GB2107032A

GB2107032A - Explosive devices

Info

Publication number: GB2107032A
Application number: GB08227666A
Authority: GB
Inventors: Michel Precoul; Jessey Armand De
Original assignee: SERAT
Current assignee: SERAT
Priority date: 1981-10-01
Filing date: 1982-09-28
Publication date: 1983-04-20
Also published as: DE3235404A1; FR2514123B1; GB2107032B; FR2514123A1

Abstract

An explosive device for use against targets in the air or on the ground comprises a casing of generally cylindrical form fabricated from a series of dihedral-section elements 1, e.g. of copper or tantalum, extending axially or helically with respect to the lengthwise axis of the casing and welded, brazed or otherwise secured together side edge to side edge, and an explosive charge 7 disposed within and shaped by the casing. The elements provide external concavities and complementary internal convexities. A priming charge 8 extends axially through the main explosive charge. The casing may comprise two or more portions each formed with external concavities as aforesaid and connected together axially end to end through connecting rings, and in this case the portions are circumferentially staggered in sequence by an angle equal to the pitch angle of the concavities divided by the number of portions. For use against concrete emplacements the casing may have a forward end wall of inwardly directed conical form. Preformed splinter elements 11 in the form of balls or cubes made from steel, tungsten or uranium may be housed in U-shaped pieces 12. <IMAGE>

Description

SPECIFICATION Explosive devices The present invention relates to explosive devices for use against flying or ground targets.

The defence against missiles or very fast travelling aircraft is ever more important and requires explosive devices which are efficient up to passing distances of the order of a metre or a few metres, taking in consideration the guidance system which is used. This efficiency has to result in very considerable damage to or total destruction of the missile or aircraft, capable of interrupting its flight substantially instantaneously. Indeed, a delay of a few seconds could lead, at the high speeds involved, to the final accomplishment of the objective of the opponent even if the missile or aircraft is only slightly damaged.

According to the invention, there is provided an explosive device comprising a metallic casing of generally cylindrical form but extending, viewed in cross-section, in a series of outwardly facing concavities and complementary inwardly facing convexities generating correspondingly shaped surfaces which extend lengthwise of the casing or helically about the lengthwise axis of the casing, and an explosive charge disposed within the casing and having its external surface against and conforming to the internal surface of the casing.

The casing is preferably made of copper or tantalum.

The concavities preferably have a general "V" or dihedral shape, and their angular opening is selected according to the effect which is sought.

The opening is preferably greater than 600 and may be greater than 1000. The casing produces the cutting effects of a dihedral shaped charge.

The casing may be made up from a plurality of axially or helically elongate metallic elements each of which provides one or more of said concavities and the complementary convexities, which elements are secured together, e.g. by welding, brazing or electronic bombardment. The casing may alternatively be formed by deformation of a plain hollow metal cylinder.

The aerodynamic efforts, such as steering moments and the handling stresses are generally taken by the casing which thus serves as a structural member. However, the structure can if necessary be reinforced by elongate intermediate members made of a suitably strong metal to which the casing elements are secured, for example by brazing, welding, gluing or crimping.

The effect of the shaped casing can be supplemented by preformed splinter elements arranged at the periphery of the charge, between adjoining concavities. Such splinter elements alter the effect of the device through a kinetic action, producing a complementary anti-aerodyne and an anti-personnel effect. Moreover a shaped-charge cone may be secured to the forward end of the casing and in substantially overall contact with the forward end of the explosive charge, the (axial) effect of which is primarily for use against tanks and concrete emplacements.

The explosive charge is preferably initiated by one or two pyrotechnic fuses operating through a column of detonating explosive extending through the whole axial length of the main explosive charge.

The main charge may be of cast hexolite or octolite based explosive, the percentage of hexogen or octogen being preferably over 80%.

The outer profile, which is preferably circularly cylindrical, of the device, is protected by a careenage or outer casing of low density and thickness, for example a plastics material, which is preferably moulded or wound.

The explosive charge may comprise two half charges placed on in front of the other with their concavities (considered in a transverse plane) staggered circumferentially by half the angular pitch of the dihedral concavities. It is thereby possible either to double the distance of action by doubling the width or opening of the V-shaped concavities for the same probability of reaching the target, or to double some probability for an equal distance of action.This principle of offsetting the half-charges can be generalized in that it is possible to divide the total charge axially into 3,4 - -n portions of 1/3, 1/4 - - 1/n with corresponding circumferential staggering of the respective axial sections of the casing and thereby vary the effective opening of the V-shaped or dihedro concavities, and therefore the pitch angle, the probability of reaching and intercepting the target, and the distance of effectiveness of the device.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a longitudinal section view along line 1-1 of Figure 2 of a first embodiment of the invention, Figure 2 is a transverse sectional view on the line 2-2 of Figure 1, Figure 3 is a longitudinal sectional view on line 3-3 of Figure 4 of a second embodiment of the invention, Figure 4 is a transverse sectional view on line 4-4 of Figure 3, Figure 5 is a longitudinal sectional view on line 5-5 of Figure 6 of a third embodiment of the invention, Figure 6 is a transverse sectional view on line 6-6 of Figure 5, Figure 7 is a longitudinal sectional view on line 7-7 of Figure 8 of a fourth embodiment of the invention, Figure 8 is a transverse sectional view on line 8-8 of Figure 7, Figure 9 is a longitudinal sectional view on line 9-9 of Figure 10 of a further embodiment of the invention, Figure 10 is a transverse sectional view on line 10-10 of Figure 9, and Figure 11 is a transverse sectional view showing schematicaily the different planes of the cutting effects obtained.

Reference being made to Figures 1 and 2, there is shown an explosive device according to the invention. The casing for the main explosive charge 7 is generally cylindrical but its periphery viewed in cross-section extends in a series of outwardly facing concavities and complementary inwardly facing convexities. The casing is of the same cross-section along its length, and is fabricated for dihedral or V-section casing elements 1 secured together by brazing, welding or electronic bombardment, and includes front and rear connecting rings 2, 3 welded or brazed to the front and rear ends respectively of elements 1. Rings 2, and 3 respectively carry closure plates 4 and 5, of which plate 5 supports a sealing sheath 6 for carrying a detonator. A column 8 of a priming explosive extends axially through the centre of the main charge.The peripheral part of the casing is itself enclosed in a thin cover 9 made from a low density material, such as a wound assembly or moulded plastics.

The dihedral elements 1 are preferably made from copper or tantalum, and the end pieces 4 and 5 of an aluminium alloy. The connecting rings 2 and 3 are welded or brazed to the dihedrons 1 and are preferably made from steel.

In alternative arrangements, the elements 1 may be inclined to the longitudinal axis of the explosive charge so as to extend helically.

This explosive device causes longitudinal cutting and perforating effects distributed in space according to planes or to helicoids corresponding to each of the elements 1. The concenration of the perforating effect along said planes or helicoids, creates shearing effects against the target. The combination of said shearing effects with the blast effects provides where the elements are relatively thin a high explosive charge coefficient, for a given mass, an increased efficiency which causes a disorganization of the opponent area reached, with a concentrated destruction and a "breaking" effect of the target, for important passage distances which can be as high as a few metres.The penetrating or piercing effects are actuated at a very high speed of the order of several thousands of m/s, thereby facilitating the setting of the proximity fuse of the missile, projectile or rocket carrying said charge as a function of the cases occurring, and thereby providing an increased interception efficiency.

Figures 3 and 4 show an embodiment an embodiment in which the charge is formed in two halves 7, 7' disposed one behind the other and each with its own encircling casing portion. The elements 1 of the two casing portions are circumferentially relative to ea'ch other by an angle equal to half the pitch angle of the elements. A connecting ring 10 is fixed, for example by brazing or welding, to the elements 1, 1', of the two casing portions and may serve for the connection of two half-charges 7, 7'.

In another embodiment shown in Figures 5 and 6, there are provided pre-formed splinter elements 11, in the form of balls or cubes for example, which are preferably made from steel, tungsten or uranium, and which are arranged between the dihedral elements 1 in order to produce a complementary anti-aircraft or antipersonnel effect. In the illustrated embodiment, a mechanical connection between the two adjacent elements 1 is provided by a longitudinal U-shaped piece 12, serving also as a housing for the splinter elements.

Figures 7 and 8 show an embodiment in which the casing comprises a front conical portion 13, preferably made from copper, and shaping the forward end of the charge. Portion 13 provides an anti-tank or an anti-concrete effect in a forward direction adding its front axial effect to the side effects of the V-shaped or dihedral elements 1.

The conical portion 13 is fixed on the front connecting ring 2.

In the construction shown in Figures 9 and 10, the casing is provided with members 14 which ara made of a reinforcing material and which reinforce the casing to take steering or handling forces. The dihedral elements 1 are preferably welded, brazed, crimped or glued to the members 14.

Figure 11 shows the various planes 15 of angular pitch a, along which are distributed the perforating and shearing effects created by the Vshaped elements 1 each having an opening of extentp.

The illustrated embodiments constitute a new type of device, particularly adapted to a missile or a rocket, or to an anti-missile or anti-aircraft projectile, which combines a blast effect and a perforating, cutting effect, acting at a very high speed along longitudinal planes, preferably extending through its longitudinal axis or along helicoids inclined relative to said axis, such that at the distance consideration the target has no possibility of escape. The said effect occurs by virtue of the longitudinal casing elements or coatings which are disposed with concavities oriented outwardly and which are centred on the longitudinal axis of the explosive charge oriented to extend helically about the longitudinal axis of the explosive charge.

Claims

1. An explosive device comprising a metallic casing of generally cylindrical form but extending, viewed in cross-section, in a series of outwardly facing concavities and complementary inwardly facing convexities generating correspondingly shaped surfaces which extend lengthwise of the casing or helically about the lengthwise axis of the casing, and an explosive charge disposed within the casing and having its external surface against and conforming to the internal surface of the casing.

2. A device as claimed in claim 1, wherein each of said concavities and convexities is of substantially dihedral form.

3. A device as claimed in claim 2 wherein the dihedral angle is in the range 60O to 1000.

4. A device as claimed in any one of the preceding claims, wherein said casing is made from copper or tantalum.

5. A device as claimed in any one of the preceding claims, wherein said casing is made up frdm a plurality of axially or helically elongate metallic elements each of which provides one or more of said concavities and the complementary convexities, which elements are secured together.

6. A device as claimed in any one of claims 1 to 4, wherein the casing is formed by deformation of a plain hollow metal cylinder.

7. A device as claimed in any one of claims 1 to 6 wherein elongate metallic members are secured to the inner surfaces of the casing where adjoining convexities meet.

8. A device as claimed in claim 5 in conjunction with claim 7, wherein said metallic members are disposed between adjoining elements, said elements each providing one concavity and the complementary convexity and being connected together through the metallic members.

9. A device as claimed in any one of claims 1 to 6 wherein metal splinter elements are disposed at the periphery of the explosive charge between adjoining convexities.

10. A device as claimed in claim 9 wherein said splinter elements are in the form substantially of balls or cubes.

1 A device as claimed in claim 8 or claim 9 wherein said splinter elements are made from steel or tungsten or uranium.

12. A device as claimed in any one of claims 9 to 11, wherein said splinter elements are incorporated in longitudinally extending housing disposed between and secured to adjoining elements providing said concavities and convexities.

13. A device as claimed in any one of the preceding claims wherein a shaped-charge cone is secured to the forward end of the casing and is in substantially overall contact with the forward end of the explosive charge.

14. A device as claimed in any one of the preceding claims, wherein the charge comprises a plural number of charge portions disposed axially end to end, the portions of the casing which surround the respective charge portions being sequentially circumferentially staggered by an angle equal to the pitch angle of the concavities divided by the number of said charge portions.

1 5. A device as claimed in any one of the preceding claims wherein an axial column of detonating explosive extends centrally along the full length of the explosive charge and is initiatable by one or two pyrotechnic fuses.

1 6. An explosive device substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2, or Figures 3 and 4, or Figures 5 and 6, or Figures 7 and 8 or Figures 9 and 10 of the accompanying drawings.