Cartridge, method for producing a cartridge, and system for producing cartridges

Abstract

The invention relates to a cartridge (1), comprising: a cartridge case (3) which defines a calibre diameter (D); a projectile (4) inserted in the neck region (31) of the cartridge case (3); and at least one annular layer (51, 52) formed from a sealing medium (5) and consisting of a sealing medium (5) between the cartridge case (3) and the projectile (4), wherein the annular layer (51, 52) is applied by means of microdosing and / or comprises no more than 1 mg sealing medium (5) per mm calibre diameter (D).

Description

[0001] The invention relates to a method for manufacturing a projectile cartridge, a system for manufacturing projectile cartridges and a projectile cartridge.

[0002] Especially with small and medium caliber firearms, seals are required that remain leak-proof for extended periods of over 10 years, even under negative or positive pressure and during intended firing temperatures. The seal between the projectile and the cartridge case should be as cost-effective as possible. Furthermore, the seal between the projectile and the cartridge case should ensure high extraction resistance and be as easy as possible to mass-produce.

[0003] Sealants with a highly viscous sealing medium are well-known in the art. Typically, a viscous sealing medium is applied to the inside of the cartridge case along with a corresponding thinner. Inserting the projectile into the case forces some of the applied sealing medium into the case. The remaining sealing medium then creates the seal. Upon firing the projectile, the sealing medium is burned. The connection between the projectile and the cartridge case via the highly viscous sealing medium is both force-fit and material-fit. However, highly viscous sealing media are very difficult to handle due to their high viscosity.

[0004] WO 2017 / 198328 A1 relates to a projectile cartridge with a projectile and a case, and with a seal between the projectile and the case, the seal being formed by two rings of a bitumen mixture. Bituminous sealants exhibit advantageous mechanical and thermal properties with regard to long-term storage as well as extraction resistance and are valued for their low cost. A spraying technique can be used to apply the bituminous sealant, in which a projectile case is held stationary with its opening pointing vertically downwards, and then a mirror is inserted into the muzzle of the case. A bitumen channel is directed against this mirror, from which bitumen is sprayed under pressure. Such a manufacturing plant is very complex in design and operation.It has been found that applying small quantities of paint below a minimum delivery quantity cannot be reliably implemented in series production. Furthermore, it has proven disadvantageous that the use of spray technology inevitably causes contamination with bitumen, for example at the muzzle and outside the bullet casing, requiring time-consuming cleaning.

[0005] In a so-called lubrication nozzle process, a sealing medium is continuously supplied at a dispensing opening. The sealing medium is wiped off along the neck of the cartridge case. Precise process control is not achievable. The process requires a very large quantity of sealing medium and is therefore disadvantageous for mass production. A process in which a sealing medium is applied using a needle similar to a hypodermic needle, and optionally supplemented with a wiper following the needle to adjust the thickness of the applied layer of sealing medium, is described, for example, in US 2005 0 056 183 A1. According to US 2005 0 056 183 A1, a light-curing lacquer should be applied because bituminous sealing media are considered unsuitable for such manufacturing processes. US 6 367 386 B1 also criticizes the fact that automated application of bituminous sealants is not feasible.

[0006] EP 0 110 862 B2 proposes designing the projectile with a circumferential groove to achieve the desired sealing effect using viscous bitumen varnish. This method has proven uneconomical and therefore unsuitable for mass production.

[0007] US 5,256,203 A describes a system for applying an anaerobic sealing medium to a cartridge case. A mandrel is inserted into the neck of the cartridge case. The mandrel has a circumferential groove on its outer surface, through which the sealing medium is applied to the neck of the cartridge case in a ring-like pattern. The circumferential groove is bounded on the interior side of the case by a fully cylindrical disc section. Five mandrels are supplied with the sealing medium via internal channels from a common metering valve. The system is unsuitable for viscous sealing media such as bitumen. A high minimum delivery rate of sealing medium per mandrel is necessary for stable process control. Due to the required quantity of sealing medium, mass production with such a system is only economically feasible to a limited extent.

[0008] Poor process control, for example, if excessive amounts of the sealing medium are applied to the sleeve, can result in an annular layer that is too thick or too wide. A ring that is too thick has the disadvantage of unnecessarily expanding the sleeve, causing the sleeve mouth to fall out of tolerance. A ring that is too wide has the disadvantage of potentially impairing the sealing effect.

[0009] From DE 3544623 A1 it is known: The method serves to apply a product that polymerizes under ultraviolet irradiation to the outside of the abutting parts of the cartridge case and projectile during assembly, which ensures a hermetic seal between the projectile and the cartridge case through ultraviolet irradiation and subsequent polymerization.

[0010] It is an object of the invention to provide a projectile cartridge and an associated manufacturing process as well as a corresponding manufacturing plant that overcome the disadvantages of the prior art, in particular ensuring cost-effective and high-quality mass production of projectile cartridges with a seal between the cartridge case and the projectile. This object is achieved by the subject matter of the independent claims.

[0011] Accordingly, the invention relates to a projectile cartridge according to claim 1, comprising a projectile case defining a caliber diameter and a projectile inserted into the neck region of the projectile case. In particular, the projectile cartridge is manufactured using the method described below. The projectile cartridge has an annular gap bounded on the inside by the projectile and on the outside by the inner circumference of the projectile case. In the projectile cartridge according to the invention, an annular layer of a sealing medium is provided between the projectile case and the projectile. The annular layer can be applied by means of micro-dosing. Alternatively or additionally, the annular layer comprises no more than 1 mg of sealing medium per mm of caliber diameter, in particular no more than 0.5 mg of sealing medium per mm of caliber diameter, preferably no more than 0.3 mg of sealing medium per mm of caliber diameter.It is preferred that the projectile cartridge comprises an annular layer of a sealing medium weighing approximately 2 mg. In particular, the projectile cartridge may be equipped with exactly one annular layer of the sealing medium. According to an alternative embodiment, the projectile cartridge may have two annular layers of the sealing material spaced apart from each other in the axial direction. Preferably, the sealing medium complies with Technical Delivery Condition TL 8010-025, Section 2-2.4.11 (Technical Requirements; abbreviated: TL 0810-025) of the German Federal Office of Defense Technology and Procurement (as of February 2021). Preferably, the sealing medium is a bituminous sealant mixture, such as a bituminous sealing lacquer, in particular according to TL 0810-025. The bituminous mixture may contain at least one additive, preferably graphite. The at least one annular layer of the sealing medium is preferably formed in a complete circular arrangement around the projectile.

[0012] In a preferred embodiment of a projectile cartridge, the sealing medium of the at least one annular layer is uniformly distributed circumferentially. Preferably, the sealing medium of the annular layer is distributed almost 100% uniformly circumferentially. In particular, the at least one annular layer exhibits circumferential deviations of no more than 50 nL / mm of ring circumference, more specifically no more than 10 nL / mm, 5 nL / mm, or 1 nL / mm, and preferably no more than 0.5 nL / mm.

[0013] According to one embodiment of a projectile cartridge, the at least one annular layer has a width of at least 1 mm, in particular at least 2 mm. Alternatively or additionally, the layer has a width of no more than 10 mm, in particular no more than 6 mm. The width of the annular layer defines its extent in the axial direction (parallel to the axis of symmetry of the projectile case).

[0014] According to one embodiment of a projectile cartridge, the at least one annular layer has a thickness of at least 0.003 mm, in particular at least 0.005 mm. Alternatively or additionally, the layer has a thickness of no more than 0.04 mm, preferably no more than 0.025 mm, in particular no more than 0.015 mm. The thickness of the annular layer is defined by its radial extent to the axis of symmetry of the projectile casing.

[0015] In one embodiment of the projectile cartridge, the annular layer is formed from multiple droplets, in particular from micro- and / or nanodroplets. Preferably, the annular layer is formed from at least 3, at least 5, or more droplets. In particular, the annular layer consists of droplets, preferably micro- and / or nanodroplets. A single droplet preferably has a diameter or width that is significantly smaller than the width of the annular layer. In particular, a droplet is at least 10 times, preferably at least 100 times, smaller than the width of the annular layer. Compared to sealing layers of conventional projectile cartridges, an annular layer formed from multiple droplets can be realized with significantly more precise manufacturing tolerances with regard to sealing effect and material consumption.

[0016] According to one design, the projectile cartridge comprises no more than a ring-shaped layer. Surprisingly, it has been shown that even with a single, thin layer of sealing medium applied using micro-dosing, a reliable seal can be achieved with minimal material usage.

[0017] In one embodiment of the projectile cartridge, the sealing medium is provided to contain or comprise 50 vol% to 70 vol% of a preferably bituminous sealant mixture, in particular 54 vol% to 65 vol% of a preferably bituminous sealant mixture, as well as 5 vol% to 20 vol% thinner, in particular 6.5 vol% to 16.5 vol% thinner, and 25 vol% to 40 vol% graphite (D90 < 10 µm), in particular 28.5 vol% to 32 vol% graphite (D90 < 10 µm). For example, the sealing medium can be provided as a mixture containing, in proportion to each other, 100 ml of a preferably bituminous sealant mixture, 10 mL to 30 mL thinner, and 44 mL to 52 mL graphite. It is conceivable that one, in particular the only or first, ring-shaped layer of the projectile cartridge is formed from such a graphite-containing sealant mixture.In a projectile cartridge with a second annular layer, the second layer can be formed from a graphite-free sealing medium. The sealing medium of the second layer can comprise, and preferably consist of, a sealant mixture containing bitumen and a thinner. For example, the sealing medium of the second layer can be provided as a mixture containing 100 mL of a sealant mixture, preferably containing bitumen, and 10 mL to 30 mL of thinner.

[0018] Furthermore, a method for manufacturing a projectile cartridge according to claim 5 is provided, wherein a projectile case is first provided, which has a neck section for receiving a projectile. The neck section defines an inner circumference that can correspond to the caliber diameter. In the method, an annular, preferably full-circumference, layer of a sealing medium is applied to a projectile case on an inner circumference in the neck region of the projectile case. Preferably, a bitumen-based sealing medium is used. The bitumen-based sealing medium can comprise bitumen and at least one thinner. The thinner can be selected from the group consisting of ketones, esters, alcohols, and hydrocarbons, in particular aromatic hydrocarbons, or a mixture thereof. In addition to a preferably bitumen-containing sealant mixture, the sealing medium can comprise an additive. For example, graphite powder is suitable as an additive.Graphite powder is suitable for adjusting the sliding properties of the bitumen mixture. According to the invention, a predetermined quantity of the applied sealing medium is supplied by a micro-dosing system. The quantity of the sealing medium can be pre-determined, for example, gravimetrically or volumetrically by the micro-dosing system. For example, the micro-dosing system can comprise a stroke chamber with a piston movably arranged therein, and the quantity of the sealing medium can be determined by the volume of the stroke chamber, the stroke of the piston, and the number of dispensing strokes. In particular, the micro-dosing system can be implemented by a jet valve or micro-dosing valve, such as a solenoid valve or a piezoelectric valve.

[0019] Surprisingly, it has been shown that, contrary to general assumptions, cost-effective and easily controllable mass production of bullet cartridges with a seal made of a preferably bituminous sealing medium is indeed achievable by using micro-dosing. Micro-dosing is a well-known technique in inkjet printing. With micro-dosing, minute quantities of a sealing medium can be precisely applied to the inner surface in the neck area of ​​the bullet casing. This allows for significant savings in the minimum required amount of sealing medium, which is particularly advantageous in the mass production of bullet cartridges.

[0020] According to a preferred embodiment, exactly two or more than two rings are applied as complete layers of the sealing medium to an inner circumference of the projectile casing. In a manufacturing process that includes the application of two or more ring-shaped layers of sealing medium, it may be preferred that at least two different rings are produced from different sealing media. For example, a first ring, particularly one near the edge, may be made of a bitumen-based sealing medium with at least one additive, which may preferably include graphite, and a second ring, particularly one further from the edge, may be made of a different sealing medium, particularly a bitumen-based one, preferably with a smaller amount of additive, and in particular without additive and / or without graphite.

[0021] According to an alternative preferred embodiment of the method, only a single ring can be applied as a complete annular layer of the sealing medium to the inner circumference of the cartridge case. This single annular layer of sealing medium is preferably applied to the outer edge of the cartridge case. By applying two annular layers of the sealing medium one after the other and separately in the axial direction of the cartridge case, the amount of sealing medium required can be reduced. It has been shown that this can be achieved, at least with some types of cartridges, without impairing the sealing effect.

[0022] In one embodiment of a method for manufacturing a projectile cartridge, a projectile is inserted into the neck region of the cartridge case following the application of at least one annular layer of a sealing medium. The sealing medium layer seals an annular gap between the inner circumference of the cartridge case neck region and the outer cylinder of the projectile inserted therein.

[0023] According to one embodiment of the method, a projectile cartridge with a specific caliber diameter is manufactured. The caliber diameter is defined according to the inner diameter of the inner circumference in the neck region of the projectile cartridge. To form the annular layer, a predetermined quantity of no more than 1 mg of sealing medium per mm of caliber diameter is applied relative to the caliber diameter of the projectile cartridge. In particular, no more than 0.5 mg of sealing medium per mm of caliber diameter is applied. Preferably, no more than 0.3 mg of sealing medium per mm of caliber diameter is applied. By applying a small quantity of the sealing medium relative to the caliber diameter using micro-dosing, it can be ensured that the applied layer of sealing medium does not form an excessively wide or thick ring on the inner circumference of the projectile cartridge case.

[0024] According to a further development of the method, a predetermined quantity of at least 0.01 mg of sealing medium per mm of caliber diameter is applied to form the annular layer in relation to the caliber diameter of the projectile cartridge. In particular, at least 0.03 mg of sealing medium per mm of caliber diameter, and preferably at least 0.05 mg of sealing medium per mm of caliber diameter, is applied.

[0025] It may be preferred that the sealing medium be applied with a layer thickness of no more than 0.1 mm, in particular no more than 0.05 mm. This ensures that the cartridge remains loadable. Alternatively or additionally, it may be preferred that the sealing medium be applied with a layer thickness of at least 0.005 mm, preferably at least 0.007 mm. It has been shown that a reliable seal can be achieved with good reproducibility from such a layer thickness. In particular, the sealing medium can be applied with a layer thickness in the range of 0.007 to 0.02 mm, preferably in the range of 0.01 mm to 0.015 mm.

[0026] In an embodiment of a method that can be combined with the preceding ones, a bitumen-containing sealant mixture is provided as the sealing medium. Preferably, the bitumen-containing mixture comprises bitumen and a thinner. Additionally, the bitumen-containing mixture can include an additive, such as graphite, in particular graphite powder, for adjusting the sliding properties of the annular layer of sealing medium. The projectile cartridge can be manufactured particularly cost-effectively if the sealing medium is a bitumen mixture. Preferably, the sealing medium is guided in the micro-dosing unit, for example, a jet valve, in particular a piezo valve or a solenoid valve, at a temperature of at least 25 °C, in particular at least 30 °C, preferably at least 35 °C, and / or at most 60 °C, in particular at most 55 °C, preferably at most 50 °C, and most preferably at most 45 °C.Temperature control in micro-dosing can be achieved, for example, by equipping the micro-dosing unit with heating and / or cooling for the sealing medium. Preferably, temperature control ensures that the sealing medium, particularly the bitumen-containing mixture, is continuously maintained within a predetermined temperature range during its delivery through the micro-dosing unit. For some sealing media, such as bitumen-based sealants, precise temperature control has proven advantageous in influencing the material properties of the dispensed sealing medium, such as its phase composition and / or viscosity.

[0027] Alternatively or additionally, an ambient temperature range can be set, particularly in a controlled manner, at least temporarily and / or section by section during the process, especially in the vicinity of the micro-dosing unit. For example, the temperature of the projectile casing and / or the temperature of a holder that accommodates the projectile casing can be set within a predetermined ambient temperature range, at least temporarily and / or section by section during the process, particularly in the vicinity of the micro-dosing unit. The ambient temperature range can, for example, be defined as at least 10°C, in particular at least 15°C, preferably at least 20°C, and / or at most 50°C, in particular at most 45°C, preferably at most 40°C. Setting a defined ambient temperature range can be advantageous when using a temperature-sensitive sealing medium.

[0028] According to one embodiment of the method, the sealing medium, particularly in micro-dosing, is adjusted to a viscosity in the range of approximately 5 s to 100 s, more specifically 10 s to 70 s, preferably in the range of 30 s to 70 s or in the range of 10 s to 20 s. The viscosity of the sealing medium, particularly the bituminous sealing medium, can be adjusted, in particular, according to a viscosity measurement method according to DIN 52211, preferably with an ISO 4 mm efflux cup. DIN 52211-1987-06 may be authoritative. To adjust the viscosity, the composition of the sealing medium can be adjusted, consisting of a sealant, for example, bitumen, and other components, for example, thinners and / or additives. Additionally or alternatively, the viscosity can sometimes be influenced in combination with the temperature control described above.

[0029] According to a further development of the process, the sealing medium is dispensed from the micro-dosing unit in mist form. The micro-dosing unit can, in particular, dispense mist in the form of nanodroplets, preferably nanodroplets with a volume in the nanoliter range, and especially with a nanodroplet volume in the range of 1 nL to 500 nL. Specifically, to dispense the sealing medium in mist form, the viscosity of the sealing medium in the micro-dosing unit is adjusted to a maximum of 30 s, particularly a maximum of 25 s, and preferably a maximum of 20 s. By atomizing the sealing medium, a particularly thin, annular layer of sealing medium can be produced, thereby saving a significant amount of bitumen material.

[0030] In an alternative embodiment of the method, the sealing medium is dispensed from the micro-dosing unit in droplet form. The dispensing of the droplet-shaped sealing medium from the micro-dosing unit preferably occurs when a droplet emerges from the micro-dosing unit, which may be implemented as a jet valve, moves away from the micro-dosing unit, and, after detaching from the micro-dosing unit, strikes the projectile casing. The micro-dosing unit dispenses precisely defined droplets of sealing medium, which, after being applied to the inner circumference, merge to form a complete, annular layer of the sealing medium. When dispensing the sealing medium in droplet form from the micro-dosing unit, the viscosity is preferably adjusted to at least 10 s, particularly at least 15 s, and preferably at least 30 s.

[0031] According to a further development of the manufacturing process, in which the sealing medium is dispensed in droplet form from the micro-dosing unit, at least one droplet is dispensed to form the annular layer for a single projectile casing. Preferably, several drops are dispensed. The micro-dosing unit can be used to dispense drops in the form of microdroplets, preferably microdroplets with a volume in the microliter range, particularly with a microdroplet volume in the range of 10 nL to 50 µL, and more specifically 100 nL to 5 µL. Five successively dispensed drops, particularly those at least partially overlapping each other, preferably exhibit a cumulative standard deviation of no more than ± 10%, particularly no more than ± 5%, and more preferably no more than 4%, based on the dispensed volume.In particular, the projectile cartridge is manufactured with a specific caliber diameter, and to form the annular layer, 1 to 5 drops per mm of caliber diameter are dispensed in relation to the caliber diameter of the projectile cartridge. Alternatively or additionally, in one embodiment, an annular layer with a width of at least 1 mm, in particular at least 2 mm, and / or not more than 10 mm, in particular not more than 6 mm, and / or with a thickness of at least 0.003 mm, in particular at least 0.005 mm, and / or not more than 0.04 mm, preferably not more than 0.025 mm, in particular not more than 0.015 mm, can be formed. It has been shown that even with thin and narrow rings consisting of, for example, no more than one drop per mm of caliber diameter, a sufficient sealing effect can be achieved by the annular or band-shaped layer on the projectile casing produced by the sealing medium.In some cases, the sealing effect can be improved by using more than one drop per mm of caliber diameter.

[0032] According to a further development of the method, which can be combined with the previous one, the droplets are dispensed in a cycle within the range of 100 Hz to 3000 Hz, particularly within the range of 250 Hz to 2000 Hz, and preferably within the range of 300 Hz to 1000 Hz. The pressure medium is supplied to the micro-dosing unit at a pressure of preferably about 1 bar. It is conceivable that the micro-dosing unit is implemented as a pump valve, for example a piezoelectric valve, and that the droplet dispensing cycle is composed of a suction time and a stroke time. Preferably, the suction time corresponds approximately to the stroke time. The suction time can be in the range of 150 µs to 400 µs or 800 µs. Alternatively or additionally, the stroke time can be in the range of 150 µs to 400 µs or 800 µs.Alternatively, the micro-dosing system can be implemented as a pressurized opening valve, for example, a solenoid valve, and the droplet dispensing cycle can consist of a valve opening time and a valve closing time. It is preferred that the valve opening time is at most as long as, or shorter than, the valve closing time. The valve opening time can be in the range of 350 µs to 1000 µs. In the micro-dosing system, particularly in a pressurized opening valve, the sealing medium can be supplied at a pressure in the range of 1 bar to 10 bar, preferably 2 bar to 5 bar.

[0033] In an embodiment of the method that can be combined with the preceding ones, it is provided that at least the neck region of the projectile case, particularly in the area of ​​an edge of the muzzle, which can be referred to as the case mouth edge, is radially expanded before the projectile is inserted. The neck region, particularly the muzzle, of the projectile case can be expanded, in particular, after the application of the sealing medium. Specifically, the neck region is expanded by a few micrometers, particularly less than 30 micrometers, preferably less than 20 micrometers, and most preferably less than 10 micrometers. By pre-expanding the case mouth, scratching deformation of the neck region by the projectile, which could impair the sealing effect, can be counteracted.

[0034] In an embodiment of a manufacturing process that can be combined with the preceding ones, the sealing medium is dispensed from the micro-dosing unit through a nozzle. Preferably, the nozzle is held at an oblique angle, particularly orthogonal, to the inner circumference for dispensing the sealing medium. This minimizes the risk of a droplet ricochet (statellites). It may be preferred to hold the nozzle oriented in a direction that differs from the direction of movement of an actuator, such as a piezo stack or a magnetic armature, of the micro-dosing unit. Alternatively or additionally, it may be preferred that the nozzle is held at a predetermined distance from the inner circumference. The nozzle can be held at a distance of at least 0.5 mm, particularly at least 1 mm, and / or at a distance of no more than 20 mm, particularly no more than 10 mm, preferably no more than 5 mm or no more than 7 mm.The distance between the nozzle and the inner circumference can be determined, in particular, by the path traveled from the nozzle to the inner circumference by the sealing medium, especially in the form of drops or spray. It has been shown that with such an arrangement of the nozzle relative to the inner circumference, a homogeneous, annular layer of sealing medium can be produced in the neck region of the projectile sleeve.

[0035] In one embodiment of the method, a movement is performed to insert the nozzle into the neck region of the projectile sleeve before the sealing medium is dispensed. In particular, a linear movement is performed, preferably parallel or coaxial to the axis of symmetry of the projectile sleeve. Preferably, the nozzle is moved into the projectile sleeve, which is held stationary, to insert the nozzle into the cartridge case. Alternatively or additionally, the cartridge case can be moved relative to the nozzle, which is held stationary, and in particular, with the valve at rest, the cartridge case is slipped over the nozzle.

[0036] In particular, the process time for coating a shell casing with at least one annular layer of sealing medium can be set to a cycle time in the range of 0.1 Hz to 10 Hz, particularly in the range of 0.2 Hz to 5 Hz, preferably in the range of 0.3 Hz to 3 Hz. For example, 3 shell casings per second can be internally coated.

[0037] In a further development of the manufacturing process, a nozzle is used which has an outlet diameter in the range of 0.05 mm to 0.5 mm, in particular in the range of 0.1 mm to 3 mm, preferably with an outlet diameter of about 0.15 mm.

[0038] According to one embodiment of the method, the projectile sleeve can be rotated about an axis of symmetry relative to the micro-dosing unit, particularly the nozzle. Preferably, the relative rotation of the projectile sleeve with respect to the micro-dosing unit, especially the nozzle, takes place during the dispensing of the sealing medium from the micro-dosing unit. In particular, the relative rotation of the projectile sleeve with respect to the micro-dosing unit can occur during the dispensing of the at least one droplet or the spray mist. It may be preferred that the projectile sleeve is rotated continuously while the sealing medium is applied to form the annular layer. Preferably, the relative positioning of the projectile sleeve with respect to the micro-dosing unit is achieved by holding the micro-dosing unit on a stationary frame, while the projectile sleeve is held by a support movable with respect to the frame.

[0039] In one embodiment of the method, the sealing medium is provided as a mixture comprising or consisting of 50 vol% to 70 vol% of a preferably bituminous sealant mixture, such as a sealing varnish, in particular 54 vol% to 65 vol% of a preferably bituminous sealant mixture, as well as 5 vol% to 20 vol% thinner, in particular 6.5 vol% to 16.5 vol% thinner, and 25 vol% to 40 vol% graphite (D90 < 10 µm), in particular 28.5 vol% to 32 vol% graphite (D90 < 10 µm). For example, the sealing medium can be provided as a mixture containing, in proportion to each other, 100 ml of sealant mixture, 10 mL to 30 mL of thinner, and 44 mL to 52 mL of graphite. It is conceivable that one, in particular the only or first, ring-shaped layer of the projectile cartridge is formed from such a graphite-containing sealant mixture.When manufacturing a projectile cartridge with a second annular layer, the second layer can be formed from a graphite-free sealing medium. The sealing medium of the second layer can be formed from a mixture comprising or consisting of a preferably bituminous sealant mixture and a thinner. For example, the sealing medium of the second layer can be provided as a mixture containing 100 mL of preferably bituminous sealant mixture and 10 mL to 30 mL of thinner.

[0040] According to the invention, a system for manufacturing projectile cartridges according to claim 11 is further provided. The system for manufacturing projectile cartridges comprises a bearing for holding a projectile case, which has a neck section for receiving a projectile and defines an inner circumference. According to the invention, the system includes a micro-dispensing unit for providing a predetermined quantity of a sealing medium for application to the inner circumference. Alternatively or additionally, the system is designed and configured to carry out a process as described above. The system can have a plurality of micro-dispensing units with which sealing medium can be applied simultaneously to several different projectile cases. In the system according to the invention, the ratio between the number of micro-dispensing units and projectile cartridges within the system can be at least 1:1.The ratio of microdosing to projectile cartridge within the system can be greater than 1:1.

[0041] In one embodiment, the system includes a temperature control for guiding the sealing medium, particularly in micro-dosing, preferably at a temperature of at least 25 °C and / or at most 60 °C. The temperature control includes at least one heating and / or cooling element and optionally a temperature sensor.

[0042] According to another embodiment, the system has one, in particular exactly one, nozzle fluidically connected to the micro-dosing unit, with an outlet diameter in the range of 0.05 mm to 0.5 mm, particularly in the range of 0.1 mm to 3 mm, for dispensing the sealing medium. Such a nozzle, in conjunction with a micro-dosing unit, in particular a jet valve or micro-dosing valve, such as a solenoid valve or a piezoelectric valve, has proven to be particularly suitable for providing sealing, fully annular layers of the sealing medium onto the projectile sleeve.

[0043] According to a further development process, the nozzle and the bearing are coordinated in such a way that the nozzle is aligned orthogonally to the inner circumference when dispensing the sealing medium. This allows for the application of a particularly clean layer of sealing medium.

[0044] According to another embodiment, the nozzle and the bearing are coordinated such that the nozzle is held at a predetermined distance of at least 0.5 mm, in particular at least 1 mm, and / or no more than 20 mm, in particular no more than 10 mm, preferably no more than 5 mm, from the inner circumference when dispensing the sealing medium. Within this distance range, clean application can be ensured without any risk of the nozzle becoming lubricated by the sealing medium along the inner circumference, even with a highly viscous sealing medium.

[0045] In a further development of the system, which can be combined with the previous ones, the nozzle and the bearing for moving the nozzle relative to the inner circumference, in particular for inserting the nozzle into the neck region of the projectile sleeve, are movable relative to each other, especially linearly. This linear mobility can be useful for applying several annular layers side by side to the inner circumference.

[0046] According to one embodiment of the system, the bearing is adapted to the micro-dosing unit and / or the nozzle in such a way that the projectile sleeve is rotatable around an axis of symmetry of the projectile sleeve, preferably continuously. By rotating the inner circumference around the dispensing opening of the micro-dosing unit, in particular the nozzle, a reliable, complete seal can be achieved.

[0047] In one embodiment, the system comprises a conveying device for feeding and / or removing at least one shell casing per second, in particular at least two shell casings per second, preferably at least three shell casings per second, to and / or from the micro-dosing unit. A conveying device can transport shell casings, particularly in or into the storage area, to the micro-dosing unit so that the sealing medium can subsequently be applied. The same or a second conveying device can remove shell casings, particularly in or from the storage area, from the micro-dosing unit after at least one annular layer of sealing medium has been applied to the inner circumference.

[0048] Further properties, advantages and features of the invention will become clear through the following description of preferred embodiments of the invention with reference to the accompanying drawings, which show: Figure 1 is a schematic sectional view of a projectile cartridge; Figure 2a is a schematic representation of a method in which a first annular layer of sealing medium is applied to a projectile casing; Figure 2b is a schematic representation of a method in which a second annular layer of sealing medium is applied; Figure 3a is a schematic representation of another method in which a first annular layer of sealing medium is applied to a projectile casing; Figure 3b is a schematic representation of the application of a second layer of sealing medium according to the other method; and Figure 4 is a schematic sectional view of a projectile casing with two annular layers of sealing medium arranged in the neck region and a separate projectile.

[0049] To simplify readability, the same or similar reference numerals are used in the following description of the invention for the same or similar components based on the preferred embodiments shown.

[0050] A projectile cartridge is generally designated by the reference numeral 1. The projectile cartridge 1 comprises as essential components a projectile case 3, a projectile 4, and a sealing medium 5 provided between the projectile 4 and the projectile case 3.

[0051] Figure 1Figure 1 shows a schematic cross-sectional view of a projectile cartridge 1. The sealing medium 5 creates a seal between the projectile 4 and the cartridge case 3. The cartridge case 3 is a body of revolution with an axis of symmetry S. The projectile cartridge 1 has a specific caliber diameter D, which can be determined from the inner diameter at the inner circumference 33 in the neck region 31 of the cartridge case 3. Typical caliber diameters D are, for example, 5.56 mm, 7.62 mm, or 8.6 mm. The neck region 31 designates the section of the cartridge case 3 into which the projectile 4 is inserted to form the projectile cartridge 1. Figures 1 and 4 In the depicted projectile sleeve 3, the neck area 31 has a narrower diameter than an area 39 located behind the muzzle 30 of the sleeve 3 for receiving the propellant charge.

[0052] On the inner circumference 33 of the sleeve 3, two annular layers 51, 52 of the sealing medium are applied in its neck region 31. A first layer 51, located closer to the free edge of the sleeve 3, contains a bituminous sealing varnish with an additive as the sealing medium 5. The sealing medium for forming the first layer 51 can, for example, comprise 42 wt.% of a bituminous sealing varnish, 42 wt.% thinner, and 16 wt.% graphite. An optional second layer 52, located deeper in the sleeve, contains a bituminous sealing varnish without additives. The second layer 52 contains 66 wt.% of a bituminous sealing varnish and 34 wt.% thinner. The same or a different mixture can be used for a design with only one annular layer 51.Alternatively, particularly for a design with only one annular layer 51, the sealing medium can comprise 50 vol% to 70 vol% of a bituminous sealing varnish, in particular 54 vol% to 65 vol% of a bituminous sealing varnish, as well as 5 vol% to 20 vol% thinner, in particular 6.5 vol% to 16.5 vol% thinner, and 25 vol% to 40 vol% graphite (D90 < 10 µm), in particular 28.5 vol% to 32 vol% graphite (D90 < 10 µm). The width of the first and / or second layer 51, 52 parallel to the direction of the axis of symmetry S of the projectile sleeve 3 is in the range of 0.5 mm to 6 mm, in particular in the range of 1 mm to 3 mm. The thickness of the first and / or second layer 51, 52 radially to the direction of the axis of symmetry S of the projectile sleeve 3 is in the range of 0.003 mm to 0.04 mm, particularly in the range of 0.005 mm to 0.015 mm. The distance between two layers 51, 52 can be less than 2 mm, particularly less than 1.5 mm.

[0053] The Figures 2a and 2b Figure 1 schematically shows a first method for applying annular layers 51 and 52 of sealing medium 5 to the inner circumference 33 of the projectile sleeve 3. The sealing medium 5 is applied to the inner circumference 33 of the projectile sleeve 3 in the neck region 31 of the projectile sleeve 3 by means of a micro-dispensing device 7. The micro-dispensing device 7 ensures that the sealing medium 5 is applied particularly evenly to the inner circumference. The micro-dispensing device 7 is held completely outside the projectile sleeve 3, in front of its muzzle 30. The projectile sleeve 3 is rotated about its axis of symmetry S relative to the micro-dispensing device 7.

[0054] Microdosing 7 is used in the Figure 2aIn the illustrated embodiment, the sealing medium 5 is applied to the inner circumference 33 in the form of drops 55. Using the micro-dispensing unit 7, several defined individual points of sealing medium 5 are applied along the inner circumference 33 of the cartridge case 3, which together form a circumferential and homogeneous coating ring. The micro-dispensing unit 7 dispenses one to five drops, which can also be referred to as shots, per mm of cartridge case diameter D, relative to the caliber diameter D of the cartridge case 3. For example, with a caliber diameter of 5.56 mm, 6 to 28 shots can be fired. With a caliber diameter of 7.62 mm, 8 to 38 shots can be fired. With a caliber diameter of 8.6 mm, 9 to 42 shots can be fired.

[0055] The micro-dosing device 7 has a nozzle 71 at its dispensing end, which is directed towards the projectile sleeve 3. The nozzle 71 has an opening diameter in the range of 0.1 mm to 0.3 mm. The nozzle 71 is designed and configured to dispense the sealing medium 5 in a specific firing direction or dispensing direction A. The dispensing direction A is oriented at an oblique angle with respect to the axis of symmetry S. The dispensing direction A can intersect the axis of symmetry S. The oblique angle between the dispensing direction A and the axis of symmetry S can, for example, be in the range of 30° to 90°. Preferably, the oblique angle is at least 45°, and in particular at least 60°. The nozzle 71 of the micro-dosing device 7 is held at a distance from the inner circumference 33 of the projectile sleeve 3 in the dispensing direction A. The individual droplets 55 of the sealing medium 5 are then not simultaneously in contact with both the nozzle 71 and the inner circumference 33.

[0056] As in Figure 2bAs shown, the annular sealing medium layer 51, located closer to the opening 30, is produced first, followed by the second layer 52, which is further away from the opening 30, made of sealing medium 5. Alternatively, the second layer 52 can be produced first, followed by the first layer 51, in reverse order.

[0057] A bituminous mixture can be used as the sealing medium 5. The sealing medium 5 can consist of a bituminous sealant mixture, such as a sealing lacquer, a thinner, and optionally an additive, such as graphite. For application using the micro-dosing unit 7, the viscosity of the bituminous mixture can be adjusted within a range of 10 s to 70 s. The viscosity of the sealing medium 5 can be determined using the viscosity measurement method according to DIN 52211 with a 4 mm ISO immersion cup.

[0058] It has proven advantageous for the microdosing unit 7 to be equipped with a heater and / or cooler 73 for controlled temperature adjustment of the sealing medium 5. With a heater and / or cooler 73, the temperature of the sealing medium 5 can be maintained within a temperature range between, for example, 30 °C and 55 °C while it is conveyed through the microdosing unit 7. The heater and / or cooler 73 can be designed and configured to impose a controlled temperature on the entire microdosing unit 7. Alternatively, the heater and / or cooler 73 can be designed and configured to independently control the temperature of different areas of the microdosing unit 7.

[0059] For example, a micro-dosing valve in the form of a solenoid valve from Fritz-Gyger AG, specifically valve type SMLD 300G (Sub-Micro-Liquid-Dispenser), can be used as the micro-dosing unit 7. The micro-dosing valve can be, for example, an electromagnetically actuated solenoid valve. The sealing medium 5 flows directly through the micro-dosing valve. In the de-energized state, the micro-dosing valve is closed. A closing spring of the micro-dosing valve acts on a movable armature with a valve ball. When the valve coil is energized, the movable armature with the valve ball is magnetically attracted by the magnetic field of a stationary armature, causing the micro-valve to open and the sealing medium, at a pressure of, for example, 1 to 5 bar, to exit the valve nozzle 71. The micro-dosing valve includes a built-in heater 73 for adjusting the temperature of the sealing medium 5.The micro-dosing valve preferably comprises a hard-sealing valve, which is preferably designed and configured to ensure a precisely reproducible opening stroke of a few hundredths of a millimeter. The micro-dosing valve can be designed for a clock rate of up to 4000 Hz. Hard materials such as sapphire and / or ruby ​​can be used for the valve seat and / or the valve ball. The micro-dosing valve is preferably designed and configured to reproducibly dispense individual shots or drops in the nanoliter range.

[0060] Alternatively, a micro-dosing valve in the form of a piezoelectric valve from VERMES Microdispensing, in particular valve type MDV 3280, can be used as the micro-dosing device 7. The micro-dosing valve is preferably designed and configured to dispense individual shots or drops in the nanoliter range in a reproducible manner. The piezoelectric valve can be designed and configured to be energized by a control unit for dispensing a sealing medium 5. The voltage pulses applied to the piezoelectric valve by the control unit open and / or close the piezoelectric valve. The piezoelectric valve can have a plunger for closing the nozzle 71. The plunger can be connected to a piezoelectric stack of the piezoelectric valve by means of a lever device. By moving the piezoelectric stack up and down, drops or shots can be dispensed precisely at a frequency of several hundred Hz.

[0061] The Figures 3a and 3bWe show a second method for producing layers 51, 52 of sealing medium 5 on the inner circumference 33 of a projectile sleeve 3. This method differs essentially only from the previously described method in that the nozzle 71 of the micro-dosing unit 7 is oriented in a substantially orthogonal dispensing direction A with respect to the inner circumference 33. To apply the sealing medium 5, the nozzle 71 is inserted into the projectile sleeve 3 through the opening 30. For this purpose, the nozzle 71 can be moved linearly into the projectile sleeve parallel to the direction of the axis of symmetry S. The nozzle 71 has a curvature 72 in the region shortly before its dispensing opening, which defines the dispensing direction A. After the sealing medium has been applied, the nozzle 71 is removed from the neck region 31 of the projectile sleeve 3, for example, by a reverse movement.

[0062] As in Figure 3bAs shown, first the annular sealing medium layer 52, which is located further away from the opening 30, and then the layer 51, which is closer to the opening 30, is produced from sealing medium 5.

[0063] In the two in the Figures 2a In the method shown in Figure 3a, the sealing medium 5 can be dispensed in the form of droplets 55 or in the form of a spray mist 57. To dispense a spray mist 57, it may be preferable to adjust the viscosity of the sealing medium 5 to no more than 20 s. This allows a spray mist 57 to be applied from the micro-dosing unit 7 to the sleeve 3. The spray mist 57 can be used to apply a particularly thin layer of sealing medium 51, 52.

[0064] After applying the single layer or, if applicable, the two layers 51 and 52, as described in Figure 3 indicated, the projectile 4 is inserted into the neck area 31 of the sleeve 3 to engage the Figure 1to form the illustrated projectile cartridge 1. The features disclosed in the foregoing description, the figures and claims can be important for the realization of the invention, both individually and in any combination, in the various embodiments that fall within the scope defined by the appended claims. Reference symbol list

[0065] 1 Cartridge 3 Cartridge 4 Projectile 5 Sealing medium 7 Micro-dosing 30 Muzzle 31 Neck area 33 Inner circumference 39 Area 51, 52 Annular layer 55, 57 Droplet or spray mist 71 Nozzle 72 Curvature 73 Heating and / or cooling A Delivery direction D Caliber diameter S Axis of symmetry

Claims

1. Projectile cartridge (1) comprising a projectile casing (3) which defines a caliber diameter (D), a projectile (4) inserted into the neck region (31) of the projectile casing (3) and at least one annular layer (51, 52) formed from a highly viscous sealing medium (5) between the projectile casing (3) and the projectile (4), wherein the annular layer (51, 52) is applied by means of microdosing and comprises not more than 0.5 mg of sealing medium (5) per mm of caliber diameter (D), preferably not more than 0.3 mg of sealing medium (5) per mm of caliber diameter (D).

2. Projectile cartridge (1) according to Claim 1, characterized in that the sealing medium (5) of the at least one annular layer (51, 52) is distributed uniformly in the circumferential direction, wherein in particular the at least one annular layer (51, 52) has deviations of not more than 50 nL / mm of annular circumferential width, in particular not more than 5 nL / mm of annular circumferential width, preferably not more than 5 nL / mm of annular circumferential width.

3. Projectile cartridge (1) according to Claim 1 or 2, characterized in that the at least one annular layer (51, 52) has a width of at least 1 mm, in particular at least 2 mm, and / or not more than 10 mm, in particular not more than 6 mm, and / or in that the at least one annular layer (51, 52) has a thickness of at least 0.003 mm, in particular at least 0.005 mm, and / or not more than 0.04 mm, in particular not more than 0.015 mm, and / or in that the at least one annular layer (51, 52) is formed from a plurality of drops, wherein in particular the projectile cartridge (1) comprises not more than one annular layer (51) of the sealing medium.

4. Projectile cartridge (1) according to one of the preceding claims, wherein the sealing medium (5) comprises, in particular consists of, 50% by volume to 70% by volume of an in particular bitumen-containing sealant mixture, in particular 54% by volume to 65% by volume of an in particular bitumen-containing sealant mixture, and also 5% by volume to 20% by volume of diluent, in particular 6.5% by volume to 16.5% by volume of diluent, and 25% by volume to 40% by volume of graphite (D90 < 10 µm), in particular 28.5% by volume to 32% by volume of graphite (D90 < 10 µm).

5. Method for producing a projectile cartridge (1) formed according to one of the preceding claims, wherein a projectile casing is provided which has a neck section for receiving a projectile which defines an inner circumference, wherein an annular, preferably full-circumference, layer (51, 52) of a highly viscous sealing medium (5), in particular a bitumen-containing sealant mixture, is applied to the projectile casing (3) at an inner circumference (33) in the neck region (31) of the projectile casing (3), wherein a predetermined amount of the applied sealing medium (5) is provided by microdosing (7), wherein a bitumen-containing sealant mixture is provided as sealing medium (5), wherein the sealing medium is guided, in the microdosing, at a temperature of at least 25°C, in particular at least 30°C, preferably at least 35°C, and / or at most 60°C, in particular at most 55°C, preferably at most 50°C, particularly preferably at most 45°C.

6. Method according to Claim 5, characterized in that the projectile cartridge (1) is produced with a specific caliber diameter (D) and, in order to form the annular layer (51, 52) in relation to the caliber diameter (D) of the projectile cartridge (1), a predetermined amount of not more than 1 mg of sealing medium (5) per mm of caliber diameter (D), in particular not more than 0.5 mg of sealing medium (5) per mm of caliber diameter (D), preferably not more than 0.3 mg of sealing medium (5) per mm of caliber diameter (D), is applied, and / or in that, in order to form the annular layer (51, 52) in relation to the caliber diameter (D) of the projectile cartridge (1), a predetermined amount of not less than 0.01 mg of sealing medium (5) per mm of caliber diameter (D), in particular not less than 0.03 mg of sealing medium (5) per mm of caliber diameter (D), preferably not less than 0.05 mg of sealing medium (5) per mm of caliber diameter (D), is applied.

7. Method according to one of Claims 5 to 6, characterized in that the sealing medium, in particular in the microdosing, is set to a viscosity in the range from approximately 5 s to 100 s, in particular 10 s to 70 s, preferably in a range from 30 s to 70 s or in a range from 10 s to 20 s, wherein in particular the viscosity is set in accordance with a viscosity measurement method according to DIN 53211 with an ISO-4 mm immersion discharge cup, wherein in particular the sealing medium (5) is dispensed from the microdosing (7) in mist form (57), wherein in particular the viscosity of the sealing medium in the microdosing (7) is set to at most 30 s, in particular at most 25 s, preferably at most 20 s, or the sealing medium (5) is dispensed from the microdosing (7) in drop form, wherein in particular the viscosity of the sealing medium (5) in the microdosing (7) is set to at least 10 s, in particular at least 15 s, preferably at least 30 s.

8. Method according to one of Claims 5 to 7, characterized in that, in order to form the annular layer (51, 52), the sealing medium (5) is dispensed from the microdosing (7) in at least one, preferably a plurality of, drops (55), wherein in particular the projectile cartridge (1) is produced with a specific caliber diameter (D) and, in order to form the annular layer (51, 52) in relation to the caliber diameter (D) of the projectile cartridge (1), 1 to 5 drops (55) per mm of caliber diameter (D) are dispensed, and / or in that an annular layer (51, 52) having a width of at least 1 mm, in particular at least 2 mm, and / or not more than 10 mm, in particular not more than 6 mm, and / or having a thickness of at least 0.003 mm, in particular at least 0.005 mm, and / or not more than 0.025 mm, in particular not more than 0.015 mm, is formed, and / or in that the drops (55) are dispensed in a cycle in the range from 100 Hz to 3000 Hz, in particular in the range from 250 Hz to 2000 Hz, preferably in the range from 300 Hz to 1000 Hz.

9. Method according to one of Claims 5 to 8, characterized in that the neck region (31) of the projectile casing (3) is widened radially, in particular along an edge of a mouth 30, before the insertion of the projectile (4), and / or in that the sealing medium (5) is dispensed from the microdosing (7) through a nozzle (71) which is preferably held orthogonally with respect to the inner circumference (33) and / or at a predetermined distance of at least 0.5 mm, in particular at least 1 mm, and / or not more than 20 mm, in particular not more than 10 mm, preferably not more than 5 mm, wherein in particular before the dispensing of the sealing medium (5) an, in particular linear, movement for introducing the nozzle (71) into the neck region (31) of the projectile casing (3) is carried out, and / or a nozzle (71) having an initial diameter in the range from 0.05 mm to 0.5 mm, in particular in the range from 0.1 mm to 0.3 mm, preferably having an initial diameter of 0.15 mm, is used.

10. Method according to one of Claims 5 to 9, characterized in that projectile casing (3) is rotated, preferably continuously, in relation to the microdosing (7), in particular the nozzle (71), about an axis of symmetry (S) of the projectile casing (3), and / or in that the sealing medium (5) is provided comprising, in particular consisting of, 50% by volume to 70% by volume of an in particular bitumen-containing sealant mixture, in particular 54% by volume to 65% by volume of an in particular bitumen-containing sealant mixture, and also 5% by volume to 20% by volume of diluent, in particular 6.5% by volume to 16.5% by volume of diluent, and 25% by volume to 40% by volume of graphite (D90 < 10 µm), in particular 28.5% by volume to 32% by volume of graphite (D90 < 10 µm).

11. Installation for producing projectile cartridges (1) formed according to one of Claims 1 to 4, comprising a mounting for holding the projectile casing, characterized by microdosing for providing a predetermined amount of a highly viscous sealing medium (5) for application to the inner circumference and furthermore by at least one heater and / or cooler and also, if appropriate, a temperature controller comprising a temperature sensor for guiding the sealing medium in the microdosing at a temperature of at least 25°C and / or at most 60°C.

12. Installation according to Claim 11, furthermore having at least one, in particular precisely one, nozzle (71) which is fluidically connected to the microdosing and has an initial diameter in the range from 0.05 mm to 0.5 mm, in particular in the range from 0.1 mm to 3 mm, for dispensing the sealing medium (5), wherein in particular the nozzle (71) and the mounting are coordinated with one another in such a way that the nozzle is oriented orthogonally with respect to the inner circumference (33) during the dispensing of the sealing medium (5).

13. Installation according to Claim 12, characterized in that the nozzle (71) and the mounting are coordinated with one another in such a way that the nozzle (71) is held at a predetermined distance of at least 0.5 mm, in particular at least 1 mm, and / or not more than 20 mm, in particular not more than 10 mm, preferably not more than 5 mm, from the inner circumference (33) during the dispensing of the sealing medium.

14. Installation according to one of Claims 12 to 13, characterized in that the nozzle (71) and the mounting of the nozzle are linearly movable relative to one another for moving the nozzle (71) relative to the inner circumference, in particular for introducing the nozzle (71) into the neck region (31) of the projectile case (3).

15. Installation according to one of Claims 12 to 14, characterized in that the mounting is coordinated with the microdosing and / or the nozzle in such a way that the projectile casing (3) is rotationally movable, preferably continuously, about an axis of symmetry (S) of the projectile casing (3), and / or furthermore having at least one conveying device for feeding and / or discharging at least one projectile casing per second, in particular at least two projectile casings per second, preferably at least three projectile casings per second, to or from the microdosing.

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