Patent Publication Number: US-2012036985-A1

Title: Reduced Collateral Damage Bomb (RCDB) and System and Method of Making Same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 11/844,804, entitled  Reduced Collateral Damage Bomb  ( RCDB )  and System and Method of Making Same , filed Aug. 24, 2007, now U.S. Pat. No. 7,992,498, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/840,232, filed Aug. 25, 2006, and entitled  Reduced Collateral Damage Bomb  ( RCDB )  and System and Method of Making Same , both incorporated by reference herein in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to bombs that are used to deliver high explosives to selected targets. More specifically, the present invention relates to bombs that deliver high explosive to selected targets but have the capability to reduce unwanted collateral damage. 
     BACKGROUND OF THE INVENTION 
     Bombs can have bomb casing of a conventional or penetrating warhead (PW) type. “Conventional” as it is used herein in describing a bomb casing means the shape and characteristics of the bomb casing as would be understood in the bomb industry. 
     Typically, bomb casings are filled with high explosive material and an end cap is used to seal the open end. Finished bombs using these bomb casings may be in 250, 500, 1000, and 2000 lb. classes or larger. The selection of the particular class of bomb will depended on the amount of high explosive that needs to be delivered to a selected target. Such bombs have been in the U.S. weapons inventory for a number of years. 
     Conventional and PW bomb casings each have a prescribed wall thickness. For any given bomb pound class, the interior cavity of the bomb casing will be tightly filled with high explosive material so that the finished bomb of a particular class will deliver predictable destructive power to a selected target. If the destructive power were not predictable, there is a strong likelihood either the appropriate destructive power will not be delivered to a target or excessive power will be delivered, but in each case there will be a waste of resources. 
     As is reported many times in the media when bombs are used, there is a problem with the amount of collateral damage near where such bombs are delivered to selected targets. The collateral damage may be to structures in the immediate area or to the civilian population. Therefore, it would be optimal for bombs to deliver high explosives to the selected target and not inflict undesired collateral damage unless that was the intention. 
     It is understood in the bomb industry that just reducing the size of the bomb, for example, from a 1000 to 500 lb. class bomb to reduce collateral damage may mean that collateral damage is reduced but there are other problems. The typical problem is that the smaller bomb may be inadequate to destroy the selected target because the mass of the 1000-pound class bomb may still be needed for target destruction. 
     There is desire for bombs of any class to have a reduced collateral damage capability yet not reduce the effectiveness of the bomb to deliver predictable destructive power for the destruction of the selected target. 
     SUMMARY OF THE INVENTION 
     The present invention is a reduced collateral damage bomb (RCDB) bomb casing and the system and method for making such casings. The RCDB bomb casings of the present invention are constructed with a filler material applied to the interior walls of the bomb casing. This filler material is applied in a controlled manner to reduce the volume of the cavity within the bomb casing. The remaining interior cavity of the bomb casing is filled with high explosive material after the filler material is applied to the interior walls. 
     The filler material is typically a material that is inert to the high explosive material even if the bombs are stored for a period of time. The filler material also may have properties that assist in providing destructive power to the bomb, but still reduce the collateral damage of the bomb. 
     An object of the present invention is to provide a conventional or PW bomb casing that will reduce the collateral damage of the finished bomb when it is delivered to a selected target. 
     Another object of the present invention is to provide a conventional or PW bomb casing that has a filler material coated on the interior walls that assists in reducing the collateral damage of the finished bomb when it is delivered to a selected target. 
     A further object of the present invention is to provide a conventional or PW bomb casing that has a filler material coated on the interior walls that has properties to enhance the destructive power of the bomb but with a reduced collateral damage effect. 
     These and other objects will be described in greater detail in the remainder of the specification referring to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a cross-sectional view of a conventional bomb casing (without the aft fuze liner or closure components) that does not incorporate the present invention. 
         FIG. 2  shows a cross-sectional view of a conventional penetrating warhead bomb casing (without the aft fuze liner or closure components) that does not incorporate the present invention. 
         FIGS. 3 and 4  show cross-sectional views of an embodiment of a conventional bomb casing (without the aft fuze liner or closure components) that has different thickness of filler material coating the interior walls of the internal cavity according to the present invention. 
         FIGS. 5 and 6  show cross-sectional views of an embodiment of a PW bomb casing (without the aft fuze liner or closure components) that has different thickness of filler material coating the interior walls of the interior cavity according to the present invention. 
         FIGS. 7A and 7B  show a conventional bomb casing for describing the method of spin coating a filler material on interior walls of the interior cavity according to the present invention. 
         FIGS. 8A and 8B  show a PW bomb casing for describing the method of spin coating a filler material on interior walls of the interior cavity according to the present invention. 
     
    
    
     DESCRIPTION OF THE PRESENT INVENTION 
     The present invention is directed to a reduced collateral damage bomb (RCDB) bomb casing and the system and method of making such bomb casings. As will be shown, the RCDB bomb casings have a filler material disposed on the interior walls of the interior cavity that will assist in controlling the collateral damage caused by the bomb but not prevent the appropriate destructive power from being delivered to a selected target. 
       FIG. 1 , generally at  100 , shows a cross-sectional view of a conventional bomb casing, for example, for Mark  80  series bomb bodies. The bomb casing includes ogive-shaped, front section  102  and cylindrical-shaped, rear section  116 . The bomb casing, preferably, is made of a low carbon steel 10××, 41×× low alloy or for a specific application can be made of a high strength alloy steel, such as a 43×× alloy or higher strength material. 
     Ogive-shaped, front section  102  and cylindrical-shaped, rear section  116  may be formed separately or as a single unit and still be within the scope of the present invention. 
     The wall thickness of ogive-shaped, front section  102  progressively increases from rear edge  110  of this section to front end  104 . Threaded bore  108  is disposed in front end  104  and extends through the front end wall thickness to central opening  114  in ogive-shaped, front section  102 . Threaded bore  108  receives threaded bomb nose plug (not shown) in a screw-nut relationship. Nose fuze liner  117  is shown that will receive the proximal end of the nose plug. 
     Preferably, cylindrical-shaped, rear section  116  has a substantially uniform wall thickness, except at rear end  124 . The wall thickness of the cylindrical-shaped, rear section is substantially the same as the wall thickness of ogive-shaped, front section  102  at rear edge  110 . The cylindrical-shaped, rear section has central opening  122 . The combination of central opening  114  in ogive-shaped, front section  102  and central opening  122  in cylindrical-shaped, rear section  116  form the interior cavity of bomb casing  102 . 
     Cylindrical-shaped, rear section  116  has threaded bores  130  and  132 . Each of the threaded bores receives the threaded base of a suspension lug (not shown). The suspension lugs are used for lifting the finished bombs and attaching them to aircraft bomb racks. 
     Cylindrical-shaped, rear section  116  also has charging receptacle  121 . Charging tube  119  connects between charging receptacle  121  and nose fuze liner  117 . Charging tube  123  connects between charging receptacle  121  and a tail fuze liner (not shown). 
     End  124  of cylindrical-shaped, rear section  116  has opening  126  that receives an aft-end fuze liner and closure structure (not shown). The aft-end closure structure holds the tail fuze liner. A fin assembly (not shown) attaches to the aft-end closure structure  124 . In the finished bomb, the interior cavity of the bomb casing is filled with high explosive material. 
       FIG. 2 , generally at  200 , shows a penetrating warhead (“PW”) bomb casing that is currently available in a variety of sizes from 250 lbs. to over 5000 lbs. The casing can have an ogive-shaped, front section  202  and cylindrical-shaped, rear section  210 . The bomb casing, preferably, is made of a high strength alloy steel, such as a 43×× or higher strength material 
     The nose shape shown is ogive-shaped, front section  202  and cylindrical-shaped, rear section  210  may be formed separately or as a single unit and still be within the scope of the present invention. 
     The nose shape shown is ogive-shaped, front section  202  has a wall thickness that progressively increases from rear edge  206  of this section to forward end  204 . The ogive-shaped, front section has central opening  208 . Front end  204  of ogive-shaped, front section  202  has threaded nose portion  205  extending from it. Threaded nose portion  205  is for receiving a retaining ring of a guidance kit (not shown) in a threaded relationship. 
     Preferably, cylindrical-shaped, rear section  210  has a substantially uniform wall thickness, except at rear end  212 . The wall thickness of the cylindrical-shaped, rear section is substantially the same as the wall thickness of ogive-shaped, front section  202  at rear edge  206 . The cylindrical-shaped, rear section has central opening  214 . The combination of central opening  208  and central opening  214  form the interior cavity of bomb casing  202 . 
     Cylindrical-shaped, rear section  210  has charging receptacle  218 . Charging tube  220  connects between charging receptacle  218  and a tail fuze liner (not shown). This charge tube is eliminated on some PW. End  212  of cylindrical-shaped, rear section  210  has opening  216  that receives the fuze liner and aft-end closure structure (not shown). The aft-end closure structure holds the tail fuze liner. A fin assembly (not shown) attaches to aft-end closure structure  212 . In the finished bomb, the interior cavity of the bomb casing is filled with high explosive material. 
     Although not shown in  FIG. 2 , cylindrical-shaped, rear section  210  may have an assembly attached to it for receiving the threaded bases of two or more suspension lugs (not shown). The suspension lugs, as stated, are used for lifting the finished bombs and attaching them to aircraft wing bomb mounts. 
     An embodiment of a RCDB conventional bomb casing according to the present invention is shown at  FIGS. 3 and 4 . With respect to  FIGS. 3 and 4 , the conventional bomb casing that is shown is the conventional bomb casing of  FIG. 1  and, therefore, the conventional bomb casing has the same reference numbers. The differences in the reference numbers between what is shown in  FIG. 1 , and  FIGS. 3 and 4  are what has been added according the present invention to make the conventional bomb casing a RCDB conventional bomb casing. 
     Referring to  FIG. 3 , a RCDB conventional bomb casing is shown generally at  300 . The RCDB conventional bomb casing has ogive-shaped, front section  102  and cylindrical-shaped, rear section  116 . Ogive-shaped, front section  102  has a wall thickness that progressively increases from rear edge  110  to forward end  104 . Threaded bore  108  is disposed in front end  104  and extends through the front end wall thickness to central opening  114  in ogive-shaped, front section  102 . 
     Cylindrical-shaped, rear section  116  has a substantially uniform wall thickness, except at rear end  124 . The wall thickness of the cylindrical-shaped, rear section is substantially the same as the wall thickness of ogive-shaped, front section  102  at rear edge  110 . The cylindrical-shaped, rear section has central opening  122 . Cylindrical-shaped, rear section  116  has threaded bores  130  and  132  for the threaded bases of suspension lugs. Cylindrical-shaped, rear section  116  also has charging receptacle  121 . Charging tube  119  connects between charging receptacle  121  and nose fuze liner  117 . Charging tube  123  connects between charging receptacle  121  and a tail fuze liner (not shown). End  124  of cylindrical-shaped, rear section  116  has opening  126  that receives an aft-end closure structure. The aft-end closure structure holds the tail fuze liner. 
     According to the present invention, filler material  302  is spin coated on the interior walls of the interior cavity formed by central openings  114  and  122 . The filler material will reduce the volume of the interior cavity, thereby reducing the side explosive impact of the finished bomb. 
     The filler material is an inert compound that will not react with the explosive material and reduce its explosive potential. The filler material although inert also may have properties that will enhance the explosive capability of the bomb when compared to a bomb that has an explosively neutral filler material. Whether the filler material is explosively neutral or will enhance the explosive capability, the finished bomb that includes filler material will reduce collateral damage. 
     Again referring to  FIG. 3  at  300 , the conventional bomb casing that includes ogive-shaped, front section  102  and cylindrical-shaped, rear section  116  has a spin coating of filler material applied to the interior walls to a thickness that reduces the interior cavity volume by 50%. Preferably, the spin coating of filler material is distributed in a manner to form an interior cylindrical channel along the longitudinal axis of the bomb casing. The cylindrical channel has a substantially uniform diameter. The cylindrical channel will be filled with high explosive material. The filler material will help focus the destructive power of the bomb through the front of the finished bomb while reducing the channeling of the destructive power out from the sides of the bomb. 
     Referring to  FIG. 4 , a RCDB conventional bomb casing is shown generally at  400 . The RCDB conventional bomb casing that is shown in  FIG. 4  differs from the RCDB conventional bomb casing in  FIG. 3  in that filler material  402  is spin coated on the interior walls to a thickness that reduces the interior cavity volume of the bomb casing by 70% rather than 50%. The other features of the filler material as described for the RCDB conventional bomb casing shown in  FIG. 3  apply equally to  FIG. 4  and are incorporated here by reference. 
     An embodiment of a RCDB PW bomb casing according to the present invention is shown at  FIGS. 5 and 6 . With respect to  FIGS. 5 and 6 , the PW bomb casing that is shown is the PW bomb casing of  FIG. 2  and, therefore, the PW bomb casing has the same reference numbers. The differences in the reference numbers between what is shown in  FIG. 2 , and  FIGS. 5 and 6  are what has been added according to the present invention to make the PW bomb casing a RCDB PW bomb casing. 
     Referring to  FIG. 5 , a RCDB PW bomb casing is shown generally at  500 . The RCDB PW bomb casing has ogive-shaped, front section  202  and cylindrical-shaped, rear section  210 . Ogive-shaped, front section  202  has a wall thickness that progressively increases from rear edge  206  of this section to forward end  204 . The ogive-shaped, front section has central opening  208 . Front end  204  of ogive-shaped, front section  202  has threaded nose portion  205  extending from it. 
     Cylindrical-shaped, rear section  210  has a substantially uniform wall thickness, except at rear end  212 . The wall thickness of the cylindrical-shape, rear section is substantially the same as the wall thickness of the ogive-shaped, front section at rear edge  206 . The cylindrical-shaped, rear section has central opening  214 . Cylindrical-shaped, rear section  210  has charging receptacle  218  to which charging tube  220  connects. End  212  of cylindrical-shaped, rear section  210  has opening  216  that receives an aft-end closure structure (not shown). The aft-end closure structure holds the tail fuze liner. 
     According to the present invention, filler material  502  is spin coated on the interior walls of the interior cavity formed by central openings  208  and  214 . The filler material will reduce the volume of the interior cavity that receives the high explosive material. 
     As stated with respect to  FIGS. 3 and 4 , filler material  502  preferably is an inert compound that will not react with the explosive material and reduce its explosive potential. Filler material  502  although inert also may have properties that will enhance the explosive capability of the bomb when compared to a bomb that has an explosively neutral filler material. Whether the filler material is explosively neutral or will enhance the explosive capability, the bomb will have reduced collateral damage. 
     Again referring to  FIG. 5  at  500 , the PW bomb casing that includes ogive-shaped, front section  202  and cylindrical-shaped, rear section  210  has a spin coating of filler material applied to the interior walls to a thickness that reduces the interior cavity volume by 50%. Preferably, the spin coating of filler material is distributed in a manner to form an interior cylindrical channel along the longitudinal axis of the bomb casing. The cylindrical channel has a substantially uniform diameter. The cylindrical channel will be filled with high explosive material. The filler material will help focus the destructive power of the bomb through the aft-end of the bomb while reducing the channeling of the destructive power out from the sides of the bomb. This application could be applied when the kinetic energy required to penetrate a structure requires the weight but the internal void only required a low volume of high explosive to neutralize the target. 
     Referring to  FIG. 6 , a RCDB PW bomb casing is shown generally at  600 . The RCDB PW bomb casing that is shown in  FIG. 6  differs from the RCDB PW bomb casing in  FIG. 5  in that filler material  602  is spin coated on the interior walls to a thickness that reduces the interior cavity volume of the bomb casing by 70% rather than 50%. The other features of the filler material as previously described for the RCDB PW bomb casing shown in  FIG. 5  apply equally to  FIG. 6  and are incorporated here by reference. 
     Referring to  FIGS. 3 ,  4 ,  5 , and  6 , the filler material shown at  302 ,  402 ,  502 , and  602 , respectively, that is spin coated on the interior walls of the interior cavity has weight properties substantially similar to those of the explosive material it replaces. This is so the finished bomb will have substantially the same weight, center of gravity, moment of inertia, and aerodynamic properties as a bomb filled only with high explosive material. 
     When the filler material, such as that shown at  302 ,  402 ,  502 , and  602  is added within the bomb casings, the resulting RCDB will provide a predictable level of reduced collateral damage destructive power. As such, bombs formed according to the present invention that include filler material may have a thickness of the filler material that will change according to the amount of high explosive material needed to be delivered to a selected target to destroy it but minimize undesired collateral damage near the target. 
     The filler material preferably will fill 25%-75% of the interior cavity volume of the bomb casing when it is spin-coated on the interior walls. The filler material will have properties that will permit it to adhere to the walls and itself when spin-coated on and cured. Preferably, the filler material will be explosively neutral or be a composite material that will provide special destructive characteristics to enhance the bomb&#39;s destructive capabilities. For example, the filler materials may include a combination of heavier and lighter materials that per unit volume is equivalent to the high explosive material it replaces. Examples of explosively inert, i.e., explosively neutral, filler material are polymer materials that use binders that will not interact with (or is inert to) the high explosive material. Further, examples of inert explosive enhancing filler materials are ones in which the polymer material with binders also has beads added to it that contain elements, such as oxygen, that can be desirable when such beads are used in an enclosed environment or such materials as tungsten or aluminum are added to create special desired effects. 
       FIGS. 7A and 7B , generally at  700 , and  FIGS. 8A and 8B , generally at  800 , will be used to describe the method of the present invention for forming the RCDB bomb casings of the present invention. The method of the present invention is substantially the same for both types of bomb casings, conventional and PW. Accordingly, in describing the method, the reference number for the conventional bomb casing in  FIGS. 7A and 7B  will be given first then the corresponding reference number for the PW bomb casing in  FIGS. 8A and 8B  will be given. 
     Open-ended bomb casing  702 / 802  is obtained that is desired to transform into a RCDB bomb casing. Charge tube stabilizer  704 / 804  is used to support and stabilize the charge tube  124 / 212  of bomb casing  702 / 802 . Charge tube stabilizer  704 / 804  includes seal  705 / 805  that is inserted into the aft-end to control the level of the inert filler material that is added into the bomb casing. Charge tube stabilizer  704 / 804  has adapter tube  710 / 810  extending though it that has a length within the interior cavity of bomb casing  702 / 802  to extend over the end of charge tube  123 / 220 , as shown at  706 / 806 . This will prevent filler material from fouling the charge tube during the spin coating process. Further, adapter tube  710 / 810  also extends outward from seal  705 / 805  a length, and the distal end of the adapter tube connects to a spin stabilizer wheel  714 / 814 . The adapter and spin stabilizer wheel will stabilize the charge tube  123 / 220  during the filler material spin coating process. 
     After level controlling seal  705 / 805  and adapter tube  710 / 810  with spin stabilizer wheel  714 / 814  are in place, bomb casing  702 / 802 , preferably, is placed in a variable speed horizontal centrifugal casting machine. The machine will have counterbalancing capabilities to provide an offset for the inserts, which are known in the industry, e.g., a gyro-based system, and inert filler material while the machine is coming up to the speed required to spin coat the inert filler material on the bomb casing walls. It is understood that other machines may be used that are capable of spinning the bomb casing and still be within the scope of the present invention. 
     The next step of the process is to insert a spout from a hopper containing the filler material with the binder and other desired materials being mixed thereto into the bomb casing through the open spoke spin stabilizer wheel at the aft-end of the item. The amount of filler material that is poured into the interior cavity of bomb casing  702 / 802  is calculated to provide a desired thickness on the interior walls of the bomb casing and form the previously discussed cylindrical channel. This amount will allow the finished bomb to provide the desired destructive power to the selected target and reduce the collateral damage. 
     Bomb casing  702 / 802  that is filled with the desired amount of filler material is spun at a predetermined speed for a predetermined period of time to spin coat the interior walls of the interior cavity with filler material. The spin coating will form a cylindrical channel within the bomb casings as shown, for example, in  FIGS. 3 and 5 . While bomb casing  702 / 802  is being spun, the exterior of the bomb casing can be heated to cure the filler material as it spin coats the interior walls of the bomb casing. 
     Following spin coating and curing the filler material to the interior walls of bomb casing  702 / 802 , the bomb casing is removed from the casting machine. Next, seal  705 / 805  is removed, which also results in adapter tube  710 / 810 , along with spin stabilizer wheel  714 / 814 , being removed from the end of charge tube  123 / 220 . Bomb casing  102 / 202  may now be made ready for normal processing into a finished bomb. 
     The terms and expressions which are used herein are used as terms of expression and not of limitation. And, there is no intention, in the use of such terms and expressions, of excluding the equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible in the scope of the invention.