Projectile with circumferential and/or longitudinal groove

The present invention relates to a projectile, in particular a full metal jacket projectile or partial metal jacket projectile, for ammunition, for example with a caliber of at most 20 mm, in particular of at most 13 mm, comprising an at least partially hollow or solid projectile body with a circumferential and/or longitudinal groove arranged on its inner and/or outer surface, which transitions seamlessly into the adjacent inner and/or outer surfaces of the projectile body and/or has a radius of at least 0.05 mm.

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Description

The present invention relates to a projectile, particularly a full metal jacket or partial metal jacket projectile, preferably with a caliber of less than 20 mm, especially less than 13 mm. Furthermore, the present invention also provides a tool, a device, and a method for introducing a circumferential and/or longitudinal groove into a projectile blank to manufacture a projectile according to the invention.

Projectiles can be equipped with various functional grooves, e.g., fixation or holding grooves, relief grooves to reduce abrasion in the firearm barrel, deformation grooves as predetermined breaking points both in the circumferential and longitudinal direction of the projectile, or knurling grooves for haptic purposes.

Circumferential functional grooves, such as the engagement groove for the case mouth, are usually produced on complex tool stations with various tool arrangements, for example, by cross-rolling or cross-wedge rolling. For instance, military full metal jacket projectiles are grooved to press the case mouth into the groove (crimping). This better holds the projectile in the case, which is advantageous in automatic weapons as it reduces the pressing of the projectile into the case.

However, the known methods have shown disadvantages such as the complex tool setup and the high number of tool parts. In particular, with the known methods for introducing functional grooves into the projectile body, it is not possible to increase the cycle rate easily, which negatively affects profitability, especially in mass production. Moreover, it has been found that cross-rolling the projectile to introduce circumferential grooves results in a marked transition from the outer circumference of the projectile to the groove, which can negatively affect the performance of the projectile, for example, its interaction with the rifling profile of a firearm barrel.

An object of the present invention is to overcome the disadvantages of the prior art, particularly to manufacture functional grooves in projectiles in a simpler manufacturing manner, thereby reducing the impairment of the projectile's performance by the functional grooves.

The object is achieved by the subject matter of the independent claims.

Accordingly, a projectile for ammunition, for example, with a caliber of at most 20 mm, especially of at most 13 mm, is provided. The projectile can be a full metal jacket or partial metal jacket projectile. The projectile can be made of brass (for example, CuZn30), copper, tombac (for example, CuZn10 or CuZn5), or steel, especially plated or coated steel. However, the projectile can also be made of aluminum or tin.

The inventive projectile comprises a projectile body that can be solid or at least partially hollow. The projectile body can have a projectile tail and a projectile front, which has an open cavity in the firing direction, bounded by a projectile wall. The projectile body has an outer surface oriented towards the surroundings. If the projectile body has a hollow section, the projectile body also has an inner surface that can be arranged on the projectile wall bounding the cavity.

According to a first aspect of the present invention, the inner and/or outer surface of the projectile body is provided with at least one circumferential and/or longitudinal groove that transitions into the adjacent inner and/or outer surfaces of the projectile body without a contour jump and/or has a radius of at least 0.05 mm, especially at most 0.1 mm. The circumferential and/or longitudinal groove, particularly its groove bottom, has a reduced diameter compared to the caliber of the projectile and the adjacent inner and/or outer surfaces of the projectile body. The groove can be, for example, a fully circumferential engagement groove for the case mouth. Longitudinal grooves extending in the longitudinal direction can be deformation and/or relief grooves. Preferably, the circumferential and/or longitudinal groove is introduced by grooving, particularly circumferential or longitudinal grooving. Due to the absence of contour jumps and/or the large radius of the groove, there is little material displacement on the projectile surface, which can lead to local hardness increases and material stresses. The grooves thus produced can also be manufactured at a higher production speed, increasing the cycle rate in the production of inventive projectiles, resulting in a more cost-effective projectile overall. The smooth transition of the projectile surfaces into the groove reduces the influence of the existing groove on the projectile's performance.

According to another aspect of the present invention, which can be combined with the previous aspects and exemplary embodiments, a projectile, particularly a full metal jacket or partial metal jacket projectile, for ammunition, for example, with a caliber of at most 20 mm, especially of at most 13 mm, is provided. The projectile can be made of brass (for example, CuZn30), copper, tombac (for example, CuZn10 or CuZn5), or steel, especially plated or coated steel. However, the projectile can also be made of aluminum or tin. The projectile comprises an at least partially hollow or solid projectile body with a circumferential groove arranged on its inner and/or outer surface, along which several radial projections extending in the longitudinal direction of the projectile, which can be referred to as flags, are arranged at a particularly constant distance from each other, and/or a longitudinal groove, along which several radial projections extending transversely to the longitudinal direction of the projectile are arranged at a particularly constant distance from each other. Particularly in the case of functional grooves that serve as holding or gripping grooves, for example, for the case mouth, the projections have a positive effect on the holding or fastening force. The spaced radial projections can achieve a form-fitting and/or force-fitting connection, especially with appropriately structured components to be connected. In the case of deformation grooves intended to achieve a desired deformation of the projectile, the deformation behavior can be finely adjusted with the help of the radial projections. For example, a predefined stepwise deformation can be achieved due to the different wall thicknesses along the groove and thus a resistance force against deformation.

In an exemplary embodiment of the inventive projectile, the radial projections have a width measured in the direction of extension of the groove of at most 0.2 mm and/or are dimensioned such that they protrude less than 0.03 mm over the adjacent inner and/or outer surfaces of the projectile body. This ensures that they do not negatively affect the projectile's performance, particularly, for example, barrel wear and/or the resistance to being pushed through the firearm barrel.

According to another aspect of the present invention, which can be combined with the previous aspects and exemplary embodiments, a tool, particularly a grooving tool, for introducing a circumferential and/or longitudinal groove into a projectile blank, especially a metallic projectile blank, to manufacture a projectile formed according to one of the previously described aspects and/or exemplary embodiments, is provided. The inventive tool can be configured to be used in an inventive device, particularly a grooving station, and/or to interact with a punch-die arrangement to groove the projectile blank.

The inventive tool comprises an elongated, particularly rotationally shaped, hollow body, especially a case body, for receiving the projectile blank. Alternatively, the hollow body can be inserted into a cavity of the projectile body. The hollow body can be at least partially adapted to the shape of the projectile blank, particularly formed complementarily to it. For example, the hollow body can comprise an ogive-shaped receiving area in which the projectile blank can be at least partially inserted and particularly held.

The hollow body has an inward or outward protruding, particularly circumferential, grooving nose. The grooving nose is configured to press the groove into the projectile blank. The grooving nose is particularly arranged in the area of the projectile blank reception of the hollow body.

According to another inventive aspect, the hollow body is longitudinally slit such that, when force is applied from the outside, if the grooving nose is arranged on the inside, or from the inside, if the grooving nose is arranged on the outside, the hollow body is particularly elastically deformable, particularly compressible or expandable, so that the grooving nose can press the circumferential and/or longitudinal groove into the projectile blank. During the deformation of the hollow body, an especially elastic deformation restoring force develops, causing the hollow body to be reusable and/or return to its original shape after a grooving process. The pressing force is exerted on the tool from the outside, and the slitting in the hollow body allows deformation of the hollow body so that the pressing force can be exerted or transferred to the projectile blank via the grooving nose to deform it, thereby introducing the circumferential and/or longitudinal groove. The inventive tool is characterized, among other things, by its simple construction and fewer individual parts. It can be integrated into a transfer tool or a station of a transfer press and used at a single, particularly inventive, grooving station. Due to the simple manufacturing application of the tool, high cycle rates can be generated, making the tool well-suited for mass production. Furthermore, the tool is characterized by its compactness. It is overall only slightly larger than the projectile blanks to be processed. The outer dimension of the tool is dimensioned to be 30-50%, particularly 35-45%, larger than the outer diameter of the projectile blank to be processed.

In an exemplary embodiment of the inventive tool, the hollow body has several longitudinally extending through-slits arranged at a particularly constant distance from each other and several bending wings separated by two through-slits each. The bending wings can be equally shaped and/or dimensioned. Each bending wing is bounded by two through-slits. The through-slits are understood to extend completely through the hollow body's outer surface to the inner surface, which bounds the cavity.

In another exemplary embodiment of the inventive tool, the through-slits extend from a particularly open groove end of the hollow body over at least 50%, particularly at least 60%, 70%, or 80%, of the hollow body's longitudinal extension to a respective slit base, at whose axial height a bending joint is defined, around which an associated bending wing is particularly elastically pivotable. In the circumferential direction of the hollow body, the slit bases of the through-slits and the bending joints of the bending wings alternate particularly evenly. When force is applied to the hollow body to deform it, so that the grooving nose presses the circumferential and/or longitudinal groove into the projectile blank, the bending wings pivot elastically around their respective bending joints.

In an exemplary further development of the inventive tool, the grooving nose is arranged in the area of the groove end. The through-slits can divide the grooving nose into several segments distributed in the circumferential direction. For example, the slitting of the hollow body with an internal grooving nose causes compression of the hollow body due to the force applied from the outside, so that the grooving nose segments particularly approach each other by the width of the through-slits. This movement amplitude of the bending wings in the area of the groove end, particularly in the area of the grooving nose, determines the depth of the circumferential or longitudinal groove.

In another exemplary embodiment of the inventive tool, the through-slits extend over at least 50%, particularly at least 60%, 70%, or 80% of the hollow body's longitudinal extension, so that an unslitted section is formed at both end sides, particularly opening sides, of the hollow body. The unslitted section can extend over at least 5% of the hollow body's longitudinal extension from the end face of the hollow body. An advantage of the hollow body design with two end-side unslitted sections compared to the fully slit design is that the hollow body has higher stability or strength, which particularly results in higher durability.

In another exemplary embodiment of the inventive tool, each through-slit ends on both sides in a respective slit base, at whose axial height a bending joint is defined, around which an associated bending wing is particularly elastically pivotable. Regarding the function of the bending wings and particularly the bending joint, reference can be made to the previous embodiments. Unlike the fully slit hollow body variant, the force applied from the outside to deform the hollow body is distributed over two bending joints per bending wing in the hollow body variant with end-side unslitted sections. Similar to the previous embodiment, the bending wings fundamentally work analogously to the functional principle of leaf spring elements.

In another exemplary further development of the inventive tool, each through-slit ends in two opposite slit bases, and the grooving nose is arranged in the range of 20% to 80% of a distance, particularly in the range of 40% to 60%, preferably centrally, between the two slit bases. Depending on the positioning of the grooving nose, the load on the respective bending joints can be adjusted or adapted.

In another exemplary embodiment of the inventive tool, the bending joints are manufactured in one piece with the associated bending wing. Particularly, the hollow body is fully manufactured in one piece, particularly from a piece of metal. The hollow body can, for example, be manufactured from a blank by turning with subsequent heat treatment and finished by grinding and possibly sinker EDM. Subsequently, the slits can be manufactured by wire EDM with a wire diameter of about 0.1 mm. For example, the bending joints are designed as film hinges and/or work at least according to the functional principle of a film hinge, without requiring a local wall thickness reduction compared to the rest of the bending wing.

In an exemplary further development of the inventive tool, the hollow body has a counter bearing, such as a particularly circumferential projection, particularly a ring projection, at about the axial height of the grooving nose, which can be acted upon with a force to deform the hollow body, particularly to preferably elastically pivot the bending wings particularly around their bending joints. The counter bearing can be designed as a defined stop for a punch-die arrangement, for example, of an inventive device, so that during a coordinated relative movement between the tool and the punch-die arrangement, the punch-die arrangement engages with the counter bearing, initiating the deformation of the hollow body.

According to another aspect of the present invention, which can be combined with the previous aspects and exemplary embodiments, a device, particularly a grooving station, is provided for introducing a circumferential and/or longitudinal groove into a projectile blank to manufacture a projectile formed according to one of the previously described aspects or exemplary embodiments.

The inventive device comprises a tool formed according to one of the previously described aspects or exemplary embodiments, such as a grooving tool, which has a grooving nose with which the circumferential and/or longitudinal groove can be introduced into the projectile blank. Regarding the tool, reference can be made to the previous embodiments.

Furthermore, the inventive device comprises a punch-die arrangement for holding the projectile blank.

According to another aspect of the present invention, the tool and the punch-die arrangement are coordinated and/or can interact such that the punch-die arrangement can elastically deform, particularly compress or expand, the tool to introduce the circumferential and/or longitudinal groove into the projectile blank. For example, the force necessary to deform the tool, which in turn causes the introduction of the groove into the projectile blank, is generated by the interaction of the punch-die arrangement with the tool.

In an exemplary further development of the inventive device, the die has a particularly form-adapted reception for the projectile blank, and the punch has a driver assigned to the tool such that during a particularly translational relative movement of the die and punch, the driver exerts a pressure or pressing force on the tool to deform it. The deformation of the tool, in turn, results in the force necessary for grooving the projectile blank, particularly the deformation force, being available. When using the inventive device, no rotating bearing of the projectile blank and/or a component of the device is necessary to groove the projectile blank; a translational relative movement between the punch and die is sufficient.

In another exemplary embodiment of the inventive device, the punch, particularly the driver, has a conical guide surface over which a continuously increasing pressure or pressing force can be generated. During the translational relative movement of the die and punch, particularly during the interlocking or disengaging of the punch and die, the driver increasingly wedges into an associated die surface with its conical guide surface, so that the force necessary to deform the projectile blank to introduce the groove, particularly the deformation force, is continuously built up.

According to another aspect of the present invention, which can be combined with the previous aspects and exemplary embodiments, a method for introducing a circumferential and/or longitudinal groove into a projectile blank is provided, particularly a grooving method, to manufacture a projectile formed according to one of the previously described aspects or exemplary embodiments.

In the inventive method, a projectile blank is inserted into an inventive tool, particularly an inventive device, and the projectile blank is locally grooved, particularly squeezed, by an especially elastic deformation, particularly compression or expansion, of the tool, forming the circumferential and/or longitudinal groove.

Preferred embodiments are indicated in the dependent claims.

The following describes further properties, features, and advantages of the invention by describing preferred embodiments of the invention with reference to the accompanying exemplary drawings, in which:

FIG. 1 shows a schematic sectional view of an exemplary embodiment of an inventive device;

FIG. 2 shows a perspective view of an exemplary embodiment of an inventive tool;

FIG. 3 shows the tool from FIG. 2 in a sectional view;

FIG. 4 shows another exemplary embodiment of an inventive tool;

FIG. 5 shows another exemplary embodiment of an inventive tool;

FIG. 6 shows a sectional view of another exemplary embodiment of an inventive device before grooving a projectile blank;

FIG. 7 shows the device from FIG. 6 during the grooving of the projectile blank;

FIG. 8 shows an exemplary embodiment of an inventive projectile;

FIG. 9 shows a detailed view of the area IX of the projectile from FIG. 8;

FIG. 10 shows a detailed view of the area X of the projectile from FIG. 8;

FIG. 11 shows another exemplary embodiment of an inventive tool;

FIG. 12 shows a detailed view of the area XII of the tool from FIG. 11;

FIG. 13 shows a side view of another exemplary embodiment of an inventive projectile; and

FIG. 14 shows the projectile from FIG. 13 in a view from the direction of the projectile tip.

In the following description of exemplary embodiments of the present invention, an inventive projectile is generally designated with reference numeral 1, an inventive tool for introducing a circumferential and/or longitudinal groove into a projectile blank is generally designated with reference numeral 10, and an inventive device for introducing a circumferential and/or longitudinal groove into a projectile blank is generally designated with reference numeral 100.

FIG. 1 shows a schematic sectional view of an inventive device 100. The inventive device 100 is used to manufacture an inventive projectile 1, which is also shown in FIG. 1.

The projectile 1 can particularly be a full metal jacket or partial metal jacket projectile. The projectile 1 comprises a projectile body 3, which has a cylindrical projectile tail 5 and an ogival projectile nose 7. The projectile body 3 can be solid or have an open cavity in the direction of the projectile tip 9, so that the projectile body 3 is partially hollow. On the outer side 11 of the projectile 1, a circumferential groove 13 is pressed, which has a smaller diameter than the outer side 11 of the projectile 1. The circumferential groove 13 can be provided, for example, as an engagement groove for the case mouth of a case.

The device 100 for manufacturing the inventive projectile 1 from a projectile blank comprises the following main components: an inventive tool 10 and a punch-die arrangement 15, which interacts with or is coordinated with the inventive tool 10 to introduce the circumferential groove 13 into a projectile blank. The punch-die arrangement 15 comprises a punch 17 and a die 19, which are translatable relative to each other in a pressing direction P.

In FIG. 1, the die 19 is rotationally shaped and has two steps on an outer side 21, where the outer diameter of the die 19 changes abruptly. Viewed from a bottom side 23 of the die 19 towards a top side 25 of the die 19 facing the punch 17, a first step 27 serves as an axial support surface for the inventive tool 10. Further towards the top side 25, a second step 29 is provided, resulting in an air gap 31 between the outer side 21 of the die 19 and the inventive tool 10, allowing the inventive tool 10 to be compressed radially, transverse to the pressing direction P, and elastically deformed or compressed. Between the step 27 and the step 29, the inventive tool 10 lies flat against the outer side 21 of the die 19 and is thus fixed to the die 19 in the pressing direction P and radially. On the top side 25 of the die 19, a receptacle 33 is formed to hold the projectile blank or the finished projectile 1. The receptacle 33 is adapted to the shape of the projectile nose 7 and is thus ogival in shape.

The punch 17 is also rotationally shaped in FIG. 1 and has a cavity 37 on a front side 35 facing the die 19. The cavity 37 and a wall 39 of the punch 17 bounding the cavity 37 are dimensioned such that at least one side of the tool 10 facing the punch is received in the cavity 39 and compressed radially by the wall 39 when the punch 17 is moved further in the pressing direction P towards the die 19, and the punch 17 and the die 19 interlock. Starting from the front side 35, the cavity 37 is initially formed by a conical wall section 41 and then transitions into a cylindrical wall section 43. Through the conical wall section 41, a continuously increasing radial pressure force is exerted on the tool 10 during a movement of the punch 17 in the pressing direction P. The conical wall section 41 can thus be referred to as a conical guide surface.

The following describes the structure of an inventive tool 10 for introducing a circumferential groove into the outer side 11 of a projectile blank based on the exemplary embodiment in FIGS. 2 and 3.

The tool 10 comprises an elongated sleeve-shaped hollow body 45, which is made in one piece, for example, from metal. The hollow body 45 is hollow cylindrical and has a hollow body wall 47 with a constant wall thickness, which bounds a cylindrical cavity 49. The wall thickness can be, for example, about 2 mm. At an end face 51 or a groove end 51 of the hollow body 45, a circumferential grooving nose 53 is formed, which protrudes from the hollow body wall 47 into the interior of the hollow body 45. For example, the grooving nose 53 can protrude about 4 mm radially into the interior of the hollow body 45, perpendicular to the longitudinal direction L of the tool 10. In the embodiment in FIGS. 2 and 3, the grooving nose 53 has a rounding 55 at the end, so that a groove with a round cross-section can be produced.

The hollow body 45 has several through-slits 57 oriented in the longitudinal direction L. The through-slits 57 extend radially completely through the entire hollow body wall 47 and through the grooving nose 53, dividing it completely into several separate segments 58 in the area of the grooving nose 53 and bending wings 59 in the area of the hollow body wall 47. In other words, the through-slits 57 extend over the entire wall thickness of the hollow body 45 from an outer side of the hollow body 45 to an inner side of the hollow body 45. In the longitudinal direction L, the through-slits 57 extend from the groove end 51 for at least 50% of the longitudinal extension of the hollow body 45 and end in a slit base 61. At the axial height of the slit bases 61, each bending wing 59 has a bending joint 63. Since the hollow body 45 is made in one piece, the bending joints 63 are each formed in one piece with the associated bending wing 59 and are designed as film hinges. When the tool 10 is compressed at the groove end 51 or in the area of the grooving nose 53, the bending wings 59 are each elastically pivotable around their associated bending joint 63. At an end of the hollow body 65 opposite the groove end 51, an unslitted section 67 is provided, with which the tool 10 in FIG. 1 rests against the die 19 of the inventive device 100.

In the exemplary embodiment in FIGS. 2 and 3, a total of 20 through-slits 57 and thus 20 bending wings 59 are formed, which are evenly distributed in the circumferential direction and arranged at a constant distance from each other. The bending wings 59 are each bounded in the circumferential direction by two through-slits 57 and are all equally dimensioned and shaped. It is clear that more or fewer than 20 through-slits can also be provided. Preferably, between 12 and 36 through-slits can be provided. For example, the width of the through-slits can be between 0.05 mm and 0.1 mm.

To introduce a groove into a projectile blank, the projectile blank is inserted from the groove end 51 of the tool 10 in the longitudinal direction L into the cavity 49 of the hollow body 45 until the point of the projectile blank where the groove is to be introduced is positioned in the longitudinal direction L at the axial height of the grooving nose 53. When force is applied from the outside, the bending wings 59 elastically pivot around the respective bending joint 63 and are elastically deformed or compressed, so that the segments 58 of the grooving nose 53 are compressed radially and approach each other by the width of the through-slits 57. As a result, the segments 58 of the grooving nose 53 press into the projectile blank material and press the desired groove. Thus, with the inventive tool 10, no rotation between the tool 10 and the projectile blank is necessary to groove the projectile blank. Once the external force no longer acts, the bending wings 59 return to their original shape due to the deformation restoring force generated by the elastic deformation, and the finished projectile 1 can be removed from the tool 10.

For a projectile blank with a cavity in the projectile nose, it can also be provided to introduce a groove on the inside of a wall bounding the cavity of the projectile blank. The inventive tool is then inserted into the cavity of the projectile blank. The grooving nose is arranged on the outer side of the slit hollow body in this embodiment and preferably protrudes outward perpendicular to the longitudinal direction. To press the groove, a force is applied from the inside to the tool, for example, with a conical punch, so that the bending wings elastically expand and introduce an internal groove into the projectile blank on the inner side of the wall.

FIG. 4 shows another exemplary embodiment of an inventive tool 10. The tool 10 in FIG. 4 differs from the tool in FIGS. 2 and 3 in that a radially outwardly protruding, circumferential projection 69 is provided at the end of the hollow body 65, leading to a larger support surface of the tool 10 on the die 19 of an inventive device 100 and additionally providing a support surface 71 for further components of the device 100 opposite the end of the hollow body 65. The tool 10 also differs in that a counter bearing 73 in the form of a circumferential ring projection is provided at the axial height of the grooving nose 53, at the groove end 51. In this embodiment, the force from the outside to elastically deform the tool 10 is applied to the ring projection 73. The ring projection 73 serves as a defined stop, for example, for the punch-die arrangement 15. The tool 10 also differs in that the end of the grooving nose 53 does not have a rounding but a flat surface 56. Thus, a groove pressed with the tool 10 according to the embodiment in FIG. 4 has a rectangular cross-section.

FIG. 5 shows another exemplary embodiment of an inventive tool 10, which differs from the previous embodiments in that an unslitted section 67 is also provided at the end face 51 of the hollow body 45. Both unslitted sections 67 extend for more than 5% of the longitudinal extension of the hollow body 45 from the respective end of the hollow body 45 in the longitudinal direction L towards the middle of the hollow body 45. The through-slits 57 in this embodiment each end in two opposite slit bases 61. Each bending wing 59 thus has two opposite bending joints 63 in this embodiment. The through-slits 57 are arranged centrally in the longitudinal direction L on the hollow body 45 in this embodiment and extend over at least 50% of the longitudinal extension of the hollow body 45. The grooving nose 53 and the support 73 are arranged in this embodiment in the longitudinal direction L in the middle between the two slit bases 61. Due to the additional unslitted section 67 at the end face 51 and the two bending joints 61 per bending wing 59, the hollow body 45 has higher stability or strength, which increases the durability of the tool 10.

FIGS. 6 and 7 show another embodiment of an inventive device 100, with the device 100 shown in FIG. 6 before introducing a circumferential groove 13 into a projectile blank 2 and in FIG. 7 during the introduction of the circumferential groove 13. The device 100 comprises, like the device in FIG. 1, an inventive tool 10, a punch 17, and a die 19.

The die 19 essentially corresponds to the die 19 from FIG. 1 but differs in that only one step 27 is provided on the outer side 21 of the die 19, on which the tool 10 rests. The reason for this is that the tool 10 used in FIG. 6 has a ring projection 73 in the area of the grooving nose 53, and thus an air gap already exists between the tool 10 and the outer side 21 of the die 19, allowing elastic deformation of the tool 10, so no further step is needed.

The die 19 stands on a base plate 75 of the device 100 in this embodiment. Additionally, a receptacle 77 with a cylindrical through-bore 79, in which the die 19 and the tool 10 are arranged, is fastened to the base plate 75, for example, with screws. Two steps are provided in the through-bore 79, where the diameter of the through-bore 79 changes abruptly. A first step 81, viewed from the direction of the base plate 75, serves to fix a holder 83 for the die 19 and the tool 10. The holder 83 rests on the projection 69 of the tool 10 and thus presses the tool 10 and the die 19 against the base plate 75. A spring 85 rests on the holder 83, which biases a pressure piece 87 against the pressing direction P. The movement of the pressure piece 87 against the pressing direction P is limited by a second step 89 of the through-bore 79.

To introduce a circumferential groove 13 into the projectile blank 2, the projectile blank 2 must first be placed in the receptacle 33 of the die 19. For this purpose, a two-part punch 91 is provided, which rests on the top and bottom of the projectile blank and is movable in the pressing direction P relative to the die 19 and the punch 17. When the projectile blank 2 is in the receptacle 33, the punch 17 is moved in the pressing direction P towards the die 19. The punch 17 then presses with the front side 35 against the pressure piece 87 and moves it against the biasing force of the spring 85 in the pressing direction P. As a result, the pressure piece 87 is pushed over the tool 10 and compresses it radially. As explained regarding FIGS. 2 and 3, the grooving nose 53 of the tool 10 then presses a circumferential groove 13 into the outer side 11 of the projectile blank 2.

After grooving, the punch 17 is retracted against the pressing direction P, and the spring 85 also pushes the pressure piece 87 away from the tool 10 against the pressing direction P, so that it returns to its original shape. With the help of the punch 91, the finished projectile 1 can then be driven out of the receptacle 33 and removed.

It can be provided that the pressure piece 87 is driven by a drive (not shown) to perform an eccentric movement during the pressing process. This ensures that the groove is reliably introduced around the entire circumference of the projectile blank.

FIG. 8 shows an inventive projectile 1 with a circumferential groove 13 introduced into the outer side 11. Regarding FIGS. 9 and 10, the geometry of the circumferential groove 13 is described below, based on which it can be identified on the finished projectile 1 that the circumferential groove 13 was produced by pressing with an inventive tool 10. It is clear that the statements apply in the same way to a longitudinal groove produced with an inventive tool.

The circumferential groove 13 has a round cross-section in this embodiment. At the transition 93 between the circumferential groove 13 and the outer wall 11 of the projectile 1, a radius of at least 0.05 mm is formed. The transition 93 between the circumferential groove 13 and the outer wall 11 is thus formed without a contour jump and has no edge, as occurs with rolled grooves in the prior art (shown in dashed lines in FIG. 9). The transition 93 is more uniform in the inventive projectile 1, so the performance or flight characteristics of the projectile 1 are not impaired by the circumferential groove 13. When pressing the groove with the inventive tool 10, the individual bending wings 59 and thus the segments 58 of the grooving nose 53 are pressed against each other or moved towards each other as described. Before the segments 58 fully contact each other, projectile blank material penetrates between the segments 58, forming several radial projections 95, which can also be referred to as flags, arranged at a constant distance from each other corresponding to the width in the circumferential direction of the segments 58 of the grooving nose 53. FIG. 10 schematically shows such a radial projection 95. The radial projections 95 extend in the longitudinal direction LG of the projectile and thus perpendicular to the circumferential groove 13. The radial projections 95 have a width B oriented in the direction of extension of the groove of at most 0.2 mm and a depth T in the radial direction of less than 0.03 mm. The radial projections 95 thus protrude by at most 0.03 mm over the outer surface 11 of the projectile 1.

FIGS. 11 and 12 show another exemplary embodiment of an inventive tool 10. This differs from the previous tools in the shape of the grooving nose 53. This has essentially a flat surface 56, like the tool from FIG. 4. Additionally, a conically shaped section 101 with a continuously decreasing inner diameter is provided on the side 99 of the grooving nose 53 facing away from the groove end 51. Fundamentally, any other shapes of the grooving nose and/or projections or recesses on the grooving nose are possible to produce grooves with a desired geometry. The tool 10 according to FIGS. 11 and 12 also differs in that the wall 47 of the hollow body 45 does not have the same wall thickness over the entire longitudinal extension. At the end of the hollow body 65, the hollow body 45 has a significantly greater wall thickness in this embodiment, which can increase the strength of the tool 10 and serve as a support surface for further components of an inventive device 100. An internal step 97 is also provided at the end of the hollow body 65, with which the tool 10 can be fastened, for example, to a die or a base plate of a device 100.

FIGS. 13 and 14 show another embodiment of an inventive projectile 1. In this embodiment, the projectile 1 has six longitudinal grooves 14 pressed into the outer side 11 of the projectile nose 7 and extending in the longitudinal direction LG of the projectile 1. The longitudinal grooves 14 are arranged at a constant distance from each other and evenly distributed in the circumferential direction. The longitudinal grooves 14 can be, for example, deformation and/or relief grooves. It is clear that the projectile in FIGS. 13 and 14 can also have one or more circumferential grooves 13 in addition to the longitudinal grooves 14.

The features disclosed in the foregoing description, the figures, and the claims can be significant both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMERALS

    • 1 Projectile
    • 10 Tool
    • 100 Device
    • 2 Projectile blank
    • 3 Projectile body
    • 5 Projectile tail
    • 7 Projectile nose
    • 9 Projectile tip
    • 11 Outer side of the projectile body
    • 13 Circumferential groove
    • 14 Longitudinal groove
    • 15 Punch-die arrangement
    • 17 Punch
    • 19 Die
    • 21 Outer side of the die
    • 23 Bottom side of the die
    • 25 Top side of the die
    • 27 Step
    • 29 Step
    • 31 Air gap
    • 33 Receptacle
    • 35 Front side of the punch
    • 37 Cavity
    • 39 Wall
    • 41 Conical wall section
    • 43 Cylindrical wall section
    • 45 Hollow body
    • 47 Hollow body wall
    • 49 Cavity
    • 51 Groove end
    • 53 Grooving nose
    • 55 Rounding
    • 56 Surface
    • 57 Through-slit
    • 58 Segment
    • 59 Bending wing
    • 61 Slit base
    • 63 Bending joint
    • 65 End of the hollow body
    • 67 Unslitted section
    • 69 Step
    • 71 Support surface
    • 73 Counter bearing/Ring projection
    • 75 Base plate
    • 77 Receptacle
    • 79 Through-bore
    • 81 Step
    • 83 Holder
    • 85 Spring
    • 87 Pressure piece
    • 89 Step
    • 91 Two-part punch
    • 93 Groove transition
    • 95 Radial projection
    • 97 Step
    • 99 End of the grooving nose
    • 101 Conical section
    • L Longitudinal direction
    • LG Longitudinal direction of the projectile
    • P Pressing direction

Claims

1. Projectile, in particular full metal jacket or partial metal jacket projectile, for ammunition, for example with a caliber of at most 20 mm, in particular of at most 13 mm, comprising an at least partially hollow or solid projectile body with a circumferential and/or longitudinal groove arranged on its inner and/or outer surface, which transitions seamlessly into the adjacent inner and/or outer surfaces of the projectile body and/or has a radius of at least 0.05 mm.

2. Projectile, in particular according to claim 1, in particular full metal jacket or partial metal jacket projectile, for ammunition for example with a caliber of at most 20 mm, in particular at most 13 mm, comprising an at least partially hollow or solid projectile body with a circumferential groove arranged on its inner and/or outer surface, along which several radial projections extending in the longitudinal direction of the projectile (LG) are arranged at a particularly constant distance from each other, and/or a longitudinal groove, along which several radial projections extending transversely to the longitudinal direction of the projectile (LG) are arranged at a particularly constant distance from each other.

3. Projectile according to claim 2, wherein the radial projections have a width (B) of at most 0.2 mm and/or protrude less than 0.03 mm in the radial direction beyond the inner or outer surface.

4. Tool, in particular grooving tool, for introducing a circumferential and/or longitudinal groove into a projectile blank to produce a projectile designed in particular according to claim 1, comprising an elongated hollow body, in particular a case body, for receiving the projectile blank or for insertion into a cavity of the projectile blank with an inward or outward projecting, in particular circumferential, grooving nose, wherein the hollow body is slit in the longitudinal direction (L) such that, under the action of an external or internal force, the hollow body is particularly elastically deformable, in particular compressible or expandable, so that the grooving nose can press the circumferential and/or longitudinal groove into the projectile blank.

5. Tool according to claim 4, wherein the hollow body has several through-slits extending in the longitudinal direction (L) arranged at a particularly constant distance from each other, and several bending wings each separated by two through-slits.

6. Tool according to claim 5, wherein the through-slits extend from one end of the hollow body over at least 50% of the longitudinal extent of the hollow body to a respective slit base, at the axial height of which a bending joint is fixed, around which an associated bending wing is particularly elastically pivotable.

7. Tool according to claim 6, wherein the grooving nose is arranged in the region of the groove end, wherein in particular the through-slits divide the grooving nose into several segments distributed in the circumferential direction.

8. Tool according to claim 5, wherein the through-slits extend over at least 50% of the longitudinal extent of the hollow body such that an unslitted section is formed at each of the two end sides of the hollow body.

9. Tool according to claim 8, wherein each through-slit opens into two opposite slit bases, at the axial height of which a bending joint is fixed, around which an associated bending wing is particularly elastically pivotable.

10. Tool according to claim 8, wherein each through-slit opens into two opposite slit bases and the grooving nose is arranged in the region of 20% to 80% of a distance, in particular in the region of 40% to 60%, preferably centrally, between the two slit bases.

11. Tool according to claim 6, wherein the bending joints are manufactured in one piece with the associated bending wing, wherein in particular the hollow body is manufactured in one piece and/or wherein the bending joints are designed as film hinges.

12. Tool according to claim 4, wherein the hollow body has a counter bearing at the axial height of the grooving nose, which can be acted upon with a force to deform the hollow body, in particular to preferably elastically pivot the bending wings particularly around the bending joints.

13. System, in particular grooving station, for introducing a circumferential and/or longitudinal groove into a projectile blank to produce a projectile, comprising a tool designed in particular according to claim 4, which has a grooving nose, and a punch-die arrangement for holding the projectile blank, wherein the tool and the punch-die arrangement are coordinated such that the punch-die arrangement can elastically deform, in particular compress or expand, the tool to introduce the circumferential and/or longitudinal groove into the projectile blank.

14. System according to claim 13, wherein the die has a particularly shape-adapted receptacle for the projectile blank and the punch has a driver which is associated with the tool such that during a particularly translational relative movement of the die and the punch, the driver exerts a compressive force on the tool to deform it.

15. System according to claim 13, wherein the punch, in particular the driver, has a conical guide surface over which a continuously increasing compressive force can be generated.

16. Method for introducing a circumferential and/or longitudinal groove into a projectile blank to produce a projectile, wherein a projectile blank is inserted into a system designed according to claim 13, and wherein the projectile blank is locally grooved by an elastic deformation, in particular compression or expansion, of the tool to form the circumferential and/or longitudinal groove.

Patent History
Publication number: 20250354787
Type: Application
Filed: Jun 20, 2023
Publication Date: Nov 20, 2025
Inventor: Peter BIEDERMANN (Lyss)
Application Number: 18/874,047
Classifications
International Classification: F42B 30/02 (20060101); F42B 33/00 (20060101);