GOLF CLUB HEAD

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Japanese Patent Application No. 2023-105691 filed on Jun. 28, 2023. The entire contents of this Japanese Patent Application are hereby incorporated by reference.

BACKGROUND
Technical Field

The present disclosure relates to golf club heads.

Description of the Related Art

From the viewpoint of lowering the position of the center of gravity of a golf club head, there has been proposed a head that includes a weight member disposed in a sole portion (see JP 2001-204864A, for example).

SUMMARY

It is preferable that a weight member is tightly fixed to a golf club head without deterioration in appearance of the golf club head. It is also preferable that the design flexibility of the center of gravity of the head is high. One of the objects of the present disclosure is to provide a golf club head including a weight member that exhibits advantageous effects enhanced by a new structure for fixing the weight member.

In one aspect, a golf club head includes a striking face that includes a face center, a sole surface, and a back surface. The golf club head includes a face member that constitutes at least a part of the striking face, a head body having a face opening, and a weight member that is fixed to the head body. The face opening is covered by the face member. The weight member includes an exposed surface that constitutes a part of the sole surface and/or a part of the back surface. The head body includes a weight member receiving portion into which the weight member is inserted from a first side and that holds the weight member. The weight member receiving portion penetrates through the head body from the first side to a second side that is a different side from the first side. The exposed surface is formed on the second side of the weight member. A welded portion is formed on a boundary between the weight member and the head body on the first side of the weight member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a golf club head according to a first embodiment as viewed from the front of its striking face;

FIG. 2 is the same drawing as FIG. 1, but also shows hidden lines with dashed lines;

FIG. 3A and FIG. 3B are perspective views of the head in FIG. 1 as viewed from its back side, and a weight member is depicted with hatching in FIG. 3B;

FIG. 4 is an exploded perspective view of the head in FIG. 1;

FIG. 5 shows a head body as viewed from the same viewpoint as in FIG. 1;

FIG. 6 is a perspective view of the head body as viewed from the back side;

FIG. 7 is a cross-sectional view taken along line A-A in FIG. 1 before a welded portion is formed;

FIG. 8 is a cross-sectional view taken along line B-B in FIG. 1 before the welded portion is formed;

FIG. 9 is a cross-sectional view taken along line C-C in FIG. 1;

FIG. 10 is a cross-sectional view in which the weight member is removed from FIG. 7;

FIG. 11A is a part of the cross-sectional view of FIG. 7, FIG. 11B is a part of the cross-sectional view of FIG. 8, and FIG. 11A and FIG. 11B shows a welded portion which is blacked out;

FIG. 12A and FIG. 12B are cross-sectional views of a modification example, FIG. 12A corresponds to FIG. 11A, and FIG. 12B corresponds to FIG. 11B;

FIG. 13 shows the head of FIG. 1 cut along line A-A in FIG. 1 as viewed from its toe side, and the head is in a reference state in FIG. 13;

FIG. 14A is a perspective view of a head according to a second embodiment as viewed from its back side, FIG. 14B is a perspective view of a head according to a third embodiment as viewed from its back side, FIG. 14C is a perspective view of a head according to a fourth embodiment as viewed from its back side, and FIG. 14D is a perspective view of a head according to a fifth embodiment as viewed from its back side;

FIG. 15 is a cross-sectional view of a head according to a sixth embodiment taken at a toe reference position, and corresponds to FIG. 7 of the first embodiment;

FIG. 16 is a cross-sectional view of a head according to a seventh embodiment taken at the toe reference position, and corresponds to FIG. 7 of the first embodiment;

FIG. 17 is a cross-sectional view of a head according to an eighth embodiment taken at the toe reference position, and corresponds to FIG. 7 of the first embodiment;

FIG. 18 is a cross-sectional view of a head according to a ninth embodiment taken at the toe reference position, and corresponds to FIG. 7 of the first embodiment; and

FIG. 19 is a conceptual diagram for illustrating the reference state.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments will be described in detail with appropriate references to the accompanying drawings.

The following terms are defined in the present disclosure.

[Reference State]

In a head having a flat striking face such as an iron type head, the reference state is a state where a head is placed on a ground plane HP in a state where score lines and the ground plane HP are parallel to each other. In a head having a curved striking face such as a wood type head, the reference state is a state where a head is placed at a predetermined lie angle on the ground plane HP. In these reference states, the center line Z of a hosel hole (shaft axis line Z) of the head lies on (is contained in) a perpendicular plane VP (see FIG. 19). The perpendicular plane VP is a plane perpendicular to the ground plane HP.

In a head having a curved striking face, its face angle is 0° when the head is in the reference state. That is, in a planar view of a head as viewed from above, a line normal to its striking face at the geometric center of the striking face is set to be perpendicular to an intersection line NL. The intersection line NL is an intersection line between the perpendicular plane VP and the ground plane HP. When the head has a flat striking face, the intersection line NL is parallel to score lines.

There has been known a club including a changing mechanism in which its loft angle, lie angle and face angle can be adjusted by changing a rotational position of a sleeve or the like provided at a tip portion of a shaft. In a head used for such clubs, the shaft axis line Z of the head which is in the reference state is determined in a state where all adjustable items are set to be neutral. The term “neutral” means the center of the range of adjustment.

[Toe-Heel Direction]

The toe-heel direction is the direction of the intersection line NL. In a head having a flat striking face, the toe-heel direction is parallel to score lines.

[Front-Rear Direction]

The front-rear direction is a direction that is perpendicular to the toe-heel direction and parallel to the ground plane HP.

[Face-Back Direction]

The face-back direction is the direction of a normal line that is normal to a striking face at its face center. In a head having a flat striking face, the face-back direction is perpendicular to the striking face.

[Top-Sole Direction]

The top-sole direction is the direction of an intersection line between the striking face and a plane perpendicular to the toe-heel direction. In a head having a non-flat striking face, a tangent plane that is a flat plane tangent to the striking face at its face center can be used instead of the striking face. That is, the top-sole direction can be the direction of an intersection line between the tangent plane and the plane perpendicular to the toe-heel direction.

[Toe Reference Position]

The toe reference position is a position that is spaced 18.5 mm apart from a toe-most point of the striking face toward the heel side (see FIG. 1). In a normal iron type golf club head, a position of a toe-side end of each of score lines coincides with the toe reference position. The toe reference position is a position in the toe-heel direction.

[Heel Reference Position]

A plurality of score lines have their respective heel-side ends. A heel-most position of the heel-side ends is the heel reference position. In a normal iron type golf club head, the position of the heel-side end of a longest score line coincides with the heel reference position. The heel reference position is a position in the toe-heel direction.

[Score Line Center Position]

A position that divides a distance between the toe reference position and the heel reference position into two equal parts is defined as the score line center position. In a normal iron type golf club head, the center position of the longest score line coincides with the score line center position. The score line center position is a position in the toe-heel direction.

[Toe Middle Position]

A position that divides a distance between the toe reference position and the score line center position into two equal parts is defined as the toe middle position. The toe middle position is a position in the toe-heel direction.

[Heel Middle Position]

A position that divides a distance between the heel reference position and the score line center position into two equal parts is defined as the heel middle position. The heel middle position is a position in the toe-heel direction.

[Vertical Cross Section]

The vertical cross section is a cross section taken in the face-back direction and in the top-sole direction.

[Leading Edge]

In a vertical cross section of a head, a point located at the front-most position in the front-rear direction is determined. This point is determined in each of vertical cross sections taken at different positions in the toe-heel direction. A set of the points is defined as the leading edge.

[Trailing Edge]

When a radius of curvature of a sole surface is sequentially measured rearward in a vertical cross section of a head, a point at which the radius of curvature becomes first less than or equal to 5 mm is determined. A set of the points is defined as the trailing edge. The trailing edge is the rear edge of the sole surface.

[Face Center]

On the score line center position, a point that divides the width of the striking face into two equal parts is defined as the face center (see FIG. 1). In a head in which the score line center position cannot be determined, a geometric center (center of figure) of the striking face in the planar view can be determined as the face center.

FIG. 1 shows a head 100 of a first embodiment as viewed from the front of its striking face. FIG. 2. is the same drawing as FIG. 1, but also shows lines of a head body 120 which are hidden by a face member 122 with dashed lines. FIG. 3A and FIG. 3B are perspective views of the head 100 as viewed from the back side. In FIG. 3B, a weight member wt1 is shown with hatching.

The head 100 includes a striking face 102, a sole portion 104, a top blade 106, and a hosel 108. The sole portion 104 includes a sole surface 104a. The sole surface 104a is the outer surface of the sole portion 104. The hosel 108 has a hosel hole 110. The hosel hole 110 has a center line Z. A shaft (not shown in the drawings) is attached to the hosel hole 110.

As shown in FIG. 3A, the head 100 includes a leading edge Le and a trailing edge Te. The trailing edge Te is the rear edge of the sole surface 104a. The sole surface 104a includes a ridgeline 112 that extends from the toe side to the heel side. The ridgeline 112 is located between the leading edge Le and the trailing edge Te.

As shown in FIG. 1, the striking face 102 includes a plurality of score lines gv. The score lines gv includes a longest score line gv1. All of the score lines gv are formed on the face member 122.

The head 100 is an iron type golf club head. The striking face 102 is a flat surface. As shown in FIG. 3A, the head 100 has a back cavity 114. The back cavity 114 is a cavity formed on the back side of the head 100. An iron type head having such a back cavity as the back cavity 114 is referred to as a cavity back iron head by those skilled in the art. The head 100 is a cavity back iron head.

The head 100 includes a back surface 116. The back surface 116 is located on the top side with respect to the trailing edge Te. Note that a part located in the back cavity 114 (for example, a rear surface 152 of the face member 122) can be excluded from the back surface 116.

Note that the head 100 does not have to be an iron type head. The head 100 may be a wood type head, a utility type head, or a putter type head. The striking face 102 does not have to be a flat surface. The head 100 is preferably an iron type head.

As shown in FIG. 1, the head 100 has a face center Fc, a toe reference position Pt, a heel reference position Ph, a score line center position Pc, a toe middle position Pt1 and a heel middle position Ph1. Definitions of these positions are as described above. In the present embodiment, the toe reference position Pt coincides with the position of the toe-side ends of the score lines gv.

FIG. 4 is an exploded perspective view of the head 100. FIG. 5 shows the head body 120 as viewed from the same viewpoint as in FIG. 1. FIG. 6 is a perspective view of the head body 120 as viewed from the back side. In FIG. 4, the score lines gv on the face member 122 are omitted.

FIG. 7 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 7 is a vertical cross-sectional view taken at the toe reference position Pt. FIG. 8 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 8 is a vertical cross-sectional view taken at the score line center position Pc. FIG. 9 is a cross-sectional view taken along line C-C in FIG. 1. FIG. 9 is a vertical cross-sectional view taken at the heel reference position Ph. Note that FIG. 7 and FIG. 8 show the head 100 before being welded, and thus do not show a welded portion.

The head 100 is constituted by a plurality of members. The head 100 includes the head body 120, the face member 122, and the weight member wt1. The face member 122 is fixed to the head body 120. The weight member wt1 is fixed to the head body 120. As shown in FIG. 7, the weight member wt1 is present at the toe reference position Pt. As shown in FIG. 8, the weight member wt1 is present at the score line center position Pc. As shown in FIG. 9, the weight member wt1 is not present at the heel reference position Ph.

The head body 120 is made of a metal. Examples of the metal include stainless steel, soft iron, maraging steel, and a titanium alloy. In the present embodiment, the head body 120 is made of stainless steel. The face member 122 is made of a metal. Examples of the metal include a titanium alloy, stainless steel, chrome vanadium steel, and maraging steel. In the present embodiment, the face member 122 is made of a titanium alloy. There is no limitation on the materials of the head body 120 and the face member 122. From the viewpoint of forgiveness, the specific gravity of the face member 122 is preferably smaller than the specific gravity of the head body 120.

The weight member wt1 is made of a metal. The specific gravity of the weight member wt1 is greater than the specific gravity of the head body 120. The specific gravity of the weight member wt1 is greater than the specific gravity of the face member 122. From the viewpoint of having a high specific gravity, the material of the weight member wt1 is preferably an alloy containing tungsten and/or nickel. Considering also formability, the material of the weight member wt1 is more preferably an alloy containing tungsten and nickel. The material of the weight member wt1 may be weldable to the head body 120, or may be non-weldable to the head body 120.

From the viewpoint of the design flexibility of the center of gravity of the head, the specific gravity of the weight member wt1 is preferably greater than or equal to 9.0, more preferably greater than or equal to 9.1, and still more preferably greater than or equal to 9.2. Considering availability of the material, the specific gravity of the weight member wt1 is preferably less than or equal to 20.0, more preferably less than or equal to 19.9, and still more preferably less than or equal to 19.8. Considering a material having a sufficient strength for the head body 120, the specific gravity of the head body 120 is preferably greater than or equal to 4.0, more preferably greater than or equal to 4.1, and still more preferably greater than or equal to 4.2. In order to enhance the design flexibility of the center of gravity of the head, the difference between the specific gravity of the head body 120 and the specific gravity of the weight member wt1 is preferably large. From this viewpoint, the specific gravity of the head body 120 is preferably less than or equal to 8.0, more preferably less than or equal to 7.95, and still more preferably less than or equal to 7.9. Considering a material having a sufficient strength for the face member 122, the specific gravity of the face member 122 is preferably greater than or equal to 4.0, more preferably greater than or equal to 4.1, and still more preferably greater than or equal to 4.2. In order to enhance the design flexibility of the center of gravity of the head, the difference between the specific gravity of the face member 122 and the specific gravity of the weight member wt1 is preferably large. From this viewpoint, the specific gravity of the face member 122 is preferably less than or equal to 8.0, more preferably less than or equal to 7.95, and still more preferably less than or equal to 7.9.

The entirety of the head body 120 is integrally formed as a single-piece member. Alternatively, a plurality of members may be joined together by, for example, welding to form the head body 120.

The head body 120 has a face opening 134. The face opening 134 penetrates through the head body 120 in the face-back direction. The face opening 134 is covered by the face member 122. The head body 120 forms a frame that surrounds the periphery of the face opening 134.

The head body 120 includes a receiving surface 136. The receiving surface 136 is a surface that fronts toward the face side. The receiving surface 136 supports the peripheral part of the face member 122 from the back side. In the present embodiment, the receiving surface 136 is provided on the outside of the face opening 134 to surround the face opening 134. The receiving surface 136 is formed along a face-side opening edge 138 of the face opening 134. The receiving surface 136 constitutes a flat surface. This flat surface is parallel to the striking face 102.

The head body 120 includes a heel stepped surface 140. The heel stepped surface 140 extends from the receiving surface 136 toward the front side. The height of the heel stepped surface 140 is equal to the wall thickness of the face member 122. The heel stepped surface 140 abuts against a side surface 142 on the heel side of the face member 122.

In the present embodiment, the face member 122 which is larger than the face opening 134 covers the face opening 134, whereby the face opening 134 is closed. Alternatively, the face member 122 may be fitted into the face opening 134.

The head body 120 has a through hole h1 that holds the weight member wt1. In a planar view of the head 100 as viewed from the front of the striking face 102, the shape of the through hole h1 corresponds to the shape of the weight member wt1 (see FIG. 2 and FIG. 5). The head body 120 includes a wall 144 located on the upper side of the through hole h1.

The through hole h1 is an example of a weight member receiving portion h2. The weight member receiving portion does not have to be a through hole. For example, the weight member receiving portion h2 may be a groove that extends from one side to another side and into which the weight member is slidably inserted (hereinafter, in the present disclosure, one side is also referred to as a first side, and another side that is a different side from the first side is also referred to as a second side).

The face member 122 has a plate shape as a whole. The face member 122 has a front surface 150 and the rear surface 152. The front surface 150 constitutes at least a part of the striking face 102. In the present embodiment, the front surface 150 constitutes the entirety of the striking face 102. The rear surface 152 is a surface opposite to the front surface 150. The peripheral part of the rear surface 152 abuts against the receiving surface 136. The face member 122 does not have to have a plate shape. For example, the face member 122 may be a cup face.

The weight member wt1 includes a front surface 160, a rear surface 162, and a side surface 164. The weight member wt1 includes a first surface 166 and a second surface 168. The first surface 166 and the second surface 168 each constitute a part of the side surface 164. The first surface 166 is the upper surface of the weight member wt1. The second surface 168 is the lower surface of the weight member wt1. A double-pointed arrow D1 in FIG. 8 shows the width of the weight member wt1 in the face-back direction (hereinafter, a width in the face-back direction is also referred to as a face-back directional width). The width D1 varies. Due to the variation of the width D1, the front surface 160 has a two-tiered shape, with two tiers and a transition part interposed between the two tiers. The width D1 on the toe side is greater than the width D1 on the heel side. As shown in FIG. 2, the weight member wt1 has a center position P1 of a width W1 in the toe-heel direction (hereinafter, a width in the toe-heel direction is also referred to as a toe-heel directional width). The center of gravity of the weight member wt1 is positioned on the toe side with respect to the center position P1. The center of gravity of the weight member wt1 is positioned on the toe side with respect to the score line center position Pc. The center of gravity of the weight member wt1 is positioned on the toe side with respect to the toe meddle position Pt1. The weight member wt1 contributes to locating the center of gravity of the head at a toe-side position.

The center of gravity of the weight member wt1 is positioned on the sole side with respect to the face center Fc. The entirety of the weight member wt1 is positioned on the sole side with respect to the face center Fc. The weight member wt1 contributes to lowering the position of the center of gravity of the head.

The position of the weight member wt1 is not limited. In the present embodiment, the weight member wt1 includes a part positioned on the toe side with respect to the score line center position Pc. The weight member wt1 includes a part positioned on the toe side with respect to the toe reference position Pt. The weight member wt1 includes a part positioned between the toe reference position Pt and the score line center position Pc. The weight member wt1 is not present at the heel reference position Ph. The entirety of the weight member wt1 is positioned on the toe side with respect to the heel reference position Ph. The weight member wt1 is not present at the heel middle position Ph1. The entirety of the weight member wt1 is positioned on the toe side with respect to the heel middle position Ph1. The center of gravity of the weight member wt1 is positioned on the sole side with respect to the face center Fc. The entirety of the weight member wt1 is positioned on the sole side with respect to the face center Fc.

As shown in FIG. 7, FIG. 8 and FIG. 9, the head 100 has a pocket space SP1. The pocket space SP1 is a gap having a face-back directional width. The pocket space SP1 is a part of a cavity space formed by the back cavity 114. The boundary of the pocket space SP1 on its face side is demarcated by the rear surface 152 of the face member 122. The boundary of the pocket space SP1 on its back side is demarcated by a surface opposite to the rear surface 152. The pocket space SP1 is continuous with an outside space of the head 100.

The surface demarcating the back side of the pocket space SP1 includes the front surface 160 of the weight member wt1. The front surface 160 faces the pocket space SP1. A gap between the front surface 160 and the rear surface 152 is the pocket space SP1. The front surface 160 is opposite to the rear surface 152.

The head body 120 includes an opposite surface 170 that is opposite to the rear surface 152 of the face member 122. The opposite surface 170 includes a top-side opposite surface 172 positioned on the top side of the weight member wt1. The top-side opposite surface 172 faces the pocket space SP1. A gap between the top-side opposite surface 172 and the rear surface 152 of the face member 122 is the pocket space SP1. In the present embodiment, the top-side opposite surface 172 is the front surface of the wall 144.

FIG. 10 is a cross-sectional view in which the weight member wt1 is removed from FIG. 7. The through hole h1 has a first opening k1 and a second opening k2. The first opening k1 has an opening edge k10. The second opening k2 has an opening edge k20. The second opening k2 forms an opening on the sole surface 104a. The second opening k2 is formed in a region that extends from the sole surface 104a into the back surface 116. In the through hole h1, the first opening k1 is an opening on a first side, and the second opening k2 is an opening on a second side that is a different side from the first side. In the present embodiment, the first opening k1 is an opening on the face side, and the second opening k2 is an opening on the back side. In the through hole h1, the second opening k2 is an opening opposite to the first opening k1. The first opening k1 faces the pocket space SP1. The through hole h1 penetrates through the head body 120 from the first opening k1 to the second opening k2. The through hole h1 (weight member receiving portion h2) penetrates through the head body 120 from the first side to the second side. The through hole h1 (weight member receiving portion h2) penetrates through the head body 120 from the face side to the back side.

The weight member wt1 is inserted into the through hole h1 (weight member receiving portion h2) from the first side. The through hole h1 (weight member receiving portion h2) has a shape that prevents the weight member wt1 from passing through the through hole h1 from the first side to the second side. The weight member wt1 is retained by the through hole h1 (weight member receiving portion h2) at a predetermined relative position. The weight member wt1 is retained by the through hole h1 (weight member receiving portion h2) so as not to move toward the second side further than the predetermined relative position. The weight member wt1 is held by the through hole h1 (weight member receiving portion h2) at the predetermined relative position. The term “relative position” means the position of the weight member wt1 relative to the through hole h1 (weight member receiving portion h2).

As shown in FIG. 7 and FIG. 8, the weight member wt1 includes an exposed surface 180. The exposed surface 180 constitutes a part of the outer surface of the head 100. The exposed surface 180 includes a part (sole exposed surface 180a) that constitutes a part of the sole surface 104a. The sole exposed surface 180a is formed on the rear surface 162 of the weight member wt1. The exposed surface 180 includes a part (back exposed surface 180b) that constitutes a part of the back surface 116. The back exposed surface 180b is formed on the rear surface 162 of the weight member wt1. The weight member wt1 includes the trailing edge Te. In the weight member wt1, the trailing edge Te is a boundary between the sole exposed surface 180a and the back exposed surface 180b.

As shown in FIG. 10, the through hole h1 (weight member receiving portion h2) has a body tapered portion 184 that becomes narrower toward the second side. The body tapered portion 184 is constituted by a first taper surface 184a and a second taper surface 184b that are disposed opposite to each other. In the present embodiment, a gap (gap in the top-sole direction) between the first taper surface 184a and the second taper surface 184b becomes narrower toward the second side from the first side. In the present embodiment, the first taper surface 184a is positioned on the top side with respect to the second taper surface 184b. In the present embodiment, the first side is the face side, and the second side is the back side.

As shown in FIG. 7 and FIG. 8, the weight member wt1 includes a taper abutment surface 186 that abuts against the body tapered portion 184. In the present embodiment, the taper abutment surface 186 is constituted by the first surface 166 and the second surface 168 described above. A distance (distance in the top-sole direction) between the first surface 166 and the second surface 168 decreases toward the second side. The first surface 166 abuts against the first taper surface 184a. The second surface 168 abuts against the second taper surface 184b.

As described above, the first surface 166 is the upper surface of the weight member wt1. The upper surface 166 is a surface that extends toward the sole side as it goes toward the back side. This surface is also referred to as a downward-facing surface. The downward-facing surface 166 constitutes a part of the taper abutment surface 186.

FIG. 11A is a cross-sectional view showing a part of FIG. 7. FIG. 11B is a cross-sectional view showing a part of FIG. 8. Unlike FIG. 7 and FIG. 8, FIG. 11A and FIG. 11B show a welded portion. Note that, although the cross-sectional shape of the welded portion is a rectangle or the like in FIG. 11A and FIG. 11B, the welded portion has an indeterminate cross-sectional shape, actually.

The head 100 includes a welded portion 190. In FIG. 11A and FIG. 11B, the cross sections of the welded portion 190 are blacked out. The welded portion 190 is formed in a region including a boundary between the weight member wt1 and the head body 120. The welded portion 190 is disposed on the first side of the weight member wt1. The welded portion 190 is disposed only on the first side of the weight member wt1. The welded portion 190 is disposed at a first-side end of the boundary between the weight member wt1 and the head body 120. The welded portion 190 is formed on the first-side surface (front surface 160) of the weight member wt1. The welded portion 190 is not present on the second side of the weight member wt1. The welded portion 190 is not present on the outer surface of the head 100. The welded portion 190 is not present on the sole surface 104a. The welded portion 190 is not present on the back surface 116. The welded portion 190 is disposed only at a position facing the pocket space SP1. The welded portion 190 is disposed only at a position opposite to the rear surface 152 of the face member 122.

The welded portion 190 is a portion formed by welding. Welding in the present disclosure includes fusion welding, pressure welding, brazing and soldering. In the welding of the present disclosure, either one of base materials (the head body 120 and the weight member wt1) may be melted, or both of the base materials may be melted. Alternatively, in the welding of the present disclosure, neither of the base materials are melted, and only a filler material (including brazing filler material) may be melted. The filler material may be used, or does not have to be used. The welded portion 190 is a concept including the following structure a, structure b, structure c, structure d, or structure e. A weld bead is an example of the welded portion 190.

(Structure a) A portion formed by melting and then solidifying a part of the head body 120 when the weight member wt1 is not melted

(Structure b) A portion formed by melting and then solidifying a part of the head body 120 and a part of the weight member wt1

(Structure c) A portion formed by melting and then solidifying a part of the head body 120 and a filler material when the weight member wt1 is not melted

(Structure d) A portion formed by melting and then solidifying a part of the head body 120, a part of the weight member wt1, and a filler material

(Structure e) A portion formed by melting and then solidifying only a filler material (brazing filler material) when neither the head body 120 nor the weight member wt1 is melted

The weight member wt1 may be integrated into the head body 120 with the welded portion 190. Alternatively, the weight member wt1 is not integrated into the head body 120, and may physically engage with the welded portion 190 integrated into the head body 120. As an example, a head 100a described later has this configuration. Further alternatively, the weight member wt1 is not integrated into the head body 120 and may be joined to the head body 120 with a brazing filler material. As long as the welded portion 190 is positioned on the first side of the weight member wt1, and engages with the through hole h1 (weight member receiving portion h2) so that the weight member wt1 cannot move toward the second side, the welded portion 190 can fix the weight member wt1 even when the welded portion 190 only physically engages with the weight member wt1. The weight member wt1 is fixed also in the head 100a described later.

In the head 100, the welded portion 190 has the above structure d. That is, the welded portion 190 is formed by melting and then solidifying a part of the head body 120, a part of the weight member wt1, and a filler material.

FIG. 12A and FIG. 12B are cross-sectional views of the head 100a which is a modification example of the head 100. FIG. 12A corresponds to FIG. 11A. FIG. 12B corresponds to FIG. 11B. The head 100a has the same configuration as the head 100 except that the structure of the welded portion 190 of the head 100a is different from that of the head 100.

In the head 100a, the welded portion 190 has the above structure c. That is, in the present embodiment, the welded portion 190 is formed by melting and then solidifying a part of the head body 120 and a filler material. In the welded portion 190 having the structure c, the weight member wt1 is not melted.

FIG. 13 shows the head of FIG. 1 cut along line A-A in FIG. 1 as viewed from the toe side. The welded portion 190 is located at a position that is unviewable from the outside of the head 100. The welded portion 190 is not viewable from any position on the outside of the head 100. No welded portion other than the welded portion 190 is present. The head 100 does not include a welded portion viewable from the outside of the head 100. A dash-dot-dot-dash line in FIG. 13 shows a straight line L1 which touches the head 100 on the back side. A vertical cross section can be taken at any position in the toe-heel direction, and the straight line L1 is determined in each vertical cross section. A set of the straight lines L1 is defined as a virtual cover surface L2. A space surrounded by the head 100 and the virtual cover surface L2 can be defined as a cavity space formed by the back cavity 114. The term “outside of the head 100” can be defined as the outside of the space surrounded by the head 100 and the virtual cover surface L2.

FIG. 14A is a perspective view of a head 200 according to a second embodiment as viewed from the back side. FIG. 14B is a perspective view of a head 300 according to a third embodiment as viewed from the back side. FIG. 14C is a perspective view of a head 400 according to a fourth embodiment as viewed from the back side. FIG. 14D is a perspective view of a head 500 according to a fifth embodiment as viewed from the back side.

As shown in FIG. 14A, in the head 200, the entirety of the exposed surface 180 of the weight member wt1 is positioned on the toe side. The entirety of the exposed surface 180 is positioned on the toe side with respect to the face center Fc. The entirety of the exposed surface 180 is positioned on the toe side with respect to the toe middle position Pt1. The center of gravity of the weight member wt1 may be positioned on the toe side with respect to the toe middle position Pt1. The exposed surface 180 is provided at a single position. The exposed surface 180 constitutes a part of the sole surface 104a and a part of the back surface 116.

As shown in FIG. 14B, in the head 300, exposed surfaces 180 of the weight member(s) wt1 are provided at a plurality of (three) positions. In this case, a plurality of (three) weight members wt1 may be provided, or one weight member wt1 is provided and the one weight member wt1 may include the plurality of (three) exposed surfaces 180 separately positioned from each other.

As shown in FIG. 14C, in the head 400, the exposed surface 180 has a long length in the toe-heel direction. The exposed surface 180 extends from a position located on the toe side with respect to the toe reference position Pt to a position located on the heel side with respect to the heel middle position Ph1. The exposed surface 180 extends from a position located on the toe side with respect to the toe reference position Pt to a position located on the heel side with respect to the heel reference position Ph. The exposed surface 180 constitutes a part of the sole surface 104a and a part of the back surface 116.

As shown in FIG. 14D, in the head 500, the entirety of the exposed surface 180 of the weight member wt1 is positioned on the heel side. The entirety of the exposed surface 180 is positioned on the heel side with respect to the face center Fc. The center of gravity of the weight member wt1 may be positioned on the heel side with respect to the face center Fc. The center of gravity of the weight member wt1 may be positioned on the heel side with respect to the heel middle position Ph1. The exposed surface 180 constitutes a part of the sole surface 104a and a part of the back surface 116.

FIG. 15 is a cross-sectional view of a head 600 according to a sixth embodiment. This cross-sectional view corresponds to FIG. 7 of the first embodiment. In the head 600, the weight member receiving portion h2 (through hole h1) has a step 192. The weight member wt1 includes an abutment step 194 that abuts against the step 192. Because of the engagement between the step 192 and the abutment step 194, the weight member wt1 is retained by the weight member receiving portion h2 so as not to move toward the second side further than a predetermined relative position. The weight member wt1 is held by the weight member receiving portion h2 at the predetermined relative position. The welded portion 190 is disposed only on the first side of the weight member wt1. The welded portion 190 is not disposed on the second side of the weight member wt1. In the present embodiment, the first side is the face side, and the second side is the back side. The body tapered portion 184 and the taper abutment surface 186 are provided also in the present embodiment. However, the body tapered portion 184 and the taper abutment surface 186 do not have to be provided. The weight member wt1 may be retained by the weight member receiving portion h2 so as not to move toward the second side further than the predetermined relative portion only because of the engagement between the step 192 and the abutment step 194.

FIG. 16 is a cross-sectional view of a head 700 according to a seventh embodiment. This cross-sectional view corresponds to FIG. 7 of the first embodiment. In the head 700, the exposed surface 180 of the weight member wt1 does not constitute any part of the sole surface 104a. The exposed surface 180 in the head 700 does not include a sole exposed surface 180a. On the other hand, the exposed surface 180 constitutes a part of the back surface 116. The exposed surface 180 in the head 700 includes the back exposed surface 180b.

FIG. 17 is a cross-sectional view of a head 800 according to an eighth embodiment. This cross-sectional view corresponds to FIG. 7 of the first embodiment. In the head 800, the exposed surface 180 of the weight member wt1 does not constitute any part of the back surface 116. The exposed surface 180 in the head 800 does not include a back exposed surface 180b. On the other hand, the exposed surface 180 constitutes a part of the sole surface 104a. The exposed surface 180 in the head 800 includes the sole exposed surface 180a.

FIG. 18 is a cross-sectional view of a head 900 according to a ninth embodiment. This cross-sectional view corresponds to FIG. 7 of the first embodiment. In the present embodiment, the first side is the top side, and the second side is the sole side. In the head 900, the weight member receiving portion h2 (through hole h1) penetrates through the head body 120 from the top side to the sole side. The exposed surface 180 is formed on the sole side of the weight member wt1. The exposed surface 180 constitutes a part of the sole surface 104a. The welded portion 190 is formed on the boundary between the weight member wt1 and the head body 120 on the top side of the weight member wt1. All the welded portion(s) 190 face(s) the pocket space SP1. The head body 120 includes a wall 145. The wall 145 is located on the top side with respect to the welded portion 190. The welded portion 190 is shielded from outside view by the wall 145. The welded portion 190 is unviewable from the outside of the head 900.

In the head 900, the weight member wt1 is inserted into the weight member receiving portion h2 (through hole h1) from the top side. The weight member receiving portion h2 includes the body tapered portion 184 which becomes narrower toward the sole side. The weight member wt1 includes the taper abutment surface 186 which abuts against the body tapered portion 184. Because of the engagement between the body tapered portion 184 and the taper abutment surface 186, the weight member wt1 is retained by the weight member receiving portion h2 so as not to move toward the sole side further than a predetermined relative position.

The above-shown embodiments exhibit the following advantageous effects.

The weight member wt1 includes the exposed surface 180 constituting a part of the sole surface 104a and/or at least a part of the back surface 116. For this reason, the weight member wt1 can be disposed close to the outer surface of the head. The weight member wt1 disposed close to the outer surface of the head can improve the design flexibility of the center of gravity of the head. The weight member wt1 disposed close to the outer surface of the head can also increase the moment of inertial of the head.

When the exposed surface 180 constitutes a part of the sole surface 104a, the weight member wt1 is disposed close to the sole surface 104a. This can lower the position of the center of gravity of the head. When the exposed surface 180 constitutes a part of the back surface 116, the weight member wt1 is disposed close to the back surface 116. This can increase the depth of the center of gravity of the head. When the exposed surface 180 constitutes a part of the sole surface 104a and a part of the back surface 116, the position of the center of gravity of the head can be lowered and the depth of the center of gravity of the head can be increased.

The welded portion 190 is disposed on the first side of the weight member wt1. The first side is opposite from the second side on which the exposed surface 180 is located. For this reason, the welded portion 190 disposed on the first side of the weight member wt1 is inconspicuous, which improves the appearance of the head.

The weight member wt1 is inserted into the weight member receiving portion h2 from the first side. The weight member wt1 is inserted into the weight member receiving portion h2 after passing through the face opening 134. The weight member receiving portion h2 has a shape that prevents the weight member wt1 from passing through the weight member receiving portion h2 from the first side to the second side, whereby the weight member receiving portion h2 retains the weight member wt1 to prevent the weight member wt1 from moving toward the second side further than a predetermined relative position. For this reason, even when the welded portion 190 is disposed only on the first side, the weight member wt1 is surely held. This achieves a head that has no welded portion 190 on the outer surface of the head, to which the weight member wt1 is surely fixed, and that has the exposed surface 180.

The engagement between the body tapered portion 184 and the taper abutment surface 186 can achieve a surface-to-surface contact between the two even when a dimensional error occurs in the weight member receiving portion h2 or the weight member wt1. Accordingly, the weight member wt1 can be surely retained by the weight member receiving portion h2.

The weight member wt1 includes the downward-facing surface 166 which extends toward the sole side as it goes toward the back side, which contributes to lowering the position of the center of gravity of the head. The downward-facing surface 166 particularly contributes to lowering the height of a sweet spot. The sweet spot means an intersection point between the striking face and a straight line that is perpendicular to the striking face and passes through the center of gravity of the head. The height of the sweet spot is measured from the ground plane HP in the direction perpendicular to the ground plane HP when the head is in the reference state.

In the embodiment in which the weight member wt1 is disposed on the toe side, the center of gravity of the head can be located on the toe side. The center of gravity of the head tends to be located on the heel side particularly in iron type heads. The advantageous effect brought by the weight member wt1 disposed on the toe side is highly effective in iron type heads.

The welded portion 190 is hidden by the face member 122. This makes the welded portion 190 inconspicuous, which improves the appearance of the head.

The face opening 134 of the head body 120 is covered by the face member 122. This structure allows the weight member wt1 to be attached to the head body 120 before the face member 122 is attached to the head body 120. Accordingly, the weight member wt1 can be easily inserted into the weight member receiving portion h2 from the first side. In addition, welding process can be performed in the state where the face member 122 is not yet attached to the head body 120, whereby the welded portion 190 can be easily formed on the first side of the weight member wt1.

A double-pointed arrow D2 in FIG. 7 shows a distance between the face member 122 and the weight member wt1. This distance D2 is measured in the face-back direction. When the weight member wt1 extends to reach a position close to the face member 122, the weight member wt1 can have a larger volume. From this viewpoint, the minimum value of the distance D2 is preferably less than or equal to 5 mm, more preferably less than or equal to 4 mm, and still more preferably less than or equal to 3 mm. From the viewpoint of increasing the depth of the center of gravity of the head, the minimum value of the distance D2 is preferably greater than or equal to 1 mm, more preferably greater than or equal to 2 mm, and still more preferably greater than or equal to 2.5 mm.

As described above, the double-pointed arrow D1 in FIG. 8 shows the face-back directional width of the weight member wt1. From the viewpoint of increasing the volume of the weight member wt1, the maximum value of the width D1 is preferably greater than or equal to 8 mm, more preferably greater than or equal to 12 mm, and still more preferably greater than or equal to 15 mm. The maximum value of the width D1 can be increased by disposing the exposed surface(s) 180 on the sole surface 104a and/or the back surface 116. Considering the dimensions of the head and the distance D2, the maximum value of the width D1 is preferably less than or equal to 20 mm, more preferably less than or equal to 19 mm, and still more preferably less than or equal to 18 mm.

In the above-described embodiments, the weight member wt1 cannot be inserted into the weight member receiving portion h2 (through hole h1) in the state where the face member 122 is attached to the head body 120. The weight member wt1 cannot be put into the pocket space SP1 formed by the head body 120 to which the face member 122 is attached. The weight member wt1 cannot be inserted into the weight member receiving portion h2 (through hole h1) from the second side which faces the outside of the head. The weight member wt1 is inserted from the first side into the head body 120 to which the face member 122 is not yet attached. Even if the weight member wt1 falls out of the weight member receiving portion h2, the weight member wt1 cannot fall out of the head.

The method for manufacturing each head of the above-described embodiments can include the following steps (1a) to (3a).

(1a) A first step of inserting the weight member wt1 into the weight member receiving portion h2 from the first side in the state where the face member 122 is not yet attached to the head body 120.

(2a) A second step of forming the welded portion 190 on the boundary between the weight member wt1 and the weight member receiving portion h2 on the first side of the weight member wt1 in an assembly obtained in the first step.

(3a) A third step of attaching the face member 122 to the head body 120 which has been subjected to the second step.

The following clauses are a part of invention included in the present disclosure.

[Clause 1]

A golf club head including:

- a striking face including a face center;
- a sole surface; and
- a back surface, wherein
- the golf club head includes a face member constituting at least a part of the striking face, a head body having a face opening, and a weight member fixed to the head body,
- the face opening is covered by the face member,
- the weight member includes an exposed surface constituting a part of the sole surface and/or a part of the back surface,
- the head body includes a weight member receiving portion into which the weight member is inserted from a first side and that holds the weight member,
- the weight member receiving portion penetrates through the head body from the first side to a second side that is a different side from the first side,
- the exposed surface is formed on the second side of the weight member, and
- a welded portion is formed on a boundary between the weight member and the head body on the first side of the weight member.

[Clause 2]

The golf club head according to clause 1, wherein

- the exposed surface constitutes a part of the sole surface.

[Clause 3]

The golf club head according to clause 1 or 2, wherein

- the weight member receiving portion has a shape that prevents the weight member from passing through the weight member receiving portion from the first side to the second side, and
- the weight member is retained by the weight member receiving portion so as not to move toward the second side further than a predetermined relative position.

[Clause 4]

The golf club head according to any one of clauses 1 to 3, wherein

- the weight member receiving portion includes a body tapered portion that becomes narrower toward the second side, and
- the weight member includes a taper abutment surface that abuts against the body tapered portion.

[Clause 5]

The golf club head according to clause 4, wherein

- an upper surface of the weight member includes a downward-facing surface that extends toward a sole side as it goes toward a back side, and
- the downward-facing surface constitutes a part of the taper abutment surface.

[Clause 6]

The golf club head according to any one of clauses 1 to 5, wherein

- the exposed surface constitutes a part of the sole surface and a part of the back surface.

[Clause 7]

The golf club head according to any one of clauses 1 to 6, wherein

- a center of gravity of the weight member is positioned on a toe side with respect to the face center.

[Clause 8]

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

- the first side is a face side, and
- the second side is a back side.

[Clause 9]

The golf club head according to any one of clauses 1 to 8, wherein

- the weight member receiving portion is a through hole.

[Clause 10]

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

- the welded portion is located at a position that is unviewable from outside of the golf club head.

LIST OF REFERENCE SYMBOLS

- 100, 100a, 200, 300, 400, 500, 600, 700, 800, 900 Golf club head
- 102 Striking face
- 104 Sole portion
- 104
  a Sole surface
- 108 Hosel
- 114 Back cavity
- 116 Back surface
- 120 Head body
- 122 Face member
- 152 Rear surface of the face member
- 180 Exposed surface
- 180
  a Sole exposed surface
- 180
  b Back exposed surface
- 184 Body tapered portion
- 186 Taper abutment surface
- 190 Welded portion
- Fc Face center
- SP1 Pocket space
- h1 Through hole
- h2 Weight member receiving portion
- k1 First opening
- k2 Second opening
- wt1 Weigh member
- gv Score lines
- gv1 Longest score line
- Pt Toe reference position
- Pc Score line center position
- Ph Heel reference position
- Le Leading edge
- Te Trailing edge

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

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.

GOLF CLUB HEAD

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Priority Claims (1)