In particular it refers to a closure, which is provided with security sealing means for ensuring that the closure has not been unduly tampered with prior to opening, said security sealing means comprising a sealing ring, joined by break- able bridges to the lower part of an outer annular wall of the lid and being de- signed to be separated from the lid when the lid is unscrewed from the neck part of the container.

Screw top closures with a sealing ring are previously known, e. g. from SE- B-468 206. This type of closure is mainly used when it is important that the user or consumer can positively determine whether the container has been previously opened or not. This is of major importance from a security point of view, in par- ticular in the medical industry and the foodstuff industry, but can also be of interest in other types of industry, where the user wants to be sure that the container and its contents cannot have been unduly tampered with. It may also be of interest for the producer and/or distributor of the goods to prevent unauthorized access to the contents of the container, in particular if the content is very valuable or dangerous in some way, or to prevent sabotage.

The opening of the sealing is often achieved by means of first protrusions arranged on the outside of the neck part opposite to and co-operating with second protrusions arranged on the inside of the sealing ring. When the lid with the seal- ing ring is turned to open the container said first protrusions and second protru- sions engage in such a way that the sealing ring is separated from the lid, by means of breaking the aforementioned bridges.

However, it has been discovered that quite often the sealing ring remains in its position very close to the lower part of the outer annular wall of the lid, even after it has been separated from the lid. The sealing ring simply stays caught with its protrusions in engagement with said protrusions on the container neck. This re- sult in the problem that it can be very difficult to discover if the seal has been bro-

ken or not. This is a disadvantage both for the producer as well as the consumer, in particularly from a safety point of view.

The main purpose of the present invention is therefore to propose a solu- tion to this problem, by providing a screw top closure having the advantageous features defined in the characterizing part of claim 1.

Through the features of claim 1, after the sealing ring is separated from the lid, it falls down onto the sloping container wall below the neck part, thereby leaving a clearly visible distance or empty space between the lid and the sealing ring, resulting in that a breaking of the sealing is clearly visible to the user.

According to another advantageous feature of the invention, directly above the protrusions, the neck part is provided on its outside with an annular, es- sentially collarshaped retaining means for preventing that the sealing ring accom- panies the lid in the direction upwards when the lid is being unscrewed for the first time. It is of course important that the sealing ring remains in its place so that the ring can effectively be separated from the lid by means of the bridges and the inter action between said first and second protrusions, otherwise there will be no visible sign that the container has been opened.

According to yet another advantageous feature, the neck part has a pro- longed neck portion below the protrusions. This prolonged neck portion is also im- portant in order to make the separation of the lid and the sealing ring clearly visi- ble. It contributes to widening the distance between the lower end of the sealing ring and the wall of the container, before unscrewing the lid, and consequently also increasing the distance between the loose sealing ring and the lower part of the lid after the sealing has been broken.

Another object of the present invention is to obtain improvements with re- gard to the gas and liquid tightness of the container. To achieve this, the lid is pro- vided with an inner tubular flange protruding downwardly from an upper portion thereof and being insertable into the neck part and being so constructed and ar- ranged that the inner flange of the lid may be inserted into sealing abutment against a portion of the inside of the neck part. Preferably this portion has a coni- cal shape.

According to one embodiment the neck part is an integral part of the upper open end of the container.

According to another, preferred embodiment, the neck part is a separate element fitted on the upper open end of the container. The neck part preferably has the shape of an annular element with an upper portion serving as a support for the lid and outer and inner concentric tubular flanges, the outer flange protrud- ing downwardly on the outside of the container and the inner flange protruding downwardly in the container, said lid being provided with an inner tubular flange protruding downwardly from an upper portion thereof and being insertable into the neck part and being so constructed and arranged that the inner flange of the lid may be inserted into sealing abutment against a portion of the inner flange of the neck part. Preferably, the latter portion is a conical portion located between an upper portion having a diameter, which is larger than the diameter of a lower por- tion.

Other features and advantages of the present invention will become ap- parent from the following detailed description of one embodiment of the invention, given as an example only, and illustrated in the accompanying drawings, in which : Figure 1 is a side view of a container with a screw top closure according to the present invention, Figure 2 is a perspective view from below, in enlarged scale, of a lid accord- ing to the present invention, Figure 3 is a perspective view from above, in enlarged scale, of a neck part according to the present invention, Figure 4 is a perspective view from below, in enlarged scale, of the neck part in figure 3, Figure 5 is a side view of the neck part in figure 3 and figure 4, and Figure 6 is a cross sectional side view, in enlarged scale, of the lid and the neck part fitted on a container, in accordance with the present inven- tion.

In figure 1 can be seen a container 1, a lid 2, and a separate neck part 3 to be fitted on top of the container and onto which the lid 2 is screwed. It should be pointed out that generally the lid 2 and the neck part 3 are assembled together

and are screwed on to the container 1 as one unit, when the container has been filled with its contents. When the user or consumer unscrews the lid 2 from the container 1 the neck portion 3 will stay on top of the container and then, after the initial opening of the container by removing the lid, the neck part 3 will function as an ordinary neck part of the container.

The lid according to the invention, which is a part of the screw top closure, is illustrated in figure 2. The lid is provided with an internal threading 6 and it is provided with security sealing means 7 in the shape of a sealing ring which is at- tached to the lower end of the outer annular wall of the lid, by means of breakable bridges, known per se (not illustrated in the drawings). The sealing ring 7 is pro- vided with a number of protrusions 8 along the inside of its periphery.

With reference now to figures 3,4 and 5 illustrating the neck part 3, the neck part is provided with an external threading 10 which will co-operate with the internal threading 6 of the lid, when screwing and unscrewing the lid onto the neck part, once the lid, the neck part and the container have been fitted together. In the preferred embodiment illustrated in the figures the neck part has the shape of an annular element with an upper portion 11. To continue, the neck part comprises two concentric tubular flanges, an outer flange 14 protruding downwardly on the outside of the container 1, once the neck part has been installed on the container, and an inner flange 15 protruding downwardly in the container. The threading 10 is provided on the external side of the outer flange. For a better understanding of this, reference is made to figure 6.

Below the threading, the flange 14 is provided with an external collar 18.

The collar runs along the periphery of the outer flange 14 and has a wedge like shape in cross section. When the lid 2 and the neck part 3 have been assembled into one unit, the collar 18, i. e. the outermost edge of the wedge shaped collar, will be located in proximity of the small gap 20 that exists between the sealing ring 7 and the lid 2. When the lid unit has been fitted on top of the container, the collar has such a tight fit in relation to the inside of the lid and the sealing ring that it may protrude slightly into said gap, with the result that the collar serves to retain the sealing ring in its place when the lid is unscrewed. This contributes to the breaking of the bridges between the sealing ring and the lid.

Below the collar 18, the neck part is provided with protrusions 22, that are intended to co-operate with the protrusions 8 on the inside of the sealing ring. It is mainly the co-action of these protrusions that result in the sealing ring being re- leased from the lid when the lid is unscrewed. Both the protrusions 8 inside the sealing ring and the protrusions 22 on the neck part preferably have a wedge or hook shape or similar, preferably with respective vertical sides that are essentially perpendicular to the surface on which they are located, said sides facing each other such that these sides engage in a hook or latch like fashion when the lid is unscrewed and consequently the sealing ring does not move when the lid is turned, which will lead to the bridges being broken. Alternatively, this co-operation between the neck part and the inside of the sealing ring can be described as the protrusions 22 of the neck part interacting with notches inside the sealing ring, these notches being located between said protrusions 8 of the sealing ring. In the illustrated embodiment there are three protrusions each on the sealing ring and the neck part, but the number of protrusions may vary indefinitely.

The neck part is also provided with hook-like protrusions 25 adjacent its upper end, which protrusions co-operate with corresponding protrusions 26 on the inside of the upper part of the lid. The purpose of these protrusions is to constitute mechanical abutment means during the assembly of the lid and the neck part.

Also the number and shape of these protrusions may be varied.

The protrusions 22 on the outer flange of the neck part have a lower end surface 26 facing the container. This lower end surface is bevelled in a direction upwards and outwards from the adjacent external surface of the outer flange/neck part. The purpose of this bevel shape is to function as a"clearance"when the lid is being initially screwed off and the sealing ring is released from the lid, such that it will contribute to the sealing ring falling down onto the upper part of the container 1. This is of major importance to the invention, since it will have the result that the visible distance between the sealing ring, once it has been broken away, and the container is increased and consequently, a clearly visible proof that the container is open or has been opened is provided. Below the protrusions 22 the neck part has a prolonged neck portion 28 which also contributes to adding to the distance between the released sealing ring and the lid.

Another important feature of the present invention is the achieved im- proved tightness and sealing of the container. In order to achieve this the inner flange 15 has an upper portion 30 and a lower portion 31, and said upper portion has a diameter, which is larger than the diameter of the lower portion. This results in a conical portion 32 located between said lower portion and said upper portion.

The lid 2 is also provided with an inner flange 34 for protruding downwards. When the lid and the neck part are assembled, and also later on when the screwed off lid is to be screwed back on to the neck part again after opening the container, the lower end 35 of the inner flange 34 of the lid will enter into contact with the conical portion 32 of the inner flange of the neck part. Thereby is achieved a substantially air tight seal between the neck part, constituting a part of the container, and the lid.

As mentioned before, the neck part and the lid are first assembled to con- stitute one unit. When the container has been filled with its product, the lid/neck unit will be fitted on top of the container. In the illustrated embodiment this can be achieved by means of a snap action between a collar 36 provided on the outside of the container, close to its upper open end, and a corresponding collar 37 on the lower inside of the outer flange 14 of the neck part. Once this has been achieved, the neck part may be considered as a part of the container. In this connection it is also important that there is adequate tightness and sealing between the neck part and the container. During the fitting of the lid/neck unit on top of the container, the upper part 38 of the container is inserted between the outer 14 and the inner 15 flanges of the neck part. This will entail that a sealing abutment is achieved be- tween the inside of the upper part 38 of the container and the external side of the lower portion 31 of the neck part.

As will be apparent to anyone skilled in the art, the invention should not be limited to the preferred embodiment described in connection with the illustrating drawings, but can be modified in many ways within the scope of the appended claims. In particular, it should be pointed out that the neck part is not necessarily a separate part but can instead be a part integral with the container. It may then comprise only one flange with an external side including all the elements that have been described as being provided on the external side of the outer flange, and an internal side designed as has been described in connection with the inner flange, in particular with regard to the air tight seal achieved together with the inner flange of the lid.