Patent Grant
6997218
This patent application is co-pending with one related patent application entitled “INFLATABLE TRAJECTORY ALTERING AND BLAST ENERGY ABSORPTION SYSTEM” (Navy Case No. 96127) by the same inventors as this patent application.
The invention relates generally to body armor, and more particularly to an inflatable body armor system that alters a projectile's trajectory as the projectile passes through an inflated plenum.
In today's world, police and military forces frequently wear some form of body armor in order to reduce the threat of severe injury or death due to an incoming projectile. Current body armor technology utilizes layers of fabrics made from aramids (e.g., SPECTRA, KEVLAR, etc.), polypropylene, polyethylene, or high-performance P-phenylene benzobisoxazole (PBO) fibers. The fabric materials can be used alone or have ceramic panels positioned between material layers sewn into a vest type arrangement to surround the front and back of a person's upper torso. In the current art, the only methods used to increase body armor's ballistic protection involve (i) adding thick metal plates, ceramic plates, or other hard materials, or (ii) increasing the thread count and number of layers of fabric material. However, both methods increase the weight and cost of the body armor.
Accordingly, it is an object of the present invention to provide a body armor system that offers the wearer protection from an incoming projectile.
Another object of the present invention is to provide a lightweight body armor system.
Other objects and advantages of the present invention will become more obvious hereinafter in the specification and drawings.
In accordance with the present invention, an inflatable body armor system includes at least one body armor section adapted to be worn by a user. Each body armor section includes a flexible/sealable plenum defined by spaced apart walls when the plenum is inflated, and a ballistic armor fabric encasing the plenum. Dispersed in the plenum are tensioned lines, shaped objects and/or ballistic fabric sheets for altering trajectory of a projectile entering the plenum.
Other objects, features and advantages of the present invention will become apparent upon reference to the following description of the preferred embodiments and to the drawings, wherein corresponding reference characters indicate corresponding parts throughout the several views of the drawings and wherein:
Prior to describing the inflatable body armor system of the present invention, a novel inflatable trajectory altering system will first be described. The trajectory altering system forms the core element for the inflatable body armor system.
Referring now to the drawings, and more particularly to
In general, the trajectory altering system of the present invention includes one or more types of material structures disposed within wall structure 12. For the illustrated embodiment, flexible lines 14 are coupled to and span major opposing walls 12A and 12B such that lines 14 are placed in tension when wall structure 12 is inflated. Each of lines 14 can be made from a single fiber strand or multiple strands of fiber. In general, lines 14 should possess a high tensile strength and be abrasion resistant. Thus, a variety of polymer materials can be used for lines 14 with certain commercially-available products being preferred when system 10 is to be used to alter the trajectory of an incoming projectile. For example, lines 14 can be fibers made from the well-known polymeric strength materials SPECTRA available from Honeywell International Inc., KEVLAR available from E.I. du Pont de Nemours and Company, ZYLON available from Toyobo Company Ltd., TWARON available from Akzo Nobel, DYNEEMA available from Koninklijke DSM N.V., and nylon, just to name a few.
Attachment of lines 14 to major opposing walls 12A and 12B is preferably accomplished by a method known as “drop stitching” which maintains the sealed and fluid-impermeable integrity of wall structure 12. Drop stitching methods are known in the art of inflatable watercraft construction. See, for example, U.S. Pat. No. 6,074,261, the contents of which are hereby incorporated by reference. The lengths of lines 14 can be varied to shape the outer contours of wall structure 12 for a particular application.
The interior surfaces of wall structure 12 can be optionally coated or covered with a viscous polymeric sealing material layer 16 that serves to seal itself in the event of a small puncture. Examples of such sealing material constructions are disclosed in U.S. Pat. Nos. 4,501,035 and 5,295,525, the contents of which are hereby incorporated by reference.
The mechanism by which system 10 alters a projectile's trajectory will now be described with the aid of
The action of circumferential forces F tends to alter the trajectory of projectile 50 thereby causing projectile 50 to encounter more of lines 14. That is, forces F cause projectile 50 to experience yaw with respect to its original straightline course thereby making projectile 50 collide with more of lines 14. Simultaneously, the change in projectile trajectory increases the projectile's force bearing area which reduces the projectile's localized pressure point to immediately reduce the projectile's penetration capability. Thus, more collisions translate to more projectile course alterations and increased projectile bearing area resulting in increased energy losses.
Trajectory alteration also dissipates large amounts of the projectile's kinetic energy in lines 14 as the larger projectile bearing area impinges on lines 14. In addition, the subsequent movement of the impacted wall(s) absorb kinetic energy in a way not conducive to penetration thereby slowing the speed of projectile 50 and reducing its lethality.
In addition, the present invention mitigates the shock wave resulting from a blast event. For many battlefield situations, this type of shock wave typically lasts for less than 30 milliseconds. The impedance mismatch between major walls 12A and 12B combined with the ability of the plenum to deform upon shock wave arrival reduces the intensity of these short-lived blast-induced shock waves impinging on the wall structure. More specifically, the impedance mismatch and flexible plenum make the present invention respond to a short-lived shock wave in a non-frangible and flexible way. As a result, a short-lived blast-induced shock wave can be absorbed during its brief period of lethality. Still further, the two spaced apart walls of wall structure 12 will aid in the jet particulation of an exploded shaped charge warhead.
Projectile trajectory alteration and energy absorbing capabilities can be further enhanced by adding other material structures within wall structure 12. Several examples will be described below with the aid of
In
In
Each of the embodiments shown in
One or more of the above-described inflatable trajectory altering systems can be utilized in the construction of an inflatable body armor system in accordance with the present invention. The body armor system can be constructed to fit any portion of one's body, although it is typically constructed as a vest as will be described herein by way of example. Accordingly, it is to be understood that the inflatable body armor vest described herein is simply a representative example and is not a limitation of the present invention.
Referring now to
By way of example, body armor vest 100 is shown using the inflatable trajectory altering system shown in
To provide inflation integrity in the event of a leak in wall structure 12, the interior portion of wall structure 12 can be divided into individual sealed chambers separated by chamber walls 12C. As would be well understood in the art, each of chamber walls 12C can incorporate a “one way valve” (not shown) to permit system inflation from a single gas source 30.
Each wall structure 12 is encased by fabric 40 having ballistic armor qualities. Currently, the preferred materials for fabric 40 are SPECTRA and KEVLAR. Panels of fabric 40 can be stitched to encase each wall structure 12. Fabric 40 can also be used to define pockets 42 designed to receive conventional rigid armor plates 44 (e.g., metal, ceramic, etc.).
The portion of fabric 40 that will come into contact with a user can be quilted or dimpled at 40A to define a three-dimensional surface that creates air gaps between fabric 40 and the user's body. The air gaps will keep a user cool during an extended wearing of vest 100.
The advantages of the present invention are numerous. The inflatable body armor system provides ballistic protection as tensioned flexible members (e.g., lines and/or fabric sheets) dispersed in the body armor's inflated plenum serve to alter an incoming projectile's trajectory while simultaneously absorbing the kinetic energy thereof. The inflated nature of the body armor makes it lightweight and buoyant. By dividing the inflated plenum into individual chambers, the body armor will not be compromised by a single point failure. In addition, the present invention mitigates shock resulting from a blast event.
The present invention provides the means to build body armor panels of relatively great thickness and relatively low weight. Armor thickness is of great importance as it is the only means available to overcome the basic thermodynamic limitation imposed by the fact that it takes time to transfer/absorb energy/work. Thus, a thicker armor provides the time necessary to effect energy transfer/absorption of a projectile or blast energy.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.
The invention described herein was made in the performance of official duties by employees of the Department of the Navy and may be manufactured, used, licensed by or for the Government for any governmental purpose without payment of any royalties thereon.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5584737 | Luhtala | Dec 1996 | A |
| 6012162 | Bullat | Jan 2000 | A |
| 6079056 | Fogelberg | Jun 2000 | A |
| 6845513 | Field et al. | Jan 2005 | B1 |
| 6861378 | Cunningham et al. | Mar 2005 | B1 |
