GB2234330A - Incendiary and fragmentation projectile - Google Patents

Abstract

A sub-calibre projectile for automatic guns has a high velocity and flat trajectory for use against airborne targets. The projectile body 12 comprises a stack of pyrophoric discs 20 and high density discs 22 positioned around an axial high density mount 16 secured to a base 18 carried by a sabot and propulsive cage assembly 14. On impact with a target the projectile fragments through predetermined fracture lines 30, 32 in the discs. The projectile does not include explosive charges or detonators. The high density and pyrophoric materials may be, respectively, a tungsten-based substance and zircon; depleted uranium performs both functions. <IMAGE>

Description

TITLE Spin stabilizad projectile.

This invention relates to a spin stabilized projectile and is primarily concerned with a projectile having a sabot and of aub-calibre construction which is designed to fragment on impact with n target but uhich does not include explosive or detonetor means. Ths projectile comprising g major proportion cf a heavy metel and being intended for automatic gune.

It is of advantege to fire et fest moving targete, auch as lo@-lavel aircreft end missiles whilst et maximum range, partioulerly th@@e in e dire@t sppro@@) flight path. The pro@ability of destruction increeses with fire rate and accuracy of @im and the minimum possible transit time of the projectile is a decisive factor.

This latter factor is conditional upon a high initial velotity end reduction of the velocity to the minimum.

Customary explo@ive incendiary ammunition of a calibre range useful in automatic barrel weapons, especially cannons has a limited initial velocity and a considerable velocity loss making it more difficult to hit the target.

A projectile is shown in DE952919807 having a core of a heavy metal with en axial channel which can contain an incendiary charge, a tracer composition and r retarding cobpositinn serving to cause the core to @elf- disintegrate. The core is also intended to fragment when passing through comparatively thin plates and thus ca@se considerable damage, by giving-up more energy to the target than if it merely passed through it without fregmenting.

This syst suffers from the disadvantage that the axial channel dis@dvantageously affects the aver ace density of the projectile core. This leeds to a sericue decrease in velocity and a corresponding increase in the time of flight.

According to this inventior there is provided a spin stabilized projectile comprising: (a) e central axially extendinp mount supportinc a stack of rotationally symmetrical disc alements of which the peripheral surfaces for. the outer periphery of the projectile, (b) some disc elemente having pre-set break zones to initiate a disintegration of the projectile on impact uith a target, (c) the mount end a first number of the discs elements comprising a material of a high density, (d) a further number of the disc elements comprising r pyrophoric material.

Since the limited quantity of explosive substance in the calibre range in question cannot be expected to provide a gas impact with any appreciable destructive effect, the rsid gas impact is dispensed with, in the ammunition according to the invention, in order to obtain a high sverage density for the projectile. The quantity of pyrophoric material incorporated into the projectile according to the invention likewise takes account of the requirement that a maximum everage density is to be obtained.

The invention is explained further and in more detail with reference to a preferred embodiment shown in the accompanying drauings.

In the drawings: Figure 1 shows a projectile according to the invention and in axial section, Figure 2 shows an end vie@, to a larger scale of a heavy metal core, and Figure 3 shows s section taken on III-III of the heavy metal core ehoun in Figure 2.

As shown in tho drawings r projectile assembly 10 haE a sub-calibre projectile part 12 in a propulsive cage 14 not described in detail. ThE part 12 is formed of a pre-selectable member of rotationally symmetrical elemente interconnected in a manner to be describet later. A central mount 16, comprising r cylindrical mandrel with diameter dl, extends along the longitudinal axis A of the projectile. the mount 16 is connected with a rotationally symmetrical tail piece 18 and for piece unit therewith.Annular disc 20 made or a pyrophoric material alternate with annular discs 22 made of a material of high density and are arranged in Z stack extending up from the tail piece 18. A front annular disc 20 is followed by a frusto-conical annular disc 261 made of a material of high density and followed by a conical circular annular disc 241 made of e pyrophorie meterial, and so forth. The tail pirce 18 end the annular discs by their respective outer peripheral surfacre form the surface of the projectile 12. the front of the stack of disos carries the nose of the projectile 12 formed by a rotationally symmetrical pointed structure 26. All the elements 20 to 2@ have a continupus central bore 34 of which the diameter d2 corresponds to the diameter di of the mount 16. This also applies to a blind hole 36 in the nose structure 28. In order to obtain a high average density for the projectile 12 the central mount 16 and tail piece 18 are made of a material of high density and the annular discs 22 and 26 occupy E greater volume than the annular discs 20 and 24.As shown in Figure 2 an. 3, the annular disca 22 (20) are provided with preset breaking points 32(30) of a triangular shape. The circular annular discs 24 and 26 are aimilarly provided with preset breaking points. In a manner not shown in detail the stacked elemente 20 to 28 are in each case connected by an adhesive to respective adjacent elemente, to the tail piece 18 and to the central mount 16. A suitable example of a material with high density is a tungsten based substance. Ziroon is an example of a @uitable pyrophoric base.

As a result of this structure the projectile 10 functions as follows:- A guide ring 15 in cooperation with further means not shown in the drauing imparts to the propulsion cage 14 ano projectile 12 a stabilized spin anc a vsry high initial velocity. After leaving the barrel of the weapon the propulsion cage 14 detachas itsell from the projectile 12 uhich then continues to the target over a generally linear flight path. This ensures the required short flight time and thus r high probability of hitting the target.

Impact with the target causes the preset breaking points 30 and 32 to take effect. As a result of high velocity and centrifugal forces produced by the spin e cone of fragments is formed having high penstrating power and ensuring a high fragmentation density. This results in a destructive effect on structural parts and on fuel cells in the target.

A projectile according to the invention provides good immunity from interfarence and has an effective apin action. Uith a short flight time and the good flight characteristics with limited lose of peed, good resulte have been obtained on compartmented aluminium targets and homogeneous armour plating at extremely emall angles of impact incidence. The ammunition according to the invention is also particularly suitable for use againet killet helicopters.

If the projectile according to the invention, with a structure similar to that described, is manufactured with a depleted uranium core, this provides the advantage of extremely hitch density, the material concerned also performing the function of the pyrophoric substence and, assuming the same mass for the prajectile, for ballistic reasons, the projectile can be rendered more slender in the same length as in the version described.

In this latter with a lower average density to obtain a preselected mass for the missile, the length-diameter ratio was a, a length-diameter ratio of b which is greater than e car be obtained for the same length and gas as before, in the second constructional version described. This provides, with a vary limited sp@@d loss, a more slong@ted flight p@th and a @horter flight time. The propulsion bas@@, which are the same in their external shape, r@quire only different mounting systems, adapted to the langth-diameter ratics i and b respectively.

Claims (4)

1. A spin stabilized projectile comprising: (a) a central axially extending mount supporting i stack of rotationally symm@trical di@c elements of which the peripheral surfaces form the outer periphery of the projectile0 (b) some disc elements having pre-set break zones to initiate a disintegration of the projectile on impact with a target, (c) the mount and a first number of the disc elements comprising a material of a high density.

(d) a further number of the disc elements comprising a pyrophoric material.

2. ; projectile in accordance with Claim 1, wherein the materiel of high density comprises a tungsten based compound.

3. A projectile in accordance with Claim 1 o@ 2, wherein the central and the first number of disc elements comprise depleted uranium.

4. Ammunition substantially as herein described with reference to and as shown in the accompanying drawings.

4. A projectile substantially as herein described with reference to and 5 shown in the accompanying drauinge.

Amendments to the claims have been filed as follows 1. Ammunition for rifled barrel automatic weapons, the ammunition having a discarding sabot and a fuseless sub-calibre impact fragmentation projectile, the projectile comprising; i) a material of high density, and ii) a pyrophoric material, the projectile having a central axially extending mount of material i) carrying a stack of rotationally and symmetrical disc elements, some of material i)/some of material ii) of which the peripheral surfaces form the outer periphery of the projectile, some at least of the disc elements having pre-set break zones to initiate fragmentation on impact.

2. Ammunition in accordance with Claim 1, wherein the pyrophoric material (ii) comprises depleted uranium.

3. Ammunition in accordance with Claim 1, wherein materials (i) and (ii) are both depleted uranium.