WO2012131176A1

WO2012131176A1 - Less lethal weapon projectile

Info

Publication number: WO2012131176A1
Application number: PCT/FR2011/050701
Authority: WO
Inventors: Marwan Dannawi; Jean-François JACQUET
Original assignee: Nobel Sport
Priority date: 2011-03-30
Filing date: 2011-03-30
Publication date: 2012-10-04
Also published as: KR101862435B1; BR112013025291A2; KR20140045932A; CN103688130A; EP2691731A1; SG194090A1; CN103688130B; RU2555254C2; US20140109790A1; ES2556706T3; EP2691731B1; BR112013025291B1; RU2013148139A; ZA201307246B

Abstract

The invention relates to a less lethal weapon projectile having an overall cylindrical shape of longitudinal axis (L) and comprising a front end (4) in the shape of a spherical or approximately spherical cap and a rear end (2). According to the invention, the projectile includes: a core (6) made from aluminium foam, having an overall cylindrical shape centred on the above-mentioned axis (L) and comprising a front end (16) and a rear end (13) with a rear face (14), said front end (16) taking the form of a spherical or substantially spherical cap; a base (5) assembled with the aforementioned rear end (13) of the core (6) and comprising a front wall (9), which is arranged transversely to the axis (L) and which covers the rear face (14) of the core (6); and an outer case (7) that covers at least the front end (16) of the core (6). The centre of gravity and the centre of thrust of the projectile correspond perfectly, so that the projectile has good external ballistics.

Description

PROJECTILE FOR ARMED LETHALITY

The present invention relates to projectiles for a weapon with reduced lethality, capable of impacting a target as would a violent punch while limiting the damage or trauma induced by this impact, particularly on the sensitive and unprotected areas of an individual (especially the head).

ALR (Reduced Lethal Weapon) projectiles are typically used by law enforcement and armed forces in external operations to neutralize or scare off certain individuals, while avoiding harm to them or minimizing injuries or injuries caused.

These projectiles are fired by means of launchers with striped tube of which the most current are with the caliber of 40 mm (designation NATO: 40 mm X 46).

Very generally, these ALR projectiles have a globally cylindrical shape whose length is of the order of 50 to 70 mm and whose diameter, as specified above, is of the order of 40 mm, with a front end in the form of a cap in general half spherical. They are conventionally made by molding thermoplastic foam.

Today, the state of the art is quite poor in the field of the search for new kinetic ammunition with reduced lethality (LR) and in particular in the improvement of the end effect of the corresponding projectiles.

Indeed, previous achievements have striven to make more ductile materials constituting these projectiles thinking that the more the projectile is "soft" less it is lethal. To the applicants' knowledge, no concrete reflection has been made on the understanding of the relationships between physical parameters and lesional effects during the impact of an LR projectile on a human target. The identification of the "good" physical parameter makes it possible to search for relevant technological solutions.

To meet this objective, a study was conducted and demonstrated and validated by tests and simulations:

- that energy is not the universal mechanical parameter of severity

- that this parameter is actually the force at impact.

It is recalled that the control of the low probability of provoking a lethal outcome with a reduced lethal projectile, serious injury or permanent injury to an individual is not easy to obtain because of a physical phenomenon well known to ballists. which is the loss of velocity on the trajectory of the projectile, caused by the resistance of the air to the advancement of the latter. Thus, with the current projectiles, one could have a very low level of efficiency at a distance of 50 m and a level of deleterious effects important to 10 m, which poses enormous employment problems for the forces of the order and the armed forces.

As previously stated, the physical parameter that is important to impact from the point of view of lesional effects is the impact force on the target. In order to improve the effectiveness and non-lethality of the reduced lethal projectiles, the main objective of the invention is to transmit at impact a programmed force which is always the same, or substantially the same, regardless of the terminal speed. , and correlatively regardless of the firing distance (this in conventional speed ranges at the time of impact (ie between about 50 to 100 m / s).

For this, the ALR projectile according to the invention, which has a generally cylindrical shape of longitudinal axis L, comprising a spherical or approximately spherical cap-shaped front end and a rear end, is characterized in that it comprises:

a core made of aluminum foam, which core has a generally cylindrical shape centered on said axis L, comprising a front end in the form of a spherical or substantially spherical cap, and a rear end with a rear face,

- A base assembled with said rear end of the core, which base comprises a wall disposed transversely to said axis L, which covers said rear face of said core, and - an outer envelope from covering at least the front end of said core.

The base of the projectile is deformed during firing by the scratches of the barrel of the weapon which allows the rotation of the projectile.

The aluminum foam core is very lightweight and offers very interesting crushing and energy absorption characteristics, homogeneous and independent of the rate of deformation in all directions; the outer casing makes it possible to optimize the ballistic flight of the projectile and to attenuate the first projectile-target contact at the moment of impact.

The impact force of this projectile is constant or almost constant regardless of its speed (in conventional impact velocity ranges, especially between 50 and 100 m / s). This impact force is in particular a function of the density of the aluminum foam, a parameter chosen according to the desired impact force.

Preferably, the density of the aluminum foam used for the core of the ALR projectile according to the invention is between 30 and 300 kg / m ³ .

The projectile base is advantageously made of thermoplastic material and its thermoplastic foam envelope.

According to an interesting characteristic, the transverse wall of the base is extended rearwardly by a tubular wall, centered on the longitudinal axis L, delimiting an opening rear cavity.

According to a particular embodiment, the transverse wall of the base is extended forward by a tubular extension, centered on the longitudinal axis L, to form a housing for receiving the rear end of the aluminum foam core.

According to yet another particular embodiment, said rear tubular wall, or said front tubular extension, comprises an annular outer guide ring. According to another particular embodiment, the transverse wall of the base is extended forward by an axial pin allowing the centering of the front part of the projectile.

According to yet another feature, the outer casing extends to the rear base to cover the entire exposed face of the core.

In a particularly advantageous embodiment, the rear end of the outer casing has an inwardly directed bead which penetrates an annular receiving groove in the aluminum foam core.

In this case, the front end of the base advantageously covers the rear end of the outer casing, to lock in position said bead in its receiving groove.

In addition, the front end of the base and the rear end of the outer casing preferably cooperate through complementary shoulders.

On the other hand, the core may comprise an axial recess opening into its rear face facing the front transverse wall of the base. This recess allows in particular to program two levels of shock force by selecting two densities of aluminum foam. It can remain as is or be filled by a more or less dense aluminum foam, to program the severity of the shock.

According to another particular embodiment, the projectile comprises an annular narrowing between its front and rear ends, corresponding to a decrease in diameter, which narrows extends forwardly from the front end of the base.

This particularity is intended in particular to avoid contact of the base in inclined shock with the target.

On the other hand, the projectile according to the invention may comprise a reversible deformation material structure, interposed at the front, on the axis L, between the outer casing and the core. This material may be a thermoplastic foam or consist of microbeads.

The base, the core and the outer shell of the projectile are made independently and they are assembled together by any appropriate means.

The invention will be further illustrated, without being limited in any way, by the following description of several possible embodiments, given solely by way of example and represented in the accompanying drawings in which:

FIG. 1 is a perspective view of an ALR projectile according to the invention;

FIG. 2 is an axial sectional view of the projectile of FIG. 1;

- Figure 3 is an axial sectional view of a first embodiment of the projectile according to the invention;

FIG. 4 is a perspective view of a second variant of the projectile according to the invention;

FIG. 5 is an axial sectional view of the projectile of FIG. 4; FIGS. 6 and 7 are curves illustrating the variation of the force during the impact as a function of time for projectiles according to the invention;

- Figure 8 is an axial sectional view of a third variant of the projectile according to the invention.

The projectile ALR 1 illustrated in Figures 1 and 2 has a generally cylindrical longitudinal axis L. Its length may be of the order of 50 to 70 mm and its diameter of the order of 35 to 45 mm.

The rear end 2 of this projectile 1 ends in a plane perpendicular to the longitudinal axis L. At this level, an axial recess 3 opening allows conventional reception of a pyrotechnic propulsion cartridge, or other mode of propulsion. Its front end 4 is shaped spherical cap or approximately spherical.

This projectile 1, symmetrical about its longitudinal axis L, consists of a rear base 5, extended forwardly by a core 6 whose outer face is substantially completely covered by an envelope 7.

The rear base 5 has a cylindrical tubular wall 8, centered on the axis L, which is closed at its front end by a transverse wall 9. The tubular wall 8 is not closed towards the rear, and with the front transverse wall 9, it defines the axial recess 3 above.

Opposite this transverse front wall 9, it is noted that the tubular wall 8 comprises a one-piece annular ring 10 which projects outwardly. The outer surface of this ring 10, of generally cylindrical shape, defines the maximum external size of the projectile and constitutes a guide face inside the barrel of the propulsion weapon.

The outer surface of the tubular wall 5 has a diameter a few millimeters smaller than that of the guide surface of the one-piece ring 10.

On the side of the face 1 1 facing the front end 4 of the projectile, the transverse wall 9 of the base 5 comprises a cylindrical one-piece stud 12, centered on the axis L. This stud 12 has a diameter of the order of half the diameter of the projectile 1; its height is a few millimeters.

The base 5, comprising the tubular wall 8, the transverse wall 9, the ring 10 and the pin 12, is made in one piece by molding thermoplastic material (polycarbonate for example). The density of the thermoplastic material used may be of the order of 1200 to 1600 kg / m ³ .

Its function is to give the projectile a large part of its mass, to allow its propulsion and the connection to the front of the energy absorbing part and programming the impact force. The core 6 of the projectile 1 has a generally cylindrical overall shape centered on the axis L.

Its rear end 13 has a diameter slightly smaller than the diameter of the guide surface of the ring 10 of the base 5, and its rear face 14 is structured to fit the front face of this base 5, with the pin 12.

For this, this rear face 14 extends in the plane of the front face 1 1 of the base 5, and it comprises an axial reservation 15, corresponding to the shape of the post 12.

The front end 16 of the core 6 is in the form of a spherical or substantially spherical cap, centered on the axis L.

This core 6 may have a length of between 30 and 50 mm. It is made of aluminum foam (honeycomb aluminum structure) whose density is advantageously between 30 and 300 kg / m ³ . The length of the core 6 and the density of the aluminum foam used are a function of the desired impact force and the amount of energy to be absorbed. The core 6 is made by molding or any other method of forming or machining the honeycomb materials.

For example, an aluminum foam manufactured by CYMAT Corporation (Canada) under the designation "Cymat stabilized aluminum foam" (registered trademark), or by SHINKO WIRE CO Ltd (Japan) under the designation "Alporas" is used. " (trademark).

Such a core structure 6 has the function of limiting to impact the predetermined shock force in advance during the absorption of energy, regardless of the shock velocity of the projectile. The shape at the front of this honeycomb structure also makes it possible to maintain the rise time of the impact force, up to the nominal level, below the critical bursting value of the scalp, for example.

The rear end 13 of the core 6 is assembled with the front end 11, 12 of the base 5 by any appropriate means, for example by gluing.

The front end 16 of the core 6 is covered by the casing 7 advantageously made of thermoplastic foam; the density of this thermoplastic foam is advantageously between 100 and 150 kg / m ³ . For example, rubber, an EPDM material or a nitrile-teflon (registered trademark) mixture may be used.

This outer casing 7 has a thickness of a few millimeters (for example 1 to 3 mm, advantageously of the order of 2 mm).

In the illustrated embodiment, it covers the entire outer front and side surface of the core 6, with the exception of an annular band 18 of the rear end 13 of said core 6. So that its outer surface is in the extension the outer surface of this annular band "free" 18, the casing 7 is housed in a suitable reserve 19 formed on the outer face facing the core 6. This envelope 7, tube-shaped closed at its front end by a spherical cap or substantially spherical, is fixed on the core 6 by any suitable means, for example by gluing.

The purpose of the envelope 7 is to improve the ballistic flight of the projectile, to avoid, at the first target-projectile contact, the local bursting of the biological material of the target and to allow pre-crushing of the honeycombed aluminum structure.

FIG. 3 illustrates an alternative embodiment of the projectile of FIGS. 1 and 2. The parts identical to the previous embodiment retain the same reference marks to facilitate comprehension.

In the projectile 1 'corresponding, the core 6 has a blind axial recess 20 which opens into its rear face 14. This recess 20 preferably has a cylindrical shape whose diameter corresponds, with the game, to that of the axial pin 12 of the base 5 Its function is to make it possible to achieve during the shock a profile of impact force at two levels programmed in advance, according to the desired severity.

Still in alternative embodiments, the recess 20 can be filled by an added material. This added material may for example consist of a denser aluminum foam than that used for the periphery of the core 6, so as to increase the impact efficiency of the projectile.

For this projectile 1 ', it is noted that the length of the core 6 is less than that of the projectile core 1 of Figures 1 and 2.

Figures 4 and 5 illustrate another possible embodiment of a projectile according to the invention.

Here again, the parts identical to the embodiments of FIGS. 1 to 3 retain the same reference marks to facilitate comprehension.

The corresponding projectile 1 "has a rear base 5, extended forwards by a core 6 of aluminum foam whose outer face is covered by an envelope 7.

It is noted that the tubular wall 8 of the base 5 extends forward, beyond the transverse wall 9, by a tubular monobloc extension 21. The guide ring 10 extends facing the transverse wall 9 of the base 5, on a portion of the tubular wall 8 and on the majority of the length of the extension 21.

This extension 21 and the wall 9 of the base 5 form a housing 22 for receiving the rear end 13 of the core 6. The one-piece stud 12 of the previous embodiments is no longer present.

Again, the core 6 and the base 5 are assembled by any appropriate means, preferably by gluing. On the other hand, in this embodiment, it is noted that the envelope 7 covers the entire exposed surface of the core 6; it extends to the base 5, and in particular to the front end of the extension 21.

The embodiment of FIGS. 4 and 5 is also distinguished from the previous ones, by the presence of a necking 23, corresponding to a decrease in diameter, between its rear ends 2 and before 4.

This shrink 23 has the function of avoiding, in inclined impact of the projectile, the contact plastic-target base, thus avoiding a level of contact force incompatible with the programming of the efforts by the aluminum foam.

It is essentially obtained by a diameter reduction of the rear end 13 of the core 6.

The presence of the necking 23 gives the core 6 a particular longitudinal section, with a rear end 13 of cylindrical shape extended by a front end 16 in the form of bead or bulge, globally spherical.

The surface of the front end 4 of this projectile 1 "is particular: the spherical end surface 4a is extended by a truncated cone surface 4b itself extended by a cylindrical surface 4c (whose diameter corresponds approximately to the diameter of the ring 10) which is further extended by a "reentrant" surface 4d leading to the constriction 23. This particular shape of the front end 4 of the projectile 1 "makes it possible to calibrate the rate of rise in force (level of the force programmed on the time taken to reach it), thus avoiding the local bursting of the biological structures (scalp for example in cranial shock).

The shapes of these projectiles all have a perfect match between their center of gravity and their center of thrust to obtain good outdoor ballistics.

FIG. 6 is a curve showing the variation of the force during the impact as a function of the impact time, for the projectiles 1 and 1 "of FIGS. 1 and 2, on the one hand, and 4 and 5, on the other hand.

We distinguish :

- the rate of climb (constant force a on the rise time b).

This rate of rise must be less than a critical value in order not to burst the biological structures of surface,

- the constant level of force is programmed by the density of the aluminum foam and the geometry of the core.

This level a is calibrated to determine in advance the damage and severity desired.

- the end of the shock ç, always force a constant or substantially constant.

Figure 7 shows the force / time variation for a dual density projectile (as shown in Figure 3). The level d is obtained by the peripheral foam of the nucleus, and the level e is defined by the central core foam whose density is greater than the peripheral foam.

FIG. 8 illustrates yet another possible embodiment of a projectile according to the invention.

In the corresponding figure, the parts identical to the embodiments of Figures 1 to 5 retain the same marks to facilitate understanding.

This projectile 1 "'has a rear base 5 which covers the rear part of a core 6 of aluminum foam whose outer face of the front part is covered by an envelope 7.

The materials used for these different parts 5, 6 and 7 correspond to those described above in relation to the embodiments of FIGS. 1 to 5.

As can be seen in FIG. 8, the envelope 7 covers the front part of the core 6, as far as the base 5.

At its rear end, this envelope 7 comprises a bead 24 projecting inwards, which penetrates into a reservation or annular groove 25 formed in the core 6 of aluminum foam, ensuring the connection between the two elements 6 and 7.

This annular groove 25 of the core 6 extends in a plane perpendicular to the longitudinal axis L of the projectile 1 "'.

At the rear end of the envelope 7, there is still the presence of a shoulder 26, facing outwards, facing the bead 24.

The casing 7 is placed on the front end of the core 6 by force fitting, thanks to the elasticity of the material constituting this casing 7.

On its side, the base 5 has a rear transverse wall 9, extending forwards by a tubular monobloc extension 21 which covers the rear end 13 of the core 6 of aluminum foam.

The inner face of the transverse wall 9 is pressed against the rear face 14 of the core 6. The outer face of the tubular extension 21 comprises the projecting guide ring 10.

At its front end, the extension 21 has an annular shoulder 27 facing inwards. This annular shoulder 27 of the base 5 is complementary to the annular shoulder 26 of the envelope 7.

The base 5 is attached at the rear end of the core 6, after placement of the casing 7.

In this context, its annular shoulder 27 covers the complementary shoulder 26 of the casing 7, so as to lock the casing assembly 7 / core 6.

The base 5 is fixed on the rear end of the core 6 by any appropriate means, preferably by gluing. The inner face of the tubular extension 21 preferably comprises ridges or a set of grooves / ribs that optimize the corresponding bonding.

On the other hand, preferably, the base 5 and the casing 7 are also secured together by gluing, at their complementary shoulders 26 and 27.

After securing, the outer faces of the front end of the base 5 and the rear end of the casing 7 are located in the continuity of one another.

The absence of bonding of the envelope 7 on the front end of the core 6 allows to leave the envelope 7 during crushing and to avoid, or at least limit, the contact between the base 5 and the target , shocks offset from the longitudinal axis L.

If necessary, the tubular wall 21 can extend, rearwardly, beyond the transverse wall 9, to form a rear opening cavity, like the cavity 3 present on the embodiments of FIGS. 5.

As illustrated in Figure 8, the front end of the core 6 may be truncated to allow the positioning of a structure 28 (shown in dashed lines) for damping the shock impact.

This structure 28 can be reported between the casing 7 and the front end of the core 6; it is possible to use any damping material with reversible deformation, for example a thermoplastic foam of suitable hardness, or even microbeads (for example with a diameter of between 0.5 and 2 mm, made of elastomeric material or any other material with reversible deformation ).

In an alternative embodiment, the damping structure 28 can be obtained in one piece with the envelope 7, by the material constituting this envelope 7.

Claims

- CLAIMS -

1. - A reduced lethality weapon projectile, having a generally cylindrical shape of longitudinal axis (L), which projectile (1, 1 ', 1 ", 1"') comprises a front end (4) having a spherical cap shape or approximately spherical and a rear end (2), characterized in that it comprises:

- A core (6) made of aluminum foam, which core (6) has a generally cylindrical shape centered on said axis (L), comprising a front end (16) shaped spherical or substantially spherical cap, and an end rear (13) with a rear face (14),

- a base (5) assembled with said rear end (13) of the core (6), which base (5) has a wall (9) disposed transversely to said axis (L), which covers said rear face

(14) said core (6), and,

an outer casing (7) covering at least the front end (16) of said core (6).

2. - Projectile according to claim 1, characterized in that said core (6) is made of aluminum foam having a density of between 30 and 300 kg / m ³ .

3. Projectile according to any one of claims 1 or 2, characterized in that said base (5) is made of thermoplastic material.

4. - Projectile according to any one of claims 1 to 3, characterized in that said outer casing (7) is made of thermoplastic foam.

5. - Projectile according to any one of claims 1 to 4, characterized in that the transverse wall (9) of the base (5) is extended rearwardly by a tubular wall (8), centered on said axis (L ), delimiting an opening rear cavity (3).

6. - Projectile according to any one of claims 1 to 5, characterized in that the transverse wall (9) of the base (5) is extended forwardly by a tubular extension (21), centered on said axis (L ), to form a housing (22) for receiving the rear end (13) of the core (6) of aluminum foam.

7. - Projectile according to any one of claims 5 or 6, characterized in that said rear tubular wall (8), or said front tubular extension (21), comprises an annular outer guide ring (10).

8. - Projectile according to any one of claims 1 to 7, characterized in that the transverse wall (9) of the base (5) extends forwardly by an axial pin (12).

9. - Projectile according to any one of claims 1 to 8, characterized in that said outer casing (7) extends to the rear base (5) to cover the entire exposed face of the core (6) .

10. - Projectile according to claim 9, characterized in that the rear end of the casing (7) comprises an inwardly directed bead (24) which penetrates into an annular receiving groove (25). formed in the core (6).

1 1. - Projectile according to claim 10, characterized in that the front end of the base (5) is to cover the rear end of the casing (7) to lock in position said bead (24) in said groove (25).

12. - Projectile according to claim 1 1, characterized in that the front end of the base (5) and the rear end of the casing (7) cooperate through complementary shoulders (26, 27).

13. - Projectile according to any one of claims 1 to 12, characterized in that the core (6) comprises an axial recess (20) opening in its rear face (14) facing the front transverse wall (9) of the base (5).

14. - Projectile according to any one of claims 1 to 13, characterized in that it comprises an annular narrowing (23) between its front ends (4) and rear (2), corresponding to a decrease in diameter, which shrinks (23) extends forwardly from the front end (21) of the base (5).

15. - Projectile according to any one of claims 1 to 14, characterized in that it comprises a structure (28) of reversibly deformable material interposed on the axis (L) between the casing (7) and the nucleus (6).