US 7,578,754 B2
Iron-type gold club head
Takashi Nakamura, Kobe (Japan)
Assigned to SRI Sports Limited, Kobe-Shi (Japan)
Filed on Mar. 06, 2007, as Appl. No. 11/714,102.
Claims priority of application No. 2006-122418 (JP), filed on Apr. 26, 2006.
Prior Publication US 2007/0254749 A1, Nov. 01, 2007
Int. Cl. A63B 53/04 (2006.01)
U.S. Cl. 473—342  [473/346; 473/349; 473/350] 8 Claims
OG exemplary drawing
 
1. An iron-type golf club head having a top forming an upper surface of the club head, a sole forming a bottom surface of the club head, and a toe connecting the top and the sole on a toe side of the club head, and comprising, at least, a face plate whose front surface forms at least a part of a club face for hitting a golf ball, and a head body to which the face plate is attached;
wherein the face plate is formed by forging or rolling an iron alloy having a specific gravity of 6.6 to 7.2 and containing at least 50% by weight of Fe and 5 to 15% by weight of Al, and the head body is made from a low carbon steel having a carbon content of less than 0.3% by weight which is weldable with the face plate and having a larger specific gravity than the face plate, and
wherein the face plate has an upper edge surface located on the top side, a lower edge surface located on the sole side, and an outer peripheral edge surface including a toe side edge surface connecting the upper edge surface and the lower edge surface, and the face plate is welded to the head body and extends to the top so that at least a part of the upper edge surface includes an upper exposed portion which constitutes a part of the top,
the head body comprises an opening which passes through back and forth, a face mount portion for fitting the face plate thereto which is disposed in the periphery of the opening, a back wall portion which is disposed behind the face mount portion to form a cavity in a pocket form between it and the back face of the face plate, and a hosel, in which the face mount portion includes a receiving portion which is depressed from the face and supports a peripheral edge portion of the back face of the face plate and which has a continuous annular form surrounding the opening to thereby annularly and continuously support the peripheral edge portion of the back face of the face plate, and an outer wall portion which rises from the peripheral edge of the receiving portion and supports the outer peripheral edge surface of the face plate and which has an upper broken portion for causing the upper exposed portion of the face plate to be exposed at the top, the receiving portion having a width WU (measured from the edge of the opening in the direction perpendicular to the edge) of 2 to 8 mm, and
the face plate extends toward both the sole and toe sides and terminates before the sole face and the toe face without the lower edge surface and toe side edge surface thereof contacting the sole face and the toe face, the head body includes a sole side outer wall portion and a toe side outer wall portion for supporting the lower edge surface and the toe side edge surface, the lower edge surface of the face plate and the sole side outer wall portion of the head body are welded together on the club face, and the toe side edge surface of the face plate and the toe side outer wall portion of the head body are welded together on the club face, in which the Ws/Wt ratio of the width Ws of the sole side outer wall portion to the width Wt of the toe side outer wall portion is from 1.2 to 2.0.