Iron-type golf club head with sole having stable static address position
An iron-type golf club head having a sole, a center of gravity CG, and a static contact point SCP on the sole substantially vertically below the CG for providing stability when the club head is in an address position, but the sole has no points lower than the SCP when the club head is in the address position. Additionally, the club head may have a centerline plane orthogonal to the plane of the club face and containing the centerline of the club face, with the center of gravity lying in the centerline plane and the lowest point LP on the sole also lying substantially in the centerline plane when the centerline plane is substantially vertical, for minimizing mis-hits with the club head.
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This U.S. utility patent application is a continuation-in-part of U.S. patent application Ser. No. 10/748,670, filed Dec. 31, 2003, which claims the benefit of U.S. provisional patent application Ser. No. 60/437,047, filed Dec. 31, 2002.
BACKGROUNDThe present invention relates to the design of golf clubs, and more particularly to designs to provide golf club heads of iron-type golf clubs improved static stability when oriented in the address position.
The address position of a golf club usually refers to the orientation of the head of a golf club when a player is holding the grip and shaft of the club in a substantially vertical plane with the club head, attached to that shaft, being located just behind a golf ball before hitting same, i.e., “addressing the ball,” resting on the ground just behind the golf ball. The sole of a golf club head is the bottom surface(s) thereof, which may rest on the ground when the club head is in an address position.
As discussed later herein, the sole portion of an iron-type golf club often increases in total width (as measured in the club face-to-back direction) at locations progressing from the heel portion to the toe portion of the sole of the club head. The sole of an iron-type golf club head may be substantially flat, or may be curved from heel to toe (the so-called “radius” of the sole of a club head) and/or curved from leading edge to trailing edge of the sole (the so-called “camber” of the sole of a club head), such curves causing the sole to bulge downwardly in a convex manner.
The “radius” of the sole of an iron type golf club is preferably symmetrical with respect to the centerline plane of the club head (which plane is discussed later herein). For example, the earlier Hogan Radius irons, and Cleveland 792 VAS irons, are examples of club heads having convex “radius” and “camber” sole curvatures. Additionally, sand wedges often exhibit such sole curvatures.
Iron-type golf club heads are ideally designed to strike a ball with the face centerline, as shown in
Herein the “address position” means a position wherein the toe of a club head will be slightly raised, that is pivoted upwardly about the heel, as schematically shown somewhat exaggerated in
A “bounce line” is defined by the lowest points of the club head in a plurality of planes perpendicular to the club face along the line of contact with the ground at ball impact. This line is also the lowest line in the face profile view of the club head. When in the address position, a conventional club head is statically unstable, as shown in
Those skilled in the art will appreciate that when hitting a golf ball, a golf club should make initial dynamic contact with the ground at a low point LP on the sole, that lies substantially in the centerline plane as discussed with respect to
The ground contact lowest point LP is located slightly toward the toe a distance from the centerline plane of from about 0.050 inches to about 0.250 inches among clubs of a set of irons. To eliminate such differences, the lie angle of the club head may be adjusted by about 0.5 to about 1.5 degrees. This slight adjustment in lie angle will cause the centerline plane to be slightly out of perpendicular to a horizontal ground plane, which can result in off-center ball strikes. However, the present invention provides a solution to these problems.
BRIEF SUMMARY OF THE INVENTIONHence, a need exists for an iron-type golf club that is stable and feels steady at address, thus increasing the player's confidence in that club. It is also desirable to provide a golf club having a club head which will make initial dynamic contact with the ground at the centerline plane junction with the sole, and preferably vertically below the center of gravity of the club head, thereby minimizing the possibility of club head-induced hook or slice shots. The centerline plane can be maintained perpendicular to the ground plane by modifying sole width, radius, camber and bounce. Before such dynamic ball striking and ground contact, steady address is achieved in the golf club head of the present invention by providing in the sole of the club head a static contact point, line and area preferably vertically below the center of gravity of the club head when in an address position.
BRIEF DESCRIPTION OF THE DRAWINGSOther advantages and further features of the advantageous golf club head of the present invention are shown in and described in conjunction with the following drawings:
Referring to
Thus, as indicated in
Claims
1. An iron-type golf club head comprising
- a sole,
- a face having a leading edge,
- a center of gravity CG, and
- a static contact point SCP2 on the sole when the club head is in an address position, the SCP2 lying in an imaginary substantially vertical plane substantially parallel to the leading edge and passing through the CG when the club head is in the address position, the sole having no points lower than the SCP2 when the club head is in the address position.
2. The golf club head of claim 1, wherein the SCP2 and at least two other points are substantially coplanar and lie on an imaginary horizontal plane substantially parallel to the ground plane, characterizing a static contact surface area SCA2.
3. The golf club head of claim 2, wherein the static contact surface area SCA2 is planar.
4. The golf club head of claim 2, wherein the static contact surface area SCA2 is non-planar.
5. An iron-type golf club head, comprising
- a sole,
- a center of gravity CG, and
- having a centerline plane orthogonal to the plane of the club face and containing the centerline of the club face, with the center of gravity lying in said centerline plane and the lowest point LP on said sole also lying substantially in said centerline plane when the centerline plane is substantially vertical.
6. The golf club head of claim 5, wherein the sole additionally comprises a lowest point surface area LPA which is comprised of points substantially vertically below the center of gravity when the centerline plane is vertical, and no points on the sole are lower than said LP when the centerline plane is vertical.
7. The golf club head of claim 6, wherein the lowest point surface area LPA is planar.
8. The golf club head of claim 6, wherein the lowest point surface area LPA is non-planar.
9. The iron-type golf club head of claim 1, additionally having a centerline plane orthogonal to the plane of the club face and containing the centerline of the club face, with the center of gravity lying in said centerline plane and the lowest point LP on said sole also lying substantially in said centerline plane when the centerline plane is substantially vertical.
10. The golf club head of claim 9, wherein the SCP2 and at least two other points are substantially coplanar and lie on an imaginary horizontal plane substantially parallel to the ground plane, characterizing a static contact surface area SCA2.
11. The golf club head of claim 9, wherein the static contact surface area SCA2 is planar.
12. The golf club head of claim 9, wherein the static contact surface area SCA2 is non-planar.
13. The golf club head of claim 9, wherein the sole additionally comprises a lowest point surface area LPA which is comprised of points substantially vertically below the center of gravity when the centerline plane is vertical, and no points on the sole are lower than said LP when the centerline plane is vertical.
14. The golf club head of claim 13, wherein the lowest point surface area LPA is planar.
15. The golf club head of claim 13, wherein the lowest point surface area LPA is non-planar.
Type: Application
Filed: Nov 30, 2006
Publication Date: Apr 5, 2007
Applicant: Roger Cleveland Golf Company, Inc. (Huntington Beach, CA)
Inventors: Lionel Poincenot (Carlsbad, CA), Douglas Roberts (La Palma, CA)
Application Number: 11/606,022
International Classification: A63B 53/00 (20060101);