Golf club heads with inserts under compressive stress

Abstract

The present invention provides golf club heads, such as putter heads, with inserts that are under compressive stress, as well as methods for making such golf club heads. In preferred embodiments, the inserts are composed of low density material, such as granite, in order to help maximize the moment of inertia (MOI) of the golf club head.

1 . An article comprising a golf club head, wherein said golf club head comprises: i) a body component comprising an insert recess, and ii) an insert component seated in said insert recess, wherein said insert component is under compressive stress.  
     
     
         2 . The article of  claim 1 , wherein said insert component has a density of less than 4.0 grams/cm 3 .  
     
     
         3 . The article of  claim 1 , wherein said insert component has a hardness of at least 5.0 on Mohs hardness scale.  
     
     
         4 . The article of  claim 1 , wherein said golf club head is configured for striking a golf ball.  
     
     
         5 . The article of  claim 1 , wherein said golf club head is attached to a golf shaft.  
     
     
         6 . The article of  claim 5 , wherein said golf club head has a Moment of Inertia (MOI) about the shaft axis of at least 40.0 oz-in 2 .  
     
     
         7 . The article of  claim 1 , wherein said insert component comprises stone, glass, or ceramic.  
     
     
         8 . The article of  claim 7 , wherein said stone comprises granite.  
     
     
         9 . The article of  claim 1 , wherein said body component further comprises a hosel.  
     
     
         10 . The article of  claim 1 , wherein said compressive stress is exerted by at least a portion of said body component.  
     
     
         11 . The article of  claim 1 , wherein at least a portion of said body component is under tensile stress.  
     
     
         12 . The article of  claim 11 , wherein said tensile stress is exerted by said insert component.  
     
     
         13 . A method of making a golf club head comprising; 
 a) providing; 
 i) a body component comprising an insert recess; and  
 ii) an insert component, and  
   b) heating said body component, cooling said insert component, or both heating said body component and cooling said insert component; and    c) generating a golf club head by seating said insert component in said insert recess of said body component such that said insert component is under compressive stress upon: i) cooling of said body component; ii) warming of said insert component; or iii) cooling of said body component and warming of said insert component.    
     
     
         14 . The method of  claim 13 , wherein said insert component is between 0.0001 and 0.05 inches wider than said insert recess when both said body component and said insert component are at room temperature.  
     
     
         15 . The method of  claim 13 , wherein said insert component is between 0.0005 and 0.03 inches wider than said insert recess when both said body component and said insert component are at room temperature.  
     
     
         16 . The method of  claim 13 , wherein said insert component is between 0.002 and 0.02 inches wider than said insert recess when both said body component and said insert component are at room temperature.  
     
     
         17 . A system comprising; 
 a) a body component comprising an insert recess, and    b) an insert component, wherein said insert component is between 0.0001 and 0.05 inches wider than said insert recess.    
     
     
         18 . The system of  claim 17 , wherein said insert recess is configured to accept said insert component while at an elevated temperature such that a golf club head is generated.  
     
     
         19 . The system of  claim 17 , wherein said insert component has a density of less than 4.0 grams/cm 3 .  
     
     
         20 . The system of  claim 17 , wherein said insert component has a hardness of at least 5.0 on Mohs hardness scale.