EP3310675B1 - Can lid - Google Patents

Description

The invention relates to a can lid with a tightly resealable opening according to the preamble of claim 1.

Such a resealable can lid is from the DE 10 2010 013 531 A1 known.

Furthermore, a comparable can lid of this kind in the EP 2 354 022 B1 described. document EP2354022 discloses a can lid according to the preamble of claim 1.

From the EP 1 607 341 A1 For example, a can lid having a reclosable opening is known in which an opening is made in the metallic can lid and the edge of that opening is crimped to provide anchoring for a prefabricated plastic closure. The plastic closure part comprises a base part to be connected to the beaded edge of the can opening, in which opening formed by a flat plug is formed. The flat plug is connected to the opening edge via a plastic tear seam, so that the flat plug connected to a pull tab can be released by pulling over the tear tab of the plastic base part and pivoted into an open position. The opening can be temporarily closed again by pressing in the flat plug, which is preferably conical on its underside.

From the WO 2008/098558 A1 is a re-sealable opening having can lid, in which also in the metallic can lid an opening is introduced into which a prefabricated, rupturable plastic closure member is inserted, wherein the prefabricated plastic element has a peripheral edge double flange, in which engages the edge of the punched can opening and is fixed therein. The prefabricated plastic element comprises a closure part, which is connected to the peripheral edge of the plastic part via a tear seam. A pull tab connected to the closure part makes it possible to tear open the plastic tear seam between the peripheral area of the plastic part and the lid part and thus release the can opening. For the purpose of resealing, the closure part, which preferably remains in contact with the peripheral area via a tab region, can be pressed back into the opening.

From the GB 1 389 351 is a resealable can lid is known in which in particular the emergence of sharp edges should be avoided, as they arise when tearing ordinary tin cans over a tab. For this purpose, a prefabricated plastic part is snapped into a provided in the metallic can lid punched, which has a lid part which is connected via a thin plastic wall with the snapped into the can opening base part. About a pull tab, the thin connecting wall between the closure part and the base part destroyed and the can opening are exposed. The closure part is designed so that it engages to reclosure of the opening via a snap-locking connection in the base part.

From the DE 89 11 286 U is a beverage can with a Eindrückdeckelverschluss known in which the tear tab is rotatably mounted on the cover wall and provided on it a closure element which is taken during rotation of the pull tab from the tear position in a Verschließstellung above the open pouring and covering the pouring over covering or closing in this intervenes.

From the DE 90 05 150 U a beverage can with a lid consisting of sheet metal is known, in which a weakening line is formed and delimited by the weakening line lid part is detachable by means of a pull tab, wherein on the lid captive a substantially parallel to the lid surface pivotable closure part is attached to the removal opening.

From the DE 196 13 246 a metal lid for beverage cans is known, which has a pre-punched pouring opening in the lid surface, which is sealed by a closure element and after the first opening is again tightly closed. In this case, the lid and closure element can be positively connected to one another by means of bayonet-like interlocking elements, which are formed directly from the lid material or the closure element.

Object of the present invention is to develop the resealable can lid according to the preamble of claim 1 in such a way that while maintaining a high quality, gas- and liquid-tight closure, the functionality further improved and especially facilitates the process of opening the can, or the this required effort is reduced and that further simplifies the manufacture of the can lid due to the structural design, designed more cost-effective and automatic assembly compared to previous solutions can be made much cheaper.

This object is achieved essentially by the fact that the collar part and the lid receiving part each have a plurality of integrally formed and distributed annular projections, that these approaches extend through adapted openings in the metallic cover part, and that collar part and lid receiving part with the interposition of a primer layer by rivet-like deformation the approaches under heat with the metallic lid part form and locks and are tightly connected.

Through these measures, a separate production of plastic and metal components is made possible and avoided an injection molding of composite parts made of metal and plastic, which can achieve significant manufacturing advantages without any loss of functionality.

In order to achieve secure and permanent connections between the individual components of the can lid, it is preferably provided that the elevated temperature reactive priming layer overlap both surfaces of the metallic lid part, i. extends over the outer and inner surface of this cover part.

The thus provided sealing layer, which may be a sealing wax, ensures that the plastic materials are tightly and firmly connected to the metal parts, which is preferably done by heat sealing at elevated temperature, for example at about 150 ° C to 160 ° C.

An embodiment variant of the invention is characterized in that the opening area delimited by a peripheral tear line is connected to the adjacent lid area by a weakening groove which is partially broken, in particular in the beginning and end area associated with the tearing movement.

By providing suitably arranged partial perforations of the weakening groove, the force required to open the closure can be reduced in a defined manner, the tightness being reliably guaranteed in this case as well, by the layer of plastic material provided over the entire surface and firmly adhering to the underside of the metallic lid or the correspondingly attached plastic film.

Manufacturing technology results according to a further embodiment of the invention has a significant advantage in that collar part, lid receiving part and pull tab made of the same plastic material, in particular polypropylene, and are formed by a single interconnected via connecting plates injection molded part, which can be converted by folding in an assembly unit and on the the openings in the metallic cover part associated with approaches in a connecting step with the metallic cover part is connectable.

This is made possible in particular by the fact that the metallic can lid is provided on both sides of the entire surface with the already mentioned sealing layer, which allows all plastic components or plastic parts of a single component, in particular polypropylene, to inject in one operation and still solid and tight connections to ensure with the metallic can lid. The three interconnected components of the same plastic component are folded on each other, so that there is an element that can be done by pressing the protrusions provided on the plastic parts in the corresponding openings with the corresponding can lid areas, the rivet-like bonding and heat sealing under the effect of the sealing layer.

According to a further embodiment of the invention is provided to ensure the long-term tightness of the overall arrangement that the lid receiving part is tightly connected with its abutting the metallic cover part outer peripheral edge with this metallic cover part by heat sealing.

The pull tab preferably has at least one extension extending up to the metallic cover part, which is connected to the cover part during a sealing step.

A snap-locking connection which is particularly advantageous for closures of containers with a lid part is characterized in that the snap-locking connection between the collar part and the lid receiving part consists of a coupling and sealing rib provided on the lid receiving part, which engages in a first adapted recess in the collar part and a biasing and Verrastlippe consists, which engages latching in a second recess of the collar portion and presses the wall rib between the two recesses against the coupling and sealing rib.

A further embodiment of the invention, which is also independent of the nature of the connection of the plastic parts with the metal parts and regardless of whether only one plastic material or more plastic materials use is of particular advantage, is characterized in that the opening area of the metallic can lid of the surrounding cover surface is separated under formation of interlocking projections and recesses by a cutting, in particular punching process, that the opening portion and the surrounding cover surface over these projections and recesses are positively and non-positively held together as a component and the tightness of the finished, unopened can lid is ensured by the inner plastic coating or film.

The projections and recesses are preferably coupled via undercuts.

This particularly significant embodiment of the invention, in which the opening portion of the can lid is first cut or punched out to form a tooth structure and immediately this punched-out lid opening portion is pressed into the toothing of the remaining part of the can lid, so that in turn is a one-piece structure, which in the Production brought to the next station and connected to the plastic part can be leads to an absolutely chip-free opening of the swing-up lid part is achieved and the opening process with very little effort is feasible. This is a consequence of the fact that no metallic weakening grooves need to be torn open during the opening process, since the metal regions to be separated from each other are already completely separated from one another by the punching process. The tightness of this arrangement is again ensured by the inner plastic film having immediately adjacent to the opening area a circumferential weakening point or notch, so that the opening process is not complicated by this the tightness ensuring film.

Embodiments of the invention will be described below with reference to the drawings.

Fig. 1

eine Draufsicht eines wiederverschließbaren Dosendeckels nach der Erfindung,

Fig. 2

eine perspektivische Darstellung der gestanzten metallischen Deckelfläche vor der Verbindung mit den Kunststoffbestandteilen des Verschlusses,

Fig. 3

eine perspektivische Schnittdarstellung des Dosendeckels nach Fig. 1,

Fig. 4

eine vergrößerte Detaildarstellung zur Erläuterung der abdichtenden Kupplung zwischen einem mit dem Behältnis verbundenen Kragenteil und einem Deckelaufnahmeteil,

Fig. 5A bis 5C

Darstellungen zur Erläuterung der Fertigung sämtlicher Kunststoffkomponenten des Verschlusses in einem Fertigungsschritt,

Fig. 6

eine perspektivische Draufsicht einer besonders bevorzugten Ausgestaltung des metallischen Dosendeckelteils vor Verbindung mit den Kunststoffkomponenten, und

Fig. 7

eine Schnittdarstellung des Dosendeckels nach Fig. 6 mit schematisch eingezeichneten Kunststoffkomponenten.

In the drawing shows:

Fig. 1

a top view of a resealable can lid according to the invention,

Fig. 2

a perspective view of the stamped metallic cover surface before the connection with the plastic components of the closure,

Fig. 3

a perspective sectional view of the can lid after Fig. 1 .

Fig. 4

an enlarged detail view for explaining the sealing coupling between a container connected to the collar part and a lid receiving part,

Figs. 5A to 5C

Representations to explain the production of all plastic components of the closure in a manufacturing step,

Fig. 6

a perspective top view of a particularly preferred embodiment of the metallic can lid part before connection with the plastic components, and

Fig. 7

a sectional view of the can lid after Fig. 6 with schematically drawn plastic components.

Fig. 1 shows a conventionally designed in its basic form can lid 1 made of metal, which is connected via a flange 2 with the interposition of a sealing material with the respective associated can liquid and gas tight.

In this cover, off-center offset, a resealable opening integrated, as will be explained in detail yet.

In Fig. 1 can be seen a connected with a tear tab 15 collar part 5, which encloses the opening area and is firmly connected to the can lid surface 23. A lid receiving part 10 encloses the opening portion 11 and can be swung up by means of the tab 15 during the opening process. A buckling spring element 22 ensures that the pivoted lid is held in the open position when it is pivoted in particular by more than an angle of 90 °.

The Fig. 1 is also removable that the reclosable opening with all its associated components off-center, in fact arranged such that, despite the presence of the reclosable opening the stackability is unchanged as in conventional doses.

Prerequisite for this, apart from the positioning, is above all the compactness of the reclosable opening according to the invention. The supernatant of the components of the resealable opening over the can surface is according to the invention only about 2 mm.

Fig. 2 shows the formed as a stamped part metallic can lid of an advantageous embodiment of the invention prior to connection with the associated plastic components of the resealable lid.

Continuous openings 31 which serve to connect the plastic components to the metallic can lid and which are arranged annularly on both sides of a weakening groove or tear notch 4 can be seen in this illustration. A peculiarity of the embodiment of the weakening groove or tear-open groove 4 is that, in contrast to conventional solutions, it is not continuous, but has perforations 36, which lead to the advantageous effect that the opening process is facilitated, i. the force required to open the swing-up lid part is reduced. These openings 36 are formed during the punching process of the lid, but leave the lid part as a uniform stamped part. The tightness to be ensured by the can lid is not impaired by the perforations 36 because the required tightness is ensured by an inner sealing foil which extends over the entire inner can lid surface and also into the flanging region.

Fig. 3 shows a cross-sectional view of the can lid after the Fig. 1 and 2 , The arrangement is shown in the closed state.

The area of the can lid which lies within the tear line 4, ie the opening area 11, is enclosed by a lid receiving part 10 made of plastic, which is firmly and tightly connected to this metallic portion, by means of a plurality of molded projections 32, which are characterized by the in detail Fig. 2 extending openings 31 extend. By rivet-like deformation of these projections 32 under the action of heat, a firm connection is made, but it is essential that a heat-sensitive adhesive is provided at the contact surfaces between the plastic part and the metal part. Preferably, both the outer surface and the inner surface of the metallic can lid with a suitable adhesion promoter suitable material, in particular in the manner of a sealing wax, coated, so that the bonding agent is available wherever it is needed for connection and sealing purposes.

To cooperate with the lid receiving part 10 in the form of a snap-locking connection, a collar part 5 made of plastic material is provided radially outside the opening area, which is connected in the same way as the lid receiving part 10 through openings 31 passing through lugs 30 with the metallic can lid.

Both for the chosen connection technique between metal and plastic parts and in particular for the design of the tear line or weakening 4, the provision of a plastic layer or plastic film is important, extending over the entire bottom of the can lid into the region of the flared edge 2 and this underside covering the entire surface. This plastic layer 26 is in turn formed with the metallic can lid via a bonding agent, in particular a process which becomes effective or reacts when the heat is introduced. The Fig. 3 indicates that this sealing layer extends over both the mechanical connection points between metal and plastic parts and on the weakening 4.

The main advantage of the described connection technology between the metallic lid and plastic components is that metal stamping and plastic parts can be manufactured separately, no metal Umspritzungsvorgänge are required and the connection between metallic can lid and plastic components can be done in a single operation, when the plastic components are applied to the metallic surface and the protrusions 30 pass through the openings 31.

The detailed representation after Fig. 4 shows a principle principle applicable for snap-locking connections design principle, which is advantageously used for the resealable can lid according to the invention.

For this purpose, two encircling ribs are provided on the lid holding part 10, namely an outer coupling and sealing rib 34 and an inner preloading and locking rib 35. The coupling and sealing rib 34 sealingly engages in a first recess 39 of the collar part 5, while the preloading and Verrastrippe 35 extends into a second recess 40 of the collar member 5 and between this rib and the recess a snap-locking connection is created. But it is also essential that this rib 35 is dimensioned and designed so that it presses in the locked state against the central wall rib 41 of the collar part, so that this wall portion pressed against the sealing rib 39 and thus the sealing effect is even safer and better.

Fig. 4 also shows that the metallic can lid is covered on both sides and the entire surface with an adhesion-promoting layer 37, which also makes it possible to improve the tightness of a filled can sealingly fix the outer edge of the lid receiving part 10, which rests against the metallic can lid surface, via the bonding layer.

In a resealable can lid but not only requirements must be met in terms of tightness, but it must be achieved above all, that the can be opened easily and with little effort. Contributes to a good and comfortable to handle pull tab 15, but above all it is essential for the invention that the required tearing force is as low as possible. This objective corresponds to the aforementioned provision of apertures 36 along the elevation line or the weakening groove and, in addition, the inner plastic film 26 adjacent the elevation line is provided with a circumferential weakening notch 38 so that the film 26 can not obstruct the opening process ,

The representations in the Fig. 5a to 5c show a particularly advantageous embodiment of the invention, which consists in that all plastic components of the resealable can lid made of the same plastic material and thereby a production of these plastic components can be done in a single injection molding process.

As can be seen from the illustrations, collar part 5, lid receiving part 10 and pull tab 15 are lying in a plane and joined together by connecting tabs 42 together, so that a virtually one-piece overall structure is obtained, which can be handled as a unit in the manufacturing process and for mounting on Can lid must be folded only on each other, so that then approximately concentric with each other approaches 30 of collar part 5 and lid receiving part 10 can be pressed in a single indentation through the openings 31 in the metal can lid and then deformed in the manner already described.

In addition to the achievable in this way simplification of the production of the same material and reacting with the appropriate bonding agent 37 Plastic components will obviously also receive a corresponding handling and assembly advantage.

Fig. 6 shows a particularly preferred embodiment of a can lid according to the invention, wherein in this Fig. 6 shown metallic can lid part in particular with the plastic elements after Fig. 5 can be combined to a finished resealable can lid.

While in known reclosable standard can lids when opened by the tearing of a metallic weakening unwanted and unavoidable chip formation or the formation of metallic micro-aluminum particles, it leaves the inventive design after Fig. 6 To ensure a completely spanfreies and health risks off opening.

For this purpose, the opening portion 11 of the metallic can lid is separated from the surrounding outer, fixed lid surface 43 by a cutting or punching in particular, with the formation of interlocking projections 32 and recesses 33, as for example in US Pat Fig. 6 is shown.

Immediately after the punching operation preferably used, the two initially separate parts are again positively joined together, so that practically becomes a part of the two parts again, which can be handled as a single part. The operations of separating and nesting are carried out directly one after the other, ie the punching stroke is followed by the positive-locking merging of the two parts into a total part in the return stroke. The positive and non-positive connection between the two parts is achieved by suitable shaping or by using undercuts that a sufficient mutual Ensure mechanical connection to handle the already separated parts again as a single assembly part in the production.

If the plastic components after Fig. 5 with the metallic can lid part after Fig. 6 are in the manner already described tightly connected to each other and also the backside plastic film 26 is applied, there is an arrangement as shown schematically in a sectional view Fig. 7 is shown.

In the illustration after Fig. 7 are collar part 5 and lid receiving part 10 in the manner already explained tightly and permanently connected to the metallic can lid part and the snap-locking connection is engaged. The tightness is ensured by the up to the bead edge extending film 26. The tear line 4 is formed by the dividing line between the interlocking protrusions 32 and recesses 33.

If the filled can is opened via the pull tab, the tear line defining projections 32 and recesses 33 are disengaged, but no weakened metal areas under chip formation must be separated from each other, but only the existing positive connection must be solved, which is possible with much less effort than requires the rupture of a still existing metallic connection between the two parts to be separated.

The already mentioned use of the weakening notch 38 in the inner sealing foil contributes to the fact that the demands placed on such a resealable can lid can be optimally fulfilled, both in terms of tightness and minimized opening force, with simultaneous economic production and assembly of all can lid components.

LIST OF REFERENCE NUMBERS

1

metallic can lid

2

beaded

3

cover surface

4

Weakening groove or tear line

5

collar part

10

Cover receiving part

11

opening area

15

pull tab

22

Buckling spring part

23

Can lid surface

26

sealing plastic layer, foil

30

approach

31

opening

32

head Start

33

recess

34

Coupling and sealing rib

35

Preload and locking catch

36

breakthrough

37

Adhesive, sealing wax

38

weakening notch

39

first recess

40

second recess

41

Wandungsrippe

42

connecting strap

43

outer solid lid surface

Claims (9)

1. A can lid having a sealingly reclosable opening, in particular for beverage cans,
   comprising a bounded opening region (11) provided in the metallic lid material of a lid surface (3) as well as a two-armed lifting member intended to open this opening region (11),
   said lifting member being connected to a pull tab (15), on the one hand, and engaging at the opening region (11) of the lid surface (3), on the other hand, and being supported via a bearing translating the opening force applied to the pull tab (15),
   wherein the opening region (11) is configured as a closure lid and is connected at its outer margin in a force-transmitting manner to a collar part (5) composed of a plastic material and a lid receiving part (10) is associated with the collar part (5), said lid receiving part (10) being connected in a force-transmitting manner to the lid surface (3) outside the opening region (11) and being composed of a plastic material;
   wherein the collar part (5) furthermore engages over the lid receiving part (10) and a sealing snap-in latching connection having at least one peripheral coupling rib (34) and a cut-out (39) shaped in complementary form thereto is formed between the collar part (5) and the lid receiving part (10);
   wherein the pull tab (15) is fastened radially outside the lid receiving part (10) to a fixing region of the collar part (5) and the two-armed lever for opening the opening region is formed at a partial peripheral region of the collar part (5) associated with the fixing region (5); and
   wherein the lower side of the metallic lid is in particular coated in a firmly adhesive manner over the full surface with a plastic material and this coating is attenuated or thinner surrounding the opening region, characterized in that the collar part (5) and the lid receiving part (10) each have a plurality of molded noses (30) arranged distributed in an annular manner;
   in that these noses (30) extend through adapted openings (31) in the metallic lid part;
   and in that the collar part (5) and the lid receiving part (10) are connected to the metallic lid part in a shape-matched and force-transmitting manner as well as sealingly by a rivet-like deformation of the noses (30) under the effect of heat while interposing an adhesive promoting layer (37).
2. A can lid in accordance with claim 1,
   characterized in that
   the adhesive promoting layer or sealing layer reacting at an elevated temperature extends over both surfaces of the metallic lid part, i.e. over the outer and inner surfaces of this lid part.
3. A can lid in accordance with claim 1 or claim 2,
   characterized in that
   the opening region (11) bounded by a peripheral tear line is connected to the adjacent lid region by an attenuating groove (4) which is perforated at least in part, in particular in the starting and end regions associated with the tear movement.
4. A can lid in accordance with one or more of the preceding claims,
   characterized in that
   the collar part (5), the lid receiving part (10) and the pull tab (15) comprise the same plastic material, in particular polypropylene, and are formed by an injection molded part which coheres via connection tabs, which can be transformed into an assembly unit by folding and which can be connected to the metallic lid part via the noses (30) in a connection step.
5. A can lid in accordance with any one of the preceding claims,
   characterized in that
   the lid receiving part (10) is sealingly connected at its outer peripheral margin contacting the metallic lid part to this metallic lid part by heat sealing.
6. A can lid in accordance with claim 5,
   characterized in that
   the pull tab (15) has a nose which extends up to the metallic lid part and which is connected to the lid part by sealing.
7. A can lid, in particular in accordance with one or more of the preceding claims,
   characterized in that
   the snap-in latching connection between the collar part (5) and the lid receiving part (10) comprises a coupling and sealing rib (34) which is provided at the lid receiving part (10) and which engages into a first adapted recess in the collar part (5) and comprises a preloading and latching rib (35) which latchingly engages into a second recess of the collar part and presses the wall rib between the two recesses toward the coupling and sealing rib (34).
8. A can lid in accordance with one or more of the claims 1 to 7,
   characterized in that
   the opening region (11) of the metallic can lid (1) is separated from the lid surface surrounding it while forming mutually engaging projections (32) and recesses (33) by a cutting process, in particular a punching process; in that the opening region (11) and the lid surface surrounding it are held together as a component in a shape-matched and force-transmitting manner via these projections (32) and recesses (33); and in that the leak-tightness of the finished, unopened can lid is ensured by the inwardly disposed plastic coating or film.
9. A can lid in accordance with claim 8,
   characterized in that
   the projections (32) and recesses (33) are coupled via undercuts.

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