US20130029781A1

US20130029781A1 - Golf club with selected length to weight ratio

Info

Publication number: US20130029781A1
Application number: US13/330,157
Authority: US
Inventors: Tim A. Beno; Andrew Curtis; Oswaldo Gonzalez; Robert A. Philion; Thomas W. Preece; Douglas E. Roberts; Michael S. Yagley
Original assignee: Cobra Golf Inc
Current assignee: Cobra Golf Inc
Priority date: 2011-07-29
Filing date: 2011-12-19
Publication date: 2013-01-31
Also published as: CN102895767A; JP2013031629A; EP2550998A1

Abstract

A golf club can include a shaft and club head. The club can have a selected length to weight ratio based on the length of the shaft and the overall weight of the club. The club head can include one or more areas with selective removal of weight to lighten the club head and/or move weight around in the club head.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/513,513, filed in the United States Patent and Trademark Office on Jul. 29, 2011, the entire contents of which is incorporated herein by reference.

FIELD OF THE INVENTION

This application generally relates to golf clubs, and more specifically to golf clubs with particular length to weight ratios.

BACKGROUND OF THE INVENTION

Golf club heads come in many different forms and makes, such as wood- or metalwood-type (including drivers and fairway woods), iron-type (including wedge-type club heads), utility or specialty-type, and putter-type club heads.
The design and manufacture of golf clubs can require careful attention to club head construction. Among the many factors that can be considered are material selection, material treatment, structural integrity, and overall geometric design. Exemplary geometric design considerations include loft, lie, face angle, horizontal face bulge, vertical face roll, face size, sole curvature, center of gravity, moment of inertia, and overall head weight. The interior design of a club head can be tailored to achieve particular characteristics, such as by including a hosel or other shaft attachment structure, perimeter weighting on the face or body of the club head, and/or fillers within hollow club heads.
With golfers constantly searching for golf clubs that provide greater distance, particularly with drivers, the golf industry has responded by providing golf clubs specifically designed with distance in mind. The head sizes of wood-type golf clubs have increased, which has allowed improved mass manipulation. The manipulation of mass allows the designer to alter attributes, such as the moment of inertia and the location of the center of gravity to provide a more forgiving golf club. In particular, providing a higher moment of inertia increases the ability of the golf club head to resist twisting on imperfect golf ball impacts. Furthermore, the size of the golf club head allows more discretion in locating the center of gravity.

SUMMARY OF THE INVENTION

An aspect of at least one of the embodiments described herein includes the realization that with golfers constantly searching for golf clubs that provide greater distance, particularly with drivers, it would be advantageous to have a golf club that is both light-weight, and long in length, such that a high swing speed can be generated with relative ease, and the ball can carry optimal distances upon impact.
Thus, in accordance with an embodiment, a golf club head can comprise an elongate shaft having a shaft length, the elongate shaft comprising a grip portion, the grip portion having a grip length, and a club head attached to a distal end of the elongate shaft, wherein the golf club has a total club weight, wherein the ratio of the shaft length to the total club weight is between approximately 0.170 inch/gram and 0.185 inch/gram.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present embodiments will become more apparent upon reading the following detailed description and with reference to the accompanying drawings of the embodiments, in which:

FIG. 1 is a perspective view of a golf club according to an embodiment;

FIG. 2 is a perspective view of the club head of the golf club of FIG. 1;

FIG. 3 is a front side view of the club head of the golf club of FIG. 1;

FIG. 4 is a top plan view of the club head of the golf club of FIG. 1;

FIG. 5 is a heel side view of the club head of the golf club of FIG. 1;

FIG. 6 is a bottom plan view of the club head of the golf club of FIG. 1; and

FIG. 7 is a partial, cross-sectional view of a sole portion of the club head of FIG. 2, taken along line 7-7 in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present application is directed towards golf clubs, and in particular golf clubs that have a particular length to weight ratio. While the embodiments disclosed herein include club heads for wood-type clubs, it is contemplated that one or more of the concepts described herein can further be used for other types of club heads, including but not limited to irons and putters.
With reference to FIG. 1, a golf club 10 can comprise an elongate shaft 12. The elongate shaft 12 can include an elongate grip portion 14, the grip portion 14 thereby forming a part of the defined shaft 12 described herein. The golf club 10 can further comprise a club head 16 attached to a distal end of the shaft 12. The club head 16 can comprise a ball striking portion 18, a crown portion 20, and a sole portion 22.
With reference to FIGS. 1-3, the ball striking portion 18 can comprise, for example, any portion of the club head 16 generally configured to strike a golf ball. The ball striking portion 18 can comprise a front portion of the golf club 16. In some embodiments the ball striking portion 18 can have notches, scorelines, and/or other markings common to golf club heads. In some embodiments the ball striking portion 18 can be attached to, or integrally formed with, at least a portion of the club head 16. In some embodiments, the ball striking portion 18 can comprise a face insert or inserts.
With reference to FIGS. 1, 2, and 4, the crown portion 20 can comprise, for example, a top portion of the club head 16. In some embodiments the crown portion 20 can comprise a portion of the club head 16 that is connected to or integrally formed with the ball striking portion 18. In some embodiments, at least a portion of the crown portion 20 can be configured to be viewed by a golfer when the golf club head 16 is at an address position. In some embodiments, the crown portion 20 can comprise one or more inserts.
With reference to FIGS. 1, 2, and 5, the sole portion 22 can comprise, for example, a bottom portion of the club head 16. The sole portion 22 can comprise a portion of the club head 16 that is connected to or integrally formed with the ball striking portion 18. In some embodiments, at least a portion of the sole portion 22 can be configured to contact a playing surface or ground surface when the golf club 10 is at an address position. In some embodiments, the sole portion 22 can comprise one or more inserts.
With reference to FIGS. 1, 2, and 6, in some embodiments the club head 16 can further include a skirt area 24 that extends generally between the crown portion 20 and sole portion 22. The skirt area 24 can comprise a separate element from that of crown portion 20 and sole portion 22, or can be formed, for example, from portions of one or more of the crown portion 20 and sole portion 22. In some embodiments, the club head 16 can be considered to have only a crown portion 20 and sole portion 22, without a skirt area 24. For example, in some embodiments the crown portion 20 can extend directly to and join with the sole portion 22.
With continued reference to FIGS. 1 and 2, the club head 16 can comprise a hosel 26. The hosel 26 can be configured to receive and/or hold the shaft 12. For example, the hosel 26 can comprise an opening through which the shaft 12 can be inserted.
The club head 16 can be made of titanium, though other materials, or combinations of materials, are also possible. In some embodiments all or a significant amount of the club head 16 can be comprised of titanium, including the ball striking portion 18. In some embodiments, part or all of the ball striking portion 18 can be comprised of titanium 8-11.
With reference to FIG. 1, in some embodiments the club 10 can comprise a driver. The golf club shaft 12 can have an overall length “SL.” The length SL can be defined as a length from a proximal end of the grip 14 to a proximal end of the hosel 26, as illustrated for example in FIG. 1. In some embodiments, the shaft length SL can be approximately 48 inches, though other values and ranges are also possible. For example, in some embodiments the shaft length SL can be approximately 47 inches. In some embodiments, the shaft length SL can be approximately 46 inches. In some embodiments the shaft 12 can have a length of between approximately 47.5 to 48.5 inches. In some embodiments the shaft 12 can have a length SL of between approximately 47 to 49 inches. In some embodiments the shaft 12 can have a length SL of between approximately 46 to 50 inches. In some embodiments the shaft 12 can have a length SL of between approximately 42 to 54 inches.
When the golf club 10 is a fairway club, as opposed to a driver, in some embodiments the shaft 12 can be slightly shorter. For example, the club 10 can have a shaft 12 with an overall length SL of approximately 44 inches, though other values and ranges are also possible. For example, in some embodiments the shaft length SL can be approximately 43 inches. In some embodiments the shaft 12 can have a length SL of between approximately 43 and 45 inches.
Overall, the length of the shaft 12 can be made longer than a typical corresponding club. For example, drivers typically have shafts lengths that range from 45 inches to 46 inches, and fairways typically have shaft lengths that are approximately 43 inches.
With continued reference to FIG. 1, in embodiments where the club head 10 is a driver, the shaft 12, including the grip portion 14, can have an overall weight of approximately 50 grams, though other values and ranges are also possible. For example, in some embodiments the shaft 12 can have a weight of between approximately 49 and 51 grams. In some embodiments the shaft 12 can have a weight of between approximately 48 and 52 grams. In some embodiments the shaft 12 can have a weight of between approximately 45 and 55 grams. In some embodiments, the shaft 12 can have a weight of between approximately 45 and 65 grams. In some embodiments, the shaft 12 can have a weight of between approximately 45 and 75 grams. In some embodiments, the shaft 12 can have a weight of between approximately 45 and 85 grams. In some embodiments, the shaft 12 can be made at least in part of carbon, though other materials are also possible.
With continued reference to FIG. 1, the grip portion 14 itself along the shaft 12 can have an overall length “GL” of approximately 9 inches, though lengths are also possible. For example, in some embodiments the grip portion 14 can have a length of between approximately 8.5 and 9.5 inches. In some embodiments the grip portion 14 can have a length of between approximately 8.0 and 10.0 inches.
In some embodiments, the length of the grip portion 14 can be made specifically to be less than typical grip length on other clubs, which are generally approximately 10.5 inches in length. This shorter length for the grip portion 14 can not only help to reduce the overall weight in the shaft 12, and make the club lighter, but also inhibit a golfer from choking down on the club 10's grip portion 14, due to the smaller area along the grip portion 14 within which to grip the club 10. Inhibiting a golfer from choking down on the club 10 can be advantageous for some golfers. Also, forcing a player to grip in the same location every time may allow a more consistent address to the ball for greater consistency.
With continued reference to FIG. 1, the grip portion 14 itself can have a weight of approximately 24 grams, though other values and ranges are also possible. For example, in some embodiments the grip portion 14 can have a weight of between approximately 22 and 26 grams. In some embodiments the grip portion 14 can have a weight of between approximately 20 and 28 grams.
In some embodiments, part or all of the shaft 12 can include a coating or coatings of material which can provide increased aerodynamics to the club 10, and/or drag reduction as the club 10 is swung.
With reference to FIGS. 1-6, the ball striking portion 18, crown portion 20, and sole portion 22 of club head 16 can form an interior volume within the club head 16. The interior volume 16, particularly for a club head 10 that is a driver can be approximately 440 cc, though other values are also possible. For example, in some embodiments the interior volume of the club head 16 can range from between approximately 435 cc to 445 cc. In some embodiments, the interior volume of the club head 16 can range from approximately 430 cc to 450 cc. In some embodiments the volume of the club head 16 can range from approximately 400 cc to 480 cc. In some embodiments the volume of the club head 16 can range from between approximately 350 cc to 530 cc.
In embodiments where the golf club head 10 is a fairway club, the club head 16 can have a club head volume of approximately 239 cc, though other values and ranges are also possible. For example, in some embodiments the club head 16 can have a volume of between approximately 235 and 245 cc. In some embodiments the club head 16 can have a volume of between approximately 230 and 240 cc. In some embodiments the club head 16 can have a volume of between approximately 200 and 270 cc. In some embodiments the club head 16 can have a volume of between approximately 200 and 300 cc.
With continued reference to FIG. 1, in some embodiments where the golf club 10 is a driver, the golf club 10 can have an overall weight, which includes the weight of the shaft 12 and club head 16, of approximately 269 grams, though other values and ranges are also possible. For example, in embodiments where the club 10 is a driver, the club 10 can have an overall weight of between approximately 250 and 290 grams. In some embodiments the club head 10 can have an overall weight of between approximately 230 and 350 grams.
In embodiments where the golf club 10 is a fairway, the golf club 10 can have an overall weight, which includes the weight of the shaft 12 and club head 16, that is slightly greater than that of a driver. For example, in some embodiments the golf club 10 can have a club head weight that is approximately 10-20 grams higher than that of a driver.
In some embodiments, the club head 16 can comprise at least 50% of the overall club weight. In some embodiments the club head 16 can comprise at least 60% of the overall club weight. In some embodiments the club head 16 can comprise at least 70% of the overall club weight. In some embodiments the club head 16 can comprise at least 80% of the overall club weight. In some embodiments the club head 16 can comprise at least 90% of the overall club weight.
In some embodiments, the club 10 can have a preferred length to weight ratio, defined as the length of the shaft 12, as compared with the overall weight of the club 10. In embodiments where the club 10 is a driver, the length to weight ratio can be approximately 0.178 inch/gram, though other values and ranges are also possible. For example, in some embodiments, the length to weight ratio is between approximately 0.170 inch/gram and 0.185 inch/gram. In some embodiments, the length to weight ratio is between approximately 0.170 and 0.190 inch/gram. In some embodiments, the length to weight ratio is at least 0.170 inch/gram. In some embodiments, the length to weight ratio is at least 0.175 inch/gram. In some embodiments, the length to weight ratio is at least 0.180 inch/gram. In some embodiments, the length to weight ratio is at least 0.185 inch/gram. In some embodiments, the length to weight ratio is at least 0.190 inch/gram. In some embodiments, the length to weight ratio is no more than, for example, 0.200 inch/gram.
With reference to FIGS. 6 and 7, in some embodiments the club head 16 can be designed to selectively remove weight from one or more of the ball striking portion 18, crown portion 20, and sole portion 22. Selective removal of weight from one portion of the club head 16 can allow the weight to be moved to another portion of the club head 16, so as to advantageously adjust a center of gravity of the club head 16, and/or adjust moments of inertia about the club head 16. In some embodiments, selective removal of weight can be used primarily to lighten the overall weight of the club head 16, and make the club's overall weight lighter, facilitating a greater swing speed as described above.
For example, and with reference to FIGS. 5-7, in some embodiments the sole portion 22, or other portion of the club head 16, can comprise at least one weight removal section 28. The weight removal section 28 can be formed on the outside and/or inside of the club head 16. The weight removal section 28 can be in the form of a groove, pocket, or any other similar type structural recess on the club head 16. With reference to FIG. 7, in some embodiments the club head 16 can comprises a wall 30 having an interior surface 32 facing the interior volume of the club head 10, and an exterior surface 34 facing the outside of the club head 16. The wall 30 can comprise a first wall section 36 having a first wall thickness “t1” and a second wall section 38 having a second wall thickness “t2” in the area of a weight removal section 28. The second wall thickness t2 can be less than the first wall thickness t1. In some embodiments, the interior surface 32 can remain uninterrupted, and generally smooth, across the first and second wall sections 36, 38 without rising along the second wall section 38. For example, as illustrated in FIG. 7, the inside of the club head 10 can remain smooth. This is in contrast to an indentation or raised portion, for example along the sole portion 22 of the club head 16. In some embodiments, the sole portion 22 (or other portion of the club head 16) can have a generally continuous curved or flat surface 34 on the inside, and the selective removal of material can occur on the outside of the club head 16, giving the club head a different thickness t1 and t2. In other embodiments, an outer surface of the sole portion 22 (or other portion of the club head 16) can remain a generally continuous curved or flat surface, and the removal of material can instead occur on the interior surface 32.
In some embodiments, the thickness t1 can be approximately 0.85 mm, though other values and ranges are also possible. For example, in some embodiments the thickness t1 can range between approximately 0.82 mm and 0.88 mm. In some embodiments the thickness t1 can range between approximately 0.80 mm and 0.90 mm. In some embodiments the thickness t1 can range between approximately 0.60 mm and 1.2 mm.
In some embodiments, the smaller thickness t2 can be approximately 0.70 mm, though other values and ranges are also possible. For example, in some embodiments the thickness t2 can range between approximately 0.67 mm and 0.73 mm. In some embodiments, the thickness t2 can range between approximately 0.65 mm and 0.75 mm. In some embodiments the thickness t2 can range between approximately 0.60 mm and 1.0 mm.
While selective removal of material is shown generally along the sole portion 22 in FIG. 7, such removal can also be used in other portions of the club head 16. For example, in some embodiments the club head 16 can include one or more weight removal areas 28 along outer edges of the sole portion 22, as seen for example in FIG. 6. In some embodiments the club head 16 can include one or more weight removal areas 28 along the skirt 24, and/or the crown 20. In some embodiments the club head 16 can include a ball striking portion 18 with one or more weight removal areas 28. In some embodiments, different zones of thicknesses can be formed at least in part by selective removal of material along the ball striking portion 18. For example, in some embodiments the ball striking portion 18 can include a thick, centralized portion extending towards the interior volume of the club head 16 and other zones surrounding the centralized portion, having varying thicknesses.
In some embodiments, the club 10 can have a club head total recess volume defined as the sum volume of all recesses (e.g. weight removal areas 28) formed on an outer surface of the club head 16. In some embodiments, the club 10 can have a sole total recess volume defined as the sum volume of all the recesses (e.g. weight removal areas 28) formed on the sole of the club head 16. In some embodiments, the club head total recess volume and/or sole total recess volume can be at least 1 cc. In some embodiments, the club head total recess volume and/or sole total recess volume can be at least 5 cc. In some embodiments, the club head total recess volume and/or sole total recess volume can be at least 10 cc. In some embodiments, the club head total recess volume and/or sole total recess volume can be at least 20 cc. In some embodiments, the club head total recess volume and/or sole total recess volume can be between approximately 1 and 5 cc. In some embodiments, the club head total recess volume and/or sole total recess volume can be between approximately 10 and 20 cc.
With reference to FIGS. 3-5, the club head 16 can also include a center of gravity based on a geometric center point “GC” along the ball striking portion 18. The geometric center point can be a point that is equidistant from between a toe and heel end of the club, and equidistant from a top and bottom of the ball striking portion 18, so as to be generally in the center of the ball striking portion 18. As described above, the center of gravity can be adjusted and moved, based on the selective movement of mass within the club head 16. Advantageously, the center of gravity can be moved back, away from the ball striking portion 18, so as to make the club 10 a more forgiving club, as well as give it increased swing speed.
In some embodiments, and with reference to FIGS. 3 and 4, the center of gravity can be located generally based on an X, Y, Z coordinate system tied to the geometric center point GC. The center of gravity can be adjusted, based on the loft of the club. In some embodiments, the club 10 can have a center of gravity located at an X value of approximately 1.83 mm, a Y value of approximately 37.4 mm, and a Z value of approximately −1.5 mm. In some embodiments, the center of gravity can be located at an X value of approximately 1.85 mm, a Y value of approximately 37.26 mm, and a Z value of approximately −2.3 mm. In some embodiments, the center of gravity can be located at an X value of approximately 2.00 mm, a Y value of approximately 37.4 mm, and a Z value of approximately −3.3 mm. In some embodiments, the center of gravity can be located at an X value of between approximately 1.7 and 2.1, a Y value of between approximately 37.0 and 38.0 mm, and a Z value of between approximately −1.0 and −4.0 mm. Other values and ranges are also possible.
In some embodiments, the club head 16 can have a footprint, defined as a generally horizontal plane projected above the club head 16 when the club head is in an address position on a horizontal surface, the plane extending from a corresponding leading edge of the club head 16, to a back aft edge of the club head 16. In some embodiments, the center of gravity can be located approximately 38 mm back from the leading edge portion of the projected plane towards the aft edge, though other values and ranges are also possible. For example, in some embodiments the center of gravity can be located between approximately 37 mm and 39 mm back from the leading edge portion of the projected plane. In some embodiments the center of gravity can be located between approximately 35 mm and 41 mm back from the leading edge portion of the projected plane. In some embodiments the center of gravity can be located at least approximately 60% of the way back from the leading edge towards the aft edge. In some embodiments the center of gravity can be located at least approximately 70% of the way back from the leading edge towards the aft edge. In some embodiments the center of gravity can be located at least approximately 80% of the way back from the leading edge towards the aft edge. In some embodiments the center of gravity can be located at least approximately 90% of the way back from the leading edge towards the aft edge.
As described above, the club 10 can generally comprise a light-weight, long club, as compared with other similar clubs, that is capable of generating high swing speeds. For example, with a light-weight, long shaft 12 and club head 16, a golfer can swing the club 10 easily, and quickly, generating high swing speeds and force as the club 16 strikes a golf ball. This can especially be true where the club head 16 is designed with selective removal of weight, and wherein the center of gravity of the club head is located towards the back of the club head, as described above. The high length to weight ratios of the club 10, regardless of whether club 10 is a driver or a fairway type club, can give the club 10 an advantage over other corresponding clubs.
For example, an embodiment of the club 10, in the form of a driver, was tested against a competitive driver with a shaft length of approximately 46.5 inches, and a total club weight of approximately 279 grams. During the testing, the club head 10 showed a statistically significant increase in carry distance of approximately 5.0 yards over the competitive club. The club 10 showed a statistically significant increase in ball speed of approximately 3.0 mph over the competitive club. The club 10 showed an increase in launch angle for 7 out of the 9 players tested. The club 10 showed an increase in backspin for 6 out of the 9 players tested. This test helps demonstrate the effectiveness of having a club 10 with high length to weight ratios, and at least some of the advantages achieved by doing so.
In some embodiments, rather than having a club 10 with a longer shaft than typical as described above, in some embodiments a club 10 can have a shorter shaft than usual. For example, in some embodiments the club 10 can have a shaft that is only approximately 43 inches in length, or less than 43 inches, less than 41 inches, or less than 39 inches. In some embodiments, the club 10 can have a heavier head than what is typical, along with the shorter shaft.
Although these inventions have been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments can be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions. Thus, it is intended that the scope of at least some of the present inventions herein disclosed should not be limited by the particular disclosed embodiments described above.

Claims

1. A golf club comprising:

an elongate shaft having a shaft length, the elongate shaft comprising a grip portion, the grip portion having a grip length;

a club head attached to a distal end of the elongate shaft;

wherein the golf club has a total club weight;

wherein the ratio of the shaft length to the total club weight is between approximately 0.170 inch/gram and 0.185 inch/gram.

2. The golf club of claim 1, wherein the shaft length is between approximately 47 inches to 49 inches.

3. The golf club of claim 1, wherein the grip length is between approximately 8.5 inches to 9.5 inches.

4. The golf club of claim 1, wherein the total club weight is between approximately 265 grams and 275 grams.

5. The golf club of claim 1, wherein the shaft length is approximately 48 inches, and the total club weight is approximately 269 grams.

6. The golf club of claim 1, wherein the grip length is approximately 9 inches.

7. The golf club of claim 1, wherein the shaft has a weight of approximately 50 grams.

8. The golf club of claim 1, wherein the grip has a weight of approximately 24 grams.

9. The golf club of claim 1, wherein the club head comprises a crown portion, a sole portion, and a ball striking portion, the crown portion, sole portion, and ball striking portion forming an interior volume within the club head;

wherein sole portion comprises a wall having an interior surface facing the interior volume, the wall comprising a first wall section having a first wall thickness and a second wall section having a second wall thickness, the second wall thickness being less than the first wall thickness, wherein the interior surface remains uninterrupted, and generally smooth, across the first and second wall sections without rising along the second wall section.

10. The golf club of claim 1, wherein the club head includes a ball striking portion having a geometric center point, the wherein the club head includes center of gravity of the club head is located approximately 1.83 mm in a first direction based on the geometric center point, approximately 37.4 mm in a second direction based on the geometric center point, and approximately −1.5 mm in a third direction based on the geometric center point.