Can lid

Abstract

A reclosable can lid is described that has a collar part and a lid receiving part composed of plastic that can be coupled to one another via a snap-in latching connection, wherein a tear line closed in itself is either partly perforated or is formed as a toothed separating line and the leak-tightness is ensured by a sealing film provided at the inner side of the lid cover.

Claims

1. A can lid having a sealingly reclosable opening, the can lid comprising a bounded opening region provided in a metallic lid material of a lid surface as well as a two-armed lifting member intended to open this opening region, said lifting member being connected to a pull tab, on the one hand, and engaging at the opening region of the lid surface, on the other hand, and being supported via a bearing translating the opening force applied to the pull tab; wherein the opening region is configured as a closure lid and is connected at its outer margin in a force-transmitting manner to a collar part composed of a plastic material, and wherein a lid receiving part that is connected in a force-transmitting manner to the lid surface outside the opening region and that is composed of a plastic material is associated with the collar part; wherein the collar part furthermore engages over the lid receiving part and a sealing snap-in latching connection having at least one peripheral coupling rib and a cut-out shaped in complementary form thereto is formed between the collar part and the lid receiving part; and wherein the pull tab is fastened radially outside the lid receiving part to a fixing region of the collar part and the two-armed lever for opening the opening region is formed at a partial peripheral region of the collar part associated with the fixing region; and wherein the lower side of the metallic lid is coated and this coating is attenuated or thinner surrounding the opening region, wherein the collar part and the lid receiving part each have a plurality of molded noses arranged distributed in an annular manner; wherein these noses extend through adapted openings in the metallic lid part; and wherein the collar part and the lid receiving part 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 under the effect of heat while interposing an adhesive promoting layer.

2. The can lid in accordance with claim 1, wherein the adhesive promoting layer or sealing layer reacting at an elevated temperature extends over both surfaces of the metallic lid part, in particular over the outer and inner surfaces of this part of the lid.

3. The can lid in accordance with claim 1, wherein the opening region bounded by a peripheral tear line is connected to the adjacent lid region by an attenuating groove that is perforated at least in part.

4. The can lid in accordance with claim 3, wherein the attenuating groove is perforated in the starting and end regions associated with the tear movement.

5. The can lid in accordance with claim 1 wherein the collar part the lid receiving part and the pull tab comprise the same plastic material and are formed by an injection molded part that coheres via connection tabs, that can be transformed into an assembly unit by folding and that can be connected to the metallic lid material of the surface in a connection step.

6. The can lid in accordance with claim 5, wherein the plastic material is polypropylene.

7. The can lid in accordance with claim 1, wherein the outer peripheral margin contacting the metallic lid material of the surface of the lid receiving part is sealingly connected to this metallic lid material of the surface by hot sealing.

8. The can lid in accordance with claim 7, wherein the pull tab has a nose extending up to the metallic lid material of the surface that is connected to the can lid by sealing.

9. The can lid in accordance with claim 1, wherein the snap-in latching connection between the collar part and the lid receiving part comprises a coupling and sealing rib that is provided at the lid receiving part and that engages into a first adapted recess in the collar part and comprises a preloading and latching lip that latchingly engages into a second recess of the collar part and presses a wall rib between the first adapted recess and the second recess toward the coupling and sealing rib.

10. The can lid in accordance with claim 1 that is configured for beverage cans.

11. The can lid in accordance with claim 1, wherein the lower side of the metallic lid material of the surface is coated in a firmly adhesive manner over the full surface.

12. A can lid having a sealingly reclosable opening, the can lid comprising a bounded opening region provided in a metallic lid material of a lid surface as well as a two-armed lifting member intended to open this opening region, said lifting member being connected to a pull tab, on the one hand, and engaging at the opening region of the lid surface, on the other hand, and being supported via a bearing translating the opening force applied to the pull tab; wherein the opening region is configured as a closure lid and is connected at its outer margin in a force-transmitting manner to a collar part composed of a plastic material, and wherein a lid receiving part that is connected in a force-transmitting manner to the lid surface outside the opening region and that is composed of a plastic material is associated with the collar part; wherein the collar part furthermore engages over the lid receiving part and a sealing snap-in latching connection having at least one peripheral coupling rib and a cut-out shaped in complementary form thereto is formed between the collar part and the lid receiving part; and wherein the opening region of the can lid is separated from a fixed outer lid surface surrounding it by one of a cutting process and a punching process, and wherein the two initially separated parts are again joined to one another in a shape-matched manner such that the two parts practically become one part again that can be handled as a single part and wherein the lower side of the can lid is coated and this coating is attenuated or thinner surrounding the opening region.

13. The can lid in accordance with claim 12, that is configured for beverage cans.

14. The can lid in accordance with claim 12, wherein the can lid is coated in a firmly adhesive manner over the full surface with a plastic material.

15. The can lid in accordance with claim 12, wherein the opening region of the can lid is separated from the lid surface surrounding it while forming mutually engaging projections and recesses by a cutting process; wherein the opening region and the lid surface surrounding it are held together as a component in a shape-matched and force-transmitting manner via these projections and recesses; and wherein the leak-tightness of the finished, unopened can lid is ensured by the inwardly disposed plastic coating or film.

16. The can lid in accordance with claim 15, wherein the cutting process is a punching process.

17. The can lid in accordance with claim 15, wherein the projections and recesses are coupled via undercuts.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will be described in the following with reference to the drawings.

(2) There are shown in the drawings:

(3) FIG. 1 is a plan view of a reclosable can lid in accordance with the invention;

(4) FIG. 2 is a perspective representation of the punched metallic lid surface before the connection to the plastic components of the closure.

(5) FIG. 3 is a perspective sectional representation of the can lid in accordance with FIG. 1;

(6) FIG. 4 is an enlarged detail representation for explaining the sealing coupling between a collar part connected to the container and a lid receiving part;

(7) FIGS. 5A to 5C are representations to explain the production of all plastic components of the closure in one production step;

(8) FIG. 6 is a perspective plan view of a particularly preferred embodiment of the metallic can lid part before connection to the plastic components; and

(9) FIG. 7 is a sectional representation of the can lid in accordance with FIG. 6 with schematically drawn plastic components.

DETAILED DESCRIPTION

(10) FIG. 1 shows a can lid 1 that is designed conventionally in its base shape, that is composed of metal and that is connected in a liquid-tight and gas-tight manner to the respective associated can via a bead rim 2 while interposing a sealing material.

(11) A reclosable opening is integrated in this lid, offset off-center, as will still be explained in detail.

(12) A collar part 5 can be recognized in FIG. 1 that is connected to a tear tab 15, that surrounds the opening region and that is fixedly connected to the can lid surface 23. A lid receiving part 10 surrounds the opening region 11 and can be pivoted upwardly by means of the tab 15 in the opening process. A kink spring element 22 in this respect ensures that the upwardly pivoted lid is held in the open position when it is in particular pivoted open by more than an angle of 90?.

(13) It can also be seen from FIG. 1 that the reclosable opening with all its associated components is arranged off-center, and indeed such that the stackability as with conventional cans is maintained unchanged despite the presence of the reclosable opening.

(14) The requirement for this is above all, in addition to the positioning, the compact design of the reclosable opening in accordance with the invention. The overhang of the components of the reclosable opening over the can surface amounts to only approximately 2 mm in accordance with the invention.

(15) FIG. 2 shows the metallic can lid of an advantageous embodiment of the invention formed as a punched part before the connection to the associated plastic components of the reclosable lid.

(16) Continuous openings 31 can be seen in this representation that serve for the connection of the plastic components to the metallic can lid and that are arranged in annular form at both sides of an attenuating groove or tear notch 4. A special feature of the embodiment of the attenuating groove or tear notch 4 comprises it not being continuous, unlike in conventional solutions, but rather having perforations 36 that produce the advantageous effect that the opening process is facilitated, i.e. the force required to open the upwardly pivotable lid part is reduced. These perforations 36 are formed during the punching process of the lid, but leave the lid part as a uniform punched part. The leak-tightness to be ensured by the can lid is not impaired by the perforations 36 because the required leak-tightness is ensured by an inwardly disposed sealing film that extends over the total inner can lid surface and also into the bead region.

(17) FIG. 3 shows a cross-sectional representation of the can lid in accordance with FIGS. 1 and 2, with the arrangement being shown in the closed state.

(18) The region of the can lid disposed within the tear line 4, i.e. the opening region 11, is surrounded by a lid receiving part 10 composed of plastic that is fixedly and sealingly connected to this metallic region, and indeed by means of a plurality of molded projections 32 that extend through the openings 31 shown in detail in FIG. 2. A fixed connection is established by a rivet-like deformation of these projections 32 under the effect of heat, with it being important, however, that a bonding agent reacting under heat is provided at the contact surfaces between the plastic part and the metal part. Both the outer surface and the inner surface of the metallic can lid are preferably coated with a material effective and suitable as a bonding agent, in particular in the manner of a sealing wax, such that the bonding agent is available wherever it is needed for connection and sealing purposes.

(19) To cooperate with the lid receiving part 10 in the form of a snap-in latching connection, a collar part 5 is provided radially outside the opening region that is composed of plastic and that is connected to the metallic can lid in the same manner as the lid receiving part 10 via noses 30 passing through openings 31.

(20) The provision of a plastic layer or plastic film that extends over the total lower side of the can lid up to and into the region of the bead rim 2 and covers this lower side over the whole surface is important both for the selected connection technique between the metal and the plastic parts and in particular for the configuration of the tear line or attenuating groove 4. This plastic layer 26 is in turn formed with the metallic can lid via an adhesive agent, in particular via a lacquer that becomes effective or reacts on an introduction of heat. It can be seen from FIG. 3 that this sealing layer extends both over the mechanical connection points between the metal parts and plastic parts and over the attenuating groove 4.

(21) The substantial advantage of the described connection technique between the metallic lid and the plastic components comprises the punched metal part and the plastic parts being able to be produced separately, no metal overmolding processes being necessary, and the connection between the metallic can lid and the plastic components being able to take place in one workstep when the plastic components are applied to the metallic surface and the projections 30 pass through the openings 31.

(22) The detailed representation in accordance with FIG. 4 shows a design principle that can generally be used for snap-in latching connections and that is advantageously also used for the reclosable can lid in accordance with the invention.

(23) For this purpose two peripheral ribs are provided at the lid receiving part 10, namely an outwardly disposed coupling and sealing rib 34 and in inwardly disposed preloading and latching rib 35. The coupling and sealing rib 34 sealingly engages into a first recess 39 of the collar part 5, while the preloading and latching rib 35 extends into a second recess 40 of the collar part 5 and a snap-in latching connection is provided between this rib and the recess. It is, however, also important that this rib 35 is dimensioned and designed such that it presses toward the middle wall rib 41 of the collar part in the latched state such that this wall part is pressed toward the sealing rib 39 and thus the sealing effect becomes even more secure and better.

(24) It can also be seen from FIG. 4 that the metallic lid cover is covered at both sides and over the whole surface with an adhesion promoting layer 37, which also makes it possible to fix the outer margin of the lid receiving part 10 that contacts the metallic can lid surface in a sealing manner via the adhesion promoting layer to improve the leak-tightness of a filled can.

(25) With a reclosable can lid, however, not only demands with respect to the leak-tightness have to be satisfied, but it must also and above all be achieved that the can is able to be opened simply and with a small exertion of force. The easily and comfortably grippable pull tab 15 contributes to this, on the one hand, but it is above all important for the invention that the required tearing force is as small as possible. The already mentioned provision of perforations 36 along the tear open line or along the attenuating groove corresponds to this objective and there is additionally the fact that the inwardly disposed plastic film 26 is provided with a peripheral attenuating notch 38 next to the tear line so that the film 26 can also not impede the opening process in a disturbing manner.

(26) The representations in FIGS. 5a to 5c show a particularly advantageous embodiment of the invention that comprises all the plastic components of the reclosable can lid comprising the same plastic material and a production of these plastic components thereby being able to take place in a single injection molding process.

(27) As can be seen from the representations, the collar part 5, the lid receiving part 10 and the pull tab 15 are injected lying in one plane and connected to one another by connection tabs 42 such that a practically single-part total structure is obtained that can be handled as a unit in the production process and only has to be folded over one another for the assembly at the can lid such that the noses 30 of the collar part 5 and the lid receiving part 10 that are then disposed approximately concentrically to one another can be pressed through the openings 31 in the metallic can lid in a single pressing process and can then be deformed in the already described manner.

(28) As can be seen, a corresponding handling and assembly advantage is also obtained in addition to the simplification of the production of the plastic component comprising the same material and reacting with the suitable bonding agent 37 that can be achieved in this manner.

(29) FIG. 6 shows a particularly preferred embodiment of a can lid in accordance with the invention, wherein the metallic can lid part shown in this FIG. 6 can in particular be combined with the plastic elements in accordance with FIG. 5 to form a finished reclosable can lid.

(30) Whereas in known reclosable standard can lids an unwanted and unavoidable gap formation or the creation of very small metallic aluminum particles occurs on the opening by tearing a metallic attenuating groove, the embodiment in accordance with the invention in accordance with FIG. 6 allows an opening that is completely free of splintering and eliminates dangers to the health.

(31) For this purpose, the opening region 11 of the metallic can lid is separated from the outer, fixed can surface 43 surrounding it by a cutting process or in particular by a punching process, and indeed while forming mutually engaging projections 32 and recesses 33, such as is shown in FIG. 6.

(32) Directly after the preferably used punching process, the two initially separated parts are again joined to one another in a shape-matched manner such that the two parts practically become one part again that can be handled as a single part. The processes of separating and joining together take place directly after one another, i.e. the punching stroke is followed in the return stroke by the shape-matched joining together of both parts to form a total part. The shape-matched and force-transmitting connection between the two parts is achieved by suitable shaping or by using undercuts that ensure a sufficient mutual mechanical connection to be able to handle the parts already separated from one another as a uniform assembly part in production.

(33) When the plastic components in accordance with FIG. 5 having the metallic can lid part in accordance with FIG. 6 are sealingly connected to one another in the already described manner and when the rear plastic film 26 is also applied, an arrangement is present such as is shown schematically in a sectional representation in FIG. 7.

(34) In the representation in accordance with FIG. 7, the collar part 5 and the lid receiving part 10 are connected sealingly and permanently to the metallic can lid part in the already explained manner and the snap-in latching connection is in engagement. The leak-tightness is ensured by the film 26 extending up to the bead rim. The tear line 4 is formed by the separating line between the mutually engaging projections 32 and recesses 33.

(35) If the filled can is opened via the pull tab, the projections 32 and recesses 33 defining the tear line move out of engagement, wherein, however, no attenuated metal regions have to be separated from one another while forming splintering, but rather only the present shape-matched connection has to be released, which is possible with a substantially smaller force effort than is required by tearing a still existing metallic connection between the two parts to be separated from one another.

(36) The already mentioned use of the attenuating notch 38 in the inwardly disposed sealing film contributes to the demands made on such a reclosable can lid with respect to both leak-tightness and to minimized opening force being able to be ideally satisfied, and indeed with a simultaneously present economic production and assembly of all can lid components.

REFERENCE NUMERAL LIST

(37) 1 metallic can lid 2 bead rim 3 cover surface 4 attenuating groove or tear line 5 collar part 9 coupling rib 10 lid receiving part 11 opening region 12 recess 13 fixing region 15 pull tab 22 kink spring part 23 can lid surface 26 sealing plastic layer, film 30 nose 31 opening 32 projection 33 recess 34 coupling and sealing rib 35 preloading and latching rib 36 perforation 37 bonding agent, sealing wax 38 attenuating notch 39 first recess 40 second recess 41 wall rib 42 connection tab 43 fixed outer lid surface