Liquid dispensing appliance provided with an anti-drip valve system

Abstract

A dispensing assembly having a container containing a liquid to be dispensed and a dispensing tube bringing in fluid communication with ambient the volume inside the container containing the liquid. The dispensing tube has a flexible, resilient portion ending in an outlet of diameter, D, and is engaged in a pinch valve system. The pinch valve system has a squeezing member suitable for squeezing and obturating a section of the flexible portion located at a distance, h, from the outlet. The ratio, h/D, of the distance, h, to the outlet diameter, D, is not more than 2, preferably, not more than 1.5, more preferably, not more than 1.0.

Claims

1. A pressure driven dispensing assembly comprising a container containing a beverage to be dispensed, a dispensing tube bringing in fluid communication with ambient the volume inside the container containing the beverage, and a source of pressurized gas in fluid communication with the interior of the container for pressurizing the interior of the container and driving the dispensing of the beverage out of the container through the dispensing tube, said dispensing tube having a flexible, resilient portion ending in an outlet of inner diameter, D, is at least 3 mm, and being engaged in a pinch valve system comprising a squeezing member suitable for squeezing and obturating a single section of the flexible portion located at a distance, h, from the outlet comprised between 1 and 12 mm, wherein the ratio, h/D, of the distance, h, to the outlet inner diameter, D, is not more than 1.5, so as to reduce the dripping of the beverage out of the dispensing tube when obturating the section.

2. The dispensing assembly according to claim 1 wherein, (a) the container comprises a body, a mouth, and a closure, said closure comprising at least one dispensing opening; (b) the assembly further comprises an appliance suitable for receiving said container and for dispensing a beverage contained in said container, said appliance comprising a dispensing portion comprising the pinch valve system, (c) the dispensing tube has an inlet end introduced in the closure's dispensing opening in fluid contact with the interior of the container and the flexible portion is inserted in the valve of the dispensing portion and the outlet faces downwards.

3. The dispensing assembly according to claim 2, wherein the squeezing member can be moved from a closed position squeezing the flexible portion to an open position releasing the compressive pressure on the flexible portion by actuation of a lever.

4. The dispensing assembly according to claim 3, wherein the squeezing member comprises two complementary surfaces which can be moved relative to each other to be brought together with the flexible portion of the dispensing tube caught in between, and wherein at least one of the two complementary surfaces has a rounded portion in contact with the flexible tube portion of radius comprised between 0.2 and 3 mm.

5. The dispensing assembly according to claim 4, wherein the flexible portion of the dispensing tube is made of a natural or synthetic rubber, or a thermoplastic elastomer.

6. The dispensing assembly according to claim 5, wherein the dispensing tube is encased in a cartridge, forms smooth curves, and the longitudinal axes of the inlet and outlet form an angle, , comprised between 85 and 145 deg.

7. The dispensing assembly according to claim 6, wherein the inlet end of the dispensing tube is suitable for unsealing an initially sealed dispensing opening of the container.

8. The dispensing assembly according to claim 1, wherein the container is a bag-in-container.

9. The dispensing assembly according to claim 8, wherein the beverage contained in the container is a carbonated beverage.

10. The dispensing assembly according to claim 1, wherein the squeezing member can be moved from a closed position squeezing the flexible portion to an open position releasing the compressive pressure on the flexible portion by actuation of a lever.

11. The dispensing assembly according to 1, wherein the squeezing member comprises two complementary surfaces which can be moved relative to each other to be brought together with the flexible portion of the dispensing tube caught in between, and wherein at least one of the two complementary surfaces has a rounded portion in contact with the flexible tube portion of radius comprised between 0.2 and 3 mm.

12. The dispensing assembly according to claim 1, wherein the flexible portion of the dispensing tube is made of a natural or synthetic rubber, or a thermoplastic elastomer.

13. The dispensing assembly according to claim 1, wherein the dispensing tube is encased in a cartridge, forms smooth curves, and the longitudinal axes of the inlet and outlet form an angle, , comprised between 85 and 145 deg.

14. The dispensing assembly according to claim 1, wherein the beverage contained in the container is a carbonated beverage.

15. The dispensing assembly according to claim 14, wherein the beverage contained in the container is beer.

16. The dispensing assembly according to claim 1, wherein the ratio, h/D, of the distance, h, to the outlet inner diameter, D, is not more than 1.0.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) For a fuller understanding of the nature of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:

(2) FIG. 1: shows a dispensing assembly.

(3) FIG. 2: shows the dispensing portion of a dispensing assembly according to the present invention.

(4) FIG. 3: shows a flexible dispensing tube portion engaged in a pinch valve (a) open; (b) closed according to the present invention; and (c) closed according to prior art.

(5) FIG. 4: shows a dispensing tube encased in a dispensing cartridge.

(6) FIG. 5: shows a closure suitable for being used with the assembly of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) As can be seen in FIG. 1, a dispensing assembly comprises a container (1) and a dispensing appliance (2). The container (1) illustrated in FIG. 1(a) is a bag-in-container, comprising a collapsible flexible inner layer (1B) (the bag) containing the liquid and an outer layer (1A) and defining a space or an interface (1C) between the two layers. Bag-in-containers are particularly preferred, but the present invention is not restricted to bag-in-containers and can be used with any container provided with at least a dispensing aperture (10B), preferably disposed in a closure (8), allowing the volume containing the liquid to be brought in fluid communication with ambient. In most cases, said dispensing aperture (10B) is sealed before use and it must be unsealed upon mounting the container in the appliance (2). The closure illustrated in FIGS. 1(a) and 5 comprises a second opening (15B) for engaging a second tube, such as a gas tube for injecting pressurized gas from a source of pressurized gas (29) into the container. A second opening is not necessary for e.g., gravity dispensing systems, wherein the dispensing tube is located below the level of liquid in the container or, if necessary, it shall be located above the level of the liquid in order to balance the pressure with ambient upon dispensing.

(8) The dispensing appliance (2) comprises a holding portion (201) for holding the container in position with holding means (21, 22) and a dispensing portion (202) comprising a dispensing tube (10A) suitable for fluidly connecting the volume containing the liquid with ambient. In the embodiment depicted in FIG. 1, the flow of liquid out of the container is driven, by increasing the pressure in the space (1C) by injecting pressurized gas between the inner and outer layers (1A, 1B) of the container from the pump (29) through the gas tube (15A). The flow of liquid through the dispensing tube (10A) is controlled by a valve (300) located between the dispensing tube inlet (10IN) and outlet (10OUT). In use, the container (1) is preferably first loaded into the holding portion (201) of the appliance. Then, the dispensing tube (10A) and any other tubing (15A) are engaged into the corresponding openings (10B, 15B) in the closure (8) of the container. Preferably, as illustrated in FIG. 1, the engagement of the tubing (10A, 15A) is performed by moving the dispensing portion (201) from a first, loading position (cf. FIG. 1(b)) to a second, dispensing position (cf. FIG. 1(c)).

(9) The dispensing tube (10A) shall be periodically changed, preferably with each new container (1) mounted in the dispensing appliance (2) for hygienic reasons as well as for not mixing tastes in case a container containing a beverage different from the one dispensed from the prior container is used. In order to reduce the cost of a disposable dispensing tube (10A), the valve system (300) controlling the flow through said dispensing tube is permanently part of the dispensing portion (202) of the dispensing appliance (2) and a flexible portion (10D) of the dispensing tube is engaged in said valve system (300). According to the present invention, at least the portion (10D) extending from the point where the dispensing tube is engaged in the valve system (300) downstream to the outlet (10OUT) is made of a resilient, flexible material, such as a rubber, a thermoplastic elastomer (TPE) and the like. The material must retain its resiliency and flexibility at temperatures ranging from 2 C. as can be encountered in a conventional fridge, to up to about 40 C., if the appliance is exposed to the sun. For example, the flexible portion (10D) of the dispensing tube (10A) can be made of natural rubber or of any of the following synthetic rubbers: Bromo Isobutylene Isoprene (BIIR), Polybutadiene (BR), Chloro Isobutylene Isoprene (CIIR), Polychloroprene (CR), Chlorosulphonated Polyethylene (CSM), Epichlorohydrin (ECO), Ethylene Propylene (ECO), Ethylene Propylene Diene Monomer (EPDM), Fluoronated Hydrocarbon (FKM), Fluoro Silicone (FVQM), Hydrogenated Nitrile Butadiene (HNBR), Polyisoprene (IR), Isobutylene Isoprene Butyl (IIR), Methyl Vinyl Silicone (MVQ), Acrylonitrile Butadiene (NBR), Polyurethane (PU), Styrene Butadiene (SBR), Styrene Ethylene/Butylene Styrene (SEBS), Polysiloxane (SI), Acrylonitrile Butadiene Carboxy Monomer (XNBR), and the like.

(10) The valve system (300) of the present invention is a so-called pinch valve comprising a squeezing member (303) suitable for controllably squeezing a section of the flexible portion (10D) of the dispensing tube (10A) until sealing the passage therethrough (for general information on pinch valves, cf. e.g., http://en.wikipedia.orq/wiki/Pinch_valve). The squeezing member (303) may comprise one or more movable parts, which combined movements are suitable for obturating the passage through the flexible portion (10D) of the dispensing tube. The squeezing member generally comprises two complementary surfaces which can be moved to be brought together with the flexible portion (10D) of the dispensing tube caught in between. In the embodiment illustrated in FIG. 2, a squeezing member (303) can be moved by actuating a lever (301) to squeeze the flexible portion (10D) of the dispensing tube against a fixed surface, which can be prismatic as depicted in FIG. 2, flat, or forming a cradle mating the geometry of the squeezing member (303). Many mechanisms are known to the person skilled in the art for bringing together two complementary surfaces with a flexible tube caught in between. In the embodiment illustrated in FIG. 2, a shaft (202) pivotally mounted between the proximal and the distal ends thereof and comprising at its distal end a squeezing means (303). Resilient means (304) naturally biase the shaft (302) such that the squeezing means (303) presses against the flexible portion (10D) of the dispensing tube (10A) against a fixed surface of the spout (203) of the dispensing portion (202), such that no flow occurs through the dispensing tube. Opening of the valve system (300) can be actuated by any means such as a lever (301), which is particularly appreciated for beer dispensing appliances as it reminds of the tap in pubs. In FIG. 2, rotation of the lever (301) by a user presses the proximal end of shaft (302), which pivots like a seesaw such that the squeezing means (303) releases the pressure against the flexible portion (10D) of the dispensing tube (10A), thus allowing the liquid contained in the container to flow through the dispensing tube. Instead of a shaft (302) pivotally mounted and comprising at its distal end a squeezing means, other squeezing means can be used, such as for example a cam which rotation can be driven by actuation of a lever (301) to bring in or out of contact a squeezing means (303) as disclosed in WO2005/110912. Other pinch valve systems can be applied to the present invention, which are disclosed in e.g., DE3920348, WO2004/050535, WO2009/142662, U.S. Pat. No. 4,186,848, U.S. Pat. No. 5,022,565, or US2005072806. Actuation can be driven mechanically as discussed above, e.g., with a lever (301), or electrically. At least one of the two complemenrary surfaces forming the squeezing members (303) should be rounded with as small a radius as possible, so that a high squeezing stress can be applied to the flexible tube with a low force by an operator or a biasing means. The radius should not, however, be so thin that it could damage the tube, e.g., by indenting it or even cutting it. The radius of the rounded portion of at least one of the two complemenrary surfaces forming the squeezing members (303) is preferably comprised between 0.2 and 3 mm, preferably between 0.3 and 1 mm, more preferable between 0.4 and 0.7 mm.

(11) As illustrated in FIG. 3(c), regardless of the squeezing mechanism used, drops of liquid invariably drip out of a downwardly oriented dispensing tube directly after interrupting a dispensing operation by closing a pinch valve as used to date in dispensing appliances. This is because after closing of the valve system (300) the outlet (10OUT) of the flexible dispensing tube (10A, 10D) remains open and oriented downwards, so that any liquid still remaining in the dispensing tube downstream from the squeezing means (303) will invariably drip down. To solve this problem in a simple and economic way, it has been found that dripping can be substantially reduced and even stopped if the squeezing means (303) are located at a distance, h, sufficiently close to the flexible tube outlet (10OUT) of diameter, D, such that the ratio, h/D, of the distance, h, to the outlet diameter, D, is not more than 2, preferably, not more than 1.5, more preferably, not more than 1.0. If the dispensing tube is not cylindrical, e.g., trunco-conical, the value of the outlet diameter, D, is the inner diameter measured at the very outlet of the tube at rest (i.e., not strained). If the outlet is not circular, the value of the diameter, D, has the value of the hydraulic diameter, D.sub.H=4 A/P, wherein A is the cross-sectional area, and P is the perimeter of the outlet (10OUT). Without wishing to be bound by any theory, it is believed that several factors contribute to the substantial reduction, and even elimination of undesired dripping after closing the valve.

(12) First, there is a kinetic aspect. The liquid flowing out of the dispensing tube has a certain kinetic energy, m v.sup.2, (where m is the mass and v the velocity of the liquid downstream of the closed valve); which rapidly dissipates with friction against the tube wall. The magnitude of energy dissipation is proportional to the distance, h. It follows that with a large diameter, D, the kinetic energy is greater than with a lower diameter, D, because the mass, m, is proportional to the square of the diameter, D, and, concomitantly, the liquid reaches the outlet (10OUT) with less energy losses when the distance, h, is lower. This means that a drop of liquid will reach the outlet (10OUT) with more energy if the ratio, h/D, is low, thus ejecting a greater volume of liquid out of the tube portion downstream of the closed valve (300), and thus letting a smaller amount of liquid in the tube. Letting a smaller amount of liquid in the dispensing tube downstream of the valve has further effects, as discussed below.

(13) Second, there is a capillary aspect. Since the outlet (10OUT) is facing downwards, two forces compete: the gravity force, which tends to drag the remaining volume of liquid out of the dispensing tube, and the capillary forces, which tend to hold the remaining volume of liquid within the tube. As illustrated in FIG. 3(c), the greater the volume of liquid left in the dispensing tube portion downstream of the valve, the greater the effect of the gravitational force, until it exceeds the capillary forces and the liquid will start dripping. It is clear that if the distance, H, from the squeezing member (303) to the outlet (10OUT) is greater than, h, as defined herein, the volumei.e., mass-of liquid is greater and the gravitational force will exceed the capillary forces. On the other hand, as illustrated in FIG. 3(b), if the volume of liquid remaining in the dispensing tube is small, the capillary forces are greater than the gravitational forces, and the liquid drop is held in the tube and no dripping occurs.

(14) It has been found that good results were obtained when the distance, h, is less than 15 mm, preferably the distance, h, is comprised between 1 and 12 mm, more preferably, between 2 and 10 mm, whilst the outlet diameter, D, is at least 0.5 mm, preferably at least 3 mm, more preferably at least 5 mm, most preferably at least 10 mm. For a beer dispensing system, the diameter, D, of the outlet (10OUT) is preferably comprised between 5 and 7 mm, more preferably between 5.5 and 6.5 mm.

(15) In a preferred embodiment, the dispensing tube (10A) is encased in a cartridge (100) with the flexible portion (10D) thereof protruding out of a first face of the cartridge, and the inlet end (10IN) protruding out of a second face of said cartridge. If the container is to be held horizontally in the dispensing unit, the longitudinal axes of the inlet portion (10IN) and outlet (10OUT) form an angle comprised between 85 and 145 deg, preferably between 90 and 135 deg. In case the container stands vertically, with the closure up, then the longitudinal axis of the inlet (IN) and outlet (10OUT) form an angle comprised between 0 and 45 deg, the tube drawing a curve like a reversed U. It is preferred that the dispensing tube (10A) comprises no sharp angle to prevent excessive formation of froth in case of gaseous beverages, such a beer and sodas. It may comprise a pressure reduction portion wherein the tube forms curves and/or the cross-section thereof varies in order to create a pressure drop in the liquid, but said pressure reduction portion should preferably not comprise any sharp angle.

(16) The inlet portion (10IN) of the dispensing tube (10A) must be suitable for piercing an initially sealed opening (10B) in the closure of the container (1). It is therefore preferably made of a rigid material, like PE, PP, PET, and the like, and its edges are preferably sharp. The flexible portion (10D) of the dispensing tube may form substantially the whole length of the dispensing tube, the sharp inlet being formed by a ring inserted in one end of the flexible tube (10D) and held in place by the case of the cartridge in which it is engaged. Alternatively, a portion of the dispensing tube may be formed by two channels formed on two opposed half shells, which, upon assembly form a closed channel in the cartridge. This embodiment, illustrated in FIG. 4, is particularly suitable when a pressure reducing channel is desired. The flexible portion (10D) can be joined upon assembly of the two half shells in continuation of said channel by welding, gluing, over-injecting or any other technique known to the person skilled in the art, and protrude out of the cartridge with a length suitable for engaging into the valve system (300) of the dispensing portion (202) of the dispensing appliance, and preferably substantially flush with the outlet of the spout (203) of the dispensing portion (202).

(17) The cartridge may be provided with fixing means (16) for fixing it to the dispensing appliance. If the dispensing opening (10B) of the closure of the container (1) cannot be sealed back after removal of the dispensing tube, it may be preferable to not disengage the dispensing tube (10A) and cartridge (100) from the closure after removal of the container from the dispensing appliance and to provide the cartridge with a secondary pinch valve (110) automatically squeezing a flexible section (10D) of the dispensing tube upon removal thereof from the appliance. In this embodiment, the cartridge preferably comprises snap fitting means (14) for fixing the cartridge to the closure (8). This has the advantage that a half full container may be removed to mount another container, and yet still ensure that the removed container is sealed. If the old container is mounted back into the dispensing appliance, the secondary pinch valve (110) opens automatically upon engagement of the cartridge into the dispensing portion (202). It can thus be stored and used again later if desired. If the dispensing opening (10B) of the closure (8) can be sealed back after removal of the dispensing tube, then the cartridge (100) may be removed from the container and a secondary pinch valve (110) is not necessary anymore.