Patent Application
20240200918
This patent application claims priority to German Patent Application No. 102022113108.4, filed May 24, 2022, which is incorporated herein by reference in its entirety.
The present disclosure relates to a tool and a method for producing or manufacturing a projectile with a caliber in the range of 4.6 mm to 20 mm, in particular a deformation bullet, partial fragmentation bullet, partial or full jacket bullet, hard-core bullet or a tracer bullet. Furthermore, the present disclosure provides a projectile with a caliber in the range of 4.6 mm to 20 mm, in particular a deformation bullet, partial fragmentation bullet, partial or full jacket bullet, hard-core bullet or a tracer bullet.
German patent application DE 10 2017 011 359 A1 describes manufacturing a projectile by deep-drawing with the help of a so-called intermediate or intermediate product, whereby the deep-drawing is applied using a punch-die arrangement. According to DE 10 2017 011 359 A1, the wall to be formed into the ogive in the subsequent forming process of the intermediate has a plurality of slots extending in the axial direction of the intermediate, which form a corresponding number of tines or wall sections separated in the circumferential direction by the slots. In the intermediate and also in the projectile made therefrom, the cavity on the ogive side is at least partially closed in the circumferential direction by pressing the structurally separated tines together, only when the slotted wall is formed into an ogive section. To manufacture the intermediate, a mandrel-shaped punch with a blade corresponding to a slotted screwdriver is used, which is pressed into a blank of solid material inserted in a cylindrical die.
The intermediate and the projectile according to DE 10 2017 011 359 A1 have proven themselves in principle, as it is possible to achieve an extremely simple but uniform deformation of the blank, so that a precise projectile can be provided which is optimized with regard to the deformation property in wound ballistics, in particular for a specific range of use. The intermediate/projectile cold-formed in this way has proven to be advantageous, particularly with regard to the desired partial fragmentation- or deformation behavior in wound ballistics, in particular for an often-limited velocity range. However, it turned out that the intermediates and projectiles have limited suitability as deformation bullets for other bullet types. It has also been found that the mandrel tools are very heavily loaded and could be improved, in particular for mass production.
The heavy and/or unfavorable loading of the mandrel tools occurs in particular due to the inaccurate centering of the tools and the increased forming work. The inaccurate centering can cause not only compressive stresses, but also bending moments in the mandrel, which can ultimately lead to tensile stresses. Since in particular mandrel tools are made of carbide or hardened steel, even small tensile stresses can lead to a violent fracture of the mandrel, since these materials are very susceptible to violent fracture under tensile stresses.
For manufacturing reasons, in particular due to the intermediate-punch combination, the intermediate and the projectile according to DE 10 2017 011 359 A1 are limited by design with regard to the length-to-diameter ratio of the cavity. In this context, the cavity on the ogive side may only be approximately as deep as the diameter of the cavity. This means that a deep cavity results in a thin-walled ogive section. A thick-walled ogive section can therefore only have a minimum cavity depth. Because of these constructive constraints, the projectile is configured to be suitable for only a limited range of velocities and to deform as desired only in a limited velocity band. It may even be that a given velocity leads to an uneven deformation of the projectile in wound ballistics and this, in extreme cases, will lead to an unwanted and arbitrary disintegration of the projectile, wherein, in the end, the projectile is no longer regarded as a mass-stable deformation bullet.
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the embodiments of the present disclosure and, together with the description, further serve to explain the principles of the embodiments and to enable a person skilled in the pertinent art to make and use the embodiments.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. Elements, features and components that are identical, functionally identical and have the same effect are—insofar as is not stated otherwise—respectively provided with the same reference character.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to those skilled in the art that the embodiments, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, and components, have not been described in detail to avoid unnecessarily obscuring embodiments of the disclosure.
An object of the present disclosure is to improve the disadvantages from the known prior art, in particular to provide a method and a tool for manufacturing a projectile as well as to provide such a projectile which is easier to manufacture.
In accordance with one aspect of the present disclosure, a projectile with a caliber in the range of 4.6 mm to 20 mm for ammunition is provided. The projectile may be a deformation bullet, a partial fragmentation bullet, a partial or full jacket bullet, a hard-core bullet, or a tracer bullet. The caliber is generally referred to as a measure of the outer diameter of projectiles or bullets and the inner diameter of a firearm barrel.
In the case of partial jacket bullets or partial fragmentation bullets, the core is not enclosed by jacket material on the bullet front side and is exposed. On impact with a target, the bullet front deforms due to the high pressure on impact and when penetrating the target. For example, the projectile may deform mushroom-shaped (mushrooming) or at least partially deform. As a result, the projectile can deliver its energy to the target medium much more effectively than a full jacket bullet, in which the jacket completely surrounds the core, but has a lower penetration performance. Such bullets are used in particular as hunting bullets, since these, for a shot in compliance with hunting principles, due to the effective energy release in the deer body, more reliably lead to a faster death of the deer being shot at, as compared to full jacket bullets. Partial fragmentation bullets are usually constructed in such a way that they fragment in a controlled manner except for a defined residual body. The suction effect of the residual body ensures that the fragments of the forward, disintegrated core part leave the target for the most part. Deformation bullets mushroom on impact with the target and remain mass-stable. As a rule, deformation bullets are designed to lose very little weight in the target. The effect is achieved primarily by the increase in cross-section of the projectile mushrooming uniformly and the constant weight.
Hard-core bullets are also known as penetrators or AP (Armor Piercing) bullets and are suitable for military use against armored targets, for example armored vehicles or protective vests. Hard-core bullets generally consist of a bullet jacket and a hard core inserted and/or embedded therein. The hard core is usually made of pure tungsten, tungsten carbide or hardened steel with a hardness greater than 550 HV. Tungsten and tungsten carbide are ideally suitable for penetrating ammunition for two reasons. Due to its high specific density, the tungsten or tungsten carbide core has a high kinetic energy, which is beneficial for penetration. Furthermore, the material is very hard, which means that the abrasive penetration process causes less damage to the core itself. Due to the core hardness, barrel wear is significantly increased. For this reason, the core of the projectile is often made of two parts. The front part consists of hard material and the rear part is made of softer material in order to embody the guide band of the projectile as protective on the barrel as possible. Another hard-core bullet construction principle is only two-part, where a hard-core is inserted into a thick-walled bullet shoe. The bullet shoe is made of soft material, which means that the protective barrel aspect only comes into play due to the bullet shoe.
Full bullets are also called solid bullets or monolithic bullets and are in particular made of one material. The bullet material is usually a soft, ductile material, preferably metal with a density of more than 5 g/cm3 Copper, tombac, brass or even pure lead can be used as solid bullet material. The intended use of solid projectiles is often found in special applications. For example, to hit targets behind glass panes. The nose of the projectile is flattened so that penetration of the glass pane does not lead to a change in the trajectory. In terms of production technology, solid bullets can be produced by solid forming or metal-removing. As a result, this structure is suitable for both small and large series.
Full jacket bullets usually have a jacket of deformable material, such as tombac, and a core arranged therein, which is manufactured separately from the bullet jacket. The bullet core is usually made of a softer material compared to the deformable material of the jacket. The core represents the main weight part of the projectile and is preferably made of a high-density material. In the case of the full jacket bullet, the jacket transfers the twist transmitted from the barrel to the core. Through the jacket, low-friction pressing through the barrel of the firearm can be ensured. The jacket also has the task of protecting the core, which is usually made of soft material, from the considerable forces generated during firing and projectile flight. Due to the full-frontal enclosure of the core with the jacket, the projectile is prevented from opening in the wound ballistic medium and a certain penetration capability on hard targets is ensured. The precision of the projectile, as well as the aerodynamics, are reduced with the full jacket bullet, compared to the partial jacket bullet, due to the frontal enclosure of the core. In the case of the partial jacketed bullet, the bullet core is not completely enclosed by a jacket material, but is exposed in the area of the bullet front, which leads to a desired deformation of the projectile after penetration into a target.
Tracer bullets are generally used exclusively for military purposes, as they are used to mark a target to be fired at or a direction to be fired at in the training area or war zone. The basic construction of a tracer bullet is the same as that of a full jacket bullet. In contrast to the full jacket bullet, a pyrotechnic charge is pressed into the rear. This set burns off during projectile flight, ignited by the hot propellant powder during firing. This burning serves for visualization of the projectile flight.
According to the first aspect of the present disclosure, the projectile is made, by means of cold forming, in particular extrusion, from an intermediate with a tube section of substantially constant wall thickness, which constitutes at least 50% of the longitudinal extension of the intermediate. The tube section may also constitute at least 60%, at least 70%, at least 80%, or at least 90% of the intermediate. For example, the intermediate is tubular shaped, in particular it consists of the intermediate. It was found that with such an intermediate with a tube section of significant length, it is possible to manufacture projectiles in a particularly precise manner using much more delicate tools purely by means of a cold forming process in a simple manner in terms of manufacturing technology, whereby a much lower working pressure can be used for the forming process, which improves the possibility of mass production. In addition, manufacturing tolerances are significantly improved. A particular advantage is that the initial outer diameter of the intermediate substantially corresponds to the caliber of the projectile to be produced, so that the metal material in the area of the outer diameter, in particular near the surface, is hardly hardened or deformed on the final projectile. This makes it possible to achieve a significantly more homogeneous metal structure, which has a positive effect on precision and/or a desired deformation in the case of a deformation bullet. The tube section also makes it possible for very delicate tools to penetrate very deeply into the intermediate, whereby very long service lives can be achieved in comparison with the solid body, since the tools suffer little damage due to the tube shape of the intermediate, in particular in contrast to a solid-material intermediate, as has been common practice to date.
The tube section is characterized in particular by the fact that the outer diameter is based on the permissible tensile dimension according to CIP, SAAMI or STANAG. The tensile dimension defines the intermediate outer diameter in the range from −0.15 mm to +o.05 mm.
According to another aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, there is provided a projectile having a caliber in the range of 4.6 mm to 20 mm.
According to the further aspect of the present disclosure, the projectile is made, in particular by means of cold forming, in particular extrusion, from an intermediate with a tube section of substantially constant wall thickness, which constitutes at least 50% of the longitudinal extension of the intermediate. The tube section may also constitute at least 60%, at least 70%, at least 80% or at least 90% of the intermediate. For example, the intermediate is tubular shaped, in particular it consists of the intermediate.
Furthermore, according to another aspect of the present disclosure, an inner tube diameter of the intermediate is at most 50% of an outer tube diameter of the intermediate. The outer tube diameter serves as a reference for the inner tube diameter, since the outer tube diameter can be selected such that it already substantially corresponds to the caliber of the projectile to be produced, so that no further forming is required to obtain the desired dimensioning. As a result, working steps and thus forming steps that generate material stresses and cause hardness increases can be saved. According to this aspect of the disclosure, the thick wall thickness of the tube section is decisive, since the tube section is thus quite solid and resistant to the pressing forces that occur.
According to another aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, there is provided a projectile with a caliber in the range of 4.6 mm to 20 mm.
According to the further aspect of the present disclosure, the projectile is made, in particular by cold forming, in particular extrusion, from an intermediate with a tube section of substantially constant wall thickness, which constitutes at least 50% of the longitudinal extension of the intermediate. The tube section may also constitute at least 60%, at least 70%, at least 80% or at least 90% of the intermediate. For example, the intermediate is tubular shaped, in particular it consists of the intermediate.
Further, according to another aspect of the present disclosure, an inner cross-section of the intermediate is point-symmetric, deviates from a circular shape, and is constant in the direction of the longitudinal extension. Thus, the inner cross-section of the intermediate may have any regular or irregular point-symmetric shape. The outer surface of the tube forms a cylindrical jacket surface. In this respect, the projectile inner geometry can be realized arbitrarily and flexibly in a simple manner, by corresponding formation of the tube inner cross-section, while otherwise retaining the projectile geometry, of the, in particular forming, manufacturing process, and the outer shape of the projectile. In particular, any internal geometries with different deformation properties can be manufactured in a simple manner.
A major advantage of the fact that the defined inner contour of the intermediate is retained even after forming, in particular cold forming, of the intermediate into a projectile is that further cost reduction potentials arise because it is possible to fall back on simple, for example purely conically shaped punches. The bullet cavity can be notched either with a segmented mandrel in a round-tube shaped intermediate or with a defined inner contour and a conically shaped punch.
Defined inner contours of the tubular shaped intermediate can, for example, be star-shaped, such as a non-convex regular polygon and have, for example, 10 to 100 edges of equal length. The projectile made from the star-shaped intermediate exhibits a fast response at low impact velocities, this due to the strong notch effect. Another defined inner contour is a polygon which comprises a closed path and in particular whose 5 to 50 edges are all of the same length. The previously described inner polygonal intermediate results in a projectile that deforms at increased impact velocities because the notch effect is weaker compared to the star-shaped intermediate. The notch effect is even lower in a projectile made from an intermediate with a defined inner contour in the form of an inner hexagon, also known as polylobular, consisting of 3 to 40 circular elements of equal length joined together. Further possibilities for controlling the response sensitivity as well as the susceptibility to disassembly are conceivable by means of tubular shaped intermediates with V-shaped notches. Here, the notch depth, the notch angle and/or the number of notches can be varied and adapted to the ballistic requirements. Since the intermediate according to the disclosure is an extrusion profile, delicate designs with 5 to 10 deep grooves or 5 to 20 ribs are also conceivable.
According to an exemplary further development of the projectile according to the disclosure, an outer diameter of the intermediate substantially corresponds to the caliber of the projectile. A significant advantage of this embodiment is that the outer dimensioning of the intermediate is already selected in such a way that the intermediate already has the outer dimension of the projectile to be manufactured. In this respect, the dimension-sensitive caliber of the projectile can be set in a simpler and more precise manner already during the production of the blank or intermediate without having to change the outer skin of the intermediate during the subsequent, in particular cold forming, production of the projectile shape. It has been found that it is much easier in terms of production technology to set the outer diameter in advance rather than during the much more complex projectile production or -forming.
According to another aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, there is provided a projectile having a caliber in the range of 4.6 mm to 20 mm.
According to another aspect of the present disclosure, the projectile is made from an intermediate with a tube section of substantially constant wall thickness. The tube section may constitute at least 50%, in particular at least 60%, at least 70%, at least 80% or at least 90%, of the longitudinal extension of the intermediate. For example, the intermediate is tubular shaped, in particular it consists of the intermediate.
The tube section has a bullet jacket surrounding a central cavity, which bullet jacket has a bullet front tapering in particular in an ogive-like manner and an adjoining bullet rear with a solid rear portion which leads into a bullet bottom. In particular, the tube section, i.e. the bullet jacket with bullet rear, bullet front and bullet bottom, is made from one piece.
According to this aspect of the disclosure, an averaged hardness at the bullet bottom corresponds to at least 103%, in particular at least 105%, of that averaged hardness if the projectile were made from a solid intermediate, and/or an averaged hardness in the region of a jacket region of the bullet rear surrounding the cavity corresponds to at most 90%, in particular at most 85% or at most 80%, of that averaged hardness if the projectile were made from a solid intermediate. The averaged hardness is to be understood as an average value of the individual hardness values at the corresponding portions or sections and is intended to indicate the tendency, although it may be that the described ratios do not apply to individual values. For example, the hardness values may be determined using the hardness test according to Vickers (HV). The inventors have identified individual characteristics in the hardness profile to distinguish a projectile made in accordance with the disclosure from previously known projectiles, which reveal numerous advantages of the present disclosure. The softer area in the bullet rear has a positive effect on the barrel lifetime of the firearm and results in a longer tool lifetime. A soft intermediate region of the projectile is particularly relevant for long service lives of the tools. The softer the intermediate area of the eventual projectile remains due to the previous operations, the less forming work the tools had to perform during the operations. This results in a longer tool lifetime.
In an exemplary embodiment of the present disclosure, the hardness values are near-surface values. For example, they may be measured a few millimeters below the outer surface of the projectile.
In another exemplary embodiment of the present disclosure, the jacket region of the bullet rear surrounding the cavity comprises a guide band for engaging in a land-groove-profile of a firearm barrel, which guide band defines a maximum outer diameter of the projectile. A soft guide band enhances in particular the advantages described with regard to barrel lifetime of the firearm and a tool lifetime. According to an exemplary further development, an averaged hardness of the guide band over its entire radial depth, in particular up to the cavity, is softer, in particular at least 10%, at least 15% or at least 20% softer, than that averaged hardness if the projectile were made of a solid intermediate.
In a further exemplary embodiment of the present disclosure, the bullet rear in the axial projection of the cavity, i.e. on the rear side of the cavity, has a solidified core region, extending in the longitudinal direction of the projectile, in particular up to the bullet bottom, with a higher average hardness than bullet rear regions adjacent to the core region, whose average hardness of which corresponds to at least 140%, in particular at least 150% or at least 160%, of that average hardness if the projectile were made from a solid intermediate.
In another exemplary embodiment of the present disclosure, combinable with any of the preceding aspects and exemplary embodiments, the material of the projectile and/or intermediate is copper, aluminum, iron, such as soft iron, silver, titanium, tungsten, tin, zinc, magnesium, lead, cadmium, or alloys thereof.
According to another aspect of the present disclosure, which can be combined with the preceding aspects and exemplary embodiments, a tool for pressing an intermediate inserted in a, in particular a cylindrical, die, which has a tube section with a cavity of substantially constant diameter, is provided for producing a projectile having a caliber ranging from 4.6 mm to 20 mm, in particular according to one of the aspects or exemplary embodiments previously described.
The tool can basically be made of a rigid, in particular inelastic, material and, for example, consist of one piece.
The tool comprises a holding section at which an operator or a machine can hold and operate the tool. Furthermore, the tool has a forming section tapering in the direction away from the holding section and having a tip, an elongated, at least sectionally curved, in particular concave-shaped, or conically-shaped guide part adjoining the tip, for guiding the tool within the cavity of the intermediate, and an, in a projection-free manner adjoining, at least sectionally curved, in particular concave-shaped, or conically-shaped press part, having a different inclination to the longitudinal axis of the tool than the guide part. The guide part of the forming section arranged adjacent to the tip serves to guide the tool within the cavity of the intermediate. Guiding the tool within the cavity of the intermediate has several advantages. Firstly, it is accompanied by a kind of self-centering, which results in particularly high precision. Secondly, due to the aligned tool movement in the direction of the longitudinal axis of the cavity it is reliably ensured that, an essential aspect of the present disclosure, namely being able to apply lower pressing forces and to use more delicate tools, is maintained.
According to an exemplary further development, the inclination of the outer surface of the press part with respect to the longitudinal axis of the tool is greater than the inclination of the outer surface of the guide part with respect to the longitudinal axis of the tool. In particular, this makes it possible to produce a particularly delicate tool in which the guide part is configured thin and very elongated, so that it is possible to reach deeply into the cavity of the intermediate. By means of the tool according to the disclosure, it withstands a plurality of pressing operations, in particular at least 100, 300, 500, 700 or at least 1000, pressing operations.
According to another exemplary embodiment of the tool according to the disclosure, an axial length of the guide part is matched to an inner dimension of the intermediate in such a way that the tool has an outer dimension of up to 1.4 times the diameter of the cavity at the transition from the guide part to the press part. For this geometric matching, a particularly good guiding of the tool within the cavity of the intermediate is ensured.
According to a further exemplary embodiment of the tool according to the disclosure, an axial length of the guide part and/or the press part is at least 80% of a maximum radial distance of the cavity. In particular, the axial length of the guide part can be at least as large, at least 1.5 times as large or even at least twice as large, as the maximum radial distance of the cavity of the intermediate.
According to a further exemplary embodiment of the tool according to the disclosure, its cross-section is point-symmetrical, in particular in the region of the guide part and/or the press part, and deviates from a circular shape. In other words, any regular or irregular point-symmetrical shapes can be considered for the outer cross-section of the guide part and/or the press part, which can be selected depending on the desired inner geometry of the projectile to be produced.
According to a further aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, there is provided a method of manufacturing a projectile, in particular according to one of the aspects or exemplary embodiments described above, with a caliber in the range of 4.6 mm to 20 mm.
According to the method according to the disclosure, an intermediate with a tube section of substantially constant wall thickness is inserted into a, in particular cylindrical, die, and the intermediate is cold-formed, in particular press cold-formed, in particular by means of extrusion, by means of a tool in particular according to one of the aspects of the disclosure described above, in such a way that, at least sectionally, the outer diameter of the intermediate remains substantially constant and determines the projectile caliber. By means of the method according to the disclosure, it is possible to select the intermediate for producing the projectile in such a way that its initial outer dimension is substantially close to the caliber of the projectile to be produced, so that the metal material in the region of the outer diameter, i.e. near the surface, is hardly solidified and deformed, such that an unsolidified metal structure results, which improves the precision and/or the desired deformation and/or ballistic properties of the projectile.
According to another aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, there is provided a method adapted to produce a projectile according to the disclosure.
According to another aspect of the present disclosure, which is combinable with the preceding aspects and exemplary embodiments, a tubular metallic intermediate, in particular of copper, aluminum, iron, such as soft iron, silver, titanium, tungsten, tin, zinc, magnesium, lead, cadmium or an alloy thereof is used to manufacture a projectile, in particular according to the disclosure, such as a deformation bullet, a partial fragmentation bullet, a partial or full jacket bullet, hard-core projectile or a tracer projectile, with a caliber in the range of 4.6 mm to 20 mm for ammunition.
The basic idea underlying the present disclosure, in particular using of a substantially exclusive cold forming process for manufacturing a projectile using a tubular intermediate, that is, using an intermediate which has a tube section which constitutes substantially 50% of the longitudinal extension of the intermediate, it is possible to create a particularly precisely manufactured projectile and a projectile manufacturable with delicate tools, in a simple manner in terms of manufacturing technology, whereby a lower working pressure is required than is the case in the prior art.
In an exemplary embodiment, a tool configured according to the disclosure is used.
In the following description of exemplary embodiments of the present disclosure, a projectile according to the disclosure is generally designated by reference numeral 1, a pressed part according to the disclosure is generally designated by reference numeral 10, and a tool according to the disclosure is generally designated by reference numeral 100.
With reference to
With reference to
The die 7 comprises a rotationally shaped die-cylinder inner surface 93 with a central front side 101. As can be seen in
A projectile 1 according to the disclosure is shown in a sectional view in
With regard to internal ballistics, the guide band 63, the configuration of the cavity 45 and the choice of material and its hardness are of particular interest. The choice of material is preferably one that nestles into the land-groove-profile of the firearm barrel with little resistance so that the projectile can be accelerated efficiently. Here, the guide band 63, which is in contact with the actual land-groove-profile, is important. In addition to the obvious material parameters such as hardness and temperature resistance, the diffusion coefficient of the guide band 63 should also be as impermeable as possible to the partner material of the barrel to prevent cold welding. Low-resistance penetration of the projectile into the land-groove-profile can be realized not only by the material properties but also by the configuration of the cavity 45. The cavity 45 creates an elastic deflection possibility, which further reduces the press-through resistance.
With regard to the external ballistics of the projectile 1 shown in
The projectile 1 shown in
With reference to
First of all, an intermediate 3 made of metal, preferably a non-ferrous metal or ferrous metal, is provided (
In a first manufacturing step, the intermediate 3 is formed into a preform 9 by setting, in particular cold formed, for example by pressing or extrusion (
After setting, the preform 9 is prepressed to form the pressed part 10 according to the disclosure (
The pressed part 10 produced in this way consists of a metal body 113 of, in particular, homogeneous material, preferably ferrous or non-ferrous material, and is then further cold-formed to form a bullet body 13 shown in
With reference to
First of all, a tube-intermediate 3 made of metal, preferably a non-ferrous metal or ferrous metal, is provided (
In a first manufacturing step, the intermediate 3 is formed into a preform 9 by setting, in particular cold formed, for example by pressing or extrusion (
After setting, the preform 9 is prepressed to form a pressed part 10 (
The pressed part 10 produced in this way consists of a metal body 113 of, in particular, homogeneous material, preferably ferrous or non-ferrous material, and is then further cold-formed to form a bullet body 13 shown in
With reference to
The increase in length and diameter results from the central cavity section 75, which is introduced during setting and tapers in the direction of the opposite end face 37, and which extends from a sharp edge 23 of the preform 9 through the preform 9 to the opposite end face 37 of the preform 9. The pressing in of the conical tool 100 causes a material displacement, which manifests itself in a length expansion, in particular in the direction of the end face 31. The tapered cavity section 75, located at the opposite end face 37, is formed by a conically shaped inner wall surface 71. The setting can be carried out via a tool-die arrangement, whereby the outer geometry of the conical tool 100 determines the geometry of the cavity section 65.
Between the stage of the preform 9 and the pressed part 10, i.e. after the setting and before the prepressing, the blank is turned. In this case a, in particular mechanical, turning operation is required. The preform 9 is cold-formed in the direction of the sharp edge 23 of the preform 9 to form the pressed part 10, so that a preliminary stage of a bullet front 53 is formed by compressing the front wall 41. During prepressing, the front wall 41 is also cold-formed on the outside to a front wall 41 that tapers at least sectionally. Due to the preferably symmetrically introduced front-sided and rear-sided conical cavities, material is accumulated on the front side of the conical tool 47 by the insertion process of the punch. A central constriction 27 is created which completely separates the two conical preferred cavities.
The pressed part 10 manufactured in this way consists in particular of a metal body 113 of homogeneous material, preferably of ferrous or non-ferrous material, and is then further cold-formed to form a bullet body 13 shown in
A schematic representation of a launched, deformed projectile 33, which results from launching a projectile 1 according to the disclosure and impacting the projectile 1 on a target, in particular a standard target such as a gelatinous mass, is shown in
The deformed projectile 49 differs from prior art projectiles in particular in the formation of segment flags 111 which are bent radially outward upon impact with a target. As can be seen in
The deformation behavior results, on the one hand, from the cold forming and the geometry of the central cavity 45 and, on the other hand, from the wall slots 43 introduced into the inner wall surface 71 of the preform 9, which remain as slots on the final projectile 1 on the inner wall surface 71 of the bullet front 53. The cold forming increases the strength of the inner wall surface 71 transverse to the longitudinal direction L compared to the strength of the inner wall surface 71 in the longitudinal direction L, and the wall slots 43 allow the deformation behavior to be controlled in a targeted manner. The impact velocity at which the projectile 1 begins to deform, also referred to as the response behavior, is determined by the diameter of the opening 35. As can be seen in
In addition to the geometric effects which cause different deformation behavior when penetrating the gelatinous mass, the impact velocity of the projectile 1 on the gelatinous mass is also responsible for the final shape of the deformed projectile 49.
When the projectile impacts the gelatinous mass, a large hydrodynamic bullet opening pressure is generated, which leads to deformation of the projectile in the gelatinous mass. If this bullet opening pressure is maintained over long distances, this can lead to the tearing off of one or more segment flags 111. To prevent this, the distance between the bullet bottom 17 and the cavity base section 57 can be designed to implement a rupture-disc-like overpressure valve which can be used to relieve the excess bullet opening pressure. The hole in the bullet bottom resulting therefrom not only reduces the bullet opening pressure, but also has stabilizing effects in the gelatinous mass.
With reference to
In the side view in
In
A general advantage of the present disclosure is that the inner shape can be adapted very flexibly in tube extrusion. In particular, any internal geometries with different deformation properties can be easily manufactured in conjunction with the press head.
Metals, in particular non-ferrous metals, have the property of becoming harder due to deformation. This means that a large deformation leads to a large increase in the hardness of the raw material. On the basis of hardness profile figures, as shown in
The illustration according to
The hardness values of the tip 29 and the hardness values of the bullet front 53 of the projectile 1 are increased compared to the rest of the bullet body 13. Due to the reduced deformation during the pressing process, the projectiles 1 which are made of the tubular intermediate 3 are softer in the region of the guide band 63, as compared to the projectiles which are made of a solid intermediate, also called a wire blank. This softer region has a positive influence on the barrel lifetime of the firearm and results in a longer tool lifetime of the die 7 and the tool 100. A soft intermediate region of the projectile 1 is particularly relevant for long service lifetimes of the tools. The softer the intermediate region of the eventual projectile 1 remains due to the previous operations, the less forming work the tools had to perform during the operations. This results in a longer tool lifetime. Accordingly, a conclusion can be drawn about the tool lifetime from the hardness profile in the tube projectile according to the disclosure.
The region of tip 29 marks the hardest part of all projectiles in
However, if the blank consists of a solid material intermediate (
It is particularly advantageous in the case of projectiles 1 made from an intermediate 3 according to the present disclosure that there is only a slight increase in hardness in the region of the guide band 63, so that in the region of the land-groove dimension of the projectile 1 and in the central region of the engagement of the pressed part 80 there is a substantially low hardness according to Vickers, the hardness values being near-surface values. According to the disclosure, it was found that the homogeneous hardness distribution formed in this way has a positive effect on the ballistics and precision of the projectile 1 and, in particular, a positive effect on the tool lifetime of the delicate pressed part 80.
The projectiles 1 made of solid material intermediate 3, shown in
A subdivision of the hardness levels is shown in
The hardness zones of the projectile 1 made of a solid intermediate material have only limited ballistically optimized properties. The medium-hard zone m extends into the guide band 63. The hard zone h extends beyond the kink of the segment flags 111. The soft zone w is located exclusively in the bullet bottom 17.
On the bullet front side, the projectiles 1 made from the tubular intermediate 3 differ from those made from solid material intermediates in that the bullet front 53 has a shorter transition phase from the hard tip 29 to the soft guide band 63.
The features disclosed in the foregoing description, figures, and claims may be significant, both individually and in any combination, for the realization of the disclosure in the various embodiments.
To enable those skilled in the art to better understand the solution of the present disclosure, the technical solution in the embodiments of the present disclosure is described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the embodiments described are only some, not all, of the embodiments of the present disclosure. All other embodiments obtained by those skilled in the art on the basis of the embodiments in the present disclosure without any creative effort should fall within the scope of protection of the present disclosure.
It should be noted that the terms “first”, “second”, etc. in the description, claims and abovementioned drawings of the present disclosure are used to distinguish between similar objects, but not necessarily used to describe a specific order or sequence. It should be understood that data used in this way can be interchanged as appropriate so that the embodiments of the present disclosure described here can be implemented in an order other than those shown or described here. In addition, the terms “comprise” and “have” and any variants thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or equipment comprising a series of steps or modules or units is not necessarily limited to those steps or modules or units which are clearly listed, but may comprise other steps or modules or units which are not clearly listed or are intrinsic to such processes, methods, products or equipment.
References in the specification to “one embodiment,” “an embodiment,” “an exemplary embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The exemplary embodiments described herein are provided for illustrative purposes, and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments. Therefore, the specification is not meant to limit the disclosure. Rather, the scope of the disclosure is defined only in accordance with the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102022113108.4 | May 2022 | DE | national |
