Composite grille louvers

Abstract

A grille having a plurality of s-louvers shaped to increase the efficiency of air flow through the grille without decreasing the effectiveness of the louvers at stopping or deflecting projectiles. Each louver has a hooked portion at the end of the louver to present a ballistic hook for stopping projectiles ricocheting through the circuitous path defined between the louvers. An insert having a closeout for covering the ballistic hook is positioned within each hooked shape portion to eliminate the eddy or stall created at the end of the circuitous path by ballistic hook. The closeout can be penetrated by projectiles ricocheting through the circuitous path such that the ballistic hook can still capture projectiles within the inlet.

1 . A ballistic grille for preventing projectiles from entering a protected vehicle compartment through an air supply vent while allowing air to flow into the protected compartment through the vent, comprising:
 a plurality of S-shaped louvers each having an exterior end and an interior end, wherein each louver further comprises a hook portion at the interior end defining an inlet in the louver to form a ballistic hook for catching projectiles; and   a plurality of inserts comprising a closeout permeable by projectiles, wherein each insert is affixed to the hook portion of a corresponding louver;   wherein the S-shaped louvers are arranged in an overlapping configuration to define a plurality of circuitous paths through the vent between the louvers and to deny projectiles a linear path through the vent, wherein the inserts are positioned to enclose the inlet and the ballistic hook to maintain a continuous flow of air through the corresponding circuitous path.   
     
     
         2 . The ballistic grille of  claim 1 , wherein the exterior end of each louver comprises 1 tapered shape to facilitate the flow of the air into the circuitous paths. 
     
     
         3 . The ballistic grille of  claim 1 , wherein each closeout forms an enclosed air pocket within the corresponding inlet. 
     
     
         4 . The ballistic grille of  claim 1 , wherein each insert further comprises a foam core positioned within the corresponding inlet, wherein the foam core comprises a lower density material than the louver such that projectiles can penetrate the foam core. 
     
     
         5 . The ballistic grille of  claim 4 , wherein the foam core comprises a closed-cell foam material. 
     
     
         6 . The ballistic grille of  claim 1 , wherein the louver comprises a composite material combining a fibrous material and a matrix material. 
     
     
         7 . The ballistic grille of  claim 6 , wherein the fibrous material is selected from a group consisting of aramid, S2 glass fibers and combinations thereof. 
     
     
         8 . The ballistic grille of  claim 6 , wherein the fibrous material comprises about 60-80 wt % of the composite material and the matrix material comprises about 20-40 wt % of the composite material. 
     
     
         9 . The ballistic grille of  claim 1 , further comprising a plurality of hardened bars positioned proximate to the external ends of the louvers for fracturing and eroding incoming projectiles before the projectiles reach the louvers. 
     
     
         10 . The ballistic grille of  claim 1 , further comprising a honeycomb mesh positioned proximate to the internal ends of the louvers for capturing projectiles that ricochet through the circuitous paths. 
     
     
         11 . A louver for preventing projectiles from entering a protected vehicle compartment through an air supply vent while allowing air to flow into the protected compartment through the vent, comprising:
 an exterior end;   an interior end having a hook portion defining an inlet in the louver to form a ballistic hook for catching projectiles; and   an insert having a closeout permeable by projectiles enclosing the inlet and ballistic hook;   wherein the louver comprises an s-shape such that the louver can be arranged in an overlapping configuration with other S-shaped louvers to define at least one circuitous path through the vent between the louvers and to deny projectiles a linear path through the vent;   wherein the insert prevents the ballistic hook from disrupting the flow of air through the circuitous path.   
     
     
         12 . The louver of  claim 11 , wherein the exterior end comprises a tapered shape to facilitate the flow of the air into the circuitous path. 
     
     
         13 . The louver of  claim 11 , wherein the closeout forms an enclosed air pocket within the corresponding inlet. 
     
     
         14 . The louver of  claim 11 , wherein the insert further comprises a foam core positioned within the corresponding inlet, wherein the foam core comprises a lower density material than the louver such that projectiles can penetrate the foam core. 
     
     
         15 . The louver of  claim 14 , wherein the foam core comprises a closed-cell foam material. 
     
     
         16 . The louver of  claim 11 , wherein the louver comprises a composite material combining a fibrous material and a matrix material. 
     
     
         17 . The louver of  claim 16 , wherein the fibrous material is selected from a group consisting of aramid, S2 glass fibers and combinations thereof. 
     
     
         18 . The louver of  claim 16 , wherein the fibrous material comprises about 60-80 wt % of the composite material and the matrix material comprises about 20-40 wt % of the composite material. 
     
     
         19 . A method of preventing projectiles from entering an air supply vent for a protected compartment, comprising:
 positioning a plurality of S-shaped louvers in the vent, wherein each louver comprises a hook shape portion defining an inlet in the louver to form a ballistic hook for capturing projectiles;   arranging the S-shaped louvers in an overlapping arrangement to define a plurality of circuitous routes through the vent for the passage of air and denying projectiles linear paths through the vent; and   enclosing the inlet with a closeout permeable by a projectile to prevent the ballistic hook from disrupting the air flow through the circuitous route.