Washer such as a dishwasher or a washing machine and method for operating a washer

Abstract

The invention relates to methods for operating a washer, and in preferred embodiments to a washer having a water tank that is integrally, preferably detachably, formed with the washer, wherein the washer comprises a washing chamber for accommodating goods to be cleaned, said washing chamber having in its lower portion a sump for collecting water during operation of the washer, a water inlet, a circulating pump for circulating water through the washing chamber, and a control unit for controlling a washing cycle carried out by the washer. In accordance with the invention, in this method water is fed via the water inlet into the sump; the pressure within an inlet or outlet conduit of the circulating pump is measured; and based on the pressure measurement the washing cycle is controlled and/or indicator signals are issued to a user of the washer.

Claims

1. Washer, such as a dishwasher or a washing machine, comprising a water tank detachably formed with the washer, a washing chamber for accommodating goods to be cleaned, said washing chamber having in its lower portion a sump for collecting water during operation of the washer, a water inlet connected to the water tank for feeding water from the water tank into the sump, a circulating pump for circulating water through the washing chamber, and a control unit for controlling a washing cycle carried out by the washer, said tank being arranged to feed water into the sump by the action of the hydrostatic pressure prevailing within the tank; a pressure sensor which is located within an inlet or outlet conduit of the circulating pump, and the control unit being adapted to cause completion of an action based on signals received from the pressure sensor, the action comprising at least one of: modifying at least one parameter and/or step of the program cycle, terminating the washing cycle, or outputting an indicator signal to a user of the washer.

2. The washer of claim 1, wherein the circulating pump has a non-rotation-symmetric impeller and wherein the control unit is adapted to carry out a method for operating the washer comprising in subsequent steps: (a) feeding water via the water inlet into the sump; (b) measuring the pressure within the inlet conduit of the circulating pump by a pressure sensor when the circulating pump is started; (c) stopping operation of the circulating pump if the value measured in step (b) is above a predetermined value; (d) restarting the circulating pump; and (e) repeating steps (b) to (d) for a predetermined time interval or repeating steps (b) to (d) until the condition under step (c) is no longer fulfilled.

3. The washer of claim 1, wherein the control unit is adapted to carry out a method for operating the washer comprising in subsequent steps: (a) feeding water from the tank via the water inlet into the sump by the action of the hydrostatic pressure prevailing within the water tank; (b) at least twice measuring the pressure within an inlet or outlet conduit of the circulating pump by a pressure sensor when the water inlet is opened to feed water into the sump and storing the measured values; (c) comparing the values of subsequent measurements to obtain a differential value; and (d) generating a warning message to a user of the washer if the differential value obtained in step (c) is less than a predetermined value.

4. The washer of claim 3, further comprising a sensor which senses opening of a door of the dishwasher or the filling of the tank and issues a corresponding signal to the control unit that is adapted to: check whether there was an interaction with a user of the machine upon generation of a warning message, and if so, steps (b) through (d) are repeated.

5. The washer according to claim 1, wherein the water tank has a volume corresponding essentially to the amount of water required for executing a single program cycle.

6. The washer of claim 1, wherein the circulating pump has a non-rotation-symmetric impeller and wherein the control is adapted to carry out a method for operating the washer comprising in subsequent steps: (a) feeding water via the water inlet into the sump; (b) measuring the pressure within the outlet conduit of the circulating pump by a pressure sensor when the circulating pump is started; (c) stopping operation of the circulating pump if the value measured in step (b) is below a predetermined value; (d) restarting the circulating pump; and (e) repeating steps (b) to (d) for a predetermined time interval or repeating steps (b) to (d) until the condition under step (c) is no longer fulfilled.

7. The method of claim 6, in which a certain cavitation level is assumed in dependency of the number of subsequently measured values which exceed the predetermined value, and in which the amount of water which is fed into the sump is rated in dependency of the cavitation level.

8. The method of claim 6, in which the predetermined time interval of step (iii) has a length of about 10 s.

9. A method for operating a washer which comprises a water tank that is detachably formed with the washer, wherein the water tank has a volume corresponding essentially to the amount of water required for executing a single program cycle, a washing chamber for accommodating goods to be cleaned, said washing chamber having in its lower portion a sump for collecting water during operation of the washer, a water inlet for feeding water from the water tank into the sump, a circulating pump for circulating water through the washing chamber, and a control unit for controlling a washing cycle carried out by the washer, in which method in subsequent steps : water is fed from the tank into the sump by the action of the hydrostatic pressure prevailing within the water tank; the pressure within an inlet or outlet conduit of the circulating pump is measured by a pressure sensor; and based on the pressure measurement, cause completion of an action based on signals received from the pressure sensor, the action comprising at least one of: controlling at least one parameter and/or step of the washing cycle, terminating the washing cycle, or issuing an indicator signal to a user of the washer.

10. The method of claim 9, further comprising in subsequent steps: (i) measuring the pressure when the circulating pump is in operation and storing the measured value; (ii) comparing the values measured in step (i) with a predetermined value; (iii) feeding a rated amount of water into the sump if in step (ii) it is determined that within a predetermined time interval a predetermined number of measured values exceeds the predetermined value; and (iv) repeating steps (i) to (iii) as long as the circulating pump is operating.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

(1) An example of a washer made in accordance with the teachings of the present invention will be described below by reference to drawings, in which:

(2) FIG. 1 is a perspective view of a dishwasher in accordance with the present invention; and

(3) FIG. 2 is a schematic sectional view of the dishwasher of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 shows a dishwasher 10, which can be placed on top of a kitchen console 11 or which also could be used as a portable device for use, for example, within a camper van or yacht.

(5) Dishwasher 10 which is designed to be placed on a kitchen console 11 comprises a housing section 12 and a tank section 16 into which a volume of the water is filled as it is required for an intended washing operation. In order to access the washing chamber, housing section 12 is provided with a door 18, which is tiltable about a vertical axis and which in the usual manner constitutes in its open state a support surface, on which a basket 20 can be placed, which holds any goods to be cleaned. Within the lower section of the washing chamber 14 there is provided a sump 22, in which water that is sprayed onto the goods to be cleaned by means of a rotatable spray arm 24 collects, to be again sprayed onto the goods to be cleaned.

(6) Water flows into the sump from tank 16 via a water inlet 42 (shown in FIG. 2 only) that is located at a level below the floor of the tank, so that the water is passed from the tank into the sump solely by the action of the hydrostatic pressure prevailing within tank 16. Sump 22 is connected to an inlet opening 46 for a circulation pump 44 (see FIG. 2) the outlet 48 of which feeds water to the rotatable spay arm 24. Any water which no longer is required for the washing cycle can be drained to waste via a drain conduit 26, the free end of which can be arranged temporarily within a sink 28 or could be connected permanently for example to a drain pipe of sink 28.

(7) As shown in FIG. 1, tank 16 can be equipped with a window 30 through which the filling level of tank 16 is visible also when the lid 32 of tank 16 is closed. At the front side of the closed door or, as shown in the drawing, at a front panel 38 provided at the front side of housing section 12 there are provided a plurality of indicator lamps 34 by means of which a variety of operational states or warning messages can be issued to a user of the washing machine. Alternatively or additionally, acoustic indications can be provided by means of a speaker 40 which is provided within front panel 38.

(8) Operation of the dishwasher is effected by means of a control unit 50 (see FIG. 2) which is adapted to carry out the various methods described above, and which operates the dishwasher in dependency of user inputs, such as settings made at selector switches 52, and sensor signals, such as the signal provided form a pressure sensor 54 which is located at an inlet conduit of circulating pump 44 or form a pressure sensor 56 is located at an outlet conduit of circulating pump 44, or the signal generated by a door sensor 36 (see FIG. 1) which is arranged at the inner side of door 18 and which provides a door opening signal to the control unit of the dishwasher to indicate whether or not the dishwasher door 18 has been opened.

LIST OF REFERENCE SIGNS

(9) 10 dishwasher

(10) 11 kitchen console

(11) 12 housing section

(12) 14 washing chamber

(13) 16 tank section

(14) 18 door

(15) 20 basket

(16) 22 sump

(17) 24 spray arm

(18) 26 drain conduit

(19) 28 sink

(20) 30 window

(21) 32 lid

(22) 34 indicator lamps

(23) 36 door sensor

(24) 38 front panel

(25) 40 speaker

(26) 42 water inlet

(27) 44 circulation pump

(28) 46 inlet opening

(29) 48 outlet

(30) 50 control unit

(31) 52 selector switch

(32) 54 pressure sensor

(33) 56 pressure sensor