A golf ball includes: a land portion; and a plurality of dimples each provided to be recessed with respect to the land portion. Each of the dimples has a dimple edge and a dimple plane surrounded by the dimple edge. The dimples include a plurality of eccentric dimples each having a deepest portion that is not located on a line connecting a center point of the dimple plane of a corresponding one of the eccentric dimples and a center point of the golf ball. The eccentric dimples have respective dimple axes that are oriented randomly in the golf ball, and each of the dimple axes is obtained in a plan view of the corresponding one of the eccentric dimples by connecting the center point of the dimple plane and the deepest portion of the corresponding one of the eccentric dimples.

Provided is a spherical polyhedron division structure of a golf ball where dimples are arranged to have a well-defined symmetry and a dimple pattern. In the spherical polyhedron division structure, wherein an arbitrary point on a surface of a spherical body constituting a golf ball is defined as a pole, a great circle dividing the spherical body into a northern hemisphere and a southern hemisphere with respect to the pole as a reference point is defined as an equator, the surface of the spherical body is divided into six areas formed by segments connecting the pole and points obtained by dividing the equator in units of 60°, each area is divided into spherical polygons formed by four spherical rectangles and two spherical triangles having sides with different lengths, and the spherical polygons arranged in different adjacent areas are symmetric with each other.

A golf ball having an outer surface with a pattern forming a polyhedron. The pattern can be flat faces forming sharp edges and sharp points therebetween. In one embodiment, the polyhedron is a Goldberg polyhedron.

The present invention is a golf ball dividing method for symmetrically arranging dimples on a surface of a golf ball and a dimple arrangement method of arranging dimples along dividing lines based on sizes of dimples. The dimples having large diameters are effectively arranged on the deformed spherical triangle symmetrically over the entire surface of a sphere, so that it is possible to an effect of improving the flying stability and flight distance of the golf ball. Accordingly, it is possible to solve the problem of flying stability due to the lack of symmetry in the dimple arrangement method of the prior art for increasing an dimple area ratio by dividing the surface of the golf ball as a spherical octahedron and arranging dimples having large diameters, so that it is possible to improve a lift force to increase a flight distance and the flying stability of the golf ball.

An object of the present invention is to provide a golf ball having excellent approach spin performance under a dry condition and excellent approach spin performance under a condition that there is grass between the golf ball and the club face. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film is composed of at least one layer, and an outermost paint film layer located at the outermost layer of the golf ball contains, as a base resin, a polyurethane obtained by a reaction between (A) a polyisocyanate composition and (B) a polyol composition, (B) the polyol composition contains a urethane polyol as a polyol component, and the outermost paint film layer has a dynamic friction coefficient of from 0.65 to 1.2 measured with a dynamic friction tester under specific conditions.

A golf ball dimple pattern based on a square dipyramid, i.e., two square pyramids connected base-to-base, is disclosed. The dimples are arranged within four substantially identical triangular sections on each of two substantially identical hemispheres of the ball.

The present invention provides a golf ball wherein each hemisphere has a dimple pattern based on a pyramid having dissimilar sides. The resulting overall dimple pattern is not based on preexisting polyhedral, and is not attainable using conventional dimple packing methods.

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the envelope layer is formed into two layers—an inner envelope layer and an outer envelope layer. The inner envelope layer-encased sphere, outer envelope layer-encased sphere, intermediate layer-encased sphere and ball have respective surface hardness that satisfy a specific relationship. The inner envelope layer or outer envelope layer is formed primarily of one or more elastomer, and further the core has a particular hardness profile. This ball has an excellent flight when struck by golfers whose head speeds are not that fast and has a good, soft feel at impact, thus making it highly suitable for amateur golfers,

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.

The present invention is directed to golf balls having improved aerodynamic performance due, at least in part, to the selection of the plan shapes of the dimples thereon. 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 periodic triangle wave function mapped along a circular closed path. In addition, the present invention provides methods for designing dimples having a plan shape defined by a periodic triangle wave function mapped along a circular closed path.