Training ammunition cartridge with a gaseous plume signature

Abstract

A training ammunition projectile has a solid chemical component disposed in a base compartment that produces a gaseous visible plume after impact. The ammunition cartridge generates kinetic energy while propelling the projectile through a weapon barrel. This firing process imparts heat into a projectiles driving band. When the projectile is in flight, heat passes from the projectile's driving band into a compartment in the projectile housing the chemical component. When the component is exposed to increasing heat and low pressure, the it undergoes rapid sublimation. The projectile is configured with a vent opening in its base for emergence of the gaseous plume during flight. The opening is preferably capped to allow for stable storage and to prevent any gas from escaping until the projectile is fired.

What is claimed is: 
     
         1 . A training ammunition cartridge comprising a hollow projectile and a cartridge case with a propellant charge, the projectile having a hollow projectile body and a projectile head designed to withstand the forces applied when the projectile is fired from a gun and designed to burst when the projectile strikes a target, said projectile body having a projectile base with a compartment therein and further comprising:
 a solid first chemical component disposed in the base compartment of the projectile which sublimates and forms a gas when heated to an elevated temperature during firing and flight of the projectile,   said projectile body having an opening in said base for emergence of the gas for marking the trail of the projectile by means of a gaseous visible plume during flight.   
     
     
         2 . The training ammunition cartridge defined in  claim 1 , wherein the elevated temperature is in the range 40° to 120° C. 
     
     
         3 . The training ammunition cartridge defined in  claim 1 , wherein the first chemical component is iodine. 
     
     
         4 . The training ammunition cartridge defined in  claim 1 , further comprising a closure disposed in said opening in the projectile base to prevent the emergence of the first chemical component prior to firing the projectile, said closure being configured to open and allow emergence of the first chemical component upon firing of the projectile. 
     
     
         5 . The training ammunition cartridge defined in  claim 1 , further comprising a plurality of second chemical components each received in a respective second compartment in the projectile body, said second components being designed to react chemically exothermally when mixed, due to at least one of the initial acceleration and the centrifugal forces acting on the projectile as the projectile is fired from a weapon, causing the mixed second components to heat the first chemical component during flight of the projectile. 
     
     
         6 . The training ammunition cartridge defined in  claim 5 , wherein said projectile has a frangible ogive in the projectile head designed to burst when the projectile body strikes a target and wherein said second compartment is disposed in said head and such that said second components create a plume for Infrared marking of the target upon impact. 
     
     
         7 . The training ammunition cartridge defined in  claim 5 , wherein one of said second chemical components is a gas that includes oxygen. 
     
     
         8 . The training ammunition cartridge defined in  claim 5 , further comprising a third chemical component, disposed in a third compartment in the projectile body and designed to undergo a phase change at a prescribed temperature, said third chemical component serving to absorb heat at a prescribed temperature and thereby prevent overheating of the projectile and the marking agents during flight. 
     
     
         9 . The training ammunition cartridge defined in  claim 8 , wherein said third chemical component is a phase change material disposed within the projectile body, said phase change material being operative to melt and absorb thermal energy. 
     
     
         10 . The training ammunition cartridge defined in  claim 1 , wherein said projectile further comprises a marking agent disposed in the head for marking the position of the target upon release when the ogive has burst upon impact with the target, said marking agent comprising at least one of:
 (1) a plurality of fourth chemical components each received in separate fourth frangible compartment in the head, said fourth components being mixed and reacting chemically with each other when the compartments break, causing the mixed components to luminesce, said compartments being designed to be broken by at least one of the initial acceleration and the centrifugal forces acting on the projectile when the projectile is fired from a weapon, while retaining the fourth chemical components in the ogive so that such components are mixed at the time the projectile is fired from a weapon and luminesce by the time the projectile strikes the target; and   (2) a fifth dry powder component disposed in the head and designed to create a plume for visible marking of the target upon impact.   
     
     
         11 . The train ammunition cartridge defined in  claim 10 , wherein the marking agent includes both (1) the fourth chemical components and (2) the fifth powder component for marking the target.