GB2155553A - Fluid transfer and fluid dispensers - Google Patents

Abstract

Beer and lager barrels 10 and 14 supply dispensers 12, 112 and 16, 116, 216 respectively. A prime mover 18 operates to tend to withdraw air from a manifold 20, which is connected to the upper part of each dispenser by a valve 22. On start up, with the dispensers empty, each valve 40 and 24 is closed, and the valves 22 and 28 opened. Air is evacuated from the manifold 20, from the dispensers and from the pipes 30 and 32 leading to the barrels. The atmospheric pressure in the barrels causes the beer and lager to rise and fill the dispensers with a quantity of liquid accurately determined by the size of the dispensers. As the dispensers become full, the valves 22 and 28 are closed. When dispensing the drinks, the valves 24 are opened, automatically causing valves 40 to open and allow pressurised gas into the dispenser to force the liquid out through the valve 24. When the valve 24 is closed, the valve 40 is also closed and the dispenser can be refilled as previously described. In alternative embodiments, the liquid is raised in stages (Fig. 2), and the dispenser may comprise a separable container, eg. a drinking glass (Figs. 4-7). <IMAGE>

Description

SPECIFICATION Fluid transfer and fluid dispensers The present invention relates to a fluid transfer device, a method of transferring fluid and a fluid dispenser. The invention is particularly, although not exclusively concerned with the transfer and dispensing of drinks, for example beers and lagers.

In a known apparatus for dispensing beer at a bar, beer is supplied to a dispensing point under pressure created by Carbon Dioxide.

There are many disadvantages associated with this known system.

A major disadvantage is that it is difficult to adjust and maintain the pressure of the Carbon Dioxide at precisely the required pressure.

If the pressure is too great, then the beer becomes over saturated with Carbon Dioxide which causes frothing of the beer at the dispense point resulting in each measured quantity of beer taking a long time to deliver.

Clearly where there are a lot of people to be served, if each drink is taking perhaps several minutes to dispense then the customers will have to wait some time for their drinks or a large number of bar staff will have to be provided, either of which is an unsatisfactory way to run a business. If the Carbon Dioxide pressure is too low then it may take some time for the beer to reach the dispense point.

Furthermore, once the beer is served, it tends to lack the required amount of Carbon Dioxide which makes the beer flat and possibly useless. Either too much or too little Carbon Dioxide in the beer can severely alter the taste thereof which can also upset the customer.

A further disadvantage of using the pressurised Carbon Dioxide is that it is supplied in strong, heavy containers, recharged ones of which have to be continually supplied to the bar. Thus considerable time, and consequently money is spent in collecting, recharging and delivering the Carbon Dioxide containers. A still further disadvantage is that each dispense point at the bar has to be provided with its own Carbon Dioxide container and thus, particularly in a large busy bar, in addition to each tap periodically being out of service while a fresh barrel of beer is connected to a particular tap, each tap is also periodically out of service while a fresh Carbon Dioxide cylinder is connected thereto.

A further disadvantage with known beer dispensers is that they can only dispense a predetermined quantity of beer, for instance half a pint, at a time. Thus it is impossible, without wasting beer, to mix up a half pint of shandy.

According to one aspect of the present invention, a fluid transfer device includes a reservoir connected to a dispenser, and drive means arranged to produce a reduced pressure whereby fluid may be transferred from the reservoir to the dispenser. It will be appreciated that the apparatus can be used to transfer any fluid of any chemical make up from a reservoir to a dispenser, but the apparatus is particularly applicable to the transfer of drinks such as soft drinks, beer or lager to a dispenser. The use of drive means to create the reduced pressure for the transfer of fluid provides an extremely convenient way of transferring the fluid, and it may be easier and cheaper to create and regulate the reduced pressure than it is to create and maintain the positive pressure used in the known Carbon Dioxide system.Furthermore, as pressurised Carbon Dioxide is not used to force the beer out of the barrel, the beer will not become saturated with Carbon Dioxide and will not tend to froth at the dispense point thus enabling the beer to be served at a reasonable rate. A further advantage of the absence of pressurised Carbon Dioxide as the driving force for transferring the beer is that the precise amount of Carbon Dioxide can be added to the beer in the barrel by the brewer under controlled conditions, and thus the beer served to the customer will tend to be of uniform consistency and taste.

The drive means may be arranged to be dry or free from fluid. This may allow substantially all of the fluid to pass to the dispenser without becoming contaminated by the drive means.

The apparatus may also include a plurality of reservoirs arranged to have fluid transferred to them from a single reservoir as a result of a reduced pressure created by a single drive means. Alternatively or additionally, a plurality of reservoirs may be arranged to transfer fluid to one or more dispensers as a result of a reduced pressure created by a single drive means. Thus, for instance, in a bar in which seven lager dispensers are provided each tap may be arranged to have lager transferred to it from a single barrel as a result of a reduced pressure created by a single drive means.

Alternatively, for instance when dispensing a variety of soft drinks from a single dispenser tap, a reservoir for each of the soft drinks may be selectively supplied to the tap as a result of a reduced pressure being created by a single drive means. Where more than one dispenser is provided and, alternatively or additionally, where more than one reservoir is provided, the apparatus may be such that fluid being transferred from any one reservoir to any one dispenser will not contact any fluid being transferred between any other parts of the apparatus. This feature is particularly important where a plurality of reservoirs of different fluids are provided and contact between the liquids of any reservoir may contaminate those liquids.

The drive means may be arranged to evacuate air in order to produce the reduced pressure. Alternatively, the drive means may be arranged to evacuate a gas other than air, such as an inert gas, in order to produce the reduced pressure. This use of a gas other than air may permit fluids which would react with air to be transferred by the apparatus, one example of such fluid being Sodium Nitrate.

The drive means may be included in a closed system whereby the reduced pressure can be created without having to evacuate or take in air from the atmosphere.

The drive means may be connected to an upper part of the dispenser. This arrangement provides a convenient way of enabling air to be evacuated from the dispenser to provide the reduced pressure used to draw fluid into the dispenser from the reservoir. The liquid may be drawn into the dispenser at the same time as the air is being evacuated from the dispenser or subsequently thereto.

The drive means may include a suction control valve to provide a control of the evacuation of air and thereby control the reduced pressure. The reservoir may include a liquid control valve to control the transfer of fluid from the reservoir to the dispenser.

The reservoir for a particular fluid may include a plurality of containers, a sealed one of which is connected to the dispenser, the other or others of which are connected to the sealed container, the other, or at least one of the other containers being either pressurised or vented to the atmosphere. With such an arrangement, as fluid is transferred out of the sealed container to the dispenser, the reduced pressure thereby created in that container can allow or cause fluid to be transferred into it from the other container or containers. It is necessary that at least one of the other containers be either vented to the atmosphere or pressurised as otherwise a reduced pressure would be created in the reservoir as a result of the fluid being transferred therefrom, and this reduced pressure would counter, and ultimately overcome the reduced pressure being generated by the drive means.In a closed system the drive means can evacuate air or gas to produce the reduced pressure for the transfer of the fluid and at the same time pressurise one or more of the containers. It will be appreciated that by being able to interconnect a plurality of containers, for instance beer barrels, the dispenser or dispensers may serve an extremely large number of drinks before it is necessary to change a barrel or barrels.

The apparatus may also include monitoring means whereby an indication of the level of fluid in the reservoir may be given. The monitoring means may also include means for indicating when the level of fluid in the reservoir has dropped below a predetermined level.

An alarm may be arranged to be given when the level has dropped below a predetermined level. Thus a user of the apparatus may tell when the reservoir is about to run out and, for instance with beer barrels, either replace or refill the barrel at a convenient slack time or replace or refill the barrels before air instead of liquid is supplied to the dispenser, thus avoiding the lengthy process of reconnecting the beer to the dispensers after having got rid of the air from the apparatus.

The reservoir may include a plurality of containers located at successive levels, the containers of adjacent levels being connected to each other. With such an arrangement it is possible to raise fluid from the lowermost reservoir to any required height by use of the suction force created by the drive means. It is understood that the reduced pressure created by the drive means is only able to raise the fluid at any one time to a height dictated by the difference between atmospheric pressure and the reduced pressure. However, by applying the reduced pressure successively to the containers, the fluid can be passed from container to container until it is available for the uppermost container which is in turn connected to the dispenser.

The drive means may comprise a prime mover, for instance a suction pump or a fan. The prime mover may be arranged to be continuously operated, with means for selectively applying the reduced pressure which it generates in order to transfer the liquid from the reservoir to the dispenser. The prime mover has the advantage that it does not require continual replacement as does a Carbon Dioxide cylinder which runs out of pressurised gas. Furthermore, the prime mover may operate off low voltage or, alternatively or additionally, a d.c. power source which may allow the prime mover to operate when there is a mains supply failure by being powered from an emergency generator. Of course, the prime mover may be powered from any suitable power source, be it electric or otherwise.

Also, the prime mover may be compact and lightweight to provide a readily portable drive means which may be able to operate where only a low voltage or d.c. power supply is available. A fluid catchment device may be provided between the prime mover and the dispenser whereby fluid is prevented or hindered from passing to the prime mover.

There may be two prime movers provided in parallel. This feature enables one prime mover to act as a reserve in that it can be activated in case the other prime mover fails or requires servicing. Alternatively, there may be two or more prime movers connected in parallel, each prime mover being arranged to operate simultaneously. This may provide a greater reduction in pressure and may allow the drive means to continue to function even though one or more of the prime movers may be out of action, albeit at less of a reduction in the pressure.

According to a further aspect of the present invention, a method of transferring fluid from a reservoir to a dispenser comprises creating a reduction in pressure which is used to transfer the fluid from the reservoir to the dispenser.

According to another aspect of the present invention, a fluid dispenser comprises a chamber including a fluid inlet opening and a further opening to the upper part of the chamber, fluid being capable of entering the chamber through the fluid opening as a result of a reduced pressure being produced in the chamber through the further opening, the chamber further including a fluid outlet opening through which fluid may be dispensed.

Such a dispenser may provide a simple and cheap liquid dispenser.

The dispenser may also include a valve means for controlling the flow of fluid through the outlet opening. When the valve means is in a position in which fluid may flow from the chamber, the chamber may be vented to the atmosphere or gas pressure may be applied to the chamber. This allows the fluid to leave the chamber at a reasonable rate without a reduced pressure forming in the chamber such as would tend to prevent or restrict the flow of fluid from the chamber. Preferably means are automatically provided for venting the chamber to the atmosphere or applying air or gas pressure to the chamber when the valve means is in a position in which fluid may leave the chamber. A liquid volume indicator may be provided for the chamber.

The fluid dispenser may include a control system arranged to allow air or gas to be evacuated from the chamber through the further opening for a determined period of time, and allowing fluid to enter the chamber through the fluid opening for a determined period of time, either at the same time as air or gas is being evacuated from the chamber or after the start of, or after the end of the evacuation. The control system may be arranged to operate after each time fluid has been dispensed from the chamber. The period of time for which the fluid is allowed to enter the chamber may be determined by the level of fluid within the chamber or by a predetermined period of time.Where the period is determined by the level of fluid within the chamber, it will be appreciated that only a portion of the fluid within the chamber need be withdrawn from the chamber, and that the control system will fill up the chamber to the required level. This feature is particularly useful where the dispenser is used as a dispenser of beer, for example, as the complete volume of the chamber may be a half pint and the control system allows a quarter pint of beer to be drawn off in order to mix a quarter pint of shandy, prior to the chamber being filled up again.

The fluid dispenser may also include mixing means whereby fluids from at least two different reservoirs may be transferred by a reduced pressure and then mixed prior to being dispensed. The two fluids may be beer and lemonade whereby a ready mixed shandy may be dispensed. Alternatively the fluids may be chemicals.

It will be appreciated that the present invention also includes a liquid dispenser as hereinbefore described for use in, or when used in a liquid transfer apparatus or a method of transferring liquid as hereinbefore described.

The invention may be carried into practice in various ways, but several embodiments will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a diagram of a liquid supply apparatus; Figure 2 is a diagram of another liquid supply apparatus in which liquid is supplied to a relatively high dispenser, Figure 3 is a drawing of a liquid dispenser to which liquid may be supplied by the apparatus shown in Figures 1 and 2, or by any other suitable apparatus; Figure 4 is a schematic representation of a dispense head which engages and seals with the rim of a glass in order that a vacuum can be applied within the glass; Figure 5 is a schematic representation similar to that shown in Figure 4 in which a protective layer of film is located between the dispense head and the glass;; Figure 6 is a schematic representation of an embodiment similar to that shown in Figures 4 and 5 including a wandering dispense head which may be moved into engagement with the rim of a glass, and Figure 7 is a cross-section through one embodiment of the wandering dispense head shown in Figure 6; Although the figures will be described with reference to beer and lager being used as the liquid, it will be appreciated that any liquid can be used in any suitable application.

In Figure 1, a beer barrel, storage container or reservoir 10 is used to supply two dispensers 1 2 and 11 2, and lager barrels, storage containers or reservoirs 14 and 114 are used to supply three other dispensers 16, 11 6 and 216. A single prime mover 18 operates continuously to tend to withdraw air from a manifold 20, comprising the non-liquid part of the system, which is connected to the upper part of each of the dispensers by a valve 22, which may be a solenoid valve. A liquid catch trap 23 is disposed between the prime mover 1 8 and the valves 22 to prevent or hinder the passage of any liquid which may enter this nonliquid section of the system to the prime mover.

Beer or lager can be withdrawn from each of the dispensers through an outlet valve 24.

Start-up or priming of the dispensers and operation of the apparatus are as follows.

On start-up, with the dispensers empty, the prime mover 18 is actuated to tend to withdraw air from the manifold 20. Each dispen ser is connected to the manifold by a conduit 26, and the valves 22 disposed adjacent to each dispenser are opened. Each of the outlet valves 24 are closed, and inlet valves 28, which may be liquid solenoid valves, controlling the flow of lager or beer into the dispensers, are opened. Thus the prime mover creates a reduced pressure, which may be constant, in each of the dispensers, which reduced pressure is in turn passed through pipes 30 and 32 connected to the beer and lager barrels. As shown, the dispensers are connected to the barrels by the pipes 30 and 32 being in gangs, but each dispenser may be directly connected to the barrels or each dispenser may have a dip leg extending into the barrel.

The beer barrel 10 is vented to the atmosphere, as shown at 34, and as the pressure in the pipe 30 decreases, so the difference in atmospheric pressure and the pressure in the pipe 30 causes the beer to rise up the pipe into the dispensers 12 and 11 2, until they are filled. In effect, the atmospheric pressure causes the beer to rise. At that time the inlet valves 28 are closed, as are the valves 22 connecting the dispensers to the manifold 20.

The lager barrel 114 is vented to the atmosphere, as shown at 36, and the difference in pressure between the reduced pressure within the pipe 32 and the atmospheric pressure acting on the surface of the lager in the barrel 114 causes lager to be transferred via a pipe 38, into the sealed barrel 14 and up the pipe 32. The lager dispensers are subsequently filled, and the valves 22 and 28 closed, as previously described in relation to the beer dispensers. Thus all of the dispensers are now primed.

Once each dispenser is full, the outlet valves 24 can be opened manually as required, in order to dispense drinks. The outlet valves may be able to be opened for any required duration whereby the whole, or any part of the contents of the dispenser can be dispensed. Alternatively, the valves 24 may be unable to close until the complete contents of the dispenser have flowed out to ensure that an accurate measure is given each time the dispenser is used. With this arrangement a metered volume is first trapped and then released or ejected.

It will be appreciated that with the inlet valve 28 and the valve 22 of a dispenser in the closed position, liquid may be reluctant to leave the sealed dispenser through the oulet opening as a result of the reduced pressure created within the dispenser by evacuation of liquid therefrom. In order to overcome this difficulty, the upper part of the dispenser may be arranged to be automatically vented to the atmosphere when the oulet valve is in the open position. Alternatively, and as shown in the Figure, each dispenser is provided with a valve 40. Each valve 40 is arranged to inject pressurised air or gas, controlled and regulated by a pressure valve arrangement, into the top of the dispenser to increase the force tending to dispense the liquid through the outlet opening and thus increase the speed or pressure of the liquid leaving the dispenser.

The pressurised gas or air can be stored in pre-filled pressure bottles or in a pressure reservoir fed from a compressor device or from the exhaust of the prime mover. Furthermore, the pressure can be applied directly onto the surface of the liquid or through a diaphragm or reciprocating piston.

Once the outlet has been closed, the dispensers may be filled up again by creating a reduced pressure within the dispensers, which is achieved by evacuating air or gas through the valve 22, and allowing beer or lager through the inlet valve 28, as has previously been described. The oulet valve 24 may be unable to open again until the dispenser is completely full.

The system controlling the sequence of operation of the valves can be electronic, electromechanical, pneumatic or any other suitable system. The levels of liquid in the storage containers or barrels can be monitored electronically or electro-mechanically and the monitored information, and possibly an alarm when the level passes below a predetermined point, can be transmitted to a system operation position. If desired the amount of liquid which is dispensed can be monitored and/or recorded and possibly transmitted to the operator position, a remote recorder or other device. The monitoring can be achieved by recording the number of operations of the dispenser by electronic, electromechanical or pneumatic devices. Each dispenser can be individually monitored or can be linked or grouped with the monitoring of other dispensers, for instance those dispensing the same liquid.

Referring now to Figure 2, there is shown a dispenser 1 2 which is arranged to be supplied with liquid from a lower reservoir 42 under a force or pressure difference created by the prime mover 1 8. It will be appreciated that the maximum force which the atmospheric pressure can exert on the liquid or beer can only lift the liquid by approximately 9 metres.

In Figure 2 the difference in height between the lower reservoir 42 and the dispenser 1 2 is between 1 6 and 18 metres. Accordingly, an intermediate reservoir 44 is provided as a vertical lift or ladder boost.

On start-up of the system, with liquid only present in the lower reservoir, the prime mover evacuates air from (or reduces the pressure in) the pipe 46, the interior of the sealed dispenser 12, a pipe 48 connected to the sealed intermediate reservoir 44 and a pipe 50 (including a non-return valve 52) connected to the lower reservoir 42. The pressure difference acting on the liquid in the pipe 50 and the surface of the liquid in the reservoir 42 is sufficient to cause the liquid to rise up the pipe 50, past the non-return valve 52 and into the intermediate reservoir 44.

When the level in the intermediate reservoir 44 reaches a predetermined height an atmospheric vent valve 54 on that reservoir opens and liquid is then able to pass from the intermediate reservoir to the dispenser, as previously described in relation to Figure 1.

The vent valve 54 may be arranged to be left open until substantially all of the liquid contained in the reservoir 44 has passed up through the pipe 48 and been dispensed.

It will be appreciated that a plurality of intermediate reservoirs may be provided to allow the liquid to be raised in steps of between 8 and 9 metres to any required height. If desired, the lifting of the liquid may be assisted or achieved by a conventional pump.

The prime mover shown in Figures 1 and 2 may have a capacity to provide liquid to five or six dispensers. Should the prime mover fail then those dispensers will be out of order.

Accordingly a further prime mover may be provided in parallel to the prime mover shown. Should one prime mover fail then the other can cut in and keep the dispensers in operation until the failed prime mover can be repaired or replaced. Alternatively, for example when more than five dispensers are provided, two or more prime movers can be connected in parallel and can be arranged to function simultaneously. Should one prime mover fail then the others will maintain the dispensers in operation, albeit with slightly less of a reduced pressure being available.

The prime movers may be compact and lightweight and powered off a low voltage and d.c. power supply to allow them to be portable and able to run off emergency power supplies. Similarly any power required for operating the valves may be low voltage and d.c.

Referring now to Figure 3, there is shown a dispenser 56 similar to those shown in Figures 1 and 2, comprising a rigid hollow member of a predetermined volume of any shape or cross-section which is sealed at its upper and lower ends by flanges 58 and 60.

The upper flange 58 is connected to the dry vacuum system by a vacuum solenoid valve 62 having a pipe 64 leading to a prime mover (not shown). The upper flange also has an induced or atmospheric valve 66. The lower flange 60 has a manually operable outlet valve 68 which, when operated, activates a switch 70 to initiate the automatic system control 72. A liquid inlet valve 74 is also connected to the lower flange and is arranged to be supplied with liquid through a pipe 76 including a flow control choke device 78 along its length. If desired, the valves need not be directly attached to the flanges but could instead be connected thereto by pipes.

The flanges may have further blind or tapped holes or appendages (not shown) which can be used for fixture and securing purposes.

In an alternative arrangement (not shown) the liquid inlet valve is replaced by a nonreturn valve. Such a non-return valve could be a valve which already exists in conventional dispensing arrangements to allow the conversion of those conventional arrangements to incorporate the present invention to be a relatively quick and simple operation. In another modification (not shown) the solenoid valves are integral with the dispense head.

In a further modification, the prime mover runs only intermittently and a controlled vacuum is maintained using pressure control devices and non-return valves.

The automatic system control 72 can control the valves 62 and 74 in the manner previously described in relation to the corresponding valves shown in Figure 1.

The liquid level in the dispense unit can be governed by the predetermined volume of the dispenser, by the timing of the solenoid valve operation in conjunction with the flow control choke, or by measurement control using mechanical, optical or electronic devices, or by a combination of all three. If desired, the dispenser can be made partially of transparent material to allow the liquid being held to be visually inspected for clarity, identification of liquid type and dispense availability. Dispense availability or measured amount of liquid being held in storage may also be indicated electronically by warning lights or an illuminated message.

Thus the dispenser enables a dry vacuum or reduced pressure system to convey or move liquid and then stop the movement of the liquid at a given point in order to prevent its entry into the dry vacuum part of the system.

It then holds the liquid at this given point and, on request, diverts a measured amount of liquid out of the dispenser.

In Figure 4 a dispenser 410 is shown in which a drinking utensil or glass 412 is held with its rim in sealing engagement with a soft or resilient wad 414 to form a seal therewith.

A vacuum pipe 41 6 extends into, and removes air from within the glass to cause fluid such as beer to be drawn into the glass through a pipe 418. The pipes 416 and 418 are provided with respective valves 420 and 422, and the method of operation of the dispenser and the supply of fluid to the dispenser is similar to that described in relation to Figures 1 to 3.

When the fluid level in the glass reaches a certain predetermined height, two electronic level sensing probes 424 and 426 on the portions of the vacuum and fluid pipes which extend into the glass are simultaneously operated to cause the vacuum valve to close, the utensil to be vented to break the seal, and the supply of fluid to be stopped. Alternatively, the fluid level could be sensed by a float device or by a light sensitive electronic device.

In order to bring the glass into contact with the wad, or remove the glass from the dispenser the dispense head 432 may be moveable in the direction of arrow 434. The base section 428 is able to be stopped at locations 436A, B, C or D dependent upon whether a half pint, half litre, pint or litre glass respectively is being filled. Movement of the head or base section may be manual, mechanical, electrical or pneumatic and movement of the head may be arranged to initiate the operation sequence to fill the glass.

Figure 5 shows a modification of Figure 4 in which a sheet of film 437 (e.g. cling film) passes over the soft wad to create a hygenic barrier between the wad and the rim of the glass. The two pipes are provided with pointed ends 438 which are able to pierce the film when the dispense head is brought down into contact with the rim of the glass.

After each glass is filled, the film 437 is able to be wound on in order that a fresh surface is able to be presented to the rim of the next glass. Rollers 440 are able to pull the film off a roll 442. The film may be advanced manually or by an electric motor rotating the rollers through a set number of rotations or by indexing along using a light sensitive device to scan the pierced holes and controlling a roller or rollers using an electric motor.

In an alternative embodiment (not shown) the drinking utensil or glass is placed inside the vacuum chamber of a dispense head. This could be achieved by placing or enclosing by various methods the drinking utensil inside the vacuum chamber of the dispense head and evacuating the entire chamber, fluid being drawn into the drinking utensil until the required fluid level is obtained by methods previously described. The fluid supply is then stopped and the chamber vented. The sequence of control and level measurement may be as previously described. This embodiment may be of particular use in vending dispensers.

Figure 6 shows an alternative embodiment including a wandering dispense head 444.

The head is connected to a flexible vacuum pipe 446 and a flexible fluid pipe 448, through which fluid pipe 448 may be passed a selected fluid via one of a series of valves 450.

The wandering head is located over the rim of a glass, and a flexible head (not shown) seals with the rim of the glass. The head is similar to that shown in Figures 4 and 5 and its operation may be as described in relation to those heads. The head may include an operating switch (not shown).

When the head is not being used, or between uses, it may be placed on a stand with its wad extending upwardly, the stand being arranged to clean the wad. Alternatively, the head could be washed under a tap between uses. The stand and the fluid selection valves may be provided in a bar top package.

In Figure 6, the fluid and vacuum pipes extend downwardly at separate locations within the head. In Figure 7, the fluid pipe 448 extends concentrically within a vacuum pipe 446 in a wandering head. The location and form of the wad or lip seal 452 is also shown.

Claims (38)

1. A fluid transfer device adapted to transfer fluid from a reservoir to a dispenser, the device including evacuating means capable of causing a reduced pressure to be exerted on a portion of the fluid from the reservoir whereby a pressure greater than the reduced pressure is able to act on the liquid in the reservoir to drive the fluid from the reservoir to a fluid dispenser.

2. A device as claimed in Claim 1 in which the evacuation means is arranged to be separate from the path which the fluid may travel.

3. A device as claimed in any preceding claim in which the evacuation means is arranged to be able to drive fluid from any one of a selected number of reservoirs.

4. A device as claimed in Claim 3 in which the fluid being driven from one reservoir will not contact fluid from any other reservoir.

5. A device as claimed in any preceding claim including a plurality of dispensers to a selected one of which fluid may be driven from the reservoir.

6. A device as claimed in Claim 3 or 4 and 5 in which the reduced pressure created by the evacuating means may be able to be used to transfer fluid from a selected reservoir to a selected dispenser.

7. A device as claimed in any preceding claim in which the evacuation means is arranged to evacuate air in order to create the reduced pressure.

8. A device as claimed in any of Claims 1 to 6 in which the evacuation means, is arranged to evacuate an inert gas in order to create the reduced pressure.

9. A device as claimed in any preceding claim in which the fluid which is able to be driven from the reservoir is within a closed system which is not in contact with the ambient atmosphere.

10. A device as claimed in any preceding claim in which the evacuation means is connected to the dispenser.

11. A device as claimed in Claim 10 in which the evacuation means is able to create the reduced pressure within the dispenser at the same time as liquid is being transferred into the dispenser.

1 2. A device as claimed in any preceding claim in which the dispenser is arranged to be able to dispense a predetermined quantity of fluid.

1 3. A device as claimed in any preceding claim in which the evacuation means is arranged to create a reduced pressure within a separate container whereby fluid is capable of being dispensed into the container.

14. A device as claimed in Claim 1 3 in which the dispenser is able to move into engagement with the container.

1 5. A device as claimed in Claim 14 including guides for the movement of the container.

1 6. A device as claimed in any of Claims 1 3 to 1 5 in which the separate container is arranged to be located in a sealed chamber in which chamber a reduced pressure may be created.

1 7. A device as claimed in Claim 13, 14, 1 5 or 16 including a replaceable barrier between the dispenser and the container.

1 8. A device as claimed in Claim 1 7 in which the barrier comprises part of a strip of film which is arranged to extend between the dispenser and the container.

1 9. A device as claimed in any preceding claim in which the evacuation means includes a prime mover.

20. A device as claimed in Claim 1 9 in which the prime mover is arranged to operate continuously.

21. A device as claimed in Claim 1 9 in which the prime mover is arranged to operate periodically.

22. A device as claimed in Claim 1 9 in which the prime mover is being transferrred from the reservoir to the dispenser.

23. A device as claimed in any of Claims 1 9 to 22 in which the prime mover is electrically operated.

24. A device as claimed in any of Claims 1 9 to 23 in which two prime movers are provided in parallel.

25. A device as claimed in any of Claims 1 9 to 24 including a fluid catchment device located between the reservoir and prime mover or movers.

26. A device as claimed in any preceding claims in which the reservoir for a particular fluid includes a plurality of containers, a sealed one of which is connected to the dispenser, the other or others of which are connected to the sealed container, the other, or at least one of the other containers being vented to the atmosphere or being provided with its own pressure source.

27. A device as claimed in Claim 26 in which the containers are located at successive levels, the containers of adjacent levels being connected to each other.

28. A device as claimed in any preceding claim including level sensing means in the dispenser.

29. A fluid transfer device substantially as herein described with reference to, and as shown in any of the accompanying figures.

30. A fluid dispenser comprising a chamber including a fluid inlet opening and a further opening to the upper part of the chamber, fluid being arranged to enter the chamber through the fluid opening as a result of gas being evacuated from the chamber through the further opening, the chamber also including a fluid outlet opening through which fluid may be dispensed.

31. A fluid dispenser as claimed in Claim 29 in which, when the outlet opening is dispensing fluid therethrough, the chamber is arranged to be vented to the atmosphere.

32. A fluid dispenser as claimed in Claim 30 or 31 including a control system arranged to allow gas to be evacuated from the chamber for a predetermined period of time, and fluid to enter the chamber for a predetermined period of time.

33. A fluid dispenser as claimed in Claim 32 in which fluid is arranged to enter the chamber at the same time as gas is being evacuated from the chamber.

34. A fluid dispenser substantially as herein described with reference to, and as shown in Figures 1, 2 and 3.

35. A fluid dispenser as claimed in any of Claims 30 to 34 when included in a fluid transfer device as claimed in any of Claims 1 to 29.

36. A method of transferring fluid from a reservoir to a dispenser comprising causing a reduction in pressure which is used to transfer the fluid from the reservoir to the dispenser.

37. A method of transferring fluid substantially as herein described with reference to, and as shown in the accompanying drawings.

38. A method as claimed in Claim 36 or 37 including a dispenser as claimed in any of Claims 30 to 35 or using a device as claimed in any of Claims 1 to 29.