Patent 10151555 was granted and assigned to Bell Helicopter on December, 2018 by the United States Patent and Trademark Office.
An air cannon has a barrel and a sabot sized to fit within the barrel and configured to engage a projectile located within the barrel forward of the sabot. A flexible cord connects the sabot to a fixed location relative to the barrel. Forward motion of the sabot is decelerated by the cord after the sabot exits the forward end of the barrel, and the sabot is retained by the cord near the forward end of the barrel.