GB2487069A - Infusion Beverage Making Apparatus - Google Patents

Abstract

An infusion beverage maker comprises a head portion 18 for delivering hot water into a removable infuser 40 connected thereto in use. The head portion 18 comprises a peripheral sealing means 23 and a corresponding peripheral flange 42 arranged to be clamped against the sealing means 43 when the infuser 40 is connected to the head portion 18 in use. The head portion comprises means for supporting the infuser in an initial position and means for clamping the infuser in a final position wherein the clamping means is arranged, once the infuser is supported in the initial position, to move the infuser so as to bring the peripheral flange into contact with the sealing means in the final position. The clamping means may be electromagnetic. A plurality of different infusers may be provided, each infuser 40 comprising an infusion chamber 44 providing a different volume for containing a beverage material for infusion.

Description

Infusion Beverage Making Apparatus The present invention relates to apparatus for making infusion beverages such as coffee and tea.

There are generally two main types of apparatus commonly used to make infusion beverages, especially where water for the beverage is electrically heated by the apparatus rather than on a stovetop. A first type of beverage making apparatus, often known as a drip coffee maker or percolator, comprises an open infusion basket containing relatively coarse coffee grounds (or tea leaves). Water is heated in a reservoir to a temperature approaching boiling point, typically 80-100 °C, and is then delivered into the filter basket at atmospheric pressure. The hot water filters through the beverage material in the basket under gravity and then drips out into a carafe that collects the infused coffee or tea beverage. A second type of beverage making apparatus is an espresso coffee machine, wherein water is heated e.g. in a thermobiock and then pumped under a high pressures of 5-20 bar through a compressed cake of finely ground coffee powder. The coffee powder is held in a filter basket provided by a "group handle" that can be locked into position under a "group head" that supplies the pressurised hot water.

In both types of coffee maker described above the respective filter baskets are generally of a standard size. In drip coffee makers the filter basket is typically sized to hold enough coffee grounds to make up to 1.5 L or 12 cups of coffee in the carafe. Although the basket can be only partly filled when it is desired to make fewer cups of coffee, this requires a user to measure out the amount of coffee grounds rather than simply filling the basket to the full level. In espresso makers the filter basket holds the 7 g of coffee powder used to make a single shot (30-40 ml) of espresso. No measuring is required as a user simply fills the basket for every use, but only one serving can be made at a time.

There are several features of conventional espresso makers that can make them less than ideal for use in a domestic setting. The high pressures used to force hot water through the coffee powder in the filter basket require the apparatus to form a very robust seal between the group handle and the group head. A sealing ring or gasket provided on the group head and/or handle is arranged to be compressed as the filter basket is locked onto the group head. Typically this is achieved by locating the filter basket and then rotating the group handle to connect it tightly in a bayonet locking mechanism. A substantial degree of manual dexterity and force is required to lock and unlock the group handle.

The high pressures used by an espresso machine mean that the apparatus needs to have high safety factors built in. It would be desirable for domestic coffee makers to be able to produce espresso-type beverages at lower operating pressures. Furthermore, it is labour intensive to use an espresso machine to make several servings of coffee as each shot must be separately filtered and the basket removed and refilled with coffee grounds between brew cycles. A drip coffee maker, on the other hand, can produce multiple servings from a single brewing operation but it can take some time for the beverage to infuse at atmospheric pressure and filter out of the basket. Some coffee drinkers find the beverage made by a percolator too weak for their taste.

When viewed from a first aspect the present invention provides a kit comprising: an infusion beverage maker comprising a head portion for delivering hot water into a removable infuser connected thereto in use; and a plurality of different infusers, each infuser comprising an infusion chamber providing a different volume for containing a beverage material for infusion; wherein the head portion comprises a peripheral sealing means and each of the different infusers comprises a corresponding peripheral flange arranged to be clamped against the sealing means when the infuser is connected to the head portion in use.

It will be seen that in accordance with the invention the head portion of the infusion beverage maker provides a universal sealing connection that can be used with a number of different infusers which may not contain the same volume of beverage material. Each of the infusers has in common a peripheral flange that is preferably arranged to correspond in size/shape with the sealing means in the head portion.

However, the volume of the infusion chamber that contains beverage material is not limited by the size or geometry of the sealing means. The infusion chamber volume of each infuser may differ in terms of its magnitude and/or shape. The Applicant has recognised that simply changing the depth of an infuser to contain different volumes of a beverage material, for a given cross-sectional area, may not be appropriate for small amounts of beverage material as a minimum depth is in fact desirable for percolation and infusion to take place effectively. By providing a peripheral flange that is common to all of the different infusers, there is freedom to design the dimensions of the infusion chamber for each infuser to optimise infusion of the volume of beverage material contained therein.

According to embodiments of the invention, different infusers can be designed to contain different amounts of a beverage material, such as coffee grounds or tea leaves, and/or designed to present different cross-sectional areas through which the hot water is filtered, while being interchangeable for use with the same head portion of the infusion beverage maker. This greatly enhances the flexibility of the beverage maker for making different beverages. Firstly, different infusers may be provided for the infusion of different volumes of beverage, e.g. a large infusion chamber for making several cups of coffee or tea and a small infusion chamber for making a single cup of coffee or tea. Secondly, different inf users may allow for the infusion of different strength beverages, e.g. an infusion chamber having a large cross-sectional area may be used to make a weak beverage while an infusion chamber having a smaller cross-sectional area but the same volume may be used to make a stronger beverage.

The plurality of different infusers preferably comprises at least two, three, four or more different infusers. The different inf users have the same peripheral flange that is arranged to correspond with the sealing means provided by the head portion and may therefore differ in terms of the cross-sectional area and/or depth of the infusion chamber inwardly of the flange that is provided to contain a beverage material for infusion. The plurality of different inf users may comprise two or more infusers comprising an infusion chamber having a different internal volume for beverage material. Preferably at least one of the plurality of infusers comprises an infusion chamber having an internal volume suitable to contain beverage material for a single cup (e.g. around 30-50 cm3). Preferably at least one of the plurality of inf users comprises an infusion chamber having an internal volume suitable to contain beverage material for several cups (e.g. around 200 cm3) or even 10-12 cups (e.g. up to 500 cm3). Of course different infusers designed to contain different types of beverage, for example coffee grounds or tea leaves, may have different volumes for the same volume of infused beverage that it is desired to make.

The peripheral sealing means may take any geometrical form that prescribes a continuous seal around the periphery of an infuser when connected to the head portion in use. The sealing means is preferably annular and may, for example, be circular, oval or elliptical in shape. It will be appreciated that the sealing means may not be limited to the head portion and at least part of the sealing means may be provided by an infuser when connected thereto. However a benefit of providing the sealing means on the head portion, in addition to the universal fit discussed above, is that the seal is not on the removable part so it is less likely to be damaged than it would be if it were on an infuser that is repeatedly removed, emptied, cleaned, re-filled and replaced. Because the beverage material such as coffee grounds is contained in the infuser then it may also be less likely to interfere with the sealing means when provided on the head portion and to compromise the seal.

In one set of embodiments the peripheral flange of the infuser comprises a sealing surface. The sealing surface may be substantially flat. Or the sealing surface may be shaped so as to accommodate the sealing means of the head portion, for example with an annular groove arranged to receive an 0-ring seal. However a potential problem with such sealing surfaces is that beverage material such as coffee grounds may spill onto the surface when the infusion chamber is filled and prevent a good seal from being formed. It is therefore preferred that in at least one set of embodiments the sealing surface on the peripheral flange comprises a sharp ridge or "knife edge". The effect of the ridge is two-fold: preventing beverage material such as coffee grounds from resting on the sealing surface; and also increasing the sealing force by biting into the sealing means on the head portion.

The peripheral sealing means may simply act to form a substantially watertight connection between the head portion and one of the infusers. This can ensure that hot water delivered by the head portion does not splash out or escape from the infuser and potentially scald a user. Thus in one set of embodiments the head portion may deliver hot water substantially at atmospheric pressure. This may correspond to one mode of operation of the infusion beverage maker, similar to a drip type coffee maker.

However, in a preferred set of embodiments the head portion is arranged to deliver pressurised hot water. Thus the sealing means is preferably arranged to maintain a pressure above atmospheric in the infuser. The Applicant has recognised that it may be desirable, for example when the beverage maker is designed for use in a domestic setting, for the operating pressure to be relatively low as compared with conventional pressurised coffee makers such as espresso machines. This can make the beverage maker safer for home use while still providing a stronger infusion beverage e.g. than is possible with an atmospheric pressure percolator.

Thus in at least one set of embodiments the pressure in the infuser is preferably between 0 and 0.5 bar, further preferably between 0 and 0.3 bar, yet further preferably between 0 and 0.2 bar. In one set of embodiments infusion takes place in the infuser at a pressure of around 0.2 bar for the majority of the infusion cycle.

It will be appreciated that the pressure may vary during an infusion cycle, with substantially zero pressure when hot water first flows through the dry beverage material and an increasing pressure as the material is wetted and becomes compacted.

Each of the plurality of different infusers comprises a peripheral flange that can be clamped against the sealing means during use. The clamping means may be separate from both the head portion and the infuser. However it is preferred that a means for clamping one of the infusers against the sealing means is integrally provided by either the infuser and/or head portion, for ease of use and to minimise the number of separate components. Each infuser may be provided with means that allow it to clamp itself in a final position against the head portion. The infuser may comprise e.g. a bayonet fitting, cam surface, or screw thread that is arranged to clamp the infuser against the sealing means as the infuser is rotated into a final position. Such arrangements are similar to the locking mechanisms used in conventional espresso makers to seal the group handle against the group head.

The Applicant has appreciated that it may not be ideal for the infuser itself to comprise means for clamping against the sealing means of the head portion, as this usually requires manipulation of the infuser to apply the clamping force. Additional manipulation can be difficult in practice as a user is already holding the infuser while trying to initially position it against the head portion without spilling the beverage material e.g. coffee grounds contained therein. Thus in a preferred set of embodiments the head portion comprises means for clamping an infuser in a final position against the sealing means. The clamping means provided by the head portion may be applied independently of the infuser so that the user does not have to manipulate the infuser other than putting it into an initial position. The positioning of the infuser may even be automated rather than completely manual.

The head portion may comprise any suitable means for releasably clamping an infuser in a final position with its flange against the sealing means, such as, for example, mechanical, electromechanical, electromagnetic or other clamping means. In some embodiments the clamping means may act while an infuser is being positioned against the head portion. The head portion may comprise support means for the peripheral flange that support an infuser in an initial position in use.

The support means may be arranged such that the flange of an infuser is forced against the sealing means as the infuser is brought into contact with the support means. For example, the support means may be resiliently mounted against the sealing means such that the flange of an infuser can be pushed or slid between them with a clamping force automatically applied. Although such arrangements may allow positioning and clamping to be achieved at the same time, the simultaneous action of the clamping means may hinder a user in properly positioning one of the infusers.

In preferred sets of embodiments the head portion comprises a clamping means arranged to act independently from and/or subsequent to the infuser being initially positioned against the head portion. This can make it easier for a user to initially position an infuser in the apparatus without being hindered by clamping forces. In one set of such embodiments the head portion comprises support means for the peripheral flange of an infuser that allow the infuser to be initially positioned without coming into contact with the sealing means. For example, the head portion may comprise support means spaced from the sealing means. Thus a user can drop or slide an infuser into an initial position with its peripheral flange resting on the support means without having to push against or create sealing force. This can reduce the effort and dexterity required to attach the infuser to the apparatus.

Where an infuser can be placed in an initial position supported by the head portion without contacting the sealing means, then the clamping means preferably acts to bring the sealing means into contact with the peripheral flange of the infuser.

Preferably the clamping means seals the infuser against the head portion after the infuser has been placed into an initial position.

In one set of embodiments the clamping means may be arranged to move the head portion to bring the sealing means into contact with the infuser. The clamping means may, for example, comprise a linear actuator or rotary mechanism arranged to push the head portion and its sealing means against the peripheral flange of the infuser. However the Applicant has realised that it may not be ideal to arrange for the clamping means to move the head portion against the infuser and rather it is preferable for the clamping means to be arranged to move the infuser to bring its peripheral flange into contact with the sealing means. This is considered novel and inventive in its own right, and thus when viewed from a second aspect the present invention provides an infusion beverage maker comprising a head portion for delivering hot water and a removable infuser positioned in use to receive the hot water delivered by the head portion for infusion of a beverage material contained therein, the head portion comprising a peripheral sealing means and the infuser comprising a corresponding peripheral flange, wherein the head portion comprises means for supporting the infuser in an initial position and means for clamping the infuser in a final position, and wherein the clamping means is arranged, once the infuser is supported in the initial position, to move the infuser so as to bring the peripheral flange into contact with the sealing means in the final position.

According to this aspect of the invention an infuser is moved from an initial position, supported by the head portion, to a different, final position by clamping means provided by the head potion. The infuser is only clamped against the head portion in the final position after it has been placed into an initial position, improving ease of use, and furthermore it is the infuser that is moved rather than the head portion.

Often the removable infuser will be lighter and/or simpler to move than the head portion as it may be a smaller part. The head portion is at least connected to a source for the hot water and may itself comprise a heating means, so that it can be quite difficult to arrange for even part of the head portion to be moved by a clamping means. Such problems can be avoided by arranging for the clamping means to move the infuser into contact with the sealing means. A two-stage connection wherein an infuser is initially supported under a head portion and then clamped against the head portion in a different final position is a deviation from the connection of a group handle to the group head in an espresso machine, where the handle is turned to simultaneously connect the filter with a support means and to clamp the filter against the group head. Furthermore the clamping means is provided by the head portion according to the invention, so that clamping can be carried out independently of the infuser. The clamping means moves the infuser rather than the infuser being moved to provide a clamping force.

It is a preferred feature of both aspects of the invention that the peripheral flange of a or the infuser is clamped against the sealing means only after the infuser has been properly positioned under the head portion i.e. in an initial position to receive hot water. In other words, it is preferable for the infuser to be placed in an initial lateral position aligned so as to receive water from the head portion before it is clamped against the sealing means in a final position. Any suitable means may be provided to ensure proper positioning of the infuser before it is clamped, such as a mechanical interlock that only releases the clamping means once the infuser is in position. In preferred sets of embodiments the head portion comprises means for sensing when the infuser is in position. The sensing means may be a mechanical, electromechanical or electromagnetic sensor. In one set of embodiments the sensing means comprises a microswitch. In another set of embodiments the sensing means comprises a proximity sensor such as a magnetic field sensor.

As is mentioned above, the clamping means may be mechanical, electromechanical, electromagnetic or any combination of these. The Applicant has realised that an electromagnetic clamping means can provide certain advantages as it can be activated electrically without requiring any mechanical manipulation by a user and it may also reduce the number of mechanical or moving parts involved.

Thus in a preferred set of embodiments the clamping means is an electromagnetic clamp such as a solenoid that can act to move the infuser, or at least part of it, by magnetic force so as to bring its peripheral flange into contact with the sealing means.

This is considered novel and inventive in its own right, and thus when viewed from a third aspect the present invention provides an infusion beverage maker comprising a head portion for delivering hot water and a removable infuser connected to the head portion in use to receive hot water for infusion of a beverage material contained therein, the head portion comprising a peripheral sealing means and the infuser comprising a corresponding peripheral flange, wherein the head portion comprises electromagnetic means arranged, when energised by an electrical current, to move the peripheral flange of the infuser so as to be clamped against the sealing means when the infuser is connected to the head portion.

It will be appreciated that using an electromagnetic clamping means to seal the infuser against the head portion can provide several benefits. Using an electromagnetic force to move the infuser into contact with the sealing means eliminates the need for a user to manually apply a sealing force. The beverage maker may therefore be easier to use. The sealing step can be automated and controlled so as only to take place once the infuser has been properly positioned.

This can prevent the seal from being damaged by trying to force the infuser against the head portion in an incorrect position.

Where the head portion is provided with a sensing means, as is preferred, then an electrical signal from the sensing means indicating that the infuser is in an initial position is preferably used to activate the electromagnetic clamping means. This is a particularly advantageous embodiment that enables the infuser to be positioned and then sealed in two independent stages.

Although an electromagnetic clamping means can provide advantages in terms of independent and automatic sealing of the infuser to the head portion, the Applicant has recognised that the magnetic force typically provided by a solenoid having a size suitable for incorporation in a small domestic appliance may not always provide a very tight seal. The sealing force may be reduced if the magnetic force is working against the weight of the infuser. The sealing force may also be reduced if the magnetic force is working against the pressure of water flowing through the infuser.

It is therefore preferred in some sets of embodiments that the electromagnetic clamping means comprises a solenoid arranged to move the peripheral flange of the infuser through a mechanical linkage. Preferably the mechanical linkage is arranged to augment the force applied by the solenoid on the infuser. The mechanical linkage may, for example, comprise an over-centre or elbow latch mechanism that is flipped from an unlocked state to a locked state when the solenoid is energised. Such mechanisms can be arranged to apply a relatively high clamping force along a main axis while a lower force applied by the solenoid along a direction oblique to the main axis can lock/unlock the mechanism. Thus in a preferred set of embodiments the electromagnetic means is arranged to operate a clamping mechanism that can be moved between locked and unlocked positions, wherein in the locked position the clamping mechanism provides a clamping force along a main axis and wherein the clamping mechanism can be moved to the unlocked position by the electromagnetic means applying a force lower than the clamping force in a direction oblique to the main axis.

A mechanical linkage or mechanism can improve the sealing connection between the infuser and the head portion, which may be particularly important if the infuser is pressurised during use, as is described above. Furthermore an increase in the clamping force available from the electromagnetic means can be beneficial regardless of whether it is the infuser or the head portion that is being moved by the electromagnetic means. This is considered novel and inventive in its own right, and thus when viewed from a fourth aspect the present invention provides an infusion beverage maker comprising a head portion for delivering hot water, a removable infuser connected to the head portion in use to receive hot water for infusion of a beverage material contained therein, sealing means arranged between the head portion and the infuser, and electromagnetic clamping means arranged, when energised by an electrical current, to bring the infuser and/or head portion into contact with the sealing means so to clamp them together, wherein the electromagnetic clamping means comprises a clamping mechanism that can be moved between locked and unlocked positions, wherein in the locked position the clamping mechanism provides a clamping force along a main axis and wherein the clamping mechanism can be moved to the unlocked position by the electromagnetic clamping means applying a force lower than the clamping force in a direction oblique to the main axis.

Once a or the infuser has been initially positioned and then clamped/sealed against the head portion in a final position, the beverage maker is preferably controlled so as to supply hot water to the head portion and thus initiate an infusion cycle for the beverage material contained in the infuser. The sensing means may initiate the infusion cycle, for example sending a control signal to a heater/pump after a predetermined delay time permitting the infuser to have been clamped before the infusion cycle begins. The sensing means may act to bring the beverage maker out of a zero power or standby mode. Alternatively user intervention may be required to initiate an infusion cycle. This would allow a user to prime an infuser ready for use but then wait until a later time to make the beverage. The beverage maker may allow a user to input information relating to e.g. the type of beverage, the size of the infuser, the strength of beverage desired, etc. so that the apparatus can adjust the amount of hot water supplied and/or the pressure used.

The Applicant has realised that an electromagnetic clamping means may advantageously be used to provide an additional effect. By controlling the electrical current applied to the coil in the electromagnetic, its magnetic force and thus the clamping force on the infuser can be varied. The Applicant has realised that this can be used to depressurise or vent the infuser connected to the head portion.

Thus in one set of embodiments the electromagnetic clamping means is preferably released so as to vent the infuser to atmosphere. This can be used, if desired or necessary, to release pressure from the infuser during an infusion cycle. The clamping means may therefore be released and re-energised at times throughout operation of the beverage maker. Of course, when the clamping means is released the seal may be broken so as to allow air to enter the infuser but the infuser may not be moved out of complete contact with the head portion so as to minimise the risk of hot water or steam from spitting out.

Additionally or alternatively to releasing pressure during an infusion cycle, the electromagnetic clamping means is preferably arranged to automatically release the infuser after the beverage material therein has undergone infusion. A benefit of venting the infuser at the end of an infusion cycle is that pressure is released and any hot water remaining in the head portion may flow out, allowing the water supply pipes to empty. This can prevent water from spitting or dribbling out when a user is removing the infuser, as often happens in a conventional espresso machine where the seal is only released when a user disconnects the group head. This can also prevent water and beverage from being sucked back through the heater/pump, for example if the water level in the water reservoir is lower than the outlet to the head portion, which could cause contamination within the apparatus. Another benefit of venting the infuser as soon as infusion is complete is that it can prevent a vacuum from being formed as the infuser cools down. By restoring atmospheric pressure it is ensured that the infused beverage can flow out of the infuser freely.

The infuser may take any suitable form as long as it is suitable for containing a volume of beverage material for infusion and comprises an outlet for the infused beverage. In preferred sets of embodiments the infuser comprises an infusion chamber wherein the beverage material is contained and infusion takes place. The infusion chamber may be integral to the infuser or it may be removable, allowing it to be filled and then replaced for use. The open cross-sectional area of the infusion chamber may be defined by the peripheral flange, with a larger flange extending inwardly to define a smaller cross-sectional opening for the chamber. The volume of the infusion chamber may be varied in terms of its magnitude and/or its shape and relative dimensions. For example, the infusion chamber may be generally cylindrical or conical in shape.

In one set of embodiments the infusion chamber comprises a mesh arranged above the outlet of the infuser. The mesh prevents grounds of coffee or other beverage material passing from the chamber into the outlet of the infuser and therefore potentially into the beverage. The mesh could comprise any suitable material, e.g. metal or plastic, and preferably is arranged to comprise openings which are sized to allow liquid through but trap coffee grounds. The mesh could extend solely across the outlet, but preferably the mesh extends at least part or all the way across the infusion chamber at a level above the outlet. This allows the outlet of the infuser and/or the mesh to comprise further advantageous features which will be discussed below.

In one set of embodiments the Applicant has found that it is advantageous to provide a baffle or wall at a level above the outlet to prevent fine coffee grounds passing straight into the outlet through the mesh. Preferably the baffle or wall comprises an area greater than or equal to the cross sectional area of the outlet.

The baffle or wall could be provided instead of a mesh, but in a preferred set of embodiments it is in addition to the mesh. The baffle or wall may be provided as a separate part, e.g. at a level above or below the mesh, but preferably the baffle or wall is mechanically coupled to the mesh, e.g. the mesh extends around the baffle or wall, preferably with the mesh not extending across the outlet.

In another set of (not necessarily mutually exclusive) embodiments in, the outlet comprises means to permit automatic outflow of beverage upon the liquid reaching a predetermined level. By providing a predetermined minimum level, any fine grounds of coffee which happen to pass through the mesh (where provided) are given chance to settle in the liquid that is below the predetermined level, and therefore are less likely to pass into the outlet. This can be provided in addition to or instead of the baffle or wall, and/or the mesh to further help to prevent coffee grounds passing through the outlet of the infuser.

Conveniently the means to permit automatic outflow of beverage upon the liquid reaching a predetermined level comprises a weir, such that beverage escapes over the weir and out of the outlet when the liquid level in the infusion chamber exceeds a predetermined height (determined by the height of the weir). This therefore provides a region below the weir in which coffee grounds or other beverage material can settle and collect so that they do not pass through the outlet.

The base of the infusion chamber could also be shaped such that it tapers towards the outlet, i.e. reduces in cross sectional area. This encourages any fine material particles which may have passed through the mesh to aggregate around the base of the outlet below the predetermined level where they are unlikely to become entrained in the liquid and are therefore prevented from passing out through the outlet.

It is a preferred feature of all aspects of the invention that the beverage maker comprises a liquid heater to supply hot water to the head portion. The heater may supply hot water that is at atmospheric pressure or hot water that is pressurised.

The liquid heater could comprise any type of heater, e.g. an immersed or underfloor heater with an associated heating chamber. However in a preferred set of embodiments the liquid heater comprises a flow heater, which can provide a pumped flow of hot water after only a short heat-up time. An example of a -14-particularly suitable flow heater is described in the Applicant's published PCT application WO 2010/1 06349, which is hereby incorporated by reference.

A flow heater typically has a much lower thermal mass than a traditional coffee maker with its large thermoblock heater, and is suitable for producing both heated water and steam. The low thermal mass of a flow heater aids having a very low or zero standby power, as well as a very short start-up time, i.e. the time taken for the components to be heated up by the steam passing through the apparatus before liquid dispensing can commence.

In one set of embodiments the flow heater comprises a final heating region having a space above the liquid surface for allowing the escape of steam from the liquid surface. Preferably the final heating region is arranged to permit the exit of steam therefrom separately from heated water. In a preferred set of embodiments the heater further comprises a heated flow conduit upstream of the above-mentioned heating region and which is arranged in use to be filled with water, as is disclosed in Providing a final heating region which allows steam to escape separately from the heated water enables both heated water and steam to be produced from a single heating component. This is particularly advantageous when the heater further comprises a heated flow conduit upstream of the heating region as it overcomes the difficulties of producing steam using a conventional flow heater, e.g. spitting and overheating from localised boiling. Thus, in accordance with preferred embodiments of the present invention this arrangement can be operated to either produce steam or heated liquid, e.g. by controlling the flow rate of liquid through the heater.

In a preferred set of embodiments then infusion beverage maker comprises a liquid heater and conveying means for conveying heated liquid from the liquid heater onto the beverage material contained in the infuser, wherein the beverage maker is configured to operate in at least a first phase in which steam is passed through at least a portion of the conveying means and a second phase in which heated liquid is passed from the liquid heater through the beverage material. This sequence of operation, for example in a coffee machine, allows the components of the apparatus through which the heated liquid will flow -i.e. the conveying means but typically also the infuser and outlet components downstream thereof -to be heated by the steam that is first passed through the apparatus. This brings them up to an operating temperature such that hot liquid, when dispensed from the apparatus, will not be excessively cooled when passing through these components.

This arrangement therefore allows an apparatus which is able to operate with very low or zero stand-by power, but which also provides the ability to pre-heat the key components, i.e. the ones through which the heated liquid flows, immediately prior to use to mitigate the tendency for the beverage to be produced at a lower temperature than desired. This results in a large energy saving compared to traditional apparatus because a large thermoblock heater as well as the large thermal mass of the other components does not need to be kept hot, or heated up for a long period of time, in between or prior to each heating and dispensing cycle.

The conveying means may comprise any suitable flow pipe or tube for conveying heated liquid and steam to the head portion of the beverage maker. In a set of embodiments a steam path and a heated liquid path are provided by a double tube arrangement, e.g. with one tube adjacent or inside the other, extending from the heater. Where the flow heater has a final heating region as described above, the mouth of the steam path tube may be disposed at a level in the final heating region above the expected maximum level of liquid and the mouth of the liquid tube may be below this level. This arrangement thus maintains the important distinct paths for heated liquid and steam/vapour which is the key to minimising spitting.

In a set of embodiments the steam outlet and the heated water outlet are both directed to the head portion. This is particularly convenient in the set of embodiments in which a double tube arrangement for the steam and heated liquid are provided. Arranging for both the steam and the heated liquid to exit into the head portion together is one way in which the apparatus can be pressurised, e.g. compared to an arrangement in which the steam outlet is directed to a different part of the apparatus. This arrangement is therefore suitable to be used in combination with a centrifugal pump. In one set of embodiments the head portion comprises a shower head, i.e. arranged to distribute the heated liquid over the beverage material in an infuser connected thereto.

Preferably a pump is provided for driving liquid through the liquid heater and conveying means. A pump allows the flow of liquid or steam through the apparatus to be controlled in order to be able to selectively produce steam or heated liquid for passing through the apparatus downstream of the heating means. Any suitable pump could be used, but in a set of preferred embodiments the pump comprises a centrifugal pump. These are smaller and quieter than the reciprocating pumps used in some known coffee makers.

In one set of embodiments the centrifugal pump is arranged to deliver a pressure of less than 0.5 bar, e.g. 0.2 bar. This is a particularly low pressure for espresso coffee machines, but one for which embodiments of the present invention are particularly suited, and therefore does not require the beverage maker to be designed to withstand high pressures, e.g. up to 15 bar as in some pressurised coffee machines, which can be expensive.

When viewed from a further broad aspect the present invention provides an electrical infusion beverage maker comprising a liquid heater and a pump arranged to supply a head portion with pressurised hot water and/or steam, an infuser containing a beverage material being sealingly connected, in use, to the head portion for infusion of a beverage at a pressure of 0.1 to 0.5 bar above atmospheric pressure.

Some preferred embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 is a perspective view showing the main components of an infusion beverage maker embodying the invention; Fig. 2 is a first vertical section showing the interior of the boiling pooi seen in Fig. 1; Fig. 3 is a second vertical section showing the interior of the boiling pool seen in Fig.1; Fig. 4 is a closer perspective view of the head portion of the infusion beverage maker; Fig. 5a is a perspective view of a large infusion basket according to one S embodiment of the invention; Fig. Sb is a perspective view of a small infusion basket according to another embodiment of the invention; Fig. 6 is a cross-sectional view through the head portion with the infusion basket of Fig. 5a connected thereto; Fig. 7 is a cross-sectional view through the head portion with the infusion basket of Fig. Sb connected thereto; and Fig. 8a and Fig. 8b are schematic cross-sectional views of a clamping mechanism according to an alternative embodiment, shown in unlocked and locked positions.

Fig. 1 shows some of the main internal components of an embodiment of the invention which can be used to make infusion beverages such as coffee. Some parts of the apparatus, such as an outer housing and water tank, are omitted for clarity. From Fig. 1 there may be seen a vertical water heater 2 comprising a water distribution plenum block 4 at its lower end. Water enters the distribution plenum block 4 from a side inlet 6 connected to a water tank and centrifugal pump (not shown). The plenum block 4 distributes the water between two parallel flow heater sections 8,10.

At the downstream (upper) end of the flow heater portions 8,10 is a boiling pool 12.

This is formed by a deep-drawn stainless steel cup fitted below an approximately circular stainless steel element head 14. A control system 7 is mounted on the element head 14. The boiling pool 12 has an outlet pipe 16 projecting laterally to supply heated water to the head portion 18 of the apparatus.

Each of the parallel flow heater sections 8, 10 comprises an outer jacket and a length of a sheathed immersion-type heating element in an arrangement as set out in WO 2010/106349. The two flow heater sleeves are wider in diameter than the corresponding heating element and so define therebetween a corresponding annular channel for each of the flow heater sections 8, 10. Therefore there is a fluid path from the distribution plenum block inlet 6, via the distribution plenum block 4 to the interior annular channels of the two flow heaters 8, 10.

The outlet pipe 16 comprises a water outlet 15 which exits the boiling pool 12 horizontally, and has a steam tube 17 off-centre within it. The steam tube 17 forms an outlet for steam and vapour from the boiling pool 12 separate from the outlet path for heated liquid. The outlet pipe 16, and therefore also the water outlet 15 and steam tube 17, are fluidically connected to the head portion 18 of the apparatus.

The interior of the boiling pool 12 is best seen from the view of Figs. 2 and 3. From here it can be seen that the boiling pool 12 formed by the stainless steel cup is broadly of a squat cylindrical shape although its internal volume is limited by the bent portion of the heating element 9 that extends between the two flow heater sections 8, 10. The water outlet tube 15 exits from an upper part of the boiling pool 12, and has its lower portion covered by a weir 11. The steam outlet tube 17 has its mouth at the top of and within the water outlet tube 15. A thermistor 13 projects through the base of the boiling pool 12 and has its tip at the level of the bottom of the weir 11. A water level sensor 19 also projects through the base of the boiling pool 12 and has its tip at a level just below the bottom of the weir 11.

The weir 11 has a wider cross section in its upper portion and a narrower cross section (a slit) in its lower portion. This restricts the flow of water into the water outlet tube 15 thus ensuring that the heating element 9 remains adequately covered in water, so preventing overheating in the second phase of operation, i.e. dispensing heated water. A second function of the shape of the weir 11 is that, by having a smaller cross section in its lower portion, at the level of the bottom of the heating element 9, the boiling pool 12 drains quickly if the water flow from the flow heaters 8, 10 is suddenly reduced or stopped -owing, for example, to a blockage in the flow heaters 8, 10. This causes the highest part of the heating element 9 to overheat which can quickly be sensed via the hot return, though the minimum level of the top of the outlet tube 16 is still high enough for some water to remain in the bottom of the boiling pool 12 to provide a reliable temperature measurement from the thermistor 13.

In the first phase of operation the water level is below the level of the weir 11 SO that water is not dispensed from the boiling pool 12, but is still enough to adequately cover the heating element 9 with water, therefore also preventing overheating in the first phase of operation, i.e. producing steam. The cross sectional area of the mouths of the steam tube 17 and the water outlet tube 15 are chosen such that the boiling pool 12 becomes slightly pressurised (e.g. to about 0.2 bar) during operation.

The head portion 18 is seen in Fig. 1 and also in closer detail in Fig. 4. The water supply pipe 16 from the heater 2 is connected to a delivery chamber 20 arranged above a sealing flange 22. These parts of the head portion 18 remain stationary during use. Located below the sealing flange 22 is a U-shaped support 24 that can receive an infusion basket. The U-shaped support 24 can be moved vertically upward relative to the sealing flange 22 by a linkage frame 26 that extends from one side arm of the support 24 and up and over to the other side arm of the support 24. Arranged on top of the delivery chamber 20 and below the linkage frame 26 is a solenoid 28 that moves the frame 26 when energised with an electrical current.

The solenoid 28 is electrically connected to a microswitch sensor 30 positioned on the apex of the U-shaped support 24. The microswitch 30 is arranged to sense when an infusion basket is slid all the way along the arms of the support 24 and positioned beneath the sealing flange 22. Until the microswitch 30 is activated, the support 24 is spaced from the sealing flange 22 so that there is room for the peripheral flange of an infusion basket to be slid along the arms of the support 24 freely. A peripheral seal 23 (seen in Figs. 6 and 7) on the underside of the sealing flange 22 is not contacted until the solenoid 28 and linkage frame 26 act to pull the U-shaped support 24 closer to the sealing flange 22.

Two different infusion baskets are shown in Fig. 5. in Fig. 5a the infusion basket 40 is a large size designed to make several cups of beverage in a single infusion cycle.

-20 -In Fig. Sb the infusion basket 40' is a small size designed to make a single cup of beverage. Both of the infusion baskets 40, 40' have in common a peripheral flange 42, 42', an infusion chamber 44, 44', and a handle 46, 46'. The infusion chambers 44, 44' are provided with an outlet 48, 48' through which infused beverage can drain into a cup or carafe. On the upper sealing surface of the peripheral flanges 42, 42' there is provided a knife edge ridge 50, 50'.

As the infusion basket 40 shown in Fig. 5a is a large size, its peripheral flange 42 is narrow and the infusion chamber 44 defines a large cross-sectional area for containing beverage material and for receiving hot water from the head portion 18.

The infusion chamber 44 is also relatively deep so as to maximise its volume. On the other hand, the infusion basket 40' shown in Fig. Sb is a small size with a wide peripheral flange 42'. The infusion chamber 44' defines a much smaller cross-sectional area for containing beverage material and for receiving hot water, as well as being shallower. The wider peripheral flange 42' circumscribes the infusion chamber 44' so that the outer periphery of the infusion basket 40' is the same as that in Fig. 3a. It should be noted that despite the different dimensions of the two infusion chambers 44, 44', the outlets 48, 48' are in the same lateral position, i.e. radial distance, relative to the common outer periphery of the flanges 42, 42'. This means that the outlet 48, 48' is always in the same lateral position relative to the water delivery chamber 20 in the head portion 18, so that the flow patterns are comparable even for different infusion baskets 40, 40'.

In both Figs. 5a and Sb the outer periphery of the peripheral flange 42, 42' is identical in shape and size, with the same sealing surface carrying the knife edge ridge 50, 50'. It is this part of the peripheral flange 42, 42' that corresponds with the peripheral seal 23 on the underside of the sealing flange 22 provided by the head portion 18. Accordingly the two infusion baskets 40, 40' can be connected interchangeably to the same head portion 18 with a common sealing interface, as is seen from Figs. 6 and 7.

Turning first to Fig. 6, there is shown the infusion basket 40 of Fig. 5a after it has been connected to the head portion 18 of the beverage maker. In order to make a beverage, a user first fills the chamber 44 of the infusion basket 40 with beverage material such as coffee grounds (not shown). For a large chamber 44 designed to -21 -make up to 12 cups of beverage, coarse grinds may be used so that water can percolate through in a reasonable period of time. The infusion basket 40 is then positioned under the head portion 18 by resting its peripheral flange 42 on the ends of the arms of the U-shaped support 24 and sliding the basket 40 along the arms so that the peripheral flange 42 is positioned below the sealing flange 22 of the head portion. The infusion basket 40 can be positioned with ease as there is a vertical gap between the U-shaped support 24 and the sealing flange 22 that allows the peripheral flange 42 to pass without contacting the seal 23 on the underside of the flange 22.

When the infusion basket 40 has been pushed right under the head portion 18 its peripheral flange 42 contacts the microswitch 30 and this activates the solenoid 28.

In this embodiment the solenoid 28 comprises a metal rod 50 that passes through the centre of a coil 52 and is pulled vertically down when the coil 52 is energised with a current. The rod 50 is fixed to a central point on a horizontal crossbar 54 in the linkage frame 26. The ends of the crossbar 54 are pivotally connected to verticai side arms 56 of the frame 26, as is seen from Fig. 1 or Fig. 4. When the crossbar 54 is pulled down by the rod 50 being pulled into the coil 52, the pivoting connection cause the side arms 56 to pull up and thus to move the U-shaped support 24 up so that the peripheral flange 42 of the infusion basket 40 comes into contact with the sealing flange 22. The knife edge ridge 50 on the surface of the peripheral flange 42 compresses the seal 23 on the underside of the flange 22. As long as the solenoid is energised there is a clamping force holding the two flanges 22, 42 against each other with a sealed interface around the periphery of the infusion basket 40.

Exactly the same procedure as described above is carried out to position and clamp the smaller size infusion basket 40' as shown in Fig. 7. Comparing Figs. 6 and 7, it can be seen that the only difference is in the volume of the two infusion chambers 44, 44'. The same sealing interface is formed between the peripheral flange 42' of the smaller infusion basket 40' and the sealing flange 22 of the head portion 18 as is formed for the larger infusion basket 40.

From the cross-section shown in Figs. 6 and 7 it can also be seen that the water delivery chamber 20 in the head portion 18 opens into a distribution cavity 60 -22 -defined at its upper end by the hood of the sealing flange 22. At the interface between the delivery chamber 20 and the distribution cavity 60 there is provided a perforated cover 62 that acts to distribute the hot water in a similar way to a shower head. This helps to ensure that hot water is sprayed over most, if not all, of the open area of the infusion chamber 44, 44'. However, it can be seen from Fig. 7 that where the infusion chamber 44' is smaller, its wider peripheral flange 42' acts to close off part of the distribution cavity 60 so the water from the delivery chamber 20 is sprayed over a smaller area. In either case the peripheral seal 23, which may be a silicone 0-ring, prevents any hot water or steam from escaping. The sealed connection can also allow the infusion chamber 44, 44' to be at an elevated pressure e.g. 0.1 or 0.2 bar.

From the cross-section shown in Figs. 6 and 7 it can also be seen that the infusion baskets 40, 40' each comprise a mesh 45, 45' which extends across the bottom of the basket 40, 40' at the level of the bottom of the side walls, i.e. above the outlet 48, 48'. The mesh 45, 45' is arranged to hold the coffee grounds above it during the brewing process and to prevent any grounds passing through it and into the outlet 48, 48'. To further prevent fine grounds of coffee passing straight into the outlet 48, 48', a disc-shaped impermeable portion 47, 47' with a surface area slightly greater than the cross sectional area of the basket outlet 48, 48' is provided in the mesh 45, 45' directly above the outlet 48, 48'. The disc-shaped portion 47, 47' could simply be a part of the mesh with no holes in it, or a solid portion, e.g. made from plastic, placed over the top of the mesh 45, 45'.

If some coffee grounds do happen to pass through the mesh 45, 45', the infusion basket 40, 40' is provided with an outlet 48, 48' which protrudes into the chamber 44, 44' from the base of the basket 40, 40'. This protrusion acts as a weir so that the brewed liquid has to rise above a minimum level (the height of the weir) to be dispensed from the basket 40, 40'. The effect of this is to trap a small volume of liquid in the bottom of the basket 40, 40' in which any coffee grounds that have passed through the mesh 45, 45' will accumulate and settle, therefore preventing them from flowing into the outlet 48, 48'. The mesh 45, 45', the disc-shaped portion 47, 47' and the weir therefore act together to prevent any coffee grounds from ending up in a user's cup.

-23 -Operation of the beverage maker will now be described. A user starts by selecting an infusion basket 40, 40', e.g. depending on the quantity and/or strength of beverage required. Beverage material such as coffee grounds are placed in the infusion chamber 44, 44' and tamped down if desired. The infusion basket 40, 40' is positioned under the head portion 18 by resting the peripheral flange 42, 42' on the U-shaped support 24 and sliding the basket 40, 40' under the sealing flange 22 until it reaches the apex of the support 24. Regardless of the size of basket 40, 40', at this stage the peripheral flange 42, 42' will be aligned below the seal 23 on the sealing flange 22 and only when properly aligned will the peripheral flange 42, 42' contact the microswitch 30 and indicate the presence of the basket 40, 40'. The microswitch 30 may operate to automatically energise the solenoid 28 and thus operate the linkage frame 26 to pull the infusion basket 40, 40' up to clamp it against the sealing flange 22. The apparatus is then ready to start an infusion cycle. This step may not be automated, however, and instead user intervention may be required to initiate the clamping step at a time when it is intended to use the beverage maker.

If necessary, the user will fill the water tank (not shown), e.g. from a tap. When the user wishes to initiate the infusion cycle he/she presses a switch or other input on the appliance. The appliance may already have moved out of a zero power or standby mode upon receiving a signal from the sensor 30 that an infusion basket 40, 40' has been connected to the head portion 18. At this point the user may be able to input information concerning the amount or type of beverage, or one of several infusion programs may be selected. Initially the controlling circuit (not shown) activates the heating element 9. After a delay of one or two seconds (depending on the temperature of the water already in the heater) the pump is operated to pump water from the water tank into the distribution plenum block 6. In other embodiments the pump may be started before the heater 2.

Once water has been pumped into the distribution block 6, it is pumped through this and along the annular channels of each of the two flow heaters 8, 10 between the heating element 9 and the corresponding stainless steel outer jacket. This heats the water rapidly as it passes through from ambient temperature (of the order of 20 C) in the distribution block 6 to approximately 85 2C at the downstream ends of the flow heaters 8, 10.

-24 -In the first phase of operation (steam production) the water then passes out of the flow heaters 8, 10 and into the interior of the boiling pool 12 where it begins to partially fill this pool. The water level is monitored using a sensor 19. This information is fed back to the controlling circuit which in turn controls the speed of the pump in order to keep the level of the water below the bottom of the weir 11, i.e. to prevent any water being dispensed. Steam is generated and escapes the boiling pool 12 by means of the steam tube outlet 17 at the top. A steam pressure is allowed to develop as a result which is sufficient to force steam through the apparatus downstream of the boiling pool 12, i.e. through the steam tube 17 in the outlet pipe 16 and into the head portion 18. This steam acts to warm the outlet pipe 16 as well as the components in the head portion 18 prior to dispensing heated water from the boiling pool 12, as well as ejecting any liquid which has been retained in the appliance from the previous cycle of operation.

After a predetermined period of time, i.e. calculated to be sufficient for the steam produced to have heated all of the necessary components downstream of the boiling pool 12, the controlling circuit changes the phase of operation of the appliance to dispensing heated water, i.e. the second phase. In an alternative embodiment a temperature sensor could be used to decide when the downstream components are hot enough to switch to the second phase. The input to the controlling circuit is now the thermistor 13 in the boiling pool 12, which is used to control the speed of the pump in order to raise the level of the water above the bottom of the weir 11 so that heated water can be dispensed through the water outlet 15, but at a flow rate to ensure that the water is heated to a temperature of between 93 and 95 °C, i.e. suitable for brewing coffee. However, the appliance in accordance with the present invention is also suitable for heating water to brew tea or other beverages, and in this situation, the water may be heated to a different, e.g. higher, temperature which is suitable for brewing tea or other beverages. The pumped flow rate and the power of the heating element 9 are therefore matched, via feedback from the thermistor 13 through the controlling circuit, such that by the time the water leaves the boiling pool 12 over the weir 11 and through the outlet the tube 15 it is at the required temperature.

-25 -In this second phase of operation, when water begins to fill the boiling pool 12 after passing out of the flow heaters 8, 10, the curved portion of the heating element 9 is covered during normal operating conditions. The temperature of the water in the boiling pool 12 is monitored by the thermistor 13 which projects into the boiling pool 12 near the outlet 16. The curved part of the heating element 9 continues to heat the water in the boiling pool 12. Any steam produced from micro-boiling during heating of the water in the boiling pool 12 can easily escape by means of the steam tube 17 which opens at the top of it. The steam passes through the steam tube 17 and into the head portion 18, i.e. the same outlet 16 as the heated water which acts to pressu rise the boiling pool 12. As the steam tube 17 runs through the water outlet tube 15 it advantageously helps to keep the heated water warm as it passes from the boiling pool 12 into the head portion 18. The boiling pool 12 and the separation of the steam through the steam tube 17 from the water outlet 15 gives the advantage that water can be dispensed without spitting.

When hot water enters the delivery chamber 20 in the head portion 18, it is forced under pressure through the perforated cover 62 so as to shower down from the distribution cavity 60 into the infusion chamber 44, 44' connected below. Water percolates down through the coffee grounds and the infused beverage flows out through the mesh 45, 45' and into the bottom outlet 48, 48' to be collected in a receptacle such as a cup or carafe. After the beverage material in the infusion chamber 44, 44' is initially wetted the flow resistance will increase and the pressure contained in the infusion basket 40, 40' may increase to around 0.2 bar above atmospheric pressure.

The infusion cycle is programmed or manually controlled to last for a certain period, after which time the heater and pump are switched off and no more hot water is delivered to the head portion 18. After a predetermined delay time, or when operated by a user, the solenoid 28 is de-energised so as to release the linkage frame 26 and the infusion basket 40, 40' is then unclamped and released from its connection with the sealing flange 22. The infusion basket 40, 40' rest on the U-shaped support 24 until ready to be removed by a user. As the seal is released, the infusion chamber 44, 44' is de-pressurised and any remaining hot water in the head portion 18 and/or infusion basket 40, 40' can drain out freely through the outlet 48, 48'. This can prevent liquid from being siphoned back into the appliance and -26 -prevent the user from being scalded by trapped hot water when removing the infusion basket 40, 40.

The infusion basket 40, 40' may also be vented at times during the infusion cycle, for example by controlling the current supplied to the solenoid 28 so as to temporarily or intermittently release the clamping force and allow air to enter the infusion chamber 44, 44' past the seal 23. This may be used to control the pressure in the infusion basket 40, 40'.

In a third phase of operation after the end of the infusion cycle the appliance reverts to producing steam, i.e. as in the first stage of operation. This stage of steam operation also helps to flush out any liquid which has been retained in the apparatus and not dispensed into the user's cup, i.e. in the outlet tube 16 and the head portion 18, thereby preventing this liquid which will subsequently cool from being dispensed in the next cycle of operation.

The appliance may be operated with only the first two stages of operation, i.e. producing steam to warm the dispensing components and then dispensing heated water. In this case, the first stage of producing steam for heating in the next infusion cycle will also cause any liquid retained downstream of the boiling pool 12 to be ejected from the appliance prior to dispensing the beverage. The first phase may be made longer to account for this.

Fig. 8 depicts one example of an alternative clamping mechanism for an infusion basket 40'. Instead of a solenoid and linkage frame being provided on the head portion 18 over the delivery chamber 20, there is provided an electromagnetically operated clamping mechanism 70 that acts on the infusion basket 40' from below.

The mechanism 70 is only shown schematically in Fig. 8 and could still be provided by the head portion 18. This clamping mechanism 70 comprises a solenoid 28' that operates a push rod 50' acting on an over-centre linkage 72. The over-centre linkage 72 is shown in its unlocked position in Fig. 8a. A return spring 74 keeps the linkage 72 open in this position. As the solenoid 28' is not energised, the infusion basket 40' is supported below the sealing flange 22 of the head portion 18 but not sealed against it.

-27 -When the solenoid 28' is energised, it pushes the rod 50' against the force of the spring 74 to close the linkage 72, as is shown in Fig. 8b. The over-centre mechanism applies a clamping force along its main vertical axis that is greater than the force applied by the solenoid 28' to overcome the spring 74. The infusion basket 40' is pushed up so as to bring its peripheral flange 42' into contact with the seal 23 underneath the sealing flange 22 on the head portion 18. In this locked position the mechanism 70 acts to clamp the infusion basket 40' against the head portion 18.

When the infusion cycle is complete, the solenoid 28' is released and the linkage 72 returns to its open position under the force of the spring 74. The infusion basket 40' drops down from its sealed position and the pressure is released.

Although in Fig. 8 the clamping mechanism 70 is shown to be acting on the handle part of the infusion basket 40', this is merely for ease of illustration and the mechanism 70 could act on any suitable part of the basket 40'. The clamping mechanism 70 may be arranged in a position such that it can operate on any infusion basket regardless of its size. Alternatively the clamping mechanism 70 could move or adapt to different infusion baskets.

It will be appreciated that the beverage maker described above may be used with a variety of different infusion baskets. Suitable infusion baskets are not limited to the shape or form shown in the illustrated embodiments but may vary considerably while still providing the same outer peripheral flange corresponding to the sealing flange on the head portion. The beverage maker may also vary in the form of its sealing flange and this will affect the corresponding flange provided on infusion baskets designed to be connected thereto.