JP7351870B2 - Improved hitting face for golf club heads - Google Patents

Description

TECHNICAL FIELD This invention relates generally to improved hitting faces for golf club heads. More specifically, the invention provides one or more thicker central regions located near one or more "areas of excess performance" on the striking face, thinner regions located around the periphery of the striking face. The present invention relates to a striking face having a peripheral portion and a transition region that transitions from each of the one or more thickened central regions to the thinned peripheral portion.

The game of golf, like other sports, is notable for the performance of highly skilled professional athletes who almost defy what we often perceive to be the limits of human performance. There is. For example, in the game of basketball, it is rumored that Dr. James Naismith set the height of the basket at 10 feet because he thought this was too high for humans to dunk a basketball. Despite the fact that basketball dunks are now commonly performed, and despite the increased performance of athletes who have achieved previously unimaginable feats, the game of basketball has rarely Not changed.

Another example of professional athletes achieving amazing feats over time can be seen by one of the most basic measures of athletic performance: the 100-meter race. The current world record holder for the 100m race, and generally considered the fastest man in the world, is Usain Bolt, who ran 9.58 seconds in 2009. Just 10 years earlier, in 1999, Maurice Greene's world record for the 100 meters was 9.79 seconds. Finally, not that long ago, Carl Lewis set the 100-meter world record in 1987 with a time of 9.93 seconds. Looking back, Bob Hayes set a world record of 10.06 seconds in 1964.

The game of golf, on the other hand, has taken a very different path towards today's modern game. The game of golf, which is controlled by a governing body, has placed constraints on the abilities of athletes by limiting the performance of the equipment used to play the game. Golf governing bodies indirectly use information such as golf ball size and weight, golf ball coefficient of restitution (COR), golf club size and volume, golf club COR (and contact time [CT] developed by the USGA). ), the moment of inertia (MOI) of the golf club head, and more recently the dimensions of the scoreline, which place many limitations on game performance. These limitations all serve the purpose of limiting the performance of the golf equipment and indirectly the performance of the game itself.

In order to comply with these requirements, golf club designers have attempted to design golf clubs within the parameters of governing organizations. In one early example, U.S. Patent No. 8,221,260 (Stites et al.) shows a wood-type golf club head that includes a body, heel, toe, crown, sole, and a weighted rear portion of the club. Achieve a moment of inertia of at least 5,000 g-cm ² about a vertical axis passing through the center of gravity. This patent seeks to design a golf club that complies with USGA limits for maximum moment of inertia without exceeding the limits.

US Pat. No. 7,331,877 (Yamaguchi et al.) provides an example of a golf club with the point of maximum elasticity of the head located above the center of the hitting face according to the pendulum test determined by the USGA. This patent attempts to design a golf club that complies with USGA CT limits and volume requirements.

Figures 15a and 15b of the accompanying drawings show an analysis of two striking face portions of two prior art golf club heads according to existing approaches to striking face design. FIG. 15a shows the results of an analysis of a conventional striking face portion of a golf club head with a variable face thickness profile. Although this page may display a large number of numbers, this graph is normalized with the excessive performance limit set to zero. Therefore, if we examine this graph closely, there are a number of areas on the left and right sides of the graph that exceed this overperformance limit, indicating that this design is not only suboptimal, but could also be considered nonconforming by golf's governing body. It turns out that there is a gender. FIG. 15b shows that although the existing methodology to address the problem regarding areas of excess performance is to thicken the part of the face that contains excess performance, this methodology also This negatively impacts the performance of the golf club head across the face, making this solution less than desirable.

Therefore, based on the above, there is a need to continually improve the performance of golf club heads while remaining within the regulations provided by the governing bodies of the game.

U.S. Patent No. 8,221,260 U.S. Patent No. 7,331,877

One aspect of the invention is a golf club head, the golf club head having a perimeter defined by a striking face perimeter shape, a striking face portion positioned at a forward portion of the golf club head; and a rear body portion located behind the striking face portion in the rear portion of the club head. The striking face portion further includes a first region of excess performance forming a first peripheral shape and a first layer of increased thickness located on an interior surface of the striking face portion; a first layer of increased thickness, the perimeter of which is defined by the first perimeter shape; a second region of excess performance forming a second perimeter shape; a second layer of increased thickness located on an interior surface of the first layer, the second layer of increased thickness having a perimeter defined by the second perimeter shape; The striking face circumferential shape is different from the first circumferential shape, the second circumferential shape is different from the first circumferential shape, the second circumferential shape is different from the striking face circumferential shape, and the A transition region between the striking face portion, the first layer of increased thickness, and the second layer of increased thickness has a smooth blended portion.

Another aspect of the invention is a golf club head, the golf club head having a perimeter defined by a striking face perimeter shape, a striking face portion positioned at a forward portion of the golf club head; and a rear body portion located behind the striking face portion in the rear portion of the club head. The striking face portion includes a thickened central region having a first thickness, a transition region having a second thickness, and a thinned peripheral region having a third thickness. and the first thickness is greater than the second thickness, and the second thickness is greater than the third thickness. The striking face portion has a near-zero CT variance average of greater than about -3.5, and the CT variance average is:
It is expressed by the formula: CT variance average=average of CT values within a central 6 mm square.

Another aspect of the invention is a method of determining a posterior profile of a golf club striking face, the method comprising the steps of: providing a striking face portion having a substantially uniform thickness; and determining performance values across the striking face portion. identifying one or more regions of overperformance; and identifying one or more first surrounding shapes of the first region of overperformance. have The method further includes the steps of: applying a first layer having a perimeter defined by the first perimeter shape; and increasing the thickness of the one or more thicknesses. reanalyzing the striking face portion including the first layer with increased performance to determine a performance value across the striking face portion; re-identifying one or more second regions of excess performance; re-identifying one or more second surrounding shapes of the second region of excess performance. The method further includes the steps of: adding one or more second layers of increased thickness having a perimeter defined by the first perimeter shape; The transition between the first layer of increased thickness and the second layer of increased thickness is smoothed to form a smooth blend.

Another aspect of the invention is a golf club head having a strength-to-hardness ratio of greater than about 6.0 ksi/HRC, wherein the strength-to-hardness ratio is:
It is defined as (UTS of hitting face portion 102−UTS of main body portion 104)/(hardness of hitting face portion 102−hardness of main body portion 104)=hardness-to-strength ratio.

Another aspect of the invention is a golf club head having a MOR ratio greater than about 1.25;
The above MOR ratio is
It is defined as (MOR of hitting face portion 102)/(MOR of main body portion 104)=MOR ratio.

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

The foregoing and other features and advantages of the invention will become 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, explain the principles of the invention and further serve to enable those skilled in the relevant art to make and use the invention.

FIG. 1 of the accompanying drawings shows a perspective view of a golf club head in accordance with an exemplary embodiment of the invention. FIG. 2 of the accompanying drawings shows a front view of a golf club head in accordance with an exemplary embodiment of the invention. FIG. 3 of the accompanying drawings shows a cross-sectional view of a golf club head according to an exemplary embodiment of the invention taken along cross-section line 3-3' shown in FIG. FIG. 4 of the accompanying drawings shows a cross-sectional view of a golf club head according to an exemplary embodiment of the invention taken along cross-section line 4-4' shown in FIG. Figure 5a of the accompanying drawings shows a cutaway rear view of a striking face portion used in the methodology for designing a golf club head according to the present invention. Figure 5b of the accompanying drawings shows an analysis of the striking face portion shown in Figure 5a for areas of excessive performance. FIG. 6a of the accompanying drawings shows a cutaway rear view of the striking face portion shown in FIG. 5a modified to address the area of excessive performance identified in FIG. 5b. FIG. 6b of the accompanying drawings shows an analysis of the striking face portion shown in FIG. 6a for areas of excessive performance. FIG. 7a of the accompanying drawings shows a cutaway rear view of the striking face portion shown in FIG. 6a modified to address the area of excessive performance identified in FIG. 6b. Figure 7b of the accompanying drawings shows an analysis of the striking face portion shown in Figure 7a for areas of excessive performance. FIG. 8a of the accompanying drawings shows a cutaway rear view of the striking face portion shown in FIG. 7a modified to address the area of excessive performance identified in FIG. 7b. FIG. 8b of the accompanying drawings shows an analysis of the striking face portion shown in FIG. 8a for areas of excessive performance. FIG. 9 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an exemplary embodiment with smoothed transitions between the various layers. FIG. 10 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an alternative embodiment of the invention. FIG. 11 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an alternative embodiment of the invention. FIG. 12 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an alternative embodiment of the invention. FIG. 13 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an alternative embodiment of the invention. FIG. 14 of the accompanying drawings shows a cutaway rear view of a striking face portion according to an alternative embodiment of the invention. FIG. 15a of the accompanying drawings shows a chart analyzing the performance of the striking face portion of a prior art golf club head. FIG. 15b of the accompanying drawings shows a chart analyzing the performance of the striking face portion of other prior art golf club heads. FIG. 15c of the accompanying drawings shows a chart analyzing the performance of the striking face portion of a golf club head according to the present invention.

Detailed description of the invention

The detailed description that follows sets forth the best mode presently contemplated for carrying out the invention. This description is not to be construed in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, as the scope of the invention is best defined by the appended claims.

Various features of the invention are described below, each of which can be employed independently of one another or in combination with other features. However, a single inventive feature may not address some, all, or only one of the issues discussed above. Furthermore, one or more of the issues described above may not be fully addressed by any of the features described below.

FIG. 1 of the accompanying drawings shows a perspective view of a golf club head 100 according to an exemplary embodiment of the invention. In this exemplary embodiment of the invention, golf club head 100 can be further separated into a striking face portion 102 that includes a face insert 103 and a rear body portion 104. Here, the "separation" between the striking face portion 102 and the rear body portion 104 need not include any physically identifying characteristic, but rather that the "separation" between the striking face portion 102 and the rear body portion 104 meet the criteria described below. Note that it is further defined by The striking face portion 102 may generally refer to the front portion of the golf club head 100 having a substantially flat surface (bulges and rolls are considered substantially flat for purposes of this discussion). (which may form a slight curvature), whereas rear body portion 104 refers to any portion of golf club head 100 behind striking face portion 102 .

Note that one of the most interesting components of this invention is the face insert 103 itself, especially compared to the rest of the rear body portion 104. The unique shapes of the various striking faces 102 are shown in detail, and to accomplish this, the face inserts 103 themselves may generally be made from a titanium material that has unique properties.

The face insert 103 of the golf club head 100 according to this exemplary embodiment of the invention may be generally made from a titanium material having high strength. In this embodiment of the invention, ATI425® is the preferred material, but without departing from the scope and content of this invention, Ti-17, TIMET Other high strength titaniums such as 54, Ti-9, TIMET 639, VL-Ti, KS ELF, SP-700 can all be used. High strength values referred to in this invention may generally refer to the ultimate tensile strength (UTS) of the material rather than the yield strength. This is because elastic deformation of the striking face portion 102 is often desirable to produce more performance. However, it should be noted that in alternative embodiments of this invention, the yield strength of the material is also considered. Further, before discussing the number of UTS of striking face materials, it is necessary to recognize that there are important differences in the UTS of the material in its natural mill annealed state compared to when processed to its formed state. Unless otherwise specified, when referring to UTS, it specifically refers to UTS in its molded state, which is the state relevant to the actual performance of golf club head 100 when used with striking face portion 102.

Now that some potential ambiguities have been addressed, we can move on to addressing the actual strength values of the materials used for face insert 103. The face insert 103 of the striking face portion 102 of the golf club head 100, according to this preferred embodiment of the invention, has a UTS molding condition of greater than about 140 ksi, more preferably greater than about 145 ksi, and most preferably greater than about 150 ksi. It is good to have Although less relevant to this invention, note that the UTS of the face insert 103 material in its mill annealed condition may generally be greater than about 150 ksi, more preferably greater than about 155 ksi, and most preferably greater than about 158 ksi. is meaningful.

In addition to the UTS of the face insert 103 discussed above, another important feature of this high strength material is its relatively low hardness. Again, the hardness of the material is different in its natural mill annealed state compared to when processed into a molded state. As before, we are interested in the material in its formed state. The strength of the face insert 103 in the molded state may generally be less than 40 HRC, more preferably less than about 38 HRC, and most preferably less than about 36 HRC. Although less relevant to this invention, it remains to be noted that the UTS of the face insert 103 material in its mill annealed condition may generally be less than about 41 HRC, more preferably less than about 39 HRC, and most preferably less than about 37 HRC. Not worth it.

Finally, another important characteristic of the material used for the face insert 103 of the striking face portion 102 is the Modulus of Resilience (MOR). MOR is defined by the following equation (1).
MOR=(yield strength) ² /2×(Young's modulus) Formula (1)
Again, because the face material undergoes so many transformations to transition from its natural mill annealed state compared to when it is in its final molded state, the changes in the material within the golf club head 100 Focus on molding conditions that reproduce actual performance. The face insert 103 material, in its formed state, may generally have a MOR greater than about 3.50 MPA, more preferably greater than about 3.75 MPA, and most preferably greater than about 4.0 MPA. Although less relevant to this invention, the MOR of the face insert 103 material in the mill annealed state is generally greater than about 4.0 MPA, more preferably greater than about 4.25 MPA, and most preferably about 4.0 MPA. It is significant to note that it may be greater than 5 MPa.

It should be noted that although the inherent properties of the stronger materials used for the face insert 103 of the striking face portion are an important factor in achieving the performance of current golf club heads, the performance advantages of this invention are It is important to realize that what is produced is the relative UTS, hardness, and MOR compared to the material used for the body portion. Although both the face insert 103 and the rear body portion 104 of the striking face portion 102 are made of titanium, the relative differences between the components allow the two components to work synergistically to improve the performance of this invention. can be done. Therefore, in order to establish baseline material properties for the body portion, it is necessary to first identify one such material that is common in forming the rear body portion 104 of the golf club head 100. Various materials like Ti-8Al-1V-1Mo-1, Ti-6-4, Ti-5Al-1Sn-1Zr-1V-0.8Mo, Ti-3Al-2.5Sn, and Ti-3Al-2V This preferred embodiment of the invention employs a Ti-8Al-1V-1Mo type material for the chassis, although any other material may be selected. However, all of the materials described may be used, along with other types of titanium materials, without departing from the scope and content of this invention, as long as they include the material properties outlined in the following paragraphs.

Generally speaking, Ti-8Al-1V-1Mo may generally have a UTS of about 132 ksi, a hardness of about 34.55 HRC, and a MOR of about 2.75 MPa. Since the body portion of the golf club head is generally not heat treated, there is no difference in the material in its natural state when compared to the composition of the golf club head 100. Now that the material properties of standard materials used in the chassis have been identified, it is time to return to the features that are important for achieving a synergistic relationship of the face insert 103 of the striking face portion 102 to the rear body portion 104. I can do it. A golf club head 102 according to the present invention quantifies the difference in UTS between the striking face portion 102 and the rear body portion 104 as the ratio of the difference in hardness between the striking face portion 102 and the rear body portion 104. It's good. In other words, the golf club head 100 can be said to achieve a strength-to-hardness ratio of greater than 6.0 ksi/HRC, more preferably greater than 11 ksi/HRC, and most preferably greater than 16 ksi/HRC. The strength to hardness ratio is defined by the following equation (2).
(UTS of hitting face portion 102 - UTS of main body portion 104)/(hardness of hitting face portion 102 - hardness of main body portion 104) = hardness-to-strength ratio Formula (2)

Although the aforementioned hardness-to-strength ratios can clearly capture the synergistic relationship between the different types of titanium materials used for the face insert 103 of the striking face portion 102 and the rear body portion 104, the face of the striking face portion 102 The MOR relationship between insert 103 and rear body portion 104 is not considered. This relationship forms a MOR ratio, and the golf club head 100 of the present invention has a MOR ratio greater than about 1.25, more preferably greater than about 1.35, and most preferably greater than about 1.45. The MOR ratio is defined by the following equation (3).
(MOR of hitting face portion 102)/(MOR of main body portion 104) = MOR ratio Formula (3)

FIG. 2 of the accompanying drawings shows a front view of a golf club head 200 in accordance with an exemplary embodiment of the invention. The front view of the golf club head 200 allows cross-sectional lines 3-3' and 4-4' to be more clearly shown, thereby allowing the cross-sectional view of the golf club head 200 to be more clearly shown. Section line 3-3' is a vertical line oriented from the crown of the golf club head toward the sole through the face center 203. On the other hand, cross-sectional line 4-4' is oriented in the heel-to-toe direction and passes through the face center 203. 3 and 4 below provide actual cross-sectional views of a golf club head 200 showing an improved striking face according to the present invention. FIG. 2 of the accompanying drawings, in addition to providing reference to a cross-sectional view of golf club head 200, illustrates a coordinate system 201 that will govern any discussion related to the orientation of golf club head 200 for the remainder of the discussion. There is. For this patent, the x-axis refers to an axis oriented in a heel-to-toe direction, with the positive axis oriented toward the heel. For this patent, the y-axis refers to the axis directed from the crown to the sole, with the positive axis directed toward the crown. Finally, for this patent, the z-axis refers to the front-to-back oriented axis, with the positive axis oriented toward the front of the golf club head.

FIG. 3 of the accompanying drawings depicts a cross-sectional view of a golf club head 300 in accordance with an exemplary embodiment of the invention. In this cross-sectional view, the golf club head can be seen to have a striking face portion 302 located at the front of the golf club head 300 and a rear rear body portion 304 located at the rear and attached to the striking face portion 302. . This cross-sectional view helps identify some of the key features of the improved striking face portion 302, which is further comprised of a thickened central region 306, a transition region 308, and a thinned peripheral region 310; Each circumferentially surrounds the preceding region. Alternatively, the transition region includes a first region of excess performance having a border similar to transition region 308 and a second region of excess performance having a border similar to thickened central region 306. You can say that. The details of the "excessive performance area" are explained in detail in the following figures.

In this exemplary embodiment of the invention, the thickened central region 306 is generally between about 3.2 mm and about 3.8 mm, more preferably between about 3.4 mm and about 3.6 mm, and most preferably. may have a thickness d1 of approximately 3.5 mm. The thinned peripheral region 310 according to this embodiment of the invention generally has a thickness of about 2.4 mm to about 3.0 mm, more preferably about 2.6 mm to about 2.8 mm, and most preferably about 2.7 mm. d2. The transition region 308 in this example gradually decreases in thickness from d1 to d2 to complete the transition. Although FIG. 3 only shows a cross-sectional view of the striking face portion 302 in a crown-to-sole orientation, the same type of transition occurs in a heel-to-toe direction, as shown in FIG. 4.

FIG. 4 of the accompanying drawings shows a cross-sectional view of a golf club head 400 according to an exemplary embodiment of the invention, taken along section line 4-4' shown in FIG. In this cross-sectional view shown in FIG. 4, the golf club head 400 has a striking face portion 402 located at the front of the golf club head 400 and a rearward striking face portion 402 located behind the striking face portion 402 at the rear portion of the golf club head 400. It can be seen that the main body portion 404 is still mainly composed of the main body portion 404. This improved hitting face portion 402 achieves a profile in a heel-to-toe orientation similar to the crown-to-sole orientation shown in FIG. The golf club head 400 has a thickened central region 406, a transition region 408, and a thinned peripheral region 410. Here, the thickened central region 406 and the thinned peripheral region 410 have the same thicknesses d1 and d2 as outlined in FIG. 3, and these measurements apply here as well.

5a-9 illustrate in detail the methodology used to realize the improved striking face portion 402 of the present invention of a golf club head 400 according to the present invention, the details of which shed more light on the design process. . More specifically, Figures 5a-9 show that improvements with variable face thickness can be achieved by focusing on the baseline face design and identifying areas of excess performance two or more times until there are no areas of excess performance. Describe the methodology used to achieve a unique striking face design.

Referring now to FIG. 5a, it can be seen that the design process begins with a striking face portion 502 consisting of a striking face insert 503 attached to a central portion of the striking face portion 502. This rear cutaway view of the golf club head 500 (not shown) shows the rear surface of the striking face portion 502 in more detail, and the cutaway view allows the inner surface of the striking face portion 502 to be more clearly shown. In FIG. 5a, it is the projected face perimeter 512 of the golf striking face portion 502 that the back surface of the hitting face portion shown here allows for identification. This projected face perimeter 512 is shown in Figure 5a, in which it is drawn with thick, dark lines, and certain portions of the projected face perimeter 512 that are not visible from this figure are depicted with dashed lines in the sole hosel area. Depicted using: Projected face perimeter 512 may have a striking face perimeter shape that is important in defining the improved striking face according to the present invention. Here, the projected face circumference 512 is a projection of the circumference of the striking face portion 502 taken at an angle perpendicular to the ground with only the xy axes, as shown in the coordinate system 201 shown in FIG. It is important to keep this in mind. Finally, the projected face perimeter 512 shown here is generally defined as the boundary at which the striking face portion 502 ceases to be substantially flat on the outer front surface of the striking face portion 502, which is shown in FIG. 5a. resulting in a surrounding shape.

A projected striking face perimeter 512 having a striking face perimeter shape is defined above, wherein a method for determining an improved striking face of a golf club head analyzes a striking face portion 502 having a substantially flat rear surface. Starting from this, the thickness is approximately 2.7 mm, which creates a striking face portion 502 with a completely uniform thickness as shown in Figure 5a. The analysis performed here is a determination of the performance of the striking face portion 502 to determine areas of excessive performance. As it relates to the golf industry, determining the performance of the striking face portion 502 generally relates to coefficient of restitution (COR), contact time (CT), and/or stress distribution, any of these numbers being disclosed in this invention. adopted in this analysis without departing from its scope and content. The performance of the striking face portion 502, whether it is COR, CT, or stress distribution, is determined by finite element analysis software, actual measurements on a golf club head, or other methods that determine the performance of the striking face portion 502. The performance was simulated via the method without departing from the scope and content of this invention.

Figure 5b of the accompanying drawings shows the results of a performance analysis of the striking face portion 502 shown in Figure 5a. FIG. 5b shows different areas of performance of the striking face portion 502 showing different performance results. The different shades of gray shown here in Figure 5b indicate the different performance achieved across the face at the distances outlined by the x- and y-axis labels. The lightest shades of gray indicate areas of poor performance, and the darkest shades of gray indicate areas of high performance. The first outer region 522 here represents the region with the lowest performance in the striking face portion 502 according to the previous determination. The second outer region 524 surrounded by the first outer region 522 generally achieves higher performance than the first outer region 522. A third outer region 526 surrounded by a second outer region 524 generally achieves higher performance than the second outer region 524. A fourth outer region 528 surrounded by a third outer region 526 generally achieves higher performance than the third outer region 526. Finally, the central region 530 surrounded by the fourth outer region 528 generally achieves the best performance, which is even higher than the fourth outer region 528. The region of excess performance, determined when performance exceeds a predetermined limit, is the central region 530 in this example.

In the present exemplary embodiment of this invention, the criterion for determining the region of excess performance is chosen to be anywhere where the CT exceeds the USGACT limit of 239 μs. In an alternative embodiment of the invention, if such a design is desired, overperformance can be set in the CT measurements, including even the tolerance of the USGACT limit at 257 μs. However, this CT-based criterion can be modified to higher or lower numbers as needed without departing from the scope and content of this invention. Additionally, alternative criteria for determining areas of excessive performance, such as COR or stress, may also be used and their limitations may be determined according to the needs of the designer without departing from the scope and content of this invention. It's okay to change.

Once the central region 530 is determined to be an area of excess performance, the perimeter shape of the central region 530 is determined and used to create layers of increased thickness for the next step in the design process. The surrounding shape of is determined. Alternatively, once a first region of excess performance having a first circumferential shape is determined based on the central region 530, a first layer of increased thickness is added to an inner surface of the striking face portion. The perimeter of the layer with increased thickness is defined by the initial perimeter shape.

Figure 6a of the accompanying drawings shows the next stage in the design process, in which a first layer 613 of increased thickness is added to the striking face portion 502 of Figure 5a to create this new striking face portion 602. to address the problems associated with the areas of excessive performance in the striking face portion 502 previously identified. In this embodiment of the invention, the increased thickness first layer 613 is generally about 0.3 mm thicker than the baseline thickness of the striking face portion 502, which is greater than the increased thickness first layer 613. 613 means that the total thickness is about 3.0 mm. Referring to FIG. 6a in conjunction with FIG. 5b, FIG. 5b shows that the first layer 613 of increased thickness has a perimeter whose perimeter shape 614 is defined by the region of excess performance shown in FIG. 5b. It is necessary to confirm the previous discussion that the peripheral shape of the central region 530 is the same as the one shown in FIG. It is worth noting here that FIG. 5b is a front view of the face and FIG. 6 is a rear view of the face, so the image correlation here is a 180 degree inversion of each other.

Recognize here that the first perimeter shape 614 is completely different from the shape of the face perimeter 512 (shown in Figure 5a) since the area of excess performance is not directly correlated with the shape of the perimeter region. This is very important. This is important to recognize, since prior art logic dictates that the area of excess performance, especially in a plate of constant thickness, is a direct offset of the shape of the face perimeter 512 (shown in Figure 5a). It is a characteristic. Through analysis and testing, this invention has shown that the optimal perimeter shape of the first region of over-thickness 613 is determined based on a prior analysis protocol, rather than a direct offset of the perimeter shape of the region of overperformance. It was decided that it should be based on actual analysis.

While conventional wisdom may stop the analysis and design of improved hitting faces here, this invention recognizes that good design is never achieved without verifying the results of the improvements. Therefore, further analysis for areas of excessive performance can be performed with this new striking face portion 602. Figure 6b of the accompanying drawings shows the results of an analysis of a striking face portion 602 incorporating an increased thickness first layer 613. A closer examination of Figure 6b shows that it has very similar components to those shown in Figure 5b, but with a different shape. Figure 6b shows a first outer region 622 with the lowest performance, a second outer region 624 with slightly higher performance, a third outer region 626 with even slightly higher performance, and a fourth outer region 626 with even higher performance. 628, and finally a central region 630 with a region of excess performance. The thresholds for determining areas of excess performance are generally the same thresholds outlined by the previous steps of the analysis, but higher or lower thresholds may be used without departing from the scope and content of this invention. It may be a lower threshold.

Similar to the design process outlined earlier, the perimeter and peripheral geometry of the central region 630, which corresponds to areas of excess performance, was captured and used to implement and improve the striking face portion 602, with increased thickness A second layer 715 (shown later in FIG. 7a) is added on top of the first layer 613 of increased thickness. Compared to the first increased thickness layer 613, the increased thickness of the increased thickness layer 715 is approximately 0.3 mm thicker, such that the overall thickness of this portion of the striking face portion 702 is approximately It is 3.3 mm. FIG. 7 a of the accompanying drawings shows a striking face portion 702 having a second layer 715 of increased thickness having a periphery having a second periphery shape 716 . Again, the shape and configuration of the increased thickness second layer 715 corresponds to the central region 630 identified in the previous analysis performed on the striking face portion 602. In other words, once a second region of excess performance is determined based on the central region 630 and having a second peripheral shape, the second layer of increased thickness is the same as the first layer of increased thickness. where the second layer of increased thickness has a perimeter defined by the second perimeter shape.

Again, it is important to recognize that the second perimeter shape 716, like the first perimeter shape 614, is completely different from the face perimeter shape 512 (shown in FIG. 5a). This is because the striking face portion 602 is not directly related to either the face perimeter shape 512 or the first perimeter 614 shape.

FIG. 7b shows an analysis when the striking face portion 702 additionally includes both a first layer of increased thickness 613 and a second layer of increased thickness 715 to address areas of improved performance. Show the results. As seen in Figure 7b, a first outer region 722 with the lowest performance, a second outer region 724 with slightly higher performance, a third outer region 726 with even slightly higher performance, and even higher performance. and finally a central region 730 with a region of excess performance. Also note that the scale is different than before and actually focuses on the center of the striking face. Although the thresholds for determining areas of excess performance are generally the same thresholds outlined by the previous steps of the analysis, higher thresholds, Or it may be a lower threshold.

Since the results of the analysis still yielded an over-performing central region 730, the perimeter and peripheral shape of the central region 730 was captured again and this was used to improve the striking face portion 702, resulting in a third region of increased thickness. A layer 817 (shown later in FIG. 8a) is added on top of the second layer 715 of increased thickness. Compared to the increased thickness second layer 715, the increased thickness of the increased thickness third layer 817 is approximately 0.3 mm thicker, resulting in a total thickness of this portion of the striking face portion 702. The thickness will be approximately 3.6 mm. FIG. 8 a of the accompanying drawings shows a striking face portion 802 with a third layer 817 of increased thickness having a perimeter and a third perimeter shape 818 . Again, the shape and dimensions of the third layer of increased thickness 817 correspond to the central region 730 identified in the previous analysis performed on the striking face portion 702. In other words, once a third region of excess performance having a third peripheral shape is determined based on the central region 730, the third layer of increased thickness is added to the second layer of increased thickness. It can be said to be added to the inner surface of the layer, where a third layer of increased thickness has a perimeter defined by a third perimeter shape.

Here, in this embodiment of the invention, the increase in thickness of the various layers of increased thickness is generally about 0.3 mm for each layer, with a base layer thickness of 2.7 mm. Note that the final thickness of the central portion is approximately 3.6 mm. This is an important component to the improved striking face design according to this invention. The controlling variable here is the consistency of each layer with increasing thickness, rather than each 0.3 mm thick layer built on top of the previous layer. Therefore, the analysis starts with the difference between the base layer thickness and the final center thickness and divides it by the number of layers needed to completely eliminate the area of excess performance. This relationship can be more clearly expressed by the following equation (4).
Thickness of each layer = ((Final center thickness - Baseline thickness)) / (Number of layers) Equation (4)
Without departing from the scope and content of this invention, minor tweaks may be made to individual layers to slightly accommodate design variations, particularly in final layers of increased thickness, as needed. I can do it.

Again, it is recognized that the third perimeter shape 818, as well as the shape of the first perimeter 614 and the shape of the second perimeter 716, are completely different from the face perimeter shape 512 (shown in Figure 5a). It is important that the area of excessive performance in the striking face portion 702 is not directly related to either the face perimeter shape 512, the first perimeter shape 614, or the second perimeter shape 716. It is from.

Figure 8b of the accompanying drawings shows the final step of the analysis, as areas of excessive performance cannot be identified based on the design of the striking face portion 802 shown in Figure 8a. FIG. 8b shows a first outer region 822 with the lowest performance, a second outer region 824 with slightly higher performance, a third outer region 826 with slightly higher performance, and a third outer region 826 with slightly higher performance. A fourth outer region 828 is shown without any central region containing excess performance. Once this analysis is complete, FIG. 9 of the accompanying drawings shows a rear view of the striking face portion 902 that is the result of the previous process.

FIG. 9 of the accompanying drawings shows a rear cutaway view of a striking face portion 902 in accordance with an exemplary embodiment of the invention. The hitting face portion 902 shown in FIG. 9 is configured as follows. The striking face portion 902 shown here in FIG. 9 is derived from and is very similar to the striking face portion 802 shown in FIG. 8a, which already indicates that no areas of excessive performance are included. explained. However, in certain circumstances, a third layer 817 of increased thickness may It may be beneficial to smooth the transition between the increased thickness second layer 715, the increased thickness first layer 613, and the perimeter of the striking face portion 802 itself, which yielding what is shown in FIG. If stress levels and manufacturing are not an issue, the improved striking face of this invention may look identical to that shown in FIG. 8a, without departing from the scope and content of this invention.

Although FIG. 9 of the accompanying drawings technically has a first layer of increased thickness, a second layer of increased thickness, and a third layer of increased thickness, there is no difference between the various regions. The smoothing of the transitions makes them less visible in this example. Therefore, for ease of explanation, the striking face portion 902 shown in FIG. 9 is more easily described when labeled as a thickened central region 906, a transition region 908, and a thinned peripheral region 910. can do. These terms are familiar because the previous description of the cross-sectional views of the invention in FIGS. 3 and 4 employs these similar terms. In fact, the back cutaway view of the golf club head shown in the cross-sectional views of golf club heads 300 and 400 shown in FIGS. 3 and 4, respectively, is very similar to that shown in FIG. You will see it.

The thickened central region 906 of the striking face portion 902 may have a perimeter and geometry that is still generally consistent with the third region of overperformance previously described in FIG. 7b. This shape generally has a width d3 of between about 10 mm and about 15 mm, more preferably between about 11 mm and about 14 mm, and most preferably about 12.5 mm, without departing from the scope and content of this invention. It is good to have The thickened central region 906 may generally have a height d4 of between about 7 mm and about 11 mm, more preferably between about 8 mm and about 10 mm, and most preferably between about 9 mm.

The transition region 908 may have a shape that is still generally consistent with the first region of excess performance described above in FIG. 5b. The shape may generally have a width d5 of between about 35 mm and about 40 mm, more preferably between about 36 mm and about 39 mm, more preferably about 37.5 mm, and also between about 18 mm and about It may have a height d6 of between 24 mm, more preferably between about 20 mm and about 22 mm, most preferably about 21 mm, without departing from the scope and content of this invention.

Before moving on to the remaining figures that discuss various striking face portion profiles in accordance with alternative embodiments of this invention, it is important to note that the physical designs shown herein are not absolute and may vary depending on different chassis of different golf club heads. Note that this can vary. The focus of this invention is to identify various areas of excessive performance and build up layers of increased thickness to address these areas, resulting in the most evenly distributed performance across the face. A method of creating a face portion, and an improved striking face resulting from this method.

FIG. 10 of the accompanying drawings shows a cutaway view of the rear portion of a striking face portion 1002 in accordance with an alternative embodiment of the present invention. Although the rear view of striking face portion 1002 looks slightly different than striking face portions 902 and 802, the same design elements are present therein. The striking face portion 1002 shown here includes a first layer 1013 with increased thickness, a second layer 1015 with increased thickness, a third layer 1017 with increased thickness, a fourth layer 1019 with increased thickness, and a third layer 1019 with increased thickness. It has two layers, the fifth layer 1021a and 1021b, which have increased thickness and 1021b. This alternative embodiment illustrates several key principles previously foreseen in the previous discussion, yet not specifically shown. First and foremost, a closer examination of FIG. 10 shows that there are five layers of increased thickness compared to the three layers described in the previous example. Additional layers may be required in certain situations to ensure that the striking face portion 1002 no longer includes areas of excessive performance; in fact, the process is such that the areas of excessive performance are removed. may be repeated as many times as necessary beyond what is shown in FIG. The second important principle is illustrated here by the presence of two layers of increased thickness, the fifth layer 1021a and 1021b. The presence of two layers of increased thickness, fifth layer 1021a and 1021b, allows regions of excess performance to be easily accessed through one layer of excess performance, generally having a single geometry. Although having a single geometric shape that can be grasped, the analysis results in two completely isolated redundant regions, indicating that separate individual layers 1 of increasing thickness may be employed. , without departing from the scope and content of this invention.

Now, there are 5 layers of increased thickness as shown in Figure 10, so if the base layer thickness and the final central layer remain at 2.7 mm and 3.6 mm, respectively, the thickness has increased. It is important to reiterate that the thickness of each layer, according to equation (1) specified above, comprises a thickness of about 0.18 mm above the previous base layer. However, in alternative embodiments of this invention, the base layer and the final desired center thickness layer may have different thicknesses without departing from the scope and content of this invention.

FIG. 11 of the accompanying drawings shows a cut-away view of the back of a striking face portion 1102 in accordance with an alternative embodiment of the invention. FIG. 11 shows only two layers of increased thickness, consisting of a first layer of increased thickness 1113 and a second layer of increased thickness 1115. More specifically, the striking face portion 1102 shown here may have identified areas of excess performance that are not substantially concentrated in the previous layer of increased thickness. Even if a second layer of increased thickness 1115 is placed off-center on top of the first layer of increased thickness 1113, there will be no consistency around the entire second layer of increased thickness 1115. No transition region is obtained. A detailed inspection of the striking face portion 1102 is shown in FIG. A closer look at the striking face portion 1102 shown in FIG. 11 shows a transition section where the placement of the increased thickness second layer 1115 blends into the transition of the increased thickness first layer 1113 near the upper toe portion. , which indicates this effect.

FIG. 12 of the accompanying drawings shows a cut-away view of the rear of a striking face portion 1202 in accordance with an alternative embodiment of the present invention. In this alternative embodiment, the striking face portion 1202 may include smoothed transitions between the various layers of increased thickness, similar to that shown above in FIG. In these smoothed embodiments of the striking face portion, the distinguishable features are a thickened central region 1206, a transition region 1208, and a thinned peripheral region 1210. This embodiment of the invention illustrates a more elongated central portion 1206 and transition region 1208, which may be the result of analysis in accordance with this embodiment of the invention. The thickened central region 1206 is generally between about 20 mm and about 25 mm, more preferably between about 21 mm and about 24 mm, and most preferably about 24 mm, without departing from the scope and content of this invention. It may have a width d3 of 22.5 mm. The thickened central region 1206 may generally have a height d4 of between about 7 mm and about 11 mm, more preferably between about 8 mm and about 10 mm, and most preferably between about 9 mm.

The transition region 1208 generally has a width d5 of between about 38 mm and about 48 mm, more preferably between about 39 mm and about 42 mm, more preferably about 40.5 mm, and also between about 18 mm and about 24 mm. d6, more preferably between about 20 mm and about 22 mm, most preferably about 21 mm, without departing from the scope and content of this invention.

FIG. 13 of the accompanying drawings shows a cut-away view of the rear of a striking face portion 1302 in accordance with another alternative embodiment of the present invention. In this alternative embodiment, if the analysis to identify areas of excessive performance identifies multiple isolated locations across the face, the , multiple individual layers of increasing thickness may be employed. The striking face portion 1302 shown here includes a plurality of increased thickness first layers 1313a, 1313b, 1313c, 1313d, and 1313e in response to areas of excessive performance identified in the analysis step. . With only one layer of increasing thickness, the transition regions all blend in a consistent manner from the central region to the periphery, resulting in the shape shown in FIG. 13. In this example, since there is only one layer with increased thickness, the thicknesses of multiple layers 1313a, 1313b, 1313c, 1313d, and 1313e with increased thickness are determined based on equation (1) above. The thickness may be close to 3.6 mm. However, it is to be understood herein that the thicknesses of 1313a-1313e may differ from each other in still other embodiments of this invention without departing from the scope and content of this invention.

FIG. 14 of the accompanying drawings shows a cut-away view of the rear of a striking face portion 1402 in accordance with another alternative embodiment of the present invention. Although this alternative embodiment is very similar to the striking face portion 1302 shown in FIG. 13, only four increased thickness first layers 1413a, 1413b, 1413c, and 1413d be. Similar to the previous discussion, in certain situations, when isolated small areas of excess performance are identified, the resulting design may look like those shown here in FIGS. 13 and 14; This does not depart from the scope and content of this invention.

Figures 15a, 15b, and 15c show CT heat maps of two prior art and inventive striking face sections. These CT heatmaps are all created by replicating the front view of the hitting face, with the left side of the heatmap referring to the toe side of the golf club head, the right side referring to the heel side of the golf club head, and the top side of the heatmap referencing the golf club head. Refers to the crown of the club head, and the lower side refers to the sole side of the golf club head. Additionally, prior to discussing the various charts, please note that although there are a lot of numbers on the page, all numbers are normalized to set the "excessive performance limit" to zero. need to understand. Therefore, numbers with positive values are undesirable because they exceed the previously set limit. Conversely, a negative number that is too large is undesirable because it means that the limit has not been reached and requires unmet performance improvements. Finally, the axis of the chart indicates the distance in meters from the center of the striking face at which the measurements are taken. As shown, all charts have heel and toe direction measurements, from -0.02 meters (20mm) on the toe side to positive 0.02 meters (20mm) on the heel side. (2mm). The chart also has a range from -0.008 meters (8mm) on the sole side to positive 0.012 meters (12mm) on the crown side.

FIG. 15a shows a CT heat map distribution of a less-than-optimal prior art hitting face portion. One important indicator of good performance is the CT value near the center of the face. The CT value identified by the two zeros on the axis is -5, and the maximum CT value just above the center of the face is -1. Although these initially appear to be good performance results, a closer look at the rest of the face map reveals many locations with positive area numbers in the heel and toe portions of the face. As the previous discussion has shown, having areas that exceed performance limits is not only undesirable, but may be considered non-conforming by golf governing bodies. In addition to the following fatal flaws, the average performance around the center of the face ( heel , toe, crown, and sole, with a square created by moving 0.006 meters [6 mm] in all directions), the chart (highlighted with a dark surround) is -5.37. This is a very important factor in determining the performance of the golf club head around the center of the face, and is called the " CT Variance Average " and is further defined by the following equation (5). . Here, for convenience, it is also referred to as CT value related average performance around the center of the face.
CT variance average = average CT value within a 6 mm square at the center Formula (5)
Of course, numbers close to zero are more desirable, as negative numbers indicate less than optimal performance. In other words, this prior art golf club head can be said to have an average CT variance of about -5.37.

Figure 15b of the accompanying drawings shows a CT heat map of another prior art golf club head in which an attempt was made to address the problem of CT over performance limits, but where the CT variance average was compromised. A closer look at Figure 15b reveals that, overall, there are no positive values on the chart through efforts to eliminate areas with excessive performance, which is achieved by thickening the portion of the hitting face that exhibits excessive performance. It is shown that. However, in this design, the CT variance average is -7.00, so there is a problem with the CT variance average here.

Figure 15c of the accompanying drawing shows a CT heat map of the current golf club head of the present invention. Immediately it can be seen that this ingenious golf club head does not have any areas of excessive performance without positive range values. Furthermore, this invention has a very good CT variance average of -2.90, meaning that the center of the face performance is much closer to the limit than any previous design. In other words, the golf club head of the present invention has a CT closer to zero than about -3.5, more preferably closer to zero than about -3.2, and more preferably closer to zero than about -3.0. It can be said that it has a variance mean.

All numerical ranges, such as amounts of material, moments of inertia, center of gravity positions, lofts, draft angles, various performance ratios, etc., in the preceding portions of this specification, unless otherwise specified or unless otherwise stated. Amounts, values, and percentages may be understood as if preceded by the term "about," even if the term "about" does not explicitly appear in the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and appended claims are approximations that may vary depending on the desired properties sought to be obtained by the present invention. . At a minimum, without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed at least in light of the reported number of significant digits and by applying normal rounding techniques. be.

Notwithstanding that the numerical ranges and parameters expressing the broad scope of this invention are approximations, the numerical values set forth in the specific examples are reported as accurately as possible. However, the numbers inherently include a certain error due to the standard deviation found in each test measurement. Additionally, it is noted that when numerical ranges of various ranges are recited herein, any combination of these values including the recited values may be used.

It is, of course, understood that the foregoing description is of exemplary embodiments of the invention, and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. sea bream.
The technical features described here are listed below.
[Technical feature 1]
In golf club heads,
a striking face portion having a perimeter defined by a striking face perimeter shape and located at a forward portion of the golf club head;
a rear body portion positioned behind the hitting face portion in the rear portion of the golf club head;
The golf club head has a hardness-to-strength ratio of greater than about 6.0 ksi/HRC;
The above hardness strength ratio is
(UTS of hitting face portion 102 - UTS of main body portion 104)/(Hardness of hitting face portion 102 - Hardness of main body portion 104) = hardness strength ratio
A golf club head characterized by:
[Technical feature 2]
The golf club head of Technical Feature 1, wherein the golf club head has a strength-to-hardness ratio of greater than about 11 ksi/HRC.
[Technical feature 3]
The golf club head of Technical Feature 1, wherein the golf club head has a strength-to-hardness ratio of greater than about 16 ksi/HRC.
[Technical feature 4]
The golf club head has a MOR ratio of greater than about 1.25;
The above MOR ratio is
(MOR of hitting face portion 102)/(MOR of main body portion 104) = MOR ratio
The golf club head according to technical feature 1.
[Technical feature 5]
The golf club head of technical feature 4, wherein the golf club head has a MOR ratio greater than about 1.35.
[Technical feature 6]
The golf club head of technical feature 5, wherein the golf club head has a MOR ratio greater than about 1.45.
[Technical feature 7]
The above-mentioned hitting face part further includes:
a first region of excess performance forming a first peripheral shape;
a first layer of increased thickness located on an interior surface of the striking face portion, the first layer of increased thickness having a perimeter defined by the first perimeter shape;
a second region of excess performance forming a second peripheral shape;
a second layer of increased thickness located on an interior surface of the first layer of increased thickness, the second layer of increased thickness having a perimeter defined by the second perimeter shape; 2 layers,
The striking face peripheral shape is different from the first peripheral shape,
The second surrounding shape is different from the first surrounding shape,
The second peripheral shape is different from the striking face peripheral shape,
The golf club head of technical feature 1, wherein the transition region between the striking face portion, the first layer of increased thickness, and the second layer of increased thickness has a smooth blended area.
[Technical feature 8]
The striking face portion further has a thinned peripheral region, the thinned peripheral region surrounding the increased thickness first layer;
8. The golf club head of technical feature 7, wherein the thinned peripheral region has a thickness of about 2.4 mm and about 3.0 mm.
[Technical feature 9]
9. The golf club head of technical feature 8, wherein the thinned peripheral region has a thickness of about 2.6 mm and about 2.8 mm.
[Technical feature 10]
A golf club head according to technical feature 9, wherein the thinned peripheral region has a thickness of about 2.7 mm.
[Technical feature 11]
9. The golf club head of technical feature 8, wherein the second layer of increased thickness has a total thickness of about 3.2 mm and about 3.8 mm.
[Technical feature 12]
12. The golf club head of technical feature 11, wherein the increased thickness second layer has a total thickness of about 3.4 mm and about 3.6 mm.
[Technical feature 13]
13. The golf club head of technical feature 12, wherein the second layer of increased thickness has a total thickness of about 3.5 mm.
[Technical feature 14]
In golf club heads,
a striking face portion having a perimeter defined by a striking face perimeter shape and located at a forward portion of the golf club head;
a rear body portion positioned behind the hitting face portion in the rear portion of the golf club head;
The golf club head has a MOR ratio of greater than about 1.25;
The above MOR ratio is
(MOR of hitting face portion 102)/(MOR of main body portion 104) = MOR ratio
A golf club head characterized by:
[Technical feature 15]
15. The golf club head of technical feature 14, wherein the golf club head has a MOR ratio greater than about 1.35.
[Technical feature 16]
16. The golf club head of technical feature 15, wherein the golf club head has a MOR ratio greater than about 1.45.
[Technical feature 17]
The striking face portion has a CT variance average near zero greater than about -3.5, and the CT variance average is greater than about -3.5.
CT variance average = average CT value within a 6mm square in the center
The golf club head according to Technical Feature 16.
[Technical feature 18]
18. The golf club head of technical feature 17, wherein the striking face portion has a CT variance average near zero greater than about -3.2.
[Technical feature 19]
19. The golf club head of technical feature 18, wherein the striking face portion has a CT variance average near zero greater than about -3.0.
[Technical feature 20]
In golf club heads,
a striking face portion having a perimeter defined by a striking face perimeter shape and located at a forward portion of the golf club head;
a rear body portion positioned behind the hitting face portion in the rear portion of the golf club head;
The above-mentioned hitting face part further includes:
a first region of excess performance forming a first peripheral shape;
a first layer of increased thickness located on an interior surface of the striking face portion, the first layer of increased thickness having a perimeter defined by the first perimeter shape;
a second region of excess performance forming a second peripheral shape;
a second layer of increased thickness located on an interior surface of the first layer of increased thickness, the second layer of increased thickness having a perimeter defined by the second perimeter shape; 2 layers,
The second surrounding shape is different from the first surrounding shape,
The second peripheral shape is different from the striking face peripheral shape,
A golf club head wherein the transition region between the striking face portion, the first layer of increased thickness, and the second layer of increased thickness has a smooth blended area.
[Technical feature 21]
The striking face portion further has a thinned peripheral region, the thinned peripheral region surrounding the increased thickness first layer;
21. The golf club head of technical feature 20, wherein the thinned peripheral region has a thickness of about 2.4 mm and about 3.0 mm.
[Technical feature 22]
22. The golf club head of technical feature 21, wherein the thinned peripheral region has a thickness of about 2.6 mm and about 2.8 mm.
[Technical feature 23]
23. The golf club head of technical feature 22, wherein the thinned peripheral region has a thickness of about 2.7 mm.
[Technical feature 24]
24. The golf club head of technical feature 23, wherein the second layer of increased thickness has a total thickness of about 3.2 mm and about 3.8 mm.
[Technical feature 25]
25. The golf club head of technical feature 24, wherein the increased thickness second layer has a total thickness of about 3.4 mm and about 3.6 mm.
[Technical feature 26]
26. The golf club head of technical feature 25, wherein said second layer of increased thickness has a total thickness of about 3.5 mm.
[Technical feature 27]
The striking face portion has a CT variance average near zero greater than about -3.5, and the CT variance average is greater than about -3.5.
CT variance average = average CT value within a 6mm square in the center
The golf club head according to Technical Feature 20.
[Technical feature 28]
28. The golf club head of technical feature 27, wherein the striking face portion has a CT variance average near zero greater than about -3.2.
[Technical feature 29]
29. The golf club head of technical feature 28, wherein the striking face portion has a CT variance average near zero greater than about -3.0.
[Explanation of symbols]
100 golf club head
102 Batting face part
103 Face insert
104 Rear main body part
200 golf club head
201 Coordinate system
203 Face center
300 golf club head
302 Batting face part
304 Rear main body part
306 Central area
308 Transition area
310 Surrounding area
400 golf club head
402 Batting face part
404 Rear main body part
406 Central area
408 Transition area
410 Peripheral area
500 golf club head
502 Batting face part
503 Batting face insert
512 Face circumference
522 First outer area
524 Second outer area
526 Third outer area
528 Fourth outer area
530 Central area
602 Batting face part
613 First layer
614 First perimeter
622 First outer area
624 Second outer area
626 Third outer area
628 Fourth outer area
630 Central area
702 Batting face part
715 Second layer
716 Second surrounding
722 First outer area
724 Second outer area
726 Third outer area
728 Fourth outer area
730 Central area
802 Batting face part
817 Third layer
818 Third surrounding
822 First outer area
824 Second outer area
826 Third outer area
828 Fourth outer area
902 Batting face part
906 Central area
908 Transition area
910 Surrounding area
1002 Batting face part
1102 Batting face part
1113 First layer
1115 Second layer
1202 Batting face part
1206 Central area
1208 Transition area
1210 Peripheral area
1302 Batting face part

Claims (11)

In golf club heads,
a hitting face portion positioned at a forward portion of the golf club head, the hitting face portion having a hitting face perimeter defined by a hitting face perimeter shape;
a rear body portion positioned behind the hitting face portion in the rear portion of the golf club head;
The golf club head has a hardness-to-strength ratio greater than 6.0 ksi/HRC,
The above hardness strength ratio is
(UTS of hitting face portion 102 - UTS of main body portion 104)/(hardness of hitting face portion 102 - hardness of main body portion 104) = hardness-to-strength ratio,
having n (n is an integer of 1 or more) inner periphery of the hitting face included in the periphery of the hitting face;
When n is 1, the periphery of the hitting face surrounds the inner periphery of the first hitting face, and the first area of the first area surrounded by the inner periphery of the first hitting face and the periphery of the hitting face. The second face thickness of the second area surrounded by the inner periphery of the first hitting face is uniform, and the second face thickness is equal to the first hitting face thickness. , and the inner periphery of the first striking face has an internal CT value under the condition that the inner face thickness of the inner periphery of the first striking face is the same as the first face thickness. is a perimeter defining an area where exceeds a predetermined threshold;
When n is an integer of 2 or more, the above-mentioned batting face periphery surrounds the first batting face inner periphery, and the m-th batting face inner periphery (where m=1, ..., n-1 ) includes the (m+1)th periphery, the first face thickness of the first region surrounded by the first inner periphery of the hitting face and the above-mentioned hitting face periphery is uniform, and the (m+1)th The (m+1)th face thickness of the (m+1)th area surrounded by the )th inner periphery of the hitting face and the mth inner periphery of the hitting face is uniform, and the second face thickness is thicker than the first face thickness, the (m+1)th face thickness is thicker than the mth face thickness, and the inner circumference of the first striking face is the inner circumference of the inner circumference of the first striking face. It is a periphery that defines an area whose internal CT value exceeds a predetermined threshold under the condition that the thickness is the same as the first face thickness, and the (m+1)th inner periphery of the hitting face is adjacent to the outside. The inner periphery of the m-th hitting face defines a region in which the CT value exceeds a predetermined threshold under the condition that the face thickness is the same as the m-th face thickness. A distinctive golf club head. The golf club head of claim 1, wherein the golf club head has a strength-to-hardness ratio of greater than 11 ksi/HRC. The golf club head has a MOR ratio greater than 1.25;
The above MOR ratio is
The golf club head of claim 1, wherein (MOR of hitting face portion 102)/(MOR of body portion 104)=MOR ratio. The inner circumference of the striking face has a first inner circumference of the striking face, and the thickness from the inner circumference of the striking face to the first inner circumference of the striking face is from 2.4 mm to 3.0 mm; The golf club head of claim 1, wherein the thickness within the inner circumference of the first striking face is from 3.2 mm to 3.8 mm. The inner periphery of the hitting face includes a first inner periphery of the hitting face included adjacent to the periphery of the hitting face, and a second inner periphery of the hitting face included adjacent to the first inner periphery of the hitting face. The thickness from the periphery of the hitting face to the inner periphery of the first hitting face is from 2.4 mm to 3.0 mm, and the thickness of the inner periphery of the first hitting face is 3.0 mm. 2. The golf club head of claim 1, wherein the golf club head is between .2 mm and 3.8 mm. The above-mentioned hitting face portion has a CT value-related average performance around the center of the face that is close to zero and is greater than -3.5, and the above-mentioned CT value-related average performance around the face center is defined as CT value-related average performance around the face center = above and below from the center of the face. 2. The golf club head according to claim 1, wherein the CT value is an average value obtained by subtracting a reference CT value from the CT values of grid points within a square having sides at positions of 6 mm on the left and right. 7. The golf club head of claim 6, wherein the striking face portion has a near-zero CT value related average performance around the center of the face greater than -3.2. 8. The golf club head of claim 7, wherein the striking face portion has a CT value related average performance around the center of the face near zero that is greater than -3.0. The golf club head according to claim 6, wherein the reference CT value is 239 μs or 257 μs. 2. The golf club head of claim 1, further comprising a smooth thickness region in a transition region around the inner circumference of the striking face. In golf club heads,
a hitting face portion positioned at a forward portion of the golf club head, the hitting face portion having a hitting face perimeter defined by a hitting face perimeter shape;
a rear body portion positioned behind the hitting face portion in the rear portion of the golf club head;
one or more inner striking face peripheries enclosed around the striking face, wherein the striking face periphery or outer striking face inner periphery sequentially encloses an adjacent inner inner striking face inner periphery; A periphery or one of the inner peripheries of the striking face includes a plurality of adjacent inner peripheries of the striking face without enclosing each other, and the inner thickness of each of the inner peripheries of the striking face is such that the inner periphery of the striking face A golf club head characterized in that it is thicker than the thickness of an area surrounded by the adjacent surrounding striking face perimeter or other inner striking face perimeter and the inner striking face perimeter.

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