The invention relates to a beverage extracting device at least comprising a vessel for receiving and mixing a powder material and hot liquid, a filter beneath the vessel, an elec trical gas pump that connects through a duct to the vessel for supplying pressurized gas into the vessel, and an outlet for extracted liquid at an outlet side of the filter which is op posite to the vessel, wherein the outlet connects to an outlet duct for the extracted liquid.

Such a beverage extracting device is described in ap plicant's earlier not pre-published Dutch patent application 2022775.

The instant invention has as an object to avoid sput tering or splashing at the outlet opening of the outlet duct when nearly all liquid has been expelled from the vessel.

According to the invention a beverage extracting de vice is proposed with the features of one or more of the ap pended claims.

In a first aspect of the invention a current sensing circuit connects to a power line of the electrical gas pump for monitoring an electrical current through the electrical gas pump, and that the current sensing circuit is directly connected to a controller for detecting whether the electrical current is above a preestablished threshold, and that the con troller is arranged to reduce power supplied to the electrical gas pump when the controller establishes that the electrical current through the electrical gas pump is above the preestab lished threshold. As a ready alternative it is also possible to separate the detection functionality from the controller.

In that case the current sensing circuit is first connected to a detector for detecting whether the electrical current is above a preestablished threshold, and the detector is then connected to a controller for the electrical gas pump, which controller is arranged to reduce power supplied to the elec trical gas pump when the detector establishes that the elec trical current through the electrical gas pump is above the preestablished threshold.

The inventor has found that the rise of the electri cal current through the electrical gas pump is a reliable measure for the situation that nearly all liquid has been ex pelled from the vessel, which is the moment that sputtering or splashing occurs at the outlet opening of the outlet duct. Therefore it is possible to avoid sputtering or splashing when the electrical current rises above a certain threshold and then smoothly reducing the power supplied to the electrical gas pump.

Preferably the detector/controller is arranged to es tablish an average current level through the electrical gas pump that corresponds with an operation of the device wherein the vessel is still filled with liquid, and liquid is still regularly pouring out of the outlet duct, and that the preestablished threshold is determined depending on the level of said average current level. In this manner a relative meas ure rather than an absolute measure is introduced into the beverage extracting device of the invention, which automati cally takes a possible level of contamination of the filter into account, which may be responsible for the power require ments of the electrical gas pump and which would otherwise de teriorate the adequacy of the response of the controller to the electrical power requirements of the electrical gas pump.

Suitably the preestablished threshold is set at a value of at least 10% above the average current level through the electrical gas pump.

It may further be desirable that the controller com prises a timer to shut off the electrical gas pump after a preestablished time period of operation. This avoids that the electrical gas pump keeps on running when a threshold value for shutting off the electrical gas pump cannot be estab lished.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of an apparatus operating according to a prior art method and ac cording to the method of the invention that is not limiting as to the appended claims.

In the drawing:

- figure 1 shows a frontal view of an embodiment of the beverage extracting device of the invention;

- figure 2 shows relevant parts of the embodiment of the beverage extracting device of figure 1; - figure 3 shows a schematic drawing of the circuitry and elements of the beverage extracting device controlling the electrical gas pump of the device; and

- figure 4 shows an example of an electrical current diagram monitored during operation of the electrical gas pump of the beverage extracting device of the invention.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

In figure 1 the beverage extracting device 1 of the invention is shown to comprise a canister 2 for beans, for in stance coffee beans. Below the canister 2 is a grinder 3 that provides grinded beans to a chute 4, as also shown in figure 2. The chute 4 also receives hot water from a duct 5 that re ceives the hot water from a heater 6 to which the duct 5 is connected. The hot water ensures that the grinded beans from the grinder 3 are transported and received in a vessel 7 to which the chute 4 connects. To accommodate one and another the vessel 7 has a closable opening at a location 13 at the upper side of the vessel 7 for receiving both the powder material and the hot liquid.

With reference also to figure 2, the closable opening is provided with a (not shown) valve at the height of arrow 13 for opening and closing of said opening, wherein the valve is arranged to provide an airtight closure of the opening of the vessel 7 such that the vessel 7 is enabled to be pressurized by the operation of a gas pump 9. The gas pump 9 connects through a duct 9 as shown in figure 2 to the vessel 7 for supplying pressurized gas into the vessel 7.

The beverage extracting device 1 also has an outlet 10, which outlet 10 is intended for release of extracted liq uid at an outlet side of the filter 8 which is opposite to the vessel 7. Said outlet 10 connects to an outlet duct 11 as shown in figures 1 and 2 for the extracted liquid, wherein the outlet duct 11 has an outlet opening 12 distant from the out let 10.

Making reference now to figures 3 and 4, the novel features that are proposed for suppressing splashing or sput tering at the outlet opening 12 of the outlet duct 11 will be discussed.

Figure 3 shows that a current sensing circuit, for instance an electrical shunt E(23), connects to a power line of the electrical gas pump 9 for monitoring an electrical cur rent through the electrical gas pump 9. The output of the cur rent sensing circuit E(23) is preferably digitized by a con verter ADC(24) which in turn is connected to a controller G(25) for detecting, amongst other functionalities as to be discussed hereafter, whether the electrical current is above a preestablished threshold. It is also possible to apply a sepa rate detector which is then to be connected to the controller. In the shown embodiment the detector is however part of the controller G(25) which has as further function to control the electrical gas pump 9. The controller G(25) is arranged to re duce power supplied to the electrical gas pump 9 when it is established that the electrical current through the electrical gas pump 9 is above the preestablished threshold. The way how this works is explained hereafter with reference to figure 4. Figure 4 depicts a typical development of the electrical cur rent through the electrical gas pump 9 during operation of the beverage extracting device 1 of the invention, representing on the x-axis a time-base representing samples taken from the measured electrical current, and on the y-axis the value of the electrical current supplied to the electrical gas pump 9 in volts.

With reference to this figure 4, it is shown that the detector G(25) is arranged to establish an average current level B through the electrical gas pump 9 that corresponds with an operation of the device 1 wherein the vessel 7 is still filled with liquid, and liquid is still regularly pour ing out of outlet opening 12 of the outlet duct 11. It is fur ther indicated in the figure that when the electric current through the electrical gas pump 9 rises according to line A above a certain threshold level, the power supplied to the electrical gas pump 9 is reduced according to trajectory C. It follows from figure 4 that the preestablished threshold value where this happens is set at a value of approximately at least 10% above the average current level B through the electrical gas pump 9. By reducing the power supplied to the electrical gas pump 9 in accordance with the trajectory C, sputtering and splashing at the outlet opening 12 of the outlet duct 11 is effectively avoided. Desirably further the controller G(25) comprises a timer to shut off the electrical gas pump after a preestab lished time period of operation.

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the beverage extracting device of the invention, the invention is not restricted to this particular embodiment which can be var ied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the appended claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exem plary embodiment.