Golf iron

Abstract

A golf club head includes a front surface, a rear surface, a sole, a top edge, a hosel, and a muscle back portion. The front surface defines a strike face. The rear surface is opposite the front surface. The muscle back portion is interposed between the front surface and the rear surface and defines a cavity disposed in the muscle back portion. An elastomer can at least partially fill the cavity.

1 . (Canceled).  
   
   
       2 . (Canceled).  
   
   
       3 . (Canceled).  
   
   
       4 . (Canceled).  
   
   
       5 . (Canceled).  
   
   
       6 . The golf club of  claim 20 , wherein the muscle back surface includes an upper ledge that generally follows the contour of the top edge.  
   
   
       7 . The golf club head of  claim 20 , wherein the cavity is vertically spaced from the sole.  
   
   
       8 . (Canceled).  
   
   
       9 . The golf club head of  claim 20 , wherein the elastomer comprises a polyurethane elastomer.  
   
   
       10 . The golf club head of  claim 20 , wherein the muscle back portion covers at least half of the surface area of the rear surface.  
   
   
       11 . (Canceled).  
   
   
       12 . (Canceled).  
   
   
       13 . (Canceled).  
   
   
       14 . A golf club comprising: 
 a shaft; and    a muscle back iron golf club head attached to the shaft, wherein the muscle back iron golf club head includes a face and back, the back having an upper portion substantially parallel to the face and an extra mass portion positioned toward the bottom of the club head, wherein the extra mass portion defines a cavity therein and the cavity is at least substantially entirely enclosed by the club head.    
   
   
       15 . (Canceled).  
   
   
       16 . The golf club of  claim 14 , further comprising a high rebound elastomer disposed in the cavity.  
   
   
       17 . The golf club of  claim 14 , wherein a substantial portion of the extra mass portion is positioned below the cavity.  
   
   
       18 . The golf club of  claim 14 , further comprising a high rebound elastomer at least substantially filling the cavity.  
   
   
       19 . The golf club of  claim 14 , wherein the cavity has a width in cross-section that is slightly less than a width of the club head measured along the same line.  
   
   
       20 . A golf club head comprising: 
 a sole;    a top edge opposite the sole;    a hosel;    a front surface defining a strike face;    a rear surface opposite the front surface, the rear surface including a blade surface and a muscle back surface, the blade surface being near the top edge and substantially parallel to the front surface, the muscle back surface being near the sole; and    a muscle back portion interposed between the front surface and the muscle back surface and defining a cavity disposed in the muscle back portion, wherein the cavity is not visible from the exterior of the golf club.    
   
   
       21 . The golf club head of  claim 20 , further comprising an elastomer material at least substantially filling the cavity, wherein the elastomer material has a specific gravity less than the material displaced by the cavity.  
   
   
       22 . A golf club head comprising: 
 a sole;    a top edge;    a hosel;    a front surface defining a strike face;    a rear surface opposite the front surface, the rear surface including an at least substantially flat blade surface and a contoured muscle back surface, the blade surface extending to the top edge and the muscle back surface being near the sole; and    a muscle back portion interposed between the front surface and the muscle back surface and defining a cavity disposed in the muscle back portion, wherein the cavity is not visible from the exterior of the golf club.    
   
   
       23 . The golf club head of  claim 22 , wherein the blade surface is at least substantially parallel to the front surface.  
   
   
       24 . The golf club head of  claim 22 , further comprising an insert disposed in the cavity.  
   
   
       25 . The golf club head of  claim 24 , wherein the insert comprises a high-rebound material.  
   
   
       26 . The golf club head of  claim 24 , wherein the insert comprises a liquid, a foam or a compressible material.