Golf club head having a stress reducing feature with aperture

Abstract

A golf club incorporating a stress reducing feature, including an aperture, located at least partially on the sole of the club head. The location and size of the stress reducing feature and aperture, and their relationship to one another, play a significant role in selectively improving the performance of the golf club.

We claim: 
     
         1 . A golf club having a stress reducing feature with aperture comprising:
 (A) a shaft ( 200 ) having a proximal end ( 210 ) and a distal end ( 220 );   (B) a grip ( 300 ) attached to the shaft proximal end ( 210 ); and   (C) a golf club head ( 400 ) attached to the shaft distal end ( 220 ) and having:
 (i) a face ( 500 ) positioned at a front portion ( 402 ) of the golf club head ( 400 ) where the golf club head ( 400 ) impacts a golf ball, wherein the face ( 400 ) includes a top edge height (TEH), a lower edge height (LEH), and a face height that is the difference between the maximum top edge height (TEH) and the minimum lower edge height (LEH); 
 (ii) a sole ( 700 ) positioned at a bottom portion of the golf club head ( 400 ); 
 (iii) a crown ( 600 ) positioned at a top portion of the golf club head ( 400 ); 
 (iv) a skirt ( 800 ) positioned around a portion of a periphery of the golf club head ( 400 ) between the sole ( 700 ) and the crown ( 600 ), wherein the face ( 500 ), sole ( 700 ), crown ( 600 ), and skirt ( 800 ) define an outer shell that further defines a head volume, and wherein the golf club head ( 400 ) has a rear portion ( 404 ) opposite the face ( 500 ); 
 (v) a bore having a center that defines a shaft axis (SA) which intersects with a horizontal ground plane (GP) to define an origin point, wherein the bore is located at a heel side ( 406 ) of the golf club head ( 400 ) and receives the shaft distal end ( 220 ) for attachment to the golf club head ( 400 ), and wherein a toe side ( 408 ) of the golf club head ( 400 ) is located opposite of the heel side ( 406 ); 
 (vi) a blade length (BL) measured horizontally from the origin point toward the toe side ( 408 ) of the golf club head ( 400 ) to the most distant point on the golf club head, wherein the blade length (BL) includes (a) a heel blade length section (Abl) measured in the same direction as the blade length (BL) from the origin point to an engineered impact point (EIP), and (b) a toe blade length section (Bbl); 
 (vii) a center of gravity (CG) of the golf club head ( 400 ) located:
 (a) vertically toward the crown ( 600 ) of the golf club head ( 400 ) from the origin point a distance Ycg; 
 (b) horizontally from the origin point toward the toe side ( 408 ) of the golf club head ( 400 ) a distance Xcg that is generally parallel to the face ( 500 ) and the ground plane (GP); and 
 (c) a distance Zcg from the origin toward the rear portion ( 404 ) in a direction generally orthogonal to the vertical direction used to measure Ycg and generally orthogonal to the horizontal direction used to measure Xcg; 
 
 (viii) a stress reducing feature ( 1000 ) including a sole located SRF ( 1300 ) located at least partially on the sole ( 700 ), wherein:
 (a) the sole located SRF ( 1300 ) has a SSRF length ( 1310 ) between a SSRF toe-most point ( 1312 ) and a SSRF heel-most point ( 1316 ) where the SSRF length ( 1310 ) is at least as great as the heel blade length section (Abl), a SSRF leading edge ( 1320 ) having a SSRF leading edge offset ( 1322 ), a SSRF trailing edge ( 1330 ), a SSRF volume, a SSRF width ( 1340 ), and a SSRF depth ( 1350 ), wherein a portion of the SSRF leading edge ( 1320 ) is located between the face and a vertical plane containing the shaft axis (SA), and at least a portion of the sole located SRF ( 1300 ) contains a secondary elastic material having a density less than 3 g/cm 3 ; and 
 (b) the sole located SRF ( 1300 ) has a SSRF aperture ( 1400 ) recessed from the sole ( 700 ) and extending through the outer shell, wherein the SSRF aperture ( 1400 ) has a SSRF aperture length ( 1410 ) between a SSRF aperture toe-most point ( 1412 ) and a SSRF aperture heel-most point ( 1416 ), the SSRF aperture length ( 1410 ) is at least fifty percent of the Xcg distance, and a SSRF aperture width ( 1440 ); and 
 (c) the golf club head ( 400 ) has a characteristic time of at least 220 microseconds. 
 
   
     
     
         2 . The golf club of  claim 1 , wherein the SSRF length ( 1310 ) is at least 50% of the blade length (BL), and the SSRF aperture width ( 1440 ) of at least a portion of the SSRF aperture ( 1400 ) is at least fifty percent of the minimum face thickness. 
     
     
         3 . The golf club of  claim 2 , wherein the SSRF aperture length ( 1410 ) is at least 50% of the blade length (BL), and a maximum SSRF width ( 1340 ) of no more than 0.750 inches. 
     
     
         4 . The golf club of  claim 3 , wherein a portion of the outer shell has a density of less than 5 g/cm 3 , and the SSRF heel-most point ( 1316 ) is located toeward of the origin point. 
     
     
         5 . The golf club of  claim 4 , wherein the SSRF toe-most point ( 1312 ) is located a SSRF toe offset ( 1314 ) distance from the most distant point on the toe side ( 408 ) of golf club head, measured in the same direction as the Xcg distance, and the SSRF toe offset ( 1314 ) is at least fifty percent of the heel blade length section (Abl). 
     
     
         6 . The golf club of  claim 5 , wherein the portion of the outer shell having the density of less than 5 g/cm 3  is a nonmetallic composite. 
     
     
         7 . The golf club of  claim 6 , wherein the face ( 400 ) has a face thickness that varies from a minimum thickness to a maximum thickness, the face minimum thickness is at least 0.050″, and the face maximum thickness is at least 25% greater than the minimum thickness. 
     
     
         8 . The golf club of  claim 6 , wherein a portion of the golf club head ( 400 ) has a density of at least 15 g/cm 3 , and the characteristic time is at least 240 microseconds. 
     
     
         9 . The golf club of  claim 6 , wherein a minimum SSRF aperture leading edge offset ( 1422 ) is at least ten percent of the face height, and the SSRF toe offset ( 1314 ) is at least 0.84 inches. 
     
     
         10 . The golf club of  claim 6 , wherein at least a portion of the SSRF aperture ( 1400 ) is located above the lower edge height (LEH). 
     
     
         11 . The golf club of  claim 6 , wherein the maximum SSRF width ( 1340 ) is at least ten percent of the Zcg distance, and the characteristic time is at least 240 microseconds. 
     
     
         12 . The golf club of  claim 11 , wherein the minimum SSRF leading edge offset ( 1322 ) is at least ten percent of the face height. 
     
     
         13 . The golf club of  claim 6 , wherein the SSRF aperture width ( 1440 ) is less than the maximum face thickness. 
     
     
         14 . The golf club of  claim 6 , wherein at least a portion of the SSRF aperture ( 1400 ) is horizontally separated from the SSRF trailing edge ( 1330 ) by a separation distance that is at least ten percent of the Zcg distance. 
     
     
         15 . The golf club of  claim 6 , wherein the SSRF aperture ( 1400 ) is located at a SSRF aperture depth ( 1450 ) measured vertically from the lower edge height (LEH) toward the center of gravity (CG), and the SSRF aperture depth ( 1450 ) of at least a portion of the SSRF aperture ( 1400 ) is greater than zero. 
     
     
         16 . The golf club of  claim 6 , wherein the secondary elastic material covers the aperture. 
     
     
         17 . The golf club of  claim 6 , wherein a portion of the secondary elastic material extends into the aperture, and the characteristic time is at least 240 microseconds. 
     
     
         18 . The golf club of  claim 6 , wherein the SSRF depth ( 1350 ) of a portion of the sole located SRF ( 1300 ) is at least ten percent of the Ycg distance. 
     
     
         19 . The golf club of  claim 6 , wherein the Ycg distance is less than 0.65″, the head volume is less than 300 cubic centimeters, the maximum top edge height (TEH) is 1.1″-2.1″, the face ( 500 ) has a loft of at least 12 degrees, and the face height is less than 1.50″. 
     
     
         20 . The golf club of  claim 19 , wherein the Ycg distance is less than 0.60″, and the characteristic time is at least 240 microseconds. 
     
     
         21 . The golf club of  claim 20 , wherein a club moment arm (CMA) from the CG to an engineered impact point (EIP) is less than 1.1″. 
     
     
         22 . The golf club of  claim 21 , wherein the Ycg distance is less than 0.55″, and the club moment arm (CMA) is less than 1.0″.