EP0144293A1

EP0144293A1 - A device for the mutual drawing away of the submunitions of spinless subammunition projectiles

Info

Publication number: EP0144293A1
Application number: EP84830249A
Authority: EP
Inventors: Rodolfo Andreetta
Original assignee: Simmel Difesa SpA; Simmel SpA
Current assignee: Simmel Difesa SpA
Priority date: 1983-11-30
Filing date: 1984-09-10
Publication date: 1985-06-12
Also published as: ES538080A0; DE3473918D1; IT1167034B; ATE37085T1; IT8323946A0; ES8700424A1; EP0144293B1

Abstract

A device for the mutual drawing away of the submunitions of a subammunition spinless projectile (1) comprises at least one flat spring (4) for each layer of submunitions (2). This spring (4) is disposed under preloaded condition between the submunitions (2), in contact at least with some of them and is adapted to stretch out when the submunitions (2) are ejected from the projectile (1) and to draw mutually said submunitions (2).

The device according to the invention makes it possible to substantially increase the coverage on the ground of an individual subammunition projectile (1).

Description

The present invention relates to spinless subammunition projectiles of the type of the mortar bombs or warheads, in which the submunitions are disposed in parallel layers, and more particularly to a device for the mutual drawing away of the submunitions once they have been ejected from the projectile in which they were contained.
It is known that, f.e., mortar shots are fired by smoothbore barrels which do not cause any spin effect. As a result, it is impossible to utilize centrifugal forces for separating parts, f.e. submunitions, intended to be mutually drawn away.
The same applies to warheads for missiles.
It is also known that the simple ejection of the composite subammunition contents from the projectile does not permit per se the achievement of the desired effect on ground, i.e. the coverage of an ample ground area, if no mutual drawing away of the submunitions is carried out, inasmuch as in this case the centri fugal component which ejects radially such submunitions does not intervene.
At the present state of the art one relies on the randomness of the distribution of the submunitions, possibly assisted by the aerodynamic effects of the armament straps of the submunitions or other similar devices provided thereon. These arrangements, however, are not normally sufficient to obtain a good distribution of the submunitions so as to cover an ample ground area.
It is the object of the present invention to eliminate this serious disadvantage of the prior art by providing a device which makes it possible to mutual ly draw away the submunitions once the projectile is ejected and to obtain a good distribution of the submunitions and to cover a ground area which is notably ample with respect to the ground area covered by the subammunition projectiles of the prior art.
More particularly, the device for mutually drawing away the submunitions according to the invention is characterized in that it comprises at least one flat spring for each subammunition layer, said spring being disposed under preloaded conditions among the submunitions, in contact at least with some of them, and being adapted to stretch out when the submunitions are ejected from the projectile thus drawing away ra dially the submunitions from one another.
The invention will be better understood from the following description, given merely as an example and therefore in no limiting sense, of two embodiments thereof, referring to the accompanying drawings in which:

Fig. 1 shows a subammunition projectile of the spinless type, partially cut away to show the arrangement of the subammunition inside it;
Fig. 2 is a cross-sectional view thereof taken along the line 2-2 of Fig. 1;
Fig. 3 shows the operation at the opening step of the device according to the invention in the case of the projectile of Figs. 1 and 2 in which three submunitions in each layer are provided;
Fig. 4 is a side view of only the flat spring of Fig. 3, seen at the same moment illustrated in Fig. 3; and
Fig. 5 shows the operation, at the opening step, of a change in the device according to the invention, in the case in which five submunitions in each layer are present.

In Figs. 1 and 2 there is shown a subammunition projec tile, of the spinless type, provided with the device for the mutual drawing away of the submunitions according to the invention. In said projectile 1 the submunitions 2 are disposed in five layers, each layer consisting of three submunitions 2. The submunitions of each layer are kept in position by three spacer elements 3, generally of plastic material shaped so as to mate the outer surface of the submunitions 2 and the inner surface of the shell of the projectile 1. These elements 3 are not indispensable and anyway we will consider them as a part of the shell of the projectile 1 and not as a part of the de vice for the mutual drawing away of the submunitions 2.
Disposed between the submunitions 2 of each layer is a flat spring 4, in the preloaded state, shaped as illustrated in Fig. 2, where the spring 4 encompasses almost completely the uppermost submunitions and partial ly the other two lower submunitions. This spring 4 is nothing but a piece of spring steel strip and has nor mally a constant width and thickness. It may, as well, however, for particular requirements, have a variable width: and/or thickne ss.
The springs 4 are disposed normally substantially in the central portion of each layer of submunitions 2 even though it is not impossible that, in order to ob tain particular effects, f.e. a spin of the submunitions, this position may be not central.
While not indispensable for the operation of the devi- oe according to the invention, the spacer elements 3 have on their concave faces, turned towards the submunitions 2, grooves adapted to receive the spring 4.
Let us see briefly now how the device for mutually drawing away the submunitions shown in Figs. 1 and 2 operates.
Once the projectile 1 has been thrown and has reached a predetermined point of its trajectory, the action of an ejection charge intervenes which is normally enclosed in the tip 5 of the projectile 1. The action of this ejection charge causes the tail 6 of the projectile 1 to detach and ejects successively the various layers of submunitions 2 from the rear side of the projectile 1. Once a layer of submunitions 2 has been ejected, the spring 4 is free to act, whereby, because of the action of the spring, the various submunitions are thrown radially with respect to the tra jectory of the projectile 1. The first steps of the stretching out of the spring 4 and of the mutual drawing away of the three submunitions forming one layer are shown diagrammatically in Fig. 3, in which, for the sake of clearness, the longitudinal dimensions of the spring 4 have been partially altered. The arrows of Fig. 3 indicate the projection directions of the individual submunitions under the action of the sprig 4.
Fig. 4 is a side view, looking from the bottom of the drawing sheet, of the sole spring 4 at the same instant shown in Fig. 3.
In the embDdiments illustrated so far there are only three submunitions for each layer. It is apparent that the number of submunitions can be even higher. In particular, in Fig. 5 there is shown a situation similar to that of Fig. 3, in which, however, the submunitions of each layer are five. Also in this figure, for the sake of clearness, the longitudinal dimensions of the spring 4 have been partially altered.
From the above stated it is apparent that the conformation of the spring can be fitted, within certain limits, to a number of submunitions different from that of the two embodiments described. In the case in which the submunitions in each layer are quite a lot, it may be possibly made recourse to the use of two or more springs to obtain the desired drawing away effect of the submunitions.
Always in the case of a plurality of submunitions in each layer, it will be in addition possible to streng then some sections of the spring, f.e. by changing its length,__Bo that some submunitions receive a radial thrust higher than the others, or it can be arranged that only the central submunitions of the layer undergo the action of the spring 4, while the other more outer will be pushed radially by the action of said more inner submunitions. In other words, it is not required that all submunitions 2 contact the spring 4 to have the desired radial thrust effect.
It is apparent from the above stated that the conforma tion of the spring used,conditions the mutual radial throw direction of the individual submunitions. Therefore, this conformation of the spring must be studied so as to obtain a good radial distribution of the throw directions of the subamunitions.
It has been spoken up to now about a spinless projectile, of the type used in mortars, and this because the device for the mutual drawing away of the submunitions according to the invention has been studied particularly for these types of projectiles. However, the device according to the invention can be also used in subammunition projectiles provided with a spin in which the effect of the centrifugal force is insufficient to obtain the desired distribution of the submunitions on the ground.
From the above stated it appears that by means of the device according to the invention there is obtained a substantial increase in the coverage on the ground of an individual subammunition projectile, whereby the efficiency of the subammunition projectile is substantially improved.

Claims

1. Device for the mutual drawing away of the submunitions of a subammunition spinless projectile or a subammunition warhead in which the submunitions are disposed in parallel layers, characterized in that it comprises at least one flat spring for each subammunition layer, said spring being disposed under preloaded conditions among the submunitions, in contact at least with some of them, and being adapted to stretch out when the submunitions are ejected from the projectile thus drawing away radially the submunitions from one another.

2. Device as claimed in claim 1, characterized in that the flat spring encompasses a portion of the side sur face of the submunitions with which it is in contact.

3. Device as claimed in the preceding claims, characterized in that the flat spring is also in contact with the inner wall of the projectile.

4. Device as claimed in claims 1 and 2, characterized in that the flat spring is in contact with the spacer elements disposed between the inner wall of the projectile and the submunitions.

5. Device as claimed in claim 4, characterized in that the spacer elements disposed between the inner wall of the projectile and the submunitions have on their concave faces in contact with the submunitions grooves adapted to receive the flat spring.

6. Device as claimed in any of the preceding claims, characterized in that the flat spring has a variable width.

7. Device as claimed in any of the preceding claims, characterized in that the flat spring has a variable thickness.