Abstract: A core 4 of a golf ball 2 includes a center 10 and an envelope layer 12 positioned outside the center 10. The ratio of the volume of the core 4 to the volume of a phantom sphere of the golf ball 2 is equal to or greater than 78%. The difference (He?Ho) between a JIS-C hardness He at the surface of the core 4 and a JIS-C hardness Ho at the central point of the core 4 is equal to or greater than 15 but equal to or less than 40. The difference (H1?Ho) between a JIS-C hardness H1 at a point P1 that is located radially outward of the boundary between the center 10 and the envelope layer 12 and whose distance from the boundary is 1 mm and the JIS-C hardness Ho is equal to or greater than 0 but equal to or less than 2.

Abstract: An object of the present invention is to provide a golf ball resin composition excellent in resilience. Another object of the present invention is to provide a golf ball excellent in a shot feeling and resilience. The golf ball resin composition of the present invention is characterized in that a storage modulus E? (Pa) and a loss modulus E? (Pa) satisfy a following expression; log(E?/E?2)??6.08 when measured at the conditions of the temperature of 12° C., the oscillation frequency of 10 Hz, and a strain of 0.05% in a tensile mode using a dynamic viscoelasticity measuring apparatus.

Abstract: A golf club shaft is manufactured using a plurality of prepreg sheets a1 to a8. The plurality of prepreg sheets a1 to a8 includes full length sheets a2 to a7 disposed all over in a shaft axis direction and partial sheets a1 and a8 partially disposed in the shaft axis direction. The number of plies is substantially an integer in all the full length sheets a2 to a7. The full length sheets a2 to a7 include four or more bias sheets a2 to a5. Circumferential winding start positions of the bias sheets a2 to a5 are dispersed in four or more positions. Preferably, the circumferential winding start positions of the full length sheets a2 to a7 are dispersed in five or more positions.

Abstract: An object of the present invention is to provide a golf ball having high resilience. The present invention provides a golf ball having a constituting member, wherein at least a part of the constituting member is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, the organic sulfur compound being derivatives of thiophenols and disulfide with a strong electron withdrawing substituent.

Abstract: A cross-sectional shape of each of dimples 8 of a golf ball 2 is a wave-like curve. The wave-like curve has two first curves 14, two second curves 16, two third curves 18, and one fourth curve 20. Each first curve 14 and each third curve 18 are upwardly convex. Each second curve 16 and the fourth curve 20 are downwardly convex. Each first curve 14 is connoted to a land 10 at an edge Ed. Each second curve 16 is connected to the first curve 14 at a first inflexion point 22. Each third curve 18 is connected to the second curve 16 at a second inflexion point 24. The fourth curve 20 is connected to the third curves 18 at third inflexion points 26. In the wave-like curve, the upwardly convex curves 14 and 18 and the downwardly convex curves 16 and 20 are alternately arranged.

Abstract: A golf ball 2 includes a core 4, a mid layer 6, and a cover 8. The core 4 includes a center 10 and an envelope layer 12. The ratio (Do/De) of an amount of compressive deformation Do of the center 10 to an amount of compressive deformation De of the core 4 is equal to or greater than 1.5 but equal to or less than 2.5. The ratio (Do/Dc) of the amount of compressive deformation Do of the center 10 to an amount of compressive deformation Dc of the golf ball 2 is equal to or greater than 1.8. The diameter of the center 10 is equal to or less than 20 mm. The difference (He?Ho) between a surface hardness He of the core 4 and a central hardness Ho of the center 10 is equal to or less than 40.

Abstract: An object of the present invention is to provide a golf ball which has an increased dry spin rate and wet spin rate on approach shots without sacrificing the processability into the cover. The present invention provides a golf ball cover material having shear loss moduli G1? (Pa), G2? (Pa), and G3? (Pa) that satisfy following equations when measured using a dynamic viscoelasticity measuring apparatus at following conditions. log G1??7.09??(1) log G2??7.17??(2) log G3??7.14??(3) G1? measuring conditions: shear mode, oscillation frequency: 10 Hz, temperature: 0° C., strain: 0.05%; G2? measuring conditions: shear mode, oscillation frequency: 10 Hz, temperature: ?30° C., strain: 0.05%; and G3? measuring conditions: shear mode, oscillation frequency: 10 Hz, temperature: 0° C., strain: 5%.

Abstract: A manufacturing method of the present invention includes the steps of: winding a fiber reinforced resin member containing a fiber and a matrix resin around a mandrel to obtain an intermediate formed body; winding a wrapping tape around the intermediate formed body with an application of a tension; heating the intermediate formed body to cure the matrix resin; and pulling the mandrel out and removing the wrapping tape after the step of heating to obtain a cured tubular body. A base polymer of a base material of the wrapping tape is a polyolefin resin and/or a polyester resin. The step of heating includes: a first heating stage for heating the intermediate formed body at a temperature of 70° C. or higher and 90° C. or lower for a time of 120 minutes or longer and 4320 minutes or shorter; and a second heating stage for heating the intermediate formed body at a temperature of 120° C. or higher and 200° C. or lower for a time of 5 minutes or longer and 20 minutes or shorter after the first heating stage.

Abstract: A golf ball 2 includes a spherical core 4, a mid layer 6 outside the core 4, and a cover 8 outside the mid layer 6. The core 4 includes a spherical center 10 and an envelope layer 12 outside the center 10. At all points P included in a zone that extends over a distance range from equal to or greater than 1 mm to equal to or less than 15 mm from the central point of the core 4, the following mathematical formula is satisfied. ?5<H2?H1<5 In the mathematical formula, H1 indicates the JIS-C hardness at a point P1 located radially inward of each point P at a distance of 1 mm from the point P, and H2 indicates the JIS-C hardness at a point P2 located radially outward of each point P at a distance of 1 mm from the point P.

Abstract: A connector device for kill- and choke lines between a riser and a floating drilling platform includes a slip joint on top of the riser including an outer barrel, a kill- and choke manifold arranged on the platform and provided with flexible kill- and choke hoses to the slip joint's outer barrel, and wherein the slip joint's outer barrel is provided with a horizontally directed kill- and choke-manifold.

Abstract: An intersection point between a shaft axis Z1 and a sole surface 18 is defined as S1. A point S2, a point S3, and a point S4 are set on the sole surface 18. An intersection point between a straight line passing through a center of gravity of the head and being perpendicular to the horizontal plane and the sole surface 18 is defined as G1. A point R1, a point R2, a point R3, and a point R4 are set on the sole surface 18. A section A1 and a section A2 are set based on the points. An angle between the shaft axis Z1 and a ground plane is defined as ?. The angle ? exists so that at least a point belonging to the section A1 and at least a point belonging to the section A2 are brought into contact with the ground plane.

Abstract: The object of the present invention is to provide a golf ball that satisfies both of the flight distance at the shot with a driver, a long iron, and a middle iron and the controllability at the approach shot with a short iron and is also excellent in the abrasion resistance of the cover.

Abstract: An object of the present invention is to provide a golf ball having high resilience. The gist of the present invention resides in selecting an organic sulfur compound used for a golf ball rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) the organic sulfur compound from organic sulfur compounds having specific structures such that a sum of substituent constants of the substituents X in a structure represented by the following formula (4) is 0.2 or more and SP value of the structure represented by the following formula (4) is in a range from 19.0 (J/cm3)1/2 to 24.0 (J/cm3)1/2 and using the same.

Abstract: A golf club 2 includes a shaft 6, a grip 8 mounted to an end part of the shaft 6, a cavity body 10 mounted to the end part of the shaft 6 to which the grip 8 is mounted, and a weight body 12 detachably mounted to the cavity body 10. The cavity body 10 includes a polymer. Preferably, an outer peripheral surface 16a of the cavity body 10 is mounted to an inner peripheral surface 6a of the shaft so as to abut on the inner peripheral surface 6a. Two or more projections are formed on one of the outer peripheral surface 16a of the cavity body 10 and the inner peripheral surface 6a of the shaft. Two or more recessed parts are formed on the other. The two or more projections are engaged with the two or more recessed parts.

Abstract: A golf club may include a front surface, a rear surface having a recess, and an insert at least partially disposed in the recess. The insert may comprise a durometer hardness of less than about 95 Shore A and a cavity having a reinforcement member disposed therein. Preferably, the durometer hardness of the reinforcement member is also less than about 95 Shore A. The insert may further comprise an anterior perimetric boundary having a first length and a posterior perimetric boundary having a second length. The ratio of the first length to the second length may be less than 1 and greater than 0.5. In one example, the insert may have a triangular front profile and a triangular side profile.

Abstract: A method for surface treating a golf club head, includes: (a) forming a depression unit in the golf club head, the depression unit being indented inwardly from an outer surface of the golf club head, the outer surface being divided into a working area and a non-working area, the depression unit being formed in the working area; (b) filling the depression unit with a shielding material and covering the non-working area with a covering material; and (c) sandblasting the golf club head after step (b) and removing subsequently the shielding material from the depression unit and the covering material from the non-working area so as to form the working area into sandblasted and non-sandblasted regions that differ in gloss intensity.

Abstract: A hollow golf club head includes a sole, a crown, a skirt, and a striking face. The golf club includes a junction interconnecting the sole, crown, and skirt to the striking face, the junction including at least one stiffening member.

Abstract: A head of a first aspect is provided with a head body h1x, a double-stick tape t1, and an adherend s1x bonded to the head body h1x by the double-stick tape t1. The double-stick tape t1 has a first adhesive layer 30 provided as an innermost layer, a second adhesive layer 36 provided as an outermost layer, and intermediate layers 32 and 34 provided between the first adhesive layer 30 and the second adhesive layer 36. The intermediate layer includes a fiber layer 34 and/or a resin layer 32. The resin layer 32 is free of bubbles. In a head of a second aspect, a head body h1y or an adherend s1y has a recessed part 27y. In a head of a third aspect, an adherend s1 has a metal member 27 and an elastic member 29. The elastic member 29 has a peripheral part 29a directly or indirectly abutting on a side surface 31 of the metal member 27.

Abstract: An exemplary golf club head having an increased amount of discretionary mass may be realized by utilizing improved drop angles, an improved average crown height, and/or articulation points. The discretionary mass may be placed low and deep in the club head to improve the location of the center of gravity as well as the inertial properties. A preferred break length may also be utilized to further improve the depth of the center of gravity. In one example, the center of gravity may be positioned to substantially align the sweet spot with the face center of the club head.

Abstract: A swing analysis apparatus 10 for a golf club includes a club camera 20 continuously photographing a behavior of a golf club 34, a ball camera 22 continuously photographing a behavior of a golf ball 36, and an information processor 32. The club camera 20 is positioned in front of a golf player. A straight line C passes through a center of a lens of the club camera 22 and a center of the golf ball 36. An angle ?c between the straight line C and a vertical line Z is 10 degrees or greater and 20 degrees or less. The information processor 32 measures a synchronized club behavior value from synchronized club image data. The information processor 32 measures a synchronized ball behavior value from synchronized ball image data. The information processor 32 stores the synchronized club behavior value and the synchronized ball behavior value.