Racket

Abstract

A racket includes a frame 4. The frame 4 includes a head 14. The head 14 includes a first high-elasticity layer 37 a and a second high-elasticity layer 37 b. Each of these high-elasticity layers 37 is positioned on an inner side in the head 14 in a thickness direction of the head 14. Each high-elasticity layer 37 includes straight-type reinforcement fibers. In the frame 4, a ratio (G2/G1) of a ball-hitting face stiffness value G2 to a side pressure stiffness value G1 is greater than or equal to 3.20. In the frame 4, a ratio (Tf/Wf) of a thickness Tf of the frame 4 to a width Wf of the frame 4 is preferably greater than or equal to 2.0.

What is claimed is: 
     
         1 . A racket comprising a frame including a head, wherein
 in the frame, a ratio (G2/G1) of a ball-hitting face stiffness value G2 to a side pressure stiffness value G1 is greater than or equal to 3.20.   
     
     
         2 . The racket according to  claim 1 , wherein
 the head includes a high-elasticity layer that is positioned on an inner side in the head in a thickness direction of the head, the high-elasticity layer including straight-type reinforcement fibers.   
     
     
         3 . The racket according to  claim 2 , wherein
 the high-elasticity layer is present in a cross section that extends along a plane that is perpendicular to an axial direction of the frame and that passes a center of the head.   
     
     
         4 . The racket according to  claim 1 , wherein
 in a cross section that extends along a plane that is perpendicular to an axial direction of the frame and that passes a center of the head, a ratio (Tf/Wf) of a thickness Tf of the frame to a width Wf of the frame is greater than or equal to 2.0.   
     
     
         5 . The racket according to  claim 1 , wherein
 the ratio (G2/G1) is greater than or equal to 3.55.   
     
     
         6 . The racket according to  claim 5 , wherein
 the ratio (G2/G1) is greater than or equal to 3.90.   
     
     
         7 . The racket according to  claim 6 , wherein
 the ratio (G2/G1) is greater than or equal to 4.10.   
     
     
         8 . The racket according to  claim 1 , wherein
 the side pressure stiffness value G1 is less than or equal to 90 kgf/cm.   
     
     
         9 . The racket according to  claim 1 , wherein
 the ball-hitting face stiffness value G2 is greater than or equal to 100 kgf/cm.