Coffee machine

Abstract

A coffee machine (1) comprising one or more coffee brewing devices (3), each with a cold water inlet (10) to receive pressurised cold. Each coffee brewing device (3) comprises a cold water heating device (5), a hot water dispensing body (6) and a filter holder (7) designed to contain, in use, an amount of coffee and to be manually removably coupled to the hot water dispensing body (6) to receive pressurised hot water therefrom for brewing. The cold water heating device (5) is an instant electric thermoblock heater and comprises a metal block (8) with electrical resistive means (14) designed to heat the metal block (8), and a water supply duct (9) formed in the metal block (8) and fluidically connected on one side to the cold water inlet (10) to receive pressurised cold water therefrom and, on the other side, to the hot water dispensing body (6) to supply pressurised heated water thereto for brewing coffee. Each coffee brewing device (3) further comprises a valve assembly (30) comprising a three-way solenoid valve (31) arranged upstream of the cold water inlet (10) and having an inlet port (32) fluidically connected to a cold water delivery duct (35), a first outlet port (34) fluidically connected to the cold water inlet (10), and a second outlet port (36) fluidically connected to a discharge duct (37). Each valve assembly (30) further comprises a two-way solenoid valve (38) having an inlet port (39) fluidically connected to an outlet section (17) of the water supply duct (9) via a drainage duct (40) formed in the metal block (8), and an outlet port (41) fluidically connected to a further discharge duct (42).

Description

[0001] COFFE MACHINE

[0002] Cross-Reference to Related Applications

[0003] This patent application claims priority to Italian patent applications nos. 102024000001668 and 102024000001662 both filed on January 29, 2024, the entire disclosures of which are incorporated herein by reference.

[0004] Technical Field of the Invention

[0005] This invention relates to a professional machine for preparing espresso coffee or similar beverages.

[0006] In particular, this invention relates to a professional espresso coffee machine of the multi-assembly type, i.e., comprising multiple brewing assemblies, to which the following description refers for descriptive convenience without any loss of generality thereby.

[0007] Prior Art

[0008] Professional espresso coffee machines of the multi-assembly type are known to use various systems for heating the brewing water. Conventionally, the most commonly used systems are single -boiler and heat exchanger systems or multi-boiler systems. More recently, systems have also been introduced whereby each brewing assembly is equipped with an individual boiler, which receives water from a main boiler common to all brewing assemblies and heats it up to an optimal temperature for brewing coffee. In some cases, individual boilers are replaced by electric continuous-flow heaters.

[0009] Sub ject and Summary of the Invention

[0010] The aim of this invention is to provide a professional coffee machine that represents an improvement over conventional espresso coffee machines in terms of both energy consumption and ease of construction and maintenance.

[0011] According to this invention, a professional coffee machine is provided as claimed in the appended claims.

[0012] Brief Description of the Drawings

[0013] Figure 1 illustrates, in perspective view, an espresso coffee machine according to a preferred embodiment of the invention. Figure 2 illustrates, on an enlarged scale and with parts removed for clarity, a detail in Figure 1.

[0014] Figure 3 is an exploded view of a detail in Figure 2.

[0015] Figures 4 and 5 illustrate, in cross section, the detail in Figure 2 in respective operative steps of the coffee brewing process.

[0016] Detailed Description of Preferred Embodiments of the Invention

[0017] This invention will now be described in detail with reference to the figures attached to enable a person skilled in the art to produce and use it. Various modifications to the embodiments described will be immediately clear to persons skilled in the art and the generic principles described may be applied to other embodiments and applications without, for this reason, departing from the protective scope of this invention, as defined in the attached claims. Therefore, this invention must not be considered as limited to the embodiments described and illustrated but they must be granted the widest protective scope compliant with the principles and features described and claimed herein.

[0018] In Figure 1, reference numeral 1 references, as a whole, a professional machine for preparing espresso coffee or similar beverages.

[0019] The machine 1 comprises an outer body 2, which protects and conceals from view a frame (not shown) designed to support all the functional components of the machine 1, some of which are referred to in the following description for the purpose of understanding this invention.

[0020] In particular, one or more coffee brewing devices 3 (in the embodiment illustrated in the number of four) and a steam wand 4 for dispensing pressurised steam for uses other than brewing coffee, e.g. for heating and frothing milk, are attached to the frame.

[0021] The functional components of the machine 1 also include a water boiler (not illustrated) for producing hot water or steam supplied to the steam wand 4, and a water pump (not illustrated), with a suction side hydraulically connected to a cold water source, typically water mains, and is controlled, in use, by an electronic control unit (not illustrated) of the machine 1 to supply pressurised cold water to the boiler and coffee brewing devices 3.

[0022] As illustrated in Figure 2, each coffee brewing device 3 comprises a water heating device 5, a water dispensing body 6 and a filter holder 7 designed to be filled, in use, with an amount of loose ground coffee or in the form of a disposable pod or capsule and to be manually removably coupled to the water dispensing body 6 to receive pressurised hot water therefrom for brewing coffee. The water heating device 5 is in the form of an instant electric thermoblock heater, i.e., an electric continuous-flow heater also known as a Thermoblock, and comprises a metal block 8, which is provided with electrical resistive means for heating the metal block 8 itself and a water supply duct 9 formed within the metal block 8 to receive, in use, pressurised cold water from a water inlet 10 fluidically connected to a delivery side of the water pump and to supply the water dispensing body 6 with water heated to a temperature required for brewing coffee. Conveniently, the water heating device 5 is supplied by the water pump with water from an external cold water source, typically water mains.

[0023] In particular, as illustrated in Figures 1 and 2, the metal block 8 is cantilevered on a support plate 11 that is in turn removably connected to a vertical portion of the frame facing the front side of the outer body 2, and the water dispensing body 6 projects downwards from a lower wall of the metal block 8. Conveniently, the outer body 2 is so shaped that a front portion 12 of it totally or at least partially covers the metal blocks 8 while leaving the water dispensing bodies 6 visible, in whole or in part.

[0024] Each metal block 8 is preferably laterally delimited by two opposing side walls 13 substantially transverse to the support plate 11 and the above-mentioned electrical resistive means comprise two electrical resistors 14, each of which is housed in a respective seat 15 formed in a respective side wall 13 with its electrical terminals extending through, and attached to, the support plate 11.

[0025] As illustrated in Figures 3, 4 and 5, the water supply duct 9 within the metal block 8 comprises a heating section 16, which is fluidically connected to the water inlet 10 in order to receive cold water therefrom, in particular, at the temperature of the water mains and pressurised, and an outlet section 17, which fluidically connects the heating section 16 to the water dispensing body 6.

[0026] The heating section 16 extends helically and is delimited partially by the outer surface of a cylindrical hole 18 formed in the metal block 8 and partially by a helical groove 19 that is formed on the outer surface of a cylindrical insert 20 extractably housed in the cylindrical hole 18 and extends helically around a longitudinal axis 21 of the insert 20.

[0027] Conveniently, as in the embodiment illustrated in the attached figures, the cylindrical hole 18 is formed in a wall of the metal block 8 facing the support plate 11 and the latter has a through opening at the cylindrical hole 18 so that the insert 20 can be inserted into, and extracted from, the cylindrical hole 18 even without disassembling the coffee brewing device 3 from the support plate 11. The heating section 16 is fluidically connected to the water inlet 10 via a connecting section 22, which is part of the water supply duct 9 and comprises, in a direction of flow of the water flowing into the insert 20, a coaxial portion 22A and a radial portion 22B with respect to the longitudinal axis 21, with the radial portion 22B preferably formed to extend downwards from the centre of the insert 20 so as to open into the helical groove 19 at an area of the cylindrical hole 18 below the longitudinal axis 21.

[0028] The radial portion 22B of the connecting section 22 is preferably formed to extend vertically so as to open into the helical groove 19 of the heating section 16 at the lowest area thereof.

[0029] At the opposite end of the heating section 16, the outlet section 17 is formed to be fluidically connected to the helical groove 19 at an area of the cylindrical hole 18 above the longitudinal axis 21.

[0030] The outlet section 17 is preferably formed to extend vertically to be fluidically connected to the helical groove 19 at the highest area of the cylindrical hole 18.

[0031] As illustrated in the attached figures, the water dispensing body 6 of each coffee brewing device 3 is generically cup shaped, with a concavity facing downwards, and is provided, on its bottom wall, with a water distribution shower 23 designed to receive pressurised hot water from the outlet section 17, and with a front gasket 24 whose function is to ensure the fluid-tight coupling of the water dispensing body 6 with the filter holder 7.

[0032] The water dispensing body 6 is made of metal and is integral with the metal block 8 so as to form an enbloc. In the embodiment illustrated in Figures 4 and 5, the water dispensing body 6 is coupled to the metal block 8 by means of screws, while in an alternative embodiment not illustrated, the water dispensing body 6 and metal block 8 are formed in one piece, preferably by moulding, on which the necessary machining is subsequently performed.

[0033] As illustrated in Figures 1 and 4, each filter holder 7 comprises a cup 25 open at the top and a handle 26 extending radially from the cup 25 to allow an operator to couple and uncouple the cup 25 to / from the water dispensing body 6 by means of a releasable quick coupling mechanism (not illustrated), typically a bayonet mechanism.

[0034] The cup 25 internally houses a filter 27, which is cup-shaped to contain an amount of loose ground coffee or coffee in the form of a pod or capsule and, when coupled to the water dispensing body 6, defines a brewing chamber with the latter that communicates fluidically, through the shower 23, with the water supply duct 9 for receiving the hot brewing water, and, on the opposite side, communicates fluidically, through a perforated bottom wall of the filter 27, with a coffee dispensing duct 28 formed in the filter holder 7 and coupled, preferably removably, to a beverage dispensing spout 29.

[0035] In addition, the filter 27 is preferably made of metal, conveniently stainless steel, and is detachably mounted to the cup 25 so that it can be replaced with another filter designed to contain a different dose of coffee or a different pod / capsule.

[0036] As illustrated in Figures 2 and 5, each coffee brewing device 3 comprises a valve assembly 30 comprising a three-way solenoid valve 31 arranged upstream of the cold water inlet 10 and having an inlet port 32 fluidically connected to the water pump (not illustrated) via a delivery duct 33, a first outlet port 34 fluidically connected to the water inlet 10 via a delivery duct 35, and a second outlet port 36 fluidically connected to a discharge duct 37.

[0037] Each valve assembly 30 further comprises a two-way solenoid valve 38, which has an inlet port 39 fluidically connected to the outlet section 17 via a drainage duct 40 formed in the metal block 8, and an outlet port 41 fluidically connected to another discharge duct 42.

[0038] The architecture of the machine 1 described above and, in particular, the architecture of the coffee brewing device 3 allows several advantages, listed below, to be achieved, deriving both from the intrinsic structural characteristics of the coffee brewing device 3 and from the management of the latter via the electronic control unit of the machine 1:

[0039] - the use of an instant electric thermoblock heater connected to each coffee brewing device 3 and supplied directly with cold water is more energy efficient, and therefore more economical, than conventional systems with a single boiler and exchangers or multiboiler systems because only the amount of water necessary for brewing coffee is heated; in addition, the heating is instantaneous and no stagnant water is used;

[0040] - the fact that the metal block 8 of the heating device 5 and the dispensing body 6 are made to be a single block (whether they are connected together to form an integral assembly or made of a single piece) means that the assembly has a thermal mass such as to achieve better thermal transmission and temperature uniformity to the advantage of both the instantaneous heating of the water to the optimal temperature for brewing coffee and maintaining the heat of the dispensing body 6, with a consequent positive effect on the stability of the temperature of the coffee produced;

[0041] - the provision of a pair of electrical resistors 14 applied to the thermal block 8 allows optimised management of water heating. In particular, the electronic control unit of the machine 1 can be programmed to manage the switching on of the electrical resistors 14 independently of each other so that, for example, only one of the two electrical resistors 14 can be switched off to decrease consumption and have greater energy savings and, at the same time, keep the coffee brewing device 3 operative so as to keep the thermal mass always hot with minimum consumption;

[0042] - the fact that the coffee brewing devices 3 are totally independent of each other both structurally and functionally entails significant advantages in terms of serviceability, i.e., ease of maintenance of the machine 1. In fact, each coffee brewing device 3 can be replaced in the field with a simple and quick operation, by disconnecting the respective support plate 11 and the hydraulic connection of the heating device 5 from the frame 2, without waiting times related to the cooling and pressure of the hydraulic circuit as in professional machines with conventional single -boiler and exchanger systems or multiboiler systems;

[0043] - the arrangement of the valve assembly 30 and the structure of the heating device 5 make it possible to solve the major problem that normally afflicts instant electric thermoblock heaters, namely the formation of limescale, which, as is well known, requires frequent and complex maintenance, if not, very often, the total replacement of the heater after a relatively short period of use.

[0044] On the one hand, in fact, the valve assembly 30 ensures that, at the end of each coffee brewing process, the water supply duct 9 inside the heating device 5 can be completely, or almost completely, emptied of the residual brewing water. On the other hand, the very structure of the heating device 5, in particular the fact that the part of the water supply duct 9 with the largest extension, i.e. the heating section 16, is formed on the removable insert 20, allows for easy and thorough cleaning that improves efficiency and prolongs the life of the heating device 5.

[0045] Regarding the emptying of the water supply duct 9 at the end of dispensing, the electronic control unit of the machine 1 is programmed to manage the solenoid valves 31 and 38 as follows:

[0046] - during the coffee brewing process, the solenoid valve 31 is controlled in such a way as to place the inlet port 32 and the outlet port 31 in fluidic communication to allow a flow of pressurised cold water to be fed to the heating device 5 via the cold water inlet 10, while the outlet port 36, which gives access to the discharge duct 37, is closed; the solenoid valve 38 is instead controlled in such a way as to close the fluidic communication between the inlet port 39 and the outlet port 41.

[0047] - at the end of the coffee brewing process, the solenoid valve 31 is controlled in such a way as to place the outlet port 31 in fluidic communication with the outlet port 36, thereby connecting the delivery duct 35 with the discharge duct 37; the solenoid valve 38 is instead controlled in such a way as to fluidically connect the inlet port 39 and the outlet port 41, thereby connecting the drainage duct 40 with the discharge duct 42. In this configuration, therefore, the water supply duct 9 is fluidically communicating with the discharge duct 37 on the side towards the water inlet 10, and with the discharge duct 42 on the side flowing into the brewing chamber. As a result of the pressure conditions occurring inside the heating device 5 and the brewing chamber at the end of the coffee dispensing process, in particular the residual pressure in the brewing chamber and in the water supply duct 9, the residual water inside the water supply duct 9 and in the brewing chamber is pushed, on one side, towards the discharge duct 37 and, on the other side, towards the discharge duct 42.

[0048] In this way, at the end of the coffee brewing process, the water supply duct 9 is emptied and limescale is prevented from forming inside it, in particular, inside the heating section 16. In addition, emptying the residual water allows the used coffee tablet to dry out in the brewing chamber.

[0049] The shape of the connecting section 22, in particular the fact that the radial portion 22B flows into the helical groove 19 in an area of the cylindrical hole 18 positioned below the longitudinal axis 21, preferably in the area of the lower cylindrical hole 18, facilitates the channelling of the water trapped in the helical groove 19 towards the connecting section 22 and, therefore, towards the discharge duct 37.

Claims

CLAIMS1. Coffee machine (1) comprising one or more coffee brewing assemblies (3), each with a cold water inlet (10) to receive pressurised cold water; each coffee brewing device (3) comprises a cold water heating device (5), a hot water dispensing body (6) and a filter holder (7) designed to contain, in use, an amount of coffee and to be manually removably coupled to the hot water dispensing body (6) to receive pressurised hot water therefrom for brewing coffee; the cold water heating device (5) is an instant electric thermoblock heater and comprises a metal block (8) with electrical resistive means (14) designed to heat the metal block (8), and a water supply duct (9) formed in the metal block (8) and fluidically connected on one side to the cold water inlet (10) to receive pressurised cold water therefrom and, on the other side, to the hot water dispensing body (6) to supply pressurised heated water thereto for brewing coffee; each coffee brewing device (3) further comprises a valve assembly (30) comprising a three-way solenoid valve (31) arranged upstream of the cold water inlet (10) and having an inlet port (32) fluidically connected to a cold water delivery duct (35), a first outlet port (34) fluidically connected to the cold water inlet (10), and a second outlet port (36) fluidically connected to a discharge duct (37); each valve assembly (30) further comprises a two-way solenoid valve (38) having an inlet port (39) fluidically connected to an outlet section (17) of the water supply duct (9) via a drainage duct (40) formed in the metal block (8), and an outlet port (41) fluidically connected to a further discharge duct (42); the valve assembly (30) is electronically controlled to cause:- during a coffee brewing process:• the three-way solenoid valve (31) to fluidically connect the inlet port (32) and the outlet port (31) to cause pressurised cold water to be supplied to the cold water heating device (5) via the cold water inlet (10) and to close the outlet port (36); and• the two-way solenoid valve (38) to close the fluidic communication between the inlet port (39) and outlet port (41); and- at the end of the coffee brewing process:• the three-way solenoid valve (31) to put the outlet port (31) in fluidic communication with the outlet port (36); and• the two-way solenoid valve (38) to put the inlet port (39) in fluidic communication with the outlet port (41).

2. The coffee machine (1) of claim 1, wherein the water supply duct (9) further comprises a heating section (16) fluidically connected on one side to the cold water inlet (10) to receive pressurised cold water therefrom, and on the other side to the hot water dispensing body (6) via the outlet section (17); the heating section (16) extends helically around a longitudinal axis (21).

3. The coffee machine (1) of claim 2, wherein the heating section (16) is fluidically connected to the cold water inlet (10) via a connection section (22), which is part of the water supply duct (9) and comprises, in a water flow direction, a coaxial portion (22 A) and a radial portion (22B) in relation to the longitudinal axis (21); the radial portion (22B) of the connection section (22) is formed to extend downwards so as to open into the heating section (16) at an area thereof below the longitudinal axis (21).

4. The coffee machine (1) of claim 3, wherein the radial portion (22B) of the connection section (22) is formed to extend vertically so as to open into the heating section (16) at the lowest area thereof.

5. The coffee machine (1) of any one of claims 2 to 4, wherein the outlet section (17) is formed to be fluidically connected to the heating section (16) at an area thereof above the longitudinal axis (21).

6. The coffee machine (1) of claim 5, wherein the outlet section (17) is formed to extend vertically to be fluidically connected to the heating section (16) at the highest area thereof.

7. The coffee machine (1) of any one of claims 2 to 6, wherein the heating section (16) is delimited partially by an outer surface of a cylindrical hole (18) formed in the metal block (8) coaxially to the longitudinal axis (21) and partially by a helical groove (19) formed on an outer surface of a cylindrical insert (20) housed in the cylindrical hole (18).

8. The coffee machine (1) of claim 7, wherein the metal block (8) is cantilever mounted on a support plate (11) removably connected to a frame of the coffee machine (1); the cylindrical hole (18) is formed in a wall of the metal block (8) facing the support plate (11), which has a through opening at the cylindrical hole (18) to cause the insert (20) to be insertable into, and removable from, the cylindrical hole (18) even without disassembling the entire brewing device (3) from the support plate (11).

9. The coffee machine (1) of any one of the preceding claims, wherein the hot water dispensing body (6) is made of metal and is integral with the metal block (8) to form an enbloc therewith.

10. The coffee machine (1) of any one of the preceding claims, wherein the electrical resistive means (14) of each metal block (8) comprise two electrical resistors (14) coupled to two opposite side walls (13) of the metal block (8).

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