Yamaha Corporation

Nippon Gakki Seizo Kabushiki Kaisha

Tatsuo Nakanishi

Itsushi Nagamoto

Masaki Fujimura

Toyohiko Tadokoro

Ryohei Tajima

Yoichi Nagasaki

Tatsuya Hirakawa

Tomoharu Yamashita

Koichi Enomoto

Noburo Sumikawa

In construction of a wood type golf club head, its main body made of a material unsuited for plastic deformation such as FRP and its and hosel made of a material suited for plastic deformation such as metal are separably coupled to each other. Subtle adjustment of ball striking characteristics such as loft and lie angles can be practiced quite freely independently of the material used for the main body.

Golf club head

In construction of a composite type iron club head for golf having a fiber reinforcement, a synthetic resin backup is used as a substitute for the conventional ring for holding the fiber reinforcement in postion, thereby improving productivity and inertia moment of iron clud head. The fiber reinforcement, which can be of solid or hollow construction, and the synthetic resin back up are disposed in a recess provided on the side of the club head remote from the shooting surface. A mass can be adjustably imbedded in the synthetic resin backup so as to increase the inertial moment of the club head. A rise member extending upwardly from the sole face of the clud head can also be provided so that the center of gravity can be more easily adjusted. Undercuts can also be provided about the periphery of the recess to further facilitate the fixing of the fiber reinforcement within the recess and to provide additional fiber reinforcement in the peripheral sections of the club head. To further provide additional fiber reinforcement in the peripheral sections of the club head, a plano-concave surface can be provided on the side of the club head remove from the shooting surface.

Iron club head for golf

A fiber reinforcement, which can be of solid or hollow construction, and a synthetic resin back up are disposed in a recess provided on the side of the club head remote from the shooting surface. A mass can be adjustably imbedded in the synthetic resin backup so as to increase the inertial moment of the club head. A rise member extending upwardly from the sole face of the club head can also be provided so that the center of gravity can be more easily adjusted. The fiber reinforcement is relatively thin for shorter shafted golf clubs having high degrees of loft, and increases progressively to a greater thickness for longer shafted golf clubs having relatively small degrees of loft. A back plate made of a woven cloth can be provided adjacent the fiber reinforcement to aid in reinforcing the shooting surface and to withstand the tension acting across the rear of the club head upon impact. The synthetic backup can be transparent or semi-transparent to expose the esthetics of the woven cloth. Bonding tape can be provided between the fiber reinforcement and the main body and between the fiber reinforcement and the back plate to facilitate the manufacture of the club head and to minimize the shock and vibration effect caused by striking a ball.

A method of forming a golf club head by placing an infusion tube with a core in a mold. Sheets of long fibrous material are placed around the core and the mold is closed. Fiber reinforced plastic is forced into the mold and a substantial portion passes through the sheets of long fiber reinforcement and orients the fiber. The material is hardened and the golf club head is removed from the mold.

Method for producing a golf club head

In production of a wood-type golf club head having a rigid shell, metal pieces are dispersed in the matrix of crude foamable synthetic resin filled in the interior of a crude rigid shell for long maintenance in position of the center of gravity of the product despite shocks at shooting balls. The golf club head is formed of a hollow shell having a sole side provided with a first opening. A lid is received within the first opening to form an enclosure. The lid includes a second opening in direct communication with the interior of the hollow shell. The synthetic resin is provided within the interior of the hollow shell through the second opening within the lid. The synthetic resin forms a foam core upon application of heat to the resin.

In production of a wood-type golf club head having a FRP shell and a foam resin core, a seat hole is formed in the sole portion of the club head and closed by a support plate having a threaded through hole at the center of gravity thereof; foamable resin is infused into the FRP shell cavity in the form of fine beads or solution, a plug as a weight balance adjusting piece is screwed into the support plate in direct contact with the foam resin core for secure holding of the weight balance adjusting piece during use of the club.

Method for producing a wood-type golf club head

In production of a composite type iron golf club head having a FRP (fiber reinforced plastic) backing in a rear recess, a peripheral flange to be caught by the main body is formed on the FRP backing by providing a bottom peripheral groove in the rear recess for fortified bonding of the FRP backing to the main body.

Method for producing an iron golf club head

In production of a wood-type golf club head having a rigid shell, metal pieces are dispersed in the matrix of crude foamable synthetic resin filled in the interior of a crude rigid shell for long maintenance in position of the center of gravity of the product despite shocks at shooting balls.

In production of a wood-type golf club head having a fiber reinforced shell, a fiber reinforced plastic covering containing long fibers is molded into the shell by application of heat under pressure which enables the shell to fairly assume the complicated configuration of the club head, and use of long fibers assure uniformly oriented reinforcement which results in enhanced elastic impact at hitting balls.

Process for producing a wood-type golf club head

In a construction of a ski having patterns visible on the bottom, the sole board is made up of a transparent polyethylene resin sheet and a thermoplastic synthetic resin composite sheet sandwiched between the polyethylene resin sheet and the main body of the ski, the patterns being formed on the mating surface of the composite sheet with the polyethylene resin sheet. In manufacturing, a composite film having patterns printed thereon is successively combined with a polyethylene resin sheet by pressure fusion at high temperature. Reduced thickness of the sole board with high masking effect, omission of the wet system painting conventionally used for masking layer formation, and employment of the economically advantageous photogravure printing of the patterns can be expected.

Growing community of inventors

Hamamatsu, Japan

Tatsuo Nakanishi