Abstract:
A detachable blast structure for use as an underbelly device of a personnel cabin for a vehicle, is disclosed. The blast structure comprises at least one modular section attachable to the underbody, and means for attaching and detaching the modular sections to the underbody. The modular sections are separately attachable and detachable from portions of the vehicle as needed, depending on the situations and environment the vehicle will be exposed to and the level of protection required.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/615,688 filed on Mar. 26, 2012. 
     
    
     TECHNICAL FIELD 
       [0002]    The present device relates to a protective armor for critical areas of vehicles, including underbody armor for military vehicles. More specifically, the device relates to a attachable/detachable blast protection structure and attachment means for use on a personnel cabin when needed to protect the vehicle occupants from blast energy and fragmentation resulting from an improvised explosive device (IED). 
       BACKGROUND 
       [0003]    Armored vehicles are threatened by IEDs designed to cause harm to the vehicle and its occupants. IEDs are found in either a pure blast mode which is comprised of a detonation of a mass of explosive material, or a fragmentation device which is made of one or more grouped artillery shells redeployed and detonated in an effort to inflict casualties. Harm from these devices typically comes in the form of high pressure blast energy or blast energy and ballistic fragmentation in the following predominant ways: (1) rapid surface pressure and destructive hull deformation resulting in hull breach and direct occupant exposure to blast pressures and intense heat; (2) high velocity, hull and/or floor accelerations resulting in occupant incapacities; and ( 3 ) high velocity fragmentation passing through armor and impacting occupants. 
         [0004]    Armor countermeasures typically consist of heavy metal structure placed between the threat and the vehicle occupants in such a way as to resist hull breach and aggressive floor accelerations. These heavy metal structures may also work in concert with layers of additional metal, ceramic, composite or plastic materials designed to prevent lethal high velocity fragments from entering the vehicle. The heavy metal structures are typically mounted to the underside of the vehicle in various shapes in an effort to take advantage of shape efficiency and deflection characteristics when presented with incoming pressure and fragmentation. Carrying heavy blast and fragment resistant hulls results in significant performance disadvantage to the vehicle in terms of reduced fuel economy, lost cargo capacity and increased transportation shipping costs, as well as, weight challenges for the environment the vehicles operate in. 
         [0005]    Therefore, it would be advantageous to have the option to attach and detach a blast protection structure, depending on the requirements of the situation and environment the vehicle will be subjected to. The present device is a removable blast protection structure having an attachment/detachment means, which permits the structure to be easily attached and detached from a vehicle depending on the specific situation. The structure is designed to protect the occupants from blast energy and fragmentation, and because it is offered as modular sections or panels, can be customized to meet different levels of threats depending on the unique operational situation. 
       SUMMARY 
       [0006]    There is disclosed herein an improved system and method for protecting a personnel cabin of a military vehicle which avoids the disadvantages of prior systems while affording additional structural and costs advantages. 
         [0007]    Generally speaking, the present device is a detachable blast structure for use as an exterior underbody protection of a personnel cabin for a vehicle. The blast structure comprises at least one modular section attachable to a side of the underbody, and means for attaching and detaching the modular sections to the underbody. 
         [0008]    In another embodiment, an armored blast system for attachment to and detachment from a vehicle having a cabin hull is disclosed. The armored blast system comprises a plurality of modular panels separately attachable to and removable from a portion of the cabin hull and a means for attaching and detaching the panels. 
         [0009]    In yet another embodiment, an armored blast system for attachment to and detachment from a vehicle having a cabin hull is disclosed. The armored blast system comprises a plurality of modular panels separately attachable to and removable from a portion of the cabin hull, a means for attaching and detaching the panels, and a comb and wedge fastening system, wherein a blast load is transferred between the modular panels and the cabin hull through the comb and wedge fastening system. 
         [0010]    These and other features and advantages of the present detachable blast structure can be more readily understood from the following detailed discussion with reference to the appended drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an isometric underbody view of a portion of a personnel cabin with the detachable blast protection structure; 
           [0012]      FIG. 2  is perspective view of a portion of a personnel cabin with the detachable blast protection structure removed to show the interface; 
           [0013]      FIG. 3  is a front cross-section view of a portion of a personnel cabin ( 12 ) with the detachable blast protection structure; 
           [0014]      FIG. 4  is cut-away view of a personnel cabin with the detachable blast protection structure removed to show the comb and wedge fastening system; 
           [0015]      FIG. 5A  and  FIG. 5B  are perspective views of the comb and wedge fastening system; and, 
           [0016]      FIG. 6A  and  FIG. 6B  are other views of the comb and wedge fastening system. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIGS. 1-6B , there is illustrated an embodiment of the detachable blast protection structure generally designated by the numeral  10 , as well as the components thereof. The device  10  is designed for use as a removable blast structure to provide additional blast protection to the personnel cabin  12  of a vehicle, particularly a military vehicle, which is used in war-zones for transporting personnel or cargo. However, other military vehicles may also be retro-fitted with embodiments of the present device  10  to protect both military personnel as well as components of the propulsion system (e.g., drive axles, engine, etc.) when the vehicle encounters an explosive device. 
         [0018]    Specifically, when needed, the blast structure  10  is designed to attach to an underbody interface  14 , forming the underside of the cabin  12 . It should be understood, however, that the blast structure can be attached to any portion of the cabin needing additional protection. In this manner, the blast structure  10  functions to diminish or halt certain classes of ballistic and blast threats, while providing a structural and automotive function as part of the occupant cabin and/or hull of the vehicle. 
         [0019]    Armored vehicles having integrated blast solutions are often extremely heavy to begin with, and face weight challenges in the environments they operate. Additionally, because of their weight, such vehicles are often a challenge for transporting to locations where they are needed. Thus, it would be advantageous to have an attachable/detachable blast system, which permits the attachment of a blast structure only when needed, or alternatively, provides the option to remove a large portion of the weight on the vehicle so it can be transported, and/or not carry weight that is not needed. 
         [0020]    The underbody interface section  14  of the vehicle is generally configured having a mounting flange to accept the load transfer comb/key structures  50 ,  51  and allow bolting of the underbody blast protection structure  10  to the cabin  12 . Alternative embodiments and configurations of the underbody can include curvilinear, saddle and sinusoidal shapes. While a specific shape or embodiment will be illustrated, it should be understood that other configurations, such as those created by sharper, rectangular, or square lines, and peaks and valleys, may also be used in creating the configuration of the underbody. 
         [0021]    The plurality of high and low areas of the underbody section  14  plus the blast protection structure  10  create deflection faces and venting openings, or blast surfaces, which deflect and vent the blast and resulting fragmentation away from the interior of the cabin  12 , as well as, provide separation distances for separating the interior of the cabin from the blast force. The high and low areas of the underbody section  14  plus the blast protection structure  10  further act to dissipate the force of the explosion. The blast structure  10  of the present disclosure is designed to be attachable and detachable to the various shapes of the underbody of the vehicle, and the modular characteristic of the blast structure provides various options, and are customizable for attachment to the possible shape variations of the underbody. 
         [0022]    In addition to the blast protection structure  10  shown in  FIG. 3  a plurality of modular sections or panels can be added to provide additional protection from artillery shell based IED&#39;s which present a fragmentation hazard to the vehicle occupants. While the embodiment of  FIG. 3  shows at least four separate additional modular sections or panels  18 ,  20 ,  22 ,  24 , which in combination with the removable blast panels comprise the underbody protection system  10 , it should be understood that any number of sections or panels may be used depending on the design of the cabin hull. The modular sections or panels  18 ,  20 ,  22 ,  24  may be a solid structure, or constructed as a layered composite structure. As a solid structure, the sections or panels may be constructed from high-strength low-alloy steel, a hardened aluminum, or high carbon steel, or any combination of these materials 
         [0023]    Attachment of the blast structure to the cabin hull can be accomplished by any known attaching and detaching means, such as a fastener. Examples of fasteners include screws or bolts  30 , which are commonly used to attach the individual panels to the chassis. Regardless of the type of fastener used, it should be compatible with standard tools that can be carried in the field, quickly attachable and detachable, and readily available. 
         [0024]    During a blast event, the energy loading between the base hull cabin  12  and the blast protection structure  10  is transferred through the use of a unique comb  50  and key or wedge  51  design. In this design, the comb material is loaded in shear as the two separate components—the removable blast protection  10  and the cabin hull  12 —are forced either apart or together by the explosive force of the blast. The key or wedge  51  component of the system keeps the comb structure  50  fully engaged between the cabin hull  12  and the removable blast protection structure  10 . 
         [0025]      FIGS. 4 ,  5 A,  5 B,  6 A and  6 B, the load transfer from the removable blast protection structures  10  to the cabin structures  12  is achieved partly by fasteners and metal to metal contact. In addition, and to ensure a significant portion of the blast load is transferred properly to the cabin walls  16 , the comb and wedge fastening system is also employed as an attachment means to secure the blast protection structures to the cabin structures. When installed, the combs  50  and wedges  51  act to both transfer vertical blast forces from the face of the blast protection structures  10  directly to the cabin  12  side walls and tunnel structures  52  and, more securely connect the blast protection structures  10  to the cab  12  side walls and tunnel structures  52  than fasteners alone. When properly sized for the structure and blast loads, the combs  50  and wedges  51  comprise a system with sufficient fastening and load transfer capability to prevent breach and enable the blast load path to enter the vertical members of the cabin structure  12 . 
         [0000]    The attachable/removable blast protection structure  10  of the present disclosure is designed to meet or exceed military requirements for hull breach and occupant performance criteria when subjected to a given type of blast threat. In addition, the blast structure meets the requirements for minimal floor (subfloor) deformation and tactical load requirements, while being manufactured at competitive costs. Finally, the blast structure and its modular components provide the advantage of accommodating various shapes of vehicles, and are independently attachable/detachable to meet weight and levels of protection requirements.