GB2145119A

GB2145119A - A method of operating a programme-controlled drum-type washing machine

Info

Publication number: GB2145119A
Application number: GB08417188A
Authority: GB
Inventors: Peter Zinkann
Original assignee: Miele und Cie KG
Current assignee: Miele und Cie KG
Priority date: 1983-07-07
Filing date: 1984-07-05
Publication date: 1985-03-20
Also published as: IT8421785A0; IT8421785A1; FR2548699A1; DE3324481A1; IT1176380B; GB8417188D0

Abstract

A method of operating a programme-controlled drum-type washing machine, in which the drum is caused to rotate at a first, lower speed (n1) at the beginning of the pre-wash cycle. After a predetermined period of time, the drum speed is increased to a second, higher speed (n2). In an alternative method, the drum speed is stepwisely increased from a first, lower speed (n1) to a second, higher speed (n2) each time the drive motor is started-up during a washing cycle. Either of these measures permits an item of washing to be soaked more satisfactorily and more rapidly. <IMAGE>

Description

SPECIFICATION A method of operating a programme-controlled drum-typewashing machine The present invention relates to a method of operating a programme-controlled drum-type washíng;rnachEne ofthe type which has control means for setting the speed ofthe drive motorforthe drum.

In most known washing machines which are commercially available, the rotational speed ofthe washing drum is maintained constant during the washing phase. It is merely the rhythm ofthe rotation of the drum which is altered in dependence upon the properties ofthetype of article being washed. Thus, for example, the drum may be rotated less during the starting-up period of the washing cycle, for example, during the period in which the water is being heated.

In addition, there are washing machineswith adjustable drum speeds, wherein, for example, during the prog ram me for washing woollen goods,thedrum is rotated at a lower speed throughoutthe programme than would be the case if, for example, cotton goods were being washed.

Various measures now permit the water consump- tionforparticularwashing programmetoberes- tricted. On the other hand, however, the disadvantage of such measures is that as the amount of water used is reduced, it becomes more difficu It to ensure that all ofthe washing load is saturated. Alternatively, a longer period of time is necessary to ensure that the load is adequately saturated. As a result, the washing results are sometimes not wholly satisfactory.

The present invention therefore seeks to provide a method of operating a programme-controlled drumtype washing machine which ensures that each item of washing is soaked more satisfactorily and more rapidly during the washing programme.

According to the present invention, there is provided a method of operating a programme-controlled drum-typewashing machine having control means for setting the speed of rotation ofthe drum by controlling the drive motor, wherein the drum speed at the outset of the first washing cycle is set at a first, lower value for a predetermined time period and is increased to a higher speed of rotation after this predetermined time period has elapsed.

Preferably, the drum speed is maintained atthefirst, lower value for a period of between 1.5 and 8 minutes atthe beginning ofthewashing cycle.

In a further aspect ofthe present invention, there is provided a method of operating a programmecontrolled drum-type washing machine having control means for setting the speed of rotation of the drum by controkling its drive motor, in which the speed of rotationofthedrum in one washing programme, duringthe starting-up period of the drive motor, is set initially at a first, lower speed and is subsequently acceleratedtothe higher washing speed.

Desirably, the lower speed of rotation is set fora time of from 2 to 6 seconds.

Advantageously, the stepwise increase of the drum rotation speed is continued cyclicallyfora period of from 1.5 to 8 minutes.

The method of the present invention appears to be advantageous in that a more satisfactory and also a more rapid soaking oftheitemstobewashedis achieved during the initial phase of the washing programme. As a general rule, therefore, better washing results are achieved, even though the general washing forces are reduced for a predetermined period oftime.

The method of operating a programme-controlled drum-type washing machine will be further explained, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a graph of the speed of rotation of the drum againsttimeforafirstmethod of operation according to the present invention; and Fig. 2 shows a graph similar to Fig. 1 butfor a second method of operation in accordance with the present invention.

In Fig. 1, there is shown a plot of the rotational speed of the drum of a washing machine (ordinate) against time (abscissa) in a washing programme. In such programme, the drum is programmed to rotate at a lower rotational speedfora predetermined period of time and thereafter is programmed to rotate at a higher speed. In Fig. 1,the lower speed is designated nl which is, in practice, 30 r.p.m. and the higher speed is designated n2which, in practice corresponds to the conventional rotational speed of 50 r.p.m. At the outset of the washing process, the reduced speed n1 is initially set and the drum rotates atthisspeedfora period which is from 1 .5to 8 minutes. The reversing cycle, that isto say rotation ofthe drum in the opposite direction is effected during this period.Conventional time periods, for example, 12 seconds of rotation in a first direction, 2 seconds pause and 12 seconds of rotation in the opposite direction to the first direction are employed. Afterthe predetermined period at the reduced drum speed nl has elapsed, the control mechanism of the machine automatically switches the drum speed to the higher, normal washing speed n2 of 50 r.p.m. The washing programme is continued and concluded with the drum rotating atthe higher speed n2.

In the case of awashing machinewhich hastwo washing solutions, the reduced speed nl is only set during the pre-wash cycle. In an operation with a single washing solution, the reduced speed is set at the beginning ofthewashing process.

Fig. 2 shows a plot of the rotation speed of the drum (ordinate) against time (abscissa) in an alternative method of operating a drum-type washing machine.

As can be seen from Fig. 2, the drum speed is increased in a stepwise manner during the starting-up period of the drive motor. Afterstarting, the drum is initially accelerated until it is rotating at a speed nl, which is 30 r.p.m. The drum is only accelerated to normal washing speed n2 of 50 r.p.m. after a period of, for example, 2 to 6 seconds has elapsed.

This stepwise increase in the drum speed may be repeated during the entire washing programme. On the other hand, however, itis also possible to operate the drum solely atthe normal washing speed n2 once a predetermined period oftime has elapsed.

In Fig. 2, the drum is rotated initiallyfor 3 seconds at a speed of 30 r.p.m. and is then accelerated to 50 r.p.m.

for 9 seconds. After 2 seconds pause, the drum is rotated in the opposite direction at30 r.p.m. for3 seconds before being accelerated to 50 r.p.m. for 9 seconds. This cycle is then repeated until the end of the washing programme.

Claims

1. A method of operating a programme-controlled drum-typewashing machine having control means for setting the speed of rotation of the drum by controlling the drive motor, wherein the drum speed at the outset of thefirstwashing cycle is set at a first, lower value for a predetermined time period and is increased to a higher speed of rotation after this predetermined time period has elapsed.

2. A method of operating a programme-controlled drum-typewashing machine as claimed in claim 1, in which the drum speed is maintained atthe first, lower value for a period of between 1.5 and 8 minutes atthe beginning ofthewashing cycle.

3. A method of operating a programme-controlled drum-typewashing machine having control means for setting the speed of rotation of the drum by controlling its drive motor, in which the speed of rotation ofthe drum in onewashing programme, during the starting-up period of the drive motor, is set initially at a first, lower speed and is subsequently accelerated to the higherwashing speed.

4. A method of operating a programme-controlled drum-typewashing machine as claimed in claim 3, in which the lower speed of rotation is set for a time of from 2 to 6 seconds.

5. A method of operating a programme-controlled drum-type washing machine as claimed in claim 3 or 4, in which the stepwise increase ofthe drum rotation speed is continued cyclically for a period of from 1.5 to 8 minutes.

6. A method of operating a programme-controlled drum-typewashing machine as claimed in any preceding claim substantially as hereinbefore described.

7. A drum-type washing machine programmed to carryoutthe method of operation claimed in anyone of claims 1 to 6.to 6.