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.

In a golf ball for professional golfers and skilled amateurs which has a single-layer core, a cover and at least one intermediate layer therebetween, the sphere obtained by encasing the core with the intermediate layer (intermediate layer-encased sphere) and the ball have a surface hardness relationship which satisfies the condition:
(surface hardness of intermediate layer-encased sphere)>(surface hardness of ball).
The core has a diameter of from 35.5 to 39.5 mm and a distinctive hardness profile that satisfies specific conditions. The ball is endowed with both an excellent flight performance and excellent durability to repeated impact.

The present invention provides golf balls having a non-straight flight trajectory due, at least in part, to a dimple pattern wherein the dimples on the opposing sides of the ball have at least one design feature that is different.

Golf ball comprising dimple(s) incorporating three or more linear channels having the same channel length L and same channel width CW; all linear channels extend radially outward from a centroid of the dimple toward a perimeter of the dimple without intersecting the dimple's centroid. Each linear channel may extend radially outward from a location on the dimple that is a distance Cd from the dimple's centroid, wherein Cd>0. Alternatively, at least one of the three or more linear channels has a different channel length L and/or a different channel width CW than at least one other linear channel. Dimple may have circular or non-circular plan shape; channels may not intersect each other; at least one linear channel may intersect the dimple's perimeter; and linear channels may be spaced by n separation angles .sub.S, wherein n is number of linear channels, which may be equal, or at least two differ.

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 low frequency periodic functions along a closed simple path. In addition, the present invention provides methods for designing dimples having a plan shape defined by a low frequency periodic function along a closed simple path.

The present invention provides a golf ball having an outer surface comprising a plurality of dimples covering greater than 70 percent of the outer surface, wherein a plurality of the dimples incorporate directional surface texturing therein. The directional surface texturing preferably comprises substantially parallel channels or protrusions formed within the dimples. The directional surface texturing can comprise of parallel linear channels or protrusions or parallel non-linear linear channels or protrusions.

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.

An object of the present invention is to provide a golf ball showing increased controllability on approach shots for less than 40 yards and showing excellent shot feeling. In the inventive golf ball, the paint film is formed from a curing type paint composition including: a base material containing a polyrotaxane, and a curing agent containing a polyisocyanate, and wherein the polyrotaxane has a cyclodextrin, a linear molecule included in a cyclic structure of the cyclodextrin in a manner of piercing through the cyclic structure of the cyclodextrin, and a blocking group located at both ends of the linear molecule to prevent disassociation of the cyclodextrin, and at least a part of hydroxyl groups of the cyclodextrin is modified with a caprolactone chain via OC.sub.3H.sub.6O group.

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.

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.