The present invention refers to a stovetop espresso maker.

In particular, the invention concerns a stovetop espresso maker for preparing a brew of coffee, barley coffee or the like, in particular a brew of espresso coffee without foam and with foam, i.e. coffee made with a professional espresso machine, obtained by means of grounds or pods.

Although numerous coffee drinkers prefer the flavour of coffee prepared with conventional domestic coffee makers, they also greatly appreciate the "crema" (head) that forms on coffee made with a professional espresso machine.

The substantial - differences between the... organoleptic properties of the two types of coffee, prepared with the professional espresso machine and prepared with the domestic stovetop espresso maker, derive from the different process with which they are obtained: espresso coffee is prepared with special machines, which in substance pressurize hot water and then make it pass through a filter, previously filled with ground coffee; the hot pressurized water, passing through the filter full of ground coffee, performs liquid/solid extraction, so that part of the aromatic substances and fats contained in the ground coffee pass into the water; in domestic coffee makers the water is brought to the boil in a boiler, and the pressure generated inside it during heating drives the water to pass through the coffee grounds inside a filter; the brew of coffee thus obtained rises along a dispensing duct arranged inside the collector into which it flows .

A solution for obtaining crema also in home brewed coffee is described in the patent IT01284992, in which on the end of the dispensing duct, from which the coffee flows into the collector of the stovetop espresso maker, there is mounted a valve unit, comprising a nozzle on which there is mounted a plug of predetermined weight; this plug is movable between a position in which it closes the nozzle through gravity, and a position in which it is moved away. When the plug is in the closing position, an overpressure occurs in the boiler. Once the overpressure reaches a given value, the plug moves away and the brew of coffee is delivered through the hole in the nozzle. In this way coffee with a crema similar to that of coffee made with a professional espresso machine is obtained. However, the aforesaid invention has some drawbacks, such as having to use a much smaller amount of water than the amount normally used in the stovetop espresso maker, thus obtaining a smaller amount of coffee with respect to the. capacity of the stovetop espresso maker, and the fact that it is impossible to obtain particularly hot coffee.

Moreover, according to the aforesaid invention, the overall dimensions inside the brew collector are substantial.

Further, given the high pressures/temperatures at which the brew of espresso coffee with foam is obtained in the aforesaid prior art stovetop espresso maker, known gasket means provided between boiler and collector of the stovetop espresso maker are subject to thermal stresses that cause, after prolonged use, significant deformations that influence the functionality of these gasket means and the ease with which the stovetop espresso maker can be disassembled and reassembled.

In addition, the overpressure valve means, provided in the aforesaid prior art stovetop espresso maker, are subject to deposits and/or incrustations and residues of coffee grounds, which compromise its proper functionality.

The present invention, taking account of the prior art considered above, and starting from the notion of the aforesaid drawbacks of the prior art cited, intends to provide a solution to these.

An object of the present invention is to provide a stovetop espresso maker provided with a device for obtaining coffee with crema of the type made with a professional espresso machine, without forgoing the qualities of coffee obtained with the classic domestic stovetop espresso maker, and without incurring the drawbacks mentioned above.

Another object of the invention is to provide a stovetop espresso maker in which the function for obtaining crema can be disabled, if it is not desired.

Moreover, an object of the present invention is to provide a stovetop espresso - maker in which said device, has essentially limited overall dimensions.

Moreover, a further object of the present invention is to provide a stovetop espresso maker in which said gasket means provided between boiler and collector of the same coffee maker do not undergo relevant deformations when subject to particularly high thermal stresses, thus preventing, even after prolonged use, any deformation that would influence the functionality of the same gasket means and the ease with which the stovetop espresso maker can be disassembled and reassembled, even at the high pressures/temperatures at which the brew of espresso coffee with foam is obtained.

In addition, an object of the present invention is to provide a stovetop espresso maker in which the overpressure valve means are not subject to deposits and/or incrustations and residues of coffee grounds, which compromise its proper functionality .

On the other hand, an object of the present invention is to provide a stovetop espresso maker which has an essentially simple structure, easy to assemble and maintain, and which can be produced on an industrial scale with essentially limited costs .

In view of these objects, the present invention provides a stovetop espresso maker, the essential characteristic of which forms the subject matter of claim 1.

Further advantageous characteristics are described in the dependent claims.

The aforesaid claims are intended as fully incorporated herein.

In particular, according to the present invention, said stovetop espresso maker according to the invention is characterized in that said device for dispensing the brew comprises:

- said overpressure valve means, in which a valve body is movable parallel to the axis of said dispensing duct, with respect to a corresponding valve seat, and opposing elastic means, which act on said valve body, are housed in a decompression chamber arranged downstream of said dispensing duct and comprising at least one brew dispensing outlet, and - manual adjustment means of the dispensing pressure of said brew, between at least a first pressure value and a second pressure value, greater than the first, in correspondence of at least one of which said overpressure valve means allow the passage of the brew from said dispensing duct to said at least one dispensing outlet, so that a brew without foam and with foam can be produced with said stovetop espresso maker.

The present invention will be more apparent from the detailed description below, with reference to the accompanying drawing, showing an example of embodiment of the stovetop espresso maker according to the present invention, wherein: - Fig. 1 is a vertical sectional view of a first example of embodiment of the stovetop espresso maker according to the present invention;

- Fig. 2 is a vertical sectional view of a variant of embodiment of the stovetop espresso maker of Fig. 1;

- Fig. 3 is a detailed and vertical sectional view of a second embodiment of a stovetop espresso maker according to a second example of embodiment of the present invention;

- Fig. 4 is a schematic perspective exploded view showing the gasket means and related protection means, with which the stovetop espresso maker according to the invention is provided;

- Fig. 5 is a schematic sectional view of a stovetop espresso maker according to a third embodiment of the stovetop espresso maker of the present invention, according to a first operating configuration; and

- Fig. 6 is a schematic sectional view of the stovetop espresso maker of Fig. 5, according to a second operating configuration.

The description of three embodiments of the present invention is set forth below.

First embodiment (Figs. 1 and 2)

According to the prior art, in a stovetop espresso maker, a boiler 3 adapted to contain water to be heated, a filter for holding ground coffee 4, adapted to receive a predetermined amount of grounds per brew, and a collector 5 adapted to collect the brew produced by means of the passage of hot water through the grounds are known, wherein between said boiler 3 and said collector 5 there is interposed an annular rubber gasket 2, and wherein the filter for holding ground coffee 4 communicates on one side with the inside of the boiler 3 and on the other side with a duct for dispensing the brew 6; said stovetop espresso maker also comprises, in a known manner, a device 10, 10', 20 for dispensing the brew, which is arranged on the dispensing duct 6 and includes overpressure valve means 19 arranged along a path of said brew from the boiler 3 to the 5 collector 5.

According to the invention, said device 10, 10', 20 advantageously comprises (Figs. 1-3):

- said overpressure valve means 19, in which a valve body 11, 11', 24.2 is movable parallel to the axis of said dispensing

10 duct 6, with respect to a corresponding valve seat 12, 12', 24.1, and opposing elastic means 13, 13', 13", which act on said valve body 11, 11', 24.2, are housed in a decompression chamber -1-4, 14', 24.3 arranged downstream of said dispensing duct 6 and comprising at least one brew dispensing outlet

15 14.1, 14.1', 21, and

- manual adjustment means of the dispensing pressure 15, 15', 23 of said brew, between at least a first pressure value and a second pressure value, greater than the first, in

. correspondence of at least one of which said overpressure 20 valve means 19 allow the passage of the brew from said dispensing duct 6 to said at least one dispensing outlet 14.1, 14.1', 21, 22, so that a brew without foam and with foam can be produced with said stovetop espresso maker.

On the other hand, according to the present invention, said 25 stovetop espresso maker comprises a protective ring 16 made of Teflon, superimposed on said rubber gasket 2, which prevents undesirable deformations of the same gasket 2 due to pressures for producing the brew corresponding to said second pressure value and, in the manner of a sliding guide, facilitates the 30 disassembly of said boiler 3 with respect to said collector 5 (Fig. 4) . Advantageously, said valve body 11, 11', 24.2 is made of silicone .

Naturally, it is understood that the use of different materials to produce said valve body 11, 11', 24.2, provided that they are suitable for the purpose, also falls within the context of the present invention.

In a first example of embodiment of the stovetop espresso maker according to the present invention, said device 10 comprises (Fig. 1):

- said overpressure valve means 19, in which said valve body 11 is movable axially with respect to said dispensing duct 6, in a corresponding valve seat 12, and said opposing elastic means 13 act axially on -said valve body 11, and are housed in an axial decompression chamber 14 arranged downstream of said dispensing duct 6 and comprising at least one brew dispensing outlet 14.1, and

- said manual adjustment means 15 of the dispensing pressure of said brew, in which a hollow axial body 15.1 includes said valve seat 12 and said valve body 11, is engaged by helical coupling with respect to a hollow axial threaded stem 15.2, integral with said dispensing duct 6 and determines, by means of helical movement with respect to said stem 15.2, a different elastic preload of said elastic means 13, interposed between said hollow body 15.1 and said valve body 11, between at least a first and a second pressure value, in correspondence of at least one of which said overpressure valve means 19 allow the passage of the brew from said dispensing duct 6 to said at least one dispensing outlet 14.1, so that a brew without foam and with foam can be produced with said stovetop espresso maker.

In a variant of the aforesaid first example of embodiment of the present invention, said device 10' comprises (Fig. 2) : - said overpressure valve means 19, in which said valve body 11' is movable axially with respect to said dispensing duct 6, in a corresponding valve seat 12 ' , provided in the same duct 6, and said opposing elastic means 13' act axially on said valve body 11' and are housed in an axial decompression chamber 14' arranged at the free end of said dispensing duct 6 and comprising at least one brew dispensing outlet 14.1', and

- said manual adjustment means 15' of the dispensing pressure of said brew, in which a hollow cup body 17 is engaged by helical coupling with respect to said threaded free end of said dispensing duct 6 and determines, by means of helical movement with respect to said threaded end, a different elastic- preload of said elastic means.13', interposed _. etween said hollow body 17 and said valve body 11', between at least a first and a second pressure value, in correspondence of at least one of which said overpressure valve means 19 allow the passage of the brew from said dispensing duct 6 to said at least one dispensing outlet 14.1', so that a brew without foam and with foam can be produced with said stovetop espresso maker.

Second embodiment (Fig. 3)

In a second example of embodiment of the stovetop espresso maker according to the present invention, said device 20 comprises (Fig. 3) a first 21 and a second 22 dispensing outlet of said brew, from said dispensing duct 6, arranged - parallel, wherein, the first dispensing outlet 21 is associated with said overpressure valve means 19 and is provided to dispense a brew with crema, said overpressure valve means 19 including said opposing elastic means 13" adapted to allow discharge of the brew only above, a predetermined pressure, and the second dispensing outlet 22 is separate from said overpressure valve means 19 and is provided to dispense a brew without crema, or with less crema than the brew discharged from the first dispensing outlet 21.

Said device 20 comprises control means 23 that can be manually operated to allow discharge of the brew selectively from said first dispensing outlet 21 or from said second dispensing outlet 22.

Advantageously, said manually operated control means 23 comprise a valve seat 23.1, in fluid communication and with axis parallel with respect to said dispensing duct 6, and in which there is selectively engaged in a fluid-tight manner a needle valve body 23.2, in turn engaged by helical coupling in a dispensing chamber 23.3 coaxial to said valve seat 23.1 and having said second outlet 22 in radial arrangement, said valve body 23.2 being selectively controllable by means of a fixed knob 23.4 (Fig. 3) .

Said overpressure valve means 19 comprise a valve seat 24.1 in fluid communication and with axis parallel with respect to said dispensing duct 6, and in which there is engaged in a fluid-tight manner a valve body 24.2, axially movable in a dispensing chamber 24.3 coaxial to said valve seat 24.2 and having said first outlet 21 in radial arrangement, said valve body 24.2 being stressed by means of opposing elastic means 13", housed in said dispensing chamber 24.3.

The parallel arrangement of the two brew dispensing units according to the second embodiment of the invention is preferred but not necessary.

Therefore, the indications on the geometry of the various parts of the device must not be intended as binding, but provided purely by way of example.

Third embodiment (Figs. 5 and 6)

With reference to the aforesaid Figs. 5 and 6, a domestic stovetop espresso maker, substantially known, is indicated with the reference numeral 12; this stovetop espresso maker comprises a boiler 13, a filter for holding coffee 14, a collector 15 and a dispensing duct 116.

The stovetop espresso maker 12 also comprises a coffee dispensing device 110, which is able to produce creitia in the brew of coffee and is mounted on the dispensing duct 116. This device 110 comprises a body 117 including a forked duct 118; the forked duct 118 comprises an ascending inlet section 118a connected directly to the dispensing duct 116, of which it forms an extension, and a first and a second outlet section 118b and 118c, connected to one end of the inlet section 118a, opposite the end of this latter that is connected to the dispensing duct 116. The first and the second outlet section 118b and 118c end respectively in a first and in a second dispensing outlet 118d and 118e that flow out into the inside of the collector 15.

Along the first outlet section 118b there are positioned overpressure valve means 19, comprising opposing means 126. The device 110 also comprises a decompression chamber 121, positioned downstream of the overpressure valve means 19. The first dispensing outlet 118d, positioned downstream of the decompression chamber 121, comprises a plurality of discharge openings 122 arranged in proximity- of a bottom wall 113 of the collector 15 and having a smaller section for fluid-dynamic passage than the section for fluid-dynamic passage of the decompression chamber 121. The overpressure valve means 19 comprise at least one plug element 124, and a respective seat 125, in particular a conical seat; the opposing means 126 comprise a spring, preloaded in compression, and acting on the plug element 124 to maintain it closed on the related seat The spring 126 is integrally constrained, at a first end 126a, to a bottom wall of the decompression chamber 121, and carries integral, at a second free end 126b, opposite the first constrained end 126a, the plug element 124.

Along the second outlet section 118c there are positioned shut-off valve means 129.

The shut-off valve means 129 comprise at least one plug element .134, and a respective seat 135, in particular a conical seat. The plug element 134 is arranged helically movable with respect to the body 117 of the device 110, and is integrally fixed to a lever element 136 arranged outside the body 117 of the device 110. The lever element 136 forms a control means that can be manually operated to allow discharge of the brew of coffee selectively from the first dispensing outlet 118d or from the second dispensing outlet 118e. The lever element 136 allows the shut-off valve means 129 to be controlled to selectively enable or disable fluid communication between the second dispensing outlet 118e and the inside of the collector 15. By rotating the lever element 136 in one direction or the other about an axis defined by the longitudinal axis of the plug element 134, it is in fact possible to translate the plug element 134 along this longitudinal axis, to selectively move the plug element 134 toward or away from the seat 135.

Fig. 5 shows a position in which the plug element 134 engages the respective . seat 135, closing the section for passage of the fluid and thus disabling fluid communication between the second dispensing outlet 118e and the inside of the collector 15. As will be explained below, with this position it is possible to produce a brew of coffee of espresso type.

Fig. 6 shows a position in which the plug element 134 is completely retracted with respect to the respective seat 135, thus completely freeing the section for passage of the fluid through the second outlet section 118c. As will be explained below, with this position it is possible to produce a brew of coffee of the type obtainable with conventional domestic coffee makers.

Intermediate positions between the one in Fig. 5 and the one in Fig. 6 are possible, as the screw movement of the plug element 134 allows fine adjustment of the position of the tip of the plug element 134 with respect to the seat 135; in particular, when the tip of the plug element 134 is very close to the seat 135 it is possible to obtain seepage of the brew of coffee through the thin gap formed between the tip of the plug element 134 and the seat 135.

Operation of the stovetop espresso maker 12 according to the present third embodiment of the invention is as follows: after placing the stovetop espresso maker 12 over a heat source, the brew of coffee, formed according to a known process and not indicated for simplicity, is driven into the dispensing duct 116, from where it then passes into the forked duct 118. Depending on the position of the shut-off valve means 129, the brew of coffee can pass through the first outlet section 118b (Fig. 5) or through the second outlet section 118c (Fig. 6) . In the condition of Fig. 5, as the second outlet section 118c is shut off by the shut-off valve means 129 in the closed position, the brew of coffee can pass exclusively through the first outlet section 118b equipped with the overpressure valve means 19. In the first outlet section 118b of the duct 118, the brew of coffee is blocked by the presence of the plug element 124, maintained by the preloaded spring 126 to close the seat 125, thus causing an overpressure inside the collector 15; after reaching a given overpressure (e.g. in the order of a few bar) , the downward thrust of the brew of coffee overcomes the upward thrust of the spring 126, and the plug element is lowered, thus allowing the brew of coffee to pass into the decompression chamber 121; the resistance of the spring 126, once the pressure exerted on the plug element 124 has been released, closes the passage of the brew of coffee once again, returning the plug element 124 to close the seat 125; subsequently, the overpressure returns to the previous values, allowing the brew of coffee to once again overcome the thrust of the spring 126, thus allowing the coffee to pass again into the decompression chamber 121; this process, which causes opening and closing of the plug element 124, is repeated cyclically until all the water contained in the boiler 13 has been dispensed as a brew of coffee; after passing into the decompression chamber 121, the brew of coffee continues to descend toward the discharge openings 122, through which it will be dispensed into the collector 15.

During passage through the decompression chamber 121, the liquid mass, formed of the brew of coffee, first expands and then retracts to be able to enter the discharge openings 122, from which it is dispensed in proximity of the bottom wall 113 of the collector 15 and therefore under the previously dispensed brew.

The combination of the passage of the brew of coffee through the decompression chamber 121, according to the methods described, with dispensing of the brew of coffee under the free surface of the brew of coffee previously dispensed, causes the formation of a mellow crema.

In this way, a process for obtaining crema during the production of a brew of coffee according to the invention is achieved: this procedure comprises, in succession, a preparation step of the brew of coffee (with substantially known method) , a containment step, in which the brew of coffee is taken to a determined overpressure, and a decompression step, in which the brew of coffee is dispensed into a collector. The containment step and the decompression step are repeated cyclically several times during the same production of a brew of coffee. After a first dispensing cycle, the brew of coffee continues to be dispensed under the free surface of the brew of coffee previously dispensed.

In the configuration of Fig. 6, as the second outlet section 118c is pervious due to the opening of the shut-off valve means 129 in open position, the brew of coffee from the dispensing duct 116 passes exclusively through the second outlet section 118c, as this section has no overpressure valve means 19, which are instead associated with the first outlet section 118b, and therefore does not obstruct the passage of the brew of coffee from the boiler 13 to the collector 15. In this condition the brew of coffee can therefore be discharged through the second outlet section 118c and the second dispensing outlet 118e. The brew of coffee discharged from the second dispensing outlet 118e is identical to the brew of coffee produced in conventional coffee makers without means for producing crema, and therefore without crema. At most, a certain amount of crema can be produced due to seepage of the brew of coffee through the seat 135, in the case in which the tip of the plug element 134 is adjusted (acting on the control lever 136) so as to be very close to the seat 135. However, the amount of crema produced in this case is less than the amount produced by the overpressure valve means 19 associated with the first outlet section 118b.

As is apparent from the above, said stovetop espresso maker according to the invention is provided with a device for obtaining coffee with crema of the type made with a professional espresso machine, without forgoing the qualities of coffee obtained with the classic domestic stovetop espresso maker, and without incurring the drawbacks mentioned above. Moreover, in said stovetop espresso maker the function to obtain crema can be disabled, if it is not desired.

In addition, in said stovetop espresso maker according to the present invention, said device 10, 10', 20; 110 has essentially limited overall dimensions.

Moreover, in said stovetop espresso maker as indicated, said gasket means provided between boiler and collector of the stovetop espresso maker do not undergo relevant deformations when subject to particularly high thermal stresses, thus preventing, even after prolonged use, any deformation that would influence- the - functionality of the same gasket means and the ease with which the stovetop espresso maker can be disassembled and reassembled, even at the high pressures/temperatures at which the brew of espresso coffee with foam is obtained.

In addition, in said stovetop espresso maker as specified, said overpressure valve means are not subject to deposits and/or incrustations and residues of coffee grounds, which compromise its proper functionality.

On the other hand, said stovetop espresso maker as mentioned has an essentially simple structure, is easy to assemble and maintain, and can be produced on an industrial scale with essentially limited costs.

As it appears from the above description, the present invention allows the objects described in the introduction to be achieved in a simple and advantageous manner.