| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a putter head prevents a ball from sliding over a green while maintaining both of golfers' preferred hitting feel and roll of the ball. <P>SOLUTION: A face insert 20 fitted in a face of the putter head has an outer layer 22 which serves as a ball-hitting surface and an inner layer 24 which is located on an inner side of a head body. A smash factor of a second polymer material forming the inner layer 24 is greater than a smash factor of a first polymer material forming the outer layer 22. Two types of groove, group 4 of a first groove group and grooves 5 of a second groove group are formed in an external surface 3 of the outer layer 22. The grooves 4 of the first groove group is 0.5 to 1.52 mm wide and 0.25 to 0.5 mm deep and the grooves 5 of the second groove group is 0.1 to 0.5 mm wide and 0.05 to 0.1 mm deep. Groove spacing L between adjacent grooves 4 of the first groove group is 0.8 to 1.5 mm, and one or more grooves 5 of the second groove group are placed between the grooves 4 of the first groove group. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
