PUTTER HEAD

Abstract

A putter head includes a head main body having a recess portion in a face surface of the putter head, and a face insert disposed in the recess portion. The face insert has a slit extending upward from a bottom face thereof In the bottom face, the slit may extend from the vicinity of a toe-side end thereof to the vicinity of a heel-side end thereof A bottom end of the slit may be located on a rear edge of the face insert. A ceiling face of the slit may be in a shape of an arch from the toe side to the heel side. The slit may be filled with a viscoelastic material.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This Application claims priority from Japanese Patent Application No. 2011-4939 filed Jan. 13, 2011, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a putter head of a golf club, and more particularly to a putter head containing a face insert mounted in a face surface of a head main body thereof.

The putter in golf is a club for use mainly for hitting a ball on a green to roll the ball toward a cup. Japanese Patent Application Publication No. 2007-117635 describes a putter head including a face insert for a face surface thereof in order to soften a feeling of putting a golf ball.

Japanese Patent Application Publication No. 2001-62008 describes a putter head including a synthetic resin integrated with a bottom portion of the face surface of the putter head to enable a player to easily apply top spin to the ball. However, because the synthetic resin foam has a high temperature dependency, a degree of top spin applied to the ball varies considerably depending on the temperature.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a putter head in which when a ball is putted, back spin is reduced compared to an ordinary putter and the top spin can be applied to the ball easily while the temperature dependency of easiness of applying the top spin is low.

According to the present invention, there is provided a putter head having a face surface thereof comprising: a head main body; and a face insert disposed on the head main body as the face surface, wherein the face insert has a slit extending upward from a bottom surface thereof, and wherein the face insert has a front face portion positioned on a face-surface side relative to the slit and a rear face portion on a backward side relative to the slit, the front and rear face portions being connected to each other through toe and heel sides of the face insert.

In the bottom face of the face insert, the slit may extend from the vicinity of a toe-side end thereof up to the vicinity of a heel-side end thereof.

The slit may be deepest at a central portion in a toe-to-heel direction of the face insert, and the slit may become shallower gradually or step by step toward the toe side and the heel side from the central portion thereof.

The putter head may further comprise a viscoelastic material disposed in the slit of the face insert.

The face insert of the putter head of the present invention includes the slit extending upward from the bottom surface, thereby, when this putter hits a ball, a bottom portion of the front face portion of the face insert is retracted to suppress back spin while facilitating the top spin to be applied easily. Accordingly, straight advancement of the hit ball is improved. In addition, a player can apply different degrees of top spin to the ball by hitting it by the center portion or the toe and heel portions of the face insert.

When the front face portion and the rear face portion of the face insert are connected at the toe and heel sides of the face insert, the face insert can have high strength and durability properties.

Accordingly, the slit preferably extends from the vicinity of the toe-side end of the bottom face to the vicinity of the heel-side end thereof.

When the slit is filled with a viscoelastic material, a hitting sound and a feeling of hitting the ball can be adjusted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1( a) is an exploded perspective view of an embodiment of a putter head according to the present invention.

FIG. 1( b) is a front view of the putter head of FIG. 1(a).

FIG. 1( c) is a cross-sectional view taken along the line C-C of FIG. 1(b).

FIG. 2 is a front view of the face insert shown in FIGS. 1(a) to 1(c).

FIG. 3 is a cross-sectional view taken along the line of FIG. 2.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3.

FIG. 5 is a cross-sectional view of the face insert in which a viscoelastic body is charged in a slit thereof.

FIG. 6 is a cross-sectional view of an example of a face insert in a putter head according to the present invention.

FIG. 7 is a cross-sectional view of an example of a face insert in a putter head according to the present invention.

FIG. 8 is a cross-sectional view of an example of a face insert in a putter head according to the present invention.

FIG. 9( a) is a cross-sectional view in a face to back direction showing an example of a face insert in a putter head according to the present invention.

FIG. 9( b) is a cross-sectional view in a face to back direction showing an example of a face insert in a putter head according to the present invention.

FIG. 10 is a cross-sectional view of another embodiment of a putter head according to the present invention.

FIG. 11( a) is a front view of still another embodiment of a putter head according to the present invention.

FIG. 11( b) is a cross-sectional view taken along the line B-B of FIG. 11(a).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of a putter head according to the present invention will be described in detail with reference to the accompanying drawings.

A putter head 1 as the first embodiment of the present invention is illustrated in FIGS. 1 to 4. This putter head 1 includes a head main body 2 having a recess portion 2H in the front face or face surface thereof and a face insert 3 disposed within this recess portion 2H. According to this embodiment, the head main body 2 is made of such a metal as aluminum alloy, titanium alloy, copper alloy, or stainless steel. The face insert 3 is made of such a synthetic resin as polyester, nylon, urethane or such a metal as aluminum alloy, copper alloy, or stainless steel. A front face of the face insert 3 is aligned with the front face of the head main body 2 around the recess portion 2H.

The recess portion 2H and the face insert 3 are of a substantially rectangular shape which is horizontally long. The depth of the recess portion 2H is entirely even and the thickness of the face insert 3 is entirely even. However, they may be provided partly with a deep portion or a thick portion or conversely may be provided partly with a shallow portion or a thin portion.

The lateral and vertical widths of the face insert 3 are slightly smaller than those of the recess portion 2H and there is a slight gap 4 between top, bottom, right and left side faces 3S of the face insert 3 and a peripheral face 2S of the recess portion 2H. Preferably, the width of this gap is 0.3 to 1.5 mm, and more preferably 0.4 to 1.0 mm. Regarding the size of the face insert 3, a vertical width H₀ is 16 to 30 mm, particularly 18 to 25 mm, a lateral width W_o is preferred to be 50 to 150 mm, particularly 70 to 100 mm, and a thickness thereof is preferred to be 2 to 10 mm, and more preferably 3 to 8 mm. However, they are not limited to these values.

As illustrated in FIGS. 2 to 4, this face insert 3 has a slit 3a which is cut in upward from a bottom face thereof. In the bottom face of the face insert 3, the slit 3a extends from the vicinity of a toe-side end thereof up to the vicinity of a heel-side end thereof. The slit 3a does not reach any side faces on the toe side and the heel side of the face insert 3. A front face portion on a forward (face) side relative to the slit 3a and a rear face portion on a backward side relative to the slit 3a are continuous to each other through the toe-side end portion and the heel-side end portion of the face insert 3. Bottom faces of the toe-side end portion and the heel-side end portion of the face insert 3 are flush with the bottom faces of the front face portion and the rear face portion of the face insert 3.

This slit 3a is deepest in the vicinity of the center in a toe-to-heel direction (right-to-left direction in the front view of the putter head), while it becomes shallower gradually toward the toe side and the heel side from the vicinity of the center. According to this embodiment, as illustrated in FIG. 4, a ceiling face of the slit 3a is of a substantially semi-elliptical arch.

In this embodiment, preferably, a length W₁ in the toe-to-heel direction of the slit 3a is 80 to 98% the length in the toe-to-heel direction of the face insert 3, and more preferably 85 to 90%.

According to this embodiment, as illustrated in FIG. 3, the slit 3a is formed perpendicularly when the face surface is set perpendicularly to the ground. A width t₂ (slit thickness) in the back-to-forth direction of the slit 3b is even throughout the entire length thereof. According to this embodiment, a thickness t₁ of the front face portion on a face side relative to the slit 3a is smaller than a thickness t₃ of the rear face portion, and although the slit 3a may be located slightly on the face side with respect to a center in the thickness direction of the face insert 3, the slit 3a may be located at the center. Preferably, the ratio of the thickness t₂ of the slit 3a with respect to a total thickness (t₁+t₂+t₃) of the face insert 3 is 10 to 50%, and more preferably 25 to 45%, and the ratio of the thickness t₁ is preferred to be 10 to 50% and more preferably 25 to 40%.

This slit 3a may be formed easily by cutting a sheet metal for the face insert 3. When forming the face insert 3 with synthetic resin, the slit 3a may be formed at the same time when the face insert is molded with a convex portion corresponding to the slit 3a prepared in an injection mold using a core or the like. The face insert 3 is disposed within the recess portion 2H such that a left side face in FIG. 3 acts as the forward side of the face of the putter, and bonded to the wall surface on the deep side of the recess portion 2H with adhesive. Although as the adhesive, epoxy base adhesive, rubber base adhesive and double-sided adhesive tape are preferably used, the present invention is not restricted to these examples.

By connecting a shaft to a hosel part 1h of the putter head 1 having such a configuration, the putter is constructed. When putting a ball with this putter (hitting the ball on a green with the face surface), the front face portion (forward side relative to the slit 3a) of the face insert 3 is slightly retracted. As a result, the top spin is easily applied to the ball, whereby the straight advancement of the hit ball being improved. Furthermore, the characteristic of deformation of the front face portion of the face insert 3 is hardly affected by a change in temperature, so that easiness of applying the top spin hardly depends on the temperature.

According to the present invention, as illustrated in FIG. 5, the slit 3a may be filled with a viscoelastic body 3b. As the viscoelastic material, rubber, elastomer, soft synthetic resin and the like are available. By filling the slit 3a with viscoelastic material, a hitting sound and a feeling of hitting the ball can be adjusted. This viscoelastic material hardly affects the deformation characteristic of the front face portion of the face insert, so that the easiness of applying the top spin hardly depends on the temperature.

In the face insert 3 of the above-described embodiment, the ceiling face of the slit 3a is foamed in the shape of a semielliptical arch from the toe side to the heel side, and this arch shape lowers in height consecutively from the vicinity of the center in the toe-to-heel direction toward the heel side (i.e., the slit 3a becomes shallower gradually). However, like a face insert 3A in FIG. 6, the ceiling face may be descended by step from the vicinity of the center in the toe-to-heel direction toward the heel side. Furthermore, while the depth of the slit 3a may be constant along the toe-to-heel direction around the center in the toe-to-heel direction thereof like a face insert 3B in FIG. 7, the slit 3a may be formed to be shallower gradually (or by step) toward the toe side and the heel side in areas near the toe and the heel.

According to the present invention, like a face insert 3D in FIG. 8, the slit 3a may be provided with shallow grooves 3d which communicate with an end face on the toe side of the face insert 3D and an end face on the heel side thereof Preferably, a depth H₂ of the shallow groove 3d is 20% or less a height H₀ of the face insert 3D, more particularly to 15% or less. If H₂ is increased excessively (e.g., if H₂ is set equal to the aforementioned H₁), a repelling force of a ball when hitting the ball drops. If H₂ is set to 20% or less (including 0%) H₀, the repelling force of the ball increases, and consequently, a distance over which the ball rolls is increased.

According to the present invention, as shown in FIG. 9(a), a face insert 3E may have a slit 3a inclined forward such that its upper portion is located nearer the face side. In contrast, as shown in FIG. 9(b), a face insert 3f may have a slit 3a inclined backward.

Although the front surface of the face insert is flat according to this embodiment, a plurality of horizontally-extending grooves may be provided in parallel. Preferably, a width (distance between the top and the bottom) of each groove may be 0.3 to 1.6 mm and a depth of the groove is preferred to be 0.05 to 1.1 mm.

Although the gap 4 is formed around the periphery of the face insert 3 as illustrated in FIGS. 1(b) and 1(c), a viscoelastic material 8 such as rubber, elastomer, synthetic resin, may be disposed in this gap. Like a putter head 1′ illustrated in FIG. 11, the face insert 3 may be formed to be fit to the recess portion 2H without any gap 4.

Other configurations of FIGS. 10 and 11 are the same as in FIG. 1 and like reference numerals indicate like components. Provision of the gap 4 and the viscoelastic material 8 between the side face 3S of the face insert 3 and the peripheral face 2S of the recess portion 2H ensures an advantage that the repulsion characteristic of the face insert is realized as designed.

Claims

1. A putter head having a face surface, comprising: a head main body; anda face insert disposed on the head main body as the face surface, wherein the face insert has a slit extending upward from a bottom surface thereof, and wherein the face insert has a front face portion positioned on a face-surface side relative to the slit and a rear face portion on a backward side relative to the slit, the front and rear face portions being connected to each other through toe and heel sides of the face insert.

2. The putter head according to claim 1, wherein in the bottom face of the face insert, the slit extends from the vicinity of a toe-side end thereof up to the vicinity of a heel-side end thereof.

3. The putter according to claim 1, wherein the slit is deepest at a central portion in a toe-to-heel direction of the face insert, and the slit becomes shallower gradually or step by step toward the toe side and the heel side from the central portion thereof.

4. The putter head according to claim 1, further comprising a viscoelastic material disposed in the slit of the face insert.