Dynamically variable tennis racket

Claim 1

A tennis racket comprising: a. a handle portion and a head portion having longitudinal and transverse axes, a closed tubular member formed to the shape of said racket and defining first and second tubular paths, said first tubular path extending on one side of said head and handle portions from the top of said head portion, along the periphery of said head portion to said handle portion, and along at least a part of said handle portion, and said second tubular path extending similarly on the side of said head and handle portions opposite that of said first tubular path; b. first and second substantially similar weighting means slidably disposed within said first and second tubular paths, respectively, and normally disposed at the handle portion of said tubular paths; and c. first and second spring means located respectively in said first and second tubular paths, each of said spring means having one end fixed at the top end of its respective tubular path, each of said spring means being substantially coextensive with its respective tubular path and having its other end engaging the weight means, each of said spring means having a stiffness and length so proportioned to the mass of said weight means and to the centrifugal forces developed during the conventional arcuate full swing of any type of hitting stroke so that the spring force produced thereby is such that the weight means remain in said normal disposition when the racket is at rest in any orientation and upon impact with the ball each of said spring means will be compressed to a degree sufficient to locate said weight means substantially on the transverse axis of said head portion.