COVER UNIT WITH ADAPTER, COVER, AND SEALING FILM FOR A CONTAINER

Abstract

The invention relates to a cover unit (10) for closing and sealing a container (1). The opening (9) is surrounded by a sealing edge (8). The cover unit has an adapter (11), a cover (12), and a sealing film (13). The adapter can be arranged on the container in the opening thereof or around said opening so as to leave the sealing edge exposed, and the adapter has a through-opening (22). The cover is removably arranged on the adapter. The sealing film is clamped between the cover and the adapter so as to cover the through-opening. The invention also relates to a container with such a cover unit and to a method for sealingly closing a container.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. national stage application under 35 U.S.C. §371 of International Application No. PCT/EP2013/051007, filed Jan. 21, 2013, which claims priority to German Patent Application No. 102012100483.8, filed Jan. 20, 2012, and German Patent Application No. 102012209597.7, filed Jun. 6, 2012, the entireties of which are incorporated herein by reference.

FIELD OF DISCLOSURE

The present invention relates to a cover unit for closing and sealing an opening, which is surrounded by a sealing edge, of a container such as a can, barrel or the like, to a container closed using a cover unit according to the invention and having an opening surrounded by a sealing edge, and to a method for sealingly closing a container of this type.

BACKGROUND

Containers are known from the art in which an end-face opening is closed and sealed using a membrane. On the container, in the opening thereof, a metal ring is generally attached to the outer container wall by means of a fold. The membrane is sealed onto the annular face of the metal ring facing the outside of the container. The seal is completed by a pull-on cover, which covers the upper container edge, the metal ring and the membrane. One problem with containers or sealing systems of this type is that during the manufacture of the metal ring a considerable proportion of the material used is wasted. So as to provide a suitably large container opening for filling with and for withdrawing a filling material after being opened, the metal ring has a correspondingly large clearance in the internal region thereof. The metal ring is produced by punching it out from a metal sheet, and so the sheet material punched out to form the internal recess becomes waste, which is inefficient, environmentally unfriendly and cost-intensive.

A container and sealing system are known in which the material use is in fact reduced by comparison with the above-described prior art. A sealing membrane is sealed directly onto the inner face of the container wall, in such a way that the aforementioned metal ring is not necessary. However, the system requires relatively high investment in facilities and machines, and attaching and sealing the sealing membrane to the generally curved inner wall of the container is generally not without difficulties in terms of manufacture, for example as a result of weld seams in the wall. A further problematic aspect is that the sealing foil is attached to the inner container wall using an adhesive material. Therefore, after a user removes the sealing film, material residues may disadvantageously remain on the inner wall of the container and in particular in the region of the opening edge thereof. Also, 100% tight sealing of the container is generally not possible, and so it is only suitable for dry filling material.

SUMMARY OF THE INVENTION

Starting from the above-described prior art, the object of the invention is to provide a cover unit and a method for closing and sealing a container by means thereof which are material-efficient, can be produced/carried out on simple, conventional machines, and can be used for various commercially conventional containers and covers without adapting them to the invention. In particular, the cover unit is to be supplied as a pre-assembled unit to a filler of a corresponding container, and, after filling with the filling material, should be able to be arranged and sealed on the container by said filler in a simple, rapid and inexpensive manner using simple, conventional machines.

The object of the invention is achieved by a cover unit for closing and sealing, in particular sealing in a tamper-evident manner, an opening, which is surrounded by a sealing edge, of a container such as a can, barrel or the like, wherein the cover unit has an adapter, a cover, and a sealing film; the adapter can be arranged on the container in the opening thereof or around said opening so as to leave the sealing edge exposed, and has a through-opening, the cover is arranged on the adapter in a removable manner, and the sealing film is clamped between the cover and the adapter so as to cover the through-opening.

The invention is further achieved by a container, which is closed using a cover unit according to the invention, in particular according to any one of the appended claims, and having an opening surrounded by a sealing edge, wherein the sealing film is positioned peripherally on the sealing edge of the container, seals the opening thereof and in particular is sealed tightly to the sealing edge.

Finally, the invention proposes a method for sealingly closing a container, such as a can, barrel or the like, wherein a cover unit according to any one of claims 1 to 7 is arranged on a container, in particular according to any one of claims 8 to 13, having an opening and a sealing edge surrounding it, in the opening or around the opening in such a way that the sealing film is positioned peripherally on the sealing edge, and the sealing film is sealed to the sealing edge by thermal action.

The invention relates in particular to two-part and three-part containers. A two-part container comprises a cover unit (as the first part) and a single-part container body (as the second part) closed or sealed thereby. The container body forms a container wall and container base in a single part, and can for example be manufactured conventionally by deep-drawing or another shaping method. A three-part container comprises a cover unit (as the first part) and a two-part container body closed or sealed thereby and consisting of the container wall (as the second part) and the container base (as the third part). The container wall and container base may for example be interconnected by means of a fold.

The sealing film and the container are the only units which come into contact with the filling material. The cover and the adapter can therefore consist of virtually any desired materials, irrespective of the filling material. In this way, cost-effective and simple materials can be used for the cover and adapter, whilst potentially high-grade materials which are adapted to the filling material need only be used for the container and the sealing film, for example materials suitable for food. The use of these expensive high-grade materials can thus be reduced. Preferably, the cover and/or adapter consist in whole or in part of plastics material. The adapter may in particular be in the form of an injection-molded plastics material element. As a result, the loss of material described in the prior art from punching out a metal ring for sealing film attachment can be prevented. The adapter is produced in a simple, cost-effective manner, for example injection-molded, in the respectively required shape.

Particularly advantageously, the cover unit can be pre-assembled from the adapter, cover and sealing film. It can be pre-assembled to seal a suitable container, and be arranged thereon in a particularly simple manner after it is filled. Naturally, the adapter, cover and sealing film may also be arranged on the container individually to seal it. In both cases, the sealing film is laid on the adapter and the cover is subsequently arranged on the adapter, in such a way that the sealing film is positioned between the adapter and the cover and is clamped in place and held at least until they seal it to the sealing edge. In the case of the pre-assembled unit, the sealing film is subsequently (after the pre-assembly) arranged on the container, lying on the sealing edge, and sealed to the sealing edge thereof. In the other case, the adapter is arranged on the container before the sealing film is put on.

The cover is preferably arranged on the adapter using a thread or a bayonet joint. As a result, the cover can be opened and reclosed in a simple manner by an end-user, in particular after the container is filled and closed. Further, it can be arranged on the adapter using a determined, defined contact pressure, in such a way that the sealing film is clamped in place and fixed sufficiently for sealing onto the sealing edge. It is advantageous for the cover to have some resilience at least in part, for example in the region of the end-face cover face thereof, since in this case the sealing film can be reliably held by way of a degree of yielding when it is placed on or screwed onto the adapter and the resulting resilient restoring force. According to the invention, a resilient intermediate layer which performs this resilient function can be laid in the cover on the adapter side between the sealing film and the cover.

The adapter may be substantially annular in form or have a substantially annular wall, for example being in the form of a retainer ring. In this last case, it is preferably provided internally or externally with the thread or the tappets of the bayonet connection. The adapter has an annular, interrupted or uninterrupted contact edge or contact face, which extends around in the cover when it is mounted on the adapter and can, along with the sealing film, be pressed against a face of the cover, preferably against the end face thereof. The contact edge may for example be the upper face of the adapter wall. It is particularly advantageous for the adapter edge to be formed by upper end regions of catch elements, which are disclosed in the following.

In one particular embodiment of the invention, the adapter comprises catch elements, which hook together with a counter structure of the container when said adapter is arranged correctly on the container. Advantageously, the adapter can be positioned and centered on the container using the catch elements. At least three catch elements of this type are required so as to ensure definite radial positioning. Preferably, however, the adapter has a large number of these catch elements, which are arranged peripherally at small intervals, since in this case particularly precise centering and positioning of the adapter on the container is possible. The adapter can be braced against the container in the axial and/or radial direction by way of the catch elements. Preferably, the catch elements are arranged on the adapter using a resilient web. In this way, they are mounted resiliently sprung with respect to the adapter or the annular wall thereof. The web may for example project radially and extend over a certain length in the axial direction, in such a way that it has the corresponding spring properties. Particularly advantageously, the sealing film can be clamped between the adapter and cover by way of the catch elements, in particular by way of the upper, cover-side end regions thereof. According to the invention, the catch elements may in particular be formed in that mutually separated incisions are made in the annular wall of the adapter and the catch elements themselves are formed by wall regions left behind between these incisions.

The container may be a conventional packaging container, preferably made of metal, having a container base and a container wall, for example a standard can for coffee powder, milk powder and the like, but also for moist or wet filling materials. The container may in principle be of any desired shape, preferably substantially cylindrical, and has a filling opening which is enclosed by a sealing edge. This edge may be formed by a planar cut face of the container material or by a flanged region or flanged edge. It is particularly advantageous for the container to be provided with a shoulder, preferably an oblique shoulder, at an axial distance from the sealing edge or flanged edge. In this case, a depression or a plurality of depressions is/are formed between the sealing edge/flanged edge and the shoulder, preferably peripherally. The catch elements of the adapter subsequently engage therein when it is arranged on the container. Preferably, the flange or flanged edge forming the sealing edge forms the counter piece which cooperates with the catch elements. The shape of the catch elements is preferably adapted to the shape of the container and in particular to the shape of the depression or neck region. The length of the catch elements may correspond to the height of the depression in the axial direction of the container, or is slightly larger, in such a way that the end faces of the catch elements lie against the flanged edge of the sealing edge and the opposing faces thereof lie against the shoulder of the depression. The axial position of the adapter and the catch elements is thus clearly defined, and a defined contact pressure of the sealing film on the cover via the catch elements is ensured. In the radial direction, the adapter may be braced on the container via the catch elements and/or via the annular wall.

To make it easier to slide the adapter onto the container, in a further inventive proposal said adapter comprises a ramp, preferably in the form of a shoulder extending in the radial and axial directions. This can lie against the shoulder of the container wall when the adapter is slid on.

In the container according to the invention, the sealing film is sealed to the sealing edge of the container. In a preferred embodiment, the sealing edge and sealing film are thermally fused together. According to the invention, the sealing film may further be attached to the sealing edge using a hot adhesive. Finally, the sealing film may be self-adhesive. Thus, the only units of the container according to the invention which come into contact with the filling material are the container itself and the sealing film. The remaining units, such as the adapter, intermediate layer and cover, do not come into contact with the filling material and can therefore be made of lower-quality materials, for example materials not suitable for food or resistant to the filling material.

In one embodiment of the invention, an anti-twist device is provided for the cover unit with respect to the container. This may in principle be implemented in a positive, non-positive or material fit. In particular, at least one catch structure may be arranged or formed in the region of the container wall on which the adapter is arranged, especially in the region of the depression between the flanged edge and the shoulder. This may in particular project radially outwards, for example in the form of a cam profile or a weld seam. When the cover unit is arranged on the container, the catch elements of the catch structure on the container cooperate in a positive fit and bring about anti-twist protection of the cover unit on the container. In this context, the catch structure on the container and the catch elements of the adapter engage in one another in the radial direction and thus prevent the cover unit from twisting with respect to the container. In another form of the invention, the anti-twist protection can be achieved in that the annular wall of the adapter is formed as an interference fit assembly or by means of a press fit with respect to the container wall, in particular with respect to the container wall on the side of the shoulder opposite the flanged edge. Finally, the adapter may with respect to the container by means of an adhesive or hot adhesive, in particular in the aforementioned region. This adhesion may be used as an alternative or in addition to the two twist protections by positive and non-positive fit. Twist protection of this type ensures that the cover can be removed from and arranged back on the container by the user in a simple and reliable manner, in such a way that the container can be opened and reclosed without difficulty.

The invention also relates to a method for sealingly closing a container, such as a can, barrel or the like, wherein a cover unit according to any one of the appended claims is arranged on a container having an opening and a sealing edge surrounding said opening, in or around the opening in such a way that the sealing film is positioned peripherally on the sealing edge, and the sealing film is sealed to the sealing edge by thermal action. As stated above, the cover unit may be fully pre-assembled and be arranged on the container as a pre-assembled unit of this type. Alternatively, the adapter may initially be mounted on the container, the sealing film subsequently being laid on the adapter and clamped by arranging the cover on the adapter. In both cases, the sealing film is subsequently sealed to the container.

Preferably, when the adapter is slid onto the container the latch elements thereof yield resiliently over a catch counter element, preferably in the form of a flanged edge, and spring back into the original position thereof when the correct axial end position of the adapter on the container is reached, and hook onto the catch counter element, preferably the flanged edge.

It is particularly preferred for the sealing edge and sealing film to be heated and sealed by induction, preferably by passing under a surface induction coil. As a result of the invention, advantageously only the material of the sealing film has to be heated to a sufficient temperature for the sealing. It is not necessary to apply an additional contact pressure to the container provided with the cover unit. The contact pressure on the sealing edge exerted on the sealing film by the cover and adapter is sufficient for the sealing, and so the device required for sealing the container can advantageously be particularly simple in construction and cost-effective. It is sufficient simply to pass the container provided with the cover unit under an induction coil and merely to ensure sufficient heating.

In a further form of the invention, a hot adhesive is applied at least to parts of the sealing edge and/or the sealing film, in particular in that the cover unit passes through a hot adhesive application as a pre-assembled unit. Alternatively, a self-adhesive film may be used.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention may be taken from the following exemplary description of a particularly preferred embodiment of the invention with reference to the drawings, in which:

FIG. 1 is a schematic plan view of a container according to the invention provided with a cover unit,

FIG. 2 is a schematic sectional view of the container of FIG. 1 along the section line A-A,

FIG. 3 is an enlarged sectional view of the upper corner region marked in FIG. 2,

FIG. 4 is an exploded view of the container shown in FIGS. 1 to 3,

FIG. 5 is a partially sectioned container having a cover in a three-part embodiment having flanging,

FIG. 6 is a detail of the container of FIG. 5,

FIG. 7 is a partially sectioned container having a cover in a two-part embodiment, and

FIG. 8 is a detail of the container of FIG. 7.

DETAILED DESCRIPTION

FIG. 1 is a plan view of a metal container 1. It is of a substantially cylindrical shape and has a container base 2 and a container wall 3. The container base 2 and container wall 3 are tightly interconnected by a fold 4. As can be seen in particular in FIG. 3, the container wall 3 is formed into a neck portion 16 in the upper region thereof. The container wall 3 here is deformed in the direction of the container interior and forms an oblique shoulder 5 and a peripheral depression 6. At the upper end, the container wall 3 is flanged to form a flanged edge 7, which forms a sealing edge 8 on the face thereof remote from the container base 2. Said edge surrounds a filling opening 9 of the container 1.

The filling opening 9 is sealed by a cover unit 10, which has a substantially annular adapter 11, a cover 12, a sealing film 13 and a resilient intermediate layer 14. The cover 12 and adapter 11 are releasably screwed together via a thread 15. The cover unit 10 can be placed on the neck region 16 of the container 1 as a pre-assembled unit, and placed in the state shown in FIGS. 1 to 3. The resilient intermediate layer 14 is inserted into the cover 12. The adapter has a substantially annular wall 17, which is provided with the thread 15 on the outside thereof. Radially obliquely inwardly resilient webs 18 project from the wall 17 and form a ramp 23, and in turn each support a catch element 19. The upper end face 20 of the catch element 19, facing the cover 12, is positioned at the level of the upper end face 21 of the wall 17 of the adapter 11, facing the cover 12. As is clear in particular from FIG. 4, the catch elements 19 are formed peripherally with equal spacing on the adapter 11. As a result of the resilience of the webs 18, they can spring resiliently in the radial direction.

In the pre-assembled state, the sealing film 13 is held clamped between the cover 12 and the adapter 11, in such a way that it is positioned directly on the sealing edge 8 when the cover unit 10 is arranged on the container 1, and preferably pressed on with the necessary pressure for the sealing. In the preassembled state, it is in contact with the resilient intermediate layer 14 and the upper end face 20 of the catch elements 19 formed on the adapter 11 and/or the upper end face 21 of the wall 17 of the adapter 11. The adapter 11 is formed in such a way that it does not cover the sealing edge 8 or only covers it in part, and the sealing film 13 is positioned directly on the entire sealing edge 8 or sub-regions thereof after the cover unit 10 is mounted on the container.

When the pre-assembled cover unit 10 is slid onto the container 1, the flanged edge 7 penetrates into the interior enclosed by the wall 17 of the adapter 11, until it is struck by the webs 18. During further sliding on, the webs 18 and the catch elements arranged thereon spring outwards in the radial direction. The cover unit 10 can therefore be slid further over the flanged edge 7. When the axial end position shown in FIG. 3 is reached, the latch elements 19 snap back into the original positions thereof as a result of the resilience of the webs 18, and thus hook onto the flanged edge 7, in such a way that the cover unit 10 is attached to the container 1 in a radially and axially defined manner. Shortly before this end position is reached, the sealing film 13 comes into contact with the sealing edge 8. Because the resilient intermediate layer 14 yields slightly, it becomes possible to slide the cover unit further onto the container 1, until the catch elements 19 snap in. Instead of the resilient intermediate layer 14, a degree of resilience of the cover 12 itself may ensure this, in which case the intermediate layer can be omitted. In both cases, the sealing film 13 is secured and attached to the sealing edge when the cover unit 10 is fully slid on. Subsequently, the sealing film 13 is sealed and attached by heating from above or from the side of the sealing region, for example by induction.

The end user opens the container 1 by unscrewing the cover 12 from the adapter 11 and thus from the container 1. Subsequently, the sealing film 13 is freely accessible, and the container can be definitively and completely opening by pulling it off. It can subsequently be sealed again by screwing on the cover 12. To make it easier to screw on and unscrew the cover 12, the adapter 11 is secured against twisting with respect to the container by stops (not shown in the drawings).

FIGS. 2, 4, 5 and 6 show the container in a three-part embodiment, in which the container base 2 as the first part and the container wall 3 as the second part are interconnected by means of the flange 4. The cover unit 10 forms the third part. FIGS. 7 and 8 show the container 1 in a variant, specifically a two-part embodiment, in which the container 1 as a first part is formed with the container base 2 and container wall 3 in a single part. In this variant, the cover unit 10 forms the second part. In the variant of FIGS. 7 and 8, the container 1 is produced by deep-drawing.

Claims

1. Cover unit (10) for closing and sealing an opening (9) of a container (1), the opening being surrounded by a sealing edge (8), the container such as a can, barrel or the like, wherein the cover unit (10) has an adapter (11), a cover (12), and a sealing film (13),

the adapter (11) is configured for arrangement the container (1) in the opening (9) thereof or around the opening (9) so as to leave the sealing edge (8) exposed, and has a through-opening (22),

the cover (12) is removably arranged on the adapter (11) and the sealing film (13) is clamped between the cover (12) and the adapter (11) so as to cover the through-opening (22) thereof.

2. Cover unit according to claim 1, wherein the adapter (11) and the cover (12) are interconnected using a thread (15) or a bayonet joint.

3. Cover unit according to either claim 1 or claim 2, wherein the adapter (11) comprises catch elements (19), which hook together with a counter structure (7) of the container (1) when said adapter (11) is arranged correctly on the container (1).

4. Cover unit according to any one of the preceding claims, wherein the adapter (11) comprises a ramp (23), preferably in the form of a shoulder extending in the radial and axial directions.

5. Cover unit according to either claim 3 or claim 4, wherein the catch elements (19) are arranged on the adapter (11) using a resilient web (18).

6. Cover unit according to any one of the preceding claims, further comprising a resilient intermediate layer (14), which is arranged between the cover (12) and the sealing film (13).

7. Container, dosed using a cover unit according to any one of the preceding claims and having an opening (9) surrounded hy a sealing edge (8), wherein the sealing film (13) is positioned circumferentially on the sealing edge (8) of the container (1), closing the opening (9) thereof and is sealed to the sealing edge (8).

8. Container according to claim 7, comprising a flanged edge (7), which cooperates with catch elements (19) of the adapter (11) and fixes it to the container (1).

9. Container according to claim 8, comprising an oblique shoulder (5) at a distance from the flanged edge (7), the distance between the oblique shoulder (5) and the flanged edge (7) being equal to or slightly less than the distance between a ramp (23) of the adapter (11) and the upper edge (20, 21) thereof.

10. Container according to any one of claims 7 to 9, wherein the sealing edge (8) and sealing film (13) are thermally fused together.

11. Container according to any one of claims 7 to 10, wherein the cover unit (10) is secured against twisting with respect to the container (1), in particular by positive fit, non-positive fit and/or adhesion.

12. Container according to claim 11, wherein catch elements (19) cooperate in a positive fit with a catch structure, which is in particular in the form of a cam profile or weld seam, projects radially outwards, and is arranged between the flanged edge (7) and the shoulder (5) of the container (1) in the axial direction of the container.

13. Container according to either claim 11 or claim 12, wherein the adapter (17), in particular an annular wall (17) of the adapter (11), is arranged on a container wall (3) of the container (1) by means of a press fit.

14. Method for sealingly closing a container (1), such as a can, barrel or the like, wherein a cover unit (10) according to any one of claims 1 to 7 is arranged on a container (1), in particular according to any one of claims 8 to 13, having an opening (9) and a sealing edge (8) surrounding the opening, in the opening (9) or around the opening (9) in such a way that the sealing film (13) is positioned circumferentially on the sealing edge (8),

and the sealing film (13) is sealed to the sealing edge (8) by thermal action.

15. Method according to claim 14, wherein the cover unit (10) is fully pre-assembled and is arranged on the container (1) as a pre-assembled unit of this type.

16. Method according to either claim 14 or claim 15, wherein when the adapter (11) is slid onto the container (1) latch elements (19) thereof yield resiliently over a catch counter element, preferably in the form of a flanged edge (7), and spring back into the original position thereof when the correct axial end position of the adapter (11) on the container (1) is reached, and hook onto the catch counter element, preferably the flanged edge (7).

17. Method according to any one of claims 14 to 16, wherein the sealing edge (8) and sealing film (13) are heated and sealed by induction, preferably by passing under a surface induction coil.

18. Method according to any one of claims 14 to 17, wherein a hot adhesive is applied at least to parts of the sealing edge (8) and/or the sealing film (13), in particular in that the cover unit (10) passes through a hot adhesive application as a pre-assembled unit.