WO2000002627A1

WO2000002627A1 - Golf club head

Info

Publication number: WO2000002627A1
Application number: PCT/US1999/015771
Authority: WO
Inventors: David H. Raymond
Original assignee: Raymond David H
Priority date: 1998-07-13
Filing date: 1999-07-13
Publication date: 2000-01-20
Also published as: AU5097899A

Abstract

A golf club head (10) has a lobe (28) defining a first club head thickness (D1) spaced between leading and trailing edges (20, 22) of the face (14). An entry region (34) of the club head is located below the lobe (28) and adjacent to the leading edge (20) on an opposite side of the club head (10) relative to the face (14), and is spaced inwardly from the lobe (28) to define a second club head thickness (D2). A curved transition portion (40) extends between the lobe (28) and the entry region (34). The club face (14) also has a central axis (C) defining a sweet spot (128). A first set of parallel score lines (130) are located on one side of the central axis (C), and a second set of parallel score lines (132) are located on an opposite side of the central axis (C).

Description

GOLF CLUB HEAD

FIELD OF THE INVENTION

The present invention relates generally to a golf club head, and more

particularly, to a golf club head which provides for ground surface penetration of the

leading edge and forward movement of the club head, prior to deflection of the club

head off of the ground surface. The present invention also relates to a golf club head

having upwardly directed score lines on the club face.

BACKGROUND OF THE INVENTION

A typical sand wedge has a lobe or downward projection located on an

opposite side of the club head relative to the face, and extending downwardly from the

lower portion or leading edge of the club head, or is otherwise designed for preventing

the leading edge from penetrating downwardly into and possibly getting stuck in the

ground. A lobe or other downward projection bounces or deflects off the ground, and

in turn, provides "bounce" or a sharp upward movement to the club head typically at

about the moment the leading edge contacts the ground. Bounce is particularly useful

when a high-angled trajectory is needed to lift a golf ball out of a steep-lipped sand

trap.

As an example. U.S. Pat. No. Des. 55,278 issued to Kraeuter shows a

golf club head having a wide portion or lobe located adjacent to the leading edge of

the club face to deflect the club head upwardly off of the ground surface during contact of the leading edge with the ground surface. U.S. Pat. No. 1,835,718 issued to

Morton shows a curved wing for collecting sand therewithin, which acts as a cushion

for bouncing the club upwardly and for minimizing the penetration of the leading edge

of the club head into the ground surface. U.S. Pat. No. Des. 339,397 issued to Enuma;

U.S. Pat. No. Des. 294,850 issued to Simmons; U.S. Pat. No. Des. 389,541 issued to

Huan-Chiang, and U.S. Pat. No. 5,480,145 issued to Sherwood, are further examples

of golf club head designs which prevent or minimize ground surface penetration

and/or deflect the club head upwardly generally upon contact of the leading edge of

the club face with the ground.

One drawback with prior art golf club heads having lobes in the above-

described or other structures designed for preventing or minimizing penetration of the

leading edge into the ground, is that if the club head contacts the ground slightly

behind the desired contact position, the design will cause the club head to bounce

upwardly as the leading edge contacts the ground, to thereby mishit or "top" the ball.

A club head which tops a ball imparts a low-angled and short trajectory thereto which

is particularly undesirable, for example, when attempting to lift a golf ball out of a

sand trap.

A golf club head defines a sweet spot typically located centrally on the club

face relative to the heel and toe. The sweet spot is defined as the area around the

center of mass of a club head that is the most effective part of the face with which to

strike a golf ball. The center of mass (or center of the sweet spot) is typically

provided along a center line of the club face extending from an upper edge to a lower edge of the club head. It is desirable to strike a golf ball on the sweet spot of the club

face in order to impart a straight trajectory to the ball and to better ensure that the ball

lands inhere desired. Mishitting the golf ball near the heel of the club face of a right-

handed club results in pivoting the club face leftwardly and, in turn, imparting a

leftward trajectory to the ball. Similarly, mishitting the golf ball near the toe of the

club face results in pivoting the club face rightwardly and, in turn, imparting a

rightward trajectory to the ball.

Golf club heads are known to provide different types of score lines

designed to correct the trajectory of mishit golf balls. U.S. Pat. No. 5,505,450 shows

a golf club head that has three sets of grooves. Two sets of upwardly directed grooves

respectively provided near the toe and heel portions permit corrective spins to a mishit

ball in order to straighten the ball trajectory. A center set of horizontal grooves

provides spin, but no trajectory correction. A drawback with this type of golf club

head is that the ball receives little or no corrective spin from the upwardly directed

grooves, unless the face strikes the ball a substantial distance from the center of the

face beyond the horizontal grooves toward either the heel or toe.

In response to the foregoing, it is an object of the present invention to

provide a golf club head that overcomes the drawbacks and disadvantages of prior art

golf club heads. SUMMARY OF THE INVENTION

The present invention is directed to a golf club head having a hosel for

attaching the club head to a club shaft, a club face defining a heel portion adjacent to

the hosel, a toe portion located on an opposite side of the face relative to the heel

portion, a leading edge extending between the toe portion and the heel portion, and a

trailing edge extending between the toe portion and the heel portion on an opposite

side of the face relative to the leading edge. A lobe defining a first club head thickness

is spaced between the leading edge and the trailing edge on an opposite side of the

club head relative to the face, and projects outwardly therefrom. An entry region of

the club head is located below the lobe and adjacent to the leading edge on an opposite

side of the club head relative to the face, and is spaced inwardly from the lobe to

thereby define a second club-head thickness less than the first club-head thickness.

The entry region permits the club head to penetrate downwardly into a ground surface.

A curved transition surface extends between the lobe and the entry region. Upon a

downward stroke of the club head, the leading edge, entry region and the curved

transition surface penetrate downwardly into and forwardly along the ground surface

prior to the lobe contacting the ground surface.

One advantage of the present invention is that if the club head contacts

the ground slightly behind the desired contact position relative to a golf ball, the entry

region of the club head first penetrates the ground surface, and then the lobe and the

transition surface engage the ground surface and guide the club head generally forwardly and under the ball into proper striking position prior to deflection of the club

head upwardly by the lobe.

The present invention is also directed to a golf club head which

includes a club face defining a sweet spot immediately surrounding a center of mass

of the club head, and wherein a central axis of the club face extends through the sweet

spot. An elongated smooth surface extends in its elongated direction along at least a

portion of the central axis and overlies the sweet spot. A first set of approximately

parallel score lines are located on one side of the central axis, and a second set of

approximately parallel score lines are located on an opposite side of the central axis.

Each score line is oriented upwardly at an oblique angle relative to the central axis for

imparting an oblique spin to a golf ball to, in turn, compensate for the direction of

impact when mishitting the ball toward the toe portion or the heel portion of the club

face. Preferably, the score lines are V-shaped in cross-section.

One advantage of the present invention is that the score lines are

located near the center of the sweet spot so as to provide corrective spin even when the

club face strikes a golf ball only slightly off of the center of the sweet spot toward the

toe portion or the heel portion of the club face.

Other objects and advantages of the present invention will become

apparent in view of the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a golf club head showing an entry

region, curved transition surface and lobe in accordance with the present invention.

FIG. 2 is an opposite, side elevational view of the golf club head of

FIG. 1.

FIG. 3 is a top plan view of the golf club head of FIG. 1.

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

FIG. 5 is a perspective view of the golf club head having on its face

oblique, upwardly directed score lines in accordance with the present invention.

FIG. 6 is a partial, cross-sectional view of the club head of FIG. 5

showing the V-shaped score lines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-4, a golf club head embodying the present

invention is generally designated by the reference number 10. The club head 10

includes a hosel 12 for attaching the club head to a club shaft 13. The club head 10

further includes a club face 14 defining a heel portion 16 adjacent to the hosel 12, and

a toe portion 18 located on an opposite side of the face 14 relative to the heel portion

16. The club face 14 further defines a leading edge 20 extending between the toe

portion 18 and the heel portion 16 at a lower portion 22 of the face, and a trailing edge 24 extending between the toe portion 18 and the heel portion 16 at an upper portion 26

of the face.

As best shown in FIGS. 1 and 2, the club head further includes a lobe

28 spaced between the leading edge 20 and the trailing edge 24 on an opposite side of

the club head 10 relative to the face 14, and projecting outwardly therefrom. The lobe

28 defines a first club-head thickness "Dl" between the face 14 of the club head and

an outermost portion 32 of the lobe 28 relative to the face, and the exterior surface of

the lobe 28 is preferably defined by a radius of curvature "Rl". The club head 10

includes means for facilitating penetration of the leading edge 20 downwardly into a

ground surface, including an entry region 34 located below the lobe 28 and adjacent to

the leading edge 20 on an opposite aide of the club head 10 relative to the face 14.

The entry region 34 is spaced inwardly from the lobe 28 and defines a second club-

head thickness D2 between the face 14 and a surface 36 of the entry region facing in a

direction opposite to the face 14.

As shown in FIGS. 1 and 2, the second club-head thickness D2 at the entry

region 34 is less than that of the first club-head thickness Dl at the lobe 28. A curved

transition surface 40 extends between the lobe 28 and the entry region 34, and is

preferably a concave surface defining a relatively large radius of curvature "R2" in

comparison to the first radius of curvature "Rl " of the lobe 28. For example, a radius

of curvature Rl of approximately 0.175 inches for the lobe 28 has been found to be

suitable in conjunction with a radius of curvature R2 of approximately 3.375 inches

for the curved transition surface 40. However, other suitable values of Rl and R2, and proportions between Rl and R2 may be employed. The curved transition surface 40

and the lobe 28 define means for guiding the club head generally forwardly upon

penetration of the ground surface by the entry region 34. As shown in FIGS. 1 and 2,

the club head thickness progressively increases in a direction from the entry region 34

(second club head thickness D2) to the lobe 28 (first club head thickness Dl).

During a downward stroke or arc of the club head 10, the entry region

34 first contacts the ground surface. The relatively small club head thickness D2 of

the entry region 34 provides a small surface area which permits the leading edge 20

and the entry region 34 to easily penetrate downwardly into the ground surface. As

the club head 10 further penetrates downwardly into the ground surface, the club head

thickness, and in turn, the surface area of the club head 10 penetrating the ground

surfaces increases from the entry region 34 along the curved transition surface 40 to

the lobe 28. This increasing surface area is resisted by the ground surface to resist

further downward penetration of the club head 10 into the ground surface. The golf

club head 10 is then guided generally forwardly by the curved transition surface 40

and the lobe 28 along the ground surface as the golf club head contacts the ground

surface progressively along the curved transition surface and the lobe in a direction

from the entry region 34 to the lobe 28. Upon the downward and forward movement

of the golf club head 10, the lobe 28 contacts the ground surface and, in turn, deflects

or "bounces" the club head upwardly off of the ground surface.

If the club head 10 strikes the ground at the desired contact position, the

face 14 will remain under the ball in proper striking position during the downward and forward movement of the club head and when the lobe 28 deflects or bounces

upwardly off of the ground surface. If the club head 10 strikes the ground surface

slightly behind the desired position for striking the golf ball, however the downward

penetration and forward movement of the club head 10 provided by the entry region

34, the curved transition surface 40 and lobe 28 permit the club face 14 to move

downwardly and forwardly under the golf ball in order place the face in proper striking

position with the golf ball as the lobe 28 deflects off of the ground surface to provide

the lift to the golf ball.

As will be recognized by those of ordinary skill in the pertinent art,

numerous modifications and substitutions may be made to the above-described and

other embodiments of the present invention without departing from the scope of the

invention as set forth in the appended claims. For example, the lobe may be

substituted by other designs for guiding the club head forwardly upon penetration of

the leading edge with the ground surface. Accordingly, the preceding portion of this

specification is to be taken in an illustrative, as opposed to a limiting sense.

Referring now to FIG. 5, the golf club 10 head illustrated and described

is for right-handed players, but it will be understood that the present invention also

applies to a golf club head for left-handed players in which the structure, as well as

spin and ball trajectory imparted by the left-handed club head is a mirror image of the

right-handed club head 10.

The club face 14 includes a sweet spot 128 which is the most effective

part of the face with which to strike a golf ball in order to impart a straight trajectory to the ball, and to best ensure that the ball lands at a desired target, such as a fairway

or putting green. As discussed above, and indicated by the broken lines in FIG. 5, the

sweet spot 128 is the area on the club face 14 immediately surrounding the center of

mass of the golf club head 10. As also shown in FIG. 5, in the preferred embodiment,

a center line or central axis "C" of the club head 10 extends through the center of the

sweet spot 128. Also in the preferred embodiment, the center line or central axis C is

located along its extent approximately midway between the heel portion 16 and the

toe portion 18 of the club face 14, and extends from the upper portion 26 to the lower

portion 22 of the club face.

The club head 10 further includes first means extending between the

central axis or center line C and the toe portion 18 of the face 14 for generating spin to

a golf ball to compensate for the direction of impact due to striking the ball toward the

toe portion 18. The first means includes a first plurality of substantially parallel

grooves or score lines 130 approximately equally spaced relative to each other and

extending between the center line C and the toe portion 18. Each score line 130

extends upwardly along an approximately straight line at an oblique angle relative to

the central axis C from a first point adjacent to the central axis C to a second point

located along the margin of the club face.

The club head 10 further includes a second means extending between the

central axis or center line C and the heel portion 16 of the face 14 for generating spin

to a golf ball to compensate for the direction of impact due to striking the ball toward

the heel portion 16. The second means includes a second plurality of substantially parallel grooves or score lines 132 approximately equally spaced relative to each other

and extending between the center line C and the heel portion 16. Each score line 132

the central axis C from a first point adjacent to the central axis to a second point

located along the margin of the club face.

Preferably, the first and the second sets of score lines 130, 132 each extend

upwardly at an angle of approximately 45° relative to the center line C. However, as

will be recognized by those skilled in the pertinent art based on the teaching herein,

other oblique angles may be equally employed. The oblique angle of the score lines

130, 132, along with the substantial percentage of club face surface area covered by

the score lines permits a substantially greater score line surface area in which to

engage and thereby correct the direction of impact or trajectory of a mishit golf ball as

compared to the score lines of prior art golf club heads.

As shown in FIG. 5, the inner ends of the first and the second sets of

score lines 130, 132 on the face 14 are located adjacent to the center line or central

axis C and are closely spaced from one another on opposite sides of the central axis so

as to define an elongated smooth surface 33 centered on and extending along the

central axis between the opposing score lines 130, 132. Preferably, and as shown in

FIG. 5, a portion of the score lines 130, 132 extend into the sweet spot 128 to provide

spin compensation when a ball is stuck even slightly off of the center of the sweet

spot. As shown in FIG. 6, each of the score lines 130 or 132 form V-shaped

cross-sections in the club face 14. The two sides forming the V-shaped cross-section

are defined by first and second surfaces 134 and 136 extending inwardly into the face

14 and converging with one another below the face at 37. Preferably, each pair of the

first and the second surfaces 134, 136 are oriented approximately perpendicular

relative to each other. It has been found that the V-shaped cross-section of the score

lines 130, 132 effectively engages the surface of a golf ball to impart an enhanced spin

to the golf ball. The enhanced spin, in turn, provides effective lift to the golf ball, and

is particularly advantageous when hitting a golf ball out of a sand trap.

In operation, when the face 14 strikes a golf ball on the sweet spot 128,

the face 14 of club head 10 remains square or normal to the direction toward the

desired target, which is typically a fairway or putting green, to thereby impart a

straight or forward trajectory to the ball (when ignoring natural factors affecting ball

trajectory such as the speed and direction of wind). Further, a plurality of the score

lines 130, 132 near the central axis C engage the ball surface to provide spin thereto.

The spins imparted by the score lines 130 or 132 are oblique (i.e., the golf ball spins

about an axis oriented at an oblique angle relative to the central axis C). Specifically,

the first set of score lines 130 provide a first oblique spin component about an axis of

the ball extending approximately in the same direction as the score lines 130, and the

second set of score lines 132 likewise provide a second oblique spin component about

a first spin axis of the ball extending approximately in the direction of the score lines 132. The simultaneous contact of the ball with the score lines 130, 132 at the sweet

spot 128 results in a straight trajectory to the ball.

When the face 14 strikes a golf ball toward the toe portion 18, the

inertial mass of a ball impacting the club head 10 retards the forward motion of the toe

portion 18 of the club face 14 relative to the heel portion 16, which in turn causes the

face 14 to pivot rightwardly about the center of mass of the club head 10 (i.e., the club

face 14 opens). The opening club face imparts a direction of impact to the ball having

a rightward trajectory component. Also, as the face 14 strikes the ball, the first set of

score lines 130 located between the central axis C and the toe portion 18 impart an

oblique spin to the ball about a first spin axis extending approximately in the direction

of the score lines 130 and oriented at an oblique angle relative to the central axis of the

club face 14 which results in generating a leftward trajectory component to the ball.

This leftward trajectory component imparted by the first set of score lines 130 tends to

correct or compensate for the direction of impact or rightward trajectory component

imparted by the rightward facing club face 14 to, in turn, direct the ball back inwardly

toward the desired target.

When the face 14 strikes a golf ball toward the heel portion 16, the

inertial mass of the ball impacting the club head 10 retards the forward motion of the

heel portion 16 of the club face 14 relative to the toe portion 18, which in turn causes

the face 14 to pivot leftwardly about the center of mass of the club head 10 (i.e., the

club face 14 closes). The closing club face imparts a direction of impact to the golf

ball having a slightly leftward trajectory component. Also, as the face 14 strikes the ball, the second set of score lines 132 located between the central axis C and the heel

portion 16 impart an oblique spin to the ball about a second spin axis extending

approximately in the direction of the score lines 132 and oriented at an oblique angle

relative to the central axis of the club face 14 which results in generating a rightward

trajectory component to the ball. This rightward trajectory component imparted by

the second set of score lines 132 tends to correct or compensate for the direction of

impact or leftward trajectory component imparted by the leftward facing club face 14

to, in turn, direct the ball back inwardly toward the desired target.

As will be recognized by those skilled in the pertinent art, numerous

modifications and substitutions may be made to the above-described and other

embodiments of the present invention without departing from the scope of the

invention as set forth in the appended claims. For example, the score lines may be

upwardly oriented at other oblique angles relative to the central axis. The score lines

may also be defined in the face as broken lines, or may be defined by different cross-

sectional shapes. Accordingly, the preceding portion of this specification is to be

taken in an illustrative, as opposed to a limiting sense.

Claims

What is claimed is:

1. A golf club head comprising: a hosel for attaching the club head to a club shaft; a club face defining a heel portion adjacent to the hosel, a toe portion located on an opposite side of the face relative to the heel portion, a leading edge extending between the toe portion and the heel portion, and a trailing edge extending between the toe portion and the heel portion on an opposite side of the face relative to the leading edge; a lobe spaced between the leading and trailing edges on an opposite side of the club head relative to the face and projecting outwardly therefrom, wherein the lobe defines a first club-head thickness; an entry region located below the lobe and adjacent to the leading edge on an opposite side of the club head relative to the face, and spaced inwardly from the lobe to thereby define a second club-head thickness less than the first club-head thickness; and a curved transition surface extending between the lobe and the entry region, whereupon a downward stroke of the club head against a ground surface, the leading edge, entry region and the curved transition surface penetrate the ground surface prior to contact of the ground surface by the lobe.

2. A golf club head as defined in claim 1 , wherein the lobe is located approximately midway between the leading edge and the trailing edge of the club face.

3. A golf club head as defined in claim 1, wherein the lobe and the transition surface each define a radius of curvature, and wherein the radius of curvature of the transition surface is larger than the radius of curvature of the lobe.

4. A golf club head as defined in claim 1, wherein the first club- head thickness of the lobe is defined as the distance between the club face and an outermost portion of the lobe relative to the club face.

5. A golf club head as defined in claim 1 , wherein the second club head thickness of the entry region is defined as the distance between the club face and an oppositely oriented surface of the entry region.

6. A golf club head as defined in claim 1, wherein the curved transition surface is generally concave.

A golf club head as defined in claim 1, wherein the club face includes: an axis, a sweet spot defined by the axis, an elongated smooth surface extending in its elongated direction along at least a portion of the axis and overlying the sweet spot, a first set of approximately parallel score lines located on one side of the axis, and a second set of approximately parallel score lines located on an opposite side of the axis, wherein each score line is oriented upwardly at an oblique angle relative to the axis.

8. A golf club head as defined in claim 7, wherein at least a plurality of score lines extend into the sweet spot.

9. A golf club head as defined in claim 7, wherein the elongated smooth surface extends from approximately the upper edge to approximately the lower edge of the club face.

10. A golf club head as defined in claim 7, wherein the elongated smooth surface is located approximately midway between the toe portion and the heel portion of the club face.

11. A golf club head as defined in claim 7, wherein the central axis extends in a direction from the upper portion to the lower portion between the toe portion and the heel portion, and the first and the second sets of score lines extend upwardly at an oblique angle of approximately 45┬░ relative to the central axis.

12. A golf club head as defined in claim 7, wherein a plurality of the first and second score lines are V-shaped in cross-section.

13. A golf club head as defined in claim 12, wherein each of the score lines is defined by first and second surfaces extending inwardly into the club face, and each pair of first and second surfaces are oriented approximately perpendicular relative to each other.

14. A golf club head as defined in claim 7, wherein each of the first set of score lines extends from approximately the smooth surface to a margin of the toe portion, and each of the second set of score lines extends from approximately the smooth surface to a margin of the heel portion.

15. A golf club head as defined in claim 7, wherein the axis coincident with the center line of the club face.

16. A golf club head comprising: a hosel for attaching the club head to a club shaft; a club face defining a heel portion adjacent to the hosel, a toe portion located on an opposite side of the face relative to the heel portion, a leading edge extending between the toe portion and the heel portion along a lower portion of the face, a trailing edge extending between the toe portion and the heel portion along an upper portion of the face, a sweet spot defined by an axis of the club face, an elongated smooth surface extending in its elongated direction along at least a portion of the axis and overlying the sweet spot, a first set of approximately parallel score lines located on one side of the axis, and a second set of approximately parallel score lines located on art opposite side of the axis, wherein each score line is oriented upwardly at an oblique angle relative to the axis.

17. A golf club head as defined in claim 16, wherein at least a plurality of score lines extend into the sweet spot.

18. A golf club head as defined in claim 16, wherein the elongated smooth surface extends from approximately the upper edge to approximately the lower edge of the club face.

19. A golf club head as defined in claim 16, wherein the elongated smooth surface is located approximately midway between the toe portion and the heel portion of the club face.

20. A golf club head as defined in claim 16, wherein the central axis extends in a direction from the upper portion to the lower portion between the toe portion and the heel portion, and the first and the second sets of score lines extend upwardly at an oblique angle of approximately 45┬░ relative to the central axis.

21. A golf club head as defined in claim 16, wherein a plurality of the first and second score lines are V-shaped in cross-section.

22. A golf club head as defined in claim 21 , wherein each of the score lines is defined by first and second surfaces extending inwardly into the club face, and each pair of first and second surfaces are oriented approximately perpendicular relative to each other.

23. A golf club head as defined in claim 16, wherein each of the first set of score lines extends from approximately the smooth surface to a margin of the toe portion, and each of the second set of score lines extends from approximately the smooth surface to a margin of the heel portion.

24. A golf club head as defined in claim 16, wherein the axis coincident with the center line of the club face.