Abstract: Apparatus for propelling tennis balls at timed intervals from a storage hopper. The hopper has the configuration of an inverted truncated cone. At the base of the cone and in a position to receive balls from the cone, is a rotating ball selector. The ball selector is driven through a clutch which disengages at a predetermined torque. Upon disengagement, the clutch permits the drive to rotate for approximately one-half revolution without transmitting any torque to the ball selector, and then induces a partial counter-rotation or reverse motion of the ball selector by the action of a spring loaded pin engaging an inclined face on a clutch cam. .Iadd.