Golf club heads with improved sound characteristics

Abstract

Golf club heads with improved sound can be provided by reducing or eliminating acoustic resonances of a club face at frequencies less than about 3.8 kHz. Club head resonance frequencies can be determined based on spectral analysis of an acoustic signal associated with a club/ball impact. Club head vibrational amplitudes at one or more selected frequencies are associated with a particular club surface (crown, face, or sole) and this surface is adjusted to attenuate or eliminate an undesired resonance.

1 . A golf club comprising:
 a golf club head with a body having a front portion, a crown portion, a sole portion, and a hosel portion, the body comprised of a first material;   a face portion comprising a second material and being attached to the front portion of the body, the face portion having a face size surface area defined by an a front wall extended surface that is offset by a distance of 0.5 mm towards a center of the head in a direction along an axis that is parallel to a face surface normal vector at the center of the face;   a coefficient of restitution greater than 0.80 and a characteristic time greater than 220 μs;   a face frequency greater than 3.8 kHz, wherein the face size surface area is at least 4,500 mm 2 .   
     
     
         2 . The golf club of  claim 1 , wherein the face size surface area is at least 5,000 mm 2 . 
     
     
         3 . The golf club of  claim 1 , wherein the first material is a metallic material. 
     
     
         4 . The golf club of  claim 3 , wherein the second material is a composite material. 
     
     
         5 . The golf club of  claim 4 , wherein the face portion includes a first metallic material, the first material and the second material being located within the face size surface area. 
     
     
         6 . The golf club of  claim 1 , wherein a peak un-weighted acoustic amplitude of the club head is less than 114 dB, a peak A-weighted sound pressure level of the club head is less than 5 Pa, and a loudness of the club head is less than 240 sones upon striking a golf ball at about 110 mph, measured by a microphone positioned at 64 inches above the golf ball. 
     
     
         7 . The golf club of  claim 1 , wherein the crown portion is a metallic material. 
     
     
         8 . The golf club of  claim 7 , wherein the body is a metallic material. 
     
     
         9 . The golf club of  claim 1 , wherein the golf club has a head volume between 400 cc to about 475 cc. 
     
     
         10 . The golf club of  claim 1 , wherein the face size surface area is between 5,000 mm 2  and 7,000 mm 2  and a loudness of the club head at impact at 110 mph with a golf ball, as measured by a microphone positioned at 64 inches above the golf ball, is less than a linear expression, where y is a sones variable and x is a face size variable, where
     y= 0.0267 x+ 81.667.   
     
     
         11 . The golf club of  claim 1 , wherein the face size surface area is between 5,000 mm 2  and 7,000 mm 2  and a face frequency is less than 4,800 Hz and greater than a linear expression, where y is a face frequency variable and x is a face size variable, where
     y=− 0.44 x+ 6300.   
     
     
         12 . The golf club of  claim 1 , wherein the face size surface area is between 5,000 mm 2  and 7,000 mm 2  and an acoustic amplitude of the club head at impact at 110 mph with a golf ball, as measured by a microphone positioned at 64 inches above the golf ball, is less than a linear expression, where y is a acoustic amplitude un-weighted signal variable and x is a face size variable, where
     y= 0.0005 x+ 110.   
     
     
         13 . The golf club of  claim 6 , wherein a maximum distance of any impact location away from the center-face of the club was 11 mm as measured from a geometric center face of the club to a center point of the impact location. 
     
     
         14 . A golf club head comprising:
 a body having a front portion, a crown portion, a sole portion, and a hosel portion;   a face portion being attached to the front portion of the body, the face portion having a face size surface area, wherein the face size surface area is at least 4,500 mm 2 ;   a coefficient of restitution greater than 0.80 and a characteristic time greater than 220 μs;   a peak un-weighted acoustic amplitude of the club head at impact is less than 114 dB when striking a golf ball at about 110 mph, measured by a microphone positioned at 64 inches above the golf ball.   
     
     
         15 . The golf club of  claim 14 , wherein the face portion is a composite material. 
     
     
         16 . The golf club of  claim 14 , wherein a face frequency is greater than 3.8 kHz. 
     
     
         17 . The golf club of  claim 16 , wherein a peak un-weighted acoustic amplitude of the club head is less than 113 dB, a peak A-weighted sound pressure level of the club head is less than 5 Pa, and a loudness of the club head is less than 240 sones upon striking a golf ball at about 110 mph, measured by a microphone positioned at 64 inches above the golf ball. 
     
     
         18 . A golf club head comprising:
 a body having a front portion, a crown portion, a sole portion, and a hosel portion;   a composite face insert being attached to a front portion of the body, the front portion having a face size surface area, wherein the face size surface area is at least 4,500 mm 2 ;   a coefficient of restitution greater than 0.80 and a characteristic time greater than 220 μs;   a peak un-weighted acoustic amplitude of the club head is less than 114 dB, a peak A-weighted sound pressure level of the club head is less than 5 Pa, and a loudness of the club head is less than 240 sones upon striking a golf ball at about 110 mph, measured by a microphone positioned at 64 inches above the golf ball.   
     
     
         19 . The golf club of  claim 18 , wherein the face size surface area is between 5,000 mm 2  and 7,000 mm 2 . 
     
     
         20 . The golf club of  claim 19 , wherein at least the crown portion is a metallic material.