Sub-body of an irritant cartridge and method for producing a sub-body of an irritant cartridge
A method for producing irritant cartridges with a continuous material transition zone addresses the complexity of heterogeneous material distribution, improving manufacturing efficiency and ignition uniformity.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- RHEINMETALL WAFFE MUNITION GMBH
- Filing Date
- 2026-01-14
- Publication Date
- 2026-07-23
AI Technical Summary
The production of irritant cartridges is complex due to the heterogeneous distribution of irritant and igniter materials, requiring laborious layering processes.
A method involving filling a sleeve with two materials, a smoldering agent and an igniter, where a depression is pressed using a punch to create a continuous transition zone between the materials, ensuring a smooth, oblique boundary layer for uniform ignition.
This method simplifies the manufacturing process and improves the burning characteristics of the sub-body by ensuring a gradual transition between materials, enhancing ignition efficiency.
Smart Images
Figure EP2026050836_23072026_PF_FP_ABST
Abstract
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 ignition element 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 irritant is contained within a smoldering agent. Upon combustion, i.e., after ignition by the primer, the igniter heats the smoldering agent 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, namely a method for producing a subbody of an irritant cartridge, wherein at least two materials, namely a first material and a second material, are filled into a sleeve, wherein the materials comprise a smoldering agent and an igniter, with the following steps:
[0009] a) Filling the first material into the sleeve, b) Pressing a depression into the first filled material using a punch, wherein the depression corresponds to the negative shape of the punch, and
[0010] c) Pouring the second material into the depression created by pressing.
[0011] Viewed axially along the sleeve, a transition zone is created at a certain height where the material ratio changes from 100% of the first material to 100% of the second material along the axial depth of the depression. This process results in a continuous change in the material ratio across axially offset cross-sectional planes within the depression area. This means that at a position in the sleeve containing only the first material (outside the depression), there is a concentration of 100% of the first material. Moving axially along the sleeve's axis of symmetry towards the depression, the second material, which was filled into the depression, becomes increasingly prevalent.In axial cross-sectional planes located within the depression, the material ratio changes continuously: It begins with a high proportion of the first material at the surface of the depression and gradually increases in favor of the second material as one progresses along the axis of symmetry. At the edge of the depression, the concentration is ultimately 100% of the second material. This continuous change in the material ratio along the axially offset cross-sectional planes creates a gradual transition zone between the two materials, in which the boundary layer is neither abrupt nor radially planar, but rather runs obliquely to the axis of symmetry. This ensures a smooth material transition structure that allows for uniform ignition of the pyrolysis compound. The pyrolysis compound is formulated as an irritant-pyrolysis compound and consists of an irritant component and a pyrolysis compound component as a homogeneous mixture.The pyrolytic component serves as a pyrotechnic heating element. After ignition, the pyrolytic component reacts in an exothermic reaction, thus generating heat and gases.
[0012] For good and consistent ignition, it is desirable to avoid harsh transitions between different layers or compositions. Therefore, "intermediate compositions" are often useful, which are a mixture of the corresponding higher and lower explosive compositions. The described method serves to fill a cartridge case with two powdered and / or paste-like materials in such a way that the boundary layer between the materials does not run in a disc-like shape at a single axial position, but rather extends over an axial area and exhibits an oblique structure relative to the cartridge's axis of symmetry. The result of this method is a boundary layer between the two materials that is not flat, but assumes a three-dimensional, oblique shape. This eliminates the need to mix intermediate compositions. The manufacturing process is simplified. The method improves the burning characteristics of the sub-body.
[0013] First, the initial material is poured into the casing. This material forms the base and is evenly distributed. In the next step, a die is used to press a depression, also called a hollow, into this material. The die can have various geometric shapes, such as a pyramid, a cone, or a truncated cone. The shape of the depression corresponds to the negative form of the die used.
[0014] After the pressing process, the first material remains on the walls of the sleeve and along the shape of the recess, creating a contoured surface. This surface serves as a base for the second material, which is subsequently poured into the recess. Due to the pressed-in structure, the second material makes contact with a surface that is not radially planar, but rather extends obliquely to the axis of symmetry of the sleeve.
[0015] The sleeve is initially open on one side. It is filled through this opening.
[0016] In a preferred embodiment, the smoldering agent is added first, followed by the ignition agent. Thus, the smoldering agent is preferably added first, and then the ignition agent. This positions the ignition agent at the opening, making it easier to ignite later.
[0017] The stamp has a defined geometric shape from the group consisting of pyramid, cone, or truncated cone shapes. These stamp shapes are easy to manufacture, and the resulting geometry of the depression is stable during filling. The stamp can be manufactured, in particular, by turning, provided the stamp is rotationally symmetrical, in which case the negative mold is also rotationally symmetrical. The stamp can have several, preferably annular, steps, which can be produced by turning.
[0018] Preferably, the recess is formed centrally to an axial axis of symmetry of the sleeve during pressing. This ensures that the wall thickness in the area of the recess of the first material is uniform in a radially extending cross-sectional plane, thus preventing the walls of the recess from collapsing when the second material is poured in.
[0019] The stamp is shaped in such a way that a gradual and sloping boundary layer is created between the materials. This improves the firing behavior of the subbody.
[0020] The igniter can be filled in powder, paste, or liquid form. The powdered igniter can, for example, be compressed again so that the subbody can be stored without damage. A paste or liquid igniter can harden.
[0021] Preferably, a swirling element, in particular a wire mesh, is arranged on the ignition device. The swirling element serves to swirl and cool the emerging irritant-smoldering agent mixture. This prevents the subbody from burning with an open flame and the irritant from being burned instead of being released into the air.
[0022] Furthermore, the problem is solved by a subbody thus produced, namely by a subbody of an irritant cartridge comprising a first material and a second material, as well as a casing of an irritant cartridge, wherein the materials comprise a smoldering agent and an igniter, the subbody being produced according to a method according to one of the preceding claims, wherein the first material has a recess and the second material is filled into the recess. The ignition behavior is improved by the fact that, in axially offset cross-sectional planes within the area of the recess, the ratio of the two materials changes continuously from a concentration of 100% of the first material to a concentration of 100% of the second material.
[0023] The recess has a defined geometric shape from the group consisting of pyramid, cone, or truncated cone shapes. The recess is rotationally symmetrical. It features several, preferably annular, steps. This can be produced by a die manufactured through turning.
[0024] The recess is centered on an axial axis of symmetry of the sleeve. This ensures maximum stability of the recess when filling it with the second material.
[0025] Alternatively, the stamp could have the shape of a case interior cut diagonally or at least obliquely to the longitudinal axis, whereby the stamping process causes the first material to accumulate in a part of the interior that rises obliquely on one side, and the remaining free part is then filled with the priming compound.
[0026] The sleeve is preferably made of aluminum. Aluminum is lightweight and easy to work with. Alternatively, the sleeve can be made of cardboard. Cardboard is inexpensive.
[0027] Furthermore, the invention relates to an irritant cartridge with a bombette, wherein at least one subbody is arranged in the bombette.
[0028] 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.
[0029] 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.
[0030] The irritant cartridge has a casing sealed 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 an ignition mechanism with, among other things, an ejection charge on the other. One layer of sub-sub ...
[0031] 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.
[0032] The subbodies are preferably arranged offset from one another. This ensures better ignition of the subbodies.
[0033] 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 subbody layer furthest from the lid, on the igniter side, ignited.
[0034] 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:
[0035] Fig. 1 shows a schematic sectional view of an irritant cartridge with a bombette and several sub-bodies arranged inside the bombette.
[0036] Fig. 2 shows the bombette in a schematic sectional view, Fig. 3 shows a first embodiment of the subbodies in a schematic sectional view,
[0037] Fig. 4 shows a schematic sectional view of a second embodiment of the subbody.
[0038] 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.
[0039] 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, a pyrotechnic composition 32 arranged in the hollow rivet 28, and an ejection charge 34 for ejecting the ignited subbodies 24 from the housing 22. The pyrotechnic composition 32 serves as the ignition charge 32. 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 cap 20.The delay charge 30 is arranged in a dome of the end wall 22a. The pyrotechnic composition 32 is arranged at the lower opening of the hollow rivet 28 and on 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.
[0040] To fire the cartridge 10, the primer 20 is ignited, for example, by means of a firing pin (not shown), which ignites 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 pyrotechnic composition 32, producing a flame that spreads upwards from below through the hollow rivet 28 into a cavity 36 between the sub-bodies 24, igniting them.
[0041] Preferably, more than 4 and fewer than 20 subbodies 24 are arranged in the bombette 14. It is conceivable that eight subbodies 24 are arranged in the bombette 14.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] The subbodies 24 of the layers are preferably arranged offset above one another. This ensures better ignition of the subbodies 24.
[0047] The subbodies 24 are preferably arranged such that the central cavity 36 remains between the subbodies 24, wherein, for example, the hollow rivet 28 with the pyrotechnic composition 32 is arranged in the cavity 36. The flame of the ignition charge burns through the cavity 36, ignites layer 24b of the subbodies 24 at the lid, up to the lid 26 of the bombette 14, ignites the ignition gauze disc 26 there, and thus the layer 24b of the subbodies 24 closest to the lid. Afterwards, the layer 24a furthest from the lid is ignited.
[0048] Each subbody 24 has a particularly cylindrical sleeve 54 made of aluminium or cardboard (see Fig. 3 and 4).
[0049] Sleeve 54 is initially open on one side. Sleeve 54 is filled through this opening.
[0050] The manufacturing process proceeds as follows:
[0051] At least two materials, namely a first material 46 and a second material 42, are filled into a sleeve 12, wherein the materials 42, 46 comprise a smoldering composition and an ignition composition, with the following steps:
[0052] a) Filling the first material 46 into the sleeve 12,
[0053] b) Pressing a depression 44 into the first filled material 46 using a punch, wherein the depression 44 corresponds to the negative shape of the punch, and
[0054] c) Pouring a second material 42 into the depression created by the pressing.
[0055] The first material, 46, is the smoldering agent, and the second material, 42, is the igniter. The igniter is positioned at the opening and can therefore be ignited more easily later.
[0056] The stamp and thus the depression 44 have a defined geometric shape from the group pyramid shape, cone shape or frustum shape.
[0057] In Fig. 3, the recess 44 has an annularly stepped truncated cone shape. The punch, and thus the recess 44, has several preferably annular steps. In Fig. 4, the recess 44 has a pointed cone shape, with the lateral surface of the punch having no steps. The recess 44 in Fig. 4 is shaped such that an inclined boundary layer is formed between the materials 42 and 46.
[0058] In both embodiments, the recesses 44 are formed centrally to an axial axis of symmetry of the sleeve 54 during pressing in.
[0059] A swirling element, in particular a wire mesh 52, is arranged on the ignition compound. The swirling element serves to swirl and cool the escaping irritant-smoldering compound mixture. This prevents the subbody from burning with an open flame and the irritant from being combusted instead of being released into the air. This final layer 42 has the highest brisance. The opening of the sleeve 54 is then preferably at least partially closed.
[0060] The ignition behavior of the subbodies 24 is improved by ensuring that, in axially offset section planes within the area of the recess 44, the ratio of the two materials 42, 46 changes as continuously as possible from a concentration of 100% of the first material to a concentration of 100% of the second material. Reference numerals:
[0061] 10 irritant cartridges
[0062] 12 sleeve
[0063] 14 Bombette
[0064] 16 propellant charge
[0065] 18 lids for 12
[0066] 20 firelighters
[0067] 22 cases
[0068] 22a Floor or lower end wall of 22
[0069] 24 subbodies
[0070] 24a first layer of subbodies 24
[0071] 24b second layer of subbodies 24
[0072] 26 lids for 22
[0073] 28 Ignition tube / hollow rivet
[0074] 30 delay or ignition charges
[0075] 32 Ignition charge / pyrotechnic set
[0076] 34 Ejection charge
[0077] 36 cavity
[0078] 38 ignition gauze disc
[0079] 40 Sealing
[0080] 42 second material with ignition set
[0081] 44 In-depth study
[0082] 46 first material with pyrolysis compound
[0083] 52 wire mesh
[0084] 54 Sleeve
Claims
Patent claims:
1. Method for manufacturing a subbody (24) of an irritant cartridge (10), wherein at least two materials, namely a first material (46) and a second material (42), are filled into a sleeve (12), wherein the materials (46, 42) comprise a smoldering composition and an igniter composition, comprising the following steps: a) Filling the first material (46) into the sleeve (12), characterized by the steps: b) Pressing a depression (44) into the first filled material (46) using a punch, wherein the depression (44) corresponds to the negative shape of the punch, and c) Pouring a second material (42) into the depression created by the pressing.
2. Method according to claim 1, characterized in that the smoldering agent is added as the first material (46) and subsequently the second material (42) in the form of the ignition agent is added.
3. Method according to claim 1 or 2, characterized in that the punch and thus the depression (44) has a defined geometric shape from the group consisting of pyramid shape, cone shape or frustum shape.
4. A method according to any one of the preceding claims, characterized in that the punch is rotationally symmetrical and thus the recess (44) is also rotationally symmetrical and / or the recess (44) is formed centrally to an axial axis of symmetry of the sleeve (12) during pressing.
5. A method according to any one of the preceding claims, characterized in that the punch and thus the recess (44) is shaped such that an inclined boundary layer is formed between the materials (42, 46).
6. Method according to one of the preceding claims, characterized in that the punch and thus the depression (44) has several preferably annular steps.
7. Method according to one of the preceding claims, characterized in that a swirling element, in particular a wire mesh (52), is arranged on the ignition set.
8. Subbody (24) of an irritant cartridge (10) comprising a first material (46) and a second material (42) as well as a casing of an irritant cartridge (10), wherein the materials (46, 42) comprise a smoldering composition and an ignition composition, the subbody (24) being manufactured according to a method according to one of the preceding claims, wherein the first material (46) has a recess (44) and the second material (42) is filled into the recess.
9. Subbody according to claim 8, characterized in that in axially offset section planes within the area of the recess (44) the ratio of the two materials changes continuously from a concentration of 100% of the first material (46) to a concentration of 100% of the second material (42).
10. Subbody according to claim 8 or 9, characterized in that the recess (44) has a defined geometric shape from the group consisting of pyramid shape, cone shape or frustum shape.
11. Subbody according to one of the preceding claims, characterized in that the recess (44) is rotationally symmetrical and / or the recess (44) is formed centrally to an axial axis of symmetry of the sleeve (12) during pressing.
12. Subbody according to one of the preceding claims, characterized in that the recess (44) has several, preferably annular, steps.
13. Subbody according to one of the preceding claims, characterized in that the sleeve (12) is made of aluminium or cardboard.
14. 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).
15. Irritant cartridge (10) according to claim 14, characterized in that the subbodies (24) are arranged in two layers (24a, 24b), wherein each layer (24a, 24b) has several, in particular four, subbodies (24) and / or the subbodies (24) are arranged offset above one another.