Tamping and infusion unit for a machine for the preparation of beverages, relative machine and method of operation

Abstract

A tamping and infusion unit (10) for a machine (60) for the preparation of beverages comprises a container (11) configured to receive a powdered substance to be subject to infusion; a hydraulic actuator (17) of the cylinder-piston type; a first feeding conduit (21) connected to said hydraulic actuator (17) and configured to feed a tamping liquid under pressure to move said cylinder (19) from said start position (Pl) to said infusion position (P2); a second feeding conduit (22) configured to feed infusion water into an infusion chamber (20).

Description

[0001] "TAMPING AND INFUSION UNIT FOR A MACHINE FOR THE PREPARATION OF BEVERAGES, RELATIVE MACHINE AND METHOD OF OPERATION"

[0002] FIELD OF THE INVENTION

[0003] The present invention refers to a tamping and infusion unit for a machine for the preparation of beverages, in particular coffee beverages, and to the relative machine. The invention also refers to a machine for the preparation of beverages comprising this unit and to the method of operation of the tamping and infusion unit.

[0004] STATE OF THE ART

[0005] Machines of the super-automatic type for the preparation of coffee are known, in which all the operations of loading the coffee powder into a brewing chamber, compressing the coffee powder, dispensing the brewing water and discharging the spent coffee powder are carried out automatically, without any intervention by an operator.

[0006] In such machines the infusion chamber is generally delimited by a piston and a cylinder, and the compression of the coffee powder generally takes place by moving the cylinder by means of a driving part in the direction towards the piston which is kept fixed.

[0007] Machines for the preparation of coffee of a semi-automatic type are also known, in which the infusion chamber is defined inside a filter holder that can be inserted and connected to the machine by an operator and in which both the loading of the coffee powder and the removal of the spent powder are carried out manually by the operator. In such machines the coffee powder compression zone is separated from the infusion zone and the operator generally has to move the filter holder from one position to the other.

[0008] However, in order to reduce the operations that an operator must carry out manually and at the same time reduce the overall dimensions of the machine, solutions of super-automatic machines have been developed in which the operations of compressing the coffee powder and infusing the beverage are carried out in a single position of the filter holder, with no need to move it.

[0009] The solutions generally used in the fully automatic machines, however, cannot be directly transferred to the semi-automatic machines, as the filter holder is not a fixed component and integrated into the machine and cannot therefore be associated with a piston like in the fully automatic machines in order to conveniently compress the coffee powder and counteract the pressure necessary for the preparation of an espresso coffee which can exceed 10 bars.

[0010] Some known solutions envisage using an actuator of the piston-cylinder type, in which the piston is moved hydraulically so as to bring the piston head inside the filter holder and into contact with the coffee powder.

[0011] US2014 / 150664A1 describes a machine for the preparation of espresso coffee and coffee of the super-automatic type comprising an infusion chamber and a cylinder-piston actuator in which the cylinder is defined by the main body and the piston is configured to move axially with respect to the infusion chamber to compress the coffee powder present therein.

[0012] There is therefore a need to improve a tamping and infusion unit and a machine for the preparation of beverages which can overcome the drawbacks of the prior art.

[0013] To do this, it is necessary to solve the technical problem of providing a tamping and infusion unit that guarantees hydraulic seal between a hydraulically-driven actuator and the filter holder at all times.

[0014] In particular, a purpose of the present invention is to realize a tamping and infusion unit, and relative method, suitable for compressing the coffee powder and withstanding the pressure required for infusion on any occasion.

[0015] Another purpose of the present invention is to make a machine for the preparation of beverages that is compact and efficient and guarantees effective and rapid compression and brewing operations of the coffee powder while minimizing the operations that must be carried out manually by a user.

[0016] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0017] SUMMARY OF THE INVENTION

[0018] The present invention is set forth and characterized in the independent claim / s. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes, and to resolve the technical problem disclosed above in a new and original way, also achieving considerable advantages compared to the state of the prior art, a tamping and infusion unit according to the present invention for a machine for the preparation of beverages, in particular espresso coffee, comprises: a container configured to receive a powdered substance to be subject to infusion; a hydraulic actuator of the cylinder-piston type, wherein the cylinder is configured to move with respect to the piston between a start position in which it is external to the container and an infusion position in which it is internal to the container and defines with it an infusion chamber; a first feeding conduit connected to the hydraulic actuator and configured to feed a tamping liquid under pressure to move the cylinder with respect to the piston from the start position to the infusion position; a second feeding conduit configured to feed infusion water into the infusion chamber; wherein the cylinder is provided with a radial sealing gasket configured to cooperate in sealing sliding contact with a side wall of the container or with a filter element arranged in said container.

[0019] According to one aspect of the invention, the container is a removable filter holder.

[0020] According to one aspect of the invention, the radial sealing gasket is configured to cooperate with an inner side of the side wall of the container or of the filter element.

[0021] According to an embodiment variant, the radial sealing gasket is configured to cooperate with an outer side of the side wall of the container or of the filter element. Thanks to this conformation, the radial sealing gasket always remains at a distance from the coffee powder and therefore the possibility that the coffee powder may enter between the outer wall and the gasket compromising the seal is prevented.

[0022] The conformation of the hydraulic actuator, in which the cylinder defines the movable part, helps to ensure the seal in the vicinity of the coffee powder container. The cylinder preferably has a cup-like shape, with the concavity facing the piston and a solid bottom wall facing the container.

[0023] In accordance with one aspect of the present invention, the cylinder comprises a head portion configured to be inserted inside the container and having a section substantially corresponding to that of the container and provided with a housing cavity for the sealing gasket, which is preferably closed on three sides so as to correctly hold the sealing gasket in place.

[0024] In accordance with another aspect of the present invention, the cylinder comprises a head portion configured to be inserted inside the container and having a section substantially corresponding to that of the container, and an annular seat surrounding the head portion, in which the aforesaid radial sealing gasket is housed and configured to accommodate the side wall of the container.

[0025] In accordance with another aspect of the invention, the radial sealing gasket is arranged near a lower edge of the annular seat.

[0026] In accordance with one aspect of the present invention, the piston is internally hollow and the tamping liquid is fed into said piston.

[0027] In accordance with another aspect of the invention, said cylinder comprises a sliding seat having a shape substantially correlated to that of the piston arranged therein, provided with a bottom wall having an upper surface on which said tamping liquid is adapted to act.

[0028] In accordance with another aspect of the present invention, said cylinder comprises a through channel, which is preferably arranged in a peripheral portion thereof, connected on one side to the second feeding circuit and on the other to a distribution chamber delimited by a lower surface of said cylinder, opposite to the upper surface.

[0029] In accordance with another aspect of the invention, the hydraulic actuator is of the single-acting type and comprises elastic means connected between said cylinder and said piston and configured to return said cylinder to said start position in the absence of the tamping fluid.

[0030] The invention also relates to a method for operating the tamping and infusion unit comprising: filling a container, in particular a removable-type filter holder, with a powdered substance and positioning it below a hydraulic actuator of the tamping and infusion unit; feeding a tamping fluid under pressure through the first feeding conduit to bring the cylinder inside the container and possibly adapt the size of the infusion chamber; feeding infusion water into the infusion chamber and performing a process of infusing the powdered substance.

[0031] At the end of the preparation of the beverage, the container can be removed from the machine and manually emptied by an operator.

[0032] In accordance with another aspect of the present invention, the tamping fluid is water that is withdrawn by a pump from a tank.

[0033] According to embodiments, the tank and the pump feed both the tamping fluid and the infusion water.

[0034] The invention also relates to a machine for the preparation of beverages comprising a tamping and infusion unit according to the invention, a water tank connected to the first and second feeding conduits, a water feeding pump and a heating device preferably configured to heat water in transit.

[0035] According to embodiments, the machine comprises a grinding device connected to a hopper for feeding coffee beans and said container in a first operating position is aligned with said tamping and infusion unit and in a second operating position is aligned with said grinding device to be filled with said powdered substance.

[0036] According to one aspect of the invention, at least one of said container and said tamping and infusion unit and / or means for feeding the coffee powder are movable between the first position and the second position.

[0037] In accordance with possible embodiments, the movement of the container between the first and second positions takes place axially along a direction lying on a median plane of the machine.

[0038] According to possible variants, the movement takes place in a lateral direction, in a rectilinear manner or according to an arc of a circle.

[0039] According to possible variants, the movement of the container can take place on a horizontal plane or slightly inclined with respect to the horizontal, for example by an angle of between 0 and 20°, preferably between 3°- 8°.

[0040] According to another aspect of the invention, the first position and the second position are such that the vertical geometric projections on a horizontal plane of the respective area occupied by the container in the first position and in the second position are intercepted by at least one same straight geometric line drawn on said horizontal plane with orientation parallel to the horizontal development direction in depth of the machine so as to keep the dimension of the machine in the width direction contained. In other words, the areas may be aligned on a same straight line in the depth direction, or be offset in opposite directions until they are tangent to that straight line.

[0041] According to further variants, it can also be provided to keep the container stationary and move the infusion unit and possibly coffee powder feeding means between an operating position in which they are respectively aligned with the container or in any case cooperating with it and a non-operating position in which they do not cooperate with the container.

[0042] DESCRIPTION OF THE DRAWINGS

[0043] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein:

[0044] - fig. 1 is a schematic view of a tamping and infusion unit according to the present invention;

[0045] - figs. 2 and 3 illustrate two operating conditions of the tamping and infusion unit in fig. 1;

[0046] - fig. 4 is an enlarged detail of fig. 2;

[0047] - fig. 4a shows a variant of the detail of fig. 2 according to the invention;

[0048] - fig. 5 shows a variant according to the invention of the container of the tamping and infusion unit;

[0049] - fig. 5a shows another variant according to the invention of the container of the tamping and infusion unit;

[0050] - fig. 6 is a schematic side view of a machine for the preparation of beverages according to the invention in which a movement of the container along a horizontal direction is diagrammed;

[0051] - fig. 6a is a schematic side view of a machine for the preparation of beverages according to the invention in which a movement of the container along an inclined direction is diagrammed;

[0052] - fig. 7 is a schematic view of a hydraulic circuit of the machine of fig. 6 in accordance with a first embodiment of the invention;

[0053] - fig. 8 is a schematic view of a hydraulic circuit of the machine of fig. 6 in accordance with a second embodiment of the invention. We must clarify that in the present description the phraseology and terminology used, as well as the figures in the attached drawings also as described, have the sole function of better illustrating and explaining the present invention, their function being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0054] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION

[0055] With reference to fig. 1, a tamping and infusion unit 10 according to the present invention comprises a container 11 configured to contain a powdered substance.

[0056] In particular, the container 11 can be a container of the type known as a filter holder, provided with a handle 12 by means of which it can be gripped and moved by a user so as to be inserted into or extracted from a housing seat 15 of the machine 60 (figs. 6, 7). The container 11 may preferably have a cylindrical shape, although different shapes are not excluded.

[0057] Inside the container 11 a filter element 13 can be arranged which is provided with holes or is in the shape of a net with meshes having dimensions suitable for retaining the coffee powder but allowing the beverage to pass towards an outlet opening 14 provided at or communicating with a bottom of the container 11.

[0058] In accordance with an exemplary embodiment shown in figs. 1-4, the filter element 13 may extend over an area substantially corresponding to the section of a bottom wall of the container 11 and be fixed by known fixing members, for example a screw or by shape coupling.

[0059] In accordance with an embodiment variant shown in fig. 5, the filter element 13 can extend substantially over the entire inner surface of the container 11 and be fixed to a side wall 16 of the container 11 , for example by shape coupling with an upper edge thereof.

[0060] The tamping and infusion unit 10 comprises a hydraulic actuator 17 of the cylinder-piston type, comprising a piston 18 and a cylinder 19 movable with respect to the piston 18 in the direction F 1.

[0061] The cylinder 19 in particular is movable between a start position P 1 in which it is external to the container 11 and an infusion position P2 in which it is arranged at least in part inside the container 11 and defines with it a substantially closed infusion chamber 20.

[0062] In accordance with the present invention, the cylinder 19 is provided with a radial sealing gasket 23 configured to cooperate in sealing sliding contact with a side wall 16 of the container 11 or with a filter element 13 arranged therein.

[0063] According to embodiments, the sealing gasket 23 is configured to cooperate with at least one of an inner 24a or outer side 24 of the side wall 16 of the container 11 or of the filter element 13.

[0064] According to embodiments illustrated in figures 1-3, 4 and 5, the sealing gasket 23 is configured to cooperate with an outer side 24 of the side wall 16 of the container 11 or of the filter element 13.

[0065] According to the embodiments illustrated in figures 4a and 5 a, the sealing gasket 23 is configured to cooperate with an inner side 24a of the side wall 16 of the container 11 or of the filter element 13.

[0066] The sealing gasket 23 may for example be an o-ring, adapted to create a continuous seal on the entire outer 24 or inner side 24a, respectively, of the side wall 16.

[0067] The cylinder 19 has a cup-like shape, with the concavity facing the piston 18 and a solid bottom wall 30 facing the container 11.

[0068] The cylinder 19 is internally hollow and comprises a sliding seat 33 having a shape substantially correlated to that of the piston 18 arranged therein and closed at one end by a solid bottom wall 30.

[0069] The solid bottom wall 30 has an upper surface 34 on which a tamping liquid is adapted to act as will be explained below.

[0070] The piston 18 may comprise an annular gasket 44 configured to cooperate with an inner surface of the sliding seat 33 to prevent leakage of the tamping liquid.

[0071] In accordance with embodiments, the cylinder 19 comprises a head portion 25, provided with the bottom wall 30, having a section substantially corresponding to or slightly smaller than the inner section of the container 11 so that it can be inserted and slide therein, and an annular seat 26 which develops around the head portion 25.

[0072] The sealing gasket 23 is positioned inside the annular seat 26, preferably near a lower edge thereof.

[0073] According to embodiments, the outer surface of the head portion 25 defines a first side of the annular seat 26, while a protruding portion 27 of the cylinder 19 defines a second opposite side.

[0074] The protruding portion 27 substantially surrounds the head portion 25 and may extend substantially as far as its end, or optionally further.

[0075] According to embodiments, the protruding portion 27 is shaped so as to define laterally a housing cavity 28 for the sealing gasket 23, which is preferably closed on three sides so as to correctly hold the sealing gasket 23 in position.

[0076] According to a variant, for example illustrated in fig. 4a, a housing cavity 28’ for the sealing gasket 23 is made in the side wall of the head portion 25. According to this conformation, the sealing gasket 23 is inserted therein, in such a way as to cooperate, in use, with the inner side 24a of the side wall 16 of the container 11 or of a filter arranged therein.

[0077] The tamping and infusion unit 10 comprises a first conduit 21 connected to the hydraulic actuator 17 and configured to feed a tamping liquid under pressure to move the cylinder 19 from the start position Pl to the infusion position P2 and a second conduit 22 configured to feed infusion water into the infusion chamber 20.

[0078] In accordance with one aspect of the invention, the piston 18 is internally hollow, i.e. it comprises at least one through channel 29 through which the tamping liquid is fed.

[0079] Said through channel 29 in the start position Pl (fig. 1) can be substantially closed at the bottom by the bottom wall 30. The bottom wall 30 can be substantially flat or be provided with a protrusion 31 adapted to be inserted into the through channel 29.

[0080] When the cylinder 19 is in the infusion position P2 (figs. 2 and 3), an accumulation chamber 32 is formed between the piston 18 and the cylinder 19.

[0081] The cylinder 19 may comprise a through channel 36, which is preferably arranged laterally with respect to the sliding seat 33, connected on one side to the second conduit 22 and on the other to a distribution chamber 37 associated with a lower surface 35 of the head portion 25 opposite to the upper surface 34.

[0082] The distribution chamber 37 can be delimited at least below by a perforated element 38 with holes and / or meshes suitable for preventing the passage of the powdered substance during compression.

[0083] In accordance with embodiments, the hydraulic actuator 17 is of the singleacting type and comprises elastic means 39 connected between the cylinder 19 and the piston 18 and configured to return the cylinder 19 to the start position Pl in the absence of the tamping fluid.

[0084] The elastic means 39 may comprise a spring 40 arranged coaxially to the piston 18 and connected on one side to the piston 18 and on the other to the cylinder 19 or to an abutment element 45 integral therewith.

[0085] The piston 18 may have a mushroom shape and comprise a head 41 having a shape and section corresponding to that of the sliding seat 33 and a body 42 having a smaller section so as to define a housing seat 43 for the spring 40.

[0086] Figs. 6 to 8 respectively illustrate a machine 60 for the preparation of beverages comprising the tamping and infusion unit 10 according to the invention and two possible embodiments of the hydraulic circuits.

[0087] The machine 60 comprises a hydraulic circuit 61 adapted to feed the tamping fluid and the infusion water to the first 21 and to the second conduit 22, along which there are arranged a pump 62 that withdraws the water from a tank 63 and a heating device 64, for example of the flow-through type and provided with an electrical resistance.

[0088] One or more sensors, such as a flow sensor 67, or flow meter, a temperature sensor 68, or the like and / or safety valves 69 may be arranged along the hydraulic circuit 61.

[0089] According to embodiments, the machine 60 may comprise a grinding device 65 which is connected to a hopper 66 for feeding coffee beans and is provided with grinders.

[0090] The container 11 can be moved manually or in a motorized manner, for example by means of a driving member 76, between a beverage preparation position in which it is aligned with the tamping and infusion unit 10 and a filling position in which it is aligned with the grinding device 65 to be filled with the powdered substance obtained by grinding the coffee beans.

[0091] In particular, the container 11, for example the filter holder, can be movable between one and the other position inside the housing seat 15, i.e. it can be moved from one to the other without being extracted from the machine 60. According to embodiments, schematically illustrated in fig. 6, the movement of the container 11 between the beverage preparation position and the filling position can take place on a substantially horizontal plane, i.e. remaining at the same height with respect to a support plane of the machine.

[0092] In accordance with possible embodiments, the movement between the first and the second position takes place axially along a direction F3 lying on a median plane of the machine 60 which in fig. 6 can be the plane passing through the centreline of the container 11 and of the handle 12 or parallel to the median plane.

[0093] According to possible variants, the movement takes place in a lateral direction, in a rectilinear manner or according to an arc of a circle.

[0094] According to embodiments, the movement of the container 11 can take place in a horizontal plane. According to embodiments, for example illustrated in fig. 6a, the movement of the container 11 between one and the other operating position can take place on a plane which is slightly inclined with respect to the horizontal, for example by an angle between 0°-20°, preferably between 3°- 8°.

[0095] In fig. 6a the filling position is illustrated at a lower height with respect to the beverage preparation position. However, solutions can also be provided in which the filling position is placed at a higher height with respect to the beverage preparation position.

[0096] Preferably the first position and the second position are such that the vertical geometric projections on a horizontal plane of the respective area occupied by the container in the first position and in the second position are intercepted by at least one same straight geometric line drawn on said horizontal plane with orientation parallel to the horizontal development direction in depth of the machine 60 so as to keep the dimension of the machine 60 in the width direction contained. In other words, the areas may be aligned on a same straight line in the depth direction, or be offset in opposite directions until they are tangent to that straight line.

[0097] According to further variants, it may also be provided that the container 11 is kept stationary in a fixed position, while the tamping and brewing unit 10 and possibly means of feeding the coffee powder are moved between an operative position in which they are respectively aligned with the container 11 or in any case cooperating with it and a non-operative position in which they do not cooperate with the container 11. The machine 60 can be provided with a control unit 70 configured to regulate its operation and / or with a user interface 80 by means of which an operator can command the preparation of a beverage, possibly by selecting between a "hot" or "cold" beverage and / or selecting the amount of beverage to be prepared, for example a single or double beverage dose.

[0098] According to embodiments the liquid used for tamping is water and the tank 63 feeds both the first 21 and the second conduit 22.

[0099] According to embodiments illustrated in fig. 7, the hydraulic circuit 61 comprises a first feeding circuit 71 for feeding the hydraulic actuator 17 and a second feeding circuit 72 for feeding the infusion chamber 20, which preferably share part of the hydraulic circuit 61 and preferably separate downstream of the pump 62.

[0100] The first circuit 71 is configured to feed the water supplied by the pump 62 along the path A indicated with a dotted line in fig. 7.

[0101] The second circuit 72 can be configured to feed the water supplied by the pump 62 along the path B indicated with a dash-dot line in fig. 7 by transiting through the heating device 64 upstream of the infusion chamber 20.

[0102] According to embodiments, a third circuit 73 can also be provided which is configured to feed the water supplied by the pump 62 to the infusion chamber 20 along the path C indicated with a dot-dot line in fig. 7.

[0103] According to embodiments, along the first circuit 71 a non-retum valve 74 is provided which allows, once the hydraulic actuator 17 is filled with water and a defined threshold pressure value has been reached, to isolate the section of hydraulic circuit D, indicated with a line-double dot-line in fig. 7.

[0104] According to embodiments, the non-retum valve 74 may be a piston-type valve.

[0105] Once the circuit section D is isolated, the water withdrawn by the pump 62 is diverted along a circuit different from the first circuit 71, in particular the second circuit 72 or possibly the third circuit 73.

[0106] According to possible embodiment solutions, the hydraulic circuit 61 may comprise a diverter valve 75, for example arranged upstream of the non-retum valve 74, which may be selectively activatable to feed the water from the tank 63 directly to the infusion chamber 20.

[0107] The path A can be connected to a drain circuit 77 by means of which the water used as tamping fluid can be drained allowing the cylinder 19 to return to the start position Pl.

[0108] A selectively controllable drain valve 78 may be arranged along the drain circuit 77 so as to open or close the drain circuit and permit removal of water from the hydraulic actuator 17.

[0109] The water used for tamping is sent to the drain tray 200.

[0110] According to a possible embodiment solution, the drain circuit 77 can be connected directly to the tank 63.

[0111] According to this embodiment, the water is initially withdrawn by the pump 62 and sent along the first circuit 71 (path A) until the cylinder 19 compresses the powdered substance and a defined pressure is reached in the infusion chamber 20, which can for example be set by a pressure reducing valve 79 placed in communication with the infusion chamber 20. The defined pressure can for example be comprised between 2-6 bar.

[0112] When the defined pressure is reached, the first circuit 71 is actually isolated and the water flow is diverted towards the second circuit 72 (path B) or possibly, by activating the diverter valve 75, towards the third circuit 73 (path C).

[0113] At the end of the infusion, the drain valve 78 is opened allowing the water to drain from the hydraulic actuator 17. The elastic means 39 no longer subjected to pressure can thus extend returning the cylinder 19 to the start position.

[0114] Fig. 8 illustrates an embodiment variant of the hydraulic circuit 161, which differs from the hydraulic circuit 61 of fig. 7 in that the first circuit 171 (path Al) and the second circuit 172 (path Bl) separate downstream of the heating element 64, whereby the hydraulic actuator 17 is operated by means of hot water. In figure 8 the elements substantially the same as those of fig. 7 have been indicated with the same reference number and will not be described further.

[0115] Also, according to the embodiment of fig. 8 the water drawn by the pump 62 feeds the hydraulic actuator 17 to compress the powdered substance and upon reaching the defined pressure in the infusion chamber 20, when the pressure reducing valve 79 comes into operation, the first circuit 171 is isolated and the water is diverted towards the infusion chamber through the second circuit 172 or possibly the third circuit 173.

[0116] At the end of the infusion the opening of the drain valve 78 allows the water to be removed from the hydraulic actuator 17 and the cylinder 19 to be reset into the start position Pl.

[0117] The control unit 60 can be operatively connected to the pump 62, to the heating device 64, to the one or more valves 75, 78, and possibly also to the grinding device 65 and be configured to adjust the operation thereof on the basis of the commands received via the interface 80 and / or the data detected by the sensors 67, 68.

[0118] The control unit 60 can also be configured to control the operation of the driving member 76 associated with the container 11 to move it between the filling position and the beverage preparation position and / or vice versa.

[0119] The method of operation of the tamping and infusion unit 10 which corresponds to a method according to the invention provides for filling the container 11 with a powdered substance and positioning it below the tamping and infusion unit 11 (fig. 1). The container 11 can for example be inserted in the axial direction in the direction F.

[0120] The method then provides for feeding a tamping fluid under pressure through the first conduit 21 to bring the cylinder 18 into the infusion position P2, with the head portion 25 arranged inside the container 11. In this way it is also possible to adapt the size of the infusion chamber 20 as a function of the amount of powdered substance.

[0121] Subsequently, the method provides for feeding infusion water into the infusion chamber 20 through the second conduit 22 and performing a process of infusing said powdered substance.

[0122] The infusion water passes through the powdered substance extracting the aromas thereof and the beverage can outflow through the outlet opening 14 of the container 11 and be received in a suitable container 46.

[0123] At the end of the preparation of the beverage, the container 11 can be removed and manually emptied by an operator.

[0124] The method provides for using the water contained in the tank 63 both as a tamping fluid and as infusion water.

[0125] According to embodiments, the method provides for feeding the hydraulic actuator 17 with cold water.

[0126] According to an embodiment variant, the method provides for feeding the hydraulic actuator 17 with hot water, heated by means of the heating device 64. According to embodiments, the method provides for heating the infusion water by means of the heating device before feeding it to the infusion chamber 20 when the preparation of an espresso coffee or in general of a "hot" coffee beverage is required.

[0127] The method may also provide for directly feeding the infusion water from the tank 63 to the infusion chamber 20 in the event that the preparation of a "cold" coffee beverage is required.

[0128] The invention also relates to a method for preparing a beverage with a machine 60 according to the invention, which provides for receiving an indication on a beverage to be prepared, filling a container with a powdered substance and performing the tamping and infusion method described above.

[0129] The method for preparing the beverage may further comprise inserting the container 11 in the housing seat 15, moving the container 11 to a filling position, filling the container 11 with a dose of powdered substance ground by a grinding device 65 and subsequently moving the container to the beverage preparation position.

[0130] According to embodiments, the indication on the beverage to be prepared comprises the selection of a "hot" or "cold" beverage and the method provides for operating the diverter valve 75 to feed the hydraulic actuator 17 and the infusion chamber 20 with hot water heated by the heating device 64 or respectively cold water directly withdrawn from the tank 63 as a function of said selection.

[0131] It is clear that modifications and / or additions of parts may be made to the tamping and infusion unit 10, and relative method, and to the machine for the preparation of beverages 60, and relative method as described heretofore, without departing from the field and scope of the present invention, as defined by the claims.

[0132] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve other equivalent forms of a tamping and infusion unit, machine for the preparation of beverages and relative methods, having the characteristics as set forth in the claims and hence all coming within the scope of protection defined thereby.

[0133] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the scope of protection defined by the claims.

Claims

CLAIMS1. Tamping and infusion unit (10) for a machine (60) for the preparation of beverages, comprising: a removable container (11) configured to receive a powdered substance to be subject to infusion; a hydraulic actuator (17) of the cylinder-piston type configured to cooperate with said container (11) and define with it an infusion chamber (20); a first feeding conduit (21) connected to said hydraulic actuator (17) and configured to feed a tamping liquid under pressure to compress said powdered substance; a second feeding conduit (22) configured to feed infusion water into said infusion chamber (20), characterized in that said hydraulic actuator (17) comprises a cylinder (19) configured to move with respect to a piston (18) between a start position (Pl) in which it is external to the container (11) and an infusion position (P2) in which it is internal to the container (11) and defines with it said infusion chamber (20), wherein said cylinder (19) is provided with a radial sealing gasket (23) configured to cooperate in sealing sliding contact with a side wall (16) of said container (11) or of a filter element (13) arranged in said container (11).

2. Tamping and infusion unit (10) as in claim 1, characterized in that said piston (18) is internally hollow and comprises a through channel (29) through which said tamping liquid is fed, which is closed at the bottom by a bottom wall (30) of said cylinder (19) in said start position (Pl).

3. Tamping and infusion unit (10) as in any claim hereinbefore, characterized in that said cylinder (19) comprises a through channel (36) connected on one side to said second circuit (22) and on the other side to a distribution chamber (34) associated with a lower surface (35) of said cylinder (19).

4. Tamping and infusion unit (10) as in any claim hereinbefore, characterized in that said hydraulic actuator (17) is of the single-acting type and comprises elastic means (39) connected between said cylinder (19) and said piston (18) and configured to return said cylinder (19) to said start position (Pl) in the absence of said tamping fluid.

5. Tamping and infusion unit (10) as in claim 4, characterized in that said piston(18) has a mushroom shape and comprises a head (41) having a shape and section corresponding to that of a sliding seat (33) of said cylinder (19) and a body (42) having a smaller section, which together with said sliding seat (33) defines a housing seat (43) for said elastic means (39).

6. Tamping and infusion unit (10) as in any claim hereinbefore, characterized in that said cylinder (19) comprises a head portion (25) configured to be inserted inside said container (11) and having a section substantially corresponding to that of said container (11), and an annular seat (26) surrounding said head portion (25), configured to receive said side wall (16) and in which said sealing gasket (23) is housed.

7. Tamping and infusion unit (10) as in any claim from 1 to 5, characterized in that said cylinder (19) comprises a head portion (25) configured to be inserted inside said container (11), having a section substantially corresponding to that of the container (11), and provided with a housing cavity (28') for the sealing gasket (23).

8. Tamping and infusion method comprising: filling a container (11) with a powdered substance and positioning it below a hydraulic actuator (17) of a tamping and infusion unit (10) as in any claim hereinbefore; feeding a tamping fluid under pressure through said first feeding conduit (21) to bring said cylinder (19) from said start position (Pl) to said infusion position (P2) where it is at least partially inside said container (11) and delimits said infusion chamber (20) while said radial sealing gasket (23) cooperates in sliding sealing contact with the side wall (16) of said container (11) or of a filter element (13) arranged in said container (11); feeding infusion water into said infusion chamber (20) and performing a process of infusing said powdered substance.

9. Tamping and infusion method as in claim 8, characterized in that said tamping fluid is water that is withdrawn by means of a pump (62) from a tank (63) configured to feed also said infusion water.

10. Tamping and infusion method as in claim 8 or 9, characterized in that it provides to feed said hydraulic actuator (17) with cold water and said infusion chamber (20) with hot water heated by a heating device (64).

11. Tamping and infusion method as in claim 8 or 9, characterized in that it provides for feeding both said hydraulic actuator (17) and said infusion chamber (20) with hot water heated by a heating device (64).

12. Machine (60) for the preparation of beverages comprising a tamping and infusion unit (10) as in any claim from 1 to 7, a water tank (63) connected to said first (21) and second conduit (22) by means of a hydraulic circuit (61 ; 161), a pump (62) and a heating device (70).

13. Machine (60) as in claim 12, characterized in that it comprises a grinding device (65) connected to a hopper (66) for feeding coffee beans and at least one of said container (11) and said tamping and infusion unit (10) is movable between a first operating position in which said container (11) is aligned with said tamping and infusion unit (10) and a second operating position in which it is aligned with said grinding device (65).

14. Machine (60) as in claim 13, characterized in that said container (11) is axially movable between said first and said second position and vice versa.

15. Machine (60) as in claim 14, characterized in that said container (11) is axially movable along a direction lying on a median plane of said machine (60).

16. Machine (60) as in claim 13, characterized in that said container (11) is movable in a lateral direction, in a rectilinear manner or according to an arc of a circle between said first and said second position and vice versa.

17. Machine (60) as in one or the other of claims 13 to 16, characterized in that the movement of the container (11) between said first and second position takes place on a substantially horizontal plane.

18. Machine (60) as in one or the other of claims 13 to 17, characterized in that the movement of the container (11) takes place on a plane which is inclined with respect to the horizontal by an angle between 0 and 20°, preferably between 3°- 8°.

19. Machine (60) as in one or the other of claims 13 to 18, characterized in that it comprises a driving member (76) configured to move said container (1 1) between said first and said second operating position and / or vice versa.

20. Machine (60) as in one or the other of claims 13 to 19, characterized in that the first position and the second position are such that the vertical geometric projections on a horizontal plane of the respective area occupied by the container (11) in the first position and in the second position are aligned on a same straightline in the direction of the depth of said machine (60), or are offset in opposite directions until they are tangent to said straight line.

21. Machine (60) as in claim 13, characterized in that said container (11) is stationary and said tamping and infusion unit (10) and / or coffee powder feeding means are movable between said first and said second operating position.

22. Machine (60) as in any claim from 12 to 21, characterized in that said hydraulic circuit (61, 161) comprises a first feeding circuit (71, 171) for feeding said hydraulic actuator (17) and a second feeding circuit (72, 172) for feeding said infusion chamber (20), which share part of said hydraulic circuit (61; 161), wherein along said first circuit (71, 171) a non-return valve (74) is provided which allows the transit of water towards said hydraulic actuator (17) until a defined threshold pressure value is reached, and which upon reaching said threshold pressure value isolates the section of circuit downstream.

23. Machine (60) as in claim 22, characterized in that said hydraulic circuit (61, 161) comprises a third circuit (73, 173) configured to feed the water supplied by said pump (62) directly to said infusion chamber (20), wherein said second (72, 172) and third circuit (73, 173) are connected by means of a selectively controllable diverter valve (75).

24. Method for preparing a beverage with a machine (60) as in any claim from 12 to 23, which provides for receiving an indication on a beverage to be prepared, filling said container (11) with said powdered substance and performing the tamping and infusion method as in one or the other of claims 8 to 11.

25. Method for preparing a beverage as in claim 24, characterized in that it comprises inserting said container (11) in a housing seat (15), moving said container (11) to a filling position, filling said container (11) with a dose of powdered substance ground by a grinding device (65) and subsequently moving the container (11) to the beverage preparation position.

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