Multi-stage forging process

Abstract

An iron-type golf club head with a cavity formed via a multi-stage forging process. The forged iron-type golf club head is formed from a single billet of material. An intermediate step of the multi-stage forging process creates a cavity in the iron-type golf club head which can receive an insert. The resultant iron-type golf club head has a substantially lower center of gravity and higher moment of inertia when compared to a traditionally forged iron-type golf club head lacking a cavity. Additionally, the resultant iron-type golf club head has a more solid feel than a traditionally cast iron-type golf club head as a result of the tighter grain structure the forging process yields.

What is claimed is: 
     
         1 . A forged golf club head, comprising:
 a top rail, a sole opposite the top rail, a hosel, a toe region, a heel region opposite the toe region, a rear portion, and a strike face, wherein:
 the rear portion comprises an upper edge and a nonlinear periphery; 
 the strike face comprises an upper region and a lower region divided by an intersection plane; 
 the intersection plane is perpendicular to the lower region;
 wherein the strike face is formed at a clearance angle, 
 the clearance angle is measured from the upper region to the intersection plane; 
 the clearance angle is between 5° and 35°; 
 wherein forged golf club head further comprises a cavity in the rear portion formed by means of hot-pressing; and 
 wherein the strike face is bent by means of forging to a final angle that is between 88° and 92° such that the strike face forms a substantially planar surface arranged for impacting a golf ball. 
 
   
     
     
         2 . The forged golf club head of  claim 1 , wherein the intersection plane intersects the forged golf club head at 40-50% of a height of the forged golf club head, and wherein the height of the forged golf club head is measured from the sole to the top rail. 
     
     
         3 . The forged golf club head of  claim 1 , wherein the cavity formed by hot-pressing comprises a volume ranging inclusively between 0.2 in 3  to 0.4 in 3 . 
     
     
         4 . The forged golf club head of  claim 1 , further comprising an insert within the cavity. 
     
     
         5 . The forged golf club head of  claim 1 , wherein the cavity further comprises an upper width and a lower width, measured from a rear of the strike face to the rear portion, in which the upper width and lower width are not equal. 
     
     
         6 . The forged golf club head of  claim 4 , wherein the insert comprises a density ranging inclusively between 1.0 g/cc and 20.0 g/cc. 
     
     
         7 . The forged golf club head of  claim 4 , wherein the insert comprises a mass ranging inclusively between 1.0 g and 30.0 g. 
     
     
         8 . The forged golf club head of  claim 4 , wherein a percentage of the cavity that is occupied by the insert ranges inclusively between 95% to 100%. 
     
     
         9 . The forged golf club head of  claim 5 , wherein the upper width ranges inclusively between 1.2 mm and 12.7 mm and the lower width ranges inclusively between 1.2 mm and 10.2 mm. 
     
     
         10 . The forged golf club head of  claim 1 , wherein the forged golf club head is formed from a singular solid billet. 
     
     
         11 . The forged golf club head of  claim 10 , wherein the singular solid billet comprises one or more of the following metals: 8620 alloy steel, S25C steel, carbon steel, maraging steel, stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, or any metal suitable for forging. 
     
     
         12 . The forged golf club head of  claim 10 , wherein the singular solid billet comprises two or more of the following metals: 8620 alloy steel, S25C steel, carbon steel, maraging steel, stainless steel, stainless steel alloy, tungsten, aluminum, aluminum alloy, or any metal suitable for forging. 
     
     
         13 . The forged golf club head of  claim 10 , wherein the singular solid billet comprises two or more metals, wherein at least one of the metals is 8620 alloy steel and at least one of the metals is tungsten. 
     
     
         14 . The forged golf club head of  claim 5 , wherein upper width is greater than the lower width. 
     
     
         15 . A golf club head forged from a single solid billet, the golf club head comprising a top rail, a heel region, a toe region, a sole opposite the top rail, a strike face, and a rear surface opposite the strike face,
 the strike face further comprising an upper region and a lower region divided by an intersection plane, the intersection plane being perpendicular to the lower region;   wherein the strike face is forged with a clearance angle measured between the upper region and the intersection plane;
 wherein the clearance angle is between 5° and 35°; 
 wherein a cavity is hot-pressed within a lower rear portion of the rear surface; 
 wherein the strike face is bent to a final angle; 
 wherein the final angle forms a substantially planar surface across the upper region and lower region of the strike face arranged for impacting a golf ball. 
   
     
     
         16 . The forged golf club head of  claim 15 , wherein the intersection plane intersects the forged golf club head at 40-50% of a height of the forged golf club head, and wherein the height of the forged golf club head is measured from the sole to the top rail. 
     
     
         17 . The forged golf club head of  claim 15 , wherein the cavity formed by hot-pressing comprises a volume ranging inclusively between 0.2 in 3  to 0.4 in 3 . 
     
     
         18 . The forged golf club head of  claim 15 , further comprising an insert within the cavity. 
     
     
         19 . The forged golf club head of  claim 18 , wherein the insert comprises a density ranging inclusively between 1.0 g/cc and 20.0 g/cc. 
     
     
         20 . The forged golf club head of  claim 18 , wherein the insert comprises a mass ranging inclusively between 1.0 g and 30.0 g.