Patent Publication Number: US-8522663-B2

Title: Multilayered ballistic protection

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 61/114,885, entitled, “MULTILAYERED BALLISTIC PROTECTION FOR WINDOWS”, filed on Nov. 14, 2008. 
    
    
     TECHNICAL FIELD 
     This application relates to window protection and, more particularly, to a window protection product that provides several performance advantages over other solutions. 
     BACKGROUND 
     Home and business owners in storm-prone areas know that, for maximum safety and protection of their belongings, their windows should be covered to prevent the penetration of flying debris. Unprotected windows may easily break during storms, causing water and other damage to the contents of the dwelling. 
     When advanced warning of such storms is available, as in the case of hurricanes, property owners often scramble to obtain some protection for the windows. Typical resolutions to the problem of securing a dwelling are to use a rigid panel to cover the windows (plywood, corrugated plastic, etc), to place tensioned fabric offset from the window, or to provide no protection at all. Preferably, the window has more permanent fixtures available, such as shutters, louvres, rolled louvres, and others. When installed correctly, these solutions generally provide effective storm protection. 
     The protection of orbiting spacecraft may be instructive. Satellites in orbit have to protect against the continual threat of micro-meteor and orbital debris (MMOD). Custom shielding is designed to break up hypervelocity particles that may damage the spacecraft. This custom shielding often uses layering to spread out the impact and disperse it by allowing subsequent layers of material to be destroyed until the impact momentum is spread across a large enough area that the forces are too low to damage the spacecraft. 
     While plywood is an effective, affordable solution, it is not convenient for all property owners. The property owner needs carpentry tools to cut the plywood to the proper size for each window and the skills to safely do so. By applying dense armor to cover the window, plywood is good for protection, but is unwieldy, particularly for larger windows. Plywood is increasingly hazardous to install in second and third floor windows without assistance. Once the storm has passed, the plywood consumes valuable storage space when not in use, and serves no useful function until the next storm. 
     There are known methods for maintaining programmed gaps between resistance layers. The columns of historic buildings built during the Roman Empire are illustrative. These buildings are designed using compressible shapes (parallel columns) between resistance layers to add structural integrity to the building and to maintain parallelism or other programmed gaps between parts of the building. 
     Thus, there is a continuing need for an alternative but effective window protection mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this document will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts throughout the various views, unless otherwise specified. 
         FIG. 1  is a schematic diagram of a multilayered ballistic protection assembly, according to some embodiments; 
         FIG. 2  is a side view of the protection assembly of  FIG. 1 , according to some embodiments; 
         FIG. 3  is a side view of a protection assembly having cylindrical tensile fasteners, according to some embodiments; 
         FIG. 4  is a depiction of tensile fasteners in both flattened and spring-like configurations, according to some embodiments; 
         FIG. 5  is a schematic drawing of the ballistic protection assembly of  FIG. 1 , shown in its initial, interim, and final configurations, according to some embodiments; 
         FIG. 6  is a schematic diagram of a ballistic protection assembly having more than two protection layers, according to some embodiments; 
         FIG. 7  is a schematic diagram of a ballistic protection assembly having protection layers that are not uniform in width, according to some embodiments; 
         FIG. 8  is a flow diagram describing operations performed by a user of the multilayered ballistic protection assembly of  FIG. 1 , according to some embodiments; 
         FIGS. 9A ,  9 B,  10 A, and  10 B are schematic diagrams of the multilayered ballistic protection assembly being affixed to a glass surface, according to some embodiments; 
         FIG. 11  is a side view of a multilayered ballistic protection assembly having inflatable tensile fasteners, according to some embodiments; and 
         FIGS. 12A and 12B  are side views of a multilayered ballistic protection assembly having spring-like tensile fasteners and air-curing compounds, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     In accordance with the embodiments described herein, a multilayered ballistic protection assembly for windows is disclosed. The multilayered ballistic protection assembly consists of a tough resistant material that prevents penetration of objects and distributes impacts to separate energy absorbing “stroking” volume(s). The stroking volume(s) absorb the energy of an impact without causing breakage of the underlying glass window or other fragile surface being protected. 
     As described herein, the multilayered ballistic protection assembly may vary considerably in material strength and assembly, depending on its intended use, cost, and other factors. In some embodiments, the number of layers making up the assembly is determined by the degree of desired protection, the size of the object to be protected, and the strength of the resistance and stroking materials that make up the assembly. Among other applications, the multilayered ballistic protection assembly is designed to protect glass from impacts due to severe weather and other debris-generating hazards. 
     In the following detailed description, reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the invention may be practiced. However, it is to be understood that other embodiments will become apparent to those of ordinary skill in the art upon reading this disclosure. The following detailed description is, therefore, not to be construed in a limiting sense, as the scope of the present invention is defined by the claims. 
       FIG. 1  is a schematic block diagram of a multilayered ballistic protection assembly  100 , according to some embodiments. The multilayered ballistic protection assembly  100  consists of an enclosure  40  that, in the depiction of  FIG. 1 , assumes a rectangular cubic shape much like an air mattress. The enclosure  40  includes a first protection layer  22 , a second protection layer  24 , and a surrounding protection layer  20 . Tensile fasteners  26  occupying a stroking space  50  are arranged between the first protection layer  22  and the second protection layer  24  to control the shape of the enclosure. 
     The enclosure  40  is designed to contain the stroking material  32 . As used herein, an enclosure is defined as a closed structure from which the stroking material  32  will not escape. The enclosure  40 , while being capable of changing shape, such as being folded into a compact form, assumes a predefined shape when the stroking material  32  is activated. There are several different embodiments described herein for activating the stroking material. 
     In some embodiments, the layers  22 ,  24 , and  20  that constitute the enclosure  40  are made from an anisotropic woven material, such as fiberglass fabric. In other embodiments, the layers  22 ,  24 , and  20  are made using isotropic materials, such as metal or plastics. In still other embodiments, the enclosure  40  is made using multiple distinct materials arranged into a composite form. Suitable materials for the multilayered ballistic protection assembly  100  include, but are not limited to, cotton, nylon, kevlar, carbon fiber, arimid fibers, perforated metal foils, thin wood, plastics, resin-filled fiberglass, and plastic-bonded fabrics. 
       FIG. 2  is a side view of the protection assembly  100 , showing how the tensile fasteners  26  are threaded between the two layers in the stroking space  50 . The tensile fasteners  26  may be made using a material that only resists tensile loads, such as rope or string, or using materials that can withstand tension and compression, such as a column of wood, plastic, ceramic, or metal. Preferably, the tensile fasteners  26  are capable of laying parallel to the layers  22 ,  24  before assembly so that the protection assembly  100  may be in a compact (initial) configuration. The tensile fasteners  26  control the distance between the protection layers  22 ,  24  and force the enclosure  40  to take a preprogrammed shape. 
     In some embodiments, the tensile fasteners are thin strips of plastic, such as fishing wire. These are a type of tension-only tensile fasteners. The plastic strips are sufficient to add structural integrity to the assembly  100  as it assumes the preprogrammed shape when the stroking material  32  is inserted within the enclosure  40 . In other embodiments, the tensile fasteners  26  are straws or other column-shaped structures, or tension and compression fasteners. Whether plastic strips, straws, or other structures, the tensile fasteners  26  lay flat against the two layers  22 ,  24  when the assembly is in its initial or interim configurations (see  FIG. 5 , below). The straws or other column-shaped structures confine the volume of the stroking material in a structural shape equivalent to a column. This forces the resistance layers to follow a predefined path while increasing strength as needed. 
       FIG. 3  is a side view of the multilayered ballistic protection assembly  100 , showing cylindrically shaped tensile fasteners  26 B. In some cases, arched shapes may be desirable for strength over longer spans, specific designs for sliding glass doors versus narrower windows. 
     In other embodiments, the tensile fasteners  26  are made using a material that can rotate and stand up to create the stroking volume. For example, the tensile fasteners  26  may be metal pieces that are formed to be curved in a free state. When compressed, the metal pieces would flatten and store energy like a spring. When the protection assembly  100  is unfurled to its interim configuration ( FIG. 5 ), a large number of the metal pieces, acting as “springs,” would rotate up and create a stand-off distance between the protection layers  22  and  24 . 
       FIG. 4  is a depiction of these alternate tensile fasteners  26 C, according to some embodiments. The tensile fastener  26 C is a square piece that lays flat when not in use. When used, the tensile fastener  26  assumes a rounded shape that has a spring-like quality. Such fasteners may be part of the multilayered ballistic protection assembly  100 . 
     Returning to  FIG. 1 , the protection assembly  100  further includes one or more stroking material delivery systems or canisters  28 , containing stroking material  32 . In the depiction of  FIG. 1 , the canisters  28  are containers containing pressurized stroking material, such as closed cell foam. Open cell foam is characterized as having interconnected pores that form a relatively soft network of foam material. Closed cell foam, by contrast, lack these interconnected pores. Because of this structure, closed cell foams generally have higher compressive strength than open cell foam. Closed cell foams also do not fill with whatever is surrounding, whether air or water. 
     Each stroking material delivery systems  28  is connected to the enclosure by a receiving means  30  consisting of an injection port and lip  34 . Each receiving means  30  accepts one of the canisters  28  containing the stroking material. Once the canister or canisters  28  are inserted, the contents of the canisters will be transferred to the inside of the enclosure  40 . The enclosure  40  receives the stroking material, such as polyurethane foam, until the enclosure is filled up. The tensile fasteners  26  help the enclosure  40  to maintain its desired shape, whether rectangular cubic shaped as in  FIG. 1  or some other desired shape. 
     In the embodiment of  FIG. 1 , the receiving means  30  are part of the surrounding protection layer  20 . The receiving means  30  consists of an injection port with a lip  34 , where the injection port is attached to the material of the surrounding protection layer  20 , with a hole cut into the layer (not shown) to enable the lip  34  to extend through the hole. The canister  28  likewise includes a receiving lip  36  to fit snugly into the lip  34  before the stroking material  32  is delivered into the enclosure  40 . Alternatively, the receiving means  30  may be part of either the first protection layer  22  or the second protection layer. 
     In other embodiments, the stroking material  32  is not inserted into the enclosure  40 , but is already present in the enclosure upon receipt by the customer. The “integrated” stroking material  32  is unactivated when in the initial configuration. The stroking material may be activated by inserting a liquid, such as water, into the enclosure  40 . Or, the integrated stroking material may be combined with another material also inside the enclosure  40 . In this embodiment, the stroking material is activated without an external catalyst, obviating the need for the enclosure to have any receiving means  30 . The integrated stroking material may be activated by some physical act, by a temperature change, or using some other non-invasive means. 
     If foam is used as the stroking material, closed cell foam will not increase in size if water is applied to the assembly  100 , whereas open cell foam operates in a sponge-like manner, changing shape as it absorbs water. Thus, during a severe weather storm, the assembly  100  may change shape if open cell foam is used. For this reason, where an open cell foam is used as the stroking material  32 , the foam is protected from exposure to the outside to prevent the foam from taking on water, in some embodiments. A liquid tight enclosure or other sealant may be used for this purpose. 
     In still other embodiments, a two-part reacting mixture is used as the stroking material  32  in the protection assembly  100 . The material that binds fibers in the resistance layer is a two-part reacting mixture, an aerobic curing material, or some other curing material, such as one that reacts with water, as in a cyanoacrylate monomer (also known as “Super Glue”). 
     Although the stroking material  32  of the multilayered ballistic protection assembly  100  is designed to deflect ballistic impacts due to a weather event, the enclosure  40  also provides some ballistic protection, in some embodiments. In addition to constraining the shape of the stroking material  32 , the enclosure  40  protects against punctures by flying objects and provides a measure of load absorption (impact attenuation). This multilayered approach provides a high degree of protection. 
     Preferably, the multilayered ballistic protection assembly  100  is available in a package that is compressed for transport. Plywood is problematic, as its transported volume is the same size as its installed volume. The multilayered ballistic protection assembly  100 , by contrast, is compact to transport prior to use, with the stroking material  32  being contained under pressure in a canister  28 . Once the stroking material fills the volume within the enclosure  40  of the assembly, the multilayered ballistic protection assembly  100  is a lightweight, yet sturdy structure suitable for protecting a window. 
       FIG. 5  shows the multilayer ballistic protection assembly  100  in both its initial form (denoted, “initial configuration”), after it has been removed from its packaging (denoted, “interim configuration”), and after the stroking material has been inserted into the enclosure  40  (denoted, “final configuration”). In any of these three configurations, the protection assembly  100  is easy to manage. 
     In some embodiments, when the multilayer ballistic protection assembly  100  is in its initial configuration, the enclosure  40  is folded to minimize its surface area relative to its volume. This makes the assembly  100  in its initial configuration smaller than it will be in its final configuration, thus being more transportable for the consumer. When unfurled into its interim configuration, the enclosure  40  is preferably flexible. When the stroking material  32  is activated within the enclosure  40 , the enclosure  40  becomes stiff in its final configuration. 
     Materials that change shape and develop stiffness when laid flat, such as is characteristic of many leaf springs, may be used for the protection layers, in some embodiments. In this embodiment, the protection layers  22  and  24  may be made using a metallic-based fabric or other material that is capable of stiffness. When being rolled out from the initial configuration to the interim configuration, the protection layers  22  and  24  would spring into a curved shape, hence becoming stronger and less flexible. 
     The multilayered ballistic protection assembly  100  is advantageous over the traditional plywood remedy for window protection because of the multiple configurations depicted in  FIG. 5 . By controlling the shape of the protection layers  22 ,  24 , particularly the ability of the layers to be flattened and thus consume less space in the initial and interim configurations, the assembly  100  is more compact to transport. Further, by transforming the assembly  100  into its final configuration only when needed, such as just before a hurricane, a consumer can purchase, transport, and store the assembly in its initial configuration at the property site well in advance of a weather event. 
     The first and second protection layers  22 ,  24  of the configuration depicted in  FIG. 1  are resistant to the penetration of a flying object, as is the stroking material embedded between the two layers. Controlling the resisting layers&#39; shape assures that the minimum amount (volume) of material is used to protect the surface. It also allows for surfaces generated by intersecting spline curves to be protected. In some embodiments, the multilayer ballistic protection assembly  100  in its initial configuration is a dense package that takes up the least amount of space, relative to other solutions. The stroking space between the two layers  22 ,  24 , when filled with the stroking material  32 , contributes to the structural integrity of the assembly  100 , but, prior to being used, is entirely contained in the canisters  28  or other delivery system, whether contained inside the enclosure or outside the enclosure prior to delivery. The stroking material may either be compressed, as in the case of the canned foam, or may be created by the reaction of uncompressed liquids to a catalyst or other agent that causes the reagent to fill the enclosure and harden. In other cases, the stroking material may be compressed as a foam, installed in the enclosure  40 , which then expands and assumes a larger volume when restraints are released. 
     The multilayered ballistic protection assembly  100  imitates the deflection and absorption approach of a micro-meteor and orbital debris (MMOD) shield. The realm of the impact velocities and impact energies due to a hypervelocity particle and a low velocity board or rock may be different. The design features of the multilayer ballistic protection assembly  100  protect against a variety of damages, both expected and unforeseen. 
     The number of protection layers and stroking spaces can vary, in some embodiments, for to protect an object. In  FIG. 6 , a protection assembly  100 A has six protection layers surrounding five stroking spaces. Protection layers  22  and  24  surround stroking space  50 ; protection layers  24  and  36  surround stroking space  52 ; protection layers  36  and  38  surround stroking space  54 ; protection layers  38  and  42  surround stroking space  56 ; and protection layers  42  and  44  surround stroking space  58 . 
     In some embodiments, the width, w, of each stroking space in the multilayered ballistic protection assembly  100 A is varied. Thus, each stroking space is characterized by its own set of tensile fasteners  26 . The tensile fasteners  26  for the stroking space  50  may be wider or narrower than the tensile fasteners  26  for the stroking space  52 , and so on. In other embodiments, the width, w, of each stroking space is the same. In this case, each stroking space may have its own tensile fasteners  26 , with each set of tensile fasteners being the same length, or a single set of tensile fasteners may extend from the first protection layer  26  to the last protection layer, in this case, the sixth protection layer  44 . 
     In still other embodiments, the stroking space between two protection layers is not uniform. As depicted in  FIG. 7 , a multilayered ballistic protection assembly  100 B includes two protection layers  46 ,  48 , with a stroking space  60  between the two layers. While part of the stroking space has a width, w, the center of the stroking space has a width, w 2 , where w 2 &lt;w. The varying width of the stroking space can be achieved using shorter tensile fasteners  26  along the column, c, as well as in columns, c−1 and c+1. The assembly  100 B may be preferred for windows with non-uniform surfaces, separation between glass pieces, and so on. Sliding glass doors, for example, typically have metal bracing between the pieces of glass, and may be more fully protected with the assembly of  FIG. 7 . In some embodiments, the number of layers and their thickness varies according to the materials used and the energy to be absorbed. 
     In addition to protecting a window or other fragile surface during a weather event, the multilayered ballistic protection assembly  100  may be used as insulation. Storm events are often followed by loss of electric power to a property. By using the assembly  100  as insulation after the storm, the property temperature may be maintained for a much longer time period than without such protection. The assembly  100  may also be used as attic or crawlspace insulation for a longer time period. The removable attic insulation may then be retrieved and used to protect the windows during subsequent weather events. Plywood stored in the attic provides no substantial additional insulation, but takes up space nevertheless. The assembly  100 , by contrast, may provide additional insulation to the property while being stored. 
     In some embodiments, the multilayered ballistic protection assembly  100  is usable as a flotation device. This may be particularly useful following a severe storm event, where flooding may damage the structure being protected and may even put the residents&#39; lives at risk. Where the stroking material  32  is made using a closed cell foam (or an open cell foam that is sufficiently contained within a water-resistant bladder), the assembly  100  makes a sturdy flotation device. Smaller assemblies may be used to protect valuable objects, pets, and young children, while large-window assemblies have sufficient strength to protect adults, in some embodiments. The assembly  100  may also be used where flooding removes topsoil, creating muddy and sometimes precarious land surfaces, making ingress and egress of the property problematic for its residents. 
     In still other embodiments, the multilayered ballistic protection assembly  100  may be used as static barriers, such as a rapid deployment retaining wall used to protect against a mudslide. 
       FIG. 8  is a flow diagram showing how the multilayered ballistic protection assembly  100  is used, according to some embodiments. The assembly  100  in its initial configuration (see  FIG. 5 ) is first retrieved (block  102 ). Due to its relatively small volume, the assembly  100  may have been previously purchased and stored for later use. The window or door or other opening is then measured (block  104 ). The assembly  100  is then laid out flat into its interim configuration (see  FIG. 3 ) and is cut to fit the measured size (block  106 ). The assembly  100  may be cut using a knife, scissors, or other cutting implement. In some embodiments, the assembly is pre-cut such that the consumer may “tear” a portion of the measured size, without need for cutting tools. In other embodiments, the assembly is cut after the stroking material is deployed inside the enclosure  40 . 
     Once the portion of the assembly needed for the surface to be protected has been obtained, the stroking material is deployed between the layers of the assembly  100  (block  108 ). Where a multiple-layered assembly is used, such as the assembly  100 A of  FIG. 6 , stroking material is inserted under pressure to one of the stroking spaces, followed by insertion into a second stroking space, and so on, until all stroking spaces have been filled with stroking material. Once the stroking material  32  becomes rigid (block  110 ), the assembled configuration, now a rigid structure, is affixed to the window, door, or open surface (block  112 ). In some embodiments, the stroking material  32  may be deployed after the interim assembly is attached to the protected object. 
     In some embodiments, the multilayered ballistic protection assembly  100  is affixed to the window, door, or other surface using a fastening means that prevents the assembly  100  from moving due to negative pressure or shearing loads. Methods to prevent these movements include adhesives, double-ended feather boards, screws, nails, staples, wedge-shaped objects, etc. The multilayered ballistic protection assembly  100  provides a layered approach using resistance layers (the stroking material  32 ) to absorb energy and deflection areas (the protective layers  22 ,  24 ) to allow for large deflections of the resistance layer without allowing damage to the projected object. The number of layers used will depend on the desired level of protection versus the strength of the materials used. In comparison to other ballistic protection materials, chiefly plywood, the assembly  100  is of a significantly lighter weight, easier to transport and store, and is rendered into its assembled configuration using only common household tools. Further, the assembly  100  provides a secondary benefit following the weather event and may be used for subsequent weather events if maintained in its assembled configuration undamaged. 
     The multilayered ballistic protection assembly  100  uses resistance layers separated by a stroking volume that allows the resistance layers to move without causing damage to the window glass, door, or other structure being protected. The assembly  100  may be pre-fabricated as a panel and purchased in its final form (final configuration). Alternatively, the assembly  100  may be packaged in a reduced volume (initial configuration) until needed, and then may be unrolled (interim configuration) and cut to size. 
       FIGS. 9A ,  9 B,  10 A, and  10 B illustrate different embodiments for affixing the assembly  100  to a window, according to some embodiments. In the side view of  FIG. 9A , the multilayered ballistic protection assembly  100 D is longer than the glass surface  90  it is designed to protect. Adhesives  80  are affixed between the assembly  100 D and the building surface  94 . Although two adhesives  80  are shown, there may be any number of adhesives used to secure the assembly  100  against the glass surface  90 . In  FIG. 9B , the multilayered ballistic protection assembly  100 E has the same length as the glass surface  90 . The adhesives  80  are thus applied directly to the glass surface  90 , disposed between the glass and the assembly. 
     In  FIGS. 10A and 10B , the space between the glass surface  90  and the building surface  94  is used to hold the multilayered ballistic protection assembly  100 F against the glass surface  90 . Two double-ended feather boards  92  or other wedge-like structures fit snugly between each side of the assembly  100 F and the building surface  94  in  FIG. 10A . During a weather event in which the assembly  100  attempts to move relative to the protected surface, the double-ended feather boards  92  apply a side load to the enclosure  40 , preventing displacement of the assembly. In  FIG. 10B , a single double-ended feather board  92  is used to hold the assembly  100 G flush against the glass surface  90 . Designers of ordinary skill in the art will recognize a variety of mechanisms for securing the multilayered ballistic protection assembly  100  against the glass surface being protected. 
     In some embodiments, the tensile fasteners  26  are not simply used to maintain a predetermined distance between the protection layers  22 ,  24 , but are also used to provide pathways that affect the distribution of stroking material  32  within the enclosure  40 . For example, the tensile fasteners  26  may be expandable bladders or other balloon-like structures that may be filled with a gas to create volume within the enclosure  40 , allowing the stroking material  32  to assume other regions of the enclosure not occupied by the gas.  FIG. 11  is a side view of a multilayered ballistic protection assembly  100 H in which the tensile fasteners  26 H are inflatable. The stroking material  32  and the gas-filled tensile fasteners may form a lattice structure, as one example. When the tensile fasteners  26 H are not filled with gas, they lay flat against the bottom of the enclosure  40 H. When filled with gas, the tensile fasteners  26  assume some volume of the enclosure space. In this way, the stroking material  32  may be distributed strategically through the enclosure  40 H, such as where uneven surfaces are to be protected. Or, the voids created by the bladder-like tensile fasteners  26  may result in less stroking material being used. The tensile fasteners  26 H in this configuration are thus used to both maintain the shape of the enclosure  40 H and to supply some of the stroking volume of the enclosure. 
       FIG. 12A  is a side view of a multilayered ballistic protection assembly  100 J, according to some embodiments. In this embodiment, the enclosure  40 J is saturated with air-curing compounds  88 , which are embedded within the protection layers of the enclosure  40 J. In other embodiments, the air-curing compounds  88  are attached to the protection layers of the enclosure  44 J. In still other embodiments, as depicted in  FIG. 12B , the fluid-curing compounds  88  (gas or liquid) are free-floating within the enclosure  40 M. (Because of the fluid-curing properties of these compounds  88 , the enclosure  40 J is compressed and packaged in an air-tight container in its initial configuration.) Within the enclosure  40 J, the tensile fasteners  26 J are springs that operate as both tensile fasteners and as stroking material. When air is allowed into the enclosure  40 J, the springs move up from a down position to an up position, forcing the enclosure  40 J into a preprogrammed shape. Further, because of the air-curing compounds  88 , the enclosure  40 J cures and become rigid. 
     In other embodiments, the multilayered ballistic protection assembly  100  may include the tensile fasteners that are springs (as in the tensile fasteners  26 J and  26 M of  FIGS. 12A and 12B , respectively), but not include the air-curing compounds. In this configuration, the springs would not be activated by air, but would move from the down to up position by some other means. The assembly  100  may receive stroking material from an external source, such as a canister, as in  FIG. 1 , or may include a two-part compound that is located inside the enclosure, as described above. In still other embodiments, the assembly  100  may include the bladder-like tensile fasteners combined with the air-curing compounds. Designers of ordinary skill in the art will recognize a number of different combinations that may be used in constructing a multilayered ballistic protection assembly based on the many embodiments described herein. 
     While the application has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of the invention.