Golf club head with optimized moment of inertia

Abstract

A driver-type golf club head comprising a cube-like body shape, wherein a ratio between the body height and the body depth is between 0.5 and 0.75, and a ratio between the body height and the body width is between 0.5 and 0.75. The golf club head further comprises a mass distribution wherein a large portion of the club head mass is located within a central mass zone centered about the Y′-axis. The golf club head further comprises an Ixx and an Iyy moment of inertia, wherein and Ixx/Iyy ratio is greater than 0.8. In many embodiments, the golf club head further comprises optimized bulge and roll curvatures determined by the Ixx, Iyy, CG position, coefficient of restitution, and/or other characteristics.

1 . A golf club head comprising;
 a strike face comprising a geometric center and a leading edge;   a body comprising a crown, a sole, a heel, a toe, and a rear end;   a center of gravity;   a ground plane;   a total club head mass;   a primary coordinate system centered about the geometric center, the primary coordinate system defining:
 an X-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y-axis extending in a crown-to-sole direction, orthogonal to the X-axis and the ground plane; 
 a Z-axis extending in a strike face-to-rear direction, orthogonal to both the X-axis and the Y-axis; 
   a secondary coordinate system centered about the center of gravity, the secondary coordinate system defining:
 an X′-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y′-axis extending in a crown-to-sole direction, orthogonal to the X′-axis and the ground plane; 
 a Z′-axis extending in a strike face-to-rear direction, orthogonal to both the X′-axis and the Y′-axis; 
   wherein the body comprises:
 a body width measured parallel to the X-axis between the heel and the toe; 
 a body depth measured parallel to the Z-axis between the leading edge and a rearward-most point of the body; 
 a body height measured parallel to the Y-axis between the ground plane and a highest point of the crown; 
 a H B /W B  ratio between 0.5 and 0.75, the H B /W B  ratio defined as the body height divided by the body width; 
   a sole mass pad located on a sole interior surface and intersected by the Y′-axis;   an Ixx moment of inertia about the X′-axis;   an Iyy moment of inertia about the Y′-axis;   an Ixx/Iyy ratio greater than 0.8;   a central mass zone defined by an imaginary cylinder centered about the Y′-axis and comprising a central mass zone radius of 0.75 inch; and   wherein greater than 20% of the total club head mass is located within the central mass zone.   
     
     
         2 . The golf club head of  claim 1 , wherein the sole mass pad is entirely bounded within the central mass zone. 
     
     
         3 . The golf club head of  claim 1 , wherein the sole mass pad comprises a mass greater than 5 grams. 
     
     
         4 . The golf club head of  claim 1 , wherein the sole mass pad is located entirely within a middle 45% of the body depth. 
     
     
         5 . The golf club head of  claim 1 , wherein the H B /W B  ratio is greater than 0.6. 
     
     
         6 . The golf club head of  claim 1 , wherein the club head comprises a volume greater than 410 cm 3 . 
     
     
         7 . The golf club head of  claim 1 , further comprising a weight member attached to the body proximate the rear end and the sole, the weight member defining:
 a weight member center of gravity;   a weight member elevation defined as a distance between the center of gravity of the club head and the weight member center of gravity, measured parallel to the Y′-axis;   a weight member depth defined as a distance between the center of gravity of the club head and the weight member center of gravity, measured parallel to the Y′-axis; and   an E W /D W  ratio greater than 0.3, the E W /D W  ratio defined as the weight member elevation divided by the weight member depth.   
     
     
         8 . The golf club head of  claim 7 , wherein the weight member further comprises a weight member mass percentage between 10 and 30% of the total club head mass. 
     
     
         9 . The golf club head of  claim 1 , further comprising a crown mass pad located on a crown interior surface and intersected by the Y′-axis. 
     
     
         10 . The golf club head of  claim 9 , wherein the crown mass pad comprises a mass greater than 5 grams. 
     
     
         11 . The golf club head of  claim 1 , wherein greater than 30% of the total club head mass is located within the central mass zone. 
     
     
         12 . A golf club head comprising;
 a strike face comprising a geometric center and a leading edge;   a body comprising a crown, a sole, a heel, a toe, and a rear end;   a center of gravity;   a ground plane;   a total club head mass;   a primary coordinate system centered about the geometric center, the primary coordinate system defining:
 an X-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y-axis extending in a crown-to-sole direction, orthogonal to the X-axis and the ground plane; 
 a Z-axis extending in a strike face-to-rear direction, orthogonal to both the X-axis and the Y-axis; 
   a secondary coordinate system centered about the center of gravity, the secondary coordinate system defining:
 an X′-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y′-axis extending in a crown-to-sole direction, orthogonal to the X′-axis and the ground plane; 
 a Z′-axis extending in a strike face-to-rear direction, orthogonal to both the X′-axis and the Y′-axis; 
   wherein the body comprises:
 a body width measured parallel to the X-axis between the heel and the toe; 
 a body depth measured parallel to the Z-axis between the leading edge and a rearward-most point of the body; 
 a body height measured parallel to the Y-axis between the ground plane and a highest point of the crown; 
 a H B /W B  ratio between 0.5 and 0.75, the H B /W B  ratio defined as the body height divided by the body width; 
   a sole mass pad located on a sole interior surface and intersected by the Y′-axis;   an Ixx moment of inertia about the X′-axis;   an Iyy moment of inertia about the Y′-axis;   an Ixx/Iyy ratio greater than 0.8;   a central mass zone defined by an imaginary cylinder centered about the Y′-axis and comprising a central mass zone radius of 0.75 inch; and   a mass distribution metric MD 2  according to equation 1:   
       
         
           
             
               
                 
                   
                       
                     
                       
                         MD 
                         2 
                       
                       = 
                       
                         
                           
                             M 
                             
                                 
                               CMZ 
                             
                           
                           
                             
                               M 
                               T 
                             
                             * 
                             V 
                           
                         
                         * 
                         1000 
                         ⁢ 
                             
                         
                           cm 
                           3 
                         
                       
                     
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         wherein M CMZ  is the amount of mass within the central mass zone, M T  is the total club head mass, and R CMZ  is the central mass zone radius; and 
         wherein the mass distribution metric MD 2  is greater than 0.5. 
       
     
     
         13 . The golf club head of  claim 12 , wherein the H B /W B  ratio is greater than 0.6. 
     
     
         14 . The golf club head of  claim 12 , wherein the mass distribution metric MD 2  is greater than 0.75. 
     
     
         15 . The golf club head of  claim 12 , wherein the club head comprises a volume greater than 410 cm 3 . 
     
     
         16 . The golf club head of  claim 12 , wherein the sole mass pad is entirely bounded within the central mass zone. 
     
     
         17 . A golf club head comprising;
 a strike face comprising a geometric center and a leading edge;   a body comprising a crown, a sole, a heel, a toe, and a rear end;   a center of gravity;   a ground plane;   a total club head mass;   a primary coordinate system centered about the geometric center, the primary coordinate system defining:
 an X-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y-axis extending in a crown-to-sole direction, orthogonal to the X-axis and the ground plane; 
 a Z-axis extending in a strike face-to-rear direction, orthogonal to both the X-axis and the Y-axis; 
   a secondary coordinate system centered about the center of gravity, the secondary coordinate system defining:
 an X′-axis extending in a heel-to-toe direction, parallel to the ground plane; 
 a Y′-axis extending in a crown-to-sole direction, orthogonal to the X′-axis and the ground plane; 
 a Z′-axis extending in a strike face-to-rear direction, orthogonal to both the X′-axis and the Y′-axis; 
   wherein the body comprises:
 a body width measured parallel to the X-axis between the heel and the toe; 
 a body depth measured parallel to the Z-axis between the leading edge and a rearward-most point of the body; 
 a body height measured parallel to the Y-axis between the ground plane and a highest point of the crown; 
 a H B /W B  ratio between 0.5 and 0.75, the H B /W B  ratio defined as the body height divided by the body width; 
   a sole mass pad located on a sole interior surface and intersected by the Y′-axis;   an Ixx moment of inertia about the X′-axis;   an Iyy moment of inertia about the Y′-axis;   an Ixx/Iyy ratio greater than 0.8;   a central mass zone defined by an imaginary cylinder centered about the Y′-axis and comprising a central mass zone radius of 0.75 inch; and   a mass distribution metric MD 3  according to equation 1:   
       
         
           
             
               
                 
                   
                       
                     
                       
                         MD 
                         3 
                       
                       = 
                       
                         
                           
                             M 
                             
                                 
                               CMZ 
                             
                           
                           
                             
                               M 
                               T 
                             
                             * 
                             Iyy 
                           
                         
                         * 
                         1000 
                         ⁢ 
                             
                         g 
                         * 
                         
                           cm 
                           2 
                         
                       
                     
                   
                 
                 
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
         wherein M CMZ  is the amount of mass within the central mass zone and M T  is the total club head mass; and 
         wherein the mass distribution metric MD 3  is greater than 0.050. 
       
     
     
         18 . The golf club head of  claim 17 , wherein the H B /W B  ratio is greater than 0.6. 
     
     
         19 . The golf club head of  claim 17 , wherein the mass distribution metric MD 3  is greater than 0.070. 
     
     
         20 . The golf club head of  claim 17 , wherein the club head comprises a volume greater than 410 cm 3 .