GOLF CLUB AND GOLF CLUB SET

- DUNLOP SPORTS CO. LTD.

A golf club in a golf club set has a shaft and a golf club head which includes a crown portion, a face portion, a sole portion, and a hosel portion to which the shaft is attached. Among the golf clubs included in the golf club set, in at least a pair of golf clubs having adjacent club numbers, the length of the face portion, in the face-back direction in a plan view, of the golf club having a higher club number is larger than that of the golf club having a lower club number. The difference between the lengths is ΔA mm. In the golf clubs, the face progression of the golf club having the higher club number is larger than the face progression of the golf club having the lower club number, and the difference between the face progressions is ΔB mm. ΔA and ΔB satisfy (⅓)×ΔA≦ΔB≦(⅔)×ΔA.

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Description

This application claims priorities to Japanese Patent Applications No. 2014-131573 filed on Jun. 26, 2014, which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a golf club and a golf club set.

BACKGROUND ART

In golf club sets made up of clubs of multiple club numbers, ordinarily, with a higher-number club having a larger loft angle, the face progression is designed to be higher. However, there is a problem in that when the face progression is higher, the leading edge protrudes forward during addressing, and thus the club is difficult to posture.

In view of this, in the golf club set according to JP 2012-61035A, the face progression is constant with multiple club numbers. A constant face progression has the advantage of facilitating the posturing of higher-number clubs during addressing.

SUMMARY OF INVENTION

However, when the face progression is constant, the position of the hosel portion relative to the face portion in the face-back direction differs greatly between club numbers. For this reason, when the club number is changed when hitting a ball (e.g., when a low-number club is used to hit a ball, and then a high-number club is used to hit a ball), a sense of discomfort is felt, and there can be a problem in that the timing of impact shifts when hitting a ball. The present invention was achieved in order to resolve the above-described issues, and an object thereof is to provide a golf club and a golf club set in which even high-number clubs are easy to posture, and a shift is not likely to occur in the timing of impact even when changing the club number.

A golf club according to the present invention is a golf club for inclusion in a golf club set having a plurality of golf clubs that have different club numbers and loft angles, the golf club including: a shaft; and a golf club head, wherein the golf club head includes a crown portion, a face portion, a sole portion, and a hosel portion to which the shaft is attached, among the plurality of golf clubs included in the golf club set, in at least a pair of golf clubs having adjacent club numbers, the length of the face portion, in a face-back direction in a plan view, of the golf club having a higher club number is larger than the length of the face portion, in the face-back direction in a plan view, of the golf club having a lower club number, and letting the difference between the lengths be ΔA mm, and in the plurality of golf clubs, a face progression of the golf club having the higher club number is larger than a face progression of the golf club having the lower club number, and letting the difference between the face progressions be ΔB mm, ΔA and ΔB satisfy (⅓)×ΔA≦ΔB≦(⅔)×ΔA.

Note that the golf clubs making up the “golf club set” of the present invention are not necessarily required to be sold at the same time, and they may be sold individually. In other words, it is sufficient that the golf club set is recognized as a combination of golf clubs having different loft angles in at least the same series, and the golf club of the present invention need only be one of such golf clubs.

In the above golf club, it is preferable that ΔA and ΔB satisfy ( 5/12)×ΔA≦ΔB≦( 7/12)×ΔA.

Also, in the above golf clubs, the loft angles of the golf clubs included in the golf club set may be 15 to 30 degrees.

A golf club set according to the present invention is a golf club set including a plurality of golf clubs that have different club numbers and loft angles, wherein each of the golf clubs has a shaft and a golf club head, each of the golf club heads includes a crown portion, a face portion, a sole portion, and a hosel portion to which the shaft is attached, and in at least a pair of golf clubs having adjacent club numbers among the plurality of golf clubs, the length of the face portion, in a face-back direction in a plan view, of a golf club having a higher club number is larger than the length of the face portion, in the face-back direction in a plan view, of a golf club having a lower club number, and letting the difference between the lengths be ΔA mm, and in the plurality of golf clubs, a face progression of the golf club having the higher club number is larger than a face progression of the golf club having the lower club number, and letting the difference between the face progressions be ΔB mm, ΔA and ΔB satisfy (⅓)×ΔA≦ΔB≦(⅔)×ΔA.

According to the present invention, it is possible for even high-number clubs to be easy to posture, and for a shift to not be likely to occur in the timing of impact even when changing the club number.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a reference state of one golf club head in a golf club set according to an embodiment of the present invention;

FIG. 2 is a plan view of FIG. 1;

FIG. 3 shows an example of a golf club set according to an embodiment, in which (a) is a plan view of golf club heads in a reference state, and (b) is a side view of the same;

FIG. 4 is a plan view comparing the golf club set of the embodiment and a conventional golf club set; and

FIG. 5 is a plan view of the golf club set of the embodiment.

 DESCRIPTION OF EMBODIMENTS

An embodiment of a golf club set according to the present invention will be described below with reference to the drawings. The golf clubs constituting the golf club set of the present embodiment are utility-type golf clubs, such as the #2 to #6 utilities. Also, as will be described later, the clubs differ mainly with respect to the loft angle, the position of the hosel portion, and the like. The following describes one golf club first as an example, then an overview will be given for common structures, and then the differences for the respective club numbers in the golf club set will be described in detail.

1. Overview of Golf Club Head

First, the following takes the example of one golf club (#3 utility) in the golf club set of the present embodiment, and describes the golf club head of this golf club. FIG. 1 is a perspective view of the reference state of one golf club head in the golf club set of the present embodiment, and FIG. 2 is a plan view of FIG. 1. Note that the reference state of the golf club head will be described later.

As shown in FIG. 1, this golf club head (hereinafter sometimes simply referred to as the “head”) is a hollow structure and has wall surfaces formed by a face portion 1, a crown portion 2, a sole portion 3, a side portion 4, and a hosel portion 5.

The face portion 1 has a face surface, which is the surface for hitting a ball, and the crown portion 2 is adjacent to the face portion 1 and constitutes the upper surface of the head. The sole portion 3 constitutes the bottom surface of the head, and is adjacent to the face portion 1 and the side portion 4. Also, the side portion 4 is the portion between the crown portion 2 and the sole portion 3, and extends from the toe side of the face portion 1, across the back side of the head, to the heel side of the face portion 1. Furthermore, the hosel portion 5 is the portion provided adjacent to the heel side of the crown portion 2, and has an insertion hole 51 for the insertion of the shaft (not shown) of the golf club. A central axis Z of the insertion hole 51 conforms to the axis of the shaft.

The following describes the aforementioned reference state. First, as shown in FIGS. 1 and 2, the reference state is defined as a state in which the central axis Z is in a plane P1 that is perpendicular to the ground (horizontal plane), and furthermore the head is placed on the ground at a predetermined lie angle and real loft angle. The plane P1 will be referred to as the reference vertical plane. Also, as shown in FIG. 2, the direction of the line of intersection of the reference vertical plane P1 and the ground will be referred to as the toe-heel direction, and the direction that is perpendicular to the toe-heel direction and parallel to the ground will be referred to as the face-back direction. Note that in the golf club set of the present embodiment, the higher the number of the club is, the larger the loft angle is, similarly to ordinary golf club sets.

In the present embodiment, the boundary between the sole portion 3 and the face portion 1, and the boundary between the sole portion 3 and the side portion 4 can be defined as follows. Specifically, if ridge lines are formed between the sole portion 3 and the face portion 1, and between the sole portion 3 and the side portion 4, those ridge lines serve as the boundaries. Also, although the golf club head of the present embodiment has the side portion 4, in the case where the side portion 4 is not provided, and the sole portion 3 and the crown portion 2 are directly connected for example, the ridge line between the sole portion 3 and the crown portion 2 serves as the boundary between the two. Also, if a clear ridge line is not formed, the boundary is the outline that is seen when the head is placed in the reference state and viewed from directly above the center of gravity of the head.

Note that although an upper limit is not particularly defined for the head volume, practically it is, for example, desirably 500 cm3 or less, or desirably 470 cm3 or less when complying with R&A or USGA rules and regulations.

Also, the head can be formed from a titanium alloy having a specific gravity of approximately 4.4 to 4.5 (Ti-6Al-4V), for example. Besides a titanium alloy, the head can be formed from one or two or more materials selected from among stainless steel, maraging steel, an aluminum alloy, a magnesium alloy, an amorphous alloy, and the like.

Note that the head of the present embodiment is constituted by combining a head body that has at least the sole portion 3 with another portion. For example, a configuration is possible in which only the face portion 1 is constituted by another member, and the head is constituted by attaching the face portion 1 to the head body, and it is also possible to constitute the head by forming a head body in which an opening is provided in the crown portion 2 and the side portion 4, and blocking the opening with another member.

2. Differences Between Club Numbers in Golf Club Set

Next, differences between club numbers in the golf club set will be described with reference to FIG. 3 as well. FIG. 3 includes a plan view (a) and a side view (b) of golf club heads in the reference state. Note that in the example shown in FIG. 3, among the golf clubs in the golf club set of the present embodiment, the heads of three golf clubs with adjacent club numbers are shown. Specifically, the #3 utility (U#3), the #4 utility (U#4), and the #5 utility (U#5) are lined up in this order from top to bottom. Note that FIG. 3 as well as later-described FIGS. 4 and 5 for describing differences between club numbers are for clarifying features of the present invention, and the heads are shown in a slightly exaggerated manner. Accordingly, although these clubs differ from the actual angles, shapes, and the like shown in Table 1 etc., the essence of the invention does not change due to this.

In FIG. 3, the positions of leading edges E of the face portions 1 of the golf club heads are aligned with each other. Specifically, the leading edges E of the face portions 1 of the golf club heads are touching a line X. Also, all of the golf club heads are formed so as to have approximately the same length L in the face-back direction (hereinafter, referred to as the “head width”) in a plan view. Note that the head width L does not need to be exactly the same between all of the club numbers, and a configuration is possible in which, for example, the higher the club number is, the lower the head width L is. In this case, in order for the head widths L to be as identical as possible, for example, between adjacent club numbers, the head width L of the higher-number club is preferably 80 to 100% the head width L of the lower-number club, more preferably 90 to 100%, and particularly preferably 95 to 100%. Note that the head width is the highest width in the face-back direction in a plan view. Also, the reference sign L in FIG. 3 indicates the head width of the #3 utility.

Also, a length A in the face-back direction in a plan view (hereinafter, referred to as the “face width”) of the face portion 1 of the head is longer the higher the club number is. The face width A is the highest width in the face-back direction in a plan view. In this way, with the golf clubs of the present embodiment, regardless of the head widths L of the heads being substantially the same, the face width A rises as the club number rises, and therefore the volumes of the heads decrease as the club number rises.

Furthermore, in the present embodiment, a distance B between the leading edge E of the face portion 1 and the hosel portion 5 of the head in the face-back direction in a plan view, that is to say the face progression, increases as the club number increases.

Also, with the golf club set of the present embodiment, the above-described face width A and face progression B satisfy the following relationship between club numbers. Specifically, the heads are designed such that in heads of adjacent club numbers, a difference ΔA between the face widths A and a difference ΔB between the face progressions B satisfy Expression 1 below, and particularly preferably satisfy Expression 2 below.


(⅓)×ΔA≦ΔB≦(⅔)×ΔA  Exp. 1


( 5/12)×ΔA≦ΔB≦( 7/12)×ΔA  Exp. 2

For example, the following shows the head width, loft angle, head volume, face width, and face progression of the #3 utility, the #4 utility, and the #5 utility of the present embodiment.

TABLE 1 #3 Utility #4 Utility #5 Utility Head width L 53.3 52.0 50.5 (mm) Loft angle 19 22 25 (degrees) Volume (cm3) 111 108 104 Face width A 9.8 11.2 12.7 (mm) Face 11.0 11.7 12.5 progression B (mm) ΔA (mm) 1.4 1.5 ΔB (mm) 0.7 0.8

According to Table 1, ΔA and ΔB of adjacent club numbers satisfy Expression 1 above.

3. Features

The following describes effects obtained by the golf club of the present embodiment with reference to FIG. 4. First, the design of conventional golf clubs will be described. The conventional golf club set described here includes utility-type golf clubs similarly to the above embodiment, and the #3 wood, #4 wood, and #5 wood will be taken as examples.

Conventional Example 1

As shown in (a) of FIG. 4, in the design of the golf club set in this example, the length of the crown portion 2 in the face-back direction in a plan view is the same between all of the club numbers. Also, the above-described head width L increases as the loft angle increases. In other words, the upper end position of the face portion 1 is the same between all of the club numbers, but the lower end position of the face portion 1 (the position of the leading edge) changes. Also, the hosel portion 5 is arranged on the face-side end portion of the crown portion 2 in the face-back direction in all of the club numbers. In other words, the face progression B increases as the club number rises.

Conventional Example 2

As shown in (b) of FIG. 4, in the design of the golf club set in this example, the head width L is roughly the same between all of the club numbers. Also, the above-described face width A increases as the loft angle increases. In other words, the upper end portion of the face portion 1 changes between the club numbers, but the lower end portion of the face portion 1 is the same. Also, the face progression is the same between all of the club numbers.

Differences Between Golf Club Set of Present Embodiment and Conventional Examples 1 and 2

First, problems such as the following exist in Conventional Examples 1 and 2. Firstly, in Conventional Example 1, the higher the club number is, the higher the face progression B is, and the higher the head width L is. For this reason, particularly with a higher-number club, the leading edge greatly protrudes forward during addressing, thus having the problem of being difficult to posture. Also, there is a problem in that the timing of impact when hitting a ball shifts between club numbers.

In Conventional Example 2, the face progression B does not change, but the position of the hosel portion 5 relative to the face portion 1 changes greatly, and therefore the sense of discomfort increases when changing the club number and hitting a ball. Also, in the exemplary case of hitting a ball with a low-number club, and then hitting a ball with a high-number club, the face lies more the higher the club number is, and therefore there is a possibility of a shift in the timing of impact.

In contrast, with the golf club set of the present embodiment, the difference ΔA between the face lengths A and the difference ΔB between the face progressions B satisfy above Expression 1 as shown in (c) of FIG. 4. For this reason, there is little difference in the face progression B between club numbers, and moreover there is little change in the position of the hosel portion 5 relative to the face portion 1. Accordingly, even with a high club number, the club is easy to posture during addressing, and it is possible to reduce the sense of discomfort when changing the club number and hitting a ball. As a result, it is possible to reduce the shift in the timing of impact when hitting a ball between club numbers. Also, the sense of discomfort can be reduced by setting the head width L approximately the same between club numbers.

Also, in the case where the relationship between ΔA and ΔB satisfies Expression 2, and particularly in the case where ΔB is close to ½×ΔA, as shown in FIG. 5, in a plan view, a distance Lh between the hosel portion 5 and a virtual straight line Y that is parallel with the toe-heel direction and passes through the center of the face portion 1 in the face-back direction is almost the same between club numbers, and therefore it is possible to further reduce shift in the timing of impact when hitting a ball between club numbers.

4. Variations

Although an embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made without departing from the gist of the invention. The following are examples of modifications that can be made.

4.1

Although the relationship of Expression 1 is satisfied between club numbers in the above embodiment in particular, it is not necessarily required that Expression 1 is satisfied by all adjacent golf club numbers in the golf club set. Specifically, it is sufficient that Expression 1 is satisfied by at least one pair of adjacent club numbers in the golf club set. Also, in the case where the head width changes between club numbers, it is sufficient that the head width changes between at least one pair of adjacent club numbers.

4.2

Although a utility-type golf club and a golf club set including such golf clubs are described in the above embodiment, the golf club and the golf club set of the present invention are not limited in this way. For example, the golf club set may include wood-type golf clubs (e.g., #1 to #9 woods). Even with this golf club set, it is possible to apply the above-described relationship between ΔA and ΔB. Also, in the case of wood-type golf clubs, the head width L does not need to be the same, and for example, the head width may decrease as the club number increases (e.g., the head width may be reduced by 1 to 30% each time).

Also, the golf club set of the present invention refers to a golf club set including the same type of golf clubs, and one golf club set includes only utility-type golf clubs or only wood-type golf clubs, for example.

REFERENCE SIGNS LIST

    • 1 Face portion
    • 2 Crown portion
    • 3 Sole portion
    • 5 Hosel portion
    • B Face progression
    • P1 Plane

Claims

1. A golf club for inclusion in a golf club set having a plurality of golf clubs that have different club numbers and loft angles, the golf club comprising:

a shaft; and
a golf club head,
wherein the golf club head includes a crown portion, a face portion, a sole portion, and a hosel portion to which the shaft is attached,
among the plurality of golf clubs included in the golf club set, in at least a pair of golf clubs having adjacent club numbers, the length of the face portion, in a face-back direction in a plan view, of the golf club having a higher club number is larger than the length of the face portion, in the face-back direction in a plan view, of the golf club having a lower club number, and letting the difference between the lengths be ΔA mm, and in the plurality of golf clubs, a face progression of the golf club having the higher club number is larger than a face progression of the golf club having the lower club number, and letting the difference between the face progressions be ΔB mm,
ΔA and ΔB satisfy (⅓)×ΔA≦ΔB≦(⅔)×ΔA.

2. The golf club according to claim 1, wherein ΔA and ΔB satisfy ( 5/12)×ΔA≦ΔB≦( 7/12)×ΔA.

3. The golf club according to claim 1, wherein the loft angles of the golf clubs included in the golf club set are 15 to 30 degrees.

4. A golf club set comprising a plurality of golf clubs that have different club numbers and loft angles,

wherein each of the golf clubs has a shaft and a golf club head,
each of the golf club heads includes a crown portion, a face portion, a sole portion, and a hosel portion to which the shaft is attached, and
in the center in a toe-heel direction in the golf club heads of the golf clubs, the length of the face portion, in a face-back direction in a plan view, of a golf club having a higher club number is larger than the length of the face portion, in the face-back direction in a plan view, of a golf club having a lower club number, and letting the difference between the lengths be ΔA mm, and in the plurality of golf clubs, a face progression of the golf club having the higher club number is larger than a face progression of the golf club having the lower club number, and letting the difference between the face progressions be ΔB mm,
ΔA and ΔB satisfy (⅓)×ΔA≦ΔB≦(⅔)×ΔA.
Patent History
Publication number: 20150375067
Type: Application
Filed: Jun 25, 2015
Publication Date: Dec 31, 2015
Applicant: DUNLOP SPORTS CO. LTD. (Kobe-shi)
Inventor: Makoto YOSHIDA (Kobe-shi)
Application Number: 14/750,456
Classifications
International Classification: A63B 53/04 (20060101);