EP0151395B1 - Case sealed with an insert, together with a method and a device for manufacturing thereof - Google Patents

Description

Cartridge sleeve sealed with an insert, and method and device for its manufacture.

The invention relates to a method for connecting a cylindrical sleeve body to an insert, in which the insert is inserted up to a stop in one end of the sleeve body and part of the sleeve body is inserted at its pushed-on end into an annular groove arranged in front of the stop, one Cartridge with an insert piece which closes the essentially cylindrical sleeve body, the end region of the sleeve body having a tapered diameter being pressed into the insert piece, and a device for connecting a sleeve body to an insert piece, with a deformation tool acting circumferentially on the parts to be connected.

When manufacturing cartridge ammunition, a sleeve body must be connected to an insert. It is important to create a reliable positive and non-positive connection between the sleeve body and the insert piece that closes off one sleeve end.

A practice cartridge for small arms is known (DE-A-3 048 599), which has a tubular steel piece as the sleeve body and a bottom piece provided with a stop as an insert piece, against which the sleeve body abuts at one end. In order to connect the sleeve body to the base piece in a positive and non-positive manner, the base piece has a groove on the sleeve side before the stop, into which part of the pushed-on sleeve body is pressed in with a pressing or rolling tool. The machine tool required for this processing is complex. To press the sleeve body into the grooves, the sleeve must be rotated so that machining takes a lot of time. The wall thickness of the sleeve body should be kept as low as possible because of its deformability and to save material. With a small wall thickness of the sleeve body, however, the cartridge cases produced in this way have a low burst resistance. They inflate very easily under internal pressure, causing the cartridge cases to leak and the insert piece to come loose from one end of the case body. In addition, the sleeve body tears open very easily.

In the manufacture of a cartridge according to FR-A-1 113 479, the starting point is a cartridge sleeve which is narrow in diameter at the end and flanged at the end towards the outside or inside. To attach the base piece, either an inner ring must be pressed in from the tip of the cartridge with a stamp or a sleeve-like part attached to the base piece must first be expanded in the front area and then pressed on again. For this operation, a rotating tool z. B. a roller required.

GB-A-11 079, A.D. 1915, a bottom cap is attached to the end of the sleeve, which was previously provided with a groove and bent up. Here, too, several process steps are required in succession and assembly is only possible individually.

According to US-A-4 087 897, a form-fitting attachment of a cylindrical sleeve to a base piece is achieved in that in a first step the end of the sleeve is pressed into a rectangular groove using a rotating tool and then by means of a roller by plastic deformation of the edge of the base piece End region of the sleeve is covered in a lip-like manner by the material of the base piece.

According to US Pat. No. 4,269,438, when connecting the ends of two pipes, the pipe diameter of one pipe end is first increased to two different values. In a second step, a bulge is formed on the other tube by compression, over which the tube end of the first tube is pressed. At the connection point, the diameter is increased by (at least) four times the wall thickness.

In DE-A-2548599 a plastic cartridge case is attached to the base body by shrinking on. The sleeve made of biaxially stretched polyethylene rotates slowly around the longitudinal axis while the end is blown with hot air, which is also a very complex manufacturing process.

In the cartridges described in FR-A-2 264 267, the pole piece is held at the elaborately shaped end of the sleeve either by a snap ring or by a thread (which is even more complex in terms of production technology).

The invention has for its object to design cartridges, preferably for exercise purposes, the connection of the cylindrical sleeve body with the insert so that cheap mass production is possible.

In terms of the method, the object is achieved in that a collar which projects essentially radially from the insert is folded over the sleeve end lying in the annular groove and is pressed from the outside against this sleeve end while the insert is supported.

Here the sleeve end is deformed in one step and at the same time the sleeve end is pressed firmly into the ring groove by folding the collar. This creates a sealed, non-detachable non-positive and positive connection between the two parts. The assembly takes place in a simple manner, which enables a fully automated mass production of the connection without complex machines. The connection is made with a single straight movement of a tool, in which the collar is folded over, without rolling the sleeve.

An externally supported plunger is preferably inserted into the sleeve body, which selects the axial forces exerted on the insert rend the collar on the insert. It can also be provided that the sleeve body is inserted into a die, which axially supports the sleeve body when the collar is folded over.

It is also possible to absorb the axial force which occurs when the collar is turned over by means of pliers which engage in a radial groove located at the free end of the insert. This enables a simplified machine design for the mass production of the connection.

In the cartridge according to the invention, the collar encloses part of the sleeve body and presses it firmly into the annular groove, as a result of which a tight and permanent connection is created. In the event of an internal overpressure, the sleeve can no longer burst open at the connection-side end. The high mechanical stresses that occur with an internal overpressure are absorbed not only by the sleeve body, but also by the collar, which completely supports the sleeve end.

The outside diameter of the folded collar is not larger than the outside diameter of the insert or the sleeve body. This is important if the sleeve has to be inserted into a tubular part, since in this case the folded collar must not protrude.

The insert preferably has a relief ring groove on the side of the collar facing away from the sleeve body. This relief ring groove advantageously facilitates the folding over of the collar and enables the folded collar not to protrude relative to the insert piece and the sleeve piece by increasing the bending area. This also avoids cracks at the root of the collar.

The device for connecting the sleeve body to the insert consists of a deformation tool, which is a substantially ring-shaped drawing tool that is axially movable relative to the sleeve body, and a supporting device that axially fixes the sleeve body or the insert. Such a device can be produced inexpensively and simply and enables the simultaneous machining of several sleeves in the case of several drawing tools.

In the case of a stationary tool, the sleeves can be pushed through the shaping tool and, after the collar has been folded over, can be pushed backwards and ejected by a subsequent sleeve to be machined.

Further advantageous embodiments of the invention can be found in claims 8 to 10.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings.

• Figur 1 eine teilweise geschnittene Ansicht einer mit einem Einsatzstück abgeschlossenen Hülse, deren Hülsenkörper nicht vollständig dargestellt ist,
• Figur 2 das Einsatzstück mit radial abstehendem Kragen und aufgeschobenem Hülsenkörper vor dem Herstellen der Verbindung,
• Figur 3 eine Darstellung gemäss Figur 2 mit einem schräg abstehenden Kragen,
• Figur 4a, 4b eine Hülse gemäss Figur 2 mit einem Verformungswerkzeug und einem das Einsatzstück verbindungsseitig abstützenden Stempel vor und während dem Herstellen der Verbindung,
• Fign. 5a, 5b eine Patronenhülse mit in einer Matrize abgestütztem Hülsenkörper vor und während dem Herstellen der Verbindung,
• Fign. 6a, 6b ein Ausführungsbeispiel einer mehrteiligen Patronenhülse vor und nach dem Herstellen der Verbindung,
• Fign. 7a, 7b eine Patronenhülse mit einem Hülsenkörper aus Kunststoff vor und nach dem Herstellen der Verbindung,
• Fign. 8a, 8b ein Verformungswerkzeug mit einer Zange zum Festhalten des Einsatzstücks einer Hülse in seiner Anfangsstellung und in seiner Endstellung.

Show it:

• FIG. 1 shows a partially sectioned view of a sleeve closed with an insert, the sleeve body of which is not shown completely,
• FIG. 2 shows the insert with a radially projecting collar and a pushed-on sleeve body before the connection is established,
• FIG. 3 shows an illustration according to FIG. 2 with an obliquely projecting collar,
• 4a, 4b a sleeve according to FIG. 2 with a deformation tool and a plunger supporting the insert on the connection side before and during the establishment of the connection,
• Fig. 5a, 5b a cartridge case with a sleeve body supported in a die before and during the establishment of the connection,
• Fig. 6a, 6b an embodiment of a multi-part cartridge case before and after the connection is established,
• Fig. 7a, 7b a cartridge case with a sleeve body made of plastic before and after the connection has been made,
• Fig. 8a, 8b a deformation tool with pliers for holding the insert piece of a sleeve in its initial position and in its end position.

The sleeve 1 shown in Fig. 1 consists of an essentially tubular sleeve body 2 and an insert 3, which closes the one sleeve end. The insert 3 is a substantially cylindrical body whose diameter at its free end corresponds to the outside diameter of the sleeve body 2 and whose diameter at the other end, which receives the sleeve body 2, corresponds to the inside diameter of the sleeve body 2. The last-mentioned sleeve-side end of the insert 3 consists of a wide support ring 4 and an adjoining annular groove 5, which essentially has the width of the support ring 4 and extends up to a stop 8 formed by a collar 6. The groove depth corresponds at least to the wall thickness of the sleeve body 2. The stop 8 for the sleeve body 2 is part of the folded collar 6 of the insert, which presses the connection-side sleeve end 7 of the sleeve body 2 firmly into the annular groove 5. The outside diameter of the folded-over collar 6 that surrounds the sleeve end 7 is not greater than the maximum outside diameter of the sleeve body 2 and the insert 3.

On the side of the collar 6 facing away from the stop 8 there is a relief ring groove 9 which is intended to reduce the forces which occur when the collar 6 (FIG. 2) which originally protrudes radially is turned over. The bottom piece 10 of the insert piece 3 adjoining the relief ring groove 9 has the same outside diameter as the sleeve body 2.

The insert 3 can also be designed such that the collar 6 protrudes obliquely at an angle of approximately 45 ° (FIG. 3). This also reduces the forces when turning the collar.

The insert 3 consists of a plastically deformable material and is preferably made in one piece. The sleeve body 2 can also be made of a plastically deformable material or for example made of plastic (FIGS. 7a, 7b). The sleeve body made of plastic may already have the narrowing of the sleeve diameter to be inserted into the annular groove 5 at its connection-side end. In this case, the sleeve end 7 initially widens when pushed onto the insert 3 to slide over the support ring 4 of the insert 3 and then snaps into the annular groove 5 (FIG. 7a).

The figures 6a, 6b show the non-positive and positive connection in a training cartridge 21, which has a plastic core 22 in the interior of the sleeve body 2, which is integrally connected to a projectile tip 23 made of plastic and which encloses a cavity 24 for a propellant charge.

The deformation tool is an essentially ring-shaped drawing tool 12 which can be moved axially relative to the sleeve body 2 and the insert 3. It acts circumferentially on the parts to be connected by folding the collar 6 and thereby pressing the sleeve end 7 into the annular groove 5. The inside diameter of the drawing tool corresponds to the outside diameter of the sleeve body 2 of the base piece 10 of the insert 3. The inside diameter of the drawing tool 12 widens at its deforming end with a transition radius to its outside diameter and thereby forms a rounded end face 20 which causes the collar 6 to deform.

To absorb the axial force when turning the collar 6, a support device for the insert 3 or the sleeve body 2 must cooperate with the drawing tool 12. Such a supporting device consists, for example, of a stop against which the sleeve body 2 is supported, or of a die 13 which is essentially adapted to the outer contour of the sleeve body (FIG. 5b).

In the embodiment according to FIGS. 4a, 4b, an externally supported plunger 14 which is guided through the sleeve body 2 and which directly absorbs the axial forces occurring at the connection-side end of the insert 3 serves as a supporting device for the insert 3.

The embodiment of a drawing tool 12 according to FIGS. 8a, 8b has an enlarged inner bore 25 which extends to just before the rounded end face 20 and allows the placement of a pair of pliers 15 inside the drawing tool 12. Instead of the bore 25, two longitudinal grooves can also be provided, in which two tong arms 16 and 17 can move. The ends of the two tong arms 16 and 17 have two inwardly directed projections 18, which can engage in a groove 19 of the insert 3 provided for the tong 15 while the collar 6 is being folded over. In this way it is achieved that the sleeve is processed and held exclusively from one side, so that one end of the sleeve 1 projects freely. This has the advantage that, in the case of automated production, the device for feeding and removing the sleeve 1 has unhindered access to the tool.

To produce the non-positive and positive connection between the sleeve body 2 and the insert 3, the sleeve body 2 is pushed onto the insert 3 up to the stop 8 formed by the collar 6. The pulling tool 12, which is guided coaxially to the sleeve 1, is then pushed onto the insert 3 and pulled over the sleeve part of the sleeve body 2 resting on the support ring 4, while a supporting device either supports the insert 3 directly or via the sleeve body 2. The drawing tool 12 places with its rounded end face 20 the collar 6 of the insert 3 in such a way that the sleeve end 7 of the sleeve body 2 is pressed firmly into the annular groove 5 without the folded collar 6 being radially opposite the base 10 of the insert 3 or the Sleeve body 2 protrudes. The resulting connection between the sleeve body 2 and the insert 3 is non-positive and positive, so that the sleeve body 2 cannot be rotated relative to the insert 3 and cannot be separated from the insert 3 without being destroyed. The secure sealing of an internal excess pressure is ensured by a total of three sealing surfaces, namely the contact surface between the support ring 4 of the insert 3 and the sleeve body 2, the contact surface between that of the sleeve end 7 and the annular groove 5 and the contact surface between the outer jacket of the sleeve end 7 and the Inside of the collar 6. Bulging or bursting of the sleeve body 2 at the connection point is reliably prevented by the collar 6 which firmly encloses the sleeve end 7.

Claims (10)

1. Process for the connecting of a cylindrical casing body (2) with an insert (3), in which the insert is pushed in up to a stop (8) in the one end of the casing body and a part of the casing body is inserted at its pushed on end into an annular groove (5) arranged forward of the stop, characterized in that a collar (6) extending essentially radially from the insert (3) is laid around over the end (7) of the casing lying in the annular groove (5) and is pressed against this end of the casing from outside, whilst the insert (3) is supported.

2. Process according to claim 1 characterised in that there is inserted into the casing body (2) an externally supported plunger (14) which absorbs the axial forces exerted on the insert (3) during the laying of the collar around the insert (3).

3. Process according to claim 1, characterised in that the casing body (2) is inserted into a die (13) which supports the casing body (2) axially when laying around the collar (6).

4. Process according to claim 1, characterised in that the axial force occurring on the laying around of the collar (6) is absorbed by a clamp (15) which engages a radial groove (19) located at the free end of the insert (3).

5. Cartridge produced according to one of claims 1 to 4, with an insert (3) closing off the essentially cylindrical casing body (2), wherein the end region of the casing body is pressed into the insert form fittingly, narrowing in diameter, characterised in that there is provided on the insert (3) a laid around collar (6) whose external diameter is not greater than the external diameter of the insert (3) and of the casing body (2) respectively and the collar (6) surrounds on the outside the essentially cylindrical end of the casing body (2).

6. Cartridge according to claim 5, characterised in that the insert (3) possesses a stress releasing annular groove (9) on the side of the collar (6) directed away from the casing body (2).

7. Arrangement for the connecting of a casing body with an insert, having a deformation tool acting peripherally on the parts to be connected, characterised in that the deforming tool is an essentially annularly shaped drawing tool (12) displaceable axially relative to the casing body (2) and that there is provided a support arrangement axially locking in position the casing body (2) or the insert (3).

8. Arrangement according to claim 7, characterised in that the support arrangement is a plunger (14) axially locking in position the insert (3).

9. Arrangement according to claim 7, characterised in that the support arrangement is a die (13) axially locking in position the casing body (3).

10. Arrangement according to claim 7, characterised in that the support arrangement is a clamp (15) which engages a groove (19) in a part of the insert (3) extending out of the casing body (2) and is arranged in the interior of the drawing tool (12).

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