WO1998032673A1

WO1998032673A1 - Closure having venting means

Info

Publication number: WO1998032673A1
Application number: PCT/NL1997/000025
Authority: WO
Inventors: Victor Alexander De Vries; André François PETERS
Original assignee: Sparkle Systems B.V.
Priority date: 1997-01-28
Filing date: 1997-01-28
Publication date: 1998-07-30
Also published as: AU1457097A

Abstract

Sealing cap for a liquid container, comprising a cover part (4) having an opening (10) and a substantially flat inner side, and a sealing member (11, 61, 71) which is made of elastic material, is arranged against the inner side and has a slit (14) opposite the opening (10), such that the cap is suitable for sealing an opening (22) in a container (20) and such that if the pressure inside the container (20) exceeds a maximum pressure with respect to the pressure outside the container, the slit (14) opens in a direction away from the container opening (22). The sealing member (11, 61, 71) has, on each side of the one slit (14), opposite the cover part (4), one or more further slits (15, 65, 75).

Description

CLOSURE HAVING VENTING MEANS

The invention relates to a sealing cap for a liquid container, comprising a cover part having an opening and a substantially flat inner side, and a sealing member which is made of elastic material, is arranged against the inner side and has a slit opposite the opening, such that the cap is suitable for sealing an opening in a liquid container and such that if the pressure inside the container exceeds a maximum pressure with respect to the pressure outside the container, the slit opens in a direction away from the container opening.

A cap of the abovementioned type is known from GB-A-1,534,570. The cover part of the known cap has a very small central opening which diverges conically towards the inside of the cap. The slit opposite the opening is only slightly longer than the largest diameter of the opening of the cover part. Towards the inside of the cap, the slit merges gradually into a groove. The known cap is specifically intended for limiting the pressure of a gas within the container to a maximum pressure, while spillage of a liquid from the container and penetration of extraneous material into the container via the cap opening and the slit is prevented.

The invention aims to provide a cap which, in addition to the said pressure safeguard, also offers the possibility of being able to pump a gas into the container using little energy, such as with the aid of a hand pump, and quickly, in particular for preventing, by means of a higher pressure in the container, gas which is dissolved in a liquid in the container from escaping. In order to achieve this objective, the invention provides a sealing cap in accordance with claim 1. This makes it possible, even with a hand pump, to achieve a desired excess pressure in the container in a particularly easy and rapid manner. It should be pointed out that a sealing cap which is suitable for pumping air into a container is known per se from US-A-4 ,723,670. In order to achieve this, this known sealing cap has an integrated hand pump. This sealing cap has the drawback that there is no safeguard against exceeding a maximum desired pressure within the container. Other drawbacks of this known cap are that the cap is complicated and expensive, the body of the pump projects completely into the container, and possibly into a liquid in the container, is difficult to clean and, as a result, in the course of time becomes unhygienic, and the cap is difficult to place in storage spaces of standardized heights, such as in refrigerators, due to the presence of a handle of the pump part of the cap.

The cap according to the invention has none of the abovementioned drawbacks of the known caps.

The invention will be explained below with reference to the drawings, in which:

Fig. 1 shows a cross-section of an embodiment of a cap according to the invention;

Fig. 2 shows a cross-section of the cap of Fig. 1, which is arranged on an opening of a liquid container and on which a pump has been placed, by means of which a pumping movement which is directed towards the cap and increases the pressure is executed;

Fig. 3 shows a cross-section of the assembly shown in Fig. 2, without the pump, and with a pressure within the container which is lower than a maximum permitted pressure. Fig. 4 shows a cross-section of the assembly of Fig. 2, when the pressure within the container exceeds the maximum permitted pressure;

Fig. 5 shows a top view of a sealing member of the type used in the sealing cap according to Figs. 1 to 4; Fig. 6 shows a top view of another embodiment of the sealing member; and

Fig. 7 shows a top view of yet another embodiment of the sealing member. Fig. 1 shows a cross-section of a cap 1 according to the invention having a cavity 2 which is delimited by a substantially cylindrical side part 3 and a top cover part 4 having a substantially flat inner side. The cavity 2 is open at 5. The cylindrical side part 3 has an inner wall 6, on which a screw thread 7 is situated.

The cover part 4 of the cap 1 has a passage or opening 10 which has a smaller passage area than the passage area of the cavity 2 , both passage areas viewed perpendicular to the inner wall 6. A substantially flat sealing member 11 made of elastic material, for example rubber, such as a silicone-type rubber, is arranged in the cavity 2 opposite the cover part'4. In particular, the sealing member 11 is in the form of a disc and it is incorporated without loss in an internal peripheral groove 12 in the cavity 2.

Opposite, preferably diametrically opposite, the opening 10, the sealing member 11 has a central slit 14 and, on each side of the central slit 14, one or more further slits 15 beyond the opening 10. Fig. 5 shows a top view of such a configuration of the sealing member 11, in which the slits 14, 15 are parallel. For the sake of clarity, the opening 10 in the cap 1 is shown by means of a dotted line in Fig. 5 (and in Figs. 6 and 7) . Fig. 2 shows a cross-section of a part of a liquid container 20 having a mouth 21. The mouth 21 has an opening 22 and defines a passage 23 for introducing liquid and/or gas or a gas mixture into the container 20 and removing it therefrom. The mouth 21 has an outer wall 24, on which a screw thread 25 which corresponds to the screw thread 7 of the cap 1 is formed.

In Fig. 2, the cap 1 is screwed onto the mouth 21 of the container 20 in such a manner that the sealing member 11 is clamped in a sealing manner between the cover part 4 of the cap 1 and rim 26 of the mouth 21.

Furthermore, Fig. 2 shows a pump 30, which does not form part of the invention, and for that reason is shown only diagrammatically and will be explained only in brief. The pump 30 has a body 31 having a cylindrical piston chamber 32, which is substantially closed at a top side by means of a top end part 33 having a central passage 34 and an extra passage 35. A piston rod 36 projects through the passage 34, with a small degree of play in the axial direction, which piston rod has at one end, in the piston chamber 32, a piston 37, and has at the other end, outside the pump body 31, a handle 38. The piston 37 is designed such that, when the piston is displaced in the direction of the arrow 40, the peripheral edge of the piston 37 is supported in a sealing manner against the inner wall 41 of the piston chamber 32 and such that when the piston 37 is displaced in the opposite direction, upwards in Fig. 2, air can flow along the peripheral edge of the piston 37 and the inner wall 41 of the piston chamber 32. The body 31 of the pump 30 has a collar 42 on the bottom side, which collar fits around the cap 1 with a degree of play. At the transition to the collar 42, the piston chamber 32 has an internal peripheral groove 44, in which a sealing ring 45 made of resilient material is situated.

If the pump 30 is placed on the cap 1 in the manner shown in Fig. 2, the sealing ring 45 ensures a suitable gas seal for the space between the cover part 4 of the cap 1 and the bottom side of the piston 37 of the pump 30. When, in the situation shown in Fig. 2, the piston 37 is moved upwards, the chamber 32 beneath the piston 37 will fill with air. When the piston 37 is then displaced downwards in the direction of the arrow 40, air will be compressed beneath the piston 37. When the pressure beneath the piston 37 (on the side of the opening 10 in the cap 1) is higher than the pressure within the container 20, the sealing member 11 will bend downwards, as shown in Fig. 2, as a result of which the slit 14 shown in Fig. 1 forms a V-shaped gap 47 on the underside of the sealing member 11. When the pressure at the top side of the sealing member 11 is sufficiently higher than on the underside of the sealing member 11, the sealing member 11 will bend downwards so far that the gap 47 also opens at the top side, as a result of which air can flow from the pump 30 into the container 20, as indicated by the arrow 48. As a result, the pressure beneath the sealing member 11 is increased, so that an excess pressure is formed in the container 20 with respect to the outside. By repeating the pumping action, the excess pressure can be increased •

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considerably larger than the opening of the cap which is known from GB-1, 534 ,570, and the central slit 14 is preferably longer than a quarter of the diameter of the disc-shaped sealing member 11 (and 61, 71) . Figs. 6 and 7 show top views of other embodiments 61 and 71, respectively, of a sealing member for the cap 1. The sealing members 61, 71 have radial slits 65 and 75, respectively, which extend from a location opposite the centre of the opening 10 in the cap. These radial slits 65, 75 have been found to facilitate the pumping operation considerably, and are preferred to the sealing member 11 shown in Figs. 1 to 5. For the purpose of uniform distribution of forces in the sealing member 61, 71 around the opening 10, the angles between the radial slits 65, 75 and the central slit 14 are preferably equal. The angle between a radial slit 65, 75 and the central slit 14 is preferably not less than 30°, in order to avoid a narrow elastic sector having such a small angle that it prevents the maximum permitted excess pressure within the container 20 from being reached and maintained.

If an excess pressure prevails in the container 20, the parallel slits 15 in the sealing member 11 can open slightly at the inside of the container 20, due to the fact that the sealing part 11 bends into the opening 10 and, as a result, material from the closer cut sides of the slits 15 is pulled towards the cap opening 10 more than material on the opposite cut sides of the slits 15. This results in the possibility of liquid from the container 20 passing into the spaces thus formed at the undersides of the slits 15, which may cause undesired, possibly unhygienic contamination. Furthermore, there is a possibility of the liquid adhering permanently to the cut sides of the slits 15, which may prevent correct operation of the cap. These drawbacks may be important if the liquid is a sugar-containing drink and the cap is intended to be used a number of times, an objective which the invention aims to make possible. In this connection, the embodiments 61, 71 of the sealing member having the radial slits 65 and 75, respectively, have the advantage, compared to the embodiment 11, that in a situation in which an excess pressure is prevailing in the container 20, the material is pulled towards the opening 10 in the cap not only on one single side but on both sides of the slits 65, 75, as a result of which the slits 65, 75 are held closed or are even pulled closed. As a result, the said contamination by liquid from the container 20 is prevented. This effect is greatest in the sealing member 61 shown in Fig. 6, which can moreover be produced more simply than the sealing member 71 shown in Fig. 7.

Instead of the straight slits 15, 65, 75 shown in the figures, it is possible to use curved slits. In order to ensure that the slits close correctly, it may then be necessary for the slits to extend at least partially obliquely with respect to the thickness dimension of the sealing member. However, this makes the cap more expensive.

Depending on the abovementioned design parameters, the possibility and admissibility of contamination of the slits, part of the non-central slits may optionally be situated opposite the cap opening 10.

The cap according to the invention is particularly suitable for use on a container 20 which contains a drink in which carbon dioxide (C0₂) is dissolved. After the container 20 has been partially emptied, the pressure of the space inside the container 20 which is not taken up by liquid can be increased in the manner as explained with reference to Fig. 2, as a result of which the carbon dioxide is prevented from escaping from the liquid and, as a result, the quality of the drink is not impaired. If the container 20 with such a drink therein is shaken so strongly that, despite any excess pressure in the container 20, gas escapes from the liquid, the pressure in the container 20 can only increase to the predetermined maximum permitted excess pressure, which means that the container 20 cannot break or tear as a result of the excess pressure being too high.

It is also possible to use other pump means which are known per se instead of the pump 30 shown in Fig. 2. Furthermore, the gas or the gas mixture which is pumped into the container 20 by pumping means is not restricted to air. If the liquid in the container 20 contains carbon dioxide, it is possible, for example, to pump carbon dioxide into the container 20.

Claims

1. Sealing cap for a liquid container, comprising a cover part (4) having an opening (10) and a substantially flat inner side, and a sealing member (11, 61, 71) which is made of elastic material, is arranged against the inner side and has a slit (14) opposite the opening (10) , such that the cap is suitable for sealing an opening (22) in a liquid container (20) and such that if the pressure inside the container (20) exceeds a maximum pressure with respect to the pressure outside the container, the slit (14) opens in a direction away from the container opening (22) , characterized in that the sealing member (11, 61, 71) has, on each side of the one slit (14) , opposite the cover part (4), one or more further slits (15, 65, 75).

2. Sealing cap according to claim 1, characterized in that the central slit (14) extends over a distance of at least a quarter of the diameter of the container opening (22).

3. Sealing cap (1) according to claim 1 or 2, characterized in that a further slit (15) is parallel to the central slit (14) .

4. Sealing cap according to claim 1 or 2 , characterized in that a further slit (65, 75) is radial with respect to the opening (10) in the cover part (4) , and an angle between the further radial slit (65, 75) and the central slit (14) is larger than 30┬░.

5. Sealing cap according to claim 4, characterized in that, on each side of the central slit (14) , angles between adjacent further radial slits (65, 75) and the central slit (14) are equal.

6. Sealing cap according to claim 5, characterized in that the number of further slits is two, and the further slits are radial slits (65) which are perpendicular to the central slit (14).