Abstract: A screw attachment (10, 10′, 10″) disposed around a fastening piece (17) secured to a main fastening body (25a), the screw attachment sandwiched between a head (17b) of the fastening piece and a securing object (22) so that the screw attachment bears a securing force of the fastening piece to press the securing object. The screw attachment includes a pair of arms (12, 13) made of a shape restoring material. Each arm has a fore end, and the fore ends are joined to each other with an adhesive material that is softened when heated. The arms expands radially such that the screw attachment is released from the head of the fastening piece when heat or force is applied to the arms.

Abstract: The present invention provides a three-piece solid golf ball having long flight distance, by accomplishing high launch angle and low spin amount immediately after hitting, while maintaining soft and good shot feel when hitting at low head speed. The present invention relates to a three-piece solid golf ball comprising a center, an intermediate layer formed on the center, and an outer layer covering the intermediate layer, wherein the center has a central point hardness in JIS-C hardness of 55 to 75 and a surface hardness in JIS-C hardness of 65 to 85, the surface hardness is higher than the central point hardness by 10 to 20, a JIS-C hardness of the intermediate layer is higher than the surface hardness of the center by 10 to 20, and a JIS-C hardness of the outer layer is higher than the hardness of the intermediate layer by 5 to 15.

Abstract: The present invention provides a multi-piece solid golf ball comprising a core consisting of an inner core and an outer core, and one or more layers of cover, wherein the inner core has a diameter of 30 to 39.5 mm and a center hardness in JIS-C hardness of 55 to 70, and is formed from press molded rubber composition comprising polybutadiene, a co-crosslinking agent, an organic peroxide and a filler, and the JIS-C hardness at a distance of 15 mm from the center point of the inner core is higher than the center hardness by 5 to 20; the outer core has a thickness of 0.3 to 2.0 mm and a surface hardness in JIS-C hardness of 75 to 90, and is formed from press molded rubber composition, and the surface hardness of the outer core is higher than the center hardness of the outer core is higher than the center hardness of the inner core by 10 to 35; and the cover contains thermoplastic resin as a base resin, and the outmost cover layer has a thickness of 1.5 to 2.

Abstract: The present invention provides a four-piece solid golf ball having excellent flight performance and good shot feel at the time of hitting. The present invention relates to a four-piece solid golf ball comprising a core, an intermediate layer formed on the core, an outer layer formed on the intermediate layer and a cover covering the outer layer, wherein the core has a surface hardness in JIS-C hardness of 67 to 85, a JIS-C hardness of the intermediate layer is higher than the surface hardness of the core, and a JIS-C hardness of the outer layer is higher than the hardness of the intermediate layer.

Abstract: The invention provides a multi-piece solid golf ball having improved flight performance, controllability and good shot feel at the time of hitting. The multi-piece solid gold ball has a core having at least one layer, an intermediate layer formed on the core, and a cover covering the intermediate layer. When thickness of the intermediate layer is represented as X (mm) and JIS-C hardness of the intermediate layer is represented as Y, then X is 0.3 to 1.5 mm, X and Y have a correlation represented 10X+55≦Y≦10X+75, and the JIS-C hardness of the cover is 70 to 93.

Abstract: A multi-piece solid golf ball core with inner layer and outer layer, and at least one layer of cover on the core, with an inner layer core diameter of 24 to 40 mm and a center hardness in JIS-C hardness of 40 to 60; a surface hardness in JIS-C hardness of the inner layer core higher than the center hardness by 20 to 40; the outer layer core thickness of 2.0 to 7.0 mm and a surface hardness in JIS-C hardness of 75 to 90; the outermost layer of the cover 1.0 to 2.0 mm thick and a Shore D of 40 to 63; and the golfball satisfies formula: 0≦{T(C−B)−(60−A)}≦10; where: A, B represent inner layer core's center hardness, surface hardness, respectively, JIS-C; C represents surface hardness (JIS-C) of outer layer core; T represents thickness of outer layer core.

Abstract: The present invention provides a multi-piece solid golf ball having very soft and good shot feel at the time of hitting, and having high rebound characteristics and excellent flight performance, while maintaining good productivity and the like. The present invention relates to a multi-piece solid golf ball comprising a core consisting of a center and at least one layer of intermediate layer formed on the center, and a cover covering the core, wherein the intermediate layer comprises at least one layer formed from a rubber composition comprising 20 to 60 parts by weight of &agr;,&bgr;-unsaturated carboxylic acid or metal salt thereof and 5 to 70 parts by weight of &agr;,&bgr;-unsaturated carboxylic acid ester, based on 100 parts by weight of a base rubber.

Abstract: A golf ball has three kinds of dimples A to C on a surface. The A, B and C dimples are circular and have different diameters from each other. In each of the A, B and C dimples, a ratio of the number of dimples to the total number of dimples is 5% or more. The C dimple has a minimum diameter. Moreover, the C dimple also has a maximum depth. In the C dimple, a value of K calculated by the following equation (I) is 0.

Abstract: A golf ball retaining high coefficient of restitution inherent and having fine shot feeling with clubs such as drivers, irons and putters is disclosed. A multi-piece golf ball comprising; a center core having a JIS-C hardness of not more than 75, a cover having a JIS-C hardness of not less than 85, a core enclosing layer which directly enclose said center core having a JIS C hardness smaller than the others, and a r.d.preventing layer which prevents a restitution coefficient degradation being internally disposed in contact with said cover and having a JIS C hardness greater than the others.

Abstract: A Golf ball retaining high coefficient of restitution inherent in solid golf balls and having excellent shot feeling is disclosed. A multi-piece golf ball comprising: an inner core which is positioned in a central part of the golf ball, and has a JIS-C hardness of 75 or smaller; an outer core which encloses the inner core; an outer cover which is positioned in a surface part of the golf ball; and an inner cover which is placed on the inside of the outer cover, and has a JIS-C hardness of 80 or larger, wherein a JIS-C hardness of the outer core is smaller than that of the other components, and a JIS-C hardness of the outer cover is larger than that of the other components.

Abstract: The present invention provides a multi-piece solid golf ball, of which flight performance, controllability and good shot feel at the time of hitting are improved.

Abstract: The present invention is directed to a multi-piece solid golf ball exhibiting excellent flight performance by optimizing the trajectory of the golf ball during flight. The golf ball of the present invention satisfies the formula 1020≦(NY+266H)≦1085 with total number of dimples being N, the quotient Y being determined by dividing A by B in which A is the total area of a plane defined by a dimple edge and B is a surface area of a sphere when the sphere is formed assuming that there is no dimple on the cover, and a deformation amount H when applying from an initial load of 10 kgf to a final load of 130 kgf on the golf ball.

Abstract: The present invention provides a solid golf ball which has an improved flying distance, controllability and shot feeling. The solid golf ball has a core and a cover. The core has a hardness of 55 to 75 at a center thereof and a hardness on a surface thereof that is greater than the hardness at the center by 10 or more. The cover has a hardness satisfying the following expressions (1) and (2): (hardness of the cover)−(hardness at the center of the core)≦17  (1), (hardness of the cover)−(hardness on the surface of the core)≦5  (2). The hardness being defined in terms of JIS-C scale hardness meter.

Abstract: The present invention provides a hollow solid golf ball having excellent flight performance and soft and good shot feel at the time of hitting. The present invention relates to a hollow solid golf ball comprising a core having a hollow portion at the center of the core and a cover formed on the core, wherein the golf ball has a diameter of 42.92 to 45.47 mm, a moment of inertia of 83 to 105 g·cm2, and a deformation amount of 2.6 to 4.0 mm, when applying from an initial load of 10 kgf to a final load of 130 kgf.

Abstract: A multi-piece solid golf ball having very soft and good shot feel at the time of hitting, and having excellent flight performance by accomplishing high rebound characteristics and high launch angle when hit by a driver and an iron club. The solid golf ball includes a core, an intermediate layer formed on the core, and a cover covering the core, wherein the intermediate layer (a) is formed from a rubber composition containing a base rubber, a co-crosslinking agent, an organic peroxide and a filler, (b) has a hardness in JIS-C hardness of 75 to 90, and the hardness of the intermediate layer is higher than a surface hardness in JIS-C hardness of the center by 1 to 12, (c) has a thickness of 0.2 to 1.3 mm, and (d) has a specific gravity of 1.20 to 1.60.

Abstract: A Golf ball retaining high coefficient of restitution inherent and having fine shot feeling with clubs such as drivers, irons and putters is disclosed. A multi-piece golf ball comprising; a center core having a JIS-C hardness of not more than 75, a cover having a JIS-C hardness of not less than 85, a core enclosing layer which directly enclose said center core having a JIS C hardness smaller than the others, and a r.d.preventing layer which prevents a restitution coefficient degradation being internally disposed in contact with said cover and having a JIS C hardness greater than the others.

Abstract: A golf ball includes a core and a cover which covers the core, wherein a ratio between the primary natural frequency (CF.sub.1) of the core and the primary natural frequency (BF.sub.1) of the golf ball satisfies a following mathematical relation:0.30.ltoreq.CF.sub.1 /BF.sub.1 .ltoreq.0.

Abstract: A three piece solid golf ball with enhanced flight performance and without diminished shot feel at a time of hitting, which includes a core, an intermediate layer formed on the core and a cover covering the intermediate layer. The golf ball, when hit at a head speed of 40 m/sec by a driver equipped with a swing robot, has a maximum impact force of 1,100 to 1,250 kgf and when hit at a head speed of 2.9 m/sec by a putter, has a maximum impact force of 40 to 50 kgf.

Abstract: An apparatus and a method for simultaneously measuring velocity and an instantaneous spatial position of a spherical object. A first group of sensors and a second ground of sensors are arranged at known positions at intervals each less than the radius of the spherical object. The times when the spherical object begins to intercept the sensors of the groups of sensors and the time lengths of the respective interceptions are measured by using an instrumentation device. The velocity and instantaneous spatial position of the spherical object are calculated by using an arithmetic unit on the basis of the measured times and time lengths.