MXPA98005126A - Cafet - Google Patents

Abstract

The present invention relates to a coffee machine with a water supply chamber, a pump, and an infusion chamber for receiving coffee, characterized in that it has a continuous flow heater for heating the water, which contains at least one insulating layer placed around the inner tube and a filament winding around the inner insulating layer at least, such that the continuous flow heater has low thermal capacity, which is equipped with at least one temperature sensor at the end of the continuous flow heater or between the latter and the infusion chamber, as well as a control loop, whose controlled variable is the water temperature at the end of the continuous flow heater and because the unheated parts on the water path between the continuous flow heater and the coffee, have a adequate resistance for a pressure in the system of 10 bars and are made of highly porous ceramic material, plastic or an ale tion of iron, in such a way that they have low thermal capacities and with respect to water, low thermal transmission coefficients

Description

COFFEE MAKER The invention relates to a coffee maker according to the preamble of claim 1. The coffee makers have a storage or water supply chamber, a heating system for heating the water, an infusion chamber, boiling or boiling in water boiling, to receive coffee and feeding means, to provide water from the water supply chamber to the infusion chamber. Conventional coffee makers differ as a function of the type of coffee to be brewed with the corresponding coffee maker. In this way, in coffee machines that prepare espresso, the water is heated and circulated by means of a pump with high pressure (approximately 10 bars) to the infusion chamber and the coffee is finely ground. In coffee machines used to prepare mocha coffee, the water is supplied in the form of steam through a riser pipe to the finely ground coffee in the infusion chamber. The water is also supplied in the form of steam through a rising tube in the case of filter coffee machines, but it condenses again and reaches fine or ground coffee as a hot liquid and then under ambient pressure passes slowly through the filter. The heating system of conventional coffee makers usually comprises a solid electric heating unit, which is a thermal deposit with high heat capacity and therefore thermally inert. On the other hand, this is an advantage, because its temperature only decreases slightly when a certain volume of water circulates through it and it withdraws a specific thermal energy. However, on the other hand, the high thermal capacity is a disadvantage, because a large amount of thermal energy must be supplied to the electric heating unit in order to raise its temperature to a desired value. After lighting, the conventional coffee maker requires a preheating time that lasts a few minutes before the first coffee can be prepared. This preheating time is an annoying waste of time for the user. In order not to have to reheat the electric heating unit before each coffee preparation, thermal energy is supplied for as long as the coffee machine is turned on. In this way, in the sleep mode, the coffeemaker constantly requires energy, which frees the environment in a useless way. If the coffee machine has been turned off for a while, the complete solid electric heating unit should be heated, even for the preparation of a single coffee and only part of the energy required for this is actually used to prepare the coffee. In this way, when summarized, it can be stated that conventional coffee makers do not make economic use of the user's time and electricity. A fast electric water heater for a coffee machine is proposed in the U.S. patent. No. 1,631,753. This water heater contains three helically coaxially coiled, telescoped copper tubes, through which the water to be heated circulates successively. A heating means with electric resistance is wound around the central tube. The tubes and resistance heating members are insulated from each other by an asbestos ribbon. As a result of this special structure the water in the central tube is heated directly by the heating means with resistance and the water in the outer and inner tubes as a result of this special arrangement, indirectly by thermal radiation. The water thus heated is then supplied to an infusion chamber containing coffee. This water heater is admittedly faster than a solid electrical heating block. However, it is still thermally inert as a result of its thin copper tubes and asbestos insulation. It takes a relatively long time for the copper tubes to heat through the asbestos insulation and for thermal energy to reach the water.

The patent of the U.S.A. No. 5,262,621 solves the problem of long heating times by an induction heating system and an electronic control and verification system. The water heating apparatus described herein uses a metal tube surrounded by an electromagnetic coil. When the water circulates through the metal tube, an AC voltage is applied to the coil. By means of electromagnetic induction, the metal tube is heated and by means of the heat conduction the water flowing through is heated. The frequency of the AC voltage is fixed by the electronic verification and control system as a function of the water outlet temperature. The problem of the invention is to provide a coffee maker, which first does not require preheating time and second does not consume energy in the standby mode. This problem is solved by the coffee machine according to the invention, as defined in the claims. The concept of the coffee machine according to the invention is based on the fact of using a rapid reaction heating medium and for removing the minimum amount of thermal energy from the hot side in its coffee path. Table 1 shows a comparison of the heating means according to the invention and those of a conventional coffee. TABLE 1 Characteristics Cafetera de acuerdo Coffeemaker of the means of with the conventional heating in ____. - High low thermal capacity Slow fast reaction Temperature change during low high coffee preparation The coffee machine according to the invention must be polyvalent, that is capable of preparing different types of coffee. This means that the parts used on the water path with respect to the mechanical force, must be designed for "the worst casq", that is to say for high pressure during preparation of espresso. The parts used must also be optimized with respect to mechanical and thermal characteristics and partly contradictory criteria must be considered, to combine them into a compromise solution. The advantages of the coffee machine of the invention are, among other things, achieved by the combination of the following characteristics. A continuous flow heater with a small thermal capacity is used, instead of a solid electric heating unit. In order to obtain the desired water start temperature, a control loop is used. Materials and design of the unheated parts on the water path, are designed in such a way that they are able to withstand the excessive pressure of the water and simultaneously withdraw from the water the minimum possible thermal energy. In particular, the unheated parts must have low thermal capacities and with respect to water, low thermal transmission coefficient, while simultaneously having adequate strength. The coffee machine according to the invention is described in more detail below with respect to the accompanying drawings, wherein: Figure 1 is a diagrammatic cross section through the complete coffee machine. Figure 2 is a perspective view of the open continuous flow heater in the form of layers for more clear representation. Figure 3 represents the continuous flow heater and pump with regulating system. Figure 4 is a cross-section through the infusion chamber and its locking mechanism. Figure 5 is an exterior view of the coffee machine. Figures 6 and 7 are cross sections through the retaining grid with two cups of different size. Figure 1 shows in cross section a diagrammatic total view of a preferred embodiment of the coffee machine according to the invention. A water supply chamber 1 is mounted on a "head" 2 in the coffee maker. It can be made of a transparent material, which has the advantage that the user can see the water level at all times and can replenish the water in a timely manner. The water supply chamber 1 can be removed by the user and washed. It has a cover 3, which rests on its loose shape, can be screwed on or can be fixed with a hinge. By means of a hose or tube 4, water passes from the water supply chamber 1 to a pump 5, which for example is located in a "neck" 6 of the coffee machine. The water is circulated through the pump 5 through a hose or tube 7 to a continuous flow heater 8 and through the latter. In the continuous flow heater it is heated to a desired temperature of more than 90 ° C or caused to evaporate. The continuous flow heater for example is in the form of a multilayer tube that is provided with an electric heating system. The details of the pump 5 and the continuous flow heater 8 are given below, in connection with Figures 2 and 3. A connection pipe 9, for example made of stainless steel, connects the flow-through heater 8 to a plenum chamber. infusion 10. It is unlikely to prevent the water from cooling a few degrees Celsius in the connection tube 9. The infusion chamber 10 contains the coffee 10", through which the hot water or steam is compressed. it essentially comprises an infusion chamber base 11 and an infusion chamber lid 12. The infusion chamber base 11 is inserted in a support 13 with handle 14. The support 13 is slid by the user to the coffee maker and fixes the latter with an interlocking mechanism 15 and simultaneously the infusion chamber 10 is locked in. Details of the infusion chamber 10 and of the interlock mechanism 15 are described in greater detail below with respect to Figure 4. The hot coffee, li This is circulated through a spout 16 outside the infusion chamber 10 in a cup 17. The cup 17 rests on a retention grid 18 which is placed in an insert 19 ', which in turn is placed on a base 19. The base 19 can be made heavier, for example with a zinc molded part or a lead part 20, in order to improve the stability of the coffee machine. The inlet 21 of a cable 20 for supplying the coffee machine with main line voltage, preferably is located in the base 1. Table 2 shows the water path as a sequence of four portions, which differ based on their temperature and pressure conditions. The numerical values given are of an approximate nature for the exemplified case of preparation of espresso and may differ from other types of coffee. Figure 2 shows the internal structure of a continuous flow heater 8, such as that which is preferably used in the coffee machine according to the invention. In comparison with a conventional solid electric heating unit, such as a continuous flow heater 8, it has the advantage of being able to quickly make temperature changes. Consequently, it does not require preheating and no energy in the sleep mode. In a preferred embodiment, the continuous flow heater 8 comprises an inner tube 23 through which water can circulate and which for example is made from aluminum, stainless steel or high temperature resistant plastic. An internal insulating layer 24-26 made from an electrically insulating heat-resistant material, for example a high-temperature resistant plastic, is placed around the inner tube 23. Around the inner insulating layers 24-26, a filament 27 made from a high impedance metal alloy, for example NiCr alloy, is wound. Around the filament 27 at least one outer insulating layer 28-30 is placed, for example again of high temperature resistant plastic. TABLE 2 Portion Temperature Pressure Water supply chamber 1 at the inlet of the pump low low 5 (20 ° C) (1 bar) Pump output 5 at the inlet of the high flow continuous pump 8 (20 ° C) (10 bars) Output of the continuous flow heater 8 to the inlet of the high-infusion chamber (>; 90 ° C) (10 bars) Output from diffusion chamber 10 to the high low cup 17 (> 90 ° C) (1 bar) The continuous flow heater 8 is the main component of the heating system of the coffee machine of the invention, the entire heating system is illustrated in Figure 3, Figure 3 only shows the filament 27 of the internal structure of the continuous flow heater 8, which is preferably in the form of a coil spring and is mounted in floating shape. At the inlet of the continuous flow heater 8, the pump 5 is provided with the tube 7, which in its outlet has the connection pipe 9. The pump 5 is preferably suspended in the mobile form or hung by the upper part and vibrates during operation, in the same way, which for example occurs with a diaphragm pump. The vibrations are transferred to the continuous flow heater 8. The forced accelerations in the continuous flow heater 8, in this way avoid or reduce scale formation of its inner tube 23 or assist in detachment of scale from the inner walls of the tube. The continuous flow heater 8 is preferably equipped with a control loop which ensures that during each coffee preparation, the water leaves the heater at the desired temperature. For this purpose, at the end of the continuous flow heater 8, a temperature sensor 31 is provided for measuring the temperature of the water T. The measured temperature T, preferably is the controlled variable for the PP energy of the pump 5 and therefore both for the flow of water F. In another variant, the temperature T is the controlled variable for the heating energy (or heating capacity) PH in the filament 27. In a third variant both the energy pumped (or pumping capacity) PP and the heating energy PH are regulated simultaneously. For regulation or control purposes, preference is given to using a microprocessor 32, which is preferably installed in the vicinity of the pump 5. Instead of the microprocessor 32, an even simpler electronic circuit can be used for regulation purposes. The temperature sensor 31 and the microprocessor 32 are also required in order to warn the user of scale formation in the continuous flow heater 8. A possible layer of scale on the inner tube wall of the continuous flow heater acts in a insulation and increases the time t required to a certain heating energy PH, in order to heat a certain amount of water. Thus, conclusions regarding the formation of incrustations of the tube or pipe can be deduced based on the heating energy PH, the pumping energy Pp and the heating time t. For each coffee preparation, the microprocessor verifies whether the formation of scale of the tube has not exceeded a critical value. If it has exceeded this value, the user is warned by an acoustic and / or optical signal. After this warning, the user can take appropriate de-scaling measures.

The infusion temperature has a very sensitive influence on the taste of the coffee. Despite the energy and time saving achieved by the invention, the coffee quality must remain constantly high and should not depend on whether the unheated portions 9 to 12 on the water path between the continuous flow heater 8 and the coffee machine 10 are cold or already hot due to a preceding infusion operation. In this way, only minimal thermal energy must be extracted from the hot water between the continuous flow heater 8 and the coffee 10 ^. For this purpose, two requirements must be met. First, the unheated parts 9 to 12, on the path of the water, must have low thermal capacities, ie low specific thermal capacities and low masses. Secondly, the unheated parts 9 to 12 must have low thermal transmission coefficients with respect to water, that is, low thermal transfer coefficients and / or low thermal conductivities. However, simultaneously, the unheated parts 9 to 12 must be able to withstand the excessive pressure of the hot water of approximately 10 bars, such as occurs in the preparation of espresso. The materials and designs of these parts 9 through 12 should be optimized with respect to the thermal and mechanical criteria that are partially opposed. The exemplified modality provides a good solution to the optimization problem. The connecting tube 9 is short and mechanically firm. The base 11 and the lid 12 of the infusion chamber 10 are made from a thermally insulating material, for example a highly porous ceramic material, such as hollow ceramic or hollow porcelain or a thermally insulating plastic, the mass or weight being Keep as low as possible. The interlocking mechanism 15 of the infusion chamber 10 and the self infusion chamber will be discussed by means of Figure 4. In conventional coffee makers, the support of the infusion chamber is fixed and is simultaneously locked by a bayonet that holds or catch the coffee maker. However, in the coffee machine according to the invention, the infusion chamber 10 is incorporated in a support 13, which is held by the user with one hand in the handle 14 and pushed type drawer inside the coffee machine. The support 13 can be made of plastic, using the other hand, the user operates the locking mechanism by means of a lever 33, visible in Figure 5, coupled to the outside of the molded part or the enclosure of the coffee machine. The rotary movement of the lever 33 is transferred to an eccentric 34, which moves the lid of the infusion chamber 12 downwards and interlocks the infusion chamber 10. By moving the lever 33 in the opposite direction, the lid of the infusion chamber 12 rises and the infusion chamber 10 opens, so that the support 13 can be removed and the coffee l? 'Replaced. The water outlet is also controlled by movement of the lever 33 or the lid of the infusion chamber 12. Only when the lid of the infusion chamber 12 is in the lower position, for example with the infusion chamber closed 10 , the hot water flows into the infusion chamber and from there to the coffee cup 17. However, if the lid of the infusion chamber 12 is in the upper position and the infusion chamber 10 is open, the hot water or as desired, the steam circulates out of the coffeemaker through a steam pipe 35. The hot water from the steam pipe 35. can for example be used to make tea and steam, for example to heat milk. The switching point position of one of the two paths is at the inlet of the connection pipe 9. The connection pipe 9 is in a pipe cover 36, the latter being sealed with two seal rings 37, 38 and moved together with the lid of the infusion chamber 12. In the upper position, the upper seal ring 37 is on the water inlet 39 and prevents the flow of hot water or steam to the connecting tube 9, so that the hot water or steam then circulates at the inlet 40 of the steam pipe 35. In the lower position, the upper seal ring 37 is below the water inlet 37 and then the hot water flows to the inlet 41 of the connecting tube 9. A type switch 42 is adapted to the coffee machine according to the invention, to choose the type of coffee desired. You can for example have the positions "espresso", "mocha", "percolated coffee", "cappuccino" or other positions or adjustments. By means of the type switch 42, different programs of the microprocessor 32 are chosen, which in each case establish the desired water temperature T and the correct pumping capacity Pp. For different types of coffee, different types of infusion chamber bases are provided. 11, and can be inserted in a modular manner in the support 13. The base of the infusion chamber 11 for espresso or mocha is a perforated screen or sieve plate, made from thermally insulating material. To make percolated coffee, the base of the infusion chamber 11 must be able to receive a filter and must have a corresponding spigot. The coffee 11"is filled in the manner intended in the infusion chamber: unpacked or packaged in convenient containers, eg bags Apart from the holder 13, the lever 33 and the type 42 switch, the coffee maker of the invention has only one control member, ie a master switch 43. The latter has three positions, which for example can be called "steam", "off" and "coffee" and combines two functions.It is first the switch to put in and out of operation To the whole coffee machine In the "off" position the coffee machine switches off and does not consume energy, unlike conventional coffee machines in the idle mode, the user determines the amount of coffee that circulates, since it starts the flow of coffee when switching from "off" to "coffee" and subsequently stops the flow when switching from "coffee" to "off." The same applies to the amount of steam.In second, the master switch is a thermostat for the medium that circulates outside the the pipe steam 35. If the lever 33 is in the upper position, in the master switching position "steam", the steam flows out of the steam pipe 35 but in the "brown" master switching position, the hot water circulates. outside. Furthermore, in the "steam" master switching position, the flow of a water ingress is mechanically locked, when the lever 33 is in the lower position. Table 3 summarizes the effects of all possible master and lever switching positions. The coffee machine according to the invention can, if desired, also be equipped with a device for automatically regulating the coffee quantity.

The holding grid 18 in which coffee cups 17 are placed, is designed in such a way that it can be turned over to the insert 19. "In this way, two different spacings between the spout 16 and the grid 18 can be adjusted, which makes possible placing the coffee cups 17, 17"in height very differently under the coffee machine. The distance between the spout 18 and the coffee cup 17 should not be too large or otherwise no foam forms in the coffee. Figure 6 shows a small coffee hunt 17 in the holding grille 18 in the raised position and Figure 7 a large coffee cup 17"in the grille 18 in the lowered position TABLE 3 Upper position lever master switch "Steam" Steam from no steam pipe 35"Disconnected" None none "Coffee" Coffee water from steam pipe 35 spout 16 In summary, the coffee machine according to the invention essentially comprises a chamber for water supply water, a pump 5, a continuous flow heater 8, for heating water and an infusion chamber 10 for receiving coffee 10". The continuous flow heater 8 has a low thermal capacity. The coffee machine of the invention is equipped with at least one temperature sensor 31 at the end of the continuous flow heater 8, or between the heater and the infusion chamber 10, as well as a control loop, whose controlled variable is the temperature of the T water at the end of the continuous flow heater. With respect to the mechanical and thermal characteristics, the non-heated parts 9-12 on the water path between the continuous flow heater and the 10"coffee are optimized in such a way that they have an adequate resistance for an excessive pressure that occurs in the system and low thermal capacities and respect to water low thermal transmission coefficients.

Claims (18)

1. CLAIMS 1. Coffee machine with a water supply chamber, a pump, and an infusion chamber for receiving coffee, characterized in that it has a continuous flow heater with low thermal capacity to heat the water, which is equipped with at least one gas detector. temperature at the end of the continuous flow heater or between the latter and the infusion chamber, as well as with a control loop, whose controlled variable is the water temperature at the end of the continuous flow heater and because with respect to the mechanical characteristics and thermal, the unheated parts on the water path between the continuous flow heater and the coffee, are optimized in such a way that they have an adequate resistance with respect to the occurrence of excessive pressure in the system and have low thermal capacities and with regarding water, low thermal transmission coefficients.
2. 2. Coffee machine in accordance with the claim

   1, characterized in that one or more parts not heated on the water path, are made from thermally insulating material.
3. 3. Coffee machine in accordance with the claim
4. 2, characterized in that one or more non-heated parts on the water path are made from
5. RS / Bms / 27 / PCT460 highly porous ceramic material, highly porous plastic or plastic. Coffee machine according to any one of claims 1 to 3, characterized in that the continuous flow heater comprises an inner tube through which water can circulate, at least one inner insulating layer placed around the inner tube, a filament wound around the inner insulating layer and at least one outer insulating layer placed around the filament. Coffee machine according to claim 4, characterized in that the inner tube of the continuous flow heater is made from aluminum, stainless steel, or high temperature resistant plastic, the insulating layers of high temperature resistant plastic and the filament of the high impedance metal alloy. Coffee machine according to claim 4 or 5, characterized in that in order to prevent scale deposition inside the tube, the continuous flow heater is mounted in a floating manner, the pump is suspended in a mobile or hung by the upper part, and vibrates during operation and the continuous flow heater and the pump are connected in such a way that the continuous flow heater can be made to vibrate by the pump.
6. RS / sms / 27 / PCT460
7. 7. Coffee machine according to one of claims 1 to 6, characterized in that it contains a microprocessor, for checking and controlling the pumping energy of the pump, the heating energy of the continuous flow heater and the heating time.
8. A coffee machine according to claim 7, characterized in that for each coffee preparation process, the microprocessor, calculates from the pumping energy of the pump, the heating energy of the continuous flow heater and the heating time, a measure for the formation of scaling of the inner tube of a continuous flow heater and emitting an acoustic and / or optical warning signal if the scale has exceeded a certain critical value. .
9. Coffee machine according to any of claims 1 to 8, characterized in that the infusion chamber essentially comprises an infusion chamber base and an infusion chamber lid.
10. 10. Coffee machine according to claim 9, characterized in that for the preparation of different types of coffee, different infusion chamber bases can be inserted in a support module-like manner by the user, the support in turn is deliverable within the coffee machine.

    RS / ßttlß / 27 / PCT460
11. 11. Coffee machine according to claim 9 or 10, characterized in that since the locking mechanism of the infusion chamber has a lever mobile by the user, an eccentric connected to the lever and an infusion chamber lid that can be moved up and down by the eccentric and which locks the infusion chamber, when its base slides inside the coffee machine.
12. 12. Coffee machine according to claim 11, characterized in that the lever simultaneously controls the exit of the water, because with the infusion chamber open, steam or hot water passes to a steam pipe and with the infusion chamber closed, hot water passes to the cafe.
13. 13. Coffee machine according to claim 12, characterized in that the position of the switching point for one of the two paths is at the entrance of a connection pipe that is located in an enclosure or pipe lining, sealed against the latter by two. seal rings and can be moved together with the lid of the infusion chamber, so that with the infusion chamber open, the upper seal ring is located over the water inlet, prevents the inflow of steam or hot water inside the connection tube, and the

    RS / sms / 27 / PCT460 steam or hot water can circulate at the inlet of the steam pipe, and with the infusion chamber closed, the upper seal ring is below the water inlet and hot water can circulate to the entrance of the connecting tube.
14. 14. Coffee machine according to claim 12 or 13, characterized in that it has a master switch, which on the one hand is the switch to put the coffee machine in and out of operation and on the other hand a temperature regulator s thermostat for the circulating medium outside the steam pipe.
15. 15. Coffee machine according to claim 14, characterized in that the master switch has three positions, which for example can be called "steam", "disconnected" and "coffee", in such a way that in the "disconnected" position the coffee machine turn off, the coffee circulates from a spigot or the flow of hot water from the steam pipe, can be achieved by switching "off" to "coffee" and can stop again when switching "coffee" to "off" and the flow out The steam from the steam pipe can be started by switching from "disconnected" to "steam" and can be stopped again when switching from "steam" to "disconnected".

    RS / sms / 27 / PCT4S0
16. 16. Coffee machine according to one of claims 1 to 15, characterized in that the water supply chamber is visibly adapted to the upper part of the coffee machine, is made from a transparent material, can be removed by the user and is provided with a lid. Coffee machine according to one of claims 1 to 16, characterized in that it has a ballasted base in order to improve its stability. A coffee machine according to claim 17, characterized in that it has, below the spout, a retaining grid inserted in the base and in which coffee cups can be placed and because the retention grid is designed in such a way that it can be to turn, in order to allow the adjustment of two different spacings between the spout and the grid.

    RS / sms / 27 / PCT460