Lightweight ceramic armor with improved blunt trauma protection

Abstract

The invention relates to armor that is intended to withstand and provide protection against blunt trauma or ballistic impact from a projectile or the impact of a stabbing weapon. Such impacts on the armor may transmit a high localized load to the body of the wearer. The invention reduces the intensity of this loading thereby reducing tissue trauma. The invention uses one or more layers of an energy absorbing material that contains a large volume fraction of fluid filled free space, distributed throughout an internal cellular structure that accommodates deformation on one surface without passing on the same degree of deformation to its adjacent surface. It is, in effect, a highly compressible layer that disperses a dynamic load applied normal to its surface (resulting for example from the bullet impact) into a more laterally extensive pressure distribution. When this material is combined with reinforcing fiber material layers, the deformation reduction is further enhanced.

We claim:  
     
         1 . Body armor comprising: 
 a penetration-resistant material layer positioned for receiving an incident projectile;    a composite backing layer positioned contiguous to said penetration-resistant layer for receiving said projectile after it has penetrated said penetration-resistant layer; and    at least one layer of multiple closed cell flexible material positioned contiguous to said composite backing layer opposite of said penetration-resistant material.    
     
     
         2 . The body armor recited in  claim 1  further comprising a spall shield enclosing said penetration-resistant layer, said composite backing layer and said multiple closed cell material layer.  
     
     
         3 . The body armor recited in  claim 1  wherein said at least one multiple closed cell flexible material layer comprises at least one layer of reinforced fiber material.  
     
     
         4 . The body armor recited in  claim 1  wherein said penetration-resistant material comprises a ceramic.  
     
     
         5 . The body armor recited in  claim 1  wherein said composite backing comprises a carbon and resin impregnated fiber.  
     
     
         6 . The body armor recited in  claim 1  wherein said at least one multiple closed cell flexible material comprises a TPU cellular honeycomb structure.  
     
     
         7 . The body armor recited in  claim 1  wherein said at least one multiple closed cell flexible material comprises a plurality of contiguous sealed cells, each such cell having a fluid therein.  
     
     
         8 . The body armor recited in  claim 7  wherein said fluid is a gas.  
     
     
         9 . The body armor recited in  claim 8  wherein said fluid is air.  
     
     
         10 . The body armor recited in  claim 3  wherein said at least one layer of reinforced fiber material comprises Kevlar®.  
     
     
         11 . An upgrade apparatus for improving projectile penetration resistance of soft body armor; the upgrade apparatus comprising: 
 a ceramic plate;    a composite backing layer in contiguous relation to said ceramic plate;    a flexible layer of cellular material having a plurality of contiguous closed cells positioned between opposed cover layers, said cellular material layer being positioned closest to said soft body armor.    
     
     
         12 . The upgrade apparatus recited in  claim 11  further comprising a spall shield enclosing said ceramic plate, said composite backing layer and said layer of cellular material.  
     
     
         13 . The body armor recited in  claim 11  wherein said closed cell flexible material layer comprises at least one layer of reinforced fiber material.  
     
     
         14 . The body armor recited in  claim 11  wherein said composite material comprises a resin impregnated fiber.  
     
     
         15 . The body armor recited in  claim 11  wherein said closed cell material comprises a TPU cellular honeycomb structure.  
     
     
         16 . The body armor recited in  claim 11  wherein said closed cell material comprises a plurality of contiguous sealed cells, each such cell having a fluid therein.  
     
     
         17 . The body armor recited in  claim 16  wherein said fluid is a gas.  
     
     
         18 . The body armor recited in  claim 17  wherein said fluid is air.  
     
     
         19 . The body armor recited in  claim 13  wherein said at least one layer of reinforced fiber material comprises Kevlar®.  
     
     
         20 . An armor apparatus comprising: 
 a rigid strike face and a composite backing affixed to said strike face; and    a layer of flexible cellular material positioned contiguous to said backing.    
     
     
         21 . The armor apparatus recited in  claim 20  wherein said strike face comprises a material taken from the group consisting of ceramic material, metallic material, plastic material and composite material.  
     
     
         22 . The armor apparatus recited in  claim 20  wherein said composite backing comprises a fiber and resin-based material.  
     
     
         23 . The armor apparatus recited in  claim 20  wherein said layer of cellular material comprises thermoplastic polyurethane.  
     
     
         24 . The armor apparatus recited in  claim 20  wherein said layer of flexible cellular material comprises at least one reinforcing layer bonded to a surface of said layer of flexible cellular material.  
     
     
         25 . The armor apparatus recited in  claim 24  wherein said at least one reinforcing layer comprises a fabric.  
     
     
         26 . A method of reducing blunt trauma to a wearer of a protective plate resulting from sudden impact of an external force applied to the plate; the method comprising the steps of: 
 providing a layer of flexible cellular material having a plurality of contiguous hollow cells; and    placing said layer between said plate and said wearer.    
     
     
         27 . The method recited in  claim 26  further comprising the step of: 
 affixing said layer to said plate.  
 
     
     
         28 . The method recited in  claim 26  further comprising the step of: 
 forming said plate out of a ceramic.  
 
     
     
         29 . The method recited in  claim 26  further comprising the step of: 
 forming said cellular material out of a thermoplastic polyurethane.  
 
     
     
         30 . The method recited in  claim 26  further comprising the step of: 
 reinforcing said cellular material by covering at least one surface of said material with a layer of reinforcing fiber.