Patent Application
20250116494
The present invention relates to an intermediate, a tool and a method for producing a deformation bullet, for example for police and/or authority ammunition with a caliber in the range of 4.6 mm to 20 mm, as well as a deformation bullet. Furthermore, the present invention relates to police and/or authority ammunition having a caliber in the range of 4.6 mm to 20 mm. Police and/or authority ammunition is characterized, inter alia, in that the firing range is generally less than 600 m, in particular less than 300 m or less than 150 m. Generic deformation bullets are characterized by a defined wound ballistic behavior, namely a predetermined deformation, in particular mushrooming, after hitting the target. They are usually produced in one piece and comprise a, in particular an ogive-shaped, bullet nose with a central cavity and a bullet tail adjoining the bullet nose.
For environmental and health reasons, the use of lead as a material for bullets is viewed critically these days. When selecting materials for bullets, there is therefore a conflict of interest, particularly between good precision and flight range and environmental compatibility. Alternative materials to lead, such as tin, zinc or copper, have proven to be less suitable due to their low density, which would ensure better environmental compatibility, but can result in significant losses in terms of precision and flight range. Furthermore, alternative solutions such as brass projectiles also have decisive disadvantages in terms of barrel service life and resistance to being pressed through the barrel of the firearm. The pressure is too high when the powder burns, while the resulting muzzle velocity is too low. Another disadvantage is that a main component of brass is copper. Copper itself is also hazardous to health and bactericidal. The use of copper is therefore undesirable in terms of future environmental requirements.
The wound ballistics or terminal ballistics of deformation bullets are largely determined by the so-called cross-sectional load, which results from the ratio of the mass of the bullet and its cross-sectional area. In general, the greater the cross-sectional load, the greater the penetration depth of the bullet in the target. It is clear that the energy dissipation of the projectile into the wound ballistics is increased by the shortened penetration depth of the projectile. This is basically due to the fact that the cross-sectional load in the terminal ballistics is determined by the increase in diameter of the bullet resulting from the expanding or mushrooming deformation, in particular in its front or nose area, in particular the ogive area. To date, there is no deformation bullet in the state of the art, particularly one that is environmentally compatible, which fulfills the wound ballistic requirements with regard to a reduced penetration depth compared to non-expanding bullets at a comparatively high cross-sectional load. The inventors have made attempts to soften the ogive-shaped nose of the bullets or to reduce the ogive wall thickness very slightly to less than 1 mm. However, the conflict of interest between cross-sectional load or desired (mushrooming) deformation behavior and predetermined penetration depth could not be resolved satisfactorily.
It is known from DE 10 2017 011 359 A1 to produce solid bullets by cold forming using a die and mandrel tool arrangement in which the mandrel has a cross-screwdriver-like front with blades distributed in the circumferential direction. When the bullet blank is pressed, its material evades the blades of the mandrel so that a corresponding negative profile is pressed into the bullet blank. The bullets according to DE 10 2017 011 359 A1 have generally proved very successful. However, it has been found that the axial slots pressed into the bullet blank by means of the mandrel result in a large increase in diameter when the bullet hits a target, which is basically positive in terms of reducing the penetration depth, but introduces an increased risk of components of the bullet breaking off or separating from the bullet.
It is the object of the present invention to overcome the disadvantages of the known prior art, in particular to improve the wound ballistic behavior of a deformation bullet, in particular to provide a deformation bullet which solves the conflict of interest of expanding deformation and reduced penetration depth with reduced risk of rupture or separation of bullet components.
This object is solved by the features of the independent claims.
The present invention relates to a bullet, in particular a deformation bullet, such as a hollow point bullet, for example for police and/or authority ammunition. In particular, the present invention relates to a bullet with a caliber in the range of 4.6 mm to 20 mm.
Cartridges usually consist of a bullet, a cartridge case, propellant powder and a primer. The bullet is the object fired by the weapon. With a cartridge caliber of 9 mm×19 (Luger or Para caliber), the weight of a bullet can be between 3 g and 10 g, in particular between 5 g and 15 g, preferably between 5.5 g and 9 g, particularly preferably between 6 g and 6.3 g, for example 6.1 g. Due to their weight and shape, the bullets of standard 9 mm Luger caliber cartridges reach muzzle velocities of 340 m/s or more. The material of the bullet is preferably lead-free and/or lead-alloy-free. 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.
A bullet according to the present invention is a so-called operational bullet, which is used, for example, by the police and/or authorities in operations. Operational bullets are normally formed as deformation bullets and have a defined wound ballistic or terminal ballistic behavior. In other words, operational bullets have a defined effect within the target after they have penetrated the target. This means that operational bullets must be distinguished from so-called practice bullets, which are used, for example, by the police and/or authorities in training or for basic and advanced firearms training. The practice bullets are intended to replicate the flight behavior of the operational bullets as accurately as possible, but differ from the operational bullets in terms of their final ballistics in that the practice bullets should have no effect or as little effect as possible on the target and, in particular, should not penetrate the target. In order to achieve this, the bullet nose of training bullets is provided to flatten on impact with a target, for example, so that the cross-sectional load is so small that the training bullet does not penetrate the target.
According to a first aspect of the present invention, a bullet according to the invention comprises a bullet body which in particular has an ogive-shaped bullet nose and an in particular cylindrical bullet tail. The bullet tail can be substantially produced from solid material and/or be formed at least sectionally fully cylindrical. The maximum outer diameter defining the caliber of the bullet may be present in the region of the bullet tail. In the present description, the terms nose, front, front-side or rear, rear-side or rear are to be understood with reference to a longitudinal axis of the bullet pointing in the direction of flight. The bullet tail can, for example, have a guide band, which in particular is formed cylindrically at least sectionally, for guiding the bullet in the barrel of the firearm. The guide band can, for example, be designed in such a way that it engages in a land-and-groove profile of the firearm barrel, which is designed in particular to impart a twist to the bullet as it slides along within the firearm barrel in order to stabilize the trajectory of the bullet. A phase section can be arranged at the tail end of the bullet tail in order to simplify the insertion of the bullet into the mouth of a cartridge case.
The bullet body has a nose wall delimiting a central cavity which is open towards the surroundings. A central cavity is understood to mean that the cavity extends along the longitudinal axis of the bullet or is formed around the longitudinal axis of the bullet. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the bullet and/or has a substantially circular cross-section. The cavity delimited by the nose wall is open towards the surroundings in the direction of the bullet nose or in the direction of the bullet front, in other words at the bullet tip, and extends from there in the direction of the bullet tail to a cavity base. The cavity is preferably empty, i.e. filled only with ambient air. The cavity allows the bullet to deform on impact with a target or other resistance. When the bullet is deformed, the bullet nose preferably deforms relative to the, in particular cylindrical, bullet tail, substantially only in the axial and radial directions. For example, the deformation can be rotationally symmetrical. In particular, the nose wall deforms radially outwards on impact with the target.
According to a first aspect of the present invention, the nose wall is notched and/or the cavity is produced by cold forming in such a way that upon impact of the bullet on a target, the nose wall is deformed such that it is widened by less than 90°, in particular less than 60°, in particular less than 45° or less than 30°, with respect to the longitudinal axis of the bullet. In an exemplary further development, the nose wall can only be widened by less than 15° or even less than 10° or less than 5°. The target can be a standard target, which can be, for example, an uncoated gelatinous mass. Furthermore, the deformation bullet can be fired at the target under idealized test conditions in order to be able to inspect the deformed bullet that has hit and been caught in the jelly mass.
In contrast to the strongly mushrooming and thereby very strongly expanding ogive walls of prior art bullets, in which the ogive wall expands and bends significantly more than 90° and sometimes up to 180° in relation to the longitudinal axis of the bullet and viewed in the firing direction when deformed after impact of the bullet on a target, the present invention does not have this strong mushrooming deformation. The deformed bullet resembles a trumpet shape in the front region. The bullet according to the invention is characterized by a low penetration depth when the bullet hits a target, despite the small increase in diameter in the frontal region compared to the prior art. This effect is related in particular to texturing of the bullet body as a result of cold forming of the cavity, which results in direction-dependent texturing, in particular in the nose wall, which leads to the identified trumpet-shaped deformation. In particular, the texturing of the bullet body is such that the strength in the region of the nose wall transversely to the longitudinal direction of the bullet is increased, in particular compared to the strength in the longitudinal direction. The increased strength transversely to the longitudinal direction results in less deformation radially outwards when the bullet hits a target, which reduces mushrooming. Alternatively or additionally, the deformation behavior of the bullet can be influenced by the fact that the nose wall is notched. A notch in the nose wall results in a local reduction in wall thickness, which weakens the nose wall locally. In other words, the notch forms one or more recesses in the nose wall, resulting in a locally reduced wall thickness of the nose wall. In particular, the notches can be introduced on an inner wall surface of the nose wall delimiting the cavity and oriented in the longitudinal direction of the bullet. The inventors of the present invention have found that the deformation behavior can be changed by a notch in the nose wall, irrespective of the strength of the nose wall, which results, among other things, from the thickness of the nose wall, from the cold forming of the cavity and/or from a subsequent heat treatment process, such as annealing. This allows the deformation behavior to be set in a particularly simple and cost-effective manner so that a required cross-sectional load and/or a required penetration depth of the bullet as well as a widening of the nose wall of less than 90°, in particular less than 60°, less than 45° or less than 30° is achieved. In addition, the deformation behavior can be set particularly reliably because it is not dependent on changes and/or hardening during cold forming and/or subsequent heat treatment processes. When the bullet is deformed, the nose wall opens along the notches introduced, while the sections of the nose wall located between the notches remain in one piece, so that the deformation, in particular the widening of the nose wall, can be specifically adjusted. Another reason for the reduced penetration depth that can be achieved with the bullet according to the invention is related to the front cavity of the bullet, which is open towards the surroundings and in which air or air bubbles remain when the bullet penetrates the target, which increase the braking effect in the sense of the “cavitation bubble theory”. Due to the small expansion of the nose wall and the comparatively large cavity still present after deformation, this effect is increased compared to prior art bullets with a larger expansion.
According to a further aspect of the present invention, which can be combined with the first aspect and the exemplary embodiments, the bullet comprises a bullet body produced in one piece. By one-piece or in one-piece it is to be understood that the entire bullet body, which may have a in particular ogive-shaped bullet nose and a in particular cylindrical bullet tail, is produced from a homogeneous material. This distinguishes the bullet according to the invention from two-piece bullets consisting of a core and a jacket, which are manufactured separately and then connected to each other.
The bullet tail can substantially be produced from solid material and/or be at least sectionally fully cylindrical. The maximum outer diameter defining the caliber of the bullet may be present in the range of the bullet tail. The bullet tail can, for example, have a guide band, which is formed cylindrically at least sectionally, for guiding the bullet in the barrel of the firearm. The guide band can, for example, be designed in such a way that it engages in a land-and-groove profile of the firearm barrel, which is designed in particular to impart a twist to the bullet as it slides along within the firearm barrel in order to stabilize the trajectory of the bullet. A phase section can be arranged at the tail end of the bullet tail in order to simplify the insertion of the bullet into the mouth of a cartridge case.
The bullet body has a nose wall delimiting a central cavity which is open towards the surroundings. A central cavity is understood to mean that the cavity extends along the longitudinal axis of the bullet or is formed around the longitudinal axis of the bullet. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the bullet and/or has a substantially circular cross-section. The cavity delimited by the nose wall is open towards the surroundings in the direction of the bullet nose or in the direction of the bullet front, in other words at the bullet tip, and extends from there in the direction of the bullet tail to a cavity base. The cavity is preferably empty, i.e. filled only with ambient air. The cavity allows the bullet to deform on impact with a target or other resistance. When the bullet is deformed, the bullet nose preferably deforms relative to the bullet tail, which is in particular cylindrical, substantially only in the axial and radial directions. For example, the deformation can be rotationally symmetrical. In particular, the nose wall deforms radially outwards on impact with the target.
According to the further aspect, an inner wall surface of the nose wall delimiting the cavity has at least two notches oriented in the longitudinal direction of the bullet, wherein the cavity is produced by cold forming. The cold forming of the cavity results in texturing of the bullet body, which results in direction-dependent texturing, in particular in the nose wall. In particular, the texturing of the bullet body is such that the strength in the region of the nose wall transversely to the longitudinal direction of the bullet is increased, in particular compared to the strength in the longitudinal direction. The increased strength transversely to the longitudinal direction is accompanied by less deformation radially outwards when the bullet strikes a target, which reduces mushrooming. The inventors of the present invention have also discovered that the deformation behavior can be changed by the notches in the nose wall, irrespective of the strength of the nose wall, which results, among other things, by the thickness of the nose wall, by cold forming of the cavity and/or by a subsequent heat treatment process. The notches each form a recess in the nose wall, resulting in a local reduction in the wall thickness of the nose wall and a resulting local weakening of the nose wall. This allows the deformation behavior to be adjusted in a particularly simple and cost-effective way so that a required cross-sectional load and/or a required penetration depth of the bullet is achieved. In addition, the deformation behavior can be set particularly reliably because it is not dependent on changes and/or hardening during cold forming and/or subsequent heat treatment processes. When the bullet is deformed, the nose wall opens along the notches introduced, while the sections of the nose wall located between the notches remain in one piece, so that the deformation, in particular the widening of the nose wall, can be specifically adjusted.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the bullet comprises a bullet body made from one piece of iron material. By one piece or in one-piece it is to be understood that the entire bullet body, which may have a, in particular ogive-shaped, bullet nose and a, in particular cylindrical, bullet tail is produced from a homogeneous iron material. This distinguishes the bullet according to the invention from two-part bullets consisting of a core and a jacket, which are manufactured separately and then connected to each other. In particular, the bullet body can be produced from one piece of soft iron. The carbon content of the iron material can be more than 0.05%, for example between 0.06% and 1.14%. Producing the bullet from iron material results in an environmentally friendly bullet with improved ballistics. Furthermore, iron material is inexpensive and is characterized by good formability, which simplifies producing the bullet. It was found that the bullets made of iron material according to the invention are particularly well suited to being produced by solid forming, in particular by cold forming, such as deep drawing or extrusion, as an alternative to machining.
The bullet tail can substantially be produced from solid material and/or be at least sectionally fully cylindrical. The maximum outer diameter defining the caliber of the bullet may be present in the region of the bullet tail. The bullet tail can, for example, have a guide band, which is formed cylindrically at least sectionally, for guiding the bullet in the barrel of the firearm. The guide band can, for example, be designed in such a way that it engages in a land-and-groove profile of the firearm barrel, which is designed in particular to impart a twist to the bullet as it slides along within the firearm barrel in order to stabilize the trajectory of the bullet. A phase section can be arranged at the tail end of the bullet tail in order to simplify the insertion of the bullet into the mouth of a cartridge case.
The bullet body has a nose wall delimiting a central cavity which is open towards the surroundings. A central cavity is understood to mean that the cavity extends along the longitudinal axis of the bullet or is formed around the longitudinal axis of the bullet. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the bullet and/or has a substantially circular cross-section. The cavity delimited by the nose wall is open towards the surroundings in the direction of the bullet nose or in the direction of the bullet front, in other words at the bullet tip, and extends from there in the direction of the bullet tail to a cavity base. The cavity is preferably empty, i.e. filled only with ambient air. The cavity allows the bullet to deform on impact with a target or other resistance. When the bullet is deformed, the bullet nose preferably deforms relative to the, in particular cylindrical, bullet tail, substantially only in the axial and radial directions. For example, the deformation can be rotationally symmetrical. In particular, the nose wall deforms radially outwards on impact with the target.
According to the further aspect, an inner wall surface of the nose wall delimiting the cavity has at least two notches oriented in the longitudinal direction of the bullet. The inventors of the present invention have found that the deformation behavior can be changed by the notches in the nose wall, irrespective of the strength of the nose wall, which results, among other things, by the thickness of the nose wall, by cold forming of the cavity and/or by a subsequent heat treatment process. The notches each form a recess in the nose wall, resulting in a local reduction in the wall thickness of the nose wall and a resulting local weakening of the nose wall. This allows the deformation behavior to be adjusted in a particularly simple and cost-effective way so that a required cross-sectional load and/or a required penetration depth of the bullet is achieved. In addition, the deformation behavior can be set particularly reliably because it is not dependent on changes and/or hardening during cold forming and/or subsequent heat treatment processes. When the bullet is deformed, the nose wall opens along the notches introduced, while the sections of the nose wall located between the notches remain in one piece, so that the deformation, in particular a widening of the nose wall, can be specifically adjusted.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a bullet according to the invention comprises a bullet body which can have a in particular ogive-shaped bullet nose and a in particular cylindrical bullet tail.
The bullet tail can substantially be produced from solid material and/or be at least sectionally fully cylindrical. The maximum outer diameter defining the caliber of the bullet may be present in the region of the bullet tail. The bullet tail can, for example, have a guide band, which is formed cylindrically at least sectionally, for guiding the bullet in the barrel of the firearm. The guide band can, for example, be designed in such a way that it engages in a land-and-groove profile of the firearm barrel, which is designed in particular to impart a twist to the bullet as it slides along within the firearm barrel in order to stabilize the trajectory of the bullet. A phase section can be arranged at the tail end of the bullet tail in order to simplify the insertion of the bullet into the mouth of a cartridge case.
The bullet body has a nose wall delimiting a central cavity which is open towards the surroundings. A central cavity is understood to mean that the cavity extends along the longitudinal axis of the bullet or is formed around the longitudinal axis of the bullet. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the bullet and/or has an substantially circular cross-section. The cavity delimited by the nose wall is open towards the surroundings in the direction of the bullet nose or in the direction of the bullet front, in other words at the bullet tip, and extends from there in the direction of the bullet tail to a cavity base. The cavity is preferably empty, i.e. filled only with ambient air. The cavity allows the bullet to deform on impact with a target or other resistance. When the bullet is deformed, the bullet nose preferably deforms relative to the, in particular cylindrical, bullet tail, substantially only in the axial and radial directions. For example, the deformation can be rotationally symmetrical. In particular, the nose wall deforms radially outwards on impact with the target.
According to the further aspect, an inner wall surface of the nose wall facing the cavity has at least two micro-notches oriented in the longitudinal direction of the bullet with a notch depth of less than 0.3 mm, in particular less than 0.2 mm or less than 0.1 mm. The micro-notches can only be detected on the bullet, for example by reflected light microscopy, and thus have no influence on the flight behavior of the bullet. The inventors of the present invention have discovered that micro-notches with a very small depth can be used to specifically adjust the deformation behavior. With regard to the mode of action and the advantages of the micro-notches, reference is made to the embodiments of the notches introduced into the inner wall surface of the nose wall in the previous aspects.
In an exemplary embodiment, the notches or micro-notches extend less than 25%, in particular less than 20% or less than 15%, of a total longitudinal extension of the bullet from the open end of the cavity towards a cavity base. Alternatively or additionally, the notches or micro-notches extend by less than 50%, in particular by less than 40%, less than 30% or less than 25% of a total longitudinal extension of the cavity from the open end of the cavity in the direction of a cavity base. In an exemplary further development, the length of the notches is in the range of 0.5 mm to 3 mm. The inventors of the present invention have discovered that the deformation behavior in the front region can be specifically influenced by short notches in the region of the bullet tip, which are particularly easy and inexpensive to produce.
In a further exemplary embodiment, the inner wall surface has 2 to 10, in particular 3 to 8, notches. Preferably, the notches are evenly distributed around the circumference of the cavity. This results in a particularly uniform deformation behavior of the nose wall when the bullet impacts the target.
According to another exemplary embodiment, the bullet is produced without a heat treatment process, in particular without annealing. By introducing the notches into the inner wall surface of the nose wall, a downstream heat treatment process can be dispensed with because the deformation behavior can be set independently of the strength of the nose wall by means of the notches. Without a downstream heat treatment process, producing the bullet is simpler and more cost-effective. Alternatively or additionally, the cavity is produced by means of backwards extrusion. In backwards extrusion, the material is pressed against the pressing direction of the press plunger used. This results in particularly good material properties and the desired geometry of the cavity can be produced particularly reliably. Alternatively or additionally, the notches are also produced by cold forming, in particular by means of backwards extrusion. Preferably, the notches can be produced in the same process step, in particular with the same tool, as the cavity. This results in a particularly simple and cost-effective way of producing the notches, for which no additional process step is required.
The present invention also relates to an intermediate for producing a bullet formed in particular according to one of the preceding aspects and exemplary embodiments.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the intermediate comprises a metal body produced by cold forming from a metal blank and having a hollow cylinder delimiting a central cavity which is open towards the surroundings. Central means that the cavity extends along the longitudinal axis of the intermediate. The cavity delimited by the hollow cylinder extends from a face side of the intermediate to a cavity base. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the intermediate. Preferably, the cavity has a substantially circular cross-section, which in particular can be constant over the entire length of the cavity; in other words, the cavity can be formed in the shape of a cylinder. The hollow cylinder later forms the, in particular the ogive-shaped, bullet nose, when the bullet is produced. The metal body can be produced from a homogeneous metal material such as copper, a copper alloy or brass, or preferably from iron material such as steel. Preferably, the metal body is produced from a lead-free material. The metal body may be produced from a cut-off blank, which may in particular be formed from a cut-off ductile metal material.
According to the invention, a hollow cylinder inner surface of the hollow cylinder facing the cavity is notched in such a way that during cold forming of the hollow cylinder of the intermediate to form a, in particular ogive shaped bullet nose, a dimension of the notch is reduced in such a way that the notch is only visible under reflected light microscopy and/or that a notch depth of less than 0.3 mm, in particular less than 0.2 mm or less than 0.1 mm, results. In other words, the notches with a certain length, depth and width are introduced into the intermediate during the production of the bullet and are compressed during the subsequent cold forming of the bullet nose from the hollow cylinder or close during the cold forming in such a way that micro-notches with significantly smaller dimensions than the originally introduced notches result on the finished bullet. These micro-notches have no influence on the flight behavior of the bullet, but do influence the deformation behavior of the finished bullet when impacting a target as described for the previous aspects, so that reference is made to the previous aspects with regard to the deformation behavior produced by the notches or micro-notches.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the intermediate comprises an iron material body produced by cold forming from an iron material blank and having a hollow cylinder delimiting a central cavity which is open towards the surroundings. Central means that the cavity extends along the longitudinal axis of the intermediate. The cavity delimited by the hollow cylinder extends from a face side of the intermediate to a cavity base. It may be provided that the cavity is rotationally symmetrical with respect to the longitudinal axis of the intermediate. Preferably, the cavity has a substantially circular cross-section, which in particular can be constant over the entire length of the cavity; in other words, the cavity can be formed in the shape of a cylinder. The hollow cylinder later forms the, in particular the ogive shaped, bullet nose, when the bullet is produced.
The iron material body may be produced from a cut-off blank, which may in particular be formed from a cut-off ductile iron material. The intermediate may in particular consist of soft iron. The carbon content of the iron material can be more than 0.05%, for example between 0.06% and 1.14%. Producing the intermediate or bullet from iron material results in an environmentally friendly bullet with improved ballistics. Furthermore, iron material is inexpensive and is characterized by good formability, which simplifies producing the intermediates or bullets. It has been found that the intermediates or bullets made of iron material according to the invention are particularly well suited to being produced by solid forming, in particular by cold forming, such as deep drawing or extrusion, as an alternative to machining. According to the invention, a hollow cylinder inner surface facing the cavity has at least two notches oriented in the longitudinal direction of the intermediate. Like the rest of the intermediate, in particular the cavity, the notches are produced by cold forming. The notches result in a defined deformation behavior on the producing bullet as described for the previous aspects, so that reference is again made to the embodiments of the previous aspects.
In an exemplary embodiment, the notches or the notch extend by less than 25%, in particular less than 20% or less than 15%, of a total longitudinal extension of the intermediate from the open end of the cavity towards a cavity base. Alternatively or additionally, the notches or the notch extend by less than 50%, in particular by less than 40%, less than 30% or less than 25% of a total longitudinal extension of the cavity from the open end of the cavity in the direction of a cavity base. In an exemplary further development, the length of the notches is in the range of 0.5 mm to 3 mm. The inventors of the present invention have discovered that the deformation behavior of the bullet made from the intermediate can be specifically influenced by short notches at the open end of the cavity, which are particularly easy and inexpensive to produce.
In a further exemplary embodiment, the depth and/or the width of the notches varies from the open end of the cavity towards the cavity base. In an exemplary further embodiment, the depth and/or the width of the notches decreases preferably continuously from the open end of the cavity. In other words, this results in pyramid-shaped notches, the cross-section of which decreases in particular continuously from the open end of the cavity towards the cavity base.
According to an exemplary embodiment, the notches have a depth of less than 1 mm, in particular a depth in the range of 0.1 mm to 0.7 mm. Alternatively or additionally, the notches have a width of less than 1.5 mm, in particular a width in the range of 0.1 mm to 1 mm.
According to another exemplary embodiment, the notches each have two V-shaped tapering notch flanks. In particular, the notch flanks can be oriented at an angle in the range of 30° to 80°, preferably at an angle of about 60°, to one another.
In a further preferred embodiment, the hollow cylinder inner surface has 2 to 10, in particular 3 to 8, notches. Preferably, the notches are distributed uniformly around the circumference of the cavity. This results in a particularly uniform deformation behavior of the nose wall of the bullet made from the intermediate.
In an exemplary further development, the notches are introduced by cold forming, in particular by means of backwards extrusion. Preferably, the notches can be introduced in the same process step, in particular with the same tool, as the cavity. This results in a particularly simple and cost-effective way of producing the notches, for which no additional process step is required.
The present invention also relates to a press mandrel for pressing a metal blank inserted in a cylindrical die along a pressing direction in order to produce an intermediate and/or bullet formed in particular according to one of the preceding aspects and exemplary embodiments. For this purpose, the press mandrel is pressed along the in particular linear pressing direction into the metal blank inserted in the cylindrical die. In particular, the press mandrel is pressed into the metal blank without rotation of the press head about a longitudinal axis of the press mandrel occurring.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the press mandrel has a, in particular cylindrical press head, which defines the longitudinal direction of the press mandrel. The press head can be formed cylindrically with respect to the longitudinal direction of the press mandrel. However, the press head can also have a cross-section deviating from a cylindrical shape. Preferably, the cross-section of the press head is rotationally symmetrical with respect to the longitudinal axis of the press mandrel. The longitudinal direction of the press mandrel is oriented along the pressing direction when pressing the metal blank and corresponds in particular to the longitudinal direction of the blank or intermediate. The press head has at least two press ribs extending in the longitudinal direction of the press mandrel. The press ribs represent elevations on the press head, which protrude in a radial direction, perpendicular to the longitudinal direction, over the remaining outer contour of the press head. The press mandrel can be used to introduce the cavity and the notches described in the previous aspects into the metal blank in a single step, wherein the notches are created by the press ribs. The geometry of the generated notches is shape-complementary to the geometry of the press ribs. According to the invention, the depth of the press ribs transversely to the longitudinal direction is less than 1 mm, in particular in the range of 0.1 mm to 0.7 mm.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the press mandrel comprises a cylindrical press head with at least two press ribs extending in the longitudinal direction of the press mandrel and protruding radially from a cylinder jacket surface of the press head. The longitudinal direction of the press mandrel is oriented along the pressing direction when pressing the metal blank and corresponds in particular to the longitudinal direction of the blank or intermediate. The press mandrel can be used to introduce the cavity and the notches described in the previous aspects into the metal blank in a single step. The notches are created by the press ribs and the cylindrical cavity is created by the cylinder jacket surface of the press mandrel between the press ribs. The geometry of the generated notches is shape-complementary to the geometry of the press ribs. The cylindrical shape of the press head makes it particularly easy and cost-effective to manufacture.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the press mandrel comprises a press head with at least two press ribs extending in the longitudinal direction of the press mandrel and protruding transversely to the longitudinal direction from an outer jacket surface of the press head. The press mandrel can be used to introduce the cavity and the notches described in the preceding aspects into the metal blank in a single step. The notches are created by the press ribs and the cavity by the outer jacket surface of the press mandrel between the press ribs. The geometry of the generated notches is shape-complementary to the geometry of the press ribs. The press ribs have a depth transversely to the longitudinal direction. According to the invention, the depth of the press ribs varies in the longitudinal direction. In particular, the depth can decrease against the pressing direction. As a result, the friction between the blank material and the press head can be reduced when the press mandrel is pressed into the metal blank. By reducing the depth of the press ribs against the pressing direction, only a small region of the press ribs comes into contact with the blank, so that the notches are created from the open end of the cavity and when the press mandrel is further introduced, when the notches have already been introduced at the upper end of the cavity and are further introduced in the direction of the cavity base, there is no contact between the already created regions of the notches and the rear region of the press ribs with less depth viewed in the pressing direction. The length of the notches produced can be determined by the position of the greatest depth of the press ribs in the longitudinal direction, because the ends of the notches facing the cavity base are at the same distance from the cavity base as the deepest point of the press ribs is from a face side of the press head.
In an exemplary further development, the depth of the press ribs decreases against the pressing direction at an angle of 6° to 15°, in particular from 6° to 10°. Alternatively or additionally, the depth of the press ribs decreases over at least 80% of a longitudinal extension of the press ribs, in particular at least 90% and/or less than the total longitudinal extension, against the pressing direction.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the press mandrel comprises a press head with at least two press ribs extending in the longitudinal direction of the press mandrel and protruding transversely to the longitudinal direction from an outer jacket surface of the press head. The press mandrel can be used to introduce the cavity and the notches described in the preceding aspects into the metal blank in a single step. The notches are created by the press ribs and the cavity by the outer jacket surface of the press mandrel between the press ribs. The geometry of the generated notches is shape-complementary to the geometry of the press ribs. According to the invention, the press flanks have two V-shaped press flanks whose transition is rounded. In particular, both the transition between the two press flanks and the transition between the press flanks and the outer jacket surface of the press head are rounded. This allows the notches to be introduced into the hollow cylinder wall delimiting the cavity without damaging the material around the notches, in particular without causing cracks at the transition between the notch flanks created by the press flanks and the hollow cylinder inner surface of the intermediate. A further advantage is that the press mandrel can be produced by die-sinking EDM, which enables the press flanks to be produced with particular precision. In an exemplary further development, a radius at the transition is at least 0.01 mm and/or at most 0.2 mm.
According to an exemplary further development, the press flanks are oriented at an angle in the range of 30° to 80°, preferably at an angle of about 60°, to one another.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, the press mandrel has a press head, in particular a cylindrical press head, which defines the longitudinal direction of the press mandrel. The press head can be formed cylindrically with respect to the longitudinal direction of the press mandrel. However, the press head can also have a cross-section deviating from a cylindrical shape. Preferably, the cross-section of the press head is rotationally symmetrical with respect to the longitudinal axis of the press mandrel. The longitudinal direction of the press mandrel is oriented along the pressing direction when pressing the metal blank and preferably corresponds to the longitudinal direction of the blank or the intermediate. The press head has at least two press ribs extending in the longitudinal direction of the press mandrel. The press ribs represent elevations on the press head which protrude in a radial direction, perpendicular to the longitudinal direction, over the remaining outer contour of the press head. The press mandrel can be used to introduce the cavity and the notches described in the previous aspects into the metal blank in a single step, wherein the notches are created by the press ribs. The geometry of the generated notches is shape-complementary to the geometry of the press ribs. According to the invention, a flat face side of the press head in particular is inclined with respect to the longitudinal direction. In an exemplary further development, a forming angle of the in particular flat face side of the press head is in the range of 105° to 135° with respect to the longitudinal direction. Due to the inclined face side, the press mandrel can penetrate the blank particularly easily and with little effort. The face side is also designed to form a cavity base of the cavity.
In an exemplary embodiment, a transition between the inclined face side and the press ribs is rounded. The radius at the transition can be comparatively large and in particular lie in the range of 1 mm to 2 mm. Alternatively or additionally, the face side has a central region oriented perpendicular to the longitudinal axis. In this embodiment, the press head is rounded at a transition between the central region and the inclined face side. A radius at the transition can be comparatively large and in particular lie in the range of 1mm to 2 mm. The curves result in a better distribution of forces and stress peaks can be prevented when the press head penetrates the blank. In addition, the service life of the press mandrel can be increased.
In an exemplary embodiment, the press head has 2 to 10, in particular 3 to 8, press ribs. Preferably, the press ribs are distributed uniformly around the circumference of the press head.
In a further exemplary embodiment, the press head has friction-reduced regions between the press ribs. In particular, the press head can have a low surface roughness, a lubrication and/or a coating on the friction-reduced regions.
In another exemplary embodiment, the press head is made of a hard material, such as a hard metal. In particular, the material can have a hardness of more than 550 HV.
The present invention also relates to a method for producing an intermediate and/or bullet formed in particular according to one of the preceding aspects and exemplary embodiments.
According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a metal blank is inserted into a cylindrical die and, in order to produce the intermediate of the bullet, is cold-formed by means of a press mandrel in particular according to one of the preceding aspects or exemplary embodiments in such a way that a hollow cylinder delimiting a central cavity which is open towards the surroundings is formed, the hollow cylinder inner surface of which facing the cavity having at least two notches oriented in the longitudinal direction (L) of the intermediate. The cavity has a constant cross-section along its longitudinal extension, which can be substantially circular. In an exemplary further development, the hollow cylinder is then cold-formed to form a, in particular an ogive-shaped bullet nose.
In an exemplary further development, the notches are introduced by cold forming, in particular by means of backwards extrusion. Preferably, the notches can be introduced in the same process step, in particular with the same tool, as the cavity. This results in a particularly simple and cost-effective way of producing the notches, for which no additional process step is required.
The invention also relates to a fired, deformed bullet resulting from firing a bullet formed according to one of the preceding aspects and exemplary embodiments and impact of the bullet on a target, in particular a standard target. The standard target can be, for example, gelatine, soap, wet newspapers or paraffin. The fired, deformed bullet is deformed in accordance with the deformation behavior described for the previous aspects.
Preferred embodiments are indicated in the sub-claims.
In the following, further properties, features and advantages of the invention will become clear by means of a description of preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which show:
In the following description of exemplary embodiments of the present invention, a bullet according to the invention is generally provided with the reference numeral 1, an intermediate according to the invention is generally provided with the reference numeral 10 and a press mandrel according to the invention is generally provided with the reference numeral 100.
A bullet 1 according to the invention is shown in
With reference to
First, a blank 13 made of metal, preferably iron material, is provided (
In a first manufacturing step, the blank 13 is cold-formed into a set workpiece 14 by setting, for example by pressing (
After setting, the set work piece 14 is pre-pressed to form an intermediate 10 according to the invention (
The intermediate 10 produced in this way consists of a metal body 12 made of homogeneous material, preferably iron material, and is then further cold-formed to form a cylinder 31 shown in
The final bullet 1 has a rear, substantially planar bullet base 35, in the center of which the centering recess 21 is located. The cavity 11 has a cavity base 37, up to which the cavity 11 extends from the bullet tip 29 in the direction of the bullet tail 7. An inner wall surface 39 of the nose wall 9 has at least two notches 27 oriented in the longitudinal direction L of the bullet 1, which were introduced into the hollow cylinder inner surface 25 delimiting the cavity 11 during preforming of the set workpiece 14 to form the intermediate 10 (
In order to illustrate the producing and subsequent compression of the notches 27, the geometry of the notches 27 at the time they are introduced into the blank 13 to form the intermediate 10 according to the invention is described with reference to
In the exemplary embodiment, the intermediate 10 according to the invention has six notches 27 uniformly distributed in the circumferential direction on the hollow cylinder inner surface 25. The notches 27 each have two V-shaped tapering notch flanks 45, which are oriented at an angle 47 of about 60° to one another, which can be seen particularly well in the detailed view of a notch 27 in
With reference to
The press mandrel 100 has a press head 49, which is pressed into the blank 13 or the set workpiece 14 produced from the blank 13 along a pressing direction P (compare
In the embodiment shown in
In
The face side 61 of the press head 49 has a central planar region 65, which is oriented perpendicularly to the longitudinal direction L, and adjacent thereto an inclined front face 67. The front face 67 is preferably inclined at an angle 68, which can be described as a forming angle and in the exemplary embodiment is between 105° and 135° with respect to the longitudinal axis L. Both at a transition 69 between the planar region 65 and the inclined front face 67 and at a transition 71 between the inclined front face 67 and the press ribs 53 or the outer jacket surface 51, the press head 49 is rounded. A radius can be comparatively large and lie between 1 mm and 2 mm. A comparison of
The press ribs 53 each have two V-shaped press flanks 73, which in the embodiment in
A schematic representation of a fired, deformed bullet 2 resulting from firing a bullet 1 according to the invention and impact of the bullet 1 on a target, in particular a standard target, such as a jelly mass, is shown in
The deformed bullet 2 differs from the prior art bullets in particular by a reduced mushrooming effect radially outwards on impact with a target. As can be seen in
The deformation behavior results on the one hand from the cold forming of the cavity 11 and on the other hand from the notches 27 introduced into the hollow cylinder inner surface 25 of the intermediate 10, which remain as micro-notches on the inner wall surface 39 of the nose wall 9 on the finished bullet 1. Cold forming increases the strength of the nose wall 9 transversely to the longitudinal direction L compared to the strength of the nose wall 9 in the longitudinal direction L and the deformation behavior can be specifically controlled by the notches 27. As can be seen in
The features disclosed in the preceding description, the figures and the claims may be of importance both individually and in any combination for the realization of the invention in the various embodiments.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 104 617.6 | Feb 2022 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/054648 | 2/24/2023 | WO |
