Racquet esp. for tennis, with enclosed inner frame with strings - has surrounding outer frame joined to inner frame by four links in form of ball and socket joints or pivot links

摘要

The racquet, esp. for tennis, has an enclosed inner frame (4) with strings surrounded at least partly by an outer frame (1) with handle (2). The frames are joined by four links (5A,5A') positioned in pairs and symmetrical with the racquet longitudinal axis (L) on the head and handle sides. The inner frame has two parallel vibration node lines (VL,VL') on the racquet plane and passing at right angles to the racquet longitudinal axis. The links are ball-and-socket joints (5A,5A') each movable on three orthogonal axes, two (8-11) of which are on the racquet plane. The links may be pivot linked each with an axis of rotation on the racquet plane. USE/ADVANTAGE - The tennis racquet playing quality is enhanced by the inner frame possessing a natural vibration shape.