U.S. patent application number 09/769205 was filed with the patent office on 2001-06-28 for three-piece wound golf ball.
This patent application is currently assigned to SPALDING SPORTS WORLDWIDE, INC.. Invention is credited to Cahill, Daniel J., Dougan, Quintus E..
Application Number | 20010005697 09/769205 |
Document ID | / |
Family ID | 25273898 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010005697 |
Kind Code |
A1 |
Dougan, Quintus E. ; et
al. |
June 28, 2001 |
Three-piece wound golf ball
Abstract
A three-piece thread wound golf ball including a central solid
core portion having increased diameter of 1.35-1.50 inch (34.3-38.1
mm) and specific gravity of 1.20-1.25, a thread-wound intermediate
portion, having diameter of 1.54-1.60 inches, and an outer dimpled
cover portion which construction provides desirable increased
moment of inertia and spin characteristics for the ball. The
resulting golf ball characteristics are such that when hit with a
Driver, other woods or the longer iron club it performs like a
distance two-piece golf ball, when hit with mid-iron clubs it
performs like a two-piece Hi-spin golf ball and soft covered multi
layered balls, and when it is struck with short iron clubs it
performs much like a Balata wound golf ball.
Inventors: |
Dougan, Quintus E.;
(Westminster, SC) ; Cahill, Daniel J.; (Fairview
Park, OH) |
Correspondence
Address: |
SPALDING SPORTS WORLDWIDE INC
425 MEADOW STREET
PO BOX 901
CHICOPEE
MA
01021-0901
US
|
Assignee: |
SPALDING SPORTS WORLDWIDE,
INC.
|
Family ID: |
25273898 |
Appl. No.: |
09/769205 |
Filed: |
January 24, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09769205 |
Jan 24, 2001 |
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09103061 |
Jun 23, 1998 |
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6179729 |
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09103061 |
Jun 23, 1998 |
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08837234 |
Apr 10, 1997 |
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5827167 |
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Current U.S.
Class: |
473/357 ;
473/365 |
Current CPC
Class: |
A63B 37/0083 20130101;
A63B 37/0004 20130101; A63B 37/0064 20130101; A63B 37/0069
20130101; A63B 37/0035 20130101; Y10S 273/10 20130101; A63B 37/0066
20130101; A63B 37/008 20130101; Y10S 273/20 20130101; A63B 37/0039
20130101; A63B 37/0054 20130101; A63B 37/0075 20130101; A63B
37/0096 20130101; A63B 37/0074 20130101; A63B 37/0017 20130101;
A63B 37/0082 20130101; A63B 37/0003 20130101; A63B 37/0021
20130101; A63B 37/0037 20130101; A63B 37/0062 20130101; Y10S 273/22
20130101; A63B 2037/087 20130101 |
Class at
Publication: |
473/357 ;
473/365 |
International
Class: |
A63B 037/06 |
Claims
We claim:
1. A three-piece wound golf ball having improved characteristics of
moment of inertia, initial spin and total flight distance with
minimal dispersion, the ball comprising: a solid center core
portion which is substantially spherical, is composed mainly of
polybutadiene having a core diameter of 1.35-1.50 inches (34.3-38.1
mm), a specific gravity of 1.23-1.24, a Shore D durometer hardness
of 55-75 and a compression of 59-75 on an Atti compression tester;
an intermediate thread-wound portion wound with an elastomeric
thread material upon said core portion to a diameter of 1.540-1.600
inches (39.1-40.6 mm); and a cover portion formed of a
thermoplastic material having a density of 1.00-1.04 g/cm.sup.3, a
flexural modulus of 5,000-10,000 psi, and a Shore D durometer
hardness of 55-65, said cover having multiple dimples provided
therein; the ball having an outside diameter of 1.680-1.688 inch
(42.7-42.9 mm), a weight of 44.5 to 45.9 grams, a density of
1.090-1.118 g/cm.sup.3, and an Atti compression reading of 85 +/-
15 points.
2. The golf ball according to claim 1, wherein the core material is
homogenous and comprises by weight 58-61% polybutadiene mixed with
15-18% zinc diacrylate and 20-24% zinc oxide.
3. The golf ball according to claim 1, wherein the core diameter is
1.400-1.450 inch (35.6-36.8 mm).
4. The golf ball according to claim 1, wherein the ratio of core
diameter expressed in inches to the core specific gravity is in a
range of 0.9/1-1.3/1.
5. The golf ball according to claim 1, wherein the intermediate
thread-wound portion has an outer diameter of 1.56-1.58 inch
(39.6-40.1 mm).
6. The golf ball according to claim 1, wherein the cover
formulation comprises by weight 25% +/- 15% of a first sodium
ionomer, 69% +/- 5% of a zinc ionomer, and about 6% of a second
sodium ionomer in combination with titanium dioxide.
7. The golf ball according to claim 1, wherein the cover
formulation comprises by weight 50% +/- 5% of a first sodium
ionomer, 44% +/- 5% of a zinc ionomer and about 6% of a second
sodium ionomer in combination with titanium dioxide.
8. The golf ball according to claim 1, wherein the ball initial
spin rate after being struck by a No. 3 iron club exceeds the
initial spin rate after being struck by a No. 1 driver club by a
spin ratio of at least about 1.80/1.
9. The golf ball according to claim 1, wherein the ball initial
spin rate after being struck by a No. 6 iron club exceeds the
initial spin rate after being struck by a No. 1 driver club by a
spin ratio of at least about 2.30/1.
10. The golf ball according to claim 1, wherein the ball initial
spin rate after being struck by a No. 9 iron club exceeds the
initial spin rate after being struck by a No. 1 driver club by a
spin ratio of at least about 3.0/1.
11. A three-piece wound golf ball having improved characteristics
of moment of inertia, initial spin and total flight distance with
minimal dispersion, the ball comprising: a solid center core
portion which is substantially spherical, is composed mainly of
polybutadiene having a core diameter of 1.40-1.45 inches,
(35.6-36.8 mm), a specific gravity of 1.23-1.24, and a Shore D
durometer hardness of 55-75; the ratio of core diameter expressed
in inches to the core specific gravity being in a range of
0.9/1-1.3/1; and a compression of 59-75 on an Atti compression
tester; an intermediate thread-wound portion wound with an
elastomeric thread upon said core portion to a diameter of
1.560-1.580 inches (39.6-40.1 mm); and a cover portion formed of a
thermoplastic material having a density of 1.00-1.04 g/cm.sup.3, a
flexural modulus of 5,000-10,000 psi, and a Shore D durometer
hardness of 55-65, said cover having multiple dimples provided
therein; the ball having an outside diameter of 1.680-1.688 inch
(42.7-42.9 mm), a weight of 44.5 to 45.9 grams, a density of
1.090-1.118 g/cm.sup.3, and an Atti compression reading of 85 +/-
15 points.
12. The golf ball according to claim 1, wherein said dimples occupy
70-80% of the surface area of the ball.
13. The golf ball according to claim 12, wherein said dimples have
a total volume of 400-500 mm.sup.3.
14. The golf ball according to claim 11, wherein said dimples
occupy 70-80% of the surface area of the ball.
15. The golf ball according to claim 14, wherein said dimples have
a total volume of 400-500 mm.sup.3.
Description
RELATED APPLICATION
[0001] This application is a continuation of pending U.S. patent
application Ser. No. 08/837,234 filed Apr. 10, 1997 and entitled
THREE-PIECE WOUND GOLF BALL which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] This invention pertains to an improved three-piece wound
golf ball construction including a solid center core, an
intermediate thread wound layer, and an outer cover piece. It
pertains particularly to such a wound golf ball in which the core
has larger diameter and decreased specific gravity so as to provide
increased moment of inertia, spin rate and improved trajectory
distance after being hit by any of various golf clubs.
[0003] Conventional known golf balls have either two-piece
construction consisting of a center core and an outer cover with
multiple dimples provided on its outer surface, or have three-piece
construction consisting of a center core, an intermediate portion
which may be solid or have elastomeric thread winding, and a solid
dimpled cover. The cores are usually made of natural or synthetic
rubber and may be either solid or have a liquid/paste form. The
cover material is usually Balata or an ionomer in combination with
a suitable filler material. Variations in the chemical or physical
properties of the ball materials or their physical orientation can
bring about changes in the golf ball characteristics, such as feel,
flight distance, rebound coefficient, durability, moment of
inertia, spin etc. as has been generally described in various prior
art patents.
[0004] For example, U.S. Pat. No. 4,076,255 to Moore et al
discloses a three-piece golf ball having a solid core formed from a
cured composition comprising polybutadiene having a high
cis-content, and a monomer capable of grafting, cross-linking or
chain-extending the elastomer. The core having a Shore C hardness
of 60-80 is wound with a conventional elastic thread and covered
with a molded cover, but the core diameter is not disclosed.
[0005] U.S. Pat. No. 4,625,964 to Yamada discloses a three-piece
solid golf ball having a core formed of polybutadiene with a
specific gravity of at least 1.50 and a diameter not exceeding 32
mm (1.26 inch). The ball intermediate layer has a specific gravity
lower than that of the core and thickness of 3.2-5.4 mm, and the
cover has a thickness of 1-3 mm and a Shore D hardness not
exceeding 64.
[0006] U.S. Pat. No. 4,696,475 to Tomita et al discloses a
three-piece thread-wound golf ball having improved impact
resiliency and increased flight distance. The core rubber and/or
the winding thread contains more than 30% by weight of an
isoprene-butadiene random copolymer and has core diameter of 28-30
mm (1.10-1.18 inch).
[0007] U.S. Pat. No. 4,714,253 to Nakahara et al, discloses a
three-piece solid golf ball having controlled diameters, specific
gravities, and hardnesses of the central core and intermediate
solid layer. The central core has a diameter of 20 to 32 mm
(0.79-1.26 inch), specific gravity of 1.03 to 1.25, and a Shore C
hardness of 57 to 80. The solid intermediate layer has 36-40 mm.
diameter, specific gravity of 1.30-2.50 and Shore C hardness of
70-83, but it does not have a thread winding.
[0008] U.S. Pat. No. 5,397,129 to Kato et al discloses a
three-piece thread-wound golf ball having a solid rubber core of 23
to 34 mm (0.91-1.34 inch) diameter. Various rubber types may be
used for the core, the intermediate winding thread, and the molded
cover, material including butadiene and natural rubbers.
[0009] U.S. Pat. No. 5,445,387 to Maruko et al discloses a
three-piece thread-wound golf ball having a solid center of high
cis-polybutadiene, a conventional thread-wound intermediate rubber
layer, and a cover. The core hardness is continuously increased
from its center to its outer surface. The solid core diameter is
26-31 mm (1.02-1.22 inch), the intermediate layer is 39-41 mm
diameter, and ball diameter is 42.5-45 mm (1.67-1.77 inch).
[0010] Also, U.S. Pat. No. 5,553,852 to Higuchi et al discloses a
three-piece solid golf ball having a center core of 29-37 mm
(1.14-1.46 inch) diameter, hardness of 45-80 JIS C and a specific
gravity of 1.05-1.4 but greater than that of the solid intermediate
layer which has thickness of 1-3.5 mm (0.039-0.138 inch) and
specific gravity of 0.9-1.2. The cover has 1-3 mm (0.039-0.118
inch) thickness and is softer than the intermediate layer.
[0011] Although golf balls having various constructions and
characteristics are known, important deficiencies have been found
by players to exist in these known golf ball constructions and
flight characteristics. Specifically, the two-piece golf balls are
far inferior in the controllability that is required when a shot is
made with the middle iron or short iron clubs. In addition, a
two-piece golf ball provides a poor shot feeling to the player.
Known three-piece Balata golf balls exhibit spin rates that are too
great for good flight distance when hit with a Driver and long iron
clubs. Thus, desirable improvements in golf ball construction and
spin characteristics, all achieved at reduced ball manufacturing
costs, have been sought.
SUMMARY OF THE INVENTION
[0012] This invention provides an improved solid three-piece golf
ball construction having a desirable combination of
characteristics, and which exhibits various desirable and
advantageous flight characteristics depending upon the type of golf
club with which it is struck. Specifically, when the present ball
is hit with a driver, other woods or longer iron club, it desirably
performs much like a distance two-piece golf ball; when hit with a
mid-iron club, it performs much like a two-piece Hi-spin golf ball
and soft covered multi-layered ball; and when hit with a short iron
or putter, the ball performs much like a three-piece liquid core
Balata wound golf ball.
[0013] These desired flight characteristics for the spherical
three-piece wound golf ball of this invention are achieved by
providing a ball having a central solid homogeneous core which is
substantially spherical and has a significantly increased diameter
of 1.350-1.500 inch (34.3-38.1 mm), and preferably has 1.400-1.450
inch (35.6-36.8 mm) core diameter. The solid core is composed
mainly of polybutadiene having some desirable additives, and has a
specific gravity of 1.20-1.25 and a Shore D durometer hardness of
55-75, and a compression of 59-75 on a Atti compression tester.
Suitable broad and preferred ranges for the chemical compositions
for the golf ball core are provided in Table 1 below.
1TABLE 1 Chemical Composition Ranges for Ball Solid Core, wt. %
Broad Preferred Polybutadiene 58-61 59-60 Zinc Diacrylate 15-18
16-17 Zinc Oxide 20-24 21-23 Dicumyl Peroxide 0.7-0.9 0.75-0.85
Peroxide Crosslinking 0.6-0.8 0.65-0.75 Antioxidant 0.2-0.4
0.25-0.35 Magnesium Stearate 0-0.4 0.2-0.35 TOTALS 100 100
[0014] The ball core diameter is significantly larger and the core
specific gravity is significantly lower than that for three-piece
solid core wound golf balls which are normally available on the
market at the present time. Accordingly, the ratio of the ball
solid core diameter or volume to its specific gravity is
significantly greater than for other known golf balls.
Specifically, for the ball diameter expressed in inches, this ratio
should be in a broad range of 0.9/1-1.30/1, and preferably should
be 1.0/1-1.25/1. The larger solid core diameter and its lower
specific gravity, in combination with the thread type for the
thread-wound intermediate layer and the outer solid cover material
and thickness, results in a significant desirable transfer of the
ball weight and moment of inertia towards its peripheral portion.
Consequently, there is a desirable increase in the total moment of
inertia for the ball, which results in a corresponding increase in
the initial relative spin rate of the ball after being hit with
various golf clubs, as compared to other known golf balls.
[0015] According to the present invention, the ball solid central
core portion having 1.35-1.50 inch (34.3-38.1 mm) diameter is
thread wound to a diameter of 1.540-1.600 inch (39.1-40.6 mm) and
preferably to 1.560-1.580 inch (39.6-40.1 mm) diameter. The winding
thread is a high velocity elastomeric thread material used to
provide a wound intermediate portion. The thread winding material
consists of blended natural and synthetic rubber having an
elongation of about 800-1,000%, tensile strength of about
4,000-5,000 psi, and a rectangular cross-section dimension of
0.0625 (+/- 0.002) inches.times.0.024 (+/- 0.006) inches. The ball
cover layer or portion consists of a solid thermoplastic material
having a density of 1.00-1.04 g/cm.sup.3, a flexural modulus of
5,000-10,000 psi, and a Shore D durometer hardness of 55-65. The
surface of the cover portion has many small shallow dimples
occupying 70-80% of the ball surface area, the dimples having a
total volume of 400-500 mm.sup.3. The finished golf ball has an
outer diameter of 1.680-1.688 inches (42.7-42.9 mm), a weight of
44.5-45.9 gr, a density of 1.090-1.113 g/cm.sup.3, and an Atti
compression reading of 85 +/- 15 points.
[0016] One useful material blend for the golf ball cover portion
contains by weight 25% +/-5% by weight of a sodium ionomer (Dupont
Surlyn 8140), 69% +/- 5% of a zinc ionomer (Dupont Surlyn 9320) and
6% of a sodium ionomer (Dupont Surlyn 8660) in combination with 58%
titanium dioxide. Another useful blend for the ball cover contains
by weight 50% +/- 5% of a sodium ionomer (Dupont Surlyn 8140), 44%
+/- 5% of a zinc ionomer (Dupont Surlyn 9320), and 6% of a sodium
ionomer (Dupont Surlyn 8660) in combination with 58% titanium
dioxide.
[0017] This invention advantageously provides a three-piece wound
golf ball having a solid center core of increased core diameter and
reduced specific gravity and an elastomeric thread wound
intermediate portion, which results in a desirable increased moment
of inertia and spin characteristic for the ball during flight after
being struck by a selected golf club. The ball thereby provides an
overall desirable combination of characteristics for use under a
wide range of playing conditions.
[0018] Another advantage of this invention is that three-piece golf
balls are usually made with a small diameter center of only about
1.0-1.06 inch diameter, which is typically either a lively rubber
ball or a liquid-filled hollow sphere. During ball manufacture,
these centers must be frozen and a considerable amount of thread
must be wound onto the center to bring it up to an established
diameter. But for the present invention, the ball manufacturing
costs are reduced by cost of the medium used to freeze the centers.
Furthermore, because the center is larger in diameter, the amount
and cost of the winding thread being applied to the center core and
the time needed to wind it to the established size are both
desirably reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0019] This invention will now be described further with reference
to the following drawings, in which:
[0020] FIGS. 1 and 2 each show a cross-sectional view of a
conventional two-piece high spin golf ball and a conventional
three-piece golf ball having a liquid center, respectively;
[0021] FIG. 3 shows a cross-sectional view of an improved
three-piece golf ball having larger solid center core and a thread
wound intermediate layer all constructed according to the present
invention; and
[0022] FIG. 4 shows golf ball comparative initial spin rates after
being struck by the various numbered standard golf clubs.
DESCRIPTION OF THE INVENTION
[0023] As shown by FIG. 1, a conventional two-piece golf ball 10
includes a solid core 11 and an outer molded cover 12, but without
an intermediate layer or portion. The conventional three-piece golf
ball 14, as shown by FIG. 2, includes a liquid core center 15, a
thread wound intermediate layer 16, and an outer molded cover
18.
[0024] The present invention is directed to an improved three-piece
thread-wound golf ball 20, as shown in cross-section by FIG. 3. The
ball comprises a solid center core 22 formed substantially of
polybutadiene material and having an increased diameter of between
1.35-1.50 inches (34.3-38.1 mm), with the preferred core diameter
being 1.400-1.450 inches (35.6-36.8 mm). The core portion 22 is
surrounded by an intermediate thread-wound portion 24, which is
surrounded by an outer solid cover 26 on which is provided multiple
shallow dimples 28 covering the outer surface of the ball.
[0025] An important characteristic of the inner core portion 22 is
that it has significantly larger diameter and lower specific
gravity than cores which are provided for known three-piece wound
golf balls at the present time. The core 22 larger diameter and
lower specific gravity in combination with the diameter and type of
winding thread used in the intermediate portion 24 and the material
for outer cover 26, results in a significant proportional transfer
of weight of the golf ball outwardly towards its perimeter. As a
result, there is an increase in the moment of inertia for the ball,
and consequently there is an increase in the initial spin rate of
the ball 20 after being hit with a particular golf club. This golf
ball construction provides a greater degree of control of the ball
spin and trajectory flight distance than is provided by other known
golf balls. The ball increased core diameter and reduced specific
gravity has a significant importance when used in combination with
the intermediate thread winding and cover dimensions and
materials.
[0026] The outer portions of the three-piece wound golf ball as
shown in FIG. 3 includes the intermediate portion 24 which is wound
tightly with a high velocity type elastomer thread material
compared of blended natural and synthetic rubbers, and the outside
cover 26 which exhibits the characteristics of a Balata cover
material. The thread winding material employed provides an increase
in initial ball velocity after being hit by a club. The ball cover
is formed of a thermoplastic material having a density of 1.00-1.04
gm/cm.sup.3 and many shallow dimples; and is able to impart flight
control over a trajectory distance similar to that for conventional
two-piece, multi-layer, and Balata three-piece wound balls.
[0027] Because of the increased diameter and lower specific gravity
of the ball center core portion, it has been found that the golf
ball according to this invention provides improved spin
characteristics when struck by various golf clubs, including a No.
1 wood driver, and No. 3, 6 and 9 iron clubs. Specifically, the
initial ball spin rate expressed in revolutions per minute after
being struck by the higher numbered clubs, i.e. by the 3-iron,
6-iron and 9-iron clubs, exceeds the ball initial spin rate after
being struck with a No. 1 Driver club by minimum initial spin
ratios as listed in Table 2 below.
2TABLE 2 Golf Ball Initial Spin Ratio Characteristics Golf Clubs
Used Ball Initial Minimum Spin Ratio 3-iron vs. Driver 1.8 6-iron
vs. Driver 2.3 9-iron vs. Driver 3.0
[0028] As a result of the improved ball spin characteristics, the
solid three-piece solid core golf ball of this invention also
provides flight trajectory distances at least equal to or exceeding
that of other known competitive golf balls.
[0029] This invention will be described further by the following
Example, which should not be regarded as limiting in its scope.
EXAMPLE 1
[0030] The three-piece solid core thread wound golf balls were
constructed having materials, dimensions and characteristics as
follows:
3 Core material polybutadiene Core diameter, in. 1.400 (3.56 mm)
Core specific gravity 1.236 Ratio core diameter/specific gravity
1.13/1 Intermediate thread winding material Natural and synthetic
rubber Thread cross-sectional dimensions, in. 0.062 .times. 0.024
Intermediate layer diameter, in. 1.550 (39.4 mm) Intermediate layer
thickness, in. 0.075 (1.90 mm) Cover material ionomer Cover
thickness, in. 0.65 (1.65 mm) Ball diameter, in. 1.680
[0031] Comparative ball spin test results for the golf ball of the
present invention as compared to known golf balls obtained using a
True Temper made robot and are listed in Table 3 below, and are
also shown graphically by FIG. 4.
4TABLE 3 Golf Ball Initial Spin Rate Comparison Using Various Clubs
Golf Clubs Used Ball Spin Ratios Ball Type Driver 3-Iron 6-Iron
9-Iron 3I/D 6I/D 9I/D 2 PC Distance 2729 4500 6286 7500 1.65 2.30
2.75 2 PC Hi-Spin 2675 4912 6673 7857 1.84 2.49 2.94 3 PC Balata*
3419 6212 7308 9700 1.82 2.14 2.84 3 PC Tour** 2734 4912 6429 9371
1.80 2.35 3.43 3 PC TourSpin** 2847 5306 6595 9471 1.86 2.31 3.33
*Balata ball has liquid center **Golf ball construction of present
invention
[0032] Based upon this golf ball comparative spin rate data in
Table 3 and FIG. 4, it is seen that the two golf balls constructed
according to the present invention provide spin results
substantially equal to or better than that for known three-piece
Balata golf balls. More specifically, as generally shown in Table 3
and FIG. 4, the ball initial spin rate expressed in revolutions per
minute show that the ball construction of the improved three-piece
wound golf ball spins much like a two piece distance golf ball when
hit with a Driver, and long irons, like a two-piece Hi Spin golf
ball when hit with mid-iron clubs, and when hit with a short iron
club, the ball performs much like a Balata wound golf ball.
[0033] Comparative test results for total flight distance for the
golf ball of the present invention as compared to other known balls
after being struck by a Driver, 5 iron club and 9 iron club is
provided in Table 4 below.
5TABLE 4 Struck Ball Total Flight Distance (Yards) Ball Type Driver
5-Iron 9-Iron Top Wind J Blend 1.400" Tour Spin 267 189 132 Top
Wind D Blend 1.400" Tour 269 187 132 Hogan Balata 260 184 132
Titleist Professional 266 188 131 Titleist tour Balata 260 188 130
Slazenger 420 Balata 265 189 131 Maxfli Ht Balata 264 189 132 Top
Flite Strata 266 189 134 Precept Tour 267 186 132
[0034] From the above comparative ball flight distance results per
Table 4, it is seen that the golf ball of the present invention has
the favorable flight characteristic of the Balata covered ball and
also the flight distance of a two-piece and multi-layer golf ball.
The combinations of elements as described provide a golf ball that
at least substantially duplicates and even improves upon the
desirable properties of the Balata covered ball while overcoming
the expense and lack of durability associated with the Balata
covered ball.
[0035] Although this three-piece wound golf ball invention has been
described broadly and also in terms of preferred embodiments, it
will be understood that minor modifications and variations can be
made to portions of the ball which is defined by the following
claims.
* * * * *