U.S. patent application number 10/385991 was filed with the patent office on 2003-08-14 for golf club head.
Invention is credited to Bottema, Robert, Woodward, Jay.
Application Number | 20030153399 10/385991 |
Document ID | / |
Family ID | 27123516 |
Filed Date | 2003-08-14 |
United States Patent
Application |
20030153399 |
Kind Code |
A1 |
Woodward, Jay ; et
al. |
August 14, 2003 |
Golf club head
Abstract
A golf club head comprises a main body that defines a front
face. The front face includes a plurality of projections extending
from the front face. The ends of the projections define a plurality
of individual contact surfaces for striking a golf ball. The
plurality of projections prevent a golf ball from contacting the
front face thereby resulting in a change of the golf ball general
contact area. A golf club incorporating the club head provides
improved control of a golf ball and also provides improved feel
when the club head impacts a golf ball.
Inventors: |
Woodward, Jay; (Rancho Santa
Fe, CA) ; Bottema, Robert; (Carlsbad, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
27123516 |
Appl. No.: |
10/385991 |
Filed: |
March 10, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10385991 |
Mar 10, 2003 |
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09595806 |
Jun 16, 2000 |
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6554721 |
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09595806 |
Jun 16, 2000 |
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09035277 |
Mar 9, 1998 |
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6089993 |
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09035277 |
Mar 9, 1998 |
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08984466 |
Dec 3, 1997 |
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08984466 |
Dec 3, 1997 |
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08811699 |
Mar 5, 1997 |
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60013012 |
Mar 7, 1996 |
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Current U.S.
Class: |
473/331 ;
473/342; 473/345; 473/349; 473/350 |
Current CPC
Class: |
A63B 53/04 20130101;
A63B 60/00 20151001; A63B 53/0445 20200801; A63B 53/0408 20200801;
A63B 53/005 20200801; A63B 53/0487 20130101; A63B 53/0416
20200801 |
Class at
Publication: |
473/331 ;
473/345; 473/350; 473/342; 473/349 |
International
Class: |
A63B 053/04 |
Claims
What is claimed is:
1. A golf club head, comprising: a main body defining a strike
portion sized to strike a golf ball, the strike portion comprising:
a main surface; a plurality of projections integrally formed with
the main surface, the plurality of projections extending outward
from the main surface, the projections being spaced apart and
defining individual flat end surfaces for contacting the surface of
a golf ball, the flat end surfaces extending along a plane
substantially parallel to the main surface, wherein the projections
are stiff enough to prevent a golf ball from contacting the main
surface when the golf club head strikes the golf ball.
2. The golf club head of claim 1, wherein the golf club head
comprises one of a wood-type head and an iron-type head.
3. The golf club head of claim 2, wherein the projections are sized
to fit within the dimples of a golf ball.
4. The golf club head of claim 1, wherein the golf club head
comprises a putter head.
5. The golf club head of claim 1, wherein the flat end surfaces
collectively define an area that is between 15%-45% of the area of
the strike portion.
6. The golf club head of claim 1, wherein the density of the
projections on the strike portion is at least 30 projections per
square inch.
7. The golf club head of claim 1, wherein the projections are
uniformly distributed on the strike portion to form a plurality of
interlinked hexagonal patterns.
8. The golf club head of claim 1, wherein each of said plurality of
projections is separated from adjacent other of said plurality of
projections by a distance between 0.020 and 0.078 inches.
9. The golf club head of claim 1, wherein the end surfaces of the
projections are circular.
10. The golf club head of claim 9, wherein the end surfaces of the
projections have a diameter of approximately 0.020-0.078
inches.
11. The golf club head of claim 1, wherein the projections have a
length of at least approximately 0.010 inches.
12. The golf club head of claim 1, wherein the projections have a
length of approximately 0.010-0.045 inches.
13. The golf club head of claim 1, wherein the projections extend
in a direction substantially normal to a plane defined by the main
surface of the front face.
14. The golf club head of claim 1, wherein the end surfaces of the
projections each define an elliptical shape or a polygonal
shape.
15. The golf club head of claim 1, wherein the head defines a lower
edge and an upper edge, and wherein the projections are uniformly
spaced from the lower edge to the upper edge.
16. The golf club head of claim 1, wherein the end surfaces of the
projections located within a lateral region of the strike portion
are larger than the end surfaces of the projections located within
a central region of the strike portion.
17. The golf club head of claim 1, wherein the main body further
comprises a face insert sized to fit within a recess, and wherein
the projections extend outward from the face insert.
18. The golf club head of claim 1, wherein the front surface and
the projections are integrally formed of a metallic material.
19. A golf club head comprising; a main body defining a front face;
a plurality of projections extending from the front face, the ends
of the projections defining a plurality of individual contact
surfaces for striking a golf ball, wherein the plurality of
projections prevent a golf ball from contacting the front face
thereby resulting in a decrease of the golf ball general contact
area.
20. The golf club head of claim 19, wherein the ends of the
projections are flat.
21. The golf club head of claim 20, wherein the ends of the
projections collectively define a strike face that is substantially
parallel to the front face.
22. The golf club head of claim 21, wherein the projections are
integrally formed with the main body.
23. The golf club head of claim 19, wherein the head comprises a
peripheral portion defining a peripheral surface and a strike
portion surrounded by the peripheral portion, and wherein the
projections extend from the strike portion.
24. The golf club head of claim 23, wherein the strike face is
recessed with respect to the peripheral surface.
25. The golf club head of claim 23, wherein the strike face is
coplanar with the peripheral surface.
26. The golf club head of claim 19, wherein the ends of the
projections collectively have an area that is between 15%-45% of
the area of the strike portion.
27. The golf club head of claim 19, wherein the density of the
projections in the strike portion of the head is at least 30
projections per square inch.
28. The golf club head of claim 19, wherein the projections are
uniformly distributed on the strike portion to form a plurality of
interlinked patterns.
29. The golf club head of claim 28 wherein the interlinked patterns
comprise hexagons.
30. The golf club head of claim 19, wherein each of said plurality
of projections is separated from adjacent other of said plurality
of projections by a distance between 0.020 and 0.078 inches.
31. The golf club head of claim 19, wherein the ends of the
projections have a circular shape.
32. The golf club head of claim 31, wherein the ends of the
projections have a diameter of approximately 0.020-0.078
inches.
33. The golf club head of claim 19, wherein the projections have a
length of at least approximately 0.010 inches.
34. The golf club head of claim 33, wherein the projections have a
length of approximately 0.010-0.045 inches.
35. The golf club head of claim 19, wherein the projections extend
in a direction substantially normal to a plane defined by the front
face.
36. The golf club head of claim 19, wherein the ends of the
projections each define an elliptical shape.
37. The golf club head of claim 19, wherein the ends of the
projections each define a polygonal shape.
38. The golf club head of claim 19, wherein the head defines a
lower edge and an upper edge, and wherein the projections are
uniformly spaced from the lower edge to the upper edge.
39. The golf club head of claim 19, wherein the size of the ends of
the projections varies across the strike portion of the golf club
head.
40. The golf club head of claim 38, wherein the sizes of the ends
of the projections located within a lateral region of the front
face are larger than the sizes of the ends of the projections
located within a central region of the front face.
41. The golf club head of claim 19, wherein the main body further
comprises a face insert sized to fit within a recess, and wherein
the projections extend outward from the face insert.
42. The golf club head of claim 19, wherein the front surface and
the projections are both formed of a metallic material.
43. In a golf club for use in striking a golf ball having a
plurality of dimples formed therein, a club having a head with a
faceplate which contacts the surface of a golf ball when said golf
ball is being driven, the improvement comprising: a plurality of
rigid projections having spaces therebetween formed on said
faceplate integrally therewith and extending therefrom, said
projections being distributed in a substantially uniform pattern
with their distal ends forming a striking surface of said face
plate, surfaces being formed in said spaces which are substantially
parallel to the striking surface of said projections, said
projections being of a small enough size to fit within the dimples
of a golf ball; whereby when said faceplate strikes a golf ball, a
substantial number of said projections enter and frictionally
engage a corresponding substantial number of dimples on a golf ball
to enhance the spin characteristics of a golf ball.
44. The golf club of claim 43, wherein said projections are all of
uniform length and diameter.
45. The golf club head of claim 43, wherein said projections are
cylindrical in shape.
46. The golf club head of claim 45, wherein said projections have a
diameter of 0.08-0.12 inch.
47. The golf club head of claim 43, wherein said projections extend
from the main body of the faceplate 0.03-0.06 inch.
48. The golf club head of claim 46, wherein the spacing between
said projections is approximately 0.14 inch.
49. The golf club head of claim 45, wherein said projections extend
in a direction substantially normal to a plane parallel to said
striking surface of said faceplate.
50. A golf club head with a faceplate for use in striking a golf
ball having a plurality of dimples formed therein, said faceplate
having a striking surface which contacts the surface of a golf ball
when a golf ball is driven, comprising: a plurality of
substantially cylindrical projections having spaces therebetween
formed on the faceplate, the distal ends of said projections
forming a striking surface of the faceplate, surfaces being formed
in the spaces which are substantially parallel to the distal ends
of the projections, said projections extending from said faceplate
in a direction substantially normal to a plane parallel to the
striking surface of said faceplate, said projections being
distributed substantially uniformly over said striking surface and
being small enough to fit within the dimples of a golf ball,
whereby when said faceplate strikes a golf ball a substantial
number of said projections enter a corresponding substantial number
of dimples on a golf ball to enhance the spin characteristics of a
golf ball.
51. The golf club head of claim 50, wherein said projections have a
diameter of 0.08-0.12 inch.
52. The golf club head of claim 50, wherein said projections extend
from the main body of the faceplate 0.03-0.06 inch.
53. The golf club head of claim 51, wherein the spacing between
said projections is approximately 0.14 inch.
54. In a golf club for use in striking a golf ball having dimples
formed therein, said club having a head with a faceplate which
contacts the surface of a golf ball when a golf ball is driven, the
improvement comprising: a plurality of projections formed on said
faceplate and extending therefrom, said projections being
distributed in a substantially uniform pattern with their distal
ends forming a striking surface of said faceplate, said projections
being of a small enough size to fit within the dimples of a golf
ball, the projections at a top of said faceplate being larger in
diameter than those at a bottom of said faceplate, the diameter of
the projections gradually decreasing from the top to the bottom of
the faceplate.
55. The golf club head of claim 54, wherein said projections have a
diameter of 0.08-0.12 inch.
56. The golf club head of claim 54, wherein said projections are
cylindrical in shape.
57. The golf club head of claim 54, wherein said projections extend
from the main body of the faceplate 0.03-0.06 inch.
58. The golf club head of claim 54, wherein said projections extend
in a direction substantially normal to a plane parallel to the
striking surfaces of said faceplate.
59. A golf club comprising; a shaft; a grip on a first end of the
shaft; a golf club head on a second end of the shaft, comprising: a
main body defining a front face; a plurality of projections
extending from the front face, the ends of the projections defining
a plurality of individual contact surfaces for striking a golf
ball, wherein the plurality of projections prevent a golf ball from
contacting the front face thereby resulting in a decrease of the
golf ball general contact area.
Description
BACKGROUND OF THE INVENTION
[0001] The present application is a continuation-in-part of: (1)
U.S. patent application Ser. No. 08/984,466, filed Dec. 5, 1997,
which is a continuation-in-part of U.S. patent application Ser. No.
08/811,699, filed Mar. 5, 1997, which claims priority from U.S.
Provisional Patent Application Serial No. 60/013,012, filed Mar. 7,
1996; and (2) U.S. patent application Ser. No. 08/811,699, filed
Mar. 5, 1997, which claims priority from U.S. Provisional Patent
Application Serial No. 60/013,012, filed Mar. 7, 1996.
[0002] 1. Field of the Invention
[0003] The invention relates to a golf club head and, more
particularly, to a golf club head having a face with projections
extending outwardly therefrom for contacting a golf ball.
[0004] 2. Discussion of the Related Art and Summary of the
Invention
[0005] The faceplates or front faces of many golf club heads often
have striations or other protrusions which extend outward from a
base surface of the faceplate. Golf club manufacturers have used
the striations or protrusions to delineate the strike area of the
club head and to vary the friction between the strike face of the
club head and the golf ball and thereby cause the ball to spin at
impact.
[0006] The Applicant has determined that the use of protrusions on
the club strike face may also be used to vary the "feel" of the
club by varying the amount of contact area between the club head
and the golf ball at impact. The "feel" of the club generally
relates to the feeling that-the club confers to the player's hands
upon impact of the club head with the golf ball. By changing the
size and shape of the projections, the amount of contact area
between the club head and the golf ball may be reduced or enlarged.
In general, it is desirable to configure the protrusions such that
the ball only contacts the tips of the protrusions at impact,
rather than also contacting the base surface of the protrusions, so
that the amount of contact area between the golf ball and the club
is not overly increased.
[0007] Depending on the particular club type, however, the optimal
amount of contact area between the tips of the protrusions and the
golf ball may vary. For example, with certain clubs types, such as
woods and irons, it is generally desirable to increase the amount
of contact area, such as to enhance the level of friction between
the club head and the golf ball at impact. This may be
accomplished, for example, by using projections that are sized to
fit within the golf ball dimples at impact. However, the
projections of prior club heads are not configured to enter the
dimples of the golf ball and thus are limited in their contact area
to the smooth surfaces of the ball. As the dimples cover most of
the ball surface, the contact area with such prior art club head
faceplates is substantially limited. This limits the striking force
on the ball and lessens the driving distance accordingly. Also with
the faceplate of the club head only contacting the smooth surfaces
of the ball, there is a strong possibility of hitting a slice or
hook shot.
[0008] On the other hand, the desired amount of contact area
between the club face and the golf ball is different for putters
than for irons and woods, as putters are used in different
environments and with a different swinging style than irons and
woods. When putting a golf ball, golfers generally use a
pendulum-type motion with a putter head to strike a golf ball with
the front face of the putter head and propel the golf ball towards
a hole in the green. As the putter head strikes the golf ball, a
portion of the front face of the putter head contacts the golf ball
for a brief period of time and transfers the momentum of the putter
head to the golf ball. The amount of time that the putter head
remains in contact with the golf ball during the putting stroke is
referred to as the "dwell time."
[0009] Golf club manufacturers are attempting to create putters
that transfer sufficient momentum to the golf ball while also
providing an improved feel for the player. The feel of the putter
head is primarily a function of the spring constant (k) of the
putter face. The spring constant is generally determined by the
Young's modulus of the material, as well as the amount of surface
area on the putter face that actually contacts the ball during the
putting stroke.
[0010] To improve the feel of the putter, golf club manufacturers
are providing the putter head with soft plastic inserts that are
mounted on the face of the putter head. The plastic inserts are
mainly directed toward improving the feel of the putter through the
use of low modulus material. U.S. Pat. Nos. 4,928,965 and 5,575,472
are examples of golf putters having soft plastic face inserts. The
plastic inserts generally have a low Young's modulus to improve the
feel of the putter, but unfortunately also presents certain
disadvantages. In particular, plastic inserts have a tendency to
lower the sound when the club impacts the ball which causes a lack
of audio feedback to the player.
[0011] The Applicant has observed that the feel of the putter head
may be improved by lowering the spring constant of the putter head.
This can be accomplished by lowering the total area of the putter
face that contacts the ball during the putting stroke. That is, the
"contact area" of the putter face on the golf ball is reduced.
Desirably, while the contact area of the putter head is reduced to
improve feel, there is still maintained a sufficient amount of
contact between the putter face and the golf ball to retain
precision and control of the putt. This may be accomplished by
manufacturing the putter face with a unique structural design
comprising projections that extend outward from the putter face to
define a reduced contact area.
[0012] In the past, golf club manufacturers have provided
projections on the face of golf clubs to impart certain
characteristics to the ball upon impact. On the other hand, most of
these designs are directed to high impact clubs, such as the irons
and woods. For example, Japanese Patent No. 0023877 to Shirayanagi
discloses a golf club head having a face plate upon which a
plurality of small synthetic resin bumps are formed. The
Shirayanagi patent is directed toward a high impact club, rather
than a putter. The primary purpose of the face plate is to provide
high friction between the ball and the face of the club.
Additionally, the inclined orientation of the Shirayanagi face and
the bumps on the face promote the transfer of spin to the ball,
which is from above a certain level undesirable for a putter. The
bumps on the face are also small and resilient so that only a very
small deformation of the golf ball causes the ball to wrap around
the bumps and contact additional club face. The contact area of the
Shirayanagi club is thus not significantly reduced.
[0013] British Patent No. 4301 discloses a golf club head for an
iron-type club. The head includes hemispherical or conical
protuberances which are formed on the club face. The protuberances
produce a certain level of roughness to the head upon impact with a
golf ball. Unfortunately, this increases the amount of friction
between the club face and the ball, which results in ball spin and
would lead, if the protuberances were applied to a putter club, to
an unpredictable putt.
[0014] When projections have been used in connection with putters,
the projections unfortunately do not have the proper structure to
effectively improve the feel and control of a putter. For example,
U.S. Pat. No. 4,964,641 to Miesch et al. discloses a golf club with
a machined face. The face of the Miesch club includes a plurality
of contiguous pyramidal-shaped elements having sharp tips which
collectively form the contact face of the club. However, because
the tips of the pyramidal-shaped elements are sharp points, the
contact area of the Miesch golf club is extremely small, which
causes the ball trajectory to be less controllable. The lack of
sufficient contact area may also result in inconsistencies between
putting strokes, since the impact of the club upon the ball varies
significantly depending upon the location and the angle of the
putter face with the ball. Additionally, the sharp ends of the
pyramidal structures increase the friction between the club face
and the ball, which can result in the club conferring too much spin
to the ball so that the golf ball trajectories are unusual and
unpredictable. None of the above-described references provides a
putter head which improves the feel of the putter at impact while
also providing satisfactory levels of control and consistency when
putting a golf ball.
[0015] Thus, there is a need for a golf club that optimizes the
contact area between the strike face and the golf ball at impact.
The club desirably has protrusions that are configured to prevent
the ball from contacting the base surface of the club face at
impact. In the case of woods and irons, the club desirably
facilitates the control of the driving action of a golf club and
has a faceplate which engages a greater surface area of a golf
ball, such as through the use of striker projections which engage
the dimples of the club at impact. In the case of a putter, the
club head desirably provides improved feel by reducing the amount
of contact area at impact, while maintaining a sufficient level of
contact area so that control and precision of the putt does not
suffer.
[0016] The aforementioned needs are satisfied by the present
invention. One aspect of the invention relates to a club head
comprising a main body defining a strike portion sized to strike a
golf ball. The strike portion comprises a main surface and a
plurality of projections integrally formed with and extending
outward from the main surface. The projections are spaced apart and
define individual flat end surfaces for contacting the surface of a
golf ball. The flat end surfaces extend along a plane substantially
parallel to the main surface, wherein the projections are stiff
enough to prevent a golf ball from contacting the main surface when
the club head strikes the golf ball.
[0017] Desirably, the flat end surfaces collectively define an area
that is between 15%-45% of the area of the strike portion. The
density of the projections on the strike portion is desirably at
least 30 projections per square inch and the projections are
desirably uniformly distributed on the strike portion to form a
plurality of interlinked hexagonal patterns. In one embodiment,
each of the plurality of projections is separated from adjacent
other of the plurality of projections by a distance between 0.020
and 0.078 inches.
[0018] In one embodiment, the end surfaces of the projections are
desirably circular and have a diameter of approximately 0.020-0.078
inches. The projections desirably have a length of at least
approximately 0.010 inches and preferably approximately 0.010-0.045
inches. The projections desirably extend in a direction
substantially normal to a plane defined by the main surface of the
front face. In another embodiment, the end surfaces of the
projections each define an elliptical shape or a polygonal
shape.
[0019] Desirably, the club head defines a lower edge and an upper
edge, and the projections are uniformly spaced from the lower edge
to the upper edge. The end surfaces of the projections located
within a lateral region of the strike portion are desirably larger
than the end surfaces of the projections located within a central
region of the strike portion.
[0020] In another embodiment, the main body further comprises a
face insert sized to fit within a recess, wherein the projections
extend outward from the face insert. The front surface and the
projections may be integrally formed of a metallic material.
[0021] In another aspect of the invention, there is disclosed a
club head comprising a main body defining a front face. Desirably,
a plurality of projections extending from the front face, the ends
of the projections defining a plurality of individual contact
surfaces for striking a golf ball. The plurality of projections
prevent a golf ball from contacting the front face thereby
resulting in a decrease of the golf ball general contact area.
[0022] In yet another aspect of the invention, there is disclosed a
club head having projections which are distributed over the
striking surface of the faceplate and extend substantially normally
from a plane parallel to the striking surface. The distal ends of
the projections form a striking surface for driving a golf ball.
These projections are of a size which permits them to enter the
dimples of the golf ball. Thus, the striking surface includes not
only the smooth portions of the ball but also the surface area
covered by the dimples. This provides a substantially greater
contact surface between the club head and the ball. Further, the
striker projections which enter the dimples are frictionally
engaged by the dimple walls to make for a straighter shot. In
addition, this engagement tends to give the ball spin for a
controlled roll. In the case of sand irons, more lift can be
attained with differences in the sizes of the projections placed in
different positions on the face thereby contributing to more or
less loft, as may be desired.
[0023] In one embodiment, the striker projections are preferably
cylindrical or oval in configuration and preferably are smooth on
their tops. The size of the projections are preferably small enough
so that they can fit within most ball dimples. For durability the
projections are generally made solid but can be made hollow to save
weight. The projections are desirably dimensioned and positioned on
the faceplate to avoid damage to the ball and to as closely as
possible align with ball dimples.
[0024] In one embodiment, all of the clubs in a set employ the same
basic striker projection design which is directed to make for a
solid hit. It has been found that forged irons produce truer online
shots with a positive feel on impact. The long irons tend to give
straighter shots adding distance while the short irons tend to have
greater accuracy. The sand irons are afforded more lift and back
spin due to the action of the projections on the dimples.
Differences in the size of the projections on different portions of
the faceplate can contribute to differences in the amount of loft
and spin obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features of the invention will now be
described with reference to the drawings of a preferred embodiment,
which are intended to illustrate and not to limit the invention and
in which:
[0026] FIG. 1 is a side elevational view of a golf iron
incorporating the device of the invention;
[0027] FIG. 1A is a cross-sectional view taken along the plane
indicated by 1A-1A in FIG. 1;
[0028] FIG. 2 is a top perspective view of one embodiment of a
putter incorporating the device of the invention;
[0029] FIG. 3 is a top perspective view of a wood incorporating the
device of the invention;
[0030] FIG. 4 is a left side elevational view showing a golf iron
engaging a golf ball;
[0031] FIG. 5 is a side elevational view illustrating a second
embodiment of the invention incorporated in a golf iron; and
[0032] FIG. 5A is a cross-sectional view taken along the plane
indicated by 5A-5A in FIG. 5 FIG. 6 is a front view of another
embodiment of a putter head of the invention;
[0033] FIG. 7 is an enlarged view of the front face of the putter
head of FIG. 6;
[0034] FIG. 8 is a cross-sectional view of the putter head of FIG.
7 taken along line 8-8;
[0035] FIG. 9 is a cross-sectional view of another embodiment of a
putter head of the invention;
[0036] FIG. 10 is a cross-sectional view of yet another embodiment
of the putter head of the invention;
[0037] FIG. 11A is a cross-sectional view of another embodiment of
a putter head of the invention;
[0038] FIG. 11B is an enlarged view of the front of the putter head
of FIG. 6A;
[0039] FIG. 12 is an enlarged cross-sectional view of a projection
on the putter head of the invention;
[0040] FIG. 13 is an enlarged view of a second embodiment of a
projection;
[0041] FIG. 14 is an enlarged view of a projection used to form the
projection of FIG. 13;
[0042] FIG. 15 is an enlarged view of a plurality of projections
arranged in a predetermined pattern;
[0043] FIG. 16 is another enlarged view of the front face of a
putter head;
[0044] FIG. 17 is a perspective view of another embodiment of the
putter head of the present invention including an insert that
attaches to the putter head;
[0045] FIG. 18 is a perspective view of a golf club of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] Referring to FIGS. 1-4, one embodiment of the invention is
shown. The device of the invention is shown as incorporated into an
iron in FIGS. 1, 1A and 4, in a putter as shown in FIG. 2, and a
wood as shown FIG. 3. As will be appreciated by one of skill in the
art, one aspect of the invention is incorporating one of any of the
embodiments of the golf club heads described herein into a golf
club having a shaft and a grip, as shown in FIG. 18.
[0047] A plurality of rigid projections 14 are distributed in a
substantially uniform pattern with their distal ends forming the
striking surface of each faceplate 11. The striking surface 11A of
the putter shown in FIG. 2 is indented. In the case of a wood or an
iron, the projections 14 preferably have rounded ends which can fit
into the dimples 16 of a golf ball, as shown in FIG. 4. In one
embodiment, the projections extend between 0.06 and 0.03 of an inch
from the main body of the faceplate and the spacing between
adjacent projections is typically 0.14 of an inch. In the
embodiments shown in FIGS. 1-4, the projections extend in a
direction substantially normal to a plane parallel to the striking
surface formed by the projections. The projections may be placed on
the surface of the faceplate by forming them in the mold from which
the faceplate is forged.
[0048] As previously noted, the projections preferably enter into
the dimples and provide both a greater contact surface and a
frictional engagement with the ball for woods and irons.
[0049] Referring now to FIGS. 5 and 5A, another embodiment of the
invention is shown. This embodiment incorporates the device of the
invention into an iron such as a wedge wherein the projections all
will fit within the dimples of the golf ball but vary in size going
from the top to the bottom of the faceplate. In one embodiment, the
projections on the top of the faceplate are about 0.12" in diameter
while those at the bottom of the faceplate are about 0.08" in
diameter. Preferably, the projections gradually decrease in
diameter between these dimensions in going from the top to the
bottom of the faceplate.
[0050] In one embodiment, the projections extend from the main body
of the faceplate between 0.06" for the largest projections and
0.03" for the smallest projections. The space between the
projections is preferably 0.14". The projections in this embodiment
may be formed in the same manner as for the first embodiment, i.e.,
by forming them in the mold from which the faceplate is forged. The
use of smaller projections near the bottom of the faceplate
contributes to greater loft. Back spin is also given the ball which
tends to make the ball stop rolling.
[0051] FIGS. 6-17 show a preferred embodiment of a putter head 30
which is used to putt a golf ball (not shown) toward a hole on a
putting green (not shown). FIG. 6 is a front view of the putter
head 30 of the present invention. The putter head 30 generally
comprises an elongated main body 32 having a neck 34 which extends
upwardly from the main body 32. The neck 34 allows the putter head
30 to be connected to a golf club shaft (not shown) in a well known
manner.
[0052] FIG. 7 is an enlarged view of a portion of a front 35 of the
putter head 30. FIG. 8 is a cross-sectional side view of the putter
head 30 along line 8-8 of FIG. 7. The main body 32 defines a bottom
or sole surface 40, a top surface 42 opposed to the bottom surface
40, and a rear surface 44 opposed to the front 35 of the putter
head 30. The front 35 of the putter head defines a lower edge 46
and an upper edge 50. The lower edge 46 extends in a substantially
horizontal direction and connects the front 35 of the putter head
30 to the sole surface 40. The upper edge 50 extends substantially
parallel to the lower edge 46 and connects the front 35 to the top
surface 42. The front 35 of the putter head 30 also defines a pair
of opposed side edges 51 and 53 (FIG. 6).
[0053] With reference to FIG. 7, the front 35 of the putter head 30
is generally divided into a peripheral portion 52 and a strike
portion 54. The peripheral portion 52 is bounded by the edges 46,
50, 51, and 53 (FIG. 6) and defines a substantially planar
peripheral surface 37. The peripheral portion 52 surrounds the
strike portion 54 of the front 35 of the putter head 30. The strike
portion 54 is the region of the putter head 30 that is adapted to
impact a golf ball during a putt.
[0054] The strike portion 54 of the front 35 of the putter head 30
defines a main or front surface 36, from which a plurality of
projections 56 extend outwardly, as described more fully below. The
strike portion 54 desirably has a shape that conforms to the
desired general strike location of a golf ball with the putter head
30, but may also define various other shapes. The strike portion 54
may comprise only a central region of the front 35 of the putter
head 30, or alternatively, the strike portion 54 may comprise the
entire front 35 of the putter head 30 so that the peripheral
portion 52 is either minimized or eliminated. If the putter head 30
has a peripheral portion 52, the strike portion 54 will generally
have visual indicia to distinguish itself from the peripheral
portion 52, such as a border, recess, or simply the projections 56
themselves.
[0055] In the embodiment shown in FIG. 8, the front face 36 of the
strike portion 54 is co-planar with the peripheral surface 37 of
the peripheral portion 52 the putter head 30. In another embodiment
shown in FIG. 9, at least a portion of the front face 36 of the
strike portion 54 may be slightly raised with respect to the
peripheral surface 37. In yet another embodiment, the front face 36
may be recessed with respect to the peripheral surface 37, as shown
in FIG. 10.
[0056] As mentioned, the plurality of projections 56 extend
outwardly from the front surface 36 defined by the strike portion
54 of the putter head 30. As shown in FIG. 8, the projections 56
each have a first end 57 that is desirably integrally formed with
the front face 36, and a second end 58 that is outwardly spaced
from the front face 36. Each projection has a length L, defined as
the distance between the first end 57 and the second end 58 of the
projection 56. The first end 57 of the projection 56 is defined as
the location on the projection where the projection 56 joins the
front face 36 on at least one side of the projection 56.
[0057] The second end 58 of each of the projections 56 defines a
substantially flat strike surface or end surface 59. The end
surfaces 59 of the projections collectively form the contact or
strike face of the putter head 30 when the putter head 30 strikes a
golf ball, as described in more detail below. Preferably, the end
surfaces 59 collectively define a strike plane 61 that is
substantially parallel to the front face 36.
[0058] In the embodiments shown in FIGS. 8 and 9, the projections
56 extend outwardly so that the end surfaces 59 of the projections
56 are spaced outward with respect to the peripheral surface 37.
That is, the strike plane 61 defined by the end surfaces 59 of the
projections 56 is spaced outward from a plane defined by the
peripheral surface 37. The projections 56 are thus visible looking
downward at the putter head 30 from the player's perspective.
Alternatively, if the front face 36 is recessed, the length L of
the projections 56 may be selected such that the strike plane 61 is
co-planar with the peripheral surface 37, as shown in FIG. 10.
Accordingly, looking downward toward the putter head 30, the
projections 56 will appear hidden from the player perspective so as
to be less distracting during a shot.
[0059] As shown in FIG. 11A, the depth of the front face 36
relative to the end surfaces 59 of the projections 56 may vary
across the strike portion 54 so that the entire front face 36 is
not coplanar. FIG. 11B is an enlarged view of the front 35 of the
putter head 30. As shown, the length L of each projection 56 is
equal to the length of the shorter side of the projection 56.
[0060] The projections 56 preferably have a length L that is
desirably at least approximately 0.010 inches and is preferably
between approximately 0.010 and 0.045 inches. As shown in FIG. 7,
the projections are preferably spaced uniformly moving from the
vicinity of the lower edge 46 of the front face 36 toward the
vicinity of the upper edge 50 of the front face 36 so as to
eliminate the possibility of a golf ball hitting the lower edge 46.
Additionally, the projections 56 are preferably arranged in a
predetermined pattern, as described in more detail below.
[0061] FIG. 12 is an enlarged cross-sectional view of one
embodiment of a single projection 56. In this embodiment, the
projection 56 comprises a cylindrically shaped structure having a
substantially uniform thickness moving along the length L. The end
surface 59 of the projection 56 is substantially flat and merges
with side surfaces 60 of the projection 56 through a rounded
connecting surface 63 having a radius R. The rounded connecting
surface 63 eliminates a sharp edge between the end surface 59 and
the side surfaces 60 of the projection 56. The rounded connecting
surfaces 63 may be formed using any of a wide variety of
manufacturing methods, such as, for example, sandblasting.
[0062] The radius R of the rounded connecting surface 63 is
desirably selected to improve the putting characteristics of the
putter head 30. For example, the radius R may be selected so that a
golf ball that impacts the end surfaces 59 over any of a wide range
of impact angles will consistently rebound off the end surfaces 59
in a desired direction. A sharp edge between the end surfaces 59
and the side surfaces 60 of the projections 56 may cause a golf
ball to rebound off the putter head 30 at wider angles so that the
ball travels widely to the left or right of the desired target.
Desirably, the radius R of the rounded connecting surface 63 is at
least 0.0001 inches, and preferably between 0.005-0.012 inches.
[0063] FIG. 13 shows a second embodiment of a projection, referred
to as projection 56a. In this embodiment, the side surfaces 60 of
the projection 56a are curved or rounded. The end surface 59 of the
projection 56a is substantially flat so that the projection 56a has
a truncated hemispherical shape. With reference to FIG. 14, the
projection 56a may be formed by first forming a
hemispherical-shaped projection 56a using a well-known
manufacturing method, such as, for example, die casting, injection
molding, forging, etc. The projection 56a is then subjected to a
finishing operation in which the second end 58a of the projection
56a is ground to form the flat end surface 59, as shown by the
dashed line.
[0064] The sizes and shapes of the projections 56 may be varied
across the front face 36 of the putter head 30. Additionally, the
flat end surfaces 59 of the projections 56 30 may define any of a
wide variety of shapes, such as circles, ellipses, or any of a wide
variety of polygons, such as, triangles, quadrilaterals, pentagons,
hexagons, etc. Preferably, the projections 56 all have the same
length L so as to ensure a consistent feel resulting from a
symmetrical contacting of the ball by the projection pattern.
[0065] As shown in FIGS. 7 and 15, the projections 56 preferably
define a series of predetermined uniform patterns across the front
35 of the putter head 30. FIG. 15 is an enlarged view of a group of
projections 56 arranged in a desired pattern. Specifically, the
projections 56 collectively form interlinked hexagonal patterns,
wherein the hexagons have a radius R. Within each of the hexagonal
patterns, the projections 56 are separated by a horizontal distance
S, which is preferably between 0.020 and 0.078 inches.
Additionally, each projection 56 has a diameter D which is
preferably between 0.020 and 0.078 inches. The spacing S is
desirably smaller than the size of the dimples on a golf ball to
prevent the projections 56 from entering the dimples when the
putter head 30 strikes the golf ball.
[0066] Desirably, the number of projections 56 within a given area
of the front 35 of the putter head 30, or the density n of the
projections, is maintained within a certain level. Preferably, the
density n of the projections 56 is at least 30 projections per
square inch. The density (n) of the projections 56 in the
interlinked hexagonal pattern may desirably be calculated by using
the following formula:
n=(2.times.{square root}{square root over
(3/3)}).times.1/(S+D).sup.2)
[0067] The putter head 30 is used to propel a golf ball toward a
hole by striking the golf ball with the strike face that is
collectively formed by the end surfaces 59 of the projections 56.
Desirably, the end surfaces 59 of the projections are the only
portion of the putter head 30 to contact the golf ball during the
putting stroke. Because the combined surface area of the end
surfaces 59 comprise only a percentage of the area of the entire
front 35 of the putter head 30, the total area of the putter head
30 that actually contacts or strikes the golf ball is
advantageously reduced. The projections 56 thus improve the feel of
the putter head 30 when striking a golf ball. However, although the
contact area is reduced, the flat end surfaces 59 of the
projections 56 still provide sufficient contact area between the
ball and the putter head 30 so that control of the golf ball is not
adversely affected.
[0068] Preferably, the combined surface area of the flat end
surfaces 59 of the projections 56 is between 15 to 45 percent of
the surface area of the strike portion 54 of the front face 36. In
general, the more the contact area of the putter head 30 is
reduced, the lower the spring constant of the front face 36 and the
softer the putter head 30 feels upon impact with a golf ball. It
has been noticed that the dwell time, or the amount of time that
the, putter head 30 remains in contact with the ball at impact,
tends to increase as the amount of contact surface of the putter
head 30 with the ball is reduced. The reason is that the reduction
of contact area results in a concentration of stress on the surface
of the ball. The concentration of stress causes the ball to -deform
more upon impact and therefore to stay more in contact with the
face. A longer dwell time provides improved control of the golf
ball and a more precise putting shot.
[0069] In a preferred embodiment, the projections 56 are stiff
enough and long enough to prevent a golf ball from contacting the
front face 36 when the putter head 30 strikes the golf ball at
normal putting speeds. The stiffness, or the resistance to
deflection upon impact, of the projections 56 thus contributes to
the improved feel of the putter head 30. Nonetheless, the
projections 56 may still have a certain degree of controlled
deflection. According to the USGA rules, the hardness of the
material constituting the projections should not be lower than 95
shore A.
[0070] As shown in FIG. 16, the size or surface area of each of the
end surfaces 59 of the projections 56 may be varied across the
strike portion 54. For example, at lateral ends 66 and 68 of the
strike portion 54, the flat end surfaces 59 of the projections 56
may be larger than the flat end surfaces 59 of the projections 56
located within a central region 70 of the strike portion 54. Such a
configuration desirably increases the area of the strike face
defined by the end surfaces 59 of the projection 56 located in the
lateral ends 66, 68 of the strike portion 54. This design results
in an enhanced distribution of energy transference to the golf ball
when struck by the putter head 30, even when the putter head 30 is
hit off-center, or near the lateral ends 66, 68 of the strike
portion 54. This compensates for the loss of energy that typically
results from off-centered hits on the front face of prior putter
heads. The increased surface area of the end surfaces 59 at the
lateral ends 66, 68 provides for a stiffer feel than in the central
region 70, where the end surfaces 59 are smaller.
[0071] FIG. 17 illustrates an alternative embodiment of the putter
head 30, which includes a face insert 74 that is sized and shaped
to fit within a recess 76 in the front 35 of the elongated body 32.
The face insert 74 comprises a plate-like structure that defines
the strike portion 54. A plurality of projections 56 extend
outwardly from the face insert 74, as described above with respect
to the previous embodiment. In use, the face insert 74 is
positioned within the recess 76 of the club head 30 and attached
thereto. The face insert 74 may be attached to the main body 32
using any suitable means, such as mechanical bonding, adhesive
bonding, welding, brazing, etc.
[0072] The face insert 74 may advantageously be formed of a
material having a lower Young's modulus than the main body 32. The
face insert 74 may be formed either from a metallic or from a
polymeric material. A metallic material for the face insert 74
provides the putter head 30 with a more solid feel at impact with a
golf ball, whereas a polymeric material, such as plastic or rubber,
provides a softer feel than a metallic face insert 74. The face
insert 74 may be manufactured of the same material as the main body
32 or it may be manufactured of a different material to vary the
characteristics of the putter head 30. For example, the face insert
74 may be manufactured of plastic for promoting a soft feel at
impact, and the main body 32 may be manufactured of a high density
material, such as brass, copper, lead, etc., which provides
improved mass distribution.
[0073] The putter head 30 of the present invention provides an
increase in dwell time and a decrease in the rebound of the putter
head 30 at impact with a golf ball. The rebound generally relates
to the tendency of the golf ball to bounce off the club head. In an
experimental test, performance characteristics of the putter head
30, such as rebound, dwell-time, and acceleration of the golf ball,
were measured. The experiment consisted of testing seven putters
including (1) a standard NC2 Taylor Made Putter, (2) an Odyssey
DF660, (3) a Titleist Cameron putter with a Teryllium insert
(copper alloy insert), (4) a Ping Isopur with a urethane insert,
(5) a steel putter head 30 of the invention with 20% contact area
(with respect to the front surface 36), (6) a steel putter head 30
of the invention with 30% contact area, and (7) a putter head 30 of
the invention with 30% contact area and a urethane insert of 95
shore A. Each of the putters were standardized with respect to
loft, lie, head mass, shaft length, and swing weight.
[0074] The testing method consisted of using a putting pendulum to
strike a golf ball, as is known in the art. An accelerometer was
attached to each of the putter heads to measure the impact force
and dwell time. An indoor artificial putting surface was used
primarily for consistency and to eliminate environmental variances.
The putting pendulum was calibrated for an approximate 100 inch
putt. The distance, peak force, and dwell time were recorded after
impact with the putters.
[0075] A rebound measurement is typically measured as a percentage
with respect to a standard putter. In the current experiment, the
NC2 Taylor Made putter was used as the standard putter based on the
uniform steel face of the NC2 putter. The rebound was calculated
using the following equation:
% Rebound=(distance of ball with putter .times.)(distance of ball
with NC2 putter).times.100
[0076] The peak force measurements relate to the maximum force
induced into the putter during impact with the golf ball. It is
assumed that a higher peak force value results in a greater shock
being transferred to the player's hands. For each putter, the
measurements were performed 10 times and averages were calculated
for more consistency. The results are reported in the following
table:
1 REFERENCE INVENTION (1) (2) (3) (4) (5) (6) (7) Rebound 104.5
101.0 102.9 113.9 98.6 100.5 95.0 (in.) Dwell Time 848 874 890 916
956 950 1139 (in .mu.sec.) Peak Accel. 0.054 N/A* 0.0516 N/A*
0.0458 0.050 N/A* (in g) *Not available
[0077] As shown, the dwell time increases significantly for the
putter head 30 of the present invention with respect to the other
putters. Additionally, the rebound and peak acceleration both
decreased for the putter head 30, which indicates that the putter
head 30 provides a user with an improved feel at impact.
[0078] The projections 56 of the putter head 30 thus improve the
feel of the putter head 30 with respect to prior putters. The
reduced contact area provided by the end surfaces 59 of the
projections 56 lowers the spring constant of the putter head 30 to
provide a softer feel. However, the flat end surfaces 59 still
provide sufficient contact area with a golf ball to provide the
putter head 30 with control and consistency in putting a golf ball.
Additionally, the projections 56 provide the putter head 30 with an
increased dwell time and a reduction in rebound and impact force to
further improve the feel of the putter head 30.
[0079] Although the foregoing description of the invention has
shown, described and pointed out fundamental novel features of the
invention, it will be understood that various omissions,
substitutions, and changes in the form of the detail of the
apparatus and method as illustrated and described, as well as the
uses thereof, may be made by those skilled in the art without
departing from the spirit of the present invention. Consequently,
the scope of the invention should not be limited to the foregoing
discussion, but should be defined by the appended claims.
* * * * *