EP0162119B1 - Apparatus for making a container from a flat blank - Google Patents

Description

The invention relates to a device for producing a container, preferably a filled container, from a flat blank of in particular semi-rigid material, e.g. B. laminated cardboard, the container having opposite, convexly curved side walls and a concave curved end wall, the device having at least one deforming station for forming a blank for the container with the end wall and folded edges at the transition area, a sealing or welding station for connecting the container edges and optionally has further processing stations for filling, closing and the like, the deforming station for forming the blank to the container with end wall and folding edges in the transition area, a sealing or welding station for connecting the container edges and optionally further processing stations for filling, closing and the like , wherein the deforming station is arranged coaxially and has at least one form stamp, a fixed die with an inner cavity designed according to the container cross section and a bottom stamp fitting into this inner cavity, and the form stamp and the Bottom stamps have facing and corresponding end faces corresponding to the outline and the shape of the end wall or the container bottom.

Such a device is known from BE-A-538 056. The die entering the die from above forces the initially flat blank deep into the opening of the die to first form the side surfaces of the container, after which the counter-punch is inserted from below into the inner cavity or die opening and then inside the die Matrix to press the bottom between the form stamp and the bottom stamp and give it its final shape. The same two stamps then bring the edges of the container between sealing wheels, which continuously weld these edges over their entire length. After the packaging has been sealed and removed from the die, the base stamp can return to its original position. This method of working with the previously known device, in which the side walls and then the end face or the bottom of the container are formed one behind the other, is unfavorable if the bottom and the side walls of the container have to be formed at the same time along certain distinct edges in order to form the resulting container to give sufficient stability. It is also disadvantageous that in the previously known device a work cycle is only completed when the edges have been sealed to one another because the base stamp cannot return to the area of the die beforehand. This results in a comparatively slow processing and production of the containers, since a corresponding amount of time is required both for the deformation and for the subsequent sealing. Thus, the manufacturing cycle with this previously known device is comparatively long, which does not meet today's production speed requirements.

Because of the above-mentioned method of operation, this known device has a die, the internal cavity of which corresponds in cross section to that of the container to be produced. However, the edges of the mouth of this inner cavity or opening at the entrance of the blank are rounded from the outside inwards due to the above-mentioned method of having to force this blank into this mouth and thereby raise the side walls, in order to impress the blank into the inner cavity of the To facilitate die. It is not possible to fold the blank exclusively along certain lines defined before folding, but the deformation takes place only approximately in the intended areas.

Only when the base die is pressed against the blank that has already been inserted into the die through the top die, whereby the blank is preformed, however, along undefined edges, are the actually intended edges formed. However, previously formed edges and folds can no longer be removed. There is therefore the danger with this previously known device and its mode of operation that the area which is important for the stabilization of the container at the transition from the side walls to the end wall or the like is weakened by the like.

Another disadvantage of this previously known device is the fact that the side edges of the packaging to be produced are not guided laterally, which can lead to a transverse displacement of the edges lying one on top of the other even after sealing. Such a side shift then requires a trimming of these side edges in a complex manner. In addition, the cut residues must then be removed. However, a specific lateral guidance would be of no use in this device, since the cut is held from the beginning by the form stamp and the base stamp and can then practically no longer be moved or centered in a slightly wrong position.

The invention is therefore based on the object of creating a device of the type mentioned at the outset, with which deformations are only made there during the manufacture of the container, which later also form folded or folded edges in the finished container. The device should be high Enable production speed and allow configurations in which a subsequent trimming, in particular of the connecting edges of the side walls, can be avoided.

To solve this problem, the device of the type mentioned is characterized in that the boundary edges of the die and the bottom die and the opening edge of the die cavity have the same shape and the same course and all three are formed as shaping edges that the bottom die for forming the The end wall and the folded edges with its boundary or end edge can be displaced approximately to the same opening edge of the inner cavity of the die facing the die and that at least some areas along the opening edge are provided for the side surfaces of the blank.

For both-sided detection of the initially flat blank, the form stamp and the base stamp are used, the base stamp being arranged in this phase relative to the fixed die in such a way that the boundary edges of the base stamp are also arranged at its sharp-edged mouth.

If at this point the flat blank is grasped and pressed with the help of the die, the end wall of the container is also formed with its curvature at a defined point with correspondingly sharp edges before it enters the inner cavity of the die, advantageously by means of in the area of the opening edge, the side walls already stand up before pulling the blank into the inner cavity of the die. This avoids that when this preformed intermediate product of the container is later drawn in, undefined kinks or folds can still occur at this important transition region between the end wall and the side walls. Rather, the end wall, which is important for the dimensional stability of the later container, is already largely finished when the blank is gripped and first pressed.

It is particularly expedient for the device according to the invention if the end face of the base stamp has a convex curvature and the die has a support side with a V-shaped incision to form the side supports, and if the curvature increases and decreases in the longitudinal direction of the incision. This takes into account the shaping of the spatial folded edges at the transition from a concavely curved end wall to convexly curved side walls. At the same time, this V-shaped design of the incision on the end face of the die with the base stamp bulging in this incision ensures that the surfaces of the V-shaped incision located next to the base stamp serve as side systems when embossing the end wall for automatically raising the side walls of the container.

It is preferred if the form stamp, the bottom stamp and the inner cavity of the die have an approximately lenticular cross-section, preferably with pointed ends corresponding to that of the container to be produced, and if the boundary lines of the die front sides and the die cavity edge are at an acute angle at the base of the V-shaped Make a cut.

The boundary surfaces of the V-shaped incision of the die can enclose an angle of 90 ° for the production of containers with parallel - albeit curved - side walls. The end faces of the stamp can each be formed by the jacket section of a cylinder. The V-shaped incision of the die gives the desired lens shape when viewed in the projection direction.

It has been shown that problem-free embossing and shaping of the concave end wall and the convex side walls and in particular the sharp folding edge provided at the transition, which leads to a stable and rigid container, the curvature radius of the concave support side of the die, the radius of curvature of the convex support side of the Ground stamp and the curvatures of the side surfaces of the stamp can be chosen the same. In practice, it then turns out that the inner walls of the inner cavity of the die are formed by the penetrating part of the lateral surfaces of two parallel, intersecting cylinders of the same diameter and that the plunger support sides which form an end face of the container form a partial region of a lateral surface of a further cylinder of the same diameter , whose central axis intersects that of the two parallel cylinders at right angles. The end wall region of the container and in particular the sharp folding edges provided there are thus defined by three simple geometric bodies of the same size which penetrate each other in the manner described above. This not only facilitates the manufacture of the container itself and results in favorable and natural lines, but also facilitates the manufacture of the corresponding molding tools.

An embodiment of the invention provides that a transfer device with at least one transfer block or the like holder for a container, which is displaceable transversely to the connecting axis of the stamp, is provided for transporting the at least preformed container from one processing station to the next, and that the transfer block or transfer blocks are arranged with their transverse transport plane between the die and the counter punch located in the extended position This arrangement enables a particularly simple transfer of the container from a processing station to the transfer device and thus also to a next station. It is also particularly advantageous that the counter-punch can engage in the die through the transfer blocks.

It is particularly advantageous and expedient if the device according to the invention is characterized as a further development in that the counter-punch can be moved axially through the transport holder and further through the inner cavity of the fixed die with its edges to approximately in accordance with the mouth edges of the die, if only at this position of the base stamp, the form stamp in the same axial direction of movement, but in the opposite direction, that is to say can be moved in the direction of the base stamp and pressed against it - so that an initially flat blank in between is shaped in the manner described above - if the shape stamp is then in its direction of movement can be moved further and, at the same time, the base stamp with the blank clamped between the two stamps can be moved back into the transport holder and when the shaped stamp can then be retracted into its initial position, so that the transport holder with the deformed blank is free is to move crosswise to the axis or direction of movement of the stamps in order to gradually bring the blank to further work stations. The aforementioned assignments of movements and directions of movement can be carried out with conventional control means in the desired order at high speed. Here, the transport holder can gradually move to other workstations after receiving the shaped blank. B. for welding the edges, filling, sealing, emptying or the like. Can be supplied and then reset in the forming station between the die and the movable base stamp, so that the base stamp then again in the aforementioned manner through the transport holder up to the top the die can be moved. This results in a device that is easy to manufacture from the design principle, but which can nevertheless emboss and shape the desired container in a sensible manner without pre-kinking or folding at defined folding edges, and nevertheless rapid movements can be carried out exactly. This enables a high production speed to be achieved.

• Fig. 1 eine Draufsicht eines flachen Zuschnittes mit eingezeichneten Knick- bzw. Faltkanten,
• Fig. 2 eine Seitenansicht eines fertigen, geschlossenen Behälters,
• Fig. 3 eine gegenüber Fig. 2 um 90 gedrehte Seitenansicht des Behälters,
• Fig. 4 eine schematische Darstellung einer Vorrichtung zum Herstellen eines Behälters insbesondere nach Fig. 1 bis 3,
• Fig. 5
• bis 9 Seitenansichten einer Verformstation in unterschiedlichen Arbeitsstellungen,
• Fig. 10 eine perspektivische Seitenansicht der wesentlichen Teile einer Verformstation in Offenstellung sowie mit einem Transferblock einer Transfereinrichtung,
• Fig. 11
• bis 13 geometrische Darstellungen der Formgebung eines Behälters mittels dreier Zylinderabschnitte und
• Fig. 14 eine Aufsicht bzw. Querschnittsdarstellung einer Versiegelungs- bzw. Schweißstation.

Additional embodiments of the invention are listed in the further subclaims. The invention with its essential details is explained in more detail below with reference to the drawing. It shows partly schematically:

• 1 is a plan view of a flat blank with crease or fold edges shown,
• 2 is a side view of a finished, closed container,
• 3 shows a side view of the container rotated by 90 relative to FIG. 2,
• 4 shows a schematic representation of a device for producing a container, in particular according to FIGS. 1 to 3,
• Fig. 5
• up to 9 side views of a forming station in different working positions,
• 10 is a perspective side view of the essential parts of a deformation station in the open position and with a transfer block of a transfer device,
• Fig. 11
• to 13 geometric representations of the shape of a container by means of three cylinder sections and
• 14 is a top view or cross-sectional view of a sealing or welding station.

A container 31 forming a package (FIGS. 2 and 3) is formed from a blank 100 (FIG. 1). This initially flat cut is divided into different areas, which are outlined for clarity. The blank 100 essentially has a central area approximately centrally, which in a flat projection is essentially formed by two circular sections placed with their straight sides and which later represents the end wall 6. This middle surface 6 is delimited by lines 1 and 2. The later side faces 8 and 9 adjoin the outside. The edge that later forms the connection area of the container is designated 52. The finished container according to FIGS. 2 and 3 then has convexly curved side surfaces 8 and 9 and an inwardly, ie concavely curved end surface or end wall 6. The end regions of the arched, central end wall or end face 6 adjoining the edges 52 are denoted by 3 and 4. The transition areas between the side surfaces 8 and 9 and the flange-like edges 52 form welding edges and are designated by 10, 11 and 12.

FIG. 4 shows, in a highly schematic manner, an apparatus for manufacturing a container 31, designated 101 as a whole. The apparatus 101 essentially has a deformation station 70, a sealing or welding station 71, a filling station 72 and a station 73 for closing the container 31.

• Von einem Stapel von Zuschnitten 100, gegebenenfalls aber auch von einer Rolle werden beispielsweise mittels eines Vakuum-Einsaugsystemes 14 einzelne Zuschnitte 100 entnommen. Diese Zuschnitte 100 werden dann einzeln über eine Transporteinrichtung 16 mit wegschwenkbaren Anschlägen 17 zu der Verformstation 70 transportiert. Diese Verformstation 70 ist besonders gut in Fig. 10 und auch in den Figuren 5 bis 9 erkennbar. Sie weist im wesentlichen in koaxialer Anordnung einen Formstempel 21 sowie einen Gegenstempel auf, der aus einer festen Matrize 19 und einem relativ zu dieser bewegbaren Bodenstempel 22 besteht. Unterhalb der Matrize 19 ist noch eine im ganzen mit 50 bezeichnete Transfereinrichtung zum Transportieren der vorgeformten Behälter 31 von einer Bearbeitungsstation zu einer nächsten vorgesehen. Die Transfereinrichtung weist nebeneinander gereihte Transferblöcke bzw. Transporthalter 20 auf, die eine Innenhöhlung zur Aufnahme von Behältern 31 haben.

A packaging container 31 is produced as follows:

• Individual blanks 100 are removed from a stack of blanks 100, but possibly also from a roll, for example by means of a vacuum suction system 14. These blanks 100 are then transported individually to the forming station 70 via a transport device 16 with stops 17 which can be pivoted away. This deformation station 70 can be seen particularly well in FIG. 10 and also in FIGS. 5 to 9. It has, essentially in a coaxial arrangement, a form stamp 21 and a counter-stamp which consists of a fixed die 19 and a bottom stamp 22 which is movable relative to the latter. Below the die 19 there is also a transfer device, generally designated 50, for transporting the preformed containers 31 from one processing station to the next. The transfer device has transfer blocks or transport brackets 20 which are arranged next to one another and have an internal cavity for receiving containers 31.

10 that the form stamp 21, the bottom stamp 22 and the inner cavity 46 of the die 19 have an approximately lenticular cross section corresponding to that of the container 31 to be produced. At the entry opening of this inner cavity 46 for the die 21, the die has a V-shaped incision 44. Corresponding to the shape of the curved central surface (FIG. 1) or the end face 6 (FIGS. 2 and 3) of the container 31, the support side 54 of the molding die 21 has a concave curvature, while the counter-die 22 has a convex support side 56. With this design, the support sides of the punches could lie directly against one another and press-fit an intermediate blank.

The arrangement and depth of the V-shaped notch 44 in the upper side of the die is now matched to the curvature of the end wall 6 of the container 31 in such a way that the transition points designated 3 and 4 are in each case at the outer end of the end face 6 in the base of the V-shaped notch 44 come to rest. At these points, the inner cavity 46 has channel-shaped longitudinal slots 47 for receiving the flange-like edges 52 of the container 31. Furthermore, it is provided that the frontal boundary edges or edges 57, 58 of the punches 21 and 22 as well as the edge 59 of the inner cavity 44 facing the forming die 21 have contours which are approximately the same shape and are adapted to the intended curvature of the one end face 6 of the container. When the counter punch 22 is in the up position (FIGS. 4 to 7), a support side corresponding to the shape of a container end face 6 is thus formed. In this position, the edges 58 of the base stamp 22 and the opening edges 59 of the die 19 lie together.

Especially in Figures 10 to 13 it is clear that both the front boundary edges or edges 57 and 58 of the punch 21 and 22 and the opening edges 59 of the female cavity 46 all have the same shape and the same course and all three as shaping Edges are formed

In a further manufacturing process, a blank 100 is guided onto the upper side of the die 19, the bottom punch 22 being in the up position and forming the counter punch with the die 19 and its V-shaped incision 44. The further course of the shaping of the blank 100 or of the container 31 can then be clearly seen in FIGS. 6 to 9. After the blank 100 has been positioned, the die 21 moves down and presses the blank 100 in the area of the central surface 6 against the counter-stamp and in particular against the end face 56 of the floor stamp 22 which is in the up position. The central surface 6 is shaped according to the stamp curvature and simultaneously the side surfaces 8 and 9, supported by the V-shaped incision 44 acting as side supports, are also folded upwards. The folding takes place exactly along the lines 1 and 2 provided (cf. FIG. 1). The punches 21, 22 then move downward and pull the blank 100 held in the region of the end face 6 into the die 19. As a result, the side surfaces 8 and 9 are guided further to one another. In the further course of the downward movement of the stamp, the shaped blank 31 is inserted into the transfer block 20, which is positioned in alignment with the die 19, or into its receiving cavity (cf. FIG. 8). A stop 45 then moves in front of a part of the upper side of the container 31 in order to prevent the container 31 from being pulled out of the transfer block 20 when the molding die is pulled out. After both stamps 21, 22 (FIG. 9) have been withdrawn, the preformed container 31 is in the transfer block 20 and the stamps are in the withdrawn position. In this position, the transfer device 50 can continue with the transfer blocks 20 according to the arrow Pf 1 to a next processing station.

From this description it follows that the bottom stamp 22 can be moved axially through the transfer block or transport holder 20 and further through the inner cavity 46 of the die 19 with its front edges 58 to approximately in accordance with the mouth edges 59 of the die, that approximately at this position of the bottom stamp 22 of the shaping stamp 21 in the same axial direction of movement, but in the opposite direction, that is to say in the direction of the bottom stamp 22, is movable and can be pressed against it, a blank 100 located and precisely aligned at this point then being gripped and shaped accordingly on both sides, after which the form stamp 21 can be moved further in its direction of movement and thus at the same time the base stamp 22 with the clamped between the two stamps Blank 100 is adjustable back into the transport holder 20 and that the shaping stamp 21 can then be retracted into its initial position and the bottom stamp can also be moved out of the area of the transport holder 20 to such an extent that the transport holder 20 with the deformed blank 31 is free, transverse to the axis or to move the stamp in order to gradually bring the blank to other workstations. The transport holder 20 is thus after receiving the shaped blank 31 step by step to other workstations, for. B. for welding the wheels, filling, closure, etc., and then resettable in the forming station between the die 19 and the movable base stamp, after which it is available for the next cycle.

Due to the above-mentioned shaping, semi-rigid material can also be used, e.g. B. from laminated cardboard, which is not deformable or stretchable, can be folded without stretching or pressure occurring, which could lead to tearing of the material or incorrect folding, can occur. The folded edges can be chamfered to prevent the blank from being damaged by sharp edges during molding.

The transfer device 50 transports the transfer blocks 20 step by step and the shaped blank is brought to a sealing or welding station 71 after the molding. An upper and a lower punch 27 or 28 (FIG. 4) can then press the container 31 out of the transfer block 20 in order to insert it into the actual sealing station 71 (cf. also FIG. 14). Movable clamping jaws 30 are provided here for sealing the two opposite sides 10 and 11. The container 31, which is laterally welded longitudinally, is then brought back into the transfer block 20 and then transported on to a filling station 72. Here, the container can be raised by a pusher 34 for the filling process and later brought down again by another pusher 35. In a further station 73, the filled container 31 is then ejected downward by a pusher 38 and then lies against a stop 39 which can be pivoted away. After the container 31 has been closed by sealing tools 40 along the line 12, the container 31 is released and, for example, comes out of the area of the device via a slide 41.

The blank 100, which is located here above the die 19, is shown in dash-dot lines in FIG. 10. It should also be mentioned that the V-shaped incision 44 encloses an angle of approximately 90 ° with its side surfaces 43. When shaping and then pulling the blank into the die, the side edges of the blank are guided in the channel-shaped longitudinal slots 47. Guide grooves 51 provided in the transfer blocks 20 can be positioned in alignment with these longitudinal slots 47. These guide troughs are of greater importance because they keep the folded cut in the edge area. These guide troughs can have inlet slopes not shown here on the input side.

As already mentioned, the curvature edges 57, 59, 58 of the stamp or the die opening are shaped approximately the same. FIGS. 11 to 13 also show the geometrical relationships of the outer walls of the container 31. One can see two imaginary cylinders 62, 63 arranged in parallel, which have the same diameter and are arranged at a distance smaller than their diameter from one another. This results in a penetration, the interfaces of which are formed by sections of the cylinder jacket. These boundary surfaces 66 (FIG. 13) correspond to the side surfaces 8 and 9 of the container 31, which is still open on one side.

Furthermore, to form an end face 6 of the container 31 through a partial region of a lateral surface, a further cylinder 65 is provided, which is arranged at right angles to the other two cylinders 62, 63 and in their connecting plane. This cylinder also has a diameter corresponding to that of cylinders 62 and 63. As a result of these geometric relationships, the curvature radii of the concave bearing side 54 of the die 21, the curvature radius of the convex bearing side 56 of the counter-stamp 21 and the curvatures of the side surfaces 53 and 55 of the stamp are approximately the same as the side walls or the end wall of the container 31.

FIG. 14 also shows a horizontal cross section of a welding station 71 approximately corresponding to the cross section A-A in FIG. 4. Two segments 67 are provided against which the side surfaces 8 and 9 of the container 31 rest. Furthermore, guide stops 38 are provided, against which the edges of the opposite edges 52 rest and are guided. With 69 movable sealing jaws are referred to, which can be designed as heatable clamping jaws or, if necessary, can also be fed by ultrasound or high frequency, etc. These sealing jaws 69 engage through gaps left between the segments 67 and the guide stops 68. With this arrangement, the shaped blank can move or align as far to the side (arrow Pf 2), so that a continuously flush stop occurs at the guide stops 68. As a result, the longitudinal edges form a smooth finish after sealing, so that subsequent trimming is no longer necessary here.

It should also be mentioned that other processing stations can also be attached to the device, be it for cleaning, checking, or putting on an outlet part, a cap, a brochure, a floor or any other element. This can be done according to the respective requirements. The same applies to the attachment or arrangement of the stations so that they can be attached both above and below the transfer blocks with appropriate movement adjustment. The transfer device itself can consist of one or more transfer blocks or the like, which can either be implemented independently of one another or else in a coherent manner, for example as a turntable. The blanks themselves can be individually or stacked, connected to one another or used from a roll. In the latter two cases, devices are provided which can separate the blanks by tearing them off or cutting them off.

It should also be mentioned that the boundary edges of the support sides of the punches and the edge of the die cavity 46 facing the forming die may not be continuously curved or curved, as described above, but rather polygonal with straight sections, in particular in accordance with the shape of the container.

Claims (13)

1. An apparatus for making a container (31), preferably a filled container, from a flat blank (100), in particular one of semi-stiff material, e.g. laminated cardboard, the container having facing side walls (8, 9) of convex curvature and an end wall (6) of concave curvature, the apparatus (101) including at least one forming stage (70) for forming the blank (100) into the container (31) with an end wall (6) and folded edges in the transition region, a sealing or welding stage (71) for connecting the edges (52) of the container and possibly further processing stages (72, 73) for filling, closing and the like, the forming stage (70) including in coaxial arrangement at least one forming punch (21), a stationary matrix (19) having an interior cavity corresponding in configuration to the cross section of the container, as well as a base punch (22) fitting into said interior cavity (46), and the forming punch (21) as well as the base punch (22) having end sides (54, 56) which face one another and correspond to the outline and shape of the end wall or of the base (6) of the container, characterized in that the boundary edges (57, 58) of the forming punch (21) and of the base punch (22) and the edge (59) of the opening of the interior cavity (46) of the matrix have the same shape and the same contour and all three are configured as forming edges, that to form the end wall (6) and the folded edges the base punch (22) is adapted to be displaced with its boundary edge or end side edge (58) towards the edge (59) of the opening of the interior cavity (46) of the matrix, said edge (59) having the same contour and facing the forming punch (21), and that at least in areas along the edge (59) of the opening provision is made for contact surfaces (43) for the side faces (8, 9) of the blank (100).

2. The apparatus as claimed in claim 1, characterized in that the end side (56) of the base punch (22) has a convex curvature and the matrix (19) has a bearing side with a V-shaped notch (44) to form the contact surfaces (43), and that the curvature takes a rising and falling course in the longitudinal direction of the notch (44).

3. The apparatus as claimed in claim 2, characterized in that the boundary surfaces (43) of the V-shaped notch (44) of the matrix (19) form an angle of 90° to produce containers having parallel side walls.

4. The apparatus as claimed in any one of claims 1 to 3, characterized in that the end sides of the punches (21, 22) are in each case formed by segments of the peripheral surface of a cylinder.

5. The apparatus as claimed in any one of claims 1 to 4, characterized in that to transport the at least preformed container (31) from one processing stage to the next there is a transferring means (50) having at least one transfer block displaceable transversely to the axis joining the punches (21, 22) or a conveying holder for a container (31), and that the transfer block(s) (20) is/are disposed with its/their plane of cross transport between the matrix (19) and the base punch (22) in its withdrawn position.

6. The apparatus as claimed in any one of claims 2 to 5, characterized in that the forming punch (21), the base punch (22) and the interior cavity (46) of the matrix (19) have an approximately lentiform cross section, preferably with pointed ends, corresponding to that of the container (31) to be made and that the boundary lines of the end sides'(54, 56) of the punches and of the edge (59) of the matrix cavity meet at the base of the V-shaped notch (44) at an acute angle.

7. The apparatus as claimed in any one of claims 1 to 6, characterized in that the matrix cavity (46) has on its converging longitudinal sides in each case one channel-shaped longitudinal groove (47) for forming and receiving the flange-like edges (52) of the container (31) and that the base of the groove in each case forms a side stop for the edges (52).

8. The apparatus as claimed in any one of claims 1 to 7, characterized in that in a sealing or welding stage (71) there is a holder which corresponds approximately to the shape of the container (31) and has in the peripheral area where the contaner is to be joined slots or similar recesses for the engagement of sealing jaws (69) as well as side stops (68) against which the outer edges of the container flanges (52) to be joined rest.

9. The apparatus as claimed in any one of claims 1 to 8, characterized in that the radius of curvature of the concave bearing side (54) of the forming punch (21), the radius of curvature of the convex bearing side (56) of the base punch (22) and the curvature of the side faces (53 and 55) of the punches (21 and 22, respectively) are the same.

10. The apparatus as claimed in any one of claims 1 to 9, characterized in that the inside walls of the interior cavity (46) of the matrix (19) are formed by the penetrating part of the peripheral surfaces of two parallel intersecting cylinder (62, 63) of the same diameter and that the bearing sides (54, 56) serving to form an end side (6) of the container form a segment of a peripheral surface of a further cylinder (65) preferably of the same diameter, the centre axis of said cylinder intersecting those of the two parallel cylinders (62, 63) at right angles.

11. The apparatus as claimed in any one of the preceding claims, characterized in that the bearing sides of the punches have their boundary edges and the interior cavity (46) of the matrix has its edge facing the forming punch configured so as not to be of continuous curvature but to be polygonal with straight portions, in particular corresponding to the shape of the container.

12. The apparatus as claimed in any one of claims 5 to 11, characterized in that the base punch (22) is movable axially through the conveying holder (20) and further through the interior cavity (46) of the stationary matrix (19) until its edges (58) are approximately in correspondence with the edges (59) of the opening of the matrix (19) at the V-shaped notch (44) thereof, that not before the base punch (22) has reached approximately this position is the forming punch (21) movable in the same axial but opposite direction of motion towards the base punch (22) and can be urged against the latter and against an interposed blank (100), that then the forming punch (21) is movable further in its direction of motion and thereby the base punch (22) can be simultaneously returned into the conveying holder (20) together with the preformed blank clamped between the two punches, and that then the forming punch (21) can be retracted into its initial position and the base punch can be retracted from the region of the conveying holder (20) so that the conveying holder (20) together with the formed blank (31) is free to move transversely to the axis or direction of motion of the punches.

13. The apparatus as claimed in any one of claims 5 to 12, characterized in that after taking up the formed blank (31) the conveying holder (20) is adapted to be conducted stepwise to further working stages, e.g. for welding the edges, filling the container, closing, emptying or the like, and then again to be returned to the forming stage between the matrix (19) and the movable base punch (22).

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