| 摘要 |
PCT No. PCT/AT89/00075 Sec. 371 Date May 16, 1990 Sec. 102(e) Date May 16, 1990 PCT Filed Aug. 28, 1989 PCT Pub. No. WO90/01975 PCT Pub. Date Mar. 8, 1990.A ball delivery apparatus, in particular for tennis balls, includes a ball magazine, a ball firing system, and a feed system that moves balls from the ball magazine one by one to the ball firing system. The ball firing system fires each ball in accordance with a preprogrammed firing setting that in each instance determines the speed, spin, and/or direction of each ball. A variable feed sequence frequency of the feed system is controlled as a function of the firing settings of the ball firing system. A time interval scale for establishing the movement of the next ball through the feed system is associated with each firing setting accepted by the ball firing system for firing a ball. The intervals between the balls can be matched to the particular ball characteristics. |
