Abstract:
A modular explosive breaching and demolition system comprised of inert light weight plastic assemblies, field custom hand packed or pre-loaded, utilizing for example cast-cure or press loaded explosives. The assemblies can be snapped together to make different geometeric shapes or lines as may be desired, for demolition objectives.

Description:
U.S. GOVERNMENT INTEREST 
     The inventions described herein may be made, used, or licensed by or for the U.S. Government for U.S. Government purposes. 
    
    
     BACKGROUND OF INVENTION 
     There exists a constant need for soldiers to enter fortified or non-fortified structures/objectives through unconventional means often referred to as breaching. With current urban type conflicts, collateral damage is a concern when insurgents reside among non-insurgents, whether in the same structure or in near-by structures. There is great need for operations which will limit collateral damage. Current theatre environments limit the ability to utilize conventional weapons to suppress an objective in a target (such as by firing for affect and demolishing such fortified or non-fortified structure), but require instead a non-conventional means of suppression through breaching, sweeping, and clearing such structures. Therefore, soldiers are often called upon to clear buildings or to produce an ingress route into a building, all while unbeknownst to the objective. This approach can allow the soldier to suprise the objective and limit confrontation, or perhaps to be able to capture the objective. 
     This invention provides a very versatile new explosive breaching system which can aid the warfighter in such operations. This system can be used (but is not limited) to produce an ingress route in fortified or non-fortified structures large enough for a soldier to gain access to an objective—an effective breaching charge. This system could also be used in structural demolition, conventional and non-conventional breaching, along with materiel demolition. The system could also be used in the field to dispose of excess ammunition or other war fighter materiel not wished to be abandoned for possible use by an adversary. The system is herein also referred to as the Modular Breaching and Demolition System (“MBDS”). 
     BRIEF SUMMARY OF INVENTION 
     This system utilizes either inert light weight non-metallic assemblies hand packed prior to a mission, or light weight pre-loaded conventional energetic assemblies utilizing cast-cure or press loaded explosives. The system is generally made so it can fit in a soldier&#39;s ruck sack, and because it is modular, its net explosive weight can be tailored to the target needs. As an added benefit, this system is only approximately one third the weight compared to conventionally issued soldier demolition kits. As a further benefit, this system can still be classified in the same safety class as bulk explosives for the configuration where the base system is not designed to produce fragments, thus there is less red tape in distributing/obtaining the system. If desired, a soldier can still choose to incorporate a liner into any one or all of the assemblies to produce a shaped charge type explosion. 
     By contrast, a current breaching system fielded to the soldiers uses home made breaching charges which are field configured on the spot to carry out the mission in a timely manner, often utilize bulk explosives, detonating cord, and often also require soldiers to improvise use of surrounding/natural resources to make a frame for the explosives. Though relatively quick to setup if not relying on natural resources, such home made breaching types still are heavy (some approximately twenty eight lbs). They are also often quantity limited in availability to soldier units, consumable, and some are in a safety class different from that of bulk explosives, making for more red tape in handling. The field produced charge versions of these conventional systems might be lighter and can be made from bulk explosives readily available to soldier units and can be configured for different breaching applications; but they still rely on having the necessary natural resources to produce a frame. They also require large amounts of detonation cord to propagate the detonation around the frame. They also require more time to produce the frame/breaching charge and they also require first hand knowledge of how to reliably build and match a breaching charge to an intended target to produce the desired effects. 
     Both the pre-loaded and hand packed versions of this MBDS invention improve over such conventional field produced breaching charges. The MBDS will be organic to a unit of soldiers. The MBDS doesn&#39;t utilize natural resources in the surroundings and doesn&#39;t need detonation cords to propagate detonation. The MBDS is light weight and, after hand packing, or if utilizing the pre-loaded version, can be assembled in a few minutes at the last concealed and covered position. Further, if the soldier wished, a liner can be snapped into the MDBS to give a capability which field produced breaching charges currently do not have (tailored fragment generation). 
     In more detail, this MDBS system is comprised of multiple assemblies which can be arranged into different geometeric shapes or lines, linked together by a hinged system with clocking features and continuous cavity paths. The assemblies are made of a few inert non-metallic material pieces which snap or slide together to produce a cavity which can be hand packed with high explosives or can be pre-loaded with high explosive. Assemblies can then be used to produce any desired shape, whether square, line, T or E shape, for example. The assemblies have features which also allow a soldier to couple a shaped charge or anti-personnel liner into the MDBS if desired. Since the liner is not permanently attached to the assemblies the soldier can choose to make the MDBS a fragment producing or non-fragmenting charge depending on the target set. 
     A novelty in the MDBS design is the fact that it utilizes press fit joints, hinged with clocking features to produce any desired shape capable of being made with line segments. The way the cavity or high explosive in each assembly is positioned with respect to another assembly when connected and adjoined allows an ignition/detonation wave to propagate from one assembly to the next without the need of multiple detonation cords or multiple initiation points as in the conventional breaching systems. Each assembly in and of itself is also capable of having a node attached to it if desired. Such could increase the net explosive weight of the breaching charge, which would allow the MDBS breaching charge to be tailored to a particular target. 
     Materials used for the MDBS structure are non-metallic; this fact leads to a weight reduction in the final breaching charge/assembly compared to metallic materials. Such therefore allows for quicker implementation and functioning of the system. Nonetheless, such non-metallic materials if desired can be impregnated with metallic particles such as aluminum which can enhance the high explosive effects. Such non-metallic materials can also be reinforced with fibers to make the pieces and assemblies more rigid. Since the material is generally entirely non-metallic, all traces of the assembly are consumed during detonation which prevents enemies from tracing the system or from reverse engineering the system. Another valued feature is the ability to also introduce a fragmenting charge if desired. Such is accomplished by snapping/coupling in a liner within the segments or otherwise by utilizing predesigned features built into the MDBS. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide soldiers with a field demolition system which comprises inert modular pieces for customized assembly of a breaching or demolition system that the soldier requires for a particular task. 
     Another object of this invention is to provide soldiers with a modular field demolition system of only a few types of basic plastic components that can be snapped together by hand without need of specialized tools of finding natural resources in the field. 
     A yet further object of this invention is to provide soldiers with a modular field demolition system which requires no detonation cord to successfully explode such entire assembled system. 
     A still further object of this invention is to provide soldiers with a field demolition system of relatively light weight, and which can also be preloaded or custom hand loaded with plasticized explosive material in the field, as the soldier requires for a particular task. 
     A yet other object of the present invention is to provide a field demolition system which can be customized to form an inert frame which can support the positioning of trimmed sheet explosive such as detasheet® explosive between frame and target. 
     A still further object of the present invention is to provide a field demolition system which can be custom loaded with fragment producing shaped liners, or with fragment producing explosively formed penetrators, or a pre-formed fragment pack similar to a claymore as the soldier may require for a particular task. 
     These and other objects, features and advantages of the invention will become more apparent in view of the within detailed descriptions of the invention, the claims, and in light of the following drawings wherein reference numerals may be reused where appropriate to indicate a correspondence between the referenced items. It should be understood that the sizes and shapes of the different components in the figures may not be in exact proportion and are shown here for visual clarity and for purposes of explanation. It is also to be understood that the specific embodiments of the present invention that have been described herein are merely illustrative of certain applications of the principles of the present invention. It should further be understood that the geometry, compositions, values, and dimensions of the components described herein can be modified within the scope of the invention and are not generally intended to be exclusive. Numerous other modifications can be made when implementing the invention for a particular environment, without departing from the spirit and scope of the invention. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a male piece  100 , part of a leg that is used to build up a demolition device according to this invention. 
         FIG. 2  shows a female piece  200 , mate of male piece  100  shown in  FIG. 1 , used to build up a leg portion of an overall demolition device according to this invention. 
         FIG. 3A  shows a circular like hub piece  300  that can be used with pieces  100 ,  200  to build up a snowflake configuration for a demolition device according to this invention. 
         FIG. 3B  shows a front side view of the circular like hub piece  300  of  FIG. 3A . 
         FIG. 3C  shows a detailed view of a recessed area  306  found on the circular like hub piece  300  of  FIG. 3A . 
         FIG. 4A  illustrates placement of a shaped charge metallic liner  401  in a cavity of a piece  100 ,  200  for a demolition device according to this invention. 
         FIG. 4B  illustrates a liner of explosively formed projectiles for insertion in a cavity of a piece  100 ,  200  for a demolition device according to this invention. 
         FIG. 5  shows a random shaped demolition line made up from three legs assembled according to this invention. 
         FIG. 6  shows a porthole shaped demolition device made from legs assembled according to this invention. 
         FIG. 7  shows an X-shape demolition device made from legs assembled according to this invention. 
         FIG. 8  shows a window frame like demolition device made from legs assembled according to this invention. 
         FIG. 9  shows a middle connect piece  500  according to this invention. 
     
    
    
     DETAILED DESCRIPTION 
     The MDBS breaching charge system according to this invention is made up essentially interconnected modular plastic “legs” which are usually filled with an explosive material; the legs are arranged in preferred patterns useful for field breaching of a target. The legs shown are made of plastic (or rubber if more flexibility of the MBDS is desired), but many other lightweight sturdy inert nonmetallic materials might be considered for substitution, if compatible to the environment used and suitable for holding explosives. The MBDS may be of nonmagnetic material, but may also employ magnetic portions (or magnets proper as portions) in the MBDS frame for additional advantage of magnetic clinging to a target set in particular cases where such is desirable. Numerous patterns for arranging/emplacing the legs in a chain should be seen as possible; while these patterns are not all fully discussed herein they are in fact best known/well know to soldiers who have performed demolition/breaching as one of their specialties. An explosive type suggested for this invention might be C-4, and would likely be handled in a plasticized form, but solid blocks of explosive are also a possibility, as well as other suitable types of explosive materials.  FIG. 1  shows an inert male plastic piece  100  which is a half section piece of what will be built up into a “leg”, when joined with a mating female piece  200  (see  FIG. 2 ). Such leg may thereafter be serially joined with one or more other male and/or female type pieces to form a chain of these “legs”. Piece  100  has a rectangular box cavity  103  (formed by sides  121 ) to hold explosives, however, box  103  also opens through passage  129  into a recessed ring area  127 . Explosive is filled throughout in recessed ring  127 , passage  129 , as well as in box  103 , and also in a passageway  125  in tab  118  (which further insures ignition contact/shock wave propagation of explosive between adjacent pieces/legs of a chain, to be explained further below). Likewise in female piece  200 , there is a recessed ring shaped area  227  which through wide passage area  229  connects up with its rectangular box cavity area  203 . Explosive will fill all of box  203 , ring area  227 , and passage  229 . (Area  209 , which reinforces hole  206 , is higher in level than ring area  227  so as to contain the). Furthermore, there is also a passageway  225 , in tab  221 , which further insures ignition contact/shock wave propagation of explosive between adjacent pieces/legs of a chain. This contiguous ignition contact/shock wave propagation through all pieces/legs in a chain makes it only necessary to have a single ignition source to ignite an entire chain, instead of multiple wires, blasting caps, and detonation cord as may have been necessary with other demolition systems. However, redundant wiring may be added to as many locations as desired to insure a successful explosion and breaching operation of the whole chain or chains of pieces/legs. The bottom side of piece  100  is generally just flat, as is the bottom side of piece  200 . 
     Female piece  200  could be used to mate to piece  100 , or else used with yet other male pieces to build up a string of legs in a chain. Piece  100  has a post  108  which will mate with hole  206  of piece  200 . (Post  108  also has a slight dimple recessed top area  106 ). Piece  200  could be joined face to face with piece  100  so that post  108  goes into hole  206 , all the while that the half cavity  103  formed by rectangular box shape  121  directly fits in to and mates into the half cavity  203  rectangular box shape  218 , and the two pieces could thus be ‘snapped together’ and joined into a completed “leg”. The leg would have a completed inside cavity which might be filled with explosive, for example. The leg is roughly an inch thick, but roughly two inches wide. The first position just mentioned can form a sealed cavity device. However, in a more preferred “second configuration” here, one of the two pieces to be joined is positioned where its longitudinal axis is 180 degrees rotated planarly than was above described. The cavity is still formed by the mating of boxes  103  and  203 , (which still snap together just as snugly even in this backwards second configuration), however in this second configuration, post  108  of male piece  100  does not mate into hole  206  of female piece  200 . Instead, the post  108  and the hole  206  are positioned at opposite poles, fully 180 degrees away from each other, and each is left exposed and not mated. Post  108  has a hole to allow the MBDS to be hung from a stud, strung together on a line, etc., for convenience. 
     Ideally, to begin constructing a “chain”, one begins with any two pieces (whether  100  and  200 , or both  100 , or both  200 ), and joins them in the “second configuration” as above described. That is, the post or hole parts of these pieces are made to not be adjacent or opposite one another, while the two rectangular box cavities are indeed adjacent and joined, then both snapped into one another permanently. These two will now be considered the “first leg” here in building up the chain. Thereafter, in either direction further pieces are mated onto this “first leg”, at either end of this first leg, by inserting a respective post or a respective hole of a new respective piece into an exposed respective hole or post, as the case may be, adding onto the existing above described “first leg”, and therefore likewise linked on. By adding on pieces theoretically ad infinitim in either direction, a chain could be created of any desired number of legs/pieces, with their flat portions alternately facing up or down (in one direction or in its opposite direction) towards the target. Like the leg, the chain would also be roughly an inch thick, but roughly two inches wide. The length of the chain depends on how many pieces are linked together. An entire geometric shape can be made of such chained pieces because it will be seen that the post (like  108 ) of a newly added piece may be rotated about its mating hole (like  206 ) by close to 90 degrees in either a clockwise or in a counterclockwise direction. This will change the direction the chain is aimed in and thus allow different, selected shapes to be created by a chain, or a joining of chains together. It will be seen that the rounded edge of piece  100  has gear shaped grooves  111  interspersed between more flat portions  115 . These grooves  111  are sized for holding a small tab (such as  221  on a to be snapped in mating piece like  200 , for example) or perhaps a tab  118  of another male piece  100  if the case might be. Thus, piece  100  can be clocked around the hole of piece  200  by close to 90 degrees in either a clockwise or a counterclockwise direction as was described, and held in place by such tab  221  being in a groove such as shown by  111  on a piece like  100 . Likewise, piece  100  has a tab  118  sized to fit into a groove  215  on a mating piece like  200 . Thus, a piece  200  could likewise be clocked around the post of a piece like a piece  100  by close to 90 degrees in either a clockwise or a counterclockwise direction, as was described. This enables the pieces in a chain to be set into a select direction at each juncture, and held by the lock of a tab in the serrated areas as was described. Chains can thus be made in many forms and contain many angles and lengths, and the chains can be combined as desired to form a larger “frame” that can be used for breaching or other demolition type tasks. Chains can be combined into, for instance, an irregular S-chain ( FIG. 5 ), E-shapes, square shapes, cross-like shapes, other polygonal type shapes, spoke-like/snowflake type configurations when used with a hub piece  300 , e.g., porthole configurations ( FIG. 6 ), X-shapes ( FIG. 7 ), and window frame like shapes ( FIG. 8 ), for example, to be further described below. There are also other possible variations of shown pieces  100  and  200  to accommodate other functions, and the pieces could also be designed to be made in other sizes, dimensions, shapes, colors, and/or even color coded as may be needed or found desirable. A middle piece  500  for example, is a component for simultaneous joining legs/chains, of three different paths, at one juncture point. 
       FIG. 3 , (which has  FIGS. 3A-3C ), shows a round hub piece  300  which is used to create a snowflake pattern of pieces. Hub piece  300  has a bulging top surface  301 . Though not fully shown here, the reverse side of hub piece  300  is open so as to be a cavity to receive explosive powder. The cavity is then fully closed by a flat matching backing piece (not shown) to simply enclose all of the back side of hub piece  300  and all of the explosive powder that may be loaded therein. The hub piece has 12 edges. Six respective equilaterally-located flat edges  303  are interspersed respectively with six respective partially rounded recessed areas  306 , though a greater or lesser number of recessed areas may be used as may be necessary, to accommodate more (or fewer) spokes, for example. A more detailed view of a recessed area  306  is shown in  FIG. 3C . Each recessed area  306  is a mate to receive a male piece  100 . One respective male piece  100  is inserted respectively into each of the recessed areas  306 . Post  108  of a male piece will plug right in to opening  309  of a recessed area  306 . Serrated areas  115  on a male piece  100  will fit snugly into corresponding areas  319  here on a recessed area  306  of hub piece  300 . The male piece  100  will be inserted until it rests flush upon flat surface  318  here in a recessed area  306  of hub piece  300 . There are open areas  311 ,  313 ,  315 ,  317  in flat surface  318 ; their purpose is to insure contiguity of ignition contact between explosive inside  300  and explosive inside an inserted piece  100 . The six male pieces  100  if inserted inside hub piece  300  as described, begin forming the spokes of a snowflake type structure. Through addition of female pieces  200 , legs are built up, which in turn can be extended by further legs as may be desired. It will be seen that one could build up a snowflake pattern for example by interconnecting a hub piece and various pieces/legs. Detonation is only needed at one place in the snowflake. Because of ignition continuity as above described all parts of the snowflake should explode in unison. The hub piece is usually detonated at its center, but it will be appreciated that the hub piece could be used (without detonation cord), to divide out and spread detonation from just one plugged in leg (if detonated from elsewhere) to up to five other legs, if those other legs are also plugged in to the hub piece. 
       FIG. 4A  generally shows the addition of a metallic liner/shape charge arrangement  401  into cavity  103  of a male piece (or cavity  203  of a female piece, e.g.). The metallic liner is a thin metal sheet roughly the length/width of the main cavity. The liner is made to be in a V-cross or C-cross sectional shape, with the crease fold part  402  positioned away from the direction the target will be. The volume lying above  401  is filled with explosive. When detonated, a line of molten metal (along the fold) ultimately should slam into the target at high speed, as the liner deforms. Instead of metallic liner  401 , one could have a copper preformed EFP (explosively formed projectile) on  403 , or a series of EFP&#39;s  407  lined up. Instead of placing the metallic liner or EFP&#39;s in the main cavity  103 ,  104 , the metallic liner or EFP&#39;s could be placed in a false bottom cavity (not shown) of a male or female piece. The direction of orientation of the metallic liner or EFP&#39;s is as before still aimed towards the target and placement of explosive is as before above the liner so as to deform the metallic liner or EFP&#39;s into the direction of a target. Metallic liners or EFP&#39;s can also be used without, or with, a further presence of explosive within the other legs of the chain (or hub piece), as may be desired. 
     Detasheet® (sheet explosive) may be placed in a leg (or legs) or between a leg (or legs) and the target. In such case, the detasheet® is trimmed to the outline profile of the frame (and hub piece if any) as against the target (it may also be used untrimmed in the proper cases as best known to the soldier). The detasheet® may also be wrapped entirely around a leg (both above the leg, draping down the long sides of the leg, then completely under the leg over against the target) or of the entire frame. Detonation of such detasheet® in known manner will produce a satisfactory breakage into the target, along the outline profile of the frame (and hub piece if any). The detasheet® can also be used without, or with, a loading of explosive or within the legs or hub piece, as may be desired. In fact, one use of the MDBS according to this invention, is simply to form an inert frame structure around which datasheet may be deployed, to breach a target. This can happen by design or in a case where the soldier might run out of explosive in the field, for instance. 
     It will be appreciated that the MBDS provides a soldier with a very versatile, lightweight system, having simple snap together building blocks, which can be conveniently loaded as desired with explosives, used with detasheet®, or metallic liners/EFP&#39;s, pre-form fragments such as balls, cubes, stars, etc., and used against a target. The soldier does not have to look for hard to obtain natural objects to build up a frame to support his demolition needs with an MBDS. 
     While the invention may have been described with reference to certain embodiments, numerous changes, alterations and modifications to the described embodiments are possible without departing from the spirit and scope of the invention as defined in the appended claims, and equivalents thereof.