Abstract:
A container for ammunition of the type comprising a case inside which an inner casing receiving the ammunition is able to slide between two axial positions, one in which it blocks the ammunition and the other in which it unblocks the ammunition, the inner casing incorporating a front sleeve having flexible fingers, such sleeve cooperating in its blocking position with a fixed limit stop integral with the case and ensuring the retention of the fingers on a zone of the projectile to limit its translation, such container wherein it incorporates means ensuring the radial spacing of the flexible fingers at a distance from the projectile in the unblocking position of the inner casing.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The technical scope of the invention is that of ammunition transportation containers and namely containers enabling the blocking of explosive ammunition. 
     2. Description of the Related Art 
     A container is known, namely by patent EP1101077 that comprises an inner casing able to be moved from a blocking position to an unblocking position. This inner casing incorporates a front part comprising flexible tongues that press on the front pocket of a fin-stabilized projectile. 
     In the blocked position, the tongues are held radially by a fixed case. In the unblocked position, traction on the ammunition radially deforms the tongues allowing the ammunition to be extracted from the container. 
     When the container falls on its closing lid, the ammunition is held in place by tongues that are not able to deform radially thanks to the case. 
     Such a container is well adapted to the retention of fin-stabilized ammunition whose projectile incorporates a front pocket whose substantially conical profile enables the tongues to be deformed and which enables the ammunition to be extracted. 
     It is, however, unsuitable for the blocking of ammunition equipped with a shaped charge explosive projectile that does not incorporate such a front pocket. 
     Common explosive projectiles have a bottle-shaped profile incorporating a substantially calibred body extended by a sub-calibred neck tipped by an impact switch. 
     The only abutment surface available for such a projectile is a flange ring generally placed alongside the impact switch. But such an abutment surface is perpendicular to the ammunition&#39;s axis and is not able to ensure the spacing of the retention fingers. This results in a risk of the ammunition being stuck in the container preventing its subsequent removal. 
     SUMMARY OF THE INVENTION 
     The aim of the invention is to propose a container that overcomes such drawbacks. 
     Thus, the container according to the invention efficiently blocks the ammunition whatever the profile of the available bearing surface on the projectile body. 
     The invention thus relates to a container for ammunition of the type comprising a case inside which an inner casing receiving the ammunition is able to slide between two axial positions, one in which it blocks the ammunition and the other in which it unblocks the ammunition, the inner casing incorporating a front sleeve having flexible fingers, such sleeve cooperating in its blocking position with a fixed limit stop integral with the case and ensuring the retention of the fingers on a zone of the projectile to limit its translation, such container wherein it incorporates means ensuring the radial spacing of the flexible fingers at a distance from the projectile in the unblocking position of the inner casing. 
     According to a particular embodiment, the means ensuring the radial spacing of the fingers may comprise a cylinder coaxial to the inner casing and integral with the fixed limit stop. 
     The fixed limit stop may incorporate a conical profile cooperating, in the blocking position, with a matching profile on the sleeve&#39;s fingers. 
     According to a particular embodiment, the fixed limit stop may comprise a conical portion connected to the coaxial cylinder by at least one radial rib. 
     The sleeve will, in this case, incorporate slots separating the fingers, such slots intended to receive the ribs on the fixed limit stop. 
     The fixed limit stop may be integral with a shim made of a compressible material fixed to the case. 
     The shim of compressible material may advantageously incorporate a conical profile extending that of the limit stop. 
     The sleeve of the inner casing will surround one front part of the projectile, an inner surface of the sleeve forming a support for the ammunition body. 
     The sleeve may be globally conical in shape surrounding a front part of the projectile, such sleeve extended by a seat fastened to the inner casing. 
     The container may incorporate at least one cylindrical shim integral with the inner casing, such shim intended to be placed between said casing and the ammunition. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become more apparent from the following description of a particular embodiment, such description being made with reference to the appended drawings, in which: 
         FIG. 1  shows a longitudinal section of a container according to the invention enclosing a piece of ammunition, such container being shown in the blocking position, 
         FIG. 2  is an analogous view to the previous one showing the container in the unblocking position with its lid removed, 
         FIGS. 3   a  and  3   b  are views of the fixed limit stop alone,  FIG. 3   b  being a section along the broken planes marked AA in  FIG. 3   a ,  FIG. 3   a  being a rear view of the limit stop, 
         FIG. 4  is a perspective view of the fixed limit stop alone, 
         FIG. 5  is a longitudinal section of the sleeve alone. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to  FIG. 1 , a container  1  according to the invention comprises a case  2  inside which an inner casing  3  enclosing ammunition  4  is able to slide. 
     The case  2  of the container is generally cylindrical in shape. It is advantageously made of cardboard and is closed off at one end by a crimped metallic bottom  5 . 
     The case is closed at its other end for example by a threaded link  7 . 
     Here the ammunition  4  is explosive tank ammunition. It comprises a combustible case  4   a  integral with a base  4   d  and a shaped charge projectile  4   b  incorporating a sub-calibred nose  4   c  tipped by an impact switch  8  fitted with a flange ring  9 . 
     The inner casing  3  incorporates a cylindrical body formed of two coaxial cardboard tubes  3   a  and  3   b , such body being mounted able to slide inside the case  2 . Cylindrical shims  23   a ,  23   b ,  23   c ,  23   d  (see  FIG. 2 ) are placed between the ammunition  4  and the casing  3 . These shims improve the retention of the ammunition and ensure that the radial shocks are absorbed. 
     The inner tube  3   b  has a collar  24  made of a plastic material that is in contact with a circular rim of the base  4   d.    
     In accordance with the invention, the inner casing  3  also incorporates a front sleeve  10  of a globally conical shape. This sleeve surrounds the nose  4   c  of the ammunition  4  and part of the front of the body  4   b  of the ammunition  4 . 
       FIG. 5  shows this sleeve  10  alone. It is made of a plastic material and incorporates a rear cylindrical part  11  that is fixed, for example by bonding to the inner tube  3   b  of the casing  3 . A shoulder  12  separates the conical part and the cylindrical seat of the sleeve  10 . This shoulder acts as a mechanical limit stop when the sleeve  10  is mounted onto the body of the inner casing  3 . The shoulder  12  enables the mechanical compressive stresses to be transmitted between the sleeve  10  and the tubes  3   a  and  3   b  of the casing  3  (tubes being assembled, for example, by stapling). 
     As may be seen in  FIG. 5 , the sleeve  10  has flexible fingers  13  at its front part that are separated by slots  14 . 
     This  FIG. 5  is a section along a median plane passing through two fingers  13  of the sleeve. Here, there are six fingers  13  separated by six slots  14  evenly spaced angularly. The fingers  13  incorporate a thickened front part  13   a  finished off by a flat part  10   b  perpendicular to the axis  15  of the sleeve (which is also the axis of the casing  3 , the ammunition  4  and the case  2 ). 
     The fingers  13  are applied on the nose  4   c  of the projectile behind the flange ring  9 . The flat part  10   b  thus forms an abutment surface preventing the ammunition from being extracted. 
     Thus, the sleeve  10  ensures that the inertial stresses of the ammunition  4  are taken up further to a fall in direction F. These inertial stresses are communicated by the projectile, via the sleeve  10 , to the inner casing  3  and to the collar  24 . 
     The lid  6  has a bottom shim  18  made of deformable foam itself pressing against a shim of rigid polystyrene  19  surrounded by a ring of cardboard  28 . This ring is crushed by the collar  24  during a fall in direction F. 
     The sleeve  10  has a conical external surface  10   a  that is intended to cooperate with the internal surface of a limit stop  16 . 
     This limit stop  16  may be seen more particularly in  FIGS. 3   a ,  3   b  and  4 . It comprises a cone portion  16   a  and an internal coaxial cylinder  16   b  connected by radial ribs  16   c  (here there are six ribs  16   c  evenly spaced angularly, but only one rib is required). 
     The limit stop  16  is made here as a single part of plastic material. As may be more particularly seen in  FIG. 3   a , the ribs  16   c  extend axially over the full height of the limit stop  16 . As will be explained hereafter, the inner cylinder  16   b  is of sufficient height to ensure sufficient opening of the sleeve  10  in its unblocking position, this in order to enable the passage of the flange ring  9  of the projectile  4   b . The base of the inner cylinder  16   b  is in the same plane as the large base  17  of the limit stop  16 . 
     The inner profile  18  of the limit stop is a cone with the same taper as the external surface  10   a  of the sleeve  10 . 
     The internal cylinder  16   b  has an inner diameter enabling the passage of the collar  9  on the nose  4   c  of the projectile  4   b.    
     When the container is being assembled, the slots  14  separating the fingers  13  receive the limit stop&#39;s ribs  16 . The sleeve  10  thus comes into contact without hindrance with the limit stop  16  despite the presence of the internal cylinder  16   b  which is thus positioned inside the sleeve  10 . 
     The fixed limit stop  16  is integral with a shim  20  of compressible material (for example foam) which is itself made integral with the case  2  (by bonding or stapling). 
     The shim  20  thus incorporates a conical inner bore  20   a  shaped so as to receive the limit stop  16 . The latter is immobilized axially with respect to the shim  20  between two counter-sinks  21   a  and  21   b . The limit stop  16  is mounted in the flexible shim  20  by being clicked into position between the counter-sinks. This is enabled by the flexibility of the material constituting the shim. 
     Furthermore, the shim  20  incorporates a conical profile  22  extending that of the limit stop  16  which is also applied against the external profile of the sleeve  10  in its blocking position. 
     When the container  1  receives a piece of ammunition  4  and is closed (position shown in  FIG. 1 ), the sleeve  10  is in contact with the limit stop  16  (as well as with the conical profile  22 ). Both limit stop  16  and profile  22  thus prevent the radial opening of the fingers  13 . This contact stiffens the fingers  13  by preventing them from buckling under the compressive stresses communicated by the ammunition  4 . The fingers  13  thus remaining positioned behind the flange ring  9  of the ammunition  4 . 
     During a fall of the container  1  in direction G, the body  4   b  of the projectile abuts against the sleeve  10  by its calibred front part  4   e  ( FIG. 1 ). 
     The inertial stresses on the ammunition are communicated by the sleeve  10  to the limit stop  16  and the shim  20  which is crushed to absorb the shock. 
     As may be more particularly seen in  FIG. 2 , to remove the ammunition from the container, the inner casing  3  is made to slide towards the rear of the container. During this movement, the fingers  13  are radially spread by the internal cylinder  16   b  which remains immobile with respect to the case  2 . The fingers thus allow the passage of the flange ring  9  of the ammunition  4 . The ammunition is thus no longer blocked in translation and may be removed without difficulty from the container  1 . 
     To introduce ammunition into the container, the casing  3  is also made to slide rearwards, thereby spreading the fingers  13  by means of the internal cylinder  16   b  and enabling the ammunition to be introduced. 
     Note that, by design, the elasticity of the fingers  13  of the sleeve  10  would enable the passage of the nose&#39;s flange ring  9  during the introduction of the ammunition (if the fingers  13  were not spread enough by the internal cylinder  16   b ). 
     Different variants are possible without departing from the scope of the invention. It is thus possible for a container to be defined whose sleeve is of a different shape and which is adapted to the profile of another type of projectile. 
     In any case, flexible fingers pressing on a zone of the projectile will be provided, the fingers being simply held in their blocking position by a fixed limit stop and spread by suitable means at a distance from the projectile in their unblocking position to allow the ammunition to be removed.