Tennis ball launching machine - has valve operated catch to trip arm selectively and provide quarter turn rotation to launcher arm

摘要

The machine is used for launching tennis balls and has a power operated launching arm. This contacts a catch mounted on the support post to selectively provide a quarter turn rotation and vary the trajectory of the ball. The catch (1) is fixed to a shaft (2) passing through a sleeve (3) on the post (4). The other end of the shaft has a plate (5) resting on an electrically operated valve (8) also mounted (9) on the post. When the valve is energised, the catch is fixed and the launcher rotates, if the valve is unenergised, the catch is free and the arm does not rotate.