Abstract:
A ballistic projectile resistant barrier apparatus combines the advantages provided by both high hardness material barriers and multiple laminate layer barriers. An outer tier of the barrier is comprised of a plurality of interconnected hard tiles. Each of the tiles has an outer, front surface designed that, upon impact by a ballistic projectile, the projectile is immediately deflected from its initial path. Subsequent tiers of the barrier are comprised of layers of a flexible material interspersed with layers of a ballistic liquid or at least one layer of ballistic fiber. When tiles are impacted by a projectile, the impacted tile is pushed into the laminate layers of the barrier, thereby substantially multiplying the area of the barrier that resists the impact force of the projectile as the projectile enters the barrier.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (1) Field of the Invention  
         [0002]     The present invention pertains to a ballistic projectile resistant barrier with improved ballistic projectile resistance. The barrier is lightweight and can be worn as a garment or draped over an object to provide ballistic projectile protection to stationary or mobile entities, military or civilian.  
         [0003]     (2) Description of the Related Art  
         [0004]     In the early development of ballistic projectile barriers such as flak jackets or vehicle armor, it was a commonly agreed upon theory that the barrier must be at least as hard, or harder than the ballistic projectile to be stopped. It was necessary that the barrier be very strong with a high degree of structural integrity so that impact of the projectile with the barrier would deform the projectile into a flattened shape, thereby transferring the kinetic energy of the projectile into a larger surface area. This would allow the barrier to absorb the impact energy of the projectile while preventing penetration of the barrier. The levels of barrier thickness and hardness were adjusted in designing barriers that were impenetrable to various ballistic threats.  
         [0005]     Another commonly accepted theory in the development of ballistic projectile barriers relies on multiple layers or laminates of a flexible material in constructing the barrier. The multiple material layers allow a degree of movement of each layer in the barrier. The movement allows a degree of stretching to occur when a layer is impacted by a projectile, which takes advantage of the material tensile strength and transfers some energy of the impact into each layer of material. The kinetic energy of the impacting projectile is more effectively spread into a larger surface area through the thickness of the barrier, with the surface area increasing on each consecutive material layer of the barrier.  
         [0006]     Materials commonly used in laminate barriers are made of woven aramid fibers that are saturated and bonded with a matrix of thermosetting plastic resin. This produces a barrier that very effectively takes advantage of the high tensile strength of the aramid fibers.  
         [0007]     The prior art ballistic projectile barriers that employ hard materials such as ballistic steel are disadvantaged in that they are very heavy. In high mobility applications, for example in flak jackets worn by soldiers, the increased weight of the ballistic barrier is a significant disadvantage. In addition, with the complex designs used in ballistic barriers today, the use of ballistic steel is further disadvantaged in that it is not easily fabricated.  
         [0008]     Ceramic barriers are less dense than steel and therefore weigh less per thickness of the barrier than steel. Ceramic materials can also be produced with extremely high levels of hardness. Thus, the ceramic materials have many advantages over ballistic steel, but are very expensive and are also very difficult to fabricate in many applications.  
         [0009]     Laminate barriers using woven layers of aramid fibers are manufactured using very complex methods. These methods of manufacture are time consuming and, in addition to the materials used, can be very expensive. Laminate barriers are most disadvantaged by their lack of hardness and their susceptibility to penetration by armor-piercing projectiles.  
       SUMMARY OF THE INVENTION  
       [0010]     The ballistic projectile resistant barrier apparatus of the invention combines the advantages provided by both high hardness material barriers and multiple laminate layer barriers. The barrier of the invention also incorporates two entirely novel concepts in the construction of ballistic projectile resistant barriers. The first of these concepts is in the surface design of the barrier that, upon impact by a ballistic projectile, the projectile is immediately deflected from its initial path. This ensures that the projectile, even when initially travelling in a perpendicular path to the surface of the barrier, will ultimately impact the barrier at an oblique angle.  
         [0011]     The second concept is in using a system of interconnected tiles of a high hardness material that when impacted by a projectile, break away from the surrounding tiles and remain substantially intact. The impacted tile is pushed into laminate layers of the barrier, thereby substantially multiplying the area of the barrier that resists the impact force of the projectile as the projectile enters the barrier.  
         [0012]     In the preferred embodiment of the ballistic projectile resistant barrier apparatus of the invention, the above novel concepts are arranged in two tiers.  
         [0013]     The outer surface of the ballistic projectile resistant barrier apparatus of the invention is comprised of a plurality of interconnected hard tiles that are arranged in a layer. Each of the tiles is the same in size and configuration. In the preferred embodiment, each of the tiles has a cubic shape with opposite front and rear surfaces, the front surface of each tile defining the outer surface of the barrier. The interconnected tiles are arranged in a two dimensional layer in which the front surfaces of the tiles define a surface structure of peaks and valleys, that appears as rows and columns of pyramids.  
         [0014]     The outer surface, or front surface of each tile, has a peripheral edge that surrounds a central area of the tile. The front surface of the tile is recessed at the central area of the surface, producing equally high points at the four corners of the front surface peripheral edge. Thus, the front surface of each tile functions as a funnel that guides a ballistic projectile impacting the front surface toward the central area of the tile. Rather than piercing through the tile, the projectile will carry or push the tile into the subsequent tier of the ballistic barrier.  
         [0015]     Each of the tiles has a substantially flat rear surface with a cylindrical projection protruding from the center of the rear surface. The projection acts as a locking mechanism that fits into a hole in the surface of the subsequent layer of the barrier. The tiles are bonded by adhesive to the barrier&#39;s subsequent layer.  
         [0016]     In the preferred embodiment of the invention, each of the tiles is comprised of reaction bonded silicone carbide. This material is substantially harder than the majority of metal ballistic projectiles, and is at least equal in hardness to many armor piercing projectiles. Other alternative materials include alumina, hot pressed silicone carbide, boron carbide, zirconium and other comparable ceramic materials.  
         [0017]     The second tier of the barrier apparatus of the invention is comprised of a flexible laminate made of consecutive layers of flexible material that may be interspersed with a ballistic liquid or a ballistic fiber. In one embodiment, portions of adjacent layers of material are bonded together in a spotted pattern with there being a void that extends between the adjacent layers and around the bonded portions of the layers. The ballistic liquid fills this void. In each subsequent layer of the laminate tier, the bonded portions of the adjacent layers of material are offset and misaligned with the bonded portions of material of the previous adjacent layers. The ballistic liquid fills the voids between the subsequent adjacent layers and extends around the bonded portions of the adjacent layers.  
         [0018]     In another embodiment adjacent layers of polycarbonate sheets or other comparable or equivalent thermoplastic materials are bonded together by layers of adhesive. The polycarbonate sheets have varying thicknesses. At least one layer of a ballistic fiber is included in the construction of the second tier laminates. This multiple laminate tier of the ballistic projectile resistant barrier apparatus of the invention gives the core of the barrier an extremely high impact resistance, and impact energy absorbing ability. This tier of the barrier also has the ability to withstand a very tight pattern of impacting ballistic projectiles.  
         [0019]     The ballistic projectile resistant barrier apparatus of the invention described above provides the advantages of being lightweight, of having a high degree of ballistic projectile impact resistance, of having a design and thickness that is readily adjustable to provide resistance to varying threat levels, is exceptionally resistant to armor-piercing projectiles, is relatively simple to manufacture, can be readily manufactured in curves or other complex shapes, and can be manufactured at relatively low cost. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0020]     Further features of the ballistic projectile resistant barrier apparatus of the invention are set forth in the following detailed description of the apparatus and in the following drawing figures in which:  
         [0021]      FIG. 1  is a side perspective view of a section of the ballistic projectile resistant barrier apparatus of the invention;  
         [0022]      FIG. 2  is an exploded view of the apparatus shown in  FIG. 1 ;  
         [0023]      FIG. 3  is a side perspective view of an individual tile that makes up a part of the apparatus;  
         [0024]      FIG. 4  is a top plan view of the tile of  FIG. 3 ;  
         [0025]      FIG. 5  is a bottom plan view of the tile of  FIG. 3 ;  
         [0026]      FIG. 6  is a side elevation view of the tile of  FIG. 3 ;  
         [0027]      FIG. 7  is a cross section of the tile along the line  7 - 7  of  FIG. 4 ;  
         [0028]      FIG. 8  is a bottom view of the array of tiles of  FIG. 1 ;  
         [0029]      FIG. 9  is a side perspective view of a section of an additional embodiment of the apparatus;  
         [0030]      FIG. 10  is an exploded view of the apparatus embodiment of  FIG. 9 ; and,  
         [0031]      FIG. 11  is a side view of the apparatus embodiment of  FIG. 9 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0032]     As stated earlier, the ballistic projectile resistant barrier apparatus of the invention combines the advantages provided by high hardness material barriers and multiple laminate layer barriers.  FIG. 1  shows a representative section of a first embodiment of the apparatus  10  of the invention. The apparatus  10  is shown as being generally flat and rectangular in  FIG. 1 . This representation of the apparatus  10  is used for illustrative purposes only. The apparatus  10  is flexible and may be shaped to cover the contour of a variety of different shaped objects. For example, the apparatus  10  may be used in the construction of a flack jacket that protects an individual, and may be used as additional armor protection for a structure or a vehicle. Thus, the representation of the apparatus  10  shown in  FIG. 1  should not be interpreted as limiting the apparatus to the particular configuration shown.  
         [0033]     In the  FIG. 1  embodiment of the ballistic projectile resistant barrier apparatus  10  of the invention, the apparatus is constructed in three tiers. These include an outer tier  12 , an intermediate tier  14 , and an inner tier  16 . The outer tier  12  faces outwardly from the entity being protected by the apparatus  10 . The inner tier  16  is positioned adjacent the protected entity. Although the apparatus  10  is show in  FIG. 1  positioned generally horizontally with the outer tier  12  positioned above the inner tier  16 , in use of the apparatus it may be oriented in a variety of different orientations other than that shown in  FIG. 1 .  
         [0034]     The outer tier  12  of the apparatus is comprised of a plurality of hard tiles  22 . Each of the tiles  22  is constructed of a material of high hardness. In the preferred embodiment, each of the tiles  22  is constructed of reaction bonded silicone carbide, although other equivalent materials may be used. Examples of these materials include alumina, hot pressed silicone carbide, boron carbide, zirconium and other comparable ceramic materials. Each of the tiles  22  is the same size and configuration. As shown in  FIG. 1 , each of the tiles  22  has a general cubic shape with an opposite front surface  24  and rear surface  26 , and four side walls  28  extending between the front and rear surfaces. In other embodiments of the apparatus, the tiles  22  can have other sizes and shapes, for example a triangular shape.  
         [0035]     As best seen in  FIG. 4 , the four sidewalls  28  of each tile give the tile front surface  24  a square peripheral edge with four straight sections  32  and four corners  34 . As best seen in  FIGS. 1 and 3 , the tile front surface  24  has a central area  36  that is recessed below the four corners  34  of the surface. Thus, the front surface central area  36  is spaced a first distance from the tile rear surface  26 , and the front surface at each of the four corners  34  is spaced a second distance from the tile rear surface  26  that is greater than the first distance. This gives the tile front surface  24  a general funnel shape that is recessed at the central area  36  and is raised at the four corners  34 . Thus, the tile front surface  24  functions as a funnel that guides a ballistic projectile impacting the front surface toward the central area  36  of the tile surface.  
         [0036]     The tiles  22  are arranged in a two dimensional arrayed layer with the sidewalls  28  of adjacent tiles closely opposing each other. This arrangement of the tiles  22  positions the front surface corners  34  of the tiles adjacent each other. As best seen in  FIG. 1 , in the two dimensional arrayed arrangement of the tiles  22 , the front surfaces  24  of the tiles define a surface structure of the barrier that has peaks and valleys that appear as rows and columns of pyramids.  
         [0037]     Each of the tile rear surfaces  26  is substantially flat. As shown in  FIG. 5 , a cylindrical projection or pin  42  protrudes a short distance outwardly from each tile rear surface  26 . The pin  42  has a cylindrical configuration and functions as a frangible connection of the tile  22  to the subsequent, intermediate tier  18  of the apparatus.  
         [0038]     The second tier or intermediate tier  14  of the apparatus is a flexible laminate comprised of consecutive layers of a flexible material  44 ,  46  interspersed with layers of a ballistic liquid or gel  48 . In the embodiment, the flexible material employed in each material layer  44 ,  46  is a polycarbonate or other equivalent thermoplastic material. As shown in  FIG. 2 , the first material layer  44  is provided with an array of holes  52  that correspond to the positions of the projections  42  on the rear surfaces of the tiles  44 . The rear surfaces  26  of the tiles  22  are secured to the first material layer  44  by a layer of adhesive  54 . Each of the tile rear surfaces  26  is secured by the adhesive layer  54  to the first material layer  44  with the tile projections  42  engaged in the material layer holes  52 , providing a frangible connection of each of the tiles  22  to the material layer  44 . The flexibility of the material layer  44  enables each of the tiles  44  to move to a limited extent relative to each other. The flexibility of the material layer  44  also enables the apparatus  10  to be formed in a variety of different configurations to conform the shape of the apparatus to the shape of a surface against which the apparatus is positioned.  
         [0039]     In the illustrative embodiment of the apparatus  10  shown, the second tier  14  of the apparatus is comprised of two layers of the flexible material  44 ,  46 , preferably polycarbonate sheets or other equivalent thermoplastic material. Additional layers of the material may be employed. Portions of the opposed surfaces of the two material layers  44 , 46  are bonded together in a spotted pattern by dabs  56  of adhesive. The spaced arrangements of the adhesive dabs  56  creates voids that extend between the opposed surfaces of the adjacent material layers  44 ,  46 . The voids extend between the layers and around the portions of the layers secured together by the adhesive dabs  56 . The ballistic liquid layer  48  fills the voids between the opposed surfaces of the material layers  44 ,  46 . The description of the liquid layer  48  is intended to include gels and other similar types of fluids that will flow between the adjacent material layers  44 ,  46 . In embodiments of the apparatus  10  in which there are several layers of the flexible material  44 ,  46 , the opposed surfaces of adjacent layers are secured together by the adhesive dabs  56  in the same manner as that explained above. In addition, the voids between the adjacent layers are filled with the ballistic liquid  48 . However, the positions of the adhesive dabs  56  between subsequent layers of the material  44 ,  46  are misaligned or staggered so that no two adhesive dabs  56  on opposite sides of a material layer are aligned with each other. This multiple laminate tier  14  of the ballistic projectile resistant barrier apparatus  10  gives the core of the barrier an extremely high impact resistance, and impact energy absorbing ability. This tier  14  of the barrier also has the ability to withstand a very tight pattern of impacting ballistic projectiles.  
         [0040]     The third, inner tier  16  of the ballistic projectile resistant barrier apparatus  10  is a more rigid, thicker laminate layer of the flexible material  62  that makes up the laminates of the barriers second, intermediate tier  14 . This backing layer or core layer of material  62  is also secured to the adjacent material layer  46  by the adhesive dabs  56 . The ballistic liquid  48  fills the void formed between the backing layer  62  and the adjacent material layer  46 . The liquid extends around the portions of the adjacent layers secured together by the adhesive dabs  56 . This backing layer  62  of the barrier provides the barrier with increased rigidity and a final impenetrable layer that offers extreme impact resistance, and further provides the barrier with energy absorbing capability.  
         [0041]      FIGS. 9-11  show a further, preferred embodiment of the ballistic projectile resistant barrier apparatus  64  of the present invention. Like the previously described embodiment, the apparatus  64  is constructed of multiple tiers. The first, or outer tier  12  is comprised of a plurality of the hard tiles  22  of the previously described embodiment of the apparatus. Each of the tiles  22  of this embodiment are substantially identical to those of the previously described embodiment, and therefore will not be described again. Because the constructions of the tiles  22  of this additional embodiment is the same as that of the previously described embodiment, the same reference numerals are used in  FIGS. 9-11  in labeling each of the features of the tiles  22 .  
         [0042]     The embodiment of the apparatus  64  shown in  FIGS. 9-11  differs from the previously described embodiment in the construction of the second or inner tier  66  of the apparatus. The second tier  66  of the apparatus is a flexible laminate comprised of consecutive layers of flexible materials interspersed with layers of an adhesive. In the preferred embodiment, the flexible material employed in each material layer is a polycarbonate or other equivalent thermoplastic material.  
         [0043]     The first material layer  68  is a polycarbonate sheet having an array of holes  72  through the sheet. The pattern of the holes  72  matches the pattern of the tile projections  42  for the particular arrangement of the tiles  22 . The holes  72  are dimensions to enable the tile projections  42  to pass through the holes.  
         [0044]     A layer of a urethane adhesive  74  is applied to the opposite side of the first material layer  68  from the array of tiles  22 . The adhesive  74  contacts each of the projections  42  of the tiles  22  and forms an interlocking connection of the tiles  22  to the first material layer  68 .  
         [0045]     The next layer of the laminate is a layer of ballistic fiber  76 . Various different types of ballistic fiber, for example S-glass, fiberglass, aramid fiber, UMHW fibers, etc. may be employed in this layer. The layer of ballistic fiber  76  is one of the thicker layers of the laminate, for example ⅜ inch thick. The layer of adhesive  74  secures the tile projections  72  to the ballistic fiber layer  76 , forming an interlocking connection between the plurality of tiles  22 . This interlocking connection of the tiles  22  secures the tiles against oblique impacts of projectiles. Other equivalent means of securing together the tile rear surfaces  26  could be employed to provide the interlocking connections between the plurality of tiles  22 .  
         [0046]     A second layer of urethane adhesive  78  secures the layer of ballistic fiber  76  to a polycarbonate sheet  82 . The polycarbonate sheet  82  has a lesser thickness than the ballistic fiber sheet  76 , for example ⅛ inch thickness.  
         [0047]     A third layer of adhesive  84  secures the polycarbonate sheet  82  to a polycarbonate sheet  86  of greater thickness. In the illustrative embodiment, the thicker polycarbonate sheet  86  has a thickness of ⅜ of an inch.  
         [0048]     A still further layer of urethane adhesive  88  secures the thicker polycarbonate sheet  86  to an additional polycarbonate sheet  92 . This last polycarbonate sheet  92  functions as the backing or core layer of the inner tier  66  of laminates.  
         [0049]     Unlike the first described embodiment, each of the adhesive layers  74 ,  78 ,  84 ,  88  extends the length and breadth of the sheets it is sandwiched between. This enables the second tier  66  to absorb the force of projectiles that impact with the tiles  22  and to catch any shattered pieces of projectiles that impact with the tiles.  
         [0050]     Each of the ballistic projectile resistant barrier apparatus  10 ,  64  described above provides the advantages of being lightweight, of having a high degree of ballistic projectile impact resistance, of having a design and thickness that is readily adjustable to provide resistance to varying threat levels, is exceptionally resistant to armor piercing projectiles, is relatively simple to manufacture, can be readily manufactured in curves or other complex shapes, and can be manufactured at relatively low cost.  
         [0051]     Although the apparatus of the invention has been described above by reference to specific embodiments of the invention, it should be appreciated that modifications and variations could be made to the apparatus described without departing from the scope of the appended claims.