Golf club head

Abstract

A golf club head having a hollow portion therein, the head includes a main body including a crown portion and a sole portion, and a face member forming at least a part of a striking face for striking a ball. The main body is made of a first material having a first specific gravity. The face member is formed of a second material having a second specific gravity smaller than the first specific gravity. The main body is provided with at least one slit that penetrates the main body, and the at least one slit extends in a head-front-back direction.

1 . A golf club head having a hollow portion therein, the head comprising:
 a main body comprising a crown portion and a sole portion; and   a face member forming at least a part of a striking face for striking a ball, wherein   the main body is made of a first material having a first specific gravity,   the face member is formed of a second material having a second specific gravity smaller than the first specific gravity,   the main body is provided with at least one slit that penetrates the main body, and   the at least one slit extends in a head-front-back direction.   
     
     
         2 . The golf club head according to  claim 1 , wherein
 the at least one slit comprises a plurality of slits, and   the plurality of slits is provided on the crown portion of the main body.   
     
     
         3 . The golf club head according to  claim 1 , wherein
 the second material comprises a fiber reinforced plastic.   
     
     
         4 . The golf club head according to  claim 1 , wherein
 the at least one slit has a length in the head-front-back direction ranging from 10 to 40 mm and has a width in a toe-heel direction ranging from 0.5 to 10 mm.   
     
     
         5 . The golf club head according to  claim 1 , wherein
 the striking face has a periphery,   the at least one slit has a frontmost end in the head-front-back direction, and   a shortest distance between the frontmost end and the periphery is equal to or less than 10 mm.   
     
     
         6 . The golf club head according to  claim 5 , wherein
 the shortest distance is equal to or less than 3 mm.   
     
     
         7 . The golf club head according to  claim 1 , wherein
 the at least one slit has a frontmost end and a backmost end in the head-front-back direction, and   in a plan view of the at least one slit, each of contours on a frontmost end side and a backmost end side has an arc shape.   
     
     
         8 . The golf club head according to  claim 1 , wherein
 the at least one slit has a frontmost end and a backmost end in the head-front-back direction, and   a width on a backmost end side of the at least one slit is greater than a width on a frontmost end side of the at least one slit.   
     
     
         9 . The golf club head according to  claim 8 , wherein
 the at least one slit comprises a first portion extending backwardly of the head from the frontmost end side and a second portion having a circular contour that is connected to the first portion.   
     
     
         10 . The golf club head according to  claim 9 , wherein
 the first portion has a portion extending with a constant width Wa, and   the second portion has a width Wb equal to or more than 1.5 times the width Wa of the first portion.   
     
     
         11 . The golf club head according to  claim 1 , wherein
 a thick-walled portion is formed at least partially around the at least one slit.   
     
     
         12 . The golf club head according to  claim 11 , wherein
 the thick-walled portion comprises an inner thick-walled portion raised on a hollow portion side of the head.   
     
     
         13 . The golf club head according to  claim 11 , wherein
 the thick-walled portion comprises an outer thick-walled portion raised on an outer surface side of the head.   
     
     
         14 . The golf club head according to  claim 11 , wherein
 the thick-walled portion is formed into a continuous shape to surround the at least one slit.   
     
     
         15 . The golf club head according to  claim 14 , wherein
 a width TW of the thick-walled portion measured orthogonally to an edge of the at least one slit ranges from 1.0 mm to 15.0 mm.   
     
     
         16 . The golf club head according to  claim 1 , wherein
 the at least one slit comprises a plurality of slits, and   the plurality of slits is provided on the sole portion of the main body.   
     
     
         17 . A golf club head having a hollow portion therein, the head comprising:
 a main body comprising a crown portion and a sole portion; and   a face member forming at least a part of a striking face for striking a ball, wherein   the main body is made of a first material having a first specific gravity,   the face member is formed of a second material having a second specific gravity smaller than the first specific gravity,   the main body is provided with at least one slit that penetrates the main body,   the at least one slit extends in a head-front-back direction,   the at least one slit has a frontmost end and a backmost end in the head-front-back direction,   the striking face has a periphery,   a shortest distance between the frontmost end and the periphery is equal to or less than 10 mm,   in a head plan view, the at least one slit defines a reference straight line passing through the frontmost end and the backmost end, and   the reference straight line has an angle equal to or less than 15 degrees with respect to the head-front-back direction.   
     
     
         18 . A golf club head having a hollow portion therein, the head comprising:
 a main body comprising a crown portion and a sole portion; and   a face member forming at least a part of a striking face for striking a ball, wherein   the main body is made of a first material having a first specific gravity,   the face member is formed of a second material having a second specific gravity smaller than the first specific gravity,   the main body is provided with at least one slit that penetrates the main body, and   the at least one slit comprises a portion extending in a head-front-back direction.