Ryobi Limited

Yasuhiro Sugioka

Yoshiaki Egoshi

Jyoji Umeda

Hiroshi Kobayashi

A sand core adapted for high pressure casting is formed by a core body and a support pin to be connected to the core body. The support pin is provided with one end portion to be embedded in said core body and the other end portion projected outwardly from the core body. A connecting means is formed to the embedded portion so as to integrally connect the core body and the support pin and a support pin positioning and supporting means is formed at the projecting portion of the support pin. Positioning pins extending from a core formation mold are engaged with the positioning and supporting means so that the embedded end portion of the support pin is positioned in the cavity of the core formation mold. The cavity is filled with core sand whereby the embedded one end of the support pin is supported to integrally form the support pin and the core body. The sand core is dipped in a slurry including a sand core coating material and then heated and dried.

High pressure casting sand core and method of manufacturing the same

The sole plate of a hollow metal golf club head includes a pair of V-shaped reinforcing ribs having their spaced apart ends engaging the rear surface of the striking face. The inner ends of the V-shaped ribs engage the front side of a protrusion on the sole plate, and the rear side of the protrusion engages a hollow weight chamber. Another reinforcing rib connects the weight chamber to the rear wall of the club head. A threaded bolt passes through an aperture in the protrusion on the sole plate, and is threaded into the upper portion of the club head, thereby fastening the sole plate thereto.

Growing community of inventors

Fuchu, Japan

Yasuhiro Sugioka