Patent Application
20130196786
The present invention relates generally to a golf ball having different play characteristics in different situations.
The game of golf is an increasingly popular sport at both amateur and professional levels. A wide range of technologies related to the manufacture and design of golf balls are known in the art. Such technologies have resulted in golf balls with a variety of play characteristics. For example, some golf balls have a greater spin rate and/or launch angle than other golf balls. To have more control over a golf ball in iron shots, especially when the golf ball flies against the wind, it is desirable for the launch angle of the ball to be low and the spin rate of the ball to be high. However, such a high spin rate may not be desirable for driver shots because driver shots may drop too soon in flight, causing the golf ball to fly a shorter distance. Thus, it would be advantageous to be able to make a golf ball that has a different spin rate associated with different types of clubs.
A golf ball that, when hit with an iron, has a higher spin rate and launch angle than existing golf balls currently available on the market is disclosed. The same golf ball has a compatible driver spin rate and launch angle against existing golf balls currently available on the market.
In one aspect, the disclosure provides a golf ball that may have an inner core layer, an outer core layer enclosing the inner core layer, an inner cover layer enclosing the outer core layer, and an outer cover layer enclosing the inner cover layer. The inner core layer may have a higher coefficient of restitution than the outer core layer, the inner cover layer, and the outer cover layer. When the golf ball is hit with a driver having a loft angle of less than 15 degrees, the golf ball may have a spin rate to launch angle ratio ranging from about 190 to about 360. When the golf ball is hit with an iron having a loft angle of less than 40 degrees, the golf ball may have a spin rate to launch angle ratio ranging from about 500 to about 600. Performing the BS/LA 160 mph driver test on the golf ball may result in the golf ball having a spin rate to launch angle ratio ranging from about 190 to about 230. Performing the BS/LA No. 4 iron test on the golf ball may result in the golf ball having a spin rate to launch angle ratio ranging from about 510 to about 580. Performing the BS/LA No. 6 iron test may result in the golf ball having a spin rate to launch angle ratio ranging from about 510 to about 580. Performing the BS/LA high loft angle test on the golf ball may result in the golf ball having a spin rate to launch angle ratio ranging from about 440 to about 480. The inner core layer may include at least one highly neutralized acid polymer composition. The inner core layer may have a coefficient of restitution value ranging from about 0.795 to about 0.88. The inner core layer may have a coefficient of restitution value that is about 0.005 to about 0.02 greater than the coefficient of restitution value of the golf ball. The inner cover layer may have a Shore D hardness ranging from about 60 to about 80.
In one aspect, the disclosure provides a golf ball that may have an inner core layer, an outer core layer enclosing the inner core layer, an inner cover layer enclosing the outer core layer, and an outer cover layer enclosing the inner cover layer. The inner cover layer may have a greater specific gravity than the thermoset outer core layer. When the golf ball is hit with an iron having a loft angle of less than 40 degrees, the golf ball may have a first spin rate to launch angle ratio. When the golf ball is hit when with a driver having a loft angle of less than 15 degrees, the golf ball may have a second spin rate to launch angle ratio that is at least 240 lower than the first spin rate to launch angle ratio. The golf ball may have a second spin rate to launch angle ratio that is at least 310 lower than the first spin rate to launch angle ratio. The inner cover layer and outer cover layer may both comprise thermoplastic materials. The outer core layer may include a polybutadiene rubber. The thickness of the outer core layer may range from about 0.5 to about 2 mm. The inner core layer may have a coefficient of restitution value that is about 0.005 to about 0.02 greater than the coefficient of restitution value of the golf ball. The inner cover layer may have a Shore D hardness ranging from about 60 to about 80.
In one aspect, the disclosure provides a golf ball that may have an inner core layer, an outer core layer enclosing the inner core layer, an inner cover layer enclosing the outer core layer, and an outer cover layer enclosing the inner cover layer. The inner core layer may have a higher coefficient of restitution than the outer core layer, the inner cover layer, and the outer cover layer. When the golf ball is hit with a driver having a loft angle of less than 15 degrees, the golf ball may have a spin rate ranging from about 2400 rpm to about 2800 rpm. When the golf ball is hit with a first iron having a loft angle of less than 40 degrees, the golf ball has a spin rate ranging from about 6800 rpm to about 7300 rpm. The first iron having a loft angle of less than 40 degrees may be a No. 6 iron. When the golf ball is hit with the first iron having a loft angle of less than 40 degrees, the golf ball may have a launch angle ranging from about 12 degrees to about 13.5 degrees. When the golf ball is hit with a second iron having a loft angle of less than 40 degrees, the golf ball may have a spin rate ranging from about 5300 rpm to about 5600 rpm. When the golf ball is hit with the second iron having a loft angle of less than 40 degrees, the golf ball may have a launch angle ranging from about 9.5 degrees to about 10.5 degrees. The second iron having a loft angle of less than 40 degrees may be a No. 4 iron. When the golf ball is hit with a second iron having a loft angle of 40 degrees or greater, the golf ball may have a spin rate ranging from about 10,500 rpm to about 11,100 rpm. When the golf ball is hit with a second iron having a loft angle of 40 degrees or greater, the golf ball may have a launch angle ranging from about 21 degrees to about 23 degrees.
Other systems, methods, features and advantages of the invention will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the invention, and be protected by the following claims.
The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.
Generally, the present disclosure relates to a golf ball having a variable spin rate (backspin) and launch angle associated with striking the golf ball with different types of golf clubs. The structure of the disclosed golf ball may cause the golf ball to experience a high spin rate when the golf ball is hit with an iron. However, the same golf ball may experience a lower spin rate when the golf ball is hit with a driver. As a result, the disclosed golf ball may have different trajectories associated with different types of golf clubs.
In addition to having different spin rates associated with different clubs, golf ball 100 may have different launch angles associated with different clubs. An angle α is the launch angle of golf ball 100 in
Tables 2-6 show the results of tests performed on test balls, which include golf balls prepared according to the present disclosure and existing golf balls currently available on the market. The golf balls prepared according to the present disclosure include Examples 1-5. The existing golf balls currently available on the market include Comparative Examples 1-8, details of which are shown in Table 1 (where PBR is polybutadiene rubber). The results shown in Tables 2-6 include initial velocity (IV), launch angle (LA), backspin (BS), and BS/LA ratio. All results for IV have an uncertainty of ±1 mph. All test results for LA have an uncertainty of ±1 degree. The tests yielding the results in Tables 2-6 are described in more detail below.
Table 2 shows the results of a BS/LA 160 mph driver test. The BS/LA 160 mph driver test involves hitting the test balls with a driver having a head speed of about 120 mph±1 mph. The driver used in the test is a Nike Victory Red Pro driver having an X-Flex (extra stiff) shaft, a 58-degree lie angle, and a 9.5-degree loft angle. The calibration ball for the BS/LA 160 mph driver test is a USGA/R&A Calibration model golf ball commercially available by Bridgestone Sports. To calibrate the BS/LA 160 mph driver test, the conditions are set to cause the calibration ball to have an initial velocity of 159.5 mph±1 mph, a launch angle of 12.9 degrees±1 degree, and a backspin of 2200 rpm±150 rpm when the calibration ball is hit with the driver having a head speed of about 120 mph±1 mph.
The results of the BS/LA 160 mph driver test show that the BS/LA ratio of golf balls prepared according to the present disclosure are comparable to the BS/LA ratio of the existing golf balls currently available on the market. For example, Comparative Example 2 has a BS/LA ratio of 198.9844. Similar to these results, Example 3 has a BS/LA ratio of 199.2000. The ranges of BS/LA ratios of the test balls and the existing golf balls currently available on the market overlap. The BS/LA ratios of the existing golf balls currently available on the market fall within a range of about 166 to about 199. The BS/LA ratios of the test balls in Table 2 fall within a range of about 199 to about 219. In some embodiments, the BS/LA ratios resulting from performing the BS/LA 160 mph driver test on a golf ball prepared according to the present disclosure may range from about 195 to about 220. In some embodiments, the BS/LA ratios resulting from performing the BS/LA 160 mph driver test on a golf ball prepared according to the present disclosure may range from about 190 to about 230.
Table 3 shows the results of a BS/LA 139 mph driver test. The BS/LA 139 mph driver test involves hitting the test balls with a driver having a head speed of about 102 mph±1 mph. The driver used in this test is a Nike Dymo2 driver having an S-Flex (stiff) shaft, a 62-degree lie angle, and a 10.5-degree loft angle. The calibration ball for the BS/LA 139 mph driver test is a USGA/R&A Calibration model golf ball commercially available by Bridgestone Sports. To calibrate the BS/LA 139 mph driver test, the conditions are set to cause the calibration ball to have an initial velocity of 137 mph±1 mph, a launch angle of 12.1 degrees±1 degree, and a backspin of 3289 rpm±150 rpm when the calibration ball is hit with the driver having a head speed of about 102 mph±1 mph.
The results of the BS/LA 139 mph driver test show that the BS/LA ratio of golf balls prepared according to the present disclosure are comparable to the BS/LA ratio of the existing golf balls currently available on the market. For example, Comparative Example 2 has a BS/LA ratio of 314.2857. Similar to these results, Example 4 has a BS/LA ratio of 328.2051. The ranges of BS/LA ratios of the test balls are substantially similar to the BS/LA ranges of the existing golf balls currently available on the market. The BS/LA ratios of the existing golf balls currently available on the market fall within a range of about 268 to about 315. The BS/LA ratios of the test balls in Table 3 fall within a range of about of about 328 to about 350. In some embodiments, the BS/LA ratios resulting from performing the BS/LA 139 mph driver test on a golf ball prepared according to the present disclosure may range from about 320 to about 360. In some embodiments, the BS/LA ratios resulting from performing the BS/LA 139 mph driver test on a golf ball prepared according to the present disclosure may range from about 315 to about 380.
Table 4 shows the results of a BS/LA No. 4 iron test. The BS/LA No. 4 iron test involves hitting the test balls with a No. 4 iron having a head speed of about 102 mph±1 mph. The No. 4 iron used in this test is a Nike Victory Red Split Cavity No. 4 iron having an X100 (extra stiff) shaft, a 60-degree lie angle, and a 24-degree loft angle. The calibration ball for the BS/LA No. 4 iron test is a USGA/R&A Calibration model golf ball commercially available by Bridgestone Sports. To calibrate the BS/LA No. 4 iron test, the conditions are set to cause the calibration ball to have an initial velocity of 137.3 mph±1 mph, a launch angle of 10.9 degrees±1 degree, and a backspin of 4186 rpm±150 rpm when the calibration ball is hit with the No. 4 iron having a head speed of about 102 mph±1 mph.
The results of the BS/LA No. 4 iron test show that the BS/LA ratio of golf balls prepared according to the present disclosure are substantially different from the BS/LA ratio of the existing golf balls currently available on the market. For example, at 467.9808, Comparative Example 2 has the highest BS/LA ratio of the existing golf balls currently available on the market. At 519.8039, Example 5 has the lowest BS/LA ratio of the golf balls prepared according to the present disclosure. The difference between the BS/LA ratio of the Comparative Example 2 and the BS/LA ratio of the Example 5 is 51.3281. The BS/LA ratios of the existing golf balls currently available on the market are substantially different from the BS/LA ratios of the golf balls prepared according to the present invention. The BS/LA ratios of the existing golf balls currently available on the market in Table 4 fall within a range of about 358 to about 468. Generally, the BS/LA ratios of the golf balls prepared according to the present disclosure in Table 4 fall within a range of about 519 to about 547. In some embodiments, the BS/LA ratios resulting from performing the BS/LA No. 4 iron test on the golf balls prepared according to the present disclosure range from about 500 to about 600. In some embodiments, the BS/LA ratios resulting from performing the BS/LA No. 4 iron test on the golf balls prepared according to the present disclosure range from about 510 to about 580.
Table 5 shows the results of a BS/LA No. 6 iron test. The No. 6 iron used in this test is a Nike Victory Red Split Cavity No. 6 iron having an X100 (extra stiff) shaft, a 62-degree lie angle, and a 31-degree loft angle. The calibration ball for the BS/LA No. 6 iron test is a USGA/R&A Calibration model golf ball commercially available by Bridgestone Sports. To calibrate the BS/LA No. 6 iron test, the conditions are set to cause the calibration ball to have an initial velocity of 126.4 mph±1 mph, a launch angle of 14.3 degrees±1 degree, and a backspin of 5504 rpm±150 rpm when the calibration ball is hit with the No. 6 iron having a head speed of about 94 mph±1 mph.
The results of the BS/LA No. 6 iron test show that the BS/LA ratio of golf balls prepared according to the present disclosure are substantially different from the BS/LA ratio of the existing golf balls currently available on the market. For example, at 462.3358, Comparative Example 2 has the highest BS/LA ratio of the existing golf balls currently available on the market. At 522.5000, Example 4 has the lowest BS/LA ratio of the golf balls prepared according to the present disclosure. The difference between the BS/LA ratio of Comparative Example 2 and the BS/LA ratio of Example 5 is 60.1642. The BS/LA ratios of the existing golf balls currently available on the market are substantially different from the BS/LA ratios of the golf balls prepared according to the present invention. The BS/LA ratios of the existing golf balls currently available on the market in Table 5 fall within a range of about 364 to about 463. The BS/LA ratios of the golf balls prepared according to the present disclosure in Table 5 fall within a range of about 522 to about 555. In some embodiments, the BS/LA ratios resulting from performing the BS/LA No. 6 iron test on the golf balls prepared according to the present disclosure range from about 500 to about 600. In some embodiments, the BS/LA ratios resulting from performing the BS/LA No. 6 iron test on the golf balls prepared according to the present disclosure range from about 510 to about 580.
Table 6 shows the results of a BS/LA high loft angle test. The high loft angle club used in this test is a Nike Victory Red Split Cavity pitching wedge having a 64-degree lie angle and a 47-degree loft angle. The calibration ball for the BS/LA high loft angle test is a USGA/R&A Calibration model golf ball commercially available by Bridgestone Sports. To calibrate the BS/LA high loft angle test, the conditions are set to cause the calibration ball to have an initial velocity of 96.1 mph±1 mph, a launch angle of 25 degrees±1 degree, and a backspin of 10137 rpm±150 rpm when the calibration ball is hit with the high loft angle club having a head speed of about 71.6 mph±1 mph.
The results of the BS/LA high loft angle test show that the BS/LA ratio of golf balls prepared according to the present disclosure are substantially different from the BS/LA ratio of the existing golf balls currently available on the market. For example, at 414.1600, Comparative Example 2 has the highest BS/LA ratio of the existing golf balls currently available on the market. At 440.4545, Example 5 has the lowest BS/LA ratio of the golf balls prepared according to the present disclosure. The difference between the BS/LA ratio of Comparative Example 2 and the BS/LA ratio of Example 5 is 26.2945. The BS/LA ratios of the existing golf balls currently available on the market are substantially different from the BS/LA ratios of the golf balls prepared according to the present invention. The BS/LA ratios of the existing golf balls currently available on the market in Table 6 fall within a range of about 348 to about 415. The BS/LA ratios of the golf balls prepared according to the present disclosure in Table 6 fall within a range of about 440 to about 461. In some embodiments, the BS/LA ratios resulting from performing the BS/LA high loft angle test on the golf balls prepared according to the present disclosure fall within a range of about 430 to about 480. In some embodiments, the BS/LA ratios resulting from performing the BS/LA high loft angle test on the golf balls prepared according to the present disclosure fall within a range of about 435 to about 465.
In some embodiments, performing the BS/LA high loft angle test with a No. 9 iron or a wedge other than a pitching wedge in place of the pitching wedge may yield the same BS/LA ratio range of about 430 to about 480. For example, performing the BS/LA high loft angle test with a lob wedge, sand wedge, or gap wedge may yield the same BS/LA ratio range of about 440 to about 461. Wedges and No. 9 irons all typically have loft angles of 40 degrees or higher.
As used herein, unless otherwise stated, compression, hardness, COR, and flexural modulus are measured as follows:
Compression deformation: The compression deformation herein indicates the deformation amount of the ball under a force; specifically, when the force is increased to become 130 kg from 10 kg, the deformation amount of the ball under the force of 130 kg subtracts the deformation amount of the ball under the force of 10 kg to become the compression deformation value of the ball.
Hardness: Hardness of golf ball layer is measured generally in accordance with ASTM D-2240, but measured on the land area of a curved surface of a molded ball. For material hardness, it is measured in accordance with ASTM D-2240 (on a plaque).
Method of measuring COR: A golf ball for test is fired by an air cannon at an initial velocity of 40 m/sec, and a speed monitoring device is located over a distance of 0.6 to 0.9 meters from the cannon. When striking a steel plate positioned about 1.2 meters away from the air cannon, the golf ball rebounds through the speed-monitoring device. The return velocity divided by the initial velocity is the COR.
As shown in
The type of materials used to make the layers of the golf ball may be selected based on a variety of factors. For example, the type of materials used to make the layers of the golf ball may be selected based on the properties of the material and/or the processes used to form the layers. Exemplary materials are discussed below with respect to the individual layers of the exemplary embodiment. In some embodiments, one or more layers may be made from different materials. In some embodiments, one or more layers may be made from the same materials.
The golf ball may be made by any suitable process. The process of making the golf ball may be selected based on a variety of factors. For example, the process of making the golf ball may be selected based on the type of materials used and/or the number of layers included. Exemplary processes are discussed below with respect to the individual layers of the exemplary embodiment.
In some embodiments, inner core layer 110 may have a diameter ranging from 19 mm to 32 mm. In some embodiments, inner core layer 110 may have a diameter ranging from 20 mm to 30 mm. In some embodiments, inner core layer 110 may have a diameter ranging from 21 mm to 28 mm.
Inner core layer 110 may be made by any suitable process. For example, in some embodiments, inner core layer 110 may be made by an injection molding process. In some embodiments, inner core layer 110 may be made by a compression molding process. The process of making the inner core layer may be selected based on a variety of factors. For example, the process of making the inner core layer may be selected based on the type of material used to make the inner core layer and/or the process used to make the other layers.
In some embodiments, inner core layer 110 may include one or more highly neutralized acid polymer compositions. For example, in the exemplary embodiments, the inner core layer 110 may include two highly neutralized acid polymer compositions. In some embodiments, suitable materials for the inner core layer may include the following highly neutralized acid polymer compositions: HPF resins such as HPF1000, HPF2000, HPF AD1024, HPF AD1027, HPF AD1030, HPF AD1035, HPF AD1040, all produced by E. I. Dupont de Nemours and Company. In some embodiments, the material used to form inner core layer 110 may include a highly neutralized acid polymer composition and optional additives, fillers, and/or melt flow modifiers. The acid polymer may be neutralized to 80% or higher, including up to 100%, with a suitable cation source, such as magnesium, sodium, zinc, or potassium. In the exemplary embodiment, the highly neutralized acid polymer compositions used to make the inner core layer may include the same cation source. Suitable additives and fillers may include, for example, blowing and foaming agents, optical brighteners, coloring agents, fluorescent agents, whitening agents, UV absorbers, light stabilizers, defoaming agents, processing aids, mica, talc, nanofillers, antioxidants, stabilizers, softening agents, fragrance components, plasticizers, impact modifiers, acid copolymer wax, surfactants. Suitable fillers may also include inorganic fillers, such as zinc oxide, titanium dioxide, tin oxide, calcium oxide, magnesium oxide, barium sulfate, zinc sulfate, calcium carbonate, zinc carbonate, barium carbonate, mica, talc, clay, silica, lead silicate. Suitable fillers may also include high specific gravity metal powder fillers, such as tungsten powder and molybdenum powder. Suitable melt flow modifiers may include, for example, fatty acids and salts thereof, polyamides, polyesters, polyacrylates, polyurethanes, polyethers, polyureas, polyhydric alcohols, and combinations thereof.
In some embodiments, outer core layer 120 may be formed by crosslinking a polybutadiene rubber composition as described in U.S. patent application Ser. No. 12/827,360, entitled Golf Balls Including Crosslinked Thermoplastic Polyurethane, filed on Jun. 30, 2010, and applied for by Chien-Hsin Chou et al., the disclosure of which is hereby incorporated by reference in its entirety. When other rubber is used in combination with a polybutadiene, polybutadiene may be included as a principal component. For example, in some embodiments, a proportion of polybutadiene in the entire base rubber may be equal to or greater than 50% by weight. In some embodiments, a proportion of polybutadiene in the entire base rubber may be equal to or greater than 80% by weight. In some embodiments, a polybutadiene having a proportion of cis-1,4 bonds of equal to or greater than 60 mol %, and further, equal to or greater than 80 mol % may be used.
In some embodiments, cis-1,4-polybutadiene may be used as the base rubber and mixed with other ingredients to form outer core layer 120. In some embodiments, the amount of cis-1,4-polybutadiene may be at least 50 parts by weight, based on 100 parts by weight of the rubber compound. Various additives may be added to the base rubber to form a compound. The additives may include a cross-linking agent and a filler. In some embodiments, the cross-linking agent may be zinc diacrylate, magnesium acrylate, zinc methacrylate, or magnesium methacrylate. In some embodiments, zinc diacrylate may provide advantageous resilience properties. The filler may be used to increase the specific gravity of the material. The filler may include zinc oxide, barium sulfate, calcium carbonate, or magnesium carbonate. In some embodiments, zinc oxide may be selected for its advantageous properties. Metal powder, such as tungsten, may alternatively be used as a filler to achieve a desired specific gravity. In some embodiments, the specific gravity of outer core layer 120 may be from about 1.05 g/cm3 to about 1.45 g/cm3. In some embodiments, the specific gravity of outer core layer 120 may be from about 1.05 g/cm3 to about 1.35 g/cm3.
In some embodiments, a polybutadiene synthesized with a rare earth element catalyst may be used to form outer core layer 120. Such a polybutadiene may provide excellent resilience performance of golf ball 100. Examples of rare earth element catalysts include lanthanum series rare earth element compound, organoaluminum compound, and almoxane and halogen containing compounds. Polybutadiene obtained by using lanthanum rare earth-based catalysts usually employs a combination of a lanthanum rare earth (atomic number of 57 to 71) compound, such as a neodymium compound.
In some embodiments, a polybutadiene rubber composition having at least from about 0.5 parts by weight to about 5 parts by weight of a halogenated organosulfur compound may be used to form outer core layer 120. In some embodiments, the polybutadiene rubber composition may include at least from about 1 part by weight to about 4 parts by weight of a halogenated organosulfur compound. The halogenated organosulfur compound may be selected from the group consisting of pentachlorothiophenol; 2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol; 2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol; 3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol; 2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol; pentafluorothiophenol; 2-fluorothiophenol; 3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol; 2,4-fluorothiophenol; 3,4-f luorothiophenol; 3,5-f luorothiophenol 2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol; 2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol; 4-chlorotetrafluorothiophenol; pentaiodothiophenol; 2-iodothiophenol; 3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol; 2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol; 2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol; 2,3,5,6-tetraiodothiophenol; pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol 4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol; 3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol; 3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol; 2,3,5,6-tetrabromothiophenol; and their zinc salts, the metal salts thereof and mixtures thereof.
Outer core layer 120 may be made by any suitable process. For example, in some embodiments, outer core layer 120 may be made by a compression molding process. The process of making the outer core layer may be selected based on a variety of factors. For example, the process of making the outer core layer may be selected based on the type of material used to make the outer core layer and/or the process used to make the other layers.
In some embodiments, outer core layer 120 may be made through a compression molding process including a vulcanization temperature ranging from 130° C. to 190° C. and a vulcanization time ranging from 5 to 20 minutes. In some embodiments, the vulcanization step may be divided into two stages: (1) the outer core layer material may be placed in an outer core layer-forming mold and subjected to an initial vulcanization so as to produce a pair of semi-vulcanized hemispherical cups and (2) a prefabricated inner core layer may be placed in one of the hemispherical cups and may be covered by the other hemispherical cup and vulcanization may be completed. In some embodiments, the surface of inner core layer 110 placed in the hemispherical cups may be roughened before the placement to increase adhesion between inner core layer 110 and outer core layer 120. In some embodiments, inner core surface may be pre-coated with an adhesive before placing inner core layer 110 in the hemispherical cups to enhance the durability of the golf ball and to enable a high rebound.
In some embodiments, inner core layer 110 may have a high resilience. Such a high resilience may cause golf ball 100 to have increased carry and distance. In some embodiments, inner core layer 110 may have a coefficient of restitution (COR) value ranging from 0.79 to 0.89. In some embodiments, inner core layer 110 may have a COR value ranging from 0.795 to 0.88. The COR value of inner core layer 110 may be greater than the COR value of golf ball 100. In some embodiments, the COR value of inner core layer 110 may be 0.005 to 0.02 greater than the COR value of golf ball 100.
In some embodiments, inner core layer 110 may have a compression deformation value ranging from 2.5 mm to 5 mm. In some embodiments, inner core layer 110 may have a compression deformation value ranging from 3.5 mm to 5 mm. Inner core layer 110 may have a surface Shore D hardness of from 40 to 60. In some embodiments, outer core layer 120 may have a surface Shore D hardness of from 50 to 60, which may be higher than the surface hardness of inner core layer 110.
In some embodiments, inner core layer 110 may have a Shore D cross-sectional hardness ranging from 40 to 60 at any single point on a cross-section obtained by cutting inner core layer 110 in half. In some embodiments, the difference in Shore D cross-sectional hardness at any two points on the same cross-section may be within ±6. In some embodiments, the difference in Shore D cross-sectional hardness at any two points on the same cross-section may be within ±3.
In some embodiments, inner core layer 110 may have a smaller specific gravity than outer layers. Such a difference in specific gravity may cause golf ball 100 to have a greater moment of inertia. In some embodiments, the specific gravity of inner core layer 110 may range from about 0.85 g/cm3 to about 1.1 g/cm3. In some embodiments, the specific gravity of inner core layer 110 may range from about 0.9 g/cm3 to about 1.1 g/cm3.
In some embodiments, inner cover layer 130 of golf ball 100 may have a thickness ranging from 0.5 mm to 1.5 mm. For example, inner cover layer 130 may have a thickness of 1 mm. In some embodiments, inner cover layer 130 may have a thickness ranging from 0.8 mm to 1 mm. For example, in some embodiments, inner cover layer 130 may have a thickness of 0.9 mm.
In some embodiments, outer cover layer 140 of golf ball 100 may have a thickness ranging from 0.5 mm to 2 mm. For example, outer cover layer 140 may have a thickness of 1 mm. In some embodiments, outer cover layer 140 may have a thickness ranging from 1 mm to 1.5 mm. For example, in some embodiments, inner cover layer 130 may have a thickness of 1.2 mm.
In some embodiments, inner cover layer 130 may have a Shore D hardness, as measured on the curved surface, ranging from about 60 to 80. In some embodiments, outer cover layer 140 of golf ball 100 may have a Shore D hardness, as measured on the curved surface, ranging from 40 to 60.
In some embodiments, inner cover layer 130 and/or outer cover layer 140 may be made from a thermoplastic material including at least one of an ionomer resin, a highly neutralized acid polymer composition, a polyamide resin, a polyester resin, and a polyurethane resin. In some embodiments, inner cover layer 130 may include the same type of material as outer cover layer 140. In some embodiments, inner cover layer 130 may include a different type of material from outer cover layer 140.
In some embodiments, golf ball 100 may have a moment of inertia between about 82 g/cm2 and about 90 g/cm2. Such a moment of inertia may produce a desirable distance and trajectory, particularly when golf ball 100 is struck with a driver or driven against the wind.
In some embodiments, golf ball 100 may include a ball compression deformation of 2.2 mm to 3.2 mm. In some embodiments, golf ball 100 may have compression deformation of 2.5 mm to 3 mm.
In some embodiments, the layers used to make golf ball 100 may have a specified relationship in terms of their respective physical properties. For example, to have greater moment of inertia, the golf ball layers may have a specific gravity gradient increased from inner core layer 110 to outer cover layer 140. In some embodiments, inner core layer 110 may have a first specific gravity, outer core layer 120 may have a second specific gravity greater than the first specific gravity by at least 0.01, and inner cover layer 130 may have a third specific gravity greater than the second specific gravity by at least 0.01.
In some embodiments, golf ball 100 may have 300 to 400 dimples on the outer surface of outer cover layer 140.
While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/512,973, entitled “Golf Ball With Specified Ratio Of Ball Spin Rate To Launch Angle”, and filed on Jul. 29, 2011, which application is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61512973 | Jul 2011 | US |
