Brewing unit for preparation of beverages, and machine comprising said brewing unit

IS 2 373 191 T3

DESCRIPTION

Infusion unit for the preparation of beverages and a machine comprising said infusion unit

Technical field

The present invention relates to improvements in infusion units for the preparation of beverages, especially although not exclusively for the preparation of coffee, and more particularly to infusion units designed for use in automatic machines, in which an infusion unit receives a predetermined dose of ground coffee (prepackaged or loose) or other products for the preparation of a drink, and performs a closing cycle of an infusion chamber, preparation of the drink by infusion with hot water and discharge of spent ground coffee or other spent product.

The invention also relates to a machine for the preparation of beverages, comprising an infusion unit of the type mentioned above.

The invention relates generally to machines for home or professional use, and also to vending machines.

State of the art

In electric machines for the preparation or production of beverages and in particular coffee, so-called infusion units are used, which comprise a plurality of mobile elements that define an infusion chamber, into which a dose of loose ground coffee or coffee is loaded. if not coffee packaged in the form of capsules, cartridges or the like. After being loaded with the ground coffee, the infusion chamber is closed and hot water is passed inside at a suitable pressure to extract the aromas from the ground coffee and produce the beverage. At the end of the infusion stage, the infusion chamber is opened and the spent ground coffee is discharged.

Some machines of this type, especially those designed to work with prepackaged products in the form of cartridges, capsules or the like, also allow the production of other types of beverages or food products, such as tea, chocolate or the like.

In US-A-4681028 an infusion unit of the type mentioned above is described, in which the infusion chamber is defined between two parts that are movable relative to each other. In greater detail, the infusion unit described in this prior patent comprises a seat or cylinder within which a plunger slides. The seat is capable of oscillating and translating with respect to a support structure to arrange itself in a ground coffee loading position and in an infusion position. This last position is reached by causing translation of the seat towards and with respect to a complementary piston fixed in the support structure. The mating plunger, seat, and plunger define a fixed volume infusion chamber. The opening and closing mechanism is such that, once said closing and infusion position has been reached, the forces acting on the parts that form the infusion chamber due to the pressure of the water supplied in the chamber itself are discharged onto the support structure without forcing the motor assembly that operates the opening and closing mechanism. Other devices or infusion sets of a similar type are described in documents ES-A-2156668, FR-A-2663216, US-A-5259296, EP-A-486433, US-A-5551988, US-A-6779436 , US-A6807898, EP-A-1459663 and EP-A-937432.

In US-A-6101923 a rotary infusion unit with a double infusion chamber is described. The two brewing chambers are used to produce coffee of two different qualities and more specifically, for example, espresso and freshly brewed coffee. The rotating assembly is provided with cams, which control the movement of the plunger within the infusion chamber.

In EP-A-0380450 a further brewing unit is described with a rotatable cylindrical chamber acting in conjunction with a complementary plunger having a limited oscillating movement from a rest position to a working position. In the working position, the complementary plunger is coupled to the cylindrical chamber to define, together with a plunger arranged within the chamber itself, an infusion volume. The plunger has a helical spring, which has the purpose of compensating for any possible variation in the volume of ground coffee contained in the brewing chamber. This infusion unit has a single infusion position with a predetermined volume of the infusion chamber and a system to block the infusion chamber in the working position to discharge the pressure stresses generated inside it on the support structure. . An activation mechanism is provided to activate and deactivate the infusion chamber locking device.

Summary of the invention

According to one aspect, the present invention refers to an infusion unit for the production of coffee or in general for the preparation of beverages that will make it possible, with a particularly resistant and reliable structure, to work with

ES 2 373 191 T3 variable volumes of the infusion chamber to produce drinks of different qualities (for example, espresso and freshly brewed coffee), and / or a variable number of doses of drink in each individual infusion cycle, for example, so just one cup of coffee or else two cups of coffee in a single infusion operation.

The brewing unit according to the invention includes a rotatable unit with a seat, in which a plunger slides, and a complementary plunger that co-operates with said cavity and said plunger to define an brewing chamber.

Hereinafter specific reference will be made to an infusion unit for the preparation of coffee. However, it should be understood that the characteristics of the brewing unit according to the invention can be advantageously applied also in other types of machines, to prepare different beverages, or else in machines that can produce coffee and also other types of beverages. Accordingly, when reference is made to coffee and ground coffee in the present description and the appended claims, it should be understood that in some embodiments the same infusion unit could be used with products other than ground coffee, possibly in single-dose containers or multiple doses, for the preparation of other types of beverages.

An infusion unit is provided for the production or preparation of coffee or other beverages in general, comprising: a seat having a rotational movement, in which a plunger is slidably housed; a complementary plunger acting in conjunction with said seat and said plunger to define an infusion chamber; cam elements to control the movements of the seat, the piston and the complementary piston. The seat, the plunger and the complementary plunger are arranged, designed and controlled to assume at least one loading position to load the product or substance (for example, ground coffee) with which the beverage is to be prepared, at least two positions of different infusion to which correspond two different volumes of the infusion chamber and a discharge position to discharge the substance or the spent product, for example the ground coffee tablet, or if not the spent coffee capsule, or cartridge.

The complementary plunger is movable to insert into and slide into the seat.

To obtain a strong and compact structure, the present invention provides an infusion unit for the preparation of hot drinks according to claim 1.

The invention provides an infusion unit for the preparation of hot beverages, in particular coffee, comprising: a seat having a rotational and translational movement and in which a plunger is slidably received; a complementary plunger that acts in conjunction with said seat and said plunger, to define an infusion chamber. The movement of each piston, the complementary piston and the seat is controlled by rotating and fixed cam profiles. More specifically, according to some embodiments, the seat is provided with a rotational movement about a first axis and a translational movement along a second axis, preferably said first and second axes being approximately orthogonal to each other. Similarly, the plunger slidably housed in said seat is also provided with a corresponding rotary and translational movement. Preferably, the complementary plunger is provided with a translational movement, but preferably has no rotational movement. Each said plunger, complementary plunger, and seat co-operate with a respective fixed and rotating cam profile or pairs of fixed and rotating cam profiles. More specifically, the movement of the seat is controlled by at least one fixed cam profile and one movable cam profile. To obtain a stronger structure, a pair of fixed cam profiles and a pair of movable cam profiles are provided, the profiles of each pair being symmetrical or identical. Similarly, the plunger is controlled by a fixed cam profile and a movable cam profile (or a pair of fixed cam profiles and a pair of movable cam profiles having the same shape) and the complementary piston is controlled by a fixed cam profile and a movable cam profile or a pair of fixed cam profiles and identical movable cam profiles respectively. In some preferred embodiments the movable cam profiles that control the plunger, mating plunger, and seat are rotating about a common axis of rotation. In some embodiments the movable cam profiles are provided on a common rotating cam. If the pairs of cam profiles are provided for each moving element (piston, seat and complementary piston) then preferably two rotary cams are provided, each of which is provided with one of the respective cam profiles of each pair of profiles of cam.

The cams are preferably slot-shaped cams, ie channel-shaped cams.

In some embodiments, the plunger and seat form a unit which is therefore supported by respective sensors, for example in the form of pins, on corresponding fixed and movable cam profiles. The rotation of the movable cam profiles causes the rotation and translation of the plunger and seat. Since separate cam profiles are provided for the plunger and the seat, it is therefore possible to confer the same rotational motion for both the plunger and the seat, but have a different translational motion for the two elements, so that the plunger slides relative to the seat. Thus, it is possible, with the same actuator, to cause movement of the seat from a loading position to an infusion position and then to a discharge position. The plunger can slide into the seat to sink possible different brewing positions (with larger or smaller volumes from the brewing chamber) and also a spent discharge position, i.e. spent coffee powder or from a cartridge , pod or capsule of coffee exhausted from the seat. Similarly, the

ES 2 373 191 T3 complementary piston is also controlled by the same motor or actuator, which controls the movement of the piston and seat. Therefore, an extremely simple and flexible structure is obtained, in which the possibility of preparing different kinds of coffee (for example freshly prepared or the so-called "American coffee"), or if not a different number of cups of coffee ( one or two, for example). At the same time, the possibility is provided to minimize or in any way greatly reduce the forces (due to compression of the coffee and / or water pressure in the brewing chamber), which are discharged onto the motor shaft, i.e. the shaft that transmits the movement to the rotating cams.

The movable cam profiles may be arranged on separate discs or else preferably on a common rotating cam.

In one embodiment, the infusion unit provides a pair of fixed plates, each having a set of fixed cam profiles that are substantially equal to each other, and a pair of rotating cams, arranged along said fixed plates, each cam having rotatable a set of rotatable cam profiles that are substantially equal to each other, and in which said seat, said piston and said complementary piston are arranged between said two fixed plates.

In one embodiment, the fixed plates support the rotating cams. Preferably, each rotary cam is carried by a fixed plate and is arranged on the outside or inside thereof, that is, the two rotary cams are arranged between the two fixed plates.

In one embodiment, the plunger, the seat, and the complementary plunger are provided with respective sensors, each of which cooperates with at least one fixed cam profile and one rotatable cam profile.

With the rotating and fixed cams it is possible to control the rotary and translation movements of the piston and the seat. In one embodiment, the cams may be provided such that the complementary plunger will instead exhibit only a translational motion relative to a fixed load bearing structure.

Further advantageous embodiments and features of the invention are indicated in the appended claims and will be described hereinafter with reference to some examples of the embodiment of the invention.

Brief description of the drawings

A clearer understanding of the invention will be obtained from the description and accompanying drawings, which show non-limiting practical embodiments of the invention, applied by way of example to infusion units for the production of ground coffee. More in particular, in the drawings:

Figure 1 shows a front view of a coffee machine in which an infusion unit according to the invention can be used;

Figure 2 shows a partially cross-sectional perspective view of an infusion unit according to one embodiment, which is not covered by the present claims;

figure 3 shows a view according to line III-III of figure 2;

figure 4 is a cross-sectional view according to line IV-IV of figure 3;

Figure 5 is a cross-sectional view according to the line VV of Figure 3;

figure 6 is a cross-sectional view according to line VI-VI of figure 3;

Figures 7 to 11 are schematic illustrations of a sequence of work of the infusion unit of Figures 1 to 6;

Figure 12 shows a perspective view with parts removed from an infusion unit according to the invention in a first embodiment;

Figure 12A shows a front view of one of the fixed plates on which the fixed cam profiles of the embodiment of Figure 12 are provided;

Figure 12B shows a front view of one of the rotating cams, with the rotating cam profiles;

Figures 13 to 18 are front and partially cross-sectional views of the infusion unit of Figure 12 in different operating positions;

Figures 19, 20 and 21 show axonometric views of a further embodiment of the infusion unit according to

ES 2 373 191 T3 invention in three different operating positions, with one of the side plates removed to show the internal mechanism;

Figure 20A is a cross-sectional view according to XXA-XXA of Figure 20;

Figure 22 is a view similar to the view of Figure 21, but without parts removed;

Figures 23 and 24 show internal views of the two fixed plates of the infusion device of Figures 19 to 22;

Figure 25 is a cross-sectional view according to XXV-XXV of Figure 23;

Figure 26 shows a front view of one of the movable cams of the infusion device of Figures 19 to 25;

Figure 27 is a cross-sectional view according to XXVII-XXVII of Figure 26;

Figure 28 shows a view similar to the view of Figure 26 of another of the two movable cams of the infusion device in this embodiment;

Figure 29 is a cross-sectional view according to XXIX-XXIX of Figure 28;

Figure 30 is a cross-sectional view according to a substantially median plane of the device of Figures 19 to 29, along the line XXX-XXX of Figure 31, in the position in which the brewing unit is ready to be loaded with coffee ground;

figure 31 shows a top plan view according to XXXI-XXXI of figure 30;

Figure 32 is a local cross-sectional view according to XXXII-XXXII of Figure 31;

Figures 33 and 34 are cross-sectional views similar to those of Figures 30 and 32, with the brewing unit in the stage of closing the brewing chamber;

Figure 35 is a cross-sectional view similar to that of Figures 30 and 33, with the brewing unit in the discharge configuration of a spent coffee cartridge;

Figures 36 and 37 show sectional and axonometric views of the plunger of the infusion device in a possible embodiment, Figure 37 being a cross section according to XXXVII-XXXVII of the plunger of Figure 36;

Figures 38 and 39 are cross-sectional views according to XXXVIII-XXXVIII of the plunger of Figures 36, 37 in two different operating configurations;

Figures 40-45 show cross sections of a further embodiment of the infusion unit according to the invention in different operating positions;

Figures 46A-46D show a back pressure adjustment valve in various possible operating positions;

Figure 47 shows a front view of one of the two fixed plates on which the fixed cam profiles of a further embodiment of the unit according to the invention are provided;

Figures 47A, 47B, 47C show local cross sections along lines AA, BB and CC of Figure 47;

Figure 48 shows a front view of one of the two rotating cams with respective rotating cam profiles corresponding to the fixed profiles of Figure 47;

Figures 49A-49D show cross sections of the unit including the fixed and rotating cam profiles of Figures 47-48 in different angular positions; and Figure 50 shows the path of the pins that drive the plunger and seat along the respective cams of Figure 47.

Detailed description of embodiments of the invention

Figure 1 is a schematic illustration, in a front view, of an automatic machine for the production of coffee, designated as a whole by 1, to which an infusion unit according to the invention can be applied. The position of the brewing unit, designated as a whole by 3, is indicated as a transparent view with a dashed and dotted line in the representation of Figure 1. The surface designated by 5 is the surface on which the cups are placed, on which the coffee supplied by the machine through the supply nozzles 7A, 7B is to be collected. The coffee machine 1 shown in figure 1 is a machine for home use. Without

ES 2 373 191 T3 however, it will be understood that the infusion unit according to the invention can also be used in professional-type coffee machines and also in automatic dispensers or so-called vending machines that normally already use infusion units similar to those used today. in more advanced automatic machines for home use.

Realization of figures 1 to 11

An embodiment of the infusion unit 3, which is not covered by the present claims, is shown in detail in Figures 2 to 11. In this embodiment the infusion unit 3 comprises two plates 9A, 9B, which are substantially equal to each other. and are joined by transverse elements 11 to form a fixed support structure, which is mounted inside the machine 1. The fixed structure 9A, 9B, 11 can be advantageously extracted from the machine 1 to allow its cleaning, maintenance, replacement or any other type of intervention that may be necessary.

A rotating unit 13 is supported between the two plates 9A, 9B. The unit 13 is supported by means of shafts or pins 13A to allow rotation about an axis AA. One of the pins or shafts 13A is connected to a drive motor, not shown. The coupling can be achieved with a slotted profile or in any other way, possibly with a torque limiter. In a possible embodiment, the rotary unit 13 has two annular projections 13B, coaxial with the axis AA of rotation and engaging in annular grooves 15 provided in the two plates 9A and 9B. The annular projections and the corresponding cavities have the purpose of improving the guiding of the rotational movement of the rotary unit 13 with respect to the support structure.

A seat 19 is provided within the rotatable unit 13. In one embodiment, seat 19 has a cylindrical development with a substantially circular cross section.

A plunger 21 is housed within the seat 19, which slides along the axis BB of the seat 19. The plunger 21 has a rod 21A hooked to a transverse pin 23, which develops in a direction substantially orthogonal to the axis BB and to the rod 21A of plunger 21.

The pin 23 protrudes from the rotatable unit 13 through two slots 13C (see in particular figure 2), provided on either side of the rotatable unit 13. The axial length of the pin 23 is such that it engages at both ends by projecting through the slots 13C in the corresponding cam profiles 25A, 25B provided in the plates 9A, 9B. The cam profiles 25A, 25B basically constitute cams with grooves and are part of the cam elements that control the movements of the movable elements that define the infusion chamber of the infusion unit 3. The cam elements comprise, in addition to the cam profiles 25A, 25B, additional cam profiles for the movement of the complementary plunger, described below.

The cam profiles or cams 25A, 25B with grooves are substantially equal to each other, and their shape is shown in detail for example in Figure 4. In one embodiment, this first cam profile 25A, 25B has a first end 25X arranged to a first distance from the axis AA of rotation of the rotary unit 13, and a second end 25Y arranged at a smaller distance from said axis AA. Between the two extremes, the cam profile develops with a curvilinear development that gradually moves away from the axis AA of rotation to a maximum distance and then approaches the axis of rotation again until it reaches the second end 25Y of the profile 25A, 25B of cam, at a minimum distance from the axis AA of rotation. The operation of this particular configuration of the cam profile 25A, 25B will be clarified hereinafter with reference to the sequence of operation of Figures 7 to 11.

The front part of the plunger 21 is provided with a filter 31, for example constituted by a perforated metal cylinder head. A cavity 33 is provided at the rear of the filter 31, in which the coffee produced during the infusion cycle is collected. The cavity 33 is in fluid connection with a conduit 35 for discharging the coffee, provided for example with a flexible tube, which allows a translational movement between the seat 19 and the plunger 21 during the various stages of the brewing cycle. The flexible tube 35 is connected to a channel 37, which in turn is in connection with the machine supply jet (s) 7A, 7B by means of a circuit not shown and which can be easily designed by one skilled in the art. Advantageously, in this embodiment, the duct 37 is coaxial with respect to the rotary unit 13, since it is provided on the rotary pin 13A.

The brewing unit further comprises a complementary plunger 41, movable in the manner hereinafter described between various operating positions. The complementary plunger 41 has a cross section substantially corresponding to the cross section of the seat 19 and the plunger head 21, in the example shown a substantially circular cross section. It is provided with a transverse pin 43, which is substantially parallel to the pin 23 and the opposite ends of which engage in cam profiles 45A, 45B provided on the fixed plates 9A, 9B, respectively. The two cam profiles 45A, 45B are equal to each other and basically constitute cams with grooves of which the pin 43 forms the sensor.

In one embodiment, the cams with grooves or cam profiles 45A, 45B have a concentric portion

ES 2 373 191 T3 approximately circumferential with respect to the axis AA of rotation of the rotary unit 13. Said circumferential part is rounded to a cam section that develops gradually away from the axis AA of rotation and has, for example, a concavity that faces the opposite side to the concavity (oriented towards the axis AA) of the circumferential part of the same. cam.

The complementary plunger 41 has a through conduit 47 (see in particular figure 6) connected to a flexible tube 49 for supplying pressurized hot water coming from the boiler (not shown) of the coffee machine 1. Hot water fed through a filter is percolated through compressed ground coffee into the brewing chamber defined within seat 19 between the top of plunger 21, i.e., filter 31, and a filter 41A front of the plunger. 41 complementary. The possibility of inverting the hydraulic circuit by supplying hot water under pressure through the plunger 21 and extracting the coffee produced in the brewing chamber through the conduit 47 provided in the complementary plunger 41 is not excluded.

The rotating unit 13 comprises a system for engaging the complementary piston 41 to move said complementary piston along a path defined by the pair of cam profiles 45A, 45B. In one embodiment, said extraction system comprises at least a first pair of tabs 51A, 53A and preferably two pairs of tabs 51A, 53A; 51B, 53B that are substantially the same as each other. The arrangement of two pairs of lugs allows the pin 43 to be engaged in a balanced manner in the vicinity of its ends, which can slide into the notched cams 45A, 45B.

In one embodiment, each of the tabs 51A, 53A; 51B, 53B has a rectilinear edge designated by 55A, 55B for tabs 51A, 51B and by 57a, 57B for tabs 53A, 53B. The edges 55A, 57A and 55B, 57B are opposite each other and define a mutual sliding channel between the edges themselves and the pin 43. Each appendix 51A, 51B, 53A, 53B also has a respective curvilinear edge or profile 59A, 61A for appendices 51A, 53A and 59B, 61B for appendices 51B, 53B. As can be seen in particular in Figure 5, the appendices 51A, 51B have a development in a radial direction greater than that of the appendices 53A, 53B for the purposes that will be clarified hereinafter. The rectilinear profiles or edges 55A, 57A, 55B, 57B, 59A, 61A, 59B, 61B act in conjunction with the pin 43 of the complementary plunger 41 to cause its movement along the path that needs to be followed in the cycle of operation and defined by cam profile 45A, 45B.

The device described so far works as explained hereinafter. The infusion cycle begins in the position schematically represented in figure 7. In this position, the rotating unit 13 is positioned in such a way that the seat 19 is arranged in a position that is for example substantially vertical below a hopper designated as a whole by T, by means of which the ground coffee C is load within the space defined between the side walls of the seat 19 and the front surface, defined by the filter 31, of the plunger 21. The ground coffee C can be produced directly by a grinder assembly contained in the machine 1, which grinds coffee beans, or if it cannot be taken from a container of ground coffee, or if it cannot be loaded again manually by an operator, for example with the help of a dosing device.

As can be seen in figure 7, the pin 23 that constitutes the sensor for the cam profiles 25A, 25B is located in a part of the curve of said cam at a maximum distance from the axis AA of rotation of the rotating unit 13 . The complementary plunger 41 is in an inoperative position, with the pin 43 (which constitutes the sensor for the cam profiles 45A, 45B) arranged in the vicinity of or in a position corresponding to the upper end of the profiles 45A, 45B of cam. An element may be provided to lock the complementary plunger 41 in this position. For example, the locking element can be an elastic element, or else an element with a control actuator. The front surface 41A of the complementary plunger 41 can advantageously be curved in order to follow the external cylindrical profile of the rotary unit 13 and thus remain at rest with said external surface during the rear rotary movement of the rotary unit 13 controlled by the motor. drive (not shown).

Figure 8 shows the first stage of rotation according to arrow f13 of the rotating unit 13 with the seat 19 and the plunger 21 housed and sliding therein. In the angular position of Figure 8, the axis BB of the seat 19 is aligned with the axis of the complementary plunger 41, and the edge 55A, 55B of each of the appendages 51A, 51B, which are fixed with respect to the unit 13 rotating, comes into contact with pin 43.

As the rotation according to the arrow f13 proceeds, the rotating unit 13 together with it extracts the complementary plunger 41 thanks to the appendices 51A, 51B. The cam profile of the grooves 45A, 45B along which the plunger 43 slides driven by the rotation of the rotary unit 13 is such that, as the rotation of the rotary unit 13 advances according to the arrow f13 around from the axis AA, the complementary piston approaches the axis AA which penetrates into the seat or cylinder 19 provided in the rotating unit 13.

Figure 10 shows the maximum rotation position of the rotatable unit 13 clockwise (in the example). In this position, the plunger 21 has been pushed by means of the pin 23 which cooperates with the cam slots 25A, 25B towards the complementary plunger, and the latter is located within the seat 19. As can be seen from a comparison between figures 9 and 10, between angular positions

ES 2 373 191 T3 assumed by the infusion unit in these two figures there is a difference in distance between the plunger 21 and the complementary plunger 41 and therefore a difference in the volume of the infusion chamber defined between the plunger 21, the plunger 41 complementary and the cylindrical wall of the seat 19 within which the elements mentioned above slide. In both positions of Figures 9 and 10, the brewing chamber is closed and within it is a dose of compressed coffee C as a result of the pressure exerted by the opposing surfaces of plunger 21 and complementary plunger 41. In all intermediate angular positions between those represented respectively in Figure 9 and Figure 10, a closed infusion chamber of gradually varying volume is defined.

According to the final angular position assumed by the rotary unit 13, it is therefore possible to define a volume infusion chamber that varies between the maximum volume (figure 9) and the minimum volume (figure 10). In each of these positions, the appropriate infusion step can take place with the introduction of the pressurized water from the boiler and the collection, through the axis AA, of the coffee produced. Thanks to the particular configuration of the brewing unit with the cam profiles 25A, 25B, 45A, 45B, the pressure exerted by the compression of the coffee and by the water supplied in the brewing chamber on the opposite surfaces of the plunger 21 and the The complementary plunger 41 is compensated to a greater degree by the reaction forces that are generated between the pins 23, 43 and the respective cam profiles 25A, 25B and 45A, 45B described above. Therefore, The infusion can take place in any of the angular positions between that of Figure 9 and that of Figure 10 without resorting to any particular measure to keep the rotating unit 13 locked in position and in particular without the pressure within the infusion chamber generates a motor torque in the motor shaft that would tend to reverse the rotational movement of the motor itself and therefore would tend to return the rotating unit 13 to the initial position of the figure

7.

Once the infusion stage has been completed, the movement of the rotating unit 13 is reversed, and the unit itself is brought from the infusion position to the discharge position to discharge the spent coffee CE, shown in figure 11. In this position, the pin 23 occupies a position corresponding to the end 25Y of the two cams with grooves or cam profiles 25A, 25B, and therefore the piston itself takes the position of maximum approach to the mouth of the seat 19. In practice, the front surface of the filter 31 is flush with the lateral cylindrical surface of the rotating unit 13. A scraper provided in this area can be useful to scrape the spent coffee from the surface of the filter 31.

In the return movement (counter-clockwise rotation as shown in the drawing) from the infusion position to the discharge position of Figure 11, the unit 13 rotates through the appendices 53A, 53B The shorter ones return the complementary plunger 41 to its rest position as shown in FIG. 11. This is obtained as a result of the pushing of the rectilinear edges 57A, 57B on the pin 43. The different length of the tabs 51A, 51B and 53A, 53B causes the complementary plunger 41 to be released by the tabs 53A, 53B from the rest position of FIG. 11 and is taken again by the longer tabs 51A, 51B at the reverse movement from the position of Figure 7 to the position of Figures 8, 9 and 10.

Realization of Figures 12 to 18

Figures 12 to 18 show a first embodiment of the infusion unit according to the invention. Furthermore the infusion unit of figures 12 to 18, again designated as a whole by 3, can be inserted in a coffee machine of the type illustrated in figure 1 or in other machines even of a professional type or in an automatic dispenser or vending machine, or similar.

In this embodiment, the brewing unit 3 has a pair of fixed plates 109A and 109B joined together by transverse elements 111 to form a support structure, possibly removable from the coffee machine. Disposed between the fixed plates 109A, 109B are a plunger 113, a seat 115 in which plunger 115 slides, within which the brew chamber is defined, and a complementary plunger 117. These three elements (plunger 113, seat 115 and complementary plunger 117) have a mutual movement to carry out the infusion cycle. As will become clear from the following, in one possible embodiment, the plunger 113 and seat 115 carry out rotary and translational movements, while in one embodiment the complementary plunger 117 performs only translational movements.

The movement of the three elements 113, 115, 117 is controlled by means of cam profiles. A first set of fixed cam profiles is provided on the fixed plates 109A, 109B. In this embodiment, both plates 109A, 109B have cam profiles, and the fixed cam profiles provided on said plates are mirror-image of each other. Accordingly, the profiles of plate 109B will be described hereinafter, it being understood that in plate 109A there are specular profiles. More specifically, the set of fixed cam profiles comprises a first cam profile 121 to control the movement of the plunger 113, a second fixed cam profile 123 to control the movement of the seat 115, and a third cam profile 125 to control the movement. of the complementary plunger 117.

The fixed cam profiles are shown in a front view in Figure 12A, in which one of the fixed plates 109A, 109B is shown in isolation from the other mechanical parts.

IS 2 373 191 T3

Within the cam profile 121 slides a sensor 113B formed by a transverse pin substantially orthogonal to the axis BB of the plunger 113 and of the infusion chamber. The plug 113B is thus orthogonal to the rod 113A of the plunger 113. By providing a double channel 121 in the two plates 109A, 109B, the plug 113B is guided at both ends along said slotted cams.

The pins 115A are fixed to the seat 115, preferably opposite and coaxial to each other, which engage in the two cam profiles 123, which are preferably equal to each other, provided in the two fixed plates 109A, 109B.

Finally, there are opposing and preferably coaxial sliding pins or blocks 117A fixed on the complementary plunger 117, which engage the cam profiles 125 of the two fixed plates 109A, 109B. More precisely, the pins 117A are mounted in a U-shaped clamp 117B fixed with respect to the complementary plunger 117 and possibly forming an integral part thereof.

There are two discs 131A, 131B arranged on the outside of the fixed plates 109A, 109B that constitute cams that rotate about a common axis AA, which coincides with the support axis of the plates 109A, 109B. In one embodiment, each rotating cam or disc 131A, 131 B carries a set of rotating cam profiles, which are preferably substantially mirror-image of each other. Hereinafter, cam profiles of disc or cam 131B are described. with particular reference to Figure 12B (showing a front view of one of the rotating cams) and to Figure 13, a first rotating cam profile 133 is arranged on the disk or cam 131B, to control the movement of the plunger 113, a second rotatable cam profile 135 to control the movement of the seat 115 and a third rotatable cam profile 137 to control the movement of the complementary plunger 117. As can be understood in particular from Figure 12, the opposite ends of the plug 113B traverse the fixed plates 109A, 109B to engage not only the two fixed cam profiles 121 but also the rotatable cam profiles 133. Practically the same applies to the two opposing pins 115A fixed with respect to the seat 115, which protrude through the cam profiles 123 provided on the fixed plates 109A, 109B and engage in the movable cam profiles 135 provided on the discs. Rotary cam 131A, 131B. The opposing pins 117A fixed with respect to the complementary plunger 117 pass through the slots or the cam profiles 125 of the plates 109A, 109B and also engage in the cam profiles 137 of the rotating cams 131A, 131B.

Basically, each of the elements 113, 115 and 117, with respective pins that act as sensors, is hooked to two pairs of cam profiles, in which each pair comprises a fixed profile and a profile that rotates around the common axis AA . In this way, the mutual rotation between the fixed plates 109A, 109B and the rotating discs or cams 131A, 131B controls the translational movement and / or rotation of the elements 113, 115, 117, with laws of motion that will be described in detail. hereinafter with reference to the sequence of Figures 13 to 18.

The rotational movement of the cams 131A, 131B can be obtained for example by providing a perimeter meshing (designated as a whole by 131D in Figure 13 for the cam 131B) with which a pair of motor-driven pinions (one of the which is designated by 132 in Figure 13). An alternative solution, for example with an axial movement transmission, is not excluded.

In the configuration of figure 13, the brewing unit 1 is in a first position, in which the coffee is loaded into the open brewing chamber, that is, in the space defined by the cylindrical wall of the seat 115 and by the end defined by plunger head 113. The plunger 113 is provided with a filter similar to the filter 31 of the plunger 21 of the embodiment shown in Figures 1 to 11, and there is a similar system associated with it to collect and discharge the beverage (coffee) obtained by extracting the aromas. from the ground coffee loaded into the brew chamber. There is a conduit associated, instead, with the complementary plunger 117 to supply the hot water under pressure. The possibility of reversing the arrangement of the water supply and the coffee supply is not excluded.

In the position of figure 13, the pin 113B fixed with respect to the plunger 113 is hooked on the cam profile or cam 121 with grooves in a position that corresponds to a curvilinear section 121A of the profile 121 itself, which is arranged at the distance with respect to the axis AA of rotation of the rotating cams or discs 131A, 131B. The pin 113B is also hooked as it passes through the thickness of the fixed plates 109A, 109B, as mentioned above, in the cams with grooves or cam profiles 133 in a position corresponding to a vertex 133A disposed between a part 133B substantially radial rectilinear and a substantially rectilinear portion 133C inclined with respect to the radius of said cam profile 133.

The pins 115A fixed with respect to the seat 115 engage in a curvilinear part 123A of fixed cam profiles or cams 123 with respective grooves and in a position corresponding to a curve or vertex 135A of the rotating cam profiles or cams 135 with grooves. .

Finally, the pins 117A fixed with respect to the complementary plunger 117 engage in the cam with rectilinear radial grooves or cam profile 125 and at an intermediate point of the notched cam or cam profile 137 having substantially the pattern of a part of a spiral about the axis AA of rotation of the cams 131A, 131B.

IS 2 373 191 T3

In figure 14 the angular position reached by the infusion unit 1 after a first rotation (in an orientation in an anti-clockwise direction as seen in the drawing) towards the infusion position is shown. In this configuration, the axis BB of the infusion chamber is aligned with the axis of the complementary plunger 117, and the latter can be inserted into the seat 115. The angular displacement from the position of figure 13 to the position of figure 14 is obtained by extraction in rotation, by means of the rotating disks or cams 131A, 131B, the pins 113B and 115A fixed with respect to the plunger 113 and the seat 115 by engaging said pins in cam profiles 133 (for plunger 113) and 135 (for seat 115). From the position of Figure 13 to the position of Figure 14, the pin 113B has been pushed by the cam profile 133 along the path 121A of the cam profile 121 substantially concentric to the axis AA so that the plunger itself it has basically performed a simple rotary movement. Similarly, the pins 115A have followed a substantially circular section concentric to the axis AA of the cam profile 123. Accordingly, also the seat 115 has at this stage made a substantial rotational movement without translation about the axis AA.

When passing from the position of figure 14 to the position of figure 15, the rotating cams or cam discs 131A, 131B have made an additional rotation around the axis AA, which causes, by means of the profiles 133, 135 and 137 rotary cam loops, a translational movement relative to each other and relative to the fixed plates 109A, 109B of the three elements: plunger 113, seat or infusion chamber 115, and complementary plunger 117.

As can be seen from a comparison between Figures 14 and 15, in particular the plunger has made a translational movement such that the pin 113B moves along a radial rectilinear portion 121B of the fixed cam profile 121, said movement being caused by the thrust exerted on said pin by the part 133C of the rotating cam profile 133. The pair of pins 115A fixed with respect to seat 115 have moved along a substantially radial rectilinear portion 123B of the notched cam or fixed cam profile 123 as a result of the thrust on the pins 115A generated by the cam or cam profile. 135 rotatable with grooves and more precisely as a result of the thrust exerted by a curvilinear part 135B of said profile. The radial movement towards the axis AA of rotation of the cams or disks 131A, 131B of the complementary plunger 117 along the rectilinear cam profile 125 has been obtained as a result of the thrust generated by the spirally rotatable cam profile 137.

The configuration of FIG. 15 is such that the complementary plunger 117 has entered the seat 115 an amount sufficient to close by means of respective seals the infusion chamber delimited between the opposite front surfaces of the complementary plunger 117 and the plunger 113 as well as by the lateral cylindrical surface of the seat 115. In this position, then, the infusion can be carried out. This is the position where the infusion chamber has the maximum possible volume. Figures 16 and 17 below show two additional mutual positions of elements 113, 115, 117 reached by means of further mutual translation of said components. The translations of the components 113, 115, 117 are obtained again as a result of the thrust of the rotating cam profiles or cams 133, 135 and 137 with grooves on the pins 113B, 115A and 117A, which are guided along the fixed cam profiles or cams 121, 123 and 125 with grooves.

More specifically, the configuration of Figure 16 is obtained with a translation along the common axis BB of both the complementary piston 117 and the piston 113 with a mutual approach of the respective front surfaces, while the seat 115 remains in a fixed position. , which corresponds to the terminal end of the rectilinear part 123B of the cam profile 123. The position is maintained thanks to the fact that the portion 135B of the rotating cam profile 135 is substantially concentric with respect to the axis AA of rotation. From figure 16 to figure 17 there has been a further movement of mutual approach of the complementary plunger 117 and of the plunger 113 again as a result of a translational movement of both elements with respect to the fixed plates 109A, 109B, controlled by a tracking of the rotational movement in a clockwise orientation (as displayed in the drawing) of the rotary cams 131A, 131B.

It is also deduced in this case that the infusion unit has a plurality of possible infusion positions: in the position of figure 15 an infusion chamber with the maximum volume is obtained; in the position of figure 16 the infusion chamber has an intermediate size; and in Figure 17 the infusion chamber has the minimum size. The latter can be used for example for the production of a single dose of espresso coffee, while the position of figure 16 can be used for example for a simultaneous supply of two espresso coffees in a single infusion operation. The position of figure 15 can be used for the production of fresh coffee. In all cases, the quantity of coffee dispensed into the brewing chamber can be regulated in a manner known per se.

It should be noted that the various positions of the infusion unit, corresponding to different volumes of the infusion chamber, are precisely controlled by the shape of the cams and by the angular rotation of the rotating cams, different infusion volumes being defined by different angular positions of the rotating cams 131A, 131B. In the same way, in the embodiment described above (Figures 1-11), the volume of the infusion chamber can be precisely controlled by the angular position of the rotating unit 13 thanks to the shape of the cams 45A, 45B; 25A, 25B.

In all positions a substantial proportion of the reaction forces are supplied to the plunger 113 and the

ES 2 373 191 T3 complementary plunger 117 necessary to resist the internal pressure of the infusion chamber by the cam profiles, which therefore discharge the stresses directly on the fixed structure 109A, 109B, with a substantial reduction in the torsional stresses on the motor shaft that transmits the movement to the rotating cams 131A, 131B.

Once the infusion has been carried out in one or other of the possible intermediate positions starting from that of figure 15 to that of figure 17, the infusion unit discharges the spent coffee from the infusion chamber. This unloading step involves reversing the rotational movement of the cams 131A, 131B until the plunger 113 is brought into the seat 115 and the complementary plunger 117 is brought into the configuration of Figure 18. This angular position is reached by passing through the coffee loading position (figure 13).

The shape of the mobile and fixed cam profiles is such that it causes, with this inverse rotational movement, the translational displacement of the piston 117 complementary to the position of maximum distance from the axis of rotation AA, as well as the angular rotation of the seat. 115 and plunger 113 from the position of Figure 17 to the position of Figure 18 with a rotation of the axis BB through an angle α, and translating both the seat 115 and the plunger 113 along the axis BB such that the plunger 113 is positioned with its head level with or slightly protruding from the seat 115 so as to push the spent cartridge out of said seat. compressed ground coffee. A scraper may be provided in the discharge area to facilitate detachment of the coffee from the front surface of plunger 113.

As can be seen in particular from a comparison between Figures 13 and 18, in the unloading position the seat 115 has undergone an oscillation or rotation through approximately 80 ° with respect to the vertical and a translation which has caused the backward movement of the same, while the plunger has undergone a similar rotation through approximately 80 ° with respect to the vertical position of FIG. 13 and a translational advance by an amount substantially corresponding to the axial extension of the seat 115.

A reverse movement through approximately 80 ° from the position of FIG. 18 returns the brewing unit to the position of FIG. 13 ready for a new infusion cycle.

Realization of figures 19 to 39

Figures 19 to 39 show an embodiment similar to that of Figures 12 to 18, with some construction variations, which will be described in greater detail hereinafter. The same reference numbers designate parts that are the same or equivalent to those of Figures 12 to 18.

First, it can be seen that in the embodiment shown in Figures 19-39, the fixed plates 109A, 109B, in which the fixed cam profiles 121, 123 and 125 are provided, are arranged on the outside, while the Moving cams 131A, 131B are arranged within the fixed plates.

The movement is supplied to the rotating cams 131A, 131B, instead of by means of pinions that mesh with gears provided in the cams themselves, by means of a hexagonal shaft 134 (Figures 28 and 29) fixed with respect to one of the two cams 131A, 131B, while the other cam 131B, 131A (figures 26 and 27) is restricted to the previous one through transverse elements 136 and has a hub 132 that constitutes a coupling and support with the corresponding fixed plate. Hex shaft 134 is coupled to a motor shaft of an electric motor (not shown) that is part of the machine into which the assembly is inserted. It can be understood that the mechanical coupling between the brewing unit and the motor can also take on a different shape, for example with a slotted profile or some others.

The shapes of the cam profiles are substantially similar (see in particular Figures 23-29) to those of the previous embodiment and are designated by the same reference numerals. On the other hand, with regard in particular to the cam profile 137, it can be seen that it is a double profile (see in particular the local cross-section of Figure 20A), that is, each cam 131 A, 131 B has a double groove 137 , wherein a corresponding restricted dual sensor is hooked to the complementary plunger 117. In this way, the resistance of the cams to the stresses that are discharged on them as a result of the pressure generated in the chamber during infusion increases.

Furthermore, the part 135B of the cam 135 is not concentric to the axis AA of rotation of the cams so that in the closing movement of the infusion chamber, after engaging the complementary plunger and the seat 115 with each other, when the cams 131A , 131B rotate, seat 115 moves along axis AA of the plunger and the complementary plunger.

Fixed cam 125 for mating plunger 117 is larger, and is engaged not by a fixed pin relative to mating plunger 117, but instead directly by clamp 117B, which in this case has no pegs 117A. In this embodiment, in order to engage the clamp 117B of the complementary plunger 117 with the cams 137 with double grooves, an oscillating sensor 117C (Figures 20, 20A) is provided for each double groove 137. The oscillating sensor 117C has two opposing appendages 117D that hook one onto each of the

ES 2 373 191 T3 two grooves of the respective cam 137.

Furthermore, the infusion unit of Figures 19-39 comprises a mechanism to facilitate the discharge of the spent product (ground coffee tablet) after infusion. Said mechanism comprises an oscillating surface 161 articulated by means of two oscillating arms 163 to the two fixed plates 109A, 109B. The oscillation of the surface 161 is controlled by means of a link-upright rod 165, articulated at one end with one of the two oscillating arms 163 by means of a slot 163A and a pin 165A. At the opposite end, the tie rod-strut 165 has a pin 165B that engages a cam profile 167. The fixed plate 109A has a rectilinear slot 168 (FIG. 23), in which the tie rod-strut 165 is guided in its movement controlled by the cam 167.

As can be seen from the movement of the brewing unit, shown in Figures 19-22 and 30, 33, 35, the cam 167 controls the rocking movement of the surface 161 so that the coffee tablet (PC, Figure 35), or other spent product exiting the brewing chamber at the end of the cycle, is discharged into a free container assembly of the brewing unit and not shown.

The mechanism described above for discharging spent tablets can also be used in the embodiments described above.

Figures 30-35 show in detail the circuit for supplying hot water to the brewing unit and for supplying coffee from the brewing chamber, as well as the operation thereof during the brewing cycle. This circuit can also be used in the embodiments described above.

In particular, associated with the complementary plunger 117 there is a valve for regulating the back pressure, designated by 169, arranged in a coffee outlet conduit 171, in communication with the compartment provided behind the filter 172, composed for example by a perforated metal plate , which prevents the exit of solid product (for example, ground coffee) from the brewing chamber during the brewing cycle. Valve 169 can be designed to regulate back pressure, for example, as described in US-B-6,382,083.

There is a fixed connection 173 with respect to the complementary plunger 117 to supply hot water coming from a boiler (not shown and of known type). Designated by 173A is the end of connector 173, to which the supply conduit coming from the boiler is connected. A first part 175A of a telescopic conduit is fixed with respect to seat 115, a second part of which designated 175B is fixed with respect to plunger 113. The two parts 175A, 175B of the telescopic conduit are always connected to each other (see in particular figure 34), and the part 175B slides inside the part 175A following the movement of the plunger 113 in the seat 115. Instead, the connector 173 can be engaged and disengaged with respect to portion 175A, depending on the relative position between mating plunger 117 and seat 115. When the connector 173 is hooked into the portion 175A of the telescopic conduit 175A, 175B (Figure 34), a continuous path is formed for the hot water from the connection 173A to the bottom of the stem or plug 113B of the plunger 113. Said stem is centrally hollow to allow the passage of hot water along the stem to the brewing chamber. This position is assumed when the parts 113, 115 and 117 that form the infusion chamber are axially aligned and engaged with each other. In the position in which the product is loaded into the infusion chamber (Figures 30-32) and in the position in which the spent product is discharged (Figure 35), on the other hand, the connector 173 is disengaged. with respect to the telescopic conduit 173A, 173B.

In some embodiments of the invention, plunger 113 may have a configuration of the type known particularly in Figures 36-39. It has a perforated cylinder head 201, fixed with respect to a rod 203 that slides in an axial sliding seat 205 made in the body of the plunger 113 and of the rod or rod 113A. The cylinder head 201 is perforated in 201A to allow the passage of the hot water under pressure coming from the telescopic conduit 175A, 175B and the distribution of the water in the ground coffee (or other product for the preparation of the beverage) compressed inside the chamber of infusion defined between plunger 113, complementary plunger 117, and seat 115. At the opposite end from the cylinder head 201, the rod 203 has an annular gasket 207, for example an O-ring, which provides a seal on the sliding seat 205.

The sliding seat 205 is in communication with the telescopic conduit 175A, 175B through a hole 209, provided in the rod 113A of the plunger 113.

The cylinder head 201 is elastically loaded by an elastic element, for example a helical compression spring 202, towards a position disposed at a distance from the piston body 113. The piston body 113 is provided with a lip seal 204, which provides a seal on the inner cylindrical surface of the seat 115 in which the plunger slides. When the brewing chamber is closed with the ground coffee inside, the relative movement between the plunger 113 and the complementary plunger 117 causes the spring 202 to be crowded, and therefore the cylinder head 201 acts on the front part of the plunger body 113 , while the joint 207 moves below a hole 209, which is in fluid connection with the telescopic conduit 175A, 175B. In this way, with the gasket 207 arranged below the hole 209, the latter is arranged in connection with the space with an annular cross section between the axial sliding seat 205 and the stem 203 of the cylinder head 201. Said seat has,

ES 2 373 191 T3 in fact, a diameter greater than the diameter of the stem 203, the latter being guided by means of an upper bushing 210, and the lower part of the sliding seat 205, which has a cross section with a smaller diameter, to allow sealing with O-ring 207.

In this way, the water is fed through the connector 173 through the telescopic conduit 175A, 175B and along the annular space between the axial slide seat 205 and the stem 203 and reaches the space behind the cylinder head 201. Through From the holes 201A of the cylinder head 201, the water reaches the brewing chamber and passes through the compressed ground coffee in the brewing chamber.

Once the preparation of the beverage is completed, when the brewing chamber opens, the cylinder head 201 pushed by the helical spring or other equivalent elastic element 202 moves away from the plunger body 113. In this way, the annular gasket 207 it moves over the hole 209 and arranges the hole 209 (and therefore the telescopic conduit 175A, 175B and the boiler) in connection with a hollow space 211A provided in the lower part of the rod 113A of the plunger 113. The hollow space 211A is connected to the outside environment by means of two discharge holes 211B. The residual water in the supply conduit between the boiler and the orifice 209 is thus discharged to the outside, and the increase in the volume of the brewing chamber due to the relative movement between the plunger 113, the seat 115 and the plunger 117 complementary before opening the infusion chamber does not cause a suction effect within the hydraulic circuit. The pressure inside the infusion chamber reaches atmospheric pressure thanks to the connection obtained through the seat 205, the orifice 209, the space 211A and the orifices 211B. The gasket 207, in fact, is arranged (when the compression spring 202 is not crowded) in a position of the seat 205 in which the latter has a diameter greater than the diameter of the gasket 207.

With the mechanism described above, it is possible to arrange the brewing chamber in connection with the boiler thanks to the pressure exerted by the compressed ground coffee on the cylinder head 201, said pressure overcoming the elastic forces of the spring 202 and therefore causing the gasket to move. 207 below hole 209. At the same time, the fact that said pressure ceases, after opening the infusion chamber, allows the discharge of residual water in the hydraulic conduit between the piston 113 and the boiler. In the absence of additional provisions, a system thus conceived would not allow a cycle of washing and / or heating of the brewing chamber in the absence of coffee, since under the thrust of the spring 202 the cylinder head 201 would remain elevated with respect to the body of the plunger 113 even with the brewing chamber closed, and thus the gasket 207 would not close the passage between the hole 209 and the underlying hollow space 211, in communication with the external environment through holes 211B.

In order to also allow the washing and heating operations to be carried out or in any case to allow the flow of water through the infusion chamber in the absence of ground coffee, in some embodiments of the invention there are two sliders 213 associated with the plunger 113 (see in particular Figures 38, 39) housed in the sliding seats 215, transverse with respect to the axial sliding seat 205 and made in the lower part of the body or rod of the plunger 113. The sliding seats 215 are in connection at the front with the hollow space 211A, and the holes 211 B cross said sliding seats. The sliders 213 are provided with annular seals 217 arranged in the vicinity of the ends of the sliders 213 facing the space 211A. Said annular joints 217 are arranged in such a way that, depending on the axial position assumed by the sliders 213 in the respective transverse sliding seats 215, they open or close the connection between the hollow space 211A and the holes 211 B. In figure 38 the sliders 213 are pushed outwards by the respective springs 219 and are in a position such that the seals 217 do not close the passage between the hollow space 211A and the discharge or decompression holes 211B. In figure 39, instead, the sliders 213 have been pushed axially inside the sliding seats 215, and the seals 217 close the passage between the hollow space 211A and the decompression or discharge holes 211B.

In order to control the sliding movement of the sliders 213, they are provided with external ends 213A on which front cam profiles act (designated as a whole by 214 for simplicity of illustration only in Figures 38 and 39) fixed with respect to the rotating cams 131A, 131B, to push the sliders into their seats. The reverse movement is obtained through coil springs 219. The cam profiles to control the movement of the sliders 213 are arranged on the cams 131A, 131B so that the sliders 213 are in the closed position (in which they interrupt the connection to the outlet holes 211B) when the chamber infusion is closed and whatever the closing position of the chamber, as well as whatever the state of the chamber (whether full or empty).

In this way, it is possible to cause hot water to circulate through the brewing chamber even without ground coffee being present in it. On the other hand, when the infusion chamber is not in the closed position, the holes 211B are in connection with the water supply conduit and allow the residual water to be purged from the circuit.

Realization of figures 40 to 45

Figures 40-45 show cross sections of a further embodiment of an infusion unit similar to the embodiment of Figures 19 onwards. Equal or corresponding parts are designated with the same numbers

Reference ES 2 373 191 T3 and are not described in detail again. The embodiment of Figures 40-45 differs from the embodiment of Figures 19 onwards in two respects.

According to a first aspect, the infusion unit shown in Figures 40-45 is provided with an additional operating position, best shown in Figures 41 and 42. Said additional operating position is intermediate between the loading position of coffee shown in Figure 40 and an infusion position shown in Figure 43. In said intermediate position, the seal 204 surrounding the plunger body 113 is free from the seat 115, so that an annular opening is created between the plunger 113 and the seat 115. If hot water is fed into the brewing chamber therein position, the coffee powder present in the brewing chamber generates a back pressure that prevents the flow of water. As a consequence, the water flows through the annular opening that surrounds the plunger 113 and thus heats the entire water conduit from the water heater to the bottom of the brewing chamber.

Once enough hot water has been fed to heat the brewing unit, the latter takes one of the coffee dispensing positions shown in Figures 43, 44, 45. Now the continuous water flow passes through the coffee powder tablet contained in the infusion chamber and extracts the drink from the coffee powder. The three positions shown in figures 43, 44 and 45 correspond to three different dispensing states: in figure 43 normal coffee is produced (called filter coffee or "American coffee"), with a fairly low water pressure and dust slightly compressed coffee; the position of Figure 44 is one where two espresso (or one double espresso) are produced during the same brew cycle; and finally, figure 45 shows the position taken by the brewing unit to produce a single espresso.

As mentioned above, an adjustable back pressure valve may be provided at the outlet port, in fluid connection with the infusion chamber, in order to maintain the desired pressure in the infusion chamber. In the embodiment of Figures 40-45 a double orifice arrangement is provided, for optimum pressure control. This double hole arrangement, which will be described hereinafter, may also be used in any one of the embodiments described above. In order to show the double hole arrangement, the cross section of Figure 42 is taken in a slightly different position from the cross section of the remaining Figures 40, 41, 43, 44, 45. These latter figures show the first beverage outlet port provided in the complementary plunger body 117, said port being formed by a conduit 301. The conduit 301 has a first part with a larger diameter and a second part with a smaller diameter. , the two parts being connected to each other in a transition zone 301A. A conduit 303 supported stationary relative to frame 109A, 109B is telescopically disposed in conduit 301, such that when mating plunger 117 moves relative to frame 109A, 109B conduit 303 and conduit 301 slide each. Conduit 303 is provided with a first annular seal 305 and a second annular seal 307, disposed near the distal end and at an intermediate position of conduit 303, respectively. The distal end of the conduit 303 is closed at the front and is provided with radial openings 309, said openings being provided behind the seal 305.

The conduit 303 can therefore put the interior of the brewing chamber in fluid communication with a coffee outlet conduit 311 arranged in the upper part of the structure 109A, 109B. When the brewing unit takes the position shown in Figure 43, the openings 309 are positioned between the brewing chamber and the transition zone 303A of the conduit 303, so that the coffee beverage produced in the brewing chamber can flow into the infusion chamber. through openings 309 to conduit 303 and from there to outlet conduit 311. The flow cross section is such that a substantial zero overpressure is generated at the outlet of the brew chamber.

A second beverage dispensing port is provided in the complementary plunger body 117, as shown in FIG. 42 at 315. The second beverage dispensing port 315 is formed by a conduit in which a Conduit 317. Similar to conduit 303, conduit 317 is also supported integrally by structure 109A, 109B. Conduit 315 and conduit arrangement 317 fluidly connect the interior of the infusion chamber to a back pressure valve 319. This valve can be adjusted and designed as disclosed in US Patent No. 6382083, the contents of which are incorporated herein by reference.

When the brew chamber is closed in the position shown in Figure 43, the coffee flows through conduit 301, 303, which offers less resistance to flow. If, on the other hand, the infusion chamber is closed in the position shown in Figures 44 or 45, flow through the conduits 301, 303 is impeded, because the openings 309 are positioned beyond the seal 305 and the latter closes against the narrowest part of conduit 301. Accordingly, under the thrust of the water feed pump of the machine, the coffee is forced to flow through the hole 315, the conduit 317 and the back pressure valve 319.

Therefore, depending on the position taken by the brewing chamber, different back pressure conditions are generated and a drink of different qualities is produced.

Back Pressure Adjustment Valve Figures 46A-46D

Figures 46A-46D show a novel back pressure valve for an infusion unit according to

ES 2 373 191 T3 invention. The valve is shown insulated but it should be understood that said valve can be arranged in the outlet conduit through which the coffee beverage produced is dispensed into the brewing chamber of the brewing unit. Said valve can be arranged for example in the coffee outlet conduit 171 (figure 30).

The back pressure valve 400 is provided with a coffee dispensing conduit 401 in fluid connection with the brewing chamber and carried by the complementary plunger of the brewing unit, such as the complementary plunger 117. The conduit 401 can be telescopically slid without a coffee outlet conduit such as conduit 171, so that the complementary plunger 117 can move relative to the support structure on which the back pressure valve 400 is supported.

The back pressure valve 400 includes an external housing 403. According to some embodiments, for design purposes said outer housing 403 is composed of two parts 403A, 403B. A slider 405 is slidably housed in housing 403. Said slider 405 can slide along double arrow f405 to selectively take one of several operating positions as disclosed herein below. In some embodiments the slide 405 has a threaded end 405A that can be engaged by a manual actuator or a servo motor or the like (not shown) to control the sliding movement of said slide and precisely position the slide in a selected one of a plurality axial positions in housing 403.

Along its side wall, housing 403 has a coffee inlet port 407 in fluid communication with conduit 401, a coffee outlet port 409 in fluid communication with a spout or nozzle from which coffee is dispensed. , and a pressure relief port 411. Additionally, a front air inlet port 412 is provided in a front position. The internal diameter of the portion 403A of the housing 403 is variable from stage to stage, with a larger diameter in the section where the decompression hole 411 is arranged, an intermediate diameter where the coffee inlet hole 407 is located, and a diameter smallest in the most forward area.

The slide 405 has an axial cavity 413 terminating with a front opening 413A and in fluid communication with two sets of radial openings 415, 417 longitudinally spaced apart. Sealing rings 419, 421, 423 are arranged on the outer surface of the slide, acting in correspondence of the three variable diameter portions of the housing portion 403A. The front opening 413A of the slide 405 is closed by a shutter or closure element 427 elastically tensioned against the slide 405 by a helical compression spring 429. Said spring 429 is retained between the shutter 427 and a front sliding pin 431 provided with a sealing ring 433, which closes the front air inlet port 412. The pin 431 is provided with a stop ring 431A and an end portion projecting from the housing 403, formed to provide a guiding effect in the air inlet hole 412 but allowing air to enter when the pin 431 is moved to the left (in the drawings), in order to put the interior of the housing 403 and of the slide 405 in communication with the surroundings, for the purposes that will be explained later.

The valve 400 described so far operates as follows. In Fig. 46A the slide 405 is located in its rightmost position (with reference to the figures), that is, with the spring 429 in its position of maximum compression. The sealing ring 423 moves beyond the section of the housing part 403 having the intermediate internal diameter, and the radial openings 417 are thus in fluid communication (through the cavity of the housing part 403B) with the coffee outlet hole 409. The coffee inlet port 401 is in fluid communication, via radial openings 415, with the internal axial cavity 413 of the slide 405. The coffee can therefore flow from the inlet port 401 to the outlet port 409. The pressure in conduit 401 is thus substantially equal to the ambient pressure (ie, the infusion takes place at substantially zero back pressure). The flow of coffee through the decompression port 411 is prevented by the sealing ring 421 and the spring 429 maintains both the front opening 413A and the air inlet port 412 in a closed position.

In Fig. 46B the slide 405 is moved slightly to the left (in the drawings) so that the radial openings 415 and 417 are in fluid communication with the conduit 401 and the internal cavity 413 of the slide 405. The spring 429 is in fluid communication. compresses slightly less than in Fig. 46A. The water flows through the brewing chamber and the coffee thus prepared flows through the conduit 401, the radial openings 415, 417, the axial cavity 413 and the outlet orifice 409 when the back pressure at the outlet of the brewing chamber , that is, in the conduit 401, it reaches a value defined by the force exerted by the spring 429, that is, when the pressure generates in the obturator 427 a force greater than the force exerted by the spring 429.

In figure 46C the slide 405 is again moved slightly more to the left (in the drawings) with respect to figure 46B, so that the spring 429 is less compressed and therefore the back pressure at which the coffee flows through Conduit 401 is less than Figure 46B (but greater than Figure 46A, where no back pressure is required). In both Figures 46B and 46C, the decompression duct 411 and the air inlet port 412 are closed.

Therefore, the position of Figure 46A is the only one in which normal coffee is prepared, substantially without

ES 2 373 191 T3 back pressure, so that a lighter drink without cream is obtained. A stronger or lighter espresso is obtained with valve 400 set to the position of FIG. 46B and 46C respectively.

The position of the slider 405 can be selected manually or automatically by the user. In some embodiments, this can be accomplished by a screw mechanism or the like. In some preferred embodiments, selection of the back pressure can be accomplished with a servo actuator, at the command of the user by means of a suitable user interface, such as a touch screen, one or more buttons, or the like. Preferably, the position of the back pressure valve 400 can be correlated to the volume of the infusion chamber so that the most appropriate infusion chamber volume is selected for each back pressure set by the user on the valve 400.

At the end of an infusion cycle, regardless of which position the slide 405 of the valve 400 took, the slide moves to the position of Figure 46D, that is, it moves all the way to the left side (in the drawings). In this position the air inlet port 412 opens and an air flow passage is created through the interior of the housing portion 403B, the axial cavity 413 of the slide 405, the radial openings 415 and the port 411 of decompression. In this way, the pressure within the brewing chamber is relieved and air enters the hydraulic circuit of the brewing unit, allowing the brewing chamber to open.

Realization of figures 47 - 50

Figures 47-50 show a further embodiment of the infusion unit according to the invention. This embodiment is similar to that shown in Figures 19-35, but the fixed cam profiles are shaped differently in order to achieve a slightly different sequence in the movement of the brewing unit. The main difference is that in the embodiment of Figures 47-50 the position in which the spent coffee powder is discharged from the brew chamber is on the opposite side of the discharge position in the previously described embodiments (Figures 1935 in particular) with respect to the coffee loading position.

Since the infusion unit according to Figures 47-50 is substantially similar to the previous embodiments in many respects, the characteristics that differ from the previous embodiments will be described hereinafter mainly, while the characteristics that are similar, identical. or equivalent to the above embodiments will not be described in further detail. It should also be noted that the infusion unit according to Figures 47-50 can be provided with any one of the back pressure regulating valves described above.

In the embodiment of Figures 47-50, the brewing unit is again composed of a pair of fixed plates, on which three fixed cam profiles are provided, each fixed plate combining with a rotating cam, on which are arranged rotating cam profiles. Figure 47 shows a front view of one of the fixed plates, designated 500. The opposite fixed plate is substantially symmetrical, at least as regards the cam profiles, which are to be described hereinafter.

The fixed plate is provided with three fixed cam profiles 501, 503, and 505, which have functions very similar to those of the fixed cams 121, 123, and 125 of Figures 19-35. More specifically, the cam profile 501 controls the movement of the infusion chamber plunger, the cam profile 503 controls the movement of the seat in which the infusion chamber plunger slides, and the cam profile 505 controls the movement. of the complementary plunger. In this embodiment, however, the cam profiles 501 and 503 are shaped primarily as closed channels, that is, endless curves in which the corresponding impeller or pin slides.

In addition, each of said cam profiles 501 and 503 has spring tabs that protrude into the channels in order to prevent some movements of the drivers or pins that are firmly attached to the plunger and the infusion chamber seat. More specifically the cam profile 501 has a first tab in the form of a laminar spring 501A with a free end 501B protruding into the channel defining the cam profile 501. The shape of said spring-loaded or resilient tab 501A is best shown in cross-section of FIG. 47A. As will be explained more clearly below, the resilient tab 501a limits the movement of the pin, which controls the movement of the plunger. A second elastic tab in the form of a laminar spring 501C is disposed along a central channel portion 501D of the cam profile 501. The tab 501C has a free end 501E and its shape is best shown in the cross section of Figure 47B. The center channel part 501D connects a lower cam channel part with an upper cam channel part of the cam profile 501. The upper channel portion is designated 501F as a whole and has a substantially outwardly concave shape. The lower channel portion has a substantially outwardly convex shape and is comprised of two sections 501 G and 501 H, the elastic tab 501A being arranged so as to prevent the pin sliding in the channel 501 from moving from the section 501 G to section 501 H and is forced to move from section 501 G to intermediate cam portion 501 D.

Similarly, the fixed cam profile 503 has a lower cam profile section 503A that is shaped with an outward-facing concavity and oriented toward the central axis AA of the brewing unit, around which the cams 510 Swivel rotates with the control of a motor (not shown). The closed path of profile 503 of

The cam is completed by an outwardly convex upper profile section or part 503B along which a tab 503C is arranged in the form of a leaf spring. The free end 503D of said tab protrudes into the channel-shaped cam profile 503, as best shown in cross-section of Figure 47C. A substantially rectilinear cam profile section 503E extends from section 503B toward cam profile 505, starting from a position substantially corresponding to the free end of tab 503C. The tab 503C prevents the respective driver or pin, which moves along the cam profile 503, from moving along the section 503B from right to left beyond the rectilinear portion 503D and forces said pin to enter said rectilinear portion 503D of the cam profile, as will be explained in more detail below.

Figure 48 shows a front view of one of the two rotary cams on which the rotary cam profiles are provided. The rotating cam is designated 510. The three rotating cam profiles are formed on said rotating cam. Such rotatable cam profiles are marked 533, 535, and 537 and have substantially the same shape and function as the cam profiles 133, 135, 137 of Figures 26, 28. Therefore, a detailed description of such cam profiles will not be provided.

Similar to the embodiment of Figures 19-35, also in the embodiment of Figures 47-50 the brewing unit includes (see in particular Figures 49A-49D) a rotatable and translatable plunger 543, similar to plunger 113, said plunger being housed in a rotatable and translatable seat 545, which corresponds to seat 115, and a complementary plunger 547, which corresponds to complementary plunger 117. A pin or driver 543B, which corresponds to the pin 113B, is firmly attached to the plunger 543, said pin forming a sensor that engages the fixed cam profiles 501 of the two opposite fixed plates 500 and the two rotating cam profiles 533 of the Rotating 510 cams. Similarly, seat 545 is provided with opposing pins or sensors 545A, which engage the two opposing fixed cam profiles 503 and the two rotatable cam profiles 535. The complementary plunger 547 engages the fixed cam profiles 505 and has actuators or sensors 547C that engage the rotatable cam profiles 537.

The operation of the infusion unit thus described will now be discussed in more detail, with reference to the sequence of Figures 49A-49D and the diagram of Figure 50, showing the path of movement of the pins 543B and 545A.

In Figure 49A the brewing unit is in the loading position. Seat 545 is in a substantially vertical position and plunger 543 is in the lower position within the seat, closing the bottom of the seat. The desired amount of coffee powder is loaded into seat 545 from a dispensing conduit, not shown. Pins 543B are located at position P0 along section 501G of cam 501. Pins 545A firmly attached to seat 545 are at position P0 along section 503B of cam 503.

Once the coffee has been loaded into the brew chamber seat, the seat 545 and plunger 543 are moved by rotating the cams 510 toward the brew position, shown in FIG. 49B. The infusion position varies according to the quality of coffee or number of coffees required, as already described above. The points P1 on the cam section 501D indicate for example the position of the pins 543B when brewing filter coffee, the point P1 on the cam section 503E being the corresponding position of the pins 545A. P2 in cam section 501D indicates the possible positions of pins 543B when preparing a single or double espresso, the corresponding positions of pins 545A being represented by point P2 along section 503E of cam 503.

The infusion position is selected by appropriately rotating the cams 510 and the corresponding rotating cam profiles. Due to the shape of the intermediate cam portions or sections 501D and 503E, the plunger 543 and seat 545 move rectilinearly along their axes which, in the infusion position, coincide with the complementary plunger axis 547. The latter is forcibly moved with a corresponding rectilinear path through the fixed cam profiles 505 and the rotatable cam profiles 537. The pins 543B are prevented from moving along the cam portion or cam section 501H by the elastic tab 501A, while the pins 545A are prevented from moving along the cam section or the cam portion 503C of cam by elastic tab 503C.

Once the infusion is complete, the spent coffee powder should be discharged. In order to achieve the unloading position, the plunger 543 and seat 545 first move toward and past the loading position, in an intermediate position shown in FIG. 49C. This movement is necessary to transfer the pins 543B from the lower cam part 501G to the upper cam part 501F and to transfer the pins 545A from the upper cam part 503B to the lower cam part 503A. In Figure 50 the positions of the pins 543B and 545A on the relevant cams 501 and 503 corresponding to the position of the infusion chamber of Figure 49B are shown at P3.

Once the position of Figure 49B has been reached, the rotation of the plates 510 and the respective rotary cams is reversed, and the pins 543B, 545B begin to move along the upper part or section 501F of the cam. 501 and the lower portion or section 503A of cam 503 respectively, until the final discharge position of FIG. 49D is reached. The elastic tab 501C on each cam profile 501 prevents the pin 543B from

ES 2 373 191 T3 between the intermediate section 501D of the cam and the force to be followed by the upper section 501F. In the discharge position of FIG. 49D, seat 545 faces a spent coffee collecting chute or the like (not shown) and plunger 543 moves toward the seat opening to push coffee out of said seat. The position of the pins 543B and 545A on the respective cam profiles when the brewing unit is in the discharge position of Figure 49D is shown at P4 in Figure 50.

From the unloading position the brewing unit is brought to the loading position again (FIG. 49A) by reversing the rotation of the rotary cams 510.

In figure 50 the arrows connecting the various points P1-P4 show the movement of the pins.

The possible presence of reference numbers in the appended claims is for the purpose of facilitating the reading thereof with reference to the description and the drawings, and in no way limits the scope of protection represented by the claims.