Abstract:
Armor apparatus comprising a non-oxide ceramic element bounded to an aramid fiber composite baking. A special ceramic and a novel aramid fiber substrate are combined in a unique arrangement that permits a single armor system to provide protection against multiple types of ballistic attack. The armor apparatus may be used alone or as a supplementary armor system to provide increased protection from ballistic attack.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to ceramic armor and, more particularly, to a single ceramic armor for protecting against multiple small arms bullets. 
     2. Description of the Prior Art 
     Ceramic armor is typically used for body armor and for the outer coverings of different types of vehicles, such as various types of land vehicles, ships, and aircraft. Typically, ceramic tiles are adhesively secured to a substrate then encapsulated in an outer cover. The armor system is then attached to a vehicle by a variety of means or merely placed in a fabric pocket, as in the case of body armor. 
     An inherent problem is the prior art is that ceramic armor is configured for a fixed level of protection against a singular ballistic threat. 
     The apparatus of the present invention overcomes the deficiencies of the prior art by providing a single arrangement of ceramic and substrate to provide protection against a variety of bullets. The appropriate ceramic and substrate arrangement provides protection against both lead-filled and steel-filled bullets with calibers of 5.56 mm and 7.62 mm, which are the common calibers used by military and civilian rifles. 
     The apparatus may be used with or without a supplementary armor system such as a body armor vest or the outer skin of a vehicle. Stealth and other features, such as durability, drop protection, field abuse, spall mitigation, etc., may also be included in the apparatus. 
     SUMMARY OF THE INVENTION 
     The ceramic armor apparatus of the present invention described and claimed herein comprises a ceramic facing element bonded to an aramid fiber composite substrate. The ceramic armor apparatus of the present invention provides protection against a 5.56 mm M193 bullet, a 5.56 mm M855 bullet, a 5.56 mm SS109 bullet, a Ace 7.62 mm M80 bullet, a 7.62 mm LPS bullet, and a 7.62 mm PS bullet either alone or in any combination thereof. The ceramic facing element may consist of a plurality of elements, such as tiles, or may be a singular ceramic plate that is either flat or molded to the desired shape. The aramid fiber composite substrate is comprised of a plurality of layers of aramid fibers arranged in either fabric or unidirectional tape structures. The aramid fiber composite substrate layers are stacked to achieve the desired thickness and protection, and are laminated using a variety of polymer compounds to create a singular element. The aramid fiber composite substrate is arranged to be generally parallel to the ceramic facing element such that the shape of the aramid fiber composite substrate mirrors that of the ceramic facing element. 
     Among the objects of the following invention are the following: 
     To provide a new and useful means of protecting against ballistic attack; 
     To provide a new and useful means of arranging ceramic tile armor elements disposed on a substrate; 
     To provide a new and useful means of arranging a composite armor substrate in conjunction with a ceramic facing; 
     To provide a new and useful ceramic armor system for protection against multiple ballistic threats, 
     To provide a new and useful means of minimizing the weight of a ceramic armor system for ballistic protection; and 
     To provide a new and useful means of creating a supplementary armor plate for use in conjunction with an existing armor system. 
    
    
     BRIEF DESCRIPTION OF DRAWING 
     DRAWING FIGURES 
     FIG. 1 is a perspective view of an embodiment of the apparatus of the present invention. 
     FIG. 2 is a view in partial section taken generally along line  2 — 2  of FIG. 1 
     FIG. 3 is a perspective view of an alternate embodiment of the apparatus of the present invention. 
     FIG. 4 illustrates via dotted lines the stitching or fiber axes relative to the x, y, and z-axis of fiber composite substrate plate  14 . 
    
    
     REFERENCE NUMERALS IN DRAWINGS 
     Item  10  is the ceramic armor apparatus 
     Item  11  is a ceramic armor assembly comprised of Items  12 ,  13 , and  14   
     Item  12  is the monolithic ceramic facing element 
     Item  13  is the adhesive element 
     Item  14  is the aramid fiber substrate element 
     Item  15  is the encapsulating cover 
     Item  16  is the optional rear portion of the encapsulating cover 
     Item  17  is the ceramic tile facing element 
     Item  18  is the ceramic tile facing element 
     Item  19  is the ceramic armor assembly comprised of Items  13 ,  14 ,  17 , and  18   
     Item  20  is the ceramic armor apparatus alternate embodiment 
     DESCRIPTION OF PREFERRED EMBODIMENT 
     FIG. 1 is a perspective view, partially broken away and in partial section, of the ceramic armor apparatus  10  of the present invention. FIG. 2 is a view in partial section of the apparatus  10  taken generally along line  2 — 2  of FIG.  1 . For the following discussion, reference will be made to FIGS. 1 and 2. 
     The ceramic armor apparatus  10  includes a cover  15  with the ceramic armor elements  11  deposed therein. The cover may include a back panel  16  that either partially or completely covers the rear surface of the plate. The cover may be comprised of a single material, such as nylon fabric, or may be a combination of fabric, rigid plastic, and foam that protects the ceramic from wear-and-tear and contains ceramic particles on impact as appropriate. 
     Within the ceramic armor elements  11  are the singular or monolithic ceramic tile or facing element  12 , the adhesive layer element  13 , and the aramid fiber composite substrate element  14 . The combined thickness of the ceramic facing element  12 , the adhesive layer element  13 , and the aramid fiber composite substrate element  14  falls in the range between 0.430-inches and 0.530-inches inclusively. The combined weights of the ceramic facing element  12 , the adhesive layer element  13 , and the aramid fiber composite substrate element  14  falls in the range between 4.00- and 5.70-pounds-per-square-foot inclusively. The ceramic facing element  12  may be made of any appropriate non-oxide ceramic material, for example, Boron Carbide, Silicon Carbide ceramics. Alternatively, a ceramic matrix composite or metal matrix composite containing Silicon Carbide or Boron Carbide particles may be used. Although ceramic thickness may be varied to suit a specific need, the preferred ceramic arrangement ranges from 0.080-inches to 0.310-inches in thickness. 
     Disposed against and roughly parallel to back of the ceramic facing element  12  is the adhesive layer element  13  that forms a discreet layer. 
     The adhesive layer  13  may be made of any approximate polymer, for example. epoxy, polyurethane, polysulfide, polyolefin. The preferred thickness of the adhesive layer is controlled to result in a thickness between 0.002-inches and 0.090-inches. For convenience, the adhesive layer illustrated in the drawing Figures are cross hatches as metal. 
     Disposed against the back of the adhesive layer  13 , and roughly parallel to the back of the ceramic facing element  12 , is aramid fiber composite substrate element or plate  14 . 
     The aramid fiber composite substrate plate  14  may be made of any appropriate aramid fiber such as Kevlar® or Twaron® fiber having a fineness ranging from 250- to 3,500-denier. Aramid fiber constructions such as fabrics, unidirectional tapes, felts, non-woven layers, or three-dimensional structures may be used. For example, aramid fiber fabrics in plain, basket, or twill weave styles with basis weights between 3.5- and 20.0-ounces-per-square-yard may be used; aramid fiber unidirectional tapes with all tapes arranged in 0, 15, 30, 45, 60, 90-degree orientation or combinations thereof may be used; or three dimensional structures that incorporate stitching or fiber axes along or about the z-axis of the fabric may be used. The aramid fiber composite substrate layer  14  is arranged to create a uniform structure that ranges from 0.130-inches to 0.350-inches thickness. 
     The aramid fibers of the aramid fiber composite substrate plate  14  are encased in a polymer matrix to from a rigid laminate. Virtually any appropriate polymer resin may be used for the matrix, for example Phenolic, Phenolic Polyvinyl Butyral rubber blends, Polyester, Vinylester, polyurethane, and polyolefin resins. For convenience, the aramid fiber composite substrate plates illustrated in the drawing Figures are cross hatches as metal. 
     When the aramid fiber composite substrate plate  14  employs a polymer resin matrix, the preferred resin content ranges from fifteen to twenty-four percent by weight. 
     An alternate embodiment  20  of the present invention is illustrated in FIG.  3 . FIG. 3 comprises a perspective view, partially broken away and in partial section, of apparatus  20  of the present invention where the ceramic armor assembly  19  comprises a plurality of individual ceramic tile elements as exemplified by elements  17  and  18 , the adhesive layer  13 , and the aramid fiber composite substrate  14 . The ceramic tile facing elements  17  and  18  can be square ceramic tiles or otherwise shaped to suit the dimensional needs of a particular application. 
     The remainder of the FIG. 3 elements are arranged and employed respectively in a similar manner as shown in FIGS. 1 and 2.