Golf club with cellular mass distribution

Abstract

The invention relates to golf club heads with improved mass distribution provided by novel cellular features. Because a club head can have very low mass density in certain parts, the club head can have much more mass in other parts, while keeping the overall club head mass equal to the mass of prior art club heads. A club head can be provided with optimized MOI and CG. The novel cellular structures of invention provide extensible functionality in the form of pockets, recesses, and windows and provide materials with excellent strength and restitution properties.

What is claimed is: 
     
         1 . A golf club head comprising:
 a body with a toe side, a heel side, a sole portion, and a top portion;   a hosel extending from the heel side;   a ball striking face member supported by the main body; and   a channel in a surface of the sole and adjacent to a back surface of the face member.   
     
     
         2 . The golf club head of  claim 1 , wherein the channel comprises a semi-circular cross-section. 
     
     
         3 . The golf club head of  claim 1 , wherein the channel extends from heel to toe. 
     
     
         4 . The golf club head of  claim 1 , wherein the channel is in an upward-facing, inner surface of the sole. 
     
     
         5 . The golf club head of  claim 1 , wherein the channel comprises a maximum cross-sectional dimension between about 0.5 mm and about 4 mm. 
     
     
         6 . The golf club head of  claim 1 , wherein the ball striking face member is a face insert comprising a first material and the body comprises a second material. 
     
     
         7 . The golf club head of  claim 6 , wherein the club head comprises one more recesses into a back side of the body. 
     
     
         8 . The golf club head of  claim 7 , wherein the club head includes a set of inserts of varying densities dimensioned to fit into the recesses. 
     
     
         9 . The golf club head of  claim 1 , wherein the club head is an iron-type club head. 
     
     
         10 . The golf club head of  claim 9 , wherein peak face stress levels in finite element analysis are 1069 MPa. 
     
     
         11 . The golf club head of  claim 9 , wherein a coefficient of restitution of the ball striking face is 0.804. 
     
     
         12 . The golf club head of  claim 9 , further comprising a loft of 21 degrees. 
     
     
         13 . The golf club head of  claim 9 , wherein the channel in the surface of the sole causes the thickness of the iron directly behind the ball-striking face to be reduced relative a hypothetical iron with no such channel. 
     
     
         14 . The golf club head of  claim 9 , wherein the channel defines a non-flat groove. 
     
     
         15 . The golf club head of  claim 9 , wherein the channel defines a curved groove. 
     
     
         16 . The golf club head of  claim 9 , wherein, when the club head impacts a golf ball, the ball-striking face flexes inward and the iron body rotates counter clockwise, from a toe-side perspective. 
     
     
         17 . The golf club head of  claim 9 , wherein the channel extends from heel to toe. 
     
     
         18 . The golf club head of  claim 9 , wherein the channel is in an upward-facing, inner surface of the sole. 
     
     
         19 . The golf club head of  claim 9 , wherein the channel comprises a maximum cross-sectional dimension between about 0.5 mm and about 4 mm. 
     
     
         20 . The golf club head of  claim 9 , wherein the ball striking face member is a face insert comprising a first material and the body comprises a second material.