This invention relates to a method and a device arranged to prevent unintended flow of liquid from drinking containers, such as bags, cartons and bottles. The device may be formed, for example, as a drinking straw or as a drinking spout, and thus it could easily replace the current drinking straws in those instances where a spill-free additional function is desired. The flow of liquid is started and controlled by means of the suction force supplied by the user. The flow stops when the suction force ceases, and then a valve seals off the through-flow, even when overpressure is present within the container.
Besides ordinary drinking straws or drinking spouts, the patent literature discloses several special devices that efficiently prevent liquid from flowing freely from a drinking container. U.S. Pat. No. 5,975,369 and U.S. Pat. No. 5,465,876 provide examples of such devices. These devices do not have automatic closing mechanisms, and the user therefore must carry out a mechanical movement when opening and closing the device. Also, devices having automatic closing functions are known, but they possess other disadvantages, such as low tolerance to pressure differences, relatively high complexity and requirements of specially designed containers. U.S. Pat. No. 5,607,073 provides an example of such a device. Moreover, a device that prevents liquid from leaking out, even if the liquid is pressurized, is known. This is described in. Norwegian patent No. 137258. This type of device enhances the overpressure force of the liquid with the aim of closing the valve, and therefore the device is not suitable for drinking from if the liquid is pressurized. A common feature of all the above-mentioned devices is that they provide for a relatively high production cost, and that the devices thus will be unavailable to the disposable items market.
The object of the invention is to remedy said disadvantages of the prior art. The object is achieved in accordance with the features specified in the following description of the invention.
The object is achieved by means of forming a drinking straw or a drinking spout, hereinafter simply termed an outer tube, in such a way that liquid cannot flow or be forced out of the drinking container until the user supplies a suction force.
The device comprises an outer tube that carries the liquid from the container to the user, that protects an inner tube against external physical loads, and that simultaneously forms a surrounding anchoring object for those parts of the device that move relative to each other when the user supplies a suction force. The outer tube also may have a pointed end that is sufficiently rigid for punching a hole in a drinking container suitable for this.
The device also comprises an inner tube formed with an attachment device for attaching to the outer tube. In a longitudinal portion the inner tube is formed as a flexible bellows. If the bellows is provided with a longitudinal helical pattern, an increased force and rotation may arise when said suction force is supplied. The design of this pattern is selected on the basis of the force need, the need for free area of liquid flow, available tube length and the nature of the material, so that an acceptable pressure difference between the inside and outside of the bellows give rise to a change in length and/or rotation of the bellows. By making the pattern deep and narrow, a more elastic bellows/helical bellows is achieved, but simultaneously the free area available for liquid flow is reduced. The pitch of the helical pattern 33 substantially determines the transmission ratio between force and movement. A large pitch provides great force but little movement; a small pitch provides the opposite situation. A pitch of between 30 and 60 degrees appears to provide appropriate force and sufficient movement at the same time. Said pattern may be varied substantially and different rotational directions and patterns can be combined in one and the same tube in order to achieve the desired function. In some cases it may be desirable to isolate the movement to vertical movement, only. This may be achieved by combining two or more zones of the bellows having patterns of opposite rotational directions, or by using a bellows provided with ring-shaped recesses. The latter solution provides little excess force, but provides a great deflection relative to the total length of the bellows. It also is possible to isolate the rotational force by combining, for example, a helical pattern and a bellows pattern having at least one ring-shaped recess wherein this bellows part absorbs the vertical movement due to its small vertical rigidity, while efficiently transmitting the rotational force. The movement is transmitted to a portion at the end of the inner tube that is arranged as a valve, and that moves relative to the outer tube in order to open and close.
For example, the valve mechanism may be made by continuing the tube, from which the bellows is formed, a distance below the bellows and by using it as a valve head that seals against the outer tube, and by providing the outer tube with one or more through-going holes positioned in such a manner that the valve head shuts off fluid flow until the movement displaces it sufficiently upwards for the holes in the outer tube not to be blocked any more by the inner tube.
Alternatively, the valve may be made by pre-deforming during production the portion following the bellows in such a way that the valve normally is closed, and that the movement transmitted from the bellows through suction force causes opening of the valve (see
In some cases, a deformation valve will require both rotation and longitudinal movement to operate optimally. It is then essential to lock both the top and bottom of the inner tube to the outer tube in such a way that rotation at the attachment points is prevented, and also that a sufficient seal against the outer tube is maintained. The locking may take place in separate grooves, whereby sealing and locking may be optimised independently of each other. Also, oblique auxiliary flutes or funnel-shaped grooves may be made in one or both parts, correcting the twisting of the valve during fitting.
Another way of making the valve may be that of introducing an extra part that seals the end of the same tube from which the bellows is formed, and that simultaneously functions as a sliding seal against the valve piece of the inner valve (see the example in
A valve of the deformation type or of the latter type may be placed freely above or below the liquid level in the container, inasmuch as it does not require suction of liquid from the sides of the tube. Moreover, it may not require closing of the lower end of the tube to form a functioning valve, which is preferred in some situations.
When not using the device, the bellows will be subjected to equal pressure on both sides, and no force arises for rotation and/or longitudinal change of the bellows. The valve part then maintains its closed position, even if an overpressure is formed in the drinking container to which it is connected.
In some cases the tube, from which the bellows is made, advantageously may be coated externally with a different plastics material than that of the inside. For example, the external plastics material may be polypropylene, thus enabling the tube to be secured by welding to an outer tube that may become part of a drinking container, for example a bag. In other cases it may be relevant to use a softer type of plastics on the inside of the tube, whereby a better tube deformation seal may be achieved. A combination of these properties also may be appropriate, whereby the tube may be welded and simultaneously maintain a soft inside that ensures sufficient sealing.
In most embodiments of the invention at least one vent is conveniently placed in the outer tube to ensure that the space between the bellows and the outer tube always is exposed to full atmospheric pressure. The same holes also may be made sufficiently small for the user to experience a certain delay in the mechanism response time when switched on and off. This adaptation also may dampen any oscillations that may occur when used. Other special adaptations also may be appropriate, such as forming one or more shaped sealing surfaces between the inner and outer tubes. Also, in some instances the bellows advantageously is provided with one or more smaller through-going holes in order to drain liquid from the zone between the outer tube and the bellows.
Another important detail of the device is that of the air inlet, which may replace the liquid volume consumed from containers, and which allows the container to maintain its physical shape (cartons, bottles and similar rigid containers). The previously mentioned time delay for switching on and off may allow air to enter the container, thereby ensuring that the container maintains its shape. Another method consists in providing one or more one-way valves for air to the outside of the part of the outer tube placed on the inside of the container. For example, one or more of the barbs that secure the device against becoming loose when used, are cut in a manner allowing them to operate as one-way valves. Alternatively, the pointed end of the outer tube may be made as a one-way valve, opening only to overpressure outside of the container. These adaptations will be explained in detail in the following drawings.
An improved attachment mechanism to prevent the drinking straw/drinking spout from becoming loose when used or when exposed to overpressure in the container, is achieved by providing the outer tube with a stop flange that ensures correct application of the drinking straw/drinking spout, by means of one or more associated barbs. Also, it is possible to make the outer tube into a part of a cap, or to provide the outer tube with threads or other securing mechanisms, whereby it may be applied to bottles or similar containers having standardized or special connectors.
When using deformation valves it also is possible to encase all or parts of the inner tube within the drinking container itself, for example as part of a bag (see
During mass production the drinking straws/drinking spouts may be packed, handled and applied in the same way as that of existing drinking straws/drinking spouts.
In the following several non-limiting examples of preferred embodiments are described, these being visualized in the accompanying drawings, where:
a shows a section of a preferred valve placed in its closed position;
b shows the same valve placed in its open position;
a, 9b, 10a, 10b, 11a, 11b, 12a and 12b show different embodiments of the valve incorporated in the device;
a and 16b show an alternative embodiment of the outer tube of the device; and
a and 17b show a further embodiment of the outer tube of the device.
In its closed position the valve 70 will be sealed, even if the liquid pressure P3 within an associated drinking container exceeds the atmospheric pressure P1.
When assembling the outer tube 1 and its inner tube 29, a connecting groove 38 at the upper end A of the tube 29 will engage a complementarily shaped groove 37 of the outer tube 1. Thereby the tube 29 is attached pressure-sealingly to the inside of the outer tube 1. The grooves 37, 38 possibly may be formed through heating subsequent to having fitted the parts together in a mutually fixed position.
At the lower end of the outer tube 1 the tube 1 is squeezed together into a tight and rigid point 35 for puncturing a drinking container, for example. The outer tube 1 also is provided with a ring 39, the purpose of which is to stabilize the extent of the folds resulting from the end 35 being squeezed together. Moreover, the device is provided with a stop flange 31 and four barbs 32a, 32b, 32c, 32d that ensure correct application, and that prevent the device from being forced out of the container when subjected to overpressure. In one of the barbs 32a, 32b, 32c, 32d a slit 2 has been cut forming a one-way and continuous air inlet mechanism into the drinking container 61. The outer tube 1 is provided with a vent 20 that delivers atmospheric pressure P1 via the slit 2 to the outside 13 of the tube 29 and to the inside of the drinking container 61.
Otherwise, the outer tube 1 is formed with a flexible joint 30, enabling a longitudinal portion 5 of the outer tube 1 to be folded parallel to the remaining length of the outer tube when being packed.
a shows a section from a similar device to that of
b shows the same valve as that of
a shows a section of the device shown in
b shows the same device as that of
Resembling that of
b shows the device of
a shows a section of the device of
b shows the device of
a shows a section of the device of
b shows the device of
a shows an alternative embodiment of the invention, in which the outer tube 1 is comprised of plastic foils that are vacuum-formed and then fixedly welded or glued together along the entire surface 93 and to the tube 29 at the surfaces 94a and 94b. The casing encloses, fixes and protects the bellows 4 and the valve 70′. The tube 29 is terminated in an obliquely cut edge 96 to facilitate insertion of the inner tube 29 into a drinking container 61. Here, the deformation valve 70′ is shown in its closed state.
b shows the embodiment of
a shows another alternative embodiment of the device according to the invention, in which the outer tube 1 is formed as a cap. The bellows 4 and the valve seat 53 are of corresponding type and provide the same function as the device shown in
b shows the device of
Number | Date | Country | Kind |
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20015957 | Dec 2001 | NO | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NO02/00460 | 12/3/2002 | WO |