High volume aerodynamic golf club head

Abstract

A high volume aerodynamic golf club head with a club head volume of at least 400 cc and a front-to-back dimension of at least 4.4 inches producing reduced aerodynamic drag forces. The club head has a crown section having a crown apex located an apex height above a ground plane, wherein a portion of the crown section between the crown apex and the face has an apex-to-front radius of curvature that is less than 3 inches. The apex height and location of the crown apex obtain desirable airflow reattachment close to the face and improve airflow attachment to the crown section.

We claim: 
     
         1 . A high volume aerodynamic golf club head ( 100 ) comprising:
 A) a hollow body ( 110 ) having a club head volume of at least 400 cc, a face ( 200 ), a sole section ( 300 ), a crown section ( 400 ), a front ( 112 ), a back ( 114 ), a heel ( 116 ), and a toe ( 118 ), wherein the hollow body ( 110 ) has a front-to-back dimension (FB) of at least 4.4 inches and a heel-to-toe dimension (HT) that is greater than the front-to-back dimension (FB);   B) the crown section ( 400 ) having a crown apex ( 410 ) located an apex height (AH) above a ground plane (GP), wherein the crown section ( 400 ) has (i) a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the face ( 200 ) having an apex-to-front radius of curvature (Ra-f) that is less than 3 inches, and (ii) a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the back ( 114 ) of the hollow body ( 110 ) has an apex-to-rear radius of curvature (Ra-r), and the apex-to-front radius of curvature (Ra-f) is at least 25% less than the apex-to-rear radius of curvature (Ra-r);   C) the face ( 200 ) having a top edge ( 210 ) and a lower edge ( 220 ), wherein a top edge height (TEH) is the elevation of the top edge ( 210 ) above the ground plane (GP), and a lower edge height (LEH) is the elevation of the lower edge ( 220 ) above the ground plane (GP), wherein a maximum top edge height (TEH) is at least 2 inches.   
     
     
         2 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein an apex ratio of the apex height (AH) to the maximum top edge height (TEH) is at least 1.13. 
     
     
         3 . The high volume aerodynamic golf club head ( 100 ) of  claim 2 , wherein the apex ratio of the apex height (AH) to the maximum top edge height (TEH) is at least 1.2. 
     
     
         4 . The high volume aerodynamic golf club head ( 100 ) of  claim 3 , wherein the apex ratio of the apex height (AH) to the maximum top edge height (TEH) is at least 1.25. 
     
     
         5 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein a portion of the crown section ( 400 ) has a heel-to-toe radius of curvature (Rh-t) at the crown apex ( 410 ), and the apex-to-front radius of curvature (Ra-f) is less than the apex-to-rear radius of curvature (Ra-r), and the apex-to-rear radius of curvature (Ra-r) is less than the heel-to-toe radius of curvature (Rh-t). 
     
     
         6 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein the apex-to-front radius of curvature (Ra-f) is less than 2.85 inches. 
     
     
         7 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein the front-to-back dimension (FB) is at least 4.6 inches. 
     
     
         8 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein less than 10% of the club head volume is above the elevation of the maximum top edge height (TEH). 
     
     
         9 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein the crown apex ( 410 ) is behind the forwardmost point on the face ( 200 ) a distance that is a crown apex setback dimension ( 412 ), and the crown apex setback dimension ( 412 ) is less than 1.75 inches. 
     
     
         10 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein a vertical projection of the center of gravity (CG) on the ground plane (GP) is further from a second vertical projection of the forwardmost point on the face ( 200 ) on the ground plane (GP), than the crown apex setback dimension ( 412 ). 
     
     
         11 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein at least fifty percent of a plurality of vertical golf club head cross sections taken perpendicular to a vertical plane passing through the shaft axis (SA), which intersect a portion of the face top edge ( 210 ) between the center of the face ( 200 ) and the toeward most point on the face ( 200 ), are characterized by an apex-to-front radius of curvature (Ra-f) of less than 3 inches. 
     
     
         12 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein at least seventy-five percent of a plurality of vertical golf club head cross sections taken perpendicular to a vertical plane passing through the shaft axis (SA), which intersect a portion of the face top edge ( 210 ) between the center of the face ( 200 ) and the toeward most point on the face ( 200 ), are characterized by an apex-to-front radius of curvature (Ra-f) of less than 3 inches. 
     
     
         13 . The high volume aerodynamic golf club head ( 100 ) of  claim 1 , wherein a frontal cross sectional area is less than 11 square inches. 
     
     
         14 . A high volume aerodynamic golf club head ( 100 ) comprising:
 A) a hollow body ( 110 ) having a club head volume of at least 400 cc, a face ( 200 ), a sole section ( 300 ), a crown section ( 400 ), a front ( 112 ), a back ( 114 ), a heel ( 116 ), and a toe ( 118 ), wherein the hollow body ( 110 ) has a front-to-back dimension (FB) of at least 4.4 inches;   B) the crown section ( 400 ) having a crown apex ( 410 ) located an apex height (AH) above a ground plane (GP), wherein the crown section ( 400 ) has a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the face ( 200 ) having an apex-to-front radius of curvature (Ra-f) that is less than 3 inches, and wherein at least fifty percent of a plurality of vertical golf club head cross sections taken perpendicular to a vertical plane passing through the shaft axis (SA), which intersect a portion of the face top edge ( 210 ) between the center of the face ( 200 ) and the toeward most point on the face ( 200 ), are characterized by an apex-to-front radius of curvature (Ra-f) of less than 3 inches;   C) the face ( 200 ) having a top edge ( 210 ) and a lower edge ( 220 ), wherein a top edge height (TEH) is the elevation of the top edge ( 210 ) above the ground plane (GP), and a lower edge height (LEH) is the elevation of the lower edge ( 220 ) above the ground plane (GP), wherein a maximum top edge height (TEH) is at least 2 inches, and wherein the crown apex ( 410 ) is behind the forwardmost point on the face ( 200 ) a distance that is a crown apex setback dimension ( 412 ), and the crown apex setback dimension ( 412 ) is less than 1.75 inches; and   D) wherein the high volume aerodynamic golf club head ( 100 ) has;
 i) a first moment of inertia (MOIy) about a vertical axis through a center of gravity (CG) of the high volume aerodynamic golf club head ( 100 ) that is at least 4000 g*cm 2 ; and 
 ii) a second moment of inertia (MOIx) about a horizontal axis through the center of gravity (CG) that is at least 2000 g*cm 2 . 
   
     
     
         15 . The high volume aerodynamic golf club head ( 100 ) of  claim 14 , wherein a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the back ( 114 ) of the hollow body ( 110 ) has an apex-to-rear radius of curvature (Ra-r), and the apex-to-front radius of curvature (Ra-f) is at least 25% less than the apex-to-rear radius of curvature (Ra-r). 
     
     
         16 . The high volume aerodynamic golf club head ( 100 ) of  claim 14 , wherein an apex ratio of the apex height (AH) to the maximum top edge height (TEH) is at least 1.13. 
     
     
         17 . The high volume aerodynamic golf club head ( 100 ) of  claim 14 , wherein a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the back ( 114 ) of the hollow body ( 110 ) has an apex-to-rear radius of curvature (Ra-r), a portion of the crown section ( 400 ) has a heel-to-toe radius of curvature (Rh-t) at the crown apex ( 410 ), and the apex-to-front radius of curvature (Ra-f) is less than the apex-to-rear radius of curvature (Ra-r), and the apex-to-rear radius of curvature (Ra-r) is less than the heel-to-toe radius of curvature (Rh-t). 
     
     
         18 . The high volume aerodynamic golf club head ( 100 ) of  claim 14 , wherein the apex-to-front radius of curvature (Ra-f) is less than 2.85 inches. 
     
     
         19 . The high volume aerodynamic golf club head ( 100 ) of  claim 14 , wherein a frontal cross sectional area is less than 11 square inches. 
     
     
         20 . A high volume aerodynamic golf club head ( 100 ) comprising:
 A) a hollow body ( 110 ) having a club head volume of at least 400 cc, a face ( 200 ), a sole section ( 300 ), a crown section ( 400 ), a front ( 112 ), a back ( 114 ), a heel ( 116 ), and a toe ( 118 ), wherein the hollow body ( 110 ) has a front-to-back dimension (FB) of at least 4.4 inches;   B) the crown section ( 400 ) having a crown apex ( 410 ) located an apex height (AH) above a ground plane (GP), wherein the crown section ( 400 ) has (i) a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the face ( 200 ) having an apex-to-front radius of curvature (Ra-f) that is less than 3 inches, and wherein at least fifty percent of a plurality of vertical golf club head cross sections taken perpendicular to a vertical plane passing through the shaft axis (SA), which intersect a portion of the face top edge ( 210 ) between the center of the face ( 200 ) and the toeward most point on the face ( 200 ), are characterized by an apex-to-front radius of curvature (Ra-f) of less than 3 inches and (ii) a portion of the crown section ( 400 ) between the crown apex ( 410 ) and the back ( 114 ) of the hollow body ( 110 ) has an apex-to-rear radius of curvature (Ra-r), and the apex-to-front radius of curvature (Ra-f) is at least 25% less than the apex-to-rear radius of curvature (Ra-r);   C) the face ( 200 ) having a top edge ( 210 ) and a lower edge ( 220 ), wherein a top edge height (TEH) is the elevation of the top edge ( 210 ) above the ground plane (GP), and a lower edge height (LEH) is the elevation of the lower edge ( 220 ) above the ground plane (GP), wherein a maximum top edge height (TEH) is at least 2 inches, and wherein the crown apex ( 410 ) is behind the forwardmost point on the face ( 200 ) a distance that is a crown apex setback dimension ( 412 ), and the crown apex setback dimension ( 412 ) is less than 1.75 inches; and   D) wherein the high volume aerodynamic golf club head ( 100 ) has;
 i) a first moment of inertia (MOIy) about a vertical axis through a center of gravity (CG) of the high volume aerodynamic golf club head ( 100 ) that is at least 4000 g*cm 2 ; and 
 ii) a second moment of inertia (MOIx) about a horizontal axis through the center of gravity (CG) that is at least 2000 g*cm 2 .