EP0364775B1 - Screw closure - Google Patents

Description

The invention relates to a screw closure for threaded containers according to the preamble of claim 1.

Screw caps of the type mentioned here are used for containers, for example bottles, jars for liquid, pasteuses or pourable goods. In their mouth area, the containers are provided with a thread, which can also consist, for example, of short thread attachments. Such threads are also referred to as twist-off threads.

The screw closures intended for such containers have a closure cap which is provided with a thread which engages with that of the container. The containers can be provided with a continuous thread or with projections that form the thread. In particular with short thread approaches, it is not necessary that these have an incline. Such threads, which are known, for example, for closing jam and jam jars, are also referred to as twist-off threads. In the case of containers with twist-off threads, the closure cap has projections which interact with the threaded approaches of the container.

In the case of screw closures made of deep-drawing material, for example made of aluminum or steel, the thread of the closure cap which meshes with the thread of the container must be produced by deforming the side walls of the closure cap. With conventional closures, the thread is often produced by a so-called rolling process. For this purpose, a cap blank is placed on the filled container without a thread and the outer wall of the screw cap is pressed in with a suitable device in such a way that a thread matching the thread of the container is formed in the screw cap. Damage to the container can occur, in particular in the case of glass containers, parts of the threaded attachment can splinter and get inside the container. This can adversely affect the consumer.

It is therefore an object of the invention to provide a screw cap for threaded containers, in which damage to the container is to be avoided. The thread of the screw cap should also be easy and inexpensive to manufacture. In addition, the forces required to open the closure should be safely transferred to the threaded ring.

This object is achieved in a screw closure of the type mentioned with the help of the features mentioned in claim 1. Because the screw cap is provided with a threaded ring which has at least one projection engaging in the thread of the container, it is no longer necessary to thread the screw cap itself, that is to say to screw its cap. This prevents damage to the container. A risk to the consumer e.g. broken glass is impossible.

In a particularly preferred embodiment of the screw closure, the projection serving as the thread thereof is arranged on a tab which merges into a spacer strip. This is arranged between the cap of the screw cap and the container to be closed so that the screw cap is centered securely. This ensures reliable operation of the thread ring's projection.

In order to particularly ensure the engagement of the projections serving as threads, a spacer strip is arranged in each case opposite a projection in a preferred embodiment of the screw closure. This can itself have a projection. With such a design of the screw cap such high forces can be ensured that a safe opening and closing of the container is ensured by means of the screw cap.

A screw closure in which the threaded ring is designed as a guarantee ring is particularly preferred. This has at least one area that the first opening the container is permanently deformable or destructible. Such a guarantee ring ensures that the consumer can check the first opening of the container. In this way, the consumer can ensure that he has an undamaged container in his hands.

Also preferred is a screw cap that has the features mentioned in claim 10. By dividing the threaded ring into an upper first ring element and a lower second ring element, this can be produced particularly easily in the plastic injection molding process. In particular, it is ensured that the demolding of the ring elements is easily possible. Due to the division of the ring into two, different materials can be selected for the upper and lower ring element. The respective loads on the elements can be taken into particular consideration.

The upper and lower ring elements are preferably connected to one another by friction and / or positive locking, by welding or by gluing. This results in an optimal functional unit from the two ring elements.

A preferred embodiment of the screw cap is characterized in that a positive connection is provided between the ring elements, which causes the ring elements to get caught when the two elements move relative to one another. This also results in an optimal functional relationship between the two elements.

In addition, a screw closure is preferred in which an annular wall provided with form-locking means on the inside of one ring element and a second ring wall provided with positive-locking means on the outside thereof is provided on the other ring element. The inside diameter of the first ring wall is matched to the outside diameter of the second ring wall in such a way that its form-locking means interlock. Such a design of the two ring elements results in a particularly large engagement surface between the two elements.

A further embodiment is characterized in that the ring walls of the ring elements are conical and are coordinated with one another in such a way that the two ring elements are automatically centered when they are mounted in the closure cap.

The form-locking means can be produced particularly easily if they have sawtooth-shaped projections. These can preferably be aligned in such a way that when the ring elements are rotated relative to one another, they snap into place, so that optimum power transmission is ensured.

The ring elements are preferably provided on their outer side with an annular bead which is arranged in an annular groove in the closure cap. Such a structure can additionally ensure good power transmission between the elements. In such cases, in which only small forces have to be transmitted, a positive connection between the ring elements can be dispensed with with such a screw closure. It is then sufficient to ensure only a frictional connection.

Also preferred is a screw closure in which the inside of the guarantee ring is provided with at least one tab which projects in the direction of the central axis of the guarantee ring and which engages in a recess on the outer surface of the container when the closure rotates while the container is being opened . So while the screw cap is being rotated, a rotation of the guarantee ring is prevented by the hooking of the tab with the container. As a result, the guarantee ring is sheared off the threaded ring or the associated ring element, the lower ring element.

An embodiment of the screw closure is particularly preferred in which the tab forms an angle with the line intersecting its origin and running through the central axis of the guarantee ring, the angle in the range between 5 ° to 85 °, preferably from 20 ° to 70 °, in particular is in the range from 35 ° to 55 °. By aligning the tab in this way, secure interlocking with the recess on the outer surface of the container is ensured. On the other hand, when the screw cap is turned, the tab is tilted, which leads to an expansion of the guarantee ring. This has the consequence that the retaining webs forming a predetermined breaking line between the guarantee ring and the threaded ring or the lower ring element are loaded not only in the circumferential direction by the hooking of the tab, but also in the radial direction. This double loading of the holding webs leads to a particularly rapid and low-force separation of the predetermined breaking line.

Preferably, the screw cap is designed so that the thickness of the tab is selected so that it acts as a spring element and resiliently presses against the outer surface of the container to be closed. Such a structure optimally compensates for differences in tolerance both of the outer container surface and of the diameter of the closure or guarantee ring. In any case, it is ensured that the tab rests on the outside of the container under pre-tension and thus engages with certainty in the associated recess.

In a particularly preferred embodiment of the closure, a line of weakness or recess is provided in the outer surface of the guarantee ring. The tabs are arranged over a large area of the circumference of the guarantee ring. However, the area with the line of weakness is free of such tabs. This ensures that the tamper-evident ring in this weakened area is not pressed outwards by the pretensioned tabs, which would incorrectly indicate an opening.

Furthermore, a screw closure is preferred which has the features mentioned in claim 31. It is particularly advantageous for the threaded ring to engage with a locking device in the bottom region of the closure cap via the latching projection, so that when the cap is rotated it is ensured that the threaded ring is set in rotation. For this purpose, the locking element is non-rotatably connected to the cap.

An embodiment is preferred in which the locking element is designed as a ring running in the transition region between the bottom and side wall of the closure cap. The production of such a locking element is particularly simple and therefore inexpensive.

In a further development of the screw closure, the locking element is designed as part of the seal arranged in the bottom region of the closure cap. Since a seal is provided anyway on the bottom of the container, such a design of the locking element is particularly easy to manufacture.

In addition, an embodiment of the screw closure is preferred, in which the latching projection is designed as a circumferential jacket region which arises from the top of the threaded ring and which engages with the locking element with its upper edge. Such a closure is characterized in that a good frictional connection between the threaded ring and the closure cap is guaranteed, moreover the friction between the closure cap and the container is greatly reduced. In particular if the contents of the container contain sugar, sticking of the screw cap to the container thread is practically excluded.

Finally, an embodiment of the screw closure is preferred in which the latching projection, which is designed as a continuous ring jacket, has at least individual areas provided with teeth that come into engagement with the locking element. A screw cap of this type becomes a special one good adhesion between the threaded ring and the sealing cap is ensured.

Further advantages and configurations result from the original subclaims.

Figur 1

einen Schraubverschluß mit einem als Garantierantiering ausgebildeten Gewindering;

Figur 2

einen auf einen Behälter aufgesetzten Schraubverschluß;

Figur 3

einen als Garantiering ausgebildeten Gewindering in Draufsicht;

Figur 4

einen entlang der in Figur 3 eingezeichneten Linie IV-IV aufgeschnittenen Gewindering in Seitenansicht;

Figur 5

eine vergrößerte Teilansicht eines entlang der in Figur 3 eingezeichneten Linie V-V geschnittenen Gewinderings;

Figur 6

eine weitere vergrößerte Teilansicht des entlang der in Figur 3 eingezeichneten Linie VI-VI Gewinderings;

Figur 7

eine vergrößerte Darstellung eines weiteren Bereichs des entlang der in Figur 3 eingezeichneten Linie VII-VII geschnittenen Gewinderings;

Figur 8

einen Teilschnitt durch einen auf einen Behälter aufgeschraubten, unbeschädigten Schraubverschluß;

Figur 9

einen Teilschnitt durch einen Schraubverschluß ohne Behälter;

Figur 10

eine Draufsicht auf ein oberes Ringelement des Gewinderings des Schraubverschlusses;

Figur 11

einen durch die Mittelachse des oberen Ringelements verlaufenden Schnitt entlang der in Figur 10 eingezeichneten Linie XI-XI;

Figur 12

einen Schnitt entlang der in Figur 11 eingezeichneten Linie XII-XII senkrecht zur Mittelachse des oberen Ringelements;

Figur 13

eine Unteransicht eines unteren Ringelements des Gewinderings des Schraubverschlusses;

Figur 14

einen durch die Mittelachse verlaufenden Schnitt des unteren Ringelements;

Figur 15

einen Schnitt entlang der in Figur 14 eingezeichneten Linie XV-XV durch das untere Ringelement;

Figur 16

einen Teilschnitt durch einen auf einen Behälter aufgesetzten Schraubverschluß;

Figur 17

einen Querschnitt durch einen Gewindering eines Schraubverschlusses gemäß Figur 16;

Figur 18

einen Querschnitt durch ein weiteres Ausführungsbeispiel eines Gewinderings eines Schraubverschlusses gemäß Figur 16;

Figur 19

einen Querschnitt durch ein weiteres Ausführungsbeispiel eines auf einen Behälter aufgesetzten Schraubverschlusses und

Figur 20

einen Querschnitt durch den Schraubverschluß gemäß Figur 19.

The invention is explained in the following with the aid of the figures depicting various exemplary embodiments. As an example, a guarantee ring is shown as a threaded ring, which has a ring part that can be opened when the container is opened for the first time. Show it:

Figure 1

a screw cap with a threaded ring designed as a guarantee ring;

Figure 2

a screw cap placed on a container;

Figure 3

a threaded ring designed as a guarantee ring in plan view;

Figure 4

a side view of a threaded ring cut along the line IV-IV shown in Figure 3;

Figure 5

an enlarged partial view of a threaded ring cut along the line VV shown in Figure 3;

Figure 6

a further enlarged partial view of the threaded ring drawn along the line VI-VI in FIG. 3;

Figure 7

an enlarged view of a further area along the drawn in in Figure 3 Line VII-VII cut threaded ring;

Figure 8

a partial section through an undamaged screw cap screwed onto a container;

Figure 9

a partial section through a screw cap without a container;

Figure 10

a plan view of an upper ring element of the threaded ring of the screw closure;

Figure 11

a section running through the central axis of the upper ring element along the line XI-XI shown in Figure 10;

Figure 12

a section along the line XII-XII shown in Figure 11 perpendicular to the central axis of the upper ring member;

Figure 13

a bottom view of a lower ring element of the threaded ring of the screw closure;

Figure 14

a section through the central axis of the lower ring element;

Figure 15

a section along the line XV-XV drawn in Figure 14 through the lower ring member;

Figure 16

a partial section through a screw cap placed on a container;

Figure 17

a cross section through a threaded ring of a screw cap according to Figure 16;

Figure 18

a cross section through a further embodiment of a threaded ring of a screw closure according to Figure 16;

Figure 19

a cross section through a further embodiment of a screw cap placed on a container and

Figure 20

a cross section through the screw closure according to Figure 19.

In the screw closure according to the invention, the closure cap can consist of a resistant, dimensionally stable plastic or of thermoformable material, such as aluminum or steel. The threaded ring is preferably made of an elastic material such as plastic.

Figure 1 shows a screw cap 1 in section. It has a metallic cap 3, which is essentially cup-shaped. The side wall 5 of the closure cap has on its edge facing away from the bottom 7 of the closure cap an edge 9 which at least partially surrounds a threaded ring 11. The threaded ring is inserted into an annular groove enclosed by the annular bead 9. The outer edge of the closure cap 3 is flanged so that the threaded ring 11 is held securely in the annular groove of the annular bead 9 by a flanged edge 13.

The threaded ring is provided here in its upper edge region with a projection 15 which projects in the direction of the central axis 17 of the screw closure 1 or of the threaded ring 11. The projection starts from a tab 19, which is in its upper, the bottom 7 the area facing the closure cap 3 merges into a spacer strip 21.

The projection 15 of the threaded ring 11 meshes with a thread provided on a container to be closed or with individual latching or threaded projections. The projection thus serves as the thread of the closure 1, which otherwise has no thread. In particular, the side wall 5 of the closure cap 3 is flat except for the annular bead 9.

In the exemplary embodiment shown in FIG. 1, the threaded ring 11 is designed as a guarantee ring and has a lower ring part 23 which is essentially V-shaped in cross section. From a side wall 25 of the lower ring part, which is substantially aligned with the inner surface of the threaded ring lying in the annular groove 9 formed in the annular groove, a diagonally inwardly and upwardly projecting barb 27 forming a truncated cone shell emerges, which is under a projection or lower thread projection of the container can engage. The barb can be designed as a continuous wall area, but can also consist of individual segments.

The closure 1 shown in FIG. 1 has a sealing insert 29 in the transition region between the bottom 7 and the side wall 5 of the closure cap 3.

FIG. 2 shows a closure 1 with a threaded ring 11 placed on a container 31. The container can be, for example, a glass bottle or a jar for preserves. The same parts are provided with the same reference symbols, so that their detailed description can be omitted.

From the illustration it is readily apparent that the screw cap 1 screwed onto the container 31 finds a secure hold in that the projection 15 of the threaded ring 11 meshes with the thread 33 of the container 31. The spacer strip 21 lies between the side wall 5 of the closure cap 3 and a thread of the container 31. It serves to center the threaded ring in the threaded area of the container. This ensures a secure engagement of the projections 15 serving as threaded knobs in the thread 33 of the container 31. It does not matter whether the thread 33 is a continuous thread or individual thread attachments or locking projections on the outside in the neck region of the container 31.

The illustration in FIG. 2 also shows that the barb 27 of the lower ring part 23 engages under the lower thread or under a suitable projection or extension provided on the neck of the container 31. The barb is preferably resilient, so that a secure engagement is ensured.

It is readily apparent that the screw cap 1 can be securely screwed onto and unscrewed from the container, although the cap 3, in particular its side wall 5, has no thread. The projection 15 of the threaded ring 11 takes on the function of a thread.

When the screw cap 1 is opened for the first time, the barb 27 hooks under the lowest thread of the container 31, so that the lower ring part 23 is torn off or blown open by the threaded ring 11. The lower ring part 23 is connected to the rest of the threaded ring 11 via a predetermined breaking line, as will be explained in more detail below.

Figure 3 shows the enlarged threaded ring 11 in plan view, seen from the bottom 5 of the cap 3. The same parts are provided with the same reference numerals, so that their detailed description can be dispensed with.

The upper part of the threaded ring 11, which lies in the annular groove enclosed by the annular bead 9, forms the outer boundary surface of the threaded ring. The projections 15, which are formed on tabs 19 extending from this ring part (see FIGS. 1 and 2), project into the interior of the ring part and can thus engage with a thread on the container.

The embodiment shown in Figure 3 is provided with three projections 15 serving as threads. The regions 27a and 27b of the barb 27 of the lower ring part 23 adjoining the projections 15 end in V-shaped incisions in the barb 27. The projections 15 are evenly distributed on the circumference of the threaded ring 11, that is to say at a distance of 120 °. In the area of the projections 15, incisions 35 are provided in the wall area of the lower ring part 23 serving as barb 27. The segments 27a and 27b of the wall area of the lower ring part serving as barb 27 also project into the interior of the threaded ring 11. They are preferably resilient, so that they abut the outer wall of the container 31 and engage securely under the corresponding projection of the container.

On the outer edge of the threaded ring 11, depressions 37 are provided which increase the friction between the closure cap 3 and the threaded ring 11, so that a secure positive fit is ensured. It is ensured that when the closure cap 3 is rotated, the threaded ring 11 moves with it and can safely assume the threaded function of the screw closure.

In FIG. 3, tear-off webs 39 are also indicated, which connect the part of the threaded ring 11 lying in the ring groove and the lower ring part 23, a predetermined breaking line being formed. This will be discussed in more detail with the help of the following figures.

Figure 4 shows a section through the threaded ring 11 along the line IV-IV Figure 1. The same parts are provided with the same reference numerals. In this illustration, the upper ring part of the threaded ring 11 is clearly visible, which engages in the annular groove 9 formed by the annular bead. The illustration shows a projection 15 in section and one in a perspective view. It can be clearly seen that the projection 15, which meshes with the thread of the container, starts from a tab 19, which sits upwards into a spacer strip 21. The lower ring part 23 of the threaded ring 11 is connected to the upper ring part of the threaded ring via thin, spaced-apart tear-off webs 39, so that a predetermined breaking line 41 is formed, at which the lower ring part is torn off from the upper ring part can. The illustration in FIG. 4 clearly shows once again the wall areas 27, which serve as barbs and extend from an essentially perpendicular wall 25 of the lower ring part 23. In the area of a protrusion 15, incisions 35 are provided here, ie the wall area of the lower ring part forming the barbs is not continuous. In the area of the incisions 35, the lower ring part 23 is connected via a web to the upper ring part of the threaded ring 11, the width of which corresponds approximately to the width of the tab 19.

The segment 27b of the wall region of the lower ring part 23 serving as the barb 27 is followed by an incision 43 which is V-shaped in plan view according to FIG. 3 and which serves as a vertical incision. In this area, the thickness of the perpendicular wall 25 of the lower ring part 23 is thinner than in the other areas. When the screw cap is opened for the first time, the lower ring part 23 can be opened here.

In FIG. 4 it is indicated by a dashed line that the projection 15 and the spacer strip 21 can be formed as part of an annular wall R starting from the upper ring part of the threaded ring 11. This gives the threaded ring a particularly high level of stability. The height of the ring wall is preferably greater than the height of a projection 15 measured in the vertical direction. The region of the ring wall projecting beyond the projection serves, like the ring wall region between the individual projections, as a spacer. The function of this Area thus corresponds to the function of the spacer strips.

Figure 5 shows an enlarged section along the line V-V in Figure 3 through the threaded ring 11. The same parts are provided with the same reference numerals.

In this illustration, a recess 37 is clearly visible, which is part of a so-called serrated edge of the threaded ring and ensures a better positive fit between the closure cap and the threaded ring. The upper part of the threaded ring 11 located in the annular groove 9 formed by the annular bead 9 is connected to the lower ring part 23 via the tear-off webs 39, the tear-off webs extending from the inner surface of the upper ring part of the threaded ring 11 and on the upper side of the vertical wall sections 25 of the lower ring part 23 open. The threaded ring 11 is preferably produced by injection molding, so that the tear-off webs are molded onto the upper and lower ring part. The wall areas of the lower ring part serving as barbs 27 extend from the lower boundary edge of the perpendicular wall sections 25 of the lower ring part.

The tear-off line 41 is formed by the tear-off webs 39 arranged at a distance.

FIG. 6 shows an enlargement of a section running along the line VI-VI in FIG. 3 through a projection 15 of the threaded ring 11. The same parts are also provided with the same reference numerals here.

It can be seen that the projection 15 starts from a tab 19 which arises in the upper inner region of the upper ring part of the threaded ring 11, which lies in the annular groove 9 formed by the annular bead. The tab 19 continues in an upwardly directed spacer strip 21. 4 that the lower ring part 23 is connected in the area of the tab 19 via a web 45, the width of which corresponds to that of the tab 19. In the area of the web 45, the vertical wall area 25 of the lower ring part 23 is designed to be thinner than in the other areas.

FIG. 7 shows an enlarged section through the threaded ring 11 along the line VII-VII in FIG. 3. The section runs through a vertical incision 43, which can also be seen in FIG. The same parts are provided with the same reference numerals.

In the area of the vertical incision 43, the vertical wall 25 of the lower ring part 23 is designed to be even thinner than in the area of the web 45. The area of the origin of the wall area serving as barb 27 at the lower edge of the lower ring part 23 is also very thin.

The predetermined breaking line 41 formed by the tear-off webs 39 continues in the area of the vertical incisions 43.

The functions of the screw cap are discussed in more detail below. If the cap 3 of the screw cap 1 is made of a thermoformable material, as indicated with reference to Figures 1 to 2, the upper part of the Threaded ring 11 inserted in the annular bead 9. Then the bottom edge of the closure cap 3 is flanged, so that a flanged edge 13 is formed and the threaded ring 11 is firmly connected to the closure cap 13. It is also possible to press the threaded ring into the fully flanged groove and snap it into place. In order to prevent a relative movement between the closure cap 3 and the threaded ring 11, a serrated edge with depressions 37 is provided here, which ensures increased friction. It is also possible to pierce the flanging edge 13 at individual points during the flanging, so that holes or depressions are formed in the flanging edge 13 here. Due to the burr of the holes or the depressions, a firm positive connection is created with the underside of the threaded ring 11, so that twisting of the threaded ring within the sealing cap is excluded.

The closure cap 3 can also consist of a rigid plastic. The connection between the closure cap and the threaded ring can be produced by snapping or stamping the two parts into one another. The inside of the closure cap and the outside of the threaded ring can be provided with corrugations, so that a mutual rotation, a relative movement of the two parts, is excluded.

The screw cap produced in this way is screwed onto a filled container, a bottle, a preserving jar or the like. Since the threaded ring 11 is made of an elastic material, preferably of plastic, the can Barb areas 27 serving wall regions of the lower ring part 23 are pivoted in the direction of the perpendicular wall regions 25 without causing an overextension of the lower ring part. After the screw cap 1 has been put on or screwed on, the barbs 27 engage under suitable projections, for example threads, of the container 31 and spring in the direction of the outer wall of the container or in the direction of the longitudinal axis 17 of the screw cap 1.

When the container is closed, the projections 15 of the threaded ring 11 engage in the thread 33 of the container 31.

When the container is opened for the first time, the projections 15 also serve as the thread of the closure 1. When the closure cap 3 is rotated, the closure 1, together with the ring part 11, lifts off the container 31. The barbs 27 hook onto the suitable projections of the container 31. The barbs cause the lower ring part 23 to be overstretched, so that it breaks off along the predetermined breaking line or tear line 41 from the upper ring part and is blown open in the region of the vertical incisions 43. The resulting three segments of the lower ring part 23 are pressed outwards by the barbs 27. The consumer can reliably recognize the first opening of the container by this.

In order to be able to apply the forces required when opening for the first time, the projections 15 must mesh securely with the thread 33 of the container 31. The spacer strips 21 of the tabs 19 serve to center the threaded ring 11 on the neck of the container 31. They lie in the space between the vertical side wall region 5 of the closure cap 3 and the outer surface of the container 31.

According to FIG. 3, it is possible to assign a spacer strip 21 to each projection 15. In the illustrated embodiment, three projections and spacer strips are provided as examples.

However, it is also possible to provide a spacer strip in each case opposite a projection 15 so that the projection is held on the thread 33 of the container 31. The spacer strips can in turn be provided with a projection.

In principle, the projections 15 could also start directly from the threaded ring 11. Due to the fact that the projections 15 are connected to the threaded ring 11 via a lug 19, a certain spring action is made possible, so that the mouth or diameter tolerances of the container 31 can be compensated for.

After all, it can be seen that the screw closure 1 is easy to produce without the need for a rolling process to produce a thread. Damage to the mouth area of the container to be closed can thereby be excluded. In a simple and therefore inexpensive way, it is possible to create a screw closure with a thread that can not only interact with normal continuous threads of a container, but also with individual thread projections of so-called twist-off containers.

In addition, it is possible to design the threaded ring serving as a thread as a guarantee ring, whereby the first opening of a container is certain to be recognizable to the consumer.

In Figure 8, a partial section through a screw cap 1 'is shown, which is placed on a container 3'. The figure only shows the upper mouth region of this container, which is provided with a thread on its outside. The thread can consist of continuous screw lines on the outside of the container or of individual thread approaches 5 '. It is not necessary that the thread approaches have a slope. It is sufficient if these, like a bayonet lock, run horizontally and end in one stop. Such thread approaches are provided for example in jam jars, but also in bottles for juices or milk.

The screw cap 1 'has a cap 7', which can consist of a resistant plastic or a thermoformable material, such as sheet metal, in particular aluminum. The bottom 9 'of the cap 7' is formed substantially flat and provided on its inside 3 'facing the container with a seal 11', which may be annular.

The side wall 13 'of the cap goes at its lower, the bottom 9' facing end into an annular bead 15 ', which includes an annular groove on its inside. The outer diameter of the annular bead is somewhat coarser than that of the side wall 13 '. The annular bead 15 'encloses a threaded ring which has an upper ring member 17' and a lower ring member 19 '. The upper ring element is on its central axis 21 'of the threaded ring facing the inside with a threaded projection 23', which comes to rest under the threaded shoulder 5 'when the screw cap 1' is screwed onto the container 3 '. The thread projection 23 'forms the thread of the screw cap 1', in which the cap 7 'in its side wall 13' has no thread.

At least one thread projection is provided on the inside of the threaded ring; the embodiment shown here is provided with three, uniformly distributed on the circumference of the screw cap 1 'threaded projections 23'.

From the illustration it can be seen that the upper ring element 17 'is provided with an annular bead 25' which is in the annular groove 15 'enclosed by the annular bead of the closure cap 7'. The annular bead need not be continuous; it is also possible to provide some bead segments on the outside of the upper ring element.

The upper ring member 17 'continues in the direction of the bottom 9' of the cap 7 'in a spacer tab, which is formed in this exemplary embodiment as a continuous spacer ring 27'. It serves to center the screw cap 1 'on the container 3'. In addition, it prevents direct contact of the cap 7 'with the container 3' and thereby reduces the frictional forces when screwing the screw cap on and off.

The lower ring member 19 'also has an annular bead 29' which is arranged in the annular groove 15 'of the closure cap 7' enclosed in the annular groove.

The height of the annular bead 15 'or that of the annular groove is so matched to the height of the annular beads of the upper ring member 17' and the lower ring member 19 'that they are tightly enclosed. The annular bead 25 'of the upper ring member 17' on the upper boundary wall 31 'of the annular groove and the lower boundary wall of the annular bead of the lower ring member 19' on the lower boundary wall 33 'of the annular groove. The lower boundary wall 33 'can be formed by flanging the cap 7'. However, it is also possible to preform the ring groove and to snap the threaded ring into this ring groove.

With the lower ring member 19 ', a guarantee ring 35' is connected, a predetermined breaking line 37 'being provided between these two parts. This can consist of a thin material wall, but also, as in this exemplary embodiment, of individual holding webs.

On the outside of the container 3 'is below the guarantee ring 35', seen from the central axis 21 ', outward-facing, circumferential safety bead 39' is provided, which protects the guarantee ring against accidental damage but also against manipulation. The guarantee ring 35 'is also protected by the fact that the outer diameter of the annular bead 15 'is substantially larger than that of the guarantee ring. This also prevents accidental damage.

From the center axis 21 'facing the inside of the guarantee ring go out several tabs 41', the resiliently press against the outside of the container 3 '. In the area of the guarantee ring or these tabs, this is provided on its outside with at least one, preferably a plurality of latching depressions into which the tabs can engage.

From the underside 45 'of the upper ring member 17' goes out at an angle obliquely outward first ring wall 47 ', which is provided with positive locking means. Correspondingly, from the top 49 'of the lower ring member 19' an obliquely inwardly extending second ring wall 51 ', which in turn is provided with positive locking means. A reverse design of the ring elements is also possible.

The provided on the ring walls 47 'and 51' interlocking, so that a relative movement, or rotation of the upper ring member 17 'relative to the lower ring member 19' is avoided.

Figure 9 shows a partially cut screw cap 1 'without a container to be closed. Parts which correspond in FIGS. 8 and 9 are provided with the same reference symbols. From this illustration, the tabs extending from the guarantee ring 35 'projecting in the direction of the central axis 21' 41 'clearly visible. In this embodiment, the width of the tabs 41 'corresponds in its origin to the height of the guarantee ring 35'. It is clear that the width of the tabs 41 'decreases towards its end opposite the origin. The upper edges of the tabs 41 'are all in one plane. The upper edge of the guarantee ring 35 'lies in this plane.

In Figure 10, a plan view of the upper ring element 17 'of the threaded ring is shown. Parts which correspond to those shown in FIGS. 8 and 9 are provided with the same reference symbols.

It can be seen that the embodiment shown here is provided with three 'from the inside of the upper ring member 17', in the direction of the central axis 21 'projecting thread projections 23', which form the thread of the screw cap 1 '.

The inner surface of the upper ring element continues in the spacer ring 27 '. The outer diameter of this ring is smaller than that of the annular bead 25 'of the upper ring member 17'.

The top of the annular bead 27 'is smooth here. However, it can also be provided with projections or depressions in order to improve the frictional connection to the annular bead 15 'of the closure cap 7' of the screw closure 1 '.

Figure 11 shows a section through the central axis 21 'of the upper ring member 17'. Parts which correspond to the previous representations are provided with the same reference numerals.

The illustration shows that the upper ring element 17 'in the region of the annular bead 25' is designed to be relatively stable, as a result of which the forces applied by the threaded projections 23 'are well absorbed and can be derived into the annular bead 15' of the closure cap 7 '. Also the shape of the projections 23 'is clear, which can in principle be designed arbitrarily, whereby they must be adapted to the thread of the container.

The projections have a substantially rectangular grind and are practically trapezoidal in cross section, their grind surface coinciding with the inner surface of the upper ring member 17 '. In this embodiment, the lateral boundary surfaces of the projections are inclined at an angle of 30 ° with respect to the horizontal. The height of the projections measured in the radial direction is approximately half as large as the width measured parallel to the central axis. The extent measured in the circumferential direction is approximately twice as large as the width of the projections measured in the direction of the central axis 21 '.

The starting from the bottom 45 'of the upper ring member 17' ring wall 47 'is inclined at an angle of about 30 ° to the vertical. From the illustration it can be seen that 47 'recesses are provided in the ring wall, which should result in a positive connection with the lower ring member 19'. The thickness of the spacer ring 27 'is between the cap 7' and the thread of the Adjusted container 3 'provided space. The height of the spacer ring 27 'depends on the height of the threaded area on the outside of the container 3'.

A section along the line XII-XII shown in Figure 11 perpendicular to the central axis 21 'of the upper ring member 17' is shown in more detail in Figure 12. Parts that correspond to those of the previous illustrations are provided with the same reference symbols. Figure 12 shows that on the first ring wall 47 'as a positive locking means several projections 53' are provided, the cross section of which is sawtooth-shaped, so that clockwise or in the direction of rotation stop surfaces 55 'are formed. It is also possible that the cross section of the projections 53 ', for example. is triangular. In any case, the transmission of force when screwing in and screwing on is essential.

In this embodiment, the projections 53 'are provided only in the area of the threaded projections 23'. However, they can also be provided on the entire ring wall 47 'of the upper ring element 17'.

Figure 13 shows a bottom view of a lower ring member 19 '. Here, too, parts that correspond to such previous representations are provided with the same reference numerals.

It can be seen that the lower boundary surface of the annular bead 29 ', which rests on the lower boundary wall 33' of the annular groove, is flat. However, it is also possible to provide depressions and / or projections here for one Ensure positive locking between the cap 7 'and the lower ring member 19'.

It can be seen that the predetermined breaking line 37 'in this embodiment is formed by a plurality of retaining webs 57' which are arranged at a distance from one another. The number of retaining webs depends on the material of the lower ring member 19 'which is preferably made of plastic. The retaining webs are provided here on the outside of the guarantee ring 35 '. They have an essentially triangular cross section, the base of this triangle coinciding with the outside of the guarantee ring. The top of the retaining webs goes into the bottom of the lower ring part, so that a connection between the guarantee ring 35 'and the lower ring member 19' is formed.

From the inside of the guarantee ring arises at least one tab 41 'which, with a line intersecting the origin of the tab and the central axis 21', encloses an angle of 5 ° to 85 °, preferably 20 ° to 70 °, in particular 35 ° to 55 ° . The length of the tabs is chosen so that they rest on the outside of the container to be closed 3 '. The material of the guarantee ring or the lower ring element 19 'is chosen so that the tabs 41' rest under tension on the outside of the container, so serve as spring elements. This compensates for differences in tolerance, i.e. fluctuations in the diameter of the container or the guarantee ring.

In the embodiment shown here, several tabs 41 'are provided, specifically over an area which corresponds to an arc with an opening angle of 210 °. This angular range can also be between 360 ° and 180 °, preferably between 250 ° and 200 °.

The wall thickness of the guarantee ring is thinner in the area in which the tabs 41 'are provided than where there are no tabs. Approximately in the middle of the area without tabs, a material weakening, here preferably a recess 59 'is provided, which here runs parallel to the central axis of the closure. The guarantee ring 35 'is not continuously formed. The areas 59 'adjacent areas are held by the holding webs 57'. In the area of this recess, no tabs 41 'are provided, so that the guarantee ring cannot be pressed outwards by the spring action of the tabs, as a result of which damage to the guarantee ring 35' and thus opening of the container 3 'would be indicated.

The thickness of the guarantee ring 35 'is in the area in which the tabs 41' are provided, here about 30% of the thickness of the lower ring element 19 '. The thickness of the guarantee ring is chosen so that when the container is opened it is possible for the retaining webs to burst open. This function of the guarantee ring is discussed in more detail below.

Figure 14 shows a section through the central axis 21 'of the screw cap through the lower ring member 19'. With the previous ones Representative parts are provided with the same reference numerals.

From the top 49 'of the lower ring member 19' goes from the second ring wall 51 '. It is inclined at an angle of approx. 30 ° to the vertical. The angle is matched to that of the ring wall of the upper ring element 17 '. Form-locking elements are also provided on the ring wall of the lower ring element 19 '.

About a predetermined breaking line 37 'is connected to the lower ring member 19' of the guarantee ring 35 ', on the inside of which the tabs 41' originate. The predetermined breaking line is formed by a plurality of retaining webs provided on the outside of the guarantee ring, which here have an essentially triangular cross section. However, it is also possible to provide such retaining webs on the inside of the lower ring member 19 '.

From this illustration it can be seen particularly clearly once again that the upper edges of the holding webs 41 'lie in one plane, the upper edge of the guarantee ring also lying in this plane. It can also be seen that the width of the tabs decreases from their origin to their opposite end.

Figure 15 finally shows a section through the lower ring member 19 'along the line XV-XV shown in Figure 14. The same parts are again provided with the same reference numerals.

It can be seen that on the top of the lower ring member 19 ', or on its ring wall 51' as Form-locking elements serving projections 61 'are provided, which have counter-clockwise or counter-rotating direction stop surfaces 63'.

The projections 61 'can also have a triangular cross section. It is also conceivable that these projections 61 ', like those on the upper ring element 17', have a substantially rectangular cross section. It is essential that a form fit is formed between the two ring elements.

In this embodiment, the projections 61 'are distributed over the entire circumference of the lower ring element 19', so that a positive connection is always guaranteed, regardless of how the upper ring element and that the lower ring element are assembled. The projections 61 'are preferably distributed offset to ensure a good locking of the ring elements.

If the two ring elements 17 'and 19' are assembled and inserted into the annular groove 15 'formed by the annular bead 15' in the closure cap 7 ', the projections 53' and 61 'act together. Due to the alignment of the stop surfaces 55 'and 63' there is particularly good interlocking between the ring elements when the lower ring element 19 'is rotated clockwise, that is to say in the unscrewing direction, with the closure cap. As a result, a particularly good force is transmitted to the upper ring element 17 'in this case. In this way it is ensured that the projections when closing a container 3 'with the help of the screw cap 23 'comb with the threaded lugs 5' and thus a tight seal of the container is achieved.

From the above it is clear that the conical design of the ring walls ensures optimal centering of the two ring elements. However, it is also possible to provide the positive locking elements on a flat underside of the upper ring element and on a flat upper side of the lower ring element. Form-locking elements can then be dispensed with entirely if the friction acting between the ring elements is sufficient to transmit the forces required to close and open the container.

The positive locking elements are preferably designed so that a secure claw takes place between the two ring elements.

In order to ensure a power transmission from the sealing cap 7 'to the threaded ring consisting of the ring elements 17' and 19 ', a plurality of holes are preferably punched into the lower boundary wall 33' of the annular groove. Due to the protruding into the ring groove perforated edge elevations, which are pressed into the underside of the lower ring element 19 ', an optimal form fit between the cap 7' and the threaded ring is guaranteed. The design of the positive connection between the sealing cap and the threaded ring is, however, freely selectable.

The function of the screw cap is described in more detail below:

The screw cap 1 'is, like conventional closures, on the container to be closed. or screwed tight. The projections 23 'of the upper ring member 17' of the threaded ring serve as the thread of the screw cap; that is, the cap 7 'is flat on its side wall 13'. It has no thread.

When screwing the screw cap onto the container, the tabs 41 'of the guarantee ring 35' lay on the inside of the guarantee ring due to their spring action and slide along the outer surface of the container 3 '. The spring action of the tabs 41 'is selected so that the holding webs 57' of the predetermined breaking line 37 'are not blown open. If the screw cap 1 'is now unscrewed from the container 3', the tabs 41 'hook with their ends facing away from the guarantee ring 35' in the recesses 43 'provided on the outside of the container. These have a corresponding stop edge for the front ends of the tabs 41 '. The tabs 41 'have equal distances from one another in the figures. But it is also possible to arrange them at different intervals on the guarantee ring 35 '. This improves the engagement with the container when the cap is screwed on.

By unscrewing the screw cap 1 'so the tabs 41' in the recesses 43 'of the container 3' so that a further rotation of the guarantee ring 35 'is not possible. There is a radial relative movement between the lower ring element 19 'of the threaded ring and the guarantee ring, whereby the retaining webs 57' of the predetermined breaking line 37 'are sheared off. Not all retaining bars are blown open, so that the guarantee ring 35 'on lower ring element 19 'hangs and is lifted off with the screw cap 1' from the container 3 '.

After the front ends of the tabs 41 'are engaged in the recesses 43', when the screw cap is turned further, the tabs 41 'tilt in such a way that the diameter of the guarantee ring 35' is widened. As a result, the holding webs 57 'of the predetermined breaking line 37' are not only subjected to a force in the circumferential direction, but also radially outward. As a result of this double loading of the holding webs, the predetermined breaking line is particularly easily, that is to say blown open, in a way that saves energy. As a result, an attempt to open the door is indicated particularly reliably.

The structure of the guarantee ring described here ensures that the predetermined breaking line 37 'is burst open after a very brief rotation of the screw cap 1'. This means that even without the screw cap being lifted by the thread when the container is opened, the guarantee ring is burst open. This is particularly important in the case of so-called twist-off closures, because there the thread attachments 5 'have no pitch. That is, after a brief twist of the screw cap, the guarantee ring 35 'is blown up. Even without the closure being lifted from the container 3 ', an attempt to open it is indicated. This avoids with certainty that an existing vacuum inside the container 3 'is unrecognizable to the consumer.

From the above it can be seen that the spring action of the tabs 41 'is essential for the function of the guarantee ring. Because the guarantee ring is composed of an upper ring element 17 'and a lower ring element 19', a particularly well resilient part, for example made of plastic, can be selected for the lower ring element. The upper ring element must absorb the forces interacting with the threaded approaches 5 'and can therefore be made of a harder plastic.

After all, it can also be seen that the connection between the two ring elements can be permanent; for example, welding or gluing of the two parts can be selected.

If the simple manufacture of the ring elements is not important, for example in small series, both elements can be produced together using the injection molding process. The guarantee ring can also be molded on at the same time.

In principle, the screw cap according to the invention can be used for any container. It is also possible to provide the threaded ring of the screw closure with a guarantee ring which is torn off or at least blown open from the rest of the threaded ring when the screw closure is first opened, so that the integrity of the container can be recognized immediately. FIGS. 16 to 20 show an example of a screw closure with a guarantee ring.

The embodiment of the screw closure 1˝ shown in FIG. 16 has a metallic closure cap 3˝ and a threaded ring 5,, which is designed here as a guarantee ring. That is, the threaded ring is provided on its underside with a lower ring part 7˝, which is connected to the upper ring part 9˝ of the guarantee ring via a predetermined breaking line. From the lower ring part 7˝ arises a resilient barb, designed as a truncated cone, which cooperates with a projection 13˝, which is provided on the outside of the container 15˝, on which the screw closure 1˝ is applied. The projection 13˝ is here part of a thread 17˝, which is provided in the upper mouth region of the container.

The cap 3˝ is substantially cup-shaped. Its side wall 19˝ has at its edge opposite the bottom 21˝ an inwardly projecting projection 22˝ which holds the threaded ring 5˝.

While the cap 3˝ has no thread on its side wall, the threaded ring 5˝ is provided on its inside with a thread projection 23˝, which engages in the thread 17˝ on the outside of the container 15˝. The projection 23˝ is provided here on the upper ring part 9˝ of the threaded ring. A locking projection 25 geht extends from the threaded ring in the region of the projection 23˝ and extends upward in the direction of the bottom 21˝ of the closure cap and interacts there with a locking element 26˝ designed here as a sealing ring.

In the illustration according to FIG. 17, the threaded ring 5˝ is removed from the screw cap. The same parts are provided with the same reference numerals.

The threaded ring 5˝ is provided with three locking projections 25˝ starting from the base body of the upper ring part 9˝, which are arranged in the region of the projection 23˝ serving as a thread. The number of locking projections and their arrangement are freely selectable. On the top, the locking projections 25˝ are provided with teeth 27˝ which engage in the sealing ring serving as a locking element 26˝. With a sufficient pressing force of the locking projection against the locking element, the toothing can be dispensed with. On the other hand, it is also possible to omit the teeth on the locking projection 25˝ and to provide the locking element 26˝ in the closure cap with teeth. Finally, it is also possible to provide both the locking projection and the locking element with a corresponding toothing.

From the illustration according to FIG. 17 it can be seen that the upper ring part 9˝ is connected to the lower ring part 7˝ via a predetermined breaking line 29˝ which is formed by a plurality of tear-off webs 31˝ which are provided between the upper and lower ring part.

According to FIG. 17, a plurality of barbs 11˝ formed in the shape of a truncated cone shell extend from the lower ring part 7˝. For example, in the area of the projection 23˝ or the latching projection 25˝, the lower ring part 7˝ with a line of weakness or be provided with a vertical incision 33˝, on which the lower ring part tears when the screw cap is opened for the first time, so that the first opening of the container is reliably indicated.

Figure 18 shows a further embodiment of a threaded ring, in which the same parts are provided with the same reference numerals.

This embodiment is characterized in that from the upper ring part 9˝ of the threaded ring 5a˝ serves as a locking projection 25aender serving continuous ring jacket, the upper edge of which cooperates with the locking element 26˝ arranged in the transition region between the bottom 21˝ and the side wall 19˝.

In a screw closure provided with such a threaded ring 5a˝, sticking between the closure cap and the container is practically impossible, even with content containing sugar.

The upper edge of the locking projection 25a˝ engaging with the locking element provided in the closure cap can be flat. With a suitable material pairing, especially if the contact pressure is chosen large enough, sufficient frictional forces can be built up which prevent the cap from spinning relative to the threaded ring. However, as shown in FIG. 18, it is possible, at least in the area of the projections 23 ′ serving as threads, to provide teeth 27 a ′ on the upper side of the ring jacket 25 a, which engage in the locking element. The teeth can either only on the locking projection, only on the Locking element or be provided on both parts.

Figure 19 shows a further embodiment of a closure cap which is provided with a two-part threaded ring 5b˝.

In Figure 19, a partial section through a screw cap 1b˝ is shown, which is placed on a container 15b˝. The figure shows only the upper mouth area of this container 15b˝, which is provided on its outside with a thread. The thread can consist of continuous screw lines running around the outside of the container or of individual thread attachments 17b˝. It is not necessary that the thread approaches have a slope. It is sufficient if these, like a bayonet lock, run horizontally and end in one stop. Such thread approaches are provided for example in jam jars, but also in bottles for juices or milk.

The screw cap 1b˝ has a cap 3b˝, which can consist of a resistant plastic or a thermoformable material, for example steel sheet, preferably aluminum. The bottom 21b˝ of the closure cap 3b˝ is essentially flat and is provided on its inside facing the container 15b˝ with a locking element 26b˝ designed as a seal, which is ring-shaped here, but can also be designed as a disk.

The side wall 19b˝ of the closure cap merges at its lower end facing away from the bottom 21b˝ into an annular bead 35˝ which includes an annular groove on its inside. The outer diameter of the ring bead is slightly larger than that of the side wall 19b˝.

The annular bead 35˝ encloses a threaded ring 5b˝, which has an upper ring part 9b˝ and a lower ring part 7b˝. The upper ring element 9b˝ is provided on its inner side facing the central axis 37˝ of the threaded ring with a projection 23b˝ serving as a thread, which comes to rest under the threaded shoulder 17b˝ when the screw closure 1b˝ on the. Container 15b˝ is screwed on. The projection 23b˝ here also forms the thread of the screw cap 1b hier, the cap 3b˝ having no thread in its side wall 19b˝.

At least one thread projection is provided on the inside of the threaded ring; the exemplary embodiment shown here is provided with three threaded projections 23b˝ distributed uniformly around the circumference of the screw closure 1b˝.

From the illustration it can be seen that the upper ring part 9b˝ is provided with an annular bead 39˝, which lies in the annular groove 35˝ enclosed by the annular bead of the closure cap 3b˝. The annular bead need not be continuous; it is also possible to provide some bead segments on the outside of the upper ring element.

The upper ring part 9b˝ continues in the direction of the bottom 21b˝ of the closure cap 3b˝ in a locking projection 25b˝, which in this embodiment is designed as a continuous ring jacket. It serves to center the screw cap 1b˝ on the container 15b˝. In addition, it prevents direct contact of the cap 3b˝ with the container 15b˝ and thereby reduces the frictional forces when screwing the screw cap on and off.

The lower ring part 7b˝ also has an annular bead 41˝, which is arranged in the annular groove enclosed by the annular bead 35˝ of the closure cap 3b˝.

The height of the annular bead 35˝ or that of the annular groove is so matched to the height of the annular beads of the upper ring part 9b˝ and the lower ring part 7b, that they are tightly enclosed. The annular bead 39˝ of the upper ring element 9b˝ lies firmly against the upper boundary wall 43˝ of the annular groove and the lower boundary wall of the annular bead 41˝ of the lower ring element 19˝ against the lower boundary wall 45˝ of the annular groove. The lower boundary wall 45˝ can be formed by flanging the cap 3b˝ while the threaded ring is already inserted in the cap. However, it is also possible to pre-form the annular groove and to have the threaded ring engage exclusively in this annular groove.

A guarantee ring 47teil is connected to the lower ring part 7b˝, a predetermined breaking or weakening line 29b˝ being provided between these two parts is. This can consist of a thin wall of material, but also of individual tear-off webs, not shown here.

On the outside of the container 15b˝ underneath the guarantee ring 47˝, seen from the central axis 37˝, outward-facing, circumferential safety bead 51˝ is provided, which protects the guarantee ring against unintentional damage but also against manipulation. The guarantee ring 47˝ is also protected in that the outer diameter of the annular bead 35˝ is larger than that of the guarantee ring. This also prevents accidental damage.

From the inside of the guarantee ring facing the central axis 37˝ there are several tabs 53˝ which press elastically and resiliently against the outside of the container 15bnd. In the area of the guarantee ring or these tabs, this is provided on its outside with at least one, preferably a plurality of latching depressions 49 'in which the tabs 53' can engage.

From the underside 55˝ of the upper ring part 9b˝ a first ring wall 57˝ extends at an angle obliquely outwards, which is provided with positive locking means. Correspondingly, from the upper side 59˝ of the lower ring part 7b˝ an obliquely inwardly extending second ring wall 61˝ starts, which in turn is provided with form-locking means, for example a toothing or with channels. A reverse design of the ring elements is also possible.

The form-locking means provided on the ring walls 57˝ and 61˝ engage in one another, so that a relative movement or twisting of the upper ring part 9b˝ relative to the lower ring part 7b˝ is avoided.

Figure 20 shows the screw cap 1b˝ placed on a container in Figure 19, partly in section. Parts corresponding in FIGS. 19 and 20 are provided with the same reference symbols. FIG. 20 shows again the tabs 53˝ extending from the guarantee ring 47˝, which project in the direction of the central axis 37˝ of the screw closure. The width of the tabs 53˝ corresponds to the height of the guarantee ring 47˝ in this embodiment. It decreases in the direction of the end of the tabs 53˝ opposite the origin thereof. The upper edges of the tabs 53˝ are all in one plane. The upper edge of the 47ings guarantee ring also lies on this level.

The outer contour of the screw closure 1b˝ shown in FIGS. 19 and 20 can also be chosen differently. The circumferential bead 35˝ can be omitted. Instead, a circumferential projection 45˝ protruding inwards from the side wall 19b˝ (see FIG. 19) is sufficient to hold the threaded ring 5b˝ securely in the closure cap 3b˝.

Instead of the metallic cap, a plastic cap can be chosen, the material should be relatively rigid. The threaded ring can be fastened in a plastic sealing cap in any known manner. The threaded ring can be placed in the plastic cap be snapped into place. It is also possible to reshape the lower edge of the plastic sealing cap after inserting the threaded ring by means of cold forming in such a way that individual projections or a continuous bead is formed which holds the threaded ring in the cap.

If the closure cap is made of plastic, it is possible to form the locking element as part of the cap. For example, a toothing can be provided in the transition area between the bottom and side wall of the plastic closure cap, into which a corresponding toothing of the locking projection of the threaded ring engages. But here, too, it is possible to apply a frictional force solely on the basis of contact pressure, which prevents the threaded ring from spinning relative to the closure cap. In this case, toothing can be dispensed with entirely.

From the above it follows that due to the locking projection originating from the base body or the upper ring part of the guarantee ring, which engages with a locking element in the transition region between the bottom and side wall of the closure cap, a turning of the closure cap relative to the threaded ring is practically impossible. In the connection between the closure cap and the threaded ring, high frictional forces or a positive or positive connection are generated so that the unit consisting of the threaded ring and the closure cap, the screw closure, can be safely unscrewed from the container. Even if the threaded ring is designed as a so-called guarantee ring and that to burst open required forces of the guarantee ring must be additionally applied by a rotary movement of the closure cap, a secure transmission of the rotational forces is guaranteed.

The transmission of the forces required to open the screw closure can finally also be ensured in that the latching projections are glued or welded to the locking element.

Instead of a single projection on the threaded ring, projecting areas serving as threads or a continuous thread can be provided.

Claims (39)

1. A screw closure for containers provided with a thread, having a closure cap, characterised by a threaded ring (11) held in a positive-locking manner by the closure cap and provided with at least one projection (15) engaging in the thread (33) of the container (31) and forming the thread of the screw closure (1).

2. A screw closure according to Claim 1, characterised in that the projection (15) is arranged on a tab (19) extending from the threaded ring (11).

3. A screw closure according to Claim 2, characterised in that the tab (19) extends into a spacing strip (21).

4. A screw closure according to any one of Claims 1 to 3, characterised in that at least two projections (15) are provided.

5. A screw closure according to Claim 3 or 4, characterised in that at least one spacing strip (21) is assigned to each projection (15).

6. A screw closure according to Claim 3 or 4, characterised in that a spacing strip with or without projection is in each case arranged opposite a projection.

7. A screw closure according to Claim 1, characterised in that the projection (15) is arranged on a ring wall (R) upstanding from the threaded ring (11).

8. A screw closure according to Claim 7, characterised in that at least two projections (15) are provided on the ring wall (R).

9. A screw closure according to any one of Claims 1 to 8, characterised in that the threaded ring (11) is formed as security ring and has at least one region (23) which can be deformed or destroyed permanently when the container (31) is first opened.

10. A screw closure according to Claim 9, characterised in that the threaded ring has a first upper ring element (17′) carrying the threaded projections (23′) and a second lower ring element (19′) on which the security ring (35′) is mounted, and in that the upper and lower ring elements are formed as separate rings.

11. A screw closure according to Claim 10, characterised in that the upper ring element (17′) and the lower ring element (19′) are interconnected by frictional locking and/or positive locking, by welding or by adhesive.

12. A screw closure according to Claim 10 or 11, characterised in that the positive locking between the ring elements is such that, during relative rotation of the two ring elements (17′, 19′) in relation to one another, hooking occurs between the ring elements.

13. A screw closure according to any one of Claims 10 to 12, characterised in that the lower side of the upper ring element (17′) is provided with projections (53′) and/or indentations which cooperate with projections (61′) and/or indentations provided on the upper side of the lower ring element (19′).

14. A screw closure according to any one of Claims 10 to 13, characterised in that a first ring wall (47′), the inner side of which is provided with positive-locking means (53′), is provided on the one ring element (17′) and a second ring wall (51′), the outer side of which is provided with positive-locking means (61′), is provided on the other ring element (19′), and in that the internal diameter of the first ring wall is coordinated with the external diameter of the second ring wall in such a manner that the positive-locking means of the ring elements interlock.

15. A screw closure according to Claim 14, characterised in that the ring walls (47′, 51′) are formed so as to be conical.

16. A screw closure according to Claim 14 or 15, characterised in that the positive-locking means have projections (53′, 61′) formed in the shape of saw teeth.

17. A screw closure according to Claim 16, characterised in that the projections (53′) on the one ring element (17′) have stop faces (55′) aligned clockwise and those on the other ring element (63′) have stop faces (63′) aligned anti-clockwise, so that at least in one direction the ring elements are prevented from twisting towards one another.

18. A screw closure according to any one of Claims 10 to 17, characterised in that the outer side of the ring elements (17′, 19′) is in each case provided with a ring-shaped bead (25′, 29′) which engages in a ring groove in the closure cap (7′).

19. A screw closure according to any one of Claims 10 to 18, characterised in that the inner side of the security ring (35′) is provided with at least one stop projection (tab 41′) which cooperates with an indentation (43′) arranged on the outer side of the container (3′).

20. A screw closure according to any one of Claims 10 to 18, characterised in that at least one tab (41′), projecting in the direction of the central axis (21′) of the security ring and serving as a stop projection, is provided on the inner side of the security ring, which tab engages in the indentation (43′) on the outer face of the container (3′) during a rotational movement of the security ring (35′) which occurs when the screw closure is opened.

21. A screw closure according to Claim 20, characterised in that the tab (41′) forms an angle (α′) with the line intersecting its origin and extending through the central axis (21′) of the security ring (35′), and in that the angle (α′) lies in the range of 5° to 85°, preferably in the range of 20° to 70°, in particular in the range of 35° to 55°.

22. A screw closure according to Claim 20 or 21, characterised in that, in the region of its origin, the width of the tab (41′) is approximately the same as the height of the security ring (35′).

23. A screw closure according to any one of Claims 20 to 22, characterised in that the width of the tab (41′) decreases towards its end located opposite the origin.

24. A screw closure according to any one of Claims 20 to 23, characterised in that the thickness of the tab (41′) is selected so that it acts as spring element and presses in a resiliently yielding manner against the outer face of the container (3′) to be closed.

25. A screw closure according to any one of Claims 10 to 24, characterised in that the wall of the security ring (35′) is provided with a thin-walled region which extends substantially parallel to the central axis of the security ring (35′).

26. A screw closure according to any one of Claims 10 to 24, characterised in that the wall of the security ring (35′) is provided with a recess (59′) which extends substantially parallel to the central axis (21′) of the security ring.

27. A screw closure according to any one of Claims 20 to 26, characterised in that several tabs (41′) are arranged on the inner side of the security ring (35′), preferably spaced at equal distances from one another.

28. A screw closure according to any one of Claims 20 to 26, characterised in that several tabs (41′) are arranged on the inner side of the security ring (35′), preferably spaced at different distances from one another.

29. A screw closure according to Claim 27 or 28, characterised in that the tabs (41′) are arranged in a region on the inner side of the security ring (35′) and in that the thin-walled region or the recess (59′) lies in the tab-free region.

30. A screw closure according to Claim 29, characterised in that the region provided with tabs (41′) corresponds to the arc of a circle with an aperture of between 340° and 180°, preferably between 250° and 200°.

31. A screw closure according to any one of Claims 1 to 30, characterised in that the threaded ring (5˝; 5a˝; 5b˝) is provided with at least one stop projection (25˝; 25b˝) which projects in the direction of the base (21˝; 21b˝) of the closure cap (3˝; 3b˝) and cooperates with a locking element (26˝; 26b˝) arranged so as to be secure against twisting in the region of the base of the closure cap.

32. A screw closure according to Claim 31, characterised in that the locking element (26˝; 26b˝) is formed as a ring element arranged in the transition region between the base (21˝; 21b˝) and the side wall (19˝; 19b˝) of the closure cap (3˝; 3b˝).

33. A screw closure according to Claim 31 or 32, characterised in that the locking element (26˝; 26b˝) is part of a seal arranged in the region of the base (21˝; 21b˝) of the closure cap (3˝; 3b˝).

34. A screw closure according to any one of Claims 31 to 33, characterised in that the stop projection (25˝; 25b˝) of the threaded ring is provided with toothing (27˝) which engages in the locking element (26˝; 26b˝).

35. A screw closure according to any one of Claims 31 to 33, characterised in that the locking element is provided with toothing which enters into engagement with the stop projection.

36. A screw closure according to any one of Claims 31 to 33, characterised in that the locking element and the stop projection are provided with a tooth construction.

37. A screw closure according to any one of Claims 31 to 36, characterised in that the stop projection is formed as a ring-casing segment (25˝) extending to the locking element.

38. A screw closure according to Claim 37, characterised in that at least one, and preferably three ring-casing segments are provided as stop projection (25˝).

39. A screw closure according to any one of Claims 31 to 36, characterised in that the stop projection is formed as a continuous ring casing (25a˝; 25b˝) issuing from the threaded ring and extending to the locking element.

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