Muscle-back iron golf clubs with higher moment of intertia and lower center of gravity

Abstract

Disclosed herein are muscle-back iron golf clubs that have improved mass qualities to provide higher rotational moments of inertia and lower center of gravity while retaining the workability of muscle-back irons and the size, shape and dimensions preferred by tour players and low handicap players.

1 . A muscle-back iron-type golf club comprising a hosel, a hitting face and a back portion, wherein the hosel and the hitting face are made integral with each other and the hitting face has a substantially uniform thickness, and wherein the back portion is made from a material having a higher density than a material of the hosel and the hitting face and the back portion is attached to the back of the hitting face to form the golf club. 
   
   
       2 . The golf club of  claim 1 , wherein the back portion forms a muscle-back of the golf club. 
   
   
       3 . The golf club of  claim 1 , wherein the back portion defines a pocket. 
   
   
       4 . The golf club of  claim 3 , wherein the pocket is formed between the hitting face and the back portion and the pocket is interior to the golf club. 
   
   
       5 . The golf club of  claim 3 , wherein the pocket is sized and dimensioned to receive a lightweight insert having a density less than a density of the hosel and the hitting face. 
   
   
       6 . The golf club of  claim 5 , wherein the lightweight insert is positioned proximate to the geometric center of the hitting face. 
   
   
       7 . The golf club of  claim 5 , wherein the lightweight insert overlaps the geometric center of the hitting face. 
   
   
       8 . The golf club of  claim 4 , wherein the pocket is filled with a lightweight-material insert having a density less than the density of the hosel and the hitting face. 
   
   
       9 . The golf club of  claim 8 , wherein the pocket is filled with a vibration dampening material. 
   
   
       10 . The golf club of  claim 1  further comprising a post connecting the hitting face to the back portion. 
   
   
       11 . The golf club of  claim 10 , wherein the post is made integral to the hitting face and the back portion defines a hole sized to receive the post and wherein a head of the post is flattened to secure the back portion to the hitting face. 
   
   
       12 . The golf club of  claim 11  further comprising a dampening layer between the hitting face and the back portion. 
   
   
       13 . The golf club of  claim 12 , wherein the dampening layer is prestressed. 
   
   
       14 . An iron-type golf club comprising a hosel, a hitting face and a back portion, wherein the back portion comprises an upper portion and a lower muscle portion, said muscle portion being substantially thicker than the upper portion, wherein the golf club further comprises at least two heavyweight inserts having higher density than a density of the hitting face and a density of the back portion and wherein the heavyweight inserts are located on opposite sides of a vertical line through the geometric center of the hitting face. 
   
   
       15 . The golf club of  claim 14 , wherein one of the heavyweight inserts is located proximate to the shaft axis. 
   
   
       16 . The golf club of  claim 15 , wherein said heavyweight insert is a hosel collar. 
   
   
       17 . The golf club of  claim 15 , wherein said heavyweight insert is a heel insert. 
   
   
       18 . The golf club of  claim 15 , wherein one of the other heavyweight inserts is a toe insert. 
   
   
       19 . The golf club of  claim 14  further comprising a lightweight insert having a density lower than the density of the hitting face and the density of the back portion, wherein the lightweight insert is positioned within the muscle portion. 
   
   
       20 . The golf club of  claim 14  further comprising a lightweight insert having a density lower than the density of the hitting face and the density of the back portion, wherein the lightweight insert is positioned within the heel of the golf club. 
   
   
       21 . The golf club of  claim 14  further comprising a lightweight insert having a density lower than the density of the hitting face and the density of the back portion, wherein the lightweight insert is a hosel collar. 
   
   
       22 . The golf club of  claim 14  further comprising a third heavyweight insert located proximate to a crown of the golf club. 
   
   
       23 . An iron-type golf club comprising a hosel, a hitting face and a back portion, wherein the back portion comprises an upper portion and a lower muscle portion, said muscle portion being substantially thicker than the upper portion, wherein the golf club further comprises:
 at least one heavyweight insert having higher density than a density of the hitting face and the back portion and wherein the heavyweight insert is located proximate to the sole of the golf club,   at least one lightweight insert having a density lower than the density of the hitting face and the back portion and wherein the lightweight insert overlaps the geometric center of the golf club.   
   
   
       24 . A method for forging a golf club head comprising the steps of:
 a. forging a workpiece into a rough shape, so that said rough shape resembles the golf club head;   b. interrupting the forging process;   c. machining a cutout in the workpiece;   d. placing an insert in the cutout, wherein said insert is made from a material different from the material of the workpiece; and   e. working the workpiece and insert into the golf club head so that the insert is locked with the golf club head.   
   
   
       25 . The method of  claim 24 , wherein step (e) comprises additional forging. 
   
   
       26 . The method of  claim 24 , wherein step (e) comprises swaging. 
   
   
       27 . The method of  claim 24 , wherein the cutout in step (c) comprises a cavity. 
   
   
       28 . The method of  claim 24 , wherein the insert in step (d) comprises chamfered shoulders. 
   
   
       29 . The method of  claim 28 , wherein after step (e) the material of the workpiece covers the chamfered shoulders. 
   
   
       30 . The golf club of  claim 3 , wherein the back portion has a “U” shape.