Golf club head

Abstract

A golf club head includes: a head body including a hosel portion, a face portion, and a sole portion; a sleeve that is detachably attached to the hosel portion; and a screw member that attaches the sleeve from a sole side by screwing. The hosel portion includes a hosel hole and a hosel end face. The hosel end face is positioned lower than an uppermost point of the head body. An end face of the sleeve is positioned lower than the uppermost point of the head body. The golf club head may have a neck length that is less than or equal to 68 mm.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to Japanese Patent Application No. 2025-8714 filed on Jan. 21, 2025. The entire contents of this Japanese Patent Application are hereby incorporated by reference.BACKGROUNDTechnical Field

[0002] The present disclosure relates to golf club heads.Description of the Related Art

[0003] A golf club has been proposed in which a sleeve is attached to a shaft to allow the shaft to be removably attached to the head. JP 6790821 B2 (US 2018 / 0185711 A1) discloses a golf club head that includes a sleeve fixed to the tip end of a shaft and a screw capable of being screw-connected to the sleeve, where rotation of the sleeve relative to a hosel hole is regulated by the engagement between an engaging projection of the sleeve and an engaging recess of the head.SUMMARY

[0004] The weight of the attachable and detachable mechanism, including a sleeve, makes it difficult to lower the position of the center of gravity of the head. The inventor of the present disclosure has also found that this mechanism tends to reduce bending of the shaft. The reduced bending of the shaft may result in deterioration of ball catchability of the head.

[0005] One of the objectives of the present disclosure is to provide a golf club head that includes an attachable and detachable mechanism including a sleeve, that has a lowered center of gravity, and that exhibits an excellent ball catchability.

[0006] In one aspect, a golf club head includes: a head body including a hosel portion, a face portion, and a sole portion; a sleeve that is detachably attached to the hosel portion; and a screw member that attaches the sleeve from a sole side by screwing. The hosel portion includes a hosel hole and a hosel end face. The hosel end face is positioned lower than an uppermost point of the head body. An end face of the sleeve is positioned lower than the uppermost point of the head body.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is an overall view of a golf club including a golf club head according to an embodiment;

[0008] FIG. 2 is a front view of the golf club head in FIG. 1;

[0009] FIG. 3 is a plan view of the golf club head in FIG. 2;

[0010] FIG. 4 is a bottom view of the golf club head in FIG. 2;

[0011] FIG. 5 is a perspective view of the golf club head in FIG. 2;

[0012] FIG. 6 is an exploded perspective view of the golf club head inFIG. 2;

[0013] FIG. 7A is the same front view as FIG. 2, and FIG. 7B is a cross-sectional view taken along line E1 in FIG. 7A, FIG. 7B showing only a part of the contour line of the outer surface of the head in the cross section;

[0014] FIG. 8A shows the golf club head in FIG. 2 as viewed from the heel-lower side, and FIG. 8B is a cross-sectional view taken along line A-A in FIG. 8A;

[0015] FIG. 9A shows a head body of the golf club head in FIG. 2 as viewed from the heel-lower side, and FIG. 9B is a cross-sectional view taken along line B- B in FIG. 9A; and

[0016] FIG. 10 is a conceptual diagram for illustrating a reference state.DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the present disclosure will be described in detail based on preferred embodiments with appropriate references to the accompanying drawings.

[0018] In the present disclosure, a reference state, a toe-heel direction, a face-back direction, an up-down direction, a face center, and a front elevation view of a head are defined.

[0019] The reference state is defined as a state where a head is placed at a predetermined lie angle on a ground plane HP. As shown in FIG. 10, in the reference state, a hosel axis line z1 lies on (is contained in) a plane VP that is perpendicular to the ground plane HP. The hosel axis line z1 is defined as the center line of a hosel hole.

[0020] In the embodiments described later, the three adjustment items, namely loft angle, lie angle, and face angle, can be adjusted by changing the rotational position of a sleeve disposed at a tip portion of the shaft. In this configuration, since a shaft hole is inclined relative to the hosel hole, the hosel axis line z1 does not coincide with the shaft axis line. In such a head, a dedicated sleeve in which the shaft hole is not inclined relative to the hosel hole is prepared so that the shaft axis line coincides with the hosel axis line z1. Using the dedicated sleeve facilitates the setting of an actual head to the reference state.

[0021] In the reference state, a face angle is 0°. That is, in a planer view of a head as viewed from above, a straight line normal to the striking face at its face center is set to be perpendicular to the toe-heel direction. The definitions of the face center and the toe-heel direction are explained below. The toe-heel direction in the present disclosure

[0022] is defined as the direction of an intersection line NL between the plane VP and the ground plane HP (see FIG. 10). The face-back direction in the present disclosure

[0023] is defined as a direction that is perpendicular to the toe-heel direction and is parallel to the ground plane HP. The face side in the face-back direction is also referred to as “face side” or “front side”. The back side in the face-back direction is also referred to as “back side” or “rear side”.

[0024] The up-down direction in the present disclosure is defined as a direction that is perpendicular to the toe-heel direction and is perpendicular to the face-back direction. In other words, the up-down direction in the present disclosure is a direction perpendicular to the ground plane HP. As used herein, “upper” in the up-down direction is also referred to as “above”, and “lower” in the up-down direction is also referred to as “below”.

[0025] In the present disclosure, the face center is determined in the following manner. First, a point Pr is selected roughly at the center of a striking face in the up-down direction and the toe-heel direction. Next, a flat plane that passes through the point Pr, extends in the direction of a line normal to the striking face at the point Pr, and is parallel to the toe-heel direction is determined. An intersection line between this flat plane and the striking face is drawn, and a midpoint Px of this intersection line is determined. Next, a flat plane that passes through the midpoint Px, extends in the direction of a line normal to the striking face at the midpoint Px, and is parallel to the up-down direction is determined. An intersection line between this flat plane and the striking face is drawn, and a midpoint Py of this intersection line is determined. Next, a flat plane that passes through the midpoint Py, extends in the direction of a line normal to the striking face at the midpoint Py, and is parallel to the toe-heel direction is determined. An intersection line between this flat plane and the striking face is drawn, and a midpoint Px of this intersection line is newly determined. Next, a flat plane that passes through this newly-determined midpoint Px, extends in the direction of a line normal to the striking face at this midpoint Px, and is parallel to the up-down direction is determined. An intersection line between this flat plane and the striking face is drawn, and a midpoint Py of this intersection line is newly determined. By repeating the above-described steps, points Px and Py are sequentially determined. In the course of repeating these steps, when the distance between a newly-determined midpoint Py and a midpoint Py determined in the immediately preceding step first becomes less than or equal to 0.5 mm, the newly-determined midpoint Py (the midpoint Py determined last) is defined as the face center.

[0026] The front elevation view of a head in the present disclosure is defined as a projection of the head obtained by projecting the head in the face-back direction as viewed from the face side. The front elevation view of a head is equivalent to a front view in the present disclosure.First Embodiment

[0027] FIG. 1 is an overall view of a golf club 2 that includes a head 4 according to a first embodiment. FIG. 2 is a front view of the head 4. FIG. 3 is a plan view of the head 4. FIG. 4 is a bottom view of the head 4. FIG. 5 is a perspective view of the head 4. FIG. 6 is an exploded perspective view of the head 4. FIG. 7A is the same front view as FIG. 2, and FIG. 7B is a cross-sectional view taken along line E1 in FIG. 7A. FIG. 7B shows only a part of the contour line of the outer surface of the head 4 (hereinafter, a contour line shown in a cross-sectional view is also referred to as a cross-sectional contour line). FIG. 8A is a side view of the head 4 as viewed from the heel side, and FIG. 8B is a cross-sectional view taken along line A-A in FIG. 8A. FIG. 9A is a side view of a head body b1 as viewed from the heel side, and FIG. 9B is a cross-sectional view taken along line B-B in FIG. 9A. In addition to the head body b1, FIG. 9B also shows a rotation prevention portion 22 and a flange forming portion 26 that are fixed to the head body b1. In FIG. 4, a screw member 24 (described later) is omitted.

[0028] As shown in FIG. 1, the golf club 2 includes the golf club head 4, a shaft 6, and a grip 8. The shaft 6 includes a tip end Tp and a butt end Bt. The head 4 is attached to an end portion at the tip end Tp of the shaft 6. The grip 8 is attached to an end portion at the butt end Bt of the shaft 6.

[0029] The golf club 2 is a driver (1—wood). The head 4 is a driver head. Typically, the club as a driver has a length of greater than or equal to 43 inches and less than or equal to 48 inches. The type of the golf club 2 is not limited. The golf club 2 is preferably a wood type golf club or a hybrid type golf club.

[0030] The shaft 6 has a tubular shape. The shaft 6 has a hollow structure. The shaft 6 is made of a carbon fiber reinforced resin. From the viewpoint of weight reduction, a carbon fiber reinforced resin is preferable as the material for the shaft 6. The shaft 6 is a so-called carbon shaft. Preferably, the shaft 6 is formed by curing layered prepreg sheets. In each prepreg sheet, fibers are substantially oriented in one direction. Such a prepreg in which fibers are oriented substantially in one direction is also referred to as a UD prepreg. The term “UD” stands for unidirectional. Alternatively, a prepreg other than the UD prepreg may be used. For example, fibers contained in the prepreg sheet may be woven. The prepreg sheet may include a metal wire. The material of the shaft 6 is not limited, and may be a metal, for example.

[0031] The grip 8 is a portion gripped by a golfer during a swing. Examples of the material of the grip 8 include rubber compositions and resin compositions. The rubber composition for the grip 8 may contain air bubbles.

[0032] The head 4 has a hollow structure. In the present embodiment, the head 4 is a wood type head. Alternatively, the head 4 may be a hybrid type head. Further alternatively, the head 4 may be an iron type head. The head 4 is preferably a wood type head or a hybrid type head, and more preferably a wood type head.

[0033] A main portion of the head 4 may be made of a metal material, for example. The entirety of the head 4 may be made of a metal material. Alternatively, a portion of the head 4 may be made of a non-metal material such as a fiber reinforced resin, and the remaining portion may be made of a metal material. For example, a portion (head body) other than a face member may be made of a metal material and the face member may be made of a non-metal material. Alternatively, for example, a portion (head body) other than a crown member may be made of a metal material and the crown member may be made of a non-metal material. The metal material is not particularly limited. Examples of the metal material include pure titanium, a titanium alloy, stainless steel, maraging steel, an aluminum alloy, a magnesium alloy, and a tungsten-nickel alloy. Examples of the fiber reinforced resin include a carbon fiber reinforced resin.

[0034] The head 4 includes the head body b1 and a sleeve mechanism s1. The sleeve mechanism s1 is fixed to the head body b1. As shown in FIG. 8B and FIG. 9B, the head 4 (head body b1) includes a hollow interior h1.

[0035] The head 4 includes a face portion 10, a crown portion 12, a sole portion 14, and a hosel portion 16. The face portion 10 includes a striking face 10a. The striking face 10a is the outer surface of the face portion 10. The striking face 10a includes a face center Fc as defined above. The face portion 10, the crown portion 12, and the sole portion 14 are included in the head body b1. The sleeve mechanism s1 forms a portion of the hosel portion 16.

[0036] As shown in FIG. 6, the sleeve mechanism s1 includes a sleeve 20, the rotation prevention portion 22, and the screw member 24. The sleeve mechanism s1 further includes a flange forming portion 26 and a washer 28.

[0037] The sleeve 20 includes an exposed portion 20a, an intermediate portion 20b, and an anti-rotation engagement portion 20c. The exposed portion 20a forms an upper end portion of the sleeve 20. The outer surface of the exposed portion 20a has a conical protrusion shape. The exposed portion 20a has an outer diameter that increases downward (toward the sole side). As shown in FIG. 2, in the head 4 in which the sleeve mechanism s1 is fixed to the head body b1, the exposed portion 20a is exposed to the outside of the head 4. The anti-rotation engagement portion 20c forms a lower end portion of the sleeve 20. The anti-rotation engagement portion 20c includes an engaging portion 201 on its outer circumferential surface. The engaging portion 201 is formed by recesses and protrusions. The anti-rotation engagement portion 20c engages with the rotation prevention portion 22, thereby preventing rotation of the sleeve 20 relative to the head body b1. The intermediate portion 20b is positioned between the exposed portion 20a and the anti-rotation engagement portion 20c. As shown in FIG. 8B, the sleeve 20 includes a female threaded hole 20f. The female threaded hole 20f is open downward. The female threaded hole 20f is formed inside the anti-rotation engagement portion 20c.

[0038] The sleeve 20 further includes a shaft hole 20d and a sleeve end face 20e. The shaft hole 20d is open upward. The shaft hole 20d penetrates through the exposed portion 20a and extends into the intermediate portion 20b. The tip end portion of the shaft 6 is inserted into and fixed to the shaft hole 20d. The shaft 6 is fixed to the shaft hole 20d using an adhesive, for example. The sleeve end face 20e is the upper end face of the sleeve 20, and thus the upper end face of the exposed portion 20a.

[0039] The rotation prevention portion 22 is a member having a tubular shape as a whole. The rotation prevention portion 22 is fixed to the head body b1. Examples of the method for fixing the rotation prevention portion 22 to the head body b1 include welding, bonding, and press fitting. In the present embodiment, the fixing is performed by welding. The rotation prevention portion 22 includes an engaging portion 221 on its inner circumferential surface. The engaging portion 221 is formed by recesses and protrusions. The anti-rotation engagement portion 20c is inserted into the rotation prevention portion 22, whereby the engaging portion 221 of the rotation prevention portion 22 meshes with the engaging portion 201 of the anti-rotation engagement portion 20c. The rotation prevention portion 22 engages with the anti-rotation engagement portion 20c, thereby preventing rotation of the sleeve 20 relative to the head body b1. The rotation prevention portion 22 may be integrally formed with the head body b1 as a single-piece member. When the rotation prevention portion 22 is a separate member from the head body b1, the rotation prevention portion 22 is independently formed and / or processed, which can improve the dimensional accuracy of the rotation prevention portion 22.

[0040] Referring to FIG. 8B, when the rotation prevention portion 22 has not yet been welded to the head body b1, the head body b1 includes an opening 23 for performing welding (hereinafter, the opening 23 is also referred to as a welding opening 23). The welding opening 23 penetrates through the wall of the head body b1 from the outer surface to a position where the rotation prevention portion 22 is located. The rotation prevention portion 22 is located at a lower position in the hosel hole 30. After placing the rotation prevention portion 22 at the predetermined position, the rotation prevention portion 22 is welded to the head body b1 from outside the head body b1 through the welding opening 23. The welding opening 23 is filled after the welding is performed. In the finished head 4, the welding opening 23 is not present. Accordingly, the welding opening 23 is eliminated in FIG. 8B. As illustrated in FIG. 8B, the position of the welding opening 23 is indicated with dashed lines. The welding opening 23 is positioned on the heel side of the rotation prevention portion 22.

[0041] The screw member 24 includes a head portion 24a and a shaft portion 24b. The shaft portion 24b includes a male threaded portion 24c. As shown in FIG. 8B, the male threaded portion 24c is screw-connected to the female threaded hole 20f of the sleeve 20.

[0042] The flange forming portion 26 is an annular member. The flange forming portion 26 is disposed between a retaining portion 29 of the head body b1 and the rotation prevention portion 22. The retaining portion 29 includes a through hole 29a at its center. The head portion 24a of the screw member 24 is dimensioned such that the head portion 24a can pass through the through hole 29a, but cannot pass through the flange forming portion 26 (see FIG. 8B). The flange forming portion 26 is sandwiched between the rotation prevention portion 22 and the retaining portion 29, thereby being fixed to the head body b1. The flange forming portion 26 includes a through hole 26a.

[0043] The sleeve mechanism s1 includes a head-fixed portion s10 that is fixed (non-removably) to the head body b1, and a detachable portion s12 that is detachably attached to the head body b1. The rotation prevention portion 22 and the flange forming portion 26 constitute the head-fixed portion s10. The sleeve 20, the screw member 24, and the washer 28 constitute the detachable portion s12.

[0044] As shown in FIG. 6 and FIG. 9B, the head body b1 includes the hosel hole 30 and a hosel end face 32. The sleeve 20 is inserted into and retained in the hosel hole 30. The hosel hole 30 includes an inner circumferential surface 30a that supports the sleeve 20. As shown in FIG. 8B, the inner circumferential surface 30a supports the outer circumferential surface of the intermediate portion 20b of the sleeve 20. The hosel end face 32 abuts a downward-facing surface 20g that is located at the lower end of the exposed portion 20a of the sleeve 20 (see FIG. 6).

[0045] As shown in FIG. 8B, in a state where the sleeve 20 is attached to the head body b1 (hereinafter, this state is referred to as an attached state), the male threaded portion 24c of the screw member 24 is inserted through the through hole 26a of the flange forming portion 26 from below the head 4 (from the sole side), and is screw-connected to the female threaded hole 20f of the sleeve 20. In the attached state, the head portion 24a of the screw member 24 abuts the flange forming portion 26 with the washer 28 interposed between the head portion 24a and the flange forming portion 26. The sleeve 20 is held in the hosel hole 30 by a downward axial force generated by the screw-connection. This axial force maintains the state where the downward-facing surface 20g of the sleeve 20 presses the hosel end face 32. Loosening the screw member 24 releases the screw-connection and allows the sleeve 20 to be removed from the head body b1. The shaft 6 to which the sleeve 20 is fixed can thus be attached to and detached from the head body b1 (hereinafter, this mechanism is referred to as a shaft attachable and detachable mechanism). The sleeve mechanism s1 constitutes the shaft attachable and detachable mechanism.

[0046] As shown in FIG. 9B, the hosel hole 30 has a center line z1. The center line z1 is also referred to as the hosel axis line. The hosel axis line z1 coincides with the center line of the outer circumferential surface of the intermediate portion 20b of the sleeve 20. The hosel axis line z1 also coincides with the center line of the outer surface of the sleeve 20. As shown in FIG. 8B, the shaft hole 20d of the sleeve 20 has a center line z2. The center line z2 is also referred to as the shaft axis line. The shaft axis line z2 is the center line of the shaft 6 inserted into and bonded to the shaft hole 20d.

[0047] As shown in FIG. 8B, the shaft axis line z2 is inclined relative to the hosel axis line z1. An angle of the shaft axis line z2 relative to the hosel axis line z1 is referred to as an inclination angle θ (degrees). The inclination angle θ enables the adjustment of the real loft angle, lie angle, and face angle of the golf club 2. The real loft angle, lie angle, and face angle are adjusted by changing the rotational position of the sleeve 20. The inclination angle θ may be set to be greater than or equal to 0.5° and less than or equal to 3.0°. The adjustments of the real loft angle, lie angle, and face angle enable club fitting suitable for individual golfers.

[0048] The hosel portion 16 includes an inner hosel portion 16a that is located inside the head body b1 and faces the hollow interior h1 (See FIG. 8B and FIG. 9B). Inside the head body b1, the inner hosel portion 16a forms a part of a cylindrical portion that faces the hollow interior h1. The interior of the inner hosel portion 16a constitutes the hosel hole 30. The inner hosel portion 16a has an opening 34 that is open toward the hollow interior h1. The opening 34 is located inside the head body b1 (head 4), and is also referred to as an inner opening. The inner opening 34 is formed by an absence of a portion of material in the cylindrical portion. The inner opening 34 is a through hole that connects the hosel hole 30 and the hollow interior h1. A part of the sleeve 20 is exposed to the hollow interior h1 by the presence of the inner opening 34. That is, the inner opening 34 allows a part of the outer surface of the sleeve 20 to face the hollow interior h1. In the embodiment of FIG. 8B, a part of the intermediate portion 20b of the sleeve 20 faces the hollow interior h1. A part of the rotation prevention portion 22 also faces the hollow interior h1. The inner opening 34 is formed on the toe side of the sleeve 20.

[0049] As shown in FIG. 2, the striking face 10a includes an outer edge k1. The outer edge k1 of the striking face 10a can be defined as follows. As shown in FIG. 7A, there are a large number of cross sections each of which contains a straight line that connects the center of gravity of the head 4 and a sweet spot SS, for example, cross sections E1, E2, and E3 in FIG. 7A. In each of the cross sections, when a curvature radius r of the cross-sectional contour line of the head outer surface is sequentially observed from the sweet spot SS toward the outside of the striking face 10a, a point at which the curvature radius r becomes 200 mm for the first time is defined as a position Pe. A set of the positions Pe can be the outer edge k1 of the striking face 10a. The sweet spot SS is defined as an intersection point between the striking face 10a and a straight line that passes through the center of gravity of the head 4 and is perpendicular to the striking face 10a.

[0050] As shown in FIG. 2, the head 4 includes an uppermost point P1. The uppermost point P1 is defined as a point that has a maximum height measured from the ground plane HP when the head 4 is in the reference state. The height is measured in a direction perpendicular to ground plane HP. The uppermost point P1 is positioned on the outer surface of the crown portion 12. The uppermost point P1 is the uppermost (highest) point of the outer surface of the crown portion 12. Unless otherwise described, the term “height” as used in the present disclosure means a height measured from the ground plane HP when the head is in the reference state. The height is measured in the up-down direction.

[0051] The hosel end face 32 is positioned lower than the uppermost point P1. That is, the height of the hosel end face 32 is smaller than the height of the uppermost point P1. Due to the lie angle, the height of the hosel end face 32 increases toward the toe side (see FIG. 2). However, even at its highest position, the hosel end face 32 is positioned lower than the uppermost point P1.

[0052] The sleeve end face 20e is positioned lower than the uppermost point P1. That is, the height of the sleeve end face 20e is smaller than the height of the uppermost point P1. Due to the lie angle, the height of the sleeve end face 20e increases toward the toe side (see FIG. 2). However, even at its highest position, the sleeve end face 20e is positioned lower than the uppermost point P1.

[0053] The striking face 10a includes a face-surface uppermost point P2. The face-surface uppermost point P2 is defined as a point that is located on the outer edge k1 of the striking face 10a and has a maximum height. The hosel end face 32 is positioned lower than the face-surface uppermost point P2. Due to the lie angle, the height of the hosel end face 32 increases toward the toe side (see FIG. 2). However, even at its highest position, the hosel end face 32 is positioned lower than the face-surface uppermost point P2.

[0054] The head 4 has a neck length L1 (see FIG. 2). The neck length L1 includes the length of the exposed portion 20a of the sleeve 20. When the head 4 is in the reference state, an intersection point P3 between the hosel axis line z1 and the ground plane HP is determined. The neck length L1 is defined as the distance from the intersection point P3 to the sleeve end face 20e. The neck length L1 is measured along the hosel axis line z1. The neck length L1 is set to be less than or equal to 68 mm.

[0055] The hosel portion 16 has a hosel length L2 (see FIG. 2). The hosel length L2 is defined as the distance from the intersection point P3 to the hosel end face 32. The hosel length L2 is measured along the hosel axis line z1. The hosel length L2 is shorter than the neck length L1.

[0056] The sleeve 20 has an exposed sleeve length L3 (see FIG. 2). The exposed sleeve length L3 is defined as the length of the exposed portion 20a of the sleeve 20. The sum of the exposed sleeve length L3 and the hosel length L2 is equal to the neck length L1. The sleeve 20 has an inserted length L4 (see FIG. 6). The inserted length L4 is the length of a part of the sleeve 20 that is inserted into the head body b1. The sleeve 20 has a total sleeve length L5 (see FIG. 6). The sum of the exposed sleeve length L3 and the inserted length L4 is equal to the total sleeve length L5. The exposed sleeve length L3, the inserted length L4, and the total sleeve length L5 are measured along the hosel axis line z1.

[0057] The head 4 has a head thickness H1 (see FIG. 2). The head thickness H1 is defined as a distance from the ground plane HP to the uppermost point P1. The head thickness H1 is equal to the height of the uppermost point P1. From the viewpoint of the rules of golf, the head thickness H1 is preferably less than or equal to 2.8 inches (71.12 mm).

[0058] The outer surface of the crown portion 12 includes an inflection point P4 (see FIG. 2). The inflection point P4 is determined in the front elevation view (FIG. 2) of the head 4. In the front elevation view of the head 4, the crown portion 12 has a contour line. The inflection point P4 is defined as a boundary point between an upwardly protruding portion and a downwardly protruding portion on the contour line. A double-pointed arrow D3 in FIG. 2 indicates a distance (shortest distance) between the inflection point P4 and the hosel axis line z1 in the front elevation view of the head 4. The distance D3 is measured in a direction perpendicular to the hosel axis line z1. The distance D3 is less than or equal to 20 mm in the present embodiment.

[0059] The head body b1 has a hosel protruding length L6 (see FIG. 7A). The hosel protruding length L6 is defined as a distance between the inflection point P4 and the hosel end face 32. The hosel protruding length L6 is measured along the hosel axis line z1. The hosel protruding length L6 is short in the present embodiment.

[0060] A double-pointed arrow H2 in FIG. 2 indicates a height of the inflection point P4. The height H2 of the inflection point P4 is defined as a distance between the ground plane HP and the inflection point P4. The height H2 of the inflection point P4 is measured in the up-down direction. The height H2 is smaller than the head thickness H1. In the present embodiment, the ratio H2 / H1 of the height H2 to the head thickness H1 is small.

[0061] A double-pointed arrow H3 in FIG. 2 indicates a difference between the height of the uppermost point P1 and the height of the sleeve end face 20e. The sleeve end face 20e is positioned lower than the uppermost point P1 by the distance H3. The distance H3 is measured in the up-down direction. The distance H3 is greater than 0.0 mm.

[0062] The striking face 10a has a face length W1 (see FIG. 3). The face length W1 is defined as a length of a region surrounded by the outer edge k1. The face length W1 is measured in the toe-heel direction.

[0063] The head 4 has a face progression FP (see FIG. 3). The face progression FP is defined as a distance between the frontmost point P5 of the head 4 and the hosel axis line z1. The distance (face progression FP) is measured in the face-back direction. In the present embodiment, the face progression FP is less than or equal to 18 mm. In the present disclosure, “FP” is used not only to indicate face progression in the drawings but also as a symbol representing the value of the face progression.

[0064] The sleeve end face 20e has an outer diameter D1 (see FIG. 8A). The hosel end face 32 has an outer diameter D2 (see FIG. 9A). The outer diameter D2 of the hosel end face 32 is greater than the outer diameter D1 of the sleeve end face 20e. In the present embodiment, the outer diameter D2 of the hosel end face 32 is less than or equal to 15 mm.

[0065] A double-pointed arrow R1 in FIG. 7 indicates a region surrounded by a virtual cylinder having a radius of 20 mm and an axis that coincides with the hosel axis line z1. Dashed lines in FIG. 7 indicate a virtual cylindrical surface CS1 having the hosel axis line z1 as its center line (axis). The diameter of the virtual cylindrical surface CS1 is 40 mm. The weight included in the region R1 is the weight of a portion of the head 4 located inside the virtual cylindrical surface CS1. That is, the weight included in the region R1 is the weight of all portions located inside the virtual cylindrical surface CS1. In the present embodiment, the weight of the region R1 includes the weights of the entire sleeve 20, the entire rotation prevention portion 22, the entire screw member 24, the entire flange forming portion 26, and the entire washer 28. The weight of the region R1 also includes the weight of a portion of the head body b1 located inside the virtual cylindrical surface CS1. The components constituting the sleeve mechanism s1 tend to increase the weight of the region R1. However, as discussed later, in the present embodiment, the weight of the region R1 is suppressed in spite of the presence of the sleeve mechanism s1. In the present embodiment, the ratio of the weight of the region R1 to the weight (total weight) of the head 4 is less than 25.0%.

[0066] A double-pointed arrow R2 in FIG. 7 indicates a region surrounded by a virtual cylinder having a radius of D3 mm and an axis that coincides with the hosel axis line z1. As described above, the distance D3 refers to the distance between the inflection point P4 and the hosel axis line z1. Thick dashed lines in FIG. 7 indicate a virtual cylindrical surface CS2 having the hosel axis line z1 as its center line (axis). The diameter of the virtual cylindrical surface CS2 is twice the distance D3. The weight included in the region R2 is the weight of a portion of the head 4 located inside the virtual cylindrical surface CS2. That is, the weight included in the region R2 is the weight of all portions located inside the virtual cylindrical surface CS2. In the present embodiment, the weight of the region R2 includes the weights of the entire sleeve 20, the entire rotation prevention portion 22, the entire screw member 24, the entire flange forming portion 26, and the entire washer 28. The weight of the region R2 also includes the weight of a portion of the head body b1 located inside the virtual cylindrical surface CS2. The components constituting the sleeve mechanism s1 tend to increase the weight of the region R2. However, as discussed later, in the present embodiment, the weight of the region R2 is suppressed in spite of the presence of the sleeve mechanism s1. In the present embodiment, the ratio of the weight of the region R2 to the weight (total weight) of the head 4 is less than or equal to 20.0%.

[0067] The sleeve 20 has a weight. The weight of the sleeve 20 is less than 3.3% of the weight of the head 4. With reference to FIG. 6, the sleeve 20 has a center of gravity Gs. The center of gravity Gs refers to the center of gravity of the sleeve 20 alone. A double-pointed arrow H4 in FIG. 2 indicates a height of the center of gravity Gs of the sleeve 20. In other words, the double-pointed arrow H4 indicates a distance between the ground plane HP and the center of gravity Gs. The distance H4 is measured in the up-down direction. In the present embodiment, the distance H4 is less than 41.0 mm.

[0068] The head 4 has a volume. The volume of the head 4 is also referred to as a head volume. In the present embodiment, the head 4 is a driver head. In the present embodiment, the head 4 has a head volume of greater than or equal to 400 cm3. The head volume is measured in accordance with the Rules of Golf established by the R&A and the USGA. To measure the head volume, place a container filled with water on a scale, set the scale to 0, and submerge the head in the water. The weight measurement shown in grams on the scale is equivalent to the volume of the head measured in cubic centimeters. When the head 4 is a driver head, the head volume can be greater than or equal to 400 cm3, further can be greater than or equal to 420 cm3, and even further can be greater than or equal to 440 cm3. The head volume can be less than or equal to 470 cm3, and further can be less than or equal to 460 cm3.

[0069] The above-described embodiments exhibit the following advantageous effects.

[0070] A head including the sleeve mechanism s1 (a shaft attachable and detachable mechanism) has an increased weight as compared to a head that does not include the sleeve mechanism s1. The increased weight can result in a higher position of the center of gravity of the head. The above-described embodiment includes a mechanism for attaching the sleeve 20 from the sole side by screwing. Of the above-described increased weight, the weight of the sole-side portion is increased because of this mechanism, which can prevent the position of the center of gravity of the head from being higher.

[0071] The hosel end face 32 is positioned lower than the uppermost point P1, and the sleeve end face 20e is also positioned lower than the uppermost point P1. A shorter hosel portion 16 creates a saved weight, which can be allocated to other desired portions, as compared to a head having a conventional shaft attachable and detachable mechanism. The saved weight can lower the position of the center of gravity of the head 4. Lowering the position of the sleeve end face 20e can also result in lowering the position of the center of gravity of the head 4. The lowered center of gravity of the head 4 can lower the backspin rate of a struck ball.

[0072] Shortening the neck length L1, which is the distance between the intersection point P3 and the sleeve end face 20e, can increase an effective length of the shaft 6. The effective length refers to the length of a portion of the shaft 6 that is not inserted into the shaft hole 20d. When a club length is maintained, the effective length of the shaft 6 can be increased by shortening the neck length L1 (see FIG. 2) measured from the ground plane HP. This configuration allows the shaft 6 to sufficiently bend, which can improve the ball catchability of the head 4. The term “ball catchability” refers to an ability of the head 4 to prevent the striking face 10a from opening at impact with a golf ball. A head having an excellent ball catchability can reduce energy loss due to an open striking face 10a at impact with a golf ball, which can increase the flight distance of the struck ball. The above-described saved weight can be allocated to a toe-side portion and a back-side portion of the head 4, which can increase the moment of inertia of the head 4 while maintaining an excellent ball catchability. The increased moment of inertia of the head 4 can improve the stability of the struck ball.

[0073] Conventionally, in a head including the sleeve mechanism s1, the neck length L1 including the exposed sleeve length L3 of the sleeve 20 is greater than 69 mm. A club that includes the sleeve mechanism s1 and can be customized to fit individual golfers is conventionally designed for intermediate to advanced players who prefer a relatively longer neck length L1. On the other hand, it is advantageous for average golfers to reduce the neck length L1 and increase the effective length of the shaft 6 to achieve an excellent ball catchability. From this viewpoint, the neck length L1 is preferably less than or equal to 69 mm, more preferably less than or equal to 68 mm, and even more preferably less than or equal to 67 mm. From the viewpoint of ensuring a sufficient length for the bonding portion between the shaft hole 20d and the shaft 6 (hereinafter, this length is also referred to as “bonding length”), the neck length L1 is preferably greater than or equal to 58 mm, more preferably greater than or equal to 60 mm, and even more preferably greater than or equal to 62 mm.

[0074] The head 4 including the sleeve mechanism s1 includes the exposed portion 20a of the sleeve 20. As shown in FIG. 3 and FIG. 5, the exposed portion 20a forms a conical surface having an outer diameter that gradually increases downward and reaches a maximum outer diameter at the lower end. As shown in FIG. 8A, the outer diameter of the lower end (downward-facing surface 20g) of the exposed portion 20a is equal to the outer diameter of the hosel end face 32. The head body b1 includes a hosel curved surface 40 that extends downward from the hosel end face 32 and has a substantially conical shape. The hosel curved surface 40 also has an outer diameter that gradually increases downward. When the hosel curved surface 40 has a great length in the axial direction, the gradual increase of the outer diameter of the hosel curved surface 40 can lead to an excessively great outer diameter, which tends to cause the hosel curved surface 40 to protrude frontward (toward the face side) (see FIG. 3). On the other hand, the striking face 10a includes a bulge. The bulge refers to the curvature (roundness) in the toe-heel direction. In the plan view (FIG. 3) of the head 4 as viewed from the crown side, the striking face 10a forms a convex curved surface. Because of the bulge curvature, the heel-side end of the striking face 10a is positioned on the back side relative to the center of the striking face 10a. In other words, because of the bulge curvature, the heel-side end of the striking face 10a is positioned closer to the hosel axis line z1. The hosel curved surface 40 protrudes frontward, and the heel-side end of the striking face 10a is positioned closer to the hosel axis line z1, whereby the hosel curved surface 40 can protrude frontward further than the heel-side end of the striking face 10a. Alternatively, the hosel curved surface 40 can protrude to reach the substantially same position (in the face-back direction) as the heel-side end of the striking face 10a. In these configurations, the heel-side portion of the striking face 10a looks as if it is recessed when addressing a golf ball (see FIG. 3), which makes it difficult to address a golf ball. This problem can be solved by increasing the face progression FP. In other words, this problem can be solved by positioning the striking face 10a further frontward relative to the hosel axis line z1. However, a large face progression FP can result in a deterioration of the ball catchability of the head 4. In the present embodiment, the neck length L1 is short, and the length of the hosel curved surface 40 in the axial direction is also short. This configuration prevents an excessive increase in the outer diameter of the lower portion of the hosel curved surface 40, which prevents the heel-side portion of the striking face 10a from looking as if it is recessed. As a result, this configuration can reduce the face progression FP while maintaining the ease of addressing. A reduced face progression FP can improve the ball catchability of the head 4.

[0075] From these viewpoints, the face progression FP is preferably less than or equal to 18.0 mm, more preferably less than or equal to 17.8 mm, and even more preferably less than or equal to 17.5 mm. Considering the dimensions required for the sleeve mechanism s1 and the hosel portion 16, the face progression FP is preferably greater than or equal to 14.0 mm, more preferably greater than or equal to 14.2 mm, and even more preferably greater than or equal to 14.5 mm.

[0076] Because of the bulge curvature, the longer the face length W1 (see FIG. 3) is, the closer the position of the heel-side end of the striking face 10a is to the hosel axis line z1. Accordingly, a greater face length W1 tends to cause the heel-side portion of the striking face 10a to look as if it is recessed. It is preferable to prevent the heel-side portion of the striking face 10a from looking as if it is recessed while minimizing the face progression FP. From this viewpoint, when the outer diameter of the hosel end face 32 is denoted by D2 (mm) (see FIG. 9A), and the bulge curvature (radius of curvature of the bulge) is denoted by Rb (mm), the face progression FP (mm) preferably satisfies the following relationship (1). That is, the face progression FP is preferably greater than “Rb−{Rb2−(W1 / 2)2}1 / 2+D2 / 2”, and is preferably less than “Rb−{Rb2−(W1 / 2)2}1 / 2+D2”. When the bulge curvature is denoted by Rb and the face length is denoted by W1, “Rb−{Rb2−(W1 / 2)2}1 / 2” is equivalent to the distance in the face-back direction between the face center Fc and the heel-side end of the striking face 10a. Rb-{Rb2-(W⁢1 / 2)2}1 / 2+D⁢2>FP>Rb-{Rb2-(W⁢1 / 2)2}1 / 2+D⁢2 / 2(1)

[0077] Reducing the outer diameter D2 (see FIG. 9A) of the hosel end face 32 can prevent the hosel curved surface 40 from protruding frontward. From the viewpoints of the ease of addressing and weight reduction of the hosel portion 16, the outer diameter D2 is preferably less than or equal to 15 mm, more preferably less than or equal to 14.5 mm, and even more preferably less than or equal to 14.0 mm. From the viewpoint of the strength of the hosel portion 16, the outer diameter D2 is preferably greater than or equal to 12.0 mm, more preferably greater than or equal to 12.5 mm, and even more preferably greater than or equal to 13.0 mm.

[0078] Shortening the hosel protruding length L6 (see FIG. 7A) can prevent the hosel curved surface 40 from protruding frontward. From the viewpoints of the ease of addressing and weight reduction of the hosel portion 16, the hosel protruding length L6 is preferably less than or equal to 9.0 mm, more preferably less than or equal to 8.0 mm, and even more preferably less than or equal to 7.0 mm. The hosel protruding length L6 may be zero. When the height H2 (see FIG. 2) of the inflection point P4 is small, a sufficient hosel protruding length L6 can be required to securely hold the sleeve 20. From this viewpoint, the hosel protruding length L6 can be greater than or equal to 1.0 mm, further can be greater than or equal to 2.0 mm, and even further can be greater than or equal to 3.0 mm.

[0079] In the present embodiment, the distance D3 between the inflection point P4 and the hosel axis line z1 is small (see FIG. 2). Reducing the distance D3 prevents the hosel portion 16 from looking as if it is lengthened, which can facilitate addressing a golf ball. From this viewpoint, the distance D3 is preferably less than or equal to 20.0 mm, more preferably less than or equal to 18.0 mm, and even more preferably less than or equal to 17.0 mm. Connecting the hosel portion 16 and the crown portion 12 smoothly to create a smoothly curved surface can prevent the sense of incongruity during addressing a golf ball. From this viewpoint, the distance D3 is preferably greater than or equal to 8.0 mm, more preferably greater than or equal to 8.5 mm, and even more preferably greater than or equal to 9.0 mm.

[0080] As described above, the region R1 is defined as a region surrounded by a virtual cylinder having a radius of 20 mm and an axis that coincides with the hosel axis line z1 (see FIG. 7A). The sleeve mechanism s1 tends to increase the weight in the region R1. Reducing the weight in the region R1 can generate a saved weight that can be allocated to other desired portions, thereby lowering the position of the center of gravity of the head 4. From this viewpoint, the ratio of the weight in the region R1 to the weight of the head 4 is preferably small. The ratio of the weight in the region R1 to the weight of the head 4 is preferably less than 25.0%, more preferably less than or equal to 24.5%, and even more preferably less than or equal to 24.0%. From the viewpoint of maintaining the strength of the sleeve mechanism s1 and the hosel portion 16, the ratio of the weight in the region R1 to the weight of the head 4 is preferably greater than or equal to 16.0%, more preferably greater than or equal to 17.0%, and even more preferably greater than or equal to 18.0%.

[0081] As described above, the region R2 is defined as a region surrounded by a virtual cylinder having a radius of D3 mm and an axis that coincides with the hosel axis line z1 (see FIG. 7A). The distance D3 refers to the distance between the inflection point P4 and the hosel axis line z1 in the front elevation view of the head 4. The sleeve mechanism s1 tends to increase the weight in the region R2. Reducing the weight in the region R2 can generate a saved weight that can be allocated to other desired portions, thereby lowering the position of the center of gravity of the head 4. From this viewpoint, the ratio of the weight in the region R2 to the weight of the head 4 is preferably small. The ratio of the weight in the region R2 to the weight of the head 4 is preferably less than or equal to 20.0%, more preferably less than 20.0%, and even more preferably less than or equal to 19.9%. From the viewpoint of maintaining the strength of the sleeve mechanism s1 and the hosel portion 16, the ratio of the weight in the region R2 to the weight of the head 4 is preferably greater than or equal to 14.0%, more preferably greater than or equal to 14.5%, and even more preferably greater than or equal to 15.0%.

[0082] From the viewpoint of lowering the position of the center of gravity of the head 4, the distance H4 (see FIG. 2) between the ground plane HP and the center of gravity Gs of the sleeve 20 is preferably less than 41.0 mm, more preferably less than or equal to 40.5 mm, and even more preferably less than or equal to 40.0 mm. Considering the structure of the sleeve mechanism s1 for attaching the sleeve 20 from the sole side by screwing, the distance H4 between the ground plane HP and the center of gravity Gs of the sleeve 20 is preferably greater than or equal to 30.0 mm, more preferably greater than or equal to 30.5 mm, and even more preferably greater than or equal to 31.0 mm.

[0083] From the viewpoint of generating the saved weight, the ratio of the weight of the sleeve 20 to the weight of the head 4 is preferably less than 3.30%, more preferably less than or equal to 3.25%, and even more preferably less than or equal to 3.20%. From the viewpoint of the strength of the sleeve 20, the ratio of the weight of the sleeve 20 to the weight of the head 4 is preferably greater than or equal to 3.00%, more preferably greater than or equal to 3.05%, and even more preferably greater than or equal to 3.10%.

[0084] The hosel portion 16 includes the inner opening 34 (see FIG. 8B). The inner opening 34 reduces the weight of the head body b1 in the region R1 and the region R2. The inner opening 34 generates the saved weight. The saved weight contributes to lowering the position of the center of gravity of the head 4.

[0085] As described above, the sleeve end face 20e is positioned lower than the uppermost point P1 by the distance H3 (see FIG. 2). From the viewpoints of generating the saved weight and lowering the position of the center of gravity of the head 4, the distance H3 is preferably greater than or equal to 2.0 mm, more preferably greater than or equal to 3.0 mm, and even more preferably greater than or equal to 4.0 mm. From the viewpoint of ensuring a sufficient bonding length, the distance H3 is preferably less than or equal to 13.0 mm, more preferably less than or equal to 12.0 mm, and even more preferably less than or equal to 11.0 mm.

[0086] From the viewpoints of generating the saved weight and lowering the position of the center of gravity of the head 4, the ratio H2 / H1 of the height H2 of the inflection point P4 to the head thickness H1 is preferably small (see FIG. 2). The ratio H2 / H1 is preferably less than or equal to 0.77, more preferably less than or equal to 0.76, and even more preferably less than or equal to 0.75. From the viewpoint of reducing the sense of incongruity in the shape of the head 4 during addressing a golf ball, the ratio H2 / H1 is preferably greater than or equal to 0.60, more preferably greater than or equal to 0.61, and even more preferably greater than or equal to 0.62.

[0087] From the viewpoint of the visibility of the sleeve 20, the exposed sleeve length L3 is preferably greater than or equal to 5 mm, more preferably greater than or equal to 6 mm, and even more preferably greater than or equal to 7 mm. From the viewpoint of improving the bending of the shaft 6, the exposed sleeve length L3 is preferably less than or equal to 16 mm, more preferably less than or equal to 15 mm, and even more preferably less than 15 mm.

[0088] From the viewpoints of generating the saved weight from the head body b1 while ensuring a sufficient bonding length, the ratio L2 / L3 of the hosel length L2 to the exposed sleeve length L3 is preferably small (see FIG. 2). The ratio L2 / L3 is preferably less than or equal to 5.4, more preferably less than or equal to 5.0, and even more preferably less than or equal to 4.6. From the viewpoint of including the structure for attaching the sleeve 20 from the sole side by screwing, the ratio L2 / L3 is preferably greater than or equal to 3.3, more preferably greater than or equal to 3.4, and even more preferably greater than or equal to 3.5.

[0089] A sufficient neck length L1 is required for ensuring a sufficient bonding length. Increasing the exposed sleeve length L3 allows the hosel length L2 to be reduced while ensuring a sufficient neck length L1. The reduction in the hosel length L2 can generate the saved weight from the head body b1. From the viewpoints of generating the saved weight from the head body b1 while ensuring a sufficient bonding length, the ratio L3 / L1 of the exposed sleeve length L3 to the neck length L1 is preferably great (see FIG. 2). The ratio L3 / L1 is preferably greater than or equal to 0.15, more preferably greater than or equal to 0.17, and even more preferably greater than or equal to 0.19. From the viewpoint of including the structure for attaching the sleeve 20 from the sole side by screwing, the ratio L3 / L1 is preferably less than or equal to 0.28, more preferably less than or equal to 0.27, and even more preferably less than or equal to 0.26.

[0090] With reference to FIG. 6 and FIG. 2, in the present embodiment, the total sleeve length L5 of the sleeve 20 includes the inserted length L4 which is inserted into the head4. From the viewpoint of the visibility of the sleeve 20, the ratio L4 / L5 of the inserted length L4 to the total sleeve length L5 is preferably small. From this viewpoint, the ratio L 4 / L5 is preferably less than or equal to 0.80, more preferably less than or equal to 0.75, and even more preferably less than or equal to 0.70. The strength for fixing the sleeve 20 is enhanced by ensuring sufficient lengths of the intermediate portion 20b and the anti-rotation engagement portion 20c. From this viewpoint, the ratio L4 / L5 is preferably greater than or equal to 0.63, more preferably greater than or equal to 0.64, and even more preferably greater than or equal to 0.65.

[0091] The following clauses are part of the invention included in the present disclosure.Clause 1

[0092] A golf club head including:

[0093] a head body that includes a hosel portion, a face portion, and a sole portion;

[0094] a sleeve that is detachably attached to the hosel portion; and

[0095] a screw member that attaches the sleeve from a sole side by screwing, wherein

[0096] the hosel portion includes a hosel hole and a hosel end face,

[0097] the hosel end face is positioned lower than an uppermost point of the head body, and

[0098] an end face of the sleeve is positioned lower than the uppermost point of the head body.Clause 2

[0099] The golf club head according to clause 1, wherein the golf club head has a neck length including a length of the sleeve of less than or equal to 68 mm.Clause 3

[0100] The golf club head according to clause 1 or 2, wherein the hosel end face has an outer diameter of less than or equal to 15 mm.Clause 4

[0101] The golf club head according to any one of clauses 1 to 3, wherein the golf club head has a face progression of less than or equal to 18 mm.Clause 5

[0102] The golf club head according to any one of clauses 1 to 4, wherein a ratio of a weight of a region of the golf club head that is surrounded by a virtual cylinder having a radius of 20 mm and an axis that coincides with a center line of the hosel hole to a total weight of the golf club head is less than 25.0%.Clause 6

[0103] The golf club head according to any one of clauses 1 to 5, wherein a ratio of a weight of the sleeve to a total weight of the golf club head is less than 3.3%.Clause 7

[0104] The golf club head according to any one of clauses 1 to 6, wherein a distance between a center of gravity of the sleeve and a ground plane on which the golf club head is placed is less than 41.0 mm.Clause 8

[0105] The golf club head according to any one of clauses 1 to 7, wherein

[0106] the head body further includes a crown portion,

[0107] the uppermost point of the head body is an uppermost point of the crown portion,

[0108] the crown portion includes an inflection point that is located on a contour line of the crown portion in a front elevation view of the golf club head, and

[0109] a distance D3 between the inflection point and a center line of the hosel hole is less than or equal to 20.0 mm.Clause 9

[0110] The golf club head according to clause 8, wherein a ratio of a weight of a region of the golf club head that is surrounded by a virtual cylinder having a radius of the distance D3 and an axis that coincides with the center line of the hosel hole to a total weight of the golf club head is less than or equal to 20.0%.Clause 10

[0111] The golf club head according to any one of clauses 1 to 9, wherein

[0112] the head body includes a hollow interior,

[0113] the hosel portion includes an inner hosel portion that is located inside the head body and faces the hollow interior, and

[0114] the inner hosel portion includes an opening that is open toward the hollow interior.LIST OF REFERENCE SYMBOLS2 Golf club

[0116] 4 Golf club head

[0117] 6 Shaft

[0118] 8 Grip

[0119] 10 Face portion

[0120] 10a Striking face

[0121] 12 Crown portion

[0122] 14 Sole portion

[0123] 16 Hosel portion

[0124] 20 Sleeve

[0125] 20a Exposed portion

[0126] 20b Intermediate portion

[0127] 20c Anti-rotation engagement portion

[0128] 20d Shaft hole

[0129] 20e Sleeve end face

[0130] 22 Rotation prevention portion

[0131] 24 Screw member

[0132] 26 Flange forming portion

[0133] 28 Washer

[0134] 30 Hosel hole

[0135] 32 Hosel end face

[0136] 34 Inner opening (opening)

[0137] h1 Hollow interior of the head

[0138] R1 Region surrounded by a virtual cylinder having a radius of 20 mm and an axis that coincides with the hosel axis line

[0139] CS1 Virtual cylindrical surface having a radius of 20 mm and an axis that coincides with the hosel axis line

[0140] R2 Region surrounded by a virtual cylinder having a radius of D3 mm and an axis that coincides with the hosel axis line

[0141] CS2 Virtual cylindrical surface having a radius of D3 mm and an axis that coincides with the hosel axis line

[0142] b1 Head body

[0143] s1 Sleeve mechanism

[0144] k1 Outer edge of the striking face

[0145] P1 Uppermost point

[0146] Fc Face center

[0147] z1 Hosel axis line (center line of the hosel hole)

[0148] z2 Shaft axis line (center line of the shaft hole)

[0149] HP Ground Plane

[0150] The above descriptions are merely illustrative and various modifications can be made without departing from the principles of the present disclosure.

[0151] The terminology used in the description of the various described embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The use of the terms “a”, “an”, “the”, and similar referents in the context of throughout this disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. As used throughout this disclosure, the word “may” is used in a permissive sense (i.e., meaning “having the potential to”), rather than the mandatory sense (i.e., meaning “must”). Similarly, as used throughout this disclosure, the terms “comprising,”“having,”“including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted.

[0152] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, sections, steps, processings, and / or operations, these elements, components, regions, layers, sections, steps, processings, and / or operations should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer, section, step, processing, or operation from another element, component, region, layer, section, step, processing, or operation. Terms such as “first,”“second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, section, step, processing, or operation discussed herein could be termed a second element, component, region, layer, section, step, processing, or operation without departing from the teachings of the example embodiments.

Claims

1. A golf club head comprising:a head body that includes a hosel portion, a face portion, and a sole portion;a sleeve that is detachably attached to the hosel portion; anda screw member that attaches the sleeve from a sole side by screwing, whereinthe hosel portion includes a hosel hole and a hosel end face,the hosel end face is positioned lower than an uppermost point of the head body, andan end face of the sleeve is positioned lower than the uppermost point of the head body.

2. The golf club head according to claim 1, wherein the golf club head has a neck length including a length of the sleeve of less than or equal to 68 mm.

3. The golf club head according to claim 2, wherein the hosel end face has an outer diameter of less than or equal to 15 mm.

4. The golf club head according to claim 3, wherein the golf club head has a face progression of less than or equal to 18 mm.

5. The golf club head according to claim 1, wherein a ratio of a weight of a region of the golf club head that is surrounded by a virtual cylinder having a radius of 20 mm and an axis that coincides with a center line of the hosel hole to a total weight of the golf club head is less than 25.0%.

6. The golf club head according to claim 5, wherein a ratio of a weight of the sleeve to the total weight of the golf club head is less than 3.3%.

7. The golf club head according to claim 1, wherein a distance between a center of gravity of the sleeve and a ground plane on which the golf club head is placed is less than 41.0 mm.

8. The golf club head according to claim 1, whereinthe head body further includes a crown portion,the uppermost point of the head body is an uppermost point of the crown portion,the crown portion includes an inflection point that is located on a contour line of the crown portion in a front elevation view of the golf club head, anda distance D3 between the inflection point and a center line of the hosel hole is less than or equal to 20.0 mm.

9. The golf club head according to claim 8, wherein a ratio of a weight of a region of the golf club head that is surrounded by a virtual cylinder having a radius of the distance D3 and an axis that coincides with the center line of the hosel hole to a total weight of the golf club head is less than or equal to 20.0%.

10. The golf club head according to claim 1, whereinthe head body includes a hollow interior,the hosel portion includes an inner hosel portion that is located inside the head body and faces the hollow interior, andthe inner hosel portion includes an opening that is open toward the hollow interior.

11. The golf club head according to claim 1, whereinthe head body further includes a crown portion,the uppermost point of the head body is an uppermost point of the crown portion,the crown portion includes an inflection point that is located on a contour line of the crown portion in a front elevation view of the golf club head, anda hosel protruding length that is defined as a distance between the inflection point and the hosel end face is greater than or equal to 0.0 mm and less than or equal to 9.0 mm.

12. The golf club head according to claim 1, whereinthe end face of the sleeve is positioned lower than the uppermost point of the head body by a distance H3, andthe distance H3 is greater than or equal to 2.0 mm and less than or equal to 13.0 mm.

13. The golf club head according to claim 1, whereinthe head body further includes a crown portion,the uppermost point of the head body is an uppermost point of the crown portion,the crown portion includes an inflection point that is located on a contour line of the crown portion in a front elevation view of the golf club head,a distance between a ground plane on which the golf club head is placed and the uppermost point of the head body is referred to as a head thickness H1,a height of the inflection point measured from the ground plane is referred to as a height H2 of the inflection point, anda ratio H2 / H1 of the height H2 of the inflection point to the head thickness H1 is greater than or equal to 0.60 and less than or equal to 0.77.

14. The golf club head according to claim 1, whereinthe sleeve includes an exposed portion that is exposed to outside of the golf club head, andan exposed sleeve length L3 that is defined as a length of the exposed portion is greater than or equal to 5 mm and less than or equal to 16 mm.

15. The golf club head according to claim 1, whereina distance from the hosel end face to an intersection point between a ground plane on which the golf club head is placed and a hosel axis line that is a center line of the hosel hole is referred to as a hosel length L2,the sleeve includes an exposed portion that is exposed to outside of the golf club head, and a length of the exposed portion is referred to as an exposed sleeve length L3, anda ratio L2 / L3 of the hosel length L2 to the exposed sleeve length L3 is greater than or equal to 3.3 and less than or equal to 5.4.

16. The golf club head according to claim 1, whereina distance from the end face of the sleeve to an intersection point between a ground plane on which the golf club head is placed and a hosel axis line that is a center line of the hosel hole is referred to as a neck length L1,the sleeve includes an exposed portion that is exposed to outside of the golf club head, and a length of the exposed portion is referred to as an exposed sleeve length L3, anda ratio L3 / L1 of the exposed sleeve length L3 to the neck length L1 is greater than or equal to 0.15 and less than or equal to 0.28.

17. The golf club head according to claim 1, whereina length of a part of the sleeve that is inserted into the head body is referred to as an inserted length L4,a length of an entirety of the sleeve is referred to as a total sleeve length L5, anda ratio L4 / L5 of the inserted length L4 to the total sleeve length L5 is greater than or equal to 0.63 and less than or equal to 0.80.

18. A golf club head comprising:a head body that includes a hosel portion, a face portion, and a sole portion;a sleeve that is detachably attached to the hosel portion; anda screw member that attaches the sleeve from a sole side by screwing, whereinthe hosel portion includes a hosel hole and a hosel end face,the hosel end face is positioned lower than an uppermost point of the head body,an end face of the sleeve is positioned lower than the uppermost point of the head body, andwhen an outer diameter of the hosel end face is denoted by D2 (mm), a bulge curvature of the golf club head is denoted by Rb (mm), and a face length of the golf club head is denoted by W1 (mm), then the golf club head has a face progression that is denoted by FP (mm) and satisfies the following relationship (1):Rb-{Rb2-(W⁢1 / 2)2}1 / 2+D⁢2>FP>Rb-{Rb2-(W⁢1 / 2)2}1 / 2+D⁢2 / 2.(1)

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