GB2301420A

GB2301420A - Projectiles

Info

Publication number: GB2301420A
Application number: GB8506754A
Authority: GB
Inventors: Laurence Goodwin
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1984-03-17
Filing date: 1985-03-15
Publication date: 1996-12-04
Anticipated expiration: 2005-03-15
Also published as: GB2301420B; GB8407007D0; GB8506754D0

Abstract

In a projectile with a shaped charge warhead, it is preferable to have as little as possible 'clutter', eg electronic fuzing units, in the path of the explosive spike produced by the charge. Herein described is a missile warhead 1 with a shaped charge 2 having an aperture 4 extending through it and a sensing system 13,14 eg a proximity fuze for sensing radiation 16 reflected from the target, which radiation has travelled through the aperture. Thereby, at least part of the sensing system can be mounted behind the charge. The radiation may be produced by a laser 10.

Description

PROJECTILES This invention relates to projectiles and warheads therefor.

Armour plating can be penetrated by weapons having a shaped-charge explosive warhead. However, the effectiveness of these weapons depends to some degree on the spacing between the warhead and the amour plating when the warhead is detonated. Where mechanical contact fuzes cannot be used, it is known to use proximity fuzes to obtain an optimum warhead-armour spacing and in some cases, laser proximity fuzes are employed.

According to one aspect of the invention, there is provided a projectile warhead comprising an explosive charge with an aperture extending through it, and a sensing system operable for sensing radiation from a target, said radiation having travelled between the projectile and target along a path which passes through said aperture.

Preferably, the charge is shaped for directing its explosive energy forward of the projectile.

Advantageously, the sensing system is a proximity fuze operable for sensing target proximity and for initiating detonation of the charge and the fuze comprises radiation generating means for projecting radiation forward of the projectile and receiving means for receiving radiation reflected back from the target, the reflected radiation passing through said aperture to the receiving means.

However, the projected radiation may also pass through said aperture.

Preferably, the radiation generating means is a laser beam generator.

According to a second aspect of the invention, there is provided a warhead for use in a projectile, the warhead including an explosive charge, shaped for directing its explosive energy forward of the projectile, a proximity sensing system for sensing the proximity of a target ahead of the projectile and initiating detonation of the charge, the proximity sensing system including means for projecting radiation forward of the warhead and receiving means for receiving radiation reflected back from a target, said charge being positioned forward of the receiving means and the charge having an aperture through it, through which aperture said reflected radiation can pass to said receiving means.

For a better understanding of the invention, reference will now be made, by way of example, to the accompanying drawings in which: Figures 1, 2 and 3 are sectional views of the warhead of a missile showing three embodiments of the invention.

The warhead 1 of figure 1, has a hollow explosive charge 2 mounted within it, the space 3 within the charge having the shape of a truncated cone and being open towards the front of the missile. A metallic liner (not shown) may be fitted into the space 3 in known manner. A detonator 20 is inserted in the base part of the charge 2.

A small aperture 4 extends through the base part of the charge 2, through the liner if it is present, and through the detonator 20. A wall 5 inside the warhead 1 defines a tubular duct 6 leading from a position forward of the charge 2 to the tip of the warhead 1 and, between the charge 2 and the duct 6 is a space 7 in which the explosion products from the charge 2 form into a jet before passing into the duct 6. The forward end of the duct 6 is closed by a cover lens 8. A laser beam projector 9 is mounted forward of the charge 2 outside the duct 6. The projector 9 consists of a laser 10, an electronic laser drive unit 11, and a fibre-optic 12 which is arranged to receive radiation from the laser 10 and to project this radiation forward of the missile tip adjacent the lens 8.A reflected radiation detector 13 is mounted to the rear of the charge 2 and is connected to an electronic control unit 14. At some instant following launch of the missile, determined by measuring out a predetermined interval following launch or by sensing a flight parameter such as acceleration which follows a known profile, the laser 10 is made to emit a beam of light 15 which is projected towards a target (not shown) by the fibre-optic 12 under the control of the drive unit 11. The laser beam 16, reflected from the target, is received at the cover lens 8 and is focussed onto the detector 13, via the duct 6 and aperture 4 in turn.

The laser may be a continuous-wave laser in which case, the control unit 14 will trigger the detonation of the charge 2 when a signal above a predetermined threshold value is received from the detector 13, the threshold value being an indication of the optimum range for detonation of the warhead 2. Alternatively, a pulsed laser may be used and then, the control unit 14 measures the time for a pulse from the laser 10 to reach the target, be reflected back and focussed on the detector 13, and uses this measurement in conjunction with an estimated or measured value of the speed of the missile to determine the range of the target. Again, when the optimum range has been reached, the charge 2 is detonated.

In figure 2, another lens 17, which in this example is a plano-convex lens, has been inserted in the duct 6 at a position which is about one-third to half-way along the duct from its rearward end.

This has the advantage of permitting a reduction in the diameter of aperture 4 as compared with the embodiment of figure 1. Also, the laser beam projector is mounted to the rear of the charge 2 and fibre-optic 18 is used, which passes from the laser 10 alongside the exterior of charge 2 and then alongside duct 6 to the missile tip.

The separate laser drive unit 11 and detector control unit 14, of figure 1, may now be combined to form an integral electronics unit 19 as shown.

In figures 1 and 2 the projected laser beam 15 and the reflected laser beam 16 have different paths. In the embodiment of figure 3, both beams 15 and 16 traverse a path extending through aperture 4 and duct 6. The laser 10 emits a beam 15 which passes through a hole 21 at the centre of a mirror-faced block 22 and then through the centres of aperture 4 and duct 6, ie so that the beam 15 passes through each lens 17 and 8 at the optical axis, thereby remaining undeviated, and onto the target. The reflected beam 16 is still received by the cover lens 8 and focussed by lens 17 but it is directed to the detector 13 by the mirror face of block 22 as shown.

The cover lens 8 may be fitted with an ejectable cover for use during launch and the early stages of flight - the cover being ejected when the proximity sensing system comes into operation.

Naturally, the material from which the lenses 8 and 17 are made has to be able to transmit the type of radiation emitted by the laser if an optical laser is used, glass may be used for the lenses, but if an infra-red laser is used the material has to be chosen accordingly.

In the embodiments described, the warhead and all its associated equipment are mounted fore and aft along the missile axis. However, in certain applications, some of the equipment may be offset at an angle to the missile axis.

Claims

1. A projectile warhead comprising an explosive charge with an aperture extending through it, and a sensing system operable for sensing radiation from a target, said radiation having travelled between the projectile and target along a path which passes through said aperture.

2. A projectile warhead according to claim 1, wherein the charge is shaped for directing its explosive energy forward of the projectile.

3. A projectile warhead according to claim 1 or 2, wherein the sensing system is a proximity fuze operable for sensing target proximity and for initiating detonation of the charge.

4. A projectile warhead according to claim 3, wherein the proximity fuze comprises radiation generating means for projecting radiation forward of the projectile and receiving means for receiving radiation reflected back from the target, the reflected radiation passing through said aperture to the receiving means.

5. A projectile substantially as hereinbefore described with reference to the accompany drawings.

5. A projectile warhead according to claim 4, wherein said projected radiation also passes through said aperture.

6. A projectile warhead according to claim 4 or 5, wherein said radiation generating means is a laser beam generator.

7. A projectile warhead according to any preceding claim, wherein said reflected radiation is focussed onto said receiving means by a lens system.

8. A warhead for use in a projectile, the warhead including an explosive charge, shaped for directing its explosive energy forward of the projectile, a proximity sensing system for sensing the proximity of a target ahead of the projectile and initiating detonation of the charge, the proximity sensing system including means for projecting radiation forward of the warhead and receiving means for receiving radiation reflected back from a target, said charge being positioned forward of the receiving means and the charge having an aperture through it, through which aperture said reflected radiation can pass to said receiving means.

9. A projectile warhead substantially as hereinbefore described with reference to the accompany drawings.

Amendments to the claims have been filed as follows 1. A projectile comprising a shaped exosive charge for forming a generally forwardly directed exEb;ive jet when detonated; a hollow space adjacent the charge for facilitating the formation of said jet; a duct leading generally forwardly from said space for receiving said jet; an aperture leading from said space through said charge to the rear of the charge; and a proximity fuze for initiating detonation of said charge, the fuze including an optical radiation sensor positioned at the rear of said charge and lens means for receiving optical radiation from a target and directing said radiation along said duct and through said aperture to said sensor.

2. A projectile according to claim 1, wherein the proximity fuze comprises radiation generating means for projecting radiation forward of the projectile and said radiation sensor is operable for sensing radiation reflected back from the target.

3. A projectile according to claim 2, wherein said projected radiation also passes through said duct and said aperture.

4. A projectile according to claim m 2 or 3, wherein said radiation generating means is a laser beam generator.