Dunlop Sports Company Limited

Sumitomo Rubber Industries Limited

Sri Sports Limited

Kosuke Tachibana

Kazuhiko Isogawa

Kazuya Kamino

Toshiyuki Tarao

Takahiro Sajima

Hidetaka Inoue

Kohei Mimura

Keiji Ohama

Mami Tanaka

Yoshiko Matsuyama

Takahiro Shigemitsu

Takashi Nakamura

Hironori Takihara

Kazuhiro Hayashi

Kasuhiko Isogawa

A golf club comprises a shaft, a golf club head fixed to one of ends of the shaft, and a grip attached to the other of the ends of the shaft and defining a grip end. The golf club head comprises a head main body and at least one weight. The head main body includes a plurality of ports for attaching the at least one weight. Each weight can be attached to and detached from each port so that the position of the center of gravity of the head can be changed by changing the position between the ports. The difference between a maximum value and a minimum value of linear distances from the grip end to the center of gravity of the weights when attached to the respective ports is not more than 20 mm.

Golf club

An object of the present invention is to provide a golf ball travelling a great flight distance on driver shots, exhibiting an excellent spin performance on approach shots under a dry condition and a wet condition, and showing an excellent shot feeling and durability. The present invention provides a golf ball comprising a golf ball body having a spherical core, an intermediate layer and a cover, and a paint film composed of two or more layers, wherein a 10% elastic modulus difference (M&#x2212;M) between an innermost layer and an outermost layer of the paint film is 25 kgf/cmor more.

Golf ball

An object of the present invention is to provide a golf ball traveling a great distance on driver shots. The present invention provides a golf ball comprising a spherical core including an inner layer and an outer layer, an intermediate layer and a cover, wherein a difference (H&#x2212;H) between a hardness (H) at a point outwardly away in a radial direction from a boundary between the inner layer and the outer layer of the spherical core by 1 mm and a hardness (H) at a point inwardly away in the radial direction from the boundary between the inner layer and the outer layer of the spherical core by 1 mm is 0 or more in Shore C hardness, a surface hardness (H) of the spherical core is more than 65 in Shore C hardness, an angle &#x3b1; of a hardness gradient of the inner layer is 0&#xb0; or more, a difference (&#x3b1;&#x2212;&#x3b2;) between the angle &#x3b1; and an angle &#x3b2; of a hardness gradient of the outer layer is 0&#xb0; or more, a total thickness of a thickness (Tm) of the intermediate layer and a thickness (Tc) of the cover is 3 mm or less, and the cover has a highest hardness among the constituent members of the golf ball.

A coating regionof a crownhas a maximum saturation portion SRat which a saturation is a maximum value Cmax, a high saturation region SRwhich includes the maximum saturation portion SRand in which a saturation difference from the saturation Cmax is not greater than 15, and a low saturation region SRin which a saturation difference from the saturation Cmax is greater than 15. When a straight line that passes through a face center Fc and extends in a face-back direction is defined as a straight line C, an area of a portion of the high saturation region SRat a toe side with respect to the straight line C is denoted by St, and an area of a portion of the high saturation region SRat a heel side with respect to the straight line C is denoted by Sh, then St&#x3e;Sh.

Golf club head

An object of the present invention is to provide a golf ball traveling a great distance on driver shots. The present invention provides a golf ball comprising a spherical core including an inner layer and an outer layer, wherein a difference (H&#x2212;H) between a hardness (H) at a point outwardly away in a radial direction from a boundary between the inner layer and the outer layer of the spherical core by 1 mm and a hardness (H) at a point inwardly away in the radial direction from the boundary between the inner layer and the outer layer of the spherical core by 1 mm is 0 or more in Shore C hardness, a surface hardness (H) of the spherical core is more than 70 in Shore C hardness, an angle &#x3b1; of a hardness gradient of the inner layer is 0&#xb0; or more, and a difference (&#x3b1;&#x2212;&#x3b2;) between the angle &#x3b1; and an angle &#x3b2; of a hardness gradient of the outer layer is 0&#xb0; or more.

A golf ballincludes a core, a first mid layer, a second mid layer, and a cover. The coreincludes a centerand an envelope layer. The centeris formed by crosslinking a first rubber composition, and the envelope layeris formed by crosslinking a second rubber composition. The first rubber composition or the second rubber composition includes a base rubber, a co-crosslinking agent, a crosslinking initiator, and an acid and/or a salt. The co-crosslinking agent is:

An object of the present invention is to provide a golf ball traveling a great flight distance on driver shots and an excellent shot feeling. The present invention provides a golf ball comprising a spherical core, an intermediate layer covering the spherical core, and a cover covering the intermediate layer, wherein a material hardness (Hm) of a resin composition constituting the intermediate layer ranges from 65 to 80 in Shore D hardness, a material hardness (Hc) of a resin composition constituting the cover ranges from 57 to 72 in Shore D hardness, a hardness difference (Hm&#x2212;Hc) between the material hardness (Hm) and the material hardness (Hc) is more than 0, and the intermediate layer has a surface hardness satisfying a hardness difference (HmsC&#x2212;HmsD) between a hardness thereof shown in Shore C hardness (HmsC) and a hardness thereof shown in Shore D hardness (HmsD) of 27 or less.

A golf ballincludes a core, amid layer, a reinforcing layer, and a cover. The coreincludes a centerand an envelope layer. The envelope layeris formed by a rubber composition being crosslinked. The rubber composition includes a base rubber (a), a co-crosslinking agent (b), a crosslinking initiator (c), and an acid and/or a salt (d). The co-crosslinking agent (b) is:

A golf ballincludes a core, a mid layer, and a cover. A difference DH in hardness between a surface and a central point of the core, a thickness Tm and a hardness Hm of the mid layer, a thickness Tc and a hardness Hc of the cover, and an amount of compressive deformation Sb of the golf ballmeet the following mathematical formulas (DH*Hm)/(Hc*Tc)&#x3e;80 and ((Sb*Tc)/(Hc*Hm*Tm))*1000&#x3e;0.75. A hardness Hc of the coveris equal to or less than 40. A material of the coveris a resin composition. The resin composition includes a polyurethane (A) and a polyrotaxane (B).

The present invention provides a golf ball comprising a spherical core composed of a spherical inner core layer and an outer core layer, an intermediate layer and a cover, wherein the inner core layer has a hardness difference (Hs1&#x2212;Ho) between a surface hardness (Hs1) and a center hardness (Ho) of 5 or less in JIS-C hardness, the outer core is such that Rof a linearly approximated curve obtained from a least square method is 0.95 or higher, when JIS-C hardness, measured at nine points obtained by dividing a thickness of the outer core in a radius direction of the spherical core into equal parts having 12.5% intervals therebetween, is plotted against distance (%) from a border point between the outer core layer and the inner core layer, and the intermediate layer has a slab hardness which is greater than a slab hardness of the cover.

A golf ballincludes an inner core, an outer core, a mid layer, and a cover. A diameter D1, a volume V1, a hardness H1o at a central point, and a boundary inside hardness H1in of the inner core; a volume V2, a boundary outside hardness H2out, and a surface hardness H2s of the outer core; a thickness Tm and a hardness Hm of the mid layer; and a thickness Tc and a hardness Hc of the covermeet the following mathematical formulas (1) to (4): 1.0&#x3c;V2/V1&#x3c;7.0 (1); &#x2212;2&#x3c;H2s&#x2212;H2out&#x3c;2 (2); 600&#x3c;(H1o+H1in)*(D1/2)/2&#x3c;1000 (3); 620&#x3c;Tc*Hc*Hm/Tm&#x3c;900 (4). The coverincludes a polyrotaxane.

An object of the present invention is to provide a golf ball showing an increased spin rate on approach shots under a wet condition while maintaining a spin rate on approach shots under a dry condition. The present invention provides a golf ball comprising a golf ball body and a paint film formed on a surface of the golf ball body, wherein the paint film has a multi-layered construction composed of two or more layers, and a difference (M&#x2212;M) between a 10% elastic modulus (M) of an innermost layer of the paint film and a 10% elastic modulus (M) of an outermost layer of the paint film is 25 kgf/cmor more.

A golf ball includes a spherical core, a mid layer, an inner cover, and an outer cover. A hardness Hm of the mid layer is greater than a hardness Hinc of the inner cover which is greater than a hardness Houc of the outer cover. A difference (Hm&#x2212;Houc) is greater than 25. A volume Vm of the mid layer is greater than a volume Vinc of the inner cover which is greater than a volume Vouc of the outer cover. A ratio [(Vm+Vinc+Vouc)/V] of a sum (Vm+Vinc+Vouc) relative to a volume V of an entirety of the golf ball is less than 0.30. A ratio (Vm/Vouc) is greater than 1.50. A product (Vm*Hm) and a product (Vouc*Houc) meet the following relationship: [(Vm*Hm)/(Vouc*Houc)]&#x3e;3.0.

An object of the present invention is to provide a golf ball having a high performance as well as the visibility and the fashionable appearance. The present invention provides a colored golf ball having a color other than white and comprising: a core having a center and at least one intermediate layer disposed around the center, and a cover disposed around the core, wherein the cover and at least one of the intermediate layer preferably contain a fluorescent dye and/or a fluorescent pigment.

Growing community of inventors

Kobe, Japan

Kosuke Tachibana