| 摘要 |
A ball pitching device includes a ball feed tube mounted on support components which are adjustable about vertical and horizontal pivot axes to vary the horizontal and vertical positions of delivery of pitched balls relative to a practicing batter standing at the position of home plate. The device also includes a pair of ball projecting wheels rotated by electric motors the speeds of which are adjusted by controlling potentiometers. Eccentric cams are included in the support components for enabling incremental adjustments about the vertical and horizontal pivot axes, preferably without recognition by the practicing batter, to make incremental changes in the horizontal and vertical positions of delivery of pitched balls. The electric circuit of the drive motors also includes adjustable electric signal generators operatively connected to the support components providing for elevation adjustments, for effecting changes in motor speed in accordance with changes in elevation of the ball feed tube.
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