EP0675051B1 - Threaded cap with a welded ring - Google Patents

Description

The present invention relates to the combination of a container lid made of plastic and a screw cap also made of plastic, which in turn consists of a Screw cap and a lower closure part, which is sealed with a locking foot can be inserted into an opening of the container lid, the screw cap on a The lower pouring spout provided can be screwed on. The present also applies Invention also a screw cap and also a screw cap with screw cap, the are designed for use in a corresponding combination.

A corresponding combination is known from EP-A-0.320.808.

In the known combination, a retaining ring for a locking foot is provided, wherein this retaining ring is made in one piece with the screw cap and radially outside of the actual screw cap is arranged so that it is on a flange that a container opening surrounds and on which already the cross-sectionally U-shaped locking foot of the Closure lower part rests, can be snapped on, the L-shaped in cross section Retaining ring has a radially inwardly projecting projection which has a smaller diameter defined as the flange of the container opening with the sealing foot resting on it, so that a outer leg of the closure foot by the radially inwardly projecting projection of the Retaining ring is pressed inward and thereby the locking foot on the flange of the   Neck of the container is securely held. The container and the container neck consist of Sheet. The retaining ring is only connected to the screw cap by tearing tabs, so that the screw cap can be released from the retaining ring for the use of the closure, which has its function of holding the closure foot on the flange of the container opening, can maintain.

The subject of EP-A-0.320.808 is not to be used on certain Container types limited because the definition of the closure described therein is not limited to the appropriate container itself, but is only in connection with Tin containers shown, the possibly obvious use of Plastic containers that have a similarly shaped flange, albeit with thicker walls, would have nothing to do with the principle of operation, namely that the locking foot by a locking engagement of a retaining ring with a radially inward projection is effected.

From EP-A-0.218.023 is a welded plastic closure for plastic containers is known in which a closure foot is so placed on a container neck, that a surface portion of the breech foot and the container neck immediately lie side by side so that a welding tool engages both surfaces simultaneously and both materials can melt. These materials should then flow into one another and so weld the closure foot to the container neck.

This not only requires special adaptations and configurations of the locking foot and the neck of the container, but in particular creates difficulties in use different materials for the lock foot and the container. The lock foot has most such closures primarily no or only a small mechanical Holding function, but should primarily the lower part of the closure on the container neck or Seal the opening edge of the container. In addition, such closure feet are often in one piece made with a bellows and a pouring spout, so that the material the closure must be relatively soft and resilient. The materials for plastic containers are comparatively hard, however, because the plastic containers themselves have high dimensional stability is in demand, especially if they are exposed to greater mechanical loads. Such different plastic materials are very difficult to combine with each other weld, since they often have different melting points and because of that Surface tensions of the melt, the confluence of different plastics can prevent. In most cases, you can only achieve one more or less well   pronounced gluing effect between the closure foot and the container neck or one must Compromises in the selection of the materials used for the closure base and container neck come in.

In addition, closures for plastic containers are known in various embodiments. Except for plastic bottles, which have a tapered neck, at least not worth mentioning the cap diameter in the area immediately below the cap exceeds, and which are therefore not considered for the present invention In particular, canisters, buckets and the like are known, which are in a section here as Cover is referred to, an inserted or placed on a short nozzle Have container closure, which is also made of plastic. Particularly common So-called bellows closures are used, which have a locking foot in a Container opening are used, with the closure foot with a bellows that can be folded over a pouring spout is connected, on which in turn a screw cap is screwed. During storage and transport, the pouring spout is screwed together with the Cap by pushing the bellows as far as possible into the container opening pushed in so that the top of the screw cap is either flush with the edge of the Closure foot or the lid surface closes, lies below or with a protruding edge rests on the edge of the container opening. On such Screw cap is usually a foldable ring bracket, which after folding up can be taken to the screw cap together with the pouring spout from the Pull out the container opening and pull the bellows outwards.

In addition, closures without bellows are known, in which a corresponding cylindrical socket with external thread inserted directly into the container opening or is directly connected to a corresponding locking foot. Finally, too so-called telescopic closures are known which have a relatively long, rigid pouring spout, which in each of its upper and lower end regions has locking points or stops, so that this spout can be moved axially in the container opening and for storage and for transport is pushed as far as possible into the container opening and for Pouring and emptying the container as far as possible, taking this both end positions can be fixed by appropriate locking elements or stops.

Basically, the present invention applies to all of the aforementioned embodiments applicable, the preferred application being the aforementioned bellows closures and the telescopic locks are.  

For reasons of the most efficient production possible, containers or container lids and Closures are made separately, often even in completely different ones Manufacturing facilities. This is mainly due to the fact that the permissible tolerance deviations for the closures are generally much smaller than those permitted for the containers themselves Tolerance deviations. Only the opening in the lid of the container, in which the closure is used, must be made sufficiently accurate so that the closure tightly in the Opening can be used. The one directly with the edge of the container opening or the inner surface closure foot which comes into contact with a container neck is generally designed in such a way that despite any deviations in the dimensions of the container opening or the container neck still a mechanically firm and leakproof seat is achieved. Of the Locking foot therefore mostly consists of a relatively flexible, elastic material Locking projections, sealing lips and / or similar devices, which on the one hand the fixed Seat and on the other hand should also ensure the tight closure. It only works therefore, a high degree of tightness and mechanical strength of the closure also ensure later use, but rather about these properties during storage and transport of appropriate containers until they are taken over by to ensure the consumer. When transporting large quantities of containers, these can For example, fall off shelves or from transport pallets and are relatively high exposed to mechanical loads. Furthermore, there is always a risk avoid manipulating the contents of the container in any way, be it exchanged, mixed with foreign material or simply partially or completely removed.

In order to meet the above requirements, the relevant container openings had to and the corresponding closures are often designed to be quite complex. How already mentioned, plastic containers mostly have a cylindrical screw connection, on which an additional outer closure cap is screwed around the closure base to hold onto the container neck or the container opening. This screw cap must be used can also be secured against unscrewing and it is generally also torn off Bridges connected with an inner screw cap and / or a ring bracket with which the inner screw cap and the attached spout are pulled out of the container neck can be. Simpler closure designs are already known, however is their application on sheet metal packaging or containers with a metallic lid limited, which have a relatively precise punched out with simple means, wherein the edge of the opening may also be shaped with punching and shaping tools can be. The edge of such container openings is much more difficult to deform than the edge of corresponding openings on plastic containers, so that one for containers with Sheet metal lids can fall back on comparatively simple closures.  

The present invention lies opposite the prior art discussed above Task based on a combination of a plastic container lid and a Screw closure and a correspondingly adapted closure and one accordingly to create customized screw cap, which have a relatively simple structure, simple can be produced, but still a firm and tight and in particular tamper-proof fit ensure the closure at the container opening.

This task is achieved with regard to the combination of container lid and closure solved that the screw cap or a ring bracket firmly connected to the screw cap one has radially beyond the breech extension extending in radial Direction beyond the breech (11, 12) extends so that it with the container lid (19) comes into contact and is welded to it, and that of the screw cap and the ring bracket is detachable.

With regard to the screw cap and the screw cap itself, which has an approach, which protrudes in the radial direction over the closure foot of the lower closure part, the Approach is designed as a circumferential ring, the task underlying the invention solved in that the approach is designed as an annular disc and in it the locking foot radially projecting region has a thickened in the axial direction, the bead is designed so that it is in the radial direction when inserted into a container opening Direction protrudes beyond this and can be brought into contact with the container, and that on the Container-facing side an annular circumferential, tapering in cross section Has a head start.  

This makes it possible to apply the relevant approach with the lid of the plastic container to weld, so that the screw cap is firmly connected to the container lid, so that also all other locking parts under the cap and the neck securely on the edge the container opening are fixed. The welding ensures that the Closure does not readily detach from the container lid even if the container falls or leaking. Manipulations are also excluded because the cap is due to the approach firmly welded to the lid can not be moved and also the other closure parts are not accessible, but at least can not be solved without not also to cut the connection between the neck and the screw cap.

For the purposes of the present invention, that part of the container is generally used as the "lid" referred to, which immediately surrounds the container opening, even if this container opening to Example not on the top of the container, but more or less close to the side the upper edge of a container or on a top and side surface connecting Inclined surface should be arranged.

It is understood that the radial extension of the approach must be sufficient to make contact and to ensure a welded connection between the neck and the lid material. So at least the radial approach must extend beyond the edge of the container opening extend and, if this edge of any closure parts, such as one Locking foot is covered, also over the radially outer edge of such Breech.

One approach is expedient at least on two diametrically opposite sides the screw cap arranged to also one-sided lifting of the screw cap or to avoid the entire closure. For example, three approaches at 120 ° each offset along the circumference on the outer circumference of the cap or one surrounding the cap Ring bracket to be arranged. The number of approaches can also be increased, although generally an embodiment is preferred in which the approach consists of one or more Ring sections exist.

An embodiment of the invention in which the mentioned approach is particularly preferred is designed as a substantially completely circumferential ring. So that the screw cap be fixed along their entire circumference over the neck on the container lid by the approach is welded to the container lid.  

In detail, the circumferential ring according to the preferred embodiment has a specific one Cross-sectional structure that can be roughly described as an annular disc or annular flange Part, on the outer edge of which a bead-like thickening is attached. It extends this bead in the axial direction predominantly only to one side, namely to that Cover facing side of the extension ring. From the top is in this bead area a circumferential groove is provided in the attachment ring, into which an ultrasonic welding tool (Sonotrode) can be used while on the underside, at the same radial distance from Center, which the groove has, an annular circumferential, tapering projection is provided, which serves as a so-called direction transmitter. This lead only ensures one narrow, approximately linear contact surface on the lid of the container, along which in the case of ultrasonic welding, the ultrasonic energy is concentrated. Usually Such projections on plastic parts are also called "direction indicators" or "energy direction indicators", because it directs the ultrasonic energy in a certain direction, namely the Contact point to the neighboring plastic part with which the welding takes place should concentrate.

Because the bead is relatively thick and possibly the effective transmission of ultrasound energy could prevent welding, is just over in the top of the bead section the energy direction sensor provided the groove for receiving a sonotrode, so that the Distance between sonotrode and welding point (= tip of the energy direction sensor) is reduced.

When the screw cap is used in conjunction with a closure that has a It has a locking foot with a ring flange-like part that covers the opening edge useful if the axial protrusion of the bead-like thickening compared to Washer part of the extension ring approximately the thickness of the flange part of the locking foot corresponds, wherein also the extension ring is dimensioned so that its bead portion is straight is located radially outside the flange part of the locking foot. This ensures that on the one hand the bead section radially outside the closure foot with the lid can be welded, on the other hand also the washer part of the extension ring the flange part of the locking foot rests, with an additional ring-shaped circumferential projection on the underside of the ring disk part has proven to be expedient, which pushes the flange part of the closure foot down onto the edge of the container opening. A such a projection can be more or less deep in the relatively soft material of such Press in the locking foot and thus compensate for any tolerance deviations and at the same time a firm and tight engagement of the breech with the edge of the   Ensure container opening.

So much for a ring bracket lying radially inside the extension for pulling up the screw cap and the pouring spout screwed to it is used, it also appears useful if this ring bracket one over the level of the cap bottom in the preferably also the extension ring is located, has protruding grip tab. This about the The handle tab protruding from the level of an attachment ring and the cap top can then be used easier to grasp and the ring bracket can be bent upwards by lifting the grip tab with any webs that connect the ring bracket to the cap top on the other hand, if necessary, also connect to the extension ring, torn or torn apart become. In addition, the extension ring can also be used directly with the screw cap or the top or jacket of the screw cap can be connected via tearable webs, which only tear off when the screw cap with the help of the ring bracket from the into the container opening is pulled out.

In an embodiment with a raised handle tab of a ring bracket should under the There should be a free space in the ring bracket, which allows the ring bracket to resiliently downward is pressed down so that the upper edge of the grip tab is substantially flush with the The surface of the screw cap closes. This avoids punctiform loads on the upright grip tab when stacking several containers.

Preferably, the screw cap and extension ring as well as the container lid are made of Polypropylene. This material offers sufficient strength and rigidity for both Container as well as for the screw cap.

Further advantages, features and possible uses of the present invention will become apparent clear from the following description of a preferred embodiment and the associated figures.

Figur 1

einen die Verschlußachse enthaltenden Schnitt durch einen erfindungsgemäßen, in eine Behälteröffnung eingesetzten Balgverschluß`

Figur 2

eine Ansicht von oben auf den entlang eines Durchmessers zur Hälfte weggeschnittenen Verschluß und

Figur 3

eine Detailansicht entsprechend dem Inhalt des Kreises Z in Figur 1.

Show it:

Figure 1

a section containing the closure axis through a bellows closure according to the invention, inserted into a container opening

Figure 2

a view from above of the closure cut away in half along a diameter and

Figure 3

a detailed view corresponding to the content of the circle Z in Figure 1.

In Figure 1 you can see a bellows closure, consisting of a screw cap 1 and Lower closure part 10. The lower closure part 10 in turn has an L-shaped closure foot Cross-section, the one L-leg 11 an axially extending, short cylindrical nozzle defined, which is inserted into an opening of the lid 19 of a container is, while the second L-leg 12 defines an annular flange on the edge of the Opening of the container 19 rests. The breech is over a bellows 13 with a Spout 14 connected, which has an external thread 15, on which the screw cap 1 with its internal thread 16 is screwed on.

The screw cap 1 consists essentially of the one provided with the internal thread 16 Screw cap jacket 3, an upper floor 2, a ring bracket 4 and the extension ring 5. Der Extension ring 5 in turn has a certain cross-sectional profile, which is even more clearly can be seen in Figure 3. In detail, the extension ring 5 consists of an annular disk section or washer part 6 and a bead part 7 attached to it on the outside Bead part 7 protrudes downward in the axial direction and in turn has a cross section again a V-shaped tip or a projection 9, which acts as an energy director serves. One is also above this ring-shaped rotating energy direction sensor 9 annular circumferential groove 8 is provided in the top of the extension ring 5, in which a Sonotrode can be used, with the help of the lead or energy direction 9 to be welded to the material of the cover 19.

The ring disk part 6 of the extension ring 5 also has a similar, annular circumference and in cross-section V-shaped projection 18, but not with the underlying one Material is to be welded, but, as can be seen in Figure 1 on the left Presses ring flange part 12 of the breech foot and thus a tight and tight fit of the Locking foot ensures on the edge of the container opening. How to continue from figure 1 can be seen, the axial projection of the bead part 7 lies opposite the underside of the Washer part 6 in the same order of magnitude as the thickness of the ring flange 12. Auf this way the simultaneous engagement of the bead with the lid (by welding), and the projection 18 with the top of the flange part 12 ensured. Because of the V-shaped cross section, the projection 18 can also be more or less deep in the generally relatively soft material (generally polyethylene) of the breech or Press in flange part 12 of the locking foot.

As can be seen from FIG. 3, the ring bracket has a raised handle tab 17 on, while the ring bracket 4 itself lies in the same axial plane as the top 2, the   Screw cap 1 and the washer-shaped part 6 of the extension ring 5.

As can be seen on the left in FIG. 1, the ring bracket 4 lies radially clearly within the Locking foot, so that the ring bracket (mirror image also on the right side in Figure 1) free can be moved down.

As can be seen from Figure 2, the elastic bending of the ring bracket 4 is in the area nothing in the way of the sectional plane shown, since the tearable webs with which the Ring bracket 4 on the one hand with the screw cap, but on the other hand also with the attachment ring 4 is connected, far outside of this sectional plane or spaced in the circumferential direction the upstanding grip tab 17 are arranged, preferably in the vicinity of one massive webs 22, which has an anchor point with articulation points 24 for two provides symmetrically arranged ring bracket 4.

Figure 2 shows the closure mentioned above and can be seen from the inside out first the top 2 of the cap 1, then a gap 23 between the Ring bracket 4 and the top 2 of the cap, this gap 23 by a massive Bridge 22 is bridged, which another, identical bridge diametrically opposite (not shown). This web 22 closes from both sides via a joint 24 each is formed by a section with a small wall thickness, a ring bracket 4, whereupon another gap follows. In the vicinity of the massive webs 22 there are small, tearable webs 21 the connection between the ring bracket and top panel 2 of the cap, while the ring bracket 4 or the web 22 is connected to the attachment ring 5 via further small, tearable webs 20 are. The dashed lines in the area of the ring attachment point radially from the inside to the outside the location of the projection 18, the transition 25 from the washer part 6 to the bead 7 and Energy direction transmitter 9 represents.

The grip tab 7 projecting axially upwards can be in the free space or the gap between the top 2 of the screw cap and the neck ring 4 are pressed down, whereby one 1 can see that there is enough space under the ring bracket 4 to to take down the depressed ring bracket, so that the upper edge of the grip tab 17 approximately flush with the surface of the top floor and the neck ring 5, if for example several containers are stacked on top of each other and pressure on the handle tab 17 is exercised. The ring bracket 4 is sufficiently elastic to remove the load by stacking containers or the like on the ring bracket again that in FIG. 1 shown starting position assumes.

Claims (17)

1. A connection consisting of a container lid (19) of plastics material and a screw closure which likewise consists of plastics material and which in turn consists of a screw cap (1) and a lower closure part which can be placed by means of a sealing foot (11, 12) sealingly in an opening in the container lid (19), wherein the screw cap (1) can be screwed onto a pouring spout provided on the lower closure part, characterised in that the screw cap (1) or a ring-pull (4) firmly connected to the screw cap (1) has an extension (5) which extends radially beyond the sealing foot (11, 12) and which extends radially beyond the sealing foot (11, 12), so that it comes into contact with the container lid (19) and is welded thereto, and can be separated from the screw cap (1) or ring-pull (4).
2. A connection according to claim 1, characterised in that the screw cap (1) has an extension on at least two diametrally oppositely disposed sides of the screw cap.
3. A connection according to claim 1, characterised in that the screw cap (1) has three extensions, each offset by 120° in relation to the other, arranged along the periphery of the screw cap.
4. A connection according to one of claims 1 to 3, characterised in that the extension consists of one or more annular sections.
5. A screw cap of plastics material for a screw closure of a plastic container, wherein the screw cap has an extension (5) which projects radially beyond the sealing foot (11, 12) of a lower closure part, wherein the extension (5) is configured as a continuous ring, characterised in that the extension is configured as a ring washer and has in the region thereof which projects radially from the sealing foot (11, 12) a bead (7) which is thickened in the axial extent and which is configured in such a way that when the lower closure part is inserted into a container opening it projects radially beyond it and can be brought into contact with the container, and, on the side facing the container, has a continuous annular projection (9) of tapering cross-section.
6. A screw cap according to claim 5, characterised in that on the side of the bead remote from the container lid a continuous, annular, groove-like recess (8) is provided.
7. A screw cap according to one of claims 5 or 6, characterised in that provided radially inside the bead, on the underside of the ring washer (6) facing the container lid is a continuous, annular projection (18) of downwardly tapering cross-section.
8. A screw cap according to one of claims 5 to 7, characterised in that, including the extension (5), it is made of polypropylene.
9. A screw cap according to one of claims 5 to 8, characterised in that the extension is connected integrally with the screw cap (1) by means of relatively easily tearable tabs (20).
10. A screw cap according to one of claims 5 to 9, characterised in that the extension is provided radially outside a ring-pull (4), and lies substantially in the same plane as the ring-pull (4) and the top (2) of the screw cap (1).
11. A screw cap according to claim 10, characterised in that the ring-pull (4) has a grip tongue (17) projecting upwardly above the surface of the top (2) and of the extension.
12. A screw cap according to claim 5 or one of the claims dependent upon claim 5, characterised in that the bead (7) is dimensioned so that the clear distance between the ring-pull (4) and the parts of the closure or container located underneath it corresponds at least to the approximate extent of the projection of the grip tongue (17) above the plane of the cap top (2).
13. A screw cap according to one of claims 5 to 12, characterised in that, like the extension, the screw cap (1) consists of polypropylene.
14. A screw closure consisting of a screw cap (1) and a lower closure part which has a sealing foot (11, 12), which can be fixed to a container opening, and a pouring spout (14) onto which the screw cap (1) can be screwed, wherein the screw cap has an extension which projects radially beyond the sealing foot (11, 12) of the lower closure part, wherein the extension (5) is configured as a continuous ring, characterised in that in the region which projects radially from the sealing foot (11, 12) the extension has a bead (7) which is thickened in the axial extent and which is configured in such a way that when the sealing foot is inserted into a container opening it projects radially beyond the sealing foot and can be brought into contact with the container, and on the side facing the container it has a continuous annular projection (9) of tapering cross-section.
15. A screw closure according to claim 14, characterised in that the screw cap of the closure has the features of one or more of claims 5 to 16.
16. A connection according to one of claims 1 to 4, characterised in that the screw cap has the features of one or more of claims 5 to 13.
17. Connections according to one of claims 1 to 4 or 16, characterised in that at least the container lid and the screw cap together with the extension consist of polypropylene.