Sub-body of an irritant cartridge and method for producing a sub-body of an irritant cartridge

Abstract

The invention relates to a method for producing a sub-body (24) of an irritant cartridge (10), wherein at least two compositions are filled into a housing (54) in different layers (42, 44, 46). The method and the sub-bodies (24) are improved in that at least one gradient layer (48, 50) is produced between two, in particular originally homogeneous, layers (42, 44, 46) by means of vibratory mixing (V).

Description

[0001] "Subbody of an irritant cartridge and method for producing a subbody of an irritant cartridge"

[0002] The invention relates to a subbody of an irritant cartridge and a method for manufacturing a subbody of the irritant cartridge.

[0003] Known irritant cartridges essentially consist of a primer located in the base of the cartridge, an igniter above it, and at least one compressed irritant compound in the form of at least one sub-body. These sub-bodies contain a pyrotechnic igniter and an irritant. The sub-bodies consist of a mixture of an igniter and a required amount of irritants such as chloroacetophenone (CN) or chlorobenzylidene malononitrile (CS). The irritants are incorporated into a smoldering mixture. Upon combustion, i.e., after ignition by the igniter, the igniter heats the smoldering mixture and releases the irritant in the form of irritant gas.

[0004] A pyrotechnic propellant charge is known from EP4013938 A1. Various types of pipes are used in the construction of underground boreholes for the extraction of liquids, minerals, or gases. To seal sections of a borehole, pyrotechnic propellant charges (pyrotechnic "power charges") are activated. These charges generate high pressures through the slow combustion of chemical substances. The propellant charge consists of a cylindrical casing with a first and second end and a middle section. The main propellant is located in the middle section, while the igniter is located at the casing ends. This igniter consists of a mixture of the main propellant and an ignition propellant.The primer is characterized by specific properties: it has a higher energy output (for example, boron-potassium nitrate with up to 1600 calories per gram), a lower ignition temperature of a maximum of 600 °C, and a propagation index. The mixture in the ignition sections is gradient-formed. Near the casing ends, it consists of more than 90% primer, while the proportion decreases to less than 10% further away. The primer material makes up approximately 1.5 to 3% of the total weight of the propellant charge. The main propellant is less sensitive and consists of metallic fuels, such as aluminum, as well as oxidizers, for example, potassium or ammonium nitrate. During manufacturing, the primer material is first filled into the casing, followed by the main propellant. The ignition zones at the ends of the casing are created by the partial mixing of the two components.

[0005] From DE 10 2020 004 562 A1, various designs of irritant cartridges with a caliber of 40 mm are known. The irritant cartridges comprise a cartridge case, a bombette, and several irritant sub-sub ...

[0006] The production of the subbodies is very complex, as the subbodies preferably do not have a heterogeneous distribution of the irritant, but rather have more irritant at one end and more igniter at the other. In the prior art, the irritant and the igniter are filled into a container in layers. Filling it with many different layers is laborious.

[0007] The invention is therefore based on the objective of improving the sub-body of an irritant cartridge and the method for manufacturing a sub-body of the irritant cartridge.

[0008] This problem underlying the invention is now solved by a method with the features of claim 1. A gradient layer is produced between two, in particular initially homogeneous, layers by means of vibration mixing. The layers can also be referred to as sets. At the beginning of the process, a first material composition and a second material composition are introduced in layers into a container. The introduced vibrations cause the particles to move, leading to mixing at the interface of the two layers. Particles from the first layer penetrate into the second layer and vice versa, creating a transition zone that forms the gradient layer.

[0009] For good and even ignition, it is desirable to avoid harsh transitions between different layers or blends. Therefore, intermediate blends, which are a mixture of the corresponding higher and lower explosive blends, are often useful. In a preferred embodiment, the layers are filled into a housing, which can also be called a sleeve, whereby the at least one gradient layer or intermediate blend is created within the housing, which later also forms the casing of the subbody. According to the invention, these gradient layers or intermediate blends are created "in-situ" within the housing by vibration, with the housing later forming the casing of the subbody. No separate mixing container is necessary, which, for example, eliminates extra dosing and preparation steps for the production of the subbodies with the different layers.

[0010] Preferably, the subbody has a first layer with a low-brisance pyrotechnic composition, a second layer with a medium-brisance pyrotechnic composition, and a third layer with a high-brisance pyrotechnic composition.

[0011] The casing is filled with a first layer of low brisance, a second layer of medium brisance, and a third layer of high brisance. Vibration mixing is then carried out. This process creates a first gradient layer between the first and second layers and a second gradient layer between the second and third layers.

[0012] As a third and final layer, an igniter, such as black powder and / or igniter gauze, is placed on the open end of the casing. A swirl element, in particular a wire mesh, is placed on top of this final layer. This improves the ignition of the sub-body. The swirl element serves to swirl and cool the escaping irritant-smoldering compound mixture. This prevents the sub-body from burning with an open flame and the irritant from being combusted instead of being released into the air. This final layer has the highest brisance. The first layer placed in the casing is an irritant smoldering compound and has the lowest brisance. The irritant smoldering compound consists of an irritant component and a smoldering compound component as a homogeneous mixture. The smoldering compound component serves as the pyrotechnic heating element. After ignition, the smoldering compound component reacts in an exothermic reaction, thus generating heat and gases.The actual irritant (CS) is not burned or ignited, as this would cause it to decompose. The heat and the resulting gases cause the CS to be emitted and dispersed into the air.

[0013] After vibration mixing, the filled layers and the at least one generated gradient layer are pressed into the housing. This pressing action prevents further, unintentional mixing of the layers during storage.

[0014] The properties of these gradient layers can be specifically influenced by controlling the vibration intensity, frequency, and mixing duration. Shorter mixing times and lower vibration intensity, for example, result in a narrow gradient layer, while longer times and more intense vibrations produce deeper mixing.

[0015] The material properties of the compositions play a role. Irritant cartridges typically contain a pyrolytic charge that releases the irritant. The irritant is contained within the pyrolytic charge. Although the exact composition can vary, different materials are frequently used for the igniter. It is conceivable that black powder or nitrous oxide—also known as nitrocellulose—is used as the igniter in the subbodies. A possible irritant is 2-chlorobenzylidene malononitrile (CS). Furthermore, the subbodies may contain oxidizers to aid combustion, binders to stabilize the mixture, and / or flow agents to improve the dispersal of the irritant.

[0016] To create at least one targeted gradient layer, it is advisable to adjust various parameters such as vibration frequency, amplitude, and mixing time in experiments. Overall, vibration mixing is an effective method for producing at least one gradient layer, especially when the materials have similar physical properties and complete homogenization is not the goal.

[0017] Furthermore, the problem is solved by a subbody produced in this way, namely by a subbody of an irritant cartridge, wherein the subbody has been produced according to the inventive method, wherein at least two compositions are arranged in different layers in a housing, wherein a gradient layer is present between two, in particular originally homogeneous, layers and this at least one gradient layer has been produced by a vibration mixing.

[0018] The layers have different brisances. Preferably, a first layer with a low brisance, a second layer with a medium brisance, and a third layer with a high brisance are present, wherein a first gradient layer is present between the first and second layers, and a second gradient layer is present between the second and third layers, and these gradient layers are generated by vibration mixing.

[0019] The housing is preferably made of aluminum. Alternatively, the housing can be made of cardboard.

[0020] The invention further relates to an irritant cartridge with a bombette, wherein at least one subbody is arranged in the bombette. Preferably, more than 4 and fewer than 20 subbodies are arranged in the bombette. It is conceivable that eight subbodies are arranged in the bombette.

[0021] The subbodies are preferably arranged in two layers, each layer having several, in particular four, subbodies. Each layer preferably has the same number of subbodies.

[0022] The irritant cartridge has a casing that is closed on one side by a cap and on the other by a terminal end containing a propellant charge. The bombette is located inside this casing. The bombette has a cap on one side and a firing mechanism with, among other things, an ejection charge on the other. One layer of sub-sub ...

[0023] The other layer is located near the base, near the ignition mechanism. The sub-layers of this base layer are arranged within the irritant cartridge case such that the layer with the highest brisance is located near the ignition mechanism, while the layer with the lowest brisance, i.e., the smoldering charges, is directed towards the center of the bombette.

[0024] The subbodies are preferably arranged offset from one another. This ensures better ignition of the subbodies.

[0025] The subbodies are preferably arranged such that a central cavity remains between them, containing, for example, a hollow rivet with an ignition charge. The hollow rivet and the ignition charge ignite the subbody layer closest to the lid first. The gauze disc on the lid intensifies and redirects the flame, and only then is the layer furthest from the lid, on the igniter side, ignited.

[0026] There are now numerous possibilities for elaborating and further developing the process. Reference is first made to the claims subordinate to claim 1. A preferred embodiment of the invention is explained in more detail below with reference to the drawing and the accompanying description. The drawing shows:

[0027] Fig. 1 shows a schematic sectional view of an irritant cartridge with a bombette and several sub-bodies arranged inside the bombette.

[0028] Fig. 2 shows a schematic sectional view of the bombette,

[0029] Fig. 3 shows a schematic sectional view of one of the subbodies, Fig. 4 shows a diagram of the brisance of the filling of the subbody before and after a vibration mixing.

[0030] Fig. 1 shows a schematic representation of an irritant cartridge 10. The irritant cartridge 10 includes, by way of example, a substantially cylindrical casing 12, a bombette 14, a propellant charge 16 for driving the bombette 14 out of the casing 12, a lid 18 that seals the upper opening of the casing 12 in a moisture-tight manner (as shown in Fig. 1), and in the base of the casing a primer 20 for igniting the propellant charge 16, as well as a seal between the bombette 14 and the propellant charge 16.

[0031] The bombette 14 is shown separately in Fig. 2 and comprises a substantially cylindrical housing 22, several subbodies 24, a lid 26, a short ignition tube 28 in the form of a hollow rivet 28, a delay charge 30 for igniting the subbodies 24, the hollow rivet 28 with an ignition charge 32, and an ejection charge 34 for ejecting the ignited subbodies 24 from the housing 22. The housing 22 is received substantially coaxially in the sleeve 12. The subbodies 24 are received in the housing 22. The cover 26 closes the upper opening of the housing 22 shown in Fig. 1. The hollow rivet 28 extends essentially coaxially within the housing 22 from a lower end wall 22a of the housing 22. The propellant charge 16 is arranged between, on the one hand, the base of the cartridge case and, on the other hand, the lower end wall 22a and the delay charge 30, and is adjacent to the primer 20. The delay charge 30 is arranged in a dome of the end wall 22a.The ignition charge 32 is arranged at the lower opening of the hollow rivet 28 and above the delay charge 30. The ejection charge 34 is arranged on a lower end wall of the housing 22 around the lower end of the hollow rivet 28.

[0032] To fire the cartridge 10, the primer 20 is ignited, for example, by means of a firing pin (not shown), thereby igniting the propellant charge 16. The ignited propellant charge 16 ignites the delay charge 30 and simultaneously pushes the bombette 14 in FIG. 1 upwards away from the base of the cartridge case, causing it to blow off the cap 18 and fly out of the cartridge case 12. The ignited delay charge 30 burns during its flight and ignites the hollow rivet 28 with its ignition charge 32, producing a flame that spreads upwards from below through the ignition tube 28 into a cavity 36 between the sub-bodies 24, igniting them. Preferably, more than four and fewer than twenty sub-bodies 24 are arranged in the bombette 14. It is conceivable that eight sub-bodies 24 are arranged in the bombette 14.

[0033] The subbodies 24 are preferably arranged in two layers 24a, 24b, each layer 24a, 24b comprising several, in particular four, subbodies 24. Each layer 24a, 24b preferably comprises the same number of subbodies 24.

[0034] One layer 24b of the subbody 24 is arranged inside the bombette 14 near the lid 26 and the other layer 24a is arranged farther from the lid, closer to the ignition mechanism.

[0035] The subbodies 24 of the layer 24b near the lid are arranged in the bombette 14 such that the layer with the highest brisance is located at the lid 26 and the layer with lower brisance, i.e., the smoldering charges, is directed towards the center of the bombette 14. A detonating gauze disc 38 is preferably arranged on the lid 26 of the bombette 14.

[0036] The other layer 24a is arranged near the front face 22a or the base 22a with the ignition mechanism. The subbodies 24 of the base-adjacent layer 24a are arranged in the bombette 14 such that the layer with the highest brisance is located at the ignition mechanism and the layer with lower brisance, i.e., the smoldering charges, is directed towards the center of the bombette 14.

[0037] The subbodies 24 of layers 24a and 24b are preferably arranged offset from one another. This ensures better ignition of the subbodies 24.

[0038] The subbodies 24 are preferably arranged such that the central cavity 36 remains between the subbodies 24, with the hollow rivet 28, for example, containing the ignition charge 32, located in the cavity 36. The flame from the ignition charge burns through the cavity 36 to the lid 26 of the bombette 14, igniting the ignition gauze disc 38 there and thus the layer 24b of the subbodies 24 closest to the lid. The hollow rivet 28 and the ignition charge 32 first ignite the layer 24b of the subbodies 24 closest to the lid. The flame is intensified and deflected by the ignition gauze disc 38 on the lid 26, and only then is the layer 24a furthest from the lid, on the detonator side, ignited.

[0039] Each subbody 24 has a housing 54 made of aluminium or cardboard (see Fig.

[0040] 3) The subbody 24 comprises a third layer 46 with a high-brisance pyrotechnic composition, a second layer 44 with a medium-brisance pyrotechnic composition, and a first layer 42 with a low-brisance pyrotechnic composition. The first layer 42 contains an irritant smoldering composition, also referred to as a smoldering composition. In Fig. 3, the ignition side is shown at the bottom. Preferably, the layer 42 with the smoldering composition is significantly thicker than the ignition or intermediate composition layer 44, 46.

[0041] The first layer 42 with a low brisance, the second layer 44 with a medium brisance, and the third layer 46 with a high brisance are first placed into the housing 54, as shown on the left in Figure 4. The vibration mixing is then carried out, as indicated by the arrow V. A first gradient layer 48 is created between the first layer 42 and the second layer 44, and a second gradient layer 50 is created between the second layer 44 and the third layer 46.

[0042] The third and final layer 46 is introduced in the form of black powder. A swirling element, in particular a wire mesh 52, is placed on the last layer 46. This improves the ignition of the sub-body 24. The swirling element serves to swirl and cool the escaping irritant-smoldering compound mixture. This prevents the sub-body 24 from burning with an open flame and the irritant from being burned instead of being released into the air. This last layer 46 has the highest brisance. The layer 42, which is filled into the casing first, is an irritant-smoldering compound and has the lowest brisance.

[0043] After vibration mixing, the filled layers 42, 44, 46 and the at least one generated gradient layer 48, 50 are pressed into the housing 54. Pressing prevents further, unintentional mixing of the layers 42 to 50 during storage. Figure 5 shows the brisance curve plotted against position. Position 56 denotes the brisance curve before vibration mixing, and position 58 denotes the brisance curve after vibration mixing.

[0044] Curve 56 shows the brisance of layer 46 before vibration mixing in the range x between 0 and 1. Curve 56 shows the brisance of layer 44 before vibration mixing in the range x between 1 and 2. Curve 56 shows the brisance of layer 42 before vibration mixing in the range x between 2 and 3. The brisance differs between these three layers (42, 44, and 46) before vibration mixing, remaining constant within each layer. There are abrupt, sharp transitions or jumps in brisance. This makes uniform ignition difficult.

[0045] After vibration mixing, curve 58 clearly shows that in the second gradient layer 50, the brisance changes gradually, for example linearly, between layers 44 and 46 in the range x between 0.75 and 1.25. In the first gradient layer 48, the brisance changes gradually, for example linearly, between layers 42 and 44 in the range x between 1.75 and 2.25. For good and uniform ignition, it is desirable to avoid "hard" transitions between different layers 42, 44, and 46. This is achieved through vibration mixing. Reference list:

[0046] 10 irritant cartridges

[0047] 12 sleeve

[0048] 14 Bombette

[0049] 16 propellant charge

[0050] 18 lids for 12

[0051] 20 firelighters

[0052] 22 cases

[0053] 22a Floor or lower end wall of 22

[0054] 24 subbodies

[0055] 24a first layer of subbodies 24

[0056] 24b second layer of subbodies 24

[0057] 26 lids for 22

[0058] 28 Ignition tube / Hollow rivet

[0059] 30 delay or ignition charges

[0060] 32 ignition charges

[0061] 34 ejection charge

[0062] 36 cavity

[0063] 38 ignition gauze disc

[0064] 40 Sealing

[0065] 42 first layer with pyrolysis compound

[0066] 44 second layer with interlude

[0067] 46 third layer with ignition set

[0068] 48 first gradient layer with mixed phase

[0069] 50 second gradient layer with mixed phase

[0070] 52 wire mesh

[0071] 54 cases

[0072] 56 Brisance curve before vibration mixing 58 Brisance curve after vibration mixing V Vibration mixing

Claims

Patent claims:

1. Method for producing a subbody (24) of an irritant cartridge (10), wherein at least two compositions are filled into a housing (54) in different layers (42, 44, 46), characterized in that at least one gradient layer (48, 50) is produced between two, in particular, originally homogeneous layers (42, 44, 46) by means of a vibration mixing (V).

2. Method according to claim 1, characterized in that the filled layers (42, 44, 46) each have a different brisance.

3. Method according to claim 1 or 2, characterized in that the layers (42, 44, 46) are filled into a housing (54), wherein the at least one gradient layer (48, 50) is generated in the housing (54), the housing (54) also forming a casing of the subbody (24).

4. Method according to one of the preceding claims, characterized in that a first layer (42) with a low brisance, a second layer (44) with a medium brisance and a third layer (46) with a high brisance is filled and then the vibration mixing (V) is carried out, wherein a first gradient layer (48) is produced between the first and the second layer (42, 44) and a second gradient layer (50) is produced between the second and the third layer (44, 46).

5. A method according to any one of the preceding claims, characterized in that an igniter, e.g., black powder and / or igniter gauze, is introduced as the last layer (46) on the open side of the housing (54) and this layer (46) has the highest brisance.

6. A method according to any one of the preceding claims, characterized in that the layer (42) first filled into the housing (54) is an irritant smoldering agent.

7. Method according to one of the preceding claims, characterized in that after vibration mixing (V) the filled layers (42, 44, 46) and the at least one generated gradient layer (48, 50) are pressed into the housing (54).

8. Method according to one of the preceding claims, characterized in that a turbulence element, in particular a wire mesh (52), is arranged on the last layer (46).

9. Subbody (24) of an irritant cartridge (10), wherein the subbody (24) has been manufactured according to a method of the preceding claims, wherein at least two compositions are arranged in different layers (42, 44, 46) in a housing (54), wherein a gradient layer (48, 50) is present between two, in particular, originally homogeneous layers (42, 44, 46) and this at least one gradient layer (48, 50) has been generated by a vibration mixing (V).

10. Subbody according to claim 9, characterized in that the layers (42, 44, 46) have different brisances.

11. Subbody according to claim 9 or 10, characterized in that the housing (22) is made of aluminium.

12. Subbody according to one of the preceding claims, characterized in that a first layer (42) with a low brisance, in particular a smoldering mixture, a second layer (44) with a medium brisance and a third layer (46) with a high brisance are present, wherein a first gradient layer (48) is present between the first and the second layer (42, 44) and a second gradient layer (50) is present between the second and the third layer (44, 46) and is produced by the vibration mixing (V).

13. Irritant cartridge (10) with a bombette (14), wherein at least one subbody (24) according to one of the preceding claims is arranged in the bombette (14).

14. Irritant cartridge according to claim 13, characterized in that the subbodies (24) are arranged in two layers (24a, 24b), each layer (24a, 24b) having several, in particular four, subbodies (24).

15. Irritant cartridge according to one of the preceding claims, characterized in that the subbodies (24) are arranged offset one above the other.

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