WO2000072736A1

WO2000072736A1 - Device for preparing coffee and method for preparing a coffee drink using said device

Info

Publication number: WO2000072736A1
Application number: PCT/DK2000/000290
Authority: WO
Inventors: Carsten Jørgensen
Original assignee: Pi-Design Ag
Priority date: 1999-06-01
Filing date: 2000-05-30
Publication date: 2000-12-07
Also published as: EP1187546A1; CN1209064C; NO20015457L; NO20015457D0; TW487561B; JP3834681B2; AU5390300A; NO320811B1; NZ515306A; JP2003500144A; CA2372941A1; HK1045243A1; DK199900771A; DK176265B1; CN1353588A; AU772899B2

Abstract

With a device for preparing coffee of the type, where water in a closed container (1) is being boiled, after which the water through an ascension pipe (12) is pressed into an open compartment (6), where the boiling water extracts aromatic carriers from the ground coffee, after which the prepared coffee drink is filtered back to the closed compartment (1) through a filter arranged at the outlet from the open compartment, it is the aim to provide a device for preparing coffee, where the aromatic components in the ground coffee is utilised in the best way under careful temperature monitoring, where the user can do without external heat sources, and where the possiibility in advance for deciding a special initiating time and later deciding a temperature sequence are present. This aim is met if the closed container (1) is equipped with at the least one heating element (10), which together and/or single have a suitable power for bringing the water in the closed compartment (1) to the boil, and that the heating element complex is controlled depending on time and temperature using suitable control means and have at least two power steps with a view to keeping the temperature of the coffee drink within a narrow temperature range below the boiling point of the coffee drink.

Description

DEVICE FOR PREPARING COFFEE AND METHOD FOR PREPARING A COFFEE DRINK

USING SAID DEVICE. Technical Field

The invention relates to a device for preparing coffee of the type, w h e r e water in a closed container is being boiled, after which the water through a n ascension pipe is pressed into an open compartment, where the boiling w ater extracts aromatic carriers from the ground coffee, after which the prep ared coffee drink is filtered back to the closed compartment through a filter a r ranged at the outlet from the open compartment.

The Prior Art

Such device for preparing coffee has been known since 1958, where it was made as a novel and improved way of preparing coffee, whereby a constant a n d high temperature was secured during the extraction or infusion time. Part of this prior art has been published in DK 90776 and DK 98310.

After finishing the ascension the closed compartment must be cooled so as to bring back the ready made coffee through a filter arrangement thereby u s ing the vacuum resulting from the cooling, where the coffee grounds will b e retained in the open compartment by a filter not further specified. However, a series of problems are connected with this preparation method, as it is dependent on an external heating source and further can not b e automated without large costs with a view to initiating preparation of coffee at a distinct, prior fixed time, like what has been common at devices for p rep arin g coffee. From EP 292 649 a similar device is known for the preparation of tea, where the device comprises two containers for fresh water, and for the ex traction of the aromatic carriers, respectively. The two containers are c onnec ted with an ascension pipe being axially slideable with a view to allowing a v ari able infusion time in the extraction compartment. A varying amount of w ater stays in the fresh water container, which is equipped with at least one h eatin g element, dependent on the distance between the lower edge of the ascension pipe and the bottom of the fresh water container, the evaporation time o f which is deciding the infusion time for the tea. The characterising features o f the specified invention are, that the ascension pipe is slidingly mounted, an d the rest amount of water is decided by the position of the ascension pipe, an d that the ascension pipe in a manner known per se has the function of an as - cension pipe and an outlet. However, those known features are made with t h e intention to enable the user to adjust the infusion time for the tea. For b e i n g able to make the adjustment of the remaining amount of water, the bottom o f the fresh water container is split in two levels. The infusion time for tea c a n perfectly vary from 5 minutes for an Assam or Ceylon tea, whereas Kemun te a is characteristic by its long infusion time of 15 minutes as a consequence of its low contents of tannic acid. Such needs are not present in the actual in ven ti on , where the coffee shall be prepared in a known manner, which with the i n v e n tion can fulfil the expectations of the consumers. Further, it is known to make coffee, where water is heated with a h e a tin g source built into the device, after which the water is guided through an asc en sion pipe to a position, from which the water can drip down into the groun d coffee, after which the prepared coffee is filtered in a filter funnel. This method is often mentioned the "Melitta^®"-method. The drawbacks at this method are that a constant, high temperature of the dripping water can not always b e secured, and that the water, as a result of the dripping, only is distributed over a very small area, having as a consequence, that the aromatic components ar e not exhaustively utilised, as the distribution of the dripping water at the ri g h t temperature is very heterogeneous.

Object of the invention

It is therefore the object of the present invention to provide a device f o r preparing coffee, where the aromatic components in the ground coffee is uti lised in the best way under careful temperature monitoring, where the user c a n do without external heat sources, and where the possibility in advance for deciding a special initiating time and later deciding a temperature sequence a r e present.

This object is met according to the invention by a device for prep ari n g coffee according to the ingress of the specification, where the closed c ontainer is equipped with at the least one heating element, which together and/or s in gle have a suitable power for bringing the water in the closed compartment to t h e boil, and that the heating element complex is controlled depending on time an d temperature using suitable control means and have at the least two power steps with a view to keeping the temperature of the coffee drink within a n a rr o w temperature range below the boiling point of the coffee drink.

A method for preparing a coffee drink using the device for preparing c offee comprise initially the following known steps a - f: a) Filling of water into the container being equipped with the heating element complex; b) Mounting the open compartment with filter; c) Filling of ground coffee beans; d) Initiating heating of the water until boiling, where the water before t h e boiling as a consequence of the heat dilatation and increasing steam pre s sure is displaced through the ascension pipe to the open compartment; e) Boiling of the water during a suitable time, where steam from the boi lin g rise through the ascension pipe to the open compartment, where t h e contents is heated to the boiling point temperature; f) Switching off the boiling, whereby the closed compartment is cooled a n d build up a vacuum sucking down the prepared coffee drink back to t h e open compartment; and the method is distinctive from the prior art technique in that g) The heating element complex belonging to the open compartment i s switched at the discontinuation of the boiling to a power step with an output power being less than the necessary power for maintaining the boiling, where the means for time control and temperature adjustment in a switching complex are used, and at the termination of the filtering h ) Is switched to a power step maintaining an optimum temperature for t h e prepared coffee drink.

With the method according to the invention the cooling time can be de - termined so that the contents of the open compartment can extract aromatic components during the time, fixed by the user according to his or her taste, being in the range between seconds until 2 to 3 minutes.

In the case, where the closed compartment is only equipped with o n e heating element, a time dependent extension of the cooling time can be p ro - vided in that the heating element is supplied with pulsating power, where t h e mean value correspond to a lower power step.

In an advantageous embodiment, it is suggested that the heating element be supplied with electric energy, whereby optimum possibilities for an effec tive control of the process are provided. This can be accomplished with a time controlled initiation of the process and an electric control of the cooling phase , step g), and the final phase, step h), where the prepared coffee drink is kep t optimally warm. Another power supply is possible in that the heating element is a catalyst carrier over which a combustible gas, e.g. a common gas for lighters. A battery - powered control of gas valves at the boiling of the water is here possible in l ocations, where a supply grid is not available. In another advantageous embodiment of the device for preparing coffee i t is equipped with a socket containing the control electronics, a switching c omplex and possibly an energy storage in the form of a gas container/cartridge o r a connection to an electric power supply.

Further advantageous embodiments of the invention are deductible fro m the dependent claims.

An example of the invention is shown in the drawings which in:

fig. 1. shows an perspective view of the device for p rep arin g coffee according to the invention, fig. 2. shows an axial section through the device for p rep ari n g coffee according to the invention, and fig. 3. shows a perspective view as in fig. 1, but with the fly-out arm shown in the outer position.

In fig. 1 and 2 a device is shown for preparing coffee being run w ith electricity; this is described in the following. The device for preparing coffee according to the embodiment is equipped with a closed compartment 1 standin g on a socket 2 with not further shown coupling means to the power supply. Un der the handle 3, a window 4 is seen, through which the process can be fol- lowed. Under the window, an electric switching arm 5 is arranged, which i s controlled partly manually, partly automatically by means of time and/or tem perature parameters. The closed compartment 1 is closed by means of a plug 14 encirculating a pipe 12 reaching out from the open compartment 6 an d through the plug 14 arranged in an opening 15 in the closed compartment 1. This opening 15 can, when the open compartment 6 is removed from the device for preparing coffee, be further closed by means of a lid 7. In addition, the o p e n compartment 1 is equipped with a lid 16 impeding the evaporation of aromatic components form the ground coffee being filled into the open compartment 6 before the preparation of the coffee. The pipe 12, which is not shown in fig. 1 , reaches down to the bottom of the closed compartment 1 without, after all, touching this. The bottom of the closed compartment 1 is in preferred embodiments e v e n with a view to the cleaning of the closed compartment. Depending of the c al - careousnes of the water scale can be deposited on that part of the closed c om partment being in direct contact with the heating element 10. Under the switch 5 there is, in the embodiment shown, arranged a window

8 on a projection on the socket 2, where different parameters can be e lectron i cally displayed. It could be the temperature of the water in the closed c ompartment 1, the volume filled in or a time display. Fig. 3 shows further, that, on a n other place of the socket 2, an extensible fly-out arm 9 is arranged, which, to- gether with a pop-up holder 17 can keep the open compartment 6 with its as cension pipe 12 after finishing the preparation of the ready coffee drin k . Thereby the open compartment 6 is secured against overturning, and possible remainings in the form of drops from the ascension pipe 12, can be catched in a not further shown tray suitable for this purpose, forming a part of the exten s i- ble fly-out arm 9. When the fly-out arm is not in use, it can be turned into t h e socket 2. To this purpose, the holder 17 can be turned down into a recess 18 i n the fly -out arm 9.

In fig. 2 it is seen, that under the bottom of the closed compartment 1 a heating element 10 is arranged, the power supply of which is controlled by t h e not further shown switching complex 11, which in principle can be an arb i trary type regarding manually or automatic working function. Concerning t h e automatic function not further shown, thermoelectric sensors are used, detecting boiling and assisting at the switching off the power supply, when boiling occur. The function of the device for preparing coffee is the following, p artl y known series of process steps: i. Water is filled into the closed compartment, before the open compartment

6 is put into the opening 15 as a plug, ii. After the arrangement of the filter 13 ground coffee is filled into the o p e n compartment 6 in an amount corresponding the amount of water filled into the closed compartment 1. iii. The switch 5 is activated, whereby the water in the closed compartment 1 is heated. During heating, the water, as the steam pressure increase s above the water, will be lifted up into the ascension pipe 12, leading to t h e open compartment 6 with the filter 13. iv. Immediately before boiling occurs, all water will be pressed up into t h e open compartment 6, and the residual in the closed compartment i s quickly brought to the boiling point. v. Hereby steam is conducted through the ascension pipe 12, through t h e filter 13, to the mixture of water and ground coffee, vi. When a suitable amount of steam has been guided through the ascen sion pipe 12, the process shall be stopped; i.e. the boiling shall be terminated . The time for the termination of the boiling depends on many parameters , among these the coffee sort and the infusion time for the aromatic c ompounds in the ground coffee, the calcareousnes of the water and c ontents of other substances. For the control of this, the means in the s w itching complex 11 are employed for time control and temperature adjustment. To this end, a time controlled delay can be employed for securing a fixed boiling time, during which the steam enters the ascension pipe 12 and f u rth e r through the filter 13 and the mixture of water and ground coffee above that . When the steam is guided through the fluid, it will condense and the l arg e amount of condensing heat passes from the steam to the fluid around it, w h at also will secure a stable temperature, being only dependent on the barometric pressure. The idea behind such heating is that the contents of the open com- partment 6 cannot be warmer than the ascending steam, as at temperature equilibrium no condensation takes place in the fluid. This is one of those c h ar acteristics at vacuum coffee, where the temperature demand for minimum 96°C can be met homogeneously for all the contents of the open compartment 6. Hereby, the temperature of the contents will asymptotically approach the tem - perature of the ascending steam from the closed compartment 1.

After the pre-set boiling time, the circuit for the heating element 10 i s switched off, or it is switched to a lower power, so that the cooling down of t h e closed compartment 1 can take place in a controlled time, whereby the aromatic carriers from the ground coffee will have time for the infusion. During t h e cooling down a vacuum is built up in the closed compartment 1, whereby t h e contents of the open compartment 6 is sucked down into the closed compartment 1. These principles belong, properly speaking, to the prior art, but as a matter of form, they are repeated here.

After having terminated the process, i.e. when the prepared coffee is b ac k in the closed compartment 1, the open compartment 6 with the filter is removed and is arranged in the holder 17 on the fly-out arm 9, which is turned out fro m the socket 2 under the closed compartment 1, and the lid 7 is turned down c ov - ering the contents of the closed compartment 1. After this, the coffee drink i s ready to be served and consumption. With a view to keep the coffee drink at a n optimal temperature, the heating element 10 can in a way known per se b e switched to a power level, where the coffee drink is kept within a narrow te m - perature range below the boiling point for the coffee drink.

Starting the preparation can at an electrically controlled heating be c on trolled electrically with a time delay, so that water and ground coffee can b e filled into the closed compartment 1 and the open compartment 6, respectively , whereby at any arbitrary time coffee can be made without direct human in ter - ference .

A similar automatic start of the heating can be arranged at a gas/catalysing heating, as the control can take place based on an electric b attery .

Such automation has not earlier been possible at the preparation of "Vac- uum" coffee, where the preparation until now has been dependent on ex ternal heating sources in the form of e.g. a spirit flame or a hot plate.

The embodiment shown is only presented as an example, but is not limited to what is shown in the drawing. In addition, amendments and variants evident to a person skilled in the art are included in the invention.

Claims

PATENT CLAIMS

1. Device for preparing coffee of the type, where water in a closed c on tai n er (1) is being boiled, after which the water through an ascension pipe (12) i s

5 pressed into an open compartment (6). where the boiling water extracts ar o matic carriers from the ground coffee, after which the prepared coffee drink i s filtered back to the closed compartment (1) through a filter arranged at t h e outlet from the open compartment, characterised in, that the closed c on tainer (1) is equipped with at the least one heating element (10), which to- o gether and/or single have a suitable power for bringing the water in the closed compartment (1) to the boil, and that the heating element complex is controlled depending on time and temperature using suitable control means and have a t the least two power steps with a view to keeping the temperature of the coffee drink within a narrow temperature range below the boiling point of the coffee s drink .

2. Device for preparing coffee according to claim 1, characterised i n , that the heating element (10) is supplied with electric energy.

3. Device for preparing coffee according to claim 1 and 2, c h a r a c t e r i s e d in, that it is equipped with a time and temperature control, being controlled o by the supplied electrical energy.

4. Device for preparing coffee according to claim 1, characterised i n , that the heating element (10) is made as a carrier of a catalyst being supplied with chemical energy.

5. Device for preparing coffee according to claim 1 and 4, c h a r a c t e r i s e d 5 in, that it is equipped with a time and temperature control, being controlled by an electrical energy store.

6. Device for preparing coffee according to claim 5, characterised i n , that the electrical energy store is an electrical battery.

7. Device for preparing coffee according to any of the preceding claims, O characterised in, that it is equipped with a socket (2) containing the control electronics, a switching complex (11) and possibly an energy storage in t h e form of a gas container/cartridge or a connection to an electric energy supply.

8. Device for preparing coffee according to any of the preceding claims, characterised in, that the socket (2) is further equipped with a fly-out a r m 5 (9) being equipped with a pivoting holder (17) with a view to fixing the op en compartment (6) using its ascension pipe (12) after the termination of t h e preparation of the finished coffee drink.

9. Device for preparing coffee according to claim 5, characterised i n , that the holder (17) could be turned down into a recess ( 18) in the fly-out arm.

10. Method for preparing a coffee drink employing the device for p re p a ri n g coffee including the following known steps a - f: a) Filling the compartment being equipped with the heating element c om plex; b) Arranging the open compartment with filter; c) The filling of ground coffee; d) Initiation of heating the water filled into the closed compartment un ti l boiling, where the water before boiling as a consequence of the h e at dilatation and increasing steam pressure of the water filled in for boiling , where the water, before boiling, caused by heat and increasing steam pressure is displaced through the ascension pipe to the open c ompartment ; e) Boiling of the water in a suitable amount of time, whereby steam of w ater from the boiling penetrate through the ascension pipe to the open c ompartment, where the contents is heated to the boiling point temperature; f) Termination of boiling, whereby the closed compartment is cooled a n d built up a vacuum sucking the prepared coffee drink back to the closed 0 compartment;

And which is characterised in, that g) The heating element complex belonging to the closed compartment at t h e termination of the boiling is switched over to a power level with an output power being essentially lower than the power needed for maintaining t h e 5 boiling, where the means included in the switching complex (11) are used for time control and temperature adjustment; h) The lower power level is switched over after the emptying of the o p e n compartment (6) with a view to maintaining the temperature of the c offee drink inside a narrow temperature range below the boiling point of t h e o coffee drink.

11. Method according to claim 10, characterised in, that during t h e method steps d) - h) electrical energy is supplied to the means (10, 11) for t h e heating and control of the preparation of the coffee.

12. Method according to claim 10, characterised in, that during t h e 5 method steps d) - h) chemical energy is supplied to the means (10, 11) for t h e heating and control of the preparation of the coffee, where the mean (10) is a catalyst carrier, and the means ( 11) are control means driven by electrical, stored energy for control of the chemical energy.