Patent ID: 7217203

Claim:
A tennis racket comprising a racket frame having a weight of not less than 100 g nor more than 270 g. a string protection member provided on at least one portion of a peripheral surface of a head part surrounding a ball-hitting face of said racket frame, said string protection member having a belt shaped portion and constructed integral with a plurality of cylindrical portions through which strings are respectively inserted wherein, if a midpoint of a maximum length of said ball-hitting face of said racket frame is set as a center thereof and that an intersection of a longest line of said ball-hitting face and an upper part of said ball-hitting face is set as a 0-degree position, a viscoelastic member is mounted on at least one portion of said head part in a range of from a 45-degree position to a 135-degree position and in a range from a 225-degree position to a 315-degree position by interposing said viscoelastic member between said string protection member and said racket frame; said viscoelastic member having a plurality of holes through which said cylindrical portions of said string protection member are penetrated; and is plate-shaped so that said viscoelastic member is interposed between said belt-shaped portion and a peripheral surface of said head part, and the moment (Is) of inertia of said tennis racket in a swing direction is set to be not less than 450,000 g/cm 2 nor more than 490,000 g/cm 2 , when said strings are not tensionally mounted thereon; and the moment (Ic) of inertia of said tennis racket in a center direction is set to be not less than 15,000 g/cm 2 nor more than 19,000 g/cm 2 , when said strings are not tensionally mounted thereon.