Abstract: A surface of a sphere is divided by using not only great circles but also small circles, forming a spherical polyhedron. The spherical polyhedron includes two spherical regular pentagons, each having a center at the pole, ten spherical isosceles triangles near the pole, ten spherical pentagons near the equator, and ten other spherical isosceles triangles near the equator. Compared to a related art, dimples are accurately arranged in spherical polygons. Thus, a dimple area ratio is improved and the number of dimples is appropriately maintained.

Abstract: The present invention concerns golf balls having a modified aerodynamic configuration and a method for creating a modified aerodynamic configuration that improves dimple coverage, interdigitation, and non-alignment in golf ball dimple patterns by rotating the repeating area elements about pre-determined center points, with further optional steps of expanding or contracting the elemental arrangements about pre-determined center points, enlarging or reducing the sizes of dimples, and adding extra dimples to occupy land areas created by the previous steps. The resulting modified aerodynamic configuration with a rotated element has increased dimple coverage, greater interdigitation and improved non-alignment.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

Abstract: Provided is a golf ball having a surface divided by small circles. A surface of a sphere is divided by small circles to generate spherical polyhedrons in order to arrange dimples in the spherical polygons, instead of arranging dimples in spherical polyhedrons that are generated by dividing the surface of the sphere by great circles. According to one or more exemplary embodiments, a land surface of the golf ball, which is generated by arranging the dimples in the spherical polyhedrons, has a dimple area ratio higher than that of a spherical truncated icosahedron of which a surface is divided by great circles on which dimples are arranged. Therefore, a flight distance of the golf ball increases.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

Abstract: Embodiments of golf balls and methods to manufacture golf balls are generally described herein. In one example, a golf ball may include a plurality of round dimples and a plurality of non-round dimples. Each round dimple may have a dimple diameter, and each non-round dimple may have a dimple diagonal. Other examples and embodiments may be described and claimed.

Abstract: A golf ball 2 has a large number of dimples 8 on a surface thereof. A trajectory of the golf ball 2 is divided into first to fourth segments. An average CD1 of drag coefficients CD and an average CL1 of lift coefficients CL in the first segment are equal to or less than 0.225 and 0.180, respectively. An average CD2 of drag coefficients CD and an average CL2 of lift coefficients CL in the second segment are equal to or less than 0.250 and 0.220, respectively. An average CD3 of drag coefficients CD and an average CL3 of lift coefficients CL in the third segment are equal to or greater than 0.260 and 0.220, respectively. An average CD4 of drag coefficients CD and an average CL4 of lift coefficients CL in the fourth segment are equal to or greater than 0.250 and 0.200, respectively.

Abstract: A designing method according to the present invention includes the steps of: (1) dividing a surface of a phantom sphere of a golf ball 2 into a plurality of units U by division lines 14 obtained by projecting edge lines of a regular polyhedron inscribed in the phantom sphere, on the surface of the phantom sphere; (2) obtaining a base pattern by randomly arranging a plurality of dimples 8 in one unit U such that the dimples 8 do not overlap each other; and (3) developing the base pattern over other units U such that patterns of two adjacent units U are not mirror-symmetrical to each other. The regular polyhedron is preferably a regular dodecahedron or a regular icosahedrons.

Abstract: Disclosed are manufacturing of a golf ball. A golf ball has a plurality of circular dimples in its spherical outer surface, dividing into the faces of a spherical polyhedron by a plurality of division lines, wherein border lines are formed at the position of ±1˜2 latitudinal degrees to the division lines, the circular dimples are arranged by using the border lines as an occupation limit line of the circular dimples positioned opposite to the division lines, and the golf ball has no dimple on the pole in the center of the spherical polyhedron is provided, thereby increasing the performance such as a carry distance by raising the proper amount of area ratio of dimples, obtaining the uniformity thickness cover molding without the inferior product due to the balanced gates with uniform size.

Abstract: Non-circular dimples such as oval form dimples are provided on the spherical surface of a ball body. A golf ball includes a spherical land surface of the ball body and a dimple pattern of a plurality of dimples formed on the spherical land surface, the spherical surface of the ball body being divided into a plurality of spherical surface parts (land surfaces) with each polygon faces of polyhedron which is virtually inscribed in said spherical surface of ball body, by a projection method from each polygon faces of the inscribed polyhedron, on each spherical surface parts some or all of the dimples being formed as non-circular dimple having a width of more than 1.5 mm and a length of more than 2 times of the width and the dimple pattern is disposed so as to make vortices generated in the non-circular dimples flow out in at least two different directions.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface that significantly improves aerodynamic symmetry and minimizes parting line visibility by arranging the dimples in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. One or more irregular domains may have an initial dimple sub-pattern of nearest neighbor dimples wherein the dimple sub-pattern is packed in one or more irregular domains; and the unfilled regions of the irregular domains are packed with dimples and the irregular domains are tessellated around the golf ball surface.

Abstract: The present invention is directed to a golf ball comprising of non-concentric arcs defining a non-planar parting line on its spherical surface resulting in having a large size disparity between dimples in one hemisphere and adjacent dimples from the opposing hemisphere. The parting line is produced by a pair of adjacent dimples, wherein D indicates dimples and N indicates dimples from the Northern hemisphere and those from the Southern hemisphere are indicated by S. A large disparity may be created, if the following condition is satisfied: D ? ( N ) D ? ( S ) > 1.25 ? ? or ? ? D ? ( N ) D ? ( S ) < 0.80 .

Abstract: A golf ball has a plurality of dimples, wherein: (1) the dimples have a peripheral edge with a radius of curvature R from 0.5 mm to 2.5 mm; (2) the surface coverage SR of the dimples, expressed as a percentage of the surface area of a hypothetical sphere representing the ball if it had no dimples, is from 60% to 74%; and (3) the ratio ER of a collective number of dimples RA having a radius of curvature R to diameter D ratio (R/D) of at least 20%, divided by a total number of dimples N on the surface of the ball, is from 15% to 95%. This combination of features enables damage to the paint film on the surface of the ball to be minimized, improves the durability of markings on the surface of the ball, and prevents a decline in ball performance.

Abstract: Disclosed herein is a golf ball which has not only an air resistance similar to or smaller than that of a dimpled golf ball, but also a significantly reduced area ratio of grooves relative to the total surface area of the golf ball, thereby achieving an enhanced carry distance and high accuracy in the directionality of putting. The golf ball has net-shaped grooves formed on an outer surface of a sphere.

Abstract: A golf mat is disclosed comprising a body portion or ground sheet; and a means for holding the body portion in a position which is elevated a first distance above a ground surface. The means for holding the body portion may be connected to the body portion substantially perpendicular to the body portion. The body portion and the means for holding the body portion may be configured so that when the body portion is placed so that it is substantially parallel to the ground surface and elevated above the ground surface, and the means for holding the body portion is in contact with the ground surface, the majority of the body portion is not in contact with the ground surface so that there is a cavity beneath the body portion in which natural grass from the ground surface can grow without being restrained at least to a height of the first distance.

Abstract: The present invention provides a method for arranging dimples on a golf ball surface in which the dimples are arranged in a pattern derived from at least one irregular domain generated from a regular or non-regular polyhedron. The method includes choosing control points of a polyhedron, generating an irregular domain based on those control points, packing the irregular domain with dimples, and tessellating the irregular domain to cover the surface of the golf ball. The control points include the center of a polyhedral face, a vertex of the polyhedron, a midpoint or other point on an edge of the polyhedron and others. The method ensures that the symmetry of the underlying polyhedron is preserved while minimizing or eliminating great circles due to parting lines.

Abstract: A golf ball having multiple sets of identical hemispheres created by multiple non-planar parting lines symmetrically arranged. The hemispheres are identical relating to dimple volume, distribution and location. The highest amplitude of a parting line, when measured from an equator, is less than 11% of the largest dimple diameter.

Abstract: A designing method according to the present invention includes the steps of: (1) dividing a surface of a phantom sphere of a golf ball 2 into a plurality of units U by division lines 14 obtained by projecting edge lines of a regular polyhedron inscribed in the phantom sphere, on the surface of the phantom sphere; (2) obtaining a base pattern by randomly arranging a plurality of dimples 8 in one unit U such that the dimples 8 do not overlap each other; and (3) developing the base pattern over other units U such that patterns of two adjacent units U are not mirror-symmetrical to each other. The regular polyhedron is preferably a regular dodecahedron or a regular icosahedrons.

Abstract: The present invention concerns a golf ball having dimple groupings comprised of multiple angular spiral shaped arms that are arrayed to form polygonal perimeters, wherein the number of arms equals the number of perimeter sides. This allows greater symmetry about the dimple grouping center, thereby improving the consistency of the aerodynamic performance of the ball. In another unique feature of the present invention, the angular shape of the arms facilitates the formation of polygonal shaped dimple groupings, which can fit closely together to cover a greater proportion of the ball's surface, preferably more than about 85% surface coverage, thereby further enhancing aerodynamic performance.

Abstract: The invention provides a golf ball excellent in abrasion resistance and a repulsion property. The present invention provides a golf ball comprising a core and a cover covering the core, wherein the cover is made from a cover composition containing, as a resin component, a thermoplastic polyurethane (A) having no ionic group; at least one kind of thermoplastic resin (B) selected from the group consisting of a binary copolymer of an olefin and an unsaturated carboxylic acid, a tertiary copolymer of an olefin, an unsaturated carboxylic acid and an unsaturated carboxylic acid ester, and neutralized products thereof; and an acid group-containing polyurethane and/or a neutralized product thereof (C).

Abstract: A golf ball having a plurality of dimples formed on its outer surface, the outer surface of the golf ball being divided into plural areas, a first group of areas containing a plurality of first dimples and a second group of areas containing a plurality of second dimples, each area of the second group abutting one or more areas of the first group, the first and second groups of areas and dimple shapes and dimensions being configured such that the golf ball is spherically symmetrical as defined by the United States Golf Association (USGA) Symmetry Rules, the plural areas configured such that the golf ball has a Drag Coefficient (CD) and a Lift Coefficient (CL) of less than about 0.330 and 0.270, respectively, at a Reynolds Number (Re) of about 80,000 and a spin rate of between about 2,900 rpm and about 3,000 rpm and a CD and CL of less than about 0.260 and 0.

Abstract: A golf ball mold having a non-planar parting surface formed by superimposing a base waveform with a least one shorter secondary waveform. The base waveform is defined by a series of concentric arcs wherein adjacent arcs are connected with a straight line segment that is tangent to the arcs and creates an acute angle. The length of the straight line segment being critical to the accuracy and predictability of the parting line.

Abstract: Golf ball 2 has numerous dimples 8. The surface of the golf ball is divided by comparting lines CM corresponds to edges of a regular icosahedron into eight first spherical regular triangles T1, six second spherical regular triangles T2, and six third spherical regular triangles T3. The first spherical regular triangles T1 do not include the equatorial line EQ. The second spherical regular triangles T2 and the third spherical regular triangles T3 include the equatorial line EQ. The dimple pattern on the first spherical regular triangle T1 is different from the dimple patterns on the second spherical regular triangle T2 and third spherical regular triangle T3. The dimple pattern on the first spherical regular triangle T1 has rotational symmetry and line symmetry. The dimple pattern on the second spherical regular triangle T2 and the third spherical regular triangle T3 has neither a rotational symmetry nor line symmetry. This golf ball 2 does not have any great circle path.

Abstract: A golf ball that is formed by a mold developed from a computerized modeling system such as CAD or CAE in combination with a CNC machine tool which superimposes a short waveform, or multiple waveforms, onto a longer base waveform to create a non-planar parting line that is functionally dependent on the underlying dimple geometry. The non-planar parting line is comprised of a plurality of peaks and valleys that are offset from the dimple perimeters, as not to bisect any dimple edge. Also, dimples on one side of the parting line interdigitate with dimples on the other side to form a more uniform distribution of dimples over the entire golf ball surface. Still further, the non-planar parting line has a amplitude which is less than 0.02 inch from an axis substantially coincident with the equator of the ball and the length of the parting line is less than 110 percent of the length of a curve defined by the circumference of the equator.

Abstract: Golf ball 2 has numerous dimples 8. The surface of the golf ball is divided by comparting lines CM corresponds to edges of a regular icosahedron into eight first spherical regular triangles T1, six second spherical regular triangles T2, and six third spherical regular triangles T3. The first spherical regular triangles T1 do not include the equatorial line EQ. The second spherical regular triangles T2 and the third spherical regular triangles T3 include the equatorial line EQ. The dimple pattern on the first spherical regular triangle T1 is different from the dimple patterns on the second spherical regular triangle T2 and third spherical regular triangle T3. The dimple pattern on the first spherical regular triangle T1 has a rotational symmetry and a line symmetry. The dimple pattern on the second spherical regular triangle T2 and the third spherical regular triangle T3 has neither a rotational symmetry nor line symmetry. This golf ball 2 does not have any great circle path.

Abstract: A golf ball having a plurality of dimples arranged on its surface is provided wherein the ball surface is free of a great circle that does not intersect with dimples, at least 7% of the total number of dimples are non-circular dimples, and some non-circular dimples lie across the equator of the ball corresponding to a parting plane of a mold. The ball is improved in flight distance and aerodynamic uniformity.

Abstract: A two piece golf ball has a core compression in the range of 75 PGA to 89 PGA, a core diameter in the range of about 1.535 inches to 1.545 inches, a cover hardness in the range of 42 to 60 Shore D, and a dimple pattern based on the geometry of a icosahedron. An uninterrupted equatorial great circle path, corresponding to a mold parting line, is provided in the design for forming a cover of the golf ball in two parts. A ball having such characteristics exhibits superior distance performance without compromising shot-making feel.

Abstract: A golf ball with multi-lobed dimples is provided. The dimple comprises a plurality of lobes positioned radially around the center of the dimple, wherein each lobe is defined by a circumferential segment. Each lobe comprises a first curved profile extending from the circumferential segment toward the center of the dimple and the first curved profile of each lobe abuts each other in an uninterrupted manner. The curvature of the circumferential segments can be defined by a ratio of an inside radius to an outside radius.

Abstract: A golf ball having a dimpled surface that is subdivided into two or more distinct regions wherein different dimple placement schemes are used in different regions. A preferred embodiment has polar regions dimpled according to an octahedral-based dimple pattern and the equatorial region dimpled according to an icosahedron-based dimple pattern. This preferred embodiment has dimples of varying sizes and has 388 total dimples.

Abstract: In a two-piece solid golf ball comprising a solid core and a cover, the JIS-C hardness at the core surface minus the JIS-C hardness at the core center is 20-30 units, the cover has a gage of 1.3-2 mm and a Shore D hardness of 40-55, and the JIS-C hardness at the cover surface is not greater than the JIS-C hardness at the core surface. Dimples are formed on the cover surface to satisfy a total number of 360-492 and a percent dimple volume VR of 0.74-0.84%. The golf ball is susceptible to spin and easy to control upon approach shots and short iron shots, travels a long distance upon driver shots, gives a pleasant feel on any shot with driver, iron and putter clubs, and offers improved playability satisfying low-handicap players.

Abstract: Golf balls are disclosed having novel dimple patterns determined by a plurality of connected polygon regions. A method of packing dimples using the connected polygons is also disclosed. For each disclosed dimple pattern, connected polygons extend from a pole of the golf ball towards the parting line. Dimples are positioned on the golf ball surface according to the pattern of connected polygons and then the remaining space of the golf ball is filled with dimples. This results in a golf ball having a dimple pattern that has some uniformity but also some variance.

Abstract: A golf ball with superior aerodynamic properties is characterized by a progressive depth of dimples on the surface of the ball. The ball surface is divided into a plurality of equal geometries such as triangles, each of which is filled with a plurality of non-overlapping dimples. Groups of dimples are provided in each geometry, the dimples of each group having different depths, respectively. A first group of dimples is arranged about the perimeter of the geometry and a second group of dimples is arranged within the first group. A third group of dimples having a third depth may be provided within the second group, with the depth of the third group being less than the depth of the second group which is less than the depth of the first group. Alternatively, the depth of the third group is greater than the depth of the second group which is greater than the depth of the first group. Similarly, the first and third groups may have the same depth but different from the second group.

Abstract: A golf ball comprising a substantially spherical outer surface and a plurality of polygonal dimples formed thereon is provided. The dimples are arranged such that the sides of adjacent dimples are substantially parallel to each other, and wherein the outer surface comprises first spacings and second spacings between adjacent dimples. The first spacings and the second spacings have substantially constant width between any two adjacent dimples and the width of the first spacings is different than the width of the second spacings. The plurality of polygonal dimples is arranged in a plurality of identifiable sections and the first spacings comprise inter-dimple spacings between dimples within one identifiable section and the second spacings comprise inter-sectional spacings between identifiable sections of dimples.

Abstract: A multi-lobed golf ball dimple is provided. The dimple comprises a plurality of lobes positioned radially around the center of the dimple, wherein each lobe is defined by a circumferential segment and may be further defined by spoke-like ridges. Each lobe comprises a first curved profile extending from the circumferential segment toward the center of the dimple and the first curved profile of each lobe abuts each other in an uninterrupted manner. The multi-lobed dimple may include uniform and non-uniform dimples. The curvature of the circumferential segments can be defined by a ratio of an inside radius to an outside radius.

Abstract: A golf ball includes a solid core, an intermediate layer, and a cover in a surface of which a plurality of dimples are formed. The solid core has a center JIS-C hardness of 50-70 and a surface JIS-C hardness of 60-80, and has a diameter of 35-40 mm. The intermediate layer is made from a material mainly containing an ionomer resin, and has a JIS-C hardness of 70-85 and a thickness of 0.5-2 mm. The cover is made from a material mainly containing an ionomer resin, and has a JIS-C hardness of 85 or more and a thickness of 0.5-2 mm. A difference in JIS-C hardness between the intermediate layer and the surface of the solid core is in a range of 15 or less. A different in JIS-C hardness between the cover and the intermediate layer is in a range of 10 or more. The hardnesses of the solid core, the intermediate layer, and the cover satisfy a relationship of (hardness gradient from intermediate layer to cover)/(hardness gradient from core center to intermediate layer)≧6.

Abstract: A resin composition comprising, in admixture, (A) a specific thermoplastic resin component, (B) at least one wax component selected from among (b-1) a fatty acid having 20-80 carbon atoms and/or a derivative thereof and (b-2) an oxidized natural wax and/or derivative having a neutralization value of 60-190 mg KOH/g, and optionally, (C) a basic inorganic metal compound capable of neutralizing acid groups in the thermoplastic resin component (A) and/or the wax component (B) is improved in flow, moldability and heat resistance and thus suitable to form a layer of a golf ball which exhibits improved rebound and distance properties.

Abstract: Disclosed herein is a golf ball having a core and a cover comprising a blend of ionomer and plastomer. The golf ball has an impact resistance and cut resistance comparable to a ball having a non-plastomer cover and containing higher quantities of ionomer.

Abstract: Golf balls are disclosed having novel dimple patterns determined by a pentagonal hexecontahedron. A method of packing dimples according to a pentagonal hexecontahedron is also disclosed. For each disclosed dimple pattern, a pentagonal hexecontahedron extend from a pole of the golf ball and dimples are positioned on the golf ball surface according to a pentagonal hexecontahedron.

Abstract: A golf ball retaining high coefficient of restitution inherent and having fine shot feeling with clubs such as drivers, irons and putters is disclosed. A multi-piece golf ball comprising; a center core having a JIS-C hardness of not more than 75, a cover having a JIS-C hardness of not less than 85, a core enclosing layer which directly enclose said center core having a JIS C hardness smaller than the others, and a r.d.preventing layer which prevents a restitution coefficient degradation being internally disposed in contact with said cover and having a JIS C hardness greater than the others.

Abstract: A two piece golf ball has a core compression in the range of 75 PGA to 89 PGA, a core diameter in the range of about 1.535 inches to 1.545 inches, a cover hardness in the range of 42 to 60 Shore D, and a dimple pattern based on the geometry of a icosahedron. An uninterrupted equatorial great circle path, corresponding to a mold parting line, is provided in the design for forming a cover of the golf ball in two parts. A ball having such characteristics exhibits superior distance performance without compromising shot-making feel.

Abstract: An ionomer resin component containing (a) a ternary ionomer resin and optionally (b) a binary ionomer resin, optionally blended with (c) a non-neutralized olefin-unsaturated carboxylic acid random copolymer, is blended with (d) a metal soap of a fatty acid neutralized with a Ca, Mg or Zn cation in a weight ratio from 95:5 to 80:20. A golf ball cover composition based on this mixture has a melt index of 1-10 dg/sec. The cover composition is drastically improved in moldability, resilience and paint coating adhesion. A golf ball having a cover made of the composition is improved in feel and flight performance.

Abstract: A golf ball has plural types of dimples on a spherical surface, which is assumed to be a regular icosahedron having twenty triangles. Apexes of five triangles join together at a vertex. Those dimples arranged in each triangle constitute an arrangement unit. A first dimple having a smallest diameter is located at the vertex, and second dimples having a greater diameter are equidistantly arranged around the first dimple. When a pentagon which circumscribes the second dimples is drawn, an average depth of those dimples located within the pentagon is up to 85% of the average depth of those dimples located in the remaining areas.

Abstract: A spherical ball and a method of making the spherical ball wherein the ball has a plurality of elongated dimples substantially covering the outer surface of the ball without any dimple overlap. The elongated dimples are of at least two types including a first plurality of dimples having a minor axis and a major axis which together form the long axis of the first plurality of dimples. The minor axis being less than the major axis. A second plurality of dimples has a minor axis equal to that of the first plurality of dimples and a major axis less than the major axis of the first plurality of dimples but greater than the minor axis.

Abstract: A golf ball is molded in a mold comprising a pair of removably joined mold sections. The golf ball has a plurality of dimples, the dimples being arranged in a polyhedral arrangement. The golf ball is free of a great circle which does not intersect with the dimples. The dimples (D2) lying across the parting line (P) between the mold sections, except for the dimples (D1) whose center lies on the parting line, are shifted upward or downward from the parting line or reduced in diameter so that these dimples are located outside the parting line (P). The dimple surface coverage is at least 71%. A golf ball having high symmetry and excellent flight performance can be prepared using a simple mold.

Abstract: In a multi-piece solid golf ball comprising a solid core and a cover with a multilayer construction including an innermost layer, an intermediate layer, and an outermost layer having a plurality of dimples on the surface thereof, the innermost and outermost layers each have a Shore D hardness of at least 60, and the intermediate layer has a Shore D hardness of at most 40. The total number of dimples is 370-450, and the dimples cover at least 65% of the golf ball surface. The ball gives a good, soft feel when hit with any type of club. The performance of the ball little depends on the head speed.

Abstract: A golf ball has a plurality of dimples in its spherical outer surface and its spherical outer surface is divided into the faces of an icosahedron consisting of 20 regular spherical triangles, and the golf ball's spherical outer surface is further divided by great circle paths which obtained by extending spherical straight lines connecting the midpoint of each side of the sperical triangles of icosahedron to its opposite apex, then large spherical pentagons will be created on the polar regions of the golf ball's spherical outer surface. The center of large pentagon as a pole, which is a common apex of 5 regular spherical triangles of the spherical icosahedron, from the pole, spherical straight lines extend along the both sides of each of the 5 spherical triangles to the equator. (Same thing happens on the opposite pole.) The spherical outer surface is further divided by the spherical straight lines into small sections to arrange the dimples.

Abstract: In a two-piece solid golf ball comprising a solid core and a cover, the JIS-C hardness at the core surface minus the JIS-C hardness at the core center is 20–30 units, the cover has a gage of 1.3–2 mm and a Shore D hardness of 40–55, and the JIS-C hardness at the cover surface is not greater than the JIS-C hardness at the core surface. Dimples are formed on the cover surface to satisfy a total number of 360–492 and a percent dimple volume VR of 0.74–0.84%. The golf ball is susceptible to spin and easy to control upon approach shots and short iron shots, travels a long distance upon driver shots, gives a pleasant feel on any shot with driver, iron and putter clubs, and offers improved playability satisfying low-handicap players.

Abstract: In a two-piece solid golf ball comprising a solid core and a cover, the JIS-C hardness at the core surface minus the JIS-C hardness at the core center is 20-30 units, the cover has a gage of 1.3-2 mm and a Shore D hardness of 40-55, and the JIS-C hardness at the cover surface is not greater than the JIS-C hardness at the core surface. Dimples are formed on the cover surface to satisfy a total number of 360-492 and a percent dimple volume VR of 0.74-0.84%. The golf ball is susceptible to spin and easy to control upon approach shots and short iron shots, travels a long distance upon driver shots, gives a pleasant feel on any shot with driver, iron and putter clubs, and offers improved playability satisfying low-handicap players.