GB2129105A - Recoilless weapons - Google Patents

Abstract

A reaction mass (7) for recoilless weapons comprises a front particle reaction mass (12) and a rear liquid reaction mass (11). The particle (e.g. steel grit) reaction mass (12) retards the extinction of the powder gasses by the liquid (e.g. alkaline solution) (11) in such a way as to achieve more effective extinction from the internal ballistic point of view, and avoiding forward projection of the liquid into the loading chamber which can occur when the powder gases are extinguished too early, thereby imparing the function of the weapon. Pressure distributing layers (16, 17) of cellular plastic are disposed between a curved steel wall (15) sealing an outer capsule (14) and a reaction mass container (13), and between the two reaction mass containers (10, 13), which containers are housed within the capsule (14) and contain the particle and liquid reaction masses (11, 12) respectively. <IMAGE>

Description

SPECIFICATION Reaction mass for recoilless weapons The present invention relates to a reaction mass for recoilless weapons consisting of at least one liquid mass intended to be placed behind a propellant charge for the weapon's projectile and intended to be ejected backwards from the weapon essentially concurrently with the projectile being fired forwards, said liquid mass being capable of being dispersed by the powder gases from the propellant charge, thereby contributing to the extinction of the powder gases.

In order to achieve freedom from recoil in weapons, it has been customary to place an extra powder charge behind the projectile and to allow the gas produced to rush out backwards through a discharge nozzle. This produces a backwarddirected movement quantum (weight times speed) which can be so arranged as to equal that of the forward-travelling projectile. However, a "backblast" weapon of this kind does not allow the firing of large-calibre projec'tiles, as this would create an inconveniently high pressure behind the weapon for the firer.

In order to increase the backward movement quantum and in so doing to permit an increase in the weight of the projectile without producing excessively high pressure behind the weapon, it has been customary in recent years to place a socalled reaction mass behind the projectile, which is made to rush backwards out of the barrel at the time of firing the projectile. The reaction mass is usually executed in such a way that it is vaporized or is pulverized to a harmless dust behind the weapon. The pressure behind such a weapon has been found to be relatively iow and to cause no inconvenience to the firer.

A further advantage of reaction mass weapons compared to backblast weapons is the considerable reduction in the flash to the rear. The position of reaction mass weapons is thus more difficult to locate.

In order to obtain proper extinction of the backward-rushing powder gases, the reaction mass has often been in the form of a liquid, usually a saline solution. It has been found, however, that the liquid in conventional reaction mass weapons causes the powder gases to be extinguished far too early. This has sometimes resulted in the liquid being projected forwards into the loading chamber, thereby impairing the function of the weapon.

A principal object of the present invention is, therefore, to propose a reaction mass which will extinguish the backward-rushing powder gases at a later stage, said extinction being more effective from the internal ballistic point of view than that achieved by the use of conventional liquid reaction masses. This object is achieved in accordance with the invention by retarding the extinction of the gases by placing between the propellant charge and the liquid mass at least a second reaction mass composed of solid particles which is capable of being dispersed by the powder gases.

The invention is described in greater detail below with reference to the enclosed drawing.

Figure 1 shows a longitudinal section, viewed from the side, of the rear part of a recoilless weapon equipped with a preferred embodiment of the reaction mass in accordance with the invention. Figures 2-4 show in diagrammatic form three modified embodiments of a reaction mass in accordance with the invention.

Figure 1 provides a schematic view of the rear part of an antitank gun with a barrel 1 into which a conventional projectile 2 (part of which is shown here) with a girdle 3 and a projectile capsule 4 containing a propellant charge in the form of a powder charge 5 has been introduced into its loaded position. The gun also has an end piece or bolt 6 inside which is located a reaction mass in accordance with the invention identified by the general designation 7. The firing direction of the weapon is indicated in Figure 1 by an arrow at the top of the drawing. Pursuant to international patent regulations, which stipulate that drawings shall appear in a standing format, the antitank gun in Figure 1 is shown pointing upwards, whereas in active service when supported against the firer's shoulder it would normally be aimed essentially horizontally.When comparing the reaction mass in Figure 1 with the reaction masses in Figures 2-4 the sheet bearing the drawing for Figure 1 must, therefore, be turned to a landscape format so that the upwards-pointing projectile 2 in Figure 1 points to the left.

The antitank gun exhibits in a conventional fashion a handle 8 for opening (unscrewing) and closing the bolt 6, so that the projectile 2 with the capsule 4 and the reaction mass 7 can be introduced into the barrel 1 and into the bolt 6.

The base of the projectile 2 is executed in a previously disclosed fashion as a bottom plate 9 which will burst as a predetermined gas pressure is reached inside the capsule 4.

The reaction mass 7 consists on the one hand of a rear reaction mass component (viewed in the firing direction of the weapon) in the form of a plastic container 10, which is preferably completely filled with a liquid 11, e.g. a saline solution, having a density preferably rather higher than 1.0 kg/dm3, e.g. approximately 1.25-1.50 kg/dm3, and on the other hand of a front reaction mass component in the form of a plastic container 1 3 preferably completely filled with particles 12, most suitably grit and preferably steel grit. The density of the particles 12 should preferably be higher and preferably several times higher than the density of the liquid mass 10.

The containers 10 and 13 are enclosed within a common, preferably metallic, polytetrafluoroethylene-lined, capsule 14, e.g.

made of aluminium. The front part of the capsule 14, e.g. the part facing the projectile 2, is sealed by means of a curved steel wall 15, the curved side of which faces the front reaction mass container 1 3. A pressure-distributing layer 1 6 of cellular plastic is placed between the wall 1 5 and the reaction mass container 13. A similar pressure-distributing layer 1 7 is likewise placed between the reaction mass containers 10 and 13.

The edge of the capsule 14 facing the steel wall 15 is expanded to form an annular collar 18 which together with an annular flange 19 on a pressureabsorbing ring 20 fitting against the capsule 14 is located in a U-shaped curved front edge 21 on the steel wall 1 5. This arrangement ensures that the capsule 14 and the wall 1 5 bear tightly against the projectile cover 4 when the bolt 6 is closed.

This sealing function is reinforced by arranging the ring 20 so as to taper towards the rear, giving it a conical, pressure-absorbing surface 22 on which the gases of the powder charge 5 are intended to exert a pressure.

The rear wall of the capsule 14 is spherically rounded and is provided with fractural impressions 23 in the form of a circular arc.

On firing the antitank gun, the powder charge 5 is ignited in a conventional manner (not shown here) in the projectile capsule 4. As a certain pressure is reached inside the capsule 4, the release resistance of the girdle 3 is overcome so that the projectile 2 is ejected. The bottom plate 9 bursts simultaneously so that the powder gases also rush backwards towards the wall 1 5 which when bursts and penetrates the cellular plastic layer 1 6. The layer 1 6 prevents the wall, as it bursts, from penetrating the reaction mass container 13 and distributes the gas pressure over the whole of the front wall of the container 13 facing the wall 1 5.

Because of the pressure which the powder gases exert on the reaction mass, the rear wall of the capsule 14 is split along the fractural impressions 23 so that the reaction mass containers 10 and 13 may pass out of the capsule 14. Initially the reaction mass container 13 will at this stage like a sabot propel the liquid reaction mass container 10 ahead of it. Quite soon, however, the wall of the plastic containers 10 and 13 will be destroyed, when the particles 12 will break through the cellular plastic layer 17 and will mix with the liquid 11, thereby extinguishing the powder gases. The whole extinction process described here takes place rapidly, and extinction is by and large complete before the reaction mass has left the bolt 6.

A number of alternative, relative positions of the liquid and the particles of the reaction mass are possible within the idea of invention. A number of examples of such alternative positions is illustrated schematically in Figures 2-4, which show longitudinal sections through the reaction mass. In these Figures the firing direction of the projectile is marked by an arrow on the left-hand side of the Figure. Furthermore, the sparsely hatched sections in Figures 2-4 denote liquid, the more densely hatched sections denote particles and the dotted sections denote a mixture of particles and liquid.

In Figure 2 the reaction mass thus consists of a rear liquid section, a front particle section and an interjacent section containing liquid mixed with particles. The liquid in the interjacent section should preferably be viscous, e.g. in the form of a gel, in order to ensure that the particles remain evenly distributed throughout all the liquid. The liquid in the rear container may in this case be either a saline solution or similar, as in the embodiment illustrated in Figure 1, or of the same nature as that contained in the interjacent section in Figure 2, e.g. of a viscous nature.

In Figure 3 the liquid is contained in a number of plastic ampoules which are embedded in a particle section. In this embodiment it is important that the particles and the liquid be distributed as evenly as possible over the cross-section of the entire reaction mass, so that a uniform pressure distribution is achieved within the reaction mass.

In Figure 4 the reaction mass is composed of four reaction mass sections arranged one after the other, consisting of liquid, particles, liquid and particles, in that order, starting from the back.

In the embodiment shown in Figure 1 , the reaction mass 7 is executed as a separate unit.

Nevertheless, it is conceivable within the idea of invention for the reaction mass to be combined with the charge section of the projectile. This is particularly advantageous in the case of singleshot weapons with a single barrel containing a factory-installed ordinary projectile without capsule.

Claims (10)

1. A reaction mass for recoilless weapons, having at least one liquid mass intended to be placed behind a propellant charge for the weapon's projectile and intended to be ejected backwards out of the weapon essentially at the same time as the projectile is fired forwards, said liquid mass being capable of being dispersed by the powder gases from the propellant charge, thereby contributing to the extinction of the powder gases, characterized in that the reaction mass also has at least one second reaction mass arranged to retard extinction of the powder gases by the liquid mass, the second reaction mass consisting of solid particles and being capable of being dispersed by the powder gases, and being positioned so as, in use, to lie between the propellant charge and the liquid mass.

2. A reaction mass according to claim 1 wherein particle reaction mass extends beyond the liquid mass so that it at least partiy surrounds it.

3. A reaction mass according to claim 2 having a second liquid mass, and an additional particle reaction mass between the first and second liquid masses.

4. A reaction mass according to claim 2 wherein the reaction mass has a plurality of liquid masses embedded in a particle reaction mass.

5. A reaction mass for recoil less weapons, having at least one liquid mass intended to be placed behind a propellant charge for the weapon's projectile and intended to be ejected backwards out of the weapon essentially at the same time as the projectile is fired forwards, said liquid mass being capable of being dispersed by the powder gases from the propellant charge, thereby contributing to the extinction of the powder gases, characterised in that said extinction is so arranged as to be retarded by at least a second reaction mass consisting of solid particles and capable of being dispersed by the powder gases, which second reaction mass is positioned between the propellant charge and the liquid mass.

6. A reaction mass according to claim 5 characterised in that the particle reaction mass section extends beyond the liquid mass so that it at least partly surrounds it.

7. A reaction mass according to any one of the preceding claims characterised in that the particles have a higher density than the liquid mass.

8. A reaction mass for a recoilless weapon substantially as any herein described with reference to the drawings.

9. A capsule or container, insertable into a recoilless weapon and containing a reaction mass according to any one of the preceding claims.

10. Ammunition for a recoilless weapon incorporating a reaction mass according to any one of claims 1 to 8.

1 A one-shot recoilless weapon incorporating a reaction mass according to any one of claims 1 to 8.