Method and apparatus for absorbing the energy of bullet impacts

Abstract

A method for and apparatus absorbing the energy of a projectile strike by a multiplicity of energy dissipating elements of high mass that are contained within a spaced defined by walls. A projectile passing through one of the walls transmits its energy to a multiplicity of energy dissipating elements, such as hardened steel balls or various shaped objects of high mass, by causing energy transfer and distribution through a loose mass of the energy dissipating elements and disintegrating the projectiles. Energy absorbing apparatus embodying this method may take the form of a static or moveable bullet or projectile trap, an energy absorbing external barrier or shelter on vehicles, and portable personnel protection structures for use in a tactical environment. The energy absorbing and dissipating elements are subject to some movement in response to the energy imparted by the projectiles and quickly settle after the energy has been dissipated.

1 . A projectile energy absorbing and dissipating device for absorbing and dissipating the energy of a class of projectiles, comprising:
 a support structure;   a rear wall being mounted to said support structure and being resistant to penetration by the class of projectiles;   a front wall being mounted in spaced relation with said rear wall and defining a compartment therewith, said front wall being readily penetrable by the class of projectiles;   containment walls defining closures for said compartment; and   a multiplicity of energy absorbing elements being arranged in loose and moveable relation within said compartment and being disposed in engagement with adjacent energy absorbing elements and being contained by said front, rear and containment walls.   
     
     
         2 . The projectile energy absorbing and dissipating device of  claim 1 , comprising:
 said support structure being a support framework;   said rear wall and said front wall being mounted to said support framework and being secured in spaced relation; and   said containment walls being mounted to said support framework and being cooperative with said rear and front walls for ensuring against displacement of said energy absorbing elements from said compartment.   
     
     
         3 . The projectile energy absorbing and dissipating device of  claim 1 , comprising:
 said projectile energy absorbing and dissipating device being a bullet trap for the class of projectiles including small arms projectiles up to 50 caliber;   said rear wall being composed of a hard and dense material of sufficient thickness to resist being penetrated by the class of projectiles; and   said front wall being composed of a material that is penetrable by the class of projectiles and which ensures minimal damage to said front wall by projectiles passing through it.   
     
     
         4 . The projectile energy absorbing and dissipating device of  claim 1 , comprising:
 said rear wall being defined by a panel composed of steel; and   said front wall being defined by a panel composed of a polymer material.   
     
     
         5 . The projectile energy absorbing and dissipating device of  claim 3 , comprising:
 said containment walls being composed of a material of sufficient structural integrity for containment of energy absorbing and dissipating elements composed of dense hard material and being sufficiently perforate to permit projectile component residue to pass therethrough and be deposited for collection.   
     
     
         6 . The projectile energy absorbing and dissipating device of  claim 1  being in the form of an exterior protective device for vehicles, comprising:
 said rear wall being mounted externally of a vehicle structure. 
 
     
     
         7 . The projectile energy absorbing and dissipating device of  claim 1  being in the form of an exterior protective device for vehicles, comprising:
 said rear wall being defined by an external surface of a vehicle and constituting said support structure. 
 
     
     
         8 . The projectile energy absorbing and dissipating device of  claim 1 , wherein said device is in the form of a rotatable bullet trap, said device comprising:
 said support structure being mounted for rotation;   said containment walls defining perforations of sufficient dimension to permit projectile component debris to pass therethrough and to prevent said energy absorbing elements from passing therethrough; and   during rotation of said device projectile component debris descending through said multiplicity of energy absorbing elements, passing through said perforations of said containment walls and being deposited for collection.   
     
     
         9 . The projectile energy absorbing and dissipating device of  claim 1 , wherein said device is in the form of a protective enclosure for personnel, said device comprising:
 said rear wall being defined by rear wall panels arranged at a site to form an inner enclosure wall structure having an opening for personnel entrance and exit;   said front wall being defined by front wall panels disposed in spaced relation with said rear wall panels and arranged to form an outer enclosure wall structure and to define said compartment; and   said The projectile energy absorbing and dissipating device of  claim 1  poured into said compartment and defining a mass of loose energy absorbing elements.   
     
     
         10 . The projectile energy absorbing and dissipating device of  claim 9 , comprising:
 said rear wall and said front wall being of portable nature and being recoverable for use at a different site when use of said protective enclosure is no longer needed at the site; and   said multiplicity of projectile energy absorbing and dissipating elements being recoverable for use at a different site.   
     
     
         11 . A projectile energy absorbing and dissipating device for absorbing and dissipating the energy of a designated class of non-explosive firearm projectiles including small arms projectiles up to 50 caliber, comprising:
 a support framework structure;   a rear wall being panel being mounted to said support framework structure and being resistant to penetration by the class of firearm projectiles, said rear wall defining a perimeter;   a front wall panel being mounted to said support framework structure and being disposed in spaced relation with said rear wall panel and defining a compartment therewith, said front wall being readily penetrable by the class of firearm projectiles and defining a perimeter;   containment walls closing said perimeters of said rear and front wall panels and defining closures for said compartment; and   a multiplicity of energy absorbing elements composed of hard and dense material and being arranged in loose and moveable relation within said compartment and being disposed in engagement with adjacent energy absorbing elements, said energy absorbing elements being contained by said front, rear and containment walls.   
     
     
         12 . The projectile energy absorbing and dissipating device of  claim 11 , comprising:
 said rear wall panel being composed of a hard and dense metal composition that is resistant to penetration by non-explosive firearm projectiles of the designated class;   said front wall panel being composed of a material that is subject to penetration by the designated class of non-explosive firearm projectiles; and   said multiplicity of energy absorbing elements being composed of a hard and dense metal material that is resistant to deformation by the designated class of non-explosive firearm projectiles.   
     
     
         13 . The projectile energy absorbing and dissipating device of  claim 12 , comprising:
 said multiplicity of energy absorbing elements being composed of hardened steel and being in the form of spheres   
     
     
         14 . The projectile energy absorbing and dissipating device of  claim 12 , comprising:
 said rear wall panel being composed of steel plate material having a thickness of from about ⅛″ to about ¾″; and   said front wall panel being composed of a material that substantially closes the path of a projectile penetration and maintains the capability for containment of said energy absorbing elements after having been penetrated many hundreds of times by the designated class of non-explosive firearm projectiles.   
     
     
         15 . The projectile energy absorbing and dissipating device of  claim 14 , comprising:
 said front wall panel being composed of a polymer material having a long chain polymer structure providing an elastic memory for substantially closing projectile penetration paths after having been penetrated by the designated class of non-explosive projectiles.   
     
     
         16 . The projectile energy absorbing and dissipating device of  claim 11  being in the form of a rotatably moveable bullet trap, and comprising:
 said support framework structure having an axis and being supported for rotation about said axis; and 
 said containment walls having perforations of a dimension preventing movement of said multiplicity of energy absorbing elements therethrough and permitting movement of bullet fragment residue therethrough for deposit and collection. 
 
     
     
         17 . The projectile energy absorbing and dissipating device of  claim 11  being in the form of a protective barrier for personnel and vehicles, and comprising:
 said rear wall being defined by rear wall panels of portable nature and being arranged to form an inner barrier wall structure and being moveable for re-use; 
 said front wall being defined by front wall panels disposed in spaced relation with said rear wall panels and arranged to form an outer barrier wall structure and to define said compartment; 
 said energy absorbing and dissipating elements being poured into said compartment and defining a mass of loose energy absorbing elements; and 
 said multiplicity of projectile energy absorbing and dissipating elements being recoverable for re-use. 
 
     
     
         18 . A method for absorbing and dissipating the energy of projectile strikes by a class of non-explosive firearm projectiles up to  50  caliber, by shrapnel and by other fast moving objects, comprising:
 positioning front and rear walls in spaced relation defining an energy absorption and dissipation compartment therebetween, said front wall being readily penetrable by the projectiles and said rear wall being resistant to penetration by the projectiles; 
 positioning a multiplicity of hardened energy absorbing elements of high mass within said energy absorption and dissipation compartment, said hardened energy absorbing elements of high mass being in contact with said front and rear walls; 
 projectiles penetrating said front wall striking at least one of said hardened energy absorbing elements and imparting energy thereto; and 
 transferring and dissipating the energy of a projectile strike through said multiplicity of hardened energy absorbing elements, causing disintegration of the projectile and providing penetration protection for said rear wall and for objects located beyond said rear wall. 
 
     
     
         19 . The method of  claim 18 , comprising:
 positioning said rear and front walls in portable fashion for movement and re-use; and   recovering said multiplicity of hardened energy absorbing elements of high mass.