Abstract: In construction of a tennis racket having a frame top and a yoke, balance adjusters having specific gravities larger than that of a frame are arranged at the frame top and the yoke, respectively, with a specified mass ratio between the two balance adjusters. Repulsion characteristics are much improved and vibratory impact is mitigated even at off-spot shooting whilst assuring long and speedy fly of balls with reduced physical damages on players.

Abstract: A tennis racket has longitudinal strings stretched in a longitudinal direction between a frame top and a grid end and transversal strings stretched in a transversal direction perpendicular to the longitudinal direction, and a ratio of a tensile force exerted on each longitudinal string to a tensile force exerted on each transversal string ranges from 2.5:1 to 4.0:1 so that a nodal line for vibrations in the secondary mode passes through a sweet area, thereby decreasing a reaction from the tennis racket at an impact against a tennis ball.

Abstract: In construction of a tennis racket provided with an oval Head Frame defining a racket face, the longitudinal size (W.sub.1) of the racket face is set to a value in a range from 320 to 390 mm, the transverse size (W.sub.2) of the same is set to a value in a range from 200 to 240 mm, and the longitudinal compressive rigidity of the head frame is adjusted to a value in a range from 30 to 200 Kgf/mm. The construction thus specified allows employment of an enlarged main/cross string tension ratio which assures high degree of spin performance at shooting balls.

Abstract: A tennis racket frame having the head and shaft, preferably made of a hollow FRP material, have uniform thickness along the longitudinal direction of the racket frame in a range from 23 to 28 mm with a natural frequency in a range from 160 to 260 Hz. Raised product of the Young's modulus (E) and moment of inertia of area (I) of the racket frame much improves its repulsion characteristics for long distance shot accurately in an intended direction. The specified natural frequency makes the vibrately performance of the racket frame very close to that of balls just after striking so that the vibration energy of the racket frame should be efficiently utilized for acceleration of balls. Further, the increased thickness of the head end assures raised accuracy in striking even when a ball is struck by a section of the face near the head end.

Abstract: In construction of a racket frame, its head defining a face is made up of a plurality of elongated members coupled to each other in a manner to allow elastic deformation at shooting balls of the elongated members towards the center of the face so that impulsion caused by shooting balls should be shared by the head in order to mitigate impulsive load on strings forming the face.

Abstract: In construction of a vibration absorber for a racket, a mass is indirectly supported by a visco-elastic member arranged within the grip or the yoke of the racket via an elongated interface so that resonant swing of the interface on receipt of vibration from the head of the racket should cause deformation of the visco-elastic member for thermal diffusion of vibration energy. The visco-elastic member is sandwiched between two elongated leaf springs. One end of the leaf spring is mounted to the wall of the racket handle and the other end of the leaf spring supports the mass. By proper choice of the component, vibration in a specified frequency range can be selectively damped so as to match vibration characteristics of rackets of various types.