Patent ID: 12201880

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part of the present disclosure. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and form part of this disclosure. For example, a system or device may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such a system or device may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. Alterations and further and further modifications of inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moments of inertias, center of gravity locations, loft and draft angles, and others in the following portion of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following 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.

In describing the present technology, the following terminology may have been used: The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to an item includes reference to one or more items. The term “plurality” refers to two or more of an item. The term “substantially” means that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. A plurality of items may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same lists solely based on their presentation in a common group without indications to the contrary. Furthermore, where the terms “and” and “or” are used in conjunction with a list of items, they are to be interpreted broadly, in that any one or more of the listed items may be used alone or in combination with other listed items. The term “alternatively” refers to a selection of one of two or more alternatives, and is not intended to limit the selection of only those listed alternative or to only one of the listed alternatives at a time, unless the context clearly indicated otherwise.

Features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the illustrated features serve to explain certain principles of the present disclosure.

Embodiments described herein generally relate to golf clubs having an improved striking face. More specifically, some embodiments relate to golf club head constructions which normalize the characteristic time across a large portion of the striking face.

In describing the present technology herein, certain features that are described in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination.

Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure as well as the principle and novel features disclosed herein.

FIG.1of the accompanying drawings shows a perspective view of a golf club head100in accordance with an exemplary embodiment of the present invention. The golf club head100shown inFIG.1may generally have a striking face portion102located at a frontal portion of the golf club head100that is adapted to strike a golf ball (not shown) and a body portion104that is connected to an aft portion of the striking face portion102. The body portion104of the golf club head100may generally include a crown portion106, a sole portion108, a skirt portion110, a hosel portion112, a toe portion114, and a heel portion116. Although not externally visible, the striking face portion102of the golf club head100may generally have a unique internal geometry that varies the thickness of the striking face portion102in a manner described in greater detail below.

FIG.2of the accompanying drawings showing a frontal view of a golf club head200provides an easy methodology to define the necessary cross-sectional views which allow for closer examination of the internal geometry of the striking face portion102. More specifically,FIG.2shows a cross-sectional line A-A′ spanning vertically in a crown to sole direction across a point214on the striking face202and cross-sectional line B-B′ spanning horizontally in a heel to toe direction across the point214. Point214is the projection on the outer surface of the striking face202of the center of the variable thickness geometry of the striking face202. According to various embodiments of the present invention, the center of the variable thickness geometry of the striking face202may coincide with a geometric center of the striking face202, a projection of the center of gravity of the golf club head200along the neutral axis on the striking face202, or at any point on the striking face. It is worthwhile to mention here that the neutral axis may generally be described as an axis passing through the center of the striking face202and normal to a loft plane of the striking face202.

FIG.3of the accompanying drawings shows a rear view of a golf club head300that has been cut open to illustrate the rear portion of the striking face302. Striking face302may generally include a central region320, a transition region322, and a perimeter region324.

At this time it is worthwhile to note that it is within the scope of this invention that the striking face302may either be formed simultaneously with, independently from, or partially independently from the other components of the golf club head300.

In the present exemplary embodiment, the central region320, the transition region322, and the perimeter region324may be elements of a striking face insert that is welded or otherwise separately attached to the front portion of the golf club head300.

The central region320may generally be substantially circular in shape and have a width w1of less than about 6.0 mm, more preferably less than about 5.0 mm, and most preferably less than about 4.0 mm. Alternatively, the central region320may be substantially elliptical or may have a shape that more closely corresponds to the overall shape of the striking face insert.

The transition region322surrounds the central region320. As the striking face302is not a perfect circle, the distance from the outer perimeter of the central region320to the outer perimeter of the transition region322varies based on the shape of the central region320and the transition region322.

As shown in this current exemplary embodiment, the transition region322may include a constant slope sub-region322athat surrounds the central region320and a blend sub-region322bthat surrounds the constant slope sub-region322a. The constant slope sub-region322ais referred to in this manner because the slope along a surface of the striking face302may be constant along any radius extending from an outer perimeter of the central region320to an outer perimeter of the constant slope sub-region322a. This feature is unique in that the slope along any given radius is substantially constant, but slopes between different radii vary based upon the unique geometry of the striking face302. Given this unique geometry, the overall shape of the constant slope sub-region322amay be that of a frustum where the base perimeter of the frustum is the outer perimeter of the constant slope sub-region322aand the upper perimeter of the frustum is the outer perimeter of the central region320.

Alternatively, in embodiments where the transition region322does not include a blend sub-region322b, the overall shape of the transition region322may be that of a frustum where the base perimeter of the frustum is the outer perimeter of transition region322and the upper perimeter of the frustum is the outer perimeter of the central region320.

As shown in this current exemplary embodiment, a crown transition length TCcof the constant slope sub-region322ais a vertical distance toward the crown between the outer perimeter of the central region320and the outer perimeter of the constant slope sub-region322aand may be about 4.0 mm to about 10.5 mm, more preferably about 5.0 mm to about 9.5 mm, and most preferably about 6.5 mm to about 8.5 mm.

A total crown transition length TCtof the transition region322is a vertical distance toward the crown between the outer perimeter of the central region320and the outer perimeter of transition region322and may be about 10.0 mm to about 18.0 mm, more preferably about 11.0 mm to about 17.0 mm, and most preferably about 12.5 mm to about 15.0 mm.

A sole transition length TScof the constant slope sub-region322ais a vertical distance toward the sole between the outer perimeter of the central region320and the outer perimeter of the constant slope sub-region322aand may be about 8.0 mm to about 17.0 mm, preferably about 10.0 mm to about 16.0 mm, and most preferably about 11.0 mm to about 15.0 mm.

A total sole transition length TStof the transition region322is a vertical distance toward the sole between the outer perimeter of the central region320and the outer perimeter of the transition region322and may be about 12.0 mm to about 20.0 mm, preferably about 13.0 mm to about 19.0 mm, and most preferably about 14.0 mm to about 18.0 mm.

The toe transition length TTcof the constant slope sub-region322ais a horizontal distance toward the toe between the outer perimeter of the central region320and the outer perimeter of the constant slope sub-region322aand may be about 18.0 mm to about 37.0 mm, more preferably about 20.0 mm to about 35 mm, and most preferably about 22.0 mm to about 33.0 mm.

The total toe transition length TTtof the transition region322is a horizontal distance toward the toe between the outer perimeter of the central region320and the outer perimeter of the transition region322and may be about 24.0 mm to about 39.0 mm, more preferably about 26.0 mm to about 37.0 mm, and most preferably about 28.0 mm to about 35.0 mm.

The heel transition length THcof the constant slope sub-region322ais a horizontal distance toward the heel between the outer perimeter of the central region320and the outer perimeter of the constant slope sub-region322aand may be about 18.0 mm to about 35.0 mm, preferable about 21.0 mm to about 33.0 mm, and most preferably about 23.0 mm to about 30 mm.

The total heel transition length THtof the transition region322is a horizontal distance toward the heel between the outer perimeter of the central region320and the outer perimeter of the transition region322and may be about 25.0 mm to about 35.0 mm, preferably about 27.0 mm to about 33.0 mm, and most preferably about 28.5 mm to about 31.5 mm.

In accordance with an exemplary embodiment as shown inFIG.3, the thickness of the constant slope transition sub-region322adecreases radially from an outer perimeter of the central region320to an outer perimeter of the constant slope transition sub-region322a. The thickness of the blend sub-region322bfurther decreases radially from the outer perimeter of the constant slope sub-region322ato the outer perimeter of the blend sub-region322b. These features are described in more detail below with reference toFIGS.4-7.

The perimeter region324surrounds the transition region322and may include one or more sub-regions of constant thickness. As shown in this current exemplary embodiment, the perimeter region324may include a first perimeter sub-region324aand a second perimeter sub-region324b.

When the perimeter region324includes more than one region of constant thickness, the perimeter region324may also include transition perimeter sub-regions324cthat transition in thickness between the constant thicknesses of the perimeter region324.

Another aspect of the present invention may be illuminated when consideringFIG.3. As shown inFIG.3, the central region320represents a small percentage of the total projected area of the striking face302, while the transition region322represents a larger percentage of the total projected area of the striking face302. In the discussion below, all projected areas are measured by projecting the striking face302on to a loft plane that is tangential to a geometric center of the striking face302.

In this current exemplary embodiment, the projected area of the central region322may be between about 6 mm2to about 25 mm2, more preferably between about 8 mm2to about 22 mm2, and most preferably between about 10 mm2to about 20 mm2.

The projected area of the constant slope sub-region322ais between about 1000 mm2to about 1600 mm2, most preferably between about 1100 mm2to about 1500 mm2, and most preferably between about 1200 mm2to about 1400 mm2. It is noted that this measurement excludes the projected area of the central region320.

The projected area of the transition region322is between about 1500 mm2to about 2200 mm2, most preferably between about 1600 mm2to about 2100 mm2, and most preferably between about 1700 mm2to about 2000 mm2. It is noted that this measurement excludes the projected area of the central region320.

The projected area of the perimeter region324is between about between about 300 mm2to about 1500 mm2, most preferably between about 500 mm2to about 1250 mm2, and most preferably between about 600 mm2to about 950 mm2. It is noted that this measurement excludes the projected area of the central region320and the transition region322.

The combined projected area of the central region320, the transition region322, and the perimeter region324is between about 2000 mm2to about 3150 mm2, preferably about 2200 mm2to about 2950 mm2, and most preferably about 2400 mm2to about 2850 mm2.

The total projected area of the striking face302is between about 2900 mm2to about 4200 mm2, preferably about 3100 mm2to about 4100 mm2, and most preferably about 3300 mm2to about 3950 mm2.

In accordance with an exemplary embodiment of the present invention, it is desirable for the projected area of the central region320to account for between about 0.1 percent to about 1.0 percent of the total projected area of the striking face302, preferably between about 0.2 percent to about 0.7 percent of the total projected area of the striking face302, and most preferably between about 0.3 percent and about 0.6 percent of the total projected area of the striking face302. A projected area of the central region320in this range is sufficiently large to form a CT hotspot at or near the center of the striking face302, while being small enough that the transition region322accounts for a large percentage of the total projected area of the striking face302.

More specifically, from the above, it can be concluded that the ratio of the projected area of the transition region322relative to the projected area of the striking face302is important. It is desirable for the projected area of the transition region322to account for between about 40.0 percent to about 65.0 percent of the total projected area of the striking face302, preferably between about 45.0 percent to about 60.0 percent of the total projected area of the striking face302, and most preferably between about 48.0 percent to about 57.0 percent of the total projected area of the striking face302.

The ratio of the projected area of the constant slope sub-region322ato the total projected area of the striking face302is also important. It is desirable for the projected area of the constant slope sub-region322ato be between about 27.0 percent to about 48.0 percent of the total projected area of the striking face302, preferably between about 30.0 percent to about 45.0 percent of the total projected area of the striking face302, and most preferably between about 33.0 percent to about 42.0 percent of the total projected area of the striking face302.

Another way to explore this relationship is to compare the projected area of the central region320to that of the transition region322. It is desirable for the projected area of the central region320to be between 0.4 percent and 2.0 percent of the projected area of the transition region322, preferably between 0.5 percent and 1.5 percent of the projected area of the transition region322, and most preferably between about 0.6 percent and about 1.1 percent of the projected area of the transition region322.

The ratio of the projected area of the central region320to that of the constant slope sub-region322ais also important. It is desirable for the projected area of the central region320to be between 0.5 percent and 3.0 percent of the projected area of the constant slope sub-region322a, preferably between 0.8 percent and 2.0 percent of the projected area of the constant slope sub-region322a, and most preferably between about 1.0 percent and about 1.5 percent of the projected area of the constant slope sub-region322a.

Projected areas of the transition region322and the constant slope sub-region322ain these ranges provide a striking face302that exhibits CT measurements that are more uniform at locations extending away from the center of the striking face302. As shown inFIG.14and discussed in greater detail below, a striking face in accordance with an exemplary embodiment of the presently claimed invention exhibits less variance in CT values measured across the face than other known striking faces.

FIG.4of the accompanying drawings shows a cross-sectional view of the golf club head200shown inFIG.2taken along cross-sectional line A-A′. This cross-sectional view of the golf club head400shown inFIG.4allows the variable thickness geometry behind the striking face402to be shown. More specifically, the striking face402may generally have a central region420, a transition region422, and a perimeter region including a first perimeter sub-region424aand a second perimeter sub-region424b.

The central region420, as shown in this current exemplary embodiment, may generally have a constant thickness d1of greater than about 3.00 mm, more preferably greater than about 3.30 mm, and most preferably greater than about 3.50 mm.

The first perimeter sub-region424aforms a portion of the perimeter region proximate the crown and has a constant thickness d2of less than about 3.1 mm, more preferably less than about 2.9 mm, and most preferably less than about 2.7 mm.

The second perimeter region424bforms a portion of the perimeter region424proximate the heel, toe, and sole and has a thickness d3of less than about 3.0 mm, more preferably less than about 2.8 mm, and most preferably less than about 2.6 mm.

The transition region422includes a constant slope sub-region422aand a blend sub-region422b. In accordance with an exemplary embodiment as shown inFIG.4, a thickness of the striking face402reduces in a substantially linear manner within the constant slope sub-region422afrom the central region420to the blend sub-region422b. The blend sub-region422btransitions in thickness between the outer perimeter of the constant slope sub-region422ato the first perimeter sub-region424aand the second perimeter sub-region424b. As described in greater detail below, as a result of this smooth transition, CT is more uniform across the entirety of the striking face402and hotspots are greatly reduced away from the center of the striking face402.

FIG.5of the accompanying drawings shows a cross-sectional view of the golf club head200shown inFIG.2taken along cross-sectional line B-B′. This cross-sectional view of the golf club head500shown inFIG.5allows the variable thickness geometry behind the striking face502to be shown. As above, according to this exemplary embodiment, the central region520is centered about a point514. The transition region522surrounds the central region520, and the thickness of the striking face502may generally gradually decrease moving further away from the central region520. The central region520has a constant thickness d1, and the perimeter region has one or more constant thicknesses that are less than the thickness d1. In the current view, the only portion of the perimeter region that is visible is the second perimeter sub-region524bhaving a thickness of d3.

To better illustrate the differences between thicknesses of the various regions of an inventive striking face in accordance with an embodiment of the present invention,FIG.6depicts an exaggerated cross-sectional view along the line A-A′ andFIG.7depicts an exaggerated cross-sectional view along the line B-B′.

Referring toFIG.6, the striking face602is shown without roll to better illustrate relative thickness, and therefore the striking surface of the striking face602appears flat. It is noted that this flattened geometry is also within the scope of the present invention and may be implemented in a golf club having a substantially flat face, such as an iron-type golf club.

Moreover, the scale of the thicknesses has been exaggerated to better show the geometry of the striking face602. In general, the thickness of the transition region622, as shown in this current exemplary embodiment, may generally linearly decrease from the central region620of the striking face602to the first perimeter sub-region624a. According to the exemplary embodiment of the present invention shown inFIG.6, the transition region622does not include a blend sub-region.

The central region620has a constant thickness d1, and the perimeter region has one or more constant thicknesses that are less than the thickness d1. As shown in this current exemplary embodiment, the perimeter region includes the first perimeter sub-region624ahaving a constant thickness d2and a second perimeter sub-region624bhaving a constant thickness d3.

In the exemplary embodiment depicted inFIG.6, the sole transition length TS is greater than the crown transition length TC and a slope TSslopealong the sole transition length TS is less than a slope TCslopealong the crown transition length TC. Slope is defined as the change in face thickness for a given transition length divided by the transition length. In accordance with embodiments of the present invention, the transition lengths may include just the constant slope sub-region, or may include the blend sub-region when a blend sub-region is incorporated into the striking face.

The slope TSslopealong the sole transition length TS may be between about 0.05 and about 0.14, preferably between about 0.06 and about 0.13, and most preferably between about 0.07 and about 0.12. TSslopeis equal to the thickness d1of the central region620minus the thickness d3of the second perimeter sub-region624bdivided by the sole transition length TS.

The slope TCslopealong the crown transition length TC may be between about 0.08 and about 0.15, preferably between about 0.09 and about 0.14, and most preferably between about 0.07 and about 0.13. TCslopeis equal to the thickness d1of the central region620minus the thickness d2of the first perimeter sub-region624adivided by the crown transition length TC.

Referring toFIG.7, the striking face702is shown without bulge to better illustrate relative thickness, and therefore the striking surface of the striking face702appears flat. It is noted that this flattened geometry is also within the scope of the present invention and may be applied to a golf club having a substantially flat face, such as an iron-type golf club.

Moreover, the scale of the thicknesses has been exaggerated to better show the shape of the striking face702. In general, the transition region722, as shown in this current exemplary embodiment, may generally linearly decrease from the central region720of the striking face702to the second perimeter sub-region724b. According to the exemplary embodiment of the present invention shown inFIG.7, the transition region722does not include a blend sub-region.

The central region720has a constant thickness d1, and the perimeter region has one or more constant thicknesses that are less than the thickness d1. As shown in this current exemplary embodiment, the perimeter region includes the second perimeter sub-region724bhaving a constant thickness d3.

The slope TTslopealong the toe transition length TT may be between about 0.03 and about 0.09, preferably between about 0.03 and about 0.07, and most preferably between about 0.04 and about 0.07. TTslopeis equal to the thickness d1of the central region720minus the thickness d3of the second perimeter sub-region724bdivided by the toe transition length TT.

The slope THslopealong the heel transition length TH may be between about 0.03 and about 0.09, preferably between about 0.03 and about 0.08, and most preferably between about 0.04 and about 0.07. THslopeis equal to the thickness d1of the central region720minus the thickness d3of the second perimeter sub-region724bdivided by the heel transition length TH.

An evaluation of the different slopes mentioned above provides a very important relationship between the projected areas and slopes about the central region and transition region of the inventive striking face. When considering the striking face602as depicted inFIG.6, a specific ratio of the average of the slopes TCslopeof the crown transition length TC and TSslopeof the sole transition length TS multiplied by the ratio of the projected area of the transition region622divided by the projected area of the central region620may generally be greater than about 6.0, more preferably greater than about 9.0, and most preferably greater than about 11.0; which is referred to as the Slope Area Ratio. The Slope Area Ratio is defined here by Equation (1) below:

Ta⁢r⁢e⁢aCa⁢r⁢e⁢a×T⁢Cs⁢l⁢o⁢p⁢e+T⁢Ss⁢l⁢o⁢p⁢e2=⁢Slope⁢Area⁢Ratio(Eq.1)

Where Tarearepresents the projected area of the transition region; Carearepresents the projected area of the central region; TCsloperepresents the slope along the crown transition length TC; and TSsloperepresents the slope along the sole transition length TS.

Referring toFIG.8of the accompanying drawings, a rear view of a golf club head800in accordance with an alternative embodiment of the present invention that has been cut open to illustrate the rear portion of the striking face802is provided. According to an exemplary alternative embodiment, striking face802may generally include central region820, transition region822, and perimeter region824. As shown inFIG.8, the perimeter region824includes only a single constant thickness portion and the transition region824does not include a blend sub-region. However, like golf club head300inFIG.3above, the transition region822still decreases in thickness radially from the central region820to the perimeter region824.

While the striking face802shares similarities with the striking face302, hereinbelow dimensions in which the striking face802differs from the striking face302are highlighted. Dimensions that fall within the ranges outlined above with regard to striking face302are omitted.

A total crown transition length TCtof the transition region822is a vertical distance toward the crown between the outer perimeter of the central region820and the outer perimeter of transition region822and may be about 6.0 mm to about 15.0 mm, more preferably about 7.0 mm to about 13.0 mm, and most preferably about 8.0 mm to about 11.0 mm.

A total sole transition length TStof the transition region822is a vertical distance toward the sole between the outer perimeter of the central region820and the outer perimeter of the transition region822and may be about 6.0 mm to about 15.0 mm, preferably about 7.0 mm to about 13.0 mm, and most preferably about 8.0 mm to about 11.0 mm.

The total toe transition length TTtof the transition region822is a horizontal distance toward the toe between the outer perimeter of the central region820and the outer perimeter of the transition region822and may be about 11.0 mm to about 20.0 mm, more preferably about 12.0 mm to about 18.0 mm, and most preferably about 13.0 mm to about 16.0 mm.

The total heel transition length THtof the transition region822is a horizontal distance toward the heel between the outer perimeter of the central region820and the outer perimeter of the transition region822and may be about 14.0 mm to about 23.0 mm, preferably about 15.0 mm to about 21.0 mm, and most preferably about 16.0 mm to about 19.0 mm.

The projected area of the transition region822is between about 300 mm2and about 1200 mm2, preferably between about 400 mm2and about 1100 mm2, and most preferably between about 500 mm2and about 1000 mm2. It is noted that this measurement excludes the projected area of the central region820.

The projected area of the perimeter region824is between about between about 1600 mm2to about 2700 mm2, most preferably between about 1800 mm2to about 2500 mm2, and most preferably between about 2000 mm2to about 2300 mm2. It is noted that this measurement excludes the projected area of the central region820and the transition region822.

In the exemplary embodiment shown inFIG.8, the projected area of the transition region822accounts for between about 11.0 percent to about 24.0 percent of the total projected area of the striking face802, preferably between about 13.0 percent to about 22.0 percent of the total projected area of the striking face802, and most preferably between about 15.0 percent to about 20.0 percent of the total projected area of the striking face802.

Another way to explore this relationship is to compare the projected area of the central region820to that of the transition region822. It is desirable for the projected area of the central region820to be between 0.5 percent and 3.5 percent of the projected area of the transition region822, preferably between 1.0 percent and 3.0 percent of the projected area of the transition region822, and most preferably between about 1.5 percent and about 2.5 percent of the projected area of the transition region822.

The perimeter region824has a substantially uniform thickness of between about 2.5 mm and about 3.1 mm, preferably between about 2.6 mm and about 3.0 mm, and most preferably between about 2.7 mm and 2.9 mm.

The slopes along the various transition lengths of striking face insert802are determined in the same manner as described above with regard toFIGS.6-7. Therefore, reference may be made toFIGS.6-7when considering the slopes of striking face802.

The slope TSslopealong the sole transition length TStmay be between about 0.07 and about 0.14, preferably between about 0.08 and about 0.13, and most preferably between about 0.10 and about 0.11. TSslopeis equal to the thickness of the central region820minus the thickness of the perimeter region824divided by the sole transition length TSt.

The slope TCslopealong the crown transition length TCtmay be between about 0.07 and about 0.14, preferably between about 0.08 and about 0.13, and most preferably between about 0.10 and about 0.11. TCslopeis equal to the thickness of the central region820minus the thickness of the perimeter region824divided by the crown transition length TCt.

The slope TTslopealong the toe transition length TTtmay be between about 0.04 and about 0.10, preferably between about 0.05 and about 0.09, and most preferably between about 0.06 and about 0.08. TTslopeis equal to the thickness of the central region820minus the thickness of the perimeter region824divided by the toe transition length TTt.

The slope THslopealong the heel transition length THtmay be between about 0.03 and about 0.09, preferably between about 0.04 and about 0.08, and most preferably between about 0.05 and about 0.07. THslopeis equal to the thickness of the central region820minus the thickness of the perimeter region824divided by the heel transition length THt.

The Slope Area Ratio of striking face802is greater than about 3, preferably greater than about 4, and most preferably greater than about 5.

Referring now toFIG.9of the accompanying drawings, a rear view of a golf club head900in accordance with an alternative embodiment of the present invention that has been cut open to illustrate the rear portion of the striking face902is provided. According to an exemplary alternative embodiment, striking face902may generally include central region920, transition region922, and perimeter region924. As shown inFIG.9, the perimeter region924may include a first perimeter sub-region924ahaving a substantially constant thickness and a second perimeter sub-region924bhaving a different substantially constant thickness. Preferably the thickness of the first perimeter sub-region924ais greater than a thickness of the second perimeter sub-region924b. Much like golf club head300inFIG.3above, the transition region1022decreases in thickness radially from the central region1020to the perimeter region1024.

The dimensions of striking face902fall within the ranges outlined above with regard to striking face302.

Referring now toFIG.10of the accompanying drawings, a rear view of a golf club head1000in accordance with an alternative embodiment of the present invention that has been cut open to illustrate the rear portion of the striking face1002is provided. According to an exemplary alternative embodiment, striking face1002may generally include central region1020, transition region1022, and perimeter region1024. As shown inFIG.10, the perimeter region1024may include a first perimeter sub-region1024ahaving a substantially constant thickness and a second perimeter sub-region1024bhaving a different substantially constant thickness. Preferably the thickness of the first perimeter sub-region1024ais greater than a thickness of the second perimeter sub-region1024b. Much like golf club head300inFIG.3above, the transition region1022decreases in thickness radially from the central region1020to the perimeter region1024.

The dimensions of striking face1002fall within the ranges outlined above with regard to striking face302.

FIG.11shows exaggerated cross-sectional views along either A-A′ or B-B′ of three alternative constructions of a striking face. The views shown inFIG.11are symmetrical, therefore no distinction is made between crown, sole, heel, or toe.

As shown (a), the cross-sectional shape of a transition region1122amay have a thickness that reduces in a linear manner from the central region1120toward the perimeter region1124. As shown in (b), the cross-sectional shape of a transition region1122bmay have a thickness that reduces in a sinusoidal, logarithmic, or gaussian manner. As shown in (c), the cross-sectional shape of a transition region1122cmay have a thickness that reduces in an arc-like manner. In each of these various embodiments, the central region1120has a constant thickness and the transition regions1122a,1122b,1122creduce in thickness from the central region1120along a transition length TL to the perimeter region1124.

FIG.14shows a normalized CT map of a striking face insert in accordance with an exemplary embodiment of the present invention, and illustrates numerous ways that the inventive striking face improves upon Prior Art striking faces, such as those represented byFIGS.12-13. The CT map ofFIG.14has been normalized against the same predetermined threshold value as inFIGS.12-13. It is noted that the predetermined threshold is within the CT limit set by the governing bodies.

Looking toFIG.14, the CT map for a striking face in accordance with an exemplary embodiment of the present invention exhibits normalized CT values that are at or below the predetermined threshold, with the highest normalized CT values being equal to the predetermined threshold and located just 2 mm heelward and 2 mm crownward of the center of the striking face.

Looking deeper atFIG.14shows that not only does the center of the face exhibit the highest CT values, but also that there is a smaller variance across the striking face as the standard deviation across the striking face depicted inFIG.14is 4.6 μs and the average normalized CT value is 7.3 μs below the predetermined threshold.

Moreover, 71 percent of the measured data points are within 10 μs of the predetermined threshold without exceeding the predetermined threshold, while none of the measured data points exceed the predetermined threshold. Normalized CT values within this range constitute CT values that correlate with substantial ball speed while still being conforming.

It is also helpful to consider how the average normalized CT values change as a distance from the center of the striking face increases. For the striking face ofFIG.14, the average normalized CT value within +/−2 mm vertically and +/−2 mm horizontally of the center of the striking face is 2.3 μs below the predetermined threshold, the average normalized CT value within +/−4 mm vertically and +/−4 mm horizontally of the center of the striking face is 3.3 μs below the predetermined threshold, and the normalized average CT value within +/−8 mm vertically and +/−8 mm horizontally of the center of the striking face is 4.4 μs below the predetermined threshold.

FIG.14shows every point on the striking face within +/−20 mm horizontally from the center of the striking face, within 8 mm toward the sole from the center of the striking face, and within 10 mm toward the crown from the center of the striking face has a CT value less than the predetermined threshold CT value.FIG.14shows every point on the striking face within +/−4 mm horizontally from the center of the striking face and within +/−4 mm vertically from the center of the striking face has a CT value within 6 μs of the predetermined threshold CT value.FIG.14shows every point on the striking face within +/−6 mm horizontally from the center of the striking face and within +/−6 mm vertically from the center of the striking face has a CT value within 8 μs of the predetermined threshold CT value.FIG.14also shows every point on the striking face within +/−8 mm horizontally from the center of the striking face and within +/−8 mm vertically from the center of the striking face has a CT value within 11 μs of the predetermined threshold CT value.

This data tells us that a striking face in accordance with an exemplary embodiment represents a marked improvement upon the Prior Art striking face represented byFIGS.12-13. A striking face in accordance with an exemplary embodiment of the present invention not only exhibits a centralized CT hotspot, but also a higher average normalized CT in areas surrounding the center of the striking face and a lower standard deviation across the striking face.

That means that the exemplary striking face exhibits high CT values not only at the center of the striking face, but across the entirety of the striking face. Moreover, as the exemplary striking face features a reduced standard deviation, the exemplary striking face yields a more uniform CT map that minimizes the likelihood of any portion of the striking face being deemed non-conforming.

Therefore, the exemplary striking face has obvious benefits in that it can be with designed with a face center having CT measurements closer to the limits set by the governing bodies with reduced possibility of exceeding said limits at any portion of said striking face. Moreover, a more uniform CT map such as illustrated by the inventive striking face ensures that ball speeds will be maximized over a larger percentage of the striking face.

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.