The present invention relates to an infusion assembly for coffee machines and in particular for coffee machines for professional use of the automatic type.

Traditionally, professional coffee machines are substantially constituted by a boiler which is connected, at its inlet point, to a feeder conduit which is connected to the water mains and, at its outlet point, to a conduit for dispensing hot water under pressure leading into one or more ports for dispensing below which an infusion chamber can be associated in a non-removable manner.

The infusion chamber is connected to a handle and can be filled with ground coffee by the machine operator.

Depending on the necessity to dispense one or two coffees, infusion chambers of different sizes are used and, consequently, they are filled with different quantities of ground coffee.

Before stably connecting the infusion assembly under the dispensing port, the operator proceeds to press, with an adapted presser body, the ground coffee into the infusion chamber.

Recently coffee machines for professional use have been offered, which are commercially designated as automatic and have, under the dispensing port for hot water under pressure, at least one infusion chamber into which the ground coffee is directly dosed by a dosage assembly.

Once the quantity of ground coffee needed for the production of a coffee has been dosed, a presser body that presses the ground coffee is moved, typically by way of a rod-and-crank assembly.

After such operation, the machine actuates the dispensing of hot water under pressure which passes through the infusion chamber in order to then be dispensed into a container that is arranged underneath the infusion chamber.

Discharge means are provided, which can be activated before each dispensing and are adapted to discharge the residual ground coffee from the infusion chamber.

It is evident that automatic machines have made it possible to automate many operations that are traditionally performed by the operator such as the dosing and the pressing of the ground coffee inside the infusion chamber thus ensuring, at the same time, better consistency and repeatability of these operations.

With particular reference to the professional machines used in bars, motorway services cafes etc., technical solutions have been devised in order to make it possible, according to requirements, to supply the quantity of coffee necessary to the infusion chamber in order to make one or two coffees.

In this case, the pressing of the ground coffee inside the infusion chamber is not performed with a rod-and-crank assembly (which has a fixed stroke) but is typically performed by moving the presser body with respect to the infusion chamber by way of drive means which mesh with an endless screw that is connected to a supporting stem of the presser body.

Normally, the arrest of the drive means, and thus of the movement of the presser body, is subject to exceeding a certain threshold value of the current absorbed by the drive means: in this manner, it is possible to vary the stroke based on the quantity of dosed ground coffee inside the infusion chamber thus achieving optimal pressing.

The solution described above, although valid from a conceptual point of view, is not however devoid of drawbacks.

In particular, it is necessary to use drive means, typically constituted by an electric motor, which are particularly expensive since they need to ensure a sufficient torque to achieve the pressing of the coffee in the infusion chamber and since they need to be associated with a device for measuring the absorbed current.

Moreover there is the difficulty of adapting the solutions known today to conventional dispensing assemblies, of the type with movement of the presser with a rod-and-crank assembly.

The aim of the present invention is to solve the above-mentioned problems and overcome the drawbacks, by providing an infusion assembly for coffee machines which is extremely reliable in use.

Within this aim, an object of the invention is to make available an infusion assembly for coffee machines which can easily be applied to conventional machines.

Another object of the invention is to provide an infusion assembly for coffee machines which is low-cost, so as to make its use advantageous from an economic viewpoint.

This aim and these and other objects which will become more apparent hereinafter are all achieved by an infusion assembly according to claim 1.

Further characteristics and advantages of the invention will become more apparent from the description of some preferred, but not exclusive, embodiments of an infusion assembly for coffee machines according to the invention, illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a perspective view of a portion of the infusion assembly according to the invention;

Figure 2 is an exploded view of the perspective view in Figure 1 ;

Figure 3 is a longitudinal sectional view of the portion of the infusion assembly shown in Figure 1 ; and

Figure 4 is a longitudinal sectional view of the infusion assembly according to the invention.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchangeable with other, different characteristics, existing in other embodiments.

With reference to the figures, the present invention relates to an infusion assembly, generally designated by the reference numeral 1, for coffee machines.

The infusion assembly 1 comprises a supporting structure 2 for an infusion chamber 3 into which at least two different quantities of ground coffee can be dosed by a dosage assembly .

Typically, the infusion chamber 1 can receive, from the dosage assembly, the quantity of ground coffee necessary for dispensing one coffee or two coffees.

According to the present invention, the infusion assembly 1 comprises a supporting body 4 for a presser 5 which is designed to press the dosed ground coffee inside the infusion chamber 3.

In particular, the supporting body 4 can move, on command, between an inactive position, in which it is arranged spaced from the infusion chamber 3, and an active position in which it is arranged close to the infusion chamber 3 and wherein the presser 5 presses the dosed ground coffee inside the infusion chamber 3.

The presser 5 is, in turn, moveable with respect to the supporting body 4 along an adjustment direction, designated with the reference numeral 100, in order to vary, on command, the distance between the presser 4 and the bottom 3a of the infusion chamber 3 when the supporting body 5 is in the active position.

Advantageously, the movement of the presser 5 with respect to the supporting body 4 along the adjustment direction 100 is performed when the supporting body 4 is in the inactive position and, according to a particularly important aspect of the present invention, such movement occurs as a function of the quantity of ground coffee dosed each time into the infusion chamber 3 by the dosage assembly.

Advantageously, the infusion assembly 1 comprises first means, generally designated with the reference numeral 10, of moving the supporting body 4 between the inactive position and the active position and vice versa.

According to a preferred embodiment, the first movement means 10 comprise a rod-and-crank assembly that is actuated by first motor means of the type normally employed to move the presser in infusion assemblies of coffee machines that are designed to dispense a single coffee at a time.

By way of example, the rod-and-crank assembly can have a pair of lateral linkages 11 which are rotatably connected, at first ends 11a thereof, to the supporting body 4 and kinematically connected, at respective coupling pivots 12, which are arranged advantageously proximate to the second ends l ib, to a command cam (not shown in the figures) which is actuated in rotation about an axis which is substantially perpendicular to the adjustment direction 100.

Conveniently, the movement of the supporting body 4 from the inactive condition to the active condition and vice versa occurs along a direction substantially parallel to the adjustment direction 100.

Conveniently, the infusion assembly 1 has a device 20 for moving the presser 5 with respect to the supporting body 4 along the adjustment direction 100.

In this regard, it is possible to associate the presser 5 with an elongated body 6 which extends along the adjustment direction 100 and is guided along a guiding element 7 which is defined, in turn, on the supporting body 4.

The adjustment device 20 can be constituted by a screw-and-nut coupling 21 between the elongated body 6 and the guiding element 7.

With reference to the embodiment shown in the figures, the guiding element 7 comprises a bushing 8 which forms internally a female thread 22 and is supported rotatably by the supporting body 4.

In this case, the elongated body 6 is stably associated with a threaded portion 23, for example formed on the outer surface of a hollow cylinder, which is engageable, in use, with the female thread 22. The movement device 20 comprises an electric motor 24 which is connected kinematically, by way of kinematic interconnection means 25, to the elongated body 6 so as to cause the rotation of the elongated body 6 about its own longitudinal axis.

The rotation of the elongated body 6 about its own longitudinal axis, which is parallel to and, advantageously, coincides with the adjustment direction 100, causes, consequently, owing to the screw-and-nut coupling 21, the movement of the presser 5 along the adjustment direction 100 thus making it possible to vary the distance between the presser 4 and the bottom 3a of the infusion chamber 3 when the supporting body 5 is in the second, active position.

The kinematic interconnection means 25 comprise, for example, an actuation gear 26 which is actuated in rotation by the electric motor 24 and meshes with an actuation gear 27 for the bushing 8.

The rotation of the bushing 8 causes, thanks to the screw-and-nut coupling 21 , the movement of the hollow cylinder on which the threaded portion 23 is formed (and thus of the presser 5) along the adjustment direction 100.

Advantageously, the adjustment device 20, and more specifically the electric motor 24, is functionally connected to the dosage assembly so as to adjust the distance between the presser 4 and the bottom 3a of the infusion chamber 3 when the supporting body 5 is in the second, active position as a function of the quantity of coffee dosed each time into the infusion chamber 3 by the dosage assembly.

The use of the infusion assembly for coffee machines according to the invention is evident from the foregoing description.

In the starting condition, with the supporting body 4 in the inactive position, the presser 5 is in the lower stroke limit position in order to allow complete pressing of a quantity of mixture, dosed into the infusion chamber 3, corresponding to one coffee, by way of actuation of the rod-and-crank assembly.

If the dosage assembly doses, into the infusion chamber, a quantity of coffee that exceeds the amount necessary for dispensing one coffee, then the electric motor will proceed to move, by way of the screw-and-nut coupling 21 , the presser 5 away from the infusion chamber 3 so as to enable, once the dosing of the coffee and the consequent adjustment by the adjustment device 20 have been completed, the pressing by way of the actuation of the rod-and-crank assembly 10.

All the characteristics of the invention, indicated above as advantageous, convenient or similar, may also be missing or be substituted by equivalent characteristics.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

In practice it has been found that in all the disclosed embodiments the invention has achieved the intended aim and objects.

In practice the dimensions employed may be any, according to requirements.

Moreover, all the details may be substituted by other, technically equivalent elements.

The disclosures in Italian Patent Application No. VR2011A000240 from which this application claims priority are incorporated herein by reference.

Where the technical features mentioned in any claim are followed by reference numerals and/or signs, those reference numerals and/or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and/or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and/or signs.