The present invention is directed to golf balls having improved aesthetics and desirable aerodynamic properties due, at least in part, to the novel shape of the dimples on the surface thereof. In particular, the present invention is directed to a golf ball that includes at least a portion of its dimples having a shape obtained from the intersection of a toroid and a sphere. The resulting curve of intersection represents the dimple perimeter and the intersecting portion of the surface of the toroid represents the dimple surface shape.

A golf ball 2 includes a large number of dimples 10 on a surface thereof. The surface has a northern hemisphere N and a southern hemisphere S. Each of the hemispheres has a high-latitude region 14, a mid-latitude region 18 and a low-latitude region 16. The high-latitude region 14 has a latitude range of 40 or greater but 90 or less. The mid-latitude region 18 has a latitude range of 20 or greater but less than 40. The low-latitude region 16 has a latitude range of 0 or greater but less than 20. The number of planes that can divide a dimple pattern of the hemisphere so that divided dimple patterns are mirror symmetry to each other is one. Neither a dimple pattern of the high-latitude region 14 nor a dimple pattern of the low-latitude region 16 is rotationally symmetrical.

The present invention concerns a golf ball having dimples with a cross-sectional profile comprising a conical top portion and a non-conical bottom portion. More particularly, the profiles of the present invention are defined by three independent parameters: dimple diameter (D.sub.D), edge angle (.sub.EDGE), and saucer ratio (S.sub.r). These parameters fully define the dimple shape and allow for greater flexibility in constructing a dimple profile versus conventional spherical dimples. Further, conical dimples provide a unique dimple cross-section which is visually distinct.

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

The present invention is a golf ball which comprises dimples having a cross section defined by the superposition of two or more continuous and differentiable functions, and particularly the superposition of a spherical curve and a cosine curve. Additionally, the dimples preferably have a circular boundary and maintain an axis coincident with the center of the circular boundary.

A golf ball includes oval dimples arranged on the surface thereof. Each of the oval dimples has a long diameter DL and a short diameter DS in a planar shape thereof and further having a depth DPL on a first cross section of the oval dimple along the long diameter DL and a depth DPS on a second cross section of the oval dimple along the short diameter DS, the depth DPL being a distance taken on the first cross section along the long diameter DL from a first line connecting both ends of the first cross section of the oval dimple to a deepest point of a dimple bottom surface, the depth DPS being a distance taken on the second cross section along the short diameter DS from a second line connecting both ends of the second cross section of the oval dimple to a deepest point of a dimple bottom surface, a relationship between the depth DPL and the depth DPS being defined as a following formula (1):
DPS>DPL(1). Each of the oval dimples further having a cross-sectional area DLA on the first cross section of the oval dimple along the long diameter DL and a cross-sectional area DSA on the second cross section of the oval dimple along the short diameter DS, the cross-sectional area DLA being surrounded by the first line connecting both ends of the first cross section of the oval dimple and the bottom surface thereof, the cross-sectional area DSA being surrounded by the second line connecting both ends of the second cross section of the oval dimple and the bottom surface thereof, a relationship between the cross-sectional area DLA and the cross-sectional area DSA being defined as a following formula (2):
DLADSA(2).

A golf ball has a plurality of dimples 12 and a land 14 on a surface thereof. The golf ball further has a large number of minute projections 18 formed on surfaces of the dimples 12 and the land 14. An average pitch Pav of these minute projections 18 is less than 100 m. An average height Hav of these minute projections 18 is not less than 0.5 m and not greater than 50 m. The golf ball satisfies the following mathematical formula.

Lav<3*Tav

In the mathematical formula, Lav represents an average value of distances L between the minute projections 18 and other minute projections 18 adjacent to the minute projections 18, and Tav represents an average value of widths T of these minute projections 18.

The present invention concerns a golf ball having dimples with a cross-sectional profile comprising a conical top portion and a non-conical bottom portion. More particularly, the profiles of the present invention are defined by three independent parameters: dimple diameter (D.sub.D), edge angle (.sub.EDGE), and saucer ratio (S.sub.r). These parameters fully define the dimple shape and allow for greater flexibility in constructing a dimple profile versus conventional spherical dimples. Further, conical dimples provide a unique dimple cross-section which is visually distinct.

The present invention is directed to golf balls having surface textures with unique appearances and improved aerodynamic characteristics due, at least in part, to the use of curvilinear dimple plan shapes. In particular, the present invention is directed to a golf ball that includes at least a portion of its dimples having a plan shape defined by a number of convex or concave arcs that are derived from the vertices of a regular n-sided polygon, for example, an equilateral triangle or square.

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.