US Patent 8485171 Apparatuses for launching projectiles

An apparatus for launching projectiles. The apparatus includes a hollow cylinder and a piston in sliding engagement through the hollow cylinder. The piston is configured to drive a fluid through the hollow cylinder. The apparatus further includes a barrel defining an open end and a chamber in fluid communication with the hollow cylinder. The chamber is configured to receive a projectile and to receive fluid driven from the hollow cylinder wherein the projectile is driven from the barrel through the open end.