Smoke payload apparatus

Abstract

The invention relates to a smoke payload apparatus, particularly a smoke payload ejection apparatus housed within a common carrier payload delivery shell, with a frangible safety link. There is provided a smoke screen munition comprising a shearable tail unit, a main body which comprises a payload cavity for receiving a smoke 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 smoke payload apparatus comprises a plurality of unconfined portions of a smoke generating energetic material, wherein said portions burn on at least two surfaces.

Claims

1. A smoke screening munition comprising a shearable tail unit, a main body which comprises a payload cavity for receiving a smoke payload apparatus, a shearable thread between the tail unit and the main body, a fuze, an ogive element located between said main body and the fuze, and an explosive train operably connected to said fuze, wherein the smoke payload apparatus comprises a plurality of portions of a smoke generating energetic material, wherein after delivery of the munition, said portions are configured to disperse in an unconfined manner and burn on at least two of their surfaces, wherein the smoke payload apparatus comprises a support shaft, with at least two vertical supports and at least two horizontal supports to each accommodate said portions of the smoke generating energetic material, and wherein each of the portions of the smoke generating energetic material abut the at least two vertical supports, and provide a flash though-hole between said portions and the support shaft, and wherein the at least two vertical supports are fixed to the support shaft or form an integral part of the support shaft.

2. The munition according to claim 1, wherein after the delivery of the munition, the portions burn on all of their surfaces.

3. The munition according to claim 1, wherein the smoke payload apparatus is tethered to the shearable tail unit.

4. The 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 a second material, wherein the second material has a lower hardness value than the first material.

5. The munition according to claim 4, wherein the first material is selected from a steel alloy and the second material is selected from aluminium or alloy thereof.

6. The munition according to claim 1, wherein the at least two vertical supports extend outwardly from the support shaft.

7. The munition according to claim 6, wherein at least one vertical support is positioned between a first portion and a second portion of the smoke generating energetic material.

8. The munition according to claim 6, wherein the portions of the smoke generating energetic material are consolidated pellets.

9. The munition according to claim 8, wherein said vertical and horizontal supports separate the pellets into stacks each comprising a plurality of said consolidated pellets.

10. The munition according to claim 9, wherein said consolidated pellets in each of the stacks are separated from each other with a barrier.

11. The munition according to claim 1, wherein the ogive element is a frangible ogive element.

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

13. The munition according to claim 1, wherein the smoke payload apparatus is capable of being dispensed rearwardly from the main body upon shearing the shearable thread.

14. A method of dispensing a smoke payload apparatus from a munition according to claim 1, wherein the explosive train is operatively coupled to an expulsion charge, and said smoke payload apparatus is tethered to the shearable tail unit, the method comprising causing initiation of the expulsion charge, which causes ignition of said portions of the smoke generating energetic material and shearing of the shearable thread, such that said smoke payload apparatus is caused to be pushed rearwardly from said main body, to disperse said portions of the smoke generating energetic material.

15. The munition according to claim 1, further comprising a locking ring located between the main body and said ogive element, to retain said smoke payload apparatus within the payload cavity and prevent movement, wherein the payload cavity has substantially parallel walls, which extend from the tail unit to the locking ring.

16. A smoke screening munition comprising: a shearable tail unit; a main body which comprises a payload cavity for receiving a smoke payload apparatus, wherein the smoke payload apparatus is tethered to the shearable tail unit, and wherein the smoke payload apparatus comprises a plurality of portions of a smoke generating energetic material, wherein after delivery of the munition, said portions are configured to disperse in an unconfined manner, each of the portions being configured to burn on at least two of its surfaces; a shearable thread between the tail unit and the main body; a fuze operatively coupled to an expulsion charge; and an ogive element located between said main body and the fuze, a support shaft, with at least two vertical supports and at least two horizontal supports to each accommodate said portions of the smoke generating energetic material, and wherein each of the portions of the smoke generating energetic material abut the at least two vertical supports, and provide a flash though-hole between said portions and the support shaft, and wherein the at least two vertical supports are fixed to the support shaft or form an integral part of the support shaft; wherein the smoke payload apparatus is capable of being dispensed rearwardly from the main body upon shearing of the shearable thread in response to the expulsion charge being stimulated.

17. The munition according to claim 16, wherein the smoke payload apparatus comprises a support shaft, with at least one vertical support and at least one horizontal support to accommodate said portions of the smoke generating energetic material, and wherein the portions of the smoke generating energetic material are consolidated pellets.

18. The munition according to claim 16, further comprising a locking ring located between the main body and said ogive element, to retain said smoke payload apparatus within the payload cavity.

19. The munition according to claim 16, wherein the ogive element is a frangible ogive element.

20. The munition according to claim 19, further comprising a locking ring located between the main body and said ogive element, to retain said smoke payload apparatus within the payload cavity and prevent movement, wherein the payload cavity has substantially parallel walls, which extend from the tail unit to the locking ring.

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 show an exploded side view of a smoke screen shell according to the invention.

(3) FIG. 2 shows a cross section along the axis of the shell in FIG. 1.

(4) FIGS. 3a and 3b show a smoke payload apparatus

(5) FIG. 4 shows a partially ejected smoke payload apparatus.

(6) 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 smoke payload apparatus 10 (shown external to the shell 1), when located in the payload cavity (not shown), inside the main body 5, 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 7 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 smoke 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 smoke payload apparatus 10 to be expelled from the shell 1.

(7) FIG. 2 shows a smoke 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.

(8) The smoke payload apparatus 25 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.

(9) 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 17 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 17 and at the bursting pressure the thread 13 shears and the smoke payload apparatus 25 is expelled from the aft of the main body 24.

(10) The smoke payload apparatus 25 is a modular smoke unit, which slides into the payload cavity 15.

(11) 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 smoke payload apparatus 25 is expelled from the aft of the main body 24. The expulsion charge may cause a delay composition 11 to ignite the smoke pellets 21.

(12) 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 smoke payload apparatus 25 to be expelled from the shell 20.

(13) FIG. 3a shows a smoke payload apparatus 30, which comprises a central support shaft 35, with threaded portion 38 which tethers to the tail unit (as shown in FIG. 4). The central support shaft 35 comprises vertical support splines 40 and horizontal support discs 36. The cavities formed between vertical support splines 40 and support discs 36 are filled with consolidated pellets of a smoke composition 31. The pellets 31 are unconfined and are thus capable of sustaining a burning front on all of their outer surfaces, when ignited. The pellets 31 are supported by the support discs 36, and are individually separated from each other by low friction paper 32, to prevent undesirable intimate contact and prevent frictional movement between adjacent pellets. A gas absorbent foamed polymer 34 is located between the pellets and the lower most disc within each cavity, such that upon gun launch the pellets move rearwardly towards the end 41 of the smoke payload apparatus, and hence move towards the support discs 36, the force exerted on the pellets 31 is reduced by action on the foam polymer 34. The foam polymer 34 is also capable of absorbing any undesirable gaseous products that evolve from the red phosphorous composition during long term storage, such as phosphine gas.

(14) The expulsion charge (as shown in FIG. 2), will cause ejection of the apparatus 30 from the shell (FIG. 4), and said expulsion charge will also cause the ignition of the pellets 31. The flame front from the expulsion charge passes in the gap 39 between the pellet 31 and the intersection of two vertical support splines 40, (exemplified in FIG. 3b) and additionally passes through slots 37 in the support discs 36, such that all of the pellets 31 are ignited by the action of the expulsion charge, at substantially the same time. The pellets 31 are not tethered to the smoke payload apparatus 31, therefore once the apparatus has been ejected, and coupled with any imparted spin on the shell the pellets are thrown and dispersed over a desired target area.

(15) FIG. 4 shows a cross section through a shell 51. The fuse 59 has been activated and has caused the expulsion charge 58 to function, the flame front causes a build up of pressure in the payload cavity 60, which causes shearing of the thread on the tail unit 52, and movement of the apparatus 55 rearwardly, to eject the apparatus from the aft end of the shell 51. The flame front 56 flashes down the channels between the pellets and apparatus and ignites the pellets 54, concomitantly with the ejection of the apparatus 55 from the munition 51. The central support shaft 57 is tethered 53 to the tail unit, by means of a screw thread, such that as the tail unit 52 is ejected the apparatus 55 exits on the same trajectory path.