BOX LID

Abstract

The invention relates to a box lid intended in particular for a beverage can, said box lid being distinguished from the lids of metal cans known per se in that the opening area (4) is designed as a tab separated from the lid area (3) by a micro-slit (8), in particular a stamped slot, which extends over the entire periphery of the tab, and the base of the tab forming part of the lid area forms a pivot bearing (9) which becomes active during the opening operation, and in that the underside of the metal lid is covered by adhesion and over its entire surface with a plastic material, in particular a plastic film (10), this coating being weakened, in particular notched, near the micro-slit located between the tab and the lid area.

Description

[0001] The invention relates to a can lid, in particular for beverage cans, with a limited opening area provided in the metallic lid material of a lid surface, and a two-armed lever element intended for opening this opening area, which is firmly connected to the lid material, in particular by riveting or welding.

[0002] Can lids of this type are used extensively worldwide. They are simple and inexpensive to manufacture and allow for space-saving stacking of cans, as well as opening the cans by simply swinging up the long arm of the lever. However, these common can lids have some serious disadvantages, primarily that the lever, which initially lies flat on the lid surface, is not easy to grip; that when the lever is swung upwards and the can is opened, the part of the lid that initially seals the opening is pushed into the can and comes into contact with the liquid, which is not hygienically sound; and that during the opening process, i.e., when the existing weakening groove between the opening area and the lid surface is torn open, the lid can become damaged.When the lid is cut, tiny aluminum particles are inevitably released from the lid material and can enter the can directly or via the portion of the lid that is pressed into the can's interior. These tiny shavings or aluminum particles pose a health risk if they enter the human body along with the beverage.

[0003] WO 2015 / 104659 discloses a can lid according to the preamble of claim 1.

[0004] The object of the present invention is to provide a can lid of the type mentioned above without at least one of the aforementioned disadvantages, i.e., in particular, a can lid that, compared to conventional can lids, can be opened with significantly less force and is easier to handle, is hygienically sound, and, above all, prevents the formation of aluminum shavings or aluminum microparticles during the opening process. Otherwise, a can fitted with the lid according to the invention should correspond to conventional cans with regard to the storage of its contents, its manufacturing, transport, and handling properties.

[0005] According to a first embodiment of the invention, this problem is solved essentially by the fact that the opening area is designed as a tongue flap, which is separated from the lid surface by a microgap extending over the circumference of the flap, in particular a punched gap, and that the tongue flap base connected to the lid surface forms a hinge bearing that becomes effective during the opening process, and that the coating is designed to be weakened adjacent to the microgap between the tongue flap and the lid surface, in particular notched and preferably at least partially notched through. Of particular importance in this embodiment of the invention is the interaction between the provided microgap and the plastic film provided on the underside of the lid, which is weakened adjacent to the microgap between the tongue flap and the lid surface.The notch design allows the can to be opened with surprisingly little force using the two-armed lever, while still ensuring the can's airtightness. This micro-gap is preferably created by a punching process followed by the return of the tongue tab, pressed out of the can lid material by the punching process, to its original position before punching. The ease of opening the can, requiring minimal effort, results from the fact that no metal needs to be cut and the underside foil is only peeled away in a very narrow area due to the notch during opening.

[0006] According to an embodiment of the aforementioned basic principle of the interaction between the microgap and the plastic coating provided on the underside of the lid, the two-armed lever element is attached to the lid surface and the short lever arm pivots the tongue tab during the opening process together with the portion of the plastic coating covering it from below, which is limited by the weakening line, into the interior of the can, whereby this is made possible by the fact that the notch line is located outside the microgap.

[0007] This eliminates any disruptive chip formation during the opening process and ensures that the can can be opened with minimal force.

[0008] A preferred embodiment of the basic principle according to the invention consists in the fact that the two-armed lever element is attached to the tongue tab and can be supported with its short lever arm on the lid surface, in particular on a stiffening area of ​​the lid surface, and that the long lever arm pivots the tongue tab outwards during the opening process together with the part of the plastic coating covering it on the underside, which is limited by the weakening line arranged within the micro gap.

[0009] This embodiment combines all the achievable advantages of the invention, since, compared to conventional can lids, the opening process requires significantly less force, the occurrence of aluminum shavings or aluminum microparticles during the opening process is completely avoided, and, moreover, an optimum is achieved in terms of hygiene, since immersion of can lid parts into the interior of the can and thus into the liquid located in the can is prevented.

[0010] An advantageous embodiment of the invention, applicable to all variants, is characterized by the fact that the tongue flap of the metallic can lid is separated from the surrounding lid surface by a cutting, and in particular a punching, process, forming interlocking projections and recesses, and that the tongue flap and the adjacent lid surface are positively and non-positively connected via the projections and recesses, forming the micro-gap, whereby the tightness of the finished, unopened can lid is ensured by the internal plastic coating or film. The sealing capacity against the internal can pressure is further improved by a concave design of the tongue flap.

[0011] The projections and recesses are preferably coupled via undercuts.

[0012] In particular, in the variant where the tongue tab is moved outwards during the opening process, the longer arm of the two-armed lever element is formed by a handle tab, in particular a ring tab, and the two-armed lever element is connected to the tongue tab off-center, in particular at the edge.

[0013] The invention includes, in addition to the can lids described in detail, all cans which are provided with a can lid according to the invention, which is preferably connected to the respective can via a respective crimped edge, wherein in particular the plastic film provided on the underside of the lid assumes a sealing function in the connection area between the can lid and the can and the specifically positioned notch enables opening with little force.

[0014] A preferred embodiment of the invention is explained below with reference to the drawing; the drawing shows: Fig. 1 a schematic top view of a can lid in the closed state, Fig. 2 a sectional view along one diameter of the can lid according to Fig. 1, Fig. 3 an enlarged partial view of the sectional view according to Fig. 2 and Fig. 4 a perspective oblique view of the can lid from above.

[0015] Fig. 1 shows a schematic top view of an embodiment of the can lid 1 according to the invention. This can lid is conventionally provided with a crimped edge 2 around its circumference, the area within which lies within the crimped edge 2 is formed by a lid surface 3 that has an opening 4, designed as a tongue flap, offset from the center. This metallic can lid, made of aluminum, is provided with a stiffening area 14 surrounding the opening 4, formed by material deformation.

[0016] A two-armed lever 5, 6 is connected to the opening area 4 or the tongue tab of the can lid, in particular by riveting or welding, so that a fixed connection point 7 is formed. This connection point 7 is located in the edge region of the opening area 4, i.e., opposite the tongue base connected to the lid surface (3), and the two-armed lever consists of a shorter and a longer section, the longer lever preferably being formed by an easily graspable ring tab 5 and the shorter section by a support leg 6 which, when the longer lever is pivoted upwards, rests on a part of the stiffening area 14 of the can lid. In its initial state, the two-armed lever 5, 6 lies essentially parallel to the lid surface 3.

[0017] The tongue tab forming the opening area 4 is positively and force-fit connected to the lid surface 3 via projections 12 and recesses 13 and preferably via suitable undercuts of these parts, with the exception of the area of ​​the tongue base 7, where opening area 4 and lid surface 3 are metallically connected, so that practically via a kind of hinge 9, when the can is opened, the tongue tab 3 can be pivoted upwards by means of the lever and then the tongue tab and lever can come to a rest position outside the interior of the can, releasing the opening.

[0018] The required tightness of the can lid is ensured, despite the lack of a continuous metallic connection between lid surface 3 and opening area 4 in the area of ​​the serration, by a plastic material, in particular a suitable plastic film, applied to the underside of the metallic lid, covering the entire surface. This material is firmly adhered to or sealed to the underside of the lid. This coating has a pronounced weakening 14 immediately adjacent to and within the opening line or microgap, in particular an indentation or partial perforation, so that when the can lid is opened and the tongue tab 4 is lifted, the narrow area 3 of the plastic film covering the microgap is practically peeled away from the metal, thus enabling the can to be opened with minimal effort.

[0019] To achieve this design, which prevents any metal shavings from forming when the can lid is opened, the opening area or the tongue flap is separated from the surrounding lid surface by a cutting or, preferably, a punching process during the manufacturing of the can lid. The resulting shavings or microparticles can be completely and easily removed during the manufacturing process. The tongue flap, which is still connected to the lid surface 3 via its base, is pressed back into the plane of the lid surface immediately after being punched out. This restores the lid surface to its original appearance, but now with a micro-gap created by the punching process.

[0020] Instead of a linear microgap, interlocking projections 12 and recesses 13 are preferably produced during the punching process, as can be seen in Fig. 1.

[0021] In this case, immediately after the stamping process, the two components, which were initially partially separated, are joined together again in a form-fitting manner, so that the can lid can be handled in further manufacturing steps in the same way as conventional can lids, which only have a weakening groove.

[0022] The processes of separating and joining occur directly one after the other; that is, following the punching stroke, the two parts are positively joined together to form a single component during the return stroke. The positive and non-positive connection between the two areas is achieved through suitable shaping or the use of undercuts, which ensure sufficient mutual mechanical connection. This allows the necessary coating processes, such as the application of the film to the underside, to be carried out as if it were a single, unified part.

[0023] Instead of the toothing shown in the drawing, other, possibly simpler, cleavage line profiles can also be provided during the punching process according to the invention, whereby in any case the opening area or the tongue flap remains connected to the cover surface 3 via the hinge bearing area 9 and the microgap is covered by the plastic film located on the inside, which is provided with a notch. The plastic film, which can be a PP film that reacts with the sealing lacquer applied to the metal when sealed, is produced in particular as a separate blister pack in which the notch is already provided. If the film is, for example, approximately 2 / 10 mm thick, the thickness is reduced to 1 / 100 mm in the notch.

[0024] The slightly enlarged partial view according to Fig. 3 shows, in addition to the design of the connection point 7 in the manner of a rivet connection, above all the full-surface application of the plastic film 10 to the underside of the can lid and in particular the formation of the weakening line 11 in the plastic film 10, preferably achieved by a notch and / or partial notching, which extends, depending on the embodiment, inside or outside the microgap around the opening area 4.

[0025] The perspective view in Fig. 4 illustrates the design features already described in a particularly clear manner and also shows that the ring tab 5, which forms the longer lever arm, can be easily gripped with a finger thanks to a recess in the lid surface 3 and pivoted upwards for opening. During this upward pivoting of the grip tab 5, the shorter lever 6 rests against the stiffened area 14, whereby, as the ring tab is pulled upwards, the opening area 4 is opened, simultaneously releasing the positive-locking connection between the lid surface 3 and the tongue tab 4 without chip formation, and separating and releasing the plastic film on the underside of the lid.

[0026] The ring flap 5 and the opening area 3 raised with it are pivoted into the free right area of ​​the can lid via the hinge bearing area 9 located below the free end of the ring flap in Fig. 4 and remain there when the can is open.

[0027] As described, this method avoids all the disadvantages of the previously known and widely used can lid, especially the potentially harmful formation of tiny micro-aluminum particles when the can is opened. Of particular importance is that all these advantages are achieved without significant additional manufacturing effort.

[0028] The closure and opening system described for a can lid can also be used analogously for other containers and packaging that are to be equipped with a tear-off closure. Reference symbol list

[0029] 1 Can lid 2 Rolled edge 3 Lid surface 4 Opening area, tongue tab 5 Lever arm 6 Lever arm 7 Attachment point, tongue base 8 Micro gap 9 Buckling bearing area 10 Plastic film 11 Weakening line, notch 12 Projection 13 Recess 14 Reinforcing area

Claims

1. A can lid, in particular for beverage cans, comprising a bounded opening region (4) provided in the metallic lid material of a lid surface (3); and a two-armed lever member (5, 6) intended for opening this opening region (4), said lever member (5, 6) being fixedly connected, in particular via a rivet connection (7) or a weld connection, to the lid material, wherein the lower side of the metallic lid (1) is coated in a firmly adhering manner, in particular over its full surface, with a plastic material, in particular a plastic film (10), characterized in that the opening region is configured as a tongue tab (4) which is separated from the lid surface (3) by a microgap (8), in particular a punched gap, extending over the tab periphery and the tongue tab base connected to the lid surface (3) forms a kink bearing (9) which becomes effective during the opening procedure; and in that the coating (10) is weakened, in particular notched and preferably at least partly notched open, adjacent to the microgap (8) between the tongue tab (4) and the lid surface (3).

2. A can lid in accordance with claim 1, characterized in that the two-armed lever member (5, 6) is fastened to the lid surface (3) and the short lever arm (6) pivots the tongue tab (4) into the can interior during the opening procedure together with the part region of the plastic coating (10) covering it at the lower side and bounded by the weakening line (11), with the weakening line or notch line (11) being disposed outside the microgap (8).

3. A can lid in accordance with claim 1, characterized in that the two-armed lever member (5, 6) is fastened to the tongue tab (4) and its short lever arm (6) can be supported on the lid surface (3), in particular on a stiffening region (14) of the lid surface (3); and in that the long lever arm (5) pivots the tongue tab (4) outwardly during the opening procedure together with the part region of the plastic coating (10) covering it at the lower side and bounded by the weakening line (11), with the weakening line or notch line (11) being disposed within the microgap (8).

4. A can lid in accordance with any one of the preceding claims, characterized in that the tongue tab (4) of the metallic can lid (1) is separated from the lid surface (3) surrounding it while forming mutually engaging projections (12) and recesses (13) by a cutting procedure, in particular by a punching procedure; and in that the tongue tab (4) and the lid surface (3) adjoining it are connected in a shape-matched and force-transmitting manner via the projections (12) and the recesses (13) while forming the microgap (8), with the leaktightness of the finished, unopened can lid being ensured by the inwardly disposed plastic coating or film (10) having a thickness preferably in the range from approximately 1 / 10 mm to 3 / 10 mm.

5. A can lid in accordance with claim 4, characterized in that the projections (12) and the recesses (13) are coupled via undercuts.

6. A can lid in accordance with claim 4 or claim 5, characterized in that the lid surface (3) is formed in a concave manner in the region of the tongue tab (4) and the pressing in the microgap is increased by the internal container pressure.

7. A can lid in accordance with any one of the preceding claims, characterized in that the plastic film (10) provided at the lower side forms a separate molded blister part prior to its sealing to the lower side and the notch (11) or the partial opening notch is already provided in said molded blister part.

8. A can lid in accordance with claim 3, characterized in that the two-armed lever member (5, 6) is connected to the tongue tab (4) off-center, in particular at the marginal side.

9. A can lid in accordance with claim 8, characterized in that the longer arm (5) of the two-armed lever member (5, 6) is formed by a gripping tab, in particular by a ring tab.

10. A can having a can lid in accordance with one or more of the preceding claims connected via a bead rim to the can.