Patent ID: 9423205
Filing Date: 2016-08-23
CPC Classification: F41B,F42B

Claim Text:
1. A method for launching a projectile, comprising: a. providing a chassis, including b. providing a core, slidably mounted on said cocking shaft, said core including a loading surface and an outward-facing helix; c. wherein said first end of said cocking spring is attached to said core using a rotation-limiting connection and said second end of said cocking spring is attached to said chassis using a rotation-limiting connection; d. providing a projectile formed as a solid of revolution around a central axis, said projectile having a central bore along said central axis and an aft extreme; e. placing said central bore of said projectile over said core and said aft extreme of said projectile against said loading surface of said core; f. compressing said cocking spring by urging said projectile and said core rearward with respect to said chassis; g. providing a tab connected to said chassis; h. torquing said cocking spring by engaging said tab in said helix so that a mechanical interface between said tab and said helix rotates said core as said core travels rearward with respect to said chassis; and i. releasing said cocking spring, said cocking spring being configured to simultaneously accelerate said core linearly and rotationally and propel said projectile away from said chassis with a linear and rotational motion.