Putter type golf club head and putter type golf club
View Patent ↗A putter type golf club head 1 having a face 2 for hitting a ball on a front side has a head main body 1 A provided in a face 2 side with a concave portion 3 and a face insert 1 B made of an elastic material attached to the concave portion 3 of the head main body 1 A. The face insert 1 B has a three-layered structure composed of a first layer 8 disposed in a frontmost side, a third layer 10 disposed in a rearmost side and a second layer 9 sandwiched between the first layer 8 and the third layer 10 , wherein hardnesses h 1 , h 2 and h 3 and moduli of repulsion elasticity r 1 , r 2 and r 3 of the first layer 8 , second layer 9 and third layer 10 , respectively, satisfy relationships: h 1 >h 2 , h 3 >h 2 , r 1 >r 2 and r 3 >r 2.
1. A putter type golf club head having a face for hitting a ball on a front side, wherein
the head has a head main body made of a metal material provided in a face side with a concave portion, and a face insert attached to the concave portion of the head main body,
the face insert has a three-layered structure made up of a first layer disposed in a frontmost side, a third layer disposed in a rearmost side and a second layer sandwiched between the first layer and the third layer, wherein each of the first, second and third layers is made of a synthetic resin or alternatively a rubbery elastomer, and
the first layer, the second layer and the third layer have hardnesses h 1 , h 2 and h 3 , respectively, and moduli of repulsion elasticity r 1 , r 2 and r 3 , respectively, which satisfy the following relationships:
h 1 >h 2,
h 3 >h 2,
r 1 >r 2 and
r 3 >r 2
wherein
the hardness is Shore D hardness measured according to ASTM-D2240-68 “Standard Test Method for Rubber Property-Durometer Hardness”, and
the modulus of repulsion elasticity is measured at a temperature of 23 degrees C. and a humidity of 50 RH % according to Japanese Industrial Standard K6255 “Rubber, vulcanized or thermoplastic—Determination of rebound resilience”.
2. The putter type golf club head according to claim 1 , wherein the hardnesses and the moduli of repulsion elasticity of the first layer and the third layer satisfy the following relationships:
h 1 =h 3 and
r 1 =r 3.
3. The putter type golf club head according to the claim 1 , in which, in the face insert, the first layer and the third layer are made of the same material.
4. The putter type golf club head according to claim 1 , in which, in the face insert, only the third layer contacts with the head main body.
5. The putter type golf club head according to claim 1 , in which the hardnesses of the first layer and the second layer satisfy the following relationship:
0 <h 1 −h 2<10 degrees.
6. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the first layer is 35 to 65 degrees.
7. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the first layer is not less than 40 degrees and not more than 63 degrees.
8. The putter type golf club head according to claim 1 , wherein the modulus of repulsion elasticity r 1 of the first layer is 50% to 70%.
9. The putter type golf club head according to claim 1 , wherein the modulus of repulsion elasticity r 1 of the first layer is not less than 53% and not more than 67%.
10. The putter type golf club head according to claim 1 , wherein the thickness of the first layer is 0.3 to 4.0 mm.
11. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the second layer is 30 to 60 degrees.
12. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the second layer is not less than 35 degrees and not more than 57 degrees.
13. The putter type golf club head according to claim 1 , wherein the modulus of repulsion elasticity r 2 of the second layer is 30 to 60%.
14. The putter type golf club head according to claim 1 , wherein the modulus of repulsion elasticity r 2 of the second layer is not less than 33% and not more than 50%.
15. The putter type golf club head according to claim 1 , wherein the thickness of the second layer is 1.0 to 5.0 mm.
16. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the third layer s 35 to 65 degrees.
17. The putter type golf club head according to claim 1 , wherein the Shore D hardness of the third layer is not less than 40 degrees and not more than 63 degrees.
18. The putter type golf club head according to claim 1 , wherein the modulus of repulsion elasticity r 3 of the third layer is 50 to 70%.
19. The putter type golf club head according to claim 1 , wherein the thickness of the third layer is 1.0 to 5.0 mm.
20. A putter type golf club comprising a shaft and the putter type golf club head according to claim 1 .