Multi-Material Iron-Type Golf Club Head

Abstract

A multi-material iron-type golf club head having a shell that defines a closed internal volume, where the head is composed of at least two different materials and achieves a high maximum characteristic time.

We claim: 
     
         1 . A multi-material iron-type golf club head comprising:
 (i) a shell having a face positioned at a front portion where the golf club head impacts a golf ball, the face being opposite a rear portion and extending between a top portion and a sole, thereby defining a closed internal volume, wherein the golf club head includes at least two different materials including a first material and a second material, wherein the first material has a first density and the second material has a second density that is at least twice the first density, and at least a portion of the face, a portion of the top portion, and a portion of the sole are formed of the first material;   (ii) the face has a face thickness, a maximum characteristic time of at least 220 microseconds, and an engineered impact point, a face height, a top edge height, and a lower edge height, wherein the face has a blade length measured horizontally from an origin point toward a toe side of the golf club head to the most distant point on the golf club head in this direction, wherein the blade length includes a toe blade length section and a heel blade length section measured in the same direction as the blade length from the origin point to the engineered impact point, the blade length is at least 3.0″, and a ratio of a front-to-back dimension to the blade length is less than 0.925, wherein the front-to-back dimension is measured from a furthest forward point on the face to the furthest rearward point at the rear portion, and a ratio of the heel blade length section to the front-to-back dimension is at least 0.32;   (iii) a bore having a center that defines a shaft axis which intersects with a horizontal ground plane to define the origin point, wherein the bore is located at a heel side of the golf club head, and wherein the toe side of the golf club head is located opposite of the heel side; and   (iv) a center of gravity located:
 (a) vertically from the origin point a distance Ycg, wherein a ratio of the Ycg distance to the top edge height is less than 0.40; 
 (b) horizontally from the origin point toward the toe side of the golf club head a distance Xcg; and 
 (c) a distance Zcg from the origin point toward the rear portion in a direction generally orthogonal to the vertical direction used to measure Ycg and generally orthogonal to the horizontal direction used to measure Xcg; 
 (d) a club moment arm from the center of gravity to the engineered impact point is less than 0.95″, wherein a ratio of the club moment arm to the heel blade length section is less than 0.9; and 
 (e) a transfer distance measured horizontally from the center of gravity to a vertical line extending from the origin point, wherein the transfer distance is at least 10% greater than the club moment arm, and a ratio of the club moment arm to the transfer distance is less than 0.75; 
   (v) wherein the engineered impact point is located:
 (a) vertically toward the top portion from the origin point a distance Yeip, wherein 0.5″>(Yeip−Ycg)>−0.5″; 
 (b) horizontally from the origin point toward the toe side a distance Xeip that is generally parallel to the face and the ground plane, wherein 0.5″>(Xeip−Xcg)>−0.5″; and 
 (c) a distance Zeip from the origin point toward the face in a direction generally orthogonal to the vertical direction used to measure Ycg and generally orthogonal to the horizontal direction used to measure Xcg, wherein (Zeip+Zcg)<2.0″. 
   
     
     
         2 . The multi-material iron-type golf club head of  claim 1 , wherein the blade length is at least  3 . 1 ″ and the heel blade length section is at least 1.1″. 
     
     
         3 . The multi-material iron-type golf club head of  claim 2 , wherein the face thickness varies from a minimum face thickness to a maximum face thickness, wherein the minimum face thickness is at least 0.050″ and the maximum face thickness is at least 25% greater than the minimum face thickness. 
     
     
         4 . The multi-material iron-type golf club head of  claim 3 , wherein the ratio of the Ycg distance to the top edge height is less than 0.375, and the transfer distance is at least 1.2″. 
     
     
         5 . The multi-material iron-type golf club head of  claim 4 , wherein the second material accounts for at least 80 grams, the maximum characteristic time of at least 240 microseconds, and the maximum face thickness is less than 0.120 inches. 
     
     
         6 . The multi-material iron-type golf club head of  claim 5 , wherein a portion of the golf club head is formed of a third material that is a nonmetallic material. 
     
     
         7 . The multi-material iron-type golf club head of  claim 5 , wherein the second density is at least 15 g/cm 3 . 
     
     
         8 . The multi-material iron-type golf club head of  claim 7 , wherein the first density is less than 5 g/cm 3 . 
     
     
         9 . The multi-material iron-type golf club head of  claim 7 , wherein the top edge height is no more than 2.1″. 
     
     
         10 . The multi-material iron-type golf club head of  claim 9 , wherein the Ycg distance is less than 0.65 inches. 
     
     
         11 . A multi-material iron-type golf club head comprising:
 (i) a shell having a face positioned at a front portion where the golf club head impacts a golf ball, the face being opposite a rear portion and extending between a top portion and a sole, thereby defining a closed internal volume, wherein the golf club head includes at least two different materials including a first material and a second material, wherein the second material accounts for at least 80 grams, and at least a portion of the face, a portion of the top portion, and a portion of the sole are formed of the first material;   (ii) the face has a face thickness that varies from a minimum face thickness to a maximum face thickness, a maximum characteristic time of at least 220 microseconds, and an engineered impact point, a face height, a top edge height, and a lower edge height, wherein the face has a blade length measured horizontally from an origin point toward a toe side of the golf club head to the most distant point on the golf club head in this direction, wherein the blade length includes a toe blade length section and a heel blade length section measured in the same direction as the blade length from the origin point to the engineered impact point, the blade length is at least 3.0″, and a ratio of a front-to-back dimension to the blade length is less than 0.925, wherein the front-to-back dimension is measured from a furthest forward point on the face to the furthest rearward point at the rear portion, and a ratio of the heel blade length section to the front-to-back dimension is at least 0.32;   (iii) a bore having a center that defines a shaft axis which intersects with a horizontal ground plane to define the origin point, wherein the bore is located at a heel side of the golf club head, and wherein the toe side of the golf club head is located opposite of the heel side; and   (iv) a center of gravity located:
 (a) vertically from the origin point a distance Ycg; 
 (b) horizontally from the origin point toward the toe side of the golf club head a distance Xcg; and 
 (c) a distance Zcg from the origin point toward the rear portion in a direction generally orthogonal to the vertical direction used to measure Ycg and generally orthogonal to the horizontal direction used to measure Xcg; 
 (d) a club moment arm from the center of gravity to the engineered impact point is less than 0.95″, wherein a ratio of the club moment arm to the heel blade length section is less than 0.9; and 
 (e) a transfer distance measured horizontally from the center of gravity to a vertical line extending from the origin point, wherein the transfer distance is at least 10% greater than the club moment arm, and a ratio of the club moment arm to the transfer distance is less than 0.75; 
   (v) wherein the engineered impact point is located:
 (a) vertically toward the top portion from the origin point a distance Yeip, wherein 0.5″>(Yeip−Ycg)>−0.5″; 
 (b) horizontally from the origin point toward the toe side a distance Xeip that is generally parallel to the face and the ground plane, wherein 0.5″>(Xeip−Xcg)>−0.5″; and 
 (c) a distance Zeip from the origin point toward the face in a direction generally orthogonal to the vertical direction used to measure Ycg and generally orthogonal to the horizontal direction used to measure Xcg, wherein (Zeip+Zcg)<2.0″. 
   
     
     
         12 . The multi-material iron-type golf club head of  claim 11 , wherein the blade length is at least 3.1″, the heel blade length section is at least 1.1″. 
     
     
         13 . The multi-material iron-type golf club head of  claim 12 , wherein the transfer distance is at least 1.2″, and the maximum face thickness is less than 0.120″. 
     
     
         14 . The multi-material iron-type golf club head of  claim 13 , wherein the minimum face thickness is at least 0.050″ and the maximum face thickness is at least 25% greater than the minimum face thickness. 
     
     
         15 . The multi-material iron-type golf club head of  claim 14 , wherein the first material has a first density and the second material has a second density that is at least twice the first density. 
     
     
         16 . The multi-material iron-type golf club head of  claim 15 , wherein a ratio of the Ycg distance to the top edge height is less than 0.40. 
     
     
         17 . The multi-material iron-type golf club head of  claim 16 , wherein the second density is at least 15 g/cm 3  and the maximum characteristic time is at least 240 microseconds. 
     
     
         18 . The multi-material iron-type golf club head of  claim 17 , wherein the ratio of the Ycg distance to the top edge height is less than 0.375. 
     
     
         19 . The multi-material iron-type golf club head of  claim 16 , wherein a portion of the golf club head is formed of a third material that is a nonmetallic material. 
     
     
         20 . The multi-material iron-type golf club head of  claim 19 , wherein a portion of the shell is formed of the third material.