Golf club head

Abstract

A golf club head includes a face, a sole, a back, and a hosel. The back is connected to at least a top blade of the face and to a trailing edge of the sole to form a cavity surrounded by the face, the sole, and the back. The cavity has an opening on a toe side. The sole is shaped into a triangle whose three vertices are a heel end of the sole, a face-side toe end of the sole, and a back-side toe end of the sole. The heel end is a point where a central axis of a bore of the hosel into which a shaft is to be inserted intersects with the sole. The face-side toe end is a point closest to a toe in a region where the sole connects to the face. The back-side toe end is the toe-side end of the trailing edge.

What is claimed is: 
     
         1 . A golf club head comprising:
 a face;   a sole;   a back connected to at least a top blade of the face and to a trailing edge of the sole to form a cavity surrounded by the face, the sole, and the back, the cavity having an opening on a side of a toe of the golf club head; and   a hosel,   wherein the sole is shaped into a triangle whose three vertices are a heel end of the sole, a face-side toe end of the sole, and a back-side toe end of the sole, the heel end being a point at which a central axis of a bore of the hosel into which a shaft is to be inserted intersects with the sole, the face-side toe end being a point closest to the toe in a region where the sole connects to the face, the back-side toe end being an end of the trailing edge on the side of the toe.   
     
     
         2 . The golf club head as claimed in  claim 1 , wherein a projection of the sole from above is completely hidden by the face when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle. 
     
     
         3 . The golf club head as claimed in  claim 1 , wherein a color of at least a portion of the sole whose projection protrudes from the face when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle is different from a color of the face. 
     
     
         4 . The golf club head as claimed in  claim 1 , wherein a cross-sectional area of the cavity in a face-back direction maximizes on the side of the toe and gradually decreases toward a heel of the golf club head. 
     
     
         5 . The golf club head as claimed in  claim 1 , wherein the back is shaped into a triangle whose three vertices are a heel end of the back, a sole-side toe end of the back, and a face-side toe end of the back. 
     
     
         6 . The golf club head as claimed in  claim 5 , wherein
 the heel end of the back is a point closest to a heel of the golf club head in a region where the back connects to the sole,   the sole-side toe end of the back is a point closest to the sole and to the toe in the region where the back connects to the sole, and   the face-side toe end of the back is a point closest to the toe in a region where the back connects to the face.   
     
     
         7 . The golf club head as claimed in  claim 1 , wherein a thickness of the face, the sole, and the back is smallest in a portion of the sole. 
     
     
         8 . The golf club head as claimed in  claim 1 , wherein a thickness of the face, the sole, and the back is smallest in a portion of the back. 
     
     
         9 . The golf club head as claimed in  claim 1 , wherein, when the golf club head is soled on a horizontal plane at a reference lie angle and a reference loft angle, letting a maximum projection length of the face in a face-back direction be 1, a length of a distance between a first line and a second line in the face-back direction is 0.75 or more, where the first line is a straight line that passes through a leading edge of the face to extend in a top-sole direction perpendicularly to the horizontal plane and the second line is a straight line that passes through the back-side toe end of the sole to extend in the top-sole direction perpendicularly to the horizontal plane.