Method And Apparatus For Protecting Against Ballistic Projectiles

Abstract

A composite material comprising a multitude of masses and fibers supported on a flexible substrate arranged in a manner to absorb energy from a ballistic projectile and thereby protect persons or property from ballistic injury or damage. An array of small, tough disc-like masses are suspended in a three dimensional cradle of high-tensile elastomeric fibers such that energy from an incoming ballistic projectile is first imparted to one or more masses and the motion of the masses are restrained by tensile strain of elastomeric fibers substantially in the direction of travel of the incoming projectile. The projectile is eventually decelerated to harmless velocity through a combination of transfer of momentum to the masses and the elastic and plastic tensile deformation of the fibers. One or more layers of the composite material can be assembled to form body protective armor (“bullet-proof vest”) or property protective armor, the number and characteristics of the layers being adjusted according to the specific ballistic threat anticipated.

1 . A ballistic projectile defeating protective armor designed to protect persons and property comprising a plurality of small masses and a framework of fibers which partially restrain movement of said masses under ballistic load. 
   
   
       2 . The armor of  claim 1  where said fibers are arranged around the masses in a multi-dimensional framework, where the arrangement of said framework is central to the function of the armor. 
   
   
       3 . The armor of  claim 1  where the arrangement of the fibers is such that said fibers may elongate in tension in a direction substantially corresponding to the direction of the ballistic projectile prior to impact on the armor. 
   
   
       4 . The armor of  claim 1  which imparts force by the said mass or masses first impacted ballistically to adjacent masses through a combination of compressive force in the elastomeric material and tensile force in the reinforcing fibers. 
   
   
       5 . The armor of  claim 2  where the fibers are arranged in a three-dimensional framework around each individual mass. 
   
   
       6 . The armor of  claim 2  where at least part of the direction of the weave of the fibers around the masses is substantially in the direction aligned with the anticipated ballistic threat. 
   
   
       7 . The armor of  claim 2  where at least part of the direction of the weave of the fibers is in a direction substantially normal to the local plane of the material. 
   
   
       8 . The armor of  claim 2  where the fibers are wound or woven alternately in regular or random or pseudo random fashion around or about masses. 
   
   
       9 . The armor of  claim 2  where said fibers are first aligned substantially in the x and y directions substantially normal to the direction of the anticipated ballistic impact and are locally rearranged upon ballistic impact such that the displacement of one mass under ballistic load relative to adjacent masses causes a rearrangement of the 3D geometry from the rest geometry to a geometry where tensile elongation of said fibers occurs substantially in the direction of the direction of the ballistic load. 
   
   
       10 . The armor of  claim 2  where under ballistic load the geometry of the fibers and masses dynamically rearrange to a 3D geometry of fibers and masses prior to the ultimate tensile stress being attained in all said fibers local to the ballistically impacted mass. 
   
   
       11 . The armor of  claim 2  which is constructed to be flexible to facilitate elastic flexing of said armor material at a bend rate of 20 degrees or more from the neutral position per linear foot of material. 
   
   
       12 . The armor of  claim 2  where the dimensions and material properties of the masses are calculated to optimally retard one or more specific ballistic threats, such as rifle bullets, cannon shells, or artillery shells of specified caliber and performance. 
   
   
       13 . The armor of  claim 2  where the dimensions and material properties of the masses are calculated to optimally retard one or more specific ballistic threats, such as rifle bullets, cannon shells, or artillery shells of specified caliber and performance and prevent punch through of the mass by the specific threat projectile. 
   
   
       14 . The armor of  claim 2  combined with at least one layer of woven ballistic cloth material. 
   
   
       15 . The armor of  claim 2  where retardation of the ballistic projectile is achieved through transfer of kinetic energy from the ballistic projectile to one or more masses. 
   
   
       16 . The armor of  claim 2  where retardation of the ballistic projectile is achieved through elastic or plastic elongation of fibers which are or become arranged substantially in the direction normal to the local plane of the material. 
   
   
       17 . The armor of  claim 2  where retardation of the ballistic projectile is achieved through elastic or plastic elongation of fibers substantially in the direction of the projectile prior to impact. 
   
   
       18 . The armor of  claim 2  where the retardation of the ballistic projectile is achieved through a combination of the transfer of kinetic energy to masses and the elastic or plastic elongation of fibers substantially in the direction of the projectile prior to impact. 
   
   
       19 . The armor of  claim 2  where the retardation of the ballistic projectile is achieved through a combination of the transfer of kinetic energy to masses and the elastic or plastic elongation of fibers substantially in the direction of the projectile prior to impact and deformation of the masses and solid material directly in contact with the masses and or fibers. 
   
   
       20 . The armor of  claim 2  where adjacent masses are configured in tessellating shapes. 
   
   
       21 . The armor of  claim 2  where the tensile strength of the material of the fibers is greater than 400 Mega Pascals. 
   
   
       22 . The armor of  claim 2  where the fibers are made from more than one tensile strength material. 
   
   
       23 . The armor of  claim 2  where the masses are constructed of one or more of the following ballistic shear resistant materials: metal, ceramic, ceramic composite, fiber composite, and or quartz composite. 
   
   
       24 . The armor of  claim 2  where the mass of an individual mass is less than one point three times the mass of the anticipated threat projectile. 
   
   
       25 . The armor of  claim 2  where the mass and size of said mass are small enough so that the mass will accelerate with an impacting ballistic projectile and not be punctured by said projectile and the mass imparts a retarding force on the projectile. 
   
   
       26 . The armor of  claim 2  where the masses are further supported by an elastomeric or plastic material which deforms compressively as a result of ballistic impact on one or more masses. 
   
   
       27 . The armor of  claim 2  where the armor material is encapsulated in elastomeric or plastic material by a process of injection or molding or vulcanizing. 
   
   
       28 . The armor of  claim 2  where the cross section of the masses orthogonal to the nominal direction of the ballistic threat is smaller in at least one dimension than the diameter of the anticipated ballistic projectile. 
   
   
       29 . The armor of  claim 2  where the fibers are woven into a fabric or cloth and the masses are interwoven into said fabric or cloth. 
   
   
       30 . The armor of  claim 2  where said masses are each manufactured of one or more component parts and enclose said fibers wholly or partially so as to effectively restrain and limit relative motion between said fiber and said masses. 
   
   
       31 . The armor of  claim 2  where the motion of a mass is restrained by the framework of fibers, and said restraining imparts a retarding force. 
   
   
       32 . A bullet proof vest constructed of one or more layers of the armor of  claim 2 . 
   
   
       33 . A bullet proof vest constructed of two or more layers of the armor of  claim 2  where said layers are separated by a layer of elastomeric material which deforms compressively under ballistic load. 
   
   
       34 . A bullet proof vest constructed of one or more layers of the armor of  claim 2  and one or more layers of conventional woven ballistic fiber cloth. 
   
   
       35 . The armor of  claim 1  where the masses have smooth and rounded surfaces in contact with the fibers so that the fibers may slide locally over the surface of the masses during ballistic load. 
   
   
       36 . The armor of  claim 35  where a solid spacer of plastic material is placed between the fibers and the masses, where said plastic material deforms and flows under ballistic loading. 
   
   
       37 . The armor of  claim 1  comprising multiple layers of a plurality of said masses and three dimensional framework of fibers which restrain movement of the masses under ballistic load. 
   
   
       38 . The armor of  claim 37  where the mass of the individual masses in the layer first impacted by the ballistic projectile is less than the mass of the individual masses in subsequently impacted layers. 
   
   
       39 . The armor of  claim 2  where upon ballistic impact of a ballistic projectile on a mass, said mass moves by a limited amount in a direction which is substantially the direction of travel of the ballistic projectile prior to impact. 
   
   
       40 . The armor of  claim 39  where the motion of the mass causes tensile stress in the fibers supporting said mass. 
   
   
       41 . The armor of  claim 40  where said tensile stress causes tensile elongation of the fibers at least part of said elongation is substantially in the direction of the motion of the mass. 
   
   
       42 . The armor of  claim 41  where the tensile elongation of some or all of said fibers causes energy to be absorbed. 
   
   
       43 . The armor of  claim 41  where the tensile elongation of some or all of said fibers results in tensile failure of some or all of said fibers. 
   
   
       44 . The armor of  claim 2  where the tensile stress imparted in the fibers by the motion of the mass or masses first impacted by a ballistic projectile causes a force to be imparted to one or more adjacent masses. 
   
   
       45 . The armor of  claim 44  where the force imparted by said first impacted mass or masses to said adjacent masses is imparted substantially by the tensile stress in the supporting fibers substantially in the direction of motion of the first impacted mass or masses. 
   
   
       46 . The armor of  claim 44  where the summed mass of the plurality of said masses which are adjacent to and directly mechanically coupled by said fibers to a mass which is first impacted by a ballistic projectile, or to masses which are first impacted by a ballistic projectile if more than one mass is directly in the path of said projectile, is greater than twice the mass of the anticipated threat projectile.