Abstract: In a golf ball having a multiplicity of dimples of circular plane shape disposed at a spacing on its surface, dimple spacings of up to 1.65 mm account for 60 to 80% of the entire dimple spacings, and an average V.sub.0 and A, defined in the specification, are limited. The shape and arrangement of dimples are correlated so that dimples may be distributed on the ball surface in a well-balanced uniform arrangement, whereby the flight behavior is drastically improved.

Abstract: In a golf ball having a multiplicity of dimples of circular plane shape on its surface, the dimples include plural types of dimples having different diameters. The dimples of at least one type are formed to at least two different cross-sectional shapes. A three-dimensionally appropriate combination and arrangement of a multiplicity of dimples on the ball surface is effective for improving the aerodynamic behavior of the golf ball so that the ball exerts excellent flight performance.

Abstract: A solid golf ball comprising a solid core and a cover has a multiplicity of dimples in its surface. The core undergoes a distortion of 2.8-4.0 mm under a load of 100 kg. The distortion (mm) of the core under a load of 100 kg divided by the distortion (mm) of the ball under a load of 100 kg is 1.0-1.3. The cover has a gage of 1.4-1.9 mm and a Shore D hardness of 53-60. Dimples of at least three types having different diameters are formed in the cover surface in a total number of 390-450. The diameter/depth ratio of each dimple is from 18/1 to 27/1. The volume of a dimple divided by the volume of a cylinder whose diameter and height correspond to the diameter and depth of the dimple, respectively, is 0.390-0.550. The golf ball is improved in flight distance, hitting feel and spin and will cover a distance even when hit at low head speeds.

Abstract: A golf ball is composed of at least a pair of adjacent concentric solid layers or three adjacent concentric solid layers. In the former case, the outer solid layer is composed of a matrix and non-metallic high-hardness grains having hardness higher than that of the matrix which has a Shore D range of 36-40. In the later case, the intermediate solid layer is composed of a matrix and high-hardness grains having hardness higher than that of the matrix. The high-hardness grains have a Shore D hardness in the range of 50-70 and penetrate the corresponding solid layer in normal directions. The golf ball can provide a player with different feels on impact depending on the direction of an external force applied thereto when the golf ball is hit.

Abstract: A golf ball having a plurality of dimples on its spherical surface molded by a mold which has a spherical cavity therein and is composed of a pair of mold sections being removably mated along with a parting surface at the position corresponding to an equator line of the spherical cavity of the mold, wherein at least one dimple lies across the equator line of the ball, such that a center of the dimple is displaced from the equator line, and the dimple is formed by a pin disposed at the parting surface of the mold sections such that a center axis passing the axial center of the pin is positioned below or above the parting line.

Abstract: A golf ball having a plurality of dimples on its surface, the dimples including dimples which are different in diameter and/or depth, the total number of dimples is 392 to 432, and the golf ball has a percent dimple surface area occupation of 77 to 82%, a percent dimple volume occupation of 0.85 to 1.2%, an average dimple diameter of 2.5 to 4.5 mm (0.098 to 0.177 inches), an average dimple depth of 0.12 to 0.18 mm (0.005 to 0.007 inches), an average dimple V.sub.0 value of 0.4 to 0.6, and a dimple edge angle of 4.0 to 17.0 degrees, where CL is a lift coefficient and CD is a drag coefficient, CL is in the range of 0.140 to 0.190, CD is in the range of 0.21 to 0.255, and CL/CD is in the range of 0.640 to 0.730 when the ball is in flight at a velocity of 65 m/s and a spin rate of 42 rps.

Abstract: A golf ball defines a dimple spherical surface having a diameter of not greater than 42.66 mm and formed with a plurality of protrusions. The ball is unable to pass through a ring gage having an inner diameter of 42.67 mm.

Abstract: A two-piece solid golf ball comprising; a solid core formed of a rubber and a cover formed of an ionomer resin, the solid core has a diameter in the range of 35 to 41 mm and a hardness corresponding to distortion of 2.0 to 4.0 mm under applied load of 100 kg, the cover has a spherical surface, a Shore D hardness in the range of 40 to 70 and a gage in the range of 0.5 to 3 mm, and the spherical surface is formed of a plurality of dimples wherein, the dimples have a depth in the range of 0.08 to 0.15 mm and an average V.sub.O value for all the dimples is 0.5 to 0.9 where V.sub.O is the volume of a dimple space below a plane circumscribed by the dimple edge divided by the volume of a cylinder whose bottom is the plane and whose height is the maximum depth of the dimple from the bottom, and a percent dimple volume Vr given by the following equation is in the range of 0.75 to 1.

Abstract: In a golf ball having a parting line formed at the junction between a pair of mold sections and a plurality of dimples some of which lie across the parting line and being free of a great circle which does not intersect with the dimples, the crossing dimples lying across the parting line have a greater edge angle than those dimples of the same diameter as the crossing dimples disposed near the poles. The ball is improved in symmetry in that the flight distance is substantially equal between seam hitting and pole hitting.

Abstract: In a golf ball having a parting line formed at the junction between a pair of mold sections and a plurality of dimples some of which lie across the parting line, the average space volume Vp of the dimples lying across the parting line is greater than the average space volume Vp' of the remaining dimples lying outside the parting line and/or the average Dp/Dm of the dimples lying across the parting line is greater than the average Dp/Dm of the remaining dimples lying outside the parting line wherein Dp and Dm are the depth and diameter of dimples, respectively. The golf ball is improved in symmetry in that no substantial difference occurs in flight distance between seam hitting and pole hitting.

Abstract: An injection mold for golf balls includes a pair of separable mold segments (1a, 1b). The mold segments (1a, 1b) are mated at their peripheral surfaces (12) along a parting line so that their inner surfaces (2a) define a spherical cavity (2). A plurality of dimple-forming projections (11) are formed on the inner surfaces (2a). At least four tubular gates (7) are disposed in the peripheral surfaces (12) and in fluid communication with the cavity (2). The peripheral surfaces (12) are furrowed except for the areas where the gates are disposed. Dimple-forming pins (14) are received in furrows (13) so as to lie across the parting line (PL). A molten stock material is injected into the cavity (2) through the gates (7) to mold a golf ball having dimples lying across the parting line.