DEVICE FOR PREPARING A DRINK

Abstract

Device for preparing a drink by extracting a measured quantity, for example of ground coffee, contained in a capsule (1) equipped with an extraction membrane (7), said device comprising a water inlet (5), a capsule holder (2), a capsule cage (3), clamping means and means for extracting said drink through the membrane (7); characterized in that the capsule cage (3) comprises capsule ejecting means (17, 18).

Description

FIELD OF THE INVENTION

The present invention lies in the field of devices for preparing drinks by extracting a serving, for example of ground coffee, contained in a cartridge.

PRIOR ART

Devices that operate according to the above-mentioned principle have existed for many decades.

U.S. Pat. No. 2,899,886, U.S. Pat. No. 2,968,560, U.S. Pat. No. 3,403,617 and U.S. Pat. No. 3,607,297 describe devices in which the cartridge is initially perforated at a number of locations and then pressurized water is passed through it.

the cartridge described in patent CH 605 293 or in patent EP 0 242 556 B1 comprises a membrane in its lower part. Pressurized water is initially introduced into the upper part of the cartridge, thereby causing the cartridge to swell, mainly at the membrane. Beyond a certain pressure, the membrane tears, and thus enables a mixture of water and coffee to flow out.

In the device presented in patent EP 0 512 470 B1, by bulging following the introduction of water into the cartridge, the membrane is squashed and perforated against a surface which comprises elements in relief.

Other devices that make use of a mode of operation identical or similar to those described above are presented in the following patents: EP 0 250 810 B1, EP 0 521 188 31, EP 0 521 397 31, EP 0 726 053 31, EP 0 469 162 31 and WO 92/07775.

Also known are devices where the mixture of water and coffee is first of all produced in the chamber containing the cartridge, but only starts to flow out when the pressure in the chamber containing the cartridge reaches a predefined minimum value. See in particular patent applications EP 0 726 053 A1, EP 0 622 039 A1 and EP 1 016 364 A2.

SUMMARY OF THE INVENTION

The present invention constitutes an improvement over the devices of the prior art. It consists in particular of a mechanism for making it easier to remove the cartridge once it has been used.

To this end, the invention relates firstly to a device for preparing a drink by extracting a serving, for example of ground coffee, contained in a cartridge equipped with an extraction membrane, said device including a water inlet, a cartridge holder, a cartridge cage, clamping means and means for extracting said drink through the membrane, characterized in that the cartridge cage comprises cartridge ejection means.

According to a first embodiment of the invention, the ejection means include a spring.

The ejection means may comprise elements for piercing the upper face of the cartridge.

Alternatively, the ejection means have no elements for piercing the cartridge.

According to another variant of the invention, the device includes a clamping piston mounted in a movable manner with respect to the cartridge cage.

In another variant, the means for extracting said drink are spikes.

Advantageously, the spikes are mounted in a movable manner in relation to the cartridge holder.

Preferably, the device includes a mechanism for securing the movable spikes to the piston.

DETAILED DESCRIPTION OF THE INVENTION

The invention is described in more detail hereinbelow by means of examples illustrated in the following figures:

FIG. 1 describes an embodiment of a device according to the invention during the introduction of a cartridge.

FIG. 2 describes the device from FIG. 1 at rest, after the cartridge holder and cartridge cage assembly has been closed.

FIG. 3 describes the device from FIG. 1 after the cartridge holder and cartridge cage assembly has been clamped.

FIG. 4 illustrates the device from FIG. 1 in the active position when water is passing through the device.

LIST OF REFERENCE NUMBERS USED IN THE FIGURES

• • 1. Cartridge
  • 2. Cartridge holder
  • 3. Cartridge cage
  • 4. Clamping piston
  • 5. Water inlet
  • 6. Spikes
  • 7. Extraction membrane
  • 8. Spike support
  • 9. Spike
  • 10. Expansion space
  • 11. Drink outlet
  • 12. Flange
  • 13. Lower end of the clamping piston
  • 14. Lower end of the cartridge cage
  • 15. Upper unit
  • 16. Upper spring
  • 17. Cartridge ejection part
  • 18. Ejection spring
  • 19. Lower unit
  • 20. Lower spring

The device illustrated in FIGS. 1 to 4 includes a cartridge cage 3 comprising in its upper part a water inlet 5 which is connected to a water tank (not illustrated) and to a pump (not illustrated). The cartridge cage 3 is furthermore fastened to an upper unit 15 of the device.

The device also includes a clamping piston 4 mounted in a sliding manner with respect to the assembly formed by the cartridge cage 3 and the upper unit 15, an upper spring 16 being located in the space formed between the inner wall of the upper unit 15 and the upper face of the clamping piston 4. The inside of the cage 3 comprises a space intended to hold a cartridge 1 having a flexible membrane 7 in its lower part. The lower part 14 of the cage 3 is designed to come into contact with the flange 12 of the cartridge 1. An ejection part 17 is located in the upper part of the cage 3 and mounted in a sliding manner with respect to the latter. The lower part of the ejection part 17 comprises spikes 9 intended to pierce the upper face of the cartridge 1. An expansion space 10 is formed between the outer upper face of the cage 3 and the inner upper wall of the clamping piston 4. The variation in the expansion space 10 will be discussed later in the text.

A cartridge holder 2 formed mainly of a perforated horizontal plate is located in the lower part of the device. A set of spikes 6 that are fixed to a support 8 located under the cartridge holder 2 is mounted in a movable manner in relation to the cartridge holder 2 through the perforations in the latter.

The device functions as follows:

A cartridge 1 is initially introduced into the cage 3 (FIG. 1).

The assembly consisting of the upper unit 15, the clamping piston 4 and the cage 3 is then lowered and reaches an intermediate position (FIG. 2) which is characterized by contact between the lower end 13 of the clamping piston 4 and the spike support 8. It should be noted that at this stage the spikes 6 emerge slightly from the cartridge holder 2 but do not pierce the membrane 7 because the latter has a certain flexibility and, moreover, pressurized water has not yet been introduced into the cartridge 1.

The assembly consisting of the upper unit 15, the clamping piston 4 and the cage 3 continues to be lowered until the device is located in a starting position (FIG. 3). This latter movement has the effect of moving the spike support 8 and the spikes 6 downward, thereby causing the spikes 6 to retract into the cartridge holder 2. At the same time, the lower part 14 of the cage 3 butts against the flange 12 of the cartridge 1, thus ensuring optimal sealing between the cartridge 1 and the inside of the cage 3.

It is noted, furthermore, that in the starting position the ejection part 17 has been retracted into a housing located in the upper part of the cage 3, thereby having the effect of compressing an ejection spring 18 which is located between the ejection part 17 and the inner wall of the housing.

Pressurized water is then introduced into the device (FIG. 4). By filling in particular the expansion space 10, this has the effect of driving the clamping piston 4 upward. At the same time, the water enters the cartridge 1. This results in an increase in pressure inside the latter and the membrane 7 stretches.

The upward movement of the clamping piston 4 also drives the spike support 8 upward.

The spikes 6 emerging through the cartridge holder 2 pierce the membrane 7. The mixture of water with the contents of the cartridge 1 (for example coffee) thus flows out through the drink outlet orifice 11.

Once the extraction operation has been carried out, the assembly consisting of the upper unit 15, the clamping piston 4 and the cage 3 is raised. The ejection spring relaxes, thereby driving the ejection part 17 downward. This movement has the effect of making it easier to eject the capsule 1 from the device.

It goes without saying that the invention is not limited to the device illustrated in FIGS. 1 to 4. It also covers any mechanism as described in the claims.

Any appropriate form is conceivable for the ejection means.

Claims

1. A device for preparing a drink by extracting a serving, for example of ground coffee, contained in a cartridge (1) equipped with an extraction membrane (7), said device including a water inlet (5), a cartridge holder (2), a cartridge cage (3), clamping means and means for extracting said drink through the membrane (7), characterized in that the cartridge cage (3) comprises cartridge ejection means (17, 18).

2. The device as claimed in claim 1, in which the ejection means (17) include a spring (18).

3. The device as claimed in claim 1, in which the ejection means (17) comprise elements for piercing the upper face of the cartridge (1).

4. The device as claimed in claim 1, in which the ejection means (17) have no elements for piercing the cartridge (1).

5. The device as claimed in claim 1, including a clamping piston (4) mounted in a movable manner with respect to the cage.

6. The device as claimed in claim 1, in which the means for extracting said drink are spikes (6).

7. The device as claimed in claim 6, in which the spikes (6) are mounted in a movable manner in relation to the cartridge holder (2).

8. The device as claimed in claim 7, including a mechanism for securing the movable spikes (6) to the piston (4).