Abstract: The present invention is a portable structure used for exhibition or sports (batting cage) applications including an expansion section with a plurality of expansion segments, each of which is self-contained. Each expansion segment is bounded by an upright member onto which an articulating arm is attached adjacent the tope and bottom. Each articulating arm bends at an elbow and folds flat against the upright members when each expansion segment is extended, the articulating arms straighten at the elbow and pivot in a scissor-type motion with respect to the upright members until the articulating arms are fully extended substantially straight. The expansion segments roll on rollers removably affixed to the upright members. The portable structure includes three positions, a transport position wherein large wheels or skids are suppled for easy manipulation of the device, an expansion segment wherein the expansion segments are extended or collapsed using smaller wheels.

Abstract: A ball control device for combination with a ball tossing machine of the type having a rotating throw arm for propelling a ball. The ball control device has a proximal end for mounting to the throw arm and a terminal end. Between the proximal and terminal ends lies a slightly arcuate, open, longitudinal channel or trough that receives and controls a ball as the throw arm rotates. The ball advances along the surface of the channel until, upon rotation to a break over point, the ball is propelled from the terminal end of the device. To impart a curve, spin or drop to the ball, a spin actuator is mounted at the terminal end of the device. A surface portion of the ball, as it reaches the terminal end of the device (at the break over point), is momentarily engaged by the spin actuator, which, when the ball is propelled, induces a spin upon the ball in a manner that mimics the action of a pitcher's grip upon the ball.