Abstract:
The present invention relates to a cartridge for smoke generation for the protection of combat vehicles, wherein the shell has the form of an integral two-chamber double can ( 2 ) including a partition wall shared by both chambers ( 10 ), the wall thickness of the partition wall ( 10 ) being greater than the wall thickness of the double can outer wall ( 22 ), and the front end of the double can ( 2 ) being closed gas-tight.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an ammunition for smoke generation for the protection of combat vehicles. 
     It is known to protect combat vehicles, in particular tanks, in combat missions by means of pyrotechnical smokes and also by means of combined pyrotechnical/infrared-emitting smokes. This protection on the one hand covers the visual range so as to withdraw a combat vehicle from direct observation and from being targeted. On the other hand, the protection also encompasses warding off, e.g., infrared-guided homing missiles. 
     From the prior art, e.g. from U.S. Pat. No. 4,700,628, there is known a smoke grenade consisting of a pyrotechnical smoke generator and an infrared smoke generator. This grenade is launched from the vehicle to be protected and ignited at a defined distance from the combat vehicle to be protected. A smoke screen then forms which lasts for several seconds. A second part of the grenade includes the infrared smoke active mass which drops to the ground as a smoke cup and forms an infrared smoke. 
     It is, however, a drawback in this prior-art smoke grenade that the infrared smoke cup released upon separation of the grenade must land on the ground in a defined position and only then generates its infrared smoke. If it drops with the opening facing down, for example, it will hardly release any smoke. 
     Another smoke-generating projectile is known from DE 28 418 15 C2 and from U.S. Pat. No. 4,324,183. 
     Smoke grenades containing several different charges for the protection of combat vehicles are moreover known from U.S. Pat. No. 4,353,301. 
     In accordance with this prior art, a can-shaped container includes in its lower portion a discharge composition which is initiated by an ignition composition for igniting a detonation separator charge, which in turn ignites a flammable smoke active mass preferably having a disc shape. In front of the first flammable smoke charge when viewed in the direction of the projectile&#39;s trajectory, another smoke charge is mounted which is more compact and therefore is ignited more slowly than the first smoke active mass. It is moreover known to combine smoke active masses and infrared-flare active masses in smoke grenades. In accordance with this prior art, a cup containing the active masses is rolled up inside a can and sealed by means of sealant. To this end several components are necessary, resulting in comparatively high material costs and costly assembly. 
     It frequently is a drawback of this ammunition that leakages occur with temperature fluctuations due to the accumulation of different interfaces owing to an increased number of components, so that the ammunition may possibly not function reliably any more. 
     SUMMARY 
     It was therefore the object of the present invention to furnish an ammunition for generating a smoke for the protection of combat vehicles, which may be manufactured more cost-effectively and more reliably. 
     The ammunition for smoke generation for the protection of combat vehicles according to the invention includes a shell, at least one active mass arranged therein, at least one detonation separator charge, at least one ejection charge for ejecting the ammunition from a conventional launcher tube, and electrical contact means for igniting the ejection charge. 
     The shell of the ammunition in accordance with the invention has the form of an integral two-chamber double can having a partition wall shared by both chambers, wherein the wall thickness of the partition wall is greater than the wall thickness of the double can outer wall, and an end of the double can located in the direction of the launcher tube muzzle (front-side end) is closed gas-tight. 
     Due to the design as a double can, a more compact construction than with the construction of the prior art is possible, together the possibility of accommodating a larger quantity of active mass, and in turn results in enhanced efficiency. 
     In comparison with the prior art, savings may be realized in that for one thing, assembly is facilitated by the smaller number of required components. The ammunition of the invention moreover allows for higher functional safety because—as a result of a reduced number of components and thus less interfaces—it is less susceptible to disturbance factors such as leakages, temperature influences, strength properties. A smaller number of components to be assembled translates into a more simple production process and thus a reduced failure frequency. 
     The ammunition according to the invention may be designed for any customary smoke cartridge calibers, thus e.g. for the applicant&#39;s products which are being distributed under the trade name MASKE (German trade mark registered in the Applicant&#39;s name) for the calibers 66 mm, 76 mm and 81 mm. 
     With the ammunition of the invention it is possible to build, in less than a second, a complete infrared and visual smoke screen which is stable up to approximately one minute. 
     The ammunition of the invention preferably is a bimodal ammunition concept wherein in general a high-velocity flare distribution and components for sustained infrared and visual screening are contained in the ammunition as active masses. 
     The ammunition of the invention is effective against simultaneous attacks by several kinds of sensor-guided weapons and has in particular found to be effective for the protection of tanks. 
     In summary it can thus be stated that the ammunition of the invention is particularly suited for the protection of combat vehicles being threatened by: 
     optical and infrared observation 
     optical and infrared aiming devices 
     optical and infrared sensor-guided weapons 
     laser illuminators and laser beam-guided weapons, as well as 
     laser-supported range finders. 
     Further advantages of the present invention are the simple and quick assembly; the enhanced effectivity due to the accommodation of more active mass; less trained personnel is required for assembly; and the quality of overall manufacture may be controlled better inasmuch as less components are being used and less interfaces with required components are necessary than in the prior art, whereby the sources of errors thereof are accordingly eliminated. Easy adaptation to semi- and fully automatic production is possible. 
     The ammunition of the invention is a self-contained unit without any costly connecting technology as hitherto required in the prior art, and with markedly simplified sealing technology. 
     Preferably the double can is manufactured of aluminum. 
     Due to the double can design it is particularly advantageous to manufacture this double can of a metal, in particular aluminum metal, by extrusion. 
     As a preferred active mass of the ammunition, smoke-generating pressed bodies which are known per se, and flares which emit infrared radiation and are also known per se, are used as the active mass. 
     In a preferred embodiment of the present ammunition, the double can is sealed with an O-ring and closed with a lid on its front side. This has the advantage that prior-art sealing materials, which may be subjected to thermal variations and thus may produce leakages, are avoided, and there is no more need to allow time for the sealing material to cure out or complete reactions. Moreover O-rings are commercially available at low cost in all sizes, dimensions and desired materials. 
     Preferably the lid is fastened by crimping on the O-ring, flanging of the front-end double can edge, and creasing in front of the lid. Hereby it is ensured that the O-ring on the one hand indeed is tight, and on the other hand there results a certain mechanical stability of the ammunition, for example during handling when a cartridge drops to the ground, or simply when subjected to vibrations inside the launcher tube, for example when a tank is travelling through difficult terrain. 
     In a preferred embodiment, the ammunition may employ the classical technology of smoke-generating ammunition, in particular smoke cartridges, wherein a detonation separator charge, igniter means for igniting the active mass and separating the double can, as well as a delay element, in particular a pyrotechnical delay element, are provided. 
     It is preferred to fasten the ejection charge on the side of the partition wall facing the bottom of the launcher tube. 
     In a preferred embodiment, the ejection charge includes an electrically ignitable primer as well as a propellant charge powder, preferably black powder. 
     Inside the double can underneath the partition wall in the direction of the launcher bottom, a disc may be arranged which is provided with venting bores preferably covered with a rupture foil. 
     Hereby it is ensured that following ignition of the propellant charge powder, initially a sufficiently great gas pressure builds up, and the gases, following rupturing of the rupture foils, then flow out through the venting bores acting as nozzles in the direction of the launcher bottom so as to expel the ammunition from the launcher tube. 
     In order to ensure smooth separation with maximum possible uniformity, in a preferred embodiment of the invention predetermined breaking points are provided in the double can outer wall in the range of the active mass. These predetermined breaking points are preferably produced by notching. 
     If necessary, the ammunition may on the front end be provided with a protective cap extending over the launcher tube to thus serve as a protection for the ammunition and the launcher tube itself in the presence of rain and soiling, and thus ensure the functionality of the launcher system together with the ammunition under adverse climate conditions and combat conditions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages and features result from the description of an embodiment by referring to the drawing, wherein: 
     FIG. 1 shows an ammunition in accordance with the invention, having the form of an infrared-smoke cartridge. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 a cartridge as ammunition for smoke generation for the protection of combat vehicles, in particular tanks, is schematically represented under  1 . 
     The caliber of cartridge  1  is 76 mm in an exemplary case. The ammunition  1  includes a double can  2  having arranged in its large chamber  3 , shown on the right in the FIGURE, active masses  4  and  5 . The active mass  4  is a smoke active mass which is present in the form of a pressed article and based, e.g., on a composition as described in EP 0 046 230 A2. 
     A typical smoke composition may, for example, be as follows. 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Red phosphorus 
                 50-85% (wt.) 
                   
               
               
                   
                 Potassium nitrate (KNO 3 ) 
                 0-24% (wt.) 
               
               
                   
                 Magnesium (Mg) 
                 4-25% (wt.) 
               
               
                   
                 Binder 
                 3-10% (wt.) 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Red phosphorus (Type HB600) 
                 66% (wt.) 
                   
               
               
                   
                 Potassium nitrate (KNO 3 ) 
                 16% (wt.) 
               
               
                   
                 Magnesium (Mg) 
                 12% (wt.) 
               
               
                   
                 Binder 
                 6% (wt.) 
               
               
                   
                   
               
             
          
         
       
     
     The IR-active mass  5  includes flares of a circle segment shape with infrared active mass on them, wherein the infrared active mass is composed on the basis of micro-encapsulated red phosphorus. 
     In an exemplary case the flare active mass  5  is arranged between two layers of smoke active masses  4 . 
     The flares form the spontaneous component of the smoke and enable building of a smoke screen within seconds. Positioning between the pressed bodies of smoke active mass ensures secure ignition. 
     For producing the cartridge  1 , the smoke active mass  4 Land the IR-active mass  5  are introduced into the double can  2 , a lid  6  with the O-ring  7  is inserted into the double can and tightly closed by crimping on the O-ring  7 . On the front-end side, the double can  2  is flanged and creased in front of the lid  6 . Both measures serve for lid fixation. 
     On the side of the small chamber  8  (on the left in FIG. 1) a detonation separator charge  9  is fixed on the partition wall  10  shared by the chambers  2  and  8 . 
     The detonation separator charge  9  contains igniter means  11  for igniting the active masses  4  and  5  and separating the double can  2 . 
     The ignition timing is determined by a pyrotechnical delay element  12  which is ignited upon launching. 
     Subsequently the ejection charge  13  is fastened to the left side of the partition wall  10  in the representation of FIG.  1 . 
     The ejection charge  13  includes electrical contact means  14 , a primer  15 , and a propellant charge  16  which is black powder in an exemplary case. The black powder as the propellant charge  16  delivers the necessary gas pressure for accelerating the cartridge  1  out of the launcher tube. 
     At the outer circumference of the double can  2 , in the range of the partition wall  10 , a groove  17  for receiving an O-ring  18  is turned. The O-ring  18  serves as a sabot. 
     When the cartridge  1  is employed, the following functions unfold: 
     The cartridge  1  is placed within a conventional launcher tube which is not shown in FIG.  1 . By a pulse of electric current the contact means  14  ignites the primer  15  which then causes the black powder to ignite as a propellant charge  16 . The hot gas ignites the delay element  12 , and the gas exits into the launcher cavity through venting bores  19  in a disc  20  arranged underneath the partition wall  10  so as to expel the cartridge  1  from the launcher. 
     The required insulation of the black powder is achieved with the aid of a rupture foil  21  pasted over the venting bores  19  of the disc  20 . 
     After ejection, the active mass  4  and  5  is ignited after lapse of the delay period of the delay element  12 , and the double can  2  is separated in the range of the active masses  4  and  5 . 
     In order to ensure smooth and homogeneous separation, the double can outer wall  22  is notched in four places distributed over the circumference in the range in which the active masses  4  and  5  are located, whereby predetermined breaking points are provided. 
     By this measure it is ensured that burning active mass fragments and metal fragments will not be hurled through the air in an uncontrolled manner to thus become a potential hazard. 
     Through these predetermined breaking points it is also ensured that the active masses  4  and  5  will be distributed within a controlled range, and thus a dense smoke screen may be built within the shortest possible period. 
     Preferably the double can outer wall  22  of the large chamber  3  of the double can  2  and the outer wall  23  of the double can  22  have different wall thicknesses, whereby the mechanical stability of the cartridge is enhanced. 
     In addition, the partition wall  10  also having a greater thickness moreover serves as a support for distributing the forces acting on the launcher tube during launching, because the pressure is annularly transmitted to the entire casing of the double can  22  via the partition wall  10 . 
     It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential it characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein. 
     List of Reference Numerals 
       1 : cartridge 
       2 : double can 
       3 : large chamber 
       4 : smoke active mass 
       5 : IR-active mass 
       6 : lid 
       7 : O-ring 
       8 : small chamber 
       9 : detonation separator charge 
       10 : partition wall 
       11 : igniter means 
       12 : pyrotechnical delay element 
       13 : ejection charge 
       14 : contact means 
       15 : primer 
       16 : propellant charge 
       17 : groove 
       18 : O-ring 
       19 : venting bores 
       20 : disc 
       21 : rupture foil 
       22 : double can outer wall, large chamber 
       23 : double can outer wall, small chamber