Patent Abstract:
A dimple pattern for a golf ball with a thermoset polyurethane cover is disclosed herein. The dimple pattern has multiple sets of dimples, each set of dimples having a different diameter. A preferred set of dimples is seven different dimples. The dimples may cover as much as eighty-six percent of the surface of the golf ball. The unique dimple pattern allows a golf ball with a thermoset polyurethane cover to have shallow dimples with steeper entry angles. The unique dimple pattern also allows a golf ball with a thermoset polyurethane cover to have greater low speed lift with a lower high speed drag.

Full Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This present application is a continuation application of U.S. patent application Ser. No. 09/398,917, which was filed on Sep. 16, 1999, now U.S. Pat. No. 6,213,898. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a golf ball with a thermoset polyurethane cover. More specifically, the present invention relates to a dimple pattern for a golf ball with a thermoset polyurethane cover in which the dimple pattern has different sizes of dimples. 
     2. Description of the Related Art 
     Golfers realized perhaps as early as the 1800&#39;s that golf balls with indented surfaces flew better than those with smooth surfaces. Hand-hammered gutta-percha golf balls could be purchased at least by the 1860&#39;s, and golf balls with brambles (bumps rather than dents) were in style from the late 1800&#39;s to 1908. In 1908, an Englishman, William Taylor, received a patent for a golf ball with indentations (dimples) that flew better ad more accurately than golf balls with brambles. A.G. Spalding &amp; Bros., purchased the U.S. rights to the patent and introduced the GLORY ball featuring the TAYLOR dimples. Until the 1970s, the GLORY ball, and most other golf balls with dimples had 336 dimples of the same size using the same pattern, the ATTI pattern. The ATTI pattern was an octahedron pattern, split into eight concentric straight line rows, which was named after the main producer of molds for golf balls. 
     The only innovation related to the surface of a golf ball during this sixty year period came from Albert Penfold who invented a mesh-pattern golf ball for Dunlop. This pattern was invented in 1912 and was accepted until the 1930&#39;s. 
     In the 1970&#39;s, dimple pattern innovations appeared from the major golf ball manufacturers. In 1973, Titleist introduced an icosahedron pattern which divides the golf ball into twenty triangular regions. An icosahedron pattern was disclosed in British Patent Number 377,354 to John Vernon Pugh, however, this pattern had dimples lying on the equator of the golf ball which is typically the parting line of the mold for the golf ball. Nevertheless, the icosahedron pattern has become the dominant pattern on golf balls today. 
     In the late 1970s and the 1980&#39;s the mathematicians of the major golf ball manufacturers focused their intention on increasing the dimpled surface area (the area covered by dimples) of a golf ball. The dimpled surface for the ATTI pattern golf balls was approximately 50%. In the 1970&#39;s, the dimpled surface area increased to greater than 60% of the surface of a golf ball. Further breakthroughs increased the dimpled surface area to over 70%. U.S. Pat. No. 4,949,976 to William Gobush discloses a golf ball with 78% dimple coverage with up to 422 dimples. The 1990&#39;s have seen the dimple surface area break into the 80% coverage. 
     The number of different dimples on a golf ball surface has also increased with the surface area coverage. The ATTI pattern disclosed a dimple pattern with only one size of dimple. The number of different types of dimples increased, with three different types of dimples becoming the preferred number of different types of dimples. U.S. Pat. No. 4,463 to Oka et al., discloses a dimple pattern with four different types of dimples on surface where the non-dimpled surface cannot contain an additional dimple. United Kingdom patent application number 2157959, to Steven Aoyama, discloses dimples with five different diameters. Further, William Gobush invented a cuboctahedron pattern that has dimples with eleven different diameters. See 500  Year of Golf Balls , Antique Trade Books, page 189. However, inventing dimple patterns with multiple dimples for a golf ball only has value if such a golf ball is commercialized and available for the typical golfer to play. 
     Additionally, dimple patterns have been based on the sectional shapes, such as octahedron, dodecahedron and icosahedron patterns. U.S. Pat. No. 5,201,522 discloses a golf ball dimple pattern having pentagonal formations with equally number of dimples therein. U.S. Pat. No. 4,880,241 discloses a golf ball dimple pattern having a modified icosahedron pattern wherein small triangular sections lie along the equator to provide a dimple-free equator. 
     Although there are hundreds of published patents related to golf ball dimple patterns, there still remains a need to improve upon current dimple patterns, particularly for golf balls with thermoset polyurethane covers. Golf balls with thermoset polyurethane covers such as the Maxfli REVOLUTION, the Maxfli HT, the Titleist PROFESSIONAL, the Titleist TOUR PRESTIGE, and the Slazenger RAM 420 all need to compensate for the inherent properties of the polyurethane material which include the increased spin, the higher drag levels, and manufacturing difficulties. There is still a need for a dimple pattern designed to maximize the aerodynamics of a golf ball with a thermoset polyurethane cover. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a novel dimple pattern that reduces high speed drag on a golf ball while increasing its low speed lift thereby providing a golf ball that travels greater distances. The present invention is able to accomplish this by providing multiples sets of dimples arranged in a pattern that covers as much as eighty-six percent of the surface of the golf ball. 
     One aspect of the present invention is a dimple pattern on a golf ball having a thermoset cover with a surface coated with at least a base coat. The preferred thermoset is polyurethane, however, those skilled in the art will recognize that other thermoset materials may be employed in practicing the present invention. The golf ball includes a plurality of different sets of dimples disposed on the surface. Each of the different sets of dimples has a different diameter than any other set of dimples. The depth of each of the dimples of the plurality of different sets of dimples is limited to 0.0060 inches from the chord of each dimple. 
     The depth of each of the dimples of the plurality of different sets of dimples may be between 0.0045 and 0.0060 inches from the chord. Each of the dimples of the plurality of different sets of dimples has an entry angle, and the entry angle of each dimple may be between 14 and 16 degrees. Each of the dimples of the plurality of different sets of dimples has an edge radius, and the edge radius of each dimple may be between 0.020 and 0.050 inches. 
     Another aspect of the present invention is a dimple pattern on a golf ball having a thermoset polyurethane cover in which the dimple pattern has at least five different sets of dimples. The golf ball includes first, second, third, fourth and fifth pluralities of dimples disposed on the surface. Each of the first plurality of dimples has a first diameter. Each of the second plurality of dimples has a second diameter that is greater than the first diameter. Each of the third plurality of dimples has a third diameter that is greater than the second diameter. Each of the fourth plurality of dimples has a fourth diameter that is greater than the third diameter. Each of the fifth plurality of dimples has a fifth diameter that is greater than the fourth diameter. The first, second, third, fourth and fifth pluralities of dimples cover at least eighty percent of the surface of the golf ball. 
     The golf ball may also include a sixth plurality of dimples disposed on the surface with each of the sixth plurality of dimples having a sixth diameter that is greater than the fifth diameter. The first, second, third, fourth, fifth and sixth pluralities of dimples cover at least eighty-three percent of the surface of the golf ball. 
     The golf ball may further include at least one seventh dimple disposed on the surface. The at least one seventh dimple has a seventh diameter that is less than the first diameter. The first, second, third, fourth, fifth and sixth pluralities of dimples and the at least one seventh dimple cover at least eighty-six percent of the surface of the golf ball. The golf ball has an equator that divides the golf ball into a first hemisphere and a second hemisphere, and the first hemisphere may be unsymmetrical with the second hemisphere. 
     Another aspect of the present invention is a dimple pattern on a golf ball with a thermoset polyurethane cover that provides greater low speed lift and lower high speed drag. The golf ball includes a plurality of different sets of dimples disposed on the surface of the coated thermoset polyurethane cover. Each of the different sets of dimples having a different diameter than any other set of dimples. The plurality of different sets of dimples cover at least eighty-three percent of the surface of the golf ball. The golf ball has a lift coefficient greater than 0.20 at a Reynolds number of 70,000 and 2000 rpm, and a drag coefficient less than 0.232 at a Reynolds number of 180,000 and 3000 rpm. 
     Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is an equatorial view of a preferred embodiment of a golf ball of the present invention. 
     FIG. 1A is the view of FIG. 1 illustrating the rows of dimples. 
     FIG. 1B is the view of FIG. 1 illustrating the transition region of dimples. 
     FIG. 2 is a polar view of the golf ball of FIG.  1 . 
     FIG. 2A is the view of FIG. 2 illustrating the cascading pentagons of dimples. 
     FIG. 2B is the view of FIG. 2 illustrating the single encompassing pentagon of dimples. 
     FIG. 3 is a polar view of the golf ball of FIG. 1 illustrating the star configuration. 
     FIG. 4 is an enlarged cross-sectional view of a dimple of a first set of dimples of the golf ball of the present invention. 
     FIG. 4A is an isolated cross-sectional view to illustrate the definition of the entry radius. 
     FIG. 5 is an enlarged cross-sectional view of a dimple of a second set of dimples of the golf ball of the present invention. 
     FIG. 6 is an enlarged cross-sectional view of a dimple of a third set of dimples of the golf ball of the present invention. 
     FIG. 7 is an enlarged cross-sectional view of a dimple of a fourth set of dimples of the golf ball of the present invention. 
     FIG. 8 is an enlarged cross-sectional view of a dimple of a fifth set of dimples of the golf ball of the present invention. 
     FIG. 9 is an enlarged cross-sectional view of a dimple of a sixth set of dimples of the golf ball of the present invention. 
     FIG. 10 is an enlarged cross-sectional view of a dimple of a seventh set of dimples of the golf ball of the present invention. 
     FIG. 11 is a polar view of an alternative embodiment of the golf ball of the present invention. 
     FIG. 12 is an equatorial view of yet another alternative embodiment of a golf ball of the present invention. 
     FIG. 13 is a graph of the lift coefficient versus Reynolds number. 
     FIG. 14 is graph of the drag coefficient versus Reynolds number. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 1-3, a golf ball is generally designated  20 . The golf ball may be a one-piece, two-piece, a three piece, or the like golf ball. Further, the three-piece golf ball may have a wound layer, or a solid boundary layer. The cover of the golf ball  20  may be any suitable material. A preferred cover is composed of a thermoset polyurethane material. However, those skilled in the pertinent art will recognize that other cover materials may be utilized without departing from the scope and spirit of the present invention. The golf ball  20  may have a finish of a basecoat and/or top coat. 
     The golf ball  20  has a surface  22 . The golf ball  20  also has an equator  24  dividing the golf ball  20  into a first hemisphere  26  and a second hemisphere  28 . A first pole  30  is located ninety degrees along a longitudinal arc from the equator  24  in the first hemisphere  26 . A second pole  32  is located ninety degrees along a longitudinal arc from the equator  24  in the second hemisphere  28 . 
     On the surface  22 , in both hemispheres  26  and  28 , are  382  dimples partitioned into seven different sets of dimples. A first set of dimples  34  are the most numerous dimples consisting of two-hundred twenty dimples in the preferred embodiment. A second set of dimples  36  are the next most numerous dimples consisting of one-hundred dimples. A third set of dimples  38  and a fourth set of dimples  40  are the next most numerous with each set  38  and  40  consisting of twenty dimples in the preferred embodiment. A fifth set of dimples  42  and a sixth set of dimples  44  are the next most numerous with each set  42  and  44  consisting of ten dimples in the preferred embodiment. The seventh set of dimples  46  consist of only two dimples. In a preferred embodiment, the 382 dimples account for 86% of the surface  22  of the golf ball. 
     The two dimples of the seventh set of dimples  46  are each disposed on respective poles  30  and  32 . Each of the fifth set of dimples  42  is adjacent one of the seventh set of dimples  46 . The five dimples of the fifth set of dimples  42  that are disposed within the first hemisphere  26  are each an equal distance from the equator  24  and the first pole  30 . The five dimples of the fifth set of dimples  42  that are disposed within the second hemisphere  28  are each an equal distance from the equator  24  and the second pole  32 . These polar dimples  42  and  46  account for approximately 2% of the surface  22  of the golf ball  20 . 
     A cross-section of a dimple of the fifth set of dimples  42  is shown in FIG.  8 . The radius R 5  of the dimple  42  is approximately 0.0720 inches, the chord depth C 5  is approximately 0.0054 inches, the entry angle θ 5  is approximately 15.7 degrees, and the edge radius ER 5  is approximately 0.0336 inches. A cross-section of a dimple of the seventh set of dimples  46  is shown in FIG.  10 . The radius R 7  of the dimple  46  is approximately 0.0510 inches, the chord depth C 7  is approximately 0.0049 inches, the entry angle θ 7  is approximately 13.4 degrees, and the edge radius ER 7  is approximately 0.0336 inches. 
     The ten dimples of the sixth set of dimples  44  account for approximately 3% of the surface  22  of the golf ball  20 . The five dimples of the sixth set of dimples  44  that are disposed within the first hemisphere  26  are each an equal distance from the equator  24  and the first pole  30 . The five dimples of the sixth set of dimples  44  that are disposed within the second hemisphere  28  are each an equal distance from the equator  24  and the second pole  32 . Also, each of the sixth set of dimples  44  is adjacent to three different sets of dimples  34 ,  36  and  40 . 
     A cross-section of a dimple of the sixth set of dimples  44  is shown in FIG.  9 . The radius R 6  of the dimple  44  is approximately 0.0930 inches, the chord depth C 6  is approximately 0.0051 inches, the entry angle θ 6  is approximately 15.2 degrees, and the edge radius ER 6  is approximately 0.0333 inches. The extraordinarily large diameter of each of the sixth set of dimples  44  allows for the extraordinary surface coverage of the dimple pattern of the present invention. This is contrary to conventional thinking that teaches that dimples with smaller diameters would provide for greater surface coverage. 
     All of the fourth set of dimples  40  are adjacent to at least one of the sixth set of dimples  44 . The twenty dimples of the fourth set of dimples  40  cover approximately 2.7% of the surface  22  of the golf ball  20 . The ten dimples of the fourth set of dimples  40  that are disposed within the first hemisphere  26  are each an equal distance from the equator  24  and the first pole  30 . The ten dimples of the fourth set of dimples  40  that are disposed within the second hemisphere  28  are each an equal distance from the equator  24  and the second pole  32 . Also, each of the fourth set of dimples  40  is adjacent to three different sets of dimples  36 ,  38  and  44 . 
     A cross-section of a dimple of the fourth set of dimples  40  is shown in FIG.  7 . The radius R 4  of the dimple  40  is approximately 0.062 inches, the chord depth C 4  is approximately 0.0052 inches, the entry angle θ 4  is approximately 15.2 degrees, and the edge radius ER 4  is approximately 0.0358 inches. 
     All of the third set of dimples  38  are adjacent to at least one of the sixth set of dimples  44 . The twenty dimples of the third set of dimples  38  cover approximately 3.8% of the surface  22  of the golf ball  20 . The ten dimples of the third set of dimples  38  that are disposed within the first hemisphere  26  are each an equal distance from the equator  24  and the first pole  30 . The ten dimples of the third set of dimples  38  that are disposed within the second hemisphere  28  are each an equal distance from the equator  24  and the second pole  32 . Also, each of the fourth set of dimples  38  is adjacent to three different sets of dimples  34 ,  36  and  40 . 
     A cross-section of a dimple of the third set of dimples  38  is shown in FIG.  6 . The radius R 3  of the dimple  38  is approximately 0.074 inches, the chord depth C 3  is approximately 0.0053 inches, the entry angle θ 3  is approximately 15.3 degrees, and the edge radius ER 3  is approximately 0.0344 inches. 
     The two-hundred twenty dimples of the first set of dimples  34  are the most influential of the different sets of dimples  34 - 46  due to their number, size and placement on the surface  22  of the golf ball  20 . The two-hundred twenty dimples of the first set of dimples  34  cover approximately 53% of the surface  22  of the golf ball  20 . The one-hundred ten dimples of the first set of dimples  34  that are disposed within the first hemisphere  26  are disposed in either a first row  80  and a second row  82  above the equator  24 , or a pseudo-star configuration  84  about the first pole  30  that is best illustrated in FIG.  3 . Similarly, the one-hundred ten dimples of the first set of dimples  34  that are disposed within the second hemisphere  28  are disposed in either a first row  90  and a second row  92  below the equator  24 , or a pseudo-star configuration  94 , not shown, about the second pole  32 , not shown. 
     A cross-section of a dimple of the first set of dimples  34  is shown in FIG.  4 . The radius R 1  of the dimple  34  is approximately 0.0834 inches, the chord depth C 1  is approximately 0.0053 inches, the entry angle θ 1  is approximately 15.3 degrees, and the edge radius ER 1  is approximately 0.0344 inches. Unlike the use of the term “entry radius” or “edge radius” in the prior art, the edge radius as defined herein is a value utilized in conjunction with the entry angle to delimit the concave and convex segments of the dimple contour. The first and second derivatives of the two Bézier curves are forced to be equal at this point defined by the edge radius and the entry angle, as shown in FIG. 4A. A more detailed description of the contour of the dimples is set forth in U.S. Pat. No. 6,331,150, filed on Sep. 16, 1999, entitled Golf Ball Dimples With Curvature Continuity, which is hereby incorporated by reference in its entirety. 
     The one-hundred dimples of the second set of dimples  36  are the next most influential of the different sets of dimples  34 - 46  due to their number, size and placement on the surface  22  of the golf ball  20 . The one-hundred dimples of the second set of dimples  36  cover approximately 22% of the surface  22  of the golf ball  20 . Thus, together the first set of dimples  34  and the second set of dimples  36  cover over approximately 75% of the surface  22  of the golf ball  20 . The fifty dimples of the second set of dimples  36  that are disposed within the first hemisphere  26  are disposed in either a third row  86  above the equator, a second pentagon  102  about the first pole  30 , or along a transition latitudinal region  70 . Similarly, the fifty dimples of the second set of dimples  36  that are disposed within the second hemisphere  28  are disposed in either a third row  96  below the equator  24 , a second pentagon  102   a , not shown, about the second pole  32 , or along a transition latitudinal region  72 . 
     A cross-section of a dimple of the second set of dimples  36  is shown in FIG.  5 . The radius R 2  of the dimple  36  is approximately 0.079 inches, the chord depth C 2  is approximately 0.0053 inches, the entry angle θ 2  is approximately 15.1 degrees, and the edge radius ER 2  is approximately 0.0315 inches. 
     As best illustrated in FIG. 1A, each hemisphere  26  and  28  begins with three rows from the equator  24 . The first and second rows  80  and  82  of the first hemisphere  26  and the first and second rows  90  and  92  of the second hemisphere  28  are composed of the first set of dimples  34 . The third row  86  of the first hemisphere  26  and the third row  96  of the second hemisphere  28  are composed of the second set of dimples  36 . This pattern of rows is utilized to achieve greater surface coverage of dimples on the golf ball  20 . However, as mentioned previously, conventional teaching would dictate that additional rows of smaller diameter dimples should be utilized to achieve greater surface area coverage. However, the dimple pattern of the present invention transitions from rows of equal dimples into a pentagonal region  98 . The pentagonal region  98  is best seen in FIG. 2A. A similar pentagonal region  98   a , not shown, is disposed about the second pole  32 . The pentagonal region  98  has five pentagons  100 ,  102 ,  104 ,  106  and  108  expanding from the first pole  30 . Similar pentagons  100   a ,  102   a ,  104   a ,  106   a  and  108   a  expand from the second pole  32 . The first pentagon  100  consists of the fifth set of dimples  42 . The second pentagon  102  consists of the second set of dimples  36 . The third pentagon  104  consists of the first set of dimples  34 . The fourth pentagon  106  also consists of the first set of dimples  34 . The fifth pentagon  108  consists of the first set of dimples  34 , the second set of dimples  36 , and the sixth set of dimples  44 . However, the greater fifth pentagon  108 ′ would include the fifth pentagon  108  and all dimples disposed between the third row  86  and the fifth pentagon  108 . The pentagonal region  98  allows for the greater surface area of the dimple pattern of the present invention. 
     FIG. 2B illustrates five triangles  130 - 138  that compose the pentagonal region  98 . Dashed line  140  illustrates the extent of the greater pentagonal region  98 ′ which overlaps with the transition latitudinal region  70 . 
     As best illustrated in FIG. 1B, all of the dimples of the third set of dimples  38 , the fourth set of dimples  40  and the sixth set of dimples  44  are disposed within the transition latitudinal regions  70  and  72 . The transition latitudinal regions  70  and  72  transition the dimple pattern of the present invention from the rows  80 ,  82 ,  86 ,  90 ,  92  and  96  to the pentagonal regions  98  and  98   a . Each of the transition latitudinal regions  70  and  72  cover a circumferencial area between 40 to 60 longitudinal degrees from the equator  24  in their respective hemispheres  26  and  28 . The first transition latitudinal region  70  has a polar boundary  120  at approximately 60 longitudinal degrees from the equator  24 , and an equatorial boundary  122  at approximately 40 longitudinal degrees from the equator  24 . Similarly, the second transition latitudinal region  72  has a polar boundary  120   a  at approximately 60 longitudinal degrees from the equator  24 , and an equatorial boundary  122   a  at approximately 40 longitudinal degrees from the equator  24 . 
     Alternative embodiments of the dimple pattern of the present invention are illustrated in FIGS. 11 and 12. The dimple pattern on the golf ball  20   a  of FIG. 11 only has five different sets of dimples  34 ,  36 ,  40 ,  42  and  44 . The dimple pattern on the golf ball  20   b  of FIG. 12 only has six different sets of dimples  34 ,  36 ,  38 ,  40 ,  42  and  44 . Both of the dimple patterns of the golf balls  20   a  and  20   b  have had the seventh set of dimples  46  that are disposed at the poles  30  and  32  removed, and the dimple patter of the golf ball  20   a  has had all of the dimples of the third set of dimples  38  substituted with dimples from the fifth set of dimples  42 . 
     The force acting on a golf ball in flight is calculated by the following trajectory equation: 
     
       
           F=F   L   +F   D   +G   ( A ) 
       
     
     wherein F is the force acting on the golf ball; F L  is the lift; F D  is the drag; and G is gravity. The lift and the drag in equation A are calculated by the following equations: 
     
       
           F   L =0.5 C   L   Aρν   2   ( B ) 
       
     
     
       
           F   D =0.5 C   D   Aρν   2   ( C ) 
       
     
     wherein C L  is the lift coefficient; C D  is the drag coefficient; A is the maximum cross-sectional area of the golf ball; ρ is the density of the air; and ν is the golf ball airspeed. 
     The drag coefficient, C D , and the lift coefficient, C L , may be calculated using the following equations: 
     
       
           C   D=2   F   D   /Aρν   2   ( D ) 
       
     
     
       
           C   L=2   F   L   /Aρν   2   ( E ) 
       
     
     The Reynolds number R is a dimensionless parameter that quantifies the ratio of inertial to viscous forces acting on an object moving in a fluid. Turbulent flow for a dimpled golf ball occurs when R is greater than 40000. If R is less than 40000, the flow may be laminar. The turbulent flow of air about a dimpled golf ball in flight allows it to travel farther than a smooth golf ball. 
     The Reynolds number R is calculated from the following equation: 
     
       
           R=νDρ/μ   ( F ) 
       
     
     wherein ν is the average velocity of the golf ball; D is the diameter of the golf ball (usually 1.68 inches); ρ is the density of air (0.00238 slugs/ft 3  at standard atmospheric conditions); and μ is the absolute viscosity of air (3.74×10 −7  lb*sec/ft 2  at standard atmospheric conditions). A Reynolds number, R, of 180,000 for a golf ball having a USGA approved diameter of 1.68 inches, at standard atmospheric conditions, approximately corresponds to a golf ball hit from the tee at 200 ft/s or 136 mph, which is the point in time during the flight of a golf ball when the golf ball attains its highest speed. A Reynolds number, R, of 70,000 for a golf ball having a USGA approved diameter of 1.68 inches, at standard atmospheric conditions, approximately corresponds to a golf ball at its apex in its flight, 78 ft/s or 53 mph, which is the point in time during the flight of the golf ball when the travels at its slowest speed. Gravity will increase the speed of a golf ball after its reaches its apex. 
     FIG. 13 illustrates the lift coefficient of a golf ball  20  with the dimple pattern of the present invention thereon as compared to the Titlelist PROFESSIONAL, the Titlelist TOUR PRESTIGE, the Maxfli REVOLUTION and the Maxfli HT URETHANE. FIG. 14 illustrates the drag coefficient of a golf ball  20  with the dimple pattern of the present invention thereon as compared to the Titlelist PROFESSIONAL, the Titlelist TOUR PRESTIGE, the Maxfli REVOLUTION and the Maxfli HT URETHANE. 
     All of the golf balls for the comparison test, including the golf ball  20  with the dimple pattern of the present invention, have a thermoset polyurethane cover. The golf ball  20  with the dimple pattern of the present invention was constructed as set forth in U.S. Pat. No. 6,190,268 filed on Jul. 27, 1999, for a Golf Ball With A Polyurethane Cover which pertinent parts are hereby incorporated by reference. The aerodynamics of the dimple pattern of the present invention provides a greater lift with a reduced drag thereby translating into a golf ball  20  that travels a greater distance than golf balls of similar constructions. 
     As compared to other golf balls having polyurethane covers, the golf ball  20  of the present invention is the only one that combines a lower drag coefficient at high speeds, and a greater lift coefficient at low speeds. Specifically, as shown in FIGS. 13 and 14, none of the other golf balls have a lift coefficient, C L , greater than 0.18 at a Reynolds number of 70,000, and a drag coefficient C D  less than 0.23 at a Reynolds number of 180,000. For example, while the Titliest PROFESSIONAL has a C L  greater than 0.18 at a Reynolds number of 70,000, its C D  is greater than 0.23 at a Reynolds number of 180,000. Also, while the Maxfli REVOLUTION has a drag coefficient C D  greater than 0.23 at a Reynolds number of 180,000, its C L  is less than 0.18 at a Reynolds number of 70,000. 
     In this regard, the Rules of Golf, approved by the United States Golf Association (“USGA”) and The Royal and Ancient Golf Club of Saint Andrews, limits the initial velocity of a golf ball to 250 feet (76.2 m) per second (a two percent maximum tolerance allows for an initial velocity of 255 per second) and the overall distance to 280 yards (256 m) plus a six percent tolerance for a total distance of 296.8 yards (the six percent tolerance may be lowered to four percent). A complete description of the Rules of Golf are available on the USGA web page at www.usga.org. Thus, the initial velocity and overall distance of a golf ball must not exceed these limits in order to conform to the Rules of Golf. Therefore, the golf ball  20  has a dimple pattern that enables the golf ball  20  to meet, yet not exceed, these limits. 
     From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.

Technology Classification (CPC): 0