JP5779445B2 - Golf ball with high initial velocity - Google Patents

Description

Cross-reference to related applications

  This application is a priority of US Provisional Application No. 61 / 375,775, filed Aug. 20, 2010, under US Patent Act 119 (e), entitled “Golf Ball with High Initial Speed”. Is an insistence. By specifying the source, all contents disclosed in this application are made part of the disclosure of this specification.

  The present disclosure relates generally to golf balls having a plurality of layers. These layers are designed to have a special relationship between coefficient of restitution and compression in order to achieve a high initial velocity.

  In the industry, manufacturing a golf ball having a plurality of layers is a standard matter. Individual designers in the industry feel that certain features are more important than others and design golf balls to optimize certain features. Individual golfers also find certain features more important and desirable than others.

  In many cases, golfers want a golf ball that is as long as possible to drive. The drive length depends on many factors that the golfer cannot control, such as the relative height of the tee box and the fairway, obstacles on or adjacent to the fairway, wind speed, climate, etc. Furthermore, the drive length depends on the club head speed, the form, and the golfer's swing parameters such as the club selected for the particular drive. Furthermore, the drive length depends on the initial speed at which the ball leaves the driver.

  In other cases, such as a short game, the golfer wants a golf ball that feels good when hit and has good spin / spin properties. The feel of a golf ball is often determined by the material of one or more cover layers. The selection of the cover material may be based on durability, fraying durability, color, and the like.

  Many golfers desire a certain balance between the length of the ball trajectory and the ball feel. Some golfers want only one or the other of these, but in many cases golfers want a certain balance of these features.

  Therefore, it is desirable to develop a ball with a combination of good feel and maximum initial speed features. This combination of features is generally considered desirable for golfers playing with the ball.

  In one embodiment, a golf ball is provided. The golf ball may include a core and a cover surrounding the core. The core may comprise a highly neutralized polymer. The cover may include a damping material. The core may have a first coefficient of restitution, and the ball may have a second coefficient of restitution. The difference between the first coefficient of restitution and the second coefficient of restitution is less than about 0.032.

In another embodiment, a golf ball is provided. The golf ball may include a core and a cover surrounding the core. The compression of the core may be x. The coefficient of restitution of the ball may be given by the equation 0.6511-0.024x ² + 0.1165x. The coefficient of restitution of the core may be given by the equation 0.7951-0.0121x ² + 0.416x. The coefficient of restitution of any ball produced according to this trend line may be suppressed to produce a conforming ball. By using a dampening material as the cover, the designer can produce a compatible ball using a high energy core.

  Golf balls can be designed to have a specific relationship between compression, coefficient of restitution, and initial velocity. The material of the core and the coefficient of restitution can be devised so that the initial velocity of the ball and / or the spin property of the ball is higher than expected. The core material and compression can be devised so that the overall coefficient of restitution of the ball is different than expected. In particular, balls made in accordance with the present invention tend to have a higher initial velocity than expected for a given coefficient of restitution. This means that the golfer has an initial speed sufficient to obtain a good driver distance and at the same time an improved spin performance with a low coefficient of restitution in a short game, especially in a half wedge shot.

  A ball in which a high energy material such as a highly neutralized polymer is used in the core and a damping material such as thermoplastic polyurethane is used in the cover can achieve these advantages. A ball with a given high energy core provides the designer with many options for a cover to achieve the desired ball performance parameters.

  Other systems, methods, features, and advantages will become apparent to those skilled in the art upon examination of the accompanying drawings and detailed description. All such additional systems, methods, features, and advantages included in this description and this summary are included within the scope of the disclosure and are protected by the following claims.

  The invention can be better understood with reference to the following drawings and description. The components in the accompanying drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the accompanying drawings, like reference numerals designate corresponding parts throughout the different views.

FIG. 1 is a side view of a golf ball according to the present disclosure. FIG. 2 is a cross-sectional view of one embodiment of a golf ball according to the present disclosure. FIG. 3 is a cross-sectional view of another embodiment of a golf ball according to the present disclosure. FIG. 4 is a cross-sectional view of yet another embodiment of a golf ball according to the present disclosure. FIG. 5 is a graph comparing the initial speed and the ball restitution coefficient when a test is performed with a driver. FIG. 6 is a graph comparing the coefficient of restitution and compression of two balls and the corresponding cores of these balls. FIG. 7 is a graph showing trend lines for the various cores of FIGS.

  A multilayer golf ball is disclosed. Although the embodiments discussed herein are limited to golf balls, the invention is not so limited. The techniques described herein may be applied to any layered article, particularly a projectile, ball, recreational device, or component thereof.

  FIG. 1 is a side view of a ball 100 manufactured in accordance with the techniques disclosed herein. 1 to 4 show a general dimple pattern applied to the outer surface 102 of the ball 100. Although the dimple pattern provided on the ball 100 affects the flight path of the ball 100, the specific dimple pattern is not important in using the embodiment disclosed herein. The designer may select any suitable dimple pattern to be applied to the ball 100.

  FIG. 2 is a cross-sectional view of the first embodiment of the ball 100 taken along line 2-2 of FIG. As shown in FIG. 2, the ball 200 may include two layers. The ball 200 may include a core 204 and a cover 206 surrounding the core 204. Any embodiment of the golf ball described herein may include, for example, compression molding and / or injection molding of the core, injection molding of any outer layer, and optionally the layers of the golf ball can be bonded together. It may be manufactured according to any well-known technique such as the technique of gluing and the technique of painting or coating by spraying, brushing, dipping, pad painting, etc.

  The core 204 may be formed of a high energy efficient material. High energy efficient materials are materials that tend to collide in a highly elastic manner. The core 204 may, in some embodiments, be formed primarily of a polymer, i.e., a highly neutralized polymer as a whole. In some embodiments, the highly neutralized polymer may be HPF 1000 or HPF 2000 available from E. I. DuPont de Nemours and Company. In some embodiments, the core 204 may have a diameter of about 38 mm to about 41 mm. The cover 206 may be formed of a low energy efficient or deadening material in some embodiments. Low energy efficient materials are materials that tend to collide in a low elastic manner. In some embodiments, the cover 206 may be formed primarily or entirely of a thermoplastic urethane resin. In some embodiments, the cover 206 may be at least 2.1 mm thick.

  In some embodiments, one or more additional outer layers may be included, but this is not shown in FIG. 2 or any other view. A top coat may be provided outside the cover 206 in FIG. The top coat is a coating applied to improve or adjust the appearance of the ball 200. For example, the top coat may be applied to change the color of the ball 200 or to change the degree of gloss of the ball 200. In another embodiment, the additional coating may take the form of a logo or other print applied on the outer surface 202 of the ball 200. Other additional coatings may be applied to the outside of the cover 206. One skilled in the art will appreciate that such an external coating may be applied to any of the embodiments described herein. Accordingly, this optional coating is not described in further detail in connection with the following examples. It should be noted that golf balls are typically coated. All balls tested in this application are provided with coatings such as paint and protective coatings. The coating has some effect on the coefficient of restitution of the ball, but is considered negligible in considering the examples described herein. However, if the coating thickness is sufficiently thick or the coating is formed of a very hard or soft material, this effect has a significant impact on the design objectives of the embodiments according to the present disclosure.

  FIG. 3 is a cross-sectional view of the second embodiment of the ball along line 2-2 in FIG. As shown in FIG. 3, the ball 300 may include three layers. The ball 300 may include a core 304, an inner cover layer 308 that surrounds the core 304, and an outer cover layer 310 that surrounds the inner cover layer 308.

  The core 304 may be formed of a high energy efficiency material. The core 304, in some embodiments, may be formed primarily, i.e., a highly neutralized polymer as a whole. In some embodiments, the highly neutralized polymer may be HPF 1000 or HPF 2000 available from E. I. DuPont de Nemours and Company. The diameter of the core 304 may be about 38 mm to about 41 mm. In some embodiments, any layer other than the cover layer may include a highly neutralized ionomer. In some embodiments, all layers except the cover layer may be agglomerated to a size of about 38 mm to 41 mm. In some embodiments, all layers except the cover layer may be agglomerated to about 38.6 mm.

  Inner cover layer 308 and outer cover layer 310 may be formed of one or more low energy efficient or damping materials in some embodiments. In some embodiments, the inner cover layer 308, the outer cover layer 310, or both may be formed primarily or entirely of a thermoplastic urethane resin or a thermoplastic polyurethane resin. In other embodiments, the inner cover layer 308, the outer cover layer 310, or both may be formed primarily or entirely of ionomer resin. In some examples, the ionomer resin may be SURLYN®, commercially available from E. I. DuPont de Nemours and Company. In some embodiments, the combined thickness of the inner cover layer 308 and the outer cover layer 318 may be about 2.1 mm.

  FIG. 4 is a cross-sectional view of the ball 400 taken along line 2-2 of FIG. As shown in FIG. 4, the ball 400 may include four layers. The first layer 412 may be an inner core layer. The second layer 414 may be an outer core layer and may surround the first layer 412. The third layer 416 may be an inner cover layer and may surround the second layer 414. The fourth layer 418 may be an outer cover layer and may surround the third layer 416. The first or inner core layer 412 and the second or outer core layer 414 may be considered together and may be referred to as the core 420. A third or inner cover layer 416 and a fourth or outer cover layer 418 may be considered together and may be referred to as a cover 422.

  The core 420 may be formed of one or more high energy efficient materials, and each of the first layer 412 and the second layer 414 may be formed of a high energy efficient material of a different formulation. . At least one layer of the core 420 may be formed primarily, i.e., entirely highly neutralized polymer, in some embodiments. In some embodiments, the highly neutralized polymer may be HPF 1000 or HPF 2000 available from E. I. DuPont de Nemours and Company. The cover 422 may be formed of a low energy efficient material, ie a damping material. In some embodiments, the third layer 416, the fourth layer 418, or both may be formed primarily or entirely of a thermoplastic urethane resin. In other embodiments, the third layer 416, the fourth layer 418, or both may be formed primarily or entirely of ionomer resin. In some embodiments, the ionomer resin may be SURLYN, commercially available from E. I. DuPont de Nemours and Company. In some embodiments, the combined thickness of the inner cover layer 416 and the outer cover layer 418 may be about 2.1 mm. In some embodiments, any layer other than the cover layer may include a highly neutralized ionomer. In some embodiments, all layers except the cover layer may be agglomerated to a size of about 38 mm to 41 mm. In some embodiments, all layers except the cover layer may be agglomerated to about 38.6 mm.

  FIG. 4 shows a ball 400 having a plurality of layers. In some embodiments, additional layers may be added. For example, in some embodiments, a mantle layer may be added between the core 420 and the cover 422. In other embodiments, an intermediate cover layer may be inserted between the inner cover layer 416 and the outer cover layer 418. In other embodiments, an intermediate core layer may be inserted between the inner core layer 412 and the outer core layer 414.

  Furthermore, similar modifications may be made to any of these embodiments based on the specific desires of the designer without departing from the embodiments disclosed herein. This will be understood by those skilled in the art. For example, a four-layer ball may include an inner core layer, an intermediate core layer, an outer core layer, and a single cover layer. Similarly, a four-layer ball may include a single core layer and an inner cover layer, an intermediate cover layer, and an outer cover layer. Furthermore, it will be apparent to those skilled in the art that the balls have different numbers of intermediate layers. Accordingly, the illustrated embodiments are examples only and are not intended to be limiting.

  Reference is now made to FIG. 5, which shows a graph illustrating the difference between the disclosed embodiment and a currently commercially available ball. These balls are described in further detail below. The value on the left y-axis is the initial velocity of the ball when tested with a driver. Each ball was hit with a Nike SQ driver with a loft angle of 9.5 under the same conditions (head speed, angle of attack, etc.).

  The initial speed is indicated in the graph by the height of each bar in the bar graph. The initial speed shown in the bar graph is shown in miles per hour. The initial speed at 150 miles per hour is equal to about 220 feet per second (67.056 meters per second). The initial speed at about 170 miles per hour is equal to about 250 feet per second (76.2 meters per second).

  The value on the right side of the graph indicates the coefficient of restitution as a whole ball. In order to measure the coefficient of restitution of the object, the object was fired with an air cannon at an initial velocity of about 40 meters per second. A steel plate was positioned about 1.2 m from the gun, and a speed monitoring device was placed at a distance of about 0.6 m to about 0.9 m from the gun. The object is fired from the air cannon, passes through the speed monitoring device, and confirms the initial speed. The object then bounces against the steel plate and passes through the speed monitoring device to confirm the return speed. The coefficient of restitution is the ratio of the return speed to the initial speed. The coefficient of restitution for each ball is shown by a line 544 in the graph.

  The X axis is the number assigned to the ball tested. Each ball was tested for initial speed and coefficient of restitution. The first nine balls (Nos. 1 to 9) are commercially available balls. Each of these golf balls has a core made of butadiene rubber compound and having a diameter of about 40 mm. For each ball, the exact formulation of the core is slightly different. The core of each ball is made of butadiene rubber with different additives or is different in size and therefore has different compression and restitution coefficients. It is considered that there is a correlation, that is, a potentially strong correlation between the coefficient of restitution and the size of the core. For this reason, even a slight change in the size of the core has a non-negligible effect on the coefficient of restitution. The cover of each of these balls has a thickness of about 1.4 mm and is mainly formed of SURLYN.

  On the other hand, the ball numbered 10 is a ball manufactured according to this example. The tenth ball has a core with a diameter of about 38 mm, which is mainly formed of a highly neutralized polymer resin. The core diameter may be about 41 mm. The thickness of the cover of the ball is about 2.1 mm, but it may be as thin as about 0.9 mm. If desired, a mantle layer may be included so that the ball meets the minimum standard of USGA size of 42.67 mm (1.680 inches).

  Comparing the relationship between the initial speed and the coefficient of restitution, there is a correlation between the coefficient of restitution and the initial speed as a whole for balls No. 1 to No. 9. For example, for balls of No. 1, No. 2, No. 4, and No. 5, whose restitution coefficient is lower than 0.795, the initial speed is reduced to about 150.2. For balls 3, 6, 7, and 8 with a coefficient of restitution less than 0.800, the initial velocity is higher than about 150.8. For the ninth ball with a coefficient of restitution of about 0.800, the initial speed is about 150.5. Therefore, the graph shows that there is an overall correlation between the coefficient of restitution and the initial speed.

  However, the graph shown in FIG. 5 shows that the initial speed of the 10th ball deviates from the expected initial speed of the conventional ball having a restitution coefficient of 0.774. For the tenth ball, the value of the coefficient of restitution is about 0.774. From the 1st to 9th conventional balls, the initial speed is expected to be lower than 150 miles per hour (67.056 meters per second), but the initial speed of the 10th ball is 150.8. This initial speed is approximately the same as the initial speed of a ball having a much higher coefficient of restitution than the 10th ball. Therefore, by using the above-described ball structure, the ball's coefficient of restitution remains relatively low for good feel and spin in short games, and a suitable high initial speed for long distances using a driver. maintain.

  This is particularly important for half wedge shots. In a ball with a low coefficient of restitution, the golfer tries to hit the ball strongly, i.e., at a relatively high head speed, because the golfer has the same distance as a ball with a high coefficient of restitution. The harder you hit (the higher the club head speed), the more spins are added to the ball. Therefore, the golfer can obtain a ball with a low coefficient of restitution that has a good initial speed and a good driver distance but has a high spin performance in a short game.

  Additional features that can be compared between the existing ball and the ball of the present disclosure can be seen in FIG. FIG. 6 is a graph showing the relationship between compression and coefficient of restitution for various balls and ball cores. The x-axis represents the compression of the inner core layer of the ball. Compression is determined by methods well known in the art. An initial load of 10 kg is applied to the spherical core and / or ball. The ball diameter is typically measured in millimeters at one or more points, such as pole (s), seams, or random points. Record either a single value or the average of the values obtained. The load is increased to 130 kg and at the same point a second measurement of the diameter of the ball is taken, also in millimeters. Record a single value or the average of the values obtained with a large load applied. The difference between the recorded millimeter values is compression.

The y-axis value represents the coefficient of restitution for each of the four possible items. Line 650 shows the relationship between compression and coefficient of restitution for a core made of butadiene rubber compound and having a diameter of about 38 mm. The equation for the trend line of this rubber core is shown in the following formula 1.

Equation 1 y = 0.7531-0.0128x ² + 0.055x
Where x is the compression of the inner core and y is the corresponding coefficient of restitution.

Line 660 shows the relationship between compression and coefficient of restitution for a ball that includes a cover covering the core indicated by line 650. The equation for this line is given by Equation 2 below.

Formula 2 y = 0.6794-0.0179x ² + 0.0831x
Where x is the core compression and y is the coefficient of restitution of the entire ball. The difference between the relative coefficient of restitution of the core and the coefficient of restitution of the ball is about 0.035 to about 0.037.

However, when comparing the relative coefficient of restitution for a ball comprising a core formed primarily of a highly neutralized polymer as a whole, a clear difference is shown. Line 670 shows the relationship between compression and coefficient of restitution for a core of about 38 mm in diameter, primarily formed of a highly neutralized polymer as a whole. The equation for this line is given by Equation 3 below.

Formula 3 y = 0.7951-0.0121x ² + 0.0416x
Where x is the compression of the core and y is the corresponding coefficient of restitution.

Line 680 shows the relationship between compression and coefficient of restitution for a ball that includes a cover covering the core indicated by line 670. The cover has the same cover structure as the ball cover represented by line 650. The equation for this line is given by Equation 4 below.

Formula 4 y = 0.6511-0.024x ² + 0.1165x
Where x is the core compression and y is the coefficient of restitution of the entire ball. The difference between the relative coefficient of restitution of the core and the coefficient of restitution of the ball is about 0.026 to about 0.031.

  Thus, as clearly shown in FIG. 6, for a given compression of the inner core, the coefficient of restitution of a ball with a rubber core is lower than a ball with a highly neutralized polymer (HNP) core. Further, to maximize the effect of the damping material, the difference between the coefficient of restitution of the core and the coefficient of restitution of the ball must be at least 0.026, but is 0.037, 0.05, or in some cases 0 .1 and much higher than this. The lower the coefficient of restitution of the ball, the better the spin performance of the ball. Therefore, a ball having a large difference in coefficient of restitution of at least 0.037 or at least 0.05 is desirable. As discussed above, cores made in accordance with the present invention have a relatively high coefficient of restitution, which can provide considerable flexibility in selecting cover materials. This is because even if a damping cover is provided, the coefficient of restitution as a whole of the ball is within the maximum performance range.

  These advantages are illustrated more simply in FIG. Here, the rubber core trend line 762 indicates that the compression of the inner core for a given coefficient of restitution is consistently lower than the trend line 760 of the HNP core. The trend line for the ball with the HNP core (the trend line for the entire ball with the HNP core) 764 is shown for reference.

Therefore, by replacing the resin core having a specific coefficient of restitution with a rubber core having the same specific coefficient of restitution, the relative coefficient of restitution of the ball and the core can be dramatically changed. This is true when the coefficient of restitution of the resin core exceeds the coefficient of restitution given by the trend line of the rubber core and the coefficient of restitution of the ball is smaller than the coefficient of restitution given by Equation 5 below.

Formula 5 y = −0.0103x + 0.8419
Where y is the coefficient of restitution and x is the compression of the inner core.

  This can typically be achieved by forming at least one inner / non-cover layer with a highly neutralized ionomer / polymer. There is no need to change the properties of the cover between a butadiene rubber core and a highly neutralized polymer core. However, the difference in coefficient of restitution between the core and the ball is at least about 0.004 lower when using a highly neutralized polymer core. Thereby, a ball having a relatively high coefficient of restitution can be manufactured using the same cover material.

Other limitations need to be observed according to the trend line for coefficient of restitution discussed above for highly neutralized polymer cores and balls with highly neutralized polymer cores. For example, the coefficient of restitution of a ball of the same shape is lower than the trend given by Equation 5, or more conservatively Equation 6 below.

Formula 6 y = −0.0103x + 0.8299
Where y is the coefficient of restitution and x is the compression of the inner core.
Therefore, the designer tries to suppress the restitution coefficient of the ball given according to Equation 4 so that the restitution coefficient does not exceed the restitution coefficient given by Equation 6.

  Balls manufactured within the scope of the above disclosure are considered to have improved properties. Such a ball is considered to have an initial velocity higher than expected. Such balls can also significantly change the cover material, in particular a low-cost cover material. Such a ball can provide a golfer with a relatively inexpensive ball having a longer trajectory than other balls.

  In order to increase these advantages, other structures of the layered article are also possible. For example, US Patent No. 12 / 860,785, the present disclosure and US patent application Ser. No. 12 / 860,785, filed Aug. 20, 2010, entitled “Golf Ball Having Multiple Layers with Specified Flexural Modulus and Hardness” Golf balls may be manufactured in accordance with the teachings of both of the articles described in __. By specifying the source, all the contents disclosed in the above application are made part of the disclosure of this specification.

  While various embodiments of the present invention have been described, the above description is for purposes of illustration and not limitation, and it is to be understood that many other embodiments within the scope of the present disclosure are possible. It will be clear to the contractor. Accordingly, the disclosure is not to be restricted except in the scope of the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

100 ball 102 outer surface 200 ball 204 core 202 outer surface 206 cover 300 ball 304 core 308 inner cover layer 310 outer cover layer

Claims (8)

In a golf ball having a diameter of 42.67 mm or more,
A core formed of a highly neutralized ionomer, having a single layer core having a diameter of 38 mm to 41 mm ;
A cover that is disposed radially outward of the core and surrounds the core, the cover being a single layer formed of thermoplastic polyurethane;
In a golf ball consisting of
The core has a first coefficient of restitution measured as an initial speed of 40 m / sec, and the ball has a second coefficient of restitution measured as an initial speed of 40 m / sec;
The difference between the first coefficient of restitution and the second coefficient of restitution being greater than 0.026, ball.
The ball according to claim 1,
A ball having a first coefficient of restitution greater than 0.78.
The ball according to claim 1,
A ball with a second coefficient of restitution less than 0.79.
The ball according to claim 3,
A ball having a second coefficient of restitution of 0.774.
In a golf ball having a diameter of 42.67 mm or more,
A core formed of a highly neutralized ionomer, a single layer core having a diameter of 38 mm ;
A cover surrounding the core, a single layer cover formed of thermoplastic polyurethane ;
In a golf ball consisting of
The coefficient of restitution of the ball is given by y = 0.6511-0.024x ² + 0.1165x,
The coefficient of restitution of the core is given by y ′ = 0.951-0.0121x ² + 0.0416x,
Here, “x” is the compression value of the core measured as the difference between the deformation amount of the 10 kg load and the deformation amount of the 130 kg load for the core with a diameter of 38 mm, and “y” is measured as the initial speed of 40 m / sec. The ball is characterized by the coefficient of restitution of the ball, wherein “y ′” is the coefficient of restitution of the core measured at an initial speed of 40 m / sec.
The ball according to claim 5 ,
A ball having a coefficient of restitution of the core greater than 0.78.
The ball according to claim 5 ,
The ball has a coefficient of restitution less than 0.79.
In a golf ball having a diameter of 42.67 mm or more,
A core formed of a highly neutralized ionomer, a single layer core having a diameter of 38 mm ;
A cover that is disposed radially outward of the core and surrounds the core, the cover being a single layer formed of thermoplastic polyurethane ;
In a golf ball consisting of
The coefficient of restitution of the core is greater than the trend line of the coefficient of restitution of the rubber core, and the trend line of the coefficient of restitution of the rubber core is given by y = −0.0128x ² + 0.055x + 0.75531,
Here, “y” is the coefficient of restitution, and “x” is the compression value of the inner core measured as the difference between the deformation amount of the 10 kg load and the deformation amount of the 130 kg load for the core with a diameter of 38 mm,
A ball characterized in that the difference between the coefficient of restitution of the core measured at an initial speed of 40 m / sec and the coefficient of restitution of the ball is greater than 0.026 .

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