Putter head

Abstract

A putter head includes a head main body having a depressed portion and a face insert disposed within the depressed portion so that the face insert is mounted in a face surface of the head main body. The face insert includes at least one low hardness portion and at least one high hardness portion. The face insert has a boundary face between the at least one low hardness portion and the at least one high hardness portion which is inclined relative to a back-to-forth direction of the putter head. The boundary face may decline toward the rear or may rise toward the rear. The face insert may comprise a plurality of the low hardness portions and a plurality of the high hardness portions so that the low and high hardness portions are arranged vertically in multiple layers. The sectional shapes taken perpendicularly to the back-to-forth direction of the high hardness portion and the low hardness portion may be substantially of a right triangle. The face insert may comprise a surface layer and groove portions on a front face thereof.

1 . A putter head comprising:
 a head main body; and   a face insert mounted in a face surface of the head main body, the face insert comprising at least one low hardness portion and at least one high hardness portion,   wherein the face insert has a boundary face between the at least one low hardness portion and the at least one high hardness portion which is inclined relative to a back-to-forth direction of the putter head.   
     
     
         2 . The putter head according to  claim 1 , wherein the face insert comprises a plurality of the low hardness portions and a plurality of the high hardness portions so that the low hardness portions and the high hardness portions are arranged in multiple layers along a direction from a top side to a sole side of the putter head. 
     
     
         3 . The putter head according to  claim 2 , wherein the face insert further comprises a surface layer of synthetic resin or metal on a front face of the face insert. 
     
     
         4 . The putter head according to  claim 2 , wherein each of the plurality of the high hardness portions is separated from a front face of the face insert by the low hardness portions so that two low hardness portions adjacent to the high hardness portion are combined with each other before a front edge of the high hardness portion and the plurality of the low hardness portions are continuous with each other. 
     
     
         5 . The putter head according to  claim 2 , wherein the face insert comprises groove portions formed in a front face of the face insert, the groove portions reaching each front edge portion of the plurality of the high hardness portion which recedes relative to each front face of the plurality of the low hardness portions. 
     
     
         6 . The putter head according to  claim 1 , wherein the boundary face declines toward the rear. 
     
     
         7 . The putter head according to  claim 1 , wherein the boundary face rises toward the rear. 
     
     
         8 . The putter head according to  claim 1 , wherein the head main body has a depressed portion in which the face insert is disposed so that a side surface around the face insert is apart from a side surface of the depressed portion. 
     
     
         9 . The putter head according to  claim 8 , further comprising a viscoelastic material applied between the side surface of the face insert and the side surface of the depressed portion.