NZ246393A - Drum closure structure with drum wall face seal and radial additional seal - Google Patents

Abstract

A drum with a drum closure provided in a drum wall (1) comprises an insert (4) and a shut-off cap which can be placed in the insert (4), which insert (4) is situated in a collar (11) on the drum wall (1) pointing towards the outside of the drum, and has a first flange (6) which rests against the inside (3) of the drum wall, and a second flange (5) which is flanged radially outwards over the collar (11), and also a sealing ring (7) which is wedged between the first flange (6) and the inside of the drum wall (3). An additional seal (10), which may or may not be connected to the sealing ring, is provided between the collar (11) and the insert (4) lying opposite, in order to improve the sealing.

Description

246393 New Zealand No. 246393 international No. PCT/NL92/00220 TO BE ENTERED AFTER ACCEPTANCE AND PUBUCAT10N Priority dates; S"-«Z.-°u International filing date: Classification: 6bS pS'nl . Publication date: 2 8 AUG 1995 Journal No.: iS'iS" NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of invention: Drum with drum closure Name, address and nationality of applicant(s) as in international application form: KONINKLIJKE EMBALLAGE INDUSTRIE VAN LEER B.V. a company incorporated under the laws of The Netherlands, of Amsterdamseweg 206, NL-1182 NL Amstelveen, The Netherlands WO 93/10986 ' • ' ' Drum with drum closure The invention relates to a drum with a drum closure provided in a drum wall, comprising an insert and a shut-off cap which can be- placed in the 5 insert, which insert is situated in a collar on the drum wall pointing towards the outside of the drum, and has a first flange which rests against the inside of the drum wall, and a second flange which is flanged radially outwards over the collar, and also a sealing ring which is wedged between the first flange and the inside of the drum wall.

Such a drum is generally known. When the insert is being fitted in the drum wall the first flange is firmly pressed against the drum wall, in such a way that the sealing ring is compressed to provide the required seal. The second flange is then flanged over the collar. The result of 15 this is that the sealing ring can be held firmly wedged with pre-tension between the first flange and the drum wall.

The required sealing of the closure is maintained so long as the sealing ring can be held firmly wedged in this way. However, as soon as the 20 wedging reduces, the risk of leakages occurs. Such a reduction of the wedging can occur if the drum falls from a certain height onto a hard surface with the closure down. The insert, which projects relative to the drum wall, is pressed inwards in this case, which results in the first flange and the drum wall being pressed apart.

As a result of its elasticity, the sealing ring can absorb deformations up to a certain level without leakages occurring. However, if the defor- ■ations become too great, as is mostly the case when the drum falls, the •WiCcb»ve seal cannot still be guaranteed. The win* of the invention is therefore 30 to equip a drum of the type described above with an improved closure, in such a way that even if the drum falls on the closure the seal will still remain.

Accordingly, the invention provides a drum with a drum closure provided in a drum wall, the 35 drum closure comprising an insert and a closure cap which can be located to close a passage extending through the insert, which insert is situated in a collar on the drum wall which collar extends outwardly of the drum wall, and a first flange which rests against the inside of the-dr-um^ wall, and a second flange which is flanged radially outwards over the collar, a sealing ring which is wedged between the first flange and the inside of the drum wail to form a first seal, and an additional seal formed either by a sealing ring integral with the first sealing ring or by a separate sealing ring, which additional seal is provided between the collar and a part of the insert lying opposite the collar, characterised in that in an area delimited by the outer peripheral edge of the first flange on the one hand, and the top edge of the collar on the other hand, the insert and the container are in contact only through the sealing rings, in such a way that the sealing action is maintained even if the insert is pressed inward relative to the collar.

Thus, the object is achived through the fact that an additional seal, which ■ay or aay not be connected to the sealing ring, is provided between the collar and the insert lying opposite. As a result of the position of the additional seal between the collar and the insert, it is ensured that the sealing is maintained, even if the insert is pressed inwards relative to the collar as the result of a fall. 246 39 3 The additional seal can be obtained in various ways. According to a first possibility, the additional seal is a loose second sealing ring which is compressed in the radial direction between collar and insert. In this case the insert can slide inwards along the sealing ring without the pretension with which it is held wedged relative to the collar decreasing. Thus even quite large deformations of the drum wall and the insert can be absorbed without leakages being able to occur.

According to a second possibility, the additional seal is a loose second 10 sealing ring which is compressed in the axial direction between the end face of the collar and the flanged part of the second flange of the insert. If the drum now falls with its closure onto a hard surface, the second sealing ring is compressed to a greater extent. The seal between insert and collar is therefore also maintained in this case.

In the case of the embodiments described above the two sealing rings can be made of different materials. This means that the original sealing ring, which is in contact with the drum contents, can be made of a material suitable for that purpose. On the other hand, a material which 20 is capable of undergoing great compression can be selected for the additional sealing ring. It is also important here that this material should have a low coefficient of friction with regard to the metal collar and the insert, in view of the great displacements which occur when they are compressed in the radial direction.

If the choice of material is not important, according to a third embodiment, the additional seal can be a sealing ring part which is fixed to the sealing ring and lies on the side of the sealing ring facing away from the firrt flange. In that case the whole sealing ring is preferably 30 made of material with a low coefficient of friction.

An embodiment of the invention will be explained in greater detail below with reference to an examplary embodiment shown in the figures.

Figure 1 shows a second embodiment of the drum closure according to the invention before it is fixed on the drum wall.

Figure 2 shows the completed drum closure.

WO 93/10986 PCT/NL92/00220 246393 Figure 3 shows the drum closure according to Figure 2 in the deformed state.

Figures 5 and 6 show a first embodiment.

Figures 7. 8 and 9 show a third embodiment.

In the embodiment shown in Figures 1, 2 and 3 the drum wall is indicated by 1. An outward pointing collar 2 is formed in this drum wall and con-10 nects by means of the recessed wall part 3 to the remainder of drum wall 1. In the situation shown in Figure 1 the insert, indicated in its entirety by k, is inserted into collar 2, while its second flange 5 projects outwards relative to collar 2. Insert 4 also has a first flange 6 which lies opposite the recessed wall part 3- A sealing ring 7 is pro-15 vided between said wall part 3 and flange 6. The insert also has an internal screw thread, into which another closing cap, not shown, can be screwed.

For fixing the insert 4 to drum wall 1, flange 6 and wall part 3 are pressed towards each other, in the course of which sealing ring 7 is compressed. In that state the flange 5 is flanged over collar 2, with the result that the sealing ring can be held under pre-tension. According to the invention, an additional sealing ring 9 is now placed on the end face of collar 2 and is also compressed when flange 2 is flanged.

In the completed state shown in Figure 2, it can be seen that there is a double seal between the insert 4 and drum wall 1, namely at the position of sealing ring 7 and at the position of the additional sealing ring 9- However, when there are great deformations, for example those which occur as the result of the drum falling with the closure facing down, the situation shown in Figure 3 occurs. The insert 4 is pressed greatly inwards, with the result that the flange 6 has come to lie at a greater distance from wall part 3> A great, part of the pre-tension in sealing ring 7 is 35 consequently lost, which could give rise to leakages.

As also shown in Figure 3. the pre-tension of the additional sealing ring 5 has not, however, decreased, so that the correct seal has been retained at that point.

WO 93/10986 PCT/NL92/00220 246 3 9? In the case of the variant shown in Figures 4-6 the additional sealing ring 10 is fitted directly beside the sealing ring 7- In order to ensure that the additional sealing ring 10 goes into the correct position between the insert 4 and the collar 11 when the insert 4 is connected to 5 the drum wall 1, the collar 11 is widened a little at the underside.

During the compression of insert 4 and drum wall 1 the additional sealing ring 10 can consequently go into the position shown in Figure 5- In this case it is radially compressed, and is consequently largely unaffected by 10 the sliding inwards of the insert k as the result of a fall: see Figure 6.

The variant shown in Figures 7 ~ 9 has a sealing ring 12 which is in one piece, and which essentially comprises the parts 13 and 14 which corre-15 spond to sealing rings 7 and 10 according to Figures 4 - 6. In this case also the collar 11 is widened a little at the underside. When insert k and end wall 1 are fixed, part 14 of sealing ring is now compressed radially, and is therefore unaffected by shifts. When deformations occur the part 13 can expand, but this is not at the expense of the overall 20 seal.

Claims (2)

WHAT WE CLAIM IS: 5 246 393

1. A drum with a drum closure provided in a drum wall, the drum closure comprising an insert and a closure cap which can be located to close a passage extending through the insert, which insert is situated in a collar on the drum wall which collar extends outwardly of the drum wall, and has a first flange which rests against the inside of the drum wall. and a second flange which is flanged radially outwards over the collar, a sealing ring which is wedged between the first flange and the inside of the drum wall to form a first seal, and an ad ditional seal formed either by a sealing ring integral with the first sealing ring or by a separate sealing ring, which additional seal is provided between the collar and a part of the insert lying opposite the collar, characterized in that in an N. area delimited by the outer peripheral edge of the first flange on the one hand, and the top edge of the collar on the other hand, the insert and the container are in contact only through the sealing rings. in such a way that the sealing action is maintained even if the insert is pressed inward relative to the collar.

2. A drug with a drum closure according to claim 1. substantially as herein described with reference to Figure 4 to 6 or 7 to 9 ot the accompanying drawings.