Low drag clubhead

Abstract

Golf club heads with improved aerodynamic properties. In an example, the golf club head has a club head frontmost point and a club head rearmost point, and the golf club head comprising: a striking face, the striking face defining the frontmost point; a sole connected to a bottom side of the striking face and having a rearmost point; a crown connected to a topside of the striking face and having a rearmost point; and a skirt, wherein the rearmost point on the sole is an intersection point of the sole and a lower boundary of the skirt, and the rearmost point on the crown is an intersection point of the crown and an upper boundary of the skirt, and wherein the lower boundary is a skirt height above a ground plane, and the skirt height satisfies a head-length-to-skirt-height ratio less than 6:1.

What is claimed is: 
     
         1 . A metal-wood type golf club head having improved aerodynamic properties, the golf club head having a club head frontmost point and a club head rearmost point, and the golf club head comprising:
 a striking face, the striking face defining the frontmost point;   a sole connected to a bottom side of the striking face, the sole having a rearmost point and a closing ascent angle of less than about 35 degrees,   a crown connected to a topside of the striking face, the crown including a rearmost point and a closing descent angle of less than about 35 degrees; and   a skirt,   wherein the rearmost point on the sole is an intersection point of the sole and a lower boundary of the skirt, and the rearmost point on the crown is an intersection point of the crown and an upper boundary of the skirt, and   wherein the lower boundary is a skirt height above a ground plane, and the skirt height satisfies a head-length-to-skirt-height ratio between 3:1 and 8:1.   
     
     
         2 . The metal-wood type golf club head of  claim 1 , wherein the skirt height satisfies a head-length to skirt-height ratio between 3.4:1 and 5.8:1. 
     
     
         3 . The metal-wood type golf club head of  claim 1 , wherein the closing ascent angle is less than 30 degrees. 
     
     
         4 . The metal-wood type golf club head of  claim 3 , wherein the closing ascent angle is less than 20 degrees. 
     
     
         5 . The metal-wood type golf club head of  claim 1 , wherein the closing descent angle is less than 30 degrees. 
     
     
         6 . The metal-wood type golf club head of  claim 5 , wherein the closing descent angle is less than 25 degrees. 
     
     
         7 . A metal-wood type golf club head having improved aerodynamic properties, the golf club head having a club head frontmost point and a club head rearmost point, and the golf club head comprising:
 a striking face, the striking face defining the frontmost point;   a sole connected to a bottom side of the striking face, the sole having a rearmost point;   a crown connected to a topside of the striking face, the crown having a rearmost point; and   a skirt,   wherein:
 the sole has a closing ascent angle of less than about 35 degrees, the closing ascent angle being an angle between (1) a line from the rearmost point of the sole to a sole point, of a projected silhouette of the golf club head from a toe-side viewpoint and (2) a plane intersecting the sole point and parallel to a ground plane; or 
 the crown has a closing descent angle of less than about 35 degrees, the closing descent angle being an angle between (1) a line from the rearmost point of the crown to a crown point, of the projected silhouette of the golf club head from the toe-side viewpoint, and (2) a plane intersecting the crown point and parallel to the ground plane, 
   wherein the rearmost point on the sole is an intersection point of the sole and a lower boundary of the skirt, and the rearmost point on the crown is an intersection point of the crown and an upper boundary of the skirt, and   wherein the lower boundary is a skirt height above the ground plane, and the skirt height satisfies a head-length-to-skirt-height ratio between 3:1 and 8:1.   
     
     
         8 . The metal-wood type golf club head of  claim 7 , wherein the skirt has a skirt thickness that satisfies a head-length-to-skirt-thickness ratio of less than 9:1. 
     
     
         9 . The metal-wood type golf club head of  claim 7 , wherein the sole point is located one half a front-to-back length from the club head rearmost point, as measured along the ground plane, and the crown point is located one half the front-to-back length from the club head rearmost point, as measured along the ground plane. 
     
     
         10 . The metal-wood type golf club head of  claim 9 , wherein the closing ascent angle is between 15 and 30 degrees, and the closing descent angle is between 15 and 30 degrees. 
     
     
         11 . The metal-wood type golf club head of  claim 7 , wherein the sole point is located one third a front-to-back length from the club head rearmost point, as measured along the ground plane, and the crown point is located one third the front-to-back length from the club head rearmost point, as measured along the ground plane. 
     
     
         12 . The metal-wood type golf club head of  claim 11 , wherein the closing ascent angle is less than 20 degrees, and the closing descent angle is less than 25 degrees. 
     
     
         13 . The metal-wood type golf club head of  claim 7 , wherein the closing descent angle is within 85%-115% of the closing ascent angle of the sole. 
     
     
         14 . The metal-wood type golf club head of  claim 13 , wherein the closing descent angle is within 95% to 105% of the closing ascent angle of the sole. 
     
     
         15 . A metal-wood type golf club head having improved aerodynamic properties, the golf club head having a club head frontmost point and a club head rearmost point, and the golf club head comprising:
 a striking face, the striking face defining the frontmost point;   a sole connected to a bottom side of the striking face and having a rearmost point;   a crown connected to a topside of the striking face and having a rearmost point; and   a skirt,   wherein the rearmost point on the sole is an intersection point of the sole and a lower boundary of the skirt, and the rearmost point on the crown is an intersection point of the crown and an upper boundary of the skirt, and   wherein the lower boundary is a skirt height above a ground plane, and the skirt height satisfies a head-length-to-skirt-height ratio less than 6:1.   
     
     
         16 . The metal-wood type golf club head of  claim 15 , wherein the skirt has a skirt thickness that satisfies a head-length-to-skirt-thickness ratio of 6:1 and 11:1. 
     
     
         17 . The metal-wood type golf club head of  claim 16 , wherein the skirt thickness satisfies a head-length-to-skirt-thickness ratio of 6.5:1 to 8.5:1. 
     
     
         18 . The metal-wood type golf club head of  claim 15 , wherein a club head length is greater than 4.0 inches, and the skirt height is between 12 mm to 35 mm. 
     
     
         19 . The metal-wood type golf club head of  claim 15 , wherein a club head length is greater than 4.0 inches, and the skirt has a skirt thickness between 8 mm and 20 mm. 
     
     
         20 . The metal-wood type golf club head of  claim 15 , wherein the skirt height is between 12 mm to 35 mm, and the skirt has a skirt thickness between 8 mm and 20 mm.