| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a racket frame improving feeling when hitting a ball and improves the controllability of hitting the ball. <P>SOLUTION: The racket frame 1 includes a ball-hitting portion 4, a shaft 6, and a grip 7. The ball-hitting portion 4 includes a high rigidity part 2, a low rigidity part 3, and an intermediate rigidity part (the area other than the high rigidity part 2 and the low rigidity part 3). The high rigidity part 2 is a part which is disposed at an end-side belly part positioned on the end side of the racket frame 1 in the ball-hitting portion 4, in a plurality of belly parts including a position showing the maximum amplitude in the out-of-plane direction when torsional vibration occurs in the ball-hitting portion 4. The high rigidity part 2 has relatively high rigidity. The low rigidity part 3 is closer to the grip 7 side than the high rigidity part 2 and has a lower rigidity than that of the high rigidity part 2. The intermediate rigidity part is closer to the grip 7 side than the low rigidity part 3, and has a rigidity higher than that of the low rigidity part 3 and lower than that of the high rigidity part 2. <P>COPYRIGHT: (C)2011,JPO&INPIT |
