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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2008/087677
Kind Code:
A coffee machine, including a dispensing assembly (9) associated with a feed circuit (1, 12, 15, 4, 2, 3) used for feeding preheated infusion water, wherein the dispensing assembly (9) is heated by means of a thermoregulation system ("temperature-controlled infusion") (13, 14).

Application Number:
Publication Date:
July 24, 2008
Filing Date:
December 19, 2007
Export Citation:
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International Classes:
A47J31/46; A47J31/36; A47J31/56
Foreign References:
Attorney, Agent or Firm:
FIAMMENGHI Carlo et al. (Via Quattro Fontane 31, ROMA, IT)
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1. A coffee machine comprising a dispensing assembly (9) associated with a feed circuit (1, 2, 3, 4, 12, 15 of Fig. 2) used to feed preheated infusion water, characterised in that said dispensing assembly (9) is heated by means of one or more electric resistances (13) to a temperature generally exceeding that of the water heated inside said feed circuit (1, 2, 3, 4, 12, 15 of Fig. 2) in order to allow the infusion water to reach the final temperature necessary to produce the coffee infusion.

2. A machine according to claim 1, wherein said electric resistance(s) (13) are controlled by means of an electronic circuit board or a thermostat, to maintain said dispensing assembly (9) at a predefined temperature, relying on one or more temperature probes (14).

3. A machine according to claim 2, wherein the predefined temperature is adjustable, provided an electronic circuit board or a thermostat are used as control unit, based on different environmental parameters and/or according to the coffee blend type, and/or according to the roasting process, and/or the type of coffee preferred in different consumer areas, and/or according to the type of beverage to be prepared.

4. A machine according to anyone of the preceding claims, wherein, in order to warm up the infusion water, heating means are used which are applied to a steam generator (2) and whose temperature is also adjusted by means of an electronic circuit board or a thermostat, or by a pressure switch, to a value generally less than that of the dispensing device (9).

5. A machine according to claim 4, wherein said feed circuit (1, 2, 3, 4, 12, 15 of Fig. 2) for feeding hot water to be used for the infusion includes the steam generator (2) and a heat exchanger (4) as heating means for heating the infusion water.

6. A machine according to anyone of the preceding claims, wherein said feed circuit (1, 2, 3, 4, 12, 15 of Fig. 2) for feeding hot water used for the infusion, is configured so as to feed the infusion water to a plurality of dispensing assemblies or infusion assemblies (9), wherein, each of these dispensing assemblies or infusion assemblies (9) is subjected to a thermoregulation independently of the other dispensing assemblies or infusion assemblies (9), by using an electronic circuit board or a thermostat.

7. A machine according to anyone of the preceding claims, wherein means (7) are provided to allow the downflow of the residual water still contained inside the dispensing assembly at the end of the infusion operation.



A coffee machine with improved thermoregulation system of the delivery assembly

Technical Field

The present invention, generally relating to a coffee machine for making an espresso coffee or the like, and also herbal infusions, comprises a delivery (that is, a dispensing) assembly associated with a water flow circuit, together with a means for heating the water contained inside said water flow circuit.

The present invention is a machine having improved features with respect to machines employed nowadays in snack-bars, restaurants, small communities, in a self-service, in a domestic environment, or in any other kind of field or place, on terrestrial means, naval means, or aeroplanes, to make coffee of any type (from ground coffee, coffee wafers, or from any other coffee shape), or in order to prepare tea or any other infusion beverage, or a drink in the form of a blend of the latter with any other beverage. Therefore, hi the present context the word "coffee" should be construed widely, although its main significance will be the actual espresso coffee. This invention more specifically refers to an improvement of the thermoregulation method as currently applied by the delivery assembly of traditional machines of this kind.

Background Art Traditional coffee machines utilise a heating means or heat exchanger, usually consisting of a steam generator, which heats to a predefined temperature the water - contained in a water flow circuit - used to prepare coffee. This temperature is adjusted by a temperature regulator according to the quality of the coffee, the

roasting process, the kind of coffee which is preferred in various consumer areas, or according to the kind of drink to be served (cappuccino, weak coffee, etc.). All this is already well known to the skilled person so that details are not required.

The coffee machine "setup" implies an accurate regulation of the predefined, settable temperature value of the water to be conveyed to the delivery assembly. In this manner the warm water flow that circulates in the ducts will be able to adequately heat the delivery assembly and at the same time this warm water can be fed to the latter at a predetermined temperature to make the coffee.

This process is carried out in traditional machines through the regulation of the warm water temperature in the steam generator in order to allow the warm water flow - circulating in the ducts - to adequately heat the delivery assembly

(dispensing assembly) and also to be fed to the latter at the predefined temperature, to allow the preparation of a coffee.

Actually, in conventional machines the delivery assembly is not directly subjected to a thermoregulation; instead, the latter is obtained by heating a carrier fluid

(water), and therefore it is obvious that an accurate thermoregulation of the delivery or dispensing assembly is difficult to carry out because of the various parameters that may play a role.

Consequently, although the temperature may be modified in order to better satisfy particular needs, a longer period of machine inactivity is required and the intervention of skilled manpower for the replacement of specific components of the water circuit.

Actually, the fact that an increasing number of different coffee blends are commercialised, with different features according to the coffee-beans used for making the blend and according to the different roasting processes, often it is necessary to regulate at different temperatures the delivery or dispensing assembly.

Moreover, the quality of the coffee served in a cup is not always at the desired

temperature as a consequence of the workload and different tastes of the clients where the coffee machine is installed.

An example of a traditional machine operating according to a water circulation circuit of the type called "radiator", is described in the French patent with publication number FR 2 797 169 (Nuova Faema Spa). According to this patent, the temperature of the dispensing device (or delivery device) used for dispensing coffee can be modified by means of an indirect regulation, that is, by displacing a movable member of a flow valve mounted on the actual water flow circuit. Therefore, from the preceding discussion it can be seen that there is a need of providing a coffee machine suited to accurately adjust to a predefined value - that can be set at will - the temperature of the various dispensing assemblies (delivery assemblies).

Therefore, summing up, the object of the present invention is to solve the problem of the difficult setup of traditional machines (in order to obtain an optimum quality of the served coffee), and the problem of being able to operate at different temperatures on different delivery assemblies of the same machine. Since in the water circuit there will be a lower amount of steam, it will be possible to obtain a coffee of better quality and more pleasing appearance. Moreover, since the machine does not include a so-called "radiator circuit" like traditional machines, it is evident that there will be less accumulation of calcium (limestone) deposits, the machine life will be longer, better coffees will be served for a longer period, and maintenance work will be reduced.

Disclosure of Invention The present invention attains its objects with a coffee machine comprising a dispensing assembly associated with a feed circuit used to feed heated infusion water, characterised in that said dispensing assembly is heated by means of one or more electric resistances to a temperature generally exceeding that of the hot water

contained in said feed circuit, in order to allow this water to reach the final temperature necessary to produce the coffee infusion.

Since the electric resistances directly heat the dispensing assembly (delivery assembly), the control of the temperature of the latter (and consequently also of the infusion water) becomes more accurate and at the same time more easy to set.

Moreover, since water is heated only inside the feed circuit, it is obvious that less limestone will deposit itself on the ducts used to feed this water to the dispensing assembly.

On the other hand, since in the preferred embodiment according to the present invention no return duct is provided, which return duct is present however in conventional circuits of the radiator type, no continuous circulation of water

(convective motion) is present, and therefore, for this reason too, as time passes there will be less deposits of limestone inside the feed duct used for feeding the warm infusion water. Thus, less maintenance is needed. The dependent claims define some important and more specific features of the invention.

Brief Description of Drawings

The features and advantages of the present invention will result in particular from the following description of an illustrative, non-binding embodiment thereof, which is shown in the drawings, wherein:

FIGURE 1 is a very schematic view of a conventional coffee machine operating according to the "radiator" system of the background art;

FIGURE 2 is a view schematically showing the structure of a possible embodiment of a machine according to the present invention;

FIGURE 3 is an exemplary view of a central electronic unit, with its display, used for the temperature regulation of the dispensing (delivery) unit.

Description of a preferred embodiment Figure 1 schematically shows a coffee machine according to the conventional technology. This machine includes a motor pump (1) that pumps water into the manifold or heat exchanger (4), through a feed duct (12) and an injection means (13). Between the manifold or exchanger (4) and the dispensing assembly (delivery assembly) (9), which in the present case - for simplicity of illustration - is represented by a single delivery assembly (9), there is provided a water flow circuit (5, 3) forming in this case a traditional "radiator" circuit. The dispensing assembly (9) is heated, maintained at a certain temperature, and fed, with the water used to prepare the coffee infusion - which water is contained in the water circuit (5, 3) - using said water circuit (5, 3) (thermal convection circuit) formed by an outgoing duct (5) and a return duct (3).

Specifically, a two-position valve (6), in one of these positions (corresponding to a lifted position) allows the circulation of water by convection, in the direction indicated by the arrows, only inside the ducts (5, 3) and through the manifold or exchanger (4), after the heating of the water contained inside this manifold (4) has been accomplished by a heating means (2) which in the present case is a steam generator (2).

Thus, in this case the steam generator (2) transfers the heat of the water contained therein, - which for instance is heated by electric resistances or a gas hot plate -, to the manifold or heat exchanger (4), so as to warm up the water contained inside the latter.

The convection motion started in this manner, caused by the temperature and pressure of the water, allows water to circulate (as shown) through the outgoing and return ducts 5 and 3.

At the time of preparation of a coffee infusion, the two-position valve (6) is opened, thereby allowing the water contained inside the circuit (5, 3) to reach the infusion chamber (10) formed in this case by a removable filter used to contain the ground coffee within a filter support provided with an arm (11) and a dispensing spout (8).

The reference number 7 indicates a hole for permitting the exit of water under pressure, which water, after termination of the pouring operation, is allowed to flow out of the delivery/ dispensing assembly.

For completeness, it should be noted that the heating means (2) could be of another type, for instance formed by electrical resistances directly applied on the wall of the manifold or heat exchanger (4) or located outside the steam generator


Instead, Figure 2 shows a particular, non-limitative embodiment of the present invention. The elements or components already present in Fig. 1, which therefore have already been described, will not be described again.

It should be noted that:

- The outgoing duct (5) of Fig. 1 has been omitted;

- The return duct (3) of Fig. 1 has become the outgoing duct (3) in Fig. 2 (note the inversion of the arrow direction denoting the water flow direction);

- Numeral 5 denotes a plug allowing to close the respective conventional duct and therefore - for instance - to directly and more easily adapt the present innovation to already existing apparatuses; the plug 5 is not, therefore, particularly important;

- Also in this figure, that is in Fig. 2, the steam generator (2) could be replaced by any other heating means.

A description will be given now of the core of the invention.

Also in this case the delivery assembly, or dispensing assembly, (9), must be heated in some way, its temperature must be maintained, and it must be fed with

water for preparing the coffee infusion. However, in the present invention, the two functions (i) feeding of the infusion water to the delivery assembly (9), and (ii) thermoregulation of the dispensing device, are so to say "separated", that is totally 'disengaged' from one another, so as to allow - as will be described later - a perfect "setup" of the machine, according to the definition given to it in the introductory part of this patent application. The motor pump (1) pumps water into the manifold or exchanger (4) through the feed duct (12 ) and the injection means (15). One or more resistances (not shown) immersed in the water contained inside the steam generator (2), or applied on it externally, or underlying gas hot plates (not shown), serve to heat the water so that this water contained in the generator (2) will heat the manifold (4) and the water contained in the latter. The pressure thereby obtained inside the manifold (4) "pushes" the water upwards along the duct (3). The dispensing assembly (9) is maintained at the selected temperature by using one or more electric resistances (13) supplied with current by an electronic (printed circuit) board (or by a thermostat) cooperating with a sensor or probe (14) apt to continuously detect the temperature of the dispensing assembly (9) and to continuously correct and compensate said temperature. Depending on the machine model, this system allows the assembly or assemblies to select the temperature best suited to the blend used by the client or used in the country where the machine is installed; moreover, this system is capable of assigning the same temperature to each dispensing assembly of the coffee machine, or to assign a different temperature to each of said dispensing assemblies, always with the aim of obtaining the coffee desired by a client. By way of example, in a machine with three assemblies, it would be possible to calibrate/set the temperature of one assembly at about 110°C in order to obtain an espresso coffee having a dark brown colour, of the type desired in South Italy,

while calibrating another assembly at 90°C in order to obtain a North European coffee, and setting the last temperature at 70° to obtain a light coffee of the kind "filter coffee".

Moreover, since no continuous motion of hot water is used in order to maintain the temperature of the delivery assembly (9) at a certain value, and since in this case the water temperature is less than that of traditional convective "radiator" circuits, a considerable reduction of calcareous deposits occurs within the ducts, thus eliminating a disadvantage of traditional machines. This implies a less frequent and easier maintenance. The function of the valve (6), which is operated manually or by means of an electric control (solenoid valve), is substantially identical to the background art; it opens when an infusion is to be prepared, while it closes (that is, it is lifted) when the infusion operation is stopped, to allow the residual water to flow out of the infusion chamber of the filter support (10) of the dispensing assembly (9). By means of the present invention, which directly feeds water to the dispensing assembly only when it is necessary to "pour the coffee", and which moreover relies on one or more electric resistances fed (supplied) and controlled by an electronic circuit board or a thermostat, it is possible for the first time to completely separate from each other the function of 'infusion water supply' to the dispensing assembly and the function of its temperature control.