Device using a pneumatically-actuated carrier to eject projectiles along a trajectory

摘要

A pneumatic device for firing projectiles with a charge of compressed air that accelerates a projectile carrier and the projectile through a barrel. The charge of compressed air is released into the barrel behind the projectile carrier and acts on the projectile carrier to initially accelerate it and a ball or other projectile down the barrel. The diameter of the projectile carrier is slightly less than that of the barrel and it includes a concave recess that receives balls of differing diameters, centering as they are accelerated through the barrel. The barrel is sufficiently long so that the projectile carrier comes to a halt before being ejected from the barrel. An intake for a compressor that develops the charge of compressed air is coupled in fluid communication with the barrel, behind the projectile carrier. Operation of the compressor produces a partial vacuum so that ambient air pressure forces the projectile carrier back to its firing position. An optical sensor is included adjacent to the open end of the barrel to sense when a ball has been loaded, which initiates a firing sequence, to prevent a ball from being fired if the barrel is obstructed, and to determine the velocity of a ball being ejected from the barrel.