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(11) | EP 0 029 274 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Screw cap |
| (57) Screw cap of the type that is formed of at least an annular body which is screw threaded
and at one end is provided with a sealing wall, characterized thereby that at the
inner side of said sealing wall (6) an annular projection (8) is provided, in the
vicinity of said sealing wall (6) the inner side of said annular body (2) possesses
a cylindrical part, and a small rib (10) is provided between the inner side (7) of
said annular body (2) and the outer side (9) of said annular projection (8). |
[0001] This invention relates to a screw cap, in other words to a cap intended to be applied to all kinds of packings, containers and the like, which packings are capable of containing any products whatsoever such as all kinds of liquids, petrochemicals, etc.
[0002] The biggest problem about sealing such containers is that the purpose of applying a screw cap, viz. the complete sealing of the packing, in many cases is not reached. Indeed, in containers for lubricating oil e.g., sealing leaves much to be desired so far, which has to be attributed among other things to the purpose of the product itself, viz. the penetration of it everywhere, thus also through the sealing of a packing, which in general can be observed in all places where such packings are used.
[0003] So, an object of the present invention is a screw cap which is carried out in such a way that the sealing function of packings, containers and the like, irrespective of the product placed in them, occurs optimally.
[0004] For this purpose the screw cap of the present invention is constituted by an annular body which is screw threaded and at one end is provided with a sealing wall, characterized thereby that at the internal side of said sealing wall an annular projection is provided whose outside diameter is determined with respect to the inside diameter of the connecting orifice of the container with which such screw cap has to co-operate, whereas in the vicinity of said sealing wall the inner side of said annular body possesses a cylindrical part, whose diameter corresponds with the outside diameter of the sealing orifice of the container with which the screw cap has to co-operate while, finally, a small rib is provided at the inner side of said sealing wall between the inner side of said annular body and the outer side of said annular projection, which rib can co-operate with the upper rim of the sealing orifice of said container.
[0005] In order to better indicate the characteristics of the present invention, a preferred embodiment of a screw cap is described below with reference to the accompanying drawings without limiting the scope of this invention. In these drawings :
Figure 1 represents a sideview of a screw cap according to the present invention;
Figure 2 represents a view according to arrow F2 in Figure 1;
Figure 3 represents a section according to line III-III in figure 2;
Figure 4 represents at a larger scale the part that is indicated by F4 in Figure 3;
Figure 5 represents a side-view of a container equipped with a screw cap according to the present invention;
Figure 6 represents a larger scale cross-section of the part indicated in Figure 5 by F6;
Figure 7 represents at a larger scale the part indicated in Figure 6 by F7;
[0006] In the Figures 1 to 4 a screw cap according to the present invention is represented consisting of the proper screw cap 2 and a removable sealing rim 3.
[0007] The screw cap part 2 mainly consists of an annular body, preferably provided at its outer side of grooves or ribs 4 for improving the grip on such screw cap, while its inner side is provided with a suitable screw thread 5, which corresponds with the screw thread provided on the container or the like, with which such screw cap has to co-operate.
[0008] The top of this annular body as usual is closed by a wall 6, which according to the present invention possesses inside a cylindrical wall part 7 the diameter of which is accurately determined with respect to a cylindrical wall part of the orifice of the container with which such screw cap has to co-operate on the one hand, and an annular projection or rib 8 applied to the inner side of wall 6 on the other hand, the diameter of which projection or rib is also accurately determined with respect to the inner diameter of the orifice of the container with which the screw cap has to co-operate, both elements being located such, that the distance a between the walls 7 and 9 is equal to or somewhat smaller than the thickness of said orifice of the container. The free end of this rib 8 preferably is rounded, at least at its outer side.
[0009] According to the present invention there is further as third sealing means a small lip 10 at the inner side of wall 6 and between the walls 7 and 9, the cross-section of which lip has a triangular form, more especially according to a preferred embodiment the form of a scalene triangle, both features being such, that the upper wall of the orifice of the container that has to co-operate with such screw cap after the latter has been applied, comes into contact with said small lip as will appear below.
[0010] Finally, the annular body of the screw cap proper is connected by means of small connecting lips 11 with the aforementioned ring 3 wich internally has a stop-forming rib 12 that can co-operate with the corresponding rim of the container or the like so as to obtain that for unscrewing screw cap I, the sealing rim 3 has to be removed first, which is possible by tearing it off all round starting from a determined place, which for that purpose is provided with a projecting lip 13.
[0011] In Figures 5 to 7 an application of screw cap 1 according to the invention is represented, which in this case is placed on a container 14 whose orifice 15 is threaded externall with thread 16 with which said thread 5 of the screw cap can co-operate in order to secure the latter onto the container and to remove it therefrom respectively.
[0012] It can be observed in Figure 6 that the aforementioned stop-forming rib 12 engages with the stop 17 placed on the orifice 15 for that purpose, when the screw cap is screwed home onto the container 14 for the first time, so that for removing the screw cap, rim 3 has to be taken away first.
[0013] In the Figures 6 and 7 it can also be seen that the orifice 15 on top of it has a wall part 18, which is completely cylindrical, while also the inner wall 19 of said orifice 15 is truly cylindrical, both features being such that these walls 18 and 19 co-operate completely sealingly with the walls 7 and 9 of the screw cap when this is screwed on, whereas a third sealing is obtained by rib 10, which co-operates with the upper rim 20 of the orifice 15 when the screw cap is screwed home.
[0014] In this way a first sealing is obtained between wall 19 of the orifice 15 and wall 9 of rib 8 of screw cap I; a second sealing by the co-operation of rib 10 with rim 20 of orifice 15; and a third sealing by the co-operation of walls 7 and 18, so that a very efficient and complete sealing is obtained, which is suited for all kinds of liquids, such as oil that has the property of penetrating everywhere, petrochemicals, etc.
[0015] This sealing is realized indeed in such a way, that a complete sealing is warranted even in the case of heavy load of the container whereon such screw cap is screwed and that absolutely no leakage takes place via this screw cap.
[0016] It is clear that the mentioned sealing can be realized efficiently not only by a judicious choice of the diameters of the parts co-operating with each other, but also by the right co-operation of the orifice with rib 10, which in a preferred embodiment is formed and placed in such a way, e.g. with the top facing the middle of the screw cap, that the sealing co-operation between rib 10 and rim 20 is optimal.
[0017] The present invention by no means is limited to the embodiment described as an example and represented in the accompanying drawings. Such screw cap can have all kinds of shapes and dimensions and co-operate with any container and/or packing whatsoever without departing from the scope of the invention.
1.- Screw cap of the type that is formed at least by an annular body which is screw
threaded and at one end is provided with a sealing wall, characterized in that at
the internal side of said sealing wall (6) an annular projection (8) is provided whose
outside diameter (9) is determined with respect to the inside diameter (19) of the
connecting orifice (15) of the container (14) with which such screw cap (1) has to
co-operate, whereas in the vicinity of said sealing wall (6) the inner side (7) of
said annular body (2) possesses a cylindrical part, whose diameter corresponds with
the outside diameter (18) of the sealing orifice (15) of the container (14) with which
the screw cap (1) has to co-operate while, finally, a small rib (lo) is provided at
the inner side of said sealing wall (6) between the inner side (7) of said annular
body and the outer side (9) of said annular projection, which rib (10) can co-operate
with the upper ring (15) of the sealing orifice of said container (14).
2.- Screw cap according to claim 1, characterized in that the cylindrical part (7)
of the inner side of said annular body (2) located in the vicinity of said sealing
wall (6) has a diameter that is equal to or somewhat smaller than the outside diameter
(18) of the free end (15) of the orifice of the container (14) with which the screw
cap (1) has to co-operate.
3.- Screw cap according to claim 1, characterized in that the outside diameter (9)
of the annular projection (8) on the inner side of said sealing wall (6) is equal
to or somewhat larger than the inside diameter (19) of the sealing orifice (15) of
the container (14) with which the screw cap (1) has to co-operate.
4.- Screw cap according to claim 1 or 3, characterized in that the free end of said
annular projection (8) on the inner side of the sealing wall (6) is rounded at least
at the outer side.
5.- Screw cap according to claim 1, characterized in that the cross-section of the
said small rib (10) has a triangular form.
6.- Screw cap according to claim 5, characterized in that said small rib (10) has
the form of a scalene triangle.
7.- Screw cap according to claim 1, 5 or 6, characterized in that the apex angle of
said small rib (10) faces the centre of the screw cap.
8.- Screw cap according to any of the foregoing claims, characterized in that the
outer side of said annular body (2) is provided with grooves and/or ribs (4).
9.- Screw cap according to any of the foregoing claims, characterized in that the
bottom part of it is provided with a removable sealing rim (3).