the central region 114a to the perimeter region 116 in a direction towards the sole 108. The central region 114a is bounded by a central region perimeter 114a1 which is located entirely radially inward of the perimeter region 116. The central region 114a has a height in a sole-to-topline direction that increases in a toeward direction.

The central region 114a has a constant thickness less than 2.2 mm, wherein the thickness is 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 a maximum thickness of the striking face 112. The first transition region 114b decreases in thickness from the central region 114a to the perimeter region 116 and has a minimum thickness less than 1.75 mm. The second transition region 114c decreases in thickness from the central region 114a to the perimeter region 116 and has a minimum thickness less than 1.6 mm. The third transition region 114d decreases in thickness from the central region 114a to the perimeter region 116 and has a minimum thickness less than 1.95 mm. The fourth transition region 114e decreases in thickness from the central region 114a to the perimeter region 116 and has a minimum thickness 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 thicknesses described are critical for achieving increased ball speed and more consistent ball speed across the striking face 112 while also distributing stress in such a way to ensure high durability.

The striking face 112 may include a ledge 120 forming at least a portion of the sole 108. A 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 radiused region 122a, a toeward radiused region 122b located toeward of the central radiused region 122a, and a heelward radiused region 122c located heelward of the central radiused region 122a. The central radiused region 122a defines a maximum radius of the radiused portion 122 between 1.5 mm and 2.5 mm. The toeward radiused region 122b has a decreasing radius from the central radiused region 122a toward the toe portion 102. The toeward radiused region 122b has a minimum radius less than 1.6 mm. The heelward radiused region 122c has a decreasing radius from the central radiused region 122a toward the heel portion 104. The heelward radiused region 122c has a minimum radius less than 1.6 mm. The radiuses described are critical for normalizing stress through the leading edge of the striking face 112 to improve performance and durability.

FIG. 5 shows a bottom cross-sectional view of the golf club head 100 showing a cross-section of the central region 114a, the first transition region 114b, and the second transition region 114c through the face center. The first transition region 114b has a constant taper from a maximum thickness at the central region perimeter 114a1 to a minimum thickness at the perimeter region 116 proximate the toe portion 102. The constant taper of the first transition region 114b creates a first transition angle θ₁ between the front surface 113 and the rear surface 114 of the striking face 112 that is between 0.2° and 0.8°. The second transition region 114c has a constant taper from a maximum thickness at the central region perimeter 114a1 to a minimum thickness at the perimeter region 116 proximate 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 that is greater than the first transition angle θ₁. The second transition angle θ₂ is between 0.6° and 1.2°.

FIG. 6 shows a heel side cross-sectional view of the golf club head 100 showing a cross-section of the central region 114a, the third transition region 114d, and the fourth transition region 114e through the face center. The third transition region 114d has a constant taper from a maximum thickness at the central region perimeter 114a1 to a minimum thickness at the perimeter region 116 proximate the topline 106. The constant taper of the third transition region 114d creates a third transition angle θ₃ between the front surface 113 and the rear surface 114 of the striking face 112 that is between 3° and 8°. The fourth transition region 114e has a constant taper from a maximum thickness at the central region perimeter 114a1 to a minimum thickness at the perimeter region 116 proximate the sole 108. The constant taper of the fourth transition region 114e creates a fourth transition angle θ₄ between the front surface 113 and the rear surface 114 of the striking face 112 that is less than the third transition angle θ₃. The fourth transition angle θ₄ is between 1° and 3°.

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

The central region 214a has a constant thickness less than 2.2 mm, wherein the thickness is measured from the front surface of the striking face 212 to the rear surface 214 of the striking face 212. The central region 214a defines a 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 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 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 thicknesses described are critical for achieving increased ball speed and more consistent ball speed across the striking face 212 while also distributing stress in such a way to ensure high durability.

The striking face 212 may include a ledge 220 forming at least a portion of the sole 108. A radiused portion 222 is formed between the rear surface 214 of the striking face 212 and the ledge 220. The radiused portion 222 includes a central radiused region 222a, a toeward radiused region 222b located toeward of the central radiused region 222a, and a heelward radiused region 222c located heelward of the central radiused region 222a. The central radiused region 222a defines a maximum radius between 1.5 mm and 2.5 mm. The toeward radiused region 222b has a decreasing radius from the central radiused region 222a toward the toe portion 102. The toeward radiused region 222b has a minimum radius less than 1.6 mm. The heelward radiused region 222c has a decreasing radius from the central radiused region 222a toward the heel portion 104. The heelward radiused region 222c has a minimum radius less than 1.6 mm. The radiuses described are critical for normalizing stress through the leading edge of the striking face 212 to improve performance and durability.

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

The central region 314a has a constant thickness less than 1.8 mm, wherein the thickness is measured from the front surface of the striking face 312 to the rear surface 314 of the striking face 312. The central region 314a defines a maximum thickness of the striking face 312. The first transition region 314b decreases in thickness from the central region 314a to the perimeter region 316 and has a minimum thickness less than 1.5 mm. The first transition region 314b may also decrease in thickness in a direction from the topline 106 towards the sole 108. The second transition region 314c decreases in thickness from the central region 214a to the perimeter region 316 and has a minimum thickness less than 1.4 mm. The second transition region 314c may also decrease in thickness in a direction from the topline 106 towards the sole 108. The third transition region 314d decreases in thickness from the central region 314a to the perimeter region 316 and has a minimum thickness 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 thicknesses described are critical for achieving increased ball speed and more consistent ball speed across the striking face 312 while also distributing stress in such a way to ensure high durability.

The striking face 312 may include a ledge 320 forming at least a portion of the sole 108. A radiused portion 322 is formed between the rear surface 314 of the striking face 312 and the ledge 320. The radiused portion 322 includes a central radiused region 322a, a toeward radiused region 322b located toeward of the central radiused region 322a, and a heelward radiused region 322c located heelward of the central radiused region 322a. The central radiused region 322a defines a maximum radius between 1.5 mm and 2.5 mm. The toeward radiused region 322b has a decreasing radius from the central radiused region 322a toward the toe portion 102. The toeward radiused region 322b has a minimum radius less than 1.6 mm. The heelward radiused region 322c has a decreasing radius from the central radiused region 322a toward the heel portion 104. The heelward radiused region 322c has a minimum radius less than 1.6 mm. The radiuses described are critical for normalizing stress through the leading edge of the striking face 312 to improve performance and durability.

FIG. 9 shows a striking face 412 according to another embodiment of the present invention which can be used with the golf club head 100. The striking face 412 has a front surface (not shown) configured to contact a golf 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 a heel-to-toe direction. In the embodiment shown in FIG. 9, the rear surface 414 of the striking face 412 includes a central region 414a which overlaps at least a portion of a geometric center of the striking face 412, a perimeter region 416 formed along an outer perimeter of the rear surface 414, a first transition region 414b extending from the central region 414a to the perimeter region 416 in a direction towards the toe portion 102, a second transition region 414c extending from the central region 414a to the perimeter region 416 in a direction towards the heel portion 104, a third transition region 414d extending from the central region 414a to the perimeter region 416 in a direction towards the topline 106, and a fourth transition region 414e extending from the central region 414a to the perimeter region 416 in a direction towards the sole 108. The central region 414a is bounded by a central region perimeter 414a1 which is located entirely radially inward of the perimeter region 416. The central region perimeter 414a1 has a rounded shape.

The central region 414a has a constant thickness less than 2.5 mm, wherein 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 a maximum thickness of the striking face 412. The first transition region 414b decreases in thickness from the central region 414a to the perimeter region 416 and has a minimum thickness less than 1.7 mm. The second transition region 414c decreases in thickness from the central region 414a to the perimeter region 416 and has a minimum thickness less than 1.7 mm. The third transition region 414d decreases in thickness from the central region 414a to the perimeter region 416 and has a minimum thickness less than 1.7 mm. The fourth transition region 414e decreases in thickness from the central region 414a to the perimeter region 416 and has a minimum thickness less than 1.7 mm. The perimeter region 416 defines a minimum thickness of the striking face 412. The thicknesses described are critical for achieving increased ball speed and more consistent ball speed across the striking face 412 while also distributing stress in such a way to ensure high durability.

In one embodiment of the striking face 412 shown in FIG. 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 shapes have a greater tangency toward the perimeter region 416 and less tangency proximate the central region 414a. This allows a larger amount of the striking face 412 to be thinned than in an otherwise linear transition from the central region 414a to the perimeter region 416. Furthermore, the concave shapes decrease the mass of the striking face 412 to use as discretionary mass elsewhere in the golf club head 100, improve ball speed performance across the striking face 412, and normalize stress to improve durability. A scoreline projection 418 is defined as the area immediately surrounding a toewardmost extent of the scorelines, a solewardmost extent of the scorelines, a heelwardmost extent of the scorelines, and a toplinemost extent of the scorelines which is projected onto the rear surface 414 of the striking face 412. The perimeter region 416 may be defined as the area radially outward from the scoreline projection 418. Along with defining the minimum thickness of the striking face 412, the perimeter region 416 may have a constant thickness. This allows a substantial area toeward of the scoreline projection 418 to include the minimum thickness which provides additional weight savings while maintaining durability.

In another embodiment of the striking face 412 shown in FIG. 9, the first transition region 414b has a convex shape relative to the rear surface 414, and 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 shapes have a greater tangency toward the perimeter region 416 and less tangency proximate the central region 414a. This allows a larger amount of the striking face 412 to be thinned than in an otherwise linear transition from the central region 414a to the perimeter region 416. Furthermore, the concave shapes decrease the mass of the striking face 412 to use as discretionary mass elsewhere in the golf club head 100, improve ball speed performance across the striking face 412, and normalize stress to improve durability. The convex shape of the first transition region 414b allows the thickness from the central region 414a to initially become thinner more gradually towards the toe portion 102 to help normalize stress in the striking face 412.

The striking face 412 may include a ledge 420 forming at least a portion of the sole 108. A radiused portion 422 is formed between the rear surface 414 of the striking face 412 and the ledge 420. The radiused portion 422 includes a central radiused region 422a, a toeward radiused region 422b located toeward of the central radiused region 422a, and a heelward radiused region 422c located heelward of the central radiused region 422a. The central radiused region 422a defines a maximum radius between 1.5 mm and 2.5 mm. The toeward radiused region 422b has a decreasing radius from the central radiused region 422a toward the toe portion 102. The toeward radiused region 422b has a minimum radius less than 1.6 mm. The heelward radiused region 422c has a decreasing radius from the central radiused region 422a toward the heel portion 104. The heelward radiused region 422c has a minimum radius less than 1.6 mm. The radiuses described are critical for normalizing stress through the leading edge of the striking face 412 to improve performance and durability.

FIG. 10 shows a rear view of a portion of the striking face 412 with a focus on the ledge 420. As shown in FIG. 10, the ledge 420 comprises a central ledge region 420a, a toeward ledge region 420b located toeward of the central ledge region 420a, and a heelward ledge region 420c located heelward of the central ledge region 420a. The central ledge region 420a has a height in a sole-to-topline direction between 1.3 mm and 1.9 mm. The toeward ledge region 420b has a height in a sole-to-topline direction between 1.0 mm and 1.6 mm. The heelward ledge region 420c has a height in a sole-to-topline direction between 1.0 mm and 1.6 mm. The height of the central ledge region 420a is greater than the height of the toeward ledge region 420b and the height of the heelward ledge region 420c. This allows the stresses to be normalized through the leading edge of the striking face 412 which improves performance and durability.

Other than in the operating example, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moment of inertias, center of gravity locations, loft, draft angles, various performance ratios, and others in the aforementioned portions of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear in the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the above specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.

It should be understood, of course, that the foregoing relates to exemplary embodiments of the present invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.