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(11) | EP 0 052 906 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Closing cap, especially for the nozzle of a container of synthetic material |
| (57) Closing cap, especially for the nozzle (1) of a container of synthetic material,
said cap (2) comprising a closing wall (3), a cylindrical outer casing (4) and a cylindrical
inner casing (5) which by means of screw thread (8,9,10,14) or such-like means co-operate
with related push rings (11,15), each being provided with a radial extending collar
(12,16). Sealing sleeves (13,17) are provided between each of said collars (12,16)
and a related collar section (6,7) of said closing wall (3), which sealing sleeves
(13,17) are compressed to engage the adjacent outer or inner wall resp. of said nozzle
(1) when by turning the cap (2) the push rings (11,15) are moved axially toward the
closing wall (3). |
[0001] The invention relates to a closing cap, especially for the nozzle of a container of synthetic material, said cap consisting of a closing wall, which is perpendicular to the centre line of the nozzle, of a cylindrical outer casing, directed away from this wall, which encloses the nozzle and which is provided with internal screw thread or such-like means, and of a sealing means which by turning the cap can be clamped between the cap and the nozzle.
[0002] Such closing caps are used at a large scale for closing the nozzle of so-called jerrycans. Especially when such containers are made of synthetic material by means of blowing in a die, the problem occurs that no complete sealing can be obtained when the nozzle is provided with external screw thread and the cap with internal screw thread, as the nozzle only can have a limited wall thickness, so that also the force with which the cap is screwed on the nozzle must remain limited. In consequence of this the sealing means, in the shape of a disc of flexible material which is pressed between the end rim of the nozzle and the closing wall of the cap, is often not compressed enough to assure a permanently good sealing.
[0003] As the nozzle at the place of the die partition is usually not provided with screw thread, as this thread might show irregularities at the die partition, the possibility exists that the cap is screwed on the nozzle obliquely, so that the risk of a less good sealing is increased even more.
[0004] It is the purpose of the present invention to overcome these drawbacks by providing a closing cap, which is characterized in that the outer casing by the screw thread or such-like means co-operates with an outer cylindrical push ring, which in the position of use of the cap is at least partially within the outer casing and which is provided with an inwards directed collar at the end which is turned away from the closing wall of the cap, between which collar and the closing wall of the cap an outer sealing sleeve is accomodated, which when the cap is used is slid over the outer wall of the nozzle and prevents the ring from turning with respect to the nozzle, in such a way that by turning the cap the push ring can be brought towards the closing wall for the longitudinal compression of the sealing sleeve so as to lie at least against the outer wall of the nozzle, the cap furthermore being provided with a cylindrical inner casing and with an inner push ring around it, which casing and ring by means of screw thread or such-like means co-operate with one another, said inner push ring being provided with an outwards directed collar for receiving an inner cylindrical sealing sleeve between this collar and the closing wall, in such a way that-when the cap is turned also this inner sealing sleeve is compressed in the longitudinal direction so as to lie at least against the inside wall of the nozzle of the container.
[0005] With such a closing cap the wall of the nozzle of the container is inserted between two sealing sleeves, which when the cap is turned, are pressed against the nozzle from both sides,so that no great forces are exerted on the material of the nozzle, so that there is no risk that the material is torn at the place of the die seam. In this way also a large sealing surface is obtained. Furthermore, the die in which the container is made, can be simpler, as the nozzle does not have to be provided with screw-thread. Therefore such a die will be considerably less expensive.
[0006] Reference can be made to German Offenlegungsschrift 1,429,908, which describes a closing cap, especially for thermos flasks, with which use is made of a sealing sleeve, which is provided between two discs, which can be drawn towards one another to press the sealing sleeve outwards against the inner wall of the nozzle of the container. Thus the nozzle is loaded internally by radial forces. With a container obtained by blowing, this involves the risk that the nozzle is torn at the place of the die seam. Furthermore no internal support of the sealing sleeve takes place, so that the risk exists that it is buckled inwards.
[0007] According to a preferred embodiment of the present invention, the closing wall of the cap is provided with two co-axial cylindrical collar sections between the outer casing and the inner casing thereof, which sections are positioned in such a way, that between the two collars the upper part of the nozzle can be received and between each of the collars and the adjacent casing the upper part of the push ring concerned, the sealing sleeves lying against the head surfaces of the collars.
[0008] In this way a good centring of the closing cap and a good support of the sealing sleeves are guaranteed.
[0009] According to a further elaboration of the invention, the outer push ring can be provided with an outwards directed collar near the inwards directed collar, the outer circumference of which comprises a toothed part, which can co-operate with the toothed part of a checking ring, which by means of tear-off sections is connected with the outer casing of the cap, the teeth of the co-operating toothed parts being of such a shape, that when the cap is screwed tightly on the nozzle of a container, the teeth snap over one another, whereas when the cap is unscrewed, the teeth will grip into one another and the checking ring will be torn off the cap.
[0010] When such a closing cap is used, it can therefore always been verified, after the cap has been put on, whether the cap was removed from the nozzle already before.
[0011] According to a preferred embodiment the toothed parts are provided on axial, oppositely located surfaces of the collar of the push ring and of the checking ring connected with the outer casing.
[0012] The toothed parts are therefore provided on axial cylindrical surfaces, which when the cap is turned will slide somewhat along each other, which in itself provides no problems.
[0013] The space between the closing wall of the cap and the inner casing can be used in a favourable way for accomodating an air bleed valve, which in certain cases is desirable or required to prevent the pressure in the container from becoming too high. Said space may e.g. also contain a foam material which is absorbing and/or resilient.
[0014] The invention will now be explained by means of an example of an embodiment, shown in the drawing, in which:
figure 1 shows a view and a partial section of
a closing cap according to the invention, and
figure 2 shows a bottom view of a part of the edge of the cap.
[0015] In the drawing the nozzle of a container is indicated by the reference number 1; on this nozzle the closing cap 2 is mounted. The closing cap 2 consists of the closing wall 3 with the outer casing 4 and the inner casing 5 perpendicular thereto. Between the outer casing 4 and the inner casing 5 the collars 6 and 7 are provided.
[0016] The outer casing 4 is provided with internal screw thread 8 and the inner casing 5 with external screw thread 9. With the thread 8 the external thread 10 of a push ring 11 co-operates, which ring is provided with an inwards directed collar 12, between the collars 6 and 12 a resilient sealing sleeve 13 being provided.
[0017] In a similar way a screw thread 14 of an inner push ring 15 co-operates with the screw thread 9 of the inner casing 5. The push ring 15 is provided with an outwards directed collar 16 and between the collars 7 and 16 there is an inner resilient sealing sleeve 17.
[0018] When the closing cap 2 is used, the push rings 11 and 15 are screwed into the casing 4 and 5, respectively, whereas simultaneously the sealing sleeves 13 and 14 are mounted. The push rings 11 and 15 are screwed in so far, that the sealing sleeves 13 and 17 are bent slightly towards one another, so that when the closing cap is placed on the nozzle 1, the sealing sleeves 13 and 17 are lying resiliently against the wall of the nozzle 1. After the closing cap 2 has been pressed on the nozzle 1 so far that the upper edge of the nozzle 1 is located between the collars 6 and 7, the closing wall 3 with the outer casing 4 is turned, the push rings 11 and 15 being prevented from turning by their co-operation with the sealing sleeves, which press firmly against the wall of the nozzle 1. The push rings 11 and 15 will thereby move inwards in the cap and press the sealing sleeves more firmly against the wall of the nozzle 1.
[0019] The way of deformation of the sealing sleeves 13 and 17 will be dependent on the original shape thereof and on the properties of the material of which the sleeves are made. Therefore it is possible, in contrast with the drawing, that the sealing sleeves remain lying over their entire length against the corresponding push ring.
[0020] Although an embodiment has been discussed and has been shown in the drawing, in which the casing and the push ring co-operate by means of screw thread, it will be obvious that use can also be made of a bayonet joint, in which case a certain axial displacement between the casing and the push ring will occur.
[0021] In order to check whether a closing cap, after its first mounting on a nozzle, has been removed therefrom already before, the outer casing 4 may be provided with a checking ring 18, which by means of small lips 19 is connected with the outer casing 4.
[0022] As appears from Figure 2, the inner surface of the checking ring 18 is provided with teeth 20, which co-operate with teeth 21, provided on the outer surface of a collar 22 of the push ring 11. The teeth 20 and 21 have such a shape and are made of such a material, that when the casing 4 is turned together with the checking ring 18 in the direction of the arrow P, the teeth 20 of the ring 18 will snap over the teeth 21 of the collar 22. When it is tried, however, to turn the closing cap 2 in the direction opposite to the arrow P, the teeth 20 will be held back by the teeth 21, so that on the ring 18 a holding force will be exerted and the lips 19 between the ring 18 and the casing 4 will be torn.
[0023] It may further be observed that under certain circumstances it has appeared to be favourable to carry out the closing capin such a way, that the collar 16 of the inner push ring 15 comes to lie lower than the point where the nozzle merges into the upper wall of the container. By this the resilient sealing sleeve 17 is deformed in a slightly different way and an improved grip of the closing cap on the nozzle is obtained, also at a very low coefficient of friction between the sealing sleeve and the nozzle wall.
1. Closing cap,.especially for the nozzle (1) of a container of synthetic material,
said cap (2) consisting of a closing wall (3), which is perpendicular to the centre
line of the nozzle, of a cylindrical outer casing (4), directed away from this wall
(3), which encloses the nozzle (1) and which is provided with internal-screw thread
(8) or such-like means, and of a sealing means which by turning the cap can be clamped
between the cap and the nozzle, characterized in that the outer casing (4) by the
screw thread (8) or such means co-operates with an outer cylindrical push - ring (11),
which in the position of use of the cap is at least partially within the outer casing
(4) and which is provided with an inwards directed collar (12) at the end which is
turned away from the closing wall (3) of the cap (2), between which collar (12) and
the closing wall (3) of the cap (2) an outer sealing sleeve (13) is accomodated, which
when the cap (2) is used is slid over the outer wall of the nozzle (1) and prevents
the ring (11) from turning with respect to the nozzle (1), in such a way that by turning
the cap (2) the push ring (11) can be brought towards the closing wall (3) for the
longitudinal compression of the sealing sleeve (13) so as to lie at least against
the outer wall of the nozzle (1), the cap (2) furthermore being provided with a cylindrical
inner casing (5) and with an inner push ring (15) around it, which casing (5) and
ring (15) by means of screw thread (9,14) or such-like means co-operate with one another,
said inner push ring (15) being provided with an outwards directed collar (16) for
receiving an inner cylindrical sealing sleeve (17) between this collar (16) and the
closing wall (3)in such a way that when the cap (2) is turned also this inner sealing
sleeve (17) is compressed in the longitudinal direction so as to lie at least against
the inside wall of the nozzle (1) of the container.
2. Closing cap according to claim 1, characterized in that the closing wall (3) of
the cap (2) is provided with two co-axial cylindrical collar sections (6,7) between
the outer casing (4) and the inner casing (5) thereof, which sections (6,7) are positioned
in such a way, that between the two collars (6,7) the upper part of the nozzle (1)
can be received and between each of the collars (6,7) and the adjacent casing (4,5)
the upper part of the push ring (11,15) concerned, the sealing sleeves lying against
the head surfaces of the collars.
3. Closing cap according to claim 1 or 2, characterized in that the outer push ring
(11) is provided with an outwards directed collar (22) near the inwards directed collar
(12) the outer circumference of which comprises a toothed part (21) which can co-operate
with the toothed part (20) of a checking ring (18), which by means of tear-off sections
(19) is connected with the outer casing (4) of the cap (2), the teeth of the co-operating
toothed parts (20,21) being of such a shape, that when the cap (2) is screwed tightly
on the nozzle (1) of a container, the teeth (20,21) snap over one another, whereas
when the cap (2) is unscrewed, the teeth (20,21) will grip into one another and the
checking ring (18) will be torn of the cap (2).
4. Closing cap according to claim 3, characterized in that the toothed parts (20,21)
are provided on axial, oppositely located surfaces of the collar (22) of the push
ring (11) and of the checking ring (18) connected with the outer casing (4).
5. Closing cap according to one or several of the preceding claims, characterized
in that in the space between the closing wall (3) of the cap (2) and the inner casing
(5) an air bleed valve is accomodated.
6. Closing cap according to claims 4 or 5, characterized in that in the space between
the closing wall (3) of the cap (2) and the inner casing (5) a foam material is placed,
which is absorbing and/or resilient.