Golf club head with composite face

Abstract

A novel material comprising collections of prepreg plies and a variable thickness core material such as sheet molding compound or metal, methods of forming said material, and golf clubs comprising said material are disclosed herein.

We claim: 
     
         1 . A method comprising:
 providing first and second pluralities of prepreg materials;   providing a sheet molding compound;   forming a combination material from the first and second pluralities of prepreg materials and the sheet molding compound;   shaping the combination material into a patch; and   affixing the patch to a surface of a golf club head,   wherein the combination material satisfies at least one equation selected from the group consisting of   
       
         
           
             
               
                 
                   Dxx 
                   Dyy 
                 
                 > 
                 
                   C 
                    
                   
                       
                   
                    
                   and 
                    
                   
                       
                   
                    
                   
                     Dyy 
                     Dxx 
                   
                 
                 > 
                 C 
               
               , 
             
           
         
         wherein D is the bending stiffness of the combination material, and 
         wherein C is at least 1 and is no more than 1.5. 
       
     
     
         2 . The method of  claim 1 , wherein the step of forming a combination material comprises co-molding the first and second pluralities of prepreg materials with the sheet molding compound. 
     
     
         3 . The method of  claim 1 , wherein the step of forming a combination material comprises bonding the first and second pluralities of prepreg materials to the sheet molding compound. 
     
     
         4 . The method of  claim 1 , wherein the step of forming a combination material comprises sandwiching the sheet molding compound between the first and second pluralities of prepreg materials. 
     
     
         5 . The method of  claim 1 , wherein the sheet molding compound comprises a variable thickness. 
     
     
         6 . The method of  claim 1 , wherein the step of affixing the patch to a surface of the golf club head comprises custom-molding the patch onto the surface of the golf club head. 
     
     
         7 . The method of  claim 1 , wherein the step of affixing the patch to a surface of the golf club head comprises bonding the patch onto the surface of the golf club head with an adhesive material. 
     
     
         8 . The method of  claim 1 , further comprising the step of affixing a cap to the patch after the patch is affixed to the golf club head, wherein the cap does not completely cover the patch. 
     
     
         9 . A method comprising
 providing first and second pluralities of prepreg plies;   providing a variable thickness core compound;   sandwiching the variable thickness core compound between the first and second pluralities of prepreg plies to form a combination material;   shaping the combination material into a patch; and   co-molding the patch to a surface of a golf club head,   wherein the combination material satisfies at least one equation selected from the group consisting of   
       
         
           
             
               
                 
                   Dxx 
                   Dyy 
                 
                 > 
                 
                   C 
                    
                   
                       
                   
                    
                   and 
                    
                   
                       
                   
                    
                   
                     Dyy 
                     Dxx 
                   
                 
                 > 
                 C 
               
               , 
             
           
         
         wherein D is the bending stiffness of the combination material, and 
         wherein C is at least 1 and is no more than 1.5. 
       
     
     
         10 . The method of  claim 9 , wherein the step of sandwiching the variable thickness core compound between the first and second pluralities of prepreg plies further comprises the step of co-molding the variable thickness core compound with the first and second pluralities of prepreg plies. 
     
     
         11 . The method of  claim 9 , wherein the step of sandwiching the variable thickness core compound between the first and second pluralities of prepreg plies further comprises the step of bonding the variable thickness core compound to the first and second pluralities of prepreg plies with an adhesive material. 
     
     
         12 . The method of  claim 9 , wherein the variable thickness core compound is selected from the group consisting of titanium alloy, foam, wood, and fiber reinforced polymer. 
     
     
         13 . The method of  claim 9 , wherein the variable thickness core compound comprises a honeycomb structure. 
     
     
         14 . The method of  claim 9 , wherein the step of providing a variable thickness core compound comprises a manufacturing step selected from the group consisting of casting, forging, injection molding, die casting, and machining the variable thickness core compound. 
     
     
         15 . The method of  claim 9 , further comprising the step of affixing a cap to the patch after the patch is co-molded to the surface of the golf club head, wherein the cap does not completely cover the patch.