Patent Publication Number: US-6901835-B1

Title: Cone and charge extractor

Description:
FIELD OF INVENTION 
   This invention relates to generally to the field of disarming munitions. In particular, this invention relates to extracting a compound (e.g., explosive) from a shaped munition (e.g., grenade). 
   BACKGROUND OF THE INVENTION 
   Due to military build-up, shelf-life expiration and technical advances, munitions are becoming obsolete or in excess of a quantity desired to be kept in reserve. This presents a need to disarm and recover salvageable material of munitions. For example, for munitions such as grenades, there is a need to recover the grenades and remove the lead charge, explosive and cone liner from the grenade, leaving a recovered grenade casing. 
   Demilitarization programs have been in operation to disarm and recover salvageable material of artillery rounds loaded with munitions, including M42, M46, M77 and M80 general purpose type grenades. Typically, the fuse housing and fuse slider are secured to prevent the fuse slider from moving into an armed position. Next, a hole (typically ⅜ of an inch in diameter) is mechanically punched through the grenade casing where the flange of a cone-shaped liner is attached to the interior of the casing, deforming the liner and exposing the explosive charge inside the grenade. The explosive charge (also referred to simply as explosive) in the grenade is then burned away in a controlled burning apparatus known as an Explosive Waste Incinerator (EWI) or, alternatively, the entire grenade assemblies are mass detonated on a controlled demolition field. 
   There are several disadvantages of these prior art methods. None of the explosive material is salvaged. The EWI process takes a long time to burn away the entire explosive, and must be carefully controlled to minimize high order detonation explosive burning. Moreover, the burning away of the explosive produces toxic fumes in the EWI which must be contained and detoxified. Thus, this prior art method contributes to high operating cost, high equipment maintenance cost and does not salvage any of the explosive material. Also, after mass detonations there is potential for ground water and air contamination. 
   Day &amp; Zimmermann, Inc. disclosed a better approach for removing the explosive charge from the grenade by removing most of the explosive before the EWI. In U.S. Pat. No. 5,974,937, entitled Method and System for Removing an Explosive Charge From a Shaped Charged Munition, and issued Nov. 2, 1999, the contents of which are incorporated by reference herein in their entirety, a hollow punch die is inserted through an open end of the grenade casing to gouge the cone out of the assembly and remove (e.g., drill or punch) most of the explosives out of the casing. The removed explosive can then be salvaged for use in commercial demolition charges and the EWI processing can be performed at higher pass through rates and with less toxic fumes and residue. However, this improved process leaves a significant amount of explosives inside the body, since, due to safety considerations, the die or drill must not come in contact with the metal components. Therefore, the EWI processing is still required to remove the residual explosives, producing toxic fumes and residue. While the improved approach is effective as a demil operation, it reduces the opportunity to reclaim the casing and liner for subsequent reuse and requires an incinerator to complete the explosive removal process. 
   The present inventor realized that it would be even more beneficial to develop an approach that safely removes the lead charge, substantially all of the explosive, and the cone-shaped liner from the munition body (e.g., casing). Recovered munition or grenade bodies can then be reused for new production or reclaimed and recycled as scrap metal. Explosives can be reused for ammunition or sold for mining operation. The cones, typically copper, can be sold as scrap. 
   SUMMARY OF THE INVENTION 
   The invention relates to an apparatus and method for removing an explosive from a shaped charged munition. A compound (e.g., explosive, packed powder, solid substance) is released from a dome end of a munition casing with a high pressure fluid (e.g., hydraulic) system including a fluid (e.g., water) pump and a water port in communication with the compound. While the preferred fluid is water, other fluids may be used to urge the compound away from the dome end. 
   In an exemplary embodiment of the present invention, an extractor releases a compound from a dome end of a casing that also has an open end opposite the dome end. The extractor includes a support device connected to the casing and adapted to stabilize the casing as the compound is released from the dome end, and a fluid port adjacent the dome end of the casing and adapted to introduce a fluid through the dome end to the compound to release the compound by separating the compound from the dome end. 
   The casing and the compound are typically elements of a munition (e.g., grenade). While not being limited to a particular theory, the munition typically includes a liner inside the casing with a flange of the liner mechanically coupled to the casing and directed toward the open end. In this example, the compound is enclosed in the casing between the dome end and the liner, and the support device may include a dejeter slidingly engaged within the open end of the casing adjacent the liner. 
   In accordance with another exemplary embodiment, the invention includes a method for releasing a compound from a dome end of a casing having an open end opposite the dome end. The exemplary method includes the steps of connecting a support device to the casing to stabilize the casing, urging the dome end of the casing against a fluid port, and introducing a fluid through the fluid port to the compound to release the compound by separating the compound from the dome end. The method may also include removing the released compound from the casing. 
   In accordance with yet another exemplary embodiment, the invention includes a method for releasing an explosive from a munition having a casing with an open end opposite a dome end, a liner mechanically coupled inside the casing and directed toward the open end, and the explosive enclosed in the casing between the dome end and the liner. The exemplary method includes the steps of inserting a fluid port into the dome end of the casing and introducing a high pressure fluid through the fluid port to the explosive to release the explosive by separating the explosive from the dome end and to shear the mechanical coupling between the liner and the casing. The method may also include removing the released explosive from the casing. 
   In accordance with still another exemplary embodiment, the invention includes an apparatus for releasing a compound from a dome end of a casing having an open end opposite the dome end. The exemplary apparatus includes means for connecting a support device to the casing to stabilize the casing, means for urging the dome end of the casing against a fluid port, and means for introducing a fluid through the fluid port to the compound to release the compound by separating the compound from the dome end. The apparatus may also include means for removing the released compound from the casing. 
   In accordance with yet still another exemplary embodiment, the invention includes an apparatus for releasing an explosive from a munition having a casing with opposite open and dome ends, a liner mechanically coupled inside the casing and directed toward the open end, and the explosive enclosed in the casing between the dome end and the liner. The exemplary apparatus includes means for inserting a fluid port into the dome end of the casing and means for introducing a high pressure fluid through the fluid port to the explosive to release the explosive by separating the explosive from the dome end and to shear the mechanical coupling between the liner and the casing. The apparatus may also include means for removing the released explosive from the casing. 
   The described characteristics of the invention are easily discernable from the drawings. Moreover, further scope of applicability of the present invention will become apparent in the description given hereafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments, are given by way of illustration only, since the invention will become apparent to those skilled in the art from this detailed description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     This invention will be described in conjunction with the following drawings, in which like reference numerals designate like elements and wherein: 
       FIG. 1  is a sectional view of an exemplary prior art grenade body loading assembly; 
       FIG. 2  is a perspective view illustrating an extractor in accordance with a preferred embodiment of the invention; 
       FIG. 3  is a partial longitudinal sectional view of the extractor of  FIG. 2  in a start position; and 
       FIG. 4  is a partial longitudinal sectional view of the extractor of  FIG. 2  in a push-out position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention is directed to an extractor and a method for extracting a compound (e.g., explosive) from a casing (e.g., munition, grenade). While not being limited to a particular theory, the invention is described below with regard to removal of an explosive from an improved conventional munition (ICM) grenade. A shaped charge munition is generally understood to include a casing enclosing an explosive charge having a generally conical indentation or shape, oriented such that the open base of the conical shape is directed toward an open end of the casing to concentrate the blasted effect in that direction. However, it is understood that the invention is adaptable to other shaped charge munitions, with and without liners or a stackable configuration. 
     FIG. 1  is a cross section view of a typical ICM grenade body loading assembly  10 . When coupled with an initiating device (e.g., fuse), the grenade body loading assembly  10  (hereinafter referred to as grenade body) becomes an ICM grenade that is typically carried to a target in large gun projectiles or rocket warheads. The grenade body  10  has a casing  12 , a lead charge  14 , a liner  16 , and an explosive  18 . The casing  12 , preferably formed of metal, is hollow with an open end  20  and a closed dome end  22  opposite the open end. 
   The exterior of the casing  12  is generally cylindrical and has a smaller diameter near the dome end  22  to permit stacking of the grenades in a delivery projectile. This can best be seen in  FIG. 1  by noting that the casing  12  has a uniform outside diameter from the open end  20  to a dome shoulder  24  and a smaller outside diameter from the shoulder  24  to the dome end  22 . To stack grenades in a delivery projectile, the dome end  22  of one grenade is inserted into the open end  20  of an identical second grenade until the rim of the open end of the second grenade rests on the dome shoulder  24  of the first grenade. 
   The interior of the casing  12  is also generally cylindrical with an interior side wall  26  having a reduced bore diameter near the dome shoulder  24 . The interior side wall  26  also has a small reduction in bore diameter near the open end  20  to form a ridge  28  that is adapted to couple with the liner  16 . 
   While not being limited to a particular theory, the liner  16  is a cone shaped copper structure having a flange  30  extending from an open base  32  of a cone shaped section  34 . The flange  30  preferably includes a groove  36  around the outer circumference wall of the flange  30  and is adapted to be mechanically coupled to the ridge  28  of the casing  12 . The liner  16  is attached to the interior side wall  26  of the casing  12  by press fitting the flange  30  against the interior side wall until the groove  36  is swedged or coupled about the ridge  28 . A charge of explosive  18  (e.g., RDX type) is enclosed in the area between the dome end  22  and the liner  16 . The casing  12  includes an opening  38  at the dome end  22  that houses the lead charge  14 . The lead charge  14  is press fitted into the opening  38  adjacent the explosive  18 . Preferably an adhesive backed aluminum foil layer is attached on the inside of the dome end between the explosive  18  and the lead charge  14  to form an internal seal between the two. Details of the aluminum foil are not important to the understanding of the invention. 
   The cone shaped cavity configuration of the explosive  18  shown in  FIG. 1  is characteristic of shaped charge munitions. Detonation of the explosive  18  directs hot expanding gases from the explosion toward the axis of the cone shaped liner  16  and out the open end  20  of the casing  12 , giving the blast a directional effect. The typically copper liner  16  is compacted along its axis and melts almost instantaneously from the explosion, where it is ejected as a high velocity molten jet out of the open end  20  of the casing  12 . This directional blast and molten metal jet provide armor penetration to a much greater depth than an omni-directional explosion. The casing  12  is typically made of steel, and breaks up from the blast of the explosion into fragments to provide anti-personnel shrapnel. 
     FIG. 2  shows a perspective view of the preferred exemplary embodiment of the invention. As shown in  FIG. 2 , an extractor  50  includes a support device  52 , a grenade support  54 , a fluid source apparatus  56 , and an air source apparatus  58 . The support device  52  stabilizes the grenade body  10  and defeats or absorbs the armor penetration capability of the grenade in the unlikely event of a detonation during the extraction process. The grenade support  54  holds the grenade body  10  and supports the casing  12  during the extraction process. It should be noted that the support device  52  could be considered to include the grenade support  54  even though they are generally discussed separately. The fluid source apparatus  56  introduces fluid, preferably under high pressure, into the dome end  22  of the grenade body  10  and between the explosive  18  and the interior side wall  26 . The fluid source apparatus  56  pushes the fluid inside the dome end  22  with enough force to move the explosive and shear the swedged liner  16  from the ridge  28  of the casing  12 . The explosive  18  and liner  16  are loosened and released from the dome end  22  by this process and easily removed from the casing  12  (e.g., in a subsequent tapping and rinsing operation). The air supply  58  acts on the support device  52  and the fluid source apparatus  56 , pushing the lead charge  14  into the explosive  18  and providing an entry point for the fluid to flow from the fluid source apparatus. 
   The support device  52  includes a dejeter  60 , a dejeter housing  62 , a dejeter housing support  64  and a back-up spring  66 . The dejeter  60  and back-up spring  66  are not shown in  FIG. 2  as both are at least partially enclosed in the dejeter housing  62  and in the casing  12 . As can be seen in  FIGS. 3 and 4 , the dejeter  60  is slidingly engaged within the dejeter housing  62  and the back-up spring  66  is located therebetween. The back-up spring  66  is preferably a compression spring and acts on the dejeter  60  by urging the dejeter away from the dejeter housing  62 . The dejeter  60  is adapted to extend out of the dejeter housing  62  and into the open end  20  of the grenade body  10 . While not being limited to a particular theory, the dejeter  60  shown in  FIGS. 3 and 4  is held in position against the casing  12  and liner  16  by the back-up spring  66 , which is also referred to as a compression spring. In this position, the dejeter  62  serves to defeat the armor penetrating capability of the grenade in the unlikely event of a detonation during the extraction process. The dejeter  60  also serves as a stabilizer to hold the liner  16  in position during the extraction process until the fluid pressure inside the grenade reaches a force sufficient to shear the liner from the ridge  28  of the grenade body  10 . It should be noted that the extractor  50  is preferably enclosed in a protective housing (e.g., cubicle) and operated remotely for safety. 
   The dejeter housing  62  sits on and is slidingly engaged with the dejeter housing support  64 . As shown in  FIGS. 3 and 4 , the dejeter housing  62  preferably includes a hub  68  at its closed end opposite the dejeter  60  that is at the open end of the dejeter housing. The hub  68  includes a sleeve  70  and connects to the air source apparatus  58  as will be described in greater detail below. The dejeter housing support  64  stays the dejeter housing  62  in axial alignment with the grenade body  10 . 
   Referring to  FIG. 2 , the fluid source apparatus  56  includes a fluid port  74  in communication with a fluid supply  76  via a fluid pump  78 , a valve assembly  80  and a fluid supply conduit  82 . The fluid source apparatus  56  also includes a fluid pressure gauge  84  in communication with the valve assembly  80  for measuring the fluid pressure of the fluid source apparatus. The fluid port  74  abuts the grenade body  10  at the dome end  22  of the grenade body. In particular, as shown in  FIG. 3 , the fluid port  74  is aligned with the opening  38  in the dome end  22  and is in communication with the lead charge  14 . The fluid port  74  introduces a fluid through the opening  38  to the explosive  18  by pushing the lead charge  14  into the explosive, providing an entry point for the fluid to follow. 
   Still referring to  FIG. 2 , the fluid enters the fluid source apparatus  56  via the fluid supply  76 . The fluid supply  76  is preferably a hose connected to a supply of the respective fluid at its distal end, and is connected to the fluid pump  78  at its proximal end. The fluid pump  78  raises fluid pressure by compressing and pushing the fluid to the fluid conduit  82  and the fluid port  74  via the valve assembly  80 . The valve assembly  80  controls the amount of fluid that flows from the fluid pump  78  to the fluid supply conduit  82 . The fluid pressure gauge  84  is preferably connected to the valve assembly  80  and measures the pressure of the fluid passing through the valve assembly. The fluid supply conduit  82  extends from the valve assembly  80  through the grenade support  54  to the fluid port  74 , as seen in  FIGS. 2-4 . This arrangement of the fluid conduit  82  through the grenade support  54  is not critical to the scope of the invention, however, it is noted that with this arrangement, the grenade support  54  also provides structural support to the fluid conduit  82  and to the fluid port  74 . 
   As can be seen in  FIG. 2 , the air source apparatus  5   8  includes an air pressure regulator  86  that sends air to a compression cylinder  88  via an air supply conduit  90 . The air supply conduit  90  receives the air, preferably under pressure from an air source (e.g., air tank), with the pressure of the incoming air regulated by the air pressure regulator  86  in a manner readily understood by a skilled artisan. The air travels through the air supply conduit  90  to the compression cylinder  88 , where it is compressed to increase its pressure. As can best be seen in  FIGS. 3 and 4 , the compression cylinder  88  includes a rod  92  that couples the compression cylinder and the dejeter housing  62  and provides fluid communication with the dejeter housing to push the dejeter housing toward the grenade body  10 . The rod  92  includes a band  94  that is externally threaded and adapted to slide along the longitudinal axis of the rod as air is supplied to the compression cylinder  88  from the air source apparatus  58 . 
   As noted above, the hub  68  and sleeve  70  are part of the dejeter housing  62  and are adapted to connect the dejeter housing to the rod  92 . The sleeve  70  has internal threads that mate with the external threads of the band  94 , connecting the dejeter housing  62  to the compression cylinder  88 . Via this connection, the dejeter housing  62  moves with the band  94  as air is supplied to the compression cylinder  88  and out of the rod  92 . Accordingly, as can best be seen in  FIG. 4 , the compression cylinder  88  is adapted to push air out of the rod  92  against the dejeter housing  62 , urging the dejeter housing toward the grenade body  10 , such that the dejeter housing abuts the casing  12 . In fact, the compression cylinder  88  continues to pneumatically push the dejeter housing  62  and, upon contact with the casing  12 , also moves the casing  12  toward the fluid port  74 . This movement of the casing  12  causes the fluid port  74  to slide into the opening  38  of the dome end  22  against the lead charge  14 , sealing the opening with the fluid port, pushing the lead charge into the explosive  18  and creating a fluid path from the fluid port to the explosive. 
   The fluid is introduced from the fluid port  74  through the opening  38  and flows between the interior side wall  26  and the adjacent surface of the explosive  18 . The fluid is continually forced into the grenade body  10 , creating enough pressure in the dome end  22  to move the explosive  18  and shear the swedged liner  16  from the ridge  28  of the casing  12 . The liner  16  is pushed over the ridge  28  and the explosive  18  detaches and is released from the dome end  22  of the casing  12 , thereby loosening both the liner and the explosive to a push-out position for removal from the grenade body  10 , preferably in a subsequent tapping and rinsing operation. The loosened explosive  18  and liner  16  can also be easily removed from the grenade body  10  in other alternative operations (e.g., suction, pulling) as readily understood by a skilled artisan. In particular, alternative approaches include but are not limited to the following: vacuum or suction directed at the loosened liner  16  allowing the liner to be removed and the loosened explosives  18  to fall out; low pressure water washout or high pressure water jet washout after the loosened liner is removed via vacuum or pulled out with a mechanical unit attached to the liner; and gravity. 
   An exemplary method for releasing a compound from the dome end  22  of the casing  12 , and, in particular, a preferred method for releasing the explosive  18  and cone shaped liner  16  from the dome end of a munition (e.g., grenade body  10 ) is described in greater detail below with reference to  FIGS. 3 and 4  of the application. In particular,  FIG. 3  is a side view, partially in section, of the extractor  50  in a start position; and  FIG. 4  illustrates the extractor  50  of  FIG. 3  in a push-out position. 
   In an initial phase of this extraction operation, a grenade body  10  is connected to the support device  52  adapted to stabilize the grenade body. While not being limited to a particular theory, the support device  52  can include any of the dejeter  60 , the dejeter housing  62 , the dejeter housing support  64 , the back-up spring  66 , and the grenade support  54 . Preferably, the support device  52  at least includes the dejeter  60  or the grenade support  54 . Referring to  FIG. 3 , the grenade body  10  is connected to both the dejeter  60  and the grenade support  54  by placing the grenade body on the grenade support and inserting the dejeter  60  into the open end  20  of the casing  12 . While not being limited to a particular theory, the casing  12  in  FIG. 3  is therefore connected to the grenade support  54  and the dejeter  60  of the extractor  50  with means using the structure of the support device  52  such as placing the grenade body  10  on the grenade support  54  and against the dejeter  60  by extending the dejeter into the open end  22  of the casing  12 . The dejeter  60  slides into the open end  22  with a diameter equal or slightly less than the diameter of the interior side wall  26  at the open end. As can be seen in  FIGS. 3 and 4 , the dejeter  60  extends into the casing  12  to the liner  16  and provides support to the liner during the extraction process. 
   The grenade body  10  is placed in contact with the fluid port  74  such that the fluid port is adjacent the lead charge  14  located in the opening  38  of the dome end  22 . The fluid port is urged or held against the casing  12 , as shown in  FIG. 3  by the back-up spring  66 . The back-up spring  66  is shown in a compressed position in  FIG. 3 , whereby the compression spring pushes the dejeter  60  out of the dejeter housing  62  into the open end  24  and toward the fluid port  74 . Accordingly, the grenade body  10  is stabilized by the dejeter  60 , the back-up spring  66 , the dejeter housing  62  and the dejeter housing support  64  on one end; by the fluid port  74  on an opposite end; and by the grenade support  54  underneath. 
   The dome end  22  of the casing  12  is further urged against the fluid port  74 , providing a means for inserting the fluid port into the dome end. As can best be seen in  FIG. 4 , the urging and inserting is accomplished pneumatically by the compression cylinder  88 , which is an exemplary pushing member. When actuated, the compression cylinder pneumatically pushes the dejeter housing  62  toward the grenade body  10  and forces the fluid port  74  into the opening  38  of the dome end  22  where the lead charge  14  is located. This action pushes the lead charge  14  into the explosive  18 , seals the opening  38  with the fluid port  74 , and provides an entry point for fluid (e.g, high pressure water) to follow. Accordingly, the fluid port  74  is inserted into the dome end  22  of the casing  12 , placing the fluid port in fluid communication with the explosive  18 . 
   While not being limited to a particular theory, the dejeter  60 , back-up spring  66 , dejeter housing  62 , and pushing member (e.g., compression cylinder  88 ) are included as structure in a means for urging the dome end  22  against the fluid port  74 . 
   In a subsequent stage of the extraction operation exemplified herein, a fluid is introduced through the fluid port  74  to the explosive  18  to separate the explosive from the dome end  22 . Referring to  FIGS. 2 and 4 , as an exemplary means for introducing a fluid, the fluid pump  78  pushes fluid from the fluid supply  76  out of the fluid port  74  and into the grenade body  10  through the opening  38  at a pressure high enough to spread over the surface of the explosive  18  adjacent the interior side wall  26  of the casing  12 . The pressure inside the dome end  22  increases as the fluid is pushed into the dome end because the seal between the fluid port  74  and the opening  38  is maintained during this stage. The fluid, which is preferably water, is continually forced into the casing  12  and creates enough pressure inside the dome end  22  to move the explosive  18  and shear or push the swedged cone liner  16  from the ridge  28  along the interior side wall  26  of the casing  12 . As shown in  FIG. 4 , the explosive  18  is separated from the dome end  22  and the explosive  18  and liner  16  are pushed away from the dome end, releasing the explosive and liner from the dome end. 
   While it is noted above that high pressure water is used as the fluid in the preferred embodiment, it is understood that other fluids, including liquids and gases, may be used to release the explosive  18  and liner  16  from the dome end  22  of the grenade casing  10 . It is also understood that other gases in addition to or including air, can be used by the compression cylinder  88  to move the dejeter housing  62  and the casing  12  against the fluid port  74  to insert the fluid port into the dome end  22  of the casing  12 , and to create a seal of the opening  38 . Moreover, pushing members alternative to the compression cylinder  88  may be used to insert the fluid port  74  into the dome end  22 , as readily understood by a skilled artisan. What is important to the invention is that a fluid is inserted into the casing  12 , creating enough pressure to push the explosive  18  away from the dome end  22 . Alternative fluids and gases will become apparent to ones having ordinary skill in the art as needed in the application of this invention. 
     FIG. 4  is an exemplary illustration of the position of the explosive  18 , liner  16  and tooling (e.g., dejeter  60 , dejeter housing  62 , back-up spring  66 , dejeter housing support  64 , hub  68 , sleeve  70 , air port  92 , compression cylinder  88 , etc.) after application of the fluid. After the explosive  18  and liner  16  release from their prior packed position in the grenade body  10  to their push-out position shown in  FIG. 4 , the fluid pressure automatically drops, the dejeter housing  62  retracts toward the compression cylinder  88 , and the grenade body  10 , with the loosened explosive  18  and liner  16 , is removable from the extractor  50 . As an exemplary means for removing the released explosive  18  and liner  16  from the casing, once the grenade body  10  is removed, the loosened explosive and liner can be safely and easily extracted from the grenade body  10  in a subsequent operation (e.g., tapping and rinsing, suction, mechanical attachment and pulling) as readily understood by a skilled artisan. The extractor  50  can then be readied for another extraction operation. 
   It should be apparent from the aforementioned description and attached drawings that the concept of the present application may be readily applied to a variety of preferred embodiments, including those disclosed herein. For example, munitions having various sizes and configurations may be used with the invention possibly requiring at most a resizing of the tooling. Moreover, the structure of the support device  52 , the fluid source apparatus  56  and the air source apparatus  58  may be modified to support and access the munition in a variety of ways, as would readily be understood by a skilled artisan. Without further elaboration, the foregoing will also fully illustrate the invention that others may, by applying current or future knowledge, readily adapt the same for use under various conditions of service. It should be understood that many modifications, variations and changes may be made without departing from the spirit and scope of the invention as defined in the claims.