SMOKE HAND GRENADE

Abstract: The present invention relates to an arrangement in a smoke hand grenade, and for the objective of achieving an instantaneous creation of a smoke screen, specifically for self screening of an individual soldier, there is according to the invention suggested a container holding a liquid smoke material (9a) separated from a composition (8a) which after bursting neutralizes the acid by-products being formed after the liquid has reacted with the air moisture whilst emitting smoke.

Description: SMOKE HAND GRENADE Field of the invention The present invention relates to an arrangement for spon¬ taneously establishing a smoke screen specifically for self screening of the individual soldier. More specifi¬ cally, the invention relates to an arrangement in a smoke hand grenade comprising a container which per se holds a liquid smoke material. Background of the invention The present invention is developed in connection with rapid self screening of the visible and proximity infra¬ red spectral range of a soldier in a critical combat situation. Existing smoke hand grenades are based on combustion of a pyrotechnical composition for generating a relatively toxic smoke which substantially comprises zink chloride. By unprofessional use of this smoke deaths have occured. Several userlands within NATO have therefore a desire to exchange this type of smoke when a smoke can be provided which is less poisonous and preferably just as effective. It is expected that the smoke thus will not comply with the environment requirements to which smoke ammunition will be subjected in the future. Further, this type of smoke has a limited application during training in dry vegetation since it can cause fire. Prior Art GB patent publication 1 149 982 discloses a shell com- prising inter alia a metal casing wherein a liquid smoke material is absorbed in a powder (calsium silicate, neu¬ tral) and is located in the cavity of the grenade. In a training field with extensive use of smoke grenades this will imply that the environment will be subjected to unwanted large stress. This is not in compliance with today's user requirements. The grenade according to said GB publication will generate an environment hostile smoke as the powder into which the liquid smoke has been absorbed, is scattered on the ground onto which the gre¬ nade lands, which will render acidic fallout which cannot be neutralized. Consequently, this principle will today not be applicable in a novel smoke grenade for the army. The suggested subject matter of the invention is a hand grenade in PCDF (plastics). The liquid smoke which is in its own room in the grenade, will react with the moisture of the air after the bursting and emit hydrochloric acid as a by-product. In order to neutralize this there is in its own, separate compartment around the inner container, located for example Dolomite, Ca g(Co 3 ) (the same material which is used for example for neutralizing acid in percipitation (fishing waters)). This powder will be scattered on the ground after the bursting and neutralize the liquid smoke which falls out in the area around the bursting point. Brief disclosure of the invention An object of the present invention is aiming for provid¬ ing a rapidly functioning smoke hand grenade which is substantially less poisonous than present smoke hand grenades based on zink chloride smoke (ZnCl 2 ) (HC-s oke). The smoke material according to the present invention is titanium tetrachloride (TiCl 4 abbreviated TTC). Besides, the toxicity of smoke based on hydrolyse of TiCl 4 is very low. If one anticipates that mortal consentration of ZnCl 2 -smoke is C D , one will even with a TiCl 4 smoke con¬ sentration which is 5 x C D , only find minor harmless changes in the lung tissue (ref Karlsson et al., 1986, Archives of Toxicology). Further, the smoke grenade is to be favourable for the environment, i.e. it should in sum not be specifically pollution and acid promotional on the environment. This objective is achieved by including calsium powder in the smoke canister in a stoichiometric relation of the hydro¬ chloric acid which is given off by hydrolyse of TTC dur¬ ing the generation of smoke. The total reaction is: 2CaC0 3 +TiCl 4 -*2CaCl 2 +Ti02+2C0 2 The reaction products calsium chloride (CaCl 2 ) and titan¬ ium dioxide (Ti0 2 ) are compounds which do not have a negative influence on the natural environment. A second aspect of the invention is that the calsium layer in the container around the inner compartment con¬ taining the liquid smoke, will neutralize the liquid smoke which diffuse through the plastics out from the inner container. Without this layer which thereby is quite substantial for the grenade, the liquid smoke/hydrochloric acid would be released and would in¬ fluence the environment in the storage. More than 10-15 years in a stand-by storage would involve unacceptable corrosion of other storage material. Contrary to mixing liquid and powder, as suggested by the prior art, it is according to the invention suggested to hold the liquid smoke in a separate inner chamber, a fact which renders substantial advantages compared with the prior art, both as regards storage and use. Possibly, the firing mechanism of the grenade could be replaced by a metal insert equipped with a blasting cap and an ejector charge, so that the smoke canister can be fired from an appropriate discharge pipe, for example for screening battle field vehicles. Brief description of the drawings Fig. 1 is a view partly in section of a smoke hand gre¬ nade, standard version, according to the invention. Fig. 2 is a view partly in section of an alternative construction of the smoke grenade according to the inven- tion. Fig. 3 is a section through a smoke canister which by removing the bottom plug (B) in standard version or in alternative version of the smoke hand grenade, can extend the screening time for the smoke hand grenade by letting the canister remain on the ground and give off smoke in approximately 20 seconds after the instantaneous part (Fig. 1 or Fig. 2) has burst and given off smoke. Fig. 4 is a section through a module which can replace the ignition mechanism for the hand grenade by being screwed thereinto in a simple manner, and thereby trans¬ fer the smoke hand grenade to a smoke ammunition which can be fired from an appropriate discharge pipe. Detailed description of embodiments As appearing from Fig. 1 there is used a hand grenade in a known manner by holding the same in the right hand, whereafter the pulling ring 1 with the safety bolt 2 is pulled out and the grenade is thrown. A spring loaded striking arm having an ignition pin will strike against a blasting cap which ignite a delay charge which when being burned out (approximately 3 seconds) thereafter will fire the bursting charge 7 in the centre pipe, whereby the canister is burst and scatters the smoke material 9 and the acid neutralizing material 8. This will be scattered on the ground under the bursting point and will neutral¬ ize the hydrochloric acid from the liquid smoke falling on the ground. In Fig. 2 there is illustrated part of a section through a variant of the smoke hand grenade, the latter compris¬ ing an outer pipe and a centre pipe including a container of shatter-proof glass which is arranged around the centre pipe, and which contains the liquid smoke, and wherein the acid neutralizing material fills up around the glass container. By reaction in the trajectory the glass container and the canister is broken by the pres¬ sure from the busting charge when this is fired, for thereby scattering smoke and the acid neutralizing compo- nent. Fig. 3 illustrates a section through a smoke canister which the smoke hand grenade according to Fig. 1 and Fig. 2 can be equipped with, by removing the plug 12 and screwing the attachment plug 17 into the bottom. Upon throwing, the bursting charge will be fired in the tra¬ jectory and the heat from the charge will fire the igni¬ tion conveyor in the attachment plug 17, which immediate¬ ly will send a flame tongue into the ignition charge 21 , which for example can be a thermite mixture, and which burns through the sleeve around the ignition charge and fires the surface of the smoke charge, preferably as a pyrotechnical charge, whereby the smoke gas escapes through the smoke channels 20 in the the charge and out through the holes 22 in the bottom of the canister. The canister will lay on the ground and burn whilst continu¬ ously releasing smoke in 20-30 seconds. It will be up to the user to decide whether the canister according to Fig. 3 should be included in the smoke hand grenade in view of the increased price entailed therewith. Fig. 4 illustrates an insert or module which can be screwed into the smoke hand grenade instead of the igni¬ tion mechanism 3, whereby the canister can be fired from its own discharge pipe eqipped with a centre blasting bolt and an inner diameter which is adapted to the canis¬ ter. The field of application can be training smoke for armoured vehicles wherein the original pipes for dis¬ charging smoke are equipped with insert pipes which have been adapted to the modified smoke hand grenade. Upon application the pipes are firstly loaded and there¬ after fired from the vehicles by pressing the discharge button for the smoke, whereby through a not specified reacation chain, the blasting bolt in the insert pipe will strike against the blasting cap 23 which ignites the conveyor 24 which in turn fires the ejector charge 26, whereby the hot combustion gases blow out through the holes 25 in the rear element and eject the canister, at the same time as the heat from the combustion also will ignite the delay unit 27 which after approximately 1 second will fire the bursting charge 28 so that the can¬ ister is bursting in the air as previously described, for generating an instantaneous, environment favourable smoke screen approximately 20 metres from the vehicle. The smoke material in the previously discussed smoke hand grenades or canisters, is titanium tetrachloride TiCl 4 . The acid neutralizing material can be calsuium CaC0 3 , ammonia (30-35%) in water or an alifatic amine or some other acid neutralizing compound. Preferably, the titanium tetrachloride can be present as a liquid phase, this liquid by contacting the moisture of the air spontaneously reacting for generation of white smoke. The heat dissipation by this reaction is relative¬ ly small. Consequently, there exists no danger for put¬ ting the vegitation on fire by using this smoke material, if the smoke canister of Fig. 3 is not attached to the smoke hand grenade. In a canister dissipating smoke from the ground there will preferably be used a pyrotechnical smoke charge. This can give off TTC smoke or HC smoke if one reduces the requirement regarding toxicity. The elements of the smoke hand grenade can appropriately be injection moulded plastics material (for example PV- DF). The bottom including pipe can be injection moulded in one member and the lid in a second member. The lid can appropriately be added to said first member by ultra sonic welding, see Fig. 1, reference numeral 8. The shatter-proof, double-walled glass container illust¬ rated in Fig. 2, can easily be manufactured by letting the glass pipe which is to constitute the wall towards the centre pipe of the container, be arranged in a second glass pipe having a diameter corresponding to the outer diameter of the glass container, whereafter the pipes are welded against each other at the ends thereof, with a successive curing. Thereafter, there is attached a smaller inlet pipe by welding, which after filling of TTC is closed by fusing.

Claims: P a t e n t c l a i m s 1. Arrangement in a smoke hand grenade (Fig. 1) com¬ prising a container which per se holds a liquid smoke material, c h a r a c t e r i z e d i n that the container which holds the liquid smoke material (9a), is separated from a composition (8a) which after bursting neutralizes the acid by-products being formed after the liquid has reacted with the air moisture whilst emitting smoke. 2. Arrangement as claimed in claim 1 , c h a r a c t e r i z e d i n that the container (Fig. 1 ) is constructed from three concentric pipes having lid and bottom and having a bursting charge (7) in the inner pipe, the liquid smoke in one of the compartments (9) and the acid neutralizing component in the second compartment (8). 3. Arrangement as claimed in claim 1, c h a r a c t e r i z e d i n that the grenade (Fig. 2) is constructed by an outer pipe (11) and a centre pipe (15) having bursting charge, there being around the centre pipe in the compartment between the outer pipe and the centre pipe provided a concentric glass container (12) having liquid smoke (13), the rest of the compart¬ ment (14) being filled up with the acid neutralizing material, through a bottom inlet (16). 4. Arrangement as claimed in claim 2, c h a r a c t e r i z e d i n that in the lid of the canister there is mounted an ignition mechanism for hand grenade (3) and which after ejection will fire, after a delay time, a bursting charge located in the centre pipe (7), whereby the canister is burst and the components scattered in the air. 5. Arrangement as claimed in claims 2 and 3, c h a r a c t e r i z e d i n that in the bottom of the container there is attached a metal canister (Fig. 3) comprising a pyrotechnical smoke charge (19). 6. Arrangement as claimed in claim 5, c h a r a c t e r i z e d i n that during the bursting of the container (Fig. 1 or Fig. 2) the flame tongue from the bursting charge will ignite a conveyer (17a) of the attachment plug, which ignites the adjacent blasting charge (21) in the metal canister for thereby firing the exposed surface of the pyrotechnical smoke charge, whereafter smoke and combustion products will escape through downwardly extending channels in the smoke charge (20) and out through holes in the bottom of the canister (22). 7. Arrangement as claimed in claims 1, 2 and 3, c h a r a c t e r i z e d i n that the hand grenade ignition mechanism (3) has been replaced with a metal member (Fig. 4), wherein are provided a blasting cap (23), a powder charge (26), discharge holes for powder gases (25) and a black powder delay unit (27) being con¬ nected with the bursting charge (28) which is present in the centre pipe. 8. Arrangement as claimed in claim 7, c h a r a c t e r i z e d i n that the hand grenade (canister) is located in an appropriate pipe having an ignition bolt and being discharged by the ignition bolt which upon firing impinges into the blasting cap (23) in the metal rear member, which thereby expels a flame tongue into a black powder conveyor (24) which ignites the powder charge (26), whereby the canister is dis- charged from the pipe due to the gun powder gases escap¬ ing through the holes in the metal rear member and the bursting charge being fired through the black powder delay unit (27) . 9. Arrangement as claimed in claims 2 and 3, c h a r a c t e r i z e d i n that the liquid smoke is titanium tetrachloride (Ti Cl 4 ) (TTC) and the acid neu¬ tralizing component is calsium powder (Ca C0 3 ), ammoniac (30-35%), or an alifatic amine or some other acid neu¬ tralizing compound, and that the canister is manufactured from polyvinylidenfluoride (PVDF) or some other type of plastics.

Inventors: HALSNES ODD, JAKOBSEN LISBETH S, WULVIK ERIK A, HALSNES, ODD, JAKOBSEN, LISBETH, S., WULVIK, ERIK, A.
Applicants: FORSVARETS FORSKNINGS, FORSVARETS FORSKNINGSINSTITUTT
Application year: 1995
Main classification: F42B12
IPC codes: F42B12