Patent ID: 7621208

Claim:
A two-piece, two-stage, reduced energy mechanically-operating cartridge for launching a projectile from a dedicated or modified firearm, comprising: (a) a piston sleeve comprising a piston sleeve jacket defining a projectile cavity at a first longitudinal end for coupling the projectile therein, and a second end for coupling with a primary case, and the piston sleeve including one or more partially annular protrusion portions (hereinafter “cogs”) or channels or both; and (b) the primary case comprising a primary case jacket for being axially coupled with the second end of the piston sleeve, and including one or more complementary partially annular cogs or channels, or both, to those of the piston sleeve, and defining a primary case cavity for coupling with a propellant mechanism, (c) wherein said primary case and piston sleeve are configured such that an axial coupling of the primary case with the second end of the piston sleeve involves mating of the complementary cogs and channels of the primary case and piston sleeve, and (d) wherein said primary case and piston sleeve are further configured such that upon the axial coupling of the piston sleeve and primary case and at least partial compression together, the primary case and the piston sleeve become relatively rotationally movable with regard to the cogs traveling within the channels, followed by relative axial movement to a fully compressed configuration, such that upon activation, when the piston sleeve and primary case telescope from the static position, the cogs move in the opposite axial direction within the channels.