| 摘要 |
A ball throwing machine for hitting out tennis balls or the like at predetermined time intervals, in which a lock cover is rotatable or slidable into engagement with a switch which is capable of making and breaking an electric current to a drive motor. Said lock cover is mounted in a position adjacent to a rotating trace of a hitting lever. In the event an object other than ball, for example, a hand, a finger or a rod, should be drawn into the interior of the machine together with the hitting lever while this lever is rotated by a motor to expand a biasing spring, the lock cover will rotate or slide to break the electric current to the motor and stop the motor immediately, thereby preventing the occurrence of injury. |
