Golf club head with vertical center of gravity adjustment
Golf club heads include at least one weight port situated to retain weights and positioned above an approximate club face geometric center with the club in a standard address position. One, two, or more weight ports can be located above the club face center in a club crown or other portion of a club body. Club head vertical center of gravity can be selected to compensate dynamic loft associated with locating the club head center of gravity well behind the club face. Three-dimensional adjustment of club head center of gravity is possible.
1. A wood-type golf club head comprising:
a body comprising a face positioned at a forward portion of the golf club head, a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion of the golf club head and having a crown surface area, and a skirt positioned around a periphery of the golf club head between the sole and crown;
wherein the head has a face center positioned on the face at an approximate geometric center of the face, the face center including a head origin x-axis tangential to the face and generally parallel to the ground when the head is ideally positioned, a head origin y-axis generally perpendicular to the head origin x-axis and generally parallel to the ground when the head is ideally positioned, and a head origin z-axis generally perpendicular to the head origin x-axis and to the head origin y-axis and generally perpendicular to the ground when the head is ideally positioned, the head having a center of gravity whose location is defined relative to the head origin x-axis via a CGx coordinate, the head origin y-axis via a CGy coordinate of no more than 50 mm, and the head origin z-axis via a CGz coordinate; and
a rear weight assembly releasably attached to the body and having a mass element and a screw at least partially contained in a rear weight port having a threaded portion defining a rear radial axis having a rear axis angle of 100-170 degrees from the head origin z-axis measured in a head origin y-z plane, wherein the rear radial axis passes through the face, and the rear weight assembly has a rear mass of 5-50 grams, a rear weight center of gravity establishing a rear weight head origin x-axis coordinate, a rear weight head origin y-axis coordinate of 80-130 mm, and a rear weight head origin z-axis coordinate of −10 mm to −30 mm;
wherein the head has an Ixx moment of inertia about a CG x-axis, and an Izz moment of inertia about a CG z-axis of 480-600 kg·mm 2 ;
wherein the crown has a crown areal weight between about 0.15 g/cm 2 and about 0.45 g/cm 2 over at least 50% of the crown surface area; and
wherein the club head has an aspect ratio that is 0.45-0.58 and a coefficient of restitution greater than 0.8.
2. The wood-type golf club head according to claim 1 , wherein the CGz coordinate is −6 mm to 1 mm.
3. The wood-type golf club head according to claim 2 , wherein Ixx is at least 310 kg·mm 2 .
4. The wood-type golf club head according to claim 3 , wherein the rear weight head origin x-axis coordinate is between about −20 mm and about 20 mm.
5. The wood-type golf club head according to claim 4 , wherein Ixx is no more than 430 kg·mm 2 .
6. The wood-type golf club head according to claim 4 , wherein the rear weight head origin y-axis coordinate is at least 98 mm.
7. The wood-type golf club head according to claim 4 , wherein the rear weight head origin z-axis coordinate is −10 mm to −20 mm.
8. The wood-type golf club head according to claim 4 , wherein the aspect ratio is 0.49-0.54.
9. The wood-type golf club head according to claim 4 , wherein Ixx is 310-400 kg·mm 2 .
10. The wood-type golf club head according to claim 9 , wherein the CGy coordinate is 20-40 mm.
11. The wood-type golf club head according to claim 4 , wherein Ixx is 400-430 kg·mm 2 .
12. The wood-type golf club head according to claim 11 , wherein the rear weight head origin y-axis coordinate is at least 98 mm, the rear weight head origin z-axis coordinate is −10 mm to −20 mm, and the aspect ratio is 0.49-0.54.
13. The wood-type golf club head according to claim 4 , wherein the golf club head is formed from a combination of an alloy of titanium and a composite material.
14. The wood-type golf club head according to claim 4 , wherein the golf club head is formed from a combination of an alloy of titanium, an alloy of aluminum, and a composite material.
15. The wood-type golf club head according to claim 4 , wherein the golf club head is formed from a combination of an alloy of steel, an alloy of aluminum, and a composite material.
16. The wood-type golf club head according to claim 4 , further including a forward weight assembly releasably attached to the body and having a forward mass element and a forward screw at least partially contained in a forward weight port having a threaded portion defining a forward radial axis having a forward axis angle from the head origin z-axis measured in the head origin y-z plane, wherein the forward weight assembly has a forward mass of 1-18 grams, a forward weight center of gravity closer to the face than the club head center of gravity and establishing a forward weight head origin x-axis coordinate, a forward weight head origin y-axis coordinate, and a forward weight head origin z-axis coordinate.
17. The wood-type golf club head according to claim 16 , wherein a difference between the rear mass and the forward mass multiplied by a distance between the rear weight assembly and the forward weight assembly is between about 950 g-mm and about 4,235 g-mm.
18. The wood-type golf club head according to claim 16 , wherein a sum of the rear mass and the forward mass multiplied by a distance between the rear weight assembly and the forward weight assembly is at least 500 g·mm and no greater than about 5,000 g·mm.
19. The wood-type golf club head according to claim 16 , wherein the forward weight assembly is positioned heel-ward of the rear weight assembly.
20. The wood-type golf club head according to claim 16 , wherein the forward weight port includes at least one rib joined to the body.
21. The wood-type golf club head according to claim 16 , wherein the forward weight head origin z-axis coordinate is −20 mm to −10 mm.
22. The wood-type golf club head according to claim 16 , wherein the forward weight head origin x-axis coordinate is 20-40 mm.
23. The wood-type golf club head according to claim 16 , wherein a relative axis angle is a differential angle between the rear axis angle and the forward axis angle, and the relative axis angle is 0-135 degrees.
24. The wood-type golf club head according to claim 16 , wherein the forward mass is 5-10 grams.
25. The wood-type golf club head according to claim 4 , wherein the face has a face plate height of no more than 59 mm and a face plate width of no more than 111 mm.
26. The wood-type golf club head according to claim 25 , wherein the face plate height is at least 53 mm.
27. The wood-type golf club head according to claim 25 , wherein the face plate width is at least 105 mm.