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 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 golf ball that plural kinds of dimples are disposed on a spherical face, and a great circle zone not including even a part of the dimples are formed on the spherical face. An imaginary great circle line is drawn on the great circle zone, and two intersections of the spherical face and a straight line, which is at right angles with a circular plane of which circumference is the imaginary great circle line, and goes through the center of the golf ball, are poles. And, in a ball hemispherical face of which border is the imaginary great circle line, when the spherical face is equally divided with imaginary arc lines which start from the pole and are at right angles with the imaginary great circle line, dimple dispositions of adjacent divided areas sharing an imaginary arc line are not line-symmetric with respect to the imaginary arc line, and the dimple dispositions of the divided areas are rotation-symmetric with respect to the straight line.

Abstract: A golf ball comprising a core, an intermediate layer, and a cover, wherein the intermediate layer is provided in its outer surface with recesses and the cover penetrates into the recesses to form protrusions, is prepared using an injection mold defining a cover-forming cavity in which a plurality of support pins are arranged for axial motion toward and away from the cavity and have distal ends with a greater diameter than the diameter of recess openings. While a spherical core body having the core enclosed within the intermediate layer is supported at the center of the mold cavity by the support pins, a cover stock is injected into the mold cavity. The support pins are withdrawn immediately before the mold cavity is filled with the cover stock.

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: The present invention provides golf balls having a cover, a core, and optionally one or more intermediate layers between the cover and the core, wherein at least one of the cover, the core and, if present, the intermediate layer(s), is formed of an ion-containing polymer composition, particularly a zwitter-ion or ionene polymer. The zwitter-ion polymers contain both cationic and anionic species on the polymer backbone or as a pendant group on the polymer backbone. The ionene polymers are contain only a cationic portion attached to the polymer backbone and are associated with another ion. These ion-containing polymer compositions can be used to provide improved characteristics to golf balls made therefrom. The invention also relates to methods of making and using the compositions in golf balls.

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: A simplified method of matching a golfer to a golf club and a golf ball by measuring the golfer's clubhead speed and comparing that measured value to recorded sets of data which correlates a few key variables that can accurately match the golfer with the most suitable golf club and golf ball designed to achieve optimum driving performance.

Abstract: A golf ball having a spherical surface is provided. When an imaginary circle with a radius of 5 mm is traced on the spherical surface and centered at any point on that surface, 3-25 raised projections of at least two types which are different in diameter and/or height and 0.01-0.30 mm high are contained in the circle, or raised projections of at least one type and 0.01-0.30 mm high and recessed dimples of at least one type are contained in a total number of 3-25 in the circle. The ball follows a straight trajectory and has an increased run and total distance of travel.

Abstract: A new configuration for dimples on the surface of a golf ball is characterized by at least a portion of the bottom surface of the dimple having a raised contour which is still below the surface of the ball. The contoured portion may comprise many shapes including a crescent or a sinusoidal configuration. Moreover, the contoured portion may have different portions having different depths. The contours within at least some of the dimples on the surface of the ball alter the air flow across the golf ball surface to reduce drag and increase the distance the ball will travel.

Abstract: In accordance with the present invention, a golf ball includes an outer surface and a plurality of dimples formed thereon. At least one of the dimples is a concentric ring dimple. Each concentric ring dimple includes a central depression, and at least one annular depression that concentrically surrounds the central depression. A land ring extends between the central depression and the annular depression. When the concentric ring dimple includes additional annular depressions, land rings extend between the adjacent annular depressions. The concentric ring dimples provide additional dimple circumference over conventional dimples that occupy the same space, thereby improving the aerodynamic performance of the golf ball.

Abstract: A new dimple configuration for the surface of a golf ball is characterized by a portion extending above the surface of the ball. Each dimple includes an annular portion having an inner diameter and an outer diameter, and a circular portion having a diameter corresponding with the annular portion inner diameter. Either, the annular portion of the circular portion is convex and elevated relative to the ball surface with the other portion being concave and extending below the ball surface. When a struck ball travels through the air, the elevated portions trip air at the ball surface to improve the flight characteristics of the ball.

Abstract: A golf ball having an outside diameter of at least 1.70 inches which includes a core, an inner cover, or mantle, and an outside cover. The mantle and the outer cover have a different Shore D hardness. Dimples cover at least seventy percent of the outer surface area of the ball. In one embodiment, the mantle has a Shore D hardness between 50 and 60 and the cover has a Shore D hardness of 65 or less with the mantle hardness being greater than the cover hardness. In another embodiment, the mantle has a Shore D hardness of 65 or less and the cover has a Shore D hardness between 50 and 60, with the cover hardness being greater than the mantle hardness.

Abstract: A golf ball formed with half metal molds having stable flying ability without dispersion, regardless of hitting point on surface of the ball.A parting line is latitude 0.degree., two pole portions are latitude 90.degree., an area of which latitude is 0.degree. to 17.degree. is a parting line vicinity, an area of which latitude is more than 17.degree. and less than 62.degree. is a shoulder portion, an area of which latitude is 62.degree. to 90 .degree. is a pole vicinity. And, when X represents total volume of dimples which belong to the parting line vicinity, Y represents total volume of dimples which belong to the pole vicinity, and Z represents total volume of dimples which belong to the shoulder portion, X/Z is set to be 0.58 to 0.72, Y/Z is set to be 0.22 to 0.30, and Y/X is set to be 0.35 to 0.48.

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: In a golf ball having a multiplicity of dimples of circular plane shape disposed at a spacing on its surface, dimple spacings of up to 1.65 mm account for 60 to 80% of the entire dimple spacings, and an average V.sub.0 and A, defined in the specification, are limited. The shape and arrangement of dimples are correlated so that dimples may be distributed on the ball surface in a well-balanced uniform arrangement, whereby the flight behavior is drastically improved.

Abstract: In a golf ball having a multiplicity of dimples of circular plane shape on its surface, the dimples include plural types of dimples having different diameters. The dimples of at least one type are formed to at least two different cross-sectional shapes. A three-dimensionally appropriate combination and arrangement of a multiplicity of dimples on the ball surface is effective for improving the aerodynamic behavior of the golf ball so that the ball exerts excellent flight performance.

Abstract: A golf ball having improved aerodynamic efficiency is characterized by the arrangement of a plurality of modified tear-drop shaped dimples arranged on the surface thereof. The ball has a dimple-free equator which divides the ball into two identical hemispheres, each of which is broken into equal quadrants by two great circles passing through the poles of the ball. Each quadrant has a maximum circular area filled with a first plurality of tear-drop shaped dimples. A second plurality of tear-drop shaped dimples is arranged between the circular areas so that the dimple coverage on the ball is maximized.

Abstract: A solid golf ball comprising a solid core and a cover has a multiplicity of dimples in its surface. The core undergoes a distortion of 2.8-4.0 mm under a load of 100 kg. The distortion (mm) of the core under a load of 100 kg divided by the distortion (mm) of the ball under a load of 100 kg is 1.0-1.3. The cover has a gage of 1.4-1.9 mm and a Shore D hardness of 53-60. Dimples of at least three types having different diameters are formed in the cover surface in a total number of 390-450. The diameter/depth ratio of each dimple is from 18/1 to 27/1. The volume of a dimple divided by the volume of a cylinder whose diameter and height correspond to the diameter and depth of the dimple, respectively, is 0.390-0.550. The golf ball is improved in flight distance, hitting feel and spin and will cover a distance even when hit at low head speeds.

Abstract: A golf ball includes a solid core, an intermediate layer, and a cover having dimples formed therein. The core has a Shore D hardness at the surface of 30-48, the intermediate layer has a Shore D hardness of 53-60, and the cover has a higher Shore D hardness of 55-65. In the cover, 370 to 450 dimples of at least two types having different diameters and/or depths are distributed so as to cover at least 63% of the ball surface. The index Dst of the overall dimple surface area is at least 4. The golf ball provides significantly improved flight distance and a good feel by virtue of a good balance in hardness and optimized dimple characteristics.

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: A golf ball having an outside surface with a plurality of dimples formed thereon that form at least four spherical-triangular regions. Each of the regions has a first set of dimples formed in a large triangle and a second set of dimples formed in a small triangle inside of and adjacent to the large triangle. The diameters of the first set of dimples vary such that at least one diameter of the first set of dimples is equal to or greater than adjacent dimples nearer to the dimples on the points of the large triangle, and the dimples cover more than 80% of the outer surface with diameters of 0.11 inches or greater. The total number of dimples on the golf ball is about 300 to 500.

Abstract: A golf ball having a plurality of dimples on its surface, the dimples including dimples which are different in diameter and/or depth, the total number of dimples is 392 to 432, and the golf ball has a percent dimple surface area occupation of 77 to 82%, a percent dimple volume occupation of 0.85 to 1.2%, an average dimple diameter of 2.5 to 4.5 mm (0.098 to 0.177 inches), an average dimple depth of 0.12 to 0.18 mm (0.005 to 0.007 inches), an average dimple V.sub.0 value of 0.4 to 0.6, and a dimple edge angle of 4.0 to 17.0 degrees, where CL is a lift coefficient and CD is a drag coefficient, CL is in the range of 0.140 to 0.190, CD is in the range of 0.21 to 0.255, and CL/CD is in the range of 0.640 to 0.730 when the ball is in flight at a velocity of 65 m/s and a spin rate of 42 rps.

Abstract: A golf ball having a diameter and comprising a fluid mass at the center of the ball, a first, solid, non-wound layer surrounding the fluid mass comprised of a non-elastic polymer material selected from the group of thermoplastic material, metal, and plastic, and having an inner diameter in the range of 30 to 70% of the ball diameter; a second, solid, non-wound layer surrounding the first mantle layer comprising an elastomeric polymer material selected from the group of thermoset rubber material and thermoplastic clastomeric material having an outer diameter in the range of 80 to 98% of the ball diameter, a hardness of less than about 65 Shore D, and a compression of about 80 or greater; and a cover surrounding the second layer.

Abstract: A golf ball defines a dimple spherical surface having a diameter of not greater than 42.66 mm and formed with a plurality of protrusions. The ball is unable to pass through a ring gage having an inner diameter of 42.67 mm.

Abstract: A two-piece solid golf ball comprising; a solid core formed of a rubber and a cover formed of an ionomer resin, the solid core has a diameter in the range of 35 to 41 mm and a hardness corresponding to distortion of 2.0 to 4.0 mm under applied load of 100 kg, the cover has a spherical surface, a Shore D hardness in the range of 40 to 70 and a gage in the range of 0.5 to 3 mm, and the spherical surface is formed of a plurality of dimples wherein, the dimples have a depth in the range of 0.08 to 0.15 mm and an average V.sub.O value for all the dimples is 0.5 to 0.9 where V.sub.O is the volume of a dimple space below a plane circumscribed by the dimple edge divided by the volume of a cylinder whose bottom is the plane and whose height is the maximum depth of the dimple from the bottom, and a percent dimple volume Vr given by the following equation is in the range of 0.75 to 1.

Abstract: The present invention provides a golf ball of improved symmetry by regulating volume, area, edge length and array symmetry indexes Vi, Si, Li, and Ni obtained from coordinates (.theta.j, .phi.j) of a dimple center as represented by the latitude (in radian) and longitude of the ball and a radius rj and a volume vj of a dimple, for correcting a difference in dimple effect caused by a distortion of roundness of the ball. The golf ball does not have dimples which intersect the mold parting line, and the dimples occupy at least 65% of the ball surface.

Abstract: In a golf ball having a parting line formed at the junction between a pair of mold sections and a plurality of dimples some of which lie across the parting line and being free of a great circle which does not intersect with the dimples, the crossing dimples lying across the parting line have a greater edge angle than those dimples of the same diameter as the crossing dimples disposed near the poles. The ball is improved in symmetry in that the flight distance is substantially equal between seam hitting and pole hitting.

Abstract: In a golf ball having a parting line formed at the junction between a pair of mold sections and a plurality of dimples some of which lie across the parting line, the average space volume Vp of the dimples lying across the parting line is greater than the average space volume Vp' of the remaining dimples lying outside the parting line and/or the average Dp/Dm of the dimples lying across the parting line is greater than the average Dp/Dm of the remaining dimples lying outside the parting line wherein Dp and Dm are the depth and diameter of dimples, respectively. The golf ball is improved in symmetry in that no substantial difference occurs in flight distance between seam hitting and pole hitting.

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 including two poles and an equator is characterized by the arrangement of a preselected number of dimples in a geometrical lattice configuration based upon a subdivided tetrahedron on the surface thereof The lattice includes six dimple-free great circles around the circumference of the ball, one of the circles corresponding with the equator and another of the circles passing through the poles. All of the circles define twenty-four generally equivalent triangles, twelve in each hemisphere of the ball. An equal number of dimples are arranged within each of the triangles, and the dimple arrangement in at least two of the triangles is different from the dimple arrangement in the remaining triangles.

Abstract: A golf ball defining a spherical surface divided into spherical polyhedrons to form dimples thereon, characterized in that at least some of the dimples are connected to one another via air connection channels no more than 4 mm wide no more than 5 mm long, and no more than 1.2 mm deep the channel depth being less that 70% of the depth of the dimples.

Abstract: In a three-piece solid golf ball of the three layer structure consisting of a solid core, an intermediate layer, and a cover, the specific gravity of the solid core is lower than the specific gravity of the intermediate layer and the cover, and the Shore D hardness of the intermediate layer is higher than the Shore D hardness of the cover. The ball as a whole has an inertia moment of at least 83 g-cm.sup.2. The desirable properties of spin, feel, control and distance are obtained.

Abstract: In a 2-piece solid golf ball comprising a solid core and a cover, the golf ball has a weight of 41-44.5 grams, the cover is formed of a thermoplastic resin having a Shore D hardness of 50-68 degrees, and the solid core has a surface hardness of 65-85 degrees and a center hardness of 60-80 degrees as measured by a JIS-C scale hardness meter, with the surface hardness.gtoreq. the center hardness+5. Despite a light weight, the golf ball is improved in flying distance and feel when hit at a relatively low head speed of 35-40 m/sec. The golf ball is thus appropriate for players of the beginner to middle rank.

Abstract: A golf ball including a core, and a gamma irradiated, ionomeric, dimpled cover having a Shore D hardness of 55 or less as measured on a non-dimpled portion of the cover, the dimples maintaining their shape when the cover is subjected to heat treatment at 160.degree.-180.degree. F. for at least one hour. In making the golf ball, the dimpled cover is subjected to gamma irradiation in a dosage sufficient to increase the vicat softening point in degrees Fahrenheit of the cover by at least 2.5%.

Abstract: A golf ball has a multiplicity of dimples formed in its surface. It is assumed that the ball has a phantom sphere and spherical surface when the ball surface is free of dimples. A tangent angle .theta. is 5.degree..ltoreq..theta..ltoreq.20.degree. wherein .theta. is defined between a tangent at an arbitrary point on an edge of an individual dimple to the phantom spherical surface and a tangent at that point to the actual ball surface. A percent dimple volume Vr is 0.8%.ltoreq.Vr.ltoreq.1.1% wherein Vr is the sum of the volumes of the entire dimples divided by the volume of the phantom sphere. This dimple design prevents lowering of spin susceptibility by repetitive hits without detracting from the dimple effect of increasing flight distance.

Abstract: A golf ball having:a core; anda cover having an exterior surface with a plurality of dimples;wherein the core, the cover, and the dimples are correlated with respect to each other such that the golf ball has a coefficient of restitution greater than 0.791 measured at an incoming velocity of 143.8 ft/sec, an initial velocity greater than 255 ft/sec when tested under the conditions set forth in the Initial Velocity rule for golf balls established by the United States Golf Association, and the ball travels less than 280 yards when tested under the conditions set forth in the Overall Distance Standard for golf balls established by the United States.

Abstract: Golf ball having a surface texture defined by fractal geometry and golf ball having indents whose orientation is defined by fractal geometry. The surface textures are defined by two-dimensional fractal shapes, partial two-dimensional fractal shapes, non-contiguous fractal shapes, three-dimensional fractal objects, and partial three-dimensional fractal objects. The indents have varying depths and are bordered by other indents or smooth portions of the golf ball surface.

Abstract: The present invention is directed to golf balls which have a lift to weight ratio greater than 1 when the ball is hit at a speed of 150 ft/sec and a spin rate of 3,000 rpm to enhance the lofting time of the ball and thereby provide the golfer with a slow swing speed increased distance and improved trajectory. The golf ball has a core and a cover. The cover has dimples ranging in number from 100 to 1,000 and having a total volume of less than 1.5% of the ball volume on its exterior surface. The dimples have diameters between 0.04 and 0.3 inch and depths between 2/1,000 and 20/1,000 of an inch. The golf ball weight ranges from 1.35 ounces (38.3 grams) 1.55 ounces (43.97 grams). The cover material has a flexural modulus of less than 65,000 p.s.i.

Abstract: A golf ball having an outside diameter of substantially 1.70 to 1.80 inches and a weight no grater than 1.62 ounces.The ball includes a spherical core, a mantel surrounding the core; and an outer cover surrounding the core and the mantle.The mantle and outer cover each have a different Shore D hardness. The ball has a dimple pattern covering at least 70% of the surface of the ball.

Abstract: In a golf ball having a multiplicity of dimples of the same type arranged thereon and an equator, 6-12 dimples are arranged along the equator at an equal spacing and centered at the equator. The remaining dimples are arranged such that a great circle which does not intersect the dimples does not exist. A space where a dimple of the same size as the dimples can be formed is not left between the dimples. Due to a uniform arrangement of dimples including equator-centered ones, the golf ball is symmetrical enough to provide an increased carry and consistent flight independent of impact points.

Abstract: A wound golf ball comprising a center, a thread rubber layer and a cover has a weight of 40-45 grams and a distortion of 2.6-3.6 mm under a load of 100 kg. The center has an outer diameter of 30-35 mm and a distortion of 1.6-4 mm under a load of 30 kg. The cover has a Shore D hardness Hd of 50-68 and a gage of 1.2-2.2 mm. A percent overall dimple volume Vr which is defined as the sum of the volumes of dimple spaces each below a circular plane circumscribed by the dimple edge divided by the volume of the ball satisfies: (0.985-0.002 Hd).ltoreq.Vr.ltoreq.(1.085-0.002 Hd). The ball launches at a greater launch angle and initial velocity upon driver full shots at low head speed, traveling a longer distance.

Abstract: A golf ball comprising a solid core, and a cover enclosing the core and having a multiplicity of dimples formed therein has a diameter of 42.70.+-.0.05 mm and a specific gravity of 1.05.+-.0.05. The cover is composed mainly of an ionomer resin and has a Shore D hardness of at least 60, and the dimples satisfy the condition of 0.80.ltoreq.V.sub.R .ltoreq.1.16 wherein V.sub.R is a percent overall dimple volume given by the formula: ##EQU1## wherein Vs is a sum of the volumes of the dimple spaces each below a circular plane circumscribed by the dimple edge and R is a radius of the ball. The ball has a weight of 40.5 grams to less than 44.5 grams, and a cover thickness of 1.4 to 2.4 mm. The core undergoes a distortion of 2.4 to 4.3 mm under a load of 100 kg. Those golf players with a slow head speed can enjoy the advantages of the ball including an increased flying distance and a pleasant hitting feel.

Abstract: There is provided a golf ball comprising a core and a cover having a plurality of dimples thereon wherein said core has a distortion of 2.8 to 4.0 mm under a load of 100 kg, the ratio of a core distortion under a load of 100 kg divided by a ball distortion under a load of 100 kg ranges from 1.0 to 1.3, said cover has a thickness of 1.4 to 1.9 mm, and a Shore D hardness of 53 to 60, said dimples are divided into at least three kinds of dimples which have different diameters each other, each dimple has the ratio of diameter (mm) divided by depth (mm) of 18 to 27, the value of the spatial volume of each dimple below a plane defined by an edge of the dimple divided by the volume of a cylinder wherein the bottom of said cylinder is defined by said plane and the height is determined by the maximum depth of the dimple from said plane ranges from 0.390 to 0.550, and the total number of said dimples is in the range of 390 to 450.

Abstract: A solid golf ball having good controllability and long flight distance which utilizes a solid core and a cover covering the core, wherein the core is formed from a rubber composition comprising a polybutadiene rubber having a cis-1,4-structure content of at least 40% and either an unsaturated carboxylic acid or a metal salt thereof or both, and the cover has a thickness of 1 to 4 mm, a Shore D hardness of 55 to 64 and has 300 to 450 dimples having a diameter of 2 to 5 mm, with the dimples having a dimple area proportion of 62 to 78% and a total dimple volume of 260 to 345 mm.sub.3.

Abstract: A practice golf ball having a multiplicity of dimples formed in its surface has a weight of 46.5-49.0 grams and undergoes a distortion of 2.5-4.0 mm under a constant load of 100 kg. A percent dimple volume Vr is in the range of 0.7%.ltoreq.Vr.ltoreq.1.1% wherein the percent dimple volume Vr is the sum of the volumes of the entire dimples divided by the volume of a phantom sphere given on the assumption that the ball surface is free of dimples. The ball offers a good feel upon shots, follows a low trajectory without substantial shortage of a flight distance, and is thus suited for use in urban golf practice pits of limited space.

Abstract: A practice golf ball having a multiplicity of dimples formed in its surface has a weight of 46.5-49.0 grams and undergoes a distortion of 2.5-4.0 mm under a constant load of 100 kg. Those dimples having a diameter/depth (Dm/Dp) ratio between 10/1 and 15/1 occupy at least 80% of the total number of dimples. The ball offers a good feel upon shots, follows a low trajectory without substantial shortage of a flight distance, and is thus suited for use in urban golf practice pits of limited space.

Abstract: A multi-piece solid golf ball comprises a solid core and a cover of at least two layers enclosing the core and having a number of dimples in cover outer layer surface. The solid core is formed of a rubber base and has a specific gravity of at least 1.00. The cover is formed of a thermoplastic resin and the cover outer layer has a greater specific gravity than the core or a cover inner layer. The golf ball has an inertia moment (M) within the range given by the following expression: M.sub.DL .ltoreq.M.ltoreq.M.sub.UL wherein M.sub.UL =0.08D+84.8 and M.sub.DL =0.08D+77.8 wherein D is a Shore D hardness of the cover, the dimples occupy at least 60% of the ball surface, and V.sub.0 is in the range of 0.4 to 0.65. The ball is improved in flight distance, controllability, roll and straight travel upon putting.

Abstract: A solid golf ball having a solid core, a cover, and dimples formed on the surface of the cover, wherein the dimples satisfy the following equation:(number of dimples).times.(ratio of the area which is not occupied by dimples).div.(Shore D hardness of the cover)=1.4 to 1.9. The cover has a shore D hardness of 55-70 and a flexural modulus of 1,000 to 2,500 kgf/cm2. The core has a deformation amount of 2.4 to 3.5 mm when applying a load of from 10 to 130 kg. The dimples have diameters of 1.0 to 6.5 mm and the number of dimples is within the range of 330-440. The ratio of the area which is not occupied by dimples is within the range of 0.20 to 0.35.

Abstract: A golf ball having a dimple-free equatorial line dividing the golf ball into two hemispheres;each of the hemispheres has an equal number of dimples;each hemisphere has a plurality of dimples arranged in a configuration about the surface thereof so that there are no repeating patterns within the hemisphere.