Golf club head

1. A golf club head comprising:

a body comprising a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion, and a skirt positioned around a periphery between the sole and the crown wherein the body has a forward portion and a rearward portion; and

a face positioned at the forward portion of the body, the face having a geometric center, wherein a face plane is defined to extend tangential to the geometric center, and a principal axis extends from the geometric center and is normal to the face plane;

wherein the body extends a distance L transversely away from the face plane and measured along the principal axis, and defines cross-sectional areas A along planes parallel to the face plane and spaced rearward from the face plane by a distance q measured along the principal axis, wherein from a dimension of q/L of 0.60 to a dimension of q/L of 0.70 at least one of the cross-sectional areas A is between an upper cross-sectional area limit Au and a lower cross-sectional area limit A l , where

A u =5512( q/L ) 2 −14026( q/L )+8875+1200( q/L )+500, and  (1)

A l =5512( q/L ) 2 −14026( q/L )+8875−2000[1−( q/L )] 2 −300;  (2)

wherein within a first bounded region at least two of the cross-sectional areas A are between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l , and the first bounded region extends from a dimension of q/L of 0.70 to a dimension of q/L of 0.80;

wherein within a second bounded region at least two of the cross-sectional areas A are between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l , and the second bounded region extends from a dimension of q/L of 0.20 to a dimension of q/L of 0.30;

wherein the distance L is between 100 mm and 170 mm;

wherein the golf club head has a head origin defined as a position on the face plane at the geometric center, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is at an address position where a positive x-axis extends towards a heel portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is at the address position where a positive y-axis extends from the face and through the rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is at the address position where a positive z-axis extends from the origin and generally upward;

wherein the golf club head has a center of gravity with:

an x-axis coordinate between −5 mm and 10 mm;

a y-axis coordinate between 20 mm and 50 mm;

a z-axis coordinate between −10 mm and 5 mm; and

wherein the golf club head has a moment of inertia about a head center of gravity x-axis of at least 310 kg·mm 2 and no more than 468 kg·mm 2 and a moment of inertia about a head center of gravity z-axis of at least 450 kg·mm 2 and no more than 692 kg·mm 2 ;

wherein the golf club head has a volume between 350 cm 3 and 500 cm 3 ; and

wherein the golf club head has a width between 100 mm and 170 mm.

2. The golf club head of claim 1 , wherein the moment of inertia about the head center of gravity z-axis is at least 495 kg·mm 2 .

3. The golf club head of claim 2 , wherein the moment of inertia about the head center of gravity x-axis is at least 350 kg·mm 2 , the center of gravity x-axis coordinate is less than 7 mm, and the center of gravity z-axis coordinate is no more than 2 mm.

4. The golf club head of claim 2 , wherein within the first bounded region at least three of the cross-sectional areas A are between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l .

5. The golf club head of claim 1 , wherein at least a portion of the sole, a portion of the face, or a portion of the crown are formed of a composite material.

6. The golf club head of claim 1 , wherein at least a portion of the face is formed of a composite material.

7. A golf club head comprising:

a body comprising a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion, and a skirt positioned around a periphery between the sole and the crown wherein the body has a forward portion and a rearward portion; and

a face positioned at the forward portion of the body, the face having a geometric center, wherein a face plane is defined to extend tangential to the geometric center, and a principal axis extends from the geometric center and is normal to the face plane;

wherein the body extends a distance L transversely away from the face plane and measured along the principal axis, and defines cross-sectional areas A along planes parallel to the face plane and spaced rearward from the face plane by a distance q measured along the principal axis, wherein:

within a first region having a dimension of q/L of 0.65 to a dimension of q/L of 0.69 at least one of the cross-sectional areas A is between an upper cross-sectional area limit Au and a lower cross-sectional area limit A l ;

within a second region having a dimension of q/L of 0.70 to a dimension of q/L of 0.74 at least one of the cross-sectional areas A is between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l ;

within a third region having a dimension of q/L of 0.75 to a dimension of q/L of 0.79 at least one of the cross-sectional areas A is between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l ;

within a fourth region having a dimension of q/L of 0.80 to a dimension of q/L of 0.84 at least one of the cross-sectional areas A is between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l ;

within a fifth region having a dimension of q/L of 0.85 to a dimension of q/L of 0.89 at least one of the cross-sectional areas A is between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l ;

within a sixth region having a dimension of q/L of 0.90 to a dimension of q/L of 0.94 at least one of the cross-sectional areas A is between the upper cross-sectional area limit Au and the lower cross-sectional area limit A l ;

where:

A u =5512( q/L ) 2 −14026( q/L )+8875+1200( q/L )+500, and  (1)

A l =5512( q/L ) 2 −14026( q/L )+8875−2000[1−( q/L )] 2 −300;  (2)

wherein the distance L is between 100 mm and 170 mm;

wherein the golf club head has a head origin defined as a position on the face plane at the geometric center, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is at an address position where a positive x-axis extends towards a heel portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is at the address position where a positive y-axis extends from the face and through the rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is at the address position where a positive z-axis extends from the origin and generally upward;

wherein the golf club head has a center of gravity with:

an x-axis coordinate between −5 mm and 10 mm;

a y-axis coordinate between 20 mm and 50 mm; and

a z-axis coordinate between −10 mm and 5 mm;

wherein the golf club head has a moment of inertia about a head center of gravity x-axis of at least 310 kg·mm 2 and no more than 468 kg·mm 2 and a moment of inertia about a head center of gravity z-axis of at least 450 kg·mm 2 and no more than 692 kg·mm 2 ;

wherein the golf club head has a volume between 350 cm 3 and 500 cm 3 ;

wherein the golf club head has a width between 100 mm and 170 mm; and

wherein at least a portion of the sole, a portion of the face, or a portion of the crown are formed of a composite material.

8. The golf club head of claim 7 , wherein the moment of inertia about the head center of gravity z-axis is at least 495 kg·mm 2 , the center of gravity x-axis coordinate is between −5 mm and 7 mm, and the center of gravity z-axis coordinate is between −7 mm and 2 mm.

9. The golf club head of claim 7 , wherein the moment of inertia about the head center of gravity x-axis is at least 350 kg·mm 2 , the moment of inertia about the head center of gravity z-axis is at least 525 kg·mm 2 , and the center of gravity z-axis coordinate is between −6 mm and 0 mm.

10. The golf club head of claim 7 , wherein at least a portion of the face is formed of a composite material.

11. A golf club head comprising:

a body comprising a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion, and a skirt positioned around a periphery between the sole and the crown wherein the body has a forward portion and a rearward portion; and

a face positioned at the forward portion of the body, the face having a geometric center, wherein a face plane is defined to extend tangential to the geometric center, and a principal axis extends from the geometric center and is normal to the face plane;

wherein the body extends a distance L transversely away from the face plane and measured along the principal axis, and a plurality of planes parallel to the face plane and spaced rearward from the face plane by a distance q measured along the principal axis define a plurality of cross-sectional areas A with each of the plurality of planes having a cross-sectional area A, wherein:

the plurality of planes includes a set quantity of planes incrementally spaced apart along the principal axis from a dimension of q/L of 0.10 to a dimension of q/L of 0.90;

the set quantity of planes is at least seventeen; and

at least 50% of the cross-sectional areas A are between an upper cross-sectional area limit Au and a lower cross-sectional area limit A l ;

where:

A u =5512( q/L ) 2 −14026( q/L )+8875+1200( q/L )+500, and  (1)

A l =5512( q/L ) 2 −14026( q/L )+8875−2000[1−( q/L )] 2 −300;  (2)

wherein the distance L is between 100 mm and 170 mm;

wherein the golf club head has a head origin defined as a position on the face plane at the geometric center, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is at an address position where a positive x-axis extends towards a heel portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is at the address position where a positive y-axis extends from the face and through the rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is at the address position where a positive z-axis extends from the origin and generally upward;

wherein the golf club head has a center of gravity with:

an x-axis coordinate between −5 mm and 10 mm;

a y-axis coordinate between 20 mm and 50 mm; and

a z-axis coordinate between −10 mm and 5 mm;

wherein the golf club head has a moment of inertia about a head center of gravity x-axis of at least 310 kg·mm 2 and no more than 468 kg·mm 2 and a moment of inertia about a head center of gravity z-axis of at least 450 kg·mm 2 and no more than 692 kg·mm 2 ;

wherein the golf club head has a volume between 350 cm 3 and 500 cm 3 ;

wherein the golf club head has a width between 100 mm and 170 mm; and

wherein between q/L of 0.65 to q/L of 0.90 the plurality of cross-sectional areas A are less than 4000 mm 2 .

12. A golf club head comprising:

a body comprising a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion, and a skirt positioned around a periphery between the sole and the crown wherein the body has a forward portion and a rearward portion; and

a face positioned at the forward portion of the body, the face having a geometric center, wherein a face plane is defined to extend tangential to the geometric center, and a principal axis extends from the geometric center and is normal to the face plane;

wherein the body extends a distance L transversely away from the face plane and measured along the principal axis, and a plurality of planes parallel to the face plane and spaced rearward from the face plane by a distance q measured along the principal axis define a plurality of cross-sectional areas A with each of the plurality of planes having a cross-sectional area A, wherein:

the plurality of planes includes a set quantity of planes incrementally spaced apart along the principal axis from a dimension of q/L of 0.10 to a dimension of q/L of 0.90;

within a first region having a dimension of q/L of 0.65 to a dimension of q/L of 0.90 all of the plurality of cross-sectional areas A are less than 4000 mm 2 and greater than a lower cross-sectional area limit A l ;

where:

A u =5512( q/L ) 2 −14026( q/L )+8875+1200( q/L )+500, and  (1)

A l =5512( q/L ) 2 −14026( q/L )+8875−2000[1−( q/L )] 2 −300;  (2)

wherein the distance L is between 100 mm and 170 mm;

wherein the golf club head has a head origin defined as a position on the face plane at the geometric center, the head origin including an x-axis tangential to the face and generally parallel to the ground when the head is at an address position where a positive x-axis extends towards a heel portion, a y-axis extending perpendicular to the x-axis and generally parallel to the ground when the head is at the address position where a positive y-axis extends from the face and through the rearward portion of the body, and a z-axis extending perpendicular to the ground, to the x-axis and to the y-axis when the head is at the address position where a positive z-axis extends from the origin and generally upward;

wherein the golf club head has a center of gravity with:

an x-axis coordinate between −5 mm and 10 mm;

a y-axis coordinate between 20 mm and 50 mm; and

a z-axis coordinate between −10 mm and 5 mm;

wherein the golf club head has a moment of inertia about a head center of gravity x-axis of at least 310 kg·mm 2 and no more than 468 kg·mm 2 and a moment of inertia about a head center of gravity z-axis of at least 450 kg·mm 2 and no more than 692 kg·mm 2 ;

wherein the golf club head has a volume between 350 cm 3 and 500 cm 3 ; and

wherein the golf club head has a width between 100 mm and 170 mm.

13. The golf club head of claim 12 , wherein within a second region all of the plurality of cross-sectional areas A are greater than 4000 mm 2 .

14. The golf club head of claim 13 , wherein at least a portion of the sole, a portion of the face, or a portion of the crown are formed of a composite material.

15. The golf club head of claim 13 , wherein at least a portion of the face is formed of a composite material.

16. The golf club head of claim 13 , wherein at least a portion of the sole, a portion of the face, and a portion of the crown are formed of a composite material.

17. The golf club head of claim 13 , wherein the moment of inertia about the head center of gravity z-axis is at least 495 kg·mm 2 .

18. The golf club head of claim 17 , wherein the moment of inertia about the head center of gravity x-axis is at least 350 kg·mm 2 , the center of gravity x-axis coordinate is less than 7 mm, and the center of gravity z-axis coordinate is no more than 2 mm.

19. The golf club head of claim 18 , wherein the center of gravity y-axis coordinate is at least 40 mm.

20. The golf club head of claim 19 , wherein at least a portion of the sole, a portion of the face, or a portion of the crown are formed of a composite material.