Putter head

Abstract

A putter head that includes: a head body having a face portion; and a face insert fitted in the face portion, the face insert including: a high-hardness portion that forms a hitting surface, and a low-hardness portion jointed to the high-hardness portion and having a hardness lower than that of the high-hardness portion. The Shore D hardness of the high-hardness portion is 30 or more, the Shore D hardness of the low-hardness portion is 10 or more, and a difference between the Shore D hardness of the high-hardness portion and the Shore D hardness of the low-hardness portion is 5 or more.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a putter head with a face insert fitted in a face portion of a head body.

[0003] 2. Description of the Related Art

[0004] Conventionally, a putter head has been proposed in which a face insert made of a material different from that of a head body is fitted in a face portion of the head body. For example, JP-A-2004-236985 discloses a putter head in which a face insert having a layered structure integrally including a rubber elastic body layer, a sintered metal layer, and a fluororesin layer is fitted in the face portion of the head body. In addition, JP-A-2005-124730 discloses a putter head in which an elastic body-made face insert whose thickness increases gradually from the side of the vicinity of a sweet spot of the head toward a peripheral edge side is fitted in a face portion of a head body.

SUMMARY OF THE INVENTION

[0005] The above-described putter head with the face insert fitted in the head body is generally aimed at softening the hitting sensation when the ball is hit by the face insert.

[0006] However, with the conventional putter head with the face insert fitted in the head body, while the hitting sensation can be made soft by the face insert, the hitting sound becomes dull (low), so that there have been cases where it is difficult to grasp a sense of distance of the putt.

[0007] One aspect of the present invention provides a putter head with a face insert fitted in a head body, in which the hitting sensation at the time of hitting a ball is soft and the hitting sound is hard (high), so that it is easy to grasp the sense of distance of the putt.

[0008] According to an aspect of the invention, there is provided a putter head including: a head body having a face portion; and a face insert fitted in the face portion, the face insert including: a high-hardness portion that forms a hitting surface, and a low-hardness portion jointed to the high-hardness portion and having a hardness lower than that of the high-hardness portion.

[0009] In the putter head in accordance with the aspect of the invention, since the hardness of the high-hardness portion for forming the hitting surface (the surface for directly hitting the golf ball) is high, it is possible to obtain a hard (high) hitting sound by means of this high-hardness portion. Accordingly, it is easy to grasp the sense of distance of the putt. In addition, since the hardness of the low-hardness portion for forming a portion other than the high-hardness portion of the face insert is lower than that of the high-hardness portion, a soft hitting sensation can be obtained by this low-hardness portion.

[0010] Hereafter, a more detailed description will be given of the aspect of the invention. In the aspect, as the material of the head body, it is possible to cite, for example, stainless steel, aluminum, an aluminum alloy, brass, copper, a titanium alloy, zinc, a carbon fiber-reinforced resin, and the like, but the material of the head body is not limited to the same.

[0011] In addition, as the materials of the high-hardness portion and the low-hardness portion of the face insert, it is possible to cite synthetic resins such as an ionomer resin, a urethane resin, a urethane-based elastomer, and a polyester-based elastomer, and rubbers such as a styrene-butadiene rubber and a butadiene rubber, but the materials of the high-hardness portion and the low-hardness portion of the face insert are not limited to the same. As the materials of the high-hardness portion and the low-hardness portion of the face insert, elastomers such as a urethane-based elastomer and a polyester-based elastomer and urethane resins are particularly preferable.

[0012] In the aspect, the Shore D hardness of the high-hardness portion is set to 30 or more, more preferably 35 to 100, the Shore D hardness of the low-hardness portion is set to 10 or more, more preferably 15 to 60, and the difference in the Shore D hardness between the high-hardness portion and the low-hardness portion is set to 5 or more, more preferably 10 to 85. If the Shore D hardness of the high-hardness portion is less than 30, there are cases where a hard hitting sound cannot be obtained. If the Shore D hardness of the low-hardness portion is less than 10, there are cases where a soft hitting sensation cannot be obtained. If the difference in the Shore D hardness between the high-hardness portion and the low-hardness portion is less than 5, there are cases where the advantages of the invention of making the hitting sensation soft and making the hitting sound hard cannot be obtained.

[0013] In the aspect, one or both of the high-hardness portion and the low-hardness portion can be provided with a multi-layered structure. In a case where only the high-hardness portion is provided with the multi-layered structure, the Shore D hardness of an outermost layer which comes into contact with the golf ball in the high-hardness portion and the difference in hardness between the outermost layer and the low-hardness portion are set to the aforementioned values. In a case where only the low-hardness portion is provided with the multi-layered structure, the Shore D hardness of an innermost layer which is closest to the head body in the low-hardness portion and the difference in hardness between the innermost layer and the high-hardness portion are set to the aforementioned values. In a case where both of the high-hardness portion and the low-hardness portion are provided with a multi-layered structure, the Shore D hardness of the outermost layer which comes into contact with the golf ball in the high-hardness portion, the Shore D hardness of the innermost layer which is closest to the head body in the low-hardness portion, and the difference in hardness between the outermost layer of the high-hardness portion and the innermost layer of the low-hardness portion are set to the aforementioned values.

[0014] In the aspect, the structure of the putter head is not particularly limited, but it is possible to suitably adopt, for instance, structures shown in the following (a) to (c):

[0015] (a) A structure in which a recessed portion is formed in one of the high-hardness portion and the low-hardness portion, and the other one thereof is joined to an inner surface of the recessed portion.

[0016] (b) A structure in which the low-hardness portion of a flat plate shape is joined to one surface of the high-hardness portion of a flat plate shape.

[0017] (c) A structure in which the high-hardness portion is jointed to an inner peripheral surface of the low-hardness portion of a loop shape.

[0018] According to the putter head in accordance with the invention, the hitting sensation at the time of hitting a ball is soft, and the hitting sound is hard, so that the sense of distance is easy to grasp.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a rear view illustrating a face insert used in a putter head according to a first embodiment of the invention;

[0020] FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1;

[0021] FIG. 3 is an exploded perspective view illustrating an example of a putter head with the face insert fitted therein;

[0022] FIG. 4 is a rear view illustrating a face insert used in a putter head according to a second embodiment of the invention;

[0023] FIG. 5 is a cross-sectional view taken along line A-A in FIG. 4;

[0024] FIG. 6 is a cross-sectional view illustrating a face insert used in a putter head according to a third embodiment of the invention;

[0025] FIG. 7 is a cross-sectional view illustrating a face insert used in a putter head according to a fourth embodiment of the invention;

[0026] FIG. 8 is a cross-sectional view illustrating a face insert used in a putter head according to a fifth embodiment of the invention; and

[0027] FIG. 9 is a cross-sectional view illustrating a face insert used in a putter head according to a sixth embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereafter, a description will be given of embodiments of the invention with reference to the drawings, but the invention is not limited to these embodiments.

First Embodiment

[0029] FIG. 1 is a rear view illustrating a face insert used in a putter head according to a first embodiment of the invention. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. A face insert 10 in accordance with this embodiment includes a high-hardness portion 12 that forms a hitting surface and a low-hardness portion 14 whose hardness is lower than that of the high-hardness portion 12. The structure provided is such that a recessed portion 16 is formed in the high-hardness portion 12 of a plate shape, and the low-hardness portion 14 of a plate shape is joined to the interior of this recessed portion 16. The face insert 10 in accordance with this embodiment is fitted in a recessed portion 104 formed in a face portion 102 of a head body 100, as shown in FIG. 3. Although, in the face insert 10 in accordance with this embodiment, the thickness of the low-hardness portion 14 and the depth of the recessed portion 16 are set to be equal, the thickness of the low-hardness portion 14 may be made greater than the depth of the recessed portion 16, and outer surfaces of peripheral edge portions of the low-hardness portion 14 and inner surfaces of peripheral edge portions of the high-hardness portion 12 may be joined.

Second Embodiment

[0030] FIG. 4 is a rear view illustrating a face insert used in a putter head according to a second embodiment of the invention. FIG. 5 is a cross-sectional view taken along line A-A in FIG. 4. A face insert 20 in accordance with this embodiment includes a high-hardness portion 22 that forms a hitting surface and a low-hardness portion 24 whose hardness is lower than that of the high-hardness portion 22. The structure provided is such that a recessed portion 26 is formed in the low-hardness portion 24 of a plate shape, and the high-hardness portion 22 of a plate shape is joined to the interior of this recessed portion 26. The use of the face insert 20 in accordance with this embodiment is similar to that of the first embodiment. Although, in the face insert 20 in accordance with this embodiment, the thickness of the high-hardness portion 22 and the depth of the recessed portion 26 are set to be equal, the thickness of the high-hardness portion 22 may be made greater than the depth of the recessed portion 26, and outer surfaces of peripheral edge portions of the high-hardness portion 22 and inner surfaces of peripheral edge portions of the low-hardness portion 24 may be joined.

Third Embodiment

[0031] FIG. 6 is a cross-sectional view illustrating a a face insert used in a putter head according to a third embodiment of the invention. A face insert 30 in accordance with this embodiment includes a high-hardness portion 32 that forms a hitting surface and a low-hardness portion 34 whose hardness is lower than that of the high-hardness portion 32. The structure provided is such that the low-hardness portion 34 of a flat plate shape is joined to one surface of the high-hardness portion 32 of a flat plate shape. The use of the face insert 30 in accordance with this embodiment is similar to that of the first embodiment.

Fourth Embodiment

[0032] FIG. 7 is a cross-sectional view illustrating a face insert used in a putter head according to a fourth embodiment of the invention. A face insert 40 in accordance with this embodiment includes a high-hardness portion 42 that forms a hitting surface and a low-hardness portion 44 whose hardness is lower than that of the high-hardness portion 42. The structure provided is such that the high-hardness portion 42 of a flat plate shape is joined to an inner peripheral surface of the low-hardness portion 44 of a substantially rectangular loop shape. In addition, in the face insert 40 in accordance with this embodiment, the thickness of the high-hardness portion 42 and the thickness of the low-hardness portion 44 are set to be equal. The use of the face insert 40 in accordance with this embodiment is similar to that of the first embodiment.

Fifth Embodiment

[0033] FIG. 8 is a cross-sectional view illustrating a face insert used in a putter head according to a fifth embodiment of the invention. A face insert 50 in accordance with this embodiment includes a high-hardness portion 52 that forms a hitting surface and a low-hardness portion 54 whose hardness is lower than that of the high-hardness portion 52. The structure provided is such that the high-hardness portion 52 of a plate shape is joined to an inner peripheral surface of the low-hardness portion 54 of a substantially rectangular loop shape. In addition, in the face insert 50 in accordance with this embodiment, the thickness of the high-hardness portion 52 is set to be greater than the thickness of the low-hardness portion 54, and inner surfaces of peripheral edge portions of the high-hardness portion 52 are joined to outer surfaces of the low-hardness portion 54. The use of the face insert 50 in accordance with this embodiment is similar to that of the first embodiment.

Sixth Embodiment

[0034] FIG. 9 is a cross-sectional view illustrating a face insert used in a putter head according to a sixth embodiment of the invention. A face insert 60 in accordance with this embodiment includes a high-hardness portion 62 that forms a hitting surface and a low-hardness portion 64 whose hardness is lower than that of the high-hardness portion 62. The structure provided is such that the high-hardness portion 62 of a plate shape is joined to an inner peripheral surface of the low-hardness portion 64 of a substantially rectangular loop shape. In addition, in the face insert 60 in accordance with this embodiment, the thickness of the high-hardness portion 62 is set to be greater than the thickness of the low-hardness portion 64, and outer surfaces of peripheral edge portions of the high-hardness portion 62 are joined to inner surfaces of the low-hardness portion 64. The use of the face insert 60 in accordance with this embodiment is similar to that of the first embodiment.

EXAMPLE

[0035] A putter was fabricated by using a putter head in which the face insert 10 in accordance with the first embodiment shown in FIGS. 1 and 2 was fitted in the head body 100 shown in FIG. 3. In this case, an aluminum alloy was used as the material of the head body; a urethane resin (Shore D hardness: 60) as the material of the high-hardness portion 12; a urethane resin (Shore D hardness: 40) as the material of the low-hardness portion 14; and steel as the material of the shaft. In addition, the height h of the face insert 10 was set to 20 mm; the width w, 70 mm; the thickness d, 4 mm; the depth m of the recessed portion 16, 2 mm; the width n of a projecting portion 18 of the high-hardness portion 12 formed by the recessed portion 16, 2 mm; the area of the face surface f, approximately 1290 mm.sup.2; and the area of the bottom surface g of the recessed portion 16, approximately 930 mm.sup.2.

[0036] Next, putting was performed by using the putter (embodiment) obtained, and the hitting sensation and the hitting sound were evaluated. As the golf balls, Tourstage X-01 manufactured by BRIDGESTONE SPORTS CO., LTD. was used. In addition, by way of comparison, similar tests were conducted by using a putter (Comparative Example 1) similar to that of the embodiment except that a recessed portion was not provided in the head body and the face insert was not fitted, a putter (Comparative Example 2) similar to that of the embodiment except that a face insert having a single-layer structure made of a urethane resin (Shore D hardness: 25) was used as the face insert, and a putter (Comparative Example 3) similar to that of the embodiment except that a urethane resin with a Shore D hardness of 60 was used for the high-hardness portion, and that a urethane resin with a Shore D hardness of 56 was used for the low-hardness portion. In Comparative Example 3, the difference in Shore D hardness between the high-hardness portion and the low-hardness portion was less than 5. The evaluation of the hitting sensation and the hitting sound was made on the basis of sensory evaluation by a plurality of golfers. The results are shown in Table 1. TABLE-US-00001 TABLE 1 Hitting Sensation Hitting Sound Sense of Distance Embodiment Soft Hard (high) Easy to grasp Comparative Hard Hard (high) Easy to grasp Example 1 Comparative Soft Dull (low) Difficult to grasp Example 2 Comparative Hard Hard (high) Easy to grasp Example 3

[0037] From the results of Table 1, it was confirmed that, as for the putter head in accordance with the invention, the hitting sensation at the time of hitting the ball is soft, and the hitting sound is hard, so that the sense of distance is easy to grasp.

Claims

1. A putter head comprising: a head body having a face portion; and a face insert fitted in the face portion, the face insert including: a high-hardness portion that forms a hitting surface, and a low-hardness portion jointed to the high-hardness portion and having a hardness lower than that of the high-hardness portion, wherein the Shore D hardness of the high-hardness portion is 30 or more, the Shore D hardness of the low-hardness portion is 10 or more, and a difference between the Shore D hardness of the high-hardness portion and the Shore D hardness of the low-hardness portion is 5 or more.

2. The putter head according to claim 1, wherein at least one of the high-hardness portion and the low-hardness portion is formed of an elastomer.

3. The putter head according to claim 1, wherein at least one of the high-hardness portion and the low-hardness portion is formed of a urethane resin.

4. The putter head according to claim 1, wherein a recessed portion is formed in one of the high-hardness portion and the low-hardness portion, and another one thereof is joined to an inner surface of the recessed portion.

5. The putter head according to claim 1, wherein the low-hardness portion formed in a flat plate shape is joined to one surface of the high-hardness portion formed in a flat plate shape.

6. The putter head according to claim 1, wherein the high-hardness portion is jointed to an inner peripheral surface of the low-hardness portion formed in a loop shape.