The invention relates to a base part for producing a cartridge case, the base part having a case base for receiving a primer cap, wherein a circumferential extractor recess is provided on the outer circumference of the base part. The invention further relates to a cartridge case having a cylindrical case which has a case opening for receiving a propellant charge and a projectile, and also has a base part opposite the case opening. In addition, the invention relates to a method for producing the base part and the cartridge case.
European patent EP 2 690 391 A1 discloses a method for producing a cartridge case. In the case of the method known in the art, an extraction groove in the form of a circumferential rotational surface is produced in a casing blank by reshaping the blank. In order to produce the extraction groove, a relatively complex reshaping tool is required, which contains a place marker among other things. The place marker in turn has 6 to 8 segments.
International patent disclosure WO 2014/051940 A1, corresponding to U.S. Pat. No. 9,016,184, and published European patent application EP 3 372 324 A1, corresponding to U.S. Pat. No. 10,495,430, disclose a method for producing a casing blank configured in one piece. The extraction groove in the form of a circumferential rotational surface is produced in the casing blank by means of a machining method. The production of a extraction groove by machining is complex.
U.S. patent Ser. No. 10/041,770 B2 discloses the production of a cartridge case with a two-part design. In order to produce a two-part cartridge case of this kind, a base part provided with a circumferential extraction groove is connected to a case. The production of two-part cartridge cases is also complex.
The problem addressed by the invention is that of eliminating the disadvantages of the prior art. In particular, a base part for producing a cartridge case and a cartridge case which can easily be produced should be specified. In addition, methods for producing a base part and/or a cartridge case which can be carried out as simply and cost-effectively as possible are specified.
This problem is solved by the features of the independent patent claims. Practical embodiments of the invention result from the features of the dependent patent claims.
In accordance with the invention, in the case of a base part for producing a cartridge case, it is proposed that the extractor recess has a polygon geometry which is formed from a closed traverse in cross section. In the case of traditional base parts, the extractor recess is configured as a groove and therefore as a circumferential rotational surface which forms a circle in cross section. The proposed polygonal shape of the extractor recess can be produced in a simplified manner, in particular by means of reshaping methods. During reshaping, material can flow from the middle of each path of the traverse towards the corners bordering the paths in cross section. Surprisingly, it has emerged that the functions of a traditional extraction groove are also satisfied by an extractor recess which has the geometry of a polygon.
A “base part” within the meaning of the present invention is normally a body with a cylindrical design, at least sectionally. The term “cross section” refers to a sectional plane which intersects the cylindrical axis perpendicularly and runs through the extractor recess. The term “extractor recess” refers to a depression extending radially inwardly from the outer circumference of the base part or a base section. The extractor recess may be produced, in that it is pressed in from the outer circumference by a radially inwardly acting force. In addition, it is also possible for the extractor recess to be produced by means of machining methods. Finally, it is also conceivable, starting from a profiled base body, for cylindrical portions to be formed on both sides of a profile section by radially outwardly acting forces, so that the extractor recess results.
According to an advantageous embodiment, at least some of the paths forming the traverse are straight. All paths are preferably straight. However, it may also be the case that at least some of the paths forming the traverse are curved (e.g. convex or concave). The paths are usually delimited by corners in the traverse. The corners may also be rounded.
According to an advantageous embodiment, the traverse is rotationally symmetrical in relation to an axis of rotation. The traverse may, in particular, have 2n-fold rotational symmetry in relation to an axis of rotation, where n is a number 3. In other words, the polygon geometry may be configured as a regular hexagon, octagon, etc.
According to a further embodiment, the case base has an opening for receiving the primer cap.
A base part having the aforementioned features may be configured in such a manner that it is suitable as an assembly part for producing a cartridge case. However, it may also be configured in such a manner that the cartridge case can be produced in part by means of a further forming method.
According to a further aspect of the invention, a cartridge case with a cylindrical case is proposed, which has a case opening for receiving a propellant charge and a projectile, and also a base part according to the invention opposite the case opening.
The cylindrical case and the base part may have an integral design. However, it may also be the case that the cylindrical case and the base part are fixedly connected by means of joining technology. The base part may be welded to the case, for example.
According to a further aspect of the invention, a method for producing a cartridge case is proposed, having a cylindrical case which has a case opening for receiving a propellant charge and a projectile, and also a base part opposite the case opening with a case base for receiving a primer cap. The method including the following steps of:
The proposed method supplies an integral cartridge case. The base body may have a cylindrical case even prior to the production of the circumferential extractor recess. However, it may also be the case that the cylindrical case is formed only following production of the extractor recess.
According to a further aspect of the invention, a method is proposed for the production of a base part for a cartridge case, which base part has a casing base for receiving a primer cap. The method contains the following steps of:
The proposed method variant supplies a base part which is particularly suitable for the production of multi-part cartridge cases, in which the base part is joined to a case.
Within the meaning of the present invention, the term “base body” should be understood to have a general meaning. It is a metal body which may be a wire section with a cylindrical outer circumference, for example. However, the base body may also be a preform part which has already been reshaped or processed by means of machining methods. The base body may already have an opening for receiving the primer cap.
According to an advantageous embodiment, the polygon geometry starting from a cylindrical base body is produced by means of a reshaping method or a machining method. The polygon geometry can easily be produced by means of a reshaping method, in particular. A hardening of the formed zones, especially at the base section, may well be desirable.
The polygon geometry is advantageously stamped in an outer circumference of the base body. It has proved particularly advantageous for the polygon geometry to be produced by means of multiple shaping steps.
Advantageously, in a first shaping step, a first polygon geometry is stamped into the outer circumference of the base body and in a second shaping step, a second polygon geometry sectionally overlaying the first polygon geometry is stamped into the first polygon geometry.
According to the proposed embodiment, in a first shaping step, a first polygon geometry is stamped into the outer circumference of the base blank. This can be done using a relatively simply formed shaping die. In a second shaping step following the first shaping step, a second polygon geometry that overlaps the first polygon geometry at least sectionally is stamped into the first polygon geometry. The second shaping step can also be carried out using a simply formed shaping die. By over-stamping the first polygon geometry, at least sectionally, in the second shaping step, an extractor recess configured as a polygon is obtained with a high degree of dimensional accuracy. As a result of the second shaping step, the number of paths or polygon paths is advantageously increased by the second shaping step compared with the first shaping step. For example, the first polygon geometry may have 6-fold rotational symmetry in relation to an axis of rotation. The second polygon geometry may have 12-fold or 24-fold rotational symmetric in relation to an axis of rotation.
According to an advantageous embodiment, first edges produced in the first shaping step are at least partially over-stamped in the second shaping step. Particularly in the closing region of the shaping dies, first edges may exhibit a burr, or the like, following the first shaping step. Since first edges produced during the first shaping step are at least partially over-stamped in the second shaping step, a polygonal shaped extractor recess can be produced in a simple and cost-effective manner with a high degree of geometric precision.
A 2-part or multi-part shaping die is advantageously used to produce the polygon geometries. A simply configured 2-, 3- or 4-part shaping die is generally sufficient. Multi-part shaping dies, e.g. 8-, 9- or 10-part shaping dies, can also be used.
According to a further embodiment of the method, the base body can be rotated axially by a predetermined angle relative to the shaping die following the first shaping step and before the second shaping step. In other words, either the base body can be rotated relative to the fixed shaping die or the shaping die can be rotated relative to the fixed base body. It is also possible for the base body to be placed in a second shaping die following the first shaping step, the shaping die being rotated by a predetermined angle with respect to the polygon geometry relative to the polygon geometry provided in the first shaping die. As a result, the edges of the second polygon geometry lie at least partially on the paths of the first polygon geometry.
It is possible for the first and the second polygon geometry to be produced using the same shaping die. In other words, two identical shaping dies can be used one after the other along a forming path to produce the first and second polygon geometry. When a first base body provided with the first polygon geometry is realized, the base body is advantageously rotated by a predetermined angle and then placed in the next shaping die, in order to produce the second polygon geometry.
According to an advantageous embodiment, the first polygon geometry is produced by means of a first shaping die and the second polygon geometry by means of a second shaping die which is different from the first shaping die. For example, a first polygon geometry with 6-fold rotational symmetry in relation to an axis of rotation can be produced using the first shaping die. A second polygon geometry can be produced using the second shaping die, which has 12-fold rotational symmetry in relation to an axis of rotation, for example. The first polygon geometry may be over-stamped by the second polygon geometry, in such a manner that the first edges of the first polygon geometry coincide with second edges of the second polygon geometry. However, it may also be the case that the first edges of the first polygon geometry do not coincide with the second edges of the subsequently produced second polygon geometry.
According to an advantageous embodiment, at least one tool can be inserted into the base body and/or applied to the outer circumference of the base body during the shaping method. By means of the tool, holding, indexing, perforating, filling, stamping and/or shaping can be applied to the base body. In this way, the dimensional accuracy during production of the base part can be improved.
According to an alternative embodiment, the base part or the cartridge case can also be produced from a further base body having the polygon geometry by means of a shaping method. In other words, in this case the polygon geometry of the extractor recess is predetermined by the further base body. The further base body is shaped in such a manner that a cylindrical outer circumference is formed, in which the extractor recess with the polygon geometry remains. Furthermore, it is also conceivable for the polygon geometry to be produced starting from a cylindrical base body by means of rolling.
The opening for receiving the primer cap can be produced before, during or after the polygon geometry is produced in the case base.
The polygon geometry advantageously has a 2n-fold rotational symmetry in relation to an axis of rotation, wherein n is a number 3. In other words, the polygon geometry of the extractor recess may have a 6-, 8-, 10-, 12-fold rotational geometry about an axis of rotation, for example.
According to a further aspect of the invention, a method for producing a cartridge case is proposed, having a cylindrical case which contains a case opening for receiving a propellant charge and a projectile, and also a base part opposite the case opening having a case bottom for receiving a primer cap. The method includes the following steps of:
The proposed method provides a cartridge case, in which the base part and the case are formed from one piece.
The forming of the cylindrical case may also advantageously take place by means of extrusion and deep-drawing.
Prior to the forming of the case, at least one tool can be inserted into the base part and/or applied to the outer circumference of the base part. By means of the tool, holding, indexing, perforating, filling, stamping and/or forming can be applied to the base part and/or the case.
A cartridge case produced according to the above method can be produced solely by means of shaping and therefore produced particularly efficiently.
Furthermore, a method for producing a cartridge case is proposed, having a cylindrical case which has a case opening for receiving a propellant charge and a projectile, and also a base part opposite the case opening with a case base for receiving a primer cap. The method includes the following steps of:
The joining method may, for example, be a welding method or other suitable methods.
It is stressed that the sequence of method steps in the methods listed in the description and in the claims is not limited to the order shown in each case and any other sequences of steps are also included.
The base body and/or the case is/are advantageously produced from a non-ferrous metal or steel. The non-ferrous metal may be selected from the following group: brass, aluminum or aluminum alloy.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a base part for producing a cartridge case and a cartridge case, a method for producing a base part for a cartridge case, and a method for producing a cartridge case, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
The invention is explained below with the help of a base body for producing a cartridge case. Instead of the base body for producing a cartridge case, a base body for producing the base part can also be supplied and the base part can be produced from this using an analogous method. A base part of this kind can be joined to a case to create a cartridge case.
Referring now to the figures of the drawings in detail and first, particularly to
As indicated by the arrows in
The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention.
Number | Date | Country | Kind |
---|---|---|---|
10 2020 003 744.5 | Jun 2020 | DE | national |
This application is a continuation, under 35 U.S.C. § 120, of copending International Patent Application PCT/EP2021/065502, filed Jun. 9, 2021, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2020 003 744.5, filed Jun. 23, 2020; the prior applications are herewith incorporated by reference in their entirety.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/EP2021/065502 | Jun 2021 | US |
Child | 18085638 | US |