Illumination munition

Abstract

The invention relates to an illumination munition, particularly an illumination payload ejection device housed within a common carrier payload delivery shell, with a frangible safety link. There is provided an illumination munition comprising a shearable tail unit, a main body which comprises a payload cavity for receiving an illumination payload apparatus, a fuze, an ogive element located between said main body and the fuze, and an explosive train operably connected to said fuze, wherein the illumination payload apparatus comprises an illumination composition, a drogue parachute and a main parachute, wherein the main parachute is tethered by a payload tether to the payload apparatus, such that after deployment of said main parachute said payload apparatus descends under the control of said main parachute.

Claims

1. An illumination munition comprising a shearable tail unit, a main body which comprises a payload cavity for receiving an illumination payload apparatus, a fuze, an ogive element located between said main body and the fuze, and an explosive train operably connected to said fuze, wherein the illumination payload apparatus comprises an illumination composition, a drogue parachute and a main parachute, wherein the main parachute is tethered by a tether arrangement to the illumination payload apparatus, such that after deployment of said main parachute only the illumination payload apparatus descends under the control of said main parachute.

2. A munition according to claim 1, wherein drogue parachute is tethered by a drogue tether to the tail unit, such that upon shearing of the tail unit causes deployment of the drogue parachute.

3. A munition according to claim 1, wherein the drogue parachute is tethered by a carrier tether to a main parachute carrier and extending therethrough to a parachute delay device, wherein said carrier comprises said main parachute therein.

4. A munition according to claim 3, wherein the parachute delay device comprises the payload tether for the main parachute, a releasable engagement device to releasably receive the drogue tether, an activator which is tethered by an activator tether to the drogue tether, wherein upon activation of said activator causes release of the drogue tether.

5. A munition according to claim 1, wherein an expulsion charge operably connected to the explosive train causes ignition of an illumination delay ignitor which is operably linked to the illumination composition.

6. A munition according to claim 1, wherein the main body comprises a first threaded portion manufactured from a first material, and the tail unit comprises a second threaded portion manufactured from second material, wherein the second material has a lower hardness value than the first material.

7. A munition according to claim 6, wherein the first material is selected from a steel alloy and the second material is selected from aluminium or alloy thereof.

8. A munition according to claim 1, wherein the main parachute is a closed arm cruciform parachute.

9. A munition according to claim 1, wherein the illumination composition is at least one consolidated pellet.

10. A munition according to claim 1, wherein the ogive element is a frangible ogive element.

11. A munition according to claim 1, further comprising a locking ring located between the main body and the ogive element, to retain said illumination payload apparatus within the payload cavity, wherein the payload cavity has substantially parallel walls, which extend from the intersection of the tail unit to the locking ring.

12. A munition according to claim 1, wherein the illumination payload apparatus is capable of being dispensed rearwardly from the main body, upon shearing a shearable thread.

13. A method of dispensing an illumination payload apparatus from a munition according to claim 1, wherein the explosive train is operatively coupled to an expulsion charge, and said illumination payload apparatus is tethered to the shearable tail unit by a shearable thread, the method comprising causing initiation of the expulsion charge, which causes ignition of illumination delay igniter and shearing of the shearable thread, such that said illumination payload apparatus is caused to be pushed rearwardly from said shell, to disperse said illumination payload apparatus.

14. An illumination munition comprising: a shearable tail unit; a main body which comprises a payload cavity for receiving an illumination payload apparatus, wherein the illumination payload apparatus comprises an illumination composition, a drogue parachute and a main parachute, wherein the main parachute is tethered by a tether arrangement to the payload apparatus, such that after deployment of said main parachute said payload apparatus descends under the control of said main parachute; a fuze operatively coupled to an expulsion charge; a frangible ogive element located between said main body and the fuze; and a locking ring located between the main body and the frangible ogive element, to retain said illumination payload apparatus within the payload cavity.

15. A munition according to claim 14, wherein drogue parachute is tethered by a drogue tether to the tail unit, such that upon shearing of the tail unit causes deployment of the drogue parachute.

16. A munition according to claim 14, wherein the drogue parachute is tethered by a carrier tether to a main parachute carrier and extending therethrough to a parachute delay device, wherein said carrier comprises said main parachute therein, wherein the parachute delay device comprises the payload tether for the main parachute, a releasable engagement device to releasably receive the drogue tether, an activator which is tethered by an activator tether to the drogue tether, wherein upon activation of said activator causes release of the drogue tether.

17. A munition according to claim 14, wherein the expulsion charge causes ignition of an illumination delay ignitor which is operably linked to the illumination composition.

18. A munition according to claim 14, wherein the main parachute is a closed arm cruciform parachute.

19. A munition according to claim 14, wherein the illumination composition is at least one consolidated pellet.

20. A munition according to claim 14, wherein the illumination payload apparatus is capable of being dispensed rearwardly from the main body, in response to the expulsion charge being stimulated.

Description

(1) Exemplary embodiments of the device in accordance with the invention will now be described with reference to the accompanying drawings in which:

(2) FIG. 1 shows an exploded side view of a shell.

(3) FIG. 2 shows a cross section of the illumination payload apparatus.

(4) FIG. 3 shows a cross section along the axis of the shell in FIG. 1.

(5) FIG. 4 shows a cross-section of an illumination shell.

(6) FIGS. 5a and 5b show a deployment sequence of the drogue parachute.

(7) FIG. 6 shows the release sequence of the main parachute.

(8) FIG. 7 shows the deployed and activated illumination composition.

(9) Turing to FIG. 1 there is provided a shell 1, with a main body 5, which is manufactured from a steel alloy. Located around the circumference of the main body 5 is a copper driving band 4, which allows engagement with the rifling on the bore of a barrel, so as to impart spin. A tail unit 2 is located at the aft of the main body 5. The tail unit 2 is made from aluminium and contains a male threaded portion 3, which engages with a reciprocal female threaded portion (not shown) located in the aft of the main body 5. The illumination payload apparatus 10 (see FIG. 2), when located in the payload cavity 10a, inside the main body, is retained in place by use of a locking ring 6, which screws into the forward end of main body 5. The frangible ogive element 7 has a frangible link 7a, in the form of an aluminium thread. The frangible ogive element 7 may be secured to the locking ring 6 or directly to the main body 5. The frangible ogive element receives the expulsion charge 8 and fuze 9. Upon operation of the fuze 9, the expulsion charge 8 builds up pressure within the frangible ogive element and at the bursting pressure the thread 3 shears and the illumination payload apparatus 10 is expelled from the aft of the main body 5. During a blind event, the shell 1 would not function as detailed above, and would hit the ground, wherein the frangible link 7a would be caused to fail, such that if fuze 9 did erroneously function, that the expulsion charge 8 would be at least partially vented and would not cause the illumination payload apparatus 10 to be expelled from the shell 1.

(10) FIG. 2 shows the illumination payload assembly 10, with a delay igniter 11 which is ignited by the expulsion charge 8 (see FIG. 1), the delay igniter after a delayed time period ignites the illumination composition 29. When the payload 10 is ejected the drogue parachute 27 functions and the parachute delay device 21 causes the main parachute 28 to be deployed as shown in more detail in FIGS. 5a and 5b.

(11) FIG. 3 shows an illumination shell 20, with a main body 24 formed from a steel alloy, with a driving band 26 located thereupon. A tail unit 12 is located at the aft of the main body 24. The tail unit 12 is made from aluminium and contains a male threaded portion 13, which engages with a reciprocal female threaded portion 14 located at the aft of the main body 24.

(12) The illumination payload apparatus 10 is located in the payload cavity 15, and is retained in place by use of a locking ring 16, which screws into the forward end of main body 24.

(13) The frangible ogive element 17 has a frangible link 17a, in the form of an aluminium thread, which is fastened to the locking ring 16. The frangible ogive element receives the expulsion charge 18 and fuze 19. Upon operation of the fuze 19, the expulsion charge 18 builds up pressure within the frangible ogive element and at the bursting pressure the thread 13 shears and the illumination payload apparatus 10 is expelled from the aft of the main body 24.

(14) The illumination payload apparatus 10 is a modular illumination unit, which slides into the payload cavity 15.

(15) Upon operation of the fuze 19, the expulsion charge 18 builds up pressure within the frangible ogive element 17 and at the bursting pressure the thread 13 on the tail unit shears and the illumination payload apparatus 10 is expelled from the aft of the main body 24. The expulsion charge may cause a delay composition 11 to ignite the illumination composition 29.

(16) During a blind event, the shell 20 would not function as detailed above, and would hit the ground, wherein the frangible link 17a would be caused to fail, such that if fuze 19 did erroneously function, that the expulsion charge 18 would be at least partially vented and would not cause the illumination payload apparatus 25 to be expelled from the shell 20.

(17) FIG. 4 shows a cross section of an illumination shell 30, where the fuze 29 has caused the expulsion charge 28 to function with an energetic output 34, which causes ignition of delay igniter 31 and concomitantly shears the tail unit 32 causing ejection of the payload 33 and tail unit 32, in a rearwards direction 35, exiting the payload cavity 36.

(18) FIG. 5a shows the initial deployment of the payload device 43. The shearable tail unit 46 has a considerable mass, is attached with a drogue tether 45 to the drogue parachute 47, such that as the tail unit 46 moves away from the shell (not shown), it causes the drogue parachute 47 to be pulled out of the payload apparatus 43 and deployed. The primary function of the drogue parachute is to cause rapid deceleration of the apparatus 43. The apparatus 43 is clear of the shell, and the delay igniter 41 is already activated with a controlled burn ready to ignite the illumination composition 42. The tail unit 46 has considerable momentum, and will be expected to continue its trajectory similar to that of the final safe zone of the empty shell.

(19) The drogue parachute 47 when it deploys acts upon the carrier tether 48 to remove the main parachute carrier 50, which contains the main parachute 51 (inside), from within the payload apparatus 43. The carrier 50 and main parachute are attached by a tether arrangement 49 to the parachute delay device 44 retained within the apparatus 43.

(20) FIG. 5b shows one arrangement for the release sequence in the parachute delay device 44 for the tether arrangement 49. The drogue parachute 47 is tethered by the carrier tether 48 which at its distil end connects to the releasable engagement device 60 which forms part of the parachute delay device 44. The carrier tether 48 is also operably attached to the main parachute carrier 50.

(21) The drogue parachute 47 acts upon the carrier tether 48, which in turn acts upon the main carrier 50, via the attachment means 58 and concomitantly applies tension to the activator tether 56. The activator tether 56 in this arrangement is already under tension compared to the carrier tether 48, such that upon a selected force being applied the activator tether acts upon the activator 53 causing deactivation of the engagement device 60, thereby releasing the carrier tether from the delay device 44. The carrier tether remains operably linked by attachment means 58 to the main parachute carrier 58, and as the drogue parachute 47 applies further tension it removes the carrier 50 from around the main parachute 51 encased therein. The main parachute 51 remains tethered by payload tether 57 to the delay device 44.

(22) FIG. 6 shows the drogue parachute 64 attached to the main parachute carrier 66 by the carrier tether 65. The drogue parachute 64 is then discarded. The main parachute 63 remains attached to the payload apparatus 61, by means of the payload tether 67, and the illumination composition 62 starts to burn.

(23) FIG. 7, shows the controlled descent 70 of the illumination payload apparatus 71, under the control of the main parachute 74. The device during its descent illuminates 72 the target area of interest, whilst ensuring that the payload apparatus 71 remains intact and under the control of the main parachute, such that it mitigates against collateral damage.