Bridgestone Sports Co., Ltd.

Bridgestone Corporation

Sidel Participations

Hisashi Yamagishi

Junji Hayashi

Hiroshi Higuchi

Atsushi Nakamura

Yasushi Ichikawa

Takashi Maruko

Yutaka Masutani

Yasunori Imamoto

Akira Kawata

Yasumasa Shimizu

Yoshinori Egashira

Hideo Watanabe

Jun Shindo

Shunichi Kashiwagi

Seisuke Tomita

Tadatoshi Yamada

Shinichi Kakiuchi

Hiroto Sasaki

Michio Inoue

Kunitoshi Ishihara

Nobuhiko Matsumura

Makoto Kubota

Atsuki Kasashima

Hideo Matsunaga

Rinya Takesue

Atuki Kasasima

Masafumi Nishitani

Koki Motoyoshi

The present invention provides a golf club head that can hit a ball with a sufficiently large amount of backspin. The golf club head according to the present invention is an iron type golf club head made of a metal and including a flat face. A plurality of traces are formed by milling on the face. The pitch of the traces is between 0.1 mm and 1 mm.

Golf club head

A three-piece solid golf ball comprising a center core, an intermediate layer, and a cover. The center core () has a diameter of at least 29 mm, a hardness in the range of 45-80 JIS C and a specific gravity of less than 1.4. The intermediate layer () has a thickness of at least 1 mm, a specific gravity of less than 1.2, and a hardness of at least 85 on JIS C scale. The cover () has a thickness of 1-3 mm and a hardness of 50-85 JIS C. The ball has a good total balance of properties in that feeling and controllability are improved at no sacrifice of flying performance and durability.

Three-piece solid golf ball

A multi-piece solid golf ball comprises a core having a 5 structure consisting of at least two layers and a cover on the core consisting of outer and inner cover layers. The outer cover layer has a Shore D hardness of 40-60 degrees. The inner cover layer has a Shore D hardness of up to 53 degrees and lower than that of the outer cover layer. The ball's carry is comparable to conventional solid golf balls and spin receptivity is approximate to wound golf balls while the ball is durable and offers pleasant feel.

Multi-piece solid golf ball

A hollow golf club head includes a head main body having a face opening portion on a face side, and a face member that closes the face opening portion. A part or all of an upper edge of the face opening portion and an upper edge of the face member extends to a crown portion.

An iron-type golf club head has a face which has a face surface of a flat shape, and a hosel which is continuous with the face on its heel side. A shaft insertion hole is disposed in the hosel. A protrusion protruding rearward is disposed in the vicinity of the center in a toe-heel direction. A material of the golf club head is pure iron having a high purity of at least 99.8%, for instance, pure iron having a purity within a range of 99.995 to 99.9999%. The golf club head is subjected to carburizing so that carbon diffuses up to about 0.2 to 0.5 mm from the surface. A region within 0.2 mm from the face surface has a hardness of HV 300 to 600, and a region where a distance from the face surface is 0.7 mm or more has a hardness of HV 100 or lower.

A golf club head includes a front body formed of a metal material, an FRP body, a metallic sole plate, and a weight member. The front body has a face portion, a metal sole portion, a metal side portion (toe), a metal crown portion, a metal side portion (heel), and a hosel portion. A slight gap in a range of 4 mm to 12 mm is formed between a front side of the sole plate and the metal sole portion. This part is formed of the FRP body. Preferably, the metal material of the front body includes a titanium-based alloy or a zirconium-based amorphous alloy. The sole plate is made of stainless steel.

A hollow golf club head includes a fiber-reinforced-plastic body and a metal body. The fiber-reinforced-plastic body includes a main portion of a crown portion. The metal body includes a face portion, a front edge portion of the crown portion continuous with the face portion, and a central portion of a sole portion in a toe-heel direction. The front edge portion of the crown portion made of a metal defines a recess portion in an upper surface thereof. A front edge portion of the fiber-reinforce-resin body overlaps and is joined to the front edge portion of the crown portion made of the metal.

A hollow golf club head includes a face portion made of metal, a sole portion, a side portion, a crown portion, and a hosel portion. The crown portion includes a main portion made of a fiber reinforced resin, and a front edge portion made of the metal. The front edge portion of the crown portion is continuous with the face portion. The sole portion comprises a center portion made of the metal in a toe-heel direction. A weight of a portion made of the fiber reinforced resin including the main portion of the crown portion is in a range of 5% to 30% of a total weight of the golf club head.

A golf club head includes a front body formed of a titanium-based metal material, an FRP body, a metallic sole plate, and a weight member. The front body has a face portion, a metal sole portion, a metal side portion (toe), a metal crown portion, a metal side portion (heel), and a hosel portion. A slight gap is formed between a front side of the sole plate and the metal sole portion. Preferably, the front body is made of a titanium alloy, while the sole plate is made of stainless steel. The height of center of gravity (mm) and the head volume V have a relationship of H&#x2266;0.05V+7.5.

A multi-piece solid golf ball comprises a core having a structure consisting of at least two layers and a cover on the core consisting of outer and inner cover layers. The core has a diameter in the range of 35 to 41 mm. The inner sphere of the core is formed of a rubber material based on polybutadiene and an outer layer is formed of a thermoplastic or rubber based material. The outer cover layer has a Shore D hardness of up to 53 degrees and lower than that of the outer cover layer. The ball's carry is comparable to conventional solid golf balls and spin receptivity is approximate to wound golf balls while the ball is durable and offers pleasant feel.

A hollow golf club head includes a face portion, a sole portion, a side portion, a crown portion and a hosel portion. A main portion of the crown portion is made of a fiber plastic resin. At least the face portion, a front edge portion of the crown portion continuous with the face portion, and a central portion of the sole portion in a toe-heel direction are made of a metal. A loft angle is in a range of 14&#xb0; to 25&#xb0;. A head volume is in a range of 100 cc to 230 cc. A weight of a fiber plastic resin portion of the golf club head is in a range of 6% to 30% of a weight of the golf club head.

Growing community of inventors

Chichibu, Japan

Hisashi Yamagishi