Abstract: A golf ball comprising a core and a cover is manufactured by the steps of (A) enclosing the core with a thermoplastic resin and (B) tailoring the thermoplastic resin layer by applying heat and pressure thereto, for adjusting the thickness of the thermoplastic resin layer to 0.3-1.0 mm. A golf ball whose cover layer has a very thin and uniform thickness as well as an improved outer appearance is manufactured. The golf ball can derive the rebound and other characteristics of the core to the maximum extent.

Abstract: In a multi-piece solid golf ball comprising a rubbery elastic solid core and a resin cover including at least an inner layer, an intermediate layer and an outer layer, the solid core undergoes a deflection of 1.6-6.0 mm under an applied load of 294 N (30 kgf), the cover inner layer has a Shore D hardness of 55-70, the cover intermediate layer has a Shore D hardness of 8-50 and a gage of 0.1-1.2 mm, and the cover outer layer has a Shore D hardness of 40-55. The ball prevents any undesired increase of spin upon driver shots without detracting from rebound, has good flight performance, and receives enough spin to facilitate control on short iron shots.

Abstract: A golf ball has a spherical surface which is integrally provided with a plurality of annular ridges. The annular ridges are effective for reducing the air resistance of the ball in flight and thus drastically improving the flight performance.

Abstract: A method of manufacturing a golf ball is disclosed. A cover is molded through use of either a thermoplastic resin having a group capable of reacting with an isocyanate group or a thermoplastic resin containing a compound having two or more groups capable of reacting with an isocyanate group. Subsequently, a polyisocyanate compound is caused to permeate into the surface layer of the cover to thereby cause the reaction between the polyisocyanate compound and the group(s) capable of reacting with the isocyanate group. As a result, a modified layer having excellent properties is formed at the surface of the cover formed from thermoplastic resin. In this case, a non-yellowing polyurethane resin is preferably used as the thermoplastic resin having a group capable of reacting with an isocyanate group, and 4,4-diphenylmethane diisocyanate (MDI) is preferably used as the polyisocyanate compound.

Abstract: In a golf ball, a plurality of flat surface regions, typically hexagonal plane regions are defined on the ball surface. The proportion of the land area in the golf ball surface area is reduced to below 20%, eventually reducing the air resistance of the ball in flight and drastically improving the flight performance.

Abstract: In a golf ball, triangular dimples each defined by combining three ridge-like lands having a side length of 2-9 mm are arranged on the spherical surface. The percent occupation of the total dimple area over the entire spherical surface area is significantly increased, even to substantially 100%, and the ball is drastically improved in flight performance.

Abstract: In a golf ball having a plurality of dimples on its surface, twelve pentagonal groups each consisting of five dimples arranged about one central dimple are dispersively distributed over the ball surface excluding the polar areas, and hexagonal groups each consisting of six dimples arranged about one central dimple are distributed over the remaining area of the ball surface. The dimples are arranged uniformly and densely so as to reduce the air resistance in flight of the ball, resulting in increased flight distance.

Abstract: A golf ball comprising an elastic solid core, an intermediate layer and a resin cover of urethane elastomer having a plurality of dimples on its surface, wherein the dimples include 330-400 circular dimples having a diameter of 3.7-5.0 mm, have a total volume of 330-380 mm3, and are substantially uniformly distributed such that there is no or only one great circle which does not intersect with the dimples exhibit uniform flight performance.

Abstract: In a multi-piece solid golf ball comprising an elastic solid core and a resin cover, the cover includes at least an inner layer and an outer layer, the solid core undergoes a deflection of 1.1-4.0 mm under a load of 294 N, the cover inner and outer layers have a Shore D hardness of 45-70 and 35-55, respectively. The ball is provided with a multiplicity of dimples which are substantially uniformly arranged such that a great circle which does not intersect with the dimples is absent. The ball exhibits consistent flight performance when hit with a driver, suppresses reduction of spin when hit in the wet state with a short iron, and offers stable ready-to-strike conditions, flight performance and spin performance under any conditions covering from the fairway to the putting green.

Abstract: A golf ball includes a multiplicity of dimples on its outer surface. At least one or more of the multiplicity of dimples are each configured to have a convex bottom portion formed by a circular-arc defined by a center positioned inside the ball and a curvature radius “r” mm smaller than a radius “R” mm of the ball but larger than a value (R−0.5) mm. The golf ball specified such that the shapes of the dimples are optimized as described above exhibits high flight characteristics.

Abstract: A golf ball having a plurality of dimples arranged on its surface is provided wherein the ball surface is free of a great circle that does not intersect with dimples, at least 7% of the total number of dimples are non-circular dimples, and some non-circular dimples lie across the equator of the ball corresponding to a parting plane of a mold. The ball is improved in flight distance and aerodynamic uniformity.

Abstract: A golf ball having a plurality of dimples on a spherical surface thereof, the dimples each having a circular shape in a plan view, is provided, wherein a virtual dimple is supposed to have a circular shape having the same diameter as the circular shape of the dimple in the plan view, and to be a part of a circle having the same sectional area as that of the dimple in the sectional view; at least 80% of the dimples have depths not less than 104% of the depth of the virtual dimple, and have a non-circular-arc-shape in a sectional view; and a total volume of the dimple is in a range of from 300 to 550 mm3.

Abstract: Disclosed is a golf ball including: a plurality of dimples arranged overall on the spherical surface of the golf ball by assuming the spherical surface of the golf ball as a spherical octahedron and using, as dimple arrangement units, eight spherical triangles constituting the spherical octahedron, on each of which a specific number of the dimples are arranged. In this golf ball, at least the four dimples are arranged on each of three sides of the spherical triangle; there is no great circle with which none of the dimples intersects; and the total number of the dimples is in a range of 380 to 450.

Abstract: A golf ball includes a multiplicity of dimples on a spherical surface of the golf ball. The dimples are rotation-symmetric of a specific angle about a rotational axis which connects both poles of the golf ball to each other while passing through the center of an equatorial plane of the golf ball, and any great circle line not crossing any one of the dimples is not present on the spherical surface of the golf ball. The golf ball is excellent in flight distance and flight uniformity.

Abstract: In a golf ball comprising an elastic solid core, a mantle layer, and a resin cover having a plurality of dimples, the difference in Shore D hardness between the cover and the mantle layer is at most 10, and the dimples have a total volume of 280-350 mm2. This combination of features provides the golf ball with an excellent balance of rebound, spin and feel, and an outstanding total distance.

Abstract: In a dimpled golf ball, those dimples in which a tangent A to the dimple wall has an inclination angle of at least 13° are included in the majority, the variation of the dimple area with different positions on the ball surface and the variation of the dimple cavity volume with different positions on the ball surface are within specific ranges. The golf ball exhibits uniform flight performance in that the variation of flight performance with a dimple arrangement is minimized.

Abstract: In a multi-piece solid golf ball comprising an elastic solid core, an intermediate layer of ionomer resin, and a cover of urethane elastomer having a plurality of dimples on its surface, those dimples disposed in one or more rows adjacent to the equator have a greater depth and/or volume than the remaining dimples in other areas. The variation of flight performance of the ball with impact points is minimized.

Abstract: In a dimpled golf ball, those dimples in which a tangent A to the dimple wall has an inclination angle of at least 13° are included in the majority, the variation of the dimple area with different positions on the ball surface and the variation of the dimple cavity volume with different positions on the ball surface are within specific ranges. The golf ball exhibits uniform flight performance in that the variation of flight performance with a dimple arrangement is minimized.