WO2001076697A1

WO2001076697A1 - Golf club with improved club head

Info

Publication number: WO2001076697A1
Application number: PCT/US2001/011149
Authority: WO
Inventors: Isamu Nakashima
Original assignee: Nakashima International, Inc.
Priority date: 2000-04-05
Filing date: 2001-04-05
Publication date: 2001-10-18
Also published as: AU2001253184A1

Abstract

A golf club has a club head having a rearmost point, a sole, and a face with a face height H, wherein the rearmost point is positioned at least 0.3*H rearwards of the face, and at least 0.66*H higher than the sole.

Description

GOLF CLUBWITH IMPROVED CLUB HEAD

This application claims the benefit of U.S. provisional application number 60/194830, filed 04/05/2000, and U.S. patent application number 09/680921, filed 10/06/2000, both of which are incorporated herein by reference in their entirety.

Field of The Invention

The field of the invention is club heads.

Background of The Invention

Many golf players desire golf clubs with characteristics that are particularly suited for their specific demands, and despite the relatively simple configuration of a golf club, there are various elements in a golf club that can be modified to change its characteristics. Modifications in the shaft and grip tend to have less influence on the characteristics of a golf club than modifications of the club head.

Various methods of modifying the characteristics of a club head are known in the art. One method of modifying the characteristics of a club head is to vary the material to improve or impart a particularly desirable characteristic in the club head. For example, Yamaguchi et al. describe in U.S.Pat. No. 4,809,978 a golf club comprising an ionomer resin to obtain a specific compression modulus. In another example, U.S.Pat. No. 4,809,978 to Nagasaki et al, a fiber reinforced plastic plate is employed in the face plate to tune the 'feel' of shooting a golf ball. Although a particular material may have a significant influence on the weight and 'feel' of the club head, the choice of material does not necessarily influence the balance of, or weight distribution within a club head to a significant extent.

Another method of modifying the characteristics of a club head is to vary the weight or weight distribution of the club head. In many cases, weight is removed from portions of the club head by forming a cavity, typically in the rear side of the club head. Although a cavity back frequently results in an improved 'feel' and extended 'sweet spot', the control over the weight distribution is generally limited by the thickness and mechanical stability of the club head.

To circumvent at least some of the disadvantages of a cavity back, additional weights can be added to the back of the club head. For example, Antonious teaches in U.S.Pat. No. 5,395,113 the use of a secondary weight system that is disposed within a cavity in the rear of the club head. The additional weight can advantageously be utilized not only to add weight to the club head, but also to modify the balance between heel and toe of the club head. However, due to the limited space within the cavity, the amount and positioning of the additional weight is restricted. In order to increase the weight on the rear side of a club head, G. W. Gorman describes in U.S.Pat. No. 5,048,834 an additional mass that extends peripherally from the rear of the club head, which forms a cavity into which a portion of the additional weight extends behind the center of percussion. Gorman 's additional weight does allow the addition of more mass to the club head as a whole, however, the peripheral layout also typically prohibits a player from modifying the balance between heel and toe. In another example, U.S.Pat. No. 5,082,278 to J Hsien, position and overall weight of additional weights can be varied to at least some degree by adding or removing weight elements disposed in multiple cavities in the back of the club head. Although Hsien 's system allows some flexibility in the overall weight and weight distribution of the club head, changing weights is a relatively cumbersome task

While most club heads with additional weights may confer some advantage to the physical properties or 'feel' of the club head, all or almost all of the known club heads with additional weights have a rearmost point close to, and downwards relative to the sweet spot of the face of the club head. Therefore, there is still a need to provide improved club heads having a rearmost point upwards and rearwards relative to the sweet spot of the face to impart a more upwardly and rearwardly balance into the club head.

Summary of the Invention

The present invention is directed to a golf club having a club head with a rearmost point, a sole, and a face with a face height H, wherein the rearmost point of the club head is positioned at least 0.3*H rearwards of the face and at least 0.66*H higher than the sole. In other aspects of the inventive subject matter the rearmost point of the club head is positioned between at least 0.5*H to 0.9*H rearwards of the face and between at least 0.66*H and 0.9*H higher than the sole.

In further aspects of the inventive subject matter a line between the rearmost point and the sole or the upper boundary of the face includes points that lie outside of the club head.

Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.

Brief Description of The Drawings Figure 1 is a schematic of a club head according to the inventive subject matter.

Figure 2 is a perspective view of one club head according to the inventive subject matter.

Figure 3 is a perspective view of another club head according to the inventive subject matter.

Detailed Description

As used herein the term "club head" refers to the terminal lower portion of a golf club extending from the shaft, which is used to propel a golf ball. While the anterior part of the club head that hits the ball during a normal swing is termed "face", the posterior part of the club head opposite the face (i.e., where the club head ends) is termed "rearmost point". Depending on the configuration of the club head, the rearmost point may also be a line or an area, and where the rearmost point is a line, or an area, any point within the line or area is considered the rearmost point.

As also used herein the term "face height " refers to the vertical distance between the highest point of the face and the lowest point of the face, when the face hits a ball during a normal swing. The "upper boundary" of the face refers to the transition between the upper portion of the face and the upper portion of a club head that does not hit the ball during a normal swing.

As further used herein, the term "sole" refers to the bottom portion of the club head that is substantially parallel to a horizontal surface when the ball is hit during a normal swing. The sole may extend to various degrees on the bottom of the club head, and depending on the configuration of the club head, the sole may be as small as a thin line where the bottom portion of a club head is curved, or may be as large as a 1cm x 6cm area in case of a driver.

In Figure 1, a club head 100 generally has a face 110 having a face height 112 and an upper boundary 114, a sole 120, and a rearmost point 130. An imaginary axis 140 is drawn 0.3 times the face height rearward of the face, and a horizontal imaginary axis 150 is drawn 0.6 times the face height higher than the sole. The term "rearward of the face" is used herein to mean rearward of the most posterior portion of the face. The club head 100 is coupled to a shaft (not shown) via a hosel (also not shown).

Figure 2 shows one embodiment according to the inventive subject matter in which a golf club 200 has a club head 210 having a face 212, a sole 214, and a center of mass 216. Rearmost point 250 is located on ballast element 220 having a center of mass 226. The ballast element 220 is coupled to the face via a weight supporting member 230. The club head 210 is coupled to the shaft (not shown) via a hosel 240.

In a preferred embodiment, the face 212 of club head 210 is fabricated from an iron- chromium-titanium alloy wherein the face has a 28° loft. Face 212 has an overall rectangular shape with a length of approximately 9cm along its longest dimension, a height of about 4cm along its highest dimension, and a thickness of about 1.2cm across its thickest point. The face height is approximately 3.8cm, and the face 212 has a series of seven grooves (not shown) running parallel to the sole 214. The weight supporting member 230 is shaped in form of a curved plate, manufactured from the same material as the face, and has a length of approximately 7cm, a width of about 9cm, and a thickness of about 0.5cm. One end of the weight supporting member is welded to the sole, while the ballast element receiving end extends approximately 6.5cm rearwards from the face and about 3.5cm upwards from the sole. The ballast element 220 is also made from the same material as the face, weighs approximately 80g, and is welded to the ballast element receiving end of the weight supporting member. In this configuration, the rearmost point is approximately 7cm behind the face and about 4cm above the sole. An aluminum hosel 240 connects the club head to the shaft of the golf club.

In alternative aspects of the inventive subject matter the face 212 may be fabricated from various materials other than an iron-chromium-titanium alloy, including metal alloys, pure metals, graphite, ceramics, synthetic polymers, and any reasonable combination thereof. For example, many metal alloys are known in the art to achieve a particular elasticity, hardness, or 'feel' of a club head, and may be employed in the fabrication of alternative club heads, including alloys with two, three, and more metal components. Thus, contemplated alloy components may include iron, molybdenum, titanium, chromium, aluminum, vanadium, and so forth. It is also contemplated that some players may desire club heads with a reduced weight, and therefore lightweight materials, including fiberglass composites, graphite, or pressed/sintered magnesium, titanium, etc. may be utilized in the manufacture of alternative club heads. With respect to the shape of the face it should be appreciated that the shape of alternative faces need not be limited to a rectangular shape, and various alternative shapes are contemplated, including triangular, trapezoid, rounded, and triangular shapes. For example, when an increased area of the face is desired to enlarge the 'sweetspot', trapezoid or rounded shapes may be especially advantageous, whereas when a particular heel- or toe-heavy club head of the golf club is preferred, a triangular or teardrop shape may be chosen. It is further contemplated that the backside of the face may have one or more than one indentations or cavities. Additional features, including grooves, or otherwise modified surface areas may also be incorporated into alternative faces to improve the spin or flight behavior of a golf ball.

In cases where the club head is utilized in a driver-type club, the face head may have an increased thickness to length ratio. For example, it is contemplated that alternative driver-type faces may have a length of approximately 6- 10cm while the thickness may range between about 4- 12cm. In contrast, where the club head is employed in a putter-type golf club, a decreased thickness to length ratio of the club head is contemplated with a length of about 6- 10cm and a thickness of approximately 1-3.5cm.

Likewise, the loft of the face may vary considerably, depending on the type of iron. Generally, a 2-iron has a loft of approximately 20° and successive irons are angled in increments of about 4° to a loft of approximately 48° in a 9-iron, however, the range of contemplated angles may be narrower or wider. For example, where steeper trajectories are desired, angles higher than 20°-40° may be employed, whereas when shallower trajectories are preferred, angles lower than 45 may be appropriate. Therefore, contemplated loft ranges may vary between angles of 5°- 30°, 5°-35°, 5°-45°, 10°-50°, 10°-60°, etc.

In still other aspects of the inventive subject matter it is contemplated that the weight supporting member may have various alternative configurations other than a curved plate, so long as the weight supporting member couples the face to the ballast element. Thus, the actual structure of contemplated weight supporting members is predominantly determined by the position and weight of the ballast element, and may include flat, round, tubular, or straight elements. For example, where the ballast elements are relatively lightweight and positioned close (e.g. lcm) to the face, a strong filament, screw, or thin plate structure may be sufficient. In other cases, where the ballast element is relatively heavy and positioned in a larger distance (e.g.5cm) from the face, the weight supporting member may comprise a relatively thick plate, a honeycomb structure, one or more than one cylinders. Contemplated weight supporting elements may also vary in their shape and may therefore include curved, straight, or angled shapes. For example, the weight supporting member may be strongly curved or angled when the golf club is used as a sand wedge to enable the sole to immerse at least in part into the sand. In contrast, where the club head moves over the ground without contacting the ground (e.g., a putter), relatively shallow angles or curved weight supporting members are contemplated.

With respect to the attachment of the weight supporting member to the face it is contemplated that the weight supporting member may be affixed to the face at various places other than the sole. Appropriate places include positions above, at and below half the face height at the back side of the face. It should also be appreciated that alternative weight supporting members may be coupled to the face in various manners other than welding. For example, where a temporary connection of the weight supporting member to the face is desired, screws, clasps, or other removable fasteners may be employed. In cases where a permanent connection is preferred, the weight supporting member may be connected to the face by soldering, gluing, bolting, etc. Alternatively, the face and the weight supporting member may be fabricated from one work piece, or molded or otherwise formed in a single unit. Likewise, it is contemplated that the weight supporting member may be an integral part of the ballast element.

Although it is preferred that the material of the weight supporting member is the same material as utilized in the face, alternative materials are also contemplated. Appropriate materials are the same as contemplated alternative materials for the face (vide supra), whereby the material of the weight supporting member may or may not match the materials employed in the face.

In still further alternative aspects of the inventive subject matter, the ballast elements need not be limited to a weight of 80g, but may have weights higher or lower than 80g, including 81g-150g and more, but also 2g-79g and less. Higher weights may be desirable where enhanced impact to the golf ball is preferred, which may result in an extended or higher trajectory, while lower weights may favorably influence the balance of the club head. It should also be noted, that where two ballast elements are employed in one club head, the weights may or may not be identical.

Contemplated ballast elements may be manufactured from various materials, including the materials already contemplated in alternative faces. Furthermore, it should be appreciated that appropriate ballast elements may be variable in weight. For example, ballast elements may comprise modular components that may be added or removed. Alternatively, appropriate ballast elements may include a container that receives liquid or solid material, including water, sand, mercury, etc. With respect to the connection of the ballast element to the weight supporting member it should be appreciated that temporary as well as permanent connections are contemplated, including screws, clamps, belts, etc., and where a permanent connection is desired, it is especially contemplated that the ballast element may be an integral part of the weight supporting member. In a further contemplated configuration, the ballast element, the weight supporting member, and the face may be fabricated from one work piece, or molded or otherwise formed in a single unit.

With respect to the position of the ballast element in the club head it is preferred that the ballast element is located closer to the rearmost point of the club head than to the face, and even more preferred that the ballast element is juxtaposed to the rearmost point of the club head.

While the rearmost point in the embodiment depicted in Figure 1 is approximately 7cm rearwards from the face of the club head and 4cm higher than the sole of the club head, many alternative positions of the rearmost point are also contemplated, so long as alternative positions are at least 0.3 time the face height (H) rearwards of the face, and at least 0.66*H higher than the sole. Thus, alternative locations may include positions that are least 0.5*H rearwards of the face, and at least 0.7*H higher than the sole, that are at least 0.7 *H rearwards of the face, and at least 0.8*H higher than the sole, or that are at least 0.9*H rearwards of the face, and at least 0.9*H higher than the sole.

Depending on the configuration of contemplated club heads, a void may be located between the rearmost point and the sole, or the rearmost point and the upper boundary of the face. Thus, a line drawn between the rearmost point and the sole may include points outside the club head, or a line drawn between the rearmost point and the upper boundary may include points outside the club head. The amount of points that are outside the club head may vary, and may be as little as 1-5% of all points on the line, but may also include higher amounts including 5-10%, 10-25%, 25-40%, 40-60%, and more than 60%.

Although club heads according to the inventive subject matter are preferably iron-type club heads, it should be appreciated that putter- or wood-type club heads are also contemplated. Figure 3 shows another embodiment according to the present inventive subject matter in which a golf club 300 has a club head 310 with a face 312, a sole 314, and a center of mass 316. A first ballast element 320A having a first center of mass 326A is coupled to the face via a first weight supporting member 330A, and a second ballast element 320B having a second center of mass 326B is coupled to the face via a second weight supporting member 33 OB. Club head 310 is coupled to the shaft (not shown) via a hosel 340.

Corresponding elements of golf club 200 (depicted in Figure 2) and golf club 300 (depicted in Figure 3) are shown with corresponding numerals, and the same considerations apply to the elements of golf club 300 with respect to corresponding elements of golf club 200.

With respect to the arrangement of the first and second weight supporting members and ballast elements it is contemplated that the first weight supporting member and first ballast element are coupled to the sole, and the second weight supporting member and second ballast are coupled to upper boundary of the face. However, it should be appreciated that various alternative arrangements of weight supporting members and ballast elements are also appropriate. For example, in cases where the centers of mass of the ballast elements are desired to be particularly high, two or more than two weight supporting members and ballast elements may be coupled to the upper boundary of the face. It should further be appreciated that a weight supporting member and a ballast element may also be coupled to the face via the sides of the face to achieve a particular toe- or heel heavy balance. Alternatively, additional weight supporting members and ballast elements may be coupled to the hosel and/or shaft of the golf club.

Thus, specific embodiments and applications of golf clubs with improved club heads have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

Claims

CLAIMSWhat is claimed is:

1. A golf club, comprising:

a club head having a rearmost point, a sole, and a face with a face height H;

wherein the rearmost point is positioned at least 0.3 *H rearwards of the face, and at least 0.66*H higher than the sole.

2. The golf club of claim 1 wherein the rearmost point is positioned at least 0.5*H rearwards of the face, and at least 0.7*H higher than the sole.

3. The golf club of claim 1 wherein the rearmost point is positioned at least 0.7*H rearwards of the face, and at least 0.8*H higher than the sole.

4. The golf club of claim 1 wherein the rearmost point is positioned at least 0.9*H rearwards of the face, and at least 0.9*H higher than the sole.

5. The golf club of claim 1 wherein a line drawn between the rearmost point and the sole includes points outside the club head.

6. The golf club of claim 1 wherein the face has an upper boundary, and wherein a line drawn between the rearmost point and the upper boundary includes points outside the club head.

7. The golf club of claim 1 wherein the club head comprises a ballast element.

8. The golf club of claim 7 wherein the ballast element is coupled to the face via a weight supporting member.

9. The golf club of claim 5 wherein the ballast element is juxtaposed to the rearmost point.

10. The golf club of claim 7 further comprising a second ballast element.

11. The golf club of claim 8 wherein the weight supporting member is detachably coupled to the club head.

12. The golf club of claim 8 wherein the ballast element is detachably coupled to the weight supporting member.

13. The golf club of claim 8 wherein the weight supporting member is comprises a material selected from the group consisting of a metal, a metal alloy, and a polymer.

14. The golf club of claim 8 wherein the weight supporting member is an integral part of the ballast element.

15. The golf club of claim 8 wherein the weight supporting member and the ballast element are an integral part of the face.

16. The golf club of claim 8 wherein the ballast element comprises a material selected from the group consisting of a metal, a metal alloy, a polymer, water, and sand.

17. The golf club of claim 11 wherein the ballast element is heavier than the second ballast element.

18. The golf club of claim 1 wherein the club head is an iron-type club head.

19. The golf club of claim 1 wherein the club head is a putter-type club head.