Patent Description:
Different cleaning systems are known in which the parts and ducts which have come into contact with the milk are periodically cleaned. In some known systems, makeshift trays are used which are filled with water and optionally detergent and into which the flexible hose that has been extracted from the milk reservoir is immersed. In other systems, parts that have come into contact with the milk are removed, and these parts are washed or disposed of.

The document <CIT> discloses a cleaning system for a beverage machine.

The object of this invention is to provide a cleaning system in which it is possible to minimize the manual operations required when cleaning the machine.

This and other objects are achieved, according to the invention, by a machine for preparing beverages, wherein said machine includes.

By using a machine according to the invention, it is possible to minimize the manual operations required to clean the milk ducts. In particular, on account of the fact that the tray has a separate collection chamber and washing chamber, the washing cycle may be carried out in a simple manner, since it is possible to manage the washing of the ducts and the discharge of the washing residues using just one means.

Further features and advantages of the invention will become clear from the detailed description that follows, given purely by way of non-limiting example and with reference to the accompanying drawings, in which:.

<FIG> shows, as a whole, a machine for preparing beverages, in particular coffee, cappuccino and the like. In general, this invention covers both domestic machines and machines used in business or public environments, as well as vending machines.

This machine comprises a water supply <NUM> configured to supply liquid water or steam within the machine. In the example shown, inside the machine, the water supply comprises a water supply system <NUM> of the kind known per se. The water supply system <NUM> typically comprises a reservoir <NUM>, an electric pump <NUM> which draws the water from the reservoir <NUM>, and a heating device <NUM> supplied with the water provided by the pump <NUM>. The heating device <NUM> is a so-called instantaneous heating device, otherwise known as a flow heater or transit heater, and is used to generate the steam or hot water flow necessary for the system to operate. In general, other means for generating steam that are of a type known to a person skilled in the art may be provided. According to an embodiment which is not shown, the machine may not have a proper water supply system. In this case, the water supply may comprise a fitting or connector for directly connecting to the mains water.

A brewing line <NUM>, a frothing line <NUM> and a washing water supply line or piping <NUM> branch off downstream of the heating device <NUM>. The brewing line <NUM> comprises a brewing valve <NUM> having an inlet 21a connected to the heating device <NUM> and an outlet 21b connected to a brewing unit <NUM> of a kind known per se, in such a way that a flow of steam is supplied to this unit <NUM> for the preparation of a brewed beverage, for example a coffee-based beverage. The brewing valve <NUM> may be switched between a first position in which the brewing unit <NUM> is in fluid communication with the heating device <NUM>, and a second position in which the brewing unit <NUM> is isolated from the heating device <NUM>. The brewing valve <NUM> may also comprise an outlet 21c which is connected to a water discharge receptacle and which, in the second position, is connected to the outlet 21b to allow water to be discharged from the brewing unit <NUM>.

The frothing line <NUM> comprises a frothing head <NUM> of a kind known per se. The frothing head <NUM> comprises a steam-driven jet pump <NUM> and a distribution duct <NUM> for distributing a beverage, which distribution duct is arranged downstream of the jet pump <NUM>. The frothing head <NUM> comprises a steam inlet 31a through which the steam produced by the heating device <NUM> may be injected into the jet pump <NUM> in order to generate a steam jet. A frothing chamber <NUM> of the kind known per se, into which the steam/milk/air mixture is conveyed in order to create an emulsion, and a subsequent dispensing duct may be arranged downstream of the jet pump <NUM> and upstream of the distribution duct <NUM>.

The frothing line <NUM> also comprises a steam valve <NUM> comprising an outlet 35a connected to the steam inlet 31a of the frothing head <NUM>, and an inlet 35b connected to the outlet of the heating device <NUM>. The steam valve <NUM> may be switched between a first position in which the frothing head <NUM> is in fluid communication with the heating device <NUM>, and a second position in which the frothing head <NUM> is isolated from the heating device <NUM>. The brewing valve <NUM> may also comprise an outlet 35c which is connected to a water discharge receptacle <NUM> and which, in the second position, is connected to the outlet 35a to allow water to be discharged from the frothing line <NUM>.

Moreover, the frothing head <NUM> comprises a milk inlet 31b and an air inlet 31c through which the respective fluids may be drawn by the steam jet within the jet pump <NUM> in order to be mixed with the steam jet. The milk inlet 31b is connected to a milk reservoir T, in the manner described in the following. This milk reservoir T is a bottle or container which is used when preparing the beverage, and then returned to a refrigerated environment to be stored. For the purposes of this invention, the term "milk" comprises milk and derivatives of animal and plant origin (soya, rice, oat, almond, hazelnut, nuts, etc.) and preparations based on milk together with other ingredients (cocoalchocolate, fruit).

The frothing line <NUM> may also comprise further valves and fluidic components arranged between the steam valve <NUM> and the frothing head <NUM>. These further valves and fluidic components do not form the subject of this invention and will therefore not be described further. It should be noted here that the frothing line <NUM> comprises an air supply <NUM> which may be put in fluid communication with the air inlet 31c of the frothing head <NUM> in order to suck air into the jet pump <NUM>.

The milk inlet 31b of the frothing head <NUM> is connected to the milk reservoir T via a milk supply line or piping <NUM>. The milk supply piping <NUM> has an inlet end 50a which may be connected to the milk reservoir T and an outlet end 50b which is connected to the milk inlet 31b of the frothing head <NUM>. At the inlet end 50a, the milk supply piping <NUM> typically comprises a flexible hose <NUM> which has a fixed end 51a, in particular an end fixed to the body of the machine for preparing beverages, and a movable part configured to be immersed into the milk reservoir T.

The machine for preparing beverages also comprises a cleaning system which may be actuated to clean the milk supply piping <NUM> and the frothing head <NUM>.

This cleaning system includes the washing water supply line or piping <NUM>. The washing water supply piping <NUM> has an inlet end 40a connected to the water supply system <NUM>, more specifically to the outlet of the heating device <NUM>, and an outlet end 40b.

The cleaning system also comprises a detergent supply <NUM> connected to the washing water supply piping <NUM>. In the example shown, a pump <NUM>, for example a peristaltic pump, is associated with the detergent supply <NUM>, which pump is configured to draw the detergent from the detergent supply <NUM> and introduce it into the washing water supply piping <NUM>. This configuration is not essential to the purposes of the invention, and other means for dosing the detergent, for example a dosing valve system, may be provided instead of the pump. According to further embodiments, the detergent may be provided without using a pump or valve means, for example by falling or gravity. According to other embodiments, the detergent may be provided in a solid form (tablets) by means of a specific dispenser.

In the example shown, the washing water supply piping <NUM> comprises a cleaning branch <NUM> and a rinse branch <NUM> arranged in parallel. The cleaning branch <NUM> is connected to the detergent supply <NUM>. A shut-off valve is associated with each of these branches, which valves are denoted by <NUM> and <NUM>, respectively, in order to selectively fluidically connect or disconnect the relevant branch to/from the water supply system <NUM>. This dual-line configuration has the advantage of providing additional guarantees in terms of reducing the risk of milk contamination as a result of the washing processes described in the following. Nevertheless, it is possible to design a configuration in which the washing water supply piping <NUM> comprises a single branch configured as the cleaning branch <NUM> or, in the event that the machine does not have a detergent supply, as the rinse branch <NUM>.

The cleaning system also comprises a washing chamber <NUM> which may be supplied with washing water provided by the washing water supply piping <NUM>. As will be described in the following, the movable part of the flexible hose <NUM> that has been extracted from the milk reservoir T may be placed in the washing chamber <NUM>.

With reference again to <FIG>, the washing chamber <NUM> is formed in a tray <NUM>" which may be coupled in a releasable manner to the body of the machine M, under the frothing head <NUM>. A collection chamber <NUM>" is also formed in this tray <NUM>", which collection chamber is separate from the washing chamber <NUM> and configured to be arranged under the distribution duct <NUM> of the frothing head <NUM>.

The cleaning system also comprises washing valve means arranged at the outlet end 40b of the washing water supply piping <NUM>. These washing valve means are also arranged between the flexible hose <NUM> and the frothing head <NUM>, and may be switched between a first position in which the flexible hose <NUM> is isolated from the milk inlet 31b of the frothing head <NUM>, and a second position in which the flexible hose <NUM> is in fluid communication with the milk inlet <NUM> of the frothing head <NUM>. In the first position of the washing valve means, the washing water supply piping may also be fluidically connected to the washing chamber <NUM> by means of the washing valve means, for washing the movable part of the flexible hose <NUM> placed in the washing chamber <NUM>. Through the flexible hose <NUM>, the washing water contained in the washing chamber <NUM> may be conveyed to the milk inlet 31b and thus, by means of the jet pump <NUM>, to the distribution duct <NUM> of the frothing head <NUM>.

In the example shown, the aforementioned valve means comprise a first washing valve <NUM> which connects the outlet end 40b of the washing water supply piping <NUM> and the flexible hose <NUM> to the milk inlet 31b of the frothing head <NUM>, and a second washing valve <NUM> which connects the outlet end 40b of the washing water piping <NUM> to the washing chamber <NUM>. The first washing valve <NUM> may be switched between a first position in which the flexible hose <NUM> is isolated from the milk inlet 31b of the frothing head <NUM> and the outlet end 40b of the washing water piping <NUM> is in fluid communication with the milk inlet 31b of the frothing head <NUM>, and a second position in which the flexible hose <NUM> is in fluid communication with the milk inlet 31b of the frothing head <NUM> and the outlet end 40b of the washing water piping <NUM> is isolated from the milk inlet 31b of the frothing head <NUM>. The second washing valve <NUM> may be switched between a first position in which the washing chamber <NUM> is in fluid communication with the outlet end 40b of the washing water piping <NUM>, and a second position in which the washing chamber <NUM> is isolated from the outlet end 40b of the washing water piping <NUM>. In <FIG> and <FIG>, reference sign 49a indicates an outlet of the second washing valve <NUM>, which outlet is positioned on the front of the machine M in a position such that, when the tray <NUM>" is fixed to the machine M, the outlet 49a is above the washing chamber <NUM>.

In the example shown, the fixed end 51a of the flexible hose <NUM> is connected to the first washing valve <NUM>. When the machine for preparing beverages is in the working condition, the movable part of the flexible hose <NUM> is immersed into the milk reservoir T while the first washing valve <NUM> is in its second position, and therefore allows the frothing head <NUM> to suck the milk from the reservoir T, through the flexible hose <NUM> and the milk supply piping <NUM>, as a result of the action of the jet pump <NUM>.

The device described above also comprises an electronic control unit operatively connected to the various devices of the machine for preparing beverages. The electronic control unit is configured to control and coordinate the aforesaid components in a predetermined manner according to instruction signals provided to the control unit.

A semi-automatic cleaning process will now be described which allows all of the ducts and components that have come into contact with the milk to be cleaned.

Firstly, a user fixes the tray <NUM>" to the machine M and positions the movable part of the flexible hose <NUM> in the washing chamber <NUM>.

By acting on a user interface of the machine M, the user starts the cleaning process. The electronic control unit of the machine then actuates the distribution of water comprising detergent to the washing chamber <NUM>; the water is delivered by the pump <NUM> of the water supply system <NUM> and mixes with the detergent in the washing water supply piping <NUM>. The washing water is then introduced into the washing chamber <NUM> through the second washing valve <NUM>, which is in a position that puts the outlet 49a in fluid communication with the washing water supply piping <NUM>. The fluid communication with the flexible hose <NUM> and with the frothing head <NUM> is blocked.

The electronic control unit then switches the valve means <NUM>, <NUM> so as to establish the fluid communication between the flexible hose <NUM> and the frothing head <NUM>, and block the fluid communication between the washing water supply piping <NUM> and the washing chamber <NUM>. The electronic control unit also activates the frothing line so that steam is delivered to the frothing head <NUM> through the steam inlet 31a thereof. The jet pump <NUM> of the frothing head <NUM> then sucks up the washing water comprising detergent present in the washing chamber <NUM>, through the flexible hose <NUM> and the rest of the milk supply piping <NUM>. The steam with the washing water and the detergent are then discharged into the collection chamber <NUM>" of the tray <NUM>", through the distribution duct <NUM>. The washing cycle described above may be carried out more than once in order to increase the effectiveness thereof.

In a possible duct rinsing phase, the process is analogous to that described above, except for the fact that the washing water supply piping <NUM> is now configured to supply water without detergent. In the event that the washing water supply piping <NUM> has a cleaning branch <NUM> and a rinse branch <NUM>, as shown in <FIG>, this involves enabling the rinse branch <NUM> and disabling the cleaning branch <NUM> via the respective valves <NUM> and <NUM>. If the washing water supply piping has just one branch, the electronic control unit may simply block the detergent supply to the washing water supply piping <NUM>. The rinsing cycle described above may be carried out more than once in order to increase the effectiveness thereof.

An alternative cleaning process may be provided which allows all of the ducts that have come into contact with the milk to be cleaned, with the exception of the flexible hose <NUM>.

By acting on the user interface of the machine M, the user starts the cleaning process. The electronic control unit of the machine then actuates the distribution of water comprising detergent to the valve means <NUM>, <NUM>; the water is delivered by the pump <NUM> of the water supply system <NUM> and mixes with the detergent in the washing water supply piping <NUM>. The valve means <NUM>, <NUM> are in a position that puts the washing water supply piping <NUM> in fluid communication with the external part of the milk supply piping <NUM> and the frothing head <NUM>. The fluid communication with the flexible hose <NUM> and with the washing chamber <NUM> is blocked.

The washing water comprising detergent then reaches the frothing head <NUM> through the milk supply piping <NUM>. The washing water and the detergent are then discharged into the collection chamber <NUM>" through the distribution duct <NUM>.

A possible duct rinsing phase is analogous to the washing phase described above, except for the fact that the washing water supply piping <NUM> is now configured to supply water without detergent.

In terms of monitoring the rinse phase, a detergent presence sensor may be provided to detect the residual presence of detergent in the rinse water. This sensor may be a turbidity sensor, for example a conductive sensor, and may be associated with the tray <NUM>" or positioned at the end 40b of the washing water supply piping <NUM> or in the milk supply piping <NUM>. On the basis of a signal provided by the detergent presence sensor, the control unit of the machine may be configured to control the number of rinse cycles required to completely remove the detergent from the ducts through which the milk is intended to pass. According to a further embodiment, a detergent presence sensor may be integrated on the pump <NUM> for the detergent.

In order to fix the tray <NUM>" to the body of the machine M, a mechanical affixing system, for example a clip-on system, may be provided, which system is denoted by <NUM>" in <FIG>. A presence sensor <NUM>" may also be provided, which presence sensor is configured to detect the presence or absence of the tray <NUM>" and provide a corresponding signal. In the example shown, the presence sensor <NUM>" is designed as a magnetic sensor, in particular a reed sensor, which is configured to detect a magnet <NUM>" mounted on the tray <NUM>". A level sensor <NUM>", for example an optical or capacitive sensor, may also be provided, which level sensor is configured to detect the level of liquid within the washing chamber <NUM> and provide a corresponding signal.

<FIG> shows a machine for preparing beverages, comprising a second embodiment of the cleaning system. Elements corresponding to those of the preceding embodiment have been assigned the same reference signs; these elements will not be described again.

The embodiment in <FIG> differs from the preceding embodiment in that valve means are not provided at the outlet end 40b of the washing water supply line or piping <NUM>. Moreover, there is no direct communication between the washing water supply line <NUM> and the milk supply line <NUM>, but only indirect communication through the washing chamber <NUM> when the flexible hose <NUM> is placed inside the washing chamber <NUM>. In the embodiment in <FIG>, the removable tray <NUM>" described above may be used; it is understood that what is shown and described in relation to <FIG> also applies to the embodiment in <FIG>. In this case, the outlet 49a is directly connected to the outlet end 40b of the washing water supply system <NUM>.

In the embodiment in <FIG>, only the cleaning cycle described above may be carried out, in which the flexible hose <NUM> inserted in the washing chamber <NUM> is used.

<FIG> shows a machine for preparing beverages, comprising a third embodiment of the cleaning system. Elements corresponding to those of the preceding embodiment have been assigned the same reference signs; these elements will not be described again.

The embodiment in <FIG> is analogous to that in <FIG>, but differs therefrom in that a specific washing water supply line is not provided, and instead a water supply line <NUM>' is provided, in particular for the distribution of hot water which is normally provided for preparing infusions such as tea and herbal tea. For the purposes of this invention, the water supply line <NUM>' therefore performs the function of distributing the washing water, and will therefore be described as such for ease. The washing water supply line <NUM>' has an inlet end 40a' connected to the water supply system <NUM>, more specifically to the outlet of the heating device <NUM>, and an outlet end 40b'. The washing water supply line <NUM>' does not have an integrated detergent supply. Therefore, if provided, the detergent is introduced directly into the collection chamber <NUM>, which also acts as a mixing chamber. The detergent may be provided using means that are entirely separate from the machine M. Alternatively, a detergent supply system that is separate from the washing water supply line <NUM>' and designed to introduce the detergent into the collection chamber <NUM> may be provided in the machine itself. This latter configuration is in fact shown in <FIG>, where 49a" denotes an outlet of the detergent supply system, which outlet is positioned on the front of the machine M in a position such that, when the tray <NUM>" is fixed to the machine M, the outlet 49a" is above the washing chamber <NUM>. The outlet 49a' may also be seen in <FIG>, which outlet is directly connected to the outlet end 40b' of the washing water supply system <NUM>', analogously to the embodiment in <FIG>. According to a further embodiment, the detergent may be introduced directly into the washing chamber <NUM> manually by the user, in liquid or solid (tablet) form.

Claim 1:
A machine (M) for preparing beverages, wherein said machine includes
a water supply (<NUM>) configured to supply liquid water or steam within the machine,
a frothing head (<NUM>) for heating and whipping milk, said frothing head comprising a milk inlet (31b) and a distribution duct (<NUM>) for distributing a hot beverage, which distribution duct is arranged downstream of the milk inlet (31b),
a milk supply piping (<NUM>) having an inlet end (50a) connectable to a milk reservoir (T) and an outlet end (50b) connected to the milk inlet (31b) of the frothing head (<NUM>), said milk supply piping comprising, at the inlet end (50a), a flexible hose (<NUM>) having a fixed end (51a) and a movable part configured to be immersed into the milk reservoir (T), and
a cleaning system including:
- a washing water supply piping (<NUM>; <NUM>') having an inlet end (40a; 40a') connected to the water supply (<NUM>) and an outlet (49a; 49a'),
- a washing chamber (<NUM>) suppliable with washing water provided by the outlet (49a; 49a') of the washing water supply piping (<NUM>), in said washing chamber there being placeable the movable part of the flexible hose (<NUM>) that has been extracted from the milk reservoir (T) in said washing chamber,
wherein, through the flexible hose (<NUM>), the washing water contained in the washing chamber (<NUM>) is conveyable to the milk inlet (31b) and to the distribution duct (<NUM>) of the frothing head (<NUM>), and
wherein the washing chamber (<NUM>) is formed in a tray (<NUM>") couplable in a releasable manner to the body of the machine (M) under the frothing head (<NUM>), a collection chamber (<NUM>") also being formed in said tray, which collection chamber is separate from the washing chamber (<NUM>) and configured to be arranged under the distribution duct (<NUM>) of the frothing head (<NUM>).