Multi-material golf club head

Abstract

A multi-material golf club head having an improved performance is disclosed. More specifically, the present invention relates to a multi-material golf club head having a metallic frontal portion and a lightweight aft portion with an addition of an internal ribbon support member. The lightweight aft portion could be formed of a multi-layered sandwich material with at least one layer having low damping properties. The lightweight aft portion may be formed out of a lightweight crown sub-shell and a lightweight sole sub-shell, both of which combine to receive a weighting system.

What is claimed is: 
     
         1 . A golf club head comprising:
 a frontal striking face portion located at a frontal portion of said golf club head having a return;
 wherein said return further comprises a rear facing engagement portion having an external bonding lip, 
   an aft body portion, attached to the rear of said striking face portion;
 wherein said aft body further comprises a front facing engagement portion having an internal molded step, 
 wherein said internal molded step further comprises a shelf, 
 wherein said internal molded step compliments said external bonding lip to form an engagement angle, 
   wherein rearmost end of said external bonding lip engages said shelf to connected said aft bod to said frontal striking face portion,   wherein said engagement angle is the same at a crown portion of said golf club head as at a sole portion of said golf club head, relative to an insertion axis, and   
       wherein said insertion axis is offset from a ground plane by an insertion angle θ of between about 0.5 degrees to about 3.5 degrees. 
     
     
         2 . The golf club head of  claim 1 , wherein said insertion angle is between about 1.5 degree to about 2.5 degrees. 
     
     
         3 . The golf club head of  claim 2 , wherein said insertion angle is about 2.0 degrees. 
     
     
         4 . The golf club head of  claim 1 , wherein said engagement angle, relative to said insertion axis, is between about 8 degrees to about 14 degrees. 
     
     
         5 . The golf club head of  claim 4 , wherein said engagement angle, relative to said insertion axis, is between about 10 degrees to about 12 degrees. 
     
     
         6 . The golf club head of  claim 5 , wherein said engagement angle, relative to said insertion axis, is about 11 degrees. 
     
     
         7 . A golf club head comprising:
 a frontal striking face portion located at a frontal portion of said golf club head having a return;
 wherein said return further comprises a rear facing engagement portion having an external bonding lip, 
   an aft body portion, attached to the rear of said striking face portion;
 wherein said aft body further comprises a front facing engagement portion having an internal molded step, 
 wherein said internal molded step further comprises a shelf, 
 wherein said internal molded step compliments said external bonding lip to form an engagement angle, 
   wherein rearmost end of said external bonding lip engages said shelf to connected said aft bod to said frontal striking face portion,   wherein said engagement angle is the different at a crown portion of said golf club head and at a sole portion of said golf club head, relative to a ground plane.   
     
     
         8 . The golf club head of  claim 7 , wherein a difference between a crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is between about 1 degree to about 13 degrees. 
     
     
         9 . The golf club head of  claim 8 , wherein said difference between said crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is between about 2 degrees to about 6 degrees. 
     
     
         10 . The golf club head of  claim 9 , wherein said difference between said crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is about 4 degrees. 
     
     
         11 . The golf club head of  claim 7 , wherein said crown engagement angle β′, relative to said ground plane, is between about 4.5 degrees to about 13.5 degrees; and said sole engagement angle γ′, relative to said ground plane, is between 8.5 degree to about 17.5 degrees. 
     
     
         12 . The golf club head of  claim 11 , wherein said crown engagement angle β′, relative to said ground plane, is between about 7.5 degrees to about 10.5 degrees; and said sole engagement angle γ′, relative to said ground plane, is between 11.5 degree to about 14.5 degrees. 
     
     
         13 . The golf club head of  claim 12 , wherein said crown engagement angle β′, relative to said ground plane, is about 9 degrees; and said sole engagement angle γ′, relative to said ground plane, is 13 degrees. 
     
     
         14 . A golf club head comprising:
 a frontal striking face portion located at a frontal portion of said golf club head having a return;
 wherein said return further comprises a rear facing engagement portion having an external bonding lip, 
   an aft body portion, attached to the rear of said striking face portion;
 wherein said aft body further comprises a front facing engagement portion having an internal molded step, 
 wherein said internal molded step further comprises a shelf, 
 wherein said internal molded step compliments said external bonding lip to form an engagement angle, 
   wherein said aft body portion further comprises a lightweight shell,
 wherein said lightweight shell further comprises,
 a lightweight crown sub-shell, and 
 a lightweight sole sub-shell, 
 wherein a said lightweight crown sub-shell and said lightweight sole sub-shell are joined together via a lap joint, and 
 wherein said lap joint is located away from a skirt portion of said golf club head 
 
   wherein rearmost end of said external bonding lip engages said shelf to connected said aft bod to said frontal striking face portion,   wherein said engagement angle is the different at a crown portion of said golf club head and at a sole portion of said golf club head, relative to a ground plane.   
     
     
         15 . The golf club head of  claim 14 , wherein a difference between a crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is between about 1 degree to about 13 degrees. 
     
     
         16 . The golf club head of  claim 15 , wherein said difference between said crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is between about 2 degrees to about 6 degrees. 
     
     
         17 . The golf club head of  claim 16 , wherein said difference between said crown engagement angle β′ and a sole engagement angle γ′, both relative to said ground plane, is about 4 degrees. 
     
     
         18 . The golf club head of  claim 14 , wherein said crown engagement angle β′, relative to said ground plane, is between about 4.5 degrees to about 13.5 degrees; and said sole engagement angle γ′, relative to said ground plane, is between 8.5 degree to about 17.5 degrees. 
     
     
         19 . The golf club head of  claim 18 , wherein said crown engagement angle β′, relative to said ground plane, is between about 7.5 degrees to about 10.5 degrees; and said sole engagement angle γ′, relative to said ground plane, is between 11.5 degree to about 14.5 degrees. 
     
     
         20 . The golf club head of  claim 19 , wherein said crown engagement angle β′, relative to said ground plane, is about 9 degrees; and said sole engagement angle γ′, relative to said ground plane, is 13 degrees.