GB2225030A

GB2225030A - Load indicator for domestic washing machines

Info

Publication number: GB2225030A
Application number: GB8925203A
Authority: GB
Inventors: Heinz Kafferlein
Original assignee: Licentia Patent Verwaltungs GmbH
Current assignee: Licentia Patent Verwaltungs GmbH
Priority date: 1988-11-18
Filing date: 1989-11-08
Publication date: 1990-05-23
Also published as: IT1236711B; IT8922385A1; IT8922385A0; GB8925203D0; DE3838998A1

Description

LOAD INDICATOR, PARTICULARLY FOR DOMESTIC WASHING MACHINES 222 2 5 0 10

This invention relates to a load indicator, particularly for domestic washing machines, and more especially for the detection and indication of the weight of washing to be boiled or normal washing in the said equipment.

Detecting the weight of the washing introduced is particularly important for the user. Only as a result of this can the latter select a suitable program (and corresponding amounts of water to be supplied), and calculate the necessary amount of detergent.

A 'method for the control of washing program of a drum-type washing machine and washing machine for carrying out the method' is know from DEOS 34 36 786. In this case, the amount of loading is detected via the dry weight of the washing by the direct picking up of measured values at the container for detergent solution or its connecting elements to the housing of the machine, or the amount of loading is calculated indirectly by measuring the motor-contro 1 ling quantities such as motor current or phase angle and the linen drum speed which is then necessary is selected independently.

Furthermore, a 'method of determining the amount of washing with which the linen drum of a washing machine or of a linen drier is loaded' is known from DE-OS 35 41 810. In this case, a sensor is disposed in the region of the opening for loading in the washing and detects the loading time via reflection or transmitted-light light barriers or through infrared elements, or adds the particular period of movement in the region of the opening for loading the washing, compares it with experi- mental.valxiet and indicates when the linen drum is full.

- It is t.rue 'that the- f irst-mentioned--- state- of the art detects the weight of the amount of washing loaded 'in and a:dapts the course of"the program accordingly, but an indication for the.user is lacking.

With the last-mentioned known method of determining the amount of washing, only the end of the loading time or the reaching of the maximum permissible filling weight is indicated. There is no indication for partial fillings.

It is an object of the invention to determine and to indicate the weight of washing introduced while the machine is at a standstill, via the change in position of the resiliently sus-pended container.

The invention provides a load indicator for domestic washing machine having a switch panel and tub for detergent solution, -which tub is suspended resiliently relatively to a mounting frame, comprising means responsive to vertical movement of said tub relatively to the mounting frame for providing a corresponding indication of the loaded state of the tub in an indicator window of the switch panel.

The advantages achieved by the invention consist, in particular, in that, by means of a first embodiment, the customer is given precise information regarding the weight of the washing introduced, in the simplest and most inexpensive -manner.;-: In -the second case, a direct 'indication in units of weight, which can be' read off easily on the switch panel,- is -effected without the use of expensive microprocessors. On the basis of these indications, the customer can measure out the 1 A 3 amount of detergent in the optimum manner and make a corresponding (water- saving) program selection.

The invention is illustrated by way of example in the drawings, in which:

Figure 1 shows a domestic washing machine with a viewing window for the load indication disposed in the switch panel, Figure 2 shows the mechanics of the load indicat- ion, Figure 3 shows the indicator plate with marking according to Figure 2, and Figure 4 shows a device for a load indication with the aid of electromagnetic means.

According to Figure 1, a washing machine 1 has a switch panel 2 and a work top 3. An indicator window 4 is left open in the switch panel 2, behind which window, according to Figures 2 and 3, an indicator plate 5 with a marker line 6 is via a leaf spring 7. the rear and rigidly mounted for vertical displacement The leaf spring 7 is bent towards connected to the f ront of a tube 8 for detergent solution. The tub 8 is in turn resiliently mounted, that is to say mounted for swinging by means of suspension springs 9 (for the sake of simplicity, only one spring is illustrated). The suspension spring 9 is itself gripped on the frame 10 of the washing machine housing and in a suspension eye 11 of the tub 8. Now the leaf spring 7 presses the indicator plate 5 against the inside of the indicator window 4 so that the marker line 6 is visible when the machine is at a standstill. In a manner not illustrated, a vertical weight scale is provided on the indicator window 4 and corresponds in its graduation to the characteristic of the suspension 9. (As is known, a spring characteristic represents the spring excursion depending on the _spring loading) When the. washing- machine -is at a standstill, -the tub 8 and with it the marker line 6, moves downwards more or less far along the scale according to the amount of loading, so that the customer can easily read off the weigh-t of the washing introduced and at the same time measure out the amount of detergent necessary for this and set the appropriate program. When the washing machine is i n operation, the tub 8 swings and with it the leaf spring 7. Damage to the indicator is avoided by this means.

A further example of a device for indicating the amoiint of loading is illustrated in Figure 4. The swinging suspension of the tub 8 is effected as illustrated in Figure 2 - A toroidal coil 12 surrounding the suspension spring 9 concentrically is connected, via a suspension 13, to the frame 10 of the washing mLqhine 1. Inside the suspension spring 9 or likewise surrounding it concentrically, a coil core 15 is rigidly secured to the tub 8 by means of a mounting web 14. The coil core 15 can now move downwards with the tub 8 (precisely centrally inside the toroidal coil 12) vertically in the manetic field of the energized coil 12, in accord9 ance with the characteristic of the suspension spring 9 as the loading of washing increases. As a result of the change in position of the magnetizable coil core 15 inside the energized toroidal coil 12 or the toroidal coil through which current is flowing, the magnetic flux is altered considerably. This change in the magnetic flux is converted into signals through electronics, and indicates the weight of the washing introduced into the drum at the indicator window 4 via a plurality 01 of light-emitting diodes or directly via a digital display.

Another displacement sensor working electrically/ electronically may also be used.

in order to increase the vertical change in position of the tub 8 with an associated increase in the sensitivity of the measured value, the container damping elements situated at the bottom but not illustrated may be put out of operation when the machine is at a standstill, that is to say only during the loading and the determination of its weight. With f rictional dampers, this can easily be ef f ected in that the brake shoes producing the friction are released mechanically or electromagnetically. These are only set in operation again automatically when the linen drum starts.

in conclusion, it may be mentioned that the type of load indication described is primarily suitable for washing to be boiled or for mixed or normal washing, such as underwear, bed linen, cotton goods, terry fabric or the like. Special programs are provided for silk orsynthetic materials.

Claims

1. A load indicator f or a domestic washing machine having a switch panel and a tub f or detergent solution, which tub is suspended resiliently relatively to a mounting f rame, comprising means responsive to vertical movement of said tub relatively to the mounting frame for providing a corresponding indication of the loaded state of the tub in an indicator window of the switch panel.

2. A load indicator according to Claim 1, comprising an indicator plate disposed behind an indicator window in the switch panel for vertical movement via a leaf spring secured to the tub for detergent solution.

3. A load indicator according to Claim 2, characterised in that a marker line is provided,on the indicator plate.

4. A load indicator according to Claim 2 or 3 characterised in that a weight scale corresponding to the characteristic of suspension springs supporting said tub is provided -on the indicator window of the switch panel.

5. A load indicator according to Claim 1, wherein a toroidal coil concentrically surrounding a suspension spring is secured to the frame of the washing machine.

6. A load indicator according to Claim 5, wherein a coil core is fixed to the tub for detergent solution by means of a mounting web.

7. A load indicator according to Claim 6, wherein the coil core is arranged concentrically inside the suspension spring and the toroidal coil respectively.

1

8. A load indicator according to Claim 6, wherein the coil core is arranged surrounding the suspension spring concentrically.

9. A load indicator according to any one of Claims 5 - 8 comprising an array of light emitting diodes arranged in said indicator window and electronic means for converting a change in the magnetic flux produced in the toroidal coil and in the coil core to a signal visible via said lightemitting diodes.

10. A load indicator according to any one of Claims 5 - 8 comprising a digital display on said switch panel and electronic means for converting a change in the magnetic flux produced in the toroidal coil into a load indicating signal visible via said digital display.

Published 1990 at The Patent Office. State House. 66 71 Hign Holborn. London WCIR4TP. Further copies mkV be obtained from The Patent OfficeSales Branch, St Marv Cray. Orpington. Kent BR5 3RD Printed by Multiplex techniques ltd. St Mary Cray, Kent. Con 1'87