Yamaha Corporation

Nippon Gakki Seizo Kabushiki Kaisha

Ryohei Tajima

Itsushi Nagamoto

Tatsuo Nakanishi

Atsushi Tsuchida

For improvement in aerodynamic characteristics of a golf club head at swing, the transverse cross-section of the hosel is defined by a winged profile which includes at least one of a convex heel and concave toe sections. The sole face is defined by a convex sphere of a specified radius of curvature. The crown and sole faces are defined with vertical symmetry by respective convex spheres of similar radii of curvature. Current transition around the club head at swing is well prevented for higher head speed. Bias buoyancy at swing are minimized for a stabilized swing line.

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 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.

Growing community of inventors

Hamamatsu, Japan

Ryohei Tajima