CAN END AND METHOD OF MANUFACTURING A CAN END

Abstract

A can end comprises a metallic end surface in which an opening is formed that is closed by a closure piece of the metallic end surface, wherein the closure piece is separated from the surrounding end surface by a microgap extending at least sectionally along the margin of the end surface. A first end region of the closure piece is connected to the surrounding end surface via a pivot bearing. The can end further comprises a tear-open member that engages at a second end region of the closure piece, said second region being opposite the pivot bearing. The microgap is interrupted between the first end region and the second end region by at least one holding web via which the closure piece and the surrounding end surface are connected to one another in a bonded manner.

Claims

1-20. (canceled)

21. A can end, comprising a metallic end surface in which an opening is formed that is bounded by a closed margin of the end surface and that is closed by a closure piece of the metallic end surface, wherein the closure piece is separated from a surrounding end surface by a microgap extending at least sectionally along the closed margin of the end surface, wherein a first end region of the closure piece is connected to the surrounding end surface via a pivot bearing; and a tear-open member that engages at a second end region of the closure piece, said second end region being opposite the pivot bearing, so that a pivoting of the closure piece out of a plane defined by the opening is made possible by pulling at the tear-open member, wherein the microgap is interrupted between the first end region and the second end region by at least one holding web via which the closure piece and the surrounding end surface are connected to one another in a bonded manner.

22. The can end in accordance with claim 21, wherein the at least one holding web has a width from 0.5 mm to 6 mm.

23. The can end in accordance with claim 21, wherein the at least one holding web has a notch.

24. The can end in accordance with claim 21, wherein the microgap is interrupted between the first end region and the second end region by a web arrangement comprising at least two holding webs via which the closure piece and the surrounding end surface are connected to one another in a bonded manner.

25. The can end in accordance with claim 24, wherein the web arrangement comprises holding webs arranged at both sides of the second end region.

26. The can end in accordance with claim 25, wherein the web arrangement comprises at least one pair of holding webs arranged disposed opposite one another with respect to a central region of the closure piece.

27. The can end in accordance with claim 24, wherein the web arrangement comprises at least four and at most eight holding webs arranged distributed along the closed margin of the end surface.

28. The can end in accordance with claim 24, wherein the holding webs of the web arrangement are of identical design.

29. The can end in accordance with claim 21, wherein the microgap is a punched gap and the at least one holding web is formed by a punched recess.

30. The can end in accordance with claim 21, wherein the microgap has a maximum width of 0.01 mm.

31. The can end in accordance with claim 21, wherein a coating composed of a plastic material is applied to a flat side of the metallic end surface in a manner covering the microgap.

32. The can end in accordance with claim 31, wherein the coating is applied to an inner side of the metallic end surface.

33. The can end in accordance with claim 31, wherein the coating is applied over a full area to the flat side of the metallic end surface.

34. The can end in accordance with claim 31, wherein the coating has a weakening that is arranged at a distance from the microgap.

35. The can end in accordance with claim 21, wherein the tear-open member is a gripping, pulling and/or lever element, in particular composed of a plastic material.

36. The can end in accordance with claim 35, wherein the tear-open member is composed of a plastic material.

37. The can end in accordance with claim 21, wherein a sealing frame composed of a plastic material and surrounding the opening is connected to the surrounding end surface and a closure unit composed of a plastic material and supporting the closure piece is pivotably attached to the surrounding end surface, with the sealing frame and the closure unit being releasably connectable in a fluid-tight manner to one another via sealing and latching ribs and associated reception grooves.

38. A method of manufacturing a can end, wherein an at least regionally flat metal element is provided, and wherein a closure piece is punched out of the metal element and is reinserted into an opening formed by the punching process, and wherein the punching out is performed using a punching die that has a cutting edge having at least one recess.

39. A can end, comprising a metallic end surface in which an opening is formed that is bounded by a closed margin of the end surface and that is closed by a closure piece of the metallic end surface, wherein the closure piece is separated from a surrounding end surface by a microgap extending at least sectionally along the closed margin of the end surface, wherein an arrangement of venting notches is formed in the metallic end surface and is in connection with the microgap.

40. The can end in accordance with claim 39, wherein the arrangement of venting notches is formed in an inner side of the metallic end surface.

41. The can end in accordance with claim 40, wherein a coating composed of a plastic material is applied to the inner side of the metallic end surface in a manner covering the microgap and at least partly covering the arrangement of venting notches.

42. The can end in accordance with claim 39, wherein the venting notches define a radial pattern and/or wherein each of the venting notches extends at least from the microgap up to a marginal region of the metallic end surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will be described in the following by way of example with reference to the drawing.

[0034] FIG. 1 is a plan view of a can end in accordance with the invention for a beverage can, said can end comprising a reclosable opening system;

[0035] FIG. 2 shows the can end in accordance with FIG. 1 with the opening system omitted;

[0036] FIG. 3 is an enlarged part representation of the can end shown in FIG. 2 that shows a holding web;

[0037] FIG. 4 shows a can end in accordance with a further embodiment of the invention; and

[0038] FIG. 5 shows, in a simplified form, the lower side of a can end in accordance with the invention.

DETAILED DESCRIPTION

[0039] FIG. 1 shows a can end 11 which is in particular intended for a beverage can and into whose metallic end surface 13 a reclosable opening system 15 is integrated. The can end 11 can be connected to an associated container, not shown, via a beaded rim 12. An opening is provided in the metallic end surface 13, which opening is closed by a section of the metallic end surface 13 in the form of a closure piece 19 in the delivery state of the can end 11 shown in FIG. 1.

[0040] As can be recognized in FIG. 2, the closure piece 19 is separated from the surrounding end surface 23 by a microgap 21. In the region of the microgap 21, the outer margin 25 of the closure piece 19 and the inner margin 27 of the surrounding end surface 23 adjoin one another.

[0041] The metallic end surface 13 is preferably formed from a sheet metal layer composed of aluminum or tin plate. A coating composed of a plastic material and covering the microgap 21 is applied to an inner flat side of the metallic end surface 13, which is not visible in FIGS. 1 and 2, however. An adhesive lacquer layer, which is likewise not visible in the Figures, can be provided for a fixed connection of this coating to the metallic end surface 13. The coating is preferably applied over the full area to the inner flat side of the metallic end surface 13. In certain applications, it could, however, also be sufficient to provide a coating only in the environment of the microgap 21. The coating can be a plastic film, for example, composed of propylene. A notch, which extends along the microgap 21 at a predefined spacing therefrom, is formed in the coating.

[0042] The can end 11 can be opened by moving the closure piece 19 out of the plane defined by the opening (in FIGS. 1 and 2, the paper plane). Since there is no bonded connection between the closure piece 19 and the surrounding end surface 23 in the region of the microgap 21, no noticeable metal separation has to take place on the first opening of a can provided with the can end 11 in accordance with the invention so that the otherwise unavoidable formation of metallic microparticles is reduced or completely prevented. This avoidance of the creation of microparticles in the opening process, in particular microparticles composed of aluminum, is of importance under health aspects since such microparticles unavoidably also enter into the product contained in the respective can and thus also into the human body.

[0043] The coating reliably seals the microgap 21. The notch, which can have a uniform depth or, if applicable, can also locally have different depths, ensures that only a comparatively small force is required to open the can end 11. The spacing between the microgap 21 and the notch 35, which preferably amounts to approximately 0.2 to 0.5 millimeters, improves the sealing effect.

[0044] The reclosable opening system 15 (FIG. 1) comprises a sealing frame, not recognizable in the plan view in accordance with FIG. 1, composed of a plastic material and surrounding the opening, said sealing frame being fixedly connected to the surrounding end surface 23. A closure unit 40 composed of a plastic material and supporting the closure piece 19 is further provided and is pivotably attached to the surrounding end surface 23. A releasable fluid-tight connection between the sealing frame and the closure unit 40 is made possible by means of a latch device that is formed by sealing and latching ribs 43 and associated reception grooves. The can end 11 is therefore reclosable.

[0045] A tear-open member 47 that is annular here, preferably likewise composed of plastic, is connected to or directly molded to the closure unit 40 and is accordingly fastened to the closure piece 19. By pulling at the tear-open member 47, a user can pivot the closure piece 19 upwardly out of the plane defined by the opening and can thus release the opening while separating the coating. A molded-on pivot bearing 48 (FIG. 1) is formed at the closure unit 40 in a manner disposed diametrically opposite the closure unit 40 and is fixedly connected to the surrounding end surface 23. Thus, a first end region 61 of the closure piece 19 is connected to the surrounding end surface 23 via the pivot bearing 48, while the tear-open member 47 engages at a second end region 62 of the closure piece 19, said second end region 62 being opposite the pivot bearing 48.

[0046] Between the first end region 61 and the second end region 62, the microgap 21 is interrupted by two holding webs 65 (FIG. 2) via which the closure piece 19 and the surrounding end surface 23 are connected to one another in a bonded manner. The two holding webs 65 form a web arrangement 70. As shown, the two holding webs 65 are arranged disposed opposite one another with respect to a central region 66 of the closure piece 19. The width of the identically designed holding webs 65 is preferably in a range from 0.5 mm to 6 mm and, for example, amounts to at least approximately 3 mm. Depending on the application, more than two holding webs 65 can also be provided. A detailed view of one of the holding webs 65 is shown in FIG. 3, wherein the microgap 21 is shown here with an exaggerated width for clarification.

[0047] The holding webs 65 preferably have respective notches 75 to avoid an undefined tearing of the metallic end material.

[0048] On the first opening of the can, a user pulls at the tear-open member 47 and thereby upwardly pivots the closure unit 40 with the closure piece 19. In this respect, the latch connection between the closure unit 40 and the sealing frame is released. Furthermore, the coating is separated along the microgap 21.

[0049] Due to the holding webs 65, only a relatively small opening is produced in the end surface 13 at the start of the pivoting process, said opening extending starting from the second end region 62 up to the region of the holding webs 65. The holding webs 65 at least briefly counteract a further opening. The relatively small opening in the environment of the second end region 62 provides a ventilation of the can. In the further course of the pivoting process, the holding webs 65 tear, in particular since they are of a relatively narrow design. After the tearing of the holding webs 65, the closure piece 19 can be pivoted completely upwardly to release the total opening. Due to the opening graduated by the holding webs 65 and the associated venting effect, no significant spraying, popping or foaming over occurs in this respect.

[0050] The contents of the can can be removed through the opening produced. When the closure unit 40 with the closure piece 19 is pivoted back again, the latch connection between the closure unit 40 and the sealing frame is established again such that the opening is sealed tightly again despite the separated coating. The opening and closing can be repeated as often as desired.

[0051] In the alternative embodiment of a can end 11 in accordance with the invention shown in FIG. 4, a web arrangement 70 comprising a total of six holding webs 65 is provided that are arranged distributed along the margin 27 of the metallic end surface 13. Specifically, an arrangement of three holding webs 65 is located at each side of a line 72 extending through the first end region 61 and the second end region 62. This enables a more finely graduated venting, on the one hand, and, on the other hand, ensures a particularly stable hold of the closure piece 19 at the intended position before the initial opening of the closure. It is understood that the number, the distribution, and the width of the holding webs 65 can vary in dependence on the respective application.

[0052] FIG. 5 shows, in a simplified form, a can end 13 in accordance with the invention from below. An arrangement of venting notches 80 is formed in the lower side, i.e. the inner side, of the metallic end surface 13. As shown, each of the venting notches 80, in particular rectilinear venting notches, extends from a marginal region 87 of the metallic end surface 13 up to the microgap 21. They could also extend slightly beyond the marginal region 27. The course of the venting notches 80 is radial. In the embodiment shown, the venting notches 80 define a radial pattern, i.e. the radially extending venting notches 80 are arranged distributed over the periphery of the metallic end surface 13 that is circular in this case. The venting notches 80 are preferably embossed into the metallic end surface 13 by means of an embossing tool, for example with an embossing depth of 0.07 mm.

[0053] The microgap 21 and the arrangement of venting notches 80 are covered by a sealing film, not visible in FIG. 5, that is composed of plastic and that is applied to the inner side of the metallic end surface 13. In particular on the application of the sealing film, the venting notches 80 cause a venting of the intermediate space between the metallic end surface and the sealing film via the microgap 2. The microgap 21 present is therefore used for a venting. In this way, the formation of bubbles and the like is prevented, and indeed across the total metallic end surface 13 due to the radiating pattern.

[0054] The effect of the holding webs 65 is independent of the presence of the reclosable opening system 15. Therefore, the provision of one or more holding webs 65 as described is also advantageous for non-reclosable can ends without a sealing frame and a closure unit, i.e. for standard can ends.

[0055] Furthermore, the effect of the venting notches 80 is independent of the presence of the holding webs 65 so that the provision of venting notches 80 is also advantageous for standard can ends and reclosable can ends whose microgaps are not interrupted by holding webs.

[0056] To manufacture a can end 11 in accordance with the invention, an areal metal element, for example a sheet metal layer composed of aluminum or tin plate, is provided and is fed to an embossing apparatus in which the beaded rim 12, the venting notches 80 as well as grooves, reinforcement beads and the like are molded into the areal metal element. The stamped metal element is fed to a punching apparatus in which the closure piece 19 is punched out of the metal element and reinserted into the opening formed by the punching process. Specifically, in the course of the return stroke of the punching die, the punched-out closure piece 19 is immediately pressed directly into the sheet metal layer again by a spring force and is held there in a force-fitted manner.

[0057] To produce the holding webs 65, the punching out is performed by means of a punching die whose cutting edge is not of a closed peripheral design, but has corresponding recesses having respective embossing stamps for producing the notches 75. The inner flat side of the metal element is subsequently provided with the coating, in particular the sealing film. The embossing apparatus and the punching apparatus can be integrated into a progressive tool, if necessary, together with further processing apparatus.

REFERENCE NUMERAL LIST

[0058] 11 can end [0059] 12 beaded rim [0060] 13 metallic end surface [0061] 15 reclosable opening system [0062] 19 closure piece [0063] 21 microgap [0064] 23 surrounding end surface [0065] 25 outer margin [0066] 27 inner margin [0067] 40 closure unit [0068] 47 tear-open member [0069] 48 pivot bearing [0070] 61 first end region [0071] 62 second end region [0072] 65 holding web [0073] 66 central region [0074] 70, 70 web arrangement [0075] 72 line [0076] 75 notch [0077] 80 venting notch [0078] 87 marginal region