EP1744968B1 - Vacuum-tight lid for containers - Google Patents

Description

The invention relates to a closure lid made of sheet metal for attachment to an opening of a container, in particular a food-containing container whose contents should be kept until the first opening of the lid under a negative pressure, as indicated in the preamble of claim 1.

There are closure lid made of sheet metal in the trade, in which the edge portion is provided with an inwardly projecting circumferential or interrupted bead. These lids are quite often used to hermetically seal filled glass containers with a food such as mustard, mayonnaise, or the like, in which the peripheral edge surrounding the container opening does not have sufficient thickness to attach a screw thread and / or the container is retracted the consumption of the container contents for further use as drinking glass should be suitable. In order to ensure the quality of the contents of the container, the contents of these containers are normally kept under a negative pressure until they are opened for the first time, which allows control of the maintenance of the seal between the closure cap and the opening edge. However, this has the consequence that when first opening such a lid not only the mechanical anchoring of the lid on the container due to the engagement of the bead behind the usually thickened peripheral edge of the container but also the negative pressure in the container is overcome. Especially with closures with a larger diameter, this is possible only with considerable effort or using technical aids, which often leads to damage to the lid.

To solve this problem was in the DE 297 11 363 U1 already proposed a closure lid having a small ventilation opening in the middle, which is closed by a sealing film. This sealing film can be before the first opening the container are withdrawn to allow ambient air to enter through the vent in the container. As a result, the negative pressure in the container is eliminated, whereupon the lid can be opened most easily.

Problems with the opening often occur in canned or jam jars with metallic screw caps, the contents of which is under a negative pressure. The screw caps of such containers also have a closure member abutting against the peripheral edge of the container opening and a peripheral portion surrounding the peripheral edge on the outer periphery thereof for engaging with projecting thread ribs on the outside of the peripheral edge at its free lower end end with an inward one protruding bead or beading is provided. This bead or crimp is pressed when tightening the lid against the thread ribs on the outside of the peripheral edge and, together with the negative pressure inside the container for a secure closure of the same. To open the screw cap must be turned off, but this is often quite difficult especially older and weaker people.

To facilitate the opening, it is for example from the DE 92 00 763 U1 even with such screw caps already known to provide on the closure part a punched vent opening, which is covered by a film seal from the outside under pressure, whereby the negative pressure in the container before unscrewing the lid can be relieved by peeling or piercing the foil seal.

However, in the known closure lids before removing the sealing film for the consumer is not readily apparent whether the container contents is still under a negative pressure and thus an uninterrupted tightness was ensured since the filling. For this purpose, the consumer would have to apply a force on the lid before pulling off the sealing foil in order to determine the resistance of to convince the tightness of the closure, as when pulling or piercing the sealing film at best, when listening carefully a slight hiss is audible, which is caused by the entry of ambient air through the vent opening into the container.

From the US-B1-6 194 011 already a closure lid for food containers is known in which this problem has been solved. The closure part of the lid is provided there in the middle with a molded-in bubble and between an outer peripheral edge of the click bubble and a circumferential sealing edge with a closed by a foil seal ventilation opening. The foil seal has a sealing part connected to the cover around the ventilation opening and a gripping tab connected in one piece to the sealing part and projecting over the sealing part on one side.

From the US-A-3,369,689 For example, a similar closure lid is known in which the ventilation opening and the sealing part of the foil seal associated with the lid are arranged in a recessed annular portion of the closure part.

Proceeding from this, the object of the invention is to improve a closure lid of the aforementioned type such that the gripping tab of the foil seal can be gripped more easily and that when the foil seal is removed, the click bubble is not concealed by the user's hand, so that the snap-up of the click bubble visually visible and acoustically better audible.

This object is achieved by the features in the characterizing part of claim 1.

Click bubbles, which are also referred to as a flip or button, have long been used on a large scale on metallic screw caps of glass jars with preserves, jam or the like glass containers. These click bubbles are circular cambers, the have been formed in the center of their closure parts in the manufacture of the screw under special stress conditions and are pressed from the ambient pressure down into the container interior when the pressure difference between the ambient pressure and the negative pressure in the containers exceeds a predetermined level. When the screw caps have been loosened the first time the containers are opened so that ambient air between a molded on the bottom of the lid seal and the peripheral edge of the container can enter through the latter, the click bubbles with an audible clicking sound back up to its unloaded position , However, the already mentioned, required to open these screw caps not inconsiderable effort to many consumers to screw the lid put her palm on the top of the lid, so that the click sound generated when the click bubble bursting cushioned or no audible click sound is generated. Moreover, because of the effort required, many consumers focus so much on the opening process themselves when opening the container that the click sound is not perceived. This is also helped by the noise produced when unscrewing the cover, which may overlap or even drown out the click sound. In addition, the flash-up of the click bubble for the consumer is not visually verifiable, since there is hardly a way to take the lid to screw on so that the click bubbles remain visible.

In contrast, the invention is based on the idea that the consumer will focus on the closure lid when removing the foil seal, so that he can easily perceive the rocketing of the click bubble provided in the center of the lid both visually and acoustically. This is achieved to a particularly high degree if the ventilation opening is arranged according to the invention with the film seal, so that the process of the snap-up of the click bubble is neither obscured nor obstructed by the consumer's finger acting on the film seal. The The arrangement according to the invention also has the advantage that the click sound generated when the click bubble flashes, unlike a foil seal which completely or partially overlaps the click bubble, does not experience any damping by the seal. However, the eccentric arrangement requires measures to ensure accurate positioning of the foil seal on the vent opening, for example, by introducing the vent opening into the closure lid after painting the closure lid and immediately prior to applying the foil seal such that there is a twist between these operations the closure lid is avoided. This, in turn, has the result that the closure lid is not coated with lacquer along the cut edges within the opening, although it has been found that this does not present any problems, particularly with aluminum caps, in most food products.

The invention provides that the sealed with the film seal ventilation opening is arranged in the radial direction of the lid between an outer edge of the click bubble and a raised, provided on the bottom with a sealing material sealing edge of the closure part, within an annular portion of the closure lid, the forms the groove bottom of a arranged between the outer edge of the click bubble and the sealing edge flat annular groove. In upwardly curved unloaded click bubble of this groove bottom is substantially parallel to the planes which are spanned by the flat top of the raised sealing edge of the lid or by the lower edge of the edge portion.

If there is a negative pressure of about 0.2 to 0.3 bar in the interior of the container, which vacuum is dependent on the diameter of the lid and can be adjusted within certain limits, for example by changing the thickness of the lid and other parameters, the click bubble will be in the environment pressure pressed retracted position in which it is under bias. If the vacuum is relieved the first time the lid is opened, Swings the click bubble upwards, producing a clearly audible click sound.

To complicate a possible manipulation of the container, provides a further advantageous embodiment of the invention that the film seal after its removal no longer adheres to the lid. However, if necessary, a seal variant can be used, which can be stuck again on the vent on the lid.

According to the invention, the film seal on the top of the lid aufgesiegelten on the edge of the vent opening seal member and integrally connected to the sealing part grip tab which protrudes on one side over the preferably substantially circular seal member, wherein its central axis is substantially perpendicular to a through the vent opening extending lid radius is aligned. In this way, the foil seal can be peeled off in a direction that runs laterally past the click bubble, so that it is not covered by the fingers of the consumer engaging with the grip tab during removal.

The foil seal itself preferably consists of a gas-tight foil, such as an aluminum or composite foil, which is connected to the lid around the circular vent opening, on a surface whose radius is a multiple of the radius of the vent opening.

In order to connect the film seal with the lid, it is preferably coated on its underside facing the lid with a plastic-containing paint, which melts with a corresponding, applied to the outside of the lid plastic-containing paint, when the applied to the lid film seal in the region of its sealed part briefly heated to a temperature exceeding the melting temperature of the paint and thereby pressed against the lid. In this case, the sealing film or the outside of the lid can be coated either over the entire surface or only partially in the areas to be sealed with the paint, but in the former case, only the sealing part may be heated and pressed against the lid. Alternatively, however, a hot melt adhesive can also be used.

Preferably, the diameter of the ventilation opening, the amount of applied to the underside of the film seal varnish or hot melt adhesive, its viscosity in the heated state and the contact pressure matched so that when pressed a small amount of paint flows into the opening to within the eccentric vent one To achieve so-called cut edge sealing, but this amount remains so small that a closing of the opening by the paint or hot melt adhesive is avoided.

In order to facilitate the gripping tab of the foil seal, the grip tab can be provided with an embossment which causes its rear edge facing away from the seal part to protrude somewhat above the cover surface. Alternatively or additionally, for the same purpose, the closure part of the lid in the vicinity of the ventilation opening can be provided with a small embossed high curvature.

Brief description of the drawings

• Fig. 1: eine Oberseitenansicht eines erfindungsgemäßen Verschlussdeckels;
• Fig. 2: eine Schnittansicht durch den gesamten Verschlussdeckel entlang der Linie A-A aus Fig. 1;
• Fig. 3: eine Schnittansicht durch einen Teil des Verschlussdeckels entlang der Linie B-B aus Fig. 1;
• Fig. 4: eine teilweise weggebrochene Schnittansicht durch einen mit dem Verschlussdeckel verschlossenen Behälter;
• Fig. 5: eine Ansicht entsprechend Fig. 4, jedoch mit teilweise geöffnetem Verschlussdeckel;
• Fig. 6: eine teilweise geschnittene Seitenansicht eines modifizierten Verschlussdeckels;
• Fig. 7: eine teilweise geschnittene Seitenansicht eines anderen modifizierten Verschlussdeckels;
• Fig. 8: eine teilweise geschnittene Seitenansicht eines weiteren modifizierten Verschlussdeckels;
• Fig. 9: eine Schnittansicht durch einen als Schraubdeckel ausgebildeten erfindungsgemäßen Verschlussdeckel;
• Fig. 10: eine teilweise weggebrochene Schnittansicht durch einen mit dem Schraubdeckel verschlossenen Behälter.

In the following the invention will be explained in more detail with reference to two illustrated in the drawings embodiments. Show it:

• Fig. 1 a top view of a closure cap according to the invention;
• Fig. 2 : A sectional view through the entire cap along the line AA Fig. 1 ;
• Fig. 3 a sectional view through a part of the closure lid along the line BB Fig. 1 ;
• Fig. 4 a partially broken away sectional view through a container closed with the closure lid;
• Fig. 5 : a view accordingly Fig. 4 , but with partially opened cap;
• Fig. 6 a partially sectioned side view of a modified cap;
• Fig. 7 a partially sectioned side view of another modified closure cap;
• Fig. 8 a partially sectioned side view of another modified closure cap;
• Fig. 9 a sectional view through a cap designed as a screw cap according to the invention;
• Fig. 10 a partially broken away sectional view through a closed container with the screw cap.

Detailed description of the embodiments

The closure lid 2 shown in the drawing for a container 4, for example a mustard or mayonnaise jar ( characters 1 to 8 ) or a jar ( FIGS. 9 and 10 ) consist essentially of a lid body 6 produced in one piece from aluminum sheet with a closure mirror 8 and an edge part 10 protruding over the closure mirror 8 on one side, adjacent to a transition 12 between the closure mirror 8 and the edge part 10 on the underside of a raised sealing edge 14 of the Closing mirror 8 annularly molded sealing material 16, as well as a mounted on the top of the closure mirror 8 film seal 18, which closes the closure mirror 8 passing through ventilation opening 20.

The closure mirror 8 has at its center a so-called click bubble 22, which consists of three successive concentric sections 24, 26, 28 of the closure mirror 8, a circular inner section 24, an annular central section 26 and an annular outer section 28. Of these sections 24, 26, 28, with the lid 2 unloaded, the inner portion 24 is substantially aligned with a plane E spanned by the flat top of the sealing rim 14, while the middle of the two portions 26 are inclined away from the plane E towards the outer portion 28 at a shallow angle of inclination which in turn is inclined at a slightly greater angle of inclination away from the plane E to the bottom 32 of a flat annular groove 30 which is concentric with the three sections 24, 26, 28, with its inner flank formed by the two sections 26, 28 becomes. How best in the FIGS. 1, 2 . 5 and 9 illustrated, the annular groove 30 extends radially outwardly to the sealing edge 14, wherein its groove bottom 32 at unloaded lid 2 (Fig. Fig. 2 and 9 ) is approximately parallel to the plane E of the top of the sealing edge 14.

When the closure lid 2 has been mounted on a previously filled container 4, that the closure mirror 8 spans the flat mouth opening 34 of the container 4 and the sealing material 16 on the underside of the Dichtunasrandes 14th around the container opening 34 rests on its thickened peripheral edge 36, and then as a result of condensing steam in a cavity 38 below the lid 2, the pressure in the container 4 drops until the pressure difference to the ambient pressure is about 0.8 bar, the click bubble 22 pressed from the ambient pressure to the container interior in a retracted position, as in Fig. 4 and 10 shown. In this position, the circular inner portion 24 is substantially aligned with the container opening 34, while the two annular portions 26, 28 are each inclined towards each other at a slight inclination angle in the direction of the plane E. The groove bottom 32 of the annular groove 30 is then inclined towards the center of the lid also at a slight angle of inclination away from the plane E. As a result of the deformation of the lid 2, the click bubble 22 is in this state under a bias, which has the consequence that it jumps up when first opening the lid 2, wherein a clearly audible click is generated. However, since the pressure in the container 4 may increase not only upon initial opening of the lid 2 but also as a result of leakage when small amounts of ambient air enter between the sealing edge 14 of the lid 2 and the peripheral edge 36 of the container 4, the click bladder 22 in its retracted position is a visible indication of the integrity of the seal of the container 4.

The sealed with the film seal 18 vent 20 has a diameter in the millimeter range and is eccentrically with respect to the click bubble 22 approximately centrally disposed on the bottom 32 of the annular groove 30, that is approximately in the middle between an outer edge 40 of the click bladder 22 and a to Sealing edge 14 towards rising groove flank 42, so that the film seal 18 is substantially completely within the annular groove 30, the click bladder 22, however, does not overlap.

The film seal 18 made of aluminum foil consists essentially of a Sieaelteil 44. The approximately circular is formed, the edge of the ventilation opening 20 overlapped on all sides and the entire surface is fixed on the top of the closure mirror 8, and a square or rectangular grip tab 46 which is integrally connected to the sealing member 44 and one side over this. In order to avoid that the pull tab 46, which is held between two fingers to remove the foil seal 18, has to be moved over the click bladder 22, which is covered by the fingers, the center axis 50 of the foil seal 18 passing through the seal part 44 and the grip tab 46 is in FIG Aligned substantially perpendicular to a radius R through the vent opening 20.

For gas- and liquid-tight fastening of the film seal 18, this is coated on its underside facing the cover 2 with a lacquer (not shown), the finely dispersed plastic, e.g. Polypropylene, contains. The outside of the lid body 6 is coated with the same paint. In this way, the two paint layers can be fused together before attaching the lid 2 on the container 4, when the sealed seal with the sealing member 44 over the ventilation opening 20 18 in the region of the sealing member 44 over a period of 200 to 300 ms to a temperature heated from 200 to 250 ° C and is pressed against the lid 2.

This type of sealing is suitable both for hot and cold filling of the container contents, with or without thermal aftertreatment, pasteurisation up to 100 ° C and / or sterilization up to 125 ° C. For products without thermal aftertreatment, the attachment of the film seal 18 could also be done in other ways, for example by means of an adhesive, preferably a hot melt adhesive.

If an eccentrically arranged ventilation opening 20 is introduced after the coating of the lid 2 and immediately before the application of the film seal, to rotate therebetween Cover 2 to avoid, the cutting edge inside the vent opening 20 is not coated with paint. However, such a coating, referred to as a cut edge seal, may be formed by the varnish or hot melt adhesive used to secure the film seal 18 by applying a small amount of the heated varnish or adhesive between the underside of the film seal 18 and the top of the film seal 18 by the contact pressure of applying the film seal 18 Cover 2 is squeezed out in the direction of the opening 20, the viscosity of which is sufficient to form a protective closed coating on the cutting edge.

In order to facilitate the gripping tab 46, it has an indentation 52 projecting beyond its underside, which holds the free rear end 54 of the gripping tab 46 at a distance from the groove base 32 ( Fig. 3 ).

To the first-time opening of the gas-tight sealed with the lid 2 container 4 ( Fig. 4 and 10 ), the foil seal 18 is first removed before the lid 2 is lifted off the container 4 ( Fig. 5 ) or is unscrewed. To remove the foil seal 18, the grip tab 46 is gripped with two fingers and in the direction of the arrow P in Fig. 1 withdrawn until ambient air enters through the opening 20 in the cavity 38 in the container 4 and the negative pressure in the container interior is eliminated. The click bubble 22 in the middle of the consumer's field of vision jumps visibly and audibly upwards with a clear click sound, so that the maintenance of the tightness of the closure up to this time is clearly visible to the consumer both acoustically and visually. Subsequently, the lid 2 can be easily removed from the container 4.

Where the lid 2, as in the FIGS. 1 to 7 1, closes a container 4 which can be used, for example, as a drinking glass with a thickened upper opening edge 36, it becomes on the container 4 from an inwardly over the edge part 10 sticking protruding bead or indentation 56 which engages behind the thickened edge 36 and is pressed from the outside against its underside, as best in Fig. 4 shown.

The bead 56 may be formed there as a continuous, around the edge portion 10 circumferential bead surround, as in the Figures 2 . 5 and 7 represented, or in the form of several, for example, depending on the lid diameter five to seven at equal intervals around the circumference distributed individual beads 56, as shown in FIGS FIGS. 6 and 8 illustrated, the latter facilitates the lifting of the lid 2.

To minimize the risk of cuts at the free lower end of the rim 10, this end is either rolled in or out, such as in FIG Fig. 2 and 4 and 6 and 7 at 58, respectively.

Where the lid 2, as in the FIGS. 8 and 9 shown, is designed as a screw cap and with a plurality of over the outer peripheral surface of the opening edge 36 of the container 2 projecting, at a shallow angle to the plane E inclined thread ribs 60 engages, he is in a known manner at the free lower end face of its edge portion 10 with a provided radially inwardly protruding circumferential flange 62. To hold the lid 2 on the container 4, the flange 62 is also provided in its upper side in a known manner with a number of thread ribs 60 of the container 2 corresponding number of angularly spaced beads or indentations 64, whereby the flange 62 at this Make something flatter and continue to protrude inward. When placing the screw 2 on the opening edge 36 of the container 2, these beads 64 each pass between two adjacent thread ribs 60 and are pressed during the subsequent tightening of the lid 2 from the outside against the underside of a thread above the thread 60.

Claims (12)

1. Closure lid (2) made of sheet metal for fitting on an opening of a container (4), in particular for foods, of which the contents should be kept under negative pressure until the lid (2) is opened for the first time, having a closure part (8), which spans the opening (34) and provides sealing in relation to a circumferential periphery (36) of the opening (34), and having a peripheral part (10), which is connected in one piece to the closure part (8) and encloses the circumferential periphery (36) on its outer side, wherein the closure part (8) is provided, in the centre, with an integrated safety button (22) and, between an outer circumferential periphery of the safety button (22) and an encircling sealing periphery (14), with an air-admission opening (20), which is closed by a sheet-material seal (18), wherein the safety button (22) springs up when the sheet-material seal (18) is pulled off from the air-admission opening (22), wherein the sheet-material seal (18) has a seal part (44), which is connected to the lid (2) around the air-admission opening (20), and a grip tab (46), which is connected in one piece to the seal part (44) and projects beyond the seal part (44) on one side, and wherein the peripheral part (10) is provided with an inwardly projecting encircling or interrupted bead (56, 64) which, once the lid (2) has been fitted on the container (4), is pressed against the circumferential periphery (36) from the outside, characterized in that the air-admission opening (20) and the sheet-material seal (18) are arranged in an annular portion of the closure part (8) forming the floor (32) of an annular groove (30) between the outer periphery (40) of the safety button (22) and the sealing periphery (14), and in that the centre axis (50) of the sheet-material seal (18), this axis running through the seal part (44) and the grip tab (46), is oriented essentially perpendicularly to a lid radius (R) through the air-admission opening (20).
2. Closure lid according to Claim 1, characterized in that the groove floor (32), with the safety button (22) curved upwards, is essentially parallel to a plane (E) of the upper side of the elevated sealing periphery (14).
3. Closure lid according to one of the preceding claims, characterized in that the sheet-material seal (18), once pulled off, no longer adheres to the lid (2).
4. Closure lid according to one of the preceding claims, characterized in that the gas-tight sheet-material seal (18) consists of an aluminium foil or of a composite material.
5. Closure lid according to one of the preceding claims, characterized in that the grip tab (46) and/or the closure part (8) of the lid (2) are/is raised up locally, and therefore a periphery (54) of the grip tab (46), said periphery being directed away from the seal part (44), is kept spaced apart from the upper side of the lid (2).
6. Closure lid according to one of the preceding claims, characterized in that the closure part (8), on at least certain regions of its upper side, has a plastics-containing coating in that the seal part (44) of the sheet-material seal (18) has a plastics-containing coating on its underside, and in that the two coatings are fused together in the region of the seal part (44).
7. Closure lid according to one of the preceding claims, characterized in that it consists of aluminium or of an aluminium alloy.
8. Closure lid according to one of the preceding claims, characterized in that the free end of the peripheral part (10) has been rolled inwards or outwards.
9. Closure lid according to one of the preceding claims, characterized in that the free end of the peripheral part (10) has been flanged inwards, and in that the interrupted bead (64) projects inwards beyond the flanged free end.
10. Container, in particular one containing foods, having an opening bounded by an encircling circumferential periphery, characterized by a closure lid (2) according to one of the preceding claims which is fitted on the circumferential periphery (36) and of which the safety button (22) is retained in a drawn-in position by a negative pressure within the container (4) and springs up as a result of the sheet-material seal (18) being pulled off from the air-admission opening (20).
11. Container according to Claim 10, characterized in that the closure lid (2) is designed as a snap-fitting lid in which the bead (56) is pressed from the outside against the underside of a circumferential periphery (36) of the opening of the container (2), said circumferential periphery being thickened in the manner of a protuberance.
12. Container according to Claim 10, characterized in that the closure lid (2) is designed as a screw-top lid in which the bead (64) is pressed from the outside against the underside of a thread rib (60) on the outside of the circumferential periphery (36) of the opening of the container (2).

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