Self-sprung stabilization fin system for gun-launched artillery projectiles

Abstract

A system and process for the aerodynamic stabilization of rocket-assisted artillery projectiles launched from smooth-bore cannons comprises multiple stabilization fins stowed circumferentially and held by a cap until muzzle exit. At muzzle exit, the cap separates and allows the fins to self-deploy using the energy stored within the fin material, which is either shape memory alloy or spring steel. The fins are then locked into place and serve to stabilize the projectile without interfering with the discharge of hot propelling gasses from the rocket nozzle.

1 . A system for providing in-flight aerodynamic stability to a projectile launched from a gun, said system comprising:
 a projectile adapted to be launched from a muzzle of a gun;   a generally cylindrical hub operatively connected to said projectile;   a notched end plate attached to an aft end of said hub;   a plurality of equally spaced fins hinged along a circumferential periphery of said hub;   a cap encapsulating said fins and said hub; and   wherein at muzzle exit, said cap is adapted to separate from said fins, said hub, and said end plate thereby allowing said fins to self-deploy using potential energy stored within said fins.   
     
     
         2 . The system of  claim 1 , further comprising an incompressible gel buffered within said cap. 
     
     
         3 . The system of  claim 1 , wherein said fins comprise a spring steel material. 
     
     
         4 . The system of  claim 1 , wherein residual muzzle exit acceleration forces said fins into a plurality of notches provided in said notched end plate thereby locking said fins into a deployed flight position is substantially perpendicular to said hub. 
     
     
         5 . The system of  claim 1 , wherein said fins are adapted to conformably fit around an outer surface of said hub when said fins are in a stowed configuration. 
     
     
         6 . The system of  claim 1 , wherein said gun is a smooth bore cannon. 
     
     
         7 . The system of  claim 1 , further comprising:
 an adapter;   a generally cylindrical boss operatively connected to said adapter, wherein said adapter connects said projectile to said hub;   hinge pins connected to said boss, wherein said hinge pins operatively connect said fins to said hub; and   a closure cap operatively connected to said hub and adapted to hold said fins to a curved shape and conform said fins to said hub when in a stowed configuration.   
     
     
         8 . The system of  claim 1 , further comprising a rocket assist sub module housed within said hub. 
     
     
         9 . A system for providing in-flight aerodynamic stability of projectiles launched from a gun, said system comprising:
 a projectile adapted to be launched from a muzzle of a gun;   a generally cylindrical open-ended hub operatively connected to said projectile;   multiple fins hinged along a circumferential periphery of said hub;   a sacrificial cap encapsulating said multiple fins and said hub until said projectile exits said muzzle.   
     
     
         10 . The system of  claim 9 , further comprising an end plate attached to said hub, wherein residual muzzle exit acceleration forces said multiple fins into notches in said end plate thereby locking said multiple fins into a deployed flight position that make said multiple fins perpendicular to said hub. 
     
     
         11 . The system of  claim 9 , further comprising a gel adapted to fill voids within said cap. 
     
     
         12 . The system of  claim 9 , wherein said multiple fins comprise a spring steel material. 
     
     
         13 . The system of  claim 9 , wherein at muzzle exit, said sacrificial cap is adapted to separate from said multiple fins, said hub, and said end plate thereby allowing said multiple fins to self-deploy using potential energy stored within said multiple fins. 
     
     
         14 . The system of  claim 9 , wherein said multiple fins are adapted to conformably fit around an outer surface of said hub when said multiple fins are in a stowed configuration. 
     
     
         15 . The system of  claim 9 , further comprising:
 an adapter;   a generally cylindrical boss operatively connected to said adapter, wherein said adapter connects said projectile to said hub;   hinge pins connected to said boss, wherein said hinge pins operatively connect said multiple fins to said hub and   a closure cap operatively connected to said hub and adapted to hold said fins to a curved shape and conform said fins to said hub when in a stowed configuration.   
     
     
         16 . The system of  claim 9 , further comprising a rocket assist sub module housed within said hub. 
     
     
         17 . A method of providing in-flight aerodynamic stability to artillery projectiles launched from a gun, said method comprising:
 storing a projectile system in a gun, wherein said projectile system comprises:
 a projectile; 
 a generally cylindrical hub operatively connected to said projectile; 
 an end plate attached to said hub; 
 a plurality of fins hinged along a circumferential periphery of said hub; 
 a cap encapsulating said multiple fins and said hub; 
   injecting a gel into voids within said cap;   launching said projectile system from a muzzle of said gun; and   said cap separating from said multiple fins and said hub.   
     
     
         18 . The method of  claim 17 , wherein residual muzzle exit acceleration forces said multiple fins into a plurality of notches provided in said end plate thereby locking said multiple fins into a deployed flight position that make said multiple fins perpendicular to said hub. 
     
     
         19 . The method of  claim 17 , wherein at muzzle exit, said cap is adapted to separate from said multiple fins, said hub, and said end plate thereby allowing said multiple fins to self-deploy using potential energy stored within said multiple fins. 
     
     
         20 . The method of  claim 17 , wherein said multiple fins are adapted to conformably fit around an outer surface of said hub when said multiple fins are in a stowed configuration.