Abstract:
An underbelly for an armored vehicle is provided, configured for providing ballistic protection against a detonation of an explosive device detonated substantially therebelow. The underbelly comprises a central portion having a lowermost area, sidewalls extending upwardly therefrom, the central portion and sidewalls constituting a main armor of the underbelly, and an auxiliary armor panel disposed so as to project downwardly from the lowermost area of the central portion. Upper portions of the sidewalls are free of any auxiliary armor panel.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to defensive armor, and more particularly to underbellies of armored vehicles providing ballistic protection thereto. 
       BACKGROUND OF THE INVENTION 
       [0002]    Vehicles for transporting personnel and/or equipment through area where it may be exposed to live fire, explosions, etc., are typically provided with ballistic armor. Such vehicles typically comprise a passenger cabin, and may further comprise an underbelly therebeneath to protect against explosions, including from fragmentation explosives, and other ballistic attacks directed from below the vehicle. 
       SUMMARY OF THE INVENTION 
       [0003]    According to one aspect of the present invention, there is provided an underbelly for an armored vehicle, the underbelly being configured for providing ballistic protection against a detonation of an explosive device detonated substantially therebelow and comprising:
       a central portion having a lowermost area;   sidewalls extending upwardly therefrom, the central portion and sidewalls constituting a main armor of the underbelly; and   an auxiliary armor panel disposed so as to project downwardly from the lowermost area of the central portion;
 
upper portions of the sidewalls being free of any auxiliary armor panel.
       
 
         [0007]    It will be appreciated that hereafter in the specification and claims, the term “ballistic protection” is to be understood in its broadest sense, referring to protection against all types of ballistic and similar threats, including, but not limited to, projectiles, fragments, detonations of explosive devices, etc. In addition, reference to higher and lower levels of ballistic protection implies that, in the case of a higher level of ballistic protection, a higher energy threat of the same type can be defeated with armor of the same weight. 
         [0008]    It will be further appreciated that hereafter in the specification and claims, terms which relate to direction, such as “above”, “below”, “upward”, “downward”, “upper”, “lower”, etc., refer to a typical configuration of the underbelly when attached to the vehicle and the vehicle is in its upright position, with the apex of the underbelly pointing away from the vehicle and towards the ground. 
         [0009]    The auxiliary armor panel may be attached or connected to the central portion, for example by any appropriate method. It may comprise at least one flexible layer made of ballistic fibers, for example aramid, which may be unidirectional or woven. This layer is useful, for example, for protecting against fragments, e.g., of the explosive device. 
         [0010]    The auxiliary armor panel may further comprise a lower hard armor layer disposed below the flexible layer. The lower hard armor layer may have a thickness which is less than that of the central portion. 
         [0011]    The central portion and the sidewalls constitute a single element. Thus, the central portion and sidewalls may constitute portions of the same armor panel, for example made of a sheet of metal or ceramic pellets formed as part of the same panel. 
         [0012]    The central portion may be distinct from the sidewalls. The may be formed with a gap between the sidewalls, the gap being bridged by the central portion. This facilitates removal of the central portion in order to access the interior of the underbelly from below the vehicle. 
         [0013]    Each of the upper portions of the sidewalls may have a cross-sectional length, in the same cross-section as the V-shape, which is at least half that of the auxiliary armor panel. 
         [0014]    The central portion may be bolted to the sidewalls. 
         [0015]    The central portion may have a V-shaped or a substantially V-shaped cross-section defining an apex constituting part of the lowermost area. 
         [0016]    The hard armor (i.e., both of the sidewalls, the central portion, and of the lower hard armor layer of the auxiliary armor panel) may be made of aluminum, titanium, magnesium, or a ballistic ceramic. It may be made of steel having a Brinell hardness between about 370 HB and 500HB. More particularly, it may be made of steel having a Brinell hardness of about 440 HB. 
         [0017]    The underbelly may further comprise a plurality of ribs disposed thereabove for facilitating connection to the vehicle, the ribs being designed so as to facilitate a tight connection between the sidewalls and the central portion, by using only mechanical means, i.e., without the need for welding. 
         [0018]    According to another aspect of the present invention, there is provided an underbelly for an armored vehicle, the underbelly being configured for providing is ballistic protection against a detonation of an explosive device detonated substantially therebelow, the underbelly defining an upper reference plane and having one or more distal portions and one or more proximal portion disposed between the distal portion and the reference plane, the distal portion being designed to provide a higher level of ballistic protection than provided by the proximal portion. 
         [0019]    The armored vehicle may comprise a passenger cabin coincident with the reference plane, the underbelly being configured for protecting the passenger cabin from the detonation. 
         [0020]    The vehicle may comprise a plurality of ribs disposed below the passenger cabin, the ribs being designed so as to facilitate a tight connection therebetween and the proximal and distal portions, by using only mechanical means, i.e., without the need for welding. 
         [0021]    The distal portion may be positioned so as to be closer to the detonation that the proximal portion is. 
         [0022]    The proximal and distal portions may be made of the same material, the distal portion being of a larger thickness than the proximal portion. 
         [0023]    The proximal and distal portions may be integrally formed with one another, or made of distinct pieces. 
         [0024]    The proximal and distal portions may be made of materials providing different levels of ballistic protection at similar thicknesses, the distal portion being made of a material which provides a higher level of ballistic protection than provided by the material of the proximal portion at the same thickness. 
         [0025]    The proximal and distal portions may be made of materials providing different levels of ballistic protection at similar weights, the distal portion being made of a material which provides a higher level of ballistic protection than provided by the material of the proximal portion at the same weight. 
         [0026]    At least the distal portion may be made of aluminum, titanium, or magnesium, or of steel having a Brinell hardness between about 370 HB and 500 HB. More particularly, it may be made of steel having a Brinell hardness of about 440 HB. 
         [0027]    The underbelly may be substantially V-shaped having a distally-directed vertex, the distal portion being at least partially located at the vertex. 
         [0028]    According to a further aspect of the present invention, there is provided an armored vehicle comprising an underbelly as described in connection with any of the above aspects. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]    In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which: 
           [0030]      FIG. 1  is a rear partial sectional view of an armored vehicle; 
           [0031]      FIGS. 2A and 2B  are, respectively, top and bottom perspective views of ribs of the armored vehicle illustrated in  FIG. 1  with an underbelly attached thereto; 
           [0032]      FIG. 3  is a cross-sectional view of a rib and an underbelly according to the present invention, taken through a rib; 
           [0033]      FIG. 4  is a side view of an additional example of an underbelly according to the present invention; 
           [0034]      FIG. 5  is a closeup view of an auxiliary armor panel attached to a portion of a central portion of the underbelly according to the present invention; and 
           [0035]      FIG. 6  is a cross-sectional view of an underbelly according to another example of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0036]    As illustrated in  FIG. 1 , there is provided an armored vehicle  10  having a passenger cabin  12 . The vehicle  10  is provided with ballistic armor to defend against expected ballistic threats. In addition, the vehicle comprises an underbelly  14  to protect the passenger cabin from ballistic threats originating therebelow, such as explosive devices (e.g., an IED—improvised explosive device) arranged to detonate below the vehicle. 
         [0037]    The vehicle, according to one design, comprises a plurality of ribs  16 , better seen in  FIGS. 2A and 2B , which span between the passenger cabin  12  and the underbelly  14 , thereby connecting the two. Examples of designs of these ribs is described in greater detail in co-pending applications IL 192447 and IL 195167, both to the present applicant, the full contents of both of which are incorporated herein by reference. These applications describe arrangements which facilitate attachment of the ribs  16  and the underbelly  14  by mechanical means, so that no welding is necessary for the attachment, for example by increasing the pressure between the ribs and the underbelly before a simple mechanical securing mechanism, such as a bolt/nut assembly is applied. However, any attachment between the underbelly  14  and the ribs  16 , or any other part of the vehicle  10  depending on its configuration, is possible without departing from the spirit and the scope of the present invention. 
         [0038]    As illustrated in  FIG. 3 , the underbelly  14  is provided as a substantially V-shaped form. It is arranges such that its apex  18  (i.e., vertex) is at the lowest point, i.e., closest to the expected location of an explosive threat. It comprises a distally disposed central portion  20 , which contains the apex  18  at a lowermost area thereof, and two proximally disposed sidewalls  22  adjacent thereto on either side. As seen, there is a gap between the sidewalls  22 , which is bridged by the central portion  20 . According to the example illustrated in  FIG. 3 , the central portion  20  and sidewalls  22  each contain apertures  24 ,  26  for passing therethrough teeth  28  of the ribs  16  in order to implement the mechanical attachment as described in the above-mentioned co-pending applications. Furthermore, additional apertures may be provided therethrough in order to facilitate the introduction of other attachment mechanisms, such as additional bolts (not illustrated). 
         [0039]    The central portion  20  is designed to provide a level of ballistic protection which protects against a close detonation of an explosive device, for example one which is in direct contact therewith during detonation. The sidewalls  22  are designed to provide a level of ballistic protection which protects against a farther detonation of the explosive device, as it is typically located a greater distance from the expected location of detonation than the central portion  20  is. 
         [0040]    The difference in levels of ballistic protection (e.g., the difference in the amount of energy each is adapted to absorb) between the central portion  20  and sidewalls  22  may be realized by forming the portions of the same material as one another, but of different thicknesses. For example, the central portion  20  may have a thickness of 12.7 mm, while the sidewalls  22  may have a thickness of 8 mm. The central portion  20  and sidewalls  22  may be made of any appropriate material, such as steel having a Brinell hardness in a range between 370 and 500 HB. According to one particular example, the metal has a Brinell hardness of 440 HB. 
         [0041]    Examples of steel which may be used to make the central portion  20  and sidewalls  22  are Armox™ 440T, manufactured by SSAB Svenskt Stål [Swedish Steel] AB (Sweden), and Bisplate® 450, manufactured by Bisalloy® (Australia). Alternatively, the central portion  20  and sidewalls  22  may be made of panel comprising ceramic pellets. 
         [0042]    Alternatively, the difference in levels of ballistic protection between the central portion  20  and sidewalls  22  may be realized by forming the portions of different materials as one another, which may or may not be of the same thickness. 
         [0043]    It will be appreciated that while an underbelly  14  having a single central portion  20  and a V-shaped form is described in reference to  FIGS. 1 through 3 , an underbelly may be provided having multiple central portion and being of a different form. For example, as illustrated in  FIG. 4 , the underbelly  14  may have a “double V-shaped” form and two central portion  20 . According to this example, three sidewalls  22  may be provided. 
         [0044]    As illustrated in  FIG. 5 , the central portion  20  may be formed as part of a “sandwich”, with an auxiliary armor panel  30  disposed therebelow. The auxiliary armor panel  30  comprises a lower hard armor layer  32  disposed below the central portion  20  and together therewith surrounding an inner flexible layer  34  made of fibers, such as an aramid material. According to this arrangement, the central portion  20  constitutes an upper hard armor layer of the “sandwich”. The aramid material may be formed in any appropriate way, including, but not limited to, unidirectionally or woven, or a combination of two or more thereof. 
         [0045]    The flexible layer  34  is useful for stopping and/or absorbing energy of fragments which impinge upon it. These fragments may be, for example, from the explosive device, or secondary projectiles from the lower hard armor layer  32  formed by the force of the explosion. In addition, it acts as a buffer between the central portion  20  and lower hard armor layer  32 , preventing them from impacting one another. 
         [0046]    Alternatively, as illustrated in  FIG. 6 , the sidewalls  22  may be formed without a gap, i.e., as a continuous armor panel. According to this arrangement, the central portion  20  constitutes an upper hard armor layer of the “sandwich”. The flexible layer  34  and lower armor panel  32  are attached below the central portion  20  at the apex  18 . 
         [0047]    The placement of the auxiliary armor panel  30  below the central portion  20  of the underbelly  14  may provide several advantages. For example, it is less likely to itself become a secondary projectile by the force of an explosion. In addition, the lower armor layer  32  may be thinner (i.e., not as heavy) as the central portion  20  or as the sidewalls  22 . 
         [0048]    According to all of the examples disclosed above, upper portions  38  of the sidewalls  22  (i.e., those closest to the vehicle) are free of an auxiliary armor panel  30 . As the center of the underbelly  14  is disposed closest to an explosive threat such as an IED, the extra weight which would be associated with providing auxiliary protection at the upper portions is not necessary. Thus, each of the upper portions  38  may have a cross-sectional length L upper  which is at least half as long as that of the cross-sectional length L auxiliary  (i.e., at least half of the underbelly  14  is free of the auxiliary armor panel  30 ). It will be appreciated that the amount of the underbelly  14  which is covered by the auxiliary armor panel  30  is to be determined by the designer, and may depend on the level of protection required, the level of protection provided by the sidewalls  22 , etc., without departing from the scope of the present invention. 
         [0049]    Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations and modifications can be made without departing from the scope of the invention mutatis mutandis.