WO2008087673A1

WO2008087673A1 - Coffee-maker with controlled delivery system

Info

Publication number: WO2008087673A1
Application number: PCT/IT2007/000040
Authority: WO
Inventors: Francesco Ranzoni
Original assignee: Bialetti Industrie S.P.A.
Priority date: 2007-01-19
Filing date: 2007-01-19
Publication date: 2008-07-24
Also published as: TW200836682A; WO2008087673A8

Abstract

The invention relates to a coffee-maker (10) comprising a boiler (12), a collecting vessel (14), a duct (16) suitable to place the boiler (12) and the collecting vessel (14) in communication with each other. The coffee-maker (10) comprises a delivery control valve (54) suitable to stop the fluid communication between the boiler (12) and the collecting vessel (14) when a given threshold value of level L of the coffee, or generally hot beverage, is achieved within the collecting vessel (14).

Description

DESCRIPTION

"Coffee-maker with controlled delivery system" [0001] . The object of the present invention is a coffee-maker, particularly a coffee-maker with controlled delivery system.

[0002] . Known domestic coffee-makers generally comprise a lower boiler, an upper vessel and a vertical duct connecting the boiler to the vessel. When the coffee- maker is placed on a heat source, such as a cooker, the temperature and pressure within the boiler increase. In these conditions, the duct is suitable to take the pressurized water from the lower boiler, pass it through the chamber containing the coffee powder (the so-called "extraction" step) and then cause it to flow into the upper vessel. The coffee beverage is thus obtained.

[0003] . These domestic coffee-makers, which have been known for a long time and appreciated for their easiness of use, are not without defects.

[0004] . It is known, in fact, that the temperature and pressure of the water rising up the duct are not constant when the coffee-maker is being heated up and the coffee beverage is being consequently produced.

[0005] . Particularly, the water starts to rise along the duct under conditions of low temperature (about 45- 55°C) and low pressure (about 0.1-0.2 bars in differential terms) . As the amount of water decreases within the boiler, at the same heat supplied by the cooker, the water temperature increases faster and faster. [0006] . Due to the quick temperature increase, steam is formed within the boiler, and hence the pressure to which the water raising along the duct from the boiler is subjected also increases as quickly. It follows that the last water passing through the chamber containing the coffee powder is subjected to high temperature (about 95- 100⁰C) and high pressure (about 0.5-1.5 bars) conditions. [0007] . Finally, when the water level within the boiler decreases below the draught level of the duct, the duct is filled by the high-temperature (100-105⁰C) steam found within the boiler.

[0008] . It has been found that the coffee beverage obtained with water at a temperature less than 90-95 ⁰C has much better and more valuable organoleptic characteristics than that obtained with water, and mainly, with steam at a higher temperature.

[0009]. It has been found, particularly, that coffee powder releases unpalatable substances having a burnt, bitter and astringent taste when it is passed through by water and mainly steam at high temperatures (100-105⁰C) . These conditions determine the so-called "overextraction" step.

[0010] . When the water pressure and temperature conditions are changed upon extraction, the substances released by the coffee powder into the water are also changed.

[0011] . The extraction pressure and temperature further depend on the amount of water that is initially filled in the boiler, the amount, compactness and grain size of the coffee powder poured in the suitable chamber and on the type and adjustment of the heat source used to heat the coffee-maker.

[0012] . In the known domestic coffee-makers, the extraction conditions thus strongly depend on the selections made by the user and are hardly predictable beforehand.

[0013] . The object of the present invention is to devise and provide a domestic coffee-maker with controlled delivery system which allows overcoming the drawbacks stated above with reference to prior art. [0014] . This object and these tasks are achieved by means of a domestic coffee-maker in accordance with claim 1.

[0015] . Further characteristics and the advantages of the coffee-maker according to the invention will be understood from the description given below of preferred embodiments thereof, which is merely illustrative and non-limiting, with reference to the annexed figures, in which:

[0016] . Figures 1 to 5 illustrate a side sectional view of a first embodiment of a coffee-maker according to the invention, in a sequence of subsequent operating configurations ;

[0017] . Figure 6 illustrates a sectional perspective view of a second embodiment of a coffee-maker according to the invention in a first operating configuration;

[0018] . Figure 7 illustrates an enlarged detail of figure 6 ;

[0019] . Figure 7A illustrates the enlarged detail of figure 7 according to a possible variant embodiment; [0020] . Figure 8 illustrates a sectional perspective view of the coffee-maker in figure 6 in a second operating configuration;

[0021] . Figure 9 illustrates an enlarged detail of figure 8 ; [0022] . Figures 10 and 11 illustrate two perspective views of a third embodiment of the coffee-maker according to the present invention in two different operating configurations;

[0023] . Figure 12 illustrates a side sectional view of a detail of the coffee-maker of figure 11; [0024] . Figure 13 illustrates a perspective view of the coffee-maker of figure 10 in a second different operating configuration;

[0025] . Figure 14 illustrates a side sectional view of a detail of the coffee-maker of figure 13 in an operating configuration;

[0026] . Figure 15 illustrates the coffee-maker in figure 14 according to a different point of view;

[0027] . Figure 16 illustrates a side sectional view of a detail of the coffee-maker of figure 13 in an operating configuration;

[0028] . Figure 17 illustrates the coffee-maker in figure 16 from a different point of view;

[0029] . Figures 18 to 21 illustrate a side sectional view of two further embodiments of a coffee-maker according to the invention, in a sequence of subsequent operating configurations.

[0030]. The meanings of the words "upper" and "lower", or "high" and "low" , or "above" and "below" , and the like, will be referred below to the coffee-maker in its normal standing orientation. The normal standing condition is when the coffee-maker can be firmly placed on a cooker in order to prepare the coffee beverage, or when the upper vessel is capable of containing the greatest amount of beverage without leakage. [0031] . The term coffee-maker is referred to the most widespread use of this equipment, i.e. the production of coffee (infusion) from water and ground coffee. Further uses are generally known and possible for producing a hot beverage from at least one liquid ingredient and at least one powdered ingredient. For clarity purposes, reference will be made herein below to the production of coffee. [0032] . With reference to figures 1 to 5, a coffee- maker according to the invention has been generally designated with 10.

[0033]. The coffee-maker 10 comprises a boiler 12, a collecting vessel 14 and a duct 16 suitable to place the boiler 12 and the collecting vessel 14 in fluid communication with each other. [0034] . In accordance with an embodiment, the duct 16 places the lower region of the boiler 12 in communication with the upper region of the collecting vessel 14.

[0035] . A chamber 18 is formed along the duct 16, which is suitable to contain the coffee powder and suitable to avoid stopping the fluid continuity of the duct 16.

[0036] . Particularly, the boiler is opened on top with an opening 20 defined by an edge 22. The boiler is suitable to receive the liquid ingredient, particularly water. The level of the liquid ingredient within the boiler in the various operating configurations of the coffee-maker has been designated with 1.

[0037] . In accordance with a possible embodiment, the collecting vessel 14 is screwed to the boiler 12 at the opening 20. The collecting vessel 14 is suitable for receiving the hot beverage, particularly the coffee infusion. With L has been designated the level of the beverage within the collecting vessel in the different operating steps or configurations of the coffee-maker according to the present invention. [0038]. A container for a powdered ingredient or bowl 24 is suitable for being housed within the boiler 12, by- being inserted in the opening 20 such that an outer edge 26 of the bowl rests on the edge 22 of the opening 20 of the boiler 12. The bowl 24 defines said chamber 18. [0039] . A bottom 28 of the collecting vessel 14 extends within the collecting vessel by means of an internally hollow tube 30. The tube 30 extends in a main longitudinal direction, preferably substantially coincident with a vertical direction in a position of normal use of the coffee-maker. The tube 30 has at least one delivery opening 32, preferably two or more delivery openings 32. Advantageously, the delivery openings are arranged laterally of the tube 30, in the proximity of an upper end of the tube. [0040] . In accordance with a possible embodiment, a further opening 34 is provided above the tube 30. Preferably, the further opening 34 widens outwardly with a step 36 forming an inner tract 38 and an outer tract 40 having greater diameter than the inner tract and forming an accommodating seat 42. In accordance with a possible embodiment, the seat 42 has at least one notch 44, preferably two notches for example arranged in diametrically opposite positions . [0041] . In accordance with a possible embodiment, a narrowing 46 is provided within the tube 30, which is arranged below the delivery openings 32. The narrowing 46 is preferably made by means of a truncated-cone shaped portion 48 and a cylindrical portion 50, which is arranged above the truncated-cone shaped one. [0042] . The bowl 24 and tube 30 are provided and arranged such as to form the duct 16 defining a delivery pathway along which the water contained within the boiler 12, after the pressure and temperature increase within the boiler, rises up along the bowl 24 thus extracting the infusion from the powdered ingredient, which rises up along the tube 30 and is collected within the collecting vessel 14 .

[0043] . The coffee-maker 10 further comprises a release valve 52 being arranged between the boiler 12 and the external environment. The release valve 52 is suitable to adopt a closed operating configuration and an opened operating configuration. The release valve 52 is suitable to pass from the closed configuration to the opened configuration after a given pressure release threshold value has been exceeded within the boiler 12.

[0044] . The release valve 52, accordingly, is suitable to hold the boiler 12 sealingly closed when the inner pressure value is lower than the release threshold value. Furthermore, the release valve 52 is suitable to place the inside of the boiler 12 in fluid communication with the external environment when the inner pressure value exceeds the release threshold value. The release threshold value can change depending on the coffee-maker size. [0045] . The coffee-maker 10 further comprises a delivery control valve 54 that is placed along the duct 16. The delivery control valve 54 is suitable to adopt an opened operating configuration and a closed operating configuration. [0046] . The delivery control valve 54 is suitable to pass from the opened configuration to the closed configuration when a given threshold level L of the coffee or generally hot beverage has been achieved within the collecting vessel 14. Preferably, though not necessarily, this condition corresponds to the occurrence of those conditions of (static and dynamic) pressure and flow rate immediately preceding the end of the water draught within the boiler and the consequent passage of high-temperature steam through the coffee powder. [0047] . The delivery control valve 54 is thus suitable to maintain the duct 16 opened until when the level L of coffee within the collecting vessel has achieved a given threshold value. In the conditions of normal usage of the coffee-maker, this condition is selected to substantially correspond to the conditions of pressure and flow rate at which the water from the boiler 12 still has a temperature less than 90-95⁰C and is still in the liquid phase. The delivery control valve 54 is thus provided to maintain the duct 16 opened under the so-called extraction conditions of the flow.

[0048] . Furthermore, the delivery control valve 54 is suitable to occlude the duct 16, i.e. stop the fluid communication between the inside of the boiler 12 and the collecting vessel 14, when the value of the threshold level L of the beverage has been exceeded within the collecting vessel 14. Preferably, the value of the threshold level L is defined such that the delivery control valve 54 closes the duct 16 before the water from the boiler 12 along the duct 16 reaches excessive temperatures (100-105⁰C) or even passes from the liquid to the gaseous phase. The delivery control valve 54 is thus preferably provided to occlude the duct 16 under the so-called overextraction conditions of the flow.

[0049] . A parameter that allows observing the passage from the extraction to overextraction conditions in a reliable and repeatable manner has been identified in a given threshold value of level L of the beverage within the collecting vessel 14, considering a given starting water level within the boiler 12. This condition is preferably selected such as to correspond to a predetermined control threshold value of the pressure within the duct 16, immediately upstream of the control delivery valve 54.

[0050] . A boiler threshold value corresponds to this control threshold value, within the boiler. When the pressure within the boiler is lower than the boiler threshold value, the flow conditions are such as to allow remaining in the extraction step. When the pressure within the boiler is higher than the boiler threshold value, the flow conditions would lead to the overextraction step.

[0051] . In accordance with an embodiment of the invention, the boiler threshold value, which substantially corresponds to the value at which the delivery control valve 54 passes from the opened configuration to the closed configuration, is less than or equal to the release threshold value.

[0052] . With reference to the embodiment illustrated in figures 1-5, with 56 has been designated a plug of the delivery control valve 54 that is housed within the duct 16, particularly within the tube 30, below the narrowing 46. The plug 56 is free to move within the duct 16 and particularly of the tube 30, preferably along the longitudinal development thereof, between a lower or opened or delivery position and an upper or closed position in which it is abutted against the narrowing 46.

[0053] . In accordance with a possible embodiment, the plug 56 comprises a stem 58, which passes through the narrowing 46. Preferably, the stem 58 extends outwardly of the duct 16, for example through the further opening

34. In accordance with a possible embodiment, the stem 58 has such a cross size as to be capable of being housed within the inner tract 38 of the opening 34.

[0054] . Reference 60 designates a widening of the stem 58, for example comprising at least one spoke 62 extending in the radial direction past the size of the duct 16. Preferably, two spokes 62 are provided that are for example arranged in a diametrically opposite position. Advantageously, it may be provided that the spokes 62 are suitable to be accommodated within respective notches 44 of the tube 30, in at least one operating configuration of the coffee-maker. [0055] . In accordance with a possible embodiment, the stem 58 widens past the radial dimensions of the duct 16 and extends below to form a cap suitable to be arranged on the duct. Preferably, the spokes 62 are connected to a cylindrical portion 64 extending downwards outwardly of the duct to form said cap. [0056] . Reference 66 designates a floater that is operatively connected to the delivery control valve 54 to cause the latter to pass from the opened configuration to the closed configuration when a given threshold value of the level L of the coffee, or generally hot beverage, is reached within the collecting vessel 14. [0057] . Preferably, the floater 66 is operatively connected to the plug 56 such as to lift the latter until when a given threshold value of the level L of the beverage is achieved within the collecting vessel 14. In accordance with a possible embodiment, the floater 66 is operatively connected to the plug 56 by means of mechanical interaction, preferably by contact between the floater and at least one portion integral with the plug.

[0058] . Preferably, the floater 66 envelops at least partially the outer surface of duct 16, particularly of the tube 30 and uses the latter as a guide. In accordance with a possible embodiment, the floater 66 has an annular shape .

[0059] . With reference to the embodiment illustrated in figures 1 to 5, the floater 66 is operatively connected to the plug 56 by being contacted to the cylindrical portion 64 after the level L of the beverage has risen within the collecting vessel 14.

[0060] . Reference 112 designates a further valve, or safety valve, which is suitable to communicate the boiler 12 with the external environment after a safety threshold value has been reached, which is greater than the release threshold value.

[0061] . The operation of the coffee-maker as described above is described below, with particular reference to the production of coffee, for clarity purposes.

[0062] . In figure 1, a coffee-maker 10 is illustrated in a first operating configuration. In this operating configuration, the coffee-maker is ready to be either placed on a heat source, such as a cooker, as in the case illustrated herein, or is ready to be operated, as in the case of an electric coffee-maker. The boiler 12 contains a suitable amount of water (level 1) and the chamber 18 a suitable amount of coffee powder. The pressure within the boiler 12, equal to the atmospheric pressure, is lower than the boiler threshold value and release threshold value as well. Consequently, the release value 52 is closed. In addition, the level L of the beverage within the collecting vessel is zero, the delivery control valve 54 is thus opened and the floater and plug 56 are in the lowered position.

[0063] . Figure 2 illustrates the coffee-maker in a second operating configuration in which the heat supplied to the coffee-maker by the heat source, such as the cooker, causes the pressure to increase within the boiler 12. The pressure within the boiler 12 is higher than atmospheric pressure but lower than the boiler and release threshold values. Consequently, the release value 52 is closed. The action of pressure (indicated by the full-background arrows) causes the water to flow upwards, along the duct 16 (indicated by the undulated arrows) . The water thus passes through the chamber 18 containing the coffee powder, becomes coffee beverage and flows inside the collecting vessel 14. The level L of coffee within the collecting vessel increases while the level 1 of water within the boiler decreases. The floater 66 rises and moves towards the cylindrical portion 64. The delivery control valve 54 is opened.

[0064] . As the floater 66 comes in contact with the cylindrical portion 64, it also begins rising the plug 56 that moves towards the narrowing 46. [0065] . Figure 3 illustrates the coffee-maker in a third operating condition in which the water, as it continues rising from the boiler to the collecting vessel due to the further heat supplied to the coffee-maker by the heat source, has reached the threshold value of level L in which the plug 56 comes in contact with the narrowing 46 thus closing the duct 16 and accordingly the delivery pathway. Consequently, the delivery control valve 54 is closed. The threshold value of level L is preferably selected depending on a given initial level of water within the boiler, such that the delivery control valve 54 closes substantially at the boiler threshold value, lower than the release threshold value. Consequently, the release value is also closed. The water flow along the duct 16 is interrupted and the pressure inside the boiler 12 continues to increase.

[0066] . Figure 4 illustrates the coffee-maker in a fourth operating configuration in which the pressure within the boiler has reached the operating pressure at which the release valve 52 opens outwardly. In fact, the further heat supplied to the coffee-maker by the heat source, such as the cooker, causes a further pressure increase within the boiler 12. The pressure within the boiler 12 is higher than the release threshold value. Consequently, the release valve 52 is opened and the delivery control valve 54 is closed. The pressure within the boiler causes the release valve 52 to open. A water steam flow (indicated with the dotted arrows) is created through the release valve 52 to the external environment and the pressure inside the boiler 12 decreases.

[0067] . As those skilled in the art may easily appreciate from the above, the operation of the coffee- maker 10 according to the invention allows stopping the water from passing through the chamber 18 when the level L of beverage within the collecting vessel has achieved a given threshold value. Starting from a given initial value of the level 1 of liquid within the boiler, which corresponds to the normal usage of the coffee-maker, the threshold value of level L is selected such as to substantially correspond to the value above which the pressure and temperature within the boiler 12 take values that are judged to be excessive. Thereby, the coffee- maker 10 according to the invention restrains the production of the coffee beverage to its best part, obtained with water at low temperature and pressure, and prevents the water from passing through the coffee powder at excessive temperature and pressure. A coffee beverage is thus obtained which has definitely improved general organoleptic characteristics . [0068] . In accordance with the embodiment of the invention as illustrated in figures 6 to 9, the elements in common with the embodiment described above have been designated with the same references.

[0069] . Also in this embodiment, the delivery control valve 54 is suitable to pass from the opened configuration to the closed configuration when a given threshold value of the level L of coffee, or generally hot beverage, has been reached within the collecting vessel 14. Particularly, the floater 66 is operatively connected to the delivery control valve 54 to cause the latter to pass from the opened configuration to the closed configuration when a given threshold value of the level L of the coffee, or generally of the hot beverage, has been exceeded within the collecting vessel 14. [0070] . Preferably also according to the embodiment illustrated in figures 6 to 9, the floater 66 is operatively connected to the plug 56 of the delivery control valve 54 such as to lift the latter to achieve a given threshold value of the level L of the beverage within the collecting vessel 14 at which the plug 56 closes the duct 16. Particularly, the floater 66 is operatively connected to the plug 56 by means of magnetic force . [0071] . Preferably, the floater 66 is not contacted with the plug 56 and the magnetic force operates through the walls of duct 16, particularly of tube 30. [0072] . In accordance with a possible embodiment, the floater 66 comprises at least one magnet 68. The magnet 68 is preferably embedded in the material of the floater 66.

[0073] . In accordance with the embodiment illustrated herein, three magnets are provided to be evenly distributed about the tube 30. [0074] . Advantageously, the floater 66 is provided by means of two portions 66a and 66b that are inserted within each other at the housing of the at least one magnet 68. Preferably, one of the two portions, for example the upper one, defines a decorative or signalling element . [0075] . In accordance with a possible embodiment, the plug 56 is completely housed within the duct 16, particularly within the tube 30. Preferably, the plug 56 is housed within an envelope 70 that is inserted within the duct 16 such as to be a portion of the duct, and thus of the delivery pathway, and suitable to define a lower stop 72 and an upper stop corresponding to the narrowing 46.

[0076] . In accordance with a possible embodiment, the envelope 70 comprises at least one inlet opening 76 and at least one outlet opening 78. In accordance with a possible embodiment, the at least one inlet opening 76 is arranged laterally with respect to the longitudinal development of the tube 30. The outlet opening 78 is suitable to be closed by the plug 56. [0077] . In the example as illustrated in the figures, reference 80 designates a nozzle connected to the envelope 70 and tube 30, and defining at least one delivery opening 32. Seals 82 and 84 are interposed between the nozzle 80 and envelope 70 and between the nozzle 80 and the duct 16, particularly the tube 30, respectively. In an embodiment not illustrated herein, the nozzle 80 and envelope 70 can be made as one piece. [0078] . Advantageously, the envelope 70 has a further opening 76a that is arranged below the envelope, for example inclined relative to the longitudinal development of the envelope. In figure 7A, a possible variant embodiment is illustrated in which the opening 76a is coaxial with the envelope 70, for example suitable to low pressures, and accordingly to small-sized coffee-makers. The further opening 76a is, for example, suitable to discharge the coffee at the end of the procedure. [0079] . In accordance with an embodiment, the plug 56 is ball-shaped. [0080] . In the event that the floater 66 comprises at least one magnet 68, the plug 56 is made of a material suitable to be dragged along the tube 30 due to the magnetic interaction with the magnet 68.

[0081] . The operation of the embodiment described above is similar to that of the embodiment illustrated in figures 1 to 5, with the difference that the interaction between the plug and floater is carried out by means of magnetic force, preferably by means of magnetic attraction. Particularly, figures 6 and 7 illustrate the opened configuration of the delivery control valve 54, in which the plug 56 is in the lowered position, corresponding to a lower stop or to the lowered position of the floater. In addition, figures 8 and 9 illustrate the closed configuration of the delivery control valve 54, in which the plug 56 is in the raised position, corresponding to the raised position of the floater at the threshold value of level L of liquid within the collecting vessel 14.

[0082] . Figures 10 to 17 illustrate a further possible embodiment. Particularly, though not being limited thereto, it is a variant of the embodiment illustrated in figures 6 to 9.

[0083]. In accordance with a possible embodiment, the coffee-maker 10 comprises selection means 86 for changing the threshold value of level L of the liquid within the collecting vessel and thus the type of beverage being produced. Particularly, the selection means allow selecting between at least two types of beverages, preferably three types of beverages. When coffee is produced, the selection means allow changing the amount of water contained in the beverage, such as providing the production of strong coffee, normal coffee or light coffee.

[0084] . In accordance with a possible embodiment, the selection means are suitable to change the threshold value of level L of liquid within the collecting vessel by changing the length of the travel of the floater before the delivery control valve 54 is closed. Particularly, the length of the travel of the plug 56 is provided to be changed. In much greater detail, the position of the narrowing 46 against which the plug closes the delivery control valve is provided to be changed.

[0085] . In the case of the embodiment as illustrated in figures 10-17, the selection means 86 comprise the envelope 70 and possibly the nozzle 80 that are slidingly mounted along the duct 16, particularly within the tube 30.

[0086] . In accordance with a possible embodiment, the movement of the envelope 70 and any nozzle 80 is generated by screw means 88 comprising a knob 90 to be operated by the user. The knob 90 is rotatably mounted at the end of the tube 30 and is associated with a plate 92 for example acting as a closure and indication of the selection made. Preferably, a screw/nutscrew 96 component 96 is provided, a first portion 96a thereof being associated with the knob 90 and a second portion 96b being associated with the envelope 70 or nozzle 80. The thread can also extend by an individual turn, preferably with a quite high pitch. Advantageously, at least one abutment 98 integral with the envelope, for example with the second portion 96b of the screw/nutscrew component 96 slides in a respective slot 100 of the tube, which is also a delivery opening 32. Preferably, two sliding abutments 98 are provided in respective slots 100, for example arranged in diametrically opposite positions of the tube 30.

[0087] . Figures 10-17 illustrate several positions of the envelope 70 as a function of the configuration adopted by the selection means. [0088] . Figures 13-17 illustrate the configuration for the production of strong coffee. The envelope 70 is in the lowermost position relative to the tube 30, thereby the travel of the plug and accordingly of the floater is quite short. The corresponding threshold value of the level L is low. [0089] . Figures 10-12 illustrate the configuration for the production of light coffee. The envelope 70 is in the uppermost position relative to the tube 30, thereby the travel of the plug and accordingly of the floater is quite long. The corresponding threshold value of the level L is high.

[0090] . An intermediate configuration between those described above corresponds to a configuration for the production of normal coffee. The envelope 70 is in the intermediate position relative to the tube 30, thereby the travel of the plug and accordingly of the floater is average. The corresponding threshold value of the level L is average. [0091] . During the operation of the coffee-maker described above, the coffee flows along the envelope 70 and nozzle 80 and flows through the slots 100 to the collecting vessel.

[0092] . To select among the possible operating configurations, the user rotates the knob 90, for example causing a notch thereof to match a reference mark on the plate 92. Preferably, the two extreme configurations

(strong coffee and light coffee) are arranged at about

180°. Any intermediate position allows obtaining a beverage having intermediate characteristics, preferably at about 90° a reference mark is provided, which indicates normal coffee. By screwing or unscrewing the knob 90, the first portion 96a is either screwed or unscrewed. The interaction with the second portion 96b and the provision of the abutments 98 forces the second portion to shift along the duct 16 between a raised position and a lowered position.

[0093] . When the coffee-maker 10 is in its normal standing orientation, the weight of the plug 56 ensures that the plug adopts the position in which the delivery control valve 54 is opened.

[0094] . Reference 112 designates a further valve, or safety valve, which is suitable to communicate the boiler 12 with the external environment after a safety threshold value has been reached, which is higher than the release threshold value.

[0095] . In accordance with a possible embodiment, for example illustrated in figures 6 and following, the connection between the boiler 12 and the collecting vessel 14 is provided by means of a bayonet connection 102, which ensures that any elements of the boiler and collecting vessel are aligned, for example the release valve 52 and a decorative element 104 of the collecting vessel 14.

[0096] . Figures 18 and 19 illustrate two operating configurations of a coffee-maker of the type in figures 6 and following, i.e. in which the floater and plug are operatively connected by means of magnetic force. In this embodiment, the plug 56 is completely housed within the duct 16, particularly within the tube 30 in which a further narrowing 106 is obtained, which acts as a lower stop for the plug 56. Preferably, the further narrowing 106 is obtained by means of a series of indentations 108. A lid 110 is screwed to duct 16, particularly to the tube 30, which lid acts as an outlet nozzle with delivery openings 32 and defines the narrowing 46 against which the plug 56 closes the duct 16. The lid 110 can be screwed to the duct 16 in a more or less tight manner such as to shift the narrowing 46 and changing the threshold value of level L in which the duct 16 is closed.

[0097] . Figures 20 and 21 are similar to figures 18 and 19. The embodiment illustrated therein is different in that an envelope 70 is provided, which defines the narrowing 106 to which the lid 110 is screwed, similarly to what has been described above.

[0098] . Two different valves can be optionally provided, which are placed on the boiler 12. A first valve is the release valve 52, while a second valve is the safety valve 112 that opens the connection between the boiler and the external environment at a pressure higher than the operating pressure.

[0099] . To the preferred embodiments of the coffee- maker described above, those skilled in the art, aiming at satisfying contingent requirements, may carry out a number of modifications, adjustments and replacements of elements with others functionally equivalent, without departing from the scope of the claims below. Each of the characteristics described as belonging to a feasible embodiment can be provided independently from the other embodiments described herein.

Claims

1. A coffee-maker (10) comprising: a boiler (12) ; a collecting vessel (14) ; a duct (16) suitable to place the boiler (12) and the collecting vessel (14) in communication with each other; and wherein said coffee-maker (10) further comprises a delivery control valve (54) suitable to stop the fluid communication between the boiler (12) and the collecting vessel (14) when a given threshold value of level L of the coffee, or generally any other hot beverage, is achieved within said collecting vessel (14) .

2. The coffee-maker (10) according to the preceding claim, further comprising a release valve (52) suitable to place the boiler (12) in fluid communication with the external environment, when a pressure release threshold value has been exceeded within the boiler (12) .

3. The coffee-maker (10) according to one of the preceding claims, further comprising a chamber (18) suitable to contain the coffee powder and suitable to avoid stopping the fluid continuity of the duct (16) .

4. The coffee-maker (10) according to any preceding claim, wherein the duct (16) places the lower region of the boiler (12) in communication with the upper region of the collecting vessel (14) .

5. The coffee-maker (10) according to any preceding claim, wherein the delivery control valve (54) is placed along the duct (16) .

6. The coffee-maker (10) according to any preceding claim, wherein said delivery control valve (54) is suitable to hold the duct (16) opened until when the level of coffee within the collecting vessel (14) has achieved a given threshold value.

7. The coffee-maker (10) according to any preceding claim, wherein said threshold value of the level of coffee within the collecting vessel (14) is selected such that, when this value is achieved, a control threshold value of the pressure within the duct (16) and a corresponding boiler threshold value beyond which the water flowing from the boiler (12) along the duct (16) would achieve excessive temperatures, or would even pass from the liquid to gaseous phase.

8. The coffee-maker (1) according to any preceding claim, wherein the delivery control valve (54) determines a passageway (54) suitable to allow the coffee beverage that flows along the duct (16) to pass therethrough.

9. The coffee-maker (1) according to any preceding claim, wherein the delivery control valve (54) closes when a threshold value of level L is achieved within the collecting vessel, which value substantially corresponds to conditions of (static and dynamic) pressure and flow rate immediately preceding the end of the water draught within the boiler and the consequent passage of high- temperature steam through the coffee powder.

10. The coffee-maker (10) according to the preceding claim, wherein said release threshold value is higher than or equal to said boiler threshold value .

11. The coffee-maker (10) according to any preceding claim, wherein said delivery control valve (54) comprises a floater (66) that is operatively connected to the delivery control valve (54) to cause the latter to pass from the opened configuration to the closed configuration when a given threshold value of the level L of the coffee, or generally hot beverage, is achieved within the collecting vessel (14) .

12. The coffee-maker (10) according to claim 11, wherein said floater (66) at least partially envelopes the outer surface of a tube (30) of the collecting vessel (14) , and uses the latter as a guide.

13. The coffee-maker (10) according to claim 11 or 12, wherein said floater (66) has an annular shape.

14. The coffee-maker (10) according to one of claims 11 to 13, wherein said floater (66) is operatively connected to a plug (56) of the delivery control valve (54) , which is housed within the duct (16) such as to raise it until when a given threshold value of level L of the beverage is achieved within the collecting vessel (14) , said plug

(56) being movable between a lower or opened or delivery position and an upper or closure position in which it abuts against a narrowing (46) .

15. The coffee-maker (10) according to claim 14, wherein said floater (66) is operatively connected to said plug (56) by means of mechanical interaction, preferably by contact between the floater and at least one portion integral with said plug.

16. The coffee-maker (10) according to claim 15, wherein said plug (56) comprises a stem (58) extending outwardly of the duct (16) , said stem comprising a widening (60) extending in the radial direction beyond the size of the duct (16) and in which said floater (66) is operatively connected to said widening (60) .

17. The coffee-maker (10) according to claim 16, wherein said widening (60) comprises spokes (62) that are connected to a cylindrical portion (64) , said floater (66) coming in contact with said cylindrical portion (64) after the level L of beverage has raised within the collecting vessel (14) .

18. The coffee-maker (10) according to claim 16, wherein said stem (10) widens past the radial dimensions of the duct (16) and extends below to form a cap suitable to be arranged on the duct .

19. The coffee-maker (10) according to claim 14, wherein said floater (66) is operatively connected to the plug (56) by means of magnetic force.

20. The coffee-maker (10) according to claim 19, wherein said floater (66) does not come in contact with the plug (56) and the magnetic force operates through the walls of the duct (16) .

21. The coffee-maker (10) according to claim 20, wherein the floater (66) comprises at least one magnet (68) and wherein the plug (56) is made of a material suitable for being dragged due to the magnetic interaction with the magnet (68) .

22. The coffee-maker (10) according to claim 21, wherein the magnet (68) is embedded in the material of the floater (66) .

23. The coffee-maker (10) according to claim 21 or 22, wherein the floater (66) is made by means of two portions (66a, 66b) that are inserted within each other at the housing of the at least one magnet (68) .

24. The coffee-maker (10) according to one of claims 21 to 23, wherein said plug (56) is completely housed within the duct (16) .

25. The coffee-maker (10) according to claim 23, wherein said plug (56) is housed within an envelope (70) that is inserted within the duct (16) such as to be a portion thereof .

26. The coffee-maker (10) according to claim 25, wherein said envelope (70) comprises at least one inlet opening

(76) and at least one outlet opening (78) , said inlet opening (76) being arranged laterally with respect to the longitudinal development of the duct (16) .

27. The coffee-maker (10) according to claim 25 or 26, wherein said envelope (70) comprises at least one further opening (76a) to discharge the coffee at the end of the procedure .

28. The coffee-maker (10) according to claim 27, wherein said further opening (76a) is arranged below the longitudinal development of duct (16) and co-axial therewith.

29. The coffee-maker (10) according to claim 27, wherein said further opening (76a) is arranged below the longitudinal development of duct (16) and inclined relative thereto.

30. The coffee-maker (10) according to one of the preceding claims, wherein the plug (56) is ball-shaped.

31. The coffee-maker (10) according to one of the preceding claims, comprising selection means (86) for changing the threshold value of level L of the liquid within the collecting vessel (14) and thus the type of beverage being produced.

32. The coffee-maker (10) according to claim 31, wherein the selection means (86) are suitable to change the threshold value of level L of liquid within the collecting vessel by changing the length of the travel of floater (66) before the delivery control valve (54) is closed.

33. The coffee-maker (10) according to claim 32, wherein the length of the travel of plug (56) is provided to be changed by changing the position of a narrowing (46) against which the plug (56) closes the delivery control valve .

34. The coffee-maker (10) according to claim 33, wherein said plug (56) is housed within an envelope (70) that is inserted within the duct (16) such as to be a portion thereof, and wherein the selection means (86) comprise said envelope (70) moving along said duct (16) .

35. The coffee-maker (10) according to claim 34, wherein said envelope (70) is connected to screw means (88) comprising a knob (90) to be operated by the user.

36. The coffee-maker (10) according to claim 35, wherein said knob (90) is rotatably mounted to the end of the duct (16) and associated with a plate (92) .

37. The coffee-maker (10) according to claim 35 or 36, wherein a screw/nutscrew component (96) is provided, a first portion (96a) thereof being associated with the knob (90) and a second portion (96b) being associated with the envelope (70) .

,5

38. The coffee-maker (10) according to one of claims 34 to 37, wherein at least one abutment (98) integral with the envelope (70) slides within a respective slot (100) of the duct (16) that is a delivery opening (32) .

39. The coffee-maker (10) according to one of the 0 preceding claims, wherein the connection between the boiler (12) and the collecting vessel (14) is made by means of a bayonet connection which ensures that any elements of the boiler and collecting vessel are aligned with each other. 5

40. The coffee-maker (10) according to any preceding claim, wherein, when the coffee-maker (10) is in the normal standing orientation, the weight of plug (56) ensures that the plug adopts the position in which the delivery control valve (54) is opened. 0

41. The coffee-maker (10) according to claim 33, wherein said narrowing (46) is operatively connected to screw means (88) comprising a knob (90) to be operated by the user.

42. The coffee-maker (10) according to claim 41, wherein 5 the plug (56) is completely housed within the duct (16) in which a further narrowing (106) is formed, which acts as a lower stop for the plug (56) .

43. The coffee-maker (10) according to claim 42, wherein the further narrowing (106) is obtained by means of a series of indentations (108) .

44. The coffee-maker (10) according to one of the preceding claims, wherein a lid (110) is screwed to the duct (16) , which acts as the outlet nozzle with delivery- openings (32) and defines the narrowing (46) against which the plug (56) closes the duct (16) .

45. The coffee-maker (10) according to claim 44, wherein the lid (110) can be screwed to the duct (16) in a more or less tight manner, such as to shift the narrowing (46) and changing the threshold value of level L at which the duct (16) is closed.