GB2300125A - Wound golf balls - Google Patents
Wound golf balls Download PDFInfo
- Publication number
- GB2300125A GB2300125A GB9608414A GB9608414A GB2300125A GB 2300125 A GB2300125 A GB 2300125A GB 9608414 A GB9608414 A GB 9608414A GB 9608414 A GB9608414 A GB 9608414A GB 2300125 A GB2300125 A GB 2300125A
- Authority
- GB
- United Kingdom
- Prior art keywords
- center
- liquid
- wound golf
- diameter
- golf ball
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/006—Physical properties
- A63B37/0062—Hardness
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/02—Special cores
- A63B37/08—Liquid cores; Plastic cores
- A63B2037/085—Liquid cores; Plastic cores liquid, jellylike
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/02—Special cores
- A63B37/08—Liquid cores; Plastic cores
- A63B2037/087—Wound cores or layers
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/0051—Materials other than polybutadienes; Constructional details
- A63B37/0052—Liquid cores
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/0051—Materials other than polybutadienes; Constructional details
- A63B37/0053—Thread wound
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/006—Physical properties
- A63B37/0064—Diameter
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/005—Cores
- A63B37/006—Physical properties
- A63B37/0066—Density; Specific gravity
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B37/00—Solid balls; Rigid hollow balls; Marbles
- A63B37/0003—Golf balls
- A63B37/007—Characteristics of the ball as a whole
- A63B37/0072—Characteristics of the ball as a whole with a specified number of layers
- A63B37/0076—Multi-piece balls, i.e. having two or more intermediate layers
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Physical Education & Sports Medicine (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The invention provides a wound golf ball comprising a liquid center in the form of a center bag filled with a liquid, a thread rubber layer, and a cover. The liquid center has a diameter D of 26-32 mm. The relationship: (AxB)/D * less than or equal to * 4.5 is met wherein A is a gage as expressed in mm and B is a hardness on JIS A scale of the center bag. A hysteresis loss of up to 7% is recorded when the liquid center is deformed to 50% of its diameter. The ball is reduced in spin and travels a longer distance.
Description
WOUND GOLF BALLS
This invention relates to thread wound golf balls1 and is particularly concerned with enabling a good flying distance.
In general, thread wound golf balls are manufactured by winding high tension thread rubber on a spherical liquid center to form a thread rubber layer thereon and enclosing the thread rubber layer with a cover of balata rubber or ionomer resin. Most often, the liquid center is a hollow spherical center bag of rubber filled with a liquid, typically water containing a specific gravity adjusting agent.
Major requirements for golf balls include a flying distance and ease of ball control. As compared with twopiece golf balls, wound golf balls have the advantages of an increased back spin, ease of control, and pleasant feel, but undesirably travel less distances because they tend to climb up due to back spin.
It was desired in the prior art to develop a wound golf ball capable of traveling a longer flying distance. A number of proposals were made to achieve such improvement, for example, by modifying the liquid center for reducing a spin rate as disclosed in Japanese Patent Application Kokai (JP-A) Nos. 168471/1985, 181070/1987, and 255162/1990, enlarging the liquid center to a diameter of 29.5 to 32 mm and providing a total dimple volume of 280 to 340 mm as disclosed in JP-A 304269/1994, and specifying the composition of a liquid to be filled in a center bag as disclosed in Japanese Patent Application No. 126923/1994.
These modified wound golf balls are successful in increasing the flying distance to some extent although a further increase of flying distance is desired.
The aim here is generally to provide new and useful golf ball constructions, a preferred aim being to provide a wound golf ball which has a good flying distance without sacrificing advantages such as ease of control and pleasant hitting feel normally associated with wound balls.
In order to reduce the spin rate of a wound golf ball to increase its flying distance, we attempted to reduce the hardness of a liquid center and increase the diameter thereof while investigating their relationship. We have found that a liquid center of optimum softness and restitution is obtained when provided that the liquid center has a diameter D as expressed in mm and the center bag has a gage A as expressed in mm and a hardness B on JIS A scale,
D, A, and B fall in a specific range, that is, the liquid center diameter D is 26 to 32 mm and D, A and B meet the relationship: (AxB)/D < 4.5, and the liquid center experiences a hysteresis loss of up to 7% upon deformation of the liquid center to 50% of its diameter D.Quite unexpectedly, a wound golf ball using thist liquid center spins less upon hitting because of greater deformation and thus travels a longer flying distance without detracting from the advantages of wound golf balls including ease of control.
Briefly stated, the present invention provides a wound golf ball comprising a liquid center in the form of a center bag filled with a liquid, a thread rubber layer, and a cover. The liquid center has a diameter D of 26 to 32 mm and the center bag has a gage A as expressed in mm and a hardness B as measured on JIS A scale in a relationshir (AxB)/D < 4.5. The liquid center experiences a hysteresis loss of up to 7% when the liquid center is deformed to 50% of its diameter D.
BRIEF DESCRIPTION OF THE DRAWINGS
The only figure, FIG. 1 is a schematic cross-sectional view of a wound golf ball,
Referring to FIG. 1, a wound golf ball generally designated at 1 according to the invention is illustrated as comprising a liquid center 4 in the form of a center bag 2 filled with a liquid 3, a thread rubber layer 5, and a cover 6.
The liquid center 4 consists of the center bag 2 and the fill liquid 3. For the purpose of increasing the flying distance, the present invention modifies the composition of a center bag to control optimum the hardness and gage of the center bag and the softness and restitution of the liquid center. More specifically, the liquid center has a diameter
D of 26 to 32 mm and the center bag has a gage A as expressed in mm and a hardness B as measured on JIS A scale in a relationship: (AxB)/D < 4.5. The liquid center experiences a hysteresis loss of up to 7% when the liquid center is deformed to 50% of its diameter D.
The liquid center of the wound golf ball of the invention has a diameter D of 26 to 32 mmF preferably 28 to 31 mm. A center diameter of less than 26 mm is ineffective for reducing spin whereas a center diameter of more than 32 mm fails to provide an adequate ball hardness. The center diameter D, center bag gage A and center bag hardness B are related such that the value of (AxB)/D is up to 4.5, preferably from 2.0 to 4.0. The benefits of the invention are more or less lost with (AxB)/D > 4.5. The relationship (AxB)/D suggests that the liquid center is better as the center bag gage A and center bag hardness B are reduced and the center diameter D is increased. A wound golf ball'ising this liquid center undergoes greater deformation and thus receives less spin upon hitting.The center bag preferably has a gage A of 1.5 to 3.0 mm, especially 1.8 to 2.5 mm and a hardness B of 40 to 60, especially 45 to 55 on JIS A scale.
The center bag may be formed from a composition of well-known components, for example, a rubber component such as natural rubber, butadiene rubber, isoprene rubber and mixtures thereof, an inorganic filler for specific gravity adjustment such as zinc white, a vulcanizing agent such as sulfur, a vulcanization promoter, process oil, crosslinking agent and stearic acid. The center bag may be formed by well-known methods.
The center bag is filled with a liquid to form a liquid center. The fill liquid may be selected from well-known liquids commonly used in the liquid center of wound Bolf balls, preferably water. The fill liquid preferably has a specific gravity of 1.0 to 2.0, especially 1.1 to 1.6. Such a specific gravity is accomplished by blending water with suitable specific gravity adjusting agents such as barium sulfate, sodium sulfate, glycerin and ethylene glycol.
According to the invention, the liquid center is formed by filling a center bag with a liquid as mentioned above such that the liquid center may experience a hysteresis loss not above 7%, preferably 3% to 5%, when the liquid center is deformed to 50% of its diameter D. A liquid center with a hysteresis loss of more than 7% is low in restitution and some benefits of the invention are lost. The term "hysteresis loss" used herein is a percent loss upon recovery after a liquid center is deformed under a load. It is a measure of the restitution of the liquid center.
The liquid center meeting the above-mentioned requirements has satisfactory softness and restitution (or repulsion).
The thread rubber layer 2 is formed by winding thread rubber on the liquid center 4 under high tension. Any wellknown thread rubber commonly used in wound golf balls jay be used to form the thread rubber layer. Winding thread rubber on the liquid center gives a wound core which preferably has an outer diameter of 38 to 41 mm, especially 39 to 40.5 mm.
The thus obtained wound core is enclosed with the cover 6 to complete the wound golf ball of the invention. Any of well-known cover materials may be used. Cover materials based on balata rubber and ionomer resins are useful. The ctver preferably has a radial thickness of 1.0 to 2.5 mm, especially 1.2 to 2.0 mm and a hardness of 70 to 93 on JIS C scale.
The cover may be a single layer or consist of multiple layers. In the multilayer cover, the thickness of the respective layers depends on particular conditions under which they are formed and may be selected without undue experimentation. Any conventional technique may be used for forming the cover around the wound core. For example, a cover is formed by placing the wound core in a mold and injection molding a cover-forming resin composition around the core. Alternatively, a cover is formed by preforming a pair of hemi-spherical half cups from a cover-forming resin composition and enclosing the wound core with the pair of half cups, followed by thermo-compression molding.
In this way, there is obtained a wound golf ball. At the same time when or after the wound core is enclosed with the cover, the cover is formed with dimples. The dimples may have any desired geometry distribution such as octahedral, eicosahedral and other polyhedral distribution, and any desired model such as square, hexagon, pentagon, and triangle models.
The wound golf ball thus completed will usually have a diameter and weight complying with the Rules of Golf, namely a diameter of at least 42.67 mm and a weight of up to 45.92 grams. From the standpoints of hitting feel, restitution and durability, the ball preferably has such a hardness that its distortion under a load of 100 kg is 2.6 to 3.6 mm.
There has been described a wound golf ball which is improved in flying distance by reducing spin without sacrificing its own advantages.
EXAMPLE
Examples of the present invention are given below by way of illustration and not by way of limitation.
Examples 1-7 & Comparative Examples 1-3
A liquid center was prepared as follows. A center bag was prepared from the composition shown in Table 1 to the specific gravity, hardness and gage shown in Table 1. The center bag was filled with a fill liquid to form a liquid center. More particularly, a barium sulfate paste was prepared according to the following formulation.
Components Parts by weight
Barium sulfate 100
Sodium carboxymethyl cellulose 6
Dodecylbenzenesulfonic acid 4
Water 30
The center bag was filled with an amount of the paste as shown in Table 1 and the remainder of water, obtaining a liquid center. It is to be noted that Examples 5 and 6 used sodium sulfate instead of the barium sulfate paste and
Comparative Examples 1 and 2 used only water as the fill liquid. The specific gravity of the fill liquid is reported in Table 1. The weight and outer diameter of the liquid center are also reported in Table 1.
Wound golf balls of Examples 1-7 and Comparative
Examples 1-3 were prepared by forming on the liquid center a layer of thread rubber and a cover of the following compositions.
Thread rubber composition Parts by weight
Polyisoprene rubber 70
Natural rubber 30
Zinc white 1.5
Stearic acid 1.0
Vulcanizing promoter + Sulfur 2.6
Balata cover composition Parts by weight
Synthetic trans-polyisoprene rubber 80
High-impact styrene resin 10
Natural rubber 10
Zinc white 10
Titanium oxide 10
- Stearic acid 1.0
Vulcanizing promoter + Sulfur 1.5
The wound golf balls thus obtained were examined for (AxB)/D, hysteresis loss after 50% deformation, ball hardness, and flying performance. The results are shown in
Table 1. It is noted that (AxB)/D is (center bag gage x center bag hardness)/liquid center diameter as previously defined. The hysteresis loss after 50% deformation, ball hardness, and flying performance were measured and evaluated by the following tests.
Hysteresis loss after 50% deformation
Using an Instron compression tester, the liquid center was compressed at a rate of 50 mm/min. to 50% of the center diameter and then allowed to resume the original position.
A hysteresis loss was calculated from a load-deformation area X upon compression and a load-deformation area Y upon restoration.
Hysteresis loss = (X - Y)/X x 100%
Ball hardness
Hardness is expressed by a distortion (mm) of a ball under a load of 100 kg applied between flat plate surfaces.
Flying test
Using a swing robot, a sample ball was hit by a driver (w#l) at a head speed (HS) of 45 m/s to measure a carry and a total flying distance. Under this hitting condition, an initial velocity, spin and elevation angle were measured. Table 1
Example Comparative Example 1 2 3 4 5 6 7 1 2 3 Center bag Composition Natural rubber 100 100 100 100 100 100 100 100 100 100 Zinc white 40 40 40 40 145 145 40 330 265 40 Process oil - - - - 25 25 - 30 25 Stearic acid 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 VP + S 4.0 4.0 4.0 4.0 4.0 4.0 3.0 4.0 4.0 4.0 Specific gravity 1.22 1.22 1.22 1.22 1.66 1.66 1.22 2.33 2.13 1.22 Hardness, JIS A 52 52 52 52 55 55 48 61 58 52 Gage, mm 2.1 2.3 2.3 2.3 2.3 2.3 2.8 2.2 2.3 2.8 Fill liquid Paste Barium Barium Barium Barium Sodium Sodium Barium Barium Water Water sulfate sulfate sulfate sulfate sulfate sulfate sulfate sulfate Volume, cm3 7.1 7.7 8.7 9.9 8.7 9.9 8.6 7.0 7.7 6.7 Paste amount, g 7.8 7.5 7.0 7.9 - - 7.6 - - 6.4 Specific gravity 1.64 1.53 1.45 1.46 1.19 1.19 1.50 1.00 1.00 1.54 Liquid center Weight, g 16.6 17.7 19.5 21.5 19.7 21.5 21.5 16.6 17.8 17.7 Diameter, mm 28 29 30 31 30 31 31 28 29 29 (AxB)/D 3.90 4.12 3.99 3.86 4.22 4.08 4.34 4.79 4.60 5.02 Hysteresis loss 3.1 3.3 3.3 3.0 3.5 3.6 3.7 9.5 7.8 3.8 Ball Weight, g 45.2 45.2 45.2 45.4 45.3 45.4 45.2 45.2 45.3 45.2 Diameter, mm 42.68 42.68 42.69 42.68 42.68 42.67 42.68 42.67 42.68 42.68 Hardness, mm 2.85 2.85 2.86 2.84 2.80 2.84 2.85 2.81 2.82 2.85 Flying test (W# ;1, HS=45m/s) Spin (rpm), 3200 3110 3030 2940 3180 3090 3120 3350 3270 3300 Initial velocity (m/s) 65.1 65.2 65.3 65.3 65.4 65.5 65.2 65.0 65.0 65.2 Elevation angle ( ) 12.1 12.1 12.1 12.0 12.1 12.2 12.2 12.2 12.2 12.2 Carry (m) 205.8 206.4 207.3 207.2 207.5 206.6 206.1 205.2 206.0 205.0 Total (m) 217.7 218.5 219.5 220.0 218.3 219.0 218.6 215.0 216.2 215.2 As is evident from Table 1, the balls embodying the he invention (Examples 1 to 7) have a reduced spin rate and travel a longer distance.
Japanese Patent Application No. 125965/1995 is itcorporated herein by reference.
Although some preferred embodiments have been described, many modifications and variations may be made thereto in the light of the above teachings. It is therefore to be understood that within the scope of the general teachings herein the invention may be practised otherwise than as described in the specific examples.
Claims (7)
1. A wound golf ball comprising a liquid center in the form of a center bag filled with a liquid, a thread rubber layer, and a cover, wherein
said liquid center has a diameter D of 26 to 32 mm and said center bag has a gage A as expressed in mm and a hardness B as measured on JIS A scale in a relationship: (AxB)/D ( 4.5, and
said liquid center experiences a hysteresis loss of up to 7% when said liquid center is deformed to 50% of its diameter D.
2. A wound golf ball of claim 1 wherein said center bag has a gage A of 1.5 to 3.0 mm.
3. A wound golf ball of claim 1 or claim 2 wherein said center bag has a hardness B of 40 to 60 of JIS A scale.
4. A wound golf ball of any one of the preceding claims wherein 2.0 < (AxB)/D < 4.0.
5. A wound golf ball of any one of the preceding claims wherein the hysteresis loss is 3 to 5%.
6. A wound galk ball of any one of the preceding claims wherein the liquid is based on water and has a specific gravity of 1.0 to 2.0.
7. A wound golf ball according to any one of Examples 1 to 7.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7125965A JPH08294548A (en) | 1995-04-26 | 1995-04-26 | Thread wound golf ball |
Publications (3)
Publication Number | Publication Date |
---|---|
GB9608414D0 GB9608414D0 (en) | 1996-06-26 |
GB2300125A true GB2300125A (en) | 1996-10-30 |
GB2300125B GB2300125B (en) | 1999-03-03 |
Family
ID=14923365
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9608414A Expired - Fee Related GB2300125B (en) | 1995-04-26 | 1996-04-24 | Wound golf balls |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPH08294548A (en) |
GB (1) | GB2300125B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6354965B1 (en) | 2000-02-02 | 2002-03-12 | Acushnet Company | Golf balls including low water activity fluid and methods for making same |
US6514157B2 (en) | 2001-03-29 | 2003-02-04 | Acushnet Company | Golf ball with non-aqueous liquid center |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9724568B2 (en) | 2013-09-03 | 2017-08-08 | Bridgestone Sports Co., Ltd. | Golf ball |
-
1995
- 1995-04-26 JP JP7125965A patent/JPH08294548A/en active Pending
-
1996
- 1996-04-24 GB GB9608414A patent/GB2300125B/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6354965B1 (en) | 2000-02-02 | 2002-03-12 | Acushnet Company | Golf balls including low water activity fluid and methods for making same |
US6514157B2 (en) | 2001-03-29 | 2003-02-04 | Acushnet Company | Golf ball with non-aqueous liquid center |
Also Published As
Publication number | Publication date |
---|---|
GB2300125B (en) | 1999-03-03 |
GB9608414D0 (en) | 1996-06-26 |
JPH08294548A (en) | 1996-11-12 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20110424 |