WO2006087699A2

WO2006087699A2 - Armor assembly

Info

Publication number: WO2006087699A2
Application number: PCT/IL2006/000162
Authority: WO
Inventors: Arie Israeli
Original assignee: Arie Israeli
Priority date: 2005-02-21
Filing date: 2006-02-08
Publication date: 2006-08-24
Also published as: WO2006087699A3; IL185389A; IL185389A0

Abstract

An armor assembly comprising: one or more substantially parallel layers, each layer comprising a two-dimensional array of packed elements that are capable of swaying about at least one axis, the elements arranged so as to create cavities between adjacent elements in a layer and across one or more layers for trapping incoming objects.

Description

ARMOR ASSEMBLY

FIELD OF THE INVENTION

[0001] The present invention relates to an armor assembly and method, which is aimed at withstanding or greatly reducing the impact of weapons, such as projectiles, and especially, but not limited to, kinetic energy penetrators, and to a method of protecting structures, equipment (mobile or stationary), and of individuals, against impact of weapons, and especially, but not limited to, a method for deflecting and/or intercepting and/or decelerating motion of bodies with high kinetic energy, utilizing dynamical geometric structure.

BACKGROUND OF THE INVENTION

[0002] Armor is a protective layer intended to defend from harm, typically associated with combat and military operations. Armor has been used throughout recorded history, beginning as body shield, and later on as vehicles shield and as shield for various types , of military equipment. Naturally, the development of armor runs parallel to the development of increasingly more efficient weapons.

[0003] Nowadays, there are three substantial kinds of weapons representing three substantial methods to penetrate and/or harm remotely a shielded objective. One is the kinetic energy projectile, second is the plastic explosive charged projectile and third is the shaped charge projectile. Kinetic energy projectiles attain high muzzle velocity, and when they collide with their objective, they release kinetic energy. Plastic explosive charged projectiles comprise a plastic explosive charge. On impact the explosive charge flattens against the face of the armor, explodes and by that transfers energy through the armor plate without actually penetrating it. When the compressive shock reflects off the air or metal interface on the inner face of the armor, it is transformed into a shock wave which spalls a piece of metal off the inner wall of the armor and sends it hurling into the protected objective causing internal damage. Shaped charge projectiles are explosive charges shaped to focus the effect of their released energy. The detonation of a shaped charge causes a jet of fluid of extremely high heat to be formed and move forward along the collision axis. The high heat material, such as copper, penetrates the armor by melting it, and creates enormous heat and pressure in the stricken area. [0004] Generally, basic and common armor comprises plating made of strong and highly resistant materials, which enables the armor to withstand impact of weapons. Accordingly, the armor passive defense ability stands in direct relation to the plating thickness, and thereof to the weight of the armor and to its cost.

[0005] Therefore, one of the well known challenges in the armor industry is creation of strong and effective armor, yet light weighted, so it would not restrict the mobility of individuals wearing it or vehicles carrying it.

[0006] Another disadvantage of the primary plating method, which is mentioned above, is the fact that once the plating is damaged, it must be replaced.

[0007] Over the years various armor technologies were developed, usually in the form of supplements or improvements to the basic plating. A substantial development was the revelation that sloping and curving the armor increases its protection. A projectile striking armor at an angle has to penetrate through more layers of armor in order to pass through than a projectile striking perpendicularly, thus increasing the armor protection ability.

[0008] Integral spaced armor comprises armor with hollow spaces, increasing the length of travel of the incoming threat from the exterior of the vehicle to the interior, in hope of reducing the shaped charge penetrating power. In some cases the interior surfaces of these hollow cavities are sloped. Another type of spaced armor is perforated steel armor with hollow perpendicular spaces. Thus, spaced armor technology grants extra protection without significant increase to armor weight.

[0009] Composite armor comprises layers of different materials, such as: ceramics, steel and plastic. This composite grants the armor the ability to blunt the projectile (by the brittle ceramics) and to absorb its kinetic energy (by the softer steel). A combination of spaced armor and composites can be found as well.

[0010] Reactive armor is a technology based on the principle of armor reacting to incoming threats and serves as a supplement to the basic armor. Two main categories of reactive armor are explosive reactive armor and non-explosive non-energetic reactive armor. These technologies are based on the principle of deflecting the projectile course and by that reducing it's penetrating ability on one hand, and increasing the effective thickness of the armor, on the other. These technologies act upon a projectile as it strikes the armor. On the other hand, active protection systems act upon an approaching projectile by detecting it and launching a counter measure.

[0011] Explosive reactive armor technology uses explosive energy in order to deflect weapons. Explosive reactive armor comprises tiles of explosive sandwiched between two plates, called "reactive elements". Once a weapon strikes, the armor produces an explosion disrupting the weapon course. This technology requires heavier armor in order for the explosion not to damage the vehicle and not to harm its crew. Another disadvantage is the danger of harming individuals outside the vehicle, which happen to be in the explosion range.

[0012] Non-explosive non-energetic reactive armor technology uses the energy of the penetrating weapon in order to deflect it. The non-explosive non-energetic reactive armor is based on the same mechanism of explosive reactive armor, using the fact that the geometry of materials changes under stress. The plate sandwich comprises inert liner, such as rubber. Therefore, when armor is struck by weapon, some of the impact energy is dissipated into the inert liner layer, and that causes a localized bending of the plates. The plate bending shifts the weapon point of impact. In comparison with the explosive reactive armor, the bending in this technology is less energetic, but the armor is lighter and safer to handle.

[0013] US 3,705,558 (McDougal et al.) provides a light weighted armor plate for use in armored vehicles or the like which protects against penetration by projectiles of 0.30 inch caliber and similar projectiles. The armor disclosed comprises a mass of closely packed hard substantially spherical ceramic balls arranged and suitably supported in abutting pyramidal relationship. When struck by a projectile, the closely packed structure causes a rapid distribution of forces in the lateral plane and by that dissipates and reduces the energy of the penetrating projectile.

[0014] US 4,179,979 (Cook et al.) discloses armor which realizes the idea of using a special geometric structure comprised of layers of uniformly geometrically shaped small objects in order to achieve a lightweight and effective armor assembly armor assembly. The small uniformly geometric shaped objects (spherical objects were disclosed) are compressed and arranged in parallel or oriented layers, where all objects are substantially in contact with adjacent objects. The objects array is interlaced with material of great tensile in order to support the array and bond the objects. The tensional relationship of the objects distributes the impact of projectiles over a greater surface area and by that increases the resistance of mass element per area.

[0015] Obvious disadvantages of the aforementioned technology are the volume waste and the damage that may be caused to the system after taking in a hit. Damaging a layer of the armor structure in one point neutralizes the entire layer and reduces the protection ability of the entire armor assembly. In addition, and according to Cook et al., tested samples of the system were proved effective only against a 14.5 mm armor piercing projectiles.

[0016] US 5,364,679 (Groves) discloses a body armor protecting from high-speed projectiles such as a bullet from a handgun or riffle. This patent utilizes energy dissipating characteristics of a dense and dynamic geometrical structure in order to flatten and trap the bullet. The disclosed armor comprises an outer component and an inner component. The outer component comprises a geometrical structure of two internested layers of hard half-hemispherical beads sandwiched between two layers of flexible high impact resistant cloth being drawn together by stitching. Flattening and trapping the bullet is performed by converting at least a portion of the kinetic energy of the bullet to rotation of the half-spherical beads. Thus, penetration threat of the impacting bullet is converted into a bruising impact threat of residual impact energy. The inner component further spreads the impact of the bullet so as to reduce the bruising impact threat.

[0017] US 5,738,925 (Chaput) discloses a flexible protective armor, which comprises a hard microstructure and a flexible macrostructure, thus flexible for nondestructively absorbing the impact of ballistic projectiles. The armor includes an outward layer of hard geometrical shapes, preferably spheres, tightly packed and interlocked in a way that enables free rotation, and firmly mounted to an outward side of a flexible membrane. The kinetic energy of a fast moving projectile is dissipated and absorbed upon impact by the spheres, curving of the layer of spheres and the flexible membrane, tensioning the ballistic fibers of the flexible membrane within the elastic range of the ballistic fibers, so that the armor rebounds after impact. It appears that the disclosed armor is restricted to projectiles not powerful enough to damage, rupture or penetrate the armor flexible structure.

[0018] US 5,866,839 (Ohayon) discloses an armor protection system for tanks and fighting vehicles against large caliber armor piercing weapons such as chemical weapons and high impact energy weapons. The system comprises containers of packed metal balls placed in vertical rows generating a blocking resistance and deflection of penetrating weapons. The weapon impact causes the balls to rotate and thus deflect the kinetic energy of the weapon.

[0019] Ohayon's protection capability depends substantially on the structure density and weight making it very massive and mainly suitable for heavy vehicles. In addition, the balls diameter limits the variety of weapons the armor assembly is effective against. The armor assembly structure is asymmetrical and non-homogeneous making the armor assembly less resistant. The armor assembly comprises containers of structured balls partitioned by voids in order to prevent neutralization of the whole system in case of an impact. On the other hand, these voids are substantially vulnerable points, which are prone to penetration. The system is also substantially ineffective against an explosive charge.

[0020] It is an objective of the present invention to provide a novel design of armor that is light-weight, highly effective against a wide range of known threats, relatively inexpensive to manufacture and fairly easy to maintain.

SUMMARY OF THE INVENTION

[0021] There is thus provided, according to some preferred embodiments of the present invention, an armor assembly comprising:

[0022] one or more substantially parallel layers, each layer comprising a two- dimensional array of packed elements that are capable of swaying about at least one axis, the elements arranged so as to create cavities between adjacent elements in a layer and across one or more layers for trapping incoming objects.

[0023] Furthermore, according to some preferred embodiments of the present invention, the two-dimensional array of packed elements is arranged in a grid pattern. [0024] Furthermore, according to some preferred embodiments of the present invention, the layers are separated by partitions.

[0025] Furthermore, according to some preferred embodiments of the present invention, the partitions are provided with rough surfaces.

[0026] Furthermore, according to some preferred embodiments of the present invention, partitions comprise two or more surfaces.

[0027] Furthermore, according to some preferred embodiments of the present invention, space is provided between surfaces of the partitions.

[0028] Furthermore, according to some preferred embodiments of the present invention, the packed elements comprise spherical elements.

[0029] Furthermore, according to some preferred embodiments of the present invention, the packed elements comprise ellipsoidal elements.

[0030] Furthermore, according to some preferred embodiments of the present invention, elements in a layer that is behind a preceding layer are smaller in size compared with elements in the preceding layer.

[0031] Furthermore, according to some preferred embodiments of the present invention, elements in a layer are smaller in size the deeper the layer is behind an impact layer.

[0032] Furthermore, according to some preferred embodiments of the present invention, elements in a layer are smaller in size the deeper the layer is behind an impact layer, maintaining a ratio of n, n being a real number between 0 and 1.

[0033] Furthermore, according to some preferred embodiments of the present invention, the cavities define a gradually narrowing space.

[0034] Furthermore, according to some preferred embodiments of the present invention, the packed elements comprise elements of different shapes.

[0035] Furthermore, according to some preferred embodiments of the present invention, the packed elements are made of material selected from a group of materials consisting of: ceramics, steel, aluminum, titanium, and composite materials.

[0036] Furthermore, according to some preferred embodiments of the present invention, at least a portion of each packed element comprise a smooth surface. [0037] Furthermore, according to some preferred embodiments of the present invention, at least a portion of each packed element comprise a rough surface.

[0038] Furthermore, according to some preferred embodiments of the present invention, there is provided a method for protection against an incoming projectile, the method comprising:

[0039] providing armor assembly comprising:

[0040] one or more substantially parallel layers, each layer comprising a two- dimensional array of packed elements that are capable of swaying about at least one axis, the elements arranged so as to create cavities between adjacent elements in a layer and across one or more layers for trapping incoming objects; and

[0041] mounting the armor assembly on an object to be protected.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to better understand the present invention, and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention. Like components are denoted by like reference numerals. [0043] Figure 1 illustrates a cross-sectional view across a section of several layers of an armor assembly of a multi-layer array of spherical elements in accordance with a preferred embodiment of the present invention.

[0044] Figure 2 illustrates a view across a section of single layer of the armor assembly of a multi-layer array of spherical elements shown in Fig. 1.

[0045] Figure 3 a illustrates a see-through view of a section of several layers of the armor assembly of a multi-layer array of spherical elements shown in Fig. 1, showing a projectile trap.

[0046] Figure 3b illustrates a sectional view of a section of several layers of armor assembly of multi-layer array of spheres across line X-X, where a projectile trap is marked. [0047] Figure 4a illustrates a cross sectional view of a section of several layers of an armor assembly of multi-layer array of ellipsoidal elements in accordance with another preferred embodiment of the present invention.

[0048] Figure 4b illustrates a view of a single ellipsoidal element of the first layer of the armor assembly shown in Fig. 4a.

[0049] Figure 4c illustrates a view of four adjacent ellipsoidal elements of the armor assembly shown in Fig. 4a.

[0050] Figure 5 illustrates a sectional view across several layers of an armor assembly in accordance with another preferred embodiment of the present invention, with different shapes of elements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0051] The armor assembly and method of the present invention utilize a multi-layer structure in order to provide a light weighted armor, which is highly resistive to armor piercing weapons and other types of ballistic missiles or projectiles. The armor according to the present invention can serve as a protection means for mobile or stationary equipment, heavy or light-weighted, and as a protection means for various other structures and individuals.

[0052] In addition, the present invention provides a modular armor assembly and method, hence, facilitating easy reparation in case of damage caused to one or more of the armor layers.

[0053] The armor assembly of the present invention generally comprises a multi-layer structure, where in each layer a plurality of elements is disposed.

[0054] The elements can take various shapes, and the basic requirement is that each element has the ability to sway about one or more axis. The elements may interact with adjacent elements, as will be explained hereinafter. Although it appears that spheres are optimal, other shapes can be used too, either rounded, curved, multi-facet objects, and even amorphous, provided they meet the requirement of being able to be tilted or sway about one or more axis. Spheres can tilt in any axis, due to their perfect shape. Other shapes may require additional bearings in order to insure that they can sway in the desired direction. [0055] The design of the layers and the arrangement of the elements in each layer is aimed at providing traps for trapping the incoming projectile, The traps comprise spaces confined between adjacent elements in each layer, where the deeper the layer the narrower the space, thus creating a gradually narrowing free-space. Upon impact the projectile is directed to the nearest trap and by activating an increasing lateral pressure on its shell, the projectile is eventually caught and stopped. The aforementioned interception process utilizes the fact that the projectile shell is far less energetic than the projectile front point, hence intercepting a projectile by its shell, requires far less energy in comparison with intercepting a projectile by confronting its point.

[0056] For sake of clarity it is noted that the layer, which is the first to encounter an incoming projectile, is referred to as the impact layer. As far as orientation is concerned, the impact layer is referred to as the first layer, the layer placed behind it is referred to as the second layer and so on until the last layer, which is the layer that faces the objective of the armor assembly. In accordance with the aforementioned, referring to the layer, which is "after", "behind", "deeper", or "lower" indicates the layer, which is farther from the impact layer.

[0057] More specifically, a multi-layer armor according to a preferred embodiment of the present invention, (21), is shown in figure 1 (note that the figures depict layers without derogating generality that can be extended in any direction and include as many layers and elements as needed). This embodiment comprises a specific geometrical structure of smooth spherical elements (27) arranged in layers. Every layer is packed between two enclosing surfaces (25), serving as partitions. The upper or the external enclosing surface of the impact layer is the impact surface (24). Each layer is laterally confined by a wall (23). It is appreciated that the partition may comprise more than just one surface. In this case the layers may be manufactured separately and be assembled in a modular way, so that upon impact and destruction of one or more layers, the damaged layers would be conveniently replaced. The enclosing surfaces (25) and the impact surface (24) in the shown embodiment are roughened, however the roughness of the partitions is optional. In addition, the plain of the impact surface (24), which faces the incoming threat, is provided with antimagnetic rustication. This supplement is optional as well. In some preferred embodiments of the present invention a space may be provided between adjacent layers, serving to absorb some of the energy of the incoming projectile, or serving to contain plasma in the case of shaped charge projectiles.

[0058] Figure 2 shows a cross sectional view of a section of a single layer of the armor assembly of a multi layer array of spherical elements (29) shown in Fig. 1. The spherical elements (27) in each layer are packed together in a single layer and are aligned in rows and columns creating a two-dimensional grid pattern. The spherical elements in each layer are substantially of the same size. Spherical elements of different layers are of different sizes in accordance with the layer position.

[0059] Figure 3 a illustrates a see-through view of a section of four layers of an armor assembly of multi-layer array of spherical elements (21) and figure 3b illustrates a cross sectional view across line X-X.

[0060] In the embodiment shown in these figures the number of the spherical elements in the first layer is notated X, the radius of the spherical elements in the first layer is notated Rl, and the Nth layer consists of X x 4"^"1 spherical elements. The radius of the spherical elements of the Nth layer is notated R_n and its size is half of the radius of the elements in the previous layer, notated R_n-1 [0.5*R_n-1]. Each layer is preferably packed under controlled pressure activated by the enclosing surfaces (25), and is separate from the other layers.

[0061] The first layer comprises four adjacent spherical elements, which are characterized by a radius notated R₁ (27a). The second layer consists of 16 (4*4*) spherical elements characterized by radius size equal to 0.5*Rt notated R2 (27b). The third layer consists of 64 (4*4²) spherical elements characterized by radius size equal to 0.5*R₂ notated R₃ (27c) and so on.

[0062] The elements in each layer (29) are arranged in a way that behind each spherical element of a layer lie aligned four adjacent spherical elements of the layer behind. The described geometrical structure of the spherical elements creates trap cavities (31). A trap cavity is defined by a series of cavities between adjacent elements (four elements in the embodiments shown) across several layers. The special geometrical structure described above assures that the cavities are aligned with each other. In addition, as the spherical elements become smaller with each layer, the cavity size becomes smaller as well, creating a cone-like shaped trap. In this manner, every series of cavities creates a tapering tunnel acting as a trap to a penetrating projectile.

[0063] Upon an impact by a projectile on the impact surface (24) two types of scenarios may evolve. One is the scenario of a projectile entering directly into a trap cavity (31), and the other is the scenario of a projectile impacting on a spherical element (27).

[0064] In the case of a projectile entering a trap cavity (31), the penetration kinetic energy of the projectile, which is particularly concentrated at its point, is not realized. Furthermore, the projectile kinetic energy is wasted on the projectile motion. As the trap cavity (31) generally tapers, at some stage, depending on the projectile dimensions and the diameter of the spherical elements, the projectile shell is squeezed inside the tapering trap and eventually halted.

[0065] During the interception process, the projectile deforms, loosing its penetration ability or at least greatly reducing this ability. The energy produced by the impact between the projectile and the spherical elements is absorbed by the spherical elements (27) surrounding the projectile in a form of radial blast wave spreading across the layer of spherical elements and thereby gradually fading. As a result of the aforementioned process, the spherical elements would rearrange in coaxial circles around the penetrating projectile activating an increasing compression on the projectile. Due to the special geometrical structure of the armor, the further the projectile penetrates, the stronger the compression becomes.

[0066] On the event of a projectile impacting the surface of a spherical element (27), it is most likely that the spherical element would direct the projectile to the nearest trap cavity (31) by rotating about its axis. After the projectile penetrates the trap cavity, the aforementioned interception process takes place.

[0067] On the event of a projectile impacting a spherical element head on there are two main options. One is the option in which the projectile pushes the spherical element towards the enclosing surface (25) of the second layer. In that case, the projectile penetration ability is greatly decreased by increasing me surface of its point, therefore the projectile movement and penetration is stopped by the armor structure. Another option would be the projectile shattering the spherical element or penetrating its body. In that case, the interception process described above takes place beginning from the second layer and so on.

[0068] Another embodiment, which discloses an armor assembly of multi-layer array of ellipsoidal elements (33), is shown in figures 4a. In this embodiment the armor structure comprises ellipsoidal (or ellipsoid-like shaped) elements (35) having rough surfaces, packed in layers. Every layer of ellipsoidal elements (35) is packed and enclosed between two enclosing surfaces (26), serving as partitions, with the size of the elements decreasing as the layer is found deeper. In the embodiment shown in this figure the plain of the impact surface (20), which faces the incoming treat, is provided with antimagnetic rustication. It should be mentioned that the antimagnetic rustication is optional.

[0069] The ellipsoidal elements (35) in each layer are arranged substantially perpendicularly to the two enclosing surfaces (26) and placed between the enclosing surfaces under controlled pressure. Every ellipsoidal element of the first layer is preferably fixed to the lower enclosing surface of the first layer by a clipping pin (37). The clipping pins add stability to the ellipsoidal elements position and prevent a chain collapse of the entire layer in case one of the ellipsoidal elements is knocked down by a penetrating projectile that passes substantially parallel to the impact surface (20). For further caution, one may add a clipping pin (37) to each of the ellipsoidal elements of the armor assembly. The ellipsoidal elements are packed together in a single layer and aligned in rows and columns creating a grid pattern. Every ellipsoidal element is in contact with all adjacent ellipsoidal elements of the same layer, while the contact points are across the ellipsoidal elements slippage segments (39).

[0070] Figure 4b shows the structure of a single ellipsoidal element (35) of the first layer. The ellipsoidal element (35) comprises a rough body, a slippage segment (39), two slippage caps (41), and a clipping pin (37). The slippage caps (41) are cap shaped segments of the ellipsoidal element with a smooth surface located at each end of the ellipsoidal element (35). The slippage segment is a peripheral segment of the ellipsoidal element with smooth surface, which extends across the perimeter created by the effective radius of the ellipsoidal element (would be clarified below). The clipping pin (37) interlocks the lower slippage cap (41) and designed to withstand a certain pressure, which is determined by the specific armor assembly requirements. Generally, roughening the body of the ellipsoidal element is desired in order to enhance the friction created while interacting with the ellipsoidal element, but the surface of the slippage segments and the slippage caps is smooth in order to facilitate a certain movement for the ellipsoidal elements and as would be elaborated below.

[0071] In the embodiment shown in these figures, similarly to the embodiment of the spherical elements, the effective radius of the ellipsoidal elements of the second layer is m times of the effective radius of the ellipsoidal elements of the first layer and so on respectively (while m is a real number between 0 and 1). Thus, the effective radius of the ellipsoidal elements of the Nth layer is m^N of the effective radius of the ellipsoidal elements of the first layer. The effective radius of the ellipsoidal elements of the first layer, and the relation m, which, as seen above, practically determine the effective radius of all of the elements of the armor structure shown in this figure, are determined according to the specific armor requirements. By "effective radius" it is meant the radius at the widest section of the element substantially perpendicular to its longer aspect. The longer aspect of the elements determines the maximal force that each element may exert on the pressed projectile, as it exerts leverage forces on the intercepted projectile.

The layers are arranged one behind the other in accordance to the effective radius size of the ellipsoidal elements of each layer. The deepest the layer goes, the smaller the effective radius of the elements becomes. The layers are aligned with each other in a way that every free space created among adjacent ellipsoidal elements is aligned with a free space created by corresponding adjacent ellipsoidal elements of the layer behind. In that manner, a series of tapering aligned free spaces is obtained, defining a trap cavity (43).

[0072] An illustration of a three-dimensional view of a free space created by adjacent ellipsoidal elements (35) (four in this embodiment) is shown in figure 4c. It should be mentioned that the special geometrical structure of the ellipsoidal elements assures the formation of trap cavities (43) as described above.

[0073] As mentioned with respect to the previous embodiment, in case of a projectile impact upon the impact surface (20) of the armor assembly, there are two main possible scenarios. One is the scenario of a projectile entering directly into a trap cavity (43), and the other is the scenario of a projectile impacting an ellipsoidal element (35). On the event of a projectile entering directly into a cavity trap, regardless of the projectile orientation, the projectile would impact, at some point, an ellipsoidal element, since the trap cavity tapers as the projectile penetrates deeper into the armor multi-layer structure. Upon impact the adjacent elements will sway in a way that draws the frontal slippage caps (41) away, causing the distal slippage caps (41) to draw nearer, thus effectively presenting some barrier in the projectile path. As the projectile passes through the layer, this motion reverses, causing the distal slippage caps to draw away and the frontal slippage caps to draw closer, squeezing the shell. Squeezing of the projectile shell, carried out by the cavity trap structure, sets in motion an interception process by distorting the projectile body, reducing its penetration ability, and reducing its speed and energy. It should be emphasized that the smoothness of the slippage segments (39) and slippage caps (41) of the ellipsoidal elements facilitates the ellipsoidal elements sway and the roughness of the ellipsoidal elements body enhances the projectile interception process.

[0074] Another embodiment, which discloses a multi-layer armor comprising an array of elements of diverse shapes (45), is shown in figure 5. This embodiment comprises at least a first layer of spherical elements (27) (two in this specific figure) and followed by layers of ellipsoidal elements (35). The layers of the spherical elements are aimed at directing the impacting projectile into a trap cavity (31 or 43) owing to their full symmetrical shape. In the case the projectile is not stopped by the layers of the spherical elements, it would be stopped by the interception process carried out by the deeper layers, which comprise ellipsoidal elements, as described above.

[0075] The armor assembly elements are preferably made of materials with high mechanical resistance, such as ceramics, steel, aluminum, titanium, or other composite materials.

[0076] The multi layer armor assembly may comprise partitions separating the armor layers from each other and/or holding the multi-layer armor structure (the enclosing surfaces (25 or 26) and surrounding walls (23) in the preferred embodiments described above). By referring to "partitions" it is meant to say any single or complex structure aimed at holding and/or separating the layers from each other, such as net shaped partition or one or more rigid surfaces serving as partitions. The partitions are preferably made of strong and highly resistant materials, such as ceramics, steel, aluminum, titanium, epoxy and kevlar (marketed by DuPont). The partitions may be made of composite materials as well. In selecting rigid materials for the partitions, some flexibility may be desired to allow the partitions to recoil.

[0077] An alternative design for a multi-layer armor assembly according to the present invention may comprise combinations of layers of elements of different shapes (or even elements of different shapes in the same layer). However locally it is recommended to provide elements of same or very similar shapes in the same layer.

[0078] For the purpose of reducing the weight of the armor assembly hollow elements can be used. It may be recommended to provide hollow elements only in the deeper layers of the armor assembly, in order to present one or more rigid impact layers to the incoming threat.

[0079] The multi-layer armor layers can be separated from each other by spaces of some extent (depending on the specific armor requirements) in order to further decrease the penetration and damage abilities of an incoming projectile and in order to decrease the impact of explosive charged projectiles. In addition, the spaces mentioned above can be filled with flameproof foam or any other flameproof substance to the purpose of making the armor assembly even more efficient against shape charge type projectiles.

[0080] In addition, an external plating shield can be added in order to reinforce the impact surface (24 or 20 in the preferred embodiments described above).

[0081] As mentioned and shown above, the impact surface of a multi-layer armor assembly can be provided with antimagnetic rustication in order to prevent magnetic coupling of mines or other explosive charges onto the external surface of the armor assembly. In addition, the impact surface or the external plating can be made in wave- like form. The wave-like surface deflects striking projectiles and by that reduces their penetration ability. Further more, the wavy shape of the surface can be made in a way that every wave directs a striking projectile to the nearest cavity trap. [0082] As mentioned and shown above, the enclosing surfaces can be roughened in order to increase the energy lose of penetrating projectiles. [0083] The dimensions and number of the elements and the number of armor layers in the armor assembly of the present invention may be determined according to the specific armor requirements.

[0084] It can be appreciated that the armor assembly of the present invention employs the energy of the incoming projectile in the interception process, and this characteristic is advantageous.

[0085] It is noted that some preferred embodiments of the present invention could comprise a single layer of elements, rather than a multiplicity of layers. This can be, for example, in the case of personal protective vest, or other applications, where it is anticipated that one layer is enough to stop an incoming projectile. The dimensions of the elements and subsequently the dimensions of the trap cavities will be designed for that aim.

[0086] Although throughout this specification reference was made to a projectile as the incoming weapon the armor assembly of the present invention is capable of protecting against various kinds of weapons, such as rockets, missiles, shape charge weapons, explosive charged weapons and kinetic energy weapons.

[0087] It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope.

[0088] It should also be clear that a person skilled in the art, after reading the present specification could make adjustments or amendments to the attached Figures and above described embodiments that would still be covered by the present invention.

Claims

1. An armor assembly comprising: one or more substantially parallel layers, each layer comprising a two- dimensional array of packed elements that are capable of swaying about at least one axis, the elements arranged so as to create cavities between adjacent elements in a layer and across one or more layers for trapping incoming objects.

2. The armor assembly as claimed in Claim 1, wherein the two-dimensional array of packed elements is arranged in a grid pattern.

3. The armor assembly as claimed in Claim 1, wherein the layers are separated by partitions.

4. The armor assembly as claimed in Claim 3, wherein the partitions are provided with rough surfaces.

5. The armor assembly as claimed in Claim 3, wherein partitions comprise two or more surfaces.

6. The armor assembly as claimed in Claim 5, wherein space is provided between surfaces of the partitions.

7. The armor assembly as claimed in Claim 1, wherein the packed elements comprise spherical elements.

8. The armor assembly as claimed in Claim 1, wherein the packed elements comprise ellipsoidal elements.

9. The armor assembly as claimed in Claim I₅ wherein elements in a layer that is behind a preceding layer are smaller in size compared with elements in the preceding layer.

10. The armor assembly as claimed in Claim 9, wherein elements in a layer are smaller in size the deeper the layer is behind an impact layer.

11. The armor assembly as claimed in Claim 10, wherein elements in a layer are smaller in size the deeper the layer is behind an impact layer, maintaining a ratio of n, n being a real number between 0 and 1.

12. The armor assembly as claimed in Claim 1, wherein the cavities define a gradually narrowing space.

13. The armor assembly as claimed in claim 1, wherein the packed elements comprise elements of different shapes.

14. The armor assembly as claimed in Claim 1, wherein the packed elements are made of material selected from a group of materials consisting of: ceramics, steel, aluminum, titanium, and composite materials.

15. The armor assembly as claimed in Claim 1 , wherein at least a portion of each packed element comprise a smooth surface.

16. The armor assembly as claimed in Claim 1 , wherein at least a portion of each packed element comprise a rough surface.

17. A method for protection against an incoming projectile, the method comprising: providing armor assembly comprising: one or more substantially parallel layers, each layer comprising a two- dimensional array of packed elements that are capable of swaying about at least one axis, the elements arranged so as to create cavities between adjacent elements in a layer and across one or more layers for trapping incoming objects; and mounting the armor assembly on an object to be protected.