Abstract
Ordinary pitching machines using two wheels with parallel rotating shafts throw only balls with spinning axis perpendicular to the thrown directions. A pitching machine using two rotating wheels arranged with offset shaft angles is developed to throw various curving balls such as gyro ball, slider ball, cut ball and so on. The machine pitches various balls as if they were thrown by real pitchers in spite of its simple mechanism. Assuming that velocities at two contact points on a ball with wheel surfaces are instantly accelerated to the wheel surface velocities, characteristics of the pitching machine are analyzed by using schematic and vector analysis.
