Sri Sports Limited

Sumitomo Rubber Industries Limited

Dunlop Sports Company Limited

Sri Sports Limted

Tomio Kumamoto

Masaru Kouno

Masahide Onuki

Takashi Nakano

Kiyofumi Matsunaga

Yasushi Sugimoto

Masaru Kono

A golf club chas a base part, a laser discoloration layer, and a protection layer. The laser discoloration layeris provided on the outer side of the base part. The protection layeris provided on the outer side of the laser discoloration layer. The protection layerhas laser beam transparency. The laser discoloration layercan be discolored by irradiation of a laser beam. Preferably, an undercoat layeris further provided between the base partand the laser discoloration layer. Preferably, the undercoat layeris not discolored by the laser beam. Preferably, the laser discoloration layerincludes abase material resin and a laser discoloration material.

Golf club

A head of a first aspect is provided with a head body h, a double-stick tape t, and an adherend sbonded to the head body hby the double-stick tape t. The double-stick tape thas a first adhesive layerprovided as an innermost layer, a second adhesive layerprovided as an outermost layer, and intermediate layersandprovided between the first adhesive layerand the second adhesive layer. The intermediate layer includes a fiber layerand/or a resin layer. The resin layeris free of bubbles. In a head of a second aspect, a head body hor an adherend shas a recessed part. In a head of a third aspect, an adherend shas a metal memberand an elastic member. The elastic memberhas a peripheral partdirectly or indirectly abutting on a side surfaceof the metal member

Golf club head

In this manufacturing method, a tubular bodyhaving a ribprovided therein is obtained. The manufacturing method includes the steps of: preparing a mandreldivided into two or more divided bodies dalong a longitudinal direction of the mandrel; winding a prepreg rfor a rib around at least one of the divided bodies d; combining all the divided bodies dto obtain a first intermediate bodyafter the step of winding the prepreg rfor the rib; winding a prepreg gfor the outer peripheral part around an outside of the first intermediate bodyto obtain a second intermediate body; heating the second intermediate body to obtain a cured laminate; and extracting the mandrelfrom the cured laminate. Preferably, the mandrel is equally divided in a circumferential direction. Preferably, a winding start end part tof the prepreg rfor the rib and a winding finish end part tthereof overlap with each other.

Tubular body

A headhas a face linehaving a depth of D1 (mm). In a section line of a surface of the face line, a boundary between a land area LA and the face lineis defined as a point Pa; a point of which a depth is [D&#xbc;] (mm) is defined as a point Pb; a point of which a depth is [D&#xbd;] (mm) is defined as a point Pc; a point of which a depth is [(D1)&#xd7;(&#xbe;)] (mm) is defined as a point Pd; a radius of a circle CLpassing through three points of the point Pa, the point Pb, and the point Pc is defined as R(mm); a straight line passing through the point Pc and the point Pd is defined as a straight line Lcd; a straight line perpendicular to the land area LA is defined as a straight line Lp; and an angle between the straight line Lcd and the straight line Lp is defined as &#x3b8;m. At that time, the radius Ris 0.01 (mm) or greater and 0.10 (mm) or less, and the angle &#x3b8;m is 40 degrees or greater and 70 degrees or less.

A golf club headof a first aspect is provided with a head body h, a double-stick tape w, and an adherend sbonded to the head body hby the double-stick tape w. When an average thickness of a lower part of the adherend sis defined as fand an average thickness of an upper part of the adherend sis defined as f, the thickness fis smaller than the thickness f. A golf club headaccording to a second aspect is provided with a head body h, a double-stick tape wand an adherend sbonded to the head body hby the double-stick tape w. When an average thickness of a heel part of the adherend sis defined as tand an average thickness of a toe part of the adherend sis defined as t, the thickness tis smaller than the thickness t

A golf club () includes a head (), a shaft () and a grip (). At least one siping groove (g) is provided on a surface of the grip (). The siping groove (g) is bent in a direction (Dd) of a depth of the grip. A width (Wg) of the siping groove (g) is set to be equal to or greater than 0.15 mm and is equal to or smaller than 1.5 mm. It is preferable that an opening edge (e) of the siping groove (g) should be bent. The width (Wg) is more preferably equal to or greater than 0.20 mm. The width (Wg) is more preferably equal to or smaller than 1.4 mm and is further preferably equal to or smaller than 1.3 mm. A depth (F) of the siping groove (g) is preferably equal to or greater than 0.5 mm and is preferably equal to or smaller than 3.5 mm.

Golf club and grip for golf club

A shaftis formed by a prepreg sheet. The sheet of the shaftincludes full length sheets (a), (a), (a) and (a) provided wholly in a longitudinal direction of the shaft, and partial sheets (a), (a), (a), (a), (a), (a), (a) and (a) provided partially in the longitudinal direction of the shaft. The number of the full length sheets is equal to or greater than two. The number of the partial sheets is equal to or greater than four. Each of the partial sheets has an end. When four sections obtained by dividing the shaft into four equal parts in the longitudinal direction are set to be first, second, third and fourth sections from a tip end side in order, the total number of ends positioned in the first section is represented as (N), the total number of ends positioned in the second section is represented as (N), the total number of ends positioned in the third section is represented as (N), and the total number of ends positioned in the fourth section is represented as (N), all of (N), (N), (N) and (N) are equal to or greater than one.

Golf club shaft

The invention prevents a resin member from being broken so as to improve durability. The invention provides a golf club head () in which at least a part of a crown portion () forming an upper surface of the head is formed by a resin member (FR) made of a fiber reinforced resin in which a fiber is oriented in a matrix resin. The resin member (FR) includes a one-way fiber reinforced resin layer in which the fiber is oriented in one direction, and a fiber intersection lamination portion which is laminated so as to differentiate a direction of the fiber. At least two one-way fiber reinforced resin layers which are adjacent in a thickness direction are intersected at an angle of 30 to 130 degrees of the fiber. Further, a compressive strength of the fiber of the one-way fiber reinforced resin layer which is arranged in an innermost side in the fiber intersection lamination portion is set to be equal to or more than 1.3 GPa.

A golf club shaft () having a weight not less than 30 g nor more than 60 g. The golf club shaft () includes a bias layer (B) composed of a prepreg whose reinforcing fibers have an orientation angle of not less than &#xb1;10&#xb0; nor more than 80&#xb0; to an axis of the golf club shaft () and a straight layers (Athrough A) each composed of a prepreg whose reinforcing fibers have an orientation angle within 0&#xb0;&#xb1;10&#xb0; to the axis of the golf club shaft (). At least one partial reinforcing hoop layer whose reinforcing fibers have an orientation angle of within 90&#xb0;&#xb1;10&#xb0; to the axis of the golf club shaft () is disposed in only an important reinforcing region in a range from a point (P) spaced at 15% of a full length (L) of the golf club shaft () from a grip-side butt () thereof to a point (Q) spaced at 45% of the full length (L) of the golf club shaft () from the grip-side butt () thereof.

A golf club shaft composed of a laminate of prepregs. A part of the laminate is formed as a fullerene-containing bias layer BF composed of prepregs containing a matrix resin and fullerene and/or a fullerene compound contained in the matrix resin. Reinforcing fibers of the prepregs form an angle of not less than &#xb1;10&#xb0; nor more than &#xb1;80&#xb0; to the axis of the shaft.

A hollow golf club head having a face portion, a crown portion, a sole portion, a side portion and a hosel portion, comprises a metal component made of a metal material, and a resin component made of a fiber reinforced resin, wherein the metal component comprises a face plate forming at least a part of the face portion, and a sole plate forming at least a part of the sole portion, and the resin component comprises a crown plate forming at least a part of the crown portion. A tubular part of the hosel portion into which a club shaft is inserted is formed (a) integrally with the metal component or (b) separately from the metal component and the resin component.

Points obtained by plotting flexural rigidity EI measured at ten sites on a shaft are defined as from T () to T () in this order from the head side, and the formula representing a line K that passes the T () and the T () is defined as [Y=aX+b1]. The values at the Y-intercepts on the lines that are parallel to the line K and that pass the points of from T () to T (), respectively, are defined as from b2 to b9, respectively, and the minimum value among the values at the Y-intercepts b2 to b9 is defined as bmin. Slope 'a' of the line K is 0.04 or greater and 0.06 or less; every one of the b3, b4, b5, b6, b7 and b8 is smaller than b1; and the bmin is any one of b4 to b7. The value (b1&#x2212;bmin) is 30 (N&#xb7;m) or greater and 40 (N&#xb7;m) or less, and the value (b9&#x2212;b1) is 4 (N&#xb7;m) or greater and 15 (N&#xb7;m) or less. This shaft either has a high-strength straight layer and a hoop layer, or has a textile layer.

Shaft for golf clubs and golf club

A golf club shaft composed of a laminate of prepregs each containing a matrix resin and reinforcing fibers impregnated with the matrix resin. The matrix resin of at least one of the prepregs contains a fullerene or/and a fullerene compound. The content of the fullerene or/and the fullerene compound contained in the prepreg is set to not less than 0.002 wt % nor more than 1 wt % of an entire weight of the prepreg. The length of the prepreg containing the fullerene or/and the fullerene compound is set to not less than 2% nor more than 90% of the full length of the golf club shaft.

The invention prevents a resin member from being broken so as to improve durability. The invention provides a golf club head () in which at least apart of a crown portion () forming an upper surface of the head is formed by a resin member (FR) made of a fiber reinforced resin in which a fiber is oriented in a matrix resin. The resin member (FR) includes a one-way fiber reinforced resin layer in which the fiber is oriented in one direction, and a fiber intersection lamination portion which is laminated so as to differentiate a direction of the fiber. At least two one-way fiber reinforced resin layers which are adjacent in a thickness direction are intersected at an angle of 30 to 130 degrees of the fiber. Further, a compressive strength of the fiber of the one-way fiber reinforced resin layer which is arranged in an innermost side in the fiber intersection lamination portion is set to be equal to or more than 1.3 GPa.

Growing community of inventors

Kobe, Japan

Tomio Kumamoto