Abstract:
A machine for in aircraft dispenses hot beverages, such as coffee, American-style coffee, and tea, as well as to dispense hot and cold water. The machine includes a hydralic circuit and an electrical circuit, and has a parallelepiped structure including a structural paneling and a paneling forming a covering, an open front compartment in which a container or jug for beverages is housed, and, located above the compartment, a front control panel and underlying cartridge-holder drawer which can be pulled out. The machine includes a heater through which passes water only at the moment of dispensing in the from of a beverage or hot water. The heater is connected to the cartridge-holder drawer and the and the hydraulic actuation system forces the heater to come down onto and close the cartridge-holder drawer in a sealed manner when the beverage or hot water is being dispensed.

Description:
SCOPE OF INVENTION 
     The present invention regards a machine for American-style coffee for use on aircraft. More in general, the machine according to the invention may be used to dispense hot beverages, such as coffee and tea, and/or hot and cold water. 
     PRIOR ART 
     For a better definition of the technical field of the present invention, it is necessary to point out that the ancillary equipment used on aircraft, such as coffee machines, must meet specific requirements that correspond to strict aeronautic standards. In particular, machines for making American-style coffee for use on aircraft, which is the technical field to which the present invention refers, must be in compliance with aeronautic standards, such as JAR25, FAR25, RTCA/DO 160C, and RAI (Italian Aeronautics Register) Technical Regulations. It should immediately be said that coffee machines not designed for use on aircraft do not meet any aeronautic standards. 
     According to JAR25, the machines must, among other things, be able to support up to nine times their own weight; withstand a given range of vibrations (for 1 hour for each Cartesian axis), and still be operative; withstand storage for 3 hours at the temperatures of −55° C. and +85° C.; operate at temperatures of between +1.7° C. and +55° C.; still be operative after being kept for 12 hours in an environment with a relative humidity of ≧95%; and be built with materials which, in the event of fire, are self-extinguishing and with low emission of smoke, so as not to give off toxic gases, and materials such as do not have compositions that are harmful to human health. 
     In addition, the machines must possess the characteristics according to which if an explosion of a component takes place, the said explosion must be extinguished inside the machine itself; they must also have dimensions such as to enable them to be accommodated and remain fixed in conditions of safety within the special compartments prepared for them on aircraft; and they must also be as light as possible, considering that aeroplanes such as the Boeing 737 or 747 can house even 10 of such machines. The reduction of approximately one kilogram of weight on board an aeroplane can mean considerable energy savings in the course of a a year. 
     At present, in the aviation field there exist coffee machines, in particular machines for dispensing American-style coffee, tea, or other hot beverages, the design of which is obsolete and which are certainly inadequate for current needs of weight-saving associated to improved functionality and safety. The said machines use a boiler container which remains pressurized for the whole time that the machines are switched on, a period in which the water is heated by means of direct contact with one or more resistors. Airline companies have therefore on numerous occasions expressed the need for innovative coffee machines characterized in particular by reduced weight and maintenance and by improved safety features. 
     In particular, EP-A387515 discloses a coffee maker for use in aircrafts which does not comprise an hydraulic circuit provided with an actuation system which vertically forces the heater to come down onto the cartridge holder drawer so as to close it in a sealed manner and also said coffee maker is not governed by a software. In addition CA 2121998, EP-A-353425 and U.S. Pat. No. 3,596,588 do not disclose any elements to provide an increased safety and easiness of the control of the brewing process. 
     There has now been found a specific combination of parts and an adequate choice of components, materials and forms which enable the construction of innovative machines that are able to dispense coffee, the so-called American or American-style coffee, and other hot beverages. The machine configuration and conformation described herein produce a longer-lasting device which is easier to use, safer, and lighter than the machines that are currently known. Further advantages of the invention will be evident from the following description. 
     In the present description the words “exchanger” and “heater” will be used indifferently, meaning thereby a thermal set comprising heating elements and elements designed for the passage of the fluid that is to be heated. 
     SUMMARY OF INVENTION 
     An object of the present invention is a machine that is able to dispense hot beverages, such as coffee, American-style coffee, tea, and/or hot and cold water, in accordance with the attached claims. In particular, the machine comprises a load-bearing structure substantially mad of aluminium, side panels, and bass and head substantially made of aluminium, the said machine being characterized in that it comprises elements configured and conformed in such a way as to be used in the aviation field. 
     A further object of the invention is a heater with two faces for heating liquids that may be used both in coffee machines of the type used on aircraft and in traditional coffee machines. 
     Further objects of the present invention will be evident from the ensuing description. 
    
    
     BRIEF DESCRIPTION OF FIGURES 
     For a better understanding of the invention, a non-limiting example of embodiment of the invention is shown in the attached figures in which: 
     FIG. 1 is a schematic front perspective view of the machine; 
     FIG. 2 is a schematic rear perspective view of the machine; 
     FIG. 3 is a schematic perspective view of the heater/cartridge-holder drawer assembly; 
     FIG. 4 is an exploded schematic view of the heater from above; 
     FIG. 5 is an exploded schematic view of the heater from below; 
     FIG. 6 a  is a first part of the flow chart of the American/coffee function; 
     FIG. 6 b  is a second part of the flow chart of the American-coffee function; 
     FIG. 6 c  is a third part of the flow chart of the American-coffee function; 
     FIG. 7 a  is a first part of the flow chart of the tea function; 
     FIG. 7 b  is a second part of the flow chart of the tea function; 
     FIG. 8 is the flow chart of the hot-water function; 
     FIG. 9 is the flow chart of the cold-water function; and 
     FIG. 10 is the hydraulic diagram. 
    
    
     In the figures, the same reference numbers refer to corresponding functions and/or elements. 
     DETAILED DESCRIPTION OF INVENTION 
     The machine according to the invention is designed for preparing hot beverages, such as coffee, American-style coffee and tea in pre-set amounts, as well as for supplying hot and cold water on board the aeroplane. For the preparation of hot beverages, the use of pre-prepared single-dose cartridges is envisaged, for example of the type known for automatic devices in which each cartridge represents a single, possibly pre-compressed, dose of powdered coffee or powdered tea enclosed in filter paper or some other wrapping, through which the hot water and/or steam can pass at pre-set temperatures for the preparation of the beverage. In particular, pre-prepared cartridges containing coffee of standard dimensions (e.g., approximately 108×134 mm) may be used. 
     The design of the outside of the machine distinguishes it completely from the other machines currently to be found in the aviation field by the rounded shape which is aimed at creating a more comfortable environment for the user. Levers and any other externally protruding systems of operation, which could create situations of danger, are absent. The controls are located on a front control panel of the touch-sensor type, with warning lights and silk-screen printed indicators. 
     The peculiar characteristic of this machine is represented by the absence of a pressurized boiler for heating the water, instead of which a heater is used inside which water passes only when the beverage is being dispensed, i.e., when the system is open to the atmosphere. In this way, the danger represented by pressurized water enclosed within a container is avoided. 
     A further characteristic of the machine is that of having the heater correspondingly connected to the cartridge-holder system, the heater and the cartridge-holder being operatively combined together vertically. This mode of operation is obtained by means of a hydraulic system. Consequently, no lever-type mechanical system is present on the machine for closing the cartridge-holder compartment. This operation is performed by the pressure supplied by a pump on a hydraulic piston that is operatively connected to the heater. In this way, the heater comes down onto the cartridge-holder compartment, substantially sealing it and preventing any steam from coming out. The cartridge-holder compartment is provided, above the cartridge itself, with a perforated plate. Between the said plate and the bottom surface of the heater a chamber is created which enables uniform distribution of the water over the cartridge. The heater is made of aluminium and heats the water without increasing its pressure since no pockets of hot air are present along the entire path of the water. The heater is of the two-faced type with plane configuration, wherein a heating element is set between two areas, one above and one below the element, in which the water to be heated passes. With such an arrangement, the thermal yield is maximized and leakage of heat is minimized. The heater/cartridge-holder coupling system may also be associated to traditional machines. 
     The machine components are chosen in such a way as to be in compliance with the aforementioned aeronautic standards and to guarantee a mean time between failures (MTBF) of 5000 hours (assuming the routine maintenance programme). 
     The machine may be built in such a way as to have preferably the following technical specifications; depth 310-390 mm; width 150-180 mm; height 290-340 mm; weight 11-16.7 kg; power supply 115 V, 400 Hz three-phase, or 28 Vdc; power up to 3500 W; pressure of incoming water 0.3-5.0 bar, preferably 1.5-2.0 bar. 
     The electrical and hydraulic interfaces are compatible with aeroplane galleys; i.e., the incoming and outgoing water connectors and the electrical connector are selected, arranged and positioned appropriately on the rear of the machine. Preferred electrical connectors are of the type MS3106A-16S-1P (ITT-Canon); preferred water connectors are of the type Hansen 2KLF16 (Hansen), or products having similar features. 
     The material used is mainly anodized aluminium machined using numerical-control machines to guarantee an adequate resistance combined with lightness and the precision of the pieces made. Such types of machining are well known to persons skilled in the art and enable pieces to be obtained that are machined with precision and very low tolerances. The use of plastic is limited to the minimum. All the materials are in compliance with the Handbook of Sanitation for Airlines (USPHS). The pipes for delivering water are made of Teflon® for foodstuffs, and the pipe fittings are made of non-harmful material. 
     The printed-circuit boards are surface-treated with a protective treatment so as to withstand vibrations, be resistant to humidity, and be resistant to fungi and bacteria or other organic contaminants. 
     The machine is equipped with a hydraulic section for water delivery and with a system of pumps for maintaining the flow of water constant inside the machine irrespective of the environmental operating pressure present in the aircraft. 
     The hydraulic circuit is designed so that the failure of any active element making it up (valves, pumps, etc.) will not create overpressures in the circuit. The movement of water inside the hydraulic system of the machine is ensured by pumps and controlled by solenoid valves. Measurement of the incoming-water pressure is made by means of a solid-state pressure sensor and is used as regulating input by a software with which the machine is equipped. When the pressure is not within the range set for machine operation, a warning light lights up on the front panel of the machine. 
     A filter  18 ′ of a commercially available type, for example an ion-fractionation filter, is located at the point of water intake to prevent deposition of lime. In order to reduce weight, the aforesaid commercially available filter may be advantageously rendered lighter by replacing the outer casing with a corresponding aluminum casing. 
     In order to prevent overpressure, a suitably calibrated air valve is positioned downstream of the pumps. 
     One hydraulic distributor for cold water and one for hot water make up the communication between the solenoid valves for distributing the incoming and outgoing fluid. The said distributors are basically parallelepipedal elements made of plastic material, such as ERTA PVDF (polyvinylidene fluoride) manufactured by Angst Pfizer or a product having similar performance features, and inside them channels are made for the passage of water, these channels being arranged in such a way as to create the appropriate connection between the solenoid valves, thus avoiding the use of cumbersome pipe fittings. 
     The solenoid valves used for the distributors are of the header type. They present the advantage of eliminating part of the pipe connections in that the header, which is provided with an inlet hole and an outlet hole for the fluid, is connected directly to the hydraulic distributor. The said valves are easy to disassemble. 
     The solenoid valves are of two types: two-way and three-way. The two-way solenoid valves control the flow of water by opening and closing. The three-way solenoid valves, which work in the same way as the two-way ones, in addition present a way for discharging the water. 
     The solenoid valves that govern the hot water stretch are chosen to withstand temperatures of up to at least 150° C. and have ruby gaskets. The other gaskets of the machine are made of Viton®. 
     The pipe fittings on the hot water parts are made of stainless steel so as to present high efficiency both from the point of view of thermal characteristics and from the point of view of alimentary characteristics (instead, the pipe fittings on machines not designed for use on aircraft are made of nickel-plated brass, which may be subject to flaking at high temperatures). 
     The electrical circuit is designed and built so as not to create any electromagnetic interference with the instrumentation on board the aircraft and, at the same time, so as not to be affected by the said instrumentation. For this reason, the cards of all the electrical supplies are filtered using, for example, EMI filters or filters  19 ′ presenting similar features, which are designed basically to eliminate the high-frequency components which could generate electromagnetic waves. 
     The machine is electrically protected against overtemperatures by manually resettable safety thermostats mounted directly on the heater (e.g., ones manufactured by the firm Termix), and inside the hydraulic circuit also in the case of failure of the control solenoid valves there is no possibility of the exchangers remaining pressurized since they are equipped with three-way solenoid valves which, when they are de-energized, are open towards the discharge. 
     The machine is designed so that water will not collect and consequently stagnate: 
     the water that is not used is all sent to be discharged. In this way, the formation of harmful micro-organisms (algae, fungi, bacteria, etc.) is prevented. 
     The machine does not have any external handles, and consequently is safer than machines currently available on the market in that it does not have any parts to get hooked on to accidentally. 
     The machine and all the elements that can be removed from it, such as the drawer and the jug, are protected against the possibility of accidental release, in that they are located in seats provided with self-locking devices which, when the items are inserted, must first be released; i.e., locking of the items in place is automatic when the items are inserted in their respective seats. 
     The machine is also equipped with a weight-sensitive safety system inserted on the jug resting surface; i.e., the plate which carries the jug for the beverages is hinged on the bottom of the machine and rests on the front of the machine on a force sensor so that, when the jug is positioned, for example partially filled, the possibility of a further non-controlled addition of water causing it to overflow is prevented; that is, the load cell governs water delivery. 
     The machine is protected from electrical overloads by a main supply switch, referred to as circuit breaker, located on the rear of the machine. As a result, the machine does not have any fuses which would have to be set one on each phase and which would entail, when they blow, disassembly, replacement and reassembly. In the event of the current on one of the three phases exceeding a pre-set threshold value, for example 10 A, in the machine according to the invention the current on all the phases is automatically cut off. Once the overload has been eliminated, the circuit breaker (e.g., Klixon—Texas Instruments) can be reset manually, just like an ordinary switch. 
     The main functions of the machine are governed by an electronic section managed by a microprocessor (CPU  16 ′) based upon an original software. The presence of a serial port  16 ″ is moreover envisaged, via which, by means of connection to a simple personal computer, it is possible to read the history file of the machine, for example, the number of operating cycles and/or the hours of operation, and/or other indications useful for routine maintenance of the machine. Through the said serial port, it is also possible to supply information to the machine and vary the machine parameters, such as amount of water for the coffee function (if, for example, the capacity of the jug varies), weight of jug, and temperature of water delivery. The corresponding software is supplied to the customer, who can make modifications to it as he wishes. 
     The invention will now be illustrated with reference to the attached figures, which are to be considered a non-limiting illustration of the invention. 
     DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
     With particular reference to FIGS. 1 and 2, the machine according to the invention has a basically parallelepipedal shape and is built of aluminum, preferably the alloy 6082T6 produced by the firm Alcoa or the firm Metra, or some other product having similar features in terms of lightness and resistance. The outer structure of the machine comprises a front control panel I of the touch-sensor type (known to persons skilled in the art), with the controls of the various functions silk-screen printed on it, for example as follows: a) ON/OFF switch; b) “coffee” switch; c) “tea” switch; d) “hot water” switch; e) “cold water” switch; f) “blocked” indicator; g) “ready” indicator; h) “no water” indicator; i) “failure” indicator; and j) “released” indicator. Beneath the front panel  1 , the pull-out drawer  2  is present, inside which the cartridge (not shown) is inserted. The drawer  2  opens and closes in a sliding way and to ensure safety it has one locking position whereby, once the drawer has been completely inserted into the machine, it may subsequently be pulled out during normal machine operation (for inserting or removing the cartridge). The drawer  2  is appropriately sized to house the cartridge and has on the bottom a hole through which the hot beverage passes to be subsequently collected in the jug. The reference numbers  3 ,  3 ′ indicate the structural or load-bearing panel of the machine, which is substantially U-shaped, built in such a way, above all in terms of thickness, as to bear the weight of the machine. The two perforated rear side panels are indicated by 4 and have the sole function of covering. On the front of the machine an open compartment is made, in which the container or jug (not shown) for the beverages is housed. The said open compartment is delimited basically by the bottom wall of the drawer  2 , by the structural panel  3 ,  3 ′, and by the surface or plate  6  for supporting the jug. On the bottom of the wall  3 ′, the following are located: a handle  7  for pulling out the machine, a spring-type sensor  8  (comprising a rod  8 ′. a spring  8 ″. a bracket  8 ′″. an optical sensor  8 ″″), which detects the presence of the jug when this is inserted and pressed against the said sensor  8 , and the spout  9  for delivering the hot or cold water to the jug. On the wall  3 ′, at the bottom, there is also set a handle  10  which may be raised and lowered, as indicated by the double-headed arrow A, so as to correspondingly raise or lower a pin (not shown) which slides in the guide  11  and has the function of blocking the machine on the aircraft galley. The housing of the machine on the galley is made in such a way that it slides on rails, the guides of which are indicated by 12 and are made of a substantially channel-shaped extruded aluminum section. 
     At the top, the machine has a covering panel  13  which has a compartment  14  in which a handle (not shown) for lifting and transporting the machine is housed. As regards the plate  6 , this is shaped so as to conveniently accommodate the bottom of the jug (not shown). The plate  6  is slightly inclined towards the rear of the machine and has a drainage hole  6 ′ connected to the discharge, so that any liquid that may accidentally be spilled is carried towards the discharge. In addition, a device is provided for safety fixing of the jug, basically consisting of a shaped rod  15  which is operated by a spring (not shown) and which moves as indicated by the double-headed arrow B. The said rod  15  must be manually lowered for insertion of the jug, which, once it is housed on the plate  6 , is held in position by the rod  15  coming back up; the rod  15 , at the same time, holds the jug in position also with respect to the presence sensor  8 . 
     The plate  6  is in turn hinged on the bottom wall  3 ′. The plate  6  rests on a load-cell system  6 ″ which is able to detect the presence and weight of the jug and correspondingly control filling thereof. 
     At the rear the machine has a first perforated rear panel  16  for covering and a second rear panel  17  for support, on which the connector for water  18  and the electrical connector  20  are present. The reference number  19  indicates the manually resettable circuit breaker, which, in this embodiment, is positioned on the supporting panel  16 . 
     FIG. 3 is a schematic perspective view of the cartridge-holder drawer  2 /exchanger  22  assembly. The exchanger  22 , which is otherwise referred to herein as heater, is illustrated in greater detail in FIGS. 4 and 5. Located on the exchanger  22  are the water inlet and water outlet. In addition, the exchanger  22  can move in the direction indicated by the double-headed arrow D along the travel guides  23 , assisted by the presence of springs  23 ′. This movement is produced by a hydraulic piston ( 114 ) the striking plate of which is indicated by 21, the said piston being pressurized by a pump (not shown) within the first two seconds of the coffee cycle, after which time it is kept pressurized by the closing of the separation solenoid valve  113 . At the end of the cycle, the pressure is discharged through the opening of the solenoid valve  113  and the solenoid valve  112  (the said solenoid valves not being shown in FIG.  3 —see FIG.  10 ), and the residual water is discharged. 
     With reference to FIGS. 4 and 5, the parts making up the exchanger  22 , which is made of machined anodized aluminium, are illustrated. In the embodiment, the exchanger  22  has a plane conformation and comprises four elements. 
     The first of these is a central element  24 , inside which at least one resistor is embedded (in the example shown there are three resistors  24   a ,  24   b ,  24   c , which may be cylindrical resistors of the type IRCA-Zoppas, 115 Vdc, 800-1000 W). The top and bottom surfaces of the element  24  are furrowed by grooves (hereinafter referred to as coils)  24   e  and  24   f  having a semicircular cross section. The two coils may be different from one another, and each of them is sized, in terms of length and section, according to the amount of water that is to be heated, this amount in turn varying according to the function chosen (coffee, tea, hot water). Advantageously, one coil may be approximately 1.5 metres long. According to a preferred arrangement, the machine is equipped with two heaters, one for the beverage and hot-water functions, and the other for the steam function. The exchanger  22  is provided with plastic gaskets and coatings such as to reduce loss of heat to a minimum and to maximize efficiency. The element  24  also has a hole  24   d  which sets the two coils  24   e  and  24   f  in communication with one another. The central element  24  is closed in a sealed manner between a further two plane elements, the overlying element  25  and the underlying element  26 . The element  25  is in turn provided, on its top face, with recesses or hollows  25   a  made for lightening the structure, the purpose of which is basically to reduce weight and to economize on material. The element  25  is further provided with a hole  25   b  for intake of water into the exchanger  22 , with a corresponding water-outlet hole  25   c , and with a further hole  25   d  for passage of water to the drawer  2 . The latter hole  25   d  corresponds to a further two holes,  24   d  and  26   d , which are also directed towards the drawer  2 . The underlying element  26  is in turn provided with the aforesaid hole  26   d  and, on its bottom face, with a recess or chamber  26   a , whilst its top face is basically plane. Underneath the element  26  is mounted the perforated plate  27 , which faces and/or is in contact with the cartridge (not shown) housed in the drawer  2 . The function of the recess  26   a , which may have a thickness of approximately 0.8 mm, is that of distributing the water evenly in the recess  26   a  itself and of making it come out, assisted by the series of holes present on the plate  27 , so as to wet the cartridge rapidly and evenly. 
     In the exchanger  22 /drawer  2  assembly, the water passes as follows: the water comes into the hole  25   b , passes into the coil  24   e , drops into the hole  24   c , runs along the coil  24   f , returns upwards through the hole  24   c , and comes out of the exchanger through the hole  25   c . It then goes to the solenoid valve  106 , returns to the hole  25   d , passes through the holes  25   d ,  24   d  and  26   d , and then arrives at the chamber  26   a , from where it is distributed, comes out from the holes in the plate  27 , and drops through the cartridge in the drawer  2 , from which it comes out through an outlet hole (not shown) located above the jug. 
     FIGS. 6 a  to  9  present, the flow charts of the “coffee” (FIGS. 6 a ,  6   b ,  6   c ), “tea” (FIGS. 7 a ,  7   b ), “hot water” (FIG.  8 ), and “cold water” (FIG. 9) functions (also referred to as cycles) that the machine is able to perform. These flow charts are self-explanatory, and a person skilled in the art is able, when reading them, to understand all the safety functions with which the machine is provided. 
     With particular reference to FIGS. 6 a ,  6   b ,  6   c , they refer to the same “coffee cycle” with the following operation steps: 
     6.1 press “coffee” switch 
     6.2 is the “water in line” condition present? 
     6.3 is the “low pressure in line” condition present? 
     6.4 is the “no water” led permanently on? 
     6.5 “no water” led flashing|stop 
     6.6 is the “temperature ready” condition present? 
     6.7 start-up of “10-sec timer” 
     6.8 is the condition “server ok” present? 
     6.9 is the condition “cartridge-holder in position” present? 
     6.10 “coffee” led flashing 
     6.11 does the “10-sec timer” stop?|stop 
     6.12 stop of “10-sec timer” 
     6.13 start-up of “4-min timer” 
     6.14 start-up of “2-sec timer” 
     6.15 does the “2-sec timer” stop? 
     6.16 is the condition “cartridge-holder in position” present? 
     6.17 “failure” led lights up|stop 
     6.18 does solenoid valve  113  deactivate? 
     6.19 flow meter  103  starts count 
     6.20 start-up of “10-sec timer” 
     6.21 activates solenoid valves  104  and  106   
     6.22 does the “10-sec timer” stop? 
     6.23 stops pump and deactivates solenoid valves  104  and  106   
     6.24 start-up of “10-sec timer” 
     6.25 does the “10-sec timer” stop? 
     6.26 starts up pump and activates solenoid valves  104  and  106   
     6.27 does the flow meter stop count? 
     6.28 is the condition “server active” present? 
     6.29 does the “4-min timer” stops? 
     6.30 stops pump and counters and deactivates solenoid valves  106  and  112 —increases by one the “coffee cycles” counter|stop 
     The characteristics of the “coffee” function are: 1.5|±10% of coffee at a temperature of approximately 85° C.±5° C. in approximately 2 min 45 sec±15 sec for a pressure line at 1.2-3.0 bar. 
     Controls and safety devices are provided, as described in what follows. The “coffee” function is operative only if the following conditions are satisfied: 
     a pressure sensor reads a line pressure of 0.3-5.0 bar; 
     a temperature probe in the exchanger  22  reads a value of approximately 98° C. when the function is requested; 
     an optical sensor is ON (i.e., the jug is present); 
     a first microswitch is ON (the drawer is completely inserted); and 
     a second microswitch is ON two seconds after the request for coffee (this means that a hydraulic piston is pressing against the exchanger  22  and the drawer  2 ). 
     During delivery, if one of the aforesaid conditions is no longer satisfied (with the exception of the condition regarding the temperature probe), the function is interrupted immediately. End-of-delivery is controlled by a flow meter. A second safety system is present, which is controlled by the force sensor located underneath the surface or plate  6  on which the jug rests and which interrupts delivery by checking the weight of the jug that is being filled. In addition, a 4-minute timer interrupts delivery if none of the above-mentioned devices is working. 
     The “coffee” function is also interrupted when the “coffee” switch on the front control panel is pressed again. 
     Both FIGS. 7 a  and  7   b  refer to the “tea” function, the characteristics, controls and safety devices of which are similar to those of the “coffee” function. 
     Herein below there are described the operation steps: 
     7.1 press “tea” switch 
     7.2 is the “water in line” condition present? 
     7.3 is the “low pressure in line” condition present? 
     7.4 is the “no water” led permanently on? 
     7.5 is the “no water” led flashing?|stop 
     7.6 is the “temperature ready” condition present?|stop 
     7.7 start-up of “10-sec timer” 
     7.8 is the condition “server ok” present? 
     7.9 is the condition “cartridge-holder in position” present? 
     7.10 “tea” led flashing 
     7.11 does the “10-sec timer” stop?|stop 
     7.12 stop of “10-sec timer” 
     7.13 start-up of “4-min timer” 
     7.14 flow meter  103  starts count 
     7.15 starts up pump and activates solenoid valves  104  and  107   
     7.16 does flow meter finish count? 
     7.17 is the “server active” condition present? 
     7.18 does the “4-min” counter stop? 
     7.19 stops pumps and counters and deactivates solenoid valves  104  and  107 —increases by one the “tea cycles” counter |stop 
     FIG. 8 refers to the “hot water” function. Herein below there are described the operation steps: 
     8.1 press “hot water” switch 
     8.2 is the “water in line” condition present? 
     8.3 is the “low pressure in line” condition present? 
     8.4 is the “no water” led permanently on? 
     8.5 “no water led flashing |stop 
     8.6 is the “temperature ready” condition present?|stop 
     8.7 start-up of “20-sec timer” 
     8.8 starts up pumps and activates solenoid valves  104  and  108   
     8.9 “20-sec” timer stops 
     8.10 stops pumps and deactivates solenoid valves  104  and  108  —increases by one the “hot water cycles” counter |stop 
     The characteristics of the “hot water” function are: approximately 0.25 l of hot water at a temperature of approximately 85° C.±5° C. in approximately 30 sec. 
     Controls and safety devices are provided, as described in what follows. The “hot water” function is operative only if the following conditions are satisfied: 
     a pressure sensor reads a line pressure of 0.3-5.0 bar; 
     a temperature probe in the exchanger  22  reads a value of approximately 98° C. when the function is requested; 
     During delivery, if the first condition is no longer satisfied, the function is immediately interrupted. Delivery is interrupted after 30 sec. or else by pressing the “hot water” switch on the front control panel again. 
     FIG. 9 refers to the “cold water” function. Herein below there are described the operation steps: 
     9.1 press “cold water” switch 
     9.2 is the “water in line” condition present? 
     9.3 is the “low pressure in line” condition present? 
     9.4 is the “no water” led permanently on? 
     9.5 “no water” led flashing|stop 
     9.6 start-up of “20-sec timer” 
     9.7 starts up pump and activates solenoid valve  111   
     9.8 “20-sec” timer stops 
     9.9 stops pump and deactivates solenoid valve  111 —increases by one the “cold water cycles” counter|stop 
     The characteristics of the “cold water” function are: approximately 0.25 l of cold water at room temperature. 
     Controls and safety devices are provided, as described in what follows. The “cold water” function is operative only if the pressure sensor reads a line pressure of 0.3-5.0 bar. Delivery is interrupted after 30 sec, or else by pressing the “cold water” switch on the front control panel again. 
     FIG. 10 is a hydraulic diagram of the machine. 
     Herein below there is the list of the reference numbers inserted: 
       101 . pressure safety switch 
       102 . pump 
       103 . flow meter 
       104 . solenoid valve for inlet to exchanger 
       105 . exchanger 
       106 . solenoid valve for coffee output 
       107 . solenoid valve for tea output 
       108 . solenoid valve for hot water output 
       109 . pump 
       110 . safety valve 
       111 . solenoid valve for cold water output 
       112 . piston solenoid valve 
       113 . separation solenoid valve 
       114 . piston 
     As may be noted, the pressure of the incoming water is detected by a pressure sensor  101  (set at the machine operating pressure), and the water then reaches the pumps  102  and  109  which send it on, via the flow meter  103 , towards the elements controlling the four functions: “hot water” (solenoid valve  108 ), “coffee” (solenoid valve  106 ), “cold water” (solenoid valve  111 ), and “tea” (solenoid valve  107 ). Part of the water is also used to push the piston  114 , together with the exchanger  22 , against the cartridge-holder drawer  2 . 
     The cold water passes through the pump  109  and the solenoid valve  111 , which controls the “cold water” function. Included in FIG. 10 is the legend. The entire hydraulic circuit is protected against overpressures by means of the air valve  110 , which opens for pressures higher than the maximum operating pressure. 
     The machine can advantageously be equipped with a second heater and with other elements, which may be easily identified by reading the description of the present invention, to produce also steam. 
     Under normal conditions, the machine is able to produce 1.5 litres of hot water at a temperature of approximately 85° C. in approximately 2 min 45 sec ±15 sec. There is nothing to prevent the machine according to the present invention from being used on other means of transport, such as trains (in particular high-speed trains), ships, etc. 
     What is illustrated in the attached figures is merely intended to provide an example of possible embodiments, and a person skilled in the art may make variations or modification without thereby departing from the spirit and scope of the invention. Any such variation or modifications are to be considered as included within the scope of the description and claims.