Insert, golf putter head including the same, and manufacturing method of insert

Abstract

To reduce a deformation amount due to a change in a temperature of an insert.SOLUTION: An insert mounted to a golf putter head, includes: a first layer 41 having a ball hitting surface 411 and formed of a first material harder than ball skin; a second layer 42 formed of the first material; and a middle layer 43 formed of a second material softer than the first material in between the first layer 41 and the second layer 42.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] This invention relates to an insert, a golf putter head including the same, and a method for manufacturing the insert.

Background Art

[0002] In conventional putter faces, development of a putter face that provides a moderate feel at impact, a good impact sound, and excellent straightness of the hit ball has been progressing. For example, Utility Model Registration No. 3156719 describes an insert-type face that can be inserted into the central portion of the hitting surface (face) of a golf putter head. Along the hitting surface, a soft resin A and a hard resin B for a golf ball skin are alternately arranged, and the resin A is in the same plane as the resin B or A protrudes slightly in the direction of the fly ball line from B. A face surface forming member and a putter face having a structure are described.

[0003] However, the putter face described in Utility Model Registration No. 3156719 has a problem in that warping occurs due to the difference in the expansion rates of the resins A and B because they are overlapped and adhered to each other, and the hitting surface is curved. By attaching the putter face to the head of a golf putter, it can be made flat following the surface of the head, but it is difficult to attach. In addition, the putter face may peel off from the head due to deterioration of the adhesive over time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One object of this invention is to provide an insert with a reduced amount of deformation due to temperature changes.

[0006] Another object of the present invention is to provide a golf putter head capable of exchanging inserts.

Means for Solving the Problems

[0007] According to one aspect of the present invention, the insert is an insert to be mounted on a golf putter head, having a hitting face, a first layer formed of a first material harder than a ball, a second layer formed of the first material, and an intermediate layer formed of a second material softer than the first material between the first layer and the second layer.

[0008] According to another aspect of the present invention, the golf putter head includes the above insert, a front portion having front and rear faces facing each other and formed with a mounting hole penetrating from the front face to the rear face, and a back portion detachably attached to a first portion of the rear face of the main body portion. The insert has the flange in contact with a second portion different from the first portion of the rear face of the front portion with the first layer entering the opening.

[0009] According to still another aspect of the present invention, a method for manufacturing an insert includes a step of injection molding a first layer formed of a material of a first material harder than a ball, a step of injection molding a second layer formed of a material of the first material, and a step of injection molding an intermediate layer formed of a material of a second material softer than the first material between the first layer and the second layer with the first layer and the second layer connected at a predetermined interval.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0012] FIG. 1 is a perspective view of a golf putter head according to this embodiment. FIG. 2 is an exploded perspective view of the golf putter head. Referring to FIGS. 1 and 2, the golf putter head 1 includes a front portion 2, a back portion 3, and an insert 4. In the following description, when hitting a golf ball stationary with the golf putter head 1, the hitting direction in which the golf ball travels is called forward, and the direction opposite to the forward is called backward.

[0013] The front portion 2 and the back portion 3 are arranged side by side in the hitting direction. The front portion 2 is arranged in front of the back portion 3. The back portion 3 has a flat mounting portion 31 in the front. The mounting portion 31 has a mounting surface 32 facing the front portion 2. Two holes 33 penetrating the mounting portion 31 are formed at a predetermined distance in the longitudinal direction. Screws 5 are inserted into the two holes 33 of the mounting portion 31 from the rear, and the screws 5 are screwed into screw holes formed in the front portion 2. Thereby, with a part of the mounting surface 32 of the mounting portion 31 in contact with the front portion 2, the back portion 3 is fixed to the front portion 2 by two screws 5.

[0014] FIG. 3 is a perspective view of the front portion. FIG. 3 is a perspective view of the front portion 2 viewed from the rear side where it is connected to the back portion 3. FIGS. 4 and 5 are exploded perspective views of the front portion. FIG. 4 is an exploded perspective view of the front portion 2 viewed from the rear. FIG. 5 is an exploded perspective view of the front portion 2 viewed from the front side. FIG. 6 is a cross-sectional view of the front portion. FIG. 7 is a cross-sectional view of the front portion 2 in a disassembled state.

[0015] Referring to FIGS. 3 to 7, the front portion 2 includes a main body portion 21, an intermediate member 22, and a neck portion 23. The main body portion 21 has a front surface 25 and a rear surface 26 facing each other, and an upper surface 27 and a bottom surface 28 connecting the front surface 25 and the rear surface 26. The front surface 25 and the rear surface 26 intersect in the hitting direction. Here, one end of the main body portion is referred to as the heel-side end portion, and the end portion opposite to the heel-side end portion is referred to as the toe-side end portion. A neck portion 23 extending upward from the upper surface 27 is fixed to the heel-side end portion of the upper surface 27 of the main body portion 21. The neck portion 23 has a vertical portion 231 extending vertically from the upper surface 27, a horizontal portion 232 extending horizontally from the upper end of the vertical portion 231 toward the front surface 25 side, and a hosel 233 attached to the end of the horizontal portion 232. The hosel 233 has a cylindrical shape. The hosel 233 is attached to the horizontal portion 232 while being inclined by a predetermined lie angle. The front portion 2 is connected to the shaft by inserting a shaft (not shown) into the hosel 233.

[0016] A through hole 24 is formed in the main body portion 21. The through hole 24 penetrates from the front surface 25 to the rear surface 26. The through hole 24 is formed in accordance with the shape of the first layer 41 of the insert 4 described later in terms of its cross-sectional shape. The rear surface 26 has a first portion 261 and a second portion 262 with different distances from the front surface 25. The distance between the first portion 261 and the front surface 25 is longer than the distance between the second portion 262 and the front surface 25. The second portion 262 is in contact with the outer periphery of the through hole 24 and has an annular shape surrounding the through hole 24. The first portion 261 has an annular shape surrounding the outer periphery of the second portion 262. The first portion 261 is parallel to the front surface 25.

[0017] The insert 4 and the intermediate member 22 are inserted in this order from the rear of the main body portion 21. Each of the insert 4 and the intermediate member 22 has a cross-sectional shape, when cut along a plane perpendicular to the hitting direction, similar to the cross-sectional shape of the through-hole 24 and the same as or slightly smaller than the cross-section of the through-hole 24. For this reason, the movement of the insert 4 in the horizontal and vertical directions intersecting the hitting direction is restricted. The flange 423 formed on the insert 4 abuts against the second portion 262 of the main body portion 21. Thereby, the forward movement of the insert 4 is restricted. The shape of the insert 4 is determined such that the hitting surface of the insert 4 is flush with the front surface 25 of the main body portion 21 in a state where the flange 423 formed on the insert 4 abuts against the second portion 262 of the main body portion 21. Further, the backward movement of the insert 4 is restricted by the intermediate member 22.

[0018] As shown in FIG. 2, the back portion 3 is fixed to the rear of the front portion 2 with screws 5. The backward movement of the intermediate member 22 is restricted by the back portion 3. For this reason, when the back portion 3 is attached to the front portion 2, the insert 4 and the intermediate member 22 are positioned inside the through-hole 24 of the front portion 2. For this reason, the insert 4 can be replaced by attaching and detaching the back portion 3 to and from the front portion 2.

[0019] FIG. 8 is a perspective view of the insert. FIG. 9 is an exploded perspective view of the insert. FIG. 10 is a plan view of the insert. FIG. 11 is a bottom view of the insert. FIG. 12 is a side view of the insert. FIG. 13 is a cross-sectional view taken along line A-A of FIG. 10. FIG. 14 is a cross-sectional view taken along line B-B of FIG. 10. Referring to FIGS. 8 to 14, the insert 4 includes a first layer 41, a second layer 42, and an intermediate layer 43. The first layer 41, the intermediate layer 43, and the second layer 42 are laminated in this order.

[0020] The first layer 41 is formed of a first material harder than the ball. Although the hardness of a golf ball may vary depending on the manufacturer, the first layer 41 is formed of a first material having a hardness greater than that of the hardest ball. The first layer 41 is manufactured by injection molding the material of the first material. The first layer 41 is a resin, metal or non-ferrous metal that is an elastomer with surface hardness and resilience characteristics equal to or greater than those of elastic rubber. The first material is metal, titanium, stainless steel, non-ferrous metal polycarbonate resin, styrene resin, polyphenylethylene resin, polyacetal resin. In the present embodiment, the first material is non-ferrous metal polycarbonate resin.

[0021] The first layer 41 has a flat plate shape and has a hitting surface 411. The first layer 41 is a plane intersecting the hitting direction. The thickness of the first layer 41 is 1.0 mm or less, preferably 0.8 mm. The first layer 41 has a plurality of openings 412 formed in the hitting surface 411. The cross section of the opening 412 is not limited, but is a shape in which a circle, an ellipse, or a semi-circle is combined at both ends of a rectangle. The maximum value of the inner diameter of the opening 412 is smaller than the dimple of the golf ball, preferably 1 / 2 or less of the diameter of the dimple. The plurality of openings 412 are arranged at intervals shorter than the diameter of the dimple of the golf ball. The distance between two adjacent openings 412 is shorter than the diameter of the dimple of the golf ball.

[0022] The second layer 42 is formed of the same material as the first layer 41. The second layer 42 is manufactured by injection molding the material of the first material. The second layer 42 has a flat plate shape. The thickness of the second layer 42 is 1.0 mm or more, preferably 1.0 mm. The second layer 42 has a superimposed portion 421 that overlaps the first layer 41 on the inner surface facing the first layer 41, and a flange 423 that contacts the outer periphery of the superimposed portion 421 and surrounds the superimposed portion 421. The back surface on the side opposite to the inner surface of the second layer 42 abuts against the above-described intermediate member 22.

[0023] The first layer 41 and the second layer 42 are connected at both longitudinal ends by two connecting parts 44. The connecting parts 44 are formed of the same material as the first layer 41. In the present embodiment, the connecting parts 44 are manufactured simultaneously with the injection molding of the first layer 41. Therefore, the connecting parts 44 and the first layer 41 are an integral body. Note that the connecting parts 44 may be manufactured simultaneously with the injection molding of the second layer 42. The length of the connecting parts 44 in the hitting direction is adjusted so that the distance between the first layer 41 and the second layer 42 is 1.00 or more and 2.0 mm or less. Preferably, the length of the connecting parts 44 is adjusted so that the distance between the first layer 41 and the second layer 42 is 1.00 mm.

[0024] The intermediate layer 43 is formed of a second material that is softer than the first material. The second material is an elastomer that is a synthetic polymer material. Preferably, the second material is a polyester-based elastomer. The second material has physical property values of a surface hardness of 40 to 60 (HS), a coefficient of restitution of 30 to 60%, and a kinetic friction coefficient of the surface of 0.4 to 2.0.

[0025] The intermediate layer 43 is disposed between the first layer 41 and the second layer 42. The intermediate layer 43 has convex portions 431 that protrude toward the first layer 41 at positions corresponding to a plurality of openings 412 formed in the first layer 41. The height of the convex portions 431 is adjusted so that the upper surfaces thereof are on the same plane as the hitting surface 411 of the first layer 41. Note that the upper surfaces of the convex portions 431 may protrude forward of the hitting surface 411. The intermediate layer 43 is formed by resin molding a polyester-based elastomer.

[0026] For example, the first layer 41 and the second layer 42 are positioned in a mold in a state where they are adhered by an adhesive or the like by the connecting parts 44. Then, the intermediate layer 43 is formed by injecting a heated and melted polyester-based elastomer between the first layer 41 and the second layer 42. Thereby, the insert 4 in which the first layer 41, the intermediate layer 43, and the second layer 42 are integrated is completed.

[0027] Assume the case of hitting a golf ball with the golf putter head 1. When the first layer 41 of the insert 4 first contacts the golf ball, the first layer 41 elastically deforms toward the second layer 42. As the amount of elastic deformation of the first layer 41 increases, the golf ball contacts the convex portion 431 of the intermediate layer 43. In this state, the first layer 41 becomes a curved surface with a smooth radius of curvature, and the golf ball is in a state of contacting both the first layer 41 and the intermediate layer 43. Therefore, the influence of the uneven shape of the ball surface due to the dimples of the golf ball is absorbed.

[0028] Furthermore, the direction in which the convex portion 431 of the intermediate layer 43 elastically deforms is such that the deformation in the direction intersecting the hitting direction is suppressed by the inner peripheral surface of the opening 412 of the first layer 41, and it becomes the direction opposite to the hitting direction. The vibration generated by the elastic deformation of the first layer 41 and the intermediate layer 43 is transmitted to the player as an appropriate hitting feeling and hitting sound.

[0029] The golf putter head 1 in the present embodiment is such that the back portion 3 can be replaced with a back portion 3A and a back portion 3B having different shapes.

[0030] FIG. 15 is a first diagram showing an example of a golf putter head to which another back portion is attached. Referring to FIG. 15, the back portion 3A is attached to the front portion 2. The back portion 3A has a different shape and weight from the back portion 3. Therefore, the golf putter head 1 in which the back portion 3A is connected to the front portion 2 has a different appearance shape and center of gravity position from the golf putter head 1 in which the back portion 3 is connected to the front portion 2.

[0031] FIG. 16 is a second diagram showing an example of a golf putter head to which another back portion is attached. Referring to FIG. 16, the back portion 3B is attached to the front portion 2. The back portion 3B has a different shape and weight from the back portion 3 and the back portion 3A. Therefore, the golf putter head 1 in which the back portion 3B is connected to the front portion 2 has a different appearance shape and center of gravity position from the golf putter head 1 in which the back portion 3 is connected to the front portion 2 and the golf putter head 1 in which the back portion 3A is connected to the front portion 2.

[0032] Therefore, the golf putter head 1 is configured by connecting one selected from among the plurality of back portions 3, 3A, 3B to the front portion 2. For this reason, the user can easily select any golf putter head 1 from among three different types of golf putter heads 1.

[0033] <Method for manufacturing insert> First, the first layer 41 is formed by injecting a heat-melted non-ferrous polycarbonate resin into a first mold (first step).

[0034] Next, the second layer 42 is formed by injecting a heat-melted non-ferrous polycarbonate resin into a second mold (second step).

[0035] The first layer 41 and the second layer 42 are adhered at the connecting portion 44 (step 3). Thereby, a combined body in which the first layer 41 and the second layer 42 are integrated is produced.

[0036] Next, the combined body is fixed to a third mold (step 4). Note that, for one side of the third mold that contacts the first layer 41, one side of the first mold may be used. Then, with the combined body fixed to the third mold, an intermediate layer 43 is formed by injecting a heat-melted polyester-based elastomer between the first layer 41 and the second layer 42 (step 5).

[0037] In the insert 4 in the present embodiment, the intermediate layer 43 is formed between the first layer 41 and the second layer 42. For this reason, even when the coefficient of thermal expansion is different between the first material forming the first layer 41 and the second layer 42 and the second material forming the intermediate layer 43, the amount of deformation due to a change in the temperature of the insert 4 can be reduced.

[0038] In addition, the first layer 41 has a plurality of openings 412 that penetrate through the front and back surfaces formed on the hitting surface 411, and the intermediate layer 43 has a plurality of convex portions 431 that fit into the plurality of openings 412. Therefore, when the golf ball hits the hitting surface 411, the first layer 41 and the intermediate layer 43 elastically deform, so that the influence of the uneven shape of the ball surface due to the dimples of the golf ball can be absorbed. Also, regardless of which part of the dimple the portion that first contacts the hitting surface 411 of the golf ball is, the probability of the golf ball traveling in a direction perpendicular to the hitting surface increases. Furthermore, the vibration generated by the elastic deformation of the first layer 41 and the intermediate layer 43 can be transmitted to the player as an appropriate hitting feeling and hitting sound.

[0039] Also, since the first layer 41 and the second layer 42 are connected by the connecting portion 44, the deformation of the insert 4 due to temperature changes can be further reduced.

[0040] Also, the second layer 42 has an overlapping portion 421 that overlaps the first layer, and a flange 423 that extends outward from the outer periphery of the overlapping portion 421. Since the flange 423 abuts against the second portion 262 of the main body portion 21 of the front portion 2, the forward movement of the insert 4 is restricted. Also, the backward movement of the insert 4 is restricted by the intermediate member 22. Therefore, the insert 4 can be easily attached to and detached from the front portion 2.

[0041] <First Modification Example of Insert> FIG. 17 is a plan view of the insert in the first modification. FIG. 18 is a bottom view of the insert in the first modification. FIG. 19 is a side view of the insert in the first modification. FIG. 20 is a cross-sectional view taken along line C-C of FIG. 17. FIG. 21 is a cross-sectional view taken along line D-D of FIG. 17. Referring to FIGS. 17 to 21, the difference between the insert 4A in the first modification and the above-described insert 4 is that a plurality of communication holes 425 penetrating the second layer 42 and the intermediate layer 43 are formed in each of the second layer 42 and the intermediate layer 43. Since the other configurations are the same as those of the above-described insert 4, the description will not be repeated here. The plurality of communication holes 425 are dispersedly arranged in the overlapping portion 421 of the second layer 42. The density of the plurality of communication holes 425 on the central side of the overlapping portion 421 is higher than that on the peripheral side.

[0042] <Manufacturing Method of Insert in the First Modification> First, the first layer 41 is formed by injecting a heat-melted non-ferrous metal polycarbonate resin into the first mold (first step).

[0043] Next, the second layer 42 is formed by injecting a heat-melted non-ferrous metal polycarbonate resin into the second mold (second step). The second mold is different from the above-described mold in that it has a shape corresponding to the plurality of communication holes 425. At this stage, the second layer 42 having the plurality of communication holes 425 is formed.

[0044] The first layer 41 and the second layer 42 are adhered at the connecting portion 44 (step 3). Thereby, a combined body in which the first layer 41 and the second layer 42 are integrated is produced.

[0045] Next, the combined body is fixed to the third mold (step 4). The third mold has a convex portion on the side of the mold that contacts the second layer 42 and enters the plurality of communication holes 425. This convex portion abuts against the first layer 41 and presses the first layer 41 against the other mold.

[0046] Then, with the binder fixed to the third mold, the molten polyester-based elastomer is injected between the first layer 41 and the second layer 42 to form the intermediate layer 43 (the fifth step).

[0047] When the molten polyester-based elastomer enters between the first layer 41 and the mold, the shape of the first layer 41 changes. In the method for manufacturing the insert in the first modification, the mold on the side of the third mold that contacts the second layer 42 has a plurality of convex portions. These convex portions abut against the first layer 41 and press the first layer 41 against the other mold. Therefore, in the fifth step, although the molten polyester-based elastomer passes through the plurality of openings 412 of the first layer 41, it can be made difficult for the molten polyester-based elastomer to enter between the first layer 41 and the mold. Since it becomes difficult for the molten polyester-based elastomer to enter between the first layer 41 and the mold, the shape of the first layer 41 can be prevented from changing.

[0048] Similar to the insert 4 described above, in the insert 4A in the first modification, the intermediate layer 43 is formed between the first layer 41 and the second layer 42. Therefore, even when the coefficient of thermal expansion is different between the first material forming the first layer 41 and the second layer 42 and the second material forming the intermediate layer 43, the deformation of the insert 4 can be reduced.

[0049] Further, in the insert 4A in the first modification, since a plurality of communication holes 425 are formed in the intermediate layer 43, the amount of elastic deformation around the communication holes 425 of the intermediate layer 43 increases. Therefore, the amount of elastic deformation of the first layer 41 when the golf ball hits the hitting surface 411 of the first layer 41 can be increased.

[0050] <Second Modification of the Insert> FIG. 22 is a plan view of the insert in the second modification. FIG. 23 is a bottom view of the insert in the second modification. FIG. 24 is a side view of the insert in the second modification. FIG. 25 is a cross-sectional view taken along line E-E of FIG. 22. FIG. 26 is a cross-sectional view taken along line F-F of FIG. 22. Referring to FIGS. 22 to 26, the insert 4B in the second modification is different from the above-described insert 4 in that a rectangular opening 427 is formed in the central portion of the second layer 42, and a plurality of communication holes 422 are provided in the peripheral portion surrounding the rectangular opening 427 of the second layer 42 and the intermediate layer 43. The rectangular opening 427 is formed in the region inside the overlapping portion 421. The plurality of communication holes 425 are dispersedly arranged in the overlapping portion 421 of the second layer 42. The density of the plurality of communication holes 425 on the central side of the overlapping portion 421 is higher than that on the peripheral side.

[0051] <Method for manufacturing the insert in the second modification> First, the first layer 41 is formed by injecting a heat-melted non-ferrous polycarbonate resin into the first mold (first step).

[0052] Next, the second layer 42 is formed by injecting a heat-melted non-ferrous polycarbonate resin into the second mold (second step). The second mold is different from the above-described mold in that it has a shape corresponding to each of the rectangular opening 427 and the plurality of communication holes 425. At this stage, the second layer 42 having the rectangular opening 427 and the plurality of communication holes 425 is formed.

[0053] The first layer 41 and the second layer 42 are adhered at the connecting portion 44 (step 3). Thereby, a combined body in which the first layer 41 and the second layer 42 are integrated is produced.

[0054] Next, the combined body is fixed to the third mold (step 4). The third mold has a convex portion on the side in contact with the second layer 42 that enters the plurality of communication holes 425. This convex portion abuts against the first layer 41 and presses the first layer 41 against the other mold.

[0055] Then, with the binder fixed to the third mold, the molten polyester-based elastomer is injected between the first layer 41 and the second layer 42 to form the intermediate layer 43 (fifth step). Note that the molten polyester-based elastomer may be injected into the portion of the rectangular opening 427.

[0056] In the method for manufacturing the insert according to the second modification, the mold on the side of the third mold that contacts the second layer 42 has a plurality of convex portions. These convex portions abut against the first layer 41 and press the first layer 41 against the other mold. Therefore, in the fifth step, the molten polyester-based elastomer passes through the plurality of openings 412 in the first layer 41, but it can be made difficult for the molten polyester-based elastomer to enter between the first layer 41 and the mold. Since it becomes difficult for the molten polyester-based elastomer to enter between the first layer 41 and the mold, the shape of the first layer 41 can be prevented from changing.

[0057] In the insert 4B according to the second modification, the thickness of the intermediate layer 43 is increased at the portion of the rectangular opening 427 formed in the second layer 42. The intermediate layer 43 directly contacts the intermediate member 22 at the portion of the rectangular opening 427 formed in the second layer 42. Therefore, the amount of elastic deformation of the first layer 41 when the golf ball hits the hitting surface 411 of the first layer 41 can be increased.

[0058] Further, since the second layer 42 has a peripheral portion surrounding the rectangular opening 427, even when the coefficient of thermal expansion is different between the first material forming each of the first layer 41 and the second layer 42 and the second material forming the intermediate layer 43, the deformation of the insert 4B can be reduced.

[0059] <Summary of the Embodiment> (Item 1) An insert to be attached to a golf putter, having a hitting surface and including a first layer formed of a first material harder than the ball, a second layer formed of the first material, and an intermediate layer formed between the first layer and the second layer of a second material softer than the first material.

[0060] In this aspect, the insert includes a first layer and a second layer formed of a first material harder than the ball, and an intermediate layer formed between the first layer and the second layer of a second material softer than the first material. Therefore, since the intermediate layer is disposed between the first layer and the second layer, even when the first material and the second material have different coefficients of thermal expansion, deformation of the insert can be reduced. As a result, it is possible to provide an insert with a reduced amount of deformation due to temperature changes.

[0061] (Item 2) The first layer has a plurality of openings penetrating through the front and back formed in the hitting surface, The insert according to item 1, wherein the intermediate layer has a plurality of convex portions fitted into the plurality of openings.

[0062] In this aspect, the probability that the golf ball will travel in a direction perpendicular to the hitting surface is high regardless of which part of the dimple first contacts the hitting surface, and a sufficient hitting feeling can be given to the player.

[0063] (Item 3) The insert according to item 1, further comprising a connecting portion connecting the first layer and the second layer.

[0064] In this aspect, since the first layer and the second layer are connected by the connecting portion, deformation of the insert due to temperature changes can be further reduced.

[0065] (Item 4) The insert according to item 1, wherein the second layer has an overlapping portion overlapping the first layer and a flange extending outward from the outer periphery of the overlapping portion.

[0066] In this aspect, the second layer has an overlapping portion overlapping the first layer and a flange extending outward from the outer periphery of the overlapping portion. Therefore, the insert can be supported by the flange.

[0067] (Item 5) The insert according to item 4, and A front portion having a front surface and a rear surface facing each other, and having a through hole formed therethrough from the front surface to the rear surface; A back portion removably attached to a first portion of the rear surface of the front portion; The insert is a golf putter head in which the flange abuts a second portion of the rear surface of the front portion different from the first portion while the first layer enters the through hole.

[0068] According to this aspect, a back portion removably attached to a first portion of the rear surface of the front portion; Since the flange abuts the second portion of the rear surface of the front portion with the first layer entering the opening, the insert is fixed between the front portion and the back portion when the back portion is attached to the front portion. Therefore, a golf putter head with an interchangeable insert can be provided.

[0069] (Item 6) A step of forming the first layer by injection molding with a material of a first material harder than the ball skin; A step of forming the second layer by injection molding with the material of the first material; A method for manufacturing an insert, including a step of forming an intermediate layer by injection molding with a material of a second material softer than the first material between the first layer and the second layer in a state where the first layer and the second layer are connected with a predetermined interval therebetween.

[0070] According to this aspect, since an intermediate layer is manufactured by injection molding a material of a second material between the first layer and the second layer of the first material, an insert with a small amount of deformation due to temperature change can be manufactured.

[0071] (Item 7) The first layer has a plurality of openings communicating through the front and back surfaces formed on the hitting surface; The step of forming the intermediate layer is the method for manufacturing an insert according to Item 6, in which injection molding is performed while pressing the first layer in a direction from the second layer toward the first layer.

[0072] According to this aspect, an intermediate layer can be formed by injection molding a material of a second material between the first layer and the second layer without changing the shape of the first layer.

[0073] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is defined by the scope of the claims rather than the above description, and all modifications within the meaning and scope equivalent to the scope of the claims are intended to be included.

Description of Reference Numerals

[0074] 1 Golf club head, 2 Front portion, 3, 3A, 3B Back portion, 4, 4A, 4B Insert, 5 Screw, 21 Body portion, 22 Intermediate member, 23 Neck portion, 24 Through hole, 25 Front surface, 26 Rear surface, 27 Upper surface, 28 Bottom surface, 31 Mounting portion, 32 Mounting surface, 33 Hole, 41 First layer, 42 Second layer, 43 Intermediate layer, 44 Connecting portion, 231 Vertical portion, 232 Horizontal portion, 233 Hosel, 261 First portion, 262 Second portion, 411 Striking surface, 412 Opening, 421 Overlapping portion, 422 Communication hole, 423 Flange, 425 Communication hole, 427 Rectangular opening, 431 Protrusion.

Claims

1. An insert to be mounted on a golf putter head, comprising a first layer having a hitting face and formed of a first material harder than a ball, a second layer formed of the first material, and an intermediate layer formed of a second material softer than the first material between the first layer and the second layer.

2. The first layer has a plurality of openings penetrating through the front and back surfaces formed in the hitting face, and the intermediate layer has a plurality of convex portions fitted into the plurality of openings. The insert according to Claim 1.

3. The insert according to Claim 1, further comprising a connecting portion connecting the first layer and the second layer.

4. The second layer has an overlapping portion overlapping the first layer and a flange extending outward from the outer periphery of the overlapping portion. The insert according to Claim 1.

5. The insert according to Claim 4, a front portion having front and rear surfaces facing each other and a through hole formed therethrough from the front surface to the rear surface, and a back portion detachably attached to a first portion of the rear surface of the front portion. The golf putter head, wherein the insert is such that the flange abuts against a second portion different from the first portion of the rear surface of the front portion with the first layer inserted into the through hole.

6. A step of forming the first layer by injection molding with a material of a first material harder than a ball, a step of forming the second layer by injection molding with the material of the first material, and a step of forming an intermediate layer by injection molding with a material of a second material softer than the first material between the first layer and the second layer while connecting the first layer and the second layer with a predetermined interval therebetween. A method for manufacturing an insert.

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