Abstract:
A ceramic armor tile for attaching internally behind a wall of a structure and for cooperation in conjunction therewith, such that the wall acts as an external protective layer of the armor.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a ceramic armor for protecting enclosures such as vehicles and structures from kinetic threats. 
     BACKGROUND OF THE INVENTION 
     Ceramic armor tiles are widely used for protection of various objects and enclosures, such as combat vehicles (e.g. personnel carriers, etc.), aircrafts, marine crafts, and different constructions e.g. bunkers and the like, which hereinafter in the specification and claims are collectively referred to as structures. Such armor tiles are articulated to an exterior surface of the structure to be protected. 
     The above arrangement has some disadvantages, as follows:
         Low survivability of the armor tile owing to mechanical hits, e.g. by accidentally impacting by maneuvering vehicles, etc.:   Increasing the silhouette of a vehicle fitted with such an armor, increasing its likelihood of being detected at a battle field;   Increasing the external dimensions of a vehicle fitted with such an armor, thus reducing its maneuverability;   Low survivability of the armor tile, i.e. low multiple hit capability;   Often, a spall-liner is fitted inside a vehicle fitted with an external ceramic tile armor, so as to offer the crew and equipment of the vehicle ballistic protection against spall and debris (fragments of the projectile and the primary armor), which are shot into the cabin with high velocity, when the vehicle is hit. Even when the projectile does not penetrate the primary armor, spalls, which are knocked off the inner side of the primary armor, can be deadly for the personnel.   A damaged exterior tile is replaceable only when threat is deceased;   An externally mounted armor renders a passenger vehicle threatening and not eye pleasing, and further may suggest that passengers of the vehicle are high ranking officers or officials.       

     As a result of some of the above and other drawbacks of exterior ceramic armor tiles, there is sometimes a tendency to prefer metal protective armor which may be considered to be more durable as compared with ceramic tiles, in spite of weight deficiency of the metal armors. 
     Israel Patent No. 139564 is directed to a bullet-proof tile mountable on an inner surface of a body of a passenger vehicle to armor the body whereby occupants of the vehicle are shielded from bullets striking and penetrating the body. Each tile comprises a composite panel impervious to bullets having an inner face which faces the inner surface of the body, and a detachable fastener having complementary opposite components, one of said components being attached to the inner face of the tile, the other of said components being attached to the inner surface of the body, whereby when the tile is pressed against the body surface it then becomes securely fastened thereto. 
     It is an object of the present invention to provide an internal ceramic protection tile, i.e. fitted on an inside surface of an external wall of the enclosure/structure to be protected. 
     Herein after in the specification and claims, the terms ‘armor panel’, ‘armor module’ and ‘armor tile’ are use interchangeably. 
     SUMMARY OF THE INVENTION 
     According to the present invention there is provided a ceramic armor tile for attaching internally behind a wall of a structure and for cooperation in conjunction therewith, such that the wall acts as an external layer of the armor. It was found that such a configuration is useful in minimizing the hazards of kinetic threats and shows improved performances as compared with an externally mounted ceramic armor of similar parameters. 
     An armor according to the disclosure of the present invention is in particular suited against kinetic threats, whilst in case of hollow-charges it is likely to minimizing damage by reducing spall dispersion (reducing the cone angle of fragments and shrapnel). The thicker the external wall of the enclosure/structure, the better is protection offered by the armor. 
     According to one embodiment of the present invention, the ceramic armor tile comprises at least a layer of ceramic material and a backing layer. Optionally, there is provided also a spall-liner, at least at a back face thereof, for reducing the cone angle of fragments dispersed form the ceramic layer in case of the ceramic layer is hit; the spall-liner may be made of ballistic fabric e.g. Kevlar™, Dyneema™, Spectra™, ballistic nylon, and non fabric materials such as steel, aluminum, etc. 
     According to one modification of the invention, the backing of the ceramic panel constitutes a spall-liner of the structure, thus reducing overall thickness and weight of the armor. 
     According to one particular embodiment, the ceramic tile is spaced from the inner surface of the wall of the construction by fasteners and spacers (optionally honeycomb-like structures or foamed material), and according to a different embodiment of the invention the ceramic tile adjoins the inner surface of the wall of the construction. However, in the later case it is preferred to introduce a confinement layer intermediate the inside surface of the wall and the ceramic tile. Such a confinement layer is typically made of a resilient material. 
     The ceramic armor may be fixedly attached to the inner wall or detachable therefrom. Attachment may be fixtures such as bolts or by adhering or by hook and pile fasteners (Velcro™), etc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to understand the invention and to see how it may be carried out in practice, some embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with a prior art exterior ceramic tile; 
         FIG. 2  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with an interior ceramic tile according to an embodiment of the present invention; 
         FIG. 3  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with a modification of a prior art exterior ceramic tile; 
         FIG. 4  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with an interior ceramic tile according to another embodiment of the present invention; 
         FIG. 5  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with an interior ceramic tile according to another embodiment of the present invention; and 
         FIG. 6  is a schematic representation illustrating a section through a side wall of an armored vehicle, fitted with an interior ceramic tile according to a different embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Attention is first directed to  FIG. 1  of the drawings schematically illustrating a section through an armored vehicle, e.g. a troop carrier where the wall generally designated  10  is for example an 8 mm steel plate fitted at its exterior with a ceramic armor module generally designated  12  and comprising a ceramic tile  14 , e.g. made of alumina with a backing  16  made for example of Kevlar™ Dyneema™, Spectra™, ballistic nylon, and non fabric materials such as steel, aluminum, fiberglass, etc. Typically, there is a distance between the pane  10  and the armor module  12  of about 20 mm. 
       FIG. 2  illustrates a first embodiment in accordance with the present invention where the wall  20  of the vehicle is external to the armor panel (module/tile)  22  namely facing the kinetic threat  24 . In this embodiment, armor module  22  comprises a ceramic layer  26  and a backing layer  28 , similar to the embodiment disclosed in connection with  FIG. 1 . It is further noticed that the ceramic panel  22  is spaced apart at distance d which distance is approximately in the range of 20 mm. 
     It was found that the arrangement disclosed in  FIG. 2  has improved features as compared with the parallel embodiment of  FIG. 1  whereby the wall  20  of the vehicle constitutes in fact a component of the armor and cooperates in conjunction with the armor module  22  whereby the kinetic threat  24  first engages the external wall  20  and loses some of its kinetic energy such that when it encounters the ceramic panel  22  it is not likely to penetrate it. 
     The embodiment of  FIG. 3  discloses a variation of the embodiments of  FIG. 1  wherein the external wall of the vehicle  30  is fitted on its outside with a ceramic armor  32  comprising a ceramic tile  34  fitted with a backing  36 , which armor faces the kinetic threat  40 . In addition, the vehicle is fitted on an inside thereof with a spall liner  44  adjoining the inner surface  46  of wall  30  which spall liner is useful in minimizing the hazards of fragments disbursed from the wall  30  (i.e. decreasing the debris cone angle). 
     With further reference now to  FIG. 4  there is illustrated still a modification of the invention wherein an external wall  50  of the protected enclosure, e.g. a structure, a vehicle, etc., is fitted on its interior with a armor module  54  fixedly secured to an inner face  56  of wall  50  by a plurality of bolt spacers  58 . The protective module comprises a ceramic layer  60 , a backing  62  and optionally, an additional layer of spall liner  64  (these however may be integrated into one layer). It is however noticed that the kinetic threat  69  first encounters the wall  50  which cooperates in conjunction with the armor module  54  and reduces the kinetic energy of the kinetic threat prior to its engagement with the protective armor  54 . 
     In the embodiment of  FIG. 5  there is illustrated a different embodiment of the present invention wherein the external wall  70  of the protected enclosure (the direction of a potential oncoming kinetic threat is illustrated by arrow  72 ), said wall  70  is fitted at its interior with a ceramic armor in accordance with the present invention generally designated  76  comprising a ceramic layer  78  and a backing  80 . However in the present embodiment, the armor module  76  adjoins the inside surface  84  of wall  70  however with an intermediate confinement layer  88  extending between the ceramic layer  78  and wall  70 . 
     The confinement layer is typically made of a resilient layer several millimeters thick which is adapted to absorb deformation of the external wall  70  upon hitting by the kinetic threat  72 . 
     In the embodiment of  FIG. 6  there is illustrated a modification of the embodiment seen in  FIG. 5  wherein the protective armor  92  comprises a ceramic layer  94 , a backing  96  and is entirely enveloped by an enveloping layer  100  of which wall  102  serves as a confinement layer whilst walls  104 ,  106  and  108  serve as spall liners, as discussed hereinabove. 
     Whilst some embodiments have been described and illustrated with reference to some drawings, the artisan will appreciate that many variations are possible which do not depart from the general scope of the invention, mutatis mutandis.