Abstract: Using a mold having typically two split mold segments which are mated in a separable manner to define a spherical mold cavity therein, a golf ball having a multiplicity of dimples in its surface is molded by feeding a molding material into the mold cavity. The mold is split along a line off a horizontal great circle of the golf ball into two split mold segments having different areas of contact with the ball. The golf ball as molded is always caught and left in the larger mold segment and thus can be easily removed from the mold by a routine operation.

Abstract: Using a mold comprising typically two split mold segments which are mated in a separable manner to define a spherical mold cavity therein, a golf ball having a multiplicity of dimples in its surface is molded by feeding a molding material into the mold cavity. The mold is split along a line off a horizontal great circle of the golf ball into two split mold segments having different areas of contact with the ball. The golf ball as molded is always caught and left in the larger mold segment and thus can be easily removed from the mold by a routine operation.

Abstract: A multi-layer structure solid golf ball is composed of a solid core (2), an intermediate layer (3), and a cover (4). An adhesive layer (5) is interposed between the intermediate layer (3) and the cover (4). The intermediate layer may be formed from an ionomer or a urethane resin, or a polyester resin. The cover may be formed of an ionomer or a polyester elastomer or a urethane resin. The adhesive is selected from the group consisting of epoxy resin adhesives, urethane resin adhesives, vinyl resin adhesives and rubber adhesives.

Abstract: In a golf ball having at least a set of large and small diameter dimples, the large and small diameter dimples are of the same cross-sectional shape in their lower portion. A master model is prepared by feeding a cutter into a hemispherical surface of a master block to different depths while rotating the cutter, thereby forming a set of large and small recesses, respectively, wherein the large and small recesses have the same cross-sectional shape. The master model having plural types of dimples can be briefly fabricated and has increased freedom of design. Using the master model, a golf ball featuring uniform and densely distributed dimples can be manufactured.

Abstract: A golf ball mold includes a pair of split mold sections which are removably mated to define a spherical cavity. The cavity surfaces are provided with a plurality of dimple-forming protrusions. Some of the dimple-forming protrusions are constructed by dimple-forming pins whose inner end has substantially the same shape as the protrusions. The dimple-forming pins are axially or radially movable so that the projection distance of the pins into the cavity is adjustable. With a single mold, golf balls having dimples of different shapes can be produced. Golf balls of quality including symmetry and flight performance can be manufactured at low cost.

Abstract: A golf ball has a coating layer formed by dispersion coating at the surface portion thereof. For example, a two-piece golf ball is produced by enclosing a solid core with a cover material; forming, by dispersion coating, a white coating layer made of a thermoplastic resin on the surface of the cover material; conducting mark stamping on the coating layer; forming, by dispersion coating, a transparent coating layer made of a thermosetting resin as an outermost layer; and then conducting dimple processing. The coatings have thicknesses in the range of 15-250 .mu.m. Even when the coating layer at a surface portion is formed relatively thick, the coating layer allows the dimples to be precisely shaped and sharp edged and can be given sufficient durability and functions to improve travel properties, spin properties, and feel on impact.

Abstract: The present invention provides a golf ball of improved symmetry by regulating volume, area, edge length and array symmetry indexes Vi, Si, Li, and Ni obtained from coordinates (.theta.j, .phi.j) of a dimple center as represented by the latitude (in radian) and longitude of the ball and a radius rj and a volume vj of a dimple, for correcting a difference in dimple effect caused by a distortion of roundness of the ball. The golf ball does not have dimples which intersect the mold parting line, and the dimples occupy at least 65% of the ball surface.

Abstract: A golf ball includes a coating layer which has a thickness of 50-700 .mu.m and is formed at the surface portion of the golf ball. When a three-piece golf ball, for example, is prepared, a solid core is enclosed with a cover material having a two-layer structure composed of inner and outer cover layers, and mark stamping is then performed on the cover material. Subsequently, a transparent coating layer having a thickness of 50-700 .mu.m and made of a thermoplastic resin is formed as an outermost layer. It is possible to impart a desired surface hardness and surface friction coefficient to the golf ball without taking account of the overall structure of the golf ball and the relationship between the hardness of the core and the hardness of the cover, thereby increasing the degree of freedom in designing of the golf ball, especially, in designing of the surface hardness and the surface friction coefficient.

Abstract: Using a mold having typically two split mold segments which are mated in a separable manner to define a spherical mold cavity therein, a golf ball having a multiplicity of dimples in its surface is molded by feeding a molding material into the mold cavity. The mold is split along a line off a horizontal great circle of the golf ball into two split mold segments having different areas of contact with the ball. The golf ball as molded is always caught and left in the larger mold segment and thus can be easily removed from the mold by a routine operation.

Abstract: A golf ball comprising a core and a cover including at least two layers is improved in overall performance including flight performance, flight distance, spin, control and feel when an outermost layer of the cover has a gage of 0.01-0.05 mm and a Shore D hardness of 48.degree.-55.degree.. The core may be solid or wound. An inner layer of the cover has a Shore D hardness in the range of 58-70 and a thickness of 1.2-4.0 mm. The outer layer may be a thin film wrapped on the inner layer.

Abstract: A two or three piece golf ball in which a boundary surface between concentric solid layers has a projection formed on the surface of a concentric solid layer having a high hardness such that the projection extends along an approximate normal direction, a depression corresponding to the projection is formed in the surface of a concentric solid layer having a low hardness, and the concentric solid layer having a high hardness and the concentric solid layer having a low hardness are joined together such that the projection is inserted into the depression. A golf ball comprising a two-layer solid core is composed of a low-hardness inner core and a high-hardness outer core joined around the low-hardness inner core.

Abstract: In a golf ball having a multiplicity of dimples of the same type arranged thereon and an equator, 6-12 dimples are arranged along the equator at an equal spacing and centered at the equator. The remaining dimples are arranged such that a great circle which does not intersect the dimples does not exist. A space where a dimple of the same size as the dimples can be formed is not left between the dimples. Due to a uniform arrangement of dimples including equator-centered ones, the golf ball is symmetrical enough to provide an increased carry and consistent flight independent of impact points.

Abstract: A golf ball comprising; a core and a multi-layered cover having an innermost layer enclosing the core, at least one intermediate layer enclosing the innermost layer, and an outermost layer enclosing the at least one intermediate layer. The innermost layer is composed of an ionomer resin, polyester elastomer, polyamide elastomer or polyurethane elastomer. The at least one intermediate layer is composed of an ionomer resin. The outermost layer is composed of an ionomer resin, ethylene-vinyl acetate copolymer, polyurethane or polyethylene or a mixture thereof, and the at least one intermediate layer includes at least one layer which is harder than the innermost layer and the outermost layer.

Abstract: There is provided a golf ball comprising a core and a cover having a plurality of dimples thereon wherein said core has a distortion of 2.8 to 4.0 mm under a load of 100 kg, the ratio of a core distortion under a load of 100 kg divided by a ball distortion under a load of 100 kg ranges from 1.0 to 1.3, said cover has a thickness of 1.4 to 1.9 mm, and a Shore D hardness of 53 to 60, said dimples are divided into at least three kinds of dimples which have different diameters each other, each dimple has the ratio of diameter (mm) divided by depth (mm) of 18 to 27, the value of the spatial volume of each dimple below a plane defined by an edge of the dimple divided by the volume of a cylinder wherein the bottom of said cylinder is defined by said plane and the height is determined by the maximum depth of the dimple from said plane ranges from 0.390 to 0.550, and the total number of said dimples is in the range of 390 to 450.

Abstract: In a golf ball, dimples are arranged in its spherical surface such that a great circle which does not intersect with the dimples is not drawable on the ball surface, thereby preventing any drop of symmetry caused by the presence of a seam line. The dimples are further arranged such that a percent dimple volume VR given as (B/A).times.100% is in the range: 0.6%<VR<1.5% wherein a phantom sphere given on the assumption that the spherical surface of the ball is free of dimples has a volume of A mm.sup.3 and the sum of the volumes of dimples distributed throughout the ball is B mm.sup.3, thereby optimizing the percent dimple volume to ensure a longer carry.

Abstract: A golf ball has a core (1) enclosed with a cover (2) wherein the cover (2) is embossed on its surface with dimples by compression molding in a mold and includes an innermost layer (3), an intermediate layer (4), and an outermost layer (5). The intermediate layer (4) and the outermost layer (5) are formed of a laminate film while the outermost layer (5) is made of a material which is smoothly releasable from the mold. The golf ball is readily removed from the mold at the end of molding and has a high precision of dimple geometry.