US Patent 9623312 Tennis training aids

A tennis teaching aid comprises a stand and a ball (10) and a guide (12) mounted on the stand for rotation about an axis. The guide (12) extends around the ball (10) and defines a planar guide plane that is parallel to but spaced from a required path of a tennis racquet to hit the ball (10) with topspin. The majority of the ball (10) projects above the guide plane for contact with a tennis racquet so that a correct contact with the ball (10) is achieved when the racquet moves parallel to, but not in contact with, the guide (12) and the ball (10) is spinning about its rotational axis.