HANDLE OF GOLF CLUB

摘要

PROBLEM TO BE SOLVED: To provide a golf club shaft with lightness, flexibility and stiffness by separating the plural layers of peripheral wall with partition layer of isotropic material along the particular proportion of the length of the tubular form, and specifying the densities of these layers to specified values. SOLUTION: The whole length of a tubular form 1 part which has the peripheral wall isolated by a foam layer 15 and includes compound material layers 14, 16 is equal to at least 30% of the length of the tubular form. The first layer 14 and the second layer 16 are separated by a separation layer 15 made of material of which density isρ3 and the longitudinal Young's modulus is E3 with about isotropy. The densitiesρ1,ρ2 respectively of the first layer 14 and the second layer 16 are greater than the densityρ3 of the separation layer 15 material, and the each of longitudinal Young's moduli E1, E2 respectively of the first layer 14 and the second layer 16 is greater than 20 Gpa, and at the same time, the longitudinal Young's modulus E3 of the separation layer 15 material is lower than 20 Gpa. In this way, the shaft can be light weight and stiff.