M¾¾ IH@ ¾ POI OF IMPACT ~~

BACKGROt D OF THE XHVEHTXOB

[001] he present iav«¾tioR l tes to the- field of training ammunition and more specifically, to a BOS-pyrotechnic training a∑rismnition cartridge having a projectile that can stark its point, of im ac both by day and by night.

[002] Military gunners often fire their weapons t long ang in militar training areas tha include grass, vegetation and low lying trees♦ Heace, whil there ia some value in firing projectiles that directly ssark a target on impact, the

morphology and terrain on a military rang® f equen ly preclude un e s from having direct views of the actual impact points .

[003] S od military training de ices should simulate the effects of live fir®· high-explos e detonations. In combat such detonations generate visual and near infra-red light and heat, forming a multi™ pectral signature. High explosive detonations also produce smoke plumes , 3?¾te light and heat esult from high"-explosi e detonations can to detected by an array of fire control devices used toy the military. The smoke plumes are also visible to the naked eye,

[004] The target locating devices used in the military have visual cameras and cameras that operate in the near and/or far !R spectrum. Accordingly it is desired tha practice mu ition simula e the effects seen in cosa-bat and that practice ammunition generate arulfci-spectral marking signatures, upon impact, that ca be viewed by these cameras . fOOSJ Currently, military fo ces s® a ¾?ide array of technologies to detect and ide tify targets and adjust fire, ditio l y,, hey have tjssd pyrotechnic devi es in training amm ni ion allowing gu ners to trace their fire and rn&rJk t¾t«ir targets , These pyrotechnic devices duce smoke and he plumes from oossb stion o pyrot@oha.ic compound . Unfortunately,, these pyrotechnic evice frequently generate dangerons nnexploded ordnance (XJ3£0) and pyrotechnic compounds frequently have

chemicals that contaminate ground w e , Sround wa e

contamination and UJtO ere expensive to remediate. Additionally _t pyrotechnic devic s can also start range fires, leading to destruction of ecosystems and soil erosion ,

[006] o revent the generation of H2£0 and rang® i es during training,, inert practice am nitio cart idges have been developed which do not employ energetic pyrotechnics to trace the flight and mark fcha impact of the projectile. For example,, low en i y,, dry fin® powders have been used to create a pluma for visibly marking the target upon impact.. This m& ki&g agent has been nsed, for example, in the US Army's W7BX 0SB» low velocity cartridge . ;007J Chemi-lisminescent -technology, such as that taught in the O.S, Patent Ho. 6,€19 _> 211 h s also been used to mark both the trace nd point of impact by night. Two liquid chemical components are placed in separate frangible compartments or ampoules that break open on setback w e the projectile is fired from a weapon, This allows the components to mix and luminesce, thereby rovi i g visible trace during flight if the

projectile ogive is transparent or translncent, and ma king the point of impact w x the projectile s r kes the target, Ά& disclosed in this ten , the frangible am o les axe located near center of a projectile' s axis of rotation and _f whe the liquids are released from their compartments , they tend to d t bil e the projeotilss as i spins ,· resulting in projectile y w <.

[008] 3? e IT-S. Patent No. 8 ,,438,978 discloses a m lti- spectral marking projectile having chemical components that a e caused to mi upon setback,, d«« to the initial acceleration and the centrifugal forces, and thereby produce an ea-othersdc

reaction which emits heat during the flight of the projectile. This se i s to warm the ehemi-luminescent materials daring flight and provides an Infrared m rking sign ure vhea the projectile strikes the target,

[009] ¾he U.S. Patent Ho>. 7,055, 38 also discloses a

blamel ss- raee m rke utilizing heat marking chemicals in addition to ehemo-luminescent materials,

[0010] The subject matter of the various patents noted above is incorporated herein by reference,

SUM ¾H OF THE IMVEM XGM

[OOli] The principal objectiv o£ the present invention is to provide a non-pyrotechnic ammunition projectile that provides a visual effec upon impact that closely simulates the effects of live fire detonations; aarking signatures that may be seen by day and detected b xsiXitary night vision and thermal sensors by night . 10012 J A f the objective of th© p es nt i venti n is to provide a training projectile, of he type described above having a configuration that can b manufactured at a reasonabl cost,

[0013] A still further objective of the present invention is to provide & training projectile of this type which c ies reactiv liquid: com o ents , such as c ®mi~I»a*ineseent _. or

exothermic materials, yet is configured to remain, stable in flight and doe not suffe from instability generally resulting from on~board liquids .

[0014] A still further objective of the present invention is to provide a training projectile of this type which carries a fine dry powder as ma king agent in the projectile head which bursts open upon impact and creates a powder plume for visibly marking the target*

[00151 l¾ase objects,- as well as othe objects which will become apparent fro the discission that follows,, are achieved according to the presen invention _r by providing th® projectile with one or more sheet of material,, each having a plurality of frangible ^' "b bble .shaped" compartments containing liquid

chemica components for optical and/or Infrared marking, he sheets are preferably flexible or conforms! sheets of plastic material in the nature of a ^-bu bl wr p" of the type -used as padding fo packaging. hese so-called ^mat i packages" ^' are installed in a compartment formed by the head of the projectile body adj cent the inner surface of the compartment wail, he "bubbles" formed in the sheet which contain the chemical components are designed to break upon impact,, releasing th components and allowing them to jaiac and cfeemieally react, he com onents m y of the type that create to areata light,, or they may be of the t¾" @ tha mix s create heat. Multiple components ay fe p ovided to create both light and heat >

[0016] ¾iva ageot^ly two or more separate shee s are

ar nged in an adjacent concentric configuration leaving an ©pea space i» the center of the projectile head. Shis spac ¾ay foe either left empt or,, in a p e red embodiment of the

invention.,, filled with a fin dry powder marking agent that is released and forms a pl«me when the projectil head b eaks open upon impact,

£0017 J For a full u de s anding o the present invention, reference should now toe m de to the following detailed

description of the p efe ed embodiments of the invention as illust ed in the accompanying drawing ,

BRI!F D SCRIP ION OF TEE DRAWINGS

£0.018] Fig, 1 is a sid view of a spi stabilized 40sa&

projectile of the type to which the present invention relates, f00193 ^' Figs < 2A, 2B and 2G are representative diagram , not to scale,, showing the method of ^* making a flexible and frangiblebubble- wrap sheet according to the invention,, with babbles

filled with a liquid. [0020] Fig, 3 is a cutaway vie of the head of he p ojectile of Fig . 1 ₁ showing th comp ment wall with inde t*fcions

d sign d to accommodate abbles of a bubble wrap sheet.

[0021] Fig. 4 is a iew of the projectile head shown in Fig, 3 with he frangible bubble wrap sheets according to the

invention., which contain liquid chemical material® ,, arranged adjacent the compartment wall, 00 23 Fig, S is an composite view of the pro ec ile he ds shewn in gs . 3 and 4 with two ^ ab l w a " sheets con aining a react! a li uid chem ~luminescent in each and a fine dry powder contained in a compartment inside the bubble wrap sheets, 0023J Fig, 6 is perspective view of the projectile of Fig, 1 showing the spin moments forces that %r©»ld occur without use of the bubble w ap sheets according to the invention,

DETAILED DESCRIP ION OF THE PR ERRED EMBODI ENTS

[002 J The preferred em odimen s of the p ese invention will now be described with reference to Figs, 1-6 of the

dr wings , Identical elements in the various figures are

designated with the same reference numerals.

[0025] The present inventio concerns a projectile with a frangible head tha can be configured in multiple calibers (with differing trajectories, spin rates, etc,} , Upon impact, th ogive (head) breaks open and releases both day and night marking agants , 10026] While most of projectiles i us® today IsehaYe as rigid bodies ¾'hile in fl ght, mo*e and more projectiles e designed to carry a liquid or non-rigid payloadL S a examples of suc a»e {1} artillery rounds that generate smoke and comprise a spin stabilized shell with a canister filled with white -phosphorous; {2} marking projectiles with liqu d eh©mi«al com nents that »ix upon impact to genorat speci c signatures in a broad range of radiation bands; (3) less~than-~Xethai projectiles hav ng a liquid with aggressive chemicals or marking paint,: and (4) projectiles that carr medical supplies (¾«g. _f intravenous fluid hags) .

C0027J Share can be a significant difference in flight

behavior £©twe®» liquid-filled and solid-filled pr ectiles .

The difference is due to motion of the liquid inside the

spinning pro ectile during fligh , T s mot on c usa® fo ces to act on he projectile body that disrupt the spin and can

p ema urely terminate the flight by instability. Characteristics of this instability are sharp increases i the angle of attack (AOA accompanied by large changes in spin rate, When launched, the motion of the projectile cansas the inid t spin up in a time ^< ™dapendent manner,, although it isay sufess&qu&afcly ach eve steady state.

[0028] According to the invention, the liquid chemical components in the proje ile are contained in a matrix of frangible "bubbles'-' or ampoules formed in a sheet of material, layered adjacent to the inner surface of the projectile body. This ''mat ix packaging «o»£iguration minimises the. problematic movement of unstable moments _t inertia friction and rssonaacss generated by a liquid _f all of which cas disturh fc¾® light characteris ies ©f t e projectile _*

[0029] She babbles or mpoules in th bubble wrap she t according to the inven ion are designed break xxp n impact whan the projectile strike th ground or a target, allowing the constitaent chemical materials to jttiss. and re c t ge ,

CO03 J Upon impact _, , the bead of the projectile (ogive) breaks apart generally releasing th .reacting chem cals into the

mosp e e,- f mi g a visual and XR signature visible at night or through near IE night vision devices , .0031 _. 3 Maintaining the !igaid chemical materials close to the inne surface o£ the outer wall of the ogiv provides for good ballistic stability of the projectile becaus its center of gravity does not shift dur ng flight. This configuration is not le to change the spin rate,, since the liquid will neither rotate nor oscillate in inertia! waves, hence having no chance to influence the so-called ^ ln deoay ^w _t topical of a iigaid payload with free liquid ia a full ooataiaer,

[0032] It should be noted that the "babble w p" packing amst be carefislly designed to avoid "eigenvalue" resoaanoe » Also both sheet layers must be properly contained so that they cannot move or be deformed during setback and in flight..

[0033] Having these issues i mind, it may be seen tha packing the liquid materials in ^ b le wrap''' ^" layers improve® th flight behavior of marking projectiles, This applies also to other ty es of on- igid payload projectiles such as non-lethal projectiles that carry liquid components.

[0034] Fig. 1 shows a 40am projectile 10 of the ty e to which the present invention relates . The various dimensions of the projectile are indicated, relative to the smbsr of calibers . The projectile has an ogive 12 that carries one or more marking agents, including liquid chemical materials which react when mixed, These li uids are c nta ned and constrained in a matrix package of fetabble wrap sheets, as will be explained below,, which maintains th stability of the projectile in flight,

[0035] The bubble wrap sheet according to the invention s illustrated in Figs. 2Ά, 2B and 2C. Fig, 2& shows a plastic sheet 14 containing de ressio s or ^bubb es" 16 filled with a iiqnid 18. Once filled,, a cover sheet 20 is applied and heat- s aXed to the sheet 14 to form a composite sheet 22. Thi

composite sheet i shown in perspective is Fig, 2C ,

[0036] ig, 3 shows the Interior of the head (|ogive) 12 of the projectile 10 without the ^btibbla ap" shee s according to the invention that contain the roa.et.ive liquid chemical

materials, The wall of the ogive 12 is formed of a plastic o composite material or of a thin-wailed metal, The inner snrfaea of the wail is provided with small indentations to receive the bubbles of the bubble wrap sheets 22,

[003?3 The wall of the ogive 12 is designed to b eak up apoa impact and release its contents. Internal to the ogive 12 is space filled by a shaped container 26 ssurronnded by two ^ ubble wr " sheets 28 and 30 having frangible bobbles filled with v ious liquid che ical materials, s is shown in Figs. 4 and 5 , I the give is latively long,, the liquid mass con ined in the babbies is preferentially located nea th front of he projectile .

[00383 As noted above, the bubbl s are designed to break open u on impact with the target, ele sing the materials end

allowing them- to mise and react chemically together. If the mate ials are chami-luminescent components they will luminesce; if hey are exothermic com o e ts they will creat heat. Both types of components may be provided either in separate

compartments or in a common compartment in the projectile.

[00393 he container 26 in the center of the ogives 1.2

adva tageously contains a dyed fine dry owde that is released u on impact for isu l {day} marking,

[00403 As is illus rate i Fig. €, a projectile 10

containing a liquid is subject to a n mber of liquid-induced forces 32, 34 and 36 ^' which can make it ^• unstable i flight, T e use of the foubfela wrap package according to the invention,

located adjacent the outer wail o the projectile,, minimizes <1) the coefficient induced side force, {2} the .moment force, and

(3) the destabilising resonanc s, when liquids are contained in the bubbles. This design minimizes spin decay and optimises gyroscopic stability of a projectile containing the reactive ligaid chemical mix that functions on impact.

100 ] There has thus been shown and described a novel

training ammunition cartridge with reactive liquid materials for marking a point of impact which achieves all of the objects and d an ages sought therefor. M ny changes _f modifications, v&ri&tion-s- aftd othe ses and applications of the s¾ibject invention will , how ve _f . ecome apparent to those skilled in fch< art f er co side ing h s specification and the accompanying d awi gs which disclose the preferred embodiments thereof. All such changes, modi ications _f variations and other ases and applications which do no depart from the spirit and scope of the invention are deemed to be covered by the invention,- which i to be limited only by the claims which follow.