IL33370A - Ammunition and a process for manufacturing the same - Google Patents

Description

mis"1? nviann Ammunition and a process for manufacturing the same PABRIQUE MATIONALE KERSTAL en abre'ge' "FN" 0/ 31622 This invention relates to an ammunition, more particularly a defensive grenade and still more particularly such a grenade provided to be thrown from a rifled bore tube, ., ·.... This , grenade is also of the type comprising an explo sive body with a preestablished fragmentation generally made of a hollow body in plastic material functioning as a binder between fragments of hard bodies, generally steel shot or balls.

A first object of this invention is to provide such a defensive grenade so that the maximum amount of pre-established fragments or the maximum proportion of steel shot or balls are incorporated in a minimum space, said explosive body being otherwise conditioned for a maximum efficiency of the ammunition, .

Another object of the invention is to manufacture suchammunition through a very simple mounting operation based on the application of the aforesaid explosive body as a binding support between all the essential parts of the ammunition.

Finally, another object of the invention concerns a sim le rocess for manufacturin such ammunition.

These various requirements are satisfied in that the defensive grenade is made from a hollow explosive body in plastic material charged through its thickness with a maximum amount of fragments having a high hardness, said explosive body being conditioned to function as a support for an inner tightness cup, a rotating band covering its free edge, a cartridge case and a fuse.

In order to reach the maximum density and efficiency for the said . fragments of hard material, the said hollow explosive body has a cylindrico-spherical shape.

The ammunition according to the invention has still different features which will be more apparent from the following detailed description of a non limitative example of an embodiment shown in the enclosed drawings in which: Figure 1 shows in an exploded view, partially in front view and partially in radial section, the characteristic elements of the ammunition according to the invention; Figure 2 shows on an enlarged scale and in radial section the explosive body provided with the tightness cup; Figure 3 is a plane view of Figure 2; Figure 1 is a partial section on the line IV-IV of Figure.3 ; Figure 5 is a view on the line V-V of figure 1; Figures 6 and 7 show respectively a section on the lines VI-VI and VII-VII of Figure 5; Figure 8 shows in a front view with a partial radial section the ammunition according to the invention after having mounted the elements shown in the exploded Figure 9 shows on a enlarged scale the portion indicated in F9 on Figure 8, In this embodiment, the essential elements of the ammunition comprise the explosive body JL, the cartridge case and the fuse _3» the explosive body comprises substantially the explosive charge (not shown) the tightness cup J+, the composite body J5 securing the fragments of hard material j3 and the rotating band _» The explosive charge, the firing device and 'the fuse proper are neither described nor illustrated, being outside the scope of this invention and likely to be thoroughly modified, it being also possible to select these elements among .the presently known means.

The explosive body 1 having a preestablished fragmentation is under the form of a cylindrico-spherical cup, i.e. it has a tubular portion j8 extended on one side by a hemispherical portion J3. The said tubular portion 8 has two parallel ribs 10-11 defining a peripheral groove JL2 therebetween. The rib 11 outlines a shoulder _13 bearing the rotating band · Normally , ' the said explosive body forms a unit with|the tightness . cup the latter having also a tubular portion l^ and a hemispheric portion 1_5, the said tubular portion having a thread l^ near its free edge. As shown more clearly on Figure 2, the composite body J5 and the tightness cu H are firmly interlocked, the said tightness cup forming the whole inner wall of the said explosive. body. Along its free edge, said explosive body has external notches of a half-circular shape. These notches have the same depth and they are equally distributed on the periphery of the free edge of the explosive body JL, is secured a maximum amount of' steel balls _6 the diameter of which is slightly lower than the thickness E' of the thinnest portion of the said explosive body 1» The rotating band £ is applied with a tight fit upon the upper edge of the said composite body, This rotating band has an annular shape the inner diameter D and the height H of which are substantially equal to the diameter D' and . the height H' of the upper tubular portion of the composite body J5, The rotating band 7_ has extra-thicknesses 18 directed inwardly and equally spaced on. the periphery of the upper edge thereof, said extra-thicknesses having a value P' = P with the same characteristics as those of notches 17^ of the composite body as regards the number, the relative position, the shape and the sizes.

Near its lower edge, the rotating band 1_ nas one or several peripheral ribs 19_ known 'per se and provided for cooperating with the riflings in the bore of the launching tube for rotating the ammunition about its longitudinal axis. The said rotating band 7. s fitted on the upper portion of the composite body 5_ so that, its lower edge contacting the shoulder l^, the extra-thicknesses 18^ are completely engaging the respective notches 7 of the said composite body. Thus, the so completed explosive body comprises the explosive charge, the inner tightness cup the composite body _5 in which are secured the hard fragments and the rotating band 7_ overtopping the explosive body. The ammunition is completed by the cartridge case. _2 tightly fitted on the explosive body and the fuse _3 the threaded extension 1 of which is screwed on the threaded portion JL6 of the tightness cup diment, the explosive body forms the binding element between the essential parts of the ammunition without any detrimental effect upon the mutual interlocking of a maximum amount of fragmented hard bodies within a minimum space.

The invention relates also to a process for the industrial manufacture of such ammunition. According to this process, by any suitable known means, the tightness cup ^ is firstly made from a thin sheet worked to form a hollow body the external shape and dimensions of which are strictly similar to those of the corresponding portions fo the explosive body which the said tightness cup must contact. This cup has namely a cylindrico-spherical shape, the free edge of the tubular cylindrical portion being profiled as a screwthread.

The so obtained cup is screwed on a metallic means (not shown) conforming perfectly to the inner shape of the cup so as to prevent it from collapsing when injecting under pressure, The resulting core is then introduced into a mould the cavity of which has the shape and the sizes of the external portion of the explosive body, Between the mould and the core are introduced hard bodies, namely balls J5, and is injected under pressure the material likely to fill up correctly all the interstices between the balls and between the latter and the constituting walls of the mould, it being apparently possible to use additional stresses such as vibrations, shakes, shocks or other similar means for placing the balls or the shot and to provide a complete filling. Of course, the binding material must be judiciously selected to satisfy various requirements such as the dimensional stability and the impact resistance as well at a normal temperature as when cold. Polyamides and superpolyamides as well as cellulose esters have been successfully experimented.

Of course, it will be possible to choose the most suitable resins in accordance with the desired . effects and the requirements being met, this being left to the appreciation of those skilled in the art, the characteristics of the synthetic resins being well known per se.

In the bottom of the mould, have been provided small ribs to maintain the balls 6 at a slight distance ε from the free edge of the composite body. When the latter has been stripped off, the rotating band._7 is applied thereto with a tight fit and the surface outlined by the upper annular edge 2_1 and the inner extra-thicknesses _18 are straightened out by mechanization so that they are outlined by the plane X-X.

The aforesaid distance e has been provided by inserting suitable small ribs 2_2 in the mould for keeping systematically the balls outside the surfacing tool.

The cartridge case 2 and the fuse _3 may be known elements made by known processes and means. Said fuse will advantageously present a centering bearing 2j3 cooperating with a corresponding annular stop' 2_3 formed on the upper free edge of the composite material jj so that both elements, namely the explosive body _1 and the fuse 3_, are perfectly concentric to each other when screwed.

As previously disclosed, for completing the ammu the said explosive body forming a unit with the tightness cup, to proceed with filling up, to fasten the cartridge case 2_ and finally to secure fuse j3.

It is of course apparent that the charges, the priming cups and the fuses will be judiciously selected among the various known means.

The invention relates to the ammunition as such and more particularly to the characteristic explosive body as well as to the process described for realizing the one and the other.

The characteristics disclosed herein may be also carried out for making ammunition not only having different sizes, but also likely to present numerous variations provided that the- essential .and characteristic elements are maintained. 33370/2

Claims (1)

1. Ammunition including an inner an outer a composite constituted by fragments of a hard material embedded in a synthetic material and located between said inner and outer a driving a fuze fixed in the open of said inner characterized in that said composite body constitutes a suppor for said casing is constituted by a thin metallic cup and said outer casing and said driving ring are both force fitted around said composite said ze head making contact with said driving Ammunition according to Claim characterized in said composite body has a cyllndrospherlcal the cylindrical portion having an outer shoulder and peripheral notches correlative with the shape and size of said driving ring force on said composite Ammunition according to Claim characterized in that said driving ring is constituted by an element inwardly and along its upper peripheral the sizes and relative position of which are conditioned in accordance with said Ammunition according to any of the preceding characterized in that said fragments are kept at a slight distance from the peripheral ee edge of said composite body when making the Ammunition according to any of the preceding characterized in that said fuze head is screwed in open end of said casing a centerin bearing cooperating wit stop of composite body so that A process fo the manufacture of an according to Claim characterized in that i comprises formin firstly the inner then screwing latter on resisting core conforming perfectly to the inner shape of the introducing the resulting into a then introducing the fragments of a hard material into the so castin the synthetic material for u all the interstices between fragments and the stripping force fitting the driving rin on the thus obtained composit fixing said fuze Ammunition aocording to Claim characterized in that thin ribs provided at the bottom mould to keep said fragments at a slight distance from the peripheral free edge of said composite Ammunition according to 6 or in that after the driving ring has been secured the composite the free edge of the ammunition is surfaced to dispose it in a perpendicular to its longitudinal Ammunition and process or manufacturing the substantially as previously illustrated insufficientOCRQuality