GOLF CLUB HEAD WITH IMPROVED INERTIA PERFORMANCE
A golf club head that is capable improving on the inertia properties of a golf club head all while also improving the Center of Gravity (CG) location is disclosed herein. More specifically, the golf club head in accordance with the present invention achieves a relative low Moment of Inertia (MOI) about the Z-axis (MOI-Z), a relatively low MOI about the Shaft-axis (MOI-SA), a low MOI about the Y-axis (MOI-Y) and a high MOI about the X-axis (MOI-X).
1 . A golf club head comprising:
a frontal portion, further comprising a striking face including a face center, located at a forward portion of said golf club head;
a central body member extending from the frontal portion to a rear edge;
a crown body member, located aft of said striking face, and coupled to said frontal portion and said central body member to define a club head volume of between about 250 cc and about 400 cc; and
at least one first weighting member located near a central portion of said golf club head in a heel to toe orientation, substantially in line with and behind said face center;
wherein an x-axis is defined as a horizontal axis tangent to a geometric center of said striking face with a positive direction towards a heel of said golf club head, a y-axis is a vertical axis orthogonal to said x-axis with a positive direction towards a crown of said golf club head, and a z-axis being orthogonal to both said x-axis and said y-axis with a positive direction towards said frontal portion of said golf club head, and
wherein said golf club head has a moment of inertia about said x-axis (MOI-X), a moment of inertia about said y-axis (MOI-Y), and a moment of inertia about said z-axis (MOI-Z), and
wherein said golf club head has a MOI-X to MOI-Y ratio of greater than about 0.65.
2 . The golf club head of claim 1 , wherein said golf club head has a MOI-X to MOI-Y ratio of between 0.69 and 0.85.
3 . The golf club head of claim 1 , wherein said golf club head has a MOI-Y to MOI-Z ratio of greater than about 1.5.
4 . The golf club head of claim 1 , wherein said golf club head has a MOI-X to MOI-Z ratio of greater than about 1.1.
5 . The golf club head of claim 1 , wherein said golf club head has a MOI-X to MOI-Z ratio of greater than about 1.20.
6 . The golf club head of claim 1 , wherein said golf club head has a center of gravity a vertical distance up from a ground plane, CG-Y, that is at less than about 0.4 times a face height from the ground plane.
7 . The golf club head of claim 1 , wherein said golf club head has a center of gravity a vertical distance up from a ground plane, CG-Y, that is at less than about 0.35 times a crown height from the ground plane.
8 . The golf club head of claim 1 , wherein said MOI-Y is less than 400 kg-mm 2 .
9 . The golf club head of claim 1 , wherein said MOI-Y is less than 300 kg-mm 2 .
10 . The golf club head of claim 1 , wherein the frontal portion is formed of a first steel, the central body member is formed of the first steel, the striking face is formed of a second steel having an Ultimate Tensile Strength of greater than 2000 MPa, and the crown body member is formed from a thermoplastic material having a density of less than 3.0 g/cc.
11 . The golf club head pf claim 10 , wherein the thermoplastic material is comprised of polyetherimide, polyether ether ketone, polyphenylene sulfide, polysulfone, polyacryletherketone, polyetherketoneketone, or polyvinyl chloride.
12 . The golf club head of claim 10 , wherein the golf club head further comprises a first weight member having a mass of between about 10 grams and 30 grams coupled to the central body member adjacent the frontal portion.
13 . A golf club head comprising:
a steel frontal portion further comprising a steel striking face that helps define a face center, located at a forward portion of said golf club head; and
a steel central body member extending from the frontal portion to a rear edge;
a thermoplastic crown body member that is u-shaped and coupled to said frontal portion and the central body member to defined a club head volume of between about 250 cc and about 400 cc;
wherein an x-axis is defined as a horizontal axis tangent to a geometric center of said striking face with a positive direction towards a heel of said golf club head, a y-axis is a vertical axis orthogonal to said x-axis with a positive direction towards a crown of said golf club head, and a z-axis being orthogonal to both said x-axis and said y-axis with a positive direction towards said frontal portion of said golf club head,
wherein said frontal portion and said central body member combine to define a club head depth, which is a distance between a leading edge of said club head to the rear edge, along said z-axis,
wherein said golf club head has a moment of inertia about said x-axis (MOI-X), a moment of inertia about said y-axis (MOI-Y), and a moment of inertia about said z-axis (MOI-Z),
wherein said MOI-Y is less than about 400 kg-mm 2 ,
wherein said golf club head has a center of gravity depth from the face center, CG-Z, that is greater than or equal to 0.33 times said club head depth.
14 . The golf club head of claim 13 , wherein said golf club head has a MOI-X to MOI-Y ratio of between about 0.69 and 0.85.
15 . The golf club head of claim 13 , wherein said volume is less than about 300 cc.
16 . The golf club head of claim 15 , wherein said MOI-Y is less than about 300 kg-mm 2 .
17 . The golf club head of claim 13 , wherein said golf club head has a center of gravity a vertical distance up from a ground plane, CG-Y, that is less than about 0.4 times a face height from the ground plane.
18 . The golf club head of claim 13 , wherein said golf club head has a center of gravity a vertical distance up from a ground plane, CG-Y, that is at less than about 0.35 times a crown height from the ground plane.