EP2804706B1 - Method for producing a can with a ring pull top, and can with a ring pull top - Google Patents

Description

Background of the invention

The invention relates to a method for producing a metal can with a tear-open according to the preamble of claim 1. Furthermore, the invention relates to a can with a can body and a bottom and tear-open according to the preamble of claim. 6

State of the art

It is known to carry out lid for can or can-like container as on the container top permanently attached tear-open, which form a discharge opening, which is closed by a tear-off film until the first use of the packaging content. This can e.g. a metal foil or composite foil. The film is applied to a Aufreissdeckelring made of metal by heat seal and tear-open film and cover ring together form the tear-open. The container body and the lid are connected together, in particular by a rabbet joint. An additional, arranged on the container over the tear-open lid made of plastic makes the container during the period of use of their contents again closed.

In the production of containers or cans with tear-open lids, it may be desirable for a storage space to be formed between the tear-open lid and a reclosable lid in which eg a dosing spoon or other object can be accommodated. This has so far been solved with a can on the market so that the jacket of the can body bent over and deep-drawn to the ground and directly forms the removal opening. On this formed by the can body, deep-drawn edge a tear-open film is sealed. This requires special sealing tools and is not optimal from the material combination can body / sealing film. DE 44 16 161 A1 wants to improve the stackability of cans with tear-open lids, which tear-open lid have a circumferential line of weakness. It is proposed to create a protuberance extending along the container end of the shell, which forms a support surface for the cans stacked above, so that the line of weakness of the respective tear-open lid is not loaded. GB 2 369 342 A shows a tear-off lid, which is formed of three parts (rim member, loopshaped member and cover panel). EP 2 062 828 A1 shows a Aufreissdeckel consists of a cover ring and a tear-open. Such tear-open lids are also in EP 1 559 655 A1 and WO 2009/065234 A1 shown.

Presentation of the invention

It is an object of the present invention to provide an improved manufacturing method for cans with tear-open lid and storage space.

This object is achieved in the aforementioned method with the features of claim 1.

The method according to the invention has the great advantage that a conventionally formed tear-open lid which has been produced on a production line for tear-open lids and whose seal or tightness of the seal can be easily controlled and tested there is used. According to the present method, such a tear-open lid can also be used for the formation of a can with a storage space, so that such a can can be produced easily and with a very good reproducible seal of the sealed joint. Next is according to the invention, a second cover by means of an outside on the can body circumferential bead and provided on the cover circumferential formation, which can engage in the bead, releasably and reattachably arranged on the container.

Preferably, the tear-open lid is fastened to the upper edge of the can body by means of a folded connection, which results in a known connection between can body and tear-open lid that is easy to control during manufacture.

Preferably, the upper edge is produced by a known as rolling up processing of the can body. Further, it is preferred that the tear-open lid is offset by deep drawing the transition area by a multiple of the Aufreissdeckelhöhe towards the bottom of the container or the lower end of the can body, in particular offset by 20 millimeters to 30 millimeters in this direction. This can be easily created a sufficiently large storage space.

The method is particularly suitable for the formation of three-piece cans, in which the bottom of the can is a separate part, which is also connected to the can body, in particular also by a rabbet joint.

The invention is further based on the object to provide a can with Aufreissdeckel and storage space, which is easy to manufacture and in which the tightness of the tear-open is guaranteed.

This is achieved with the can having the features of claim 6.

In such a can a Aufreissdeckel is provided, which is formed by a Aufreissdeckelring with a Aufgesissiegel aufgesiegelten. This results in the advantages that result from separately forming such a tear-open lid on a specialized tear-line production line, in particular the well reproducible and testable tightness of the sealed joint. The box comprises a second lid, which is arranged on the container by means of a bead arranged circumferentially on the outside of the can body and a circumferential formation provided on the lid, which engages in the bead, being releasably and re-attachable.

Brief description of the drawings

• Figur 1 eine perspektivische Ansicht einer herkömmlichen Dose mit einem Aufreissdeckel aber ohne Aufbewahrungsraum;
• Figuren 2 bis 8 verschiedene Stadien der Herstellung von Aufreissdeckeln nach Stand der Technik;
• Figur 9 eine Ansicht des Aufreissdeckelrandes;
• Figur 10 eine Ansicht einer bekannten Falzverbindung zwischen Aufreissdeckel und dem Dosenrumpf;
• Figuren 11 bis 17 Herstellungsschritte einer Dose gemäss einer Ausführungsform der Erfindung zur Erläuterung des Verfahrens, wobei jede Figur eine Seitenansicht eines Dosenteils bzw. der Dose, eine Draufsicht von oben, eine Schnittansicht und ein Detail zeigt;
• Figuren 18 bis 24 jeweils eine schaubildliche Ansicht und eine schaubildliche Detailansicht entsprechend den Figuren 11 bis 17;
• Figur 25 eine Schnittansicht des Dosenrumpfs mit Aufreissdeckel während des Tiefziehvorgangs; und Figur 26 eine Detailansicht von Figur 25.

Further advantageous embodiments of the invention will become apparent from the embodiments illustrated below with reference to the drawings. Show it:

• FIG. 1 a perspective view of a conventional box with a Aufreissdeckel but without storage space;
• FIGS. 2 to 8 various stages of manufacturing prior art tear-open lids;
• FIG. 9 a view of the Aufreissdeckelrandes;
• FIG. 10 a view of a known hinge connection between tear-open and the can body;
• FIGS. 11 to 17 Manufacturing steps of a can according to an embodiment of the invention for explaining the method, wherein each figure shows a side view of a can part, a top view, a sectional view and a detail;
• FIGS. 18 to 24 in each case a perspective view and a diagrammatic detail view according to the FIGS. 11 to 17 ;
• FIG. 25 a sectional view of the can body with tear-open during the thermoforming process; and FIG. 26 a detailed view of FIG. 25 ,

Ways to carry out the invention

The size relationships contained in the figures are to be interpreted as purely exemplary and not restrictive. In the figures, like reference numerals designate structurally the same or functionally equivalent components. The geometry of the can and thus of the tear-open lid and any second lid is not limited to round packaging bodies or cans; oval, rectangular or other shapes are also possible. In the present case, such forms should always be included in the term can, tear-open lid and tear-open lid ring. The term tear-open ring designates an annular metal carrier for a sealing film. The can body is also made of metal.

The FIGS. 1 to 8 show a known box with a Aufreissdeckel or show tear-open and serve to illustrate manufacturing steps in the production of known tear-open. The present invention uses a tear-open lid previously made in this or a similar manner, and therefore its manufacture is explained here for the sake of completeness. However, this method of preparation is not intended to be limiting for the present invention. This only assumes that a tear-open lid with a tear-open lid ring and a tear-open foil sealed on it is available.
Devices for the production of metal lids with tear-open film generally have on a machine frame a plurality of linearly or rotationally arranged processing stations and a conveyor, which conveys the lid parts or lids from the beginning of the device where preformed lid parts enter the device until the end of the device where the finished tear-open lids pass through slides in shelves. FIG. 2 shows stacked metal lid blanks 20 "as an example of lid parts." For example, these blanks 20 "are round metal discs of, for example, 11 cm in diameter. As mentioned, other basic shapes, such as square, oval or rectangular Slices and other diameters readily possible. The blanks 20 "have already been preformed in a known manner in a processing machine, not shown, at its edge, as described later by hand FIG. 9 is explained in more detail. This edge shaping is suitable for a rabbet connection of tear-open lid and container body or can body, which is also the preferred connection for the present invention. In FIG. 2 and the following ones FIGS. 3 to 8 In each case only one sector of the entire disk is shown to simplify the drawing. In a first processing station, an opening 26 is punched into the disc by punching with upper and lower tool, which in FIG. 3 it can be seen in which the edge of the opening is denoted by 21 and the punched round disc with 27. Thus, a cover ring 20 is formed. At a next processing station pulling the edge 21 takes place downwards, whereby the in FIG. 4 shown course 22 of the edge is achieved. The cover rings 20 now reach a further processing station in which a film 25 is placed over the opening 26 of the cover ring 20 and fixed there by heat sealing, which in the FIGS. 5 and 6 is apparent. The metal foil or composite film 25 is provided in a known manner on its underside with a plastic layer. The required film blank 25 is usually punched out of a wide film web and placed over the central recess or lid opening of the annular disc and the film is pressed by heat sealing at the edge of the circular recess of the ring 20 under heat, so that the film 25th is sealed to the cover ring 20 by melting and subsequent cooling of the plastic layer. Thus, a tear-open lid 20 'is formed, which comprises a tear-open lid ring and a tear-open foil. At most, a cooling processing station can be provided for cooling. In another processing station For example, the film 25 can be provided with a stamping 24 (FIG. 7) and the edge 22 is further crimped to the finished edge 23. Different crimping forms can be provided. Other measures to protect the cutting edge may be provided. The explained production of tear-open lids 20 'is known to the person skilled in the art and need not be explained further here.

FIG. 1 shows for further explanation of the prior art as an example a known three-piece box 1 with a cylindrical can body 4 in this example and with a Aufreissdeckel 2, the lid opening is closed by the tear film 25, and in particular a tear-open, as previously on hand of the FIGS. 2 to 8 has been explained. This film 25 is provided with a tab 28 for tearing the film from the lid ring. The box 1 also has a bottom cover or bottom 5, which can be designed in particular as a metal floor attached to the hull by means of a fold. About the Aufreissdeckel, as mentioned previously in the prior art, a - not shown here - further lid may be present. The attachment of the tear-open lid 2 on the container or the can can take place in any known manner in the context of the present invention. This also applies to the attachment of the bottom 5. However, it is preferred in the present invention that a known rabbet connection of tear-open and can body or bottom and can body is used. The FIGS. 9 and 10 serve here to explain a known seam connection, as it can also be used in the present invention. FIG. 9 shows the formation of the can side Aufreissdeckelrandes for the rabbet joint, and FIG. 10 shows a corresponding detailed view of a rabbet connection of tear-open and can body 4, as is known in the art.

In FIG. 9 is only a part of the tear-open 2 in cross-section visible. This embodiment the lid points, as in the Figures 2-8 , a folding edge 30 (seaming panel), which is on the cover outside with a curl 31 (curl) is provided. On the inside, a sealing compound 8 is preferably provided on the seam edge. To the removal opening with the tear-open film, not shown, the cover 2 has a seaming radius 32 (seaming panel radius), with which the seam edge in the lid core wall 34 (chuck wall) merges, which core wall of the core depth radius 33 follows (chuck wall radius). The radii mentioned with the lid core wall give the lid core depth d (countersink depth). If we speak below of the "height" of the tear-open lid, then this measure d is meant. If such a cover 2 is connected to the can body 4, which is provided with a flange on the end face, the seam connection 16 results according to FIG FIG. 10 , The seam connection is made in a manner known to those skilled in the art by a Verschliesskopf engages the Aufreissdeckel and the outside of successive tools with different roles make the fold. This can be done in the present invention in this known manner. The finished compound according to FIG. 10 in which the same reference numerals as in FIG. 9 denote like elements, takes place in that a folded body hook 37 (body hook) with the lid hook 38 (endhook) is engaged. This results in a stable connection between the tear-open lid 2 and the fuselage 4, wherein the lid-core wall 34, as shown, can rest against the fuselage inner side 7. The mentioned sealant 8 (lining compound) seals the seam connection. Such a folding joint known to the person skilled in the art, or else a similar seaming connection known to the person skilled in the art, is in the context of the present invention the preferred connection between the tear-open lid and the can body and also the bottom and can body of the three-piece can. In this case, however, the upper edge of the can body is reduced in diameter, such as before attachment of the Aufreisseckels this will be explained below, but this has no effect on the design of the hinge connection as such.

The FIGS. 11 to 17 and 18 to 24 now show an embodiment of the present invention. FIG. 11 shows the can body 4 of the box, wherein in the drawing above a side view, including a view from above with a cut line (here section line AA), below the corresponding section and below a detail (here detail H) is shown. This representation is also with the others FIGS. 12 to 17 selected. The FIGS. 18 to 24 respectively show a perspective view of the can body 4 and the can respectively. The can body has been formed in a known manner as is the prior art in can making and need not be discussed further here.

FIG. 12 shows a preferred embodiment in which the can body has been rolled at its lower end 5 ', so that the outwardly curved shape of the lower end 5' of the can body 4 results, which gives the can body increased stability. It can be seen the sectional view along the section line BB and the detail I of the outwardly bent end 5 'of the can body 4. The bottom cover 5 of the container, as known, only later after filling the container or the box with its content Filler applied. Preferably, the attachment of the bottom cover 5 by means of a folding connection, for example, a folding connection according to FIG. 10 or a similar folded seam connection. The bottom is a (here round) metal lid. In FIG. 19 is the corresponding perspective view of the can body with the rolled end shown.

FIG. 13 shows a first step that distinguishes the present invention from the prior art. The upper portion of the can body is reshaped, so that an upper edge 7 of the can body 4 results with the end face 3, whose diameter is smaller than the inner diameter of the undeformed can body. This results in a transition region 6 between the undeformed can body 4 and the edge 7. This is well visible in the side view and in the sectional view (section line CC) and in detail K and in the perspective view of FIG. 20 , The deformation or retraction of the upper edge 7 can by rolling in with a in FIG. 13 be done by 30 schematically illustrated curling. Such tools are known to the person skilled in the art.

FIG. 14 shows that a flare has been formed at the upper edge 7 in a manner known to those skilled in the art. The hemming serves for the subsequent folding connection between a tear-open lid and the can body. This results in the folding of the hull hook 37 (body hook), see FIG. 10 , FIG. 21 shows the flanging as a perspective view.

FIG. 15 shows that the Aufreissdeckel 2 has been attached to the can body 4. This is done here with a rabbet joint, which is preferred, and it can be to explain a rabbet on FIG. 10 and the associated description. In the present invention find the known tools application. Such a tool for the hinge connection is shown schematically at 31. Of course, the diameter of the tear-open lid is selected according to the reduced diameter of the upper edge of the can body 4 and thus smaller than the diameter of the bottom lid 5 of the finished container. This is also from the perspective view of FIG. 22 clearly visible.

FIG. 16 shows the state as it results after the further forming step, in which the transition region 6 has been transformed such that the tear-open lid 2 has been offset against the lower end 5 'of the can body 4. This is done by a specialist known deep drawing. In the Figures 25 and 26 are the annular Tiefziehwerke used for this purpose shown, which by a drive, not shown, of the tool against each other movable (and for Enformen again moved apart) are to move the Aufreissdeckel downwards. With the thermoforming tool, the transition region 6 is reshaped, so that he in FIG. 16 and particularly in detail N assumes the same shape as illustrated and thus forms a storage space 10 which is formed on its underside by the tear-open lid 2 and which is delimited laterally by the deformed part of the transitional area 6 and thus directly by the can body 4. The upper limit of the box is denoted by 13 and is formed at these doses according to the invention of the can body 4 itself and not as in conventional cans from the tear-open, as in the conventional box 1 according to the FIGS. 1 and 10 shown. In the storage space 10, for example, a dosing spoon can be arranged or another object. FIG. 23 shows the box with the storage space diagrammatically. The degree of deformation by deep drawing depends on the one hand on the desired size or depth of the storage space and on the other hand by the deep drawing ability of the transition region. A displacement of the tear-open lid by several times the height of the tear-open lid (or the dimension d of FIG. 9 ) can be achieved and according to the invention, the Aufreissdeckel is offset during deep drawing by 20mm to 30mm downwards.

The resealability of the can after it has been opened by tearing open the tear-open lid is achieved according to the invention so that a second lid 14 made of plastic is provided, as shown in FIG FIG. 17 or in FIG. 24 is shown. The second cover is attached to the can 4 such that a bead 15 is formed or rolled in the can body so that an annular formation 17 on the cover 14 can engage in the bead. This gives a secure hold of the second lid 14.

The Figures 25 and 26 show the completion of the step of deep drawing of the transition region 6 and thus the completion of moving the already attached to the can body tearing cover down to the open end of the can body. The deep-drawing step is carried out with corresponding positive and negative works, which are movable relative to each other via a drive (not shown). The drive can in particular be electromotive or pneumatic or hydraulic. In the Figures 25 and 26 is the lower tool 8 can be seen, which is inserted from below into the can body and the upper tool which engages from the outside to the can body. The detail view of FIG. 26 shows how the transition region 6 has been deformed, wherein the previously attached to the upper edge of the can body tearing cover has been offset down.

Claims (9)

1. Method for the manufacture of a metal can having a tear-open lid (2) wherein

   - a top edge (7) of the can body (4) is formed, the diameter of which is less than the inside diameter of the can body, wherein a transition region (6) is formed between the can body and the top edge, characterized in that

   - a previously formed tear-open lid (2) with a metal tear-open lid ring (20) and a tear-open foil (25) which is sealed on the tear-open lid ring is attached to the top edge (7), in that

   - the transition region (6) is reformed in such a way that the tear-open lid is displaced in the direction of the bottom end of the can body (5') in order to create a storage space for an object, which storage space is arranged above the tear-open lid and is laterally bounded above the tear-open lid by the can body (4) and in that

   - after reforming the transition region (6) an object is placed into the storage space (10), and

   - a second lid (14) is arranged on the container in a releasable and re-attachable manner by means of a circumferential bead (15) running externally around the can body and a circumferential molding (17) provided on the lid which can engage in the bead.
2. Method according to claim 1, characterized in that the tear-open lid (2) is attached to the top edge by means of a folded joint (16).
3. Method according to claim 1 or 2, characterized in that the tear-open lid is displaced towards the bottom end of the can body by approx. 20 mm to 30 mm by the reforming operation.
4. Method according to claim 1 to 3, characterized in that before the step of forming the top edge (7) the can body (4) is curled at its bottom end so that a shape bent to the outside is formed at the bottom end (5').
5. Method according to claim 1, characterized in that the can body is closed by a bottom lid (5) which is attached to the can body by a folding joint after the can body has been filled with a substance.
6. Can having a can body (4) as well as a bottom (5) and a tear-open lid (2), wherein the tear-open lid is formed by a tear-open lid ring (20) with a tear-open foil (25) attached thereto such that it can be torn off, wherein the tear-open lid is offset with respect to the top boundary (13) of the can towards the bottom of the can, thus forming a storage space (10) between the tear-open lid (2) and the top boundary (13) of the can, characterized in that the storage space (10) is laterally confined by the can body (4) and that the upper edge (13) of the can is formed by the can body (4) and in that the can comprises a second lid (14) which is arranged on the container in a releasable and re-attachable manner by means of a bead (15) arranged circumferentially on the outside of the can body and a circumferential molding provided on the lid which engages in the bead.
7. Can according to claim 6, characterized in that the tear-open lid is attached to the can body by means of a folded joint (16).
8. Can according to claim 6 or 7, characterized in that the tear-open lid is displaced with respect to the top boundary of the container towards the bottom of the container by approx. 20 mm to 30 mm.
9. Can according to one of the claims 6 to 8, characterized in that the can is formed as a three-part can with a separate bottom (5) attached to the can body (4).

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