Abstract: A tennis practicing device includes a foldable base frame assembly, a tube pivotally mounted on the base frame assembly, and a ball returning assembly mounted in the tube. The ball returning assembly includes a tubular member consisting of an upper elastomeric section and a lower rigid section, a spring position in the tubular member, and a connecting member. A tennis ball is pre-drilled in its diameter before it is mounted to the ball returning assembly. The connecting member passes through the holes of the ball until an enlarged head end of the member grips the surface of the ball. A first end of the spring is attached to a tail end of the connecting member and the second end of the spring is attached to the lower end of the lower rigid section. The tube has a engaging means, in the form of a knob in an upper portion of the tube to clamp releasably the ball returning means.

Abstract: A tennis ball throwing machine which comprises a motor secured to a frame board, the output end of the motor shaft having a gear wheel securely mounted thereon, first and second transmission shaft respectively fixed to a gear wheel at one end thereof and engaged with the gear wheel of the motor, a bat pivotally attached to the first transmission shaft, one end of the bat being a hitting portion, and the other end thereof being attached to a tension spring, a cam pivoted on the second transmission shaft, a ball guiding groove being pivoted on a supporting shaft and having a portion thereof in contact with the cam to move upward, downward, leftward and rightward, a tension spring at the bottom end of the ball guide groove.