Coffee brewing device and method of operating the same

Abstract

A coffee brewing device (100) is provided having a conduit (108) extending from a one-way valve (106) to a delivery outlet (109). Water is supplied via the delivery outlet into a reservoir (102) for holding coffee grounds. Water in a heatable section (110) of the conduit is heated to generate water vapour bubbles. The one-way valve is arranged to restrict backflow in a direction away from the delivery outlet, so that heated water including water vapour bubbles is transported in the conduit from the heatable section to the delivery outlet. A sensor (120) senses bubbling in the water in the conduit between the heatable section and the delivery outlet. It has been found that this sensor helps to control how much heated water is carried to the reservoir, and correspondingly the amount of brewed coffee produced, in a reliable, compact and relatively low cost manner. A method of operating such a coffee brewing device and a related computer program are also provided.

Description

TECHNICAL FIELD

[0001] The invention relates to a coffee brewing device. The invention further relates to a method of operating such a coffee brewing device and a related computer program. BACKGROUND

[0002] Various types of coffee machines are known. One example is the so-called drip coffee machine, in which a heating pipe is used to boil water and to pump the water to a delivery outlet, for example in the form of a shower head or a drip zone, which is arranged above a reservoir holding coffee grounds. The heated water is distributed over the coffee grounds by the delivery outlet and flows through the coffee grounds. Coffee oils, also called coffee solubles, are extracted during this coffee brewing process. The brewed coffee can then drip into a coffee pot arranged below the reservoir.

[0003] In a conventional drip coffee machine, all the water in the water reservoir upstream of the heating pipe tends to be heated and delivered to the reservoir to drip through the coffee grounds, unless the user manually cuts off the power supply to the heating pipe.

[0004] In such conventional drip coffee machines, the strength of the brewed coffee is manually controlled by the user, which depends in part on the amount of coffee grounds relative to the amount of heated water added thereto.

[0005] In high-end coffee machines, a motorized pump and a flow meter can be used to control the amount of water that drips through the coffee grounds. However, such components increase the structural complexity and cost of such high-end coffee machines and can also increase their size. SUMMARY

[0006] The invention is defined by the claims.

[0007] According to examples in accordance with an aspect of the present application, there is provided a coffee brewing apparatus comprising: a reservoir for storing water; a receptacle for holding coffee grounds; a delivery outlet at which water is supplied into the receptacle; a one-way valve; a conduit for conveying water from the one-way valve to the delivery outlet, a heatable section of the conduit being configured such that water in the heatable section is heated to generate water vapour bubbles, and the delivery outlet is in use at an elevated position relative to the heatable section, wherein the one-way valve is arranged to permit water to be transported from the reservoir therethrough towards the heatable section, but to restrict the transport of heated water including said water vapour bubbles from the heatable section back towards the reservoir, thereby causing heated water including said water vapour bubbles to rise in the conduit from the heatable section to the delivery outlet; a sensor configured to sense bubbling in the water in the conduit between the heatable section and the delivery outlet; and a controller configured to: determine, based on sensing data from the sensor, a start of bubbling in the conduit after a power supply is initiated to heat water in the heatable section; and control delivery of heated water to the receptacle based on the determined start of bubbling.

[0008] The coffee brewing apparatus can operate to deliver water into a receptacle that can receive coffee grounds as a result of heating of water in the heatable section of the conduit resulting in a mixture of heated water and water vapour bubbles.

[0009] The density of this mixture can be less than the density of water supplied from the reservoir to the heatable section of the conduit, such that the buoyancy of the mixture can be greater than the buoyancy of water supplied to the heatable section. This can result in the mixture being carried up the conduit from the heatable section to the delivery outlet as a result of the one-way valve restricting, e.g. hindering, flow in the opposite direction from the heatable section towards the reservoir.

[0010] The present application is based at least in part on the recognition that a sensor configured to sense bubbling of water in the conduit between the heatable section and the delivery outlet can facilitate controlling how much heated water is carried to the receptacle, and correspondingly controlling the amount of brewed coffee produced, in a reliable, compact and relatively low cost manner. This is because the sensor can be used to determine when bubbling of water in the conduit starts, and correspondingly determine the point at which heated water starts to be delivered to the receptacle.

[0011] Given that heated water can be delivered at a relatively constant flow rate, or at least at a predictable flow rate, the ability of the sensor to determine when bubbling in the water starts means that the amount of water delivered to the receptacle is directly controllable, e.g. by controlling the duration of heating water starting from the sensed point at which bubbling from water heated in the conduit starts to occur.

[0012] By configuring the controller to control the delivery of heated water to the reservoir based on the determined onset of bubbling, the bubbling sensor-based control of the delivery of water to the delivery outlet can be automatic.

[0013] For example, the supply of power initiation can refer to the initial activation of the heating element when power is supplied to the heating element, such that water is heated in the heatable section.

[0014] This initial activation can be implemented by, for example, turning on the coffee brewing device via a power supply switch.

[0015] In some embodiments, the sensor comprises a pair of electrodes for contacting the water in the conduit. Such an electrical sensor can provide a convenient, compact and relatively low cost way of sensing the onset of bubbling in the water being heated in the conduit.

[0016] In such embodiments, the sensor can be configured to provide a measure of the electrical resistance or current between the pair of electrodes. The sensor providing such a measure of the electrical resistance or current between the pair of electrodes can reflect a change in the electrical resistance of the water due to the generation of water vapour bubbles, in particular a decrease in the electrical resistance of the water.

[0017] The heatable section of the conduit can have an inlet and an outlet, through which inlet water to be heated is deliverable into the heatable section, and through which outlet heated water exits the heatable section. In such embodiments, the sensor can be arranged to sense bubbling in the water exiting the outlet of the heatable section.

[0018] Positioning the sensor in this way, in other words at or near the outlet of the heatable section, can enable reliable sensing of the point at which heated water starts to be delivered to the reservoir. It can also be relatively simple to install the sensor at such a location.

[0019] In some embodiments, the coffee brewing device comprises a connector member configured to house at least a portion of the sensor, wherein the conduit comprises a further conduit section for carrying heated water from the heatable section towards the delivery outlet. In such embodiments, the connector member can connect the heatable section to the further conduit section.

[0020] Such a connector member can facilitate mounting of the sensor, for example a pair of electrodes, at a location that permits reliable sensing of the point at which heated water starts to be delivered to the reservoir.

[0021] In some embodiments, the controller is configured to determine the onset of bubbling based on the sensor output satisfying a given threshold.

[0022] For example, in the case of an electrical sensor, a resistance threshold or a current threshold can be reached. The given threshold can be indicative of the point at which bubbling in the heated water causes heated water to be delivered to the reservoir.

[0023] The timer can be comprised in the coffee brewing device, e.g. as part of a controller. In such embodiments, the controller can control the delivery of heated water to the reservoir based on a duration timed by the timer, the duration starting at the determined start of frothing.

[0024] Such a duration, e.g. a preset duration, can enable the amount of brewed coffee to be reliably and directly controlled via the amount of heated water delivered to the reservoir.

[0025] For example, the controller can be configured to control the heating of water in the heatable section based on a duration timed by the timer, the duration starting at the determined start of frothing.

[0026] In some embodiments, the controller is configured to reduce or stop the power supply to heat water in the heatable section after the duration is completed. Thus, the delivery of heated water to the reservoir can be stopped.

[0027] In some embodiments, the coffee brewing device comprises a user interface configured to enable a user to input a desired amount of brewed coffee to be produced, wherein the controller is configured to control the delivery of heated water to the reservoir based on the determined start of frothing and the user input.

[0028] For example, the user input can be used to set a duration timed by the timer, the duration starting at the determined start of frothing.

[0029] In this way, the amount of brewed coffee produced by the coffee brewing device does not need to simply depend on the volume of water in the reservoir, nor on the power supply to the heating element being manually terminated by a user.

[0030] According to another aspect, there is provided a method of operating a coffee brewing device, the coffee brewing device having: a reservoir for storing water; a receptacle for holding coffee grounds; a delivery outlet at which water is supplied into the receptacle; a one-way valve; a conduit for carrying water from the one-way valve to the delivery outlet, a heatable section of the conduit being configured such that water in the heatable section is heated to generate bubbles of water vapour, and the delivery outlet is in use at an elevated position relative to the heatable section, wherein the one-way valve is arranged to permit water to be transported therethrough from the reservoir towards the heatable section, but to restrict the transport of heated water including said bubbles of water vapour from the heatable section towards the reservoir, thereby causing heated water including said bubbles of water vapour to rise in the conduit from the heatable section to the delivery outlet; and a sensor configured to sense bubbling of water in the conduit between the heatable section and the delivery outlet, the method comprising: determining, based on sensing data received from the sensor, that bubbling in the conduit begins after power to heat water in the heatable section is initiated; and controlling delivery of heated water to the receptacle based on the determined beginning of bubbling.

[0031] In some embodiments, and as described above in relation to the coffee brewing device, the sensor comprises a pair of electrodes for contacting water in the conduit. In such embodiments, the sensing data can comprise a measure of electrical resistance or current between the pair of electrodes.

[0032] In some embodiments, controlling delivery of heated water to the receptacle comprises controlling heating of water in the heatable section.

[0033] Alternatively or additionally, controlling delivery of heated water to the receptacle can be based on a duration of time starting from the determined beginning of bubbling.

[0034] In such embodiments, controlling delivery of heated water to the receptacle can comprise reducing or stopping power to heat water in the heatable section after the duration of time is complete.

[0035] In some embodiments, the method comprises receiving a user input of a desired amount of brewed coffee to be produced, wherein controlling delivery of heated water to the receptacle is based on the determined beginning of bubbling and the user input.

[0036] For example, the user input (e.g. via a user interface included in the coffee brewing device) can be used to set a duration of time to be timed by a timer, the duration of time starting from the determined beginning of bubbling.

[0037] In this way, the amount of brewed coffee produced does not need to simply depend on the volume of water in the reservoir, nor does it need to depend on power to the heating element being manually terminated by a user.

[0038] According to another aspect, there is provided a computer program comprising computer program code which, when run on a computing device having a processing system, causes the processing system to perform all the steps of the method according to any embodiment described herein.

[0039] One or more non-transitory computer readable media can be provided having computer programs stored thereon, wherein the computer programs comprise computer program code configured to cause a processing system to implement a method according to any embodiment described herein when the computer program is run on the one or more processors.

[0040] The processing system can for example be comprised in a controller of a coffee brewing device as described herein.

[0041] More generally, embodiments described herein in relation to a coffee brewing device can be applicable to the method and computer program, and embodiments described herein in relation to the method and computer program can be applicable to a coffee brewing device.

[0042] These and other aspects of the application will be apparent from and elucidated with reference to the embodiments (one or more) described hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0043] For a better understanding of the present application, and to show how it can be put into effect, reference will now be made, purely by way of example, to the accompanying drawings in which:

[0044] Figure 1 A coffee brewing device according to one example is schematically depicted;

[0045] Figure 2 A graph of heated water volume versus flow time delivered via a tube from a bubble build-up in a coffee brewing device according to one example is provided;

[0046] Figure 3 A sensor according to one example is schematically depicted;

[0047] Figure 4 A perspective view of a water heating and sensing assembly of a coffee brewing device according to one example is provided, wherein the water heating and sensing assembly is in a partially disassembled state;

[0048] Figures 5A to 5C A view of the water heating and sensing assembly is provided, when in an assembled state; Figure 4 A view of the water heating and sensing assembly is provided, when in an assembled state; and

[0049] Figure 6 A flowchart of a method according to one example is provided DETAILED DESCRIPTION

[0050] The application will be described with reference to the Figures.

[0051] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of apparatuses, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the present application. These and other features, aspects, and advantages of the apparatuses, systems and methods of the present application will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0052] A coffee brewing apparatus is provided having a conduit extending from a one-way valve to a delivery outlet. Water is supplied via the delivery outlet into a reservoir for holding coffee grounds. Water is heated in a heatable section of the conduit to generate water vapor bubbles. The one-way valve is arranged to restrict backflow in a direction away from the delivery outlet, so that heated water including water vapor bubbles is transported in the conduit from the heatable section to the delivery outlet. A sensor senses bubbling in the water in the conduit between the heatable section and the delivery outlet. It has been found that this sensor helps to control how much heated water is carried to the reservoir, and correspondingly the amount of brewed coffee produced, in a reliable, compact and relatively low cost manner. A method of operating such a coffee brewing apparatus and a related computer program are also provided.

[0053] Figure 1 A coffee brewing apparatus 100 according to one example is schematically depicted. The coffee brewing apparatus 100 includes a reservoir 101 for storing water before it is heated. The heated water is eventually delivered to coffee grounds held in a reservoir 102.

[0054] A coffee filter (not visible) can be inserted into the reservoir 102, and coffee grounds can be placed on the coffee filter. Such a coffee filter can help to retain the coffee grounds in the reservoir 102 while permitting brewed coffee to pass through the coffee filter.

[0055] In some embodiments, for example Figure 1 The depicted embodiment, the coffee brewing apparatus 100 includes a brewed coffee container 103, such as a coffee pot, that receives brewed coffee from the reservoir 102.

[0056] For example, the brewed coffee container 103 receives brewed coffee that has passed through a coffee filter received in the reservoir 102.

[0057] While not visible in Figure 1 , one or more channels for brewed coffee can extend through a base of the reservoir 102. Brewed coffee can be conveyed from the reservoir 102 to the brewed coffee container 103 via the one or more channels.

[0058] The reservoir 101 can be delimited by one or more reservoir walls. Such reservoir wall(s) can be formed of any suitable material capable of retaining water within the reservoir 101, such as a plastic material or glass.

[0059] In some embodiments, for example Figure 1 In the illustrated embodiment, the reservoir wall(s) are at least partially made of an optically transmissive material, such as an optically transmissive plastic material or glass, which allows to identify the water level in the reservoir 101.

[0060] The optically transmissive reservoir wall(s) can be provided with volume markings 104. Such volume markings 104 conventionally serve as a guide to help the user determine how much brewed coffee is produced. In a conventional drip coffee maker, all the water held in such a reservoir 101 can be delivered to the brewed coffee receptacle 103, unless the user manually cuts off the power supply in order to stop the heating of water when there is still water in the reservoir 101. As will be explained in more detail hereinafter, the amount of brewed coffee produced by the coffee brewing apparatus 100 according to the present disclosure does not need to be determined by the volume of water in the reservoir 101.

[0061] The delivery of heated water is implemented via a one-way valve 106 and a pipe 108 extending from the one-way valve 106 to the delivery outlet 109. The water is heated in a heatable section 110 of the pipe 108, and the heated water is supplied into the receptacle 102 via the delivery outlet 109.

[0062] The delivery outlet 109 can be defined by the holes of a perforated plate. Such holes can distribute the heated water to various regions of the coffee grounds held in the receptacle 102.

[0063] It should be noted that the perforated plate can be considered as being included in or defining a showerhead or drip zone from which the heated water is supplied to the coffee grounds held in the receptacle 102. The heated water can be relatively uniformly dripped from the delivery outlet 109 onto the coffee grounds.

[0064] More generally, when the use orientation of the coffee brewing apparatus 100 is assumed, the delivery outlet 109 can be arranged above the receptacle 102 so that the heated water falls from the delivery outlet 109 into the receptacle 102, while the brewed coffee drips from the receptacle 102 downward into the brewed coffee receptacle 103 below the receptacle 102.

[0065] The coffee brewing apparatus 100 can thus be considered as comprising a so-called “drip coffee maker”.

[0066] The heated water can flow through the ground coffee beans, taking their essence (coffee oils released during the roasting process, known as coffee alcohols) with them on the way down into the brewing coffee vessel 103.

[0067] The reservoir 102 can be bounded by a wall(s) formed of any suitable material capable of withstanding the temperature of the heated water being delivered into the reservoir 102 to brew coffee. In some embodiments, the wall(s) bounding the reservoir 102 is formed of a plastic material.

[0068] The reservoir 102 can be funnel-shaped, such that the reservoir 102 tapers in the direction of the brewing coffee vessel 103, as Figure 1 illustrated.

[0069] The reservoir 102 can be detachable from the rest of the coffee brewing apparatus 100, to facilitate dispensing coffee grounds into the reservoir 102 and removing used coffee grounds from the reservoir 102, and for example, to change the coffee filter. To this end, a handle 111 can be provided to assist a user in detaching the reservoir 102.

[0070] The water in the reservoir 101 can flow through the one-way valve 106 into the pipe 108 in the direction of the heatable section 110 by gravity.

[0071] The water is heated in the heatable section 110 of the pipe 108 to generate water vapour bubbles. In other words, the water in the heatable section 110 is heated and eventually boils (at 1 atmosphere, sea level, 100°C). This boiling creates bubbles, and thus pressure, which pushes the water flow.

[0072] The one-way valve 106 is arranged to permit the water to be transported therethrough from the reservoir 101 towards the heatable section 110, but restricts the heated water including water vapour bubbles from being transported back from the heatable section 110 to the reservoir 101. In other words, the passage back to the reservoir 101 is obstructed by the one-way valve 106, such that the heated water flows towards the delivery outlet 109. It should be noted that, if there were no one-way valve 106, the boiling water could flow back into the reservoir 101.

[0073] Since the mixture of heated water and water vapour bubbles has a lower density than the water supplied from the reservoir 101, the buoyancy of the mixture can be greater than the buoyancy of the water supplied from the reservoir 101 to the heatable section 110. This can result in the mixture being carried from the heatable section 110 to the delivery outlet 109 via the other pipe section 112 of the pipe 108. This is due to the one-way valve 106 restricting (e.g. obstructing) the flow in the opposite direction from the heatable section 110 towards the reservoir 101.

[0074] As the water continues to boil, bubbles can rise in another pipe section 112, such as another vertically extending pipe section 112.

[0075] The inner diameter of another pipe section 112 can be small enough relative to the size of the bubble so that the water column can travel upward to the delivery outlet 109 on top of the bubble.

[0076] Therefore, this design eliminates the need for an electric pump to deliver heated water to the reservoir 102. Consequently, the design of the coffee brewing device 100 can be relatively simple and low-cost.

[0077] The heatable section 110 of pipe 108 can be heated in any suitable manner. In some embodiments, for example... Figure 1 In the embodiment shown, the heating element 113 is arranged as a heatable section 110 of the heating pipe 108.

[0078] The heating element 113 is, for example, a resistance heating element 113.

[0079] In some embodiments, the heatable section 110 includes, for example, a heating conduit that includes a heating element 113 as an integral component.

[0080] As an example of such a heating conduit, a heatable section 110 formed of an aluminum tube is attached (e.g., adhered) to a resistance heating element 113. Reference will be made below. Figure 4 and Figures 5A to 5C An illustrative example describing this type of heating pipe.

[0081] More generally, the heatable section 110 of the conduit 108 can be formed of any suitable material, such as metal or metal alloy. By forming the heatable section 110 from such metal or metal alloy, heat can be effectively transferred from the heating element 113 to the water inside the heatable section 110.

[0082] For example, the heatable section 110 can be formed of aluminum.

[0083] It should be noted that the upstream and downstream sections of the pipe 108 of the heatable section 110, such as another pipe section 112, can be formed of any suitable material, such as plastic or elastic material.

[0084] For example, sections of pipe 108 upstream and / or downstream of the heatable section 110, such as another pipe section 112, may be formed of silicone resin.

[0085] like Figure 1As shown, when the use orientation of the coffee brewing device 100 is adopted, the delivery outlet 109 is in an elevated position relative to the heatable section 110 of the tube 108. Another tube section 112 of the tube 108 can thus extend upwardly from the heatable section 110 to the delivery outlet 109 which is in an elevated position. In this case, the heated water including water vapor bubbles rises in the other tube section 112 from the heatable section 110 to the delivery outlet 109.

[0086] In at least some embodiments, for example Figure 1 The embodiment shown, the reservoir 102 is arranged above the brewed coffee container 103, with the heatable section 110 of the tube 108 arranged in proximity to, for example below, the brewed coffee container 103.

[0087] This positioning of the heatable section 110 can enable the heatable section 110 to heat the brewed coffee container 103 in addition to heating the water used to brew coffee, to keep the brewed coffee warm. By enabling both functions with the heatable section 110, the coffee brewing device 100 can not need to include an additional heating element dedicated to heating the brewed coffee container 103. This helps to make the design of the coffee brewing device 100 simpler and less costly.

[0088] In some embodiments, for example Figure 1 The embodiment shown, the coffee brewing device 100 includes a heatable plate 114 arranged to heat the brewed coffee container 103 receiving brewed coffee from the reservoir 102. As Figure 1 The heatable plate 114 can be arranged to support and heat the brewed coffee container 103 when the brewed coffee container 103 is placed on the heatable plate 114, as shown.

[0089] The heatable plate 114 and the heatable section 110 of the tube 108 can be heated by a common heating element 113, for example by a heating element 113 included as an integral component of the heating tube.

[0090] The heating element 113 can be powered from a main power source, for example via a power cable 115 from a main power source, the heating element 113 being included as an integral component of the heating tube.

[0091] The coffee brewing device 100 can include an electrical fuse 116 connected between the power cable 115 and the heating element 113.

[0092] The brewed coffee container 103 can be bounded by a wall(s) of any suitable material, such as a metal material and / or a glass, such as a borosilicate glass, for example Such material can help transfer heat from the heating element 113 (e.g. via the heatable plate 114) to the brewed coffee in the brewed coffee container 103.

[0093] In some embodiments, the wall(s) bounding the brewed coffee container 103 can be vacuum insulated. This can help the brewed coffee to remain warm without requiring heating via the heatable plate 114, or in some cases without requiring heating at all via the heatable plate 114.

[0094] The brewed coffee container 103 can be detachable from the rest of the coffee brewing apparatus 100, so as to enable a user to pour brewed coffee from the brewed coffee container into a cup or other vessel. To this end, a handle 117 can be provided to assist a user in detaching the brewed coffee container 103 and pouring brewed coffee therefrom.

[0095] In some embodiments, the heating element 113 can be controlled to heat the brewed coffee container 103, e.g. to keep brewed coffee therein warm, for a predetermined period of time before automatically stopping the supply of power to the heating element 113.

[0096] The predetermined period of time can be, for example, 30 minutes to 1 hour, e.g. about 40 minutes.

[0097] As Figure 1 illustrated, the coffee brewing apparatus 100 comprises a sensor 120 configured to sense bubbling in the water in the pipe 108 between the heatable section 110 and the delivery outlet 109. This can help to control how much heated water is carried into the reservoir 102, and correspondingly the amount of brewed coffee produced, in a reliable, compact and relatively low cost manner.

[0098] To this end, the controller (not visible) can be configured to determine, based on sensing data from the sensor 120, when bubbling in the pipe 108 between the heatable section 110 and the delivery outlet 109 begins after the supply of power is initiated to heat the water in the heatable section 110. The controller can further control the delivery of heated water to the reservoir 102 based on the determined bubbling onset.

[0099] The sensor 120 in conjunction with the controller can be used to determine when bubbling in the heated water in the pipe 108 begins, and correspondingly the point at which heated water begins to be delivered to the reservoir 102.

[0100] The initiation of the supply of power can for example refer to the initial activation of the heating element 113 when power is supplied to the heating element 113, such that the heatable section 110 heats the water therein.

[0101] Such initial activation can be implemented by turning on the coffee brewing apparatus 100, e.g. by a user actuating a power supply switch.

[0102] In view of the fact that the heated water can be delivered at a relatively constant flow rate or at least at a predictable flow rate, the ability of the sensor 120 in combination with the controller to determine when the bubbling in the water starts means that the amount of water delivered to the reservoir 102 can be reliably and directly controlled.

[0103] Figure 2 Graphs of water volume versus flow time delivered via the pipe 108 from the start of bubble accumulation in the coffee brewing device 100 according to one example are provided. These graphs plot the measured data of a coffee brewing device 100 having a resistive heating element 113 included in an aluminium heating pipe with an internal diameter of 9 mm. The heating element is powered by a 220V 50Hz, 920W AC power supply. Still referring to Figure 2 It should be noted that a conventional drip coffee maker can provide 1 to 10 cups of brewed coffee, in other words 125 to 1250 ml, with an average flow rate of about 2.552 ml / s.

[0104] Figure 2 The graphs provided in the above show that the amount of water delivered to the reservoir 102 can be directly and reliably controlled via the duration of time starting from the start of bubbling in the heated water in the pipe 108.

[0105] A timer can be included in the coffee brewing device 100, for example as part of the controller. In such embodiments, the controller can control the delivery of heated water to the reservoir 102 based on a duration of time timed by the timer, the duration of time starting from the determined start of bubbling in the pipe 108.

[0106] Such a duration of time, for example a preset duration of time, can enable the amount of brewed coffee to be reliably and directly controlled via the amount of heated water delivered to the reservoir 102.

[0107] For example, the controller can be configured to control the heating of water in the heatable section 110 based on a duration of time timed by the timer, the duration of time starting from the determined start of bubbling.

[0108] In some embodiments, the controller is configured to reduce or stop the power supply, for example to the heating element 113, which heats the water in the heatable section 110 after the duration of time is completed.

[0109] In some embodiments, the coffee brewing device 100 comprises a user interface, such as one or more buttons, dials and / or a touch screen, configured to enable a user to input a desired amount of brewed coffee to be produced, wherein the controller is configured to control the delivery of heated water to the reservoir 102 based on the determined start of brewing and the user input.

[0110] For example, the user input can be used to set a duration to be timed by the timer, the duration starting from the determined onset of bubbling. Thus, when the user desires to produce more, e.g. larger quantities of brewed coffee, the timer can time a longer duration.

[0111] In this way, the quantity of brewed coffee produced by the coffee brewing apparatus 100 need not simply depend on the volume of water in the reservoir 101 nor on the manual termination of the supply of power to the heating element 113 by the user.

[0112] More generally, the controller can have any suitable design and be arranged in any suitable way in order to implement the functionality described herein.

[0113] In at least some embodiments, the controller can comprise a microcontroller unit provided in a coffee machine comprised in the coffee brewing apparatus 100.

[0114] Such a microcontroller unit can for example be mounted on a printed circuit board assembly comprised in the coffee machine.

[0115] Any suitable type of sensor 120 can be used to sense the bubbling in the pipe 108 between the heatable section 110 and the delivery outlet 109.

[0116] In some embodiments, for example Figure 1 and Figure 3 the illustrated embodiment, the sensor 120 comprises a pair of electrodes 122A, 122B for contacting the water in the pipe 108. Such an electrical sensor 120 can provide a convenient, compact and relatively low cost way of sensing the bubbling in the heated water in the pipe 108.

[0117] In such embodiments, the sensor 120 can be configured to provide a measure of the electrical resistance or current between the pair of electrodes 122A, 122B. The sensor 120 providing such a measure of the electrical resistance or current between the pair of electrodes 122A, 122B can reflect a change in the electrical resistance of the water, in particular a decrease in the electrical resistance of the water, caused by the generation of water vapour bubbles.

[0118] When measuring the electrical resistance at the outlet of the heatable section 110 using a 9V multimeter, for a prototype coffee brewing apparatus 100 for which the measurements plotted in Figure 2 Fig. 4 were made, the electrical resistance between the electrodes 122A, 122B was about 1 MΩ before the water was heated. When the water was heated to boiling and the heated water started to flow towards the delivery outlet 109, the electrical resistance decreased to about 0.3 MΩ.

[0119] Reference is made to Figure 3The sensor 120 can comprise an AC power source 123 connected to a pair of electrodes 122A, 122B. For safety reasons, the voltage across the electrodes 122A, 122B provided by the AC power source 123 can be a low voltage. This current is schematically represented in Figure 3 by double arrow 124. In this non-limiting example, an ammeter 125 is comprised in the sensor 120. This circuit is completed by the positive 126 and negative 127 ions inherently present in the water between the electrodes 122A, 122B. The electrodes 122A, 122B are spaced apart from each other by a distance 128.

[0120] In some embodiments, the controller is configured to determine the start of frothing based on the output of the sensor 120 satisfying a given threshold.

[0121] For example, in the case of an electrical sensor 120, a resistance or current threshold can be reached. The given threshold can indicate the point at which frothing in the heated water causes the heated water to be delivered to the reservoir 102.

[0122] It should be noted that alternative sensor types can be envisaged for sensing frothing in the heated water between the heatable section 110 and the delivery outlet 109, such as a vibration sensor 120, for example a microelectromechanical system (MEMS) vibration sensor 120. Such a vibration sensor 120 can sense vibrations caused by frothing of the heated water.

[0123] In some embodiments, for example in the embodiments shown in Figure 4 and Figures 5A to 5C , the heatable section 110 has an inlet 140 through which water to be heated can be delivered into the heatable section 110 and an outlet 142 through which heated water exits the heatable section 110, wherein the sensor 120 is arranged to sense frothing in the water exiting the outlet 142 of the heatable section 110.

[0124] Positioning the sensor 120 in this way, in other words at or near the outlet 142 of the heatable section 110, can enable reliable sensing of the point at which the heated water starts to be delivered to the reservoir 102. The installation of the sensor 120 at this location can also be relatively simple.

[0125] Arranging the sensor 120 to sense frothing in the water exiting the outlet 142 of the heatable section 110 can be implemented in any suitable way.

[0126] In some embodiments, and with reference to Figure 1 , Figure 4 and Figures 5A to 5CThe connector member 144 is configured to house at least a portion of the sensor 120, and the connector member 144 can connect the heatable section 110 to another pipe section 112. Thus, the connector member 144 can be considered an adapter, the function of which is in part to enable the heatable section 110 to be fitted to another pipe section 112.

[0127] Such a connector member 144 can facilitate the installation of the sensor 120 (e.g. a pair of electrodes 122A, 122B) at a location that permits reliable sensing of heated water as it begins to be delivered to the reservoir 102.

[0128] As shown in Figure 4 , a seal 145 can be interposed between the connector member 144 and the outlet end of the heatable section 110. The seal 145 can help to minimise water leakage between the outlet end of the heatable section 110 and the connector member 144. The seal 145 can be formed of any suitable material, such as an elastomer, for example silicone rubber.

[0129] The connector member 144 can include a recess 146 in which the outlet end of the heatable section 110 can be received. In Figure 4 and Figures 5A to 5C non-limiting examples, the outlet end of the heatable section 110 is received in the recess 146 of the connector member 144, together with the seal 145.

[0130] The connector member 144 can include a connector portion 147 to which another pipe section 112 can be connected, for example by sleeving an end of the other pipe section 112 around the connector portion 147.

[0131] In embodiments such as Figure 1 , Figure 4 and Figures 5A to 5C in which the sensor 120 includes a pair of electrodes 122A, 122B, the connector member 144 can define apertures 148A, 148B through which the electrodes 122A, 122B extend from outside the connector member 144 to inside the connector member 144. Thus, the electrodes 122A, 122B can extend to the inside of the connector member 144, at which they can be in contact with heated water. Outside the connector member 144, the electrodes 122A, 122B can be connected to sensing circuitry of the sensor 120, for example of the type shown in Figure 3 .

[0132] It is reiterated that Figure 4 and Figures 5A to 5CAn example is depicted in which the heatable section 110 comprises a heating tube that includes the heating element 113 as an integral component.

[0133] In Figure 4 And Figures 5A to 5C Visible in Figs. 1 1 and 12 are electrical connections 149A, 149B by which the heating element 113 can be connected to a control circuit, such as a controller. The heating element 113 extends from the electrical connection 149A proximate the outlet end of the heatable section 110 to the other electrical connection 149B proximate the inlet end of the heatable section 110.

[0134] Water flow rate in the heating tube can be difficult to control in production, for example due to variations in power, internal diameter, etc., in part because such heating tubes are relatively low cost components. However, the actual appliance water flow rate can be measured during production, and the production fixture can automatically program this data to the controller, such as a microcontroller unit.

[0135] Figure 4 And Figures 5A to 5C Can be considered to depict a water heating and sensing assembly 150 that includes the heatable section 110, at least a portion of the sensor 120, and the connector member 144 configured to house at least a portion of the sensor 120, such as the electrodes 122A, 122B.

[0136] Figure 4 The water heating and sensing assembly 150 shown is in a partially disassembled state in which the connector member 144 is detached from the heatable section 110, and in which at least a portion of the sensor 120, in this case the electrodes 122A, 122B, are detached from the connector member 144.

[0137] Figures 5A to 5C The water heating and sensing assembly 150 shown is in an assembled state in which the connector member 144 is attached to the heatable section 110 at the outlet end of the heatable section 110, and in which at least a portion of the sensor 120, in this case the electrodes 122A, 122B, are housed and mounted within the connector member 144.

[0138] Figure 6 A flowchart of a method 200 according to one example is provided. The method 200 is a method 200 of operating a coffee brewing device 100 according to any of the embodiments described herein.

[0139] The method 200 includes initiating 202 power to heat water in the heatable section 110. The initiation 202 can be implemented, for example, by a user turning on the coffee brewing device 100, such as by actuating a power switch.

[0140] In step 204, a start of frothing in the pipe 108 after the powering on 202 is determined based on the sensing data received from the sensor 120. The method 200 further comprises controlling 206 the delivery of heated water to the reservoir 102 based on the determined start of frothing.

[0141] In some embodiments, and as described above with respect to the coffee brewing device 100, the sensor 120 comprises a pair of electrodes 122A, 122B for contacting water in the pipe 108. In such embodiments, the sensing data can comprise a measure of electrical resistance or current between the pair of electrodes 122A, 122B.

[0142] In some embodiments, controlling 206 the delivery of heated water to the reservoir 102 comprises controlling heating of water in the heatable section 110.

[0143] Alternatively or additionally, controlling 206 the delivery of heated water to the reservoir 102 can be based on a duration of time starting from the determined start of frothing.

[0144] In such embodiments, controlling 206 the delivery of heated water to the reservoir 102 can comprise reducing or stopping, for example, the power supply to the heating element 113 that heats water in the heatable section 110 after the duration of time is completed.

[0145] In some embodiments, the method 200 comprises receiving a user input of a desired amount of brewed coffee to be produced, wherein the controlling 206 of the delivery of heated water to the reservoir 102 is based on the determined start of frothing and the user input.

[0146] For example, the user input (e.g. via a user interface comprised in the coffee brewing device 100) can be used to set a duration of time to be timed by a timer, the duration of time starting from the determined start of frothing.

[0147] In this way, the amount of brewed coffee produced does not need to simply depend on the volume of water in the reservoir 101 nor on the manual termination of the power supply to the heating element 113 by the user.

[0148] There is also provided a computer program comprising computer program code which, when executed on a computing device having a processing system, causes the processing system to perform the steps of the method 200 according to any of the embodiments described herein, and in particular steps 204 and 206. The processing system may, for example, be comprised in a controller of the coffee brewing device 100.

[0149] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality.

[0150] A single processor or other unit can implement the functions of several items listed in the claims.

[0151] The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0152] A computer program can be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state storage medium supplied together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems.

[0153] If the term "comprises" is used in the claims or specification, it should be noted that the term "comprises" is intended to be equated with the term "configured to".

[0154] No reference signs in the claims shall be construed as limiting the scope.

Claims

1. A coffee brewing apparatus (100), comprising: Storage container (101), the storage container being used for storing water; Storage container (102) for holding coffee grounds; Delivery outlet (109), at which water is supplied to the reservoir; One-way valve (106); A conduit (108) for conveying water from the one-way valve to the delivery outlet, wherein a heatable section (110) of the conduit is configured such that water in the heatable section is heated to generate water vapor bubbles, and the delivery outlet is in an elevated position relative to the heatable section during use, wherein the one-way valve is arranged to allow water to be conveyed from the reservoir through the one-way valve toward the heatable section, but to restrict the return flow of heated water including the water vapor bubbles from the heatable section toward the reservoir, thereby causing the heated water including the water vapor bubbles to rise in the conduit from the heatable section to the delivery outlet; Sensor (120), the sensor being configured to sense bubbling in the water in the pipe between the heatable section and the delivery outlet; as well as The controller is configured to: Based on sensing data from the sensor, it is determined that bubbling begins in the pipe between the heatable section and the delivery outlet after power is supplied to heat the water in the heatable section; and The delivery of heated water to the reservoir is controlled based on the determined start of bubbling.

2. The coffee brewing apparatus (100) according to claim 1, wherein the sensor (120) includes a pair of electrodes (122A, 122B) for contacting the water in the conduit (108).

3. The coffee brewing apparatus (100) according to claim 2, wherein the sensor (120) is configured to provide a measurement of the resistance or current between the pair of electrodes (122A, 122B).

4. The coffee brewing apparatus (100) according to any one of claims 1 to 3, wherein the heatable section (110) has an inlet (140) and an outlet (142), water to be heated can be delivered into the heatable section through the inlet, and heated water leaves the heatable section through the outlet, wherein the sensor (120) is arranged to sense foaming in the water leaving the outlet of the heatable section.

5. The coffee brewing apparatus (100) according to any one of claims 1 to 3, comprising a connector member (144) configured to receive at least a portion of the sensor (120), wherein the conduit (108) includes another conduit section (112) for conveying heated water from the heatable section (110) toward the delivery outlet (109), the connector member being configured to connect the heatable section to the other conduit section.

6. The coffee brewing apparatus (100) according to any one of claims 1 to 3, wherein the controller is configured to determine the start of bubbling based on the output of the sensor (120) that satisfies a given threshold.

7. The coffee brewing apparatus (100) according to any one of claims 1 to 3, comprising a timer, the controller being configured to control the delivery of heated water to the reservoir (102) based on a duration timed by the timer, the duration starting at the determined start of bubbling.

8. The coffee brewing apparatus (100) according to claim 7, wherein the controller is configured to reduce or stop the power supply to heat the water in the heatable section (110) after the duration has elapsed.

9. A method (200) of operating the coffee brewing apparatus according to claim 1, the method comprising: Based on sensing data received from the sensor, it is determined (204) that bubbling begins in the pipe between the heatable section and the delivery outlet after power is supplied to heat the water in the heatable section; and The delivery of heated water to the reservoir is controlled (206) based on the determined start of bubbling.

10. The method (200) of claim 9, wherein the sensor comprises a pair of electrodes for contacting the water in the pipe.

11. The method (200) of claim 10, wherein the sensing data includes a measurement of resistance or current between the pair of electrodes.

12. The method (200) according to any one of claims 9 to 11, wherein the delivery of heated water to the reservoir by the control (206) includes controlling the heating of the water in the heatable section.

13. The method (200) according to any one of claims 9 to 11, wherein the control (206) of delivering the heated water to the reservoir is based on the duration starting from the determined foaming start.

14. The method (200) of claim 13, wherein the control (206) of delivering the heated water to the reservoir comprises reducing or stopping the power supply to heat the water in the heatable section after the duration has elapsed.

15. A computer program product comprising computer program code, which, when executed on a computing device having a processing system, causes the processing system to perform all the steps of the method (200) according to any one of claims 9 to 14.

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