AU772899B2

AU772899B2 - Device for preparing coffee and method for preparing a coffee drink using said device

Info

Publication number: AU772899B2
Application number: AU53903/00A
Authority: AU
Inventors: Carsten Jorgensen
Original assignee: Pi Design AG
Current assignee: Pi Design AG
Priority date: 1999-06-01
Filing date: 2000-05-30
Publication date: 2004-05-13
Anticipated expiration: 2020-05-30
Also published as: EP1187546A1; CN1209064C; NO20015457L; NO20015457D0; TW487561B; JP3834681B2; AU5390300A; WO2000072736A1; NO320811B1; NZ515306A; JP2003500144A; CA2372941A1; HK1045243A1; DK199900771A; DK176265B1; CN1353588A

Description

WO 00/72736 PCT/DK00/00290

I

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, where 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 water extracts aromatic carriers from the ground coffee, after which the prepared coffee drink is filtered back to the closed compartment through a filter arranged 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 and 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 using the vacuum resulting from the cooling, where the coffee grounds will be 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 be 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 preparing 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 extraction of the aromatic carriers, respectively. The two containers are connected with an ascension pipe being axially slideable with a view to allowing a variable infusion time in the extraction compartment. A varying amount of water stays in the fresh water container, which is equipped with at least one heating element, dependent on the distance between the lower edge of the ascension pipe and the bottom of the fresh water container, the evaporation time of which is deciding the infusion time for the tea. The characterising features of the specified invention are, that the ascension pipe is slidingly mounted, and the rest amount of water is decided by the position of the ascension pipe, and that the ascension pipe in a manner known per se has the function of an as- P:AOPERW D24761I4 spl.do-10/04 2 cension pipe and an outlet. However, those known features are made with the intention to enable the user to adjust the infusion time for the tea. For being able to make the adjustment of the remaining amount of water, the bottom of the fresh water container is split in two levels. The infusion time for tea can perfectly vary from 5 minutes for an Assam or Ceylon tea, whereas Kemun tea is characteristic by its long infusion time of minutes as a consequence of its low contents of tannic acid. Such needs are not present in the actual invention, where the coffee shall be prepared in a known manner, which with the invention can fulfil the expectations of the consumers.

Further, it is known to make coffee, where water is heated with a heating source built into the device, after which the water is guided through an ascension pipe to a position, from which the water can drip down into the ground 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 be secured, and that the water, as a result of the 15 dripping, only is distributed over a very small area, having as a consequence, that the o aromatic components are not exhaustively utilised, as the distribution of the dripping water at the right temperature is very heterogeneous.

Summary of the Invention In accordance with the invention, there is provided a device for preparing coffee, 20 including a first compartment where water is boiled, and an ascension pipe for transferring the 6 boiling water from the first compartment to a second compartment, where the boiling water S. extracts aromatic carriers from ground coffee, after which the resultant coffee drink is filtered back to the first compartment through a filter arranged at an outlet of the second compartment, wherein the first compartment is provided with at least one heating element for bringing the water in the first compartment to the boil, and the at least one heating element is controlled depending on time and temperature using suitable control means to operate at least at two nonzero power levels so as, after boiling the water, to keep the temperature of the coffee drink within a temperature range below boiling point of the coffee drink.

In another aspect, there is provided a method for preparing a coffee drink using a device, as described above, including: a) Placing water in the first compartment; b) Providing a filter in the second compartment; P:OPERDH2476184 spal.do -10/03/04 3 c) Placing ground coffee in the second compartment; d) Heating the water in the first compartment until boiling whereby, before boiling, the water is caused by heat and increasing steam pressure to be displaced through the ascension pipe to the second compartment; e) Boiling of the water for a suitable amount of time, whereby steam from the boiling water penetrates through the ascension pipe to the second compartment, where the contents is heated to boiling point temperature; f) Terminating the boiling, whereby the first compartment cools and creates a vacuum, sucking the coffee drink from the second compartment back into the first compartment through the filter; wherein g) A heating element of the first compartment, at the termination of the boiling, is switched over to a power level lower than the power needed for maintaining the :-**.boiling; and h) The lower power level is switched over to for maintaining the temperature of the S: 15 coffee drink within the first compartment inside a temperature range below the .boiling point of the coffee drink.

Throughout the remainder of the description, the "first compartment" will be referred to as either the "closed compartment" or "closed container" and the "second compartment" will be referred to as either the "open compartment" or "open container".

.:ee S 20 With the method according to the invention the termination of boiling and associated cooling time can be determined 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 one heating element, a time dependent extension of the cooling time can be provided in that the heating element is supplied with pulsating power, where the 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 effective 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 and the final phase, step h), where the prepared coffee drink is kept 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 batterypowered control of gas valves at the boiling of the water is here possible in locations, where a supply grid is not available.

In another advantageous embodiment of the device for preparing coffee it is equipped with a socket containing the control electronics, a switching complex and possibly an energy storage in the form of a gas container/cartridge or a connection to an electric power supply.

An example of the invention is shown in the drawings which in: fig. 1. shows an perspective view of the device for preparing coffee according to the invention, fig. 2. shows an axial section through the device for preparing S coffee according to the invention, and fig. 3. shows a perspective view as in fig. 1, but with the fly-out S. arm shown in the outer position.

o In fig. I and 2 a device is shown for preparing coffee being run with electricity; this is described in the following. The device for preparing coffee according to the embodiment is equipped with a closed compartment 1 standing on a socket 2 with not further shown coupling means to the power supply. Un- oo o der the handle 3, a window 4 is seen, through which the process can be fol- 25 lowed. Under the window, an electric switching arm 5 is arranged, which is controlled partly manually, partly automatically by means of time and/or temperature parameters. The closed compartment I is closed by means of a plug 14 encirculating a pipe 12 reaching out from the open compartment 6 and 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 open 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.

WO 00/72736 PCTDK00/00290 The bottom of the closed compartment I is in preferred embodiments even with a view to the cleaning of the closed compartment. Depending of the calcareousnes of the water scale can be deposited on that part of the closed compartment being in direct contact with the heating element s 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 electronically displayed. It could be the temperature of the water in the closed compartment 1, the volume filled in or a time display. Fig. 3 shows further, that, on another place of the socket 2, an extensible fly-out arm 9 is arranged, which, to- 1o gether with a pop-up holder 17 can keep the open compartment 6 with its ascension pipe 12 after finishing the preparation of the ready coffee drink.

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 extensible fly-out arm 9. When the fly-out arm is not in use, it can be turned into the 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 the not further shown switching complex 11, which in principle can be an arbitrary type regarding manually or automatic working function. Concerning the 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, partly 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 open 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 increases above the water, will be lifted up into the ascension pipe 12, leading to the open compartment 6 with the filter 13.

WO 00/72736 PCTIDK00/00290 6 iv. Immediately before boiling occurs, all water will be pressed up into the open compartment 6, and the residual in the closed compartment is quickly brought to the boiling point.

v. Hereby steam is conducted through the ascension pipe 12, through the filter 13, to the mixture of water and ground coffee.

vi. When a suitable amount of steam has been guided through the ascension 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 compounds in the ground coffee, the calcareousnes of the water and contents of other substances. For the control of this, the means in the switching 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 further 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 large amount of condensing heat passes from the steam to the fluid around it, what 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 cornpartment 6 cannot be warmer than the ascending steam, as at temperature equilibrium no condensation takes place in the fluid. This is one of those characteristics 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 ternperature of the ascending steam from the closed compartment 1.

After the pre-set boiling time, the circuit for the heating element 10 is switched off, or it is switched to a lower power, so that the cooling down of the 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 the cooling down a vacuum is built up in the closed compartment 1, whereby the 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 back 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 from the socket 2 under the closed compartment i, and the lid 7 is turned down coyering the contents of the closed compartment 1. After this, the coffee drink is ready to be served and consumption. With a view to keep the coffee drink at an 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 tems perature range below the boiling point for the coffee drink.

Starting the preparation can at an electrically controlled heating be controlled electrically with a time delay, so that water and ground coffee can be filled into the closed compartment 1 and the open compartment 6, respectively, whereby at any arbitrary time coffee can be made without direct human interference.

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 battery.

Such automation has not earlier been possible at the preparation of "Vacis uum" coffee, where the preparation until now has been dependent on external 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.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

o

Claims

1. Device for preparing coffee, including a first compartment where water is boiled, and an ascension pipe for transferring the boiling water from the first compartment to a second compartment, where the boiling water extracts aromatic carriers from ground coffee, after which the resultant coffee drink is filtered back to the first compartment through a filter arranged at an outlet of the second compartment, wherein the first compartment is provided with at least one heating element for bringing the water in the first compartment to the boil, and the at least one heating element is controlled depending on time and temperature using suitable control means to operate at least at two non-zero power levels so as, after boiling the water, to keep the temperature of the coffee drink within a temperature range below boiling point of the coffee drink.

2. Device for preparing coffee according to claim 1, wherein the at least one heating see* 0:0 element is supplied with electric energy. 0

3. Device for preparing coffee according to claim 2, further including a time and i temperature control, being controlled by the supplied electrical energy. 9% a4. Device for preparing coffee according to claim 1, wherein the at least one heating 0000 0 .element is made as a carrier ofa catalyst being supplied with chemical energy. o°°o

5. Device for preparing coffee according to claim 4, further including a time and temperature control, being controlled by an electrical energy store. 0.. S6. Device for preparing coffee according to claim 5, wherein the electrical energy store is an electrical battery.

7. Device for preparing coffee according to any one of the preceding claims, further including a socket containing control electronics, a switching assembly and an energy storage in the form of a gas container/cartridge or a connection to an electric energy supply.

8. Device for preparing coffee according to claim 7, wherein the socket is further P:\OPER\DK\2476184 spldo-10/03/04 9 equipped with a moveable arm having a pivoting holder for holding the second compartment via the ascension pipe after the termination of the preparation of the coffee drink.

9. Device for preparing coffee according to claim 8, wherein the holder is adapted to be turned down into a recess in the arm. Method for preparing a coffee drink using the device as claimed in any one of the preceding claims, including: a) Placing water in the first compartment; b) Providing a filter in the second compartment; c) Placing ground coffee in the second compartment; d) Heating the water in the first compartment until boiling whereby, before boiling, ~the water is caused by heat and increasing steam pressure to be displaced through 0 w 0. 0:0. the ascension pipe to the second compartment; S e) Boiling of the water for a suitable amount of time, whereby steam from the boiling 15 water penetrates through the ascension pipe to the second compartment, where the •contents is heated to boiling point temperature; f) Terminating the boiling, whereby the first compartment cools and creates a 0:0 vacuum, sucking the coffee drink from the second compartment back into the first 0.0 compartment through the filter; wherein 20 g) A heating element of the first compartment, at the termination of the boiling, is switched over to a power level lower than the power needed for maintaining the

55.55. S: boiling; and h) The lower power level is switched over to for maintaining the temperature of the coffee drink within the first compartment inside a temperature range below the boiling point of the coffee drink. 11. Method according to claim 10, wherein during the method steps d) h) electrical energy is supplied to heating element and control means for the heating and control of the preparation of the coffee. 12. Method according to claim 10, wherein during the method steps d) h) chemical P:\OPER\DHU476194 gpl.do-10/03/04 energy is supplied for the heating and control of the preparation of the coffee, from a catalyst carrier driven by electrical, stored energy for control of the chemical energy. 13. Device for preparing coffee, substantially as hereinbefore described with reference to the drawings and/or Examples. 14. Method for preparing coffee, substantially as hereinbefore described with reference to the drawings and/or Examples. DATED 11 March 2004 PI-DESIGN AG By DAVIES COLLISON CAVE Patent Attorneys for the applicant *go *0* 00•. 0o•o .:oo0: