Abstract: A ball projecting apparatus includes a housing with a frontward opening. The interior of the housing has an elongated ball guider which extends inclinedly and longitudinally from a position near the frontward opening and which terminates at a lower position, an electrically driven rotor which is mounted below the elongated ball guider, and a torsion spring which is mounted pivotally to the housing. The torsion spring has a first end portion which engages by a stopper and a second end portion which extends into a circular path that is traveled by the rotor when the rotor is activated.

Abstract: A racket stringing apparatus includes a frame unit, a racket retaining device and a string tautening device. The string tautening device includes a string clamping unit, a swing lever and a counterweight mounted movably on the swing lever. A stringing receiving groove unit is formed in the top surface of the string clamping unit and has a non-clamping section and a clamping section. The non-clamping section has a fixed width, while the clamping section has a width which can be adjusted to clamp tightly a string therein. The string tautening device includes a limit member which has a first limit peripheral surface and a second limit peripheral surface. The swing lever has a lower end which normally abuts against the first limit peripheral surface so as to prevent the actuator end portion of the swing lever from turning toward the racket retaining device and to permit the actuator end portion to turn away from the racket retaining device until the swing lever contacts the second limit peripheral surface.