GB2449070A

GB2449070A - Cocktail dispenser

Info

Publication number: GB2449070A
Application number: GB0708777A
Authority: GB
Inventors: David Crowther
Original assignee: EASY COCKTAILS Ltd
Current assignee: EASY COCKTAILS Ltd
Priority date: 2007-05-08
Filing date: 2007-05-08
Publication date: 2008-11-12
Also published as: GB0708777D0

Abstract

An apparatus 10 for automatically dispensing a beverage comprising at least one liquid ingredient, the apparatus comprising at least one dispenser 18, 20, 22 for dispensing a desired quantity of a liquid ingredient from a reservoir 12 into a receptacle 30 and a control circuit 16 operatively connected to the dispenser and being arranged to stop dispensation when the desired quantity of ingredient has been dispensed. The control circuit 16 is adapted to control the rate of dispensation such that the desired quantity of ingredient is dispensed within a predetermined time interval. The dispenser may comprise a peristaltic pump controlled by a speed controller. A dc motor speed controller is also disclosed.

Description

1 2449070 Title: Dispensers

Description:

This invention relates to dispensers, and in particular, but without limitation to, dispensers for dispensing beverages.

Mixing beverages, particularly cocktails, can be difficult and time consuming.

At busy times, a bar tender may be required to make up multiple orders. The bartender may be subject to time pressures and there is scope for mistakes to be made, which can lead to poorly mixed cocktails, waste and/or over-use of expensive ingredients. Similar mistakes can occur in a domestic setting.

According to a first aspect of the invention, there is provided an apparatus for automatically dispensing a beverage comprising at least one liquid ingredient, the apparatus comprising: a dispenser for dispensing a desired quantity of a liquid ingredient from a reservoir into a receptacle and a control circuit operatively connected to dispenser, the control circuit being arranged to stop dispensation when the desired quantity of ingredient has been dispensed, wherein the control circuit is adapted to control the rate of dispensation such that the desired quantity of ingredient is dispensed within a predetermined time interval.

An automatic beverage mixer may need to be able to dispense widely different amounts of an ingredient for different recipes. For example, one recipe may call for 6 ml of an ingredient, whereas making a jug of a different recipe may require 500 ml.

To maintain accuracy and reasonable speed over such a wide range, it is necessary for the system to be able to vary the speed of dispensation according to the quantity being dispensed.

Advantageously, the first aspect of the invention enables different quantities of liquid ingredients to be dispensed within predetermined intervals, which may thereby address the above problem.

Preferably, the apparatus comprises a plurality of dispensers. In a preferred S embodiment of the invention, the apparatus comprises 24 dispensers.

The, or each, reservoir may comprise a refillable tank. The reservoir may comprise a coupling arranged to sealingly engage with the open neck of a bottle.

The, or each, dispenser may comprise: a pump for dispensing a desired quantity of liquid ingredient from a reservoir into a receptacle; a meter arranged to measure the quantity of ingredient dispensed; and a speed controller operatively connected to, and for controlling the speed of the pump. Accordingly, the, or each, dispenser may be able to control the rate of dispensation of the ingredient.

The, or each, pump is preferably a peristaltic pump as such pumps are relatively inexpensive, reliable and can, in use, provide an enhanced visual effect, compared to a turbine or impeller pump.

The, or each meter may comprise a flow meter for measuring the volume throughput of liquid dispensed, and/or the rate of dispensation. Additionally or alternatively, the, or each, meter may comprise a weighing means, e.g. a load cell, for measuring the weight of a receptacle containing the dispensed liquid: the weight of the receptacle and its contents being proportional to the volume of a particular liquid dispensed.

The control circuit is preferably operatively connected to the meter and the speed controller and is preferably arranged to stop the pump when the desired quantity of ingredient has been dispensed. The control circuit is also preferably adapted to control the speed controller to control the rate of dispensation such that the desired quantity of ingredient is dispensed within the predetermined interval.

A second aspect of the invention provides a computer operatively connected to, and programmed to control, a dispenser arranged to dispense a desired quantity of a liquid, the computer also being operatively connected to a means for measuring the amount of liquid dispensed by the dispenser, wherein the computer is programmed to control the dispenser such that the desired quantity of liquid is dispensed within a predetermined interval.

Preferably, the computer comprises an electronic controller for interfacing with the dispenser.

The dispenser is preferably adapted to dispense a quantity of liquid ingredient from a reservoir into a receptacle. The receptacle can be a drinking vessel, e.g. a glass, or a funnel or hopper arranged to direct the ingredient or ingredients into a drinking vessel, or ajug.

The computer is preferably operatively connected to, and programmed to control a plurality of dispensers.

The, or each, dispenser may comprise: a pump; a speed controller for controlling the speed of the pump; and a meter for measuring the amount of liquid dispensed by the pump. The computer is preferably operatively connected to the, or each, speed controller and meter and programmed to control the speed of the pump such that the desired quantity of liquid is dispensed within the predetermined interval.

The computer may comprise a data carrier, e.g. a computer disk, a hard drive, or a memory card, for storing a configurable database of recipes.

The computer may comprise a user interface to enable a user to select a recipe from the database and to command the computer to automatically dispense one or more ingredients in accordance with the said recipe. Where provided, the user interface may comprise a visual display unit and a keypad. The visual display unit and the keypad may be integral, i.e. the keypad may comprise a touch-sensitive area of a screen of the visual display unit. The computer may be integrated into a point of sale device.

A third aspect of the invention provides a program for controlling the operation of the aforedescribed computer. The program may comprise any one or more of the group comprising: a device driver for interfacing with a pump, a speed controller and/or a meter; a control module that interfaces with the device drivers and applies an algorithm to control the operation of the pump, the speed controller and the meter; and a configurable database comprising parameters corresponding to desired dispensation intervals and/or recipes.

The meter may comprise a flow meter and/or a weighing means, such as a load cell.

The relatively inexpensive DC motors used in many low-cost peristaltic pumps respond fairly well to changes in driving voltage. However, differences between individual motors and pumps as well as in the ingredient viscosity mean that open-loop speed control using voltage is very unreliable.

A fourth aspect of the invention provides a speed controller for a DC motor comprising a variable voltage power supply for varying the voltage applied to the terminals of the motor, a current sensor for sensing the current delivered to the motor and a circuit adapted to control the variable voltage power supply according to a parameter sensed by the current sensor, wherein the sensed parameter comprises a rate of current rippling corresponding to the rotational speed of the motor.

Each current ripple may occur at the point where two contacts of the commutator simultaneously contact to the brushes.

Advantageously, the fourth aspect of the invention may provide a closed-loop feedback without having to fit sensors to each motor or pump.

The ripple may be sensed by passing the current through a low resistance causing a small voltage with a ripple on it. The voltage ripple may be isolated by capacitive coupling and amplified by, e.g. a high gain amplifier. The amplified signal can be clipped and the clipped signal fed as a train of pulses into a digital input of a microprocessor. The pulse rate can be proportional to the motor speed, thereby enabling the microprocessor to continuously monitor the motor speed. The microprocessor may use this information to determine how to vary the driving voltage of a pump to maintain a desired motor speed.

Preferably, the microprocessor is connected to a plurality of pumps that runs sequentially, which enables speed sensing and voltage controlling circuitry to be shared.

Preferred embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic of a first automatic beverage mixer incorporating a dispenser according to the invention; Figure 2 is a graph of current against time for a DC motor supplied by a constant voltage; Figure 3 is a schematic circuit diagram. of a control circuit for monitoring the speed of a DC motor; and Figure 4 is a screen shot of a computer screen running a program according to an aspect of the invention.

Referring to Figure 1, an automatic beverage mixer 10 is arranged to deliver beverages from a plurality of bottles 12 into a funnel 14. A control circuit 16 is provided to control the operation of the various components of the beverage mixer 10.

Specifically, the beverage mixer 10 comprises a plurality of flexible pipes 18 that each communicate with the interior of a bottle 12 for receiving liquid therefrom.

Each flexible pipe 18 passes through a respective peristaltic pump 20, which is arranged to pump liquid from the bottle 12, along the pipe 18 and through a respective discharge nozzle 22, into the funnel 14.

The funnel 14, which is positioned below the discharge nozzles 22, has an outlet port 24 that is normally closed by a first solenoid 26 actuated in-line flow valve 28. Energising the solenoid 26 of the first valve 28 causes the valve to open, thereby allowing the contents of the funnel 14 to be discharged into a receptacle 30 placed beneath it. The receptacle is supported on a drip tray 32 located below the outlet of the first valve 28. The drip tray 32 is connected to a drain or waste storage tank (not shown) so that it can never overflow.

The funnel 14 is mounted on a floating platen 34 that contacts a load cell. The load cell is thus arranged to measure the gross weight of the funnel 14, its contents and the platen 34. An electrical signal indicative of the measured weight is fed, via a cable 38, to the control circuit 16.

A rinsing device 40 is provided for periodically rinsing the funnel 14. The rinsing device 40 comprises a tank 42 containing a quantity of rinse liquid, e.g. water, or a very dilute detergent solution. An outlet pipe 44 with a spray nozzle 45 fitted thereto is positioned above the funnel 14. A second, normally closed, in-line solenoid-actuated flow valve 48 is provided for controlling the flow of rinse liquid from the tank 42 into the funnel 14.

A user interacts with the control circuit 16, via a user interface, to initiate an automatic mixing cycle. The control circuit 16 determines the desired quantity of each ingredient by referring to a database of beverage recipes. The control circuit 16 then calculates the required weight of each ingredient by multiplying the required volume by the specific gravity of each ingredient. The control circuit 16 also consults the database to establish the target dispensation time for the recipe and calculates the flow rate required to dispense the desired quantity of each ingredient within the target time. That done, the control circuit 16 sends a signal, via a cable 50, to a first pump to commence dispensation of the first ingredient. The speed of the pump 20, and hence the rate of dispensation, is continuously monitored and adjusted (as will be explained later) to ensure dispensation takes place within the specified time period.

Meanwhile, the load cell 36 monitors the weight of the funnel 14 and relays that data to the control circuit 16. Once the net weight of the funnel (i.e. the weight of the ingredient dispensed) reaches the calculated value, the control circuit 16 commands the pump 20 to stop. This process is then repeated for each ingredient until the desired recipe has been made up in the funnel 14.

That done, the control circuit signals, via a cable 52, the first valve 28 to open thereby allowing the contents of the funnel 14 to pour into the receptacle 30 below.

Advantageously, pouring of the beverage from the funnel 14 into the receptacle 30 serves to effect mixing thereof. The receptacle 30 can then be removed.

The second valve 48 is then opened to effect rinsing of the funnel 14. After rinsing, both the first valve 28 and the second valve 48 are closed. The cycle can then be repeated.

The peristaltic pumps 20 comprise DC motors 60, which drive rollers that bear against, and squeeze, the flexible pipe 18 to effect delivery of ingredient from the bottle 12 to the funnel 14. The pumps 20 utilise relatively inexpensive DC motors, which makes pump 20 and/or motor 60 replacement more economic. However, due to their construction, identically labelled, low-cost DC motors can have quite different operating characteristics. It is therefore highly desirable for the beverage mixer 10 to comprise a speed controller and feedback ioop for each motor 60 to ensure that each motor 60 operates within desired parameters. In the present case, this is achieved by continuously measuring the current, and adjusting the voltage applied, to each motor 60.

In Figure 2, a graph shows current versus time corresponding to a continuous voltage applied to a brushed DC motor 60. Above the graph is a sequence showing, schematically, the rotation of two pairs of commutator segments 62, 64 relative to the brushes 66, 68 of a DC motor 60. The commutator segments 62, 64 are rigidly mounted on an axle 70 that is arranged to rotate clockwise as indicated by arrow 72.

Initially, the shaded pair of commutator segments 62 contact the brushes 66, 68thereby enabling current to flow to the motor wmdings (not shown). As can be seen from the sequence, the axle 70 rotates clockwise until the both the shaded commutator segments 62 and the unshaded commutator segments 64 contact the brushes 66, 68 thereby energising two sets of motor windings (not shown).

Eventually, the shaded commutator segments 62 break contact with the brushes 66, 68 thereby leaving only one set of motor windings energised. As can be seen in the graph, the current rises and falls in sequence with energising a first motor winding, then the first motor winding and the second motor winding, and then just the second motor winding. The current draw is smoothed somewhat due to the inductance of the motor windings. Thus, an integer number of times per complete rotation of the motor, the current draw of the motor rises and falls. The frequency of rise and fall (i.e. the rate of "rippling") corresponds directly to the speed of rotation of the motor.

The ripple is detected using a circuit as shown in Figure 3 by passing the current through a low resistance (RI) causing a small voltage with a ripple on it. The voltage ripple is isolated by capacitive coupling (via capacitor C2) and amplified to more than 5 volts peak-to-peak by a high gain amplifier (Ula).

This amplified signal is then clipped to the range 0 to 5 volts (using diodes to the microprocessor supply rails which are not shown). The clipped signal is fed as a train of pulses into one of the digital inputs on the microprocessor (not shown in the diagram), allowing it to monitor the motor speed moment by moment. The microprocessor uses this information to tell it how to vary the driving voltage to maintain the desired motor speed.

The microprocessor controls the driving voltage using two pulse-width-modulated output ports (PWMI and PWM2). When the voltage required is less than 24 volts, the components Ti, Di, LI and Cl form a buck' converter. The processor keeps T2 switched off and uses the signal PWM I to control the current flowing into the storage capacitor CI. A higher duty cycle on PWMI keeps TI switched on for longer and raises the voltage on Cl (up to a maximum of 24 volts at a duty cycle of 100%).

When the voltage required is greater than 24 V. the microprocessor keeps Ti switched on permanently and uses PWM2 to switch T2 on with a variable duty cycle.

In this mode, the components Ll, 12, D2 and Cl form a boost' converter which is capable of generating up to about 40 volts from the 24 volt supply.

The transistors 13, T4, 15 and T6 form an H-bridge' which allows the pumps to be run in either direction. The microprocessor switches on T3 and T6 to run a pump forwards, or 14 and T5 to run it backwards. Each pump has a triac (T7 and 18 in the diagram) in series with it to allow the microprocessor to select which pump to run.

No matter which pump is selected or which direction it runs, the current flows back via Ri, which allows the microprocessor to close the control loop.

Thus, the dispenser operates, by way of example only, as follows: When, say ml of ingredient is required, the computer looks-up the target dispensation time from a database. If the target dispensation time is, say 2 seconds, then the pump will need to deliver the ingredient at I OmI/sec to deliver the required amount in the required time interval. The computer commands the electronic controller to deliver a supply voltage to the motor that will result in the requisite motor speed to make the pump deliver the ingredient at 10 mI/sec. If the required supply voltage, is say 22V, then 22V will be applied to the terminals of the pump, which should result in a pump speed of, say 30rpm. The electronic controller will monitor the ripple rate of the current flowing through the motor to ensure that the pump' rotates at the requisite 30rpm. If the actual speed is too low, the electronic controller will increase the supply voltage, or vice versa, to achieve the target pump speed. At the same time, the weight of ingredient dispensed will be monitored using the load cell. The load cell outputs are analysed every 10 milliseconds by the electronic controller and are converted to signals representative of the weight sensed. These signals are fed back to the computer which keeps track of the weight of ingredient dispensed. Once the sensed weight of ingredient dispensed is equal to the target volume multiplied by the ingredient's specific gravity, the computer commands the electronic controller to stop the pump and hence the delivery of further ingredient.

The automatic beverage dispenser 10 is computer-controlled using software pre-loaded on a computer. The software has a graphical user interface, as shown in Figure 4. In use, a bar tender takes a customer's order and selects a suitably sized receptacle from a pre-set list of receptacles 80. The bartender then selects the beverage ordered by the customer from a list 82 by tapping the appropriate area of the touch-sensitive screen of a computer, ideally a point of sale device. The order is then sent to the bottom of an order queue 84. The computer operates the beverage dispenser to mix and dispense requested beverages in the order they go into the queue 84, which makes it possible for the bartender to take multiple orders from customers and to allow the beverage mixer 10 to make them up in sequence.

Provided the beverages have not already been mixed, the interface provides queue edit facilities, such as "delete drink" 86, which deletes the highlighted beverage from the queue 84 to prevent it from being mixed, and "move to top of queue" 88, which advances the highlighted beverage to the top of the queue 84 so that it is mixed next.

The invention is not limited to the details of the foregoing embodiments. In practice, the beverage mixer would have more than the two bottles/dispensers shown in the drawings. In practice the beverage mixer may have 24 bottles/dispensers.

The flexible pipes may have a seal for sealingly engaging with the neck of the bottle. Additionally or alternatively, the bottles could be placed, inverted, on a bung that seals to the neck of the bottle: the flexible pipe sealingly passing through a through hole in the bung.

The rinsing device of the beverage mixer could be connected to a mains water supply, rather than to the tank shown in the drawings.

The load cell and first valve could be replaced by an in-line flow meter and a third valve fitted to each flexible pipe. Using such an arrangement, it would be possible to measure and control the volume throughput, rather than relying on weighing the funnel. Such a configuration could, advantageously, facilitate simultaneous dispensation of multiple ingredients, thereby reducing the lead time for mixing each beverage.

The transistors TI to 16 are shown as MOSFETs, but other types of transistors could also be used. The signals from the microprocessor which control the transistors TI to 16 all require circuitry to shift them to the correct level. This circuitry has been omitted for clarity, and would anyway depend on the type of transistor used. The gate signals for the triacs may also need their levels shifting. Circuitry may be provided to protect transistor T2 in case the microprocessor software malfunctions and turns it on permanently, to detect a motor short-circuit and trip out the power, to control the H-bridge transistors (T3 to T6) to prevent the microprocessor from switching on other combinations than the two described above, and/or to control the triac gates to make it impossible to switch on more than one motor at a time.

Claims

Claims: 1. An apparatus for automatically dispensing a beverage

comprising at least one liquid ingredient, the apparatus comprising: at least one dispenser for dispensing a desired quantity of a liquid ingredient from a reservoir into a receptacle and a control circuit operatively connected to the dispenser, the control circuit being arranged to stop dispensation when the desired quantity of ingredient has been dispensed, wherein the control circuit is adapted to control the rate of dispensation such that the desired quantity of ingredient is dispensed within a predetermined time interval.
2. A computer operatively connected to, and programmed to control, at least one dispenser arranged to dispense a desired quantity of a liquid, the computer also being operatively connected to a means for measuring the amount of liquid dispensed by the dispenser, wherein the computer is programmed to control the dispenser such that the desired quantity of liquid is dispensed within a predetermined interval.
3. An apparatus or computer as claimed in claim I or claim 2. wherein the, or each, dispenser comprises: a pump for dispensing a desired quantity of liquid ingredient from a reservoir into a receptacle; a meter arranged to measure the quantity of ingredient dispensed; and a speed controller operatively connected to, and for controlling the speed of, the pump.
4. An apparatus or computer as claimed in any of claims 1, 2 or 3, wherein the, or each pump comprises a peristaltic pump.
5. An apparatus or computer as claimed in claim 3 or claim 4, wherein the, or each, meter comprises a flow meter.
6. An apparatus or computer as claimed in claim 3 or claim 4, wherein the, or each, meter comprises a weighing means.
7. An apparatus or computer as claimed in claim 6, wherein the, or each, meter comprises a load cell.
8. An apparatus or computer as claimed in any of claims I to 7, wherein the control circuit is operatively connected to the meter and the speed controller and is arranged to stop the pump when the desired quantity of ingredient has been dispensed.
9. An apparatus or computer as claimed in any preceding claim, wherein the control circuit is adapted to control the speed controller to control the rate of dispensation.
10. An apparatus or computer as claimed in any preceding claim further comprising a solenoid actuated valve.
11. An apparatus as claimed in any of claims 1, or 3 to 10, further comprising a rinsing device.
12. An apparatus or computer as claimed in any preceding claim further comprising a data carrier for storing a database of operating parameters.
13. An apparatus or computer as claimed in claim 12, wherein the data carrier stores a database of recipes.
14. An apparatus or computer as claimed in claim 13, further comprising a user interface comprising a visual display unit and a keypad comprising a touch-sensitive area of a screen of the visual display unit.
15. A program for controlling the operation of a computer as claimed in any of claims 3 to 14, comprising any one or more of the group comprising: a device driver for interfacing with a pump, a speed controller and/or a meter; a control module that interfaces with the device drivers and applies an algorithm to control the operation of the pump, the speed controller and the meter; and a configurable database comprising parameters corresponding to desired dispensation intervals and/or recipes.
16. A program as claimed in claim 15. further comprising a graphical user interface comprising any one or more of the group comprising: a list of receptacles, a list of beverage recipes, an order queue; and an order queue editor.
17. A point of sale device comprising a computer according to any of claims 2 to 16.
18. A speed controller for a DC motor comprising a variable voltage power supply for varying the voltage applied to the terminals of the motor, a current sensor for sensing the current delivered to the motor and a circuit adapted to control the variable voltage power supply according to a parameter sensed by the current sensor, wherein the sensed parameter comprises a rate of current rippling.
19. A speed controller as claimed in claim 18, wherein the current sensor comprises a resistor for converting the current ripple into a voltage ripple.
20. A speed controller as claimed in claim 19, further comprising a high gain amplifier for amplifying the voltage ripple.
21. A speed controller as claimed in any of claims 18, 19 or 20, further comprising a microprocessor for calculating the rate of current rippling and using the rate of current rippling as an input for controlling the variable voltage power supply.
22. An apparatus substantially as hereinbefore described with reference to and as illustrated in Figure 1 of the accompanying drawings.
23. A speed controller substantially as hereinbefore described with reference to and as illustrated in Figures 2 and 3 of the accompanying drawings.
24. A graphical user interface substantially as hereinbefore described with reference to and as illustrated in Figure 4 of the accompanying drawings.