Golf club head

Abstract

Disclosed herein is a driver-type golf club head that has a strike face. The strike face has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction. The driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at any point within the central region is less than 256 microseconds and the CT at the geometric center of the strike face is no more than five microseconds different than the initial CT value.

1 . A driver-type golf club head, comprising:
 a forward portion, comprising a strike face;   a rearward portion, opposite the forward portion;   a crown portion;   a sole portion, opposite the crown portion;   a skirt portion, positioning around a periphery of the golf club head between the sole portion and the crown portion;   a heel portion;   a toe portion, opposite the heel portion;   a hollow interior region defined by the forward portion, the rearward portion, the crown portion, the sole portion, the skirt portion, the heel portion, and the toe portion;   at least one of a crown opening, formed in the crown portion, or a sole opening, formed in the sole portion, each one of the crown opening and the sole opening is open to the hollow interior region; and   an insert covering each one of the at least one crown opening, to form part of the crown portion, and the sole opening, to form part of the sole portion, the insert is made of a non-metal material having a density between about 1 g/cm 3  and about 2 g/cm 3 ;   wherein:
 the strike face is void of through-apertures open to the hollow interior region; 
 a volume of the driver-type golf club head is between 350 cm 3  and 500 cm 3 ; 
   
     
     
         1 . A driver-type golf club head, comprising:
 a forward portion, comprising a strike face;   a rearward portion, opposite the forward portion;   a crown portion;   a sole portion, opposite the crown portion;   a skirt portion, positioning around a periphery of the golf club head between the sole portion and the crown portion;   a heel portion;   a toe portion, opposite the heel portion;   a hollow interior region defined by the forward portion, the rearward portion, the crown portion, the sole portion, the skirt portion, the heel portion, and the toe portion;   at least one of a crown opening, formed in the crown portion, or a sole opening, formed in the sole portion, each one of the crown opening and the sole opening is open to the hollow interior region; and   an insert covering each one of the at least one crown opening, to form part of the crown portion, and the sole opening, to form part of the sole portion, the insert is made of a non-metal material having a density between about 1 g/cm 3  and about 2 g/cm 3 ;   wherein:
 the strike face is void of through-apertures open to the hollow interior region; 
 a volume of the driver-type golf club head is between 350 cm 3  and 500 cm 3 ; 
 the golf club head has a center-of-gravity (CG) with an x-axis coordinate, on an x-axis of a head center face origin coordinate system of the golf club head, between-7 mm and 7 mm and a y-axis coordinate, on a y-axis of the head center face origin coordinate system of the golf club head, between 25 mm and 50 mm, and a z-axis coordinate, on a z-axis of the head center face origin coordinate system of the golf club head, less than 2 mm; 
 the strike face of the forward portion has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction; 
 a coefficient of restitution (COR), at the geometric center of the strike face, is at least 0.8; 
 a summation of a moment of inertia of the golf club head about a z-axis of a head center-of-gravity coordinate system (I ZZ ) and a moment of inertia of the golf club head about an x-axis of the head center-of-gravity coordinate system (I XX ) is between about 700 kg mm 2  and about 1,100 kg mm 2 ; 
 the CT of the strike face, within the central region, is no more than 257 microseconds; 
 before the strike face impacts a golf ball, a characteristic time (CT) of the strike face, at the geometric center of the strike face, has an initial CT value of at least 237 microseconds; and 
 the driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at the geometric center of the strike face is no more than five microseconds different than the initial CT value. 
   
     
     
         2 . The driver-type golf club head according to  claim 1 , wherein the CT of the strike face, within the central region, is no more than 251 microseconds. 
     
     
         3 . The driver-type golf club head according to  claim 2 , wherein the CT of the strike face, within the central region, is no more than 245 microseconds. 
     
     
         4 . The driver-type golf club head according to  claim 1 , wherein the initial CT value is at least 242 microseconds. 
     
     
         5 . The driver-type golf club head according to  claim 4 , wherein the initial CT value is at least 245 microseconds. 
     
     
         6 . The driver-type golf club head according to  claim 1 , wherein the initial CT value is at least 239 and the CT of the strike face, within the central region, is no more than 245 microseconds. 
     
     
         7 . The driver-type golf club head according to  claim 1 , wherein the CT of the strike face, within the central region, is no more than between 3 microseconds and 5 microseconds more than the initial CT value. 
     
     
         8 . The driver-type golf club head according to  claim 1 , wherein the CT of the strike face, within the central region, is no more than between 1% and 2% greater than the initial CT value. 
     
     
         9 . The driver-type golf club head according to  claim 1 , wherein the driver-type golf club head is configured such that after 500 impacts of the standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at any point within the central region is less than 245 microseconds. 
     
     
         10 . The driver-type golf club head according to  claim 1 , wherein the COR, at the geometric center of the strike face, is at least 0.81. 
     
     
         11 . The driver-type golf club head according to  claim 1 , wherein the COR of the strike face, within a surface area of the strike face of at least 200 mm 2 , is at least 0.79. 
     
     
         12 . The driver-type golf club head according to  claim 11 , wherein the COR of the strike face, within a surface area of the strike face of at least 250 mm 2 , is at least 0.79. 
     
     
         13 . The driver-type golf club head according to  claim 1 , wherein the COR is at least 0.8 for at least 25% of the strike face within the central region. 
     
     
         14 . The driver-type golf club head according to  claim 1 , wherein the driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at the geometric center of the strike face is no more than three microseconds different than the initial CT value. 
     
     
         15 . The driver-type golf club head according to  claim 1 , wherein the strake face is made of a fiber-reinforced polymer. 
     
     
         16 . A driver-type golf club head, comprising:
 a forward portion, comprising a strike face made of a fiber-reinforced polymer;   a rearward portion, opposite the forward portion;   a crown portion;   a sole portion, opposite the crown portion;   a skirt portion, positioning around a periphery of the golf club head between the sole portion and the crown portion;   a heel portion;   a toe portion, opposite the heel portion;   a hollow interior region defined by the forward portion, the rearward portion, the crown portion, the sole portion, the skirt portion, the heel portion, and the toe portion;   at least one of a crown opening, formed in the crown portion, or a sole opening, formed in the sole portion, each one of the crown opening and the sole opening is open to the hollow interior region; and   an insert covering each one of the at least one crown opening, to form part of the crown portion, and the sole opening, to form part of the sole portion, the insert is made of a non-metal material having a density between about 1 g/cm 3  and about 2 g/cm 3 ;   wherein:
 the strike face is void of through-apertures open to the hollow interior region; 
 a volume of the driver-type golf club head is between 350 cm 3  and 500 cm 3 ; 
 the golf club head has a center-of-gravity (CG) with an x-axis coordinate, on an x-axis of a head center face origin coordinate system of the golf club head, between-7 mm and 7 mm and a y-axis coordinate, on a y-axis of the head center face origin coordinate system of the golf club head, between 25 mm and 50 mm, and a z-axis coordinate, on a z-axis of the head center face origin coordinate system of the golf club head, less than 2 mm; 
 the strike face of the forward portion has a central region, defined by a 40 mm by 20 mm rectangular area centered on a geometric center of the strike face and elongated in a heel-to-toe direction; 
 a coefficient of restitution (COR), at the geometric center of the strike face, is at least 0.8; 
 a summation of a moment of inertia of the golf club head about a z-axis of a head center-of-gravity coordinate system (I ZZ ) and a moment of inertia of the golf club head about an x-axis of the head center-of-gravity coordinate system (I XX ) is between about 740 kg mm 2  and about 1,100 kg·mm 2 ; 
 the CT of the strike face, within the central region, is no more than 257 microseconds; 
 before the strike face impacts a golf ball, a characteristic time (CT) of the strike face, at the geometric center of the strike face, has an initial CT value of at least 237 microseconds; and 
 the driver-type golf club head is configured such that after 500 impacts of a standard golf ball at the geometric center of the strike face, where at each impact the standard golf ball has a velocity of 52 meters per second, the CT of the strike face at the geometric center of the strike face is no more than three microseconds different than the initial CT value. 
   
     
     
         17 . The driver-type golf club head according to  claim 16 , wherein the initial CT value is at least 245 microseconds. 
     
     
         18 . The driver-type golf club head according to  claim 16 , wherein the initial CT value is no more than 245 microseconds. 
     
     
         19 . The driver-type golf club head according to  claim 16 , wherein the CT of the strike face, within the central region, is no more than 251 microseconds. 
     
     
         20 . The driver-type golf club head according to  claim 19 , wherein the CT of the strike face, within the central region, is no more than 245 microseconds. 
     
     
         21 - 22 . (canceled)