Golf club head

Abstract

Disclosed herein is a golf club head that comprises a strike face. The strike face has a central region, defined by a forty millimeter by twenty millimeter rectangular area centered on a center of the strike face and elongated in a heel-to-toe direction. Within the central region, the strike face has a characteristic time (CT) of no more than 257 microseconds. Within the central region, no less than 25% of the strike face has a coefficient of restitution (COR) of at least 0.8. Within the central region, no less than 60% of the strike face has a CT of at least 235 microseconds. Within the central region, no less than 35% of the strike face has a CT of at least 240 microseconds.

1 . A golf club head, comprising:
 a body, defining an interior cavity and comprising:
 a sole portion, positioned at a bottom region of the golf club head, the sole portion having a sole surface area; 
 a crown portion, positioned at a top region of the golf club head, the crown portion having a crown surface area; 
 a skirt portion, positioned around a periphery of the golf club head between the sole portion and the crown portion; 
 a forward region; 
 a rearward region, opposite the forward region; 
 a heel region; and 
 a toe region, opposite the heel region; 
   a face portion, coupled to the body, at the forward region of the body, and comprising a strike face and an interior surface, opposite the strike face; and   a stiffener located within the interior cavity of the body and in direct contact with the interior surface of the face portion, wherein the stiffener is made of a material having a hardness of at least Shore 5.95D;   wherein:
 an areal weight of the crown portion of the golf club head is less than about 0.35 g/cm 2  over more than about 50% of an entire surface area of the crown portion; 
 the golf club head has a center of gravity (CG) with a head center face origin x-axis coordinate between about −5 mm and about 5 mm and a head center face origin y-axis coordinate between about 25 mm and about 50 mm, and a center face head origin z-axis coordinate less than 2 mm; 
 the strike face has a central region, defined by a forty millimeter by twenty millimeter rectangular area centered on a center of the strike face and elongated in a heel-to-toe direction; 
 the face portion has a thickness that varies; 
 within the central region, the face portion has a maximum face thickness no more than 4.5 mm and a minimum face thickness no less than 2.0 mm; 
 within the central region, the strike face has a characteristic time (CT) of no more than 257 microseconds; 
 within the central region, no less than 25% of the strike face has a coefficient of restitution (COR) of at least 0.8; 
 within the central region, no less than 60% of the strike face has a CT of at least 235 microseconds; 
 within the central region, no less than 35% of the strike face has a CT of at least 240 microseconds; 
 the golf club head has a volume between about 350 cm 3  and about 500 cm 3 , a moment of inertia about a head center of gravity z-axis (Izz), and a moment of inertia about a head center of gravity x-axis (Ixx); and 
 a summation of Izz and Ixx is between about 740 kg·mm 2  and about 1100 kg·mm 2 . 
   
     
     
         2 . The golf club head according to  claim 1 , wherein more than 20% of the strike face has a CT of at least 245 microseconds. 
     
     
         3 . The golf club head according to  claim 1 , wherein, within the central region, no less than 50% of the strike face has a COR of at least 0.8. 
     
     
         4 . The golf club head according to  claim 3 , wherein, within the central region, no less than 55% of the strike face has a COR of at least 0.8. 
     
     
         5 . The golf club head according to  claim 4 , wherein, within the central region, no less than 68% of the strike face has a COR of at least 0.8. 
     
     
         6 . The golf club head according to  claim 1 , wherein at least a portion of the crown portion is made of a non-metallic composite material. 
     
     
         7 . The golf club head according to  claim 1 , wherein the crown portion is made of a metal alloy. 
     
     
         8 . The golf club head according to  claim 1 , wherein an areal weight of the sole portion of the golf club head is less than about 0.35 g/cm 2  over more than about 50% of an entire surface area of the sole portion. 
     
     
         9 . The golf club head according to  claim 1 , wherein the body and the face portion form a one-piece, unitary, monolithic construction. 
     
     
         10 . The golf club head according to  claim 1 , wherein the face portion comprises a face opening and a strike plate welded to the face opening. 
     
     
         11 . The golf club head according to  claim 1 , wherein the summation of Izz and Ixx is greater than about 790 kg·mm 2 . 
     
     
         12 . The golf club head according to  claim 1 , wherein the summation of Izz and Ixx is greater than about 805 kg·mm 2 . 
     
     
         13 . The golf club head according to  claim 1 , wherein Ixx is no less than 305 kg·mm 2 . 
     
     
         14 . The golf club head according to  claim 1 , wherein Ixx is no less than 320 kg·mm 2 . 
     
     
         15 . The golf club head according to  claim 1 , wherein Ixx is no less than 350 kg·mm 2 . 
     
     
         16 . The golf club head according to  claim 1 , wherein at least 60% of the strike face within the central region has a CT of at least 240 microseconds. 
     
     
         17 . The golf club head according to  claim 16 , wherein at least 70% of the strike face within the central region has a CT of at least 240 microseconds. 
     
     
         18 . The golf club head according to  claim 1 , wherein at least 40% of the strike face within the central region has a CT of at least 245 microseconds. 
     
     
         19 . The golf club head according to  claim 18 , wherein at least 50% of the strike face within the central region has a CT of at least 245 microseconds. 
     
     
         20 . The golf club head according to  claim 1 , wherein at least 10% of the strike face within the central region has a CT of at least 250 microseconds. 
     
     
         21 - 61 . (canceled)