Games using tangible projectile – Golf – Club or club support
Reexamination Certificate
1998-12-15
2001-08-07
Chapman, Jeanette (Department: 3711)
Games using tangible projectile
Golf
Club or club support
C473S322000
Reexamination Certificate
active
06270426
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a golf club shaft made of a composite of a fiber material and a synthetic resin material.
2. Description of the Related Art
Recently, a golf club shaft is made of a combination of a fiber material such as glass fiber or carbon fiber, and a compound synthetic resin. It is known for fiber material to be formed as a diagonal fiber layer, an axial fiber layer, a triaxial fabric layer; or a combination thereof. A diagonal fiber layer refers to a fiber layer in which pairs of yarn paths defined by fiber bundles are inclined in opposite directions with respect to the longitudinal axis of the shaft. An axial fiber layer refers to a fiber layer in which the yarn paths extend in parallel with the longitudinal axis of the shaft. A triaxial fabric layer refers to a fabric layer in which yarns are woven so that three directions of the yarn paths form approximately 60° or 120°. These fiber or fabric materials are provided with thermoplastic resin or thermosetting resin impregnated therein to form a prepreg, which is then wound by several turns, and is hardened to obtain a golf club shaft.
The assignee of the present application has proposed a golf club shaft made of a triaxial fabric (layer) in Japanese Utility Model Registration No. 2,553,611 or No. 2,553,612, and has marketed the same. In these utility model applications, it was considered essential or preferable that the triaxial fabric layer be uniformly provided over the entire length of the shaft, and one of the yarn paths to extend in the axial direction of the shaft.
However, it has been found by recent studies of triaxial fabrics that it is not necessary for the triaxial fabric layer to be uniformly provided over the entire length of the shaft, nor for one of the yarn paths to extend in the axial direction of the shaft; furthermore, triaxial fabrics having a variety of specifications can be advantageously used to respond to various requirements of a golf club shaft.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a golf club shaft made of a composite of a fiber material and a synthetic resin material, wherein the bending rigidity, the torsional rigidity or the deformation rigidity (rigidity against the partial collapse of the circular shape in section), etc., is achieved so as to be varied in accordance with need in the direction of the longitudinal axis of the shaft.
To achieve the object mentioned above, according to an aspect of the present invention, there is provided a golf club shaft made of a composite of a fiber material and a synthetic resin material, wherein the fiber material is composed of triaxial fabric layers having three yarn paths of three directions which are located at least on the butt end side and the tip end side of the golf club shaft; wherein either the fiber density, the kind of fiber, the physical property of the fiber, or a combination of two or more thereof, of the yarn paths of three directions that form the triaxial fabric layers, is varied with respect to the longitudinal axis of the shaft in accordance with a required specification of the shaft.
Preferably, the fiber density of the triaxial fabric layers is determined based on either the specification of the triaxial fabric layer, the arrangement of the triaxial fabric layer, or both the specification and arrangement thereof.
Preferably, the specification of the triaxial fabric layers is determined based on either the kind, the number, the distance, the thickness, or a combination of one or more thereof, of the fiber of the yarn paths of three directions.
Preferably, the yarn paths in three directions have different numbers of fibers.
The arrangement of the triaxial fabric layers can be such that a plurality of triaxial fabric layers having different winding radii in the axial direction of the shaft mutually overlap each other in part.
Alternatively, the arrangement of the triaxial fabric layers is such that the triaxial fabric layers are spaced from one another in the axial direction of the shaft.
Alternatively, a plurality of triaxial fabric layers which are multi-layered are provided so that the direction of the yarn paths of the triaxial fabric layers are different from one another.
Preferably, the triaxial fabric layers includes at least one layer which extends along the overall length of said golf club shaft and another triaxial fabric layer which does not extend along the overall length of the golf club shaft.
Preferably, the fiber of the triaxial fabric layers is selected from one or more of the following: carbon fiber, alumina fiber, aramid fiber, tyranno fiber, amorphous fiber, or glass fiber.
Preferably, the physical property of the triaxial fabric layers includes either a high tensile strength, a high tensile elasticity modulus, or a combination of both.
The present disclosure relates to subject matter contained in Japanese Patent Application No.10-117161 (filed on Apr. 27, 1998) and Japanese Patent Application No. 10-155842 (filed on Jun. 4, 1998) which are expressly incorporated herein by reference in their entireties.
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patent: 5979288 (1999-11-01), Gallagher
Blau Stephen L.
Chapman Jeanette
Fujikura Rubber Ltd.
McCormick Paulding & Huber LLP
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