US Patent 7082938 Baseball fielding practice machine

The present invention provides a baseball practice machine for propelling balls onto a practice field thereby providing simulated hits for use in fielding practice for ball players. The practice machine includes a ball hopper, a propulsion unit for propelling a ball toward a practice field, a movable barrel through which a ball is propelled. A barrel positioner is coupled to the propulsion unit and the movable barrel for adjusting the position of the barrel thereby controlling the trajectory of a propelled ball. A programmable control system controls the operation of the practice machine. Trajectory parameters for the propelled balls are selected from predetermined parameters defining the path of the ball to a location of a practice field where the ball is intended to land. Information defining the dimensions of a practice field are stored in a memory of the control system and used in determining the trajectory parameters.