WO2021043928A1

WO2021043928A1 - Telescoped ammunition round comprising a sub-caliber projectile stabilized by a deployable empennage

Info

Publication number: WO2021043928A1
Application number: PCT/EP2020/074651
Authority: WO
Inventors: Bruno Barratault
Original assignee: Cta International
Priority date: 2019-09-03
Filing date: 2020-09-03
Publication date: 2021-03-11
Also published as: US20220290953A1; EP4088082A1; FR3100323A1; KR20220056230A; FR3100323B1

Abstract

The invention relates to an ammunition round (1) of the telescoped type, comprising a case (2) which accommodates a sub-caliber projectile (16) equipped with a segmented ejectable sabot (11), a propellant charge (8) and a device (4) for igniting the propellant charge, characterized in that said sub-caliber projectile (16) comprises an extension (10) receiving an empennage (19) that is able to move between a position in which it is folded back against said extension and a deployed position, said sabot (11) holding said empennage (19) in said folded-back position, said sabot (11) wrapping around said empennage (19) to isolate it in order to prevent contact between said empennage (19) and said propellant charge (8).

Description

Telescoped ammunition comprising a sub-calibrated projectile stabilized by a deployable tail unit

FIELD OF THE INVENTION

The technical sector of the present invention is that of telescoped type ammunition comprising a sub-calibrated projectile.

STATE OF THE ART

These telescoped ammunition generally comprise a substantially cylindrical case, inside which are arranged a projectile assembly and a propellant charge.

The projectile assembly is located entirely inside the holster. It can be a one-piece projectile, gun caliber, or it can be a sub-caliber projectile and a sabot, gun caliber, which surrounds and holds the sub-caliber projectile.

The present invention is particularly applicable to such telescoped munitions containing a projectile assembly formed by a subcaliber projectile and a sabot.

When firing an ammunition comprising a subcaliber projectile, the set of projectiles consisting of the sabot and the subcaliber projectile is propelled into the barrel of the weapon. On exiting this tube, the sabot detaches from the sub-calibrated projectile, which then continues its trajectory.

To travel a predictable long distance trajectory, the projectile exiting the barrel of the weapon must be stabilized.

This stabilization can be a gyroscopic stabilization, resulting from a rapid rotation of the projectile around its longitudinal axis, imparted to the projectile by the rifled barrel of the weapon. Such stabilization is generally used for projectiles of the caliber of the weapon. It can also be implemented for sub-calibrated projectiles. In this case, the slip belt that surrounds the sabot, and which contacts the rifled barrel of the weapon, transmits rotation to the projectile assembly.

However, when the projectile is undersized, the rotation which is transmitted by the skid belt may not be sufficient to stabilize the projectile satisfactorily.

In addition, ammunition projectiles are increasingly used to carry charges such as explosive charges, electronic components or gyroscopes. Such charges may be sensitive to too rapid rotation of the projectile, which may impair their operation.

Stabilization by stabilization of the sub-calibrated projectile

It is also known to ensure the aerodynamic stabilization of the projectile on its trajectory using a tail unit. The tail unit ensures a stable trajectory of the projectile over very long distances, for example greater than 3 km. Subcaliber projectiles equipped with empennages generally rotate at a moderate speed much slower than gyro-stabilized projectiles.

Thus, in patent FR-2647891 which corresponds to the preamble of claim 1, a telescoped munition comprising a projectile assembly, consisting of a sabot and a sub-projectile equipped with a tail unit, is known.

Limitations of prior art stabilization by tail

Such stabilization by stabilizing a sub-caliber projectile, however, can only be applied to projectiles of relatively small diameter compared to the caliber of the weapon. Indeed, to ensure effective stabilization, the wingspan, which must be less than the caliber of the weapon, must be greater than the diameter of the body of the subcaliber projectile.

There is, however, a need for relatively large projectiles stabilized by a stabilizer, to allow the transport of explosive charges, electronic components, for example for tracking a moving target, or a gyroscope making it possible to know the trajectory of the projectile. Such charges in fact occupy an important place and can be disturbed by too rapid rotation of the projectile.

The aim of the present invention is therefore to provide a telescoped munition, comprising a sub-calibrated projectile, making it possible to overcome such drawbacks.

In particular, the invention aims in particular to provide such a munition in which the sub-caliber projectile has relatively large dimensions, compared to the caliber of the barrel of the weapon.

Another object of the invention is to provide such a munition in which the sub-projectile is effectively stabilized, without undergoing too rapid rotation liable to disturb the operation of the load it carries.

The subject of the invention is therefore a telescoped type ammunition, comprising a case inside which are housed a sub-calibrated projectile equipped with a segmented ejectable sabot, a propellant charge and a device for igniting the propellant charge, characterized in that said sub-calibrated projectile comprises an extension receiving a tail unit movable between a folded position against said extension and a deployed position, said sabot maintaining said tail unit in said folded position.

According to one characteristic of the invention, said shoe envelops said tail unit to isolate it in order to prevent contact between said tail unit and said propellant charge.

According to another feature of the invention, the tail unit comprises fins hingedly attached to the extension of the sub-caliber projectile through hinges with axes parallel to the longitudinal axis of the sub-caliber projectile.

According to yet another characteristic of the invention, each of said fins is movable between:

a folded position, in which each fin extends along an outer surface of said sub-calibrated projectile, and
a deployed position, in which each fin extends radially around the extension of the subcaliber projectile.

Advantageously, said hinges are equipped with stops preventing the pivoting of said fins outside an angular range between said folded position and said deployed position. If necessary, keys can be used to prevent the fins from closing in the path.

According to yet another characteristic of the invention, the tail unit has, in said deployed position, a diameter greater than the caliber.

Advantageously, the case consists of a substantially cylindrical envelope, one end of which is closed by a base, and the other end is equipped with a guide ring, in which said projectile is engaged.

According to yet another characteristic of the invention, the sabot has, over at least part of its length, a substantially cylindrical outer section in caliber and a substantially cylindrical outer section in caliber over the entire length of said subcaliber projectile.

According to yet another characteristic of the invention, the extension of the sub-caliber projectile has flat faces aligned with the longitudinal axis of the sub-caliber projectile on which the fins are folded in the folded position.

Other characteristics, details and advantages of the invention will emerge more clearly from the detailed description given below for guidance in relation to drawings in which:

FIG. 1 shows in axial section a munition according to one embodiment of the invention;

FIG. 2 shows the projectile assembly of the ammunition of FIG. 1, part of the sabot of which has been removed to allow the sub-calibrated projectile to be seen;

FIG. 3 represents the sub-calibrated projectile of the ammunition of FIG. 1, outside the sabot;

Figure 4 is a cross section of the projectile assembly of the ammunition of Figure 1, at the tail of the subcaliber projectile;

FIG. 5 is a cross section of the sub-calibrated projectile of the munition of FIG. 1, outside the sabot, at the level of its deployed tail.

DESCRIPTION DETAILLEE DE MODES DE REALISATION DE L’INVENTIONDETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention will now be described in further detail.

Figure 1 shows, in sectional view along the longitudinal axis, a telescoped type ammunition 1. Such ammunition comprises a case, consisting of a cylindrical casing 2, closed by a base 3 and a guide ring 6.

The base 3 closes the rear end of the casing 2. It is preferably metallic and carries, in its center, an ignition device 4 of known type, conventionally comprising a primer and an ignition relay (not described). The base 3 is linked to the casing via a lip 5, which may be made of plastic.

The guide ring 6 is placed at the front end of the casing 3. It is preferably made of plastic and is reinforced by a metal ring 7. This guide ring 6 has a tubular shape, which defines an axial bore, the caliber of the weapon intended to fire the ammunition.

The ammunition case 1 comprises a propellant charge 8 surrounding a projectile 9 consisting of a sub-calibrated projectile 16 which is integrated in an ejectable segmented sabot 11, the front end of which is at the caliber of the weapon and is engaged in the axial bore of the guide ring 6.

The projectile 9 is also shown, outside the case, in Figure 2. In this figure, however, only half of the sabot 11 is shown, so as to make the subcaliber projectile 16 visible.

This projectile 9 is intended to be propelled out of the ammunition case 1, after it has passed through the barrel of the weapon, under the effect of the pressure generated by the combustion of the propellant charge 8.

The sabot 11, which may be aluminum, has a generally cylindrical outer shape, the caliber of the barrel of the weapon in which it must engage. In a manner known per se, this shoe 11 consists of several segments, four segments in the embodiment shown, which are separable from one another at the outlet of the tube. In Figure 2, only two of these segments are shown.

These four segments are kept in contact with each other, and against the sub-calibrated projectile 16, by a skid belt 12 (not shown in FIG. 2) fitted in a peripheral bore of the sabot 11, near the front end. of this shoe 11.

This slip belt 12 is preferably formed from a plastic material allowing it to deform when the shoe 11 passes through the axial bore of the guide ring 6, then in the barrel of the weapon. In a known manner, the skid belt 12 then seals between the projectile assembly 9 and the barrel of the weapon. When the barrel of the weapon is scratched, this slip belt 12 can also impart to the projectile assembly 9 a rotation imparted by the helical stripes of the barrel.

As it exits the barrel of the weapon, the segments forming the sabot 11 tend to move apart from each other, under the effect of centrifugal force or aerodynamic forces. This separation leads to the rupture of the skid belt 12, and the separation of the segments of the sabot 11 from the sub-calibrated projectile 16, which then continues its trajectory. The slip belt 12 can have, in a known manner, rupture initiators facilitating this separation.

The segments of the sabot 11 are also held in contact with each other, and against the sub-caliber projectile 16, by a retaining ring 13 (not shown in FIG. 2) fitted in a peripheral bore of the sabot 11 close to the 'rear end of this shoe 11. In the same way as the slip belt 12, this retaining ring 13, preferably of plastic material, is intended to break during the separation of the segments of the shoe 11.

The sabot 11 has an axial bore shaped to receive and hold the sub-calibrated projectile 16.

This subcaliber projectile 16 is shown, apart from the sabot 11, in Figure 3. It extends along a main axis, which corresponds to the firing axis of ammunition 1.

The subcaliber projectile 16 is formed of several components assembled together. At its front end, it has an ogive 14, preferably metallic. In the embodiment shown, this warhead is made of aluminum, and is provided with small-scale canard planes intended to participate in guiding the sub-calibrated projectile 16 towards the target.

The axial bore of the shoe 11 has, at the level of this ogive 14, an enlarged diameter making it possible to surround these duck planes.

The warhead 14 is assembled on the front of a projectile body 15, preferably made of a metallic material such as tungsten. This projectile body 15 is followed by an extension 10 and has an internal chamber 16 in which can be placed a charge, such as an explosive charge or electronic components, for example projectile guidance. The outer surface of this projectile body 15 has a thread, or peripheral grooves. The axial bore of the shoe 11 preferably has, at the level of this projectile body 15, a shape complementary to this thread or these grooves, in order to secure the shoe 11 to the sub-calibrated projectile 16, in the axial direction.

This internal chamber 18 is closed at the rear by a plug 17.

The axial bore of the shoe 11 is itself closed, at the rear by the stopper 17 protecting the rear of the sub-calibrated projectile 16. This stopper 17 can be held by the segments of the shoe 11. Preferably, it is also fixed to the ignition device 4, which makes it possible to maintain the projectile assembly 9 in the correct position in the case.

During the combustion of the propellant charge, the increase in pressure in the ammunition causes the rupture of this attachment, to allow the closure plate to be propelled into the barrel of the weapon, with the projectile assembly 9.

On the extension 10 close to the rear end of the sub-calibrated projectile 16, there is provided an empennage 19 which in the embodiment shown consists of four

fins

19a, 19b, 19c and 19d distributed angularly around the tail of the projectile under -calibrated 16. Each fin is positioned in the folded position on a flat surface provided at the level of the extension 10. FIG. 3 shows the flat surface 21 onto which the fin 19c can be folded into the folded position.

It goes without saying that this stabilizer 19 is deployable, the

fins

19a, 19b, 19c and 19d being movable between a folded position and a deployed position.

The tail unit 19 is thus shown in its folded position in Figures 1 and 2, as well as in Figure 4 which is a cross section of the projectile assembly 9, at the level of the extension 10 carrying this tail.

The tail unit 19 is instead shown in its deployed position in Figure 3 as well as in Figure 5, which is a cross section of the sub-calibrated projectile 16 at the level of the extension 10 carrying this tail.

To be movable between these two positions, the

fins

19a, 19b, 19c and 19d forming the tail assembly 19 are each pivotally mounted, on the extension 10 of the sub-calibrated projectile 16, around a hinge, respectively 20a, 20b, 20c and 20d, the axes of which are substantially parallel to the longitudinal axis of the sub-calibrated projectile 16.

Preferably, as shown in Figures 5 and 6, the extension 10 of the projectile 9 has in section, at the tail section 19, a substantially square outer section. The hinges, respectively 20a, 20b, 20c and 20d, of the

fins

19a, 19b, 19c and 19d, are placed along the edges of this square section, so that each

fin

19a, 19b, 19c and 19d can, in its folded position, extend against each of the substantially planar faces 21 with a square section of the extension 10 of the sub-calibrated projectile 16.

Preferably, the internal shape of the axial bore of the shoe 11 matches, at the level of the tail assembly 19, the shape of the fins in this folded position, as illustrated in FIG. 4 which shows the

segments

11a, 11b, 11c and 11d of the shoe 11. The shoe 11, when it surrounds the sub-calibrated projectile 16, therefore maintains the

fins

19a, 19b, 19c and 19d of the stabilizer 19 in their folded position on the corresponding flat face 21. This tail unit 19 then has a very small wingspan, less than the caliber of the barrel of the weapon.

When, at the exit of the barrel of the weapon, the

segments

11a, 11b, 11c and 11d of the sabot 11 separate from the sub-calibrated projectile 10, the

fins

19a, 19b, 19c and 19d are no longer maintained in their folded position . These

fins

19a, 19b, 19c and 19d then pivot, around their

respective hinges

20a, 20b, 20c and 20d, to their deployed position.

Preferably, this pivoting takes place under the effect of centrifugal force, as well as under the effect of aerodynamic forces, the pivoting of each fin from its folded position towards its deployed position being in a direction opposite to the direction of rotation. of projectile 9 in the air. It is also possible, in other embodiments, for springs to be provided to drive the fins from their folded position to their deployed position.

In their deployed position, the

fins

19a, 19b, 19c and 19d preferably extend in a radial direction, relative to the longitudinal axis of the sub-calibrated projectile 16. The

hinges

20a, 20b, 20c and 20d are advantageously equipped stops preventing the

fins

19a, 19b, 19c and 19d from pivoting beyond this radial orientation which corresponds to their deployed position.

In this position of the

fins

19a, 19b, 19c and 19d, the tail unit 19 in the deployed position has a large wingspan, greater than the caliber of the barrel of the weapon. It can then effectively stabilize the sub-caliber 16 projectile which can thus travel a trajectory of great length.

The subcaliber projectile of a telescoped ammunition according to the invention can thus be effectively stabilized by the tail unit while having a large diameter, relative to the caliber of the barrel of the weapon. This peculiarity gives it a higher payload capacity than subcaliber telescoped munitions projectiles of the prior art. For example, in the embodiment shown, the subcaliber projectile has a diameter of about 20 mm, while the diameter of the weapon is 40 mm.

The solution of the invention therefore enables larger loads to be carried in a telescoped ammunition projectile. It also allows this charge to be subjected only to rotation at a relatively low speed, which decreases the risk of malfunction of the charge associated with the rotation of the projectile.

It should also be noted that this solution of the invention makes it possible to use ammunition of relatively low caliber equipped with a deployable tail unit, which therefore comprises small mechanical elements. This implementation is made possible by the fact that the shoe completely envelops the tail unit, in its folded position. When the pressure builds up in the ammunition, the tail unit is thus protected by the sabot, which prevents it from being damaged.

A person skilled in the art will be able without difficulty to make variations on the solution presented, without departing from the scope of the present invention. In particular, he can adapt the solution of the invention to telescoped type ammunition of various calibers.

It can also implement the deployable tail unit according to the invention with a different number of fins by providing the necessary flat surfaces. Thus, it is possible to manufacture such a tail unit with two or three fins, or with five or even six fins.

In this case, the outer section of the sub-calibrated projectile at the level of the tail unit may be chosen such that each of the fins can, in its folded position, extend against one of the substantially flat outer faces. This section could for example be triangular if there are three fins, pentagonal if there are five fins or hexagonal if there are six fins.

Likewise, it is advantageous that the shoe is divided into a number of segments identical to the number of fins, but it is also possible to provide a different configuration of the shoe. It is thus possible, for example, to assemble a sabot divided into three segments on the sub-caliber 16 projectile which carries four fins. The three segments will then have to be machined so as to form together a shoe whose axial bore will have a shape complementary to the shape of the tail unit in the folded position.

Claims

Telescoped type ammunition (1), comprising a case (2) inside which are housed a sub-calibrated projectile (16) equipped with a segmented ejectable sabot (11), a propellant charge (8) and a device for 'ignition (4) of the propellant charge, characterized in that said sub-calibrated projectile (16) comprises an extension (10) receiving a tail unit (19) movable between a folded position against said extension and a deployed position, said sabot (11 ) maintaining said tail (19) in said folded position.
Ammunition (1) according to claim 1, characterized in that said sabot (11) envelops said tail unit (19) to isolate it in order to prevent contact between said tail unit (19) and said propellant charge (8).
Ammunition (1) according to claim 1 or 2, characterized in that said tail unit (19) comprises fins (19a, 19b, 19c, 19d) fixed in an articulated manner with respect to the extension (10) of the sub-calibrated projectile (16 ) by means of hinges (20a, 20b, 20c, 20d) of axes parallel to the longitudinal axis of the sub-calibrated projectile (19).
Ammunition (1) according to claim 3, characterized in that each of said fins (19a, 19b, 19c, 19d) is movable between: a folded position, in which each fin (19) extends along an outer surface of said sub-caliber projectile (16), and a deployed position, in which each fin (19) extends radially around the extension (10) of the sub-caliber projectile (16).
Ammunition (1) according to claim 4, characterized in that said hinges (20a, 20b, 20c, 20d) are equipped with stops preventing the pivoting of said fins (19a, 19b, 19c, 19d) outside an angular range included between said folded position and said deployed position.
Ammunition (1) according to any one of the preceding claims, characterized in that said tail unit (19) has, in said deployed position, a diameter greater than the caliber.
Ammunition (1) according to any one of the preceding claims, characterized in that said case consists of a substantially cylindrical casing (2), one end of which is closed by a base (3), and the other end is equipped with a guide ring (6), in which is engaged said projectile (9).
Ammunition (1) according to any one of the preceding claims, characterized in that said sabot (11) has, over at least part of its length, an outer section which is substantially cylindrical in caliber.
Ammunition (1) according to the preceding claim, characterized in that said sabot (11) has a substantially cylindrical outer section in caliber over the entire length of said sub-caliber projectile (16).
Ammunition (1) according to any one of the preceding claims, characterized in that the extension (10) of the sub-calibrated projectile (16) comprises flat faces (21) aligned with the longitudinal axis of the sub-calibrated projectile on which the fins (19) are folded in the folded position.