WO1997024051A1

WO1997024051A1 - Coffee feeding device

Info

Publication number: WO1997024051A1
Application number: PCT/IB1996/001423
Authority: WO
Inventors: Nobuaki Ochiyama; Franciscus Nicolaas Matthieu Catharina Trines; Johan Pragt; Leonardus Petrus Antonius Kloosterhof
Original assignee: Philips Electronics N.V.; Philips Norden Ab
Priority date: 1995-12-28
Filing date: 1996-12-12
Publication date: 1997-07-10
Also published as: EP0818969A1; JPH09182666A

Abstract

This invention pertains to a coffee feeding device wherein the coffee that is extracted is foamed in order to give a good mouth touch. The device comprises a mixing chamber (9) in which a rotor (11) is driven. An air feeding pipe (5) is connected to the mixing chamber. Extracted coffee is introduced in the mixing chamber. Rotation of the rotor causes a suction of air which is mixed with the extracted coffee to obtain a foamed coffee in order to give a good mouth touch. Preferably, the rotor (11) is driven by a motor (7). To arrange the motor outside the mixing chamber, the rotor is magnetically coupled to the motor.

Description

Coffee feeding device.

This invention pertains to a coffee feeding device wherein the coffee that is extracted is foamed in order to give a good mouth touch. The coffee feeding device herein means a device for the feeding of coffee after extraction in a coffee cup, but the said coffee feeding device may also be used as coffee extracting device.

Various elements determine the flavour of coffee, such as the kind of coffee bean and the way of grinding of the coffee. Even with the same method of grinding and with the use of the same coffee bean, however, the flavour of the coffee is different if much air is present in the extracted coffee. In the case that the coffee contains much air, viz., in the case that many air bubbles are present in the surface of the coffee in the coffee container, in general a coffee with a good flavour and a good mouth touch is obtained.

As one of such coffees that contain much air, expresso coffee is known from official bulletin 4037366 of public disclosures of German patents. In the existing devices that extract and feed expresso coffee the expresso coffee feeding pipe is bifurcated in order to simultaneously produce a number of cups of expresso coffee, viz. , 2 cups. Moreover, in the existing device, a screw is established in the branching part of this bifurcated coffee feeding pipe. Expresso coffee is extracted under high pressure and becomes steam, and reaches the above mentioned bifurcated coffee feeding pipe, and hits the above mentioned screw. By the fact that the above mentioned screw rotates by the steam of the expresso coffee that contains much air, the steam of the said expresso coffee is divided in almost equal halves in the respective forks of the above mentioned bifurcated coffee feeding pipe and 2 cups of expresso coffee are produced.

Thus, coffee that is extracted with steam under high pressure such as expresso coffee, has a good mouth touch because it contains much air. Because the usual coffee that is not extracted by a high pressure, does not contain much air, however, it could not always be called a coffee with a good mouth touch and a good flavour. The above mentioned existing device is equipped with a screw, but this screw serves to evenly distribute the expresso coffee in 2 cups, and not to include air in the coffee. The reason is that whereas expresso coffee traps air in this extraction process the usual process of coffee extraction does not contain a process of trapping air in the coffee. Hitherto, devices to get air trapped in the extracted coffee in order obtain a smooth mouth touch of the usual coffee that is not extracted by high pressure, did not exist. Moreover, because rotation of the screw only occurs during the passage of the coffee liquid in the case that in such existing devices the situation is arranged that air is mixed in the said coffee liquid the speed of the screw rotation is extremely slow and good mixing of air in the coffee liquid was difficult.

This invention comprises that a mixing chamber wherein coffee is introduced, and a rotor for mixing that has been arranged in the above mentioned mixing chamber, and an air feeding pipe that communicates with the above mentioned mixing chamber in the vicinity of the above mentioned rotor, and a coffee outlet pipe that communicates with the above mentioned mixing chamber in the vicinity of the above mentioned rotor for the outlet of the coffee in the above mentioned mixing chamber, and a driving means to drive the above mentioned rotor are established.

The above mentioned driving means that serves to drive the above mentioned rotor of the coffee feeding device of this invention is a motor, and the above mentioned rotor is established on the shaft of this motor. In the coffee feeding device of this invention, also the above mentioned rotor rotates with a high speed, geared to the rotation of the above mentioned shaft of the above mentioned motor. Because the above mentioned rotor rotates with a high speed, eddies of the coffee occur and the coffee is introduced in the above mentioned mixing chamber. In the same way, the situation occurs that also air is introduced in the above mentioned mixing chamber, via the above mentioned air feeding pipe. In this case, the coffee and air that have been drawn in the above mentioned mixing chamber pass through the coffee outlet pipe while being mixed, and coffee that contains much air is poured in the coffee cup. Because coffee and air are mixed in this way, the result is that coffee with a good foaming is produced. By the effect of this foam, a coffee with a good mouth touch is produced. In the coffee feeding device of this invention, in addition the above mentioned rotor is mechanically joined with a first magnetic body, and on the other hand, the above mentioned driving means that serves to drive the above mentioned rotor, has a motor and a second magnetic body is installed on the shaft of this motor. Thus, the above mentioned rotor and the above mentioned motor are mechanically separated. By the magnetic force of the first magnetic body and second magnetic body, the above mentioned rotor rotates, geared to the driving of the above mentioned motor. By this rotation of the rotor eddies of the coffee occur, and coffee and air are drawn into the above mentioned mixing room, and coffee and air are mixed, and coffee with a good foam is produced. Because the above mentioned rotor and the above mentioned motor are mechanically separated, the above mentioned shaft of the above mentioned motor is not directly immersed in the coffee, and corrosion of the above mentioned shaft of the above mentioned motor is prevented.

Moreover, in the coffee feeding device of this invention, the inner wall of the above mentioned mixing chamber has at least one recess in order to produce small eddies of coffee and air.

When the above mentioned rotor rotates, small eddies of coffee are generated in each of the above mentioned depressions. By these small eddies, the situation is created that an even better mixing of coffee and air occurs. Consequently, coffee with a good foaming is obtained, even when the number of revolutions of the above mentioned motor is suppressed. Because the number of revolutions of the motor is suppressed, the driving (electric) current of the motor may be small and the freedom of choice of the motor is wide.

Below examples of execution of this invention are described in the details referring to figures.

Figure 1 shows the schematic construction of the coffee feeding device of the first example of execution that is based on this invention and a part as a cross section,

Figure 2 shows a plane view of the rotor that is used in figure 1, Figure 3 shows the schematic construction of another good example of execution of the coffee feeding device by this invention, and a part as a cross section,

Figure 4 schematically shows a plane view of the rotor and the inner wall of the mixing chamber that are used in the coffee feeding device of figure 3 by this invention.

Figure 1 shows the general construction of the coffee feeding device of the first example of execution that is based on this invention, with a part as a cross section. In figure 1 , the coffee feeding device 1 has coffee container 2 and motor controlling part 3, partitioned by partitioning plate 4. For the side walls of above mentioned coffee container 2 and above mentioned partitioning plate 4, a material with warm keeping properties, such as for instance a thermos can is preferred. In the center of the said partitioning plate 4, long, narrow air feeding pipe 5 is installed, and this protrudes vertically into the above mentioned coffee container 2. The said air feeding pipe 5 may also be integrated to one body with above mentioned partitioning plate 4. At the side that is opposite to the above mentioned air feeding pipe 5, motor installation part 6 protrudes from above mentioned partitioning plate 4 in the direction of above mentioned motor controlling part 3. The position of the front tip of above mentioned air feeding pipe 5 is preferably higher than the upper rim of the side wall of above mentioned coffee container 2. The reason is that the upper end of the above mentioned air feeding pipe 5 should not be in contact with air. If above mentioned air feeding pipe 5 is lower than the side wall of above mentioned coffee container 2, it is necessary that coffee that is poured to above mentioned coffee container 2 is poured in such a way that it does not go beyond the above mentioned upper end of above mentioned air feeding pipe 5.

The said motor installation part 6 may also have the possibility of attachment to and detachment from above mentioned partitioning plate 4. By the above mentioned motor installation part 6 and above mentioned partitioning plate 4, mixing chamber 9 is formed. In above mentioned motor installation part 6, motor 7 is installed. The (electric) current input terminal (not shown in the figure) of above mentioned motor 7 is connected with motor controlling unit 8, and the said motor controlling unit 8 is electrically connected with external switch 12. Shaft 10 of above mentioned motor 7 has an air-tight extension in above mentioned mixing chamber 9, and inside said mixing chamber 9, rotor 11 for mixing is installed. Said rotor 11 is placed almost below above mentioned air feeding pipe 5. Outlet pipe 15 extends firom a part of the wall around the above mentioned rotor of above mentioned mixing chamber 9, via the side wall of above mentioned coffee container 2, to the outside of above mentioned coffee container 2. Above mentioned air feeding pipe 5 and above mentioned outlet pipe 15 are respectively connected with above mentioned mixing chamber 9. In the case of this example of execution, the interior diameter of above mentioned air feeding pipe 5 is 2 to 3 mm, and the interior diameter of above mentioned outlet pipe 15 is 5 mm. Above mentioned partitioning plate 4 has opening 14 for the introduction of coffee from above mentioned coffee container 2 into above mentioned mixing chamber 9 in two places around above mentioned air feeding pipe 5.

Figure 2 shows a plane view of rotor 11 that is used in figure 1. Said rotor 11 has disc 20 and a number of fins 22 that protrude upwards from the said disc 20, and installation hole 23 for the installation on above mentioned shaft 10 of above mentioned motor 7, is arranged in the center. In this example of execution, the diameter of above mentioned disc 20 is 22 mm, and the thickness is 1 mm, and the height of above mentioned fins 22 firom above mentioned disc 20 is 2 mm.

Coffee cover 16 is opened, and the coffee is poured in above mentioned coffee container 2. After the pouring of the coffee, above mentioned coffee container 2 is covered by above mentioned coffee cover 16. Via above mentioned openings 14, also above mentioned mixing chamber 9 is filled with coffee. By the pressure of the coffee, coffee also flows into the interior of above mentioned air feeding pipe 5.

Below the outlet opening of above mentioned outlet pipe 15, a coffee cup (not shown in the figure) is placed. By pressing, above mentioned switch 12 is switched ON. When above mentioned motor controlling unit 8 detects that the switch has been switched ON, a current flows from above mentioned motor controlling unit 8 to above mentioned motor 7, and above mentioned shaft 10 of above mentioned motor 7 and above mentioned rotor 11 rotate. The velocity of the rotation may range firom 16000 revolutions per minute to 19000 revolutions per minute. The reason is that the quantities of coffee and air that are drawn in, increase by rotation at a high speed. By the rotation of above mentioned rotor 11, the coffee is drawn into mixing chamber 9 via above mentioned openings 14. The reason is that the above mentioned fins 22 of above mentioned rotor 11 rotate, and produce eddies in the water stream by stirring the coffee thoroughly. Moreover, in the same way, air from outside flows towards above mentioned mixing chamber 9 via above mentioned air feeding pipe 5 by this rotation. These two, coffee and air, are pushed out while being mixed towards above mentioned outlet pipe 15. Via above mentioned outlet pipe 15, coffee that contains a large quantity of air, drops down from the discharge opening of above mentioned outlet pipe 15 in the above mentioned coffee cup. When the said coffee cup is filled with the desired quantity of coffee above mentioned switch 12 is pressed again. When above mentioned motor controlling unit 8 detects that the switch has been pressed again, the current that has flown in above mentioned motor 7 stops, and the rotation of above mentioned motor 7 stops. Hereby, coffee no longer drops down via above mentioned outlet pipe 15 from the above mentioned discharge opening. Because these electric means such as motor controlling unit 8 are well known to those skilled in the art, a detailed explanation will not be necessary. The coffee that has been filled in the above mentioned coffee cup, contains sufficient air, and the surface has the form of a foam. Due to the said foamy coffee, the mouth touch is extremely smooth. Figure 3 shows the schematic construction of another good example of execution of the coffee feeding device of this invention with a part as a cross section. The construction of coffee feeding device 31 of figure 3 is almost the same construction as that of the coffee feeding device 1 of figure 1. What is different, is the construction of the rotor and around the rotor. For the construction that is the same as that of figure 1, an explanation will not be necessary.

Air feeding pipe 35 and outlet pipe 45 each communicate with mixing chamber 39. Coffee container 32 has a depression in the bottom, and in this depression, above mentioned mixing chamber 39 is mechanically inserted. Above mentioned mixing chamber 39 has openings 44 for the inflow of coffee from above mentioned coffee container 32 in above mentioned mixing chamber 39 in two places around above mentioned air feeding pipe 35. Inside above mentioned mixing chamber 39, rotor 41 and first magnet 47 are accommodated. Said rotor 41 and first magnet 47 are mechanically combined to one body, and the first magnet is accommodated inside above mentioned mixing chamber 39 so that it borders on the bottom of above mentioned coffee container 32. Motor controlling part 33 has motor 37, motor controlling unit 38 and switch 42. On shaft 40 of above mentioned motor 37, second magnet 48 is installed. In this second magnet 48, the N pole and the S pole are preferably polarized parallel to the axis of above mentioned shaft 40. Also first magnet 47 is preferably polarized in the same way. The reason is that the property of the rotation of the first magnet to follow the rotation of the second magnet becomes better when they are polarized in this way, because a force whereby they repel each other, acts when the same poles of the first and second magnet are piled upon each other by rotation of the second magnet.

When switch 42 is pressed down, above mentioned motor 37 is driven via above mentioned motor controlling unit 38. Above mentioned shaft 40 and second magnet 48 rotate. When second magnet 48 rotates, first magnet 47 is linked and rotates by the magnetic force, and also above mentioned rotor 41 rotates. In the same way as in the coffee feeding device of figure 1, coffee and air are sucked into above mentioned mixing chamber 39 by the fact that said rotor 41 rotates, and via above mentioned outlet pipe 45, foamed coffee is produced.

Because in this example of execution motor and rotor are separated, the shaft of the motor is not immersed in the coffee.

Hereby, adherence of rust in the motor is avoided. Moreover, because motor and rotor mutually have magnets, the motor controlling unit 38 can control the rotation of the rotor, although motor and rotor are mechanically separated.

Figure 4 schematically shows a plane view of above mentioned rotor 41 with fins 52, that is used in the coffee feeding device of figure 3 of this invention, and lower element 39a of above mentioned mixing chamber 39 with the possibility of separation. Above mentioned lower element 39a of above mentioned mixing chamber 39 has recesses 53 for generation of eddies in the inner wall 6. When above mentioned rotor 41 rotates, geared to the rotation of shaft 40 of above mentioned motor 37, small eddies of coffee are generated around above mentioned recesses 53. By these eddies, the situation is created that coffee and air are still better mixed. It is preferred that the base end of above mentioned outlet pipe 45 borders on one of the 6 above mentioned recesses 53. Because by the above mentioned recesses 53, the situation is created that coffee and air are still better mixed, the number of revolutions of the motor can be made lower than in the case wherein no recesses are present. Because hereby the electric power of the motor can be reduced, the result is obtained that a small motor can be used and also the driving current can be reduced and that also economy of consumed electric current occurs.

According to the coffee feeding device of this invention, coffee with a good flavour and with an extremely smooth mouth touch, that contains sufficient air, is obtained. Because in addition in another example of this invention wherein by a magnet, motor and rotor are mechanically separated, and the shaft of the motor is not immersed in the coffee, adherence of rust on the motor is avoided, and via the magnetic force, the rotation of the rotor can be controlled. Because in addition recesses have been established in the inner wall of the mixing chamber, small eddies of the coffee are generated in the said recesses, and the situation that coffee and air are mixed well, is created. Because consequently coffee and air can be mixed well even when the electric power of the motor is small, the result is obtained that a small motor can be used and also the driving current can be reduced, and that also economy of consumed electric current occurs.

In this example of execution, coffee that has already been extracted was poured in the coffee feeding device of this invention, but the coffee feeding device of this invention itself of course also may be equipped with a coffee extracting device.

Claims

Claims:

1. A coffee feeding device with the characteristic that it has a mixing chamber wherein coffee is introduced, and a rotor for mixing that has been arranged in the above mentioned mixing chamber, and an air feeding pipe that communicates with the above mentioned mixing chamber in the vicinity of the above mentioned rotor, and a coffee outlet pipe that communicates with the above mentioned mixing chamber in the vicinity of the above mentioned rotor for the outlet of the coffee in the above mentioned mixing chamber, and a driving means to drive the above mentioned rotor.

2. A coffee feeding device with the characteristic that in the coffee feeding device that has been described in claim 1, the above mentioned driving means has a motor and that, when the said motor is driven, the above mentioned rotor in the above mentioned mixing chamber is magnetically linked and driven.

3. A coffee feeding device with the characteristic that in the coffee feeding device that has been described in claim 1 or 2, the inner wall of the above mentioned mixing chamber has at least one recess for the production of small eddies of coffee and air.