Combustible cartridge case for ammunition

Abstract

The invention relates to a combustible cartridge case (1) for ammunition, comprising a cylindrical envelope (2) intended to contain a propellant charge and to receive a projectile at a front end (AV). The cartridge case comprises, at a rear end (AR), a bottom (3) that is integral with the cylindrical envelope (2) and is intended to be positioned in a base. The cartridge case is characterised in that the bottom (3) comprises a combustible central ring (5) that is connected to a peripheral cup (4) by at least two combustible radial arms (6) delimiting openings (7).

Description

Combustible case for ammunition.

[0001] The technical field of the invention is that of combustible cases for ammunition and in particular for large caliber ammunition (greater than 45mm).

[0002] It is conventional to produce large-caliber cartridge ammunition in the form of combustible cases carrying a projectile at one front end and a base at the rear end.

[0003] The base receives an igniter which allows the initiation of a propellant charge contained in the case. The projectile is fixed to the case, for example by a weakened connecting ring (as described in patent EP0307307).

[0004] A base is attached to the socket, most often by means of a plastic interface cup, as described by patent EP1092939.

[0005] Such combustible case ammunition reduces unburned material and firing residue, which is then limited to the base, which is ejected from the weapon chamber and stored in the vehicle's turret.

[0006] Patent EP1092939 also discloses a combustible case ammunition whose combustible case has a base which is also combustible and which is housed in the base and which carries an igniter support tube.

[0007] Such a support tube, just like the connecting cup, remains a plastic part which forms a firing residue which, most often, separates from the base and remains in the chamber of the weapon, with the risk of causing firing incidents.

[0008] The aim of the invention is to propose a combustible case which makes it possible to reduce the proportion of unburned material and firing residue, while making the connection between the base and the case more reliable.

[0009] Thus, the invention relates to a combustible case for ammunition, case comprising a cylindrical casing intended to contain a propellant charge and to receive a projectile at a front end, case comprising at a rear end a base made in a single piece with the cylindrical casing and which is intended to be positioned in a base, case characterized in that the base comprises a central combustible ring which is connected to a peripheral bowl by at least two combustible radial arms delimiting openings.

[0010] According to a particular embodiment, the central ring may include an annular surface intended to receive an ignition means.

[0011] Advantageously, the annular surface may be delimited by at least one partially cylindrical zone intended to cooperate with a flat of the ignition means and intended to form a rotation stop means for the ignition means.

[0012] According to a particular embodiment, each connecting arm may have a reinforced connection profile both at the central ring and at the peripheral bowl.

[0013] Advantageously, each arm may include a radial slot reducing its thickness and extending from the central ring to the peripheral bowl.

[0014] The bottom may include at least one structural reinforcement material.

[0015] The reinforcing material may, for example, include synthetic or mineral fibers distributed in the combustible material of the socket.

[0016] The reinforcing material may include at least one openwork insert such as a canvas or mesh embedded in the combustible material of the socket.

[0017] The invention will be better understood on reading the following description of a particular embodiment, a description made with reference to the appended drawings and in which:

[0018] is a rear perspective view of a combustible socket according to the invention;

[0019] is a view of the bottom of the socket, seen from outside the socket;

[0020] is a view of the bottom of the socket, seen from inside the socket;

[0021] is a partial longitudinal sectional view of the socket carrying a base and an ignition means.

[0022] Referring to Figures 1 to 3, a combustible case 1 according to the invention comprises a cylindrical casing 2 which is intended to contain a propellant charge (not shown) and to receive a projectile (not shown) at a front end AV.

[0023] This socket 1 has at a rear end AR a base 3 which is made in a single piece with the cylindrical casing 2 and which is intended to be positioned in a base (not shown).

[0024] As seen in the figures, the base 3 comprises a peripheral bowl 4 which has a diameter smaller than that of the casing 2 and a central combustible ring 5 which is connected to the peripheral bowl 4 by at least two radial arms 6 delimiting openings 7. The openings 7 are intended to allow the loading of the case with a propellant powder before fixing the base.

[0025] The entire base 3, like the casing 2, is made of a combustible material, for example a mixture of Kraft paper pulp and nitrocellulose. This sleeve can be painted.

[0026] Thus, the socket 1 according to the invention is a single-piece and entirely combustible and it is no longer necessary to fix a plastic base (or cup) on the cylindrical casing 2 to connect it to the base.

[0027] Lamontre shows the adaptation of a base 8 on the bottom 3 of the socket 1.

[0028] The base 8 is fixed by a nut 9 screwed onto an ignition means 10 which is metallic (for example brass).

[0029] The fixing by nut of a base on an ignition means is described by patent EP1092939.

[0030] Thus the ignition means 10 comprises a threaded rear part 10a which receives the nut 9. The latter comes to bear against a counterbore 8a of the base 8.

[0031] A lip seal 17 (made of rubber) is interposed between the bottom 3 and the base. This is a bowl-shaped seal. It would of course be possible to use a base bearing a sealing lip integrated by overmolding, as described by patent FR2215603.

[0032] The ignition means 10 is also integral with the bottom 3 of the socket.

[0033] Thus the central ring 5 comprises an annular bearing surface 11 on which a collar 12 of the ignition means 10 rests.

[0034] The ignition means 10 comprises a groove 13 in which is housed an elastic ring 14 which ensures the translational connection of the ignition means 10 and the base 3. This elastic ring can be completed with a support washer in order to distribute the force on the central ring 5.

[0035] Furthermore, as can be seen more clearly in the, the annular bearing surface 11 is delimited at the internal end of each arm 6 by a partially cylindrical zone 15 which is intended to cooperate with a flat 10b of the ignition means. These zones 15 are intended to form a rotation stop means for the ignition means 10. Of course, at least one zone 15 (and not one per arm) is sufficient to form a rotation stop. Furthermore, these zones could not be positioned at the end of the arms but for example between two neighboring arms.

[0036] In order to secure the connection between the socket 1 and the base 8, each connecting arm 6 has a connection profile which is reinforced, both at the level of the central ring 5 and the peripheral cup 4. As can be seen in the, the thickness E of the socket 1 is increased at the level of the cup 4 (thickness E1) and the ring 5 (thickness E2).

[0037] As seen in Figures 1 and 2, each arm 6 also has a radial slot 16 which reduces its thickness and which extends radially from the central ring 5 to the peripheral cup 4. These radial slots facilitate the fragmentation of the arms 6 during firing. This facilitates the combustion of the entire case 1, even at the level of the areas with reinforced thickness E1 and E2.

[0038] According to an alternative embodiment, in order to improve the mechanical resistance of the socket 1, at least one structural reinforcement material may be provided at the base 4.

[0039] This reinforcing material may include synthetic or mineral fibers which will be distributed in the combustible material of the socket 1 at the time of molding thereof.

[0040] According to another variant, the structural reinforcement material may comprise at least one openwork insert (not shown) such as a canvas or a mesh which will be embedded in the combustible material of the socket at the level of the bottom 4 and / or the arms 6 and / or the central combustible ring 5.

[0041] This last variant allows for better control of the location of the reinforcement materials.

[0042] The cartridge case 1 according to the invention is therefore devoid of a cup or plastic support tube at the connection of the base and the ignition means. The removal of the support cup also allows the removal of the rivets which, in the solution described by patent EP1092939, made it possible to mechanically connect the combustible cartridge case and the plastic cup. These rivets also formed firing residues.

[0043] The ignition means 10 remains integral with the solid base 8 and is ejected with it after firing.

[0044] The pressure of the propellant gases associated with the possible presence of embrittlements (such as the radial slots 16) causes the fragmentation of the bottom 3 of the case 1, which promotes its combustion.

[0045] The cartridge case 1 according to the invention thus makes it possible to avoid firing residues and therefore secures the operation of the ammunition.

Claims

Combustible casing (1) for munition, casing comprising a cylindrical sleeve (2) intended to contain a propellant charge and to receive a projectile at a front end (AV), casing having at a rear end (AR) a base (3) made in one piece with the cylindrical sleeve (2) and which is intended to be positioned in a base (8), the base (3) having a central combustible ring (5) which is connected to a peripheral cup (4) by at least two radial combustible arms (6) delimiting openings (7), casing characterized in that each connecting arm (6) has a reinforced connection profile both at the central ring (5) and at the peripheral cup (4). Combustible socket according to claim 1, characterized in that the central ring (5) has an annular bearing surface (11) intended to receive an ignition means (10). Combustible socket according to claim 2, characterized in that the annular bearing surface (11) is delimited by at least one partially cylindrical zone (15) intended to cooperate with a flat (10b) of the ignition means (10) and intended to form a rotational stopping means for the ignition means (10). Combustible socket according to any one of claims 1 to 3, characterized in that each arm (6) has a radial slot (16) reducing its thickness and extending from the central ring (5) to the peripheral cup (4). Combustible socket according to any one of claims 1 to 4, characterized in that the base (3) comprises at least one structural reinforcing material. Combustible socket according to claim 5, characterized in that the reinforcing material comprises synthetic or mineral fibers distributed in the combustible material of the socket. Combustible socket according to claim 5, characterized in that the reinforcing material comprises at least one openwork insert such as a canvas or mesh embedded in the combustible material of the socket.

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