MACHINE

DESCRIPTION

The present invention relates to a heating system for heating the brewing unit of a coffee machine.

It is known that to obtain an optimal quality beverage, also during the first use, the coffee brewing must preferably take place at a certain temperature, which is determined by a series of variables such as the type of blend used, the degree of roasting and the degree of grinding.

To guarantee the correct temperature or at least to guarantee the constancy thereof, different systems have been available on the market for some time. One of the most commonly used is thermosyphon circulation, in which a flow of water is generated in the coffee machine connecting the boiler where the hot brewing water is produced with the brewing unit.

Therefore, during operation, the heat losses in the brewing unit due to convection, conduction and radiation are balanced by the continuous supply of energy through the mentioned water flow. This system is shown to be efficient and effective, even if it cannot usually be easily modified by the user as it derives from an energy balance involving many factors.

Solutions are also known which disconnect the direct dependence between the boiler and the brewing unit, through the use of heating elements, armoured or cartridge resistances which, as well as enabling the heating of the brewing unit, also control the temperature thereof.

Such known systems and solutions are notoriously ineffective as, in all the known solutions, the thermodynamic chain meets a weak point in the filter holder of the brewing unit.

In fact, the filter holder is usually coupled to its housing through a helix portion which enables a vertical translation by performing the classic rotation of the filter holder.

Other coupling solutions are known in which the helix portion is replaced by slides through which the filter holder is translated into position and the hydraulic seal is obtained through relevant mechanical movements.

The contact of the filter holder with its housing consists of a surface portion comprising “wings” of the filter holder, minimum two, which mechanically rest on the lower part of a same surface of the housing.

The upper part of the filter holder is instead in contact with a gasket made of plastic material, to which the function of guaranteeing the hydraulic seal during the brewing process is appointed.

Therefore, to guarantee that the coffee, once the brew is obtained, does not lose the necessary temperature, the time factor is generally relied upon.

In professional coffee machines, such aspect is not critical. The waiting time for reaching the operating temperature of switching on the machine can vary according to the type of circuit and the capacity of the boilers used, however in the order of several minutes. The professional coffee machine then stays on almost continuously and the operating temperature is easily maintained.

In the domestic world, in which on the other hand the machine preparation time is fundamental, storage boilers are replaced by quick exchangers and the use of plastic materials is preferred, which enable the fluid to be transferred without excessive heat exchanges.

For the same reason, plastic inserts are introduced into the filter holder which, particularly in the dispensing of the first coffee after switching the machine on, enable a contained temperature loss thereof.

Such solution is however a compromise between the speed of obtaining the first coffee and the deterioration in quality that derives from the temperature loss. In fact, only waiting for a certain amount of time enables an acceptable heat regime to be obtained in the brewing unit.

Another known process which promotes the reaching of the optimal temperature enables the preliminary dispensing of hot water only. However, this still implies that the operator needs to perform additional operations which are certainly not complicated but are not aimed the readiness of use of the coffee machine.

The traditional use of noble materials such as brass and steel for filters and filter holders, with the related mass and thermal inertia, therefore implies long waiting times for reaching an optimal temperature for brewing the coffee.

It is known that in instant boilers, especially used in the domestic environment, coffee can now be prepared in just a few seconds after switching on the machine. This speed is incongruous with the time necessary for the traditional heating of the brewing unit which instead requires some minutes, hence undermining the benefit of instant boilers.

Therefore, the need is perceived to propose to users, typically of coffee machines for domestic use, an efficient system for heating the brewing unit with very reduced waiting times with respect to what is applied in the prior art.

The technical task of the present invention is, therefore, to provide a heating system for heating the brewing unit of a coffee machine which obviates the technical drawbacks described above of the prior art.

Within the context of this technical task an object of the invention is to provide a heating system for heating the brewing unit of a coffee machine which enables efficient heating with very reduced waiting times.

Another object of the invention is to provide a heating system for heating the brewing unit of a coffee machine which is simple to use and does not involve the user in complex operations.

Not least, an object of the invention is to provide a heating system for heating the brewing unit of a coffee machine that brings it to the correct temperature in a few seconds, preserving the temperature of the coffee as it passes through, especially during the first use of the coffee machine.

The technical task, as well as these and other objects according to the present invention, are attained by providing a coffee machine having a brewing unit comprising a plurality of components at least including a filter holder, a filter for the coffee powder, a housing where said filter holder can be engaged, and a brewing head, said filter holder in turn comprising a grip, a cup housing said filter and having an upper mouth engageable with said brewing head, and a plurality of wings that extend out of said cup and can be engaged in connection seats present in said housing, characterised in that it comprises a magnetic induction heating means for heating at least one of said components of said brewing unit.

Advantageously, at least one of said components is made of material susceptible to heating by magnetic induction. In particular, at least one of said components is made of magnetic metal or magnetic metal alloy or another electrically conducting material.

Advantageously said heating means comprises at least one solenoid.

Other characteristics of the present invention are further defined in the following claims.

Further characteristics and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a coffee machine according to the invention, illustrated by way of indicative and nonlimiting example in the accompanying drawings, in which: figure 1 is a perspective view, from below, with respect to the conditions of use, of a traditional filter holder; figure 2 shows a typical vertical section of a traditional brewing unit according to the prior art; figures 3A, 3B, 3C show a typical vertical section of a brewing unit according to the present invention, according to different preferred embodiments; figures 4A, 4B show perspective views of a brewing unit according to the present invention, according to a further preferred embodiment.

For simplicity and clarity reasons, the figures do not show the coffee machine, of the known type, which includes a supply pump and a boiler through which water at the necessary temperature and pressure is sent to a brewing unit.

With reference to the mentioned figures, a brewing unit 30 is shown comprising a plurality of components including a filter holder 10, a filter 20 for the coffee powder, a housing 31 where the filter holder 10 can be engaged, and a brewing head 32, in particular cylinder shaped. Typically, the housing 31 of the filter holder 10 and the brewing head 32 are supported by the frame of the coffee machine.

The filter holder 10 comprises a grip 11, a cup 12 housing the filter 20 and having an upper mouth 14, particularly with a circular shape, which is engaged coaxially with the brewing head 32, and a plurality of wings 13 that extend out of the cup 12. The wings 13 can be engaged in connection seats 33 present in the housing 31.

In the traditional known embodiment represented in figure 2, the area affected by the heat exchange between the filter holder 10 and the brewing unit 30 is limited to the connection seats 33 present in the housing 31 and to the upper circumferential area of the mouth 14 where a gasket 34 made of plastic material is positioned to guarantee the hydraulic seal of the filter 20 during the brewing of the beverage.

The possible advantageous heat exchange between the housing 31, the connection seats 33, which are typically hot, and the filter holder 10 loaded with coffee powder, which is typically cold, is limited to reduced and also thermally insulating surfaces. It follows that to statically reach a suitable temperature of the filter holder 10 it is necessary to wait at least several minutes.

The solution to the technical problem and object of the present invention is represented by an innovative filter holder heating system, obtained by applying the principles of electromagnetic induction.

Advantageously, according to the present invention, the brewing unit 30 comprises a magnetic induction heating means for heating at least one component of such brewing unit.

Such induction heating means comprises at least one solenoid 100 appropriately positioned on the brewing unit 30. The solenoid 100 is supplied by an electric circuit on board the coffee machine. When crossed by an alternating current with fixed or variable frequency, the solenoid 100 generates an electromagnetic flow which is connected with at least one component of the brewing unit 30 made of a material susceptible to heating through electromagnetic induction.

Appropriately, such material may be a magnetic metal or an alloy of a magnetic metal or an electrically conductive material.

The filter holder 10, and/or the housing 31 of the filter holder 10, and/or the connection seats 33, and/or the brewing head 32 and/or the filter 20 may therefore be made of material susceptible to heating through electromagnetic induction. Typically, a solenoid 100 has a toroidal shape and a vertical axis of symmetry Y oriented like the vertical axis Y’ of the brewing head 32.

The solenoid 100 may have circular coils and an arrangement coaxial to the vertical axis of symmetry Y’ of the cylindrical brewing piston 32, as shown in figures 3A - 3C.

Alternatively, the solenoid 100 has oblong shaped coils and an axis of symmetry Y parallel to the vertical axis of symmetry Y’ of the cylindrical brewing head 32, as shown in figures 4A, 4B.

Figures 3A, 3B and 3C illustrate some preferred but not exclusive embodiments of the configuration and arrangement of the solenoid 100.

In a preferred embodiment, shown in figure 3 A, the solenoid 100 is configured and arranged below the housing 31 and the connection seats 33 on which the wings 13 are engaged. The flow lines XX of the magnetic field generated by the electrically activated solenoid 100, graphically indicated in the figure, are connected with the connection seats 33, with the wings 13 and with the perimeter wall in proximity to the cup 12, heating them.

In a preferred embodiment, represented in figure 3B, the solenoid 100 is configured and supported by the brewing head 32 above the cup 12 and the filter 20. The flow lines XX of the magnetic field generated by the electrically activated solenoid 100, graphically indicated in the figure, are connected with the perimeter wall of the brewing head 32 and with the upper circumferential wall of the filter holder 10 and with the perimeter wall of the filter 10, heating them.

In a preferred embodiment, represented in figure 3C, the solenoid 100 is configured and arranged laterally to the brewing head 32. The flow lines XX of the magnetic field generated by the electrically activated solenoid 100, graphically indicated in the figure, are connected with the perimeter wall of the brewing head 32, with the upper circumferential wall of the filter 20, with the wings 13 and with the perimeter wall near the cup 12, heating them.

In a preferred embodiment, shown in figures 4A and 4B, the solenoid 100 is supported below the housing 31, and is configured and arranged to partially surround the cup 12 of the filter holder 10.

In this case, the solenoid 100 has arcuate oblong coils following the profile of the outer wall of the cup 12.

The flow lines XX of the magnetic field generated by the electrically activated solenoid 100, graphically indicated in the figure, are prevalently connected with the cup 12, heating it.

Advantageously, the innovative characteristics of the heating system for heating a filter holder according to the present invention can also be applied to a device for grinding coffee beans, so that the filter holder associated with the grinding device can be removed from the grinding device and transferred already heated for engagement with the housing of the brewing unit.

The grinding device has a grinding unit and a housing where the filter holder can be engaged.

The coffee bean grinding device therefore comprises a magnetic induction heating means for heating the filter holder according to the present invention and as described above, where the characteristics of the grinding unit are to be considered analogous to those of the brewing unit.

In practice, it has been observed how the heating system for heating the brewing unit of a coffee machine according to the invention is particularly advantageous for obtaining efficient heating with very reduced waiting times, especially during the first use of the coffee machine, without involving the user in complex operations.

A heating system for heating the brewing unit of a coffee machine as conceived herein is susceptible to many modifications and variants, all falling within the scope of the inventive concept as defined by the claims; furthermore, all the details are replaceable by technically equivalent elements.

In practice, the materials used, as well as the dimensions, can be any according to the needs and the state of the art.