| 摘要 |
Table tennis balls are pushed by a rotated, notched, feed disc from a hopper to a pair of rotated throwing discs which move each ball along either an adjustable, spin producing, bottom guide or an adjustable, spin producing, upper guide. Thrown balls hit back by a player into a retrieving net roll into a vertical tube having a hose connected to the upper end of the hopper which has a fan mounted therein to draw the balls through the hose into the hopper. The tube is mounted on legs, and the hopper and a drive of the discs are mounted on a bar pivotal on a rod mounted adjustably on the tube. A crank drive carried by the bar and connected to the rod oscillates the bar to vary the direction of throw of the discs. Remote controls are manually actuated to vary the rate of oscillation, to vary the rate of rotation of the feed disc, and to vary the speed of the throwing discs. The net is mounted on segmental rod frames mounted on the tube and an upright secured to the tube.
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