The present invention relates to golf balls having improved packing efficiency and aerodynamic characteristics and a high degree of dimple interdigitation. In particular, the present invention relates to a golf ball including at least a portion of dimples having a plan shape defined by low frequency periodic functions having high amplitudes. The present invention is also directed to methods of developing the dimple plan shape geometries, as well as methods of making the finished golf balls with the inventive dimple patterns applied thereto.

A golf ball 2 includes a core 4 and a cover 6 positioned outside the core 4. The cover 6 is molded in a mold having support pins by injection molding. A ratio (K/S) of a surface hardness K of the core 4 to an amount of compressive deformation S of the core 4 satisfies the following mathematical formula.

13.0K/S24.0

The cover 6 has a hardness H of not greater than 62. A product (*V) of a latitude of each support pin and a volume V of the cover 6 is not less than 300.

A golf ball 2 includes a core 4 and a cover 6 positioned outside the core 4. The cover 6 is formed in a mold having support pins by injection molding. A ratio (V/S) of a volume V (mm.sup.3) of the cover 6 to an amount of compressive deformation S (mm) of the core 4 is not less than 1000 and not greater than 1900. The cover 6 has a shore D hardness of not greater than 62. The golf ball 2 has a plurality of dimples 8 on a surface thereof. A total volume W of these dimples is not less than 490 mm.sup.3 and not greater than 620 mm.sup.3. A ratio (/P) of a latitude (degree) of each support pin to a total cross-sectional area P (mm.sup.2) of the support pins is not less than 0.35 and not greater than 0.60.

A golf ball 2 has a core 4, an inner cover 6, a main cover 8, and an outer cover 10. A product TH2 of a thickness T2 (mm) and a Shore C hardness H2 of the main cover 8 and a product THs of a value of 5% of a radius (mm) of the core 4 and a Shore C hardness Hs at a surface of the core 4 satisfy the following mathematical formula.

15(TH2THs)100

A product TH1 of a thickness T1 (mm) and a Shore C hardness H1 of the inner cover 6, a product TH3 of a thickness T3 (mm) and a Shore C hardness H3 of the outer cover 10, and the product TH2 satisfy the following mathematical formula.

0.25<((TH1+TH3)/2)/TH2<0.65

Golf balls according to the present invention achieve flight symmetry and overall satisfactory flight performance due to a dimple surface volume ratio that is equivalent between opposing hemispheres despite the use of different dimple geometries, different dimple arrangements, and/or different dimple counts on the opposing hemispheres.

A golf ball includes a core and a cover. The cover has a shore D hardness of not less than 50. The cover has a thickness of not less than 1.00 mm. The golf ball has a plurality of dimples 10 on a surface thereof. A standard deviation Su of areas of all the dimples 10 is not greater than 1.7 mm.sup.2. A standard deviation Pd of distances L between dimples of all neighboring dimple pairs is less than 0.500 mm. A dimple pattern of each hemisphere of a phantom sphere of the golf ball includes three units (T1, T2, T3) that are rotationally symmetrical to each other. A dimple pattern of the unit T1 includes two small units (T1a, T1b) that are mirror-symmetrical to each other.

In a golf ball, dimples are arranged on a spherical polyhedron formed by dividing a surface of a sphere using small circles and great circles only on the equator, without arranging the dimples on a spherical polyhedron formed by dividing a surface of a sphere using great circles. The formed spherical polyhedron includes two spherical regular hexagons centered on a pole, twelve near-pole spherical isosceles triangles, twelve near-equator spherical pentagons, and twelve near-equator spherical isosceles triangles, in which the dimples are arranged. Thus, a dimple area ratio may be improved by 2 to 4%, compared to the prior art in which dimples are arranged in spherical polygons of a cubeoctahedron (or an octahedron) divided by great circles.

A golf ball 2 includes a center 8, a mid layer 10, a cover 6 and dimples 12. The cover 6 has a Shore D hardness of 30-50. The golf ball 2 has an amount of compressive deformation of 3.0-5.0 mm. The ball 2 meets a mathematical formula (I):

0.80((L1+L2)/2)0.95(I).

L1 represents a ratio of a lift coefficient CL1 relative to a drag coefficient CD1, the lift coefficient CL1 and the drag coefficient CD1 being measured under conditions of a Reynolds number of 1.29010.sup.5 and a spin rate of 2820 rpm. L2 represents a ratio of a lift coefficient CL2 relative to a drag coefficient CD2, the lift coefficient CL2 and the drag coefficient CD2 being measured under conditions of a Reynolds number of 1.77110.sup.5 and a spin rate of 2940 rpm.

A golf ball 2 has a large number of dimples 10 on a surface thereof. A dimple pattern of each hemisphere of the golf ball 2 includes three units (T1, T2, and T3) that are rotationally symmetrical to each other. A dimple pattern of each unit includes two small units (T1a, T1b) that are mirror-symmetrical to each other. A standard deviation Su of areas of all the dimples 10 is not greater than 1.7 mm.sup.2. A standard deviation Pd of distances L between dimples 10 of all neighboring dimple pairs is less than 0.500 mm. A ratio So of a sum of areas of the dimples 10 relative to a surface area of a phantom sphere of the golf ball 2 is not less than 78.0%.

In a golf ball, dimples are arranged on a spherical polyhedron formed by dividing a surface of a sphere using small circles and great circles only on the equator, without arranging the dimples on a spherical polyhedron formed by dividing a surface of a sphere using great circles. The formed spherical polyhedron includes two spherical regular hexagons centered on a pole, twelve near-pole spherical isosceles triangles, twelve near-equator spherical pentagons, and twelve near-equator spherical isosceles triangles, in which the dimples are arranged. Thus, a dimple area ratio may be improved by 2 to 4%, compared to the prior art in which dimples are arranged in spherical polygons of a cubeoctahedron (or an octahedron) divided by great circles.