Abstract:
Embodiments and methods of manufacturing a golf club head having a crown with thin sections are generally described herein. Other embodiments may be described and claimed.

Description:
[0001]    This application is a continuation application claiming priority of co-pending U.S. application Ser. No. 11/516,373 filed Sep. 6, 2006. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to golf equipment and, in particular, to a golf club head having a crown with thin regions. 
         [0003]    U.S. Pat. No. 5,954,596 to Noble et al discloses a golf club head including a hollow body with a front wall, a top wall or crown, a bottom wall or sole, and a side wall or skirt. The front wall varies in thickness while the top, bottom and side walls are substantially uniform in thickness. 
         [0004]    U.S. Pat. No. 6,776,723 to Bliss et al discloses a golf club head including a hollow body with a front wall, a top wall, a bottom wall and a side wall as disclosed in the Noble et al patent. The front wall varies in thickness, and a weight member located on the sole lowers the center of gravity of the club head. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a front elevation view of a golf club head according to one embodiment of the present invention; 
           [0006]      FIG. 2  is a rear perspective view of the golf club head of  FIG. 1 ; 
           [0007]      FIG. 3  is a top view of the golf club head of  FIG. 1 ; and 
           [0008]      FIG. 4  is a top view of a golf club head according to another embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0009]    With reference to  FIGS. 1-3 , a golf club head  10  comprises a hollow body  12  preferably formed of titanium having a front wall  14  for impacting a golf ball, and a hosel  16  adapted to receive a golf club shaft  17 . Hollow body  12  further includes a crown  20 , a sole  22  and a skirt  24 . The crown  20  extends rearwardly from an upper portion of the front wall  14 , and the sole  22  extends rearwardly from a lower portion of the front wall  14 . Crown  20  and skirt  24  meet along an outer edge  26  of the crown  20  which, preferably, extends in an arcuate path between a heel end  28  of hollow body  12  and a toe end  30  of hollow body  12 . The skirt  24  extends from the crown outer edge  26  toward the sole  22 . The crown  20  has a thickness dimension measured between its inner and outer surfaces. 
         [0010]    The region surrounding crown outer edge  26  preferably forms an outer perimeter region  32  that smoothly blends crown  20  and skirt  24  together. Outer perimeter region  32  preferably ranges from about 0.700 inch above and about 0.700 inch below the crown outer edge  26 , more preferably about 0.350 inch above and about 0.350 inch below the crown outer edge  26 , and most preferably about 0.250 inch above and about 0.250 inch below the crown outer edge  26 . 
         [0011]    Hollow body  12  may be formed by investment casting or it may be assembled from a series of forged pieces that are welded or brazed together. Crown  20  is formed with a plurality of thin regions  34 ,  35  arranged in a web-shaped pattern. The plurality of thin regions  34 ,  35  includes a first row of thin regions  34  disposed adjacent the crown outer edge  26 , and a second row of thin regions  35  disposed inwardly of the first row of thin regions  34 . 
         [0012]    The first row of thin regions  34  is spaced from the crown outer edge  26  to form a substantially arcuate rib  38  that extends along the outer perimeter region  32 . In addition, the thin regions  34  and  35  are spaced apart to form substantially linear ribs  40  that are connected to the arcuate rib  38 . The first and second rows of thin regions  34 ,  35  are spaced apart to form a substantially arcuate rib  42  disposed radially inward from arcuate rib  38 . The arcuate ribs  38 ,  42  and the linear ribs  40  define the web-shaped pattern in which the thin regions  34 ,  35  are arranged while maintaining the strength of the crown  20 . 
         [0013]    The thin regions  34 ,  35  are formed such that the thickness dimension of the crown  20  in the thin regions  34 ,  35  is reduced when compared with the thickness dimension of the crown  20  in other regions of the crown  20 . The approximate thickness dimension of the thin regions  34 ,  35  may range from 0.016 to 0.030 inch, or more preferably from 0.018 to 0.028 inch, and most preferably from 0.020 to 0.026 inch. Other regions of the crown  20  have a thickness dimension greater than 0.030 inch. 
         [0014]    The web-shaped pattern in which the thin regions  34 ,  35  are arranged removes approximately 3 grams of unneeded material in the crown  20 . The material removed from the crown  20  is preferably redistributed to the sole  22  thereby lowering the center of gravity of the club head  10  approximately 0.020 inch toward the sole  22 . 
         [0015]    In the embodiment of the golf club head  10  shown in  FIG. 4 , a third row of thin regions  36  is disposed inwardly of the second row of thin regions  35 . A further substantially arcuate rib  44  is disposed radially inward from the arcuate rib  42  between the second and third rows of thin regions  35 ,  36 . 
         [0016]    As is well-known in the art, investment casting of thin-wall sections presents special difficulties since the rapidly-cooling metal tends to solidify in the thin-wall areas of the mold. The solidified metal prevents complete filling of the mold thereby causing voids in the finished part. Consequently, conventional investment casting methods cannot reliably produce a large (e.g. 460 cc) titanium alloy driver with a crown less than 0.030 inch thick. Without being held to a particular theory of operation, it is believed that the linear ribs  40  and the arcuate ribs  42  act as cast-in runners enabling the molten metal to fully fill-in the thin sections despite the large thin wall comprising the crown.