Fujikura Rubber Ltd.

Fujikura Composites, Inc.

Masaki Wakabayashi

Norio Matsumoto

Yoshihito Kogawa

Hideaki Sanekata

Masaki Nakamura

Akiyasu Higuchi

Takato Nakamura

Keigo Takahashi

Tomonobu Kanno

To obtain a golf club and a combining member of a golf club shaft and a golf club head that can provide a flexibility in choice of reshafting to a user regardless of types of the golf club shaft and the golf club head. A golf club includes an inner-hosel-type golf club shaft, an over-hosel-type golf club head, and a combining member that combines the inner-hosel-type golf club shaft with the over-hosel-type golf club head.

Golf club and combining member of golf club shaft and golf club head

A metal foil satisfies following conditional equations (1), (2) and (3) to smoothly increase rigidity in the longitudinal direction of the shaft main body from a distal end side to a base end side while increasing a weight of a wound part of the metal foil0.50&#x3c;&#x2003;&#x2003;(1)&#x3c;0.90&#x2003;&#x2003;(2)0.03&#x3c;&#x3c;0.09&#x2003;&#x2003;(3)

Golf club shaft and golf club

A golf club shaft and a golf club using such a golf club shaft are achieved, wherein the golf club shaft is capable of suppressing variations of various parameters at impact by reducing the difference in rigidity between the layers of the shaft body. The golf club shaft includes full-length bias prepregs provided only as a plurality of pairs thereof and as full-length layers that extend over an entire length of the shaft body, wherein fiber directions of each pair of the full-length bias prepregs are inclined at an angle within a range of 22 degrees through 28 degrees relative to a longitudinal direction of the shaft body, respectively.

Golf club shaft and golf club provided with the same

A golf club shaft formed by winding prepregs, made of reinforced fibers impregnated with a thermosetting resin, into layers and thermally curing the prepregs. The golf club shaft includes a 90-degree prepreg, a fiber direction of which is orthogonal to a longitudinal direction of the golf club shaft and which is provided on each of an inner layer side and an outer layer side, and the golf club shaft satisfies the following condition: 2.0&#x2266;D/D&#x2266;4.0, wherein Ddesignates a thickness of the inner-layer-side 90-degree prepreg, and Ddesignates a thickness of the outer-layer-side 90-degree prepreg.

Golf club shaft and golf club using the same

A golf club shaft in which the isotropy of the prepregs configuring a torsion rigidity holding layer is high and in which sufficient torsional rigidity can be secured with fewer plies of fewer prepregs. The golf club shaft includes a torsional rigidity holding layer made of a thermosetting resin which contains reinforced fibers extending obliquely to a longitudinal direction of the shaft. The torsional rigidity holding layer includes a multilayer set prepreg, in which at least two layers of prepregs made of reinforced fibers are impregnated with a thermosetting resin. A plurality of prepregs in the multilayer set prepreg include reinforced fibers extending in mutually different directions. The multilayer set prepreg is continuously wound by at least two turns with the plurality of prepregs layered on each other. A golf club uses the shaft.

An object is to achieve a golf club shaft and a method of producing the same, wherein the weight balance in the shaft longitudinal direction can be reproducibly and easily set and wherein the golf club shaft is produced at a low cost and has high durability. The golf club shaft includes a hollow-cylindrical shaft body made of fiber-reinforced resin and a weight-adding cylinder installed in a cylindrical space of the shaft body. At least a part of an outer diameter side of the weight-adding cylinder is embedded in an cylindrical embedded recess that is formed in an inner wall of the shaft body, wherein a grip-side cylindrical end surface of the weight-adding cylinder and a grip-side cylindrical end surface of the cylindrical embedded recess are in contact with each other.

Golf club shaft and method of producing the same

A golf club shaft formed by winding prepregs made of uncured thermosetting resin into a tapered shape and curing the prepregs thermally, the prepregs include a first woven fabric prepreg which is made of one of a triaxial woven fabric or a tetra-axial woven fabric that are impregnated with uncured thermosetting resin, and a second woven fabric prepreg which is made of one of a triaxial woven fabric or a tetra-axial woven fabric that are impregnated with uncured thermosetting resin.

A golf club shaft is provided in which the flexural rigidity of the distal end portion can be improved with no change in flexural rigidity on the proximal end while the dispersion in the values of the flexural rigidity in the circumferential direction can be reduced without the use of a distal-end reinforcing layer that causes discontinuous points in the lengthwise direction in flexural rigidity. A golf club shaft is provided which satisfies the following conditions: that the golf club shaft includes at least three rectangular carbon prepregs as full-length layers, that all the rectangular carbon prepregs are each composed of a 0-degree layer, the long fiber direction of which is coincident with the longitudinal direction of the golf club shaft, that all the rectangular carbon prepregs are configured such that the amount of overlapping of each rectangular carbon prepreg is zero on the large-diameter proximal end portion of the gold club shaft and increasingly overlaps at positions increasingly toward the distal end of the golf club shaft, and that wind start positions of the rectangular carbon prepregs are different from one another.

An apparatus for forming a hollow FRP article by internal pressure molding includes a vacuum chamber, a forming die positioned in the vacuum chamber, a vacuum-chamber opening/closing mechanism, a composite-body support device for supporting a composite body without making the composite body come into contact with the forming die in a state where the forming die is opened by the vacuum-chamber opening/closing mechanism, the composite body including an airtight internal-pressure holding tube and a prepreg fitted on said airtight internal-pressure holding tube, an evacuation system for evacuating the vacuum chamber, an internal-pressure supplying device for applying pressure to an inside of the internal-pressure holding tube, and a controller for actuating the vacuum-chamber opening/closing mechanism to clamp the forming die to thereby bring the forming die and the composite body into intimate contact with each other.

Method and apparatus for forming a hollow FRP article by internal pressure molding

It is object of the present invention to provide a golf club shaft superior in accuracy, minimizing a displacement between thermosetting resin layers, capable of obtaining a feeling close to the feeling of a steel shaft, and superior in stability. To solve the above problems, a golf club shaft of the present invention uses a golf club shaft comprising a torsional rigidity holding layer made of thermosetting resin including reinforcing fibers diagonally crossed in the longitudinal direction of said shaft and a UD flexural rigidity holding layer made of thermosetting resin including reinforcing fibers aligned in parallel to the longitudinal direction of said shaft, characterized in that at least a part of said torsional rigidity holding layer includes a plain weave fabric layer obtained by winding and curing like a shaft-shape a plain weave prepreg which lets a plain weave fabric having mutually woven warps and wefts impregnate with thermosetting resin in such a way that said warps and wefts are diagonally crossed in the longitudinal direction of said shaft.

Golf club shaft

A method for forming a hollow FRP article by internal pressure molding includes positioning a FRP prepreg on a periphery of an airtight internal-pressure holding tube, inserting a composite body including the internal-pressure holding tube and the prepreg into a vacuum chamber containing a forming die, evacuating the vacuum chamber in an isolation state where the composite body and the forming die do not contact each other, and clamping the forming die to bring the forming die and the composite body into contact with each other and heating the forming die with an application of pressure to an inside of the internal-pressure holding tube after completion of the evacuating step.

Growing community of inventors

Saitama, Japan

Masaki Wakabayashi