GB2137962A - Liquid Dispenser - Google Patents

Abstract

A dispenser for a liquid comprises a primary container 10 for storing the liquid and outlet means from the primary container through which the liquid is dispensed. The outlet means includes a secondary container 11 which is smaller than the primary container 10 and is connected to the primary container by means which are capable of preventing back flow into the primary container. The secondary container 11 has a flexible wall which allows the secondary container to be compressed to cause the liquid to be dispensed therefrom. The dispenser is suitable for comestible liquids such as milk, and may be used in a vending machine. Secondary container 11 may be compressed by levers 22 acting about fulcrum 21 which causes opening of jaws 23 which act as a pinch valve. Tubing 12 may be lay- flat tube which acts as a non-return valve between containers 11 and 10. <IMAGE>

Description

SPECIFICATION Dispenser for Liquids This invention relates to dispensers for liquids.

It has been proposed to store liquid in a flexible walled container connected to an outlet pipe and to provide means for applying a pressure to the outside of the container to dispense a desired quantity of liquid through the outlet pipe under pressure. Such a system combines a pressure feed with the ability to control the amount of liquid dispensed. It also allows the dispensing to be performed without contact between the pressure applying means and the liquid being dispensed, and is applicable to the dispensing of liquids from known forms of disposable unit. Both those advantages are especially important when the liquid is a comestible liquid such as milk.

However, this proposed system suffers from the disadvantage that an unacceptably high pressure may have to be applied to the storage container.

According to the invention a dispenser for a liquid comprises a primary container for storing the liquid, and outlet means from the primary container through which the liquid is dispensed, wherein the outlet means includes a secondary container which is smaller than the primary container and is connected to the primary container by means which are at least capable of preventing back flow into the primary container, the secondary container having a flexible wall which allows the secondary container to be compressed to cause the liquid to be dispensed therefrom.

Preferably the secondary container is a bag formed of plastics material which is flexible but non-elastic. It is also preferred that the primary container is a similar bag, and the two bags together may comprise a disposable item.

The dispenser is preferably used in combination with means for applying pressure to the secondary container, which means may be coupled to a valve arrangement for controlling the flow of liquid through an outlet pipe leading from the secondary container. In one convenient embodiment, the pressure applying means is a mechanical lever mounted for pivotal movement between operative and inoperative positions, one end of the lever acting as a pinch valve on the outlet pipe from the secondary container thereby closing the outlet pipe when the lever is in its inoperative position. Movement of the lever towards its operative position may be manually or, for example, cam-actuated, the pinch valve opening simultaneously. In either case, it is preferred that the lever has a quick return movement, e.g. effected by a spring.

The connection means between the primary and secondary containers may be a length of layflat tubing arranged to provide the desired nonreturn characteristic between the two containers.

The secondary container may have an outlet pipe which again may be a length of lay-fat tubing. Alternatively, the secondary container may be attached to an outlet pipe prior to the liquid being dispensed.

The dispenser may be used on its own, or in combination with other apparatus. For example, the dispenser may be adapted for use in a vending machine.

The invention also provides a vending machine including a dispenser as defined above.

By way of example, specific embodiments in accordance with the invention will be described with reference to the accompanying drawings in which: Figure 1 is a perspective view of a dispenser for a liquid; Figure 2 is a side view of the dispenser of Figure 1 in combination with one form of means for applying pressure to the secondary container of the dispenser; and Figure 3 is a similar view to Figure 2 illustrating another form of pressure applicator.

This example is concerned with a dispenser for liquids, and particularly beverages, for example, milk or other comestible liquid which is required to be dispensed under pressure and without contact being made with the liquid. The dispenser is also particularly suitable for dispensing a predetermined amount of liquid during each cycle of operation which is desirable in the case of the dispenser being used in a coin-operated vending machine.

Referring to Figure 1, the dispenser comprises a primary container 10 and a secondary container 11 interconnected by a short length of lay-flat tubing 1 2. Each container 10, 11 is a bag formed of a flexible but non-elastic, plastics material with a heat-sealed edge 13, but the secondary container is much smaller, having a volume of, say, 200 cc. The lay-flat tubing 12 is known per se and formed of a laminate material with the inside layer having a high melting point and the outside layer being the same material as each container 10, 1 The tubing has a natural tendency to close.

One end of the lay-flat tubing 12 is heat-sealed into the edge seam of the primary bag 10 such that the end of the tube projects only a small distance into the bag, preferably by no more than 2 mm. Liquid will flow freely from the primary bag 10 into the lay-flat tubing 12.

The other end of the lay-fiat tubing 1 2 is sealed into the seam of the secondary bag 11 but with that end of the tubing projecting into the secondary bag by at least 25 mm. Liquid can therefore flow from the primary bag 10 into the secondary bag 11. When flow stops the tubing 1 2 will tend to close, the tubing thereby acting as a non-return valve to prevent liquid returning from the secondary bag to the primary bag. Moreover, external pressure applied to the secondary bag 11 can hold the tubing 12 closed and prevent the secondary bag from refilling until the pressure has been released.

An outlet tube 14 is sealed into the bottom of the secondary bag 1 This tube 14 may be similar to the outlet tube of a conventional milk pack or may also be a length of lay-flat tubing.

Within the heat-sealed edge 13 at the top of the primary bag is a hole 1 5 for suspending the primary bag during the dispensing operation.

Further suspension holes 1 6 are also provided within the edge 13 at the bottom of the primary bag 10. These holes 16 allow the primary bag to be filled through the lay-flat tubing 12 prior to the tubing 12 being sealed into the secondary bag 11.

Initially, the dispenser may be packed in a cardboard box which is well known for conventional milk packs, the free end of the outlet tube 14 from the secondary bag being closed.

However, in this embodiment, before use, the dispenser is removed from its box and suspended by means of the hole 1 5. If the outlet tube 14 were then cut or provided with a tap, liquid could be dispensed under gravity.

It will be seen from Figure 1 that both the layflat tubing 12 and the outlet tube 14 are attached in positions which allow the primary bag 10 and the secondary bag 11 to empty completely.

However, as described above, it is the intention that the liquid should be dispensed under pressure. For example, this may be desirable in a vending machine to achieve mixing of the liquid with other beverage ingredients in a cup, or it may be necessary to allow the liquid to be dispensed at a level above the level of liquid in the dispenser.

For this purpose, the secondary bag 11 is attached to, or assembled in relation to, means for applying external pressure to the secondary bag.

In this embodiment the pressure means are linked to an external pinch valve for closing the outlet tube 14 from the secondary bag 1 the pinch valve being opened as the bag is pressurised. As explained above, the effect of increasing pressure inside the secondary bag 11 is to hold the lay-flat tubing 1 2 closed and so prevent liquid passing back into the primary bag.

Holding the lay-flat tubing closed also stops further liquid entering the secondary bag whereby metering of the liquid dispensed may be achieved.

Desirably the pressure means has a quick return action, e.g. spring-operated, to effect an immediate cut-off of flow through the outlet tube 14 when the pressure applied to the secondary bag is released and to effect closure of the pinch valve before refilling of the secondary bag begins.

One embodiment of suitable pressure applying means is illustrated in Figure 2. A pincer-type arrangement comprises a pair of levers 20 pivoted at 21 on opposite sides of the secondary bag 11 adjacent its lower end. These levers have upwardly extending portions 22 for applying pressure to the secondary bag and shorter downwardly extending portions 23 to squeeze between them the outlet tube 14 in the manner of a pinch valve. The pressure applying portions 22 may be operated manually, or power-operated if preferred, e.g. in the case of a vending machine, by means (not shown) and returned to their inoperative positions by springs 24. Suitable power-operated means may include a spirally increasing cam having a sudden drop off at the end of the pressure applying stroke.

It will be appreciated that movement of the portions 22 towards each other effects opening of the pinch valve and applies pressure to the secondary bag thereby causing liquid to be dispensed therefrom under pressure into a cup 25. At the same time the lay-flat tubing 12 will be maintained closed. Release of the portions 22 will effect closure of the pinch value and allow the layflat tubing to open and the secondary bag to refill.

The volume of liquid dispensed can be adjusted by aitering the movement of the pressurising portions 22, i.e. either the stroke of movement or the time period.

The pressure applying arrangement of Figure 5 performs the same function, but comprises a fixed, vertical member 30 which supports the secondary bag 11 during the pressure action of movable member 31. One end of member 31 is pivoted to a shaft 32 whilst its other end cooperates with the lower end of the fixed member to form a pinch valve 33 for the outlet tube 14. Thereby pressure applied at 34 will cause the pinch valve 33 to open and pressure to be applied to the secondary bag 11. Return movement of the member 31 is effected by a spring 35.

In each embodiment the system is hygienic since no part of the dispensing device comes into contact with the liquid being dispensed. It is also intended, in these embodiments, that when the primary bag is empty, the complete dispenser comprising the primary bag 10, the lay-flat tubing 12, the secondary bag 11 and the outlet tube 14 is disposable.

However, in other embodiments it may be that at least part of the outlet tube 14 is retained, or the liquid is of a kind which allows the dispenser to be refilled and used again.

The main advantage of the dispenser described above is that the cross-sectional area of the secondary bag may be sufficiently small that required liquid pressures and flow rates can be achieved by an acceptable force acting on the disperser.

The system is also suitable for controlled volume dispensing of any liquid from any size primary bag whether the bag is suspended as shown in the drawings or otherwise supported, e.g. in a conventional cardboard box.

It will be appreciated that the dispenser may be suspended or supported in a free state, e.g.

beneath a counter, for actuation manually or by power means to dispense liquid at dispensing station above the counter. Alternatively, the dispenser may be suspended or supported in a vending machine, and thus the invention is concerned with a vending machine having a dispenser of the type described above from which liquid, e.g. milk, can be suppiied.

In either case, if the dispenser is contained within refrigeration apparatus, the direct contact between the primary bag and the refrigeration apparatus which may be achieved can result in efficient refrigeration taking place.

Claims (18)

1. A dispenser for a liquid comprising a primary container for storing the liquid, and outlet means from the primary container through which the liquid is dispensed, wherein the outlet means includes a secondary container which is smaller than the primary container and is connected to the primary container by means which are at least capable of preventing back flow into the primary container, the secondary container having a flexible wall which allows the secondary container to be compressed to cause the liquid to be dispensed therefrom.

2. A dispenser as claimed in Claim 1, wherein the secondary container is a bag formed of plastics material which is flexible but non-elastic.

3. A dispenser as claimed in Claim 1 or Claim 2, wherein the primary container is a bag formed of plastics material which is flexible but nonelastic.

4. A dispenser as claimed in Claim 3, wherein the two bags together comprise a disposable item.

5. A dispenser as claimed in any one of the preceding claims, wherein the secondary container has an outlet pipe.

6. A dispenser as claimed in any one of Claims 1 to 5, wherein the secondary container is associated with an outlet pipe to which the secondary container is adapted to be attached prior to the liquid being dispensed.

7. A dispenser as claimed in Claim 5 or Claim 6, including a valve arrangement for controlling the flow of liquid through the outlet pipe leading from the secondary container.

8. A dispenser as claimed in any one of the preceding claims, in combination with means for applying pressure to the secondary container.

9. A dispenser as claimed in Claim 8 when dependent on Claim 7, wherein the pressure applying means is coupled to the valve arrangement for controlling the flow of liquid through the outlet pipe of the secondary container.

10. A dispenser as claimed in Claim 8 or Claim 9, wherein the pressure applying means is a mechanical lever or pincer-type arrangement mounted for pivotal movement between operative an inoperative positions.

1 A dispenser as claimed in Claim 10 when dependent on Claim 5 or Claim 6, wherein one end of the lever or the pincers acts as a pinch valve on the outlet pipe from the secondary container thereby closing the outlet pipe when the lever or pincers is in its inoperative position.

12. A dispenser as claimed in Claim 11, wherein movement of the lever or pincers towards its operative position is manually or, for example, cam-actuated, the pinch valve opening simultaneously.

13. A dispenser as claimed in Claim 12, wherein the lever or pincers has a quick return movement, e.g. effected by a spring.

14. A dispenser as claimed in any one of the preceding claims, wherein the connection means between the primary and secondary containers is a length of lay-flat tubing arranged to provide the desired non-return characteristic between the two containers.

15. A dispenser as claimed in any one of Claims 5 to 7, wherein the outlet pipe of the secondary container, or the outlet pipe associated therewith, is a length of lay-flat tubing.

16. A dispenser as claimed in any one of the preceding claims, wherein the dispenser is adapted for use in a vending machine.

17. A dispenser as claimed in any one of the preceding claims, wherein the liquid to be dispensed is a comestible liquid.

18. A dispenser for a liquid substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

1 9. A vending machine including a dispenser as claimed in any one of the preceding claims.