LIQUID DISPENSING SYSTEM

Abstract: A system for coupling a liquid filled container 1 to a duct 43 is provided with a valve coupling 9 which co-operates with the duct 43 to enable connection of the container 1 to the duct 43, and subsequent disconnection, while the valve coupling 9 is lowermost and therefore below the liquid level, without spillage. Preferably the valve coupling 9 or a separate gas passage 101 has means 23,103 permitting escape of excess pressure while the container 1 is stored, means 38,103 admitting air during liquid outflow into the duct 43 and means 39 co-operating with the valve coupling 9 to assist closing of the valve coupling on disconnection.

Description: The present invention relates to a liquid dispensing system, more in particular to a container coupling system which can be used for dispensing liquid detergent products from a container. DE-A-3 246 127 discloses a container coupling system comprising a container for liquid and a liquid duct for connection to the container, the said container comprising a valve coupling providing entrance to the container for transfer of liquid between container and duct, the said duct and valve coupling having cooperating configurations enabling connection together and disconnection of the said duct and valve coupling, without spillage of liquid, the valve coupling comprising a valve sealing member and resilient means urging the sealing member into a position closing the valve, the duct being provided with openings means positioned to displace the sealing member when the duct and valve coupling come into sealing engagement upon connection thereof, said opening means projecting beyond a terminal portion of the duct, whereby sealing means are provided to seal between the valve coupling and the terminal portion of the duct, the opening means and the valve coupling being configured to co-operate with one another to assist closing of the valve coupling as the duct is disconnected therefrom, and wherein a projection from either the opening means or the valve sealing member engages an undercut recess in the other of them. GB-A-2 147 163 discloses a liquid tight connection formed between the outlet of a reservoir and a dispenser, comprising valve means which allows the passage of liquid from the reservoir outlet to the dispenser, but closes the reservoir outlet when the reservoir is withdrawn from its operative position. Normally, with a closed system as described in the German patent application, it is necessary to have a collapsible container in order to be able to extract liquid. However, it would be desirable to use a rigid container because with collapsable (e.g. plastics bottles) of the conventional kind, as the bottle collapses, irregular wrinkles are formed in the walls, which may trap part of the liquid product, resulting in unacceptable wastage. To prevent such wastage, we have now devised a container coupling system of the afore mentioned kind which is characterized in that the duct incorporates an air passage, the said duct and the valve coupling having configurations to enable air to flow into the container via the air passage as liquid flows from the container into the duct. Preferably, the opening means comprises a pillar having a channel through the pillar leading from atmosphere to one or more openings in the pillar and provided with valve means serving to admit air to the container as liquid flows from the container into the duct. It is also preferred that the duct has a protective shield resiliently biased to a position covering an entrance to the duct, and forced to a position exposing the entrance to the duct when the duct and valve coupling are connected. Conveniently, the duct is provided with a level sensor to indicate when liquid from the container is substantially exhausted. A problem may also arise when it is desired to feed a modular system from a reservoir containing a liquid chlorine-based bleach, or a detergent product including the same. Such compositions inevitably release oxygen under the influence of heat and/or light. The oxygen gas thus released increases the pressure above the liquid surface, which could risk rupturing the container, or result in excess internal pressures which can have hazardous effects when the container is coupled to the rest of the system. A similar problem can be encountered with other noxious agents giving rise to gassing or development of volatile components. To overcome the above mentioned problem of excess pressure in the container, the valve coupling is preferably constructed such that when the container is not connected to the duct, the valve coupling substantially prevents escape of liquid during storage, whilst permitting escape to atmosphere of excess pressure within the container. Preferably the valve coupling comprises a sealing member, which may be a sealing washer, resiliently biased against a valve seat, which may be a lip. Such a washer may be provided with a suitably dimensioned slit which allows vapours of gases at excess pressure to escape, yet prevents passage of liquid when the container is inverted ready to be coupled to the duct, by virtue of the weight of the liquid contents. As an alternative to providing for escape of excess pressure through the valve coupling, or admission of air through the valve coupling, or both, the container may be provided with a gas flow passageway closed by a porous membrane. The membrane may be made of microporous polytetrafluoroethylene (PTFE) with a pore size which will not allow liquid to pass, yet which will allow air in, or excess gas out, according to the pore size employed. Such a gas passage could be separate from the valve coupling, for instance positioned alongside it. The present invention will now be better explained by the following exemplary embodiment and with reference to the accompanying drawings in which:- Figure 1 shows a cross section through a liquid filled container illustrating the invention; Figure 2 shows an exploded view of the container of Figure 1, at rest in storage position; Figure 3 shows the container of Figures 1 and 2 positioned prior to insertion in a receiving module, showing in fragmentary view and containing a duct; Figure 4 shows a cross sectional view of the container, receiving module and duct of Figure 3, when coupled; Figure 5 shows a part cross sectional view of an alternative form of construction of duct, having a sliding protective shield, with the container mouth just prior to coupling or just after coupling; Figure 6 shows a cross section through part of a second form of liquid filled container; Figure 7 is a detailed view of the sealing washer of the container of Figure 6; Figure 8 shows a part cross section through the same container, fitted to a receiving module and duct. Referring to Figures 1 and 2, a container 1, having a plastics wall 3, is filled with a liquid detergent composition 5. The container wall terminates in neck 7 to which is fitted a valve coupling 9. The valve coupling comprises a collar 11 fitted to the container neck by a screw thread arrangement. A bayonet or irremovable snap-fit arrangement is also possible. The valve coupling further comprises a resilient washer 13 mounted on a compression spring 15 which urges said washer against a lip 17. The compression spring is held in place by basket 19. The action of the spring urging the washer against the lip results in sealing of the opening 21 so that substantially none of the liquid contents can escape, even if the container is inverted. However, the washer is provided with a slit 23 which is dimensioned so as to open at 0.10-0.12 bar excess pressure within the container. Thus, where the liquid detergent composition contains volatile components giving rise to gassing, for example a chlorine bleach, any gas at excess pressure above the liquid can degas i.e. escape to atmosphere. Preferably, an annular sealing washer 25 is also provided to ensure good sealing of the container against the collar. Referring now to Figure 3, in use, the container and valve coupling are positioned mouth downwards, by virtue of the container being manipulated with handle 27. The container is inserted in receiving module 29 having a lid 31 which is closed by means of a hinge 33. Within the receiving module is positioned a valve opening means having a head 35, at the top of a hollow pillar 37. An internal channel 38 within the pillar 37 leads from an air inlet, as seen in Figure 4. A nipple 39 is situated on the top of the valve opening means. A probe 41 to detect presence of a container 1 and connected to a reset switch is located inside the receiving module to trigger pumping control equipment (not shown) when an exhausted container is removed and a new one inserted. The valve opening means is positioned at the mouth of a duct 43 provided with an O-ring for ensuring a good seal with the mouth of the container/valve coupling. As will be explained in more detail below, the duct mouth is connected via chamber 45 containing a float level sensor (provided with output wire 49) to an outlet duct connector 51. By means of this connector, the container and duct may be coupled to modular pumping and control equipment of the kind described in the aforementioned UK patent specification. As shown in Figure 4, to connect the container to the duct, the valve coupling is pushed over the valve opening means, a seal being achieved by means of O-ring 44. The nipple 39 locks within a recess 53 within the resilient washer, forcing it away from the lip 17 against the biasof the compression spring. This allows free passage of liquid from inside the container, into the duct. The head 35 is dimensioned to seal the opening 21 until the O-ring 44 enters this opening. Although the container is rigid, liquid is able to flow out of it readily because air is allowed to enter via channel 38 from air inlet 55. The valve opening means is provided with a plurality of valved openings 57 which allow the air to escape into the liquid, through the basket. The valve openings 57 are covered with a sheath 58 of a suitable resilient material which provides the necessary valve action thus allowing the air to enter without liquid escaping through the air channel. It will be appreciated that this obviates the necessity for having a collapsable container. The liquid leaving the container and entering the duct first enters an ante-chamber 59 before the chamber 45 which contains the float level sensor 47, which is provided with an appropriate electrical transducer of any kind which will be well known to those skilled in the art. The output of the transducer is conducted by means of wire 49 which is lead through opening 61 in the chamber, a water-tight seal being effected by means of rubber grommet 63. The float sensor chamber leads on to channel 65 which is joined to the duct outlet connector 51 shown in Figure 3. The floor of the channel is raised above that of the ante-chamber and float chamber so that a level establishes itself within the float chamber. When the contents of the container are susbtantially exhausted, the level in the float chamber will fall, and will be detected by the sensor, the output of which can be used to trigger an alarm and/or initiate switching off of ancillary equipment as necessary. It will be appreciated that when the container 1 is removed from the duct 43, because the nipple 39 of the valve opening means is located within the recess 53 in the washer of the valve coupling, at first the washer will be pulled back towards the lip 17, assisted by the pressure of the spring 15. Only when the washer has come to rest completely against the lip 17 does additional force break the nipple 39 free of the recess 53. In this way, accidental spillage of residual liquid is avoided. As an additional safety measure, especially when the liquid contents of the container are of a noxious nature, as shown in Figure 5, the valve opening means can be provided with a cylindrical shield 67 fixed to the upper end of compression spring 71, the lower end of this spring being located in annular groove 73. Connection or disconnection of the container and its associated valve coupling (in the direction of double-headed arrows 75) causes corresponding sliding movements of the shield, respectively against or with the bias of the compression spring 71 (in the direction of double-headed arrows 77). Thus, it can be appreciated that without the container and valve coupling in place, the shield covers the mouth of the duct 43 between the end of this duct and the head 35 of the opening means, to inhibit any back-seepage of liquid in the duct, and avoid any residual liquid coming into contact with the user. The provision of annular groove 73 means that the float chamber 45 is of an alternative shape to that shown in Figure 4 (sensor not shown). The embodiment shown by Figures 6 to 8 has some constructional differences. The container 1 terminates in a neck 7 onto which is screwed a cap 81. This is shaped to provide an encircling collar 83 and a flat face 85 within the neck 7. Upstanding from the centre of face 85 is a tubular portion 87 which is equivalent to opening 21. Extending into the container from face 85 are legs 89 providing a basket accommodating spring 15 which biases a sealing washer 93 to a position as shown in Figure 6 where the washer seals to the tubular portion 87. The washer's relaxed shape is shown in Figure 7. It has a main body similar to that of washer 13, shown in Figure 1, with an undercut recess 53 and a slit 23 as previously described. The body of the washer is joined by thin annuli 95 to sealing lips 97 which seal against the walls of the tubular portion 87. This form of washer is beneficial in giving reliable operation of the slit 23. The container 1 is inserted in a receiving module 29, as shown by Figure 8. This receiving module has a duct 43 projecting from which is a valve opening means with a head 35 at the top of a solid pillar 99. The portion 87 is fitted over the valve opening means and seals onto the duct 43 which may be provided with an O-ring similar to O-ring 44. The valve opening means displaces the washer 93 against the bias of spring 15 allowing liquid to flow between the legs 89 and into the duct 43 through the gap between the duct 43 and the head 35. Extending into the container 1 from the face 85 is a short tube 101 which is closed at its inner end by a membrane 103 of microporous polytetrafluoroethylene (PTFE). This tube acts as a gas passage, by passing the washer 93. The membrane 103 will not allow liquid passage, but has pores of a size allowing gas to escape when the container 1 is disconnected as in Figure 6, and allowing air to vent into the emptying container, as in Figure 8. The gas passage 101 might be relied on for only one of these functions if desired.

Claims: A container coupling system comprising a container (1) for liquid and a liquid duct (43) for connection to the container, the said container comprising a valve coupling (9) providing entrance to the container for transfer of liquid between container and duct, the said duct and valve coupling having co-operating configurations enabling connection together and disconnection of the said duct and valve coupling, without spillage of liquid, the valve coupling comprising a valve sealing member (13) and resilient means (15) urging the sealing member into a position closing the valve, the duct being provided with openings means (35) positioned to displace the sealing member when the duct and valve coupling come into sealing engagement upon connection thereof, said opening means projecting beyond a terminal portion of the duct, whereby sealing means (44) are provided to seal between the valve coupling and the terminal portion of the duct, the opening means (35) and the valve coupling (9) being configured to co-operate with one another to assist closing of the valve coupling as the duct is disconnected therefrom, and wherein a projection (39) from either the opening means or the valve sealing member engages an undercut recess (53) in the other of them, characterized in that the duct (43) incorporates an air passage (38), the said duct (43) and the valve coupling (9) having configurations to enable air to flow into the container via the air passage as liquid flows from the container into the duct. A system according to claim 1 wherein the opening means (35) comprises a pillar (37) having a channel (38) through the pillar leading from atmosphere to one or more openings in the pillar and provided with valve means (57) serving to admit air to the container as liquid flows from the container into the duct. A system according to any one of the preceding claims wherein the duct (43) has a protective shield (67) resiliently biased to a position covering an entrance to the duct, and forced to a position exposing the entrance to the duct when the duct and valve coupling are connected. A system according to any one of the preceding claims wherein the duct is provided with a level sensor (47) to indicate when liquid from the container is substantially exhausted. A system according to anyone of the preceding claims wherein the valve coupling incorporates means to release excess pressure within the container to atmosphere, while the container is disconnected from the duct. A system according to claim 5 wherein the valve coupling incorporates a resilient sealing member, and the said means to release excess pressure is a slit (23) in the sealing member. A system according to any one of the preceding claims wherein the container incorporates a gas flow passageway (101) additional to the valve coupling, which passageway is closed by a porous membrane (103).

Inventors: BUNSCHOTEN, GERRIT KLAAS, DER KINDEREN, WILHELMUS KLAAS, VAN DER HEYDEN, LAMBERTUS GERARDUS PETRUS
Applicants: UNILEVER NV, UNILEVER PLC
Application year: 1987
Main classification: D06F39
IPC codes: D06F39