Domestic dishwasher and dosing system therefor

Abstract

A dosing system for installation in a domestic dishwasher is disclosed. The dosing system in some embodiments permits the automated delivery of a defined dose of a detergent in powder form into a dishwashing chamber of the dishwasher. It comprises for this purpose a supply chamber for receiving a supply of the detergent and an extracting mechanism for extracting a dose of the detergent from the supply and for delivering the extracted dose into a fall channel. In order to assist with expelling an extracted dose of the detergent powder from the fall channel or/and to accelerate drying of the fall channel, the dosing system in some embodiments includes a fan for generating a blowing air stream which flows through at least parts of the fall channel.

Claims

1. A dosing system for a detergent in powder form, the dosing system comprising: a supply chamber for receiving a supply of the detergent; an extracting mechanism for extracting a dose of the detergent from the supply and for delivering the extracted dose into a fall channel; and a fan for generating a blowing air stream, wherein a pressure side of the fan is in permanently open communication with at least parts of the fall channel.

2. A dosing system for a detergent in powder form, the dosing system comprising: a supply chamber for receiving a supply of the detergent; an extracting mechanism for extracting a dose of the detergent from the supply and for delivering the extracted dose into a fall channel; and a fan for generating a blowing air stream, wherein the extracting mechanism has a movably arranged extracting member having at least one dosing pocket dimensioned to receive a dose of the detergent, wherein, by driving the extracting member, the dosing pocket is movable from a receiving position, in which the dosing pocket is open towards the supply chamber, into a delivery position, in which the dosing pocket is open towards the fall channel, wherein a blowing air inlet which is able to be charged with blowing air by the fan opens into the fall channel downstream—based on the direction of fall of the detergent in the fall channel—of the extracting member.

3. The dosing system as claimed in claim 2, wherein the blowing air inlet opens into the fall channel upstream of a blocking element which is arranged so as to be movable between a blocking position, which blocks the fall channel so that detergent cannot fall through, and a freeing position, which frees the fall channel so that detergent can fall through.

4. The dosing system as claimed in claim 2, wherein the extracting member is arranged so as to be rotatable about an axis of rotation and has a plurality of dosing pockets which are distributed in the circumferential direction and are each dimensioned to receive a dose of the detergent, wherein, by rotation of the extracting member, each dosing pocket is movable from a receiving position, in which the dosing pocket in question is open towards the supply chamber, into a delivery position, in which the dosing pocket in question is open towards the fall channel, wherein, as a dosing pocket moves from the receiving position into the delivery position, multiple other dosing pockets of the extracting member pass the receiving position.

5. A dosing system for a solid detergent, the dosing system comprising: a hollow-chamber arrangement which forms a supply chamber for receiving a supply of the detergent and a fall channel for discharging a portion of the detergent extracted from the supply to an outlet opening; and a fan for supplying blowing air to at least parts of the hollow-chamber arrangement, wherein a configuration or/and operational control of the dosing system ensures that blowing air is introduced into parts of the hollow-chamber arrangement that are located on the far side of the supply chamber.

6. The dosing system as claimed in claim 5, wherein the parts of the hollow-chamber arrangement that are located on the far side of the supply chamber comprise an extracting chamber arranged between the supply chamber and the fall channel, in which extracting chamber there is received a movably arranged extractor for extracting a portion of the detergent from the supply and for delivering the extracted portion into the fall channel.

7. The dosing system as claimed in claim 5, wherein the parts of the hollow-chamber arrangement that are located on the far side of the supply chamber include a chamber having a maintenance opening, which chamber is covered by a cover element which is removable or able to be moved away.

8. A dosing system for a solid detergent, the dosing system comprising: a hollow-chamber arrangement which forms a supply chamber for receiving a supply of the detergent; a fall channel for discharging a portion of the detergent extracted from the supply to an outlet opening; and a blocking member which is arranged so as to be movable between a blocking position and a freeing position and which, in the freeing position, frees the fall channel so that an extracted portion of the detergent can fall through it to the outlet opening and, in the blocking position, blocks the fall channel so that an extracted portion of the detergent cannot fall through it, wherein the dosing system comprises a fan for supplying at least parts of the hollow-chamber arrangement with blowing air, wherein the fan is controlled in such a manner that it is active at least during a phase in which the blocking member is in the freeing position.

9. The dosing system as claimed in claim 8, wherein the fan is controlled in such a manner that it is additionally active during a phase in which the blocking member is in the blocking position.

10. A domestic dishwasher comprising: a machine body delimiting a dishwashing chamber; a door mounted on the machine body about a pivot axis close to a floor; and a dosing system arranged on the door, wherein the dosing system comprising: a supply chamber for receiving a supply of a solid detergent; and a fall channel for discharging, under gravity, a portion of the detergent extracted from the supply to an outlet opening; and a fan for introducing a blowing air stream into at least one of the fall channel and the supply chamber, wherein the fan is controlled in such a manner that it is active in at least one of the following phases: a phase in which a portion of the detergent removed from the supply is delivered into the fall channel by the dosing system, for example for expelling the detergent from the fall channel with the assistance of blowing air; a phase following completion of a dishwashing operation during execution of a cleaning program of the dishwasher, in particular during or after a drying phase of the cleaning program.

11. The domestic dishwasher as claimed in claim 10, wherein the dosing system comprises a blocking element which is arranged so as to be movable between a blocking position, which blocks the fall channel so that detergent cannot fall through, and a freeing position, which frees the fall channel so that detergent can fall through, wherein the fan is controlled in such a manner that it is activated in dependence on a transfer of the blocking element into its freeing position while an operating program of the dishwasher is running.

12. The domestic dishwasher as claimed in claim 10, wherein the dosing system comprises a blocking element which is arranged so as to be movable between a blocking position, which blocks the fall channel so that detergent cannot fall through, and a freeing position, which frees the fall channel so that detergent can fall through, wherein the fan is controlled in such a manner that it is always active when the blocking element is in the freeing position while an operating program of the dishwasher is running.

13. A domestic dishwasher, comprising: a machine body delimiting a dishwashing chamber; a door mounted on the machine body about a pivot axis close to a floor; a dosing system for a solid detergent arranged on the door, the dosing system comprising: a supply chamber for receiving a supply of the detergent and an extracting mechanism for extracting a portion of the detergent from the supply and for delivering the extracted portion into a fall channel; and a control unit for controlling the dosing system, wherein, wherein the control unit is adapted to effect the delivery of a changeable number of portions of the detergent during execution of a cleaning program of the dishwasher.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows, schematically, a domestic dishwasher having a powder dosing system according to an exemplary embodiment.

[0024] FIG. 2 shows, in a sectional view, an exemplary embodiment of the powder dosing system of FIG. 1.

[0025] FIG. 3 is a partially cutaway perspective view of a detail of the powder dosing system of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Reference will first be made to FIG. 1. The dishwasher illustrated therein, which is intended for domestic use, is designated generally 10. It comprises a machine body (dishwashing container) 12 in which a dishwashing chamber 14 is formed. There is mounted on the machine body 12 a door 16 which is pivotable about a horizontal pivot axis (not shown) close to the floor. One or more crockery baskets and optionally a cutlery drawer for receiving the items of crockery and cutlery that are to be cleaned can be inserted in a manner known per se into the dishwashing chamber 14. A control unit 18 is responsible for controlling operation of the dishwasher 10. In the example shown, the control unit 18 is fitted into the door 16. It will be appreciated that in other embodiments the control unit 18 can be arranged on the machine body 12.

[0027] The control unit 18 is responsible not only for controlling the dishwashing operation and optionally a drying operation of the dishwasher 10 but also for controlling a powder dosing system 20 by means of which a suitably dimensioned powder dose can be removed from a supply of a detergent in powder form and delivered into the dishwashing chamber 14. The powder dosing system 20 is arranged on the door 16, wherein in the example shown it is not fitted in a concealed manner into the door but is placed on the outside of an inner lining panel 22 of the door 16 and fastened thereto. The powder dosing system 20 has an outlet opening (not shown in FIG. 1), from which the dosed amount of powder falls from the powder dosing system 20. In dishwashing operation of the dishwasher 10, the detergent powder that falls out or that has fallen out is picked up and carried along by the dishwashing water. It will be appreciated that in other embodiments the powder dosing system 20 can be fitted into the door 16 in such a manner that it is concealed behind the inner lining panel 22, wherein the extracted powder dose then falls out of the door 16 into the dishwashing chamber 14 through an outlet opening formed in the inner lining panel 22, for example as part of a hood.

[0028] Reference will now additionally be made to FIGS. 2 and 3. The powder dosing system 20 according to the exemplary embodiment of FIGS. 2 and 3 can be preassembled as a modular unit and mounted on the door 16 of the dishwasher 10 as a preassembled modular unit. In the exemplary embodiment of FIGS. 2 and 3, the powder dosing system 20 comprises a system housing 24 in which there is formed a connected hollow-chamber arrangement 25, which in the example shown forms a supply chamber 26, which tapers downwards in the manner of a funnel, and a fall channel 28 arranged beneath the supply chamber 26. The supply chamber 26 serves to store a larger amount of the detergent powder. At the lower end of the funnel, the supply chamber 26 opens into a dosing chamber 30 (extracting chamber), in which a powder dosing wheel 32 (extractor) is received so as to be rotatable about an axis of rotation 34. The powder dosing wheel 32 forms a plurality of dosing pockets 36 which are arranged distributed in the circumferential direction and are open radially towards the outside and each of which is dimensioned to receive a defined dose of the detergent powder. The powder dosing wheel 32 is able to be driven about the axis of rotation 34 by means of an electrically controllable, in particular electromotive dosing drive unit, not shown in the drawings. The powder dosing wheel 32 and the dosing drive unit together form an extracting mechanism within the meaning of the present disclosure.

[0029] The fall channel 28 opens from the dosing chamber 30 at an angular distance from the region in which the supply chamber 26 opens into the dosing chamber 30. By rotating the powder dosing wheel 32, a powder dose which has slid by gravity out of the supply chamber 26 into one of the dosing pockets 36 can be conveyed into the region of the start of the fall channel 28. The powder dose there falls out of the dosing pocket 36 in question (provided that the door 16 is closed) and then falls down in the fall channel 28 in the direction towards an outlet opening 38 formed by the system housing 24, at which outlet opening the powder dose leaves the powder dosing system 20.

[0030] The powder dosing system 20 additionally contains a blocking slide 40, which is adjustable by means of an electrically controllable, in particular electromotive slide drive unit 42 between a blocking position and a freeing position. In FIGS. 2 and 3, the blocking slide 40 is in its blocking position; in this position, the blocking slide 40 blocks the passage through the fall channel 28. In the freeing position, on the other hand, the blocking slide 40 frees the fall channel 28, so that detergent powder is able to fall in the fall channel 28 to the outlet opening 38. In the example shown, the blocking slide 40 is in the form of a linear slide; it will be appreciated that this is only an exemplary form and that, for example, a configuration of the blocking slide as a rotary slide is conceivable as an alternative. In the example shown, the slide drive unit 42 comprises a drive pinion 44, for example a motor-driven drive pinion, which is in meshing engagement with a tooth system 46 of the blocking slide 40 (FIG. 2).

[0031] Most of the time during dishwashing operation of the dishwasher 10, the blocking slide 40 is in its blocking position in order to prevent water and hot steam from entering the dosing chamber 30 and from there, in some circumstances, entering the supply chamber 26. If detergent powder is to be delivered from the dosing system 20 into the dishwashing chamber 14, the blocking slide 40 is moved into its freeing position and thereby frees the fall channel 28 for the passage of detergent powder. After the detergent powder has been delivered, the blocking slide 40 is moved back into its blocking position again.

[0032] However, the blocking slide 40 is often not able to completely prevent the ingress of splash water or/and steam into the fall channel 28. It must be expected that moisture will be deposited on the channel walls of the fall channel 28 upstream of the blocking slide 40 and in some circumstances also on the powder dosing wheel 32 and on the channel walls of the dosing chamber 30. Such residual moisture can be troublesome specifically when a detergent in powder form is used, because it can lead to clumping of the detergent powder. In the exemplary embodiment of FIGS. 2 and 3, the powder dosing system 20 therefore comprises a fan 48 (FIG. 3) having an impeller 52 seated in a fan chamber 50. Adjoining the fan chamber 50 is a blowing air feed channel 54, which opens into the fall channel 28 at a permanently open opening point 56 (blowing air inlet). There is thus a permanently open connection between the fan chamber 50 and the fall channel 28. The opening point 56 is located upstream of the blocking slide 40 but downstream of the powder dosing wheel 32. With its pressure side, that is to say the axial side at which the blowing air is discharged from the impeller 52, the impeller 52 faces the blowing air feed channel 54.

[0033] The impeller 52 is able to be driven about an axis of rotation 60 by means of an electrically controllable, in particular electromotive fan drive unit 58, shown schematically in FIG. 3. In the example shown, the axis of rotation 60 runs substantially parallel to the axis of rotation 34 of the powder dosing wheel 32, wherein the two axes of rotation 34, 60 are oriented substantially perpendicularly to the plane of the door 16 in the finally mounted state of the powder dosing system 20 (i.e. when the powder dosing system 20 is mounted on the door 16).

[0034] The fan 48 is activated at least in some embodiments for at least two purposes.

[0035] A first purpose consists in expelling detergent powder, which is delivered from the powder dosing wheel 32 into the fall channel 28, from the fall channel with the assistance of blowing air. The blowing air is intended to assist the powder as it falls or/and to free portions of the powder that have stuck to the channel walls of the fall channel 28. The geometry of the blowing air feed channel 54 and of the opening point 56 is suitably configured to generate in the fall channel 28 a blowing air stream oriented in the direction towards the outlet opening 38 when the impeller 52 is actuated. This blowing air stream carries the detergent powder falling from the powder dosing wheel 32 in the direction towards the outlet opening 38 (when the blocking slide 40 is open, i.e. when the blocking slide 40 is in its freeing position) and thereby also prevents portions of the detergent powder from adhering and sticking to the walls of the fall channel 28. Expelling the detergent powder from the fall channel 28 with the assistance of blowing air reduces the tendency for the development of permanent powder residues on the walls of the fall channel 28.

[0036] A second purpose consists in drying the fall channel 28 by blowing in blowing air. As explained, the accumulation of moisture on the channel walls of the fall channel 28 and in the region of the dosing chamber 30 during dishwashing operation of the dishwasher 10 cannot be ruled out. In order to dispel such moisture, which also carries the risk of the formation and adhesion of powder clumps, the fan 48 can be activated during execution of a cleaning program of the dishwasher 10, after the end of the dishwashing operation, that is to say when water is no longer being sprayed into the dishwashing chamber 14. The fan 48 can be activated, for example, during a drying phase of the cleaning program, that is to say in an operating phase in which drying (in particular active drying) of the dishwashing chamber 14 and of the dishes located therein is carried out. Alternatively or in addition, the fan 48 can be activated once the drying phase is complete, in some circumstances even with a considerable time delay after the end of the drying phase. For example, it is conceivable to start up the fan 48 only several minutes or even several tens of minutes (e.g. half an hour or even a whole hour) after the end of the drying operation.

[0037] If the fan 48 is activated for drying purposes, the blocking slide 40 can be moved into its freeing position, at least in phases, while the fan is operating. The air blown into the fall channel 28 by means of the fan 48 can then escape via the outlet opening 38 into the dishwashing chamber 14. However, it is also possible to leave the blocking slide 40 in its blocking position, at least in phases, while the fan is operating in order thus to force or at least promote the ingress of blowing air also into the regions of the fall channel 28 that are located upstream of the opening point 56 and in some circumstances also into the dosing chamber 30. In this manner, the upstream parts of the fall channel 28 and optionally the dosing chamber 30 with the powder dosing wheel 32 located therein can also actively be dried by means of the blowing air. In order to avoid an accumulation of air, an air outlet opening (or multiple such air outlet openings), for example of slot shape, can be formed in the walls of the fall channel 28. Blowing air which is blown into the fall channel 28 by means of the fan 48 is able to escape from the fall channel 28 through such an outlet opening. It is thus possible, with the fall channel 28 blocked, by activating the fan 48, to generate a forced circulation of air from the interior of the door 16 through the blowing air feed channel 54 into the fall channel 28 and, via the mentioned air outlet opening(s), out of the fall channel 28 back into the interior of the door 16. With the fall channel 28 open (when the blocking slide 40 is in its freeing position), on the other hand, blowing air blown into the fall channel 28 can emerge into the dishwashing chamber 14 at the outlet opening 38.

[0038] In order move from a powder receiving rotational position, in which one of the dosing pockets 36 is situated at the opening point to the supply chamber 26 and is accordingly ready to accept detergent powder from the supply chamber 26, into a powder delivery rotational position, in which the dosing pocket 36 in question has been transferred to the opening point to the fall channel 28 and is accordingly ready to deliver the received detergent powder into the fall channel 28, the powder dosing wheel 32 must be rotated through a specific angle of rotation. In the exemplary embodiment shown, this angle of rotation is such that in the meantime (i.e. while the dosing pocket 36 in question is moving from the powder receiving rotational position into the powder delivery rotational position), at least two other dosing pockets 36 of the powder dosing wheel 32 pass the opening point to the supply chamber 26 and are filled with detergent powder. The powder dosing wheel 32 thus always has further extracted doses of the detergent powder available, which can be delivered into the fall channel 28 at any time by rotating the powder dosing wheel 32 further comparatively briefly. In some embodiments, this configuration of the powder dosing wheel 32 can be used to deliver a variable number of doses of the detergent powder into the dishwashing chamber 14 during execution of a cleaning program. For example, if, during execution of a cleaning program, the control unit 18 determines, on the basis of the signals of a turbidity sensor (not shown in the drawings) that measures the turbidity of the dishwashing liquor, that a first dose of the detergent powder was not sufficient to achieve a desired cleaning result, the control unit 18 can effect the delivery of a further powder dose by briefly rotating the powder dosing wheel 32 further. In this manner, a suitable number of powder doses can be delivered dependent on the situation.

[0039] Although the preferred embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.