Patent Application
20080092729
Representative elements, operational features, applications and/or advantages of the present invention reside in the details of construction and operation as more fully hereafter depicted, described and claimed—reference being made to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. Other elements, operational features, applications and/or advantages may become apparent in light of certain exemplary embodiments recited in the Detailed Description, wherein:
Elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms “first”, “second”, and the like herein, if any, are generally used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms “front”, “back”, “top”, “bottom”, “over”, “under”, and the like, if any, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position or order. Any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein, for example, are capable of operation in orientations and environments other than those explicitly illustrated or otherwise described.
The following representative descriptions of the present invention generally relate to exemplary embodiments and the inventor's conception of the best mode, and are not intended to limit the applicability or configuration of the invention in any way. Rather, the following description is intended to provide convenient illustrations for implementing various embodiments of the invention. As will become apparent, changes may be made in the function and/or arrangement of any of the elements described in the disclosed exemplary embodiments without departing from the spirit and scope of the invention.
In the past, multiple layers of glass in thicknesses in the vicinity of ½″ were used in ballistic glass applications. The resultant peripheral damage, both ballistically and optically, was severe and broad in scope. Various embodiments of the present invention provide a tough kinetic backing layer with an overlying, relatively thin glass facing. The glass facing, being only of sufficient thickness to spoil the pointedness of the incoming projectile (e.g., ⅛″) may be bonded to the kinetic layer with an elastic medium.
When a projectile strikes the thin glass facing, the facing fractures, but in a much smaller area than that of convention ballistic glass assemblies.
In accordance with an exemplary embodiment representatively depicted in
Generally, the thickness ratio of the kinetic layer 100 (e.g., polymeric material) to the facing layer 110 (e.g., glass material) should be at least approximately unity. It will be appreciated, however, that various other thickness ratios may be alternatively, conjunctively or sequentially employed to achieve a substantially similar result. It will also be appreciated that different thickness ratios will produce different armor characteristics that are uniquely adapted for particular threats or operating environments.
The facing layer 110 may be comprised of a hard, glass-like material that operates to blunt or otherwise deform a bullet or projectile incident to its surface. The facing material may be almost any composition, such as, for example: soda lime; crown; borosilicate; aluminum oxynitride; sapphire; etc. Any glass material, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed in order to achieve a substantially similar result.
It should be noted that the term “projectile” may refer to any object that may strike the surface of a optically transmissive armor assembly. These may include projectiles used to attack the integrity of the optically transmissive armor such as ballistic items (bullets, shrapnel, thrown objects such as bricks, stones and other similar objects) and self-propelled items (such as RPGs, missiles, and other rocket-like objects). Projectiles may also include objects used to directly strike the surface of the optically transmissive armor, such as, for example: bricks, bats, metal objects, stones, wooden clubs, etc. Finally, projectiles may also include other objects that come into contact with the surface of the optically transmissive armor. For example, if the optically transmissive armor is used as part of a vehicle and that vehicle were to be involved in an accident, portions of other vehicles, the road, buildings or other objects may strike the surface of the optically transmissive armor.
In the present embodiment, facing layer 110 has a preferable thickness of about ⅛″ (±approximately 50%). This is in contrast to the conventional art, in which the principle structure consists of a plurality of thick layers of glass—as conventional glass layers are primarily used as kinetic depletion layers rather than as facing and blunting layers, as representatively disclosed and claimed in the instant application. In the present invention, the glass material generally serves to merely blunt or otherwise deform a projectile that is striking its surface, as opposed to depleting a substantial fraction of the kinetic energy of the projectile. Accordingly, glass facing layers in accordance with the instant invention may be relatively thin compared to those of the conventional art. A thinner layer of glass material is preferable because it significantly reduces the weight of the armor assembly without substantially decreasing penetration impedance, and simultaneously provides improved optical characteristics and retention of localized structural integrity after the armor assembly is struck by a projectile.
For comparable stopping power, the present invention weighs considerably less than that of conventional transparent armor alternatives. Optical clarity after a projectile strike (i.e., hit proximity performance) is also improved. As the thickness of the glass facing material decreases, the damaged area (i.e., hit radius) and glass loss also decreases. For example, the glass loss in a ⅛″ facing is only about 1″ diameter; however, with ¼″ glass, this area extends out to roughly 3″ in diameter or greater. Accordingly, after a hit on a thinner layer of glass, less of the material's optical characteristics will have been compromised.
By way of comparison, the optical occlusion of conventional transparent armor extends out over a 6″ radius from any given hit. Various exemplary embodiments of the present invention present an occluded area of only about 1.5″ radius under similar conditions. Second hit capability (i.e., the ability of the optically transmissive armor assembly to stop a projectile that strikes its surface in close proximity to the location of a prior hit) is substantially improved due to the minimized glass loss that results from use of thinner layers of glass facing. Generally, the glass loss area after a first hit is greatly weakened and will not provide much protection against a second hit. Accordingly, it is preferable to employ a thinner layer of glass material in the facing layer 110, thereby minimizing the amount of glass loss.
Present performance specifications for transparent armor generally can require successful stoppage in a close hit pattern. The disconcerting issue is that realistic threats are likely to greatly exceed the specification requirement. The present invention operates to overcome many problems associated with the conventional art by providing a hit (and stoppage) capability in as low as ¾″ spacing in all directions.
The kinetic layer 100 of the optically transmissive armor generally comprises a tough, semi-rigid material having a high cut and puncture resistance capable of catching the blunted projectile by depleting its kinetic energy. For example, a single casting of a clean, hard urethane polymer is an exemplary material that may be employed in accordance with various embodiments of the present invention. Hard urethane has demonstrated ease of casting and superb close hit capability. Other materials having similar characteristics (e.g., polycarbonate and acrylic), whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed to achieve a substantially similar result.
In accordance with another exemplary embodiment, as generally depicted in
In accordance with another exemplary embodiment, as generally depicted in
In accordance with still another exemplary embodiment, as generally depicted in
An exemplary glass/polymer composite embodiment comprises borosilicate glass (having a refractive index of about 1.48) and a low modulus, low temperature curing urethane. By addition of low R1 plasticizers, the index of refraction match can be nearly perfect (within a given temperature range). This limit of temperature range may preclude the use of sphere tile elements, but flat mosaics may be useful under similar conditions. Although it is generally preferable to match the indices of refraction for certain applications, substantial benefit may be derived from an optically transmissive armor where the indices of refraction are dissimilar. For example, even with mismatched indices of refraction, optically transmissive armor would still function well under a variety of conditions in diverse operating environments. Articulation of the facing layer 410 has demonstrated minimization of the glass loss that results after a projectile strikes the surface of the first layer 410 by inter alia localizing fracture expansion to a single tile (or nearest-neighbors) regime. Accordingly, the loss of facing material will generally be confined to the particular tile or tiles 420 that were struck by the projectile.
In accordance with yet another exemplary embodiment, as generally depicted in
Substantial benefit may be derived for configurations of the facing layer(s) where some sheets of facing material are substantially articulated and others are not. For example, the first layer of facing material 540 presented to a projectile may not be articulated, but the other sheets of facing material may be articulated—thereby minimizing glass loss within those layers, as well as reducing construction complexity and fabrication costs.
In accordance with yet another exemplary embodiment, as generally depicted in
Optically transmissive armor composite assemblies, in accordance with various embodiments disclosed herein, may be constructed using vacuum and autoclave processes of laminate stack-ups. The stacks may comprise a combination of multi-layered thick glass, polymeric inner-layers and polymeric backing. The composite laminate assembly may then be heated and cooled under pressure. Various other embodiments of the present invention may also be cast with conventional equipment.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth herein. The specification and Figures are to be regarded in an illustrative manner, rather than a restrictive one and all such modifications are intended to be included within the scope of the present invention. Accordingly, the scope of the invention should be determined by the claims and their legal equivalents rather than by merely the examples described above.
For example, the steps recited in any method or process claim may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any apparatus embodiment may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the claims.
Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problem or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of the invention.
As used herein, the terms “comprising”, “having”, “including” or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus. Other combinations and/or modifications of the above-described structures, arrangements, applications, proportions, elements, materials or components used in the practice of the present invention, in addition to those not specifically recited, may be varied or otherwise particularly adapted to specific environments, manufacturing specifications, design parameters or other operating requirements without departing from the general principles of the same.
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/633,365 (entitled ‘Transparent Armor’) filed in the United States Patent and Trademark Office on Dec. 3, 2004 by Richard Cook.
| Number | Date | Country | |
|---|---|---|---|
| 60633365 | Dec 2004 | US |
