WO2009047672A2

WO2009047672A2 - Automatic filling of a fluid container member by a flow of fluid from another fluid container member

Info

Publication number: WO2009047672A2
Application number: PCT/IB2008/054011
Authority: WO
Inventors: Peng C Quah; Godwin D. Zwanenburg; Henk Smitt
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2007-10-09
Filing date: 2008-10-02
Publication date: 2009-04-16
Also published as: WO2009047672A3

Abstract

In a device (1) which is adapted to using a fluid such as water during its operation and which has an external container member (10), an internal container member (20) and a fluid conveying path (32) between the container members (10, 20), at least a portion of a fluid containing space (11) of the external container member (10) is at a higher level than a bottom (25) of a fluid containing space (21) of the internal container member (20) in a normal operational orientation of the device (1), and the fluid conveying path (32) is adapted to allow a flow of fluid from the external container member (10) to the internal container member (20) under the influence of hydrostatic pressure of the fluid. In this way, it is possible to realize automatic (initial) filling of the internal container member (20) on the basis of a flow of fluid from the external container member (10).

Description

Automatic filling of a fluid container member by a flow of fluid from another fluid container member

FIELD OF THE INVENTION

The present invention relates to a device which is adapted to using a fluid such as water during its operation, comprising two members having a space for containing the fluid, wherein one container member is an external member which is accessible from the outside of the device, and which is intended to receive fluid supplied from outside of the device to the device, and wherein another container member is an internal member which is connected to the external container member through a fluid conveying path, and which is intended to receive fluid from the external container member.

BACKGROUND OF THE INVENTION

Various types of a device as mentioned in the opening paragraph are known in practice. For example, the device may be a coffee maker, wherein the external container member is constituted by a water tank being adapted to receive water that is supplied by a user of the coffee maker, or by an external water supplying system. In the first case, it may be convenient if the water tank is removably arranged with respect to the rest of the device, so that the user is capable of easily filling the water tank by taking the water tank to a tap or the like. Furthermore, the internal container water may be part of a boiler for heating a quantity of water in order to obtain the hot water which is needed in a coffee making process.

The coffee maker as mentioned in the preceding paragraph may be a cup-to- cup coffee maker, which has a brew chamber for receiving and accommodating a quantity of coffee extract, wherein this quantity may be supplied in a suitable envelope or the like, and a pump for displacing water through the coffee maker. During operation of such a coffee maker, the following steps take place in order to obtain at least one cup of coffee. In the first place, heating means associated with the boiler are activated, so that water that is present inside the boiler is heated. When the water has reached a predetermined temperature, the pump is activated during a certain period of time, so that a certain quantity of water is forced to flow through the brew chamber. The coffee is obtained under the influence of an interaction between the quantity of water and the coffee extract that is present inside the brew chamber. Usually, as a space-saving measure, the boiler of the cup-to-cup coffee maker has dimensions which are as small as possible. Hence, every time the coffee maker is operated, it is necessary that the boiler is filled with water, so that it is possible to obtain a required quantity of hot water, and to avoid a situation of the boiler running dry and getting too hot. In principle, it is possible to start every coffee making process with filling the boiler. However, it is advantageous if filling of the boiler does not require a separate pumping action. This may be achieved by allowing for a flow of fresh water from the water tank to the boiler at the same time that hot water is transported from the boiler to the brew chamber. Although this way of doing has the advantage of minimizing pumping action and thereby minimizing noise generated during operation of the coffee maker, there is a disadvantage associated with it, namely that it does not provide for an initial filling of the boiler when the coffee maker is operated for the very first time, i.e. when the coffee maker is brand-new and has never been used before.

According to the state of the art, a solution to the above-mentioned problem is found by instructing the user of the coffee maker to take special action when the coffee maker is used for the first time, namely action that is aimed at filling the boiler with water. This solution is not ideal, as it negatively affects user convenience. Moreover, if a user does not understand the fact that special action is needed for initial operation of the coffee maker, the coffee maker will not start working, and the user may tend to think that it is defective. Furthermore, in case of a coffee maker with mechanical control, additional components like a pump switch and a thermostat for boiler dry heating protection are needed, which has a negative impact to the cost price of the coffee maker without any user benefit.

SUMMARY OF THE INVENTION It is an objective of the present invention to provide another solution than the above-mentioned known solution to the problem of ensuring filling of the boiler in the case of first time use of the coffee maker. In particular, as far as the first time use is concerned, it is an objective of the present invention to provide a solution according to which there is no need for other user action than the usual action that is required in operating the coffee maker. According to the present invention, a device having an external container member, an internal container member and a fluid conveying path between the container members is provided, wherein at least a portion of a fluid containing space of the external container member is at a higher level than a bottom of a fluid containing space of the internal container member in a normal operational orientation of the device, and wherein the fluid conveying path is adapted to allow a flow of fluid from the external container member to the internal container member under the influence of hydrostatic pressure of the fluid.

It is noted that within the scope of the present invention, the fluid may be water, as will be the case in many practical applications, but that in principle, the present invention is applicable in a context of any type of fluid.

The present invention makes use of the phenomenon of hydrostatic pressure of fluids, and the associated possibility to realize an equal level of fluid in two spaces which are in communication with each other, and which are open to the atmosphere. In this way, when fluid is taken from one of the spaces, it is possible to have an automatic flow of fluid from another of the spaces to this one of the spaces. According to an insight underlying the present invention, it is possible to apply this principle in a device such as a coffee maker for the purpose of automatically filling the internal container member to a certain extent by fluid flowing from the external container member. To this end, the configuration of the container members is such that at least a portion of a fluid containing space of the external container member is at a higher level than a bottom of a fluid containing space of the internal container member in a normal operational orientation of the device. Furthermore, the fluid conveying path between the two container members is adapted to allow a flow of fluid from the external container member to the internal container member under the influence of hydrostatic pressure of the fluid, so that it is really possible for a level of fluid in the external container member to determine a level of fluid in the internal container member.

When the present invention is applied in the cup-to-cup coffee maker as described in the foregoing, a required initial filling of the boiler may take place without a need for special action. In particular, all that a user needs to do when the coffee maker is used for the first time is to fill the water tank with at least a minimum quantity of the water, which is a normal action. Under the influence of the hydrostatic pressure of the water in the water tank, a quantity of water is automatically displaced to the boiler, until the water level in the boiler equals the water level in the water tank and/or the boiler is completely filled. The solution according to the present invention does not require the application of any additional electrical component or controlling measures. Instead, all that is basically required is a prescribed positioning of the container members with respect to each other, in particular a positioning in which at least a portion of the fluid containing space of the external container member is at a higher level than a bottom of the fluid containing space of the internal container member. It does not require much effort to adapt the design of the device having the two container members to this requirement. All in all, the present invention provides a cheap solution to the problem of initial filling of the internal container member.

In a preferred embodiment, the device according to the present invention comprises valve means which are arranged in the fluid conveying path between the external container member and the internal container member, which are adapted to allow a flow of fluid in a direction from the external container member to the internal container member under the influence of hydrostatic pressure of the fluid, and which are capable of blocking a flow of fluid in the opposite direction. In this way, it is achieved that an automatic filling process of the internal container member may always take place in an unhindered fashion when the level of the fluid in the internal container member is below the level of the fluid in the external container member. Furthermore, it is achieved that it is possible to have a level of the fluid in the internal container member which is higher than a level of the fluid in the external container member, without the risk of fluid flowing from the internal container member to the external container member under the influence of the hydrostatic pressure of the fluid, as the valve means are suitable to be used to prevent the fluid from flowing in this direction.

The above-mentioned possibility of applying valve means which are arranged in the fluid conveying path is relevant in case the device according to the present invention comprises components adapted to realize a flow of fluid from the external container member to the internal container member, other than the flow of fluid which automatically takes place under the influence of the hydrostatic pressure when the level of the fluid in the internal container member is lower than the level of the fluid in the external container member. For example, the device may comprise a second fluid conveying path extending between the external container member and the internal container member, and pumping means for actively displacing fluid in the direction from the external container member to the internal container member during their operation, which pumping means are arranged in the second fluid conveying path. In a device having pumping means, the option of automatically filling the internal container member may only be relevant in respect of first time use, wherein all other fluid displacements which are required during the life span of the device are realized by the pumping means.

Besides the possibility of having valve means and/or pumping means, there is also a possibility of having heating means, in particular heating means which are adapted to generate heat during their operation for heating fluid contained by the internal container member. This is relevant in case the device according to the present invention is a device for making a hot beverage such as coffee, for example. In such a case, in order to be able to create a situation in which the pressure conditions in the external container member and the internal container member are practically equal, so that a process of fluid displacement under the influence of hydrostatic pressure may take place in an unhindered fashion, it is advantageous if means for allowing a de-airing process of the internal container member are provided, wherein these means are valve means associated with the internal container member.

When the device according to the present invention comprises heating means as mentioned in the foregoing, there is a need for suitable control of the operation of the heating means. In particular, it is preferred if the heating means are shut off automatically after having been used for the purpose of heating a certain quantity of fluid, so that a safe operation of the device is ensured under all circumstances, wherein overheating can not occur. In order to have a preferred possibility of automatically terminating an operation of the heating means, the device according to the present invention may comprise an energizing circuit having a heating circuit for energizing the heating means, and a combination of a switching device and a detecting device, wherein the switching device is arranged in the heating circuit, and which is capable of either interrupting or closing the heating circuit, wherein the detecting device is capable of monitoring at least one physical property which is influenced by a displacement of fluid through the device, and wherein the detecting device is adapted to put the switching device to a position for interrupting the heating circuit when a value of the physical property appears to have reached a set point of the switching device. In particular, the detecting device may be capable of monitoring a temperature of the fluid.

When it is assumed that the device as described in the preceding paragraph comprises pumping means for actively displacing fluid in the direction from the external container member to the internal container member during their operation, wherein a second fluid conveying path between the container members is provided and the pumping means are arranged in this second fluid conveying path, the device may be operated in the following manner. When the device is used for the very first time, a user of the device fills the external container member with fluid. Under the influence of the hydrostatic pressure, the internal container member gets filled as well until an equilibrium of the pressure in both container members is reached. In case both container members are open to the atmosphere, the levels of the fluid in both container members are equal in the situation of equilibrium, assuming that the container members are arranged more or less next to each other. A first step in the operation of the device is activating the heating means for the purpose of heating the fluid that is present in the internal container member. When the fluid is at a desired temperature and the pumping means are activated, the situation of equilibrium between the container members is disturbed, and fluid is displaced from the external container member to the internal container member. At the same time, fluid is pumped out of the internal container member for a further destination and use. In the process, the heating means remain activated until the temperature at the detecting device is increased under the influence of the flow of the heated fluid to such an extent that this device puts the switching device to a position for interrupting the heating circuit. In this way, it is achieved that the heating means are automatically shut off shortly after initiation of a pumping action. Assuming that the pumping action is not started until the fluid is at a desired temperature, it is ensured that the heating means are not shut off prematurely. On the other hand, it is ensured that the heating means are shut off at a certain point during the pumping action, so that overheating is avoided.

It has already been pointed out that the device according to the present invention may be a device which is adapted to make a beverage by forcing a quantity of hot fluid to flow through a quantity of beverage extract. In such a case, the device comprises a brew chamber for receiving and accommodating the quantity of beverage extract, which is connected to the internal container member through a fluid conveying path. Furthermore, when the combination of a switching device and a detecting device as described in the foregoing is present, the detecting device is located between the internal container member and the brew chamber.

With respect to the switching device, it is noted that this device may be only manually settable to a position for closing the heating circuit. In a practical embodiment of the device according to the present invention having such a switching device, an actuation member which is movable to a position for setting the switching device to the position for closing the heating circuit may be provided.

In case a manually settable switching device is provided, it is advantageous if measures are taken for avoiding a situation in which a user may erroneously activate the heating means when there is an insufficient quantity of fluid in the device. In view of this, it is advantageous if the device according to the present invention comprises a mechanism for blocking the actuation member. For the purpose of activating the blocking mechanism when a level of the fluid in the external container member is below a predetermined minimum level, any suitable means may be provided, such as a floating member which is located in the external container member, and which is intended to float on the fluid. In order to have a high user convenience, in a device according to the present invention having both heating means and pumping means, it is not only advantageous if the heating means may be shut off automatically, but also if the pumping means may be activated automatically as soon as the fluid that is present inside the boiler has been heated to a predetermined temperature and is suitable to be displaced to a further destination. To this end, the device according to the present invention may comprise a second combination of a switching device and a detecting device, wherein the switching device is arranged in a pumping circuit for energizing the pumping means, which is part of the energizing circuit of the device, and wherein the switching device is capable of either interrupting or closing this pumping circuit, wherein the detecting device is capable of monitoring at least one physical property which is influenced by a heating action of the heating means, and wherein the detecting device is adapted to put the switching device to a position for closing the pumping circuit when a value of the physical property appears to have reached a set point of the switching device. For example, the pumping means are activated as soon as a temperature of fluid which is heated inside the internal container member appears to have reached a predetermined value. The combination of the switching device and the detecting device which is used for the purpose of activating the pumping means at a suitable moment may comprise a simple thermostat.

In the device according to the present invention, the internal container member may be part of a boiler which is suitable for generating steam, wherein pumping means for filling the boiler with water from a water tank of the device are not necessary. In a case in which pumping means are omitted, indeed, and in which filling of a boiler for steam generation only takes place automatically under the influence of a suitable positioning of an external container member and the boiler, wherein at least a portion of a fluid containing space of the external container member is at a higher level than a bottom of a fluid containing space of the boiler, the automatic filling process only takes place between steam generation processes. During the steam generation processes, pressure builds up in the boiler, so that a flow of fluid from the external container member to the boiler is not possible. It is clear that the application of valve means or the like is necessary in order to avoid a flow of fluid from the boiler to the external container member during the steam generating processes. In order not to hinder a proper flow of fluid, i.e. a flow of fluid from the external container member to the boiler, the valve means are advantageously adapted to allow such a flow of fluid to take place under the influence of hydrostatic pressure of fluid that is present in the external container member. The above-described and other aspects of the present invention will be apparent from and elucidated with reference to the following description of a number of embodiments of a device according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which: figure 1 diagrammatically shows a number of components of a cup-to-cup coffee maker according to the present invention; and figure 2 diagrammatically shows a number of components of a steam station according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS Figure 1 diagrammatically shows components 10, 20, 30, 40, 50 of a beverage maker 1 according to the present invention. In particular, this beverage maker 1 is adapted to function as a cup-to-cup coffee maker 1, i.e. this beverage maker 1 is suitable for making coffee on the basis of hot water and a coffee pad (not shown) filled with ground coffee beans. Nevertheless, the coffee maker 1 may just as well be suitable for preparing other hot drinks such as tea.

The coffee maker 1 comprises a water tank 10 having an interior space 11 for containing water, a boiler 20 having an interior space 21 for containing water and a heating element 22 for supplying heat to the water, an electric pump 30 for pumping water from the water tank 10 to the boiler 20, and a sealable brew chamber 40 for receiving and accommodating a coffee pad. Figure 1 illustrates the fact that the boiler 20 is located at a lower level than the water tank 10.

In the shown example, there are two water paths 31, 32 extending between the water tank 10 and the boiler 20, wherein the pump 30 is arranged in one of these water paths 31, 32. In another of these water paths 31, 32, a one-way valve 33 is arranged. In a direction from the water tank 10 to the boiler 20, the one-way valve 33 has a very low fluid restriction, so that a flow of water from the water tank 10 to the boiler 20 through the water path 32 in which the one-way valve 33 is arranged is possible under the influence of hydrostatic pressure of water. In the other direction, it is possible for the one-way valve 33 to be closed in order to prevent a flow of water from the boiler 20 to the water tank 10. In a practical embodiment, the one-way valve 33 maybe of a ball- spring-type, wherein a spring force is so small that a situation in which the ball is pushed away under the influence of the hydrostatic pressure of water may be realized.

At a water outlet 23 of the boiler 20, a three-way valve 50 is arranged, which comprises an inlet 51, a first outlet 52 and a second outlet 53. The first outlet 52 serves for de-airing of the boiler 20, and also for returning water to the water tank 10, whereas the second outlet 53 serves for conducting water in the direction of the brew chamber 40.

When a user desires to make a quantity of coffee by using the coffee maker 1, the user inserts a coffee pad into the brew chamber 40, and activates the coffee maker 1. In a situation in which the coffee maker 1 is used for the first time, or a situation in which the water tank 10 appears to contain a smaller quantity of water than a prescribed minimum, the user takes care that the water tank 10 is filled first. In case the boiler 20 is empty, which is surely the case when the coffee maker 1 has never been used before, the boiler 20 is automatically filled with water flowing from the water tank 10 under the influence of the hydrostatic pressure of the water, through the water path 32 in which the one-way valve 33 is arranged. The automatic filling process continues until the boiler 20 is completely filled, due to the fact that there is a natural action aimed at having the same water levels in the water tank 10 and the boiler 20. The user may fill the water tank 10 once more in case the level of water in the water tank 10 ends up to be lower than a predetermined minimum level 12 after an automatic filling process has taken place. The predetermined level 12 is represented by a dashed line in figure 1.

The fact that an initial filling of the boiler 20 takes place automatically when the water tank 10 is filled, simply under the influence of hydrostatic pressure of the water and without the need for a pumping action, is very advantageous. In the first place, the user of the coffee maker 1 does not need to follow a special procedure when the coffee maker 1 is used for the first time, but may simply perform the normal task of filling the water tank 10. As soon as the level of the water in the water tank 10 has stabilized and is higher than the minimum level 12, the coffee maker 1 may further be operated in a normal manner. In the second place, all that is needed for enabling the automatic filling is a water path 32 extending between the water tank 10 and the boiler 20, parallel to the water path 31 in which the pump 30 is arranged. For the purpose of preventing leakage from the boiler 20 to the water tank 10 under the influence of pressure prevailing during a pumping action, a one-way valve 33 is arranged in the water path 32. As a first step in a process of making coffee, the water inside the boiler 20 is heated by means of the heating element 22. When the temperature of the water has reached a predetermined level, the pump 30 is activated automatically, so that cold water is transported from the water tank 10 to the boiler 20, and hot water is transported from the boiler 20 to the brew chamber 40, through a water path 41. Due to the presence of the one-way valve 33, a flow of water from the boiler 20 back to the water tank 10 through the water path 32 in which the valve 33 is arranged is prevented. During the pumping action, as a second step in a process of making coffee, inside the brew chamber 40, an interaction between the hot water and the quantity of ground coffee beans that is contained by the coffee pad takes place. As a result, hot coffee is obtained, which flows from the brew chamber 40 to an outlet 42 of the coffee maker 1. The quantity of the water that is used in the process of making coffee is adapted to the quantity of ground coffee beans that is used.

An electronics circuit of the coffee maker 1 comprises several components, which will be identified in the following description of the way in which the above-described operation of the coffee maker 1 is controlled. In the electronics circuit, two specific circuits may be distinguished, namely a pumping circuit which serves for supplying electric power to the pump 30 and a heating circuit which serves for supplying electric power to the heating element 22 of the boiler 20.

The electronics circuit comprises a thermostat 61, which is only manually settable to a closed condition, and which comprises a sensing member 61a for sensing a temperature of water at a location between the boiler 20 and the brew chamber 40. The manually operable thermostat 61 is adapted to open or close the heating circuit which is part of the electronics circuit.

Besides the thermostat 61 as described in the foregoing, the electronics circuit of the coffee maker 1 comprises a normally opened thermostat 62, i.e. a thermostat 62 that switches to a closed position when a temperature that is detected by a sensing member 62a of the thermostat 62 exceeds a set point of the thermostat 62, and that maintains an opened position in all other circumstances. The normally opened thermostat 62 is arranged in the pumping circuit, and the sensing member 62a of the thermostat 62 is arranged at a position in the boiler 20.

When the thermostat 61 arranged in the heating circuit is closed by the user, the water inside the boiler 20 is heated. In the process, any water that is overflowing from the boiler 20 is diverted back to the water tank 10 through the first outlet 52 of the three-way valve 50. The heating process is continued until a temperature of the water reaches a set point of the normally opened thermostat 62. At that moment, the thermostat 62 switches to a closed position, as a result of which the pumping circuit is closed and the pump 30 is activated. Under the influence of the pump 30, water is displaced through the coffee maker 1, wherein cold water is transported from the water tank 10 to the boiler 20, and wherein hot water is transported from the boiler 20 to the brew chamber 40, through the water path 41 extending between the boiler 20 and the brew chamber 40. On the way to the brew chamber 40, the hot water passes the sensing member 61a of the thermostat 61 arranged in the heating circuit. The set point of the thermostat 61 is chosen such that the thermostat 61 switches to an opened position as soon as the hot water reaches the sensing member 61a. At that moment, the heating circuit is interrupted, and the heating action is terminated. Hence, in the coffee maker 1, the heating action is terminated a certain period of time after the pumping action is started, wherein the length of this period of time depends on the location of the sensing member 61a of the thermostat 61 with respect to the second outlet 53 of the three-way valve 50.

During a pumping action, hot water exits the boiler 20 and cold water enters the boiler 20, wherein a separation layer is present between the two different quantities of water. The normally opened thermostat 62 switches back to an opened position as soon as a front of the cold water reaches the sensing member 62a of the thermostat 62, and the detected temperature suddenly falls below a set point of the thermostat 62. At that moment, the operation of the pump 30 is terminated. It follows from the preceding paragraph that the time during which the pump

30 is operated for the purpose of pumping cold water into the boiler 20 and hot water out of the boiler 20 is determined by the position of the sensing member 62a of the normally opened thermostat 62 with respect to a water inlet 24 of the boiler 20. Consequently, the quantity of the water that is displaced during a pumping action is determined by the position of the sensing member 62a of the normally opened thermostat 62 with respect to the water inlet 24 of the boiler 20. Therefore, the quantity of coffee that is made during operation of the coffee maker 1 is accurately controlled on the basis of the application of the normally opened thermostat 62.

It follows from the above description of the coffee maker 1 that all that a user needs to do for the purpose of obtaining coffee is taking care that the water tank 10 contains at least a minimum quantity of water, and putting the thermostat 61 to the closed position. From that moment on, the process of making coffee and supplying the coffee to a cup (not shown) or the like is performed automatically. In the process, the normally opened thermostat 62 switches to a closed position when the temperature of the water inside the boiler 20 has reached a predetermined level, the manually settable thermostat 61 switches back to the opened position when the temperature of water that has been heated inside the boiler 20 and that passes the sensing member 61a of the thermostat 61 reaches a predetermined level, and the normally opened thermostat 62 switches back to the opened position when the temperature of the water inside the boiler 20 falls below a predetermined level. The latter takes place when a separation layer between cold water and hot water, which moves through the boiler 20 during a pumping action, reaches the sensing member 62a of the normally opened thermostat 62.

For the purpose of allowing a user of the coffee maker 1 to put the manually settable thermostat 61 to the closed condition, the coffee maker 1 comprises an actuation member 71 such as a push button by means of which the manually settable thermostat 61 may be put to the closed condition, and a mechanism 72 for blocking the actuation member 71. For the purpose of activating the blocking mechanism 72 when a level of the water in the water tank 10 is at the predetermined minimum level 12 or below this minimum level 12, a float 73 is provided, which is arranged in the water tank 10, and which is intended to float on the water. When the level of the water inside the water tank 10 is at the minimum level 12 or below the minimum level 12, the blocking mechanism 72 is activated under the influence of the weight of the float 73, and a user of the coffee maker 1 can not put the actuation member 71 to the position for putting the thermostat 61 to the closed position until water is added to the water tank 10, such that the level of the water rises above the predetermined minimum level 12, and the float 73 is lifted by the water again.

By using the blocking mechanism 72 and the float 73, a prevention of dry pumping of the coffee maker 1 is realized in a mechanical manner, wherein there is no need for applying an additional electrical component. As long as the level of the water in the water tank 10 is below the minimum level 12, both the heating element 22 and the pump 30 can not be activated. Within the scope of the present invention, other manners of realizing such a dry pump protection exist, but the above-described dry pump protection is advantageous, as it does not involve high costs and is very reliable.

It is noted that within the scope of the present invention, the way in which the coffee making process is controlled may deviate from the above-described way, and there may be other types of controlling members than the manually operable thermostat 61 and the normally opened thermostat 62 as mentioned. In any case, the present invention involves the positioning of at least a portion of a space of the water tank 10 at a higher level than a bottom 25 of the interior space 21 of the boiler 20 and the application of a water path 32 between the water tank 10 and the boiler 20, wherein it is possible for water to flow from the water tank 10 to the boiler 20 under the influence of hydrostatic pressure. In case the device 1 according to the present invention comprising a pump 30 or other means for exerting pressure on the water in the device 1, it is advantageous if means 33 are arranged in the water path 32 for preventing leakage from the boiler 20 to the water tank 10.

Figure 2 diagrammatically shows components 10, 20, 50 of a steam station 2 according to the present invention. This steam station 2 is adapted to delivering steam to any apparatus which needs steam for its operation, such as a steam iron.

Like the coffee maker 1, the steam station 2 comprises a water tank 10 and a boiler 20, wherein at least a portion of a space 11 of the water tank 10 is located at a higher level than a bottom 25 of a space 21 of the boiler 20. Furthermore, the water tank 10 and the boiler 20 are connected through a water path 32, in which a one-way valve 33 is arranged, which allows a flow of water from the water tank 10 to the boiler 20 under the influence of hydrostatic pressure, and which is capable of blocking a flow of water in the opposite direction. In this way, a water level in the water tank 10 determines a water level in the boiler 20.

For the purpose of providing the heat that is necessary for turning water to steam, the steam station 2 comprises a heating element 22 that is attached to the bottom 25 of the boiler 20, at the outside of the boiler 20. At a steam outlet 23 of the boiler 20, an electronic valve 50 is arranged. By means of this valve 50, a supply of steam from the steam station 2 to a steaming appliance (not shown) connected to the steam station 2 is actively controlled. In the shown example, besides the steam outlet 23 and the electronic valve 50, the steam station 2 has a de-airing outlet 26 and a de-airing valve 54 that is arranged at this outlet 26. In the case of initial use of the steam station 2, when the steam station 2 has never been used before, a user fills the water tank 10, as a result of which the boiler 20 is filled as well, until a level of the water in the boiler 20 equals a level of the water in the water tank 10. In the process, de-airing of the boiler 20 takes place through the de-airing outlet 26 and the de-airing valve 54. When the heating element 22 is activated, steam is generated. As soon as steam leakage through the de-airing valve 54 is at a lower rate than the steam creation, steam pressure builds up inside the boiler 20. Under the influence of the pressure, the one-way valve 33 will block the water path 32. The one-way valve 33 will remain closed until the boiler 20 is de-pressurized again. At that point, the boiler 20 may be filled with a quantity of water again, wherein the water flows automatically from the water tank 10 to the boiler 20, after which a new steam generation process may take place.

In an alternative embodiment of the steam station 2, the de-airing valve 54 may be omitted, and de-airing may take place through the electronic valve 50. To this end, the electronic valve 50 will have to remain open during power off stages.

It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the present invention as defined in the attached claims. While the present invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments.

Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word "comprising" does not exclude other steps or elements, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope of the present invention. Summarizing, in a device 1 , 2 which is adapted to using a fluid such as water during its operation and which has an external container member 10, an internal container member 20 and a fluid conveying path 32 between the container members 10, 20, at least a portion of a fluid containing space 11 of the external container member 10 is at a higher level than a bottom 25 of a fluid containing space 21 of the internal container member 20 in a normal operational orientation of the device 1, 2, and the fluid conveying path 32 is adapted to allow a flow of fluid from the external container member 10 to the internal container member 20 under the influence of hydrostatic pressure of the fluid. In this way, it is possible to realize automatic (initial) filling of the internal container member 20 on the basis of a flow of fluid from the external container member 10.

Claims

CLAIMS:

1. Device (1, 2) which is adapted to using a fluid such as water during its operation, comprising two members (10, 20) having a space (11, 21) for containing the fluid, wherein one container member (10) is an external member (10) which is accessible from the outside of the device (1, 2), and which is intended to receive fluid supplied from outside of the device (1, 2) to the device (1, 2), and wherein another container member (20) is an internal member (20) which is connected to the external container member (10) through a fluid conveying path (32), and which is intended to receive fluid from the external container member (10), wherein at least a portion of a fluid containing space (11) of the external container member (10) is at a higher level than a bottom (25) of a fluid containing space (21) of the internal container member (20) in a normal operational orientation of the device (1, 2), and wherein the fluid conveying path (32) is adapted to allow a flow of fluid from the external container member (10) to the internal container member (20) under the influence of hydrostatic pressure of the fluid.

2. Device (1, 2) according to claim 1, comprising valve means (33) which are arranged in the fluid conveying path (32) between the external container member (10) and the internal container member (20), which are adapted to allow a flow of fluid in a direction from the external container member (10) to the internal container member (20) under the influence of hydrostatic pressure of the fluid, and which are capable of blocking a flow of fluid in the opposite direction.

3. Device (1) according to claim 1, comprising a second fluid conveying path

(31) extending between the external container member (10) and the internal container member (20), and pumping means (30) for actively displacing fluid in the direction from the external container member (10) to the internal container member (20) during their operation, which pumping means (30) are arranged in the second fluid conveying path (31).

4. Device (1, 2) according to claim 1, comprising heating means (22) adapted to generate heat during their operation for heating fluid contained by the internal container member (20).

5. Device (2) according to claim 4, comprising means (50, 54) for allowing a de- airing process of the internal container member (20), being valve means (50, 54) associated with the internal container member (20).

6. Device (1) according to claim 4, comprising an energizing circuit having a heating circuit for energizing the heating means (22), and a combination of a switching device (61) and a detecting device (61a), wherein the switching device (61) is arranged in the heating circuit, and which is capable of either interrupting or closing the heating circuit, wherein the detecting device (61a) is capable of monitoring at least one physical property which is influenced by a displacement of fluid through the device (1), and wherein the detecting device (61a) is adapted to put the switching device (61) to a position for interrupting the heating circuit when a value of the physical property appears to have reached a set point of the switching device (61).

7. Device (1) according to claim 6, wherein the detecting device (61a) is capable of monitoring a temperature of the fluid.

8. Device (1) according to claim 6, being a device (1) adapted to make a beverage by forcing a quantity of hot fluid to flow through a quantity of beverage extract, comprising a brew chamber (40) for receiving and accommodating the quantity of beverage extract, which is connected to the internal container member (20) through a fluid conveying path (41), wherein the detecting device (61a) is located between the internal container member (20) and the brew chamber (40).

9. Device (1) according to claim 6, wherein the switching device (61) is only manually settable to a position for closing the heating circuit.

10. Device (1) according to claim 6, comprising an actuation member (71) which is movable to a position for setting the switching device (61) to the position for closing the heating circuit, a mechanism (72) for blocking the actuation member (71), and a floating member (73) which is located in the external container member (10), which is intended to float on the fluid, and which is adapted to activate the blocking mechanism (72) when a level of the fluid in the external container member (10) is below a predetermined minimum level (12).

11. Device (1) according to claim 6, comprising pumping means (30) for forcing fluid to flow through the device (1), a pumping circuit for energizing the pumping means (30), which is part of the energizing circuit of the device (1), and a second combination of a switching device (62) and a detecting device (62a), wherein the switching device (62) is arranged in the pumping circuit and capable of either interrupting or closing the pumping circuit, wherein the detecting device (62a) is capable of monitoring at least one physical property which is influenced by a heating action of the heating means (22), and wherein the detecting device (62a) is adapted to put the switching device (62) to a position for closing the pumping circuit when a value of the physical property appears to have reached a set point of the switching device (62).