Iron golf club head
The iron golf club head with toe-side and heel-side slits in the sole portion addresses the challenge of providing a sweet spot at low positions, enhancing rebound performance and increasing ball flight distance by storing and restoring elastic energy.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SUMITOMO RUBBER INDUSTRIES LTD
- Filing Date
- 2022-09-01
- Publication Date
- 2026-07-29
AI Technical Summary
Iron golf club heads face challenges in providing a sweet spot at low positions, making it difficult to achieve a large hitting distance when striking a golf ball directly placed on the grass.
The iron golf club head features a novel structure with toe-side and heel-side slits in the sole portion, allowing the central sole portion to flex easily, storing elastic energy and enhancing the rebound performance of the face portion, thereby increasing the ball flight distance.
The novel structure increases the distance of the ball flight by improving the rebound performance through the flex and restorative force of the sole portion, even when struck at lower positions on the hitting surface.
Smart Images
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Abstract
Description
Technical Field
[0007]
[0001] The present disclosure relates to an iron golf club head.
Background Art
[0002] There is a demand for an iron golf club head that can increase the hitting distance. Generally, a large hitting distance can be obtained when hitting a ball at the sweet spot of the face portion. The sweet spot is the point where the normal line drawn from the head center of gravity to the hitting surface of the face portion intersects the hitting surface.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] By the way, an iron golf club head often has an opportunity to hit a golf ball directly placed on the grass. Therefore, the ball is frequently hit at a position about 15 mm upward from the lowermost end of the hitting surface.
[0005] However, due to its structure, it is difficult for an iron golf club head to provide a sweet spot at such a low position as described above.
[0006] The present disclosure has been devised in view of the above circumstances, and the main object thereof is to provide an iron golf club head capable of increasing the hitting distance with a novel structure.
Means for Solving the Problems
[0007] This disclosure relates to an iron golf club head, which, when placed in a reference state, includes a face portion having a striking surface, a face center on the striking surface, a virtual vertical plane passing through the face center and perpendicular to the striking surface, a toe, a heel opposite the toe, and a sole portion extending from the face portion to the rear of the head and forming the bottom surface of the head, wherein the sole portion includes a toe-side slit extending from the rear end of the sole to the front of the head on the toe side of the virtual vertical plane, a heel-side slit extending from the rear end of the sole to the front of the head on the heel side of the virtual vertical plane, a sole central portion divided between the toe-side slit and the heel-side slit, a sole toe portion separated from the sole central portion by the toe-side slit, and a sole heel portion separated from the sole central portion by the heel-side slit. [Effects of the Invention]
[0008] The iron golf club head disclosed herein, through its novel structure, can increase the distance of the ball flight. [Brief explanation of the drawing]
[0009] [Figure 1] This is a front view of the iron golf club head of this embodiment. [Figure 2] This is a rear view of the iron golf club head of this embodiment. [Figure 3] This is a bottom view of the iron golf club head of this embodiment. [Figure 4] This is a cross-sectional view taken along line IV-IV in Figure 2. [Figure 5] Figure 2 is a cross-sectional view along the VV line. [Figure 6] This is a cross-sectional view taken along the line VI-VI in Figure 2. [Figure 7] This is a perspective view illustrating the standard condition of an iron golf club head. [Figure 8] This is a perspective view of the iron golf club head of this embodiment, seen from the rear. [Figure 9] This is a perspective view of the iron golf club head of this embodiment, seen from the rear and below. [Figure 10] This is an enlarged cross-sectional view of the iron golf club head of this embodiment. [Modes for carrying out the invention]
[0010] Embodiments of this disclosure will be described below with reference to the drawings. The embodiments described herein are not intended to limit the disclosure in any way. Furthermore, the various examples described in the embodiments may be implemented individually or in combination with several other examples.
[0011] Figures 1 to 3 are the front view, rear view, and bottom view, respectively, of the iron golf club head (hereinafter sometimes simply referred to as "head") 1 of this embodiment. Figures 4 to 6 are cross-sectional views taken along lines IV-IV, VV, and VI-VI in Figure 2, respectively.
[0012] As shown in Figures 1-6, the head 1 includes, for example, a face 2, a top 3, a sole 4, a toe 5, a heel 6, and a hosel 7. In this embodiment, the head 1 is, for example, entirely made of a metal material. A portion of the head 1 may be made of a non-metallic material, such as fiber-reinforced plastic.
[0013] The face portion 2 includes a striking surface 21, which is the surface for striking the ball. The striking surface 21 is the primary striking area intended for the head 1. As shown in Figure 1, the striking surface 21 has multiple face lines 8 formed on it. The face lines 8 are narrow grooves that extend linearly in the toe-heel direction. The face lines 8 help to increase friction with the ball. Note that the face lines 8 are omitted in all figures except Figure 1.
[0014] [Standard state] In FIGS. 1 and 2, the head 1 is in a reference state. As conceptually shown in FIG. 7, in this specification, the "reference state" of the head 1 means a state where the head 1 is placed on the horizontal plane HP such that the face line 8 formed on the striking face 21 is parallel to the horizontal plane HP. In the reference state, the central axis line CL of the hosel 7 of the head 1 (which corresponds to the axis of the golf club shaft) is arranged within the plane of the reference vertical plane VP. The reference vertical plane VP is a plane perpendicular to the horizontal plane HP. In the reference state, the face line 8 is parallel to both the horizontal plane HP and the reference vertical plane VP. In this specification and the claims, unless otherwise particularly stated, the head 1 is assumed to be in the reference state, and the configuration of each part is described.
[0015] In FIG. 7, the symbol α indicates the lie angle, and the symbol β indicates the loft angle. The lie angle α is the angle between the horizontal plane HP and the central axis line CL of the hosel 7. The loft angle β is the angle between the reference vertical plane VP and the striking face 21. These lie angle α and loft angle β are predetermined for the head 1 and are usually listed in the product catalog.
[0016] [Directions of the Head] In the head 1, the front side or the front means the side of the striking face 21. The rear side or the rear of the head 1 means the side of the opposite face (the back face 22). Also, in FIG. 7, the head front-rear direction is the direction of the x-axis orthogonal to the reference vertical plane VP. Also, the toe-heel direction of the head 1 is the horizontal y-axis direction orthogonal to the head front-rear direction. The up-down direction of the head 1 is the direction of the z-axis orthogonal to both the x-axis and the y-axis. The "upper side" and "lower side" of the head 1 respectively mean the "upper side" and "lower side" in the reference state.
[0017] [Structure of Each Part of the Head] Referring to FIGS. 1 to 2, the face portion 2 has a striking face 21 and a back face 22 which is the opposite face thereof. In the present embodiment, the striking face 21 is formed as a single plane except for the face line 8.
[0018] The face portion 2 further includes a face center 23 and a virtual vertical plane 24.
[0019] The face center 23 is a point on the hitting surface 21, midway along the toe-heel direction between the toe-side end 8 and the heel-side end 8. Furthermore, at this midpoint, the face center 23 is also midway along the hitting surface 21 between the top-side end 3 and the sole-side end 4. The face center 23 is one of the ideal hitting positions for many golfers.
[0020] The virtual vertical plane 24 is a virtual vertical plane that passes through the face center 23 and is perpendicular to the striking surface 21.
[0021] As shown in Figure 5, the top 3 extends, for example, from the upper edge of the striking surface 21 to the rear of the head 1, and constitutes the upper portion of the head 1.
[0022] As shown in Figures 1 and 2, the toe 5 is the end portion of the head 1 furthest from the hosel 7 in the toe-heel direction, and smoothly connects the top 3 and the sole 4.
[0023] Heel 6 is the end portion of head 1 located opposite to toe 5 in the toe-heel direction. The hosel 7 extends upward from heel 6.
[0024] As shown in Figure 1, the hosel 7 is provided with a shaft insertion hole 7a for receiving a golf club shaft (not shown). The central axis CL of the hosel 7 is defined by the central axis of the shaft insertion hole 7a.
[0025] Figure 3 is a bottom view of the head 1 as seen from a direction along the striking surface 21. As shown in Figures 3 to 4, the sole portion 4 extends, for example, from the face portion 2 to the rear of the head and forms the bottom surface of the head. The sole portion 4 extends to the rear end 4e of the sole, which is located at its furthest rear of the head. In the bottom view of Figure 3, the rear end 4e of the sole is located at the furthest rear of the head and extends in the toe-heel direction.
[0026] As shown in Figure 5, the sole portion 4 of this embodiment includes a first portion 41 located on the face portion side and a second portion 42 located behind the head and rising above the head. The second portion 42 has a front surface 42a that is separated from the back surface 22 of the face portion 2. The front surface 42a faces the back surface 22 of the face portion 2. A cavity C is formed between the front surface 42a and the back surface 22 of the face portion 2, extending toward the bottom surface of the head. The cavity C of this embodiment is a so-called undercut cavity.
[0027] Figures 8 and 9 are perspective views of the head 1 as seen from the rear. As shown in Figures 8 and 9, the sole portion 4 includes a toe-side slit 10 and a heel-side slit 11.
[0028] In this embodiment, the toe-side slit 10 is located on the toe 5 side of the virtual vertical plane 24. Furthermore, the toe-side slit 10 extends, for example, from the rear end 4e of the sole towards the front of the head. Additionally, the toe-side slit 10 penetrates the sole portion 4 in the vertical direction of the head.
[0029] In this embodiment, the heel-side slit 11 is located on the heel 6 side of the virtual vertical plane 24. Furthermore, the heel-side slit 11 extends, for example, from the rear end 4e of the sole towards the front of the head. Additionally, the heel-side slit 11 penetrates the sole portion 4 in the vertical direction of the head.
[0030] Furthermore, the sole portion 4 comprises a sole center portion 14, a sole toe portion 16, and a sole heel portion 18.
[0031] The central part of the sole 14 is separated in the sole 4 between the toe-side slit 10 and the heel-side slit 11. The sole toe part 16 is the part of the sole 4 that is closer to the toe 5 than the toe-side slit 10. The sole heel part 18 is the part of the sole 4 that is closer to the heel 6 than the heel-side slit 11. Therefore, the sole toe part 16 is separated from the central part of the sole 14 by the toe-side slit 10. Similarly, the sole heel part 18 is separated from the central part of the sole 14 by the heel-side slit 11.
[0032] [Operation of this embodiment] As shown in Figures 8 and 9, in this embodiment, the sole center portion 14 of the head 1 is separated from the sole toe portion 16 and the sole heel portion 18. Therefore, the sole center portion 14 is easily able to flex in the front-to-back direction of the head on its own. Focusing on this characteristic, the head 1 of this embodiment generates flex between the face portion 2 and the sole center portion 14 when the ball is struck, and the restorative force of this flex acts on the face portion 2, thereby increasing the rebound performance of the head 1. This action will be described in more detail below.
[0033] Figure 10 is an enlarged cross-sectional view of the head 1 at the position of the virtual vertical plane 24. In Figure 10, the arrow SW indicates the swing direction of the head 1. During the swing, when the ball collides with the striking surface 21 of the head 1, the face portion 2 receives a force f1 and flexes backward. At this time, since the central portion 14 of the sole is configured to move relatively easily, a large elastic flex (bend) occurs near the connection between the face portion 2 and the central portion 14 of the sole, and elastic energy is stored there. Next, after a small amount of time has elapsed from the moment of impact, the flex between the face portion 2 and the central portion 14 of the sole is gradually restored. At this time, since the central portion 14 of the sole has momentum P in the swing direction SW, much of the restoring force acts as a repulsive force that pushes the face portion 2 forward. In this embodiment, the head 1 improves the repulsive performance of the face portion 2 through this action and increases the distance the launched ball travels.
[0034] As described above, the head 1 of this embodiment can increase the distance of the shot by having a novel structure that differs from the low center of gravity head design that has been used in iron golf club heads to date. However, it goes without saying that this disclosure may be implemented in combination with conventional low center of gravity head design techniques in order to further increase the distance. A more preferred embodiment of this disclosure is described below.
[0035] [Thickness of Part 1] As shown in Figure 10, the thickness t1 of the first part 41 may be smaller than the thickness t2 of the second part 42. In this case, at the moment of ball impact, the first part 41 acts as the starting point, and the central part 14 of the sole (second part 42) is more likely to flex towards the face part 2. As the amount of flex of the central part 14 of the sole increases, the restoring force (rebound force) acting on the face part 2 also increases proportionally. Therefore, in this example, a further improvement in the rebound performance of the face part 2 can be expected. In particular, by reducing the thickness t1 of the first part 41, a sufficient improvement in rebound performance can be expected even when the ball is struck at a lower position on the hitting surface 21.
[0036] The thickness t1 of the first portion 41 is not particularly limited, but from the viewpoint of promoting the deflection of the sole center portion 14, it may be, for example, 3.0 mm or less, preferably 2.5 mm or less, and more preferably 2.0 mm or less. On the other hand, from the viewpoint of the durability of the head 1, the thickness t1 of the first portion 41 may be, for example, 1.0 mm or more, preferably 1.5 mm or more. In this specification, the thickness t1 of the first portion 41 is defined as the thickness measured parallel to the striking surface 21 of the face portion 2.
[0037] [Part 2, Thickness t2] The thickness t2 of the second part 42 is not particularly limited, but it is desirable that it be greater than the thickness t1 of the first part 41. This increases the weight of the second part 42 and, consequently, the kinetic energy of the second part 42 during the swing. Therefore, in this example, the restoring force (rebound force) acting on the face part 2 increases, and a further improvement in the rebound performance of the head 1 can be expected.
[0038] The thickness t2 of the second portion 42 is not particularly limited, but from the viewpoint of promoting the deflection of the sole center portion 14, it may be, for example, 3.0 mm or more, more preferably 4.0 mm or more, and even more preferably 5.0 mm or more. On the other hand, from the viewpoint of the practical upper limit weight of the head 1, the thickness t2 of the second portion 42 may be, for example, 20 mm or less, preferably 15 mm or less, and even more preferably 10 mm or less. In this specification, the thickness t2 of the second portion 42 is defined as the thickness measured parallel to the striking surface 21 of the face portion 2.
[0039] [Cavity shape] The length L of the cavity C in the direction perpendicular to the striking surface 21 should preferably increase toward the top of the head. This shape of the cavity C allows the second portion 42 to bend more significantly toward the face portion 2, starting from the first portion 41, at the moment of ball impact. Therefore, in this example, a further improvement in the rebound performance of the head 1 can be expected. The length L of the cavity C is not particularly limited, but should be determined appropriately so that the bent second portion 42 does not come into contact with the back surface 22 of the face portion 2 at the time of ball impact.
[0040] [Preferred examples of toe-side slits and heel-side slits] As shown in Figures 4 and 6, when the sole portion 4 includes a second portion 42, it is desirable that the toe-side slit 10 and the heel-side slit 11 extend into the second portion 42. The second portion 42 has a relatively large thickness. By providing the toe-side slit 10 and the heel-side slit 11 in this second portion 42, the central portion 14 of the sole becomes more flexible when hitting the ball. From this viewpoint, as shown in Figures 4 and 6, it is even more desirable that the toe-side slit 10 and the heel-side slit 11 extend over the entire range of the second portion 42 in the front-to-back direction of the head.
[0041] If the sole portion 4 includes a first portion 41, the toe-side slit 10 and the heel-side slit 11 may extend to the first portion 41. In such an example, the central portion 14 of the sole becomes more flexible when hitting the ball. On the other hand, in order to avoid compromising the durability of the face portion 2, it is desirable that the toe-side slit 10 and the heel-side slit 11 terminate so as not to reach the face portion 2. More specifically, as shown in Figure 4, when a virtual thinnest face line Y is defined that passes through the minimum thickness of the face portion 2 and is parallel to the hitting surface 21, it is preferable that the toe-side slit 10 and the heel-side slit 11 terminate without reaching this thinnest face line Y.
[0042] The positions of the toe-side slit 10 and heel-side slit 11 in the toe-heel direction are not particularly limited. Considering the distribution of impact positions for various golfers, it is desirable that the toe-side slit 10 and heel-side slit 11 be located outside their respective distribution ranges. This allows the central part 14 of the sole to flex more easily when the ball is struck. From this viewpoint, as shown in Figure 2, it is desirable that the toe-side slit 10 and heel-side slit 11 be separated from the virtual vertical plane 24 by a toe-heel distance A of 15 to 35 mm.
[0043] As shown in Figure 3, the widths W of the toe-side slit 10 and the heel-side slit 11 are not particularly limited. In a preferred example, the widths W of the toe-side slit 10 and the heel-side slit 11 are determined so that the deflection of the sole center portion 14 is not hindered by contact with the sole toe portion 16 and the sole heel portion 18 during a typical ball strike. For example, the widths W of the toe-side slit 10 and the heel-side slit 11 are, for example, 1 mm or more, more preferably 2 mm or more. Alternatively, the widths W of the toe-side slit 10 and the heel-side slit 11 are, for example, 5 mm or less, preferably 4 mm or less, and even more preferably 3 mm or less. Furthermore, the length of the toe-side slit 10 and the heel-side slit 11 in the head-front-rear direction, as measured in the bottom view of Figure 3, may be, for example, 5 mm or more, preferably 10 mm or more.
[0044] [Weight member] As shown in Figure 10, the sole portion 4 may include a main body 421 having a first specific gravity and a weight member 422 having a second specific gravity greater than the first specific gravity. Such a configuration may be applied together with the preferred examples described herein, or independently.
[0045] In this embodiment, the weight member 422 is positioned, for example, at a low position behind the central sole portion 14 of the sole portion 4. This allows more weight to be distributed to the rear end 4e side of the sole, making the sole portion 4 more flexible towards the face portion 2, starting from the connection point with the face portion 2. The weight member 422 can also help lower the center of gravity of the head 1.
[0046] When the central part 14 of the sole is composed of a first part 41 and a second part 42, the weight member 422 is preferably positioned in the second part 42. In a particularly preferred embodiment, the second part 42 is composed of a main body 421 and a weight member 422.
[0047] The main body 421 includes a front wall portion 421a that constitutes the front surface of the second portion 42, and an upper wall portion 421b that extends from the upper part of the front wall portion 421a to the rear of the head and constitutes the upper surface of the second portion 42. In this example, the main body 421 is made of metal that constitutes the face portion 2 and hosel 7 of the head 1, and is integrally formed with them. Examples of metal materials for the main body 421 include carbon steel, stainless steel, maraging steel, titanium, titanium alloy, etc.
[0048] The weight member 422 is positioned in the lower space enclosed by the front wall portion 421a and the upper wall portion 421b. In a preferred example, the weight member 422 is, for example, a solid structure, including a first surface S1 that contacts the front wall portion 421a, a second surface S2 that contacts the upper wall portion 421b, and a third surface S3 that forms the outer surface of the sole portion 4. To allow the second portion 42 to flex more significantly when the ball is struck, the contact length between the front wall portion 421a and the first surface S1 is preferably, for example, 5 mm or more. Similarly, the contact length between the upper wall portion 421b and the second surface S2 is preferably, for example, 5 mm or more.
[0049] The second specific gravity of the weight member 422 is not particularly limited as long as it is greater than the first specific gravity of the main body 421, but may be, for example, 10.0 or more, preferably 12.0 or more. The weight member 422 is preferably made of an alloy containing tungsten.
[0050] The toe-side slit 10 and the heel-side slit 11 may be left as empty spaces. In other examples, the toe-side slit 10 and the heel-side slit 11 may be fitted with covers or inserts (not shown) made of rubber, resin, elastomer, etc., that are soft enough not to hinder the deformation of the central part 14 of the sole when the ball is struck. These covers or inserts can prevent foreign objects from getting stuck in the toe-side slit 10 and the heel-side slit 11.
[0051] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and can be modified in various ways. The present disclosure also includes equivalents.
[0052] [Note] This disclosure includes the following aspects.
[0053] [Disclosure 1] An iron golf club head, when placed in a standard state, Face portion having a striking surface, The center of the face on the striking surface, A virtual vertical plane passing through the face center and perpendicular to the striking surface, Tou, The heel opposite to the aforementioned toe, and Including the sole portion that extends from the face portion to the rear of the head and forms the bottom surface of the head, The sole portion is, The toe side of the aforementioned virtual vertical plane is provided by a toe-side slit extending from the rear end of the sole to the front of the head, The heel side of the aforementioned virtual vertical plane is provided by a heel-side slit extending from the rear end of the sole towards the front of the head, The central part of the sole is divided between the toe-side slit and the heel-side slit, The sole toe portion, separated from the central part of the sole by the toe-side slit, Including the sole heel portion separated from the central portion of the sole by the heel-side slit, Iron golf club head. [Disclosure 2] The sole portion includes a first portion located on the face side and a second portion located behind the head and rising above the head. The thickness of the first part is less than the thickness of the second part. The toe-side slit and the heel-side slit extend from the second portion, as described in Disclosure 1, for the iron golf club head. [Disclosure 3] The toe-side slit and the heel-side slit extend over the entire length of the second portion of the head in the front-to-back direction, as described in Disclosure 2. [Disclosure 4] The toe-side slit and the heel-side slit extend to the first portion, as described in Disclosure 2, for the iron golf club head. [Disclosure 5] An iron golf club head according to any one of disclosures 2 to 4, wherein the thickness of the first portion is 1.0 to 3.0 mm. [Disclosure 6] An iron golf club head according to any one of disclosures 2 to 4, wherein the thickness of the second portion is 3.0 mm or more. [Disclosure 7] The face portion has a back surface opposite to the striking surface, The second portion includes a front surface that forms a cavity between the striking surface and the back surface, The length of the cavity in the direction perpendicular to the striking surface increases toward the top of the head, as described in any of disclosures 2 to 4, for an iron golf club head. [Disclosure 8] The iron golf club head according to disclosure 1 or 2, wherein the central portion of the sole includes a body having a first specific gravity and a weight member having a second specific gravity greater than the first specific gravity. [Disclosure 9] The toe-side slit and the heel-side slit are each separated from the virtual vertical plane by a distance of 15 to 35 mm in the toe-heel direction, as described in disclosure 1 or 2 of the iron golf club head. [Disclosure 10] The iron golf club head according to disclosure 1 or 2, wherein the width of the toe-side slit and the heel-side slit are each 2 mm or more. [Explanation of Symbols]
[0054] 1 head 2 Face section 4. Sole 4e sole rear end 5 Tou 6 heels 10 Toe-side slits 11 Heel-side slit 14 Center of the sole 16. Sole and toe area 18. Sole heel section 21 Hitting surface 22 Back 23 Face Center 24 Virtual Vertical Plane 41 Part 1 42 Part 2 42a front 421 Main Unit 422 Weight member C Cavity
Claims
1. An iron golf club head, when placed in a standard state, Face portion having a striking surface, The center of the face on the striking surface, A virtual vertical plane passing through the face center and perpendicular to the striking surface, Tou, The heel opposite to the aforementioned toe, and Including the sole portion that extends from the face portion to the rear of the head and forms the bottom surface of the head, The sole portion is, The toe side of the aforementioned virtual vertical plane is provided by a toe-side slit extending from the rear end of the sole to the front of the head, The heel side of the aforementioned virtual vertical plane is provided by a heel-side slit extending from the rear end of the sole towards the front of the head, The central part of the sole is divided between the toe-side slit and the heel-side slit, The sole toe portion, separated from the central part of the sole by the toe-side slit, The heel portion of the sole is separated from the central portion of the sole by the heel-side slit, The sole portion includes a first portion located on the face side and a second portion located behind the head and rising above the head. The thickness of the first part is less than the thickness of the second part. The toe-side slit and the heel-side slit extend over the entire range of the second portion in the front-to-back direction of the head, and extend to the first portion. Iron golf club head.
2. The iron golf club head according to claim 1, wherein the thickness of the first portion is 1.0 to 3.0 mm.
3. The iron golf club head according to claim 1 or 2, wherein the thickness of the second portion is 3.0 mm or more.
4. The face portion has a back surface opposite to the striking surface, The second portion includes a front surface that forms a cavity between the striking surface and the back surface, The iron golf club head according to claim 1 or 2, wherein the length of the cavity in the direction perpendicular to the striking surface increases toward the top of the head.
5. The iron golf club head according to claim 1, wherein the central part of the sole includes a body having a first specific gravity and a weight member having a second specific gravity greater than the first specific gravity.
6. The iron golf club head according to Claim 1, wherein the toe-side slit and the heel-side slit are each separated by a distance of 15 to 35 mm in the toe-heel direction from the virtual vertical plane.
7. The iron golf club head according to claim 1, wherein the width of the toe-side slit and the heel-side slit are each 2 mm or more.