US20170129644A1

US20170129644A1 - Reclosable tear-open lid

Info

Publication number: US20170129644A1
Application number: US15/317,605
Authority: US
Inventors: Udo Jobges
Original assignee: Ball Europe Gmbh
Current assignee: Ardagh Metal Packaging Europe GmbH
Priority date: 2014-06-12
Filing date: 2015-04-29
Publication date: 2017-05-11
Also published as: EP3154865A1; WO2015188974A1; DE102014211265A1; CA2989058A1; BR112016028844A2

Abstract

The invention relates to a tear-off lid made of metal sheet which has a central lid plane and, within that, a breakout portion, as well as a grip tab made of metal sheet that can be swiveled about a swivel axis extending at least approximately perpendicular to the lid plane and that has an opener portion on one side of the swivel axis and a grip portion on the opposing side of the swivel axis. The grip portion is shaped such that, upon opening the breakout portion, it can be swiveled over an opening created thereby and enclosed by an outer contour and can tightly seal the opening. The metal sheet that forms the grip portion has apertures, and an elastomer seal is provided on a bottom side of the grip portion facing toward the lid plane that is connected in a form-fitting manner to the grip portion and extends through the apertures.

Description

The invention relates to a resealable tear-off lid for beverage cans or similar containers. Moreover, the invention relates to a beverage can with such a tear-off lid, a grip tab for such a tear-off lid, and a method for manufacturing a corresponding grip tab.
Tear-off lids typically have a central lid plane within which a breakout portion is arranged that is defined, for example, by a line of weakening that can be broken in order to open the lid, so that the breakout portion uncovers an opening, for example a drinking opening. A grip tab is typically provided for opening the breakout portion that is generally connected in a swiveling manner to the lid plane, for example by means of a rivet formed from the lid plane. Such a grip tab typically has a grip portion and an opener portion. The grip tab is shaped such that, when the grip portion is lifted, the opener portion presses against the breakout portion and breaks a line of weakening that defines the breakout portion. Such tear-off lids are generally known.
Moreover, there are concepts in which the resealing of the opening defined by the breakout portion occurs as a result of the grip portion of the grip tab being swiveled or twisted over the opening and subsequently onto or into the opening such that the opening is sealed again. In that case, the swiveling or twisting occurs about a swivel axis or axis of rotation which, at least in the original, unused state of the breakout lid, extends approximately perpendicular to the lid plane. Such a concept is described, for example, in WO 2004/056667 A1.
It is the object of the invention to improve a corresponding tear-off lid.
According to the invention, a tear-off lid made of metal sheet is proposed which has a central lid plane and, within that, a breakout portion, as well as a grip tab made of metal sheet that can be swiveled about a swivel axis extending at least approximately perpendicular to the lid plane and has an opener portion on one side of the swivel axis and a grip portion on the opposing side of the swivel axis. The grip portion is shaped such that, upon opening the breakout portion, it can be rotated over an opening created thereby and tightly seal the opening. The opening is enclosed by an outer contour that forms the edge of the opening. The metal sheet that forms the grip portion has apertures, and an elastomer seal is provided on a bottom side of the grip portion facing toward the lid plane that is connected in a form-fitting manner to the grip portion and extends through the apertures.
The elastomer seal is preferably part of an integrally formed elastomer body that extends both on the bottom side of the grip portion facing toward the lid plane (forming the elastomer seal there) and on the top side of the grip portion facing away from the lid plane.
By virtue of the fact that the elastomer seal, or the elastomer body, extends through the apertures in the metal sheet forming the grip portion, the elastomer seal is reliably connected in a form-fitting manner to the grip portion and can neither be lost nor slip, independently of whether the elastomer seal is additionally connected to the grip portion by other means, for example through adhesion. This means that, in order to produce a suitable grip tab, no adhesion promoter or other agent creating an adhesion between elastomer seal and the metal sheet of the grip portion is required in order to reliably connect the elastomer seal to the grip portion; rather, the elastomer seal is already connected in a defined manner to the grip portion in that the elastomer body forming the elastomer seal extends on both sides of the grip tab (bottom and top side) and through the apertures in the metal sheet of the grip tab. Such an elastomer body can be produced by injection using the injection-molding process.
Due to the fact that the elastomer body and hence the elastomer seal is connected mechanically in a form-fitting manner to the grip portion, no great consideration need be taken of other characteristics (besides the mechanical characteristics), such as adhesion characteristics, etc., in selecting the elastomer. Instead, the elastomer can be selected entirely based on mechanical requirements. There is complete freedom in the design of the seal geometry as well.
What is more, such an elastomer seal is cost-effective to manufacture in conjunction with such a grip portion, because the apertures for the elastomer body can be created in one work step with other apertures of the grip tab, such as the central openings for the rivet, for example. Nor does the injection molding of the elastomer body require more effort than the injection molding of another type of seal, as it is not necessary with the elastomer body according to the invention to take any preparatory measures to improve adhesion.
The apertures are preferably arranged along a contour of the grip portion corresponding more or less to an outer contour of an opening to be produced by opening the breakout portion, i.e., to the outer contour and hence the edge of what will later be the drinking opening. The apertures are thus located where stress is presumably most strongly applied on the elastomer seal during use. This makes it possible to implement the elastomer seal in the form of a relatively thin elastomer body.
Preferably, between 2 and 24 apertures are provided along this contour, with a number between 4 and 12 or 4 and 8 apertures being preferred. Just 2 apertures will enable achievement of a defined positioning of the elastomer seal in relation to the grip portion such that no rotation of the elastomer seal is permitted, for example. A greater number of apertures may counteract deformation of the elastomer seal, if required.
The apertures are preferably approximately circular in shape and have a diameter of 2 mm or less. Alternatively, the apertures can be slits that are opened by the injection pressure upon injection molding of the elastomer body.
The elastomer seal preferably forms an unbroken surface on the bottom side of the grip portion, with the unbroken surface being structured such that it completely covers an opening to be produced by opening the breakout portion when the grip portion seals this opening. This results in an unbroken elastomer surface that completely covers the drinking opening when the lid is in the closed state. The only contact surface between the grip portion acting as a seal and the drinking opening is therefore that between the edge of the drinking opening and the elastomer seal. It is advantageous if the elastomer seal has a sealing ridge there that is, along the outer contour of the opening to be produced by opening the breakout portion.
The elastomer body preferably extends on the outer side of the grip portion facing away from the lid plane beyond several of the apertures. As a result, the elastomer body cannot detach from the grip portion without destroying the elastomer body.
Preferably, on the outer side of the grip portion facing away from the lid plane, the elastomer body forms a sign, e.g., a graphic symbol, that is recognizable to the user. It is thus unnecessary to imprint a symbol that may be desired into the metal sheet forming the grip portion. Such an imprinting step can thus be omitted.
Preferably, the grip tab can be swiveled over a rivet shaped from the lid plane and is rotatably connected thereto. Such a connection between grip tab and lid plane is inherently known, but it has special importance in the case of a grip tab whose grip portion is used simultaneously as a closure for the drinking opening and, in particular, must permit an appropriate rotation.
The tear-off lid and the grip tab are preferably made of aluminum sheet. This material has proven to be the most suitable for the manufacture of lid and grip tab.
According to another aspect of the invention, a beverage can with a can body and a tear-off lid is proposed, with the tear-off lid being connected tightly over its entire periphery to the can body and being a tear-off lid of the type described herein. The connection between tear-off lid and can body is preferably achieved with a double seam and is hermetically tight.
According to another aspect of the invention, a grip tab made of metal sheet for a tear-off lid of the type described herein is proposed. The grip tab has a grip portion that is designed to seal a drinking opening in a tear-off lid and has an elastomer seal that is part of an integrally formed elastomer body that extends through apertures of the grip portion and, as a result of this, is connected in a form-fitting manner to the grip portion.
Preferably, such a grip tab is produced by placing a finished sheet-metal part forming the grip tab into an injection mold and injecting a preferably thermoplastic elastomer against the sheet-metal part such that an integrally formed elastomer body is formed that penetrates through apertures in the sheet-metal part.

The invention will now be explained in further detail on the basis of an exemplary embodiment with reference to the figures.

FIG. 1 shows a two-part beverage can with a can body and a lid;

FIG. 2 shows a tear-off lid according to the invention;

FIG. 3 shows a top view of a grip tab for a tear-off lid according to the invention;

FIG. 4 shows a bottom view of a grip tab for a tear-off lid according to the invention;

FIG. 5 shows a partial section through the grip tab and the injection-molded elastomer body;

FIG. 6 shows an alternative design variant of a grip tab for a tear-off lid according to the invention; and

FIG. 7 shows another alternative design variant of a grip tab for a tear-off lid according to the invention.

FIG. 1 shows a beverage can 10 with a can body 12 and a lid 14 that is connected tightly by means of a double seam to the can body 12. Can body 12 and lid 14 are each made of metal sheet. The can body can be made of aluminum sheet or tinplate, whereas the lid 14 is preferably made of aluminum sheet.
As can be seen from FIG. 2, the lid 14 has an ordinary lid plane 20 within which a breakout portion 22 is defined by a line of weakening 24. The line of weakening 24 defines the edge and hence the outer contour of the drinking opening that is formed upon breaking-open of the breakout portion 22. A grip tab 28 is connected by a rivet 26 to the lid plane 20 of the lid 14.
The grip tab 28 has a grip portion 30 and an opener portion 32 between which a rivet opening 34 for the rivet 26 of the lid 14 is located. The grip tab 28 is formed in an inherently known manner from a piece of aluminum sheet. An elastomer body 36, which forms an elastomer seal 38 on the bottom side of the grip portion of the grip tab 28, is injection-molded against the grip tab 28. The elastomer body 36 extends through apertures 40 in the metal sheet forming the grip portion 30 and forms, on the top side of the grip portion 30, an integrally formed, closed and circumferential elastomer ridge 42. The elastomer body 36 is connected integrally and by means of injection molding to the metal sheet of the grip tab 28.
To create the grip tab 28, the completely formed metal sheet of the grip tab 28 is placed into a corresponding injection mold, and the elastomer body 36 is then injected.
As can be seen particularly from FIG. 5, the elastomer body 36 extends through the apertures 40 in the metal sheet of the grip portion 30, so that the elastomer seal 38 on the bottom side of the grip portion 30 and the elastomer ridge 42 on the top side of the grip portion 30 are integrally connected to one another and the elastomer body 36 can no longer detach from the metal sheet of the grip tab 28.
Adhesive forces between the elastomer body 36 in the metal sheet of the grip tab 28 are not necessary, so no adhesion promoter is required for the joining of the elastomer body 36 with the metal sheet of the grip tab 28.
Rather, the connection between the elastomer body 36 and the grip of the sheet-metal tab 28 is achieved by purely mechanical means by positive locking, with the elastomer body 36 extending through the apertures 40 in the metal sheet of the grip tab 28.
As can be seen from FIGS. 3 and 4, a total of six apertures 40 are provided in the depicted exemplary embodiment that are arranged along a contour corresponding at least approximately to the outer contour of the breakout portion 22, which, in turn, is defined by the line of weakening 24. Instead of a total of six apertures, it is also possible to provide only at least two apertures, but also up to 24 apertures. FIG. 6 shows an exemplary embodiment of a grip tab 28′ with a total of 24 apertures 40′.
The arrangement of the apertures 40 along the outer contour of the breakout portion 22 is advantageous because, in the resealed state of the lid 14, the elastomer seal 38 is intended to rest tightly along the outer contour of the breakout portion 22 against the edge of the drinking opening produced by breaking open the breakout portion 22. For this purpose, the elastomer seal 38 formed by the elastomer body 36 also has a sealing ridge 44 that extends along the outer contour of the breakout portion 22 and is reliably held in place by the apertures 40 that are also arranged along the sealing ridge 44.
As can be seen particularly from FIG. 4, the elastomer seal 38 forms an unbroken surface that encloses the sealing ridge 44 and is completely enclosed within the surface enclosed by the sealing ridge 44. This has the effect that, when the lid 14 is in the resealed state, a drinking opening formed after the breaking-open of the breakout portion 22 is completely covered by the elastomer seal 38.
Alternatively, instead of a completely closed elastomer seal 38, it is also possible for only a sealing ridge 44′ to be provided along the edge of the drinking opening (that is, along the outer contour of the breakout portion 22). Such an alternative sealing ridge 44′ would then have not only a sealing surface associated with the edge of the drinking opening, but also a second sealing surface that faces toward the bottom side 46 of the grip portion 30 of the grip tab 28. A corresponding exemplary embodiment is illustrated in FIG. 7.

List of Reference Symbols

10 beverage can
12 can body
14 lid
20 lid plane
22 breakout portion
24 line of weakening
26 rivet
28 grip tab
30 grip portion
32 opener portion
34 rivet opening
36 elastomer body
38 elastomer seal
40 apertures
42 elastomer ridge
44, 44′ sealing ridge
46 bottom side of the grip portion 30

Claims

1. A resealable tear-off lid made of metal sheet for beverage cans or the like, comprising a central lid plane within which a breakout portion is arranged, as well as a grip tab made of metal sheet that can be swiveled about a swivel axis extending at least approximately perpendicular to the lid plane and has an opener portion on one side of the swivel axis and a grip portion on the opposing side of the swivel axis, with the grip portion being shaped such that, upon opening the breakout portion it can be rotated over an opening produced in this manner and enclosed by an outer contour and can tightly seal the opening, characterized in that the metal sheet forming the grip portion has apertures and that an elastomer seal is provided on a bottom side of the grip portion facing toward the lid plane that is connected in a form-fitting manner to the grip portion and extends through the apertures.

2. The tear-off lid as set forth in claim 1, wherein the apertures are arranged along a contour of the grip portion corresponding more or less to the outer contour of an opening to be produced by opening the breakout portion.

3. The tear-off lid as set forth in claim 2, wherein at least 2 and no more than 12 apertures, and preferably between 4 and 8 apertures, are arranged along the contour.

4. The tear-off lid as set forth in claim 1, wherein the apertures have a substantially circular shape and a diameter of 2 mm or less.

5. The tear-off lid as set forth in claim 1, wherein the apertures are formed by slits that can be opened by the injection pressure of the injection-molding of the elastomer body.

6. The tear-off lid as set forth in claim 1, the elastomer seal forms an unbroken surface on the bottom side of the grip portion that completely covers an opening to be produced by opening the breakout portion when the grip portion seals this opening.

7. The tear-off lid as set forth in claim 6, wherein the elastomer seal has a sealing ridge along the outer contour of the opening to be produced by opening the breakout portion.

8. The tear-off lid as set forth in claim 1, wherein the elastomer sear is part of an integrally formed elastomer body that extends both on the bottom side of the grip portion facing toward the lid plane and forming the elastomer seal there and on the top side of the grip portion facing away from the lid plane.

9. The tear-off lid as set forth in claim 8, wherein the elastomer body extends beyond several of the apertures on the outer side of the grip portion.

10. The tear-off lid as set forth in claim 8, wherein the elastomer body forms a symbol that is recognizable to the user on the outer side of the grip portion facing away from the lid plane.

11. The tear-off lid as set forth in claim 8, wherein the elastomer body is produced by injection molding with a grip portion placed in an injection mold.

12. The tear-off lid as set forth in claim 1, wherein the grip tab is connected in a swiveling and rotating manner to the lid plane by means of a rivet formed from the lid plane.

13. The tear-off lid as set forth in claim 1, wherein the tear-off lid and the grip tab are manufactured from aluminum sheet.

14. A beverage can comprising a can body and a tear-off lid as set forth in claim 1, wherein the tear-off lid is tightly connected to the can body over its entire periphery.

15. A grip tab made of metal sheet for a tear-off lid as set forth in claim 1, wherein the grip tab has a grip portion that is designed to seal a drinking opening in a tear-off lid and has an elastomer seal that is part of an integrally formed elastomer body that extends through apertures of the grip portion and is consequently connected in a form-fitting manner to the grip portion.

16. A method for manufacturing a grip tab as set forth in claim 15, wherein a finished sheet-metal part forming the grip tab is placed into an injection mold and a preferably thermoplastic elastomer is injected against the sheet-metal part such that an integrally formed elastomer body is formed that penetrates through apertures in the sheet-metal part.