Beverage frothing assembly

Abstract

A beverage foaming assembly 100a is disclosed comprising a beverage-maker 200a, a beverage foaming device 200a removably attachable to the beverage-maker, wherein the beverage-foaming device includes an air input line 311a and a beverage input line 330a, and wherein the beverage foaming device is configured to combine air from the air input line 311a and beverage from the beverage input line 330a to produce foamed beverage. A valve 350a is integrally provided with the beverage foaming device 300a, the valve 350a being configured to directly control flow through one of the beverage-input line 330a and the air-input line 311a, the valve comprising a flow-passage and a restricting element configured to be moveable to vary a width of the flow-passage for controlling a flow of beverage or air therethrough. The beverage foaming assembly 100a comprises a user-interface configured to receive a user-selection of options including a cold beverage foaming operation and a hot beverage foaming operation. The beverage- maker device 200a is configured, responsive to user selection in the user-interface, to actuate the restricting element in the valve 350a of the beverage foaming device 300a, to move to vary the width of the flow-passage between a first width corresponding to the cold beverage foaming operation wherein cold foamed beverage is made, and a second width of the flow-passage, narrower than the first width, corresponding to the hot beverage foaming operation.

Description

[0001] "BEVERAGE FROTHING ASSEMBLY"

[0002]

[0003] FIELD

[0004] The present invention relates to an assembly for carrying out frothing of a beverage.

[0005] BACKGROUND

[0006] Foamed beverages, particularly coffee beverages including foamed milk, are increasingly popular with consumers. Home appliances (e.g., fully automatic coffee machines) are made to which foaming devices can be attached to produce the requisite foam in order to meet this demand. However, since these devices should be washable (either by hand or using a dish-washing machine) it is hard to integrate electronic components into them. Additionally, any electronic components would have to be powered either by an internal battery or externally through a plug, which both increases complexity and decreases safety. This lack of electronics in turn results in these components either operating with fixed characteristics, or operational characteristics that can only be altered using manually-adjustable valves.

[0007] One particular problem in the field of beverage foaming attachments is the requirement for attachments capable of producing both hot and cold foam. As the operational characteristics of the beverage foamer cannot be altered electronically, this issue is typically addressed by providing two beverage foaming devices - one for producing hot foam and one for producing cold foam. This is an unsatisfactory solution as it is inefficient to have two attachments, and increases expense.

[0008] Document EP3000363A1 discloses a beverage foaming assembly with a beverage-maker, a removable beverage foaming device having air and beverage input lines, and a valve to control airflow. Document EP2989944B1 discloses an apparatus for producing a milk-air mixture, which provides for controlling the air supply for the milk-air mixture in order to change the consistency of the milk-air mixture. Document US2017 / 367525A1 discloses a device for producing milk-air emulsions with valve arrangements for varying air flow.

[0009] The present invention aims to at least partially ameliorate the above-described problems of the prior art.

[0010] SUMMARY OF THE INVENTIONIn an aspect of the invention, a beverage foaming assembly is disclosed comprising a beverage-maker, and a beverage foaming device removably attachable to the beverage-maker. The beverage foaming device includes an air input line and a beverage input line. The beverage foaming device is configured to combine air from the air input line and beverage from the beverage input line to produce foamed beverage. A valve is integrally provided with the beverage foaming device, the valve being configured to directly control flow through one of the beverage input line and the air input line. The valve comprises a flow-passage and a restricting element configured to be moveable to vary a width of the flowpassage for controlling a flow of beverage or air therethrough. The beverage foaming assembly comprises a user-interface configured to receive a userselection of options including a cold beverage foaming operation and a hot beverage foaming operation. The beverage-maker device is configured, responsive to user selection in the user-interface, to actuate the restricting element in the valve of the beverage foaming device, to move to vary the width of the flow-passage between a first width corresponding to the cold beverage foaming operation wherein cold foamed beverage is made, and a second width of the flow-passage, narrower than the first width. The second width corresponds to the hot beverage foaming operation wherein a hot beverage warmer than the cold beverage is made. Optionally, the valve is a continuously variable valve. This can have the advantage of allowing a range of options between the hot and cold options.

[0011] Preferably, the beverage-maker comprises an actuator movable to mechanically actuate the valve, preferably moveable from a retracted position to an extended position. This can provide a reliable way of controlling the valve.

[0012] In an optional configuration, the beverage-maker comprises a magnetic actuator and the restricting element is a magnetically actuatable restricting element. This can provide a non-contact, more hygienic way of controlling the valve.

[0013] The magnetic actuator may optionally comprise a magnetic element mounted on a moveable actuator. The moveable actuator is configured to be moveable to magnetically actuate the restricting element using the magnetic element. The configuration can be more reliable.

[0014] Preferably, the restricting element is a magnetically actuatable obstruction configured to be actuatable from a non-attracted position corresponding to one ofthe first width and the second width, to an attracted position corresponding to the other of the first width and the second width. This can provide a simple, noncontact way of controlling the valve.

[0015] The magnetically actuatable obstruction may preferably be located within the flow-passage, wherein the flow-passage comprises a narrow section and a wider section, in the non-attracted position the magnetically actuatable obstruction rests in one of the narrow section and the wider section, and in the attracted position the magnetic element is moved at least partly into the other of the narrow section and the wider section. Providing the obstruction within the flow-passage like this can simplify construction.

[0016] The restricting element can optionally comprise a rotary element having at least one hole defined therein, and a fixed element with at least one fixed hole defined therein, and wherein in the rotary element is configured to be rotatable relative to the fixed element between a first position where a flow-channel having the first width is co-operatively formed therebetween and a second position where a flowchannel having the second width is co-operatively formed therebetween. This can allow accurate control of flow.

[0017] Optionally, the rotary element further comprises a rack-and-pinion drive, wherein a pinion of the rack-and-pinion drive is mechanically connected to the rotary element for transmitting rotary drive thereto. This provides a simple construction.

[0018] Preferably, the beverage foaming device comprises a Venturi foamer and a steam-inlet, and the beverage-maker comprises a steam generator comprising a steam outlet, wherein the steam outlet is configured to be removably attachable to the steam inlet, and wherein the Venturi foamer is configured to generate suction in the air inlet and beverage inlet using steam from the steam generator. A Venturi foamer can be driven just using steam generated by the beverage maker.

[0019] The valve can optionally be configured to control flow through the air-input line. The second width is sized to achieve an air flow-rate of less than 20 litres per hour when the suction of the Venturi foamer is between -0.2 and -0.8 bar, and the first width is sized to achieve an air flow-rate of 20 litres per hour or more when the suction of the Venturi foamer is between -0.2 and -0.8 bar. The first width can be sized to achieve an air flow-rate of 20-60 litres per hour. Controlling air-flowcan allow for reducing components in contact with the beverage, allowing easier cleaning and better hygiene.

[0020] Optionally the restricting element in the valve of the beverage foaming device is configured to move to vary the width of the flow-passage width to a third width wider than the first width such that an air flow-rate of 80 litres per hour or more is achieved. This can permit automatic cleaning.

[0021] Preferably, the valve is a pressure-actuated valve wherein the restricting element is actuatable by varying a pressure of steam generated by the beverage-maker. This can provide a simple way of controlling the valve without additional components.

[0022] The beverage foaming assembly optionally further comprises an air-flow sensor configured to output an air-flow value, and wherein the beverage-maker is configured to output a control signal responsive to the detected air-flow value. Accurate, on-the-fly control of the valve can thus be enabled.

[0023] Preferably, the valve is configured to control flow through the beverage line, and the first width corresponds to a beverage flow-rate of 0.4-0.5 litres / minute and the second width corresponds to a beverage flow-rate of 0.2-0.3 litres / minute, preferably wherein the first width is between 2.5mm and 3.5mm, and the second width is between 0.5mm and 1.5mm. Since the beverage is denser than air, this can allow cold foamed beverage production without adding excessive air.

[0024] In an aspect of the invention a method of creating a foamed beverage is disclosed, comprising steps of providing a beverage-maker-appliance, providing a beverage-foamer device removably attached to the beverage-maker-appliance, receiving a user-selection of one of a cold-foamed-beverage option or a hot- foamed-beverage option at a user-interface in electronic communication with the beverage-maker-appliance, actuating a beverage and / or air supply-line of the beverage-foamer-device responsive to the user-selection to obtain hot or cold foamed beverage.

[0025] In an aspect of the invention, a beverage-foaming device having a magnetically- actuatable valve controlling flow through an air and / or beverage supply-line is disclosed, preferably wherein the beverage foaming device is a milk-foaming carafe, preferably wherein the valve is magnetically actuated by a manually- operated magnetic actuator.

[0026] The beverage foaming device can optionally comprise a beverage-holdingcarafe, preferably wherein the valve is located in a lid of the carafe. This can provide a convenient arrangement for the consumer.

[0027] Any apparatus feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.

[0028] It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and / or supplied and / or used independently. In this specification the word 'or' can be interpreted in the exclusive or inclusive sense unless stated otherwise.

[0029] BRIEF DESCRIPTION OF DRAWINGS

[0030] One or more aspects will now be described, by way of example only and with reference to the accompanying drawings having like-reference numerals, in which: Fig. 1 shows a side-on, cut-away, schematic view of a beverage foaming assembly according to an embodiment of the invention;

[0031] Fig. 2 shows a schematic diagram of a control system for the beverage foaming assembly of Fig. 1;

[0032] Fig. 3 shows a side-on, cut-away drawing of a beverage foaming assembly according to another embodiment of the invention;

[0033] Fig. 4 shows a side-on, cut-away drawing of the carafe of Fig. 3;

[0034] Fig. 5 a shows a top-down, horizontal section through the carafe of Fig. 4;

[0035] Fig. 5b shows the detail section J showing the valve from the drawing of Fig.

[0036] 5 a;

[0037] Fig. 5c shows a side-on, vertical section through the valve of Fig. 5b in a first configuration;

[0038] Fig. 5d shows a top-down, horizontal section through the carafe of Fig. 5a in a second configuration, and Fig. 5e shows the detail section P from Fig. 5d;

[0039] Fig. 5f shows a side-on, vertical section through the valve of Fig. 5b in a second configuration;

[0040] Fig. 6a shows a side-on, cut-away drawing of a carafe in a first configuration according to yet another embodiment of the invention, and Fig. 6b shows the detail section D of Fig. 6a;

[0041] Fig. 6c shows the carafe of Fig. 6a in second configuration, and Fig. 6d showsthe detail section F carafe of Fig. 6c;

[0042] Fig. 7a shows a side-on, cut-away drawing of a carafe in a first configuration according to an embodiment of the invention, Fig. 7b shows the detail D of Fig.

[0043] 7a, and Fig. 7c shows the detail D of Fig. 7a in a second configuration;

[0044] Fig. 7d shows a side-on drawing of a ball and blocking element from Fig. 7b, and Fig. 7e shows a top-down drawing of the ball and blocking element from Fig.

[0045] 7b;

[0046] Fig. 8a shows a side-on, cut-away drawing of a carafe according to still another embodiment of the invention, and Fig. 8b shows detail F of Fig. 8a;

[0047] Figs. 9a and 9b show exemplary user- interfaces for use in the beverage foaming assembly of Fig 1; and,

[0048] Fig 9c shows a flow-chart illustrating a method of using a beverage foaming assembly according to the present invention.

[0049] SPECIFIC DESCRIPTION

[0050] Fig. 1 shows a beverage foaming assembly 100, including a beverage machine 200 (in this case a coffee machine) and a beverage foaming carafe 300.

[0051] The beverage machine 200 includes an ingredient store 201 (for example, a coffee bean or coffee grounds container) from which flavoured beverages can be produced and dispensed into a cup 400. Spilled excess beverage can be caught by the drip-tray 203. To control the beverage machine 200, a user-interface 210 is provided, for example on an upper, user-facing surface in which the user can input instructions and receive feedback. The user interface 210 may be, for example, a touch-screen user interface. Alternatively, the user interface 210 may be a remote device physically separated from, but wirelessly connected to the beverage machine 200 (e.g., a mobile phone, laptop, tablet, or other portable electronic device).

[0052] A PCB (printed circuit board) 220 is provided in bi-directional electronic communication with the user interface 210 for receiving instructions therefrom and providing feedback for display to the user thereto. The PCB 220 can include an electronic memory for storing data and instructions, and a computer processor for processing data and carrying out programs stored on the memory. A wifi module or other form of internet connection may also be provided with the PCB 220 for receiving wireless instructions from the user via a mobile device, and providingfeedback thereto.

[0053] As shown by the thin inter-connecting lines in Fig. 1, the PCB 220 is provided in electronic communication with a pump 230, a steam generator 240, a milk- flow regulator 250, and an air valve 260. This electronic communication may be via wires, or wireless using a wifi module. This electronic communication may be bidirectional so that the PCB 220 can receive and process sensor data (e.g., temperature sensor data, speed-sensor data, or level-sensor data) from these components.

[0054] The pump 230 may be, for example, a vibration pump. The pump 230 is connected to a water source (for example a water tank) of the beverage machine 200, not shown. As is shown by the arrowed line in Fig. 1, under the control of the PCB 220 the pump 230 can then feed this water to the steam generator 240 which can be controlled by the PCB 220 to heat it in to steam. The steam generator 240 may be, for example, a through-flow steam generator consisting of a bent pipe or boiling vessel surrounded by an electrical heating element.

[0055] Steam generated by the steam generator 240 of the beverage machine 200 then flows along suitable pipes and connectors into a beverage frothing carafe 300. The carafe 300 has a lid 310 containing a steam-powered venturi beverage-frother, a beverage tank 320 (in this case one containing milk), and a beverage feed-pipe 330, or tube, feeding beverage from the beverage tank 320 into the lid 310. The Venturi beverage frother creates suction using the Venturi effect driven by steam, resulting in suction that sucks beverage from the beverage tank 320 and air through the air valve 260 into a mixing chamber where it is combined, with the resulting frothed beverage being output through a dispensing nozzle 340.

[0056] Fig. 2 shows an exemplary control schema of the beverage foaming assembly 100, where a carafe 300 with a Venturi mixing chamber 313 is connected to a beverage machine 200 by a connector 312. In this control schema, the beverage machine 200 controls the steam, air, and milk flow into the Venturi mixing chamber 313 using its steam generator 240, the milk flow regulator 250 and the air management system 260. As such the flow of milk is controlled by the beverage machine 200 using the milk flow regulator 250 without needing to have complex control elements within the carafe 300. The foamed beverage is then dispensed into a cup 400 through the nozzle 340, and depending on the quantity of milkand / or air used, may be hot (i.e., 50 degrees Celsius or more, and preferably 50-65 degrees) or cold (30 degrees Celsius or lower, and preferably 15-30). Since the control elements can all be located in the beverage machine 200, this enables the carafe 300 to be easily washable (e.g., dish washer machine washable) and simple in structure making it cheaper and easier to manufacture.

[0057] A valve 370 may be integrally provided with the beverage foaming device 300, the valve being configured to control flow through one of a beverage-input line and an air-input line.

[0058] Whilst the air-flow is shown as coming from the beverage machine 200, air may additionally or alternatively flow to the Venturi mixing chamber 313 directly through an air inlet in the carafe 300. In this case a manual control 311 (e.g., manually-operated valve) may be used to control the airflow.

[0059] Figs 3 to 5d illustrate another embodiment of a beverage foaming assembly 100a, similar to the beverage foaming assembly 100. As is shown in Fig. 3, in this arrangement the beverage machine 200a is connected to the foaming lid 310a of the carafe 300a by the connector 312a. In this connected configuration the beverage machine 200a can control a milk flow from the milk tank 320a of the carafe 300a through the beverage feed-pipe 330a into the foaming lid 310a, using the solenoid actuator 250a.

[0060] Fig. 4 shows the carafe 300a in greater detail. Steam flows from the beverage machine 200a into the carafe lid 310a through the steam-inlet 312-1 a of the connector 312a. A ball-valve 312-2a is provided in the stem-inlet 312- la biased towards a closed position by a coil-spring 312-3a (though other resilient means may also be used). This ball-valve 312-2a ensures that the steam-inlet 312-la is kept closed except when steam pressure sufficient to push the ball-valve 312-2a back against the biasing of the spring 312-3a is flowing through the steam inlet 312-la.

[0061] The steam flowing into the steam-inlet 312-la flows through a narrowing 312- 4a into a mixing chamber 313a resulting, by virtue of the Venturi effect, in suction causing air to be drawn through a manually -variable air valve 311a and through a milk inlet 314a connected to the milk tank 320a by the beverage feed-pipe 330a. The resulting mixture of air, milk, and steam then flows into a further mixing chamber 315a where mixing of air and milk resulting in frothed milk is enhancedby the chaotic flow of the mixture. This mixture then flows out of the further mixing chamber 315a through the outlet 316a into a dispensing nozzle (not shown). The flow of the milk from the tube 330a, that is from the beverage feed-pipe, into the milk inlet 314a is controlled by a gasket 350a and tube 330a. The tube 330a is actuated by a solenoid-driven actuator 250a of the machine 200a in a manner that will be described further with reference to Figs. 5a to 5f.

[0062] Figs. 5a, 5b, and 5c show the carafe 300a in a first configuration. The gasket 350a consists of a static plate 352a, fixed to, and extending across the width of, the milk inlet 314a. The static plate 352a is provided with an off-centre static hole 351a defined therethrough, such that milk can flow through the static hole 351a into the milk inlet 314a. A corresponding off-centre rotary hole 331a is provided in an upper wall element 332a of the tube 330a, with the upper wall element 332a extending across the width of the upper end of the tube 330a and being in flush contact with the static plate 352a. The tube 330a is surrounded by and fixed to a rotary toothed gear element 333a at an upper end close to the upper wall element 332a so that it can be driven to rotate around its major axis by the machine 200a. Depending on the rotational position of the tube 330a, the rotary hole 331a may either be partially communicated with the static hole 35 la providing only a channel of small width through the gasket 350a, or the static hole 351a and the rotary hole 331a may be located concentrically so as to maximise a width of the flow-channel through the gasket 350a. In the first configuration of Figs. 5a, 5b, and 5c, the static hole 351a is partly occluded by the upper wall element 332a, meaning that only a narrow flow-channel is available for milk to flow through the gasket 350a. Since the flow of milk is lower, the resulting mixture will have a higher temperature resulting in a “hot” foam.

[0063] The static hole 351 and the rotary hole 331 may define a valve 370a configured to directly control flow through the tube 330a to the milk inlet 314a.

[0064] For example, in this first configuration the width of the channel between the static hole 351a and the rotary hole 331a may be calibrated such that a suction of between -0.2 bar and -0.8 bar within the Venturi mixing chamber 313a results in a flow-rate of 200 and 300 millilitres per minute. A width of between 0.5 and 1 ,5mm may achieve this. This low flow-rate, combined with the use of steam pressure between 1.5 bar and 3 bar and steam temperature of 105-125 degrees Celsius,results in “hot” foamed milk of 50-65 degrees Celsius.

[0065] The machine 200a drives the tube 330a to rotate using the solenoid 250a driving an actuator rod 251a with a toothed rack element 252a at one end. In this first configuration the solenoid 250a is not energised so that a coil spring 253a provided concentrically around the actuator rod 251a pushes the actuator rod 251a away from the carafe 300a, placing the toothed rack element 252a attached to an end of the actuator rod 251a located within the carafe 300a in a retracted position. The teeth of the toothed rack element 252a are engaged and inter-leaved with the teeth of a rotary gear 333 a that surrounds and is mechanically attached to the tube 330a, meaning that the tube 330a is thus held in this first position.

[0066] Figs 5d, 5e, and 5f show the carafe 300a in a second configuration (please note that Figs. 5 d and 5e show a horizontal section taken through the end plate 332a of the tube 330a, slightly lower than the horizontal section shown in Figs. 5a and 5b, which is taken through the static plate 352a). In this configuration the solenoid 250a is energised pushing the actuator rod 251a into the carafe 300a against the bias of the spring 253a. Due to the interleaving of the teeth of the toothed rack element 252a attached to the actuator rod 251a with the teeth of the gear 333a, the linear motion of the toothed rack element 252a is converted into rotary movement of the tube 330a. This driving of the actuator rod 251a into the carafe 300a thus causes the gear 333a and the tube 330a to which it is attached to rotate to a second position. In this second position the rotary hole 331a is located concentrically with the static hole 351a such that a width of the passage formed between them is maximised. This wider passage maximises milk-flow meaning that the resulting foamed beverage, made as it is with more room-temperature (or lower) milk, is “cold”.

[0067] For example, in this second configuration, the width of the passage formed between the rotary hole 331a and the static hole 351a can be calibrated such that a milk flow rate is in the range 400 to 500 millilitres per minute, with the conditions otherwise kept the same as in the first configuration. A width of between 2.5 and 3.5mm may achieve this.

[0068] To facilitate rotation of the tube 330a relative to the static gasket 350a, the tube 330a comprises a radial flange 334a extending circumferentially near the upper end. This flange 334a bears rotationally against a lower end of the static gasket350a on its upper side, and on its lower side against a static bearing 317a which extends below the flange 334a, and which holds the flange 334a in close contact with the gasket 350a.

[0069] Whilst the tube 330a is described as rotating relative to the gasket 350a, with the gasket 350a remaining static, the gear 333a could instead be provided on the gasket 350a and the gasket 350a be rotatable relative to the tube 330a and the inlet 314a without changing the essential principle of operation. This would mean that the tube 330a could be more easily removable for cleaning and / or replacement as the static bearing 317a extending beneath the flange 334a could be omitted, and instead a keyed element be provided circumferentially around the flange 334a with the flange 334a fitting into it to prevent rotation. For example, the keyed-element could be a square-shaped-hole into which a square-shaped flange 334a could be inserted and fit frictionally to prevent it falling out.

[0070] However, having the tube 330a rotatable relative to the gasket 350a is advantageous as it means that only the tube 330a and the gasket 350a need to be held in a close, but relatively-rotatable relationship. In contrast having the gasket 350a rotate relative to both the inlet 314a and the tube 330a could complicate manufacturing, assembly, and use of the device, as bearing surfaces would have to be provided between each of them.

[0071] The current flowing to the solenoid 250a provided by the machine 200a can have two settings (i.e., energised and not energised) corresponding to “hot” and “cold” beverage production. Alternatively, it may be continuously variable so as to allow varying along a range of temperature values between the “hot” and “cold” settings, with the gasket 350a and tube 330a acting as a proportional valve. This would give the user greater control over foam temperature.

[0072] Whilst the tube 330a and the gasket 350a are shown as each having only one off-centre hole, more holes may be provided. For example, the tube could have multiple rotary holes 331a, including a smallest hole having a diameter of 0.5mm to 1.5mm, an intermediate hole having a diameter 2mm to 3mm, and a largest hole having a diameter of 2.5 to 3.5. In this case the static plate would have a static hole 351a as large or larger than the largest rotary hole 331a provided in the tube. In this case the tube 330a would be rotated to select a desired flow-channel-width by rotating the tube 330a until the desired rotary hole 331a was located concentricwith the static hole 351a. Alternatively, there could be multiple static holes 351a selectively alignable with a single rotary hole 331a, or even multiple static holes 351a and rotary holes 331a. Using multiple holes in this fashion would advantageously reduce the material used, and require less fine control of rotation of the rotary hole 331a allowing for easier manufacturing and control.

[0073] Figs. 6a, 6b, 6c, and 6d show an alternative way of controlling milk- flow to that of Figs. 5a to 5f. The carafe 300b shown in Fig. 6a is similar to the carafe 300a, with the lid 310b having a manually-controlled air inlet 311b, and a connector 312b through which steam can flow from the machine 200b (indicated by the dotted line in Fig. 6a) to a Venturi mixing chamber 313b to create suction resulting in air being sucked in through the inlet 311b and milk sucked into the milk inlet 314b from the tank 320b through the tube 330b, that is from the beverage feed-pipe. Mixing of the resulting mixture is then enhanced in the further mixing chamber 315b, before the frothed beverage is dispensed to the user through the outlet 316b.

[0074] However, as shown particularly in Fig. 6b, the carafe 300b differs in that the tube 330b is static and has a widened upper end 331b (with a correspondingly wider inner bore), which is frictionally retained by a collar 350b in fluid communication with the milk inlet 314b. A magnetic ball 360b is located within the wider upper end 33 lb of the tube 330b, and retained therein by a grill or mesh 332b. The ball 360b is dimensioned such that it fits loosely within the wider bore of the upper end 331b, but is too wide to fit in the narrower bore of the rest of the tube 330b. When the carafe 300b is oriented upright, therefore, the ball 360b rests at the lower end of the upper end 331b, where the upper end 331b is connected to the rest of the tube 330b by an upwardly-opening frusto-conical-shaped section 331-lb. However, the ball 360b does not completely occlude the inner bore of the tube 330b, as one or more vane-shaped ribs 333b are provided along the tube 330b within the frusto-conical-shaped section 331-lb, extending inwardly from an inner wall of the tube 330b. These ribs 333b therefore prevent the ball 360b from completely abutting the inner wall of the tube 330b about its entire circumference, allowing milk to flow through the tube 330b even when the ball 360b is in a resting position.

[0075] The magnetic ball 360b and the tube 330b may define a valve 370b configured to control flow through the tube 330b to the milk inlet 314b.The position of the ball 360b is controlled by the beverage machine 200b energising a solenoid 250b which drives an actuator rod 251b to move against the bias of the coil spring 253b towards the upper end 331b of the tube 330b. The actuator rod 251b has a permanent magnet 252b mounted on an end proximate the tube 330b.

[0076] As shown in Figs. 6a and 6b, in the un-energised position of the solenoid 250b, the permanent magnet 252b is held away from the tube 330b such that the ball 360b is insufficiently attracted towards the permanent magnet 252b to overcome the force of gravity and thus rests at the bottom of the upper end 331b. This results in the restricting the width of the tube 330b that milk can flow through into the milk inlet 314b of the Venturi mixing chamber 313b, resulting in “hot” foam.

[0077] In Figs. 6c and 6d, the permanent magnet 252b is shown in its extended position, with the solenoid 250b energised to drive the actuator rod 251b against the bias of the coil spring 253b. In this extended position the permanent magnet 252b is located sufficiently close to the ball 360b, and above the frusto-conical-shaped section 331 -lb, for the magnetic attraction of the permanent magnet 252b to overcome the force of gravity and attract the ball 360b upwards into the wider upper end 331b. In this position, with the ball 360b located in a wider section of the tube 330b, more space is available around the ball 360b for milk to flow through, and as such more milk flows into the Venturi mixing chamber 313b through the milk inlet 314b resulting in “cold” foam.

[0078] The ball 360b is made of a food-safe, dish-washer-washable, but also magnetically-attractable material. For example, the ball 360b may be made of a magnetic / magnetisable / paramagnetic stainless steel such as ferritic or martensitic stainless steel (e.g., stainless steel grades 409, 420, 430, 439, or 440), or a suitable food-safe, dish-washer-safe plastic (e.g., Nylon) or glass doped with magnetic material, or a magnetic material coated with food-safe / dish-washer-safe material. The weight of the ball 360b should be calibrated such that the upward force of the flow of liquid through the tube 330b when the ball 360b is in lower position is insufficient to overcome the force of gravity.

[0079] Whilst gravity is described as the restoring force returning the ball 360b to its lower position when not influenced by the permanent magnet 252b, another restoring force may alternatively or additionally be provided. For example, a coilspring may be provided urging the ball 360b towards its lower position, or a weaker magnet than the magnet 252b may be provided attracting it towards the lower position. Whilst using gravity is simpler and cheaper, using an alternative restoring force would make the arrangement capable of operating at a different orientation and allow the use of a lighter ball 360b. Additionally, with a non-gravitational restoring force, further sections of the tube 330b having inner bores of different widths intermediate between the widths of the narrow tube 330b and the wider upper end 331b may be provided. The permanent magnet 252b may then be extended to a position where its attractive force is balanced by the restoring force of e.g., the coil spring such that the ball 360b locates within these intermediate sections, allowing intermediate flow-rates of milk and more precise control of the resulting foam temperature to be achieved.

[0080] Whilst a permanent magnet 252b is described as being used in the above carafe 300b, an electromagnet may instead be provided at the end of the actuator rod 251b, powered from within the device 200b via suitable wiring. Indeed, rather than using an actuator rod to move the magnet towards and / or away from the tube 330b, the magnet may be fixed within the machine 200b and the power flowing to it may be varied so as to attract the ball 360b upwards.

[0081] Rather than being a spherical ball, the ball 360b may be a movable obstruction of a differing shape. Whilst a spherical shape is advantageous as it allows the ball to roll over obstructions, a rod-like shape would allow the obstruction to keep the same orientation within the tube 330b as it would be prevented from rotating by the sides of the tube 330b. In this case it would be possible to make the obstruction itself a permanent magnet and both attract it and repel it using magnet forces of differing polarity without the obstruction rotating. When combined with a non- gravitational restoring force (e.g., coil spring) the obstruction could be located in a narrow section between two chambers of wider, but different width, and moved into these wider sections controllably by either attracting it (e.g., upwards in to a first wider chamber above it) or repelling it (e.g., downwards into a second wider chamber having differing width to the first chamber).

[0082] Figs. 7a to 7e illustrate a carafe 300c similar to the carafe 300b except as herein described. The carafe 300c includes a magnetically-actuatable ball 360c similar to the ball 360b, except that it need not be so dense in its construction and can, when(as in Fig. 7b) not being actuated and milk is flowing through the tube 330c, float upwards with the flow of milk. The ball 360c is prevented from flowing upwards into the Venturi mixing chamber 313c by a blocking element 332c. As can be seen in Figs. 7d and 7e, the blocking element 332c comprises a lower axially-extending skirt element 332-lc extending concentrically and downwardly within the tube 330c from a wider ring-shaped flange element 332-2c which seals with the inner wall of the tube 330c. The skirt 332-lc is dimensioned such that the ball 360c will sit within it when pressed upwards by milk flow, blocking its central bore and the central hole of the ring-shaped flange 332-2c. The blocking element 332c defines a through-hole 332-3c extending radially on the flange 332-2c and axially along the skirt 332-lc through which milk can flow even when the ball 360c is pressed against the blocking element 332c by the flow of milk. Milk can thus flow between the inner wall of the tube 330c and the ball 360c, and then through the through-hole 332-3c into the Venturi mixing chamber 313c when steam is supplied and the ball 360c is not actuated by the magnet 252c of the valve 250c. However, since the milk-flow is restricted by the relatively small size of the through-hole 332-3c, this milk-flow corresponds to “hot” foam production.

[0083] The magnetic ball 360c and the blocking element 332c may define a valve 370b configured to control flow through the tube 330c to the milk inlet 314b.

[0084] In a second configuration, shown in Fig. 7c, the magnet 252c is moved near to the tube 330c by the beverage machine 200c, so as to be proximate to the tube 330c at its upper end 331c. The ball 360c is attracted towards the magnet 252c, moving it in to a lower part of the upper end 331c, and away from the blocking element 332c. Since the ball 360c is prevented from being pressed against the blocking element 332c by the flow of the milk by the counter-action of the magnet 252c, the central bore of the blocking element 332c is unblocked, and a wider cross-section of the tube 330c is available for milk- flow. This second configuration therefore corresponds to “cold” foam due to the larger milk-flow than in the first configuration.

[0085] In order to prevent the ball 360c falling out of the tube 330c when not in use, a narrowing 331-lc narrower than the diameter of the ball 360c is provided in the tube 330c at the bottom of the upper end of the tube 331c. When no other force is acting on the ball 360c, it rests against this narrowing 331-lc under the influenceof gravity.

[0086] Whilst the carafes 300b and 300c have been described with reference to the magnetically actuatable balls 360b and 360c being actuated by magnets controlled by their respective machines 200b and 200c, the concept of magnetic control of the valve can be advantageously applied in alternative embodiments where alternative driving arrangements are provided. For example, the magnets 252b and 252c may be manually movable towards and away from the tubes 330b and 330c. Examples of such manually actuatable systems can include a bi-stable-position button apparatus, or a rotatable knob attached to a rack-and-pinion system. Such a manually- actuatable system could be provided directly on carafes 300b and 300c, with the user thus enjoying a simple, accurate, and non-contact way of controlling the valve that can avoid having elements that are both sealed but also relatively-rotatable.

[0087] The concept of a magnetically-actuatable valve is also not limited to the two-position ball arrangement discussed with reference to the carafes 300b and 300c. It also includes a proportional valve similar to that discussed with reference to the carafe 300a, where the rotary valve is magnetically actuated by having, for example, a rack-and-pinion with the rack being moved magnetically. This would have the advantage of allowing a proportional valve (i.e., a continuously variable one) but controlled in a non-contact way.

[0088] Figs. 8a and 8b illustrate another way of achieving selectable foamed beverage temperature in a carafe 300d that is similar to the carafe 300b except as is herein described.

[0089] As in the carafe 300b, the carafe 300d receives steam from the machine 200d via the connector 312d into the Venturi mixing chamber 313d, resulting in suction that draws air from the air inlet 311 d, and milk from the milk tank 320d through the tube 330d, that is the beverage feed-pipe, (which locates in the gasket 350d) and then through the milk inlet 314d. The resulting mixture then flows into a further mixing chamber 315d before being dispensed through the outlet 316d. Also, as in the carafe 300b, in the carafe 300d, when operating in a “hot” mode, the flow of milk through the tube 330d is restricted by a ball 360d located within a wider upper end 33 Id that rests at the bottom of the upper end 33 Id within the frusto-conically-shaped section 331-ld against the rib 333d resulting in limitedmilk flow of between 200 millilitres per minute and 300 millilitres per minute. The ball 360d and the tube 330d may define a valve 370d configured to control flow through the tube 330d to the milk inlet 314d.

[0090] However, in the “cold” mode the operation of the carafe 300d is different to that of the carafe 300b. Instead of actuating the ball 360d magnetically, the ball 360d is instead lifted against the force of gravity away from the frusto-conically-shaped section 331-ld by an increase in the suction provided in the Venturi mixing chamber 313d. This increase in suction is provided by increasing the temperature of the steam generator in the machine 300d from its typical operational temperature of roughly 115-125 degrees Celsius into the range 130-150 degrees Celsius to generate an increased steam pressure from around 1 bar, to a pressure of 1.2 bar or more, and potentially as high as 8-10 bar. This partial removal of the obstruction of the tube 330d by the ball 360d by lifting it into the wider upper part of the tube 33 Id results in an increase in flow greater than that that would result simply from increasing the suction whilst keeping the usable diameter of the tube 330d the same. The resulting flow is in the range of 400 to 500 millilitres per minute, resulting in “cold” foamed beverage. In order to prevent the ball 360d being sucked entirely into the milk inlet 314d, a mesh or grid 332d is provided in the tube retaining the ball 360d within the tube 330d.

[0091] The ball 360d is preferably made of a food-safe, dishwasher-safe material, for example a BP A- free plastic such as Nylon. To achieve the result of the ball 360d resting at the bottom of the upper end of the tube 33 Id under normal conditions, and being lifted when the steam pressure is increased, the density of the ball 360d should be in the approximate range of 0.8 to 1.2 g / cm2.

[0092] Whilst a milk-flow rate has been described as being controlled within the carafes 300a, 300b, 300c and 300d, the air-flow rate may instead be controlled in substantially the same way by providing similar control mechanisms in the airflow channels of their respective air- inlets 311a, 311b, 311c and 311 d controllable respectively by the machines 200a, 200b, 200c and 200d. In this case, assuming a milk-flow-rate of 200 to 300 millilitres per minute and a steam pressure of between 1.5 and 3 generating a suction of between -0.2 and -0.8 bar within the Venturi mixing chamber, the width of an air-flow channel would be controlled to produce frothed milk (or another beverage) or varying temperature. For the operatingcharacteristics above, the width of the air-inlet channel would be calibrated such that an air flow rate for “hot” beverage would be 20 litres per hour or lower, and that the “cold” beverage would be generated with a channel-width corresponding to a flow rate at between 20 and 60 litres per hour. With variable- width air- intake, a third width, wider than that of the “cold” setting, could also be provided, corresponding to a flow-rate of 80 litres per hour or more, to provide sufficient airflow for cleaning the Venturi mixing apparatus.

[0093] The beverage foaming assembly 100 could, in a further development of this concept, include a sensor 318 for detecting a flow-rate of air into the carafe. For example, a pressure-drop across a hole of known dimensions provided along the air flow channel before the Venturi mixing chamber could be measured. By measuring this pressure-drop, it would be possible for the machine 200 to detect when the milk in the carafe is finished and display (or otherwise communicate) this information to the user, avoiding the need for e.g., an additional optical sensor for detecting a carafe milk-level. The machine 200 could also adjust the width of the air-flow channel to achieve a desired result based on feedback from such a sensor.

[0094] Temperature sensors could also be deployed to control the width of the flowchannel to achieve a desired effect, both in cases where the air-flow is varied and cases where the milk- flow is varied. For example, shape-memory-alloy elements in thermally-conductive relation with the foamed beverage produced by the Venturi foamer could be used to quickly actuate valve elements.

[0095] Whilst Venturi-effect-driven foaming is used in the above illustrative examples of foam-producing devices, other foaming drives may also benefit from milk and / or air-flow control. This includes impeller-driven foaming (e.g., a battery- driven impeller provided within the carafe-lid), vibration-driven foaming, and other foaming devices. Whilst examples of the air and milk flow are controlled are discussed separately, a device in which both are controlled simultaneously by suitable valve-arrangements is also possible.

[0096] Figs. 9a to 9c depict a user interaction with the beverage machine 200 in order to obtain foamed beverage using carafe having the milk-flow control mechanism of any one of the milk carafes 300a, 300b, 300c or 300d.

[0097] As shown in Fig. 9c, in the work-flow 500 the user first fills the carafe with milkat a filling step 501. At a beverage selection step 502 the user then interacts with the user interface 210, which can display user-interface screens 210a to allow the user to select the beverage-type they would like, including (assuming the desired beverage is a foamed beverage), the thickness (i.e. , depth above the liquid portion of the beverage, which can vary between, e.g., 0 to 70mm) of the foam, the texture (i.e., density), and finally the temperature of the foam.

[0098] At the optional step 503 the user may also select a type of the milk, for example, the user may, via the user interface 210, select the kind of milk they are using from a list of potential milks, including nut milk (e.g., almond milk), cow’s milk (skimmed or non-skimmed), goafs milk, soya milk etc. As these milks each have differing density, fat / sugar content, and temperature characteristics, they may require differing steam-pressure, temperature, and milk / air flow rates which the PCB 220 may store in its memory or access on-the-fly using its internet access. If this optional step 503 is not included, then operational parameters may be used calibrated assuming that the milk is e.g., full-fat cow’s milk.

[0099] Based on the user-input at step 502 (and optional step 503) the PCB 220 will then control the machine 200 to create the requested beverage by determining, at step 504, a steam generator temperature, at step 505 an air flow-rate, and at step 506, a milk flow-rate. Dependent on the requested foam-temperature, the machine 200 will control the attached carafe 300a, 300b, 300c, or 300d to vary the temperature in the way discussed above. As shown in Fig 9b, the user may desire, during the production of the beverage, to vary the foam thickness and / or texture so as to produce, for example, a foamed beverage of varying density. These instructions may be entered using a user interface screen 210b.

[0100] As used herein, the term "removable attachment" (and similar terms such as “removably attachable”), as used in relation to an attachment between a first object and a second object, preferably connotes that the first object is attached to the second object and can be detached (and preferably re-attached, detached again, and so on, repetitively), and / or that the first object may be removed from the second object without damaging the first object or the second object; more preferably the term connotes that the first object may be re-attached to the second object without damaging the first object or the second object, and / or that the first object may be removed from (and optionally also re-attached to) the second object by hand and / orwithout the use of tools (e.g. screwdrivers, spanners, etc.). Mechanisms such as a snap-fit, a bayonet attachment, and a hand-rotatable locking nut may be used in this regard.

[0101] “Food safe” in this context means any substance that does not shed substances harmful to human health in clinically significant quantities if ingested. For example, it should be BPA-free.

[0102] “Dishwasher safe” means that it should be physically and chemically stable during prolonged exposure to the conditions prevailing within a dishwasher machine. For example, it should be able to withstand exposure to a mixture of water and a typical dishwasher substance (e.g., washing with FairyTM or FinishTM dishwasher tablets and water, at temperatures of 82 degrees centigrade for as long as 8 hours without visibly degrading (e.g., cracking)).

[0103] It will be understood that the present invention has been described above purely by way of example, and modifications of details can be made within the scope of the invention.

[0104] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.

Claims

CLAIMS1. A beverage foaming assembly (100, 100a) comprising:a beverage-maker (200, 200a, 200b, 200c, 200d),a beverage foaming device (300, 300a, 300b, 300c, 300d) removably atachable to the beverage-maker, wherein the beverage-foaming device includes an air input line (311a, 311b, 311c, 31 Id) and a beverage input line (330, 330a, 330b, 330c, 330d), and wherein the beverage foaming device is configured to combine air from the air input line (311a, 311b, 311c, 31 Id) and beverage from the beverage input line (330, 330a, 330b, 330c, 330d) to produce foamed beverage,a valve (370, 370a, 370b, 370c, 370d) integrally provided with the beverage foaming device, the valve (370, 370a, 370b, 370c, 370d) being configured to directly control flow through one of the beverage-input line (330, 330a, 330b, 330c, 330d) and the air-input line (311a, 311b, 311c, 3 lid), the valve comprising a flow-passage and a restricting element configured to be moveable to vary a width of the flow-passage for controlling a flow of beverage or air therethrough,wherein the beverage foaming assembly (100, 100a) comprises a user- interface (210) configured to receive a user-selection of options including a cold beverage foaming operation and a hot beverage foaming operation, and wherein the beverage-maker (200, 200a, 200b, 200c, 200d) is configured, responsive to user selection in the user-interface (210), to actuate the restricting element in the valve (370, 370a, 370b, 370c, 370d) of the beverage foaming device, to move to vary the width of the flow-passage between a first width corresponding to the cold beverage foaming operation wherein cold foamed beverage is made, and a second width of the flow-passage, narrower than the first width, corresponding to the hot beverage foaming operation wherein a hot beverage warmer than the cold beverage is made.

2. The beverage foaming assembly of claim 1, wherein the valve (370, 370a, 370b, 370c, 370d) is a continuously variable valve.

3. The beverage foaming assembly of claims 1 or 2, wherein the beverage-maker (200, 200a) comprises an actuator (250a) movable to mechanically actuate the valve (370, 370a), preferably moveable from a retracted position to an extended position.

4. The beverage foaming assembly of claims 1 or 2, wherein the beverage-maker (200, 200b, 200c) comprises a magnetic actuator (250b, 250c) and the restricting element is a magnetically actuatable restricting element (360b, 360c).

5. The beverage foaming assembly of claim 4, wherein the magnetic actuator comprises a magnetic element (252b, 252c) mounted on a moveable actuator (251b, 251c), and the moveable actuator is configured to be moveable to magnetically actuate the restricting element (360b, 360c) using the magnetic element (252b, 252c).

6. The beverage foaming assembly of any one of claims 4 o 5, wherein the restricting element is a magnetically actuatable obstruction (360b, 360c) configured to be actuatable from a non-attracted position corresponding to one of the first width and the second width, to an attracted position corresponding to the other of the first width and the second width.

7. The beverage foaming assembly of claim 6, wherein the magnetically actuatable obstruction (360b, 360c) is located within the flow-passage, and wherein the flowpassage comprises a narrow section and a wider section, in the non-attracted position the magnetically actuatable obstruction (360b, 360c) rests in one of the narrow section and the wider section, and in the attracted position the magnetically actuatable obstruction is moved at least partly into the other of the narrow section and the wider section.

8. The beverage foaming assembly of any one of claims 6 or 7, wherein the magnetically actuatable obstruction is a ball (360b) located within a tube (330b) having a widened upper end (331b), the ball being dimensioned such that it fits loosely within the wider bore of the upper end but is too wide to fit in the narrower bore of the rest of the tube, and wherein one or more vane-shaped ribs (333b) are provided preventing the ball (360b) from completely abutting the inner wall of the tube (330b) about its entire circumference.

9. The beverage foaming assembly of any one of claims 4 to 8, wherein the magnetically actuatable obstruction is made of a food-safe, dishwasher-washable, magnetically-attractable material selected from the group consisting of: ferritic or martensitic stainless steel, a food-safe plastic doped with magnetic material, glass doped with magnetic material, or a magnetic material coated with food-safe material.

10. The beverage foaming assembly of any one of claims 1 to 5, wherein the restricting element comprises a rotary element (330a, 350a) having at least one hole (331a, 351a) defined therein, and a fixed element (350a, 330a) with at least one fixed hole (351a, 331a) defined therein, and wherein in the rotary element is configured to be rotatable relative to the fixed element between a first position where a flow-channel having the first width is co-operatively formed therebetween and a second position where a flow-channel having the second width is co¬ operatively formed therebetween.

11. The beverage foaming assembly of claim 10, wherein the rotary element (330a, 350a) further comprises a rack-and-pinion drive (333a, 252a), and wherein a pinion (333a) of the rack-and-pinion drive is mechanically connected to the rotary element (330a, 350a) for transmitting rotary drive thereto.

12. The beverage foaming assembly of any preceding claim, wherein the beverage foaming device comprises a Venturi foamer (313) and a steam-inlet (312-1 a), and the beverage-maker comprises a steam generator (240) comprising a steam outlet, wherein the steam outlet is configured to be removably attachable to the steam inlet, and wherein the Venturi foamer is configured to generate suction in the air inlet and beverage inlet using steam from the steam generator.

13. The beverage foaming assembly of claim 12, wherein the valve (370) is configured to control flow through the air- input line (311 a, 31 lb, 311c, 31 Id), and wherein the second width is sized to achieve an air flow-rate of less than 20 litres per hour when the suction of the Venturi foamer is between -0.2 and -0.8 bar, and the first width is sized to achieve an air flow-rate of 20 litres per hour or more when the suction of the Venturi foamer is between -0.2 and -0.8 bar, preferably wherein the first width is sized to achieve an air flow-rate of 20-60 litres per hour, preferably wherein the restricting element in the valve of the beverage foaming device is configured to move to vary the width of the flow-passage width to a third width wider than the first width such that an air flow-rate of 80 litres per hour or more is achieved.

14. The beverage foaming assembly of claim 13 as dependent from claim 1, wherein the valve (370) is a pressure-actuated valve wherein the restricting element is actuatable by varying a pressure of steam generated by the beveragemaker.

15. The beverage foaming assembly of any claim 12 to 14, wherein the beverage foaming assembly further comprises an air-flow sensor (318) configured to output an air-flow value, and wherein the beverage-maker is configured to output a control signal responsive to the detected air-flow value.

16. The beverage foaming assembly of any one of claims 1 to 11 , wherein the valve (370a, 370b, 370c, 370d) is configured to control flow through the beverage line, preferably wherein the first width corresponds to a beverage flow-rate of 0.4-0.5 litres / minute and the second width corresponds to a beverage flow-rate of 0.2-0.3 litres / minute, more preferably wherein the first width is between 2.5mm and 3.5mm, and the second width is between 0.5mm and 1.5mm.

17. The beverage foaming assembly of any preceding claim, wherein the beverage foaming device comprises a beverage-holding carafe, preferably wherein the valve (370, 370a, 370b, 370c, 370d) is located in a lid (310) of the carafe.

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