GOLF CLUB SHAFT

摘要

PROBLEM TO BE SOLVED: To enhance the strength and rigidity of a shaft against impact and bending when striking a golf ball by providing lightweight dividing wall members by which the inside of a shaft main body having reinforcing fibers is divided into a number of sealed vacant spaces, and making the internal pressure of the vacant space greater than the atmospheric pressure. SOLUTION: A shaft main body 2 has a group of bias layers, in which reinforcing fibers 1a, 1b are spirally wound so that the orientation angles of the reinforcing fibers 1a, 1b cross each other, and a straight layer in which reinforcing fibers 1c are aligned approximately parallel to the longitudinal direction of the shaft main body 2, on the outside of the group of bias layers. Lightweight dividing wall members 5 which divide the inside of the shaft main body 2 into a number of vacant spaces 4 while sealing them are provided inside the shaft main body 2, and the internal pressure P of the vacant space 4 is made larger than the atmospheric pressure. A tensile force is constantly and uniformly applied to the overall surface of the shaft main body 2 by the combined effect of the internal pressure P and a pressure exerted in the direction of the outside diameter by the dividing wall members 5. Thus the bending strength of the shaft can be enhanced, and destruction of the shaft whereby it buckles at the application of an external bending force because it cannot resist compressive stresses can surely be prevented.