EP0985468B1 - Apparatus for connecting a part of a packaging container with a with a cover member - Google Patents

Abstract

The walls (45, 46) of the container (40) are opposite each other in the closing region. An expanding tool (24) is lowered until the expanding rolls (16, 17) lie opposite one wall (46), and the tool is then rotated. The expanding rolls are moved radially outwards, expanding the closing region of the container until its components are locked positively to each other.

Description

The invention relates to a device according to the preamble of the claim 1 (see, for example, DE-A-86165).

From CH 642 316 A5 and DE 196 18 310 A1 closures for packaging containers known. Here comes a comparatively complex Expanding tool for use, which has segments that can be driven radially are and in their radially outer operating end position a distance have from each other. According to non-circular the sealing area of the on this way formed container.

From DE 26 40 215 A1 is a from a lower part and one with the Upper edge region cooperating closure element existing known metallic container. The upper edge area of the lower part consists from a radially outside projecting, formed by a roll Bead on which interposition of a sealant with a a core-side depression formed closure element is placed. The outside of the closure element is in the initial state according to Art an open towards the bottom, intended to superimpose the bead Ringsick formed and ends also with a curl, which to the outside, i.e. oriented away from the annular bead. In the area of the core depression of the closure element run in the initial state, the walls of the closure part and the bottom approximately vertically, leaving a thin layer of adhesive along the entire boundary region of closure element and lower part extends, starting from this state a positive Fixing both parts is achieved by forming a bead, the starting from the core part of the closure element both of said walls penetrates in the radial direction. For beading a sickle roller is used and it finds a beading substantially in the vertical Wall sections of the closure element and the lower part instead.

From DE 36 24 769 A1 it is known per se, a substantially in cross section rectangular, cup-shaped container with an outward extending peripheral flange through a sheet-shaped, flat lid blank to close off from a metal foil. This happens with one in several movable sections divided crimping frame. With the sections will the edge of the lid blank is crimped around the peripheral flange. It lies a tool shell on the lid portion. Each section is with one Articulated quadrilateral articulated to a stationary holding part. A lower, hook-like Brödelkante each section is in an axial closing movement of Tool guided in the arc from outside to inside and completes the Rolled beads.

From GB-PS 357 558 it is known per se, the edges of a container opening and a cup-shaped lid inserted into the container opening to join together positively by joint expansion. Radial outside the edges there is a longitudinally divided, composed of sectors Retaining ring with radially inwardly molded circumferential grooves. Within the edges is a rubber ring arranged. The rubber ring sits on one Rod, which carries a plate below the rubber ring. On the top of rubber ring lies a push ring, which with an upper bushing on the Rod is guided. Has an axial approach of the plate and the pressure ring As a result, the rubber ring expands radially outward and thereby the Pressing edges into the grooves of the retaining ring. When the connection is tight Should be, is introduced between the edges of wax.

From DE-PS 86 165 it is known per se, the free edge of the lower part a packaging container radially inwardly around a reinforcing insert wire to roll around. Around this free edge is an annular bead of a Cover set. From the annular bead extends outside a vertical Flange down over the first edge region of the lower part of the packaging container. Outside over the flange will be an exact matching ring inverted, which presses with an annular approach on top of the ring bead. From the annular bead extends inside down a second edge region of the Cover. Radial inside to the second edge area are opposite each other Expander rollers attached, each on a curved lever is freely rotatably mounted. A radially outer end of each lever is on a yoke, while a radially inner end of each lever by a Block can be raised and lowered. When lowering the block relative to the yoke The expansion rollers are pivoted radially outward while they are around the Revolve longitudinal axis of the packaging container. This will be the second border area the lid to achieve a positive connection under the Curling of the lower part into contact with an inner surface of the first Border area of the lower part expands. The ring acts as a counterhold and prevents radial expansion of the first edge region of the lower part and the outer flange of the lid. The beading at the out of this Well known device corresponds essentially to that of DE 26 40 215.

Finally, from DE-AS 1 196 616 an automatic Deckelverschließmaschine for drums and the like. With an axial edge of a Drum lower part is connected to a radially outer edge of a cover ring. A radially inner edge of the cover ring ruptures a Außenanrollung, the surrounds an opening to be closed by a lid. A kind of push-in lid is pressed into the opening and lays down with an annular edge hook about the external roll. A capping head has several pairs of rollers each with a radially inner counter-pressure roller of a radially outer locking roller on. In radial relative movement between the drum and a circulating locking head through the roles of each pair of rollers a lever mechanism pivoted to each other. Here, the counter-pressure roller sets radially inward on the edge hook, while the closing roller the radially outer, free portion of the edge hook around the Außenanrollung the cover ring shapes around.

It is the object of the invention to provide a device of the type described above Type with regard to the security against leaks and the sealing effect of packaging containers to increase and an improved, in particular more cost-effective To propose an expansion tool. This task is solved in one Such device by the features of the claim 1.

A relative rotation can basically by rotation of the expanding tool and / or the packaging container, but with a Rotation of the expansion tool is preferred when the packaging container is stationary becomes. The expanding tool is easier in this case, cheaper and easier to maintain. The sheet deformation by the Expanding is much gentler and more even over the circumference than before, so that in the episode an even better sealing effect between the lower part and the closure element results. Also results a particularly gentle way of sheet metal deformation, which leads to a circular and circumferentially uniformly deformed closure area between the lower part and the closure area leads. Of the Closed packaging containers can easily be removed from the machine become.

The design of the device is structurally simple and inexpensive and it can be considered as particularly safe. As a drive for the actuator according to the invention is preferably a pneumatic piston-cylinder unit into consideration. As a result of the invention Training the leadership of the sledges results in a very uniform and reliable operation of the expanding rollers. This is true especially if more than one expanding roll, e.g. three expanding rollers be used in the expansion tool.

Due to the features of claim 2, the expansion tool can be particularly easy and fast and with little effort on packaging containers convert different diameter.

The features of claim 3 are structurally particularly advantageous.

In most cases, the features of claim 4 lead to a completely sufficient Sealing the container. If you go beyond that in the field the first and second wall of the edge regions a positive connection wishes, one can proceed according to claim 5 or 6.

Fig. 1 eine teilweise geschnittene Seitenansicht einer Verschließmaschine;

Fig. 2 die Draufsicht auf die Maschine gemäß Fig. 1;

Fig. 3 die Ansicht gemäß einer Linie III-III in Fig. 1 in vergrößerter Darstellung;

Fig. 4 im Wesentlichen die Schnittansicht nach Linie IV-IV in Fig. 3 durch eine Vorrichtung zum Verschließen eines Verpackungsbehälters als Bestandteil der Verschließmaschine gemäß Fig. 1;

Fig. 5 und 6 jeweils einen Längsschnitt durch die Vorrichtung gemäß Fig. 4 in unterschiedlichen weiteren Betriebsphasen,

Fig. 7 die Ansicht gemäß Linie VII-VII in Fig. 6,

Fig. 8 das Detail VIII in Fig. 6 in vergrößerter, spiegelbildlicher Darstellung,

Fig. 9 einen Längsschnitt durch einen Teil einer anderen Ausführungsform der Vorrichtung,

Fig. 10. die Expandierrolle gemäß Fig. 9 in vergrößerter Darstellung mit einem Teil des zugehörigen Verpackungsbehälters,

Fig. 11 einen Längsschnitt durch einen Teil der Ausführungsform gemäß Fig. 3,

Fig. 12 die Expandierrolle gemäß Fig. 11 mit einem Teil des zugehörigen Verpackungsbehälters im Längsschnitt,

Fig. 13 einen Längsschnitt durch einen Betätigungsantrieb der Vorrichtung,

Fig. 14 eine schematische Darstellung des Expandiervorgangs für eine Vorrichtung mit drei Expandierrollen und

Fig. 15 eine schematische Darstellung des Expandiervorgangs für eine Vorrichtung mit zwei Expandierrollen.

These and other features and advantages of the invention are explained below with reference to the embodiments illustrated in the drawings. Show it:

Fig. 1 is a partially sectioned side view of a closing machine;

FIG. 2 shows the plan view of the machine according to FIG. 1; FIG.

3 shows the view according to a line III-III in Figure 1 in an enlarged view ..;

FIG. 4 shows essentially the sectional view according to line IV-IV in FIG. 3 through a device for closing a packaging container as part of the closing machine according to FIG. 1; FIG.

5 and 6 each show a longitudinal section through the device according to FIG. 4 in different further operating phases,

7 is the view according to line VII-VII in Fig. 6,

8 shows the detail VIII in FIG. 6 in an enlarged, mirror-image representation,

9 shows a longitudinal section through part of another embodiment of the device,

10 shows the expansion of FIG. 9 in an enlarged view with a part of the associated packaging container,

11 is a longitudinal section through part of the embodiment of FIG. 3,

FIG. 12 shows the expansion roll according to FIG. 11 with a part of the associated packaging container in longitudinal section, FIG.

13 is a longitudinal section through an actuating drive of the device,

Fig. 14 is a schematic representation of the expansion process for a device with three expanding rollers and

Fig. 15 is a schematic representation of the expansion process for a device with two expanding rollers.

Fig. 1 shows a closing machine 1 with a stand 2. In the Stand 2 is rotatably mounted with vertical longitudinal axis 3, a spindle 4, via a bevel gear 5 either in the two directions of rotation is rotationally drivable. With the spindle 4 is a spindle nut 6 engaged, on the - secured against rotation - a Traverse 7 is attached.

With the crossmember 7, a holder 8 is firmly connected, in a Guide 9 of the stand 2 is displaced up and down. The holder 8 carries an electric drive motor 10, which has a drive belt 11 a pulley 12 rotatably drives. On the pulley 12 is Coaxially attached to a shaft 13, extending down the length extends through a two-stage piston-cylinder unit 14. At the bottom End of the shaft 13, a plate 15 is attached. The plate 15 carries in this embodiment radially displaceable three expanding rollers 16, 17 and 18 (see Fig. 3) at the same angular distance from each other. A longitudinal axis 19, 20 and 21 of each expansion roller 16 to 18 is parallel to a longitudinal axis 22 of this device 23 for closing arranged by packaging containers. The plate and the expanding rollers 16 to 18 are components of an expansion tool 24 the device 23.

FIG. 2 illustrates further features of the closing machine 1.

According to FIG. 3, each expansion roller 16 to 18 is freely rotatable on one Axis 25, 26 and 27 stored. Each axis 25 to 27 is in a Bore formed receptacle 28, 29 or 30 of a carriage 31, 32nd and 33 set. This determination can be made, for example, according to FIG. 11 happen. Each carriage 31 to 33 is in a guide 34, 35 and 36 of the plate 15 radially displaceable. The plate 15 is over stable Columns 37, 38 and 39, which extend parallel to the longitudinal axis 22, rotatably connected to the shaft 13.

With the expansion tool of FIG. 3 can easily Packing containers are closed with different diameters. The receptacles 28 to 30 of each carriage 31 to 33 are related on the longitudinal axis 22, arranged in the radial direction at a distance from each other. The radial arrangement of the receptacles 28 to 30 depends according to the different diameters of those packaging containers, which should be closed with this expanding tool 24. In Fig. 3 stuck the axes 25 to 27 respectively in the middle recording 29. Accordingly, with this arrangement, a packaging container be closed with medium diameter. Should now a packaging container be closed with a larger diameter the expanding rollers 16 to 18 with their axes 25 to 27 from the recordings 29 away and only in the farther outward shots 28 transferred. On the other hand, a packaging container with a smaller Diameter be closed, the axes are 25 to 27 with the expansion rollers 16 to 18 inserted into the receptacles 30.

In all drawing figures are the same parts with the same reference numbers Mistake.

The expansion tool 24 shown in FIG. 4 differs from those in Fig. 3, as in Fig. 4, each carriage, for example, 31, 32, only the one receptacle 29 for the axis, for example, 25, 26, the associated Expanding roller 16, 17 has. This inexpensive embodiment the carriage 31, 32 is intended for large quantities of packaging containers 40 with constant diameter to close. However, packaging containers can also be provided with the expansion tool 24 according to FIG. 4 40 closed with different diameter are, if appropriate sets of Expandierrollen 16, 17 with larger or smaller diameter, as shown in Fig. 4, used become.

The packaging container 40 according to FIG. 4 has a lower part 41 Sheet metal and a closure element 42 made of sheet metal. Edge areas of the lower part 41 and the closure element 42 are intended to be in a radially inwardly opening interior 43 of a locking ring 44 expands become. Details will be clarified in connection with FIG. 8 become. For expansion, there is a first wall 45 of the lower part 41 and a second wall 46 of the closure element 42nd across from.

The plate 15 is lifted by a parallel to the longitudinal axis 22 and surrounded lowerable pressing tool 47.

The plate 15 has a central bearing bush 48, in which a lower Pin 49 of an actuating element 50 parallel to the longitudinal axis 22 is slidably guided. Similarly, an upper one Pin 51 of the actuator 50 in a bearing bushing 52 of the shaft 13 mounted axially displaceable. Between the pins 49, 51 is a radial outwardly projecting collar 53 of the actuating element 50 attached. Each on a bearing pin 54 of the collar 53 is an end a tab 55 raised and lowered articulated. The other end of everyone Tab 55 is connected to a bearing pin 56 of the associated carriage 31, 32 articulated.

An illustrated in Fig. 13 in detail lower stage of the two-stage Piston-cylinder unit 14 serves to the actuator 50th controlled to raise or lower parallel to the longitudinal axis 22. To is the upper pin 51 of the actuating element 50 on a piston rod 57 attached to which a lower piston 58 is fixed, the is slidably mounted and sealed in a cylinder 59. Of the lower piston 58 serves to the actuator to a stroke 60th lower. For this purpose, the top of the lower piston 58 by a Channel 61 controlled compressed air supplied (see also Fig. 13). The end the stroke 60 is defined by a bottom 62 of the lower Piston 58 touches on a stop surface 63 of the cylinder 59. Of the Cylinder 59 is otherwise part of the shaft 13th

In Fig. 4 are the expanding rollers 16, 17 in a radial inner starting position, in which the expanding rollers 16, 17 in the second wall 46 of the packaging container 40 can dive.

This is done by means of the upper stage of the two-stage piston-cylinder unit 14, the entire expanding tool together with the shaft 13 and the lower stage of the two-stage piston-cylinder unit 14 shown in FIG. 13 lowered. This first stage consists of a pneumatic piston-cylinder unit, coaxially up to the structure in Fig. 13 connects and not shown in detail needs. In Figs. 5 and 6, the expansion tool 24 is on this Way maximum lowered. In this state, the expanding rollers 16, 17 into the second wall 46 of the closure element 42 (FIG. 4) immersed.

In Fig. 5 is between the Expander 16 and the opposite second wall 46 a slight radial clearance recognizable. This means that the expansion has not yet begun. Before that was the pusher 47 in contact with the circlip 44 (FIG. 8) lowered. The force exerted on the retaining ring 44 axial pressure force 64 (FIG. 8) is chosen so large that a sufficient Sealing compression of a ring seal 65 (Fig. 8) sets.

Now, in Fig. 5, compressed air is applied to the top of the lower piston 58 headed. This has the consequence that the actuating element 50 to the Stroke 60 moved to the position shown in Fig. 6 down becomes. In this position, the expansion roller 17 is in her radially outer operating end position and is the closure of the packaging container 40 fully expanded and closed.

Once this is done, the pusher 47 can again out of touch lifted with the packaging container 40 and also the actuator 50 raised again. This moves the Tab 55 from the horizontal end position in Fig. 6 back in the inclined starting position shown in FIG Expanding rollers 16 to 18 (Fig. 3) from its radially outer operating position back into its radially inner starting position according to FIG. 5. Thereafter, the expansion tool 24 is returned to its upper starting position lifted as shown in FIG. 4, whereby at its upper end sealed packaging containers 40 free for removal from the capping machine 1 is.

Fig. 7 shows further details of the design of the actuating element 50, the tab 55, the carriage 32 and the guide 35th

According to Fig. 8 is an upper opening 66 of the lower part 1 of the packaging container 40 sealed by the closure member 42. The lower part 41 and the closure element 42 are made of tinplate of, for example, 0.31 mm thickness.

A first edge region 67 of the lower part 41 is provided with a second Edge region 68 of the closure element 42 tightly connected. A first free end portion 69 of the first edge portion 67 is as an outer roll educated. The second wall 46 is at the top second free end portion 70 of the second edge portion 68 at. Of the second free end portion 70 terminates in a curl 71 and carries inside the ring seal 65. The ring seal 65 acts with the first free End region 69 sealing together. The required axial Dichtanpressung happens even before expanding the expanding rollers, for Example 17, in that the pressing tool 47, the axial compressive force 64 exerts on the upper limit of the locking ring 44.

In the one shown in Fig. 8, by the expanding rollers 16 to 18 (Fig. 3) expanded end state are the first 69 and the second End portion 70 in the interior 43 of the locking ring 44. It has a radially outer side 72 of the first wall 45 against a Stop acting radially inner edge 73 of a lower belt 74 of the Circlip 44 laid. The positive locking is according to Fig. 8 came about by the fact that during the expansion of first free end portion 69 in full on the lower flange 74th has moved. The locking ring 44 may be in any, in itself be formed known manner. It can be, for example, around act a clamping ring that open easily and also close again leaves.

During the expansion is shown in FIG. 8 at an axially outer end of second wall 46 extends radially inwardly beyond the outer end extending bead 75 has been formed. The bead 75 stiffens the second edge region 68 and allows the second free end region 70 an optimal shape design within the interior 43.

From Fig. 9 it can be seen how the Expandierrolle 16 dashed over registered rolling bearing 76 on a lower extension 77 of Axis 25 is freely rotatably mounted. Once the Expandierrolle 16 radially moved outwardly into contact with the packaging container 40 is, it is driven by friction rotating. The active, radial outer surface of the expansion roller 16 is contoured in a special way. This will be explained in connection with FIG.

In the embodiment of FIG. 10 finds a closure element 42 with a central discharge opening 78 use. The removal opening 78 is through a removable and repositionable plug 79 sealed in plastic. But everyone else can do it Plastic or metal closures available on the market be, for example, plastic screw caps.

10, the expansion of the first wall 45 and the second wall 46, at least over part of its axial length, under a negative angle 80 to the longitudinal axis 22 is formed, wherein the diameter increases to an interior 81 of the packaging container 40. This taper results at the end of expansion the positive locking between the first wall 45 and the second wall 46, without here an additional locking ring, such as the locking ring 44 in Fig. 8, would be required.

Fig. 11 shows the carriage 31 of FIG. 3 in longitudinal section. Indeed here is the axis 25 not in the middle shot 29, but inserted into the radially inner receptacle 30. The axis 25 is at the top secured axially by a locking ring 82. The expanding roller has at its radially outer, active surface 83 a radially to outwardly extending perimeter profiling 84. As in this embodiment the Expandierrolle 16 relatively far radially inside sits around a packaging container of relatively small diameter to close, the spinning tool 47 in Fig. 11 is corresponding pulled radially inward.

FIG. 12 shows the expansion roller 16 according to FIG. 11 in its radial direction outer operating end position. The circumferential profile 84 has the Expanding roller 16 in the walls 45, 46 complementary peripheral beads 85th and 86 formed. The circumferential beads 85, 86 lead to a positive fit Locking of the edge regions 67, 68 with respect to each other.

Fig. 13 shows a longitudinal section through the actuating drive for the radial displacement of the carriages 31 to 33 (FIG. 3). The lower part This actuator was already described in connection with FIG. 4 Service. The piston rod 57 continues upwards and is guided with its upper end 87 in a bore 88 of the shaft 13. On a thread of the piston rod 57, a nut 89 is screwed, with an upper piston 90 axially on the lower piston 58th and this in turn axially on the upper pin 51 of the actuating element 50 is stretched. The upper piston 90 is sealed in one top cylinder 91 out, like the lower cylinder 59 component the shaft 13 is. Between the cylinders 59, 91 a plate 92 is sealed clamped. Another plate 93 is between the upper one Cylinder 91 and an air guide portion 94 of the shaft 13 also as Part of the shaft 13 is provided. The air guiding portion 94 is by rolling bearings 95 and 96 in a stationary sleeve 97 rotatable stored. A first inner annular groove 98 of the sleeve 97 may, as indicated by the dot-dashed arrow 99. compressed air controlled to be forwarded. This compressed air passes through Channel system 100 in the air guide portion 94 and the plate 93 and a connecting line 101 in the channel 61 and thus on the Top of the lower piston 58. This causes a downward movement of the actuating element 50 and thus a radially outwardly directed Movement of the expansion rollers 16 to 18 (FIG. 3).

If, however, a second annular groove 102 of the sleeve 94 in the sense of dot-dashed arrow 103 compressed air is supplied, it passes into a duct system 104 in the air duct 94 and the plate 93 and from there through a connection line 105 into a channel 106 of the Plate 92 and on the underside of the upper piston 90. This causes a lifting of the actuator 50 and a radial retraction the expanding rollers 16 to 18.

In Fig. 14, the operation of the expansion tool 24 is schematic shown. The expanding rollers 16 to 18 are fully extended Circles in their radially inner starting position (Figure 5) each in an angular distance of 120 ° degrees from each other. they lay inside on the second wall 46 (Figure 5). This is going to expand Expanding tool 24 with the expanding rollers 16 to 18 in the direction of Arrow 107 um. The expanding rollers 16 to 18 are becoming increasingly on spiral tracks in the direction of arrow 107 and radially outward moves until the second wall 46 and thus the closure region of the packaging container 40 has been expanded enough. This final state is for the expansion roller 16 in dotted lines at the top right in Fig. 14. Of course, the other two have Expanding rollers 17 and 18 until then the same radially outer position as the Expandierrolle 16 occupied. The speed of the radial Outward movement of the expansion rollers 16 to 18 and thus given Circulation speed of the expansion tool 24, the number of helical paths 108, each expansion roller 16 to 18 to completion The expansion depends on several parameters. Such parameters are, for example, the deformability and thickness of the Sheets of the lower part 41 and the closure element 42 in the closure area. In any case, the expansion can be so gentle, that is a perfect seal in the closure area after expansion results.

Fig. 15 is a schematic representation corresponding to Fig. 14 in the event that the expansion tool 24 only two, diametrically opposite expansion rollers 16 and 17 has. The expanding rollers 16, 17 are in their radially inner starting position in FIG. 15 again shown with fully drawn circles and are inside the second wall 46 (see Fig. 5). The second wall 46 has in this Initial state an inner radius 109.

To expand, the expansion tool 24 runs in the direction of the arrow 107 with the packaging container stationary. In the process, the expanding rollers become 16, 17 continuously moved radially outwards, so that the contact zone of each expansion roller 16, 17 on a spiral Web 110 and 111 are moved by an angle 112 and 113 of 180 ° degrees. At the end of this path, the expansion rollers 16, 17 take the in Fig. 15 dash-dotted marked positions. It is assumed that this is already the radially outer operating end positions (Figure 6) of the expanding rollers 16, 17. Would at this point the circulation of the expanding tool 24 in the direction of the arrow 107 ends, There would be no circular cylindrical inner surface of the second wall 46 result. This ideal annular cylindrical surface 46 is in Fig. 15 shown in dashed lines. Rather, then before each expanding roll 16, 17 crescent-shaped contours of the second wall 46 between the respective spiral track 108, 109 and the dashed Stop circle 46. These crescent-shaped contours are thereby eliminates the expansion rollers 16, 17 from their dash-dotted lines in Fig. 15 registered positions still at least each 180 ° degree on be circulated in the direction of arrow 107, without doing so a further radial outward movement of the expansion rollers 16, 17th takes place. After this smoothing step, the second wall 46 has the in Fig. 15 by dashed lines circular cylindrical shape with the Radius 114 on. In Fig. 15 is also the radial stroke 115 of the expansion rollers 16, 17 between their radially inner starting position (FIG. 5) and its radially outer operating end position (FIG. 6).

Claims (6)

1. Device for connecting a first edge region (67) of a base portion (41) of a sheet metal packaging container (40) in a sealing manner to a second edge region (68) of a sheet metal closure element (42),
   wherein the second edge region (68) supports an annular seal (65) which cooperates with the first edge region (67),
   wherein within the annular seal (65) a first wall (45) of the first edge region (67) and a second wall (46) of the second edge region (68) lie opposite each other in a radial manner, wherein the closure element (42) can be placed with the annular seal (65) on to the first edge region (67),
   having a pressing tool (47) which is intended to exert an axial compressive force (64) until a sufficient sealing compression of the annular seal (65) is achieved,
   having an expansion tool (24) which can be brought into contact with a radially inner side of the second edge region (68), wherein the first (67) and second edge region (68) can be expanded jointly by means of the expansion tool (24), until a positive locking arrangement is achieved,
   wherein at least during an expansion cycle the expansion tool (24) and the packaging container (40) can be rotated relative to each other about their common longitudinal axis (22),
   wherein the expansion tool (24) comprises at least one expansion roller (16 to 18) and
   wherein each expansion roller (16 to 18) can be moved during each expansion cycle between a radially inner starting position and a radially outer operating position,
   characterised in that
   each expansion roller (16 to 18) is mounted in a freely rotatable manner on a slide (31 to 33), wherein each slide (31 to 33) can be displaced radially in a guide of a disk (15),
   the disk (15) is connected in a non-rotatable manner via a shaft (13) to a drive motor (10),
   each slide (31 to 33) is articulated to an end of a bracket (55),
   the other end of each bracket (55) is articulated to an actuating element (50) which can be moved in parallel with the longitudinal axis (22) of the expansion tool (24) along the shaft (13),
   the expansion tool including the actuating element (50) can be driven reciprocally in a controlled manner by means of a piston-cylinder unit (14) along the shaft (13) between a non-operative position, in which the at least one expansion roller (16 to 18) is located outside the edge regions (67, 68), and an operating position, in which the at least one expansion roller (16 to 18) is received into the edge regions (67, 68), and
   the shaft (13) extends through the piston-cylinder unit (14).
2. Device as claimed in claim 1,
   characterised in that each slide (31 to 33) comprises several receptacles (28 to 30) for the associated expansion roller (16, to 18), said receptacles being disposed at a radial spacing from each other.
3. Device as claimed in claim 1 or 2,
   characterised in that a longitudinal axis (19 to 21) of each expansion roller (16 to 18) is disposed in parallel with the longitudinal axis (22) of the expansion tool (24).
4. Device as claimed in any one of claims 1 to 3,
   characterised in that a surface (83) of each expansion roller (16 to 18) which comes into contact with the second edge region (68) is circular-cylindrical.
5. Device as claimed in any one of claims 1 to 3,
   characterised in that a surface (83) of each expansion roller (16 to 18) which comes into contact with the second edge region (68) is formed in the shape of a truncated cone widening towards the inner space (81) of the packaging container (40).
6. Device as claimed in any one of claims 1 to 3,
   characterised in that a surface (83) of each expansion roller (16 to 18) which comes into contact with the second edge region (68) comprises a peripheral profile (84).

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