GB2039008A

GB2039008A - Improved tandem hollow explosive charges

Info

Publication number: GB2039008A
Application number: GB7944092A
Authority: GB
Original assignee: Luchaire SA
Current assignee: Luchaire SA
Priority date: 1979-01-05
Filing date: 1979-12-21
Publication date: 1980-07-30
Also published as: CH635422A5; GB2039008B; DE3000036A1; DE8000028U1; FR2445945B1; FR2445945A1; BE880990A

Abstract

An explosive system intended more particularly for anti-tank projectiles of the weapon-fired or hand grenade type has two hollow charges a and b of unequal size disposed in tandem and operating in cascade, one charge a operating first and constituting the exciter charge located at the rear of the main charge b to be fired thereby, the latter comprising a central aperture c through which the jet from the exciter charge is transmitted to the main charge through a pyrotechnical relay i acting as an accelerator or a retarder respectively according as the exciter charge passes through the aperture and is energized by the jet of the main charge, before the passage of the exciter charge core, or according as the coreless exciter charge jet precedes the main charge jet. <IMAGE>

Description

SPECIFICATION Improved tandem hollow explosive charges The invention relates in general to explosive systems, notably for antitank projectiles which are usually enclosed in the ogives thereof, said systems comprising at least two hollow tandem charges of unequal power and operating in cascade, one charge being fired by the detonation wave produced by the other charge, so-called exciter charge.

In known explosive systems of this character the smallest charge, disposed in general in the projectile ogive, operated first. The second hollow charge having substantially the same crosssectional size as the projectile becomes operative.

The delay occuring between the two operations in controlled in general by electronic means.

However, these known arrangements are subject to requirements which in many cases are difficult to meet and, in all cases, a source of inconveniences.

Thus, a first requirement is to provide means for dissipating the charge "core" completely before the perforating jet is delivered from the rear or main charge, a feature ratherdifficult to obtain.

Furthermore, a perfect alignment between the two charge bodies is necessary, this leading to structures increasing the weight of the ogive, thus detrimentally affecting the ballistic properties of the projectile.

Moreover, these known systems require two separate firing means and also a delay system for firing the main charge which is energized from a special power source, thus increasing their complication and cost.

Finally, these known projectiles prevent the front hollow charge from operating at its optimal effective distance for at the impact time it is generally too close to the target.

With the present invention the above-described drawbacks and limitations are eliminated.

The invention consists essentially in reversing the relative position of the two tandem charges, i.e. by disposing the exciter charge, which operates first, at the rear end of the main charge, so that the detonation wave of the exciter charge which causes the operation of the main charge is transmitted to the latter through a pyrotechnical relay advantageously protected by screen means.

The various features and advantages of the present invention will appear as the following description proceeds with reference to a typical form of embodiment thereof, it being understood that this form of embodiment is given by way of illustration, not of limitation, and that many other shapes, proportions and relative arrangements of parts could be adopted without departing from the basic principies of the invention.

This description is made with reference to the single Figure of the attached drawing showing in longitudinal axial section a hollow tandem-charge projectile arranged according to the teachings of the invention.

Through the exemplary form of embodiment illustrated and described herein refers to an antitank rifle grenade, it will readily occur to those conversant with the art that the invention is applicable to any type of projectile, irrespective of its intended purpose.

The explosive charge of the grenade according to the form of embodiment of the invention illustrated in the drawing comprises a pair of tandem hollow charges a and b operating in the cascade fashion.

According to this invention, the charge a, which is the exciter charge, intended to operate first, is disposed at the rear end of the main charge b. The jet emitted by the exciter charge a is adapted to pass through an axial opening c formed at the top of its casing and thus penetrates into the explosive body constituting the main charge b.

The assembly comprising the two charges a and b is fired by means of a single priming unit e excited by a detonator fprojecting into the fuse system shown diagrammatically at g.

Advantageously a screen h is disposed between the priming unit e and the exciter charge a. The detonation wave produced by the exciter charge a is transmitted to the main charge b through a pyrotechnical relay protected by a screen.

As a function of the explosive composition selected for the pyrotechnical relay i, the necessary delay preceding the operation of the main charge with respect to that of the exciter charge may be varied as desired.

Two possibilites are available, according as the pyrotechnical relay acts an an "accelerator" or as a "retarder" with respect to the priming of the main charge by the exciter charge: 1) The jet from the exciter charge passes through the aperture of the main charge and is then enlarged by the hollow charge jet of this main charge, before the passage of the "core" of the exciter charge; 2) Alternatively, the coreless jet from the exciter charge is produced before the main charge jet.

In addition to the flexibility of use and the eliminations of a priming device, the structure according to this invention is characterized by the following advantages: In the case of a compound armor-plating illustrated diagrammatically at 1 and 2 in the drawing both the exciter charge a and the main charge b are located at an optimal active distance a', b', respectively, since they lie in the areas corresponding to their maximal efficiency as a function of distance.

On the other hand, the two casings are maintained by a rigid sheath k connected at one end of the base fuse g and at the opposite end to the ogive m. Therefore, it is possible by construction to obtain a perfect alignment of the two casings by using particularly simple means, so that it is unnecessary to complicate the ogive structure with centering means, the only function of the ogive in the present invention being its primary and essential function, i.e. imparting a proper streamlining to the projectile.

Of course, this invention should not be construed as being strictly limited by the specific forme, of embodiment illustrated and described herein, since many modifications may be brought thereto without departing from the basic principles of the invention, some of these possible changes applying more particularly to the casing shape, the relative importance of the exciter and main charges, the use of priming means with or without screens, the shape of the pyrotechnical relay, etc. Moreover, this invention is also applicable to any projectile, whatever its conception and intended purpose.

Claims

1. An explosive system, more particularly for antitank projectiles, which comprises at least two hollow charges of unequal size, disposed tandemwise and operating in cascade, one charge being adapted to be fired by the detonation wave from the other, so-called "exciter" charge operating first, said exciter charge being disposed at the rear end of the main charge to be fired thereby.

2. An explosive system as claimed in Claim 1, wherein said detonation wave of the exciter charge is transmitted to the other charge through a pyrotechnical relay advantageously protected by a screen.

3. A system as claimed in Claim 2, wherein the jet from the hollow exciter charge passes through an opening formed in the casing and the body of the other charge.

4. A system as claimed in Claim 3, wherein the composition of said pyrotechnical relay is such that it acts as an accelerator or as a retarder according as the exciter charge jet passes through the aperture of the other charge and is energized by the jet of said other charge, before the passage of the exciter charge core, or according as the jet of the exciter charge without core precedes the jet of the other charge.

5. A system as claimed in Claim 4, wherein a single priming device is provided for firing both charges.

6. A system as claimed in Claim 5, wherein said single priming device consists of a frustoconical annular body separated by a screen from said excite charge.

7. A system as claimed in Claim 6, wherein said tandem-arranged charges are cont < .ined in a casing cr necking the ogive to the base fuse nf the carrier projectile.

8. A projectile, notably an antitank projectile, of any type, whether self-propelled or not, wherein the explosive charge consists of an explosive system according to any of the preceding claims.