Golf club head with improved striking face

Abstract

Provided is a golf club head having an improved striking face. 【Solution means】The golf club head includes a central opening and a face insert covering the central opening. The face insert may include a thick central region 2414, a central transition region 2416 extending radially outward from the thick central region, a thin intermediate region 2418 extending radially outward from the central transition region, and a thick stress reduction region extending radially outward from the thin intermediate region. The striking face portion 2402 may include a thin peripheral region extending radially outward from the thick stress reduction region. The thick stress reduction region forms a horseshoe ring protruding rearward from the face insert.

Description

Technical Field

[0001] Generally speaking, this invention relates to a golf club head with an improved striking face. More specifically, this invention relates to a metal wood type golf club head in which the striking face further has a central thickness region positioned near the geometric center of the striking face portion, a central transition region extending radially outward from the central thickness region, a thin middle region extending radially outward from the central transition region, a thick stress reduction region extending radially outward from the thin middle region, and a thin peripheral region extending radially outward from the thick stress reduction region, and these are combined to form an improved striking face.

Background Art

[0002] The striking face of a golf club head is the only part of the golf club head that receives the highest level of stress when hitting a golf ball. Further, since the striking face is the only part that contacts the golf ball, it is one of the important parts for the design of any golf club.

[0003] In order to improve the performance of the golf club head through the striking face, golf club designers have tried to create a very thin striking face. Thereby, when colliding with the golf ball, the striking face elastically deforms, and thereby the speed of the golf ball increases after leaving the striking face of the golf club head. However, it is necessary to comply with the rules of golf. U.S. Patent No. 4,432,549 granted to Zebelean shows one of the initial attempts to thin the striking face of a golf club head by thinning the upper portion of the striking face.

[0004] Thinning the face is not the only way to improve the performance of the striking face of a golf club head. More recent improvements include adjusting the thickness of various portions of the striking face to improve performance. Based on a face that is already thin, U.S. Patent No. 6,863,626 to Evans et al. illustrates one of the initial attempts to vary the thickness of the striking face of a golf club head, which discloses that a thick central region decreases from the center outward, assisting in reducing the speed of the golf ball at the center and creating a large region with improved speed and performance.

[0005] Based further on known art of a thin face combined with a thick central portion, U.S. Patent No. 10,758,789 to Bacon et al. adds a thick peripheral region to the end of the striking face, which the inventors claim improves durability, increases ball speed, and increases the characteristic time. However, while adding this is beneficial, it is not optimized. This is because, as shown in U.S. Patent No. 10,758,789, the benefits of the thick peripheral region are generally local and it is not necessary to extend it all the way to the perimeter of the striking face.

[0006] Thus, it can be seen that for a golf club head having a thin face, a thick central region, and also a thick peripheral region, further improvements can be made by removing unnecessary weight from the peripheral edges of the striking face and localizing the thickened peripheral region only at the optimized locations where the benefits of such features can be received.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0008] One aspect of this invention is a golf club head, which may include a striking face portion adapted to strike a golf ball and positioned at the front portion of the golf club head, and a body portion attached behind the striking face portion. The striking face portion may include a central opening and a face insert covering the central opening. The face insert may include a thick central region having a first thickness positioned near the geometric center of the face insert, a central transition region extending radially outward from the thick central region and having a variable thickness, a thin intermediate region extending radially outward from the central transition region and having a third thickness, and a thick stress reduction region extending radially outward from the thin intermediate region and having a fourth thickness.

[0009] In some embodiments, the fourth thickness of the thick stress reduction region may be the hottest part of the face insert.

[0010] In some embodiments, the fifth thickness may be greater than the third thickness.

[0011] In some embodiments, the thick stress reduction region may have a T-to-H ratio between about 0.6 and about 1.1, and the T-to-H ratio is defined as follows. T-to-H ratio = (the fourth thickness T4 of the thick stress reduction region) / (the height H4 of the thick stress reduction region)

[0012] In some embodiments, the T-to-H ratio may be between about 0.7 and about 0.9.

[0013] In some embodiments, the T-to-H ratio may be about 0.8.

[0014] In some embodiments, the thick stress reduction region may further include an upper thick stress reduction region and a lower thick stress reduction region. The upper thick stress reduction region and the lower thick stress reduction region may have the same height.

[0015] In some embodiments, the thick stress reduction region may further include an upper thick stress reduction region and a lower thick stress reduction region. The upper thick stress reduction region and the lower thick stress reduction region may have different heights.

[0016] In some embodiments, the height of the upper thick stress reduction region may be smaller than the height of the lower thick stress reduction region.

[0017] In some embodiments, the height of the upper thick stress reduction region may be smaller than the height of the lower thick stress reduction region by about 0.5 mm.

[0018] Another aspect of the technology disclosed herein is a golf club head. The golf club head may include a striking face portion positioned at a front portion of the golf club head and adapted to strike a golf ball, and a body portion attached behind the striking face portion. The striking face portion may include a central opening and a face insert covering the central opening. The face insert may include a thick stress reduction region extending radially outward from a thin middle region and having a fourth thickness, and a thick central region positioned near a geometric center of the face insert and having a first thickness. The thick stress reduction region may form a ring protruding rearward from the face insert. The fourth thickness may be greater than the first thickness.

[0019] In some embodiments, the top ledge of the central opening may be positioned at a distance of less than about 1.5 mm from the crown tip of the face insert.

[0020] In some embodiments, the top ledge of the central opening may be positioned at a distance of less than about 1.0 mm from the crown tip of the face insert.

[0021] In some embodiments, the aspect ratio of the face insert may be from about 1.3 to about 1.7.

[0022] In some embodiments, the top ledge of the central opening may be positioned at a distance of less than about 10 mm from the crown vertex.

[0023] In some embodiments, the fourth thickness of the thick stress reduction region may be the thickest part of the face insert.

[0024] In some embodiments, the thick stress reduction region may be measured across any radial direction and positioned at a distance between about 15.0 mm and about 46.0 mm from the geometric center of the face insert.

[0025] In some embodiments, the thick stress reduction region may be measured across a vertical cross-section passing through the geometric center of the face insert and positioned at a distance between about 20 mm and about 25 mm from the geometric center of the face insert.

[0026] Another aspect of the technology disclosed herein is a golf club head. The golf club head may include a striking face portion positioned at a front portion of the golf club head and adapted to strike a golf ball, and a body portion attached behind the striking face portion. The striking face portion may include a central opening and a face insert covering the central opening. The face insert may include a thick stress reduction region positioned adjacent to the perimeter of the face insert. The thick stress reduction region may form a ring protruding rearward from the face insert. The thick stress reduction region may be measured across a vertical cross-section passing through the geometric center of the face insert and positioned at a distance between about 15 mm and about 30 mm from the geometric center of the face insert.

[0027] In some embodiments, the thick stress reduction region may have a T-to-H ratio between about 0.6 and about 1.1, where the T-to-H ratio is defined as follows. T-to-H ratio = (the fourth thickness T4 of the thick stress reduction region) / (the height H4 of the thick stress reduction region)

[0028] These and other features, aspects, and advantages of the present invention will be better understood by reference to the following drawings, description, and claims for utility model registration.

Brief Description of the Drawings

[0029] These and other features and advantages of the present invention will become apparent from the following description of the present invention, as shown in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the principles of the present invention and further serve to enable those skilled in the relevant art to practice and use the present invention.

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BEST MODE FOR CARRYING OUT THE INVENTION

[0030] The following detailed description describes the presently contemplated best mode of practicing this invention. Since the scope of this invention is most preferably defined by the appended utility model registration claims, this description should not be construed in a limiting sense but is made merely for the purpose of explaining the general principles of this invention.

[0031] The various features of this invention will be described below. Each can be used independently of one another or in combination with other features. However, any one of the single features of this invention may or may not address any or all of the above-mentioned problems, and may only address one of the above-mentioned problems. Furthermore, one or more of the above-mentioned problems may not be fully addressed by any of the features described below.

[0032] FIG. 1 of the accompanying drawings shows a front view of a golf club head 100 according to an exemplary embodiment of this invention. First and foremost, FIG. 1 of the accompanying drawings shows a coordinate system 101 that defines the orientation of the golf club head 100 along the x, y, and z axes. The x-axis shown here is horizontal, extends in the direction from heel to toe, and the positive axis points to the heel of the golf club head 100. The y-axis shown here is vertical and extends in the direction from crown to sole. Finally, the z-axis shown here refers to the axis that spans the front and back of the paper, with the positive axis pointing in the front direction. The front view of this golf club head 100 shows a striking face portion 102 that is further composed of a face insert 104 and a face perimeter 106 in this embodiment. FIG. 1 of the accompanying drawings also shows a vertical cutting line A-A' along the y-axis and along the y-z plane, which enables a clearer display of the internal shape of the striking face portion 102.

[0033] Figure 2 of the accompanying drawings shows a cross-sectional view of the golf club head 200 along the section line A-A' shown in Figure 1. In this cross-sectional view of the golf club head 200 shown in Figure 2, it can be seen that the golf club head 200 has a striking face portion 202 and a rear body portion 203 attached to the rear of the striking face portion 202. The striking face portion 202 as defined in this invention is substantially planar, is located at the front of the golf club head 200, and refers to the portion of the golf club head 200 adapted to strike a golf ball. The striking face portion 202 is manufactured by a thickness formed by a substantially flat front striking surface 210 and a rear inner surface 212 having a variable contour, forming a striking face portion having a variable face thickness profile. The boundary between the striking face portion 202 and the rear body portion 203 occurs when the rear inner surface 212 deviates from a substantially planar vertical direction towards a substantially horizontal direction.

[0034] Finally, Figure 2 of the accompanying drawings shows that in this embodiment, a face insert 204 is used to close the opening of the striking face portion 202 created by the face perimeter 206. In this embodiment of this invention, the face insert 204 may generally be made of a titanium material to achieve lightweight and high durability characteristics, and may also be made significantly thinner than a conventional golf club head having a similar structure by a unique thickened stress reduction region 220 around the face perimeter 206. In this embodiment of this invention, the thickened stress reduction region 220 around the face perimeter 206 enables the face insert 204 to be made thinner and lighter, resulting in a mass of less than about 25 grams, more preferably less than about 24 grams, and most preferably less than about 23 grams, all of which do not depart from the scope and content of this invention. The mass of the face insert is reduced by about 12 grams compared to a face insert attached without the thickened stress reduction region 220 around the face perimeter 206.

[0035] To more particularly describe the thick stress reduction region 220 around the face perimeter 206 in conjunction with the geometry of the remaining portions of the impact face portion 202, such as the thick central region 214, the central transition region 216, the thin intermediate region 218, and the thin peripheral region 222, an enlarged view of the impact face portion 202 is provided in FIG. 3.

[0036] FIG. 3 of the accompanying drawings shows an enlarged cross-sectional view of the impact face portion 202 of the golf club head 200. This enlarged cross-sectional view enables a clearer indication of the various heights of the impact face portion 202, while FIG. 4 of the accompanying drawings shows the various thicknesses of the impact face portion 202. According to this illustrated exemplary embodiment of the invention, the impact face portion 202 further includes an upper thin peripheral region 222-a and a lower thin peripheral region 222-b, which together form the thin peripheral region 222. The impact face portion 202 has an upper thick stress reduction region 220-a and a lower thick stress reduction region 220-b that are positioned inwardly from the thin peripheral region and joined to form the thick stress reduction region 220. In other words, it can be said that the thick stress reduction region 220 forms a ring that projects rearwardly from the inner surface 212 of the impact face portion 202. The impact face portion 202 has an upper thin intermediate region 218-a and a lower thin intermediate region 218-b that are positioned inwardly from the thick stress reduction region and combined to form the thin intermediate region 218. The impact face portion 202 has an upper central transition region 216-a and a lower central transition region 216-b that are positioned inwardly from the thin intermediate region and combined to form the central transition region 216. Finally, the impact face portion 202 includes a thick central region 214 that is positioned inside the central transition region 216.

[0037] In this embodiment of the invention shown in FIG. 3, the height H1 of the thick central region 214 is generally between about 4.0 mm and about 15.0 mm, more preferably between about 4.0 mm and about 10.0 mm, and most preferably about 4.0 mm.

[0038] According to this embodiment of the present invention, the height of the central transition region 216 may be higher below the central region 214 with a thick wall than above the central region 214 with a thick wall. Therefore, according to this embodiment, the height H2-a of the upper central transition region 216-a is between about 7.0 mm and about 11.0 mm, more preferably between about 8.0 mm and about 10.0 mm, and most preferably about 9.0 mm. The height H2-b of the lower central transition region 216-b may generally be between about 13.0 mm and about 17.0 mm, more preferably between about 14.0 mm and about 16.0 mm, and most preferably about 15.0 mm. However, it should be noted that in an alternative embodiment, the heights of the upper central transition region 216-a and the lower central transition region 216-b may be the same without departing from the scope and content of the present invention.

[0039] According to this embodiment of the present invention, the height of the thin intermediate region 218 may also be higher below the central region 214 with a thick wall than above the central region 214 with a thick wall. Therefore, according to this embodiment, the height H3-a is generally between about 3.5 mm and about 5.5 mm, more preferably between about 4.0 mm and about 5.0 mm, and most preferably about 4.5 mm. The height H3-b of the lower intermediate region 218-b may generally be between about 6.5 mm and about 8.5 mm, more preferably between about 7.0 mm and about 8.0 mm, and most preferably about 7.5 mm. However, it should be noted that in a large-boat-like embodiment, the heights of the upper intermediate region 218-a and the lower intermediate region 218-b may be the same without departing from the scope and content of the present invention.

[0040] The height of the thick stress reduction region 220 is the same measurement value, regardless of whether the measurement is related to the upper thick stress reduction region 220-a or the lower thick stress reduction region 220-b, unlike the previous measurement values. Thus, according to this embodiment, both the heights H4-a and H4-b are from about 4.0 mm to about 6.0 mm, more preferably from about 4.5 mm to about 5.5 mm, and most preferably about 5.0 mm. Similar to the above logic, having different H4-a and H4-b values also does not deviate from the scope and content of this invention as long as both are within the above range. Here, it is worth noting that the height of the thick stress reduction region 220 is important for the proper functioning of this invention. This is because it is necessary to carefully balance the requirement of not adding excessive unnecessary mass to the striking face portion 202 and the requirement of providing sufficient structural rigidity to reduce the stress from the face periphery 106 (shown in FIG. 1) so as to make the remaining portion of the striking face portion 202 thinner and more efficient. The height of the thick stress reduction region 220, in combination with the thickness of the thick stress reduction region 220 (described later in FIG. 4), outlines an optimized shape for achieving performance improvement of this invention.

[0041] Before moving on to the discussion regarding the peripheral region 222 of the thin portion, it is important to note that the placement of the thick-portion stress reduction region 220 with respect to the geometric face center 108 (shown in FIG. 1) is important for achieving performance improvement in this invention. This is particularly true along a vertical cross-sectional plane passing through the geometric face center 108 (shown in FIG. 1), as represented in the enlarged cross-sectional view shown in FIG. 3. The importance of this particular cross-section and the placement of the thick-portion stress reduction region 220 along this cross-section achieve a higher stress improvement in the upper face portion along this plane, and thus, it is due to the tendency of the striking face portion 202 to add the thick-portion stress reduction region 220. In this embodiment of the invention, the thick-portion stress reduction region 220 can generally be placed at a distance of about 15 mm to about 30 mm away from the geometric face center 108 along cross-section A-A', preferably, it can be placed at a distance of about 17 mm to about 28 mm away from the geometric face center 108 (shown in FIG. 1) along the cross-sectional plane A-A', and most preferably, it can be placed between about 20 mm and about 25 mm from the geometric face center 108 (shown in FIG. 1) along the cross-sectional plane A-A'.

[0042] The height of the peripheral region 222 of the thin portion can also be higher below the central region 214 of the thick portion than above the central region 214 of the thick portion. Thus, according to this embodiment, the height H5-a can be between about 1.8 mm and about 2.8 mm, more preferably between about 2.1 mm and about 2.5 mm, and most preferably about 2.3 mm. The height H5-b is generally between about 2.3 mm and about 3.3 mm, more preferably between about 2.6 mm and about 3.0 mm, and most preferably about 2.8 mm. However, it should be noted that in an alternative embodiment, without departing from the scope and content of this invention, the heights of the upper peripheral region 222-a and the lower peripheral region 222-b of the thin portion can be the same.

[0043] Figure 4 of the accompanying drawings shows another enlarged cross-sectional view of the striking face portion 202 of the golf club head 200. In this cross-sectional view, the various thicknesses of the components of the striking face portion 202 are shown in more detail. In this current embodiment of the present invention, the thick central region 214 may generally have a thickness T1 of less than about 3.6 mm, more preferably less than about 3.4 mm, and most preferably less than about 3.2 mm. The purpose of the present invention is to minimize the thicknesses of the various components of the striking face portion 202 by introducing a thick stress reduction region 220 that relieves the stress applied to the striking face portion 202.

[0044] The thickness of the thin intermediate region 218 may generally be the same regardless of whether it is located in the upper thin intermediate region 218-a or the lower thin intermediate region 218-b. Thus, both thicknesses T3-a and T3-b are less than about 2.5 mm, more preferably less than about 2.4 mm, and most preferably less than about 2.3 mm. However, in another embodiment of the present invention, the values of T3-a and T3-b may differ slightly from each other, as long as both are within the above range and do not deviate from the scope and content of the present invention.

[0045] Here, the thickness of the thick stress reduction region 220, shown as the upper thick stress reduction region 220-a having a thickness T4-a and the lower thick stress reduction region 220-b having a thickness T4-b, in combination with the width of the thick stress reduction region 220, defines a geometry that is important for the improved performance of the striking face portion 202 of the golf club head. In this embodiment, the respective thicknesses T4-a and T4-b of the upper thick stress reduction region 220-a and the lower thick stress reduction region 220-b are the same, and thus are between about 3.6 mm and about 4.4 mm, more preferably between about 3.8 mm and about 4.2 mm, and most preferably about 4.0 mm. However, in another embodiment of the present invention, the thicknesses T4-a and T4-b may deviate slightly from each other without departing from the scope and content of the present invention, as long as they do not fall outside the previously defined thickness range.

[0046] Once the thickness T4 and height H4 of the thick stress reduction region 220 are defined, the preferred geometric shape of the thick stress reduction region 220 can be established as the ratio of thickness to height. The preferred geometric shape has a T-to-H ratio defined by the following equation (1). T-to-H ratio = (thickness T4 of the thick stress reduction region) / (height H4 of the thick stress reduction region) --- Equation (1) The T-to-H ratio of the thick stress reduction region 220 of the impact face portion 202 according to this invention is generally between about 0.6 and about 1.1, more preferably between about 0.7 and about 0.9, and most preferably about 0.8. Although it is repetitive, as described above, this ratio is important for achieving the stress reduction characteristics of the impact face portion 202 while minimizing the unnecessary mass added by the addition of the thick stress reduction region 220.

[0047] The thickness of the thin peripheral region 222 can generally be the same regardless of whether it is located in the upper thin peripheral region 22-a or the lower thin peripheral region 222-b. Accordingly, both thicknesses T5-a and T5-b are less than about 3.0 mm, more preferably less than about 2.8 mm, and most preferably less than about 2.7 mm. However, in another embodiment of this invention, the values of T5-a and T5-b may be slightly different from each other, and as long as both are within the above range, they do not deviate from the scope and content of this invention.

[0048] Another important relationship that is valuable to emphasize here is the ratio of the thickness T1 of the thick central region 714 to the thickness T4 of the thick stress reduction region 720. Introducing the thick stress reduction region 720 significantly reduces the overall thickness and mass of the entire striking face portion 702, so the resulting relationship between the two thicknesses is very important for achieving the improved performance of this invention. In this exemplary embodiment of this invention, the ratio of T4 to T1 is generally greater than about 1, more preferably greater than about 1.15, and most preferably greater than about 1.375. In other words, it can be said that the thickness T4 of the thick stress reduction region 220 is greater than the thickness T1 of the thick central region 214 or any other position along the entire striking face portion 202. The thickest part of the striking face portion 202 is located on the thick stress reduction region 220.

[0049] FIG. 5 of the accompanying drawings shows an enlarged cross-sectional view of the striking face portion 202 of the golf club head 200 similar to FIGS. 3 and 4. However, this time, the focus is on the transition from the thick stress reduction region 220 to the adjacent thin intermediate region 218 and the thin peripheral region 222. In this embodiment of this invention, the various radii around the thick stress reduction region 220 are also important for the proper functioning of this invention. This is because undesirable radii not only do not serve the purpose of reducing stress but may also add manufacturing challenges. Above all, the radii need to minimize the undesirable weight addition caused by the addition of the thick stress reduction region 220 on the one hand and balance the stress and manufacturing challenges caused by the thick stress reduction region 220 on the other hand.

[0050] The radii R5-a and R5-b represent the blend from the stress reduction regions 220-a and 220-b with a large thickness to the peripheral regions 222-a and 222-b with a small thickness, which is a radius of curvature. In this embodiment, R5-a and R5-b may generally be the same number. Typically, it is about 1.0 mm to about 1.4 mm, more preferably about 1.1 mm to about 1.3 mm, and most preferably about 1.2 mm. However, in other embodiments of this invention, it should be noted that as long as R5-a and R5-b are within the above-mentioned radius range, they may be different from each other without departing from the scope and content of this invention.

[0051] The radii R3-a and R3-b represent the blend from the stress reduction regions 220-a and 220-b with a large thickness to the intermediate regions 218-a and 218-b with a small thickness, which is a radius of curvature. In this embodiment, R3-a and R3-b may generally be the same, and may also be the same as the above-mentioned R5-a and R5-b. They may be between about 1.0 mm and about 1.4 mm, more preferably between about 1.1 mm and about 1.3 mm, and most preferably about 1.2 mm. However, in other embodiments of this invention, it should be noted that as long as R3-a and R3-b are within the above-mentioned radius range, they may be different from each other without departing from the scope and content of this invention.

[0052] Here, it is beneficial to note that the radii of the blends from the stress reduction region 220 with a large thickness to the peripheral region 222 and the intermediate region 218 with a small thickness, respectively denoted as R5 and R3, may generally be the same as each other. However, as described above, in other embodiments of this invention, as long as these numbers are within the above-mentioned range, they may be different from each other without departing from the scope and content of this invention.

[0053] Figures 6a through 6L of the accompanying drawings show alternative shapes of the thick stress reduction region 220. Referring to FIG. 6a, a substantially rectangular design is shown here, similar to the aforementioned design with an added transition radius. FIG. 6b of the accompanying drawings shows an alternative outward taper design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6c of the accompanying drawings shows another inward taper design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6d of the accompanying drawings shows an alternative outward taper with a constant offset design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6e of the accompanying drawings shows an alternative outward taper with an inner offset design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6f of the accompanying drawings shows an alternative outward taper with an outward offset design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6g of the accompanying drawings shows an alternative triangular chevron design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6h of the accompanying drawings shows an alternative inner offset triangular chevron design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6i of the accompanying drawings shows an alternative outward offset triangular chevron design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6j of the accompanying drawings shows an alternative hemispherical design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6k of the accompanying drawings shows an alternative organic design of the thick stress reduction region 220 according to an alternative embodiment of this invention. FIG. 6L of the accompanying drawings shows an alternative tapered design of a recessed channel of the thick stress reduction region 220 according to an alternative embodiment of this invention.

[0054] Figures 7a and 7b show rear views of the striking face portion 702 of a golf club head according to an exemplary embodiment of the present invention. In FIG. 7a, a shaded view is presented to better visualize the various components of the striking face portion 702. In FIG. 7a, the thin peripheral region 722 forms the outer periphery of the striking face portion 702. Looking inward from the thin peripheral region 722, a thick stress reduction region 720 can be seen. Inside the thick stress reduction region 720 is a thin intermediate region 718. Inside the thin intermediate region 718 is a central transition region 716. Finally, at the geometric center of the striking face portion 702 is a thick central region 714. In addition to showing the various components of the striking face portion 702, FIG. 7a also shows how the heights of the various components vary depending on where they are on the face, and previous measurements of the heights of the various components referred only to cross-sections along the geometric center of the face, as shown in FIG. 1. In one example, the height of the intermediate transition region 718 is generally smaller at the crown and sole portions of the striking face portion 702 compared to the height of the intermediate transition region 718 at the heel and toe portions of the striking face portion 702.

[0055] Stated another way, the striking face can be said to have a thick central region 714 located near the geometric center of the striking face portion 702, a central transition region 716 extending radially outward from this thick central region 714, a thin intermediate region 718 extending radially outward from the central transition region 716, a thick stress reduction region 720 extending radially outward from the intermediate region 718, and finally, a thin peripheral region 722 extending outward from the thick stress reduction region 720.

[0056] To better show the differences in height of various components along different parts of the face, FIG. 7b shows a rear view of the striking face portion 702 without shading. In addition to the above, FIG. 7b enables a more detailed indication of the radial distances of the various components since all measurements are obtained from the geometric face center 108 (shown in FIG. 1). This is similar to the above description regarding the position of the thick stress reduction region 220 in FIG. 2. However, the distances provided here are not restricted to a specific cross-section A-A' as in the previous description in FIG. 2, but rather are measurements of the minimum and maximum radial distances. In the rear view of the striking face portion 702 shown in FIG. 7b, it can be seen that the outer perimeter of the thick central region 714 is generally located within a projection distance D1 between approximately 4.00 mm and approximately 14.0 mm from the geometric face center over any radial direction. The outer perimeter of the central transition region 716 can generally be positioned at a distance D2 between approximately 13.0 mm and approximately 30.0 mm from the geometric face center over any radial direction. The outer perimeter of the thin intermediate region 718 can generally be positioned at a distance D3 between approximately 17.0 mm and approximately 40.0 mm from the face center over any radial direction. The outer perimeter of the thick stress reduction region 720 can generally be positioned at a distance D4 between approximately 15.0 mm and approximately 46.0 mm from the face center over any radial direction. Finally, the outer perimeter of the thin peripheral region 722 can generally be positioned at a distance D5 between approximately 25.50 mm and approximately 55.5 mm from the face center over any radial direction.

[0057] FIG. 8 of the accompanying drawings shows a cross-sectional view of a golf club head 800 according to an alternative embodiment of this invention along the section line A-A' shown in FIG. 1. In this cross-sectional view of this invention, the shape and geometry of the upper thick stress reduction region 820-a are changed to be different from those of the lower thick stress reduction region 820-b, generally serving to address the high stress levels occurring in the upper crown region of the striking face portion 802. To show the differences in height and radius of curvature of the blend between the upper thick stress reduction region 820-a and the lower thick stress reduction region 820-b, an enlarged view of the striking face portion 802 is provided in FIG. 9.

[0058] Figure 9 of the accompanying drawings shows an enlarged view of a cross-sectional view of the hitting face portion 802 of the golf club head 800 shown in Figure 8. In this enlarged cross-sectional view, only the features that distinguish this embodiment of the present invention from the previous embodiments are emphasized. In this alternative embodiment of the present invention, the height H4-a of the upper thick stress reduction region 820-a is no longer the same as the height H4-b of the lower thick stress reduction region 820-b. In fact, the height H4-a of the upper thick stress reduction region 820-a is reduced to address the stress increase factors that often occur at the upper part of the hitting face portion 802. When the upper stress reduction region 820-a becomes thicker, the height H3-a of the upper thin intermediate region 818-a increases. In addition to the above points, in order to further reduce stress, the radius R3-a between the upper thick stress reduction region 820-a and the upper thin intermediate region 818-a is increased to create a smoother blend at this position. Finally, regardless of dealing with the stress level of the hitting face portion 802, the radius R5-a between the upper thick stress reduction region 820-a and the upper thin peripheral region 822-a is also increased to soften the blend and make it easier to manufacture.

[0059] Digging deeper into the numbers, the height H4-a of the upper thick stress reduction region 820-a according to this embodiment of the present invention is generally between about 3.1 mm and about 3.9 mm, more preferably between about 3.3 mm and about 3.7 mm, and most preferably about 3.5 mm, and can be between, which is about 0.5 mm shorter than the corresponding portion H4-b located in the lower thick stress reduction region 820-b. The height H3-a of the upper thin intermediate region 818-a according to the current embodiment of the present invention is generally between about 6.5 mm and about 8.5 mm, more preferably between about 7.0 mm and about 8.0 mm, and most preferably about 7.5 mm, and thus becomes almost the same as the corresponding portion H3-b located in the lower thin intermediate region 818-b.

[0060] In addition to the change in height, the radii R3-a and R5-a of the upper thick-walled stress reduction regions 820-a are also changed to be different from the corresponding portions of the lower thick-walled stress reduction regions 820-b. By increasing the radius of curvature of R3-a, the transition between two adjacent components becomes smoother, which helps to eliminate the possible stress increase that may occur at that portion of the striking face portion 802. R3-a according to this embodiment of the present invention may generally exceed about 1.50 mm, more preferably exceed about 1.60 mm, and more preferably exceed about 1.70 mm. On the other hand, although the radius of curvature R5-a also increases to be smoother, this time, in consideration of the less prominent region of the reduced casting flow for manufacturing reasons. Therefore, R5-a according to this embodiment of the present invention may generally exceed about 1.50 mm, more preferably exceed about 1.60 mm, and more preferably exceed about 1.70 mm. Therefore, it is worth noting here that in this embodiment, it is important that the radius of curvature of the transition portion of the upper thick-walled stress reduction region 820-a is larger than the radius of curvature of the transition portion of the lower thick-walled stress reduction region 820-b. Because the striking face portion 802 often exhibits a higher stress level at that position.

[0061] Figures 10a and 10b show rear views of the striking face portion 1002 of a golf club head according to an exemplary embodiment of the present invention. In Figure 10a, a shaded view is presented to provide a better visualization of the various components of the striking face portion 1002. In the shaded view shown in Figure 10a and the wireframe view shown in Figure 10b, an adjustment to the upper thick stress reduction region 1020-a is seen, and its height H4-a (shown in Figure 9) is small compared to the rest of the thick stress reduction region 1020-a. Here, another notable thing not previously mentioned is that in the current exemplary embodiment of the present invention, the entire thick stress reduction region 1020 takes the form of a ring surrounding the central portion of the striking face portion 1002. However, in an alternative embodiment of the present invention, the thick stress reduction region 1020 need not completely surround the striking face portion 1002 and may partially surround the striking face portion without departing from the scope and content of the present invention. In other words, the thick stress reduction region 1020 may surround less than 360 degrees around the face, less than about 270 degrees around the face, or less than 180 degrees around the face without departing from the scope and content of the present invention.

[0062] Figures 11 through 15 of the accompanying drawings show golf club heads according to still other embodiments of the present invention, where the thick stress reduction region is formed from a plurality of materials to achieve further improvement in the stress reduction ability of the thick stress reduction region.

[0063] Figure 11 of the accompanying drawings shows an exploded perspective view of a golf club head 1100 according to yet another embodiment of the present invention, and the thick stress reduction region is formed from a plurality of materials. In this exploded cross-sectional view of the golf club head 1100 shown in FIG. 11, as shown in FIG. 11, the body portion 1103 has a pocket 1134 with a peripheral ledge 1132, and the peripheral ledge 1132 aids in accommodating the gasket 1130, and the gasket 1130 separates the face insert 1104 from the peripheral ledge 1132. In this embodiment of the present invention, the combination of the peripheral ledge 1132, the gasket 1130, and the periphery of the face insert 1104 combine to create a thickened stress reduction region (shown in FIG. 12).

[0064] [Figure 12 of the accompanying drawings shows a cross-sectional view of a golf club head 1200 according to an alternative embodiment of the present invention along the section line A-A' shown in FIG. 1. In this cross-sectional view of the golf club head 1200, it can be seen that the golf club head 1200 can be divided into a front hitting face portion 1202 and a rear body portion 1203, similar to the previous embodiment. The front hitting face portion 1202 is further composed of an open pocket 1234 adapted to receive a face insert 1204 as in the previous embodiment. However, in this embodiment of the present invention, instead of directly welding the face insert 1204 around the pocket 1234 as is generally known in the industry, the open pocket 1234 creates a peripheral ledge 1232 recessed from the outer surface of the hitting face, and this peripheral ledge 1232 is adapted to receive a gasket 1230 that separates the face insert 1204 from the peripheral ledge 1232. In this cross-sectional view of the present invention, it is clearly seen that the combination of the peripheral ledge 1232, the gasket 1230, and the periphery of the face insert 1204 combine to create a thick stress reduction region 1220. The thick stress reduction region 1220 in this embodiment may be further formed as an upper thick stress reduction region 1220-a and a lower thick stress reduction region 1220-b, both of which have dimensional measurements similar to those of the previous embodiment described above.

[0065] In this embodiment of the present invention, the face insert 1204, the gasket 1230, and the peripheral ledge 1232 may generally be bonded together using a certain type of adhesive. However, in an alternative embodiment of the present invention, the three components that form the thick stress reduction region 1220, which may have different material properties, may all rely on various joining techniques such as brazing, swaging, or mechanical fasteners without departing from the scope and content of the present invention. This does not depart from the scope and content of the present invention as long as the face insert 1204 is not directly bonded to the peripheral ledge 1232 itself.

[0066] The material used to create the gasket 1230 is also important in this embodiment of the present invention and can help reduce the stress around the front impact face portion 1202. In this embodiment, the material used to create the gasket may generally have a modulus of elasticity, or Young's modulus, between about 5 GPa and about 120 GPa, more preferably between about 10 GPa and about 80 GPa, and most preferably about 30 GPa. In addition to the above, the gasket 1230 may also have a density of less than about 2,000 g / cc, more preferably less than about 1,900 g / cc, and most preferably less than about 1,800 g / cc, all without departing from the scope and content of the present invention.

[0067] To show a part of the dimensions of the gasket 1230 itself, an enlarged cross-sectional view of the front impact face portion 1202 is shown in FIG. 13. In the portion shown in this FIG. 13, it can be seen that the gasket 1230 can have substantially the same upper gasket height H6-a and lower gasket height H6-b. H6-a and H6-b according to this embodiment of the present invention can generally be from about 3.0 mm to about 7.0 mm, more preferably from about 4.0 mm to about 6.0 mm, and most preferably about 5.0 mm. FIG. 13 also shows the gasket thickness T6, shown as the upper gasket thickness T6-a and the lower gasket thickness T6-b, both of which are substantially the same in this embodiment of the present invention. Therefore, T6-a and T6-b according to this embodiment of the present invention can generally be between about 0.3 mm and about 0.7 mm, more preferably between about 0.4 mm and about 0.6 mm, and most preferably about 0.5 mm.

[0068] Based on the above thickness and height measurements, it can be said that the gasket 1230 may have a T-to-H ratio defined by the following formula (2). T-to-H ratio = (gasket thickness T6) / (gasket height H6) --- (2) The T-to-H ratio of the gasket 1230 can generally be between about 0.04 and about 0.23, more preferably between about 0.06 and about 0.15, and most preferably about 0.1.

[0069] Although the thickness and height of gasket 1230 are the same for the upper part of gasket 1230 and the lower part of gasket 1230, it should also be noted that the thickness and height of the gasket may be different from each other. This does not deviate from the scope and content of this invention. In an exemplary embodiment, the upper part of gasket 1230 can be made thicker and the lower part of gasket 1230 can be made thinner so that when colliding with a golf ball, the striking face portion 1202 deflects more downward, which can assist in reducing the downward launch and spin, and this does not deviate from the scope and content of this invention. Needless to say, when operating the thickness of gasket 1230, usually, the depth of the peripheral ledge 1232 is adjusted accordingly to create a seamless and flat appearance of the golf club head at the rest neutral position. Alternatively, although the thickness of the material can also be maintained, the elastic modulus is adjusted to achieve the same effect without deviating from the scope and content of this invention.

[0070] FIG. 14 of the accompanying drawings shows a rear view of the striking face portion 1402 of a golf club head according to a further alternative embodiment of this invention. In this embodiment of this invention shown in FIG. 14, it can be seen that the front striking face portion 1402 may include a thick stress reduction region 1420 that only partially forms a part of the ring, as shown in the previous embodiments. More specifically, the thick stress reduction region 1420 shown in this embodiment of this invention shown in FIG. 14 only exists in the upper crown region and the lower sole region through the upper thick stress reduction region 1420-a and the lower thick stress reduction region 1420-b.

[0071] Here, the rear view of the hitting face portion 1402 shown in FIG. 14 shows, in addition to the upper thick - stress - reduction region 1420 - a and the lower thick - stress - reduction region 1420 - b, a thick - central region 1414, a central - transition region 1416, a thin - middle region 1418, and a thin - peripheral region 1422. This rear view of the hitting face portion 1402 shows that the upper thick - stress - reduction region 1420 - a and the lower thick - stress - reduction region 1420 - b are joined together to form only a part of the ring shape as previously shown in FIG. 7. In other words, the thick - stress - reduction region 1420 does not completely surround the thin - middle region 1418, but only partially surrounds it. It can also be said that the thick - stress - reduction region is formed over less than 360 degrees in the radial direction around the thin - middle region 1418.

[0072] In addition to visually highlighting the currently - separated upper thick - stress - reduction region 1420 - a and the lower thick - stress - reduction region 1420 - b, FIG. 14 of the accompanying drawings also creates a ray mark (clock grid) 1440 to more specifically identify the positions of the upper thick - stress - reduction region 1420 - a and the lower thick - stress - reduction region 1420 - b with respect to the geometric face center 1408. More specifically, the ray mark 1440 comprises a 12 - o'clock ray mark 1440 - 12, a 1 - o'clock ray mark 1440 - 1, a 2 - o'clock ray mark 1440 - 2, a 3 - o'clock ray mark 1440 - 3, a 4 - o'clock ray mark 1440 - 4, a 5 - o'clock ray mark 1440 - 5, a 6 - o'clock ray mark 1440 - 6, a 7 - o'clock ray mark 1440 - 7, an 8 - o'clock ray mark 1440 - 8, a 9 - o'clock ray mark 1440 - 9, a 10 - o'clock ray mark 1440 - 10, and an 11 - o'clock ray mark 1440 - 11, dividing various parts of the hitting face portion 1402 into 12 separate regions in the radial direction.

[0073] When the light mark 1440 is established, in this exemplary embodiment of the present invention, it can be seen that the upper thick-thickness stress reduction region 1420-a is positioned in the upper region located between the light mark 1440-10 at 10 o'clock and the light mark 1440-2 at 2 o'clock. The lower thick-thickness stress reduction region 1420-b is positioned in the lower region located between the light mark 1440-4 at 4 o'clock and the light mark 1440-8 at 8 o'clock. The said ranges of the positions of the upper thick-thickness stress reduction region 1420-a and the lower thick-thickness stress reduction region 1420-b are important for this invention because they maintain structural rigidity, reduce the stress level of the striking face portion 1402 only at the positions where it is specified to be necessary, and are removed from the places where such a function is not required.

[0074] Here, it should be noted that in order to avoid confusion when referring to ranges in this application, the boundaries of the light marks are always referred to in the clockwise direction.

[0075] In other words, it can be said that the thick-thickness stress reduction region is only located in the region consisting of the upper region between the light mark 1440-10 at 10 o'clock and the light mark 1440-2 at 2 o'clock and the lower region between the light mark 1440-4 at 4 o'clock and the light mark 1440-8 at 8 o'clock.

[0076] FIG. 15 of the accompanying drawings shows a rear view of the striking face portion 1502 of a golf club head according to a further alternative embodiment of the present invention. In this embodiment of the present invention, the upper thick-thickness stress reduction region 1520-a is located in the upper region between the light mark 1540-9 at 9 o'clock and the light mark at 2 o'clock, while the lower thick-thickness stress reduction region 1520-b is located in the lower region between the light mark 1540-3 at 3 o'clock and the light mark 1540-9 at 9 o'clock, which does not deviate from the scope and content of this invention. Here, it should be noted that the boundaries between the upper thick-thickness stress reduction region 1520-a and the lower thick-thickness stress reduction region 1520-b may have a certain degree of overlap with each other, and they should be noted as individual components involving separation, which remains within the scope and content of this invention.

[0077] In other words, it can be said that the thick-thickness stress reduction region is only located in the upper region between the light ray mark 1540-9 at 9 o'clock and the light ray mark 1540-2 in the 2 o'clock direction and the lower region between the light ray mark 1540-3 at 3 o'clock and the light ray mark 1540-9 at 9 o'clock.

[0078] FIG. 16 of the accompanying drawings shows an enlarged cross-sectional view of the striking face portion 1602 according to an alternative embodiment of the present invention, and can show in more detail the thick-thickness stress reduction region 1620 that does not cover 360 degrees. In this figure, it can be seen that the actual cross-sectional view of the striking face portion 1602 including the upper thin-thickness intermediate region 1618-a, the lower thin-thickness intermediate region 1618-b, the upper thick-thickness stress reduction region 1620-a, the lower thick-thickness stress reduction region 1620-b, the upper thin-thickness peripheral region 1622-a, and the lower thin-thickness peripheral region 1622-b is not very different from the cross-sectional view of the striking face portion 802 shown in FIG. 9 in the previous embodiment of the present invention. However, upon examining the cross-sectional view of the striking face portion 1602 in detail, it will be found that the inner toe region of the striking face portion 1602 does not contain any features similar to the thick-thickness stress reduction region 1620 as in the previous embodiments shown in FIGS. 14 and 15.

[0079] Figure 17 of the accompanying drawings shows a rear view of the striking face portion 1702 of a golf club head according to yet another alternative embodiment of the present invention. In this embodiment of the present invention, a well-known ray mark 1740 having ray marks 1740-12 at 12 o'clock, 1740-1 at 1 o'clock, 1740-2 at 2 o'clock, 1740-3 at 3 o'clock, 1740-4 at 4 o'clock, 1740-5 at 5 o'clock, 1740-6 at 6 o'clock, 1740-7 at 7 o'clock, 1740-8 at 8 o'clock, 1740-9 at 9 o'clock, 1740-10 at 10 o'clock, and 1740-11 at 11 o'clock can be seen, which radially divides various portions of the striking face portion 1702 into 12 separate regions. However, unlike the embodiment before the thick stress reduction region 1420 (shown in FIG. 14) completely disappears at the heel and toe portions of the striking face portion 1702, the thick stress reduction region 1720 shown in FIG. 17 maintains a minimum wall thickness at the heel portion and toe portion of the striking face portion 1702.

[0080] In this embodiment of the present invention shown in FIG. 17, the thick stress reduction region 1720 is a single continuous structure, which includes an upper thick stress reduction region 1720-a, a lower thick stress reduction region 1720-b, a toe thick stress reduction region 1720-c, and a heel thick stress reduction region 1720-d. The toe thick stress reduction region 1720-c and the heel thick stress reduction region 1720-d have relatively small thicknesses compared to the upper thick stress reduction region 1720-a and the lower thick stress reduction region 1720-a.

[0081] In other words, in this embodiment of the present invention, the thick stress reduction region may include a region where the thickness decreases between the ray mark 1740-1 at 1 o'clock and the ray mark 1740-4 at 4 o'clock to form the toe thick stress reduction region 1720-c, and a region where the thickness is reduced between the ray mark 1740-8 at 8 o'clock and the ray mark 1740-10 at 10 o'clock to form the heel thick stress reduction region 1720-d.

[0082] Figure 18 of the accompanying drawings shows an enlarged cross-sectional view of the striking face portion 1802 according to an alternative embodiment of the present invention, and can show in more detail the thick stress reduction region 1820 with reduced thickness. Similar to the previous embodiment, this cross-sectional view of the striking face portion 1802 includes an upper thin middle region 1818-a, a lower thin middle region 1818-b, an upper thick stress reduction region 1820-a, a lower thick stress reduction region 1820-b, an upper thin peripheral region 1822-a, and a lower thin peripheral region 1822-b. However, this figure shown in FIG. 18 can show the reduced thickness of the toe thick stress reduction region 1820-c.

[0083] Figure 19 of the accompanying drawings shows a rear view of the striking face portion 1902 of a golf club head according to still another embodiment of the present invention. In this embodiment of the present invention, the thickened stress reduction region 1920 extends radially outward from the thinner middle region 1918. However, in this embodiment of the present invention, the thickened stress reduction region 1920 has a horseshoe shape rather than a ring shape, and serves to accommodate face inserts 1904 of different shapes that can improve the performance of the striking face portion 1902. More specifically, from FIG. 19, it can be seen that the thickened stress reduction region 1920 may include two upper stress reduction regions 1920a designated as a toe-side upper thick stress reduction region 1920-a1 and a heel-side upper thick stress reduction region 1920-a2. It should be noted that both the toe-side upper thick stress reduction region 1920-a1 and the heel-side upper thick stress reduction region 1920-a2 are directly connected to the crown transition portion of the striking face portion 1902. That is, instead of directly connecting to each other at the crown portion of the striking face portion 1902 to form a complete ring, rather, it creates a discontinuity that forms an incomplete circle. Alternatively, it can be said that the stress reduction region 1920 forms the above-mentioned horseshoe shape. As a result, due to the thickened horseshoe-shaped stress reduction region 1920, an opening is formed near the upper crown portion of the striking face portion 1902.

[0084] Here, the toe-side upper thick stress reduction region 1920-a1 is connected to the toe-side thick stress reduction region 1920-c on the toe side of the striking face portion 1902. This region is connected to the lower thick stress reduction region 1920-b on the sole side of the striking face portion 1902, and this region is connected to the heel-side thick stress reduction region 1920-d. However, it remains cut in the upper crown region of the striking face portion 1902 and houses the higher face insert 1904. This face insert 1904 is designed to be higher in the central region of the face insert 1904, which helps to move the weld line between the face insert 1904 and the surrounding region 1903 (shown in FIG. 20) further away from the location where high stress is generated in this current design. To further show the shapes of the surrounding region 1903 and the central opening 2050 (shown in FIG. 20), FIG. 20 shows the state with the face insert 1904 removed.

[0085] Finally, in FIG. 20, it can be seen that the cross-section line 22-22’ is drawn vertically through the striking face portion 1902 such that it passes through the geometric face center 1908 of the striking face portion 1902. The cross-sectional view of the striking face portion 1902 of the golf club head shown in FIG. 22, which will be presented later, can show the various dimensions of the striking face portion 1902 in more detail later.

[0086] Figure 20 of the accompanying drawings shows a rear view of the striking face portion 2002 of a golf club head according to yet another embodiment of the present invention. The face insert 1904 shown in FIG. 19 is removed, and the central opening 2050 is more clearly shown together with the boundary of the face periphery 2006. The striking face portion 2002 shown in FIG. 20 has a central opening 2050 that substantially coincides with the inner circumference of the horseshoe-shaped thickened stress reduction region 2020 in order to pair with the horseshoe-shaped thickened stress reduction region 2020. FIG. 20 of the accompanying drawings shows not only the boundary of the central opening 2050 but also the distance from the top ledge of the central opening 2050 to the crown tip of the striking face portion 2002, and this distance is indicated by the distance D6 shown here. The distance D6 shown in FIG. 20 indicates how much the distance is shortened compared to a conventional golf club head, and is generally less than about 1.25 mm, more preferably less than about 1.00 mm, and most preferably less than about 0.95 mm. The distance D6 shown in this embodiment of the present invention is generally taken at the geometric center 2008 of the Y-axis shown in FIG. 1, that is, the plane indicated by the dashed line shown in FIG. 20.

[0087] The conventional face insert 104 (see FIG. 1) typically has a substantially elliptical shape designed to match the contour of the striking face portion 102 (see FIG. 1) with an aspect ratio of about 2.0. However, the face insert 2104 according to this embodiment of the present invention has a high face, so the aspect ratio is about 1.3 to about 1.7, more preferably about 1.4 to about 1.6, and most preferably about 1.5. FIG. 21 of the accompanying drawings shows a rear view of only the face insert 2104 according to this alternative embodiment of the present invention. The aspect ratio of the face insert 2104 can generally be defined as the ratio of the width D7 of the face insert 2104 divided by the height D8 of the face insert 2104. In one exemplary embodiment of the present invention, the width D7 of the face insert 2104 is generally between about 60 mm and about 64 mm, more preferably between about 61 mm and about 63 mm, and most preferably about 62 mm. The height D8 of the face insert 2104 is generally between about 40 mm and about 44 mm, more preferably between about 41 mm and about 43 mm, and most preferably about 42 mm. Needless to say, it is the central opening 2050 (shown in FIG. 20).

[0088] In other words, it can be said that the striking face portion 1902 is disposed at the front portion of the golf club head adapted to strike a golf ball and at the body portion attached to the rear portion of the striking face portion 1902. The striking face portion 1902 includes a face perimeter 2006 having a central opening 2050, and the face perimeter 2006 includes a horseshoe-shaped thick stress reduction region 2020 having a fourth thickness. The striking face portion 1902 further includes a face insert 2104 adapted to engage with the central opening 2050, and the face insert 2104 includes a thickened central region located near the geometric center 2108 of the face insert 2104 that defines a first thickness. The thick stress reduction region 2020 within the face perimeter 2006 of the striking face portion 1902 is formed such that no portion of the thick stress reduction region 2020 engages with the face insert 2104. The fourth thickness of the thick stress reduction region 2020 according to a preferred embodiment of the present invention is greater than the first thickness of the central region of the face insert 2104.

[0089] FIG. 22 of the accompanying drawings shows an enlarged cross-sectional view of the striking face portion 2202 of the golf club head taken along the section line 22-22' shown in FIG. 19. In this cross-sectional view of the striking face portion 2202, it can be seen that the face insert 2204 is disposed at a position a distance D6 away from the crown tip of the striking face portion 2202. The crown tip defined in this invention is the position where the striking face portion 2202 ceases to be substantially planar with the striking face plane and begins to transition to the crown. Since the value of the distance D6 has already been described above, it will not be repeated here. In addition to the distance D6, FIG. 22 of the accompanying drawings also shows a distance D9 for measuring the position of the upper end of the face insert 2204 measured from the crown apex 2252. The crown apex 2252 is generally defined as the highest point of the crown in the central cross-section 22-22' shown in FIG. 19. The distance D9 shown in this exemplary embodiment of the present invention is generally less than about 10 mm, more preferably less than about 9 mm, and most preferably less than about 8 mm, none of which depart from the scope and content of the present invention.

[0090] Since the sectional line 22-21' is located at the geometric face center 1908 (see FIG. 19), the thick stress reduction region 2220 bisects the club head at a discontinuous position. Therefore, in this sectional view, the actual thickness of the upper thick stress reduction region is not shown. However, FIG. 22 shows the thickness of the lower thick stress reduction region 2220-b having a thickness T4-b, which is the same as the aforementioned thickness. At the top of the club head, the thickness of the upper thick stress reduction region 1920-a (see FIG. 19) is not visible, but the upper thick stress reduction region 2220-a1 on the toe side appears to be directly connected to the crown transition portion.

[0091] FIG. 22 of the accompanying drawings also shows the thickness of the upper thin peripheral region 2218-a having a thickness T3-a different from the previous embodiments of this invention. The increase in the thickness of the upper thin peripheral region 2218-a is necessary to relieve some of the high stress generated at specific positions of the striking face portion 2202 when hitting a golf ball. The thickness T3-a according to this alternative embodiment of this invention is usually between about 2.3 mm and about 2.6 mm, more preferably between about 2.4 mm and about 2.5 mm, and most preferably about 2.45 mm, none of which deviate from the scope and content of this invention. This position of the upper thin peripheral region 2218-a usually extends above the striking face portion 2202 more than in other embodiments where the thick stress reduction region 2220 forms a complete ring.

[0092] FIG. 23 of the accompanying drawings shows an exploded perspective view of a golf club head 2300 according to this alternative embodiment of this invention. In the exploded view shown in FIG. 23, the face insert 2304 has been moved away from the face perimeter 2306 to expose the central opening 2350, and the relationship between these joined components is shown more clearly. In addition to the above, in the exploded view of the golf club head 2300 shown in FIG. 23, the distance D6 between the top ledge of the central opening and the crown leading edge can be shown from another perspective.

[0093] Figures 24 to 26 show the striking face portion 2402 according to one or more embodiments of the technology disclosed herein. For example, FIG. 24 shows a rear view of the striking face portion 2402 according to one or more embodiments of the technology disclosed herein. FIG. 25 shows cross-sectional views of the striking face portions 2402a, 2402b according to one or more embodiments of the technology disclosed herein taken along line 23-23' of FIG. 24 and line 24-24' of FIG. 24. FIG. 26 shows an exploded perspective view of the striking face portion 2402 according to one or more embodiments of the technology disclosed herein. These figures may each provide different views of the same or similar components and may be described together here. Referring first to FIG. 24, the striking face portion 2402 may include a face insert 2404, a rear inner surface 2412, and / or a central opening 2450. The striking face portion 2402 may include a thick central region 2414, a central transition region 2416, a thin intermediate region 2418, a thick stress reduction region 2420, and / or a thin peripheral region 2422. The striking face portion 2402 may include metal, plastic, composite material, and / or other materials. The metal may include tungsten, steel, titanium, aluminum, scandium, zinc, nickel, copper, iron, alloy, and / or other metals, which is not departing from the spirit and scope of the currently disclosed technology. The plastic may include thermosetting resin, thermoplastic resin, and / or other plastics. The composite material may include various materials known to those skilled in the art, such as graphite, carbon fiber, resin, ceramic, boron fiber, polymer, foam, etc. The rear inner surface 2412, the thick central region 2414, the central transition region 2416, the thin intermediate region 2418, the thick stress reduction region 2420, the thin peripheral region 2422, and / or the central opening 2450 may be the same as or substantially similar to the rear inner surface, thick central region, central transition region, thin intermediate region, thick stress reduction region, thin peripheral region, and / or central opening described herein.

[0094] One or more of these regions may be positioned on and / or integrated with the face insert 2404. For example, the face insert 2404 may include a central region 2414, a central transition region 2416, a thin intermediate region 2418, a thick stress reduction region 2420, and / or a thin peripheral region 2422. One or more of these regions may be of a material different from that of the face insert 2404 or may be of different materials from each other. For example, the central region 2414 may be steel, and the thick stress reduction region 2420 may be, as described herein, other metals (e.g., titanium), plastics, and / or composite materials. The thick stress reduction region 2420 may be horseshoe-shaped as described herein. In some embodiments, the thick stress reduction region 2420 may be co-molded with the face insert 2404. In some embodiments, the thick stress reduction region 2420 may be fixed to the face insert 2404 by welding, brazing, adhesion, or other means. In some embodiments, the thick stress reduction region 2420 and / or other regions may be manufactured by machining, forging, casting, printing, and / or other means. In some embodiments, the face insert 2404 may include a part of the thin peripheral region 2422. In some embodiments, the face insert 2404 may include a part of the thick stress reduction region 2420. The face insert 2404 may be manufactured by machining, forging, casting, printing, and / or other means.

[0095] Referring to FIG. 25, one or more components of the striking face portion 2402a may be more apparent in this figure. For example, the thicknesses of the thick central regions 2414a, 2414b, the central transition regions 2416a, 2416b, the thin intermediate regions 2418a, 2418b, the thick stress reduction regions 2420a, 2420b, and / or the thin peripheral regions 2422a, 2422b may be more apparent. In the case of the U-shaped thick stress reduction region 2420a, the thick stress reduction region 2420a may appear only at the lower part of the stress reduction region 2402a. In the cross-section along 23-23’, the thick stress reduction region 2420a is U-shaped, and its upper part may not be visible. This is because the toe tip of the thick stress reduction region 2420a extends upward and does not extend rearward toward the center of the face insert 2404a. The contours of the central openings 2450a, 2450b are more apparent in this figure above the upper part of the face insert 2404a, below the bottom of the face insert 2404a, and on the heel side and toe side of the face insert 2404b.

[0096] Referring to FIG. 26, one or more components of the striking face portion 2402 become more apparent in this figure. For example, the central opening 2450 will become apparent in this figure. The face insert 2404 may cover the central opening 2450. The face insert 2404 may fit into the central opening 2450. At the fitting position, the face insert 2404 may be fixed to the striking face portion 2402 by bonding, welding, brazing, adhesion, or other methods so as to cover the central opening 2450.

[0097] By incorporating one or more of these regions into the face insert 2404, the presently disclosed golf club head can be manufactured more consistently. This reduces the additional finishing and / or manufacturing steps for attaching the face insert 2404 to the central opening 2450. Also, with minimal additional finishing steps, the accuracy of the intended tolerances of one or more components of the technology disclosed herein can be improved. Incorporating one or more regions into the face insert 2404 may also be useful for characteristic time, center of gravity, stress, mass properties, undercuts, and / or golf club characteristics.

[0098] Most of the embodiments described herein are intended to create a releasable hosel hole cover, but it should be noted that all of these embodiments may include an adhesive to keep the hosel hole cover within the hosel hole, making the hosel hole cover non-removable. This does not depart from the scope and content of this invention.

[0099] Except for the operating examples, or unless otherwise specified, all numerical ranges, amounts, values, and percentages such as the amount of material, moment of inertia, center of gravity position, loft, draft angle, various performance ratios, and others in the previous part of this specification should be understood as if the term "about" preceded the value, amount, or range, even if the term "about" does not explicitly appear in the value, amount, or range. Accordingly, unless otherwise indicated, the numerical parameters set forth in the above specification and the appended utility model registration claims are approximate values that may vary depending on the desired characteristics required to be obtained by this 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 by applying ordinary rounding techniques in light of the reported significant digits.

[0100] Numerical ranges and parameters which show the broad scope of this invention are approximations, and although the numerical values shown in specific examples are reported as accurately as possible, each numerical value inherently contains certain errors resulting from the standard deviation found in each respective test measurement. Further, when numerical ranges of various values are set forth herein, it should be noted that any combination of these values including the recited values may be used.

[0101] Of course, it should be understood that the foregoing description relates to exemplary embodiments of this invention and that modifications can be made without departing from the spirit and scope of this invention as set forth in the following claims for utility model registration.

Explanation of Signs

[0102] 100 Golf club head 101 Coordinate system 102 Impact face portion 104 Face insert 106 Periphery of face 108 Geometric face center 200 Golf club head 202 Impact face portion 203 Rear body portion 204 Face insert 206 Periphery of face 210 Front impact surface 212 Rear inner surface 214 Central region 216 Central transition region 216-a Upper central transition region 216-b Lower central transition region 218 Intermediate region 218-a Upper intermediate region 218-b Lower intermediate region 220 Stress reduction region 220-a Stress reduction region 220-b Stress reduction region 222 Peripheral region 222-a Upper peripheral region 222-b lower peripheral region 702 hitting face portion 714 central region 716 central transition region 718 thin middle region 720 stress reduction region 722 thin peripheral region 800 golf club head 802 hitting face portion 818-a middle region 818-b middle region 820-a stress reduction region 820-b stress reduction region 822-a peripheral region 1002 hitting face portion 1020 stress reduction region 1020-a thin stress reduction region 1100 golf club head 1103 body portion 1104 face insert 1130 gasket 1132 peripheral ledge 1134 pocket 1200 golf club head 1202 hitting face portion 1203 rear body portion 1204 face insert 1220 stress reduction region 1220-a stress reduction region 1220-b stress reduction region 1230 gasket 1232 peripheral ledge 1234 open pocket 1402 hitting face portion 1408 geometric face center 1414 thick central region 1416 central transition region 1418 thin middle region 1420 thick stress reduction region 1420-a upper thick stress reduction region 1420-b Lower thick meat stress reduction area 1422 Thin meat surrounding area 1440 Light mark 1502 Impact face part 1520-a Upper thick meat stress reduction area 1520-b Lower thick meat stress reduction area 1540 Light mark 1602 Impact face part 1618-a Upper thin meat middle area 1618-b Lower thin meat middle area 1620 Thick meat stress reduction area 1620-a Upper thick meat stress reduction area 1620-b Lower thick meat stress reduction area 1622-a Upper thin meat surrounding area 1622-b Lower thin meat surrounding area 1702 Impact face part 1720 Thick meat stress reduction area 1720-a Upper thick meat stress reduction area 1720-b Lower thick meat stress reduction area 1720-c Toe thick meat stress reduction area 1720-d Heel thick meat stress reduction area 1740 Light mark 1802 Impact face part 1818-a Upper thin meat middle area 1818-b Lower thin meat middle area 1820 Thick meat stress reduction area 1820-a Upper thick meat stress reduction area 1820-b Lower thick meat stress reduction area 1820-c Toe thick meat stress reduction area 1822-a Upper thin meat surrounding area 1822-b Lower thin meat surrounding area 1902 Impact face part 1903 Surrounding area 1904 Face insert 1908 Geometric face center 1918 Middle area 1920 Stress reduction area 1920-a Thick-Flesh Stress Reduction Region 1920-a1 Toe-Side Upper Thick-Flesh Stress Reduction Region 1920-a2 Heel-Side Upper Thick-Flesh Stress Reduction Region 1920-b Lower Thick-Flesh Stress Reduction Region 1920-c Toe-Side Thick-Flesh Stress Reduction Region 1920-d Heel-Side Thick-Flesh Stress Reduction Region 1920a Upper Stress Reduction Region 2002 Impact Face Portion 2006 Face Periphery 2008 Geometric Center 2020 Horseshoe-Shaped Thick-Flesh Stress Reduction Region 2050 Central Opening 2104 Face Insert 2108 Geometric Center 2202 Impact Face Portion 2204 Face Insert 2218-a Upper Thin-Flesh Peripheral Region 2218-a Peripheral Region 2220 Thick-Flesh Stress Reduction Region 2220-a1 Upper Thick-Flesh Stress Reduction Region 2220-b Lower Thick-Flesh Stress Reduction Region 2252 Crown Apex 2300 Golf Club Head 2304 Face Insert 2306 Face Periphery 2350 Central Opening 2402 Impact Face Portion 2402a Impact Face Portion 2404 Face Insert 2404a Face Insert 2404b Face Insert 2412 Rear Inner Surface 2414 Central Region 2414a, 2414b Central Region 2416 Central Transition Region 2416a, 2416b Central Transition Region 2418 Intermediate Region Intermediate region between 2418a and 2418b Stress reduction region 2420 Stress reduction regions 2420a and 2420b Peripheral region 2422 Peripheral regions 2422a and 2422b Central opening 2450 Central openings 2450a and 2450b

Claims

1. In the golf club head, a striking face portion positioned at a forward portion of the golf club head and adapted to strike a golf ball; a body portion attached rearwardly of the striking face portion; The striking face part is A central opening; a face insert covering the central opening; The face insert is a thickened central region located near a geometric center of the face insert, the thickened central region having a first thickness; a central transition region extending radially outward from the thickened central region and having a variable thickness; a reduced-walled intermediate region extending radially outward from the central transition region and having a third thickness; a thickened stress reduction region extending radially outward from the thinned intermediate region, the thickened stress reduction region having a fourth thickness; a thinned peripheral region extending radially outward from the thickened stress reduction region and having a fifth thickness; the thickened stress reduction region forms a horseshoe shaped ring projecting rearwardly from the face insert; The fourth thickness is greater than the first thickness.

2. 2. The golf club head of claim 1, wherein the opening in the horseshoe ring is positioned near a crown transition portion of the face insert.

3. The thickened stress reduced region further comprises: a thickened stress reduction region on the upper toe side; a lower pressure reduction area; and a heel-side upper thickened stress reduction region, 3. The golf club head of claim 2, wherein said toe side upper thickened stress relief region and said heel side upper thickened stress relief region are discontinuous with each other.

4. 4. The golf club head of claim 3, wherein said toe upper thickened stress reduced region is directly bonded to said crown transition portion.

5. 5. The golf club head of claim 4, wherein said heel-side upper thickened stress reduced region is directly bonded to said crown transition portion.

6. The thickened stress reduced region comprises a T to H ratio of between about 0.6 and about 1.1, the T to H ratio being defined as: T-to-H ratio=(fourth thickness T4 of thick stress reduced region) / (height H4 of thick stress reduced region) 6. The golf club head according to claim 5.

7. 7. The golf club head of claim 6, wherein the T to H ratio is between about 0.7 and about 0.

9.

8. 8. The golf club head of claim 7, wherein the T to H ratio is about 0.

8.

9. 2. The golf club head of claim 1, wherein the face insert has an aspect ratio between about 1.3 and about 1.

7.

5. The golf club head according to claim 4.

10. 2. The golf club head of claim 1, wherein the top ledge of the central opening is positioned less than about 10 mm away from the crown apex.

Images