Two-piece insert and/or flash tube for polymer ammunition cartridges

Abstract

A high strength polymer-based cartridge casing can include an upper polymer component, molded from a polymer. The upper component has a first end having a mouth, at least a wall between the first end and a second end of the upper component opposite the first end, an overlap portion extending from the wall near the second end. An upper insert is included and has a first end and an opposing second end, a molded area disposed approximate the first end, that engages the overlap portion to join the upper polymer component and the upper insert, and an insert engagement area disposed approximate to the second end. Further, a lower insert has a front end and a back end, an upper insert engagement area engaging with the insert engagement area, a rim and groove disposed around an outside of the lower insert, and a primer pocket disposed inside the back end. Lastly, a flash hole is inside the lower insert and communicates between the primer pocket and upper polymer component.

1 . (canceled) 
     
     
         2 . A high strength polymer-based cartridge casing comprising:
 an upper polymer component, molded from a polymer, comprising:
 a first end having a mouth; 
 at least a wall between the first end and a second end of the upper component opposite the first end, a volume inside the wall at least partially forming a propellant chamber; and 
 an overlap portion extending from the wall near the second end; 
   an insert, having a first end and an opposing second end, comprising:
 a molded area disposed approximate the first end, that engages the overlap portion to join the upper polymer component and the insert; 
 a rim and groove disposed around an outside of the insert approximate the second end; 
 a primer pocket disposed inside the second end; and 
 a flash hole, inside the insert and communicating between the primer pocket and upper polymer component; and 
 a flash tube in fluid communication with the primer pocket and the propellant chamber. 
   
     
     
         3 . The high strength polymer-based cartridge casing of  claim 2 , wherein the flash tube comprises:
 a front end disposed in the propellant chamber;   a back end disposed in the primer pocket comprising a washer end sized larger than the flash hole and preventing the back end from passing through the flash hole.   
     
     
         4 . The high strength polymer-based cartridge casing of  claim 3 , wherein the back end of the flash tube is sized approximately to a diameter of the primer pocket. 
     
     
         5 . The high strength polymer-based cartridge casing of  claim 2 , wherein the flash tube comprises:
 a vent hole disposed on a perimeter of the flash tube.   
     
     
         6 . The high strength polymer-based cartridge casing of  claim 2 , wherein the flash tube extends approximately 50% to 90% of a length of the propellant chamber.