CASING FOR A FRAGMENTATION WEAPON, FRAGMENTATION WEAPON, AND METHOD OF MANUFACTURE

Abstract

A casing for a fragmentation weapon has a fragmentation layer 1 of preformed fragments 3 slidably fitted within preformed cells 6 of a lattice 2 sandwiched between an inner casing layer 4 and outer casing layer 5. The casing is particularly suited to use in fragmentation weapons and warheads. Upon detonation of the weapon, the preformed fragments 3 can freely separate from their cells 6 without being attached to the lattice 2 or other fragments 3.

Claims

1. A casing for a fragmentation weapon, comprising an inner casing layer, an outer casing layer, and a plurality of preformed fragments located between the layers, wherein the casing further comprises a preformed lattice defining a plurality of preformed cells shaped to fit the preformed fragments, each preformed fragment being slidably fitted within a respective preformed cell, the preformed lattice and fragments being sandwiched between the inner and outer casing layers, such that the preformed fragments are held within the preformed cells by confinement, and such that when a fragmentation weapon comprising the casing is detonated the preformed fragments are freely separable from the preformed lattice.

2. The casing according to claim 1, wherein the lattice is tubular shaped.

3. The casing according to claim 1, wherein the lattice has an axial length equal to a full axial length of the casing.

4. The casing according to claim 1, wherein the lattice has an axial length less than a full axial length of the casing.

5. The casing according to claim 1, wherein a single preformed fragment is fitted within each preformed cell.

6. The casing according to claim 1, wherein every preformed cell in the preformed lattice comprises a preformed fragment.

7. The casing according to claim 1, wherein a portion of the preformed cells in the preformed lattice comprise a preformed fragment.

8. The casing according to claim 1, wherein the lattice is formed from a homogeneous material.

9. The casing according to claim 8, wherein the homogenous material is a high hardness Steel, high tensile steel or Tungsten.

10. The casing according to claim 8, wherein the homogenous material is a carbon fibre material.

11. The casing according to claim 1, wherein the preformed fragments comprise a plurality of different shapes and sizes.

12. The casing according to claim 1, wherein all the preformed fragments comprise a uniform size and shape.

13. The casing according to claim 12, wherein the uniform shape has a square cross section.

14. The casing according to claim 13, wherein the preformed cells are square and orientated parallel to an axial plane of the lattice.

15. The casing according to claim 1, wherein the preformed fragments comprise Tungsten or a high hardness steel.

16. The casing according to claim 1, wherein the inner casing layer and/or outer casing layer comprise a metal such as Aluminium, Titanium or Steel.

17. A fragmentation weapon comprising a casing according to claim 1.

18. A method of manufacturing a casing for a fragmentation weapon, the method comprising: a) Providing a casing for the fragmentation weapon, the casing comprising an inner casing layer and an outer casing layer. b) Providing a plurality of preformed fragments; c) Providing a preformed lattice defining a plurality of preformed cells shaped to fit the preformed fragments, each preformed fragment being slidably fitted within a respective preformed cell; d) Arranging the inner and outer casing layers to sandwich the preformed lattice such that the preformed fragments are held within the preformed cells by confinement, and such that when a fragmentation weapon comprising the casing is detonated the preformed fragments are freely separable from the preformed lattice.

19. The method of claim 18, wherein providing the preformed lattice comprises constructing the lattice from a flat sheet of metal.

20. The method of claim 19, wherein the metal is high hardness or high tensile steel.

21. The method of claim 19, wherein providing the preformed lattice further comprises: a) stamping the preformed cells into the metal; and then b) shaping the metal to form the preformed lattice.

22. The method of claim 21, wherein shaping the metal to form the preformed lattice comprises wrapping the metal to form a multi-layered preformed lattice.

23. The method of claim 18, wherein the lattice has a thickness within a range of 1 mm to 5 mm.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0038] Preferred embodiments of the invention will now be described by way of example only, with reference to the figures, in which:

[0039] FIG. 1 provides an illustration of an embodiment of a tubular fragmentation layer in perspective view.

[0040] FIG. 2 provides an illustration of the tubular fragmentation layer of FIG. 1 in cross section view.

[0041] FIG. 3a provides an illustration of an embodiment of a preformed lattice comprising square cells arranged in a square pattern with and without cubic preformed fragments.

[0042] FIG. 3b provides an illustration of an embodiment of a preformed lattice comprising circular cells arranged in a hexagonal pattern with and without spherical preformed fragments.

[0043] FIG. 4 provides an illustration of a cylindrical warhead embodiment having a tubular fragmentation layer.

DETAILED DESCRIPTION

[0044] Turning to FIG. 1, one embodiment of a tubular shaped fragmentation layer 1 is shown which would be suitable for a cylindrical shaped warhead. The fragmentation layer 1 comprises a tubular lattice 2 with preformed square cells 6 each containing a cubic preformed fragment 3. The fragmentation layer 1 and lattice 2 have an axial length z of 800 mm. The lattice 2 is formed from a single flat sheet of steel having a thickness of 5 mm shaped to provide the tubular lattice 2.

[0045] FIG. 2 shows the cross-sectional view of an embodiment of a tubular shaped casing having the fragmentation layer 1 of FIG. 1. The figure illustrates that the casing comprises 3 layers: an inner casing layer 4, a fragmentation layer 1 and an outer casing layer 5. In this embodiment, the inner casing layer 4 has an internal diameter k of 139.87 mm and an external diameter m of 149.6 mm giving an inner casing layer 4 thickness of 4.87 mm. The fragmentation layer 1 has an internal diameter p of 150 mm and an external diameter q of 160 mm giving a fragmentation layer 1 thickness of 5 mm. The outer casing layer 5 has an internal diameter x of 160 mm and an external diameter y of 165.1 mm giving an outer casing layer 5 thickness of 2.55 mm.

[0046] In this embodiment, the inner casing layer 4 and outer casing layer 5 are pressed up against the fragmentation layer 1 such that they are sandwiching the preformed lattice 2 and the preformed fragments 3 (i.e. there isn't a gap between them). Note in FIG. 2 there is a small gap between the layers however this is for illustrative purposes only. The sandwiching of the fragmentation layer 1 by the inner casing layer 4 and outer casing layer 5 ensures that the preformed fragments 3 are held within the preformed cells 6 in the preformed lattice 2 by confinement. FIG. 2 also shows some preformed cells 6 are empty.

[0047] Each cell 6 is separated from tangentially adjacent cells 6 by a distance of 2.08 mm on the external surface and 1.95 mm on the internal surface of the fragmentation layer 1. Each cell 6 is separated from axially adjacent cells 6 by a distance of 2.08 mm on both the internal and external surfaces of the fragmentation layer 1.

[0048] In this embodiment, the preformed fragments 3 are 5 mm×5 mm×5 mm cubes made from solid high hardness steel having a mass of approximately 1 g each. FIG. 3a shows the preformed lattice 2 having square preformed cells 6 arranged in a regular square pattern that are shaped to fit the cubic preformed fragments 3. Each square preformed cell 6 loosely holds and confines a single preformed fragment 3 using friction such that when the charge is detonated, the preformed fragments 3 can freely separate from the lattice 2 and consequently have an improved predictable lethal effect and reduced collateral damage when compared with fragmentation weapons in the prior art.

[0049] In another embodiment, as shown in FIG. 3b, the preformed cells 7 comprise circular holes of 5 mm diameter that have been stamped into the sheet in a regular hexagonal pattern. In this embodiment, the preformed fragments 8 are solid high hardness steel spheres having a diameter of 5 mm.

[0050] FIG. 4 shows an embodiment wherein the fragmentation layer 1 has been integrated into a tubular warhead 9. A single homogeneous tubular piece of steel of with an axial length d of 900 mm, a circular cross section having an internal diameter of 139.87 mm and an external diameter of 165.1 mm forms the tubular casing of the warhead 9. A cavity 10 has been carved into the casing such that the fragmentation layer 1 (comprising the preformed lattice 2 with the preformed fragments 3 inserted into their preformed cells 6) can be inserted into the cavity 10. The walls of the cavity 10 therefore form the homogeneous inner and outer casing layers; 4 and 5 respectively. The inner casing layer 4 internal diameter is 139.87 mm and external diameter is 149.6 mm. The outer casing layer 5 internal diameter is 160 mm and external diameter is 165.1 mm. This provides an inner casing layer thickness of 4.87 mm, an outer casing layer thickness of 2.55 mm.

[0051] In this embodiment, the warhead 9 is provided with an end and/or nose cap 11 as required by the warhead 9 design

[0052] Whilst the embodiments described relate to a casings for fragmentation weapons, and warheads comprising the casings, they are not intended to be limiting. For instance, the other aspects of fragmentation weapon and warhead design are implicitly disclosed. For instance, the casing may be provided enclosing an energetic material or explosive, and may be provided with an end and/or nose cap as required by the warhead or bomb design. The shape, size and mass of the casings will be tailored to the particular application.

[0053] In use, the tubular warhead 9 contains an explosive charge within the casing (i.e. encircled by the inner casing layer 4). The tubular warhead 9 also contains a guidance system connected to a flight control system to control and guide its trajectory towards the target and a fuse to detonate the warhead when the fuse condition is met. The base of the tubular warhead 9 is attached to a propellant engine to provide propulsion throughout the engagement. On detonation, the resulting shock wave shatters the inner casing layer 4, preformed lattice 2 and outer casing layer 5 (which naturally fragments) and propels the cubic preformed fragments 3 out of their preformed cells 6 in a substantially radially outwards direction. Being physically unattached to any part of the preformed lattice 2 or any other part of the casing, the preformed fragments 6 freely separate from their cells 6 unattached to anything and thus having a known mass. The momentum of the preformed fragments can therefore be predicted when a known explosive charge is used.