WO1998029594A2

WO1998029594A2 - Washing method to achieve a superior washing performance by intermittent and variable oscillating drum movements

Info

Publication number: WO1998029594A2
Application number: PCT/TR1997/000025
Authority: WO
Inventors: Merih Pasin; Mustafa TÜZÜNGÜÇ; Evren GÜNEN; Mehmet Kaya
Original assignee: Arçelik A.S.
Priority date: 1996-12-30
Filing date: 1997-12-30
Publication date: 1998-07-09
Also published as: ATE239814T1; EP0973968A2; DE69721834D1; DE69721834T2; AU5353998A; TR199601081A2; ES2199381T3; WO1998029594A3; EP0973968B1

Abstract

The present invention is related to a method providing an improvement of the washing performance for the washing machines with horizontally positioned tubs and drums by making the drum movements intermittent and with modulating oscillation. In the method according to the present invention, the rotations of any drum used for washing are realized as intermittent and with variable oscillations, the rotational speed of the said drum being increased or reduced with the desired acceleration rate that may be variable and this movement can be stopped at any desired angle thus obtaining the intended falling angles and heights at the desired cylces and by creating the desired velocity differences between water and clothes to be washed, as the result of these movements, the washing performance is improved by means of various drum movements. Said drum movements are realized by means of the washing programmes selected with regard to the type of textile to be washed. While washing wool, the requirement of keeping the material to be washed continuously in water is met using less water by keeping said drum movements between given limit values.

Description

WASHING METHOD TO ACHIEVE A SUPERIOR WASHING PERFORMANCE BY INTERMITTENT AND VARIABLE

OSCILLATING DRUM MOVEMENTS

As the water used as the carrying medium during the washing operation is required priorly to carry the heat energy and the washing material (detergent) to the areas to be washed, and then to realize the process of removing the soil decomposed from the textile (fabric) after being washed; a velocity difference so that it can pass through the fibers of the fabric being washed and subsequently a difference of pressure acting on the water must be created. In addition to these, soil is also removed off the fabric by mechanical movements through the friction between the fibers.

In the existing washing machines, the process of penetrating water into the fibers as well as the aid of mechanical movement to washing are obtained by means of rotating the drum both in clockwise and anti-clockwise directions with full rotations at a constant speed. The rotational speed of the said movement is generally around 50-55 rpm and this value is determined based on the diameter of the drum. So that the vertical component of the centrifugal force acting upon the clothes being washed is less than gravity before the top point of the drum, at which the clothes are dropped down to the bottom of the drum.

Washing performance of the washing machines with tubs placed on a horizontal axis is higher than that of the top loading washing machines with vertically positioned tubs. The major reason of this is that the gravitational acceleration created due to its horizontal positioning together with the centrifugal acceleration created by rotation, enhance the process of removing soil off the clothes. In standard machines this process is realized by changing the rpm of the drum. In this method, by keeping the vertical component of the centrifugal acceleration higher or lower than the gravitation, the drum angles or in other words the falling heights of the clothes within the drum can be controlled. Main problem seen in this method is the fact that the rpm of the drum and the drop height cannot be controlled independently from each other. This limits the optimisation of the mechanical movements according to the characteristic of the fabric being washed.

Another significant drawback in the washing machines wherein the drum performs the washing operation by making full rotations, is the fact that they have to intake more water during the wool washing programme, to keep clothes in water at all times. Wool clothing's must be continuously in water in order to obtain an acceptable degree of shrinkage. This brings the water consumption of the machine during the wool washing programme to high values.

One object of the present invention is to realize the rotational movements of any tub used in a washing machine as intermittent and with modulating oscillations, to increase or reduce the revolution cycle of the said tub with the desired acceleration that may be variable and to realize a method that provides an improvement in the washing performance by creating desired speed differences between water and clothes by means of stopping this movement at a desired angle and thus obtaining the intended falling angles and heights in desired cycles.

Another object of the present invention is to realize a method to keep the wool clothes continuously in the water during washing cycle using less water, by applying to the drum the oscillating movements of variable amplitude and frequencies.

A general schematic drawing of an embodiment wherein the method realized to achieve the objects of the present invention is applied, is attached to this document. Here, the tub is horizontally positioned and supported by the body (1) by using spring (3) and damper elements (2). The drum (5) is positioned in such a manner that it can perform rotational movements within the horizontal tub (4). Clothes (6) are loaded into the drum and washing is performed by means of rotation around the drum shaft axis (7). Drum movements are realized through the washing programmes selected according to the type of the fabric to washed.

During wool program, the drum rotates at approximately 3 rad/s² of angular acceleration and 20 rpm of rotational speed for 1.25 seconds clockwise and 1.25 seconds in counter-clockwise directions in order to meet the requirement of keeping the wool clothes to be washed continuously in water using less water and additionally in order to provide a better washing performance. Thus the drum never makes a full (complete) revolution and performs an oscillating movement between the proper angle limit values towards both directions. As the result of the washing movement realised in this way, better shrinkage performance values as compared to a standard wool programme, can be obtained although 40% less washing water is consumed for main wash.

Besides wool washing programme, the above mentioned oscillating movement can also be applied in cotton washing programme. As cotton fabrics do not require to be continuously kept in water, oscillation angles may reach to higher values compared to the wool programme during the washing cycle for cotton textiles. Additionally, the fact that the acceleration acting upon the fabric during washing is variable improves the soil removal process off the clothes. By means of variable accelerations cleaning chemicals are carried into the pores of the fabric and soil removed off the fabric is carried away from the clothes more efficiently.

For these reasons oscillating movement is provided in progressive amplitudes thus obtaining the modulation of the acceleration acting upon the fabric in the course of time, for cotton washing cases where washing performance is more important. This movement which starts as small oscillations and progressively increases its amplitude until it reaches full-cycle levels, is repeated periodically all through the washing programme.

By increasing or reducing the drum speed with a desired and variable acceleration and by stopping the rotation at a desired angle, the falling of the clothes down from a desired height can be provided.

Another factor increasing the washing performance is simulating the rubbing action used while hand washing by providing the friction of the fabrics being washed. For this purpose, in addition to the drum movement with variable oscillations, the drum is rotated at such a speed that a centrifugal acceleration more than gravitational acceleration is obtained, thus the clothes in the tub are left immobile around the drum and the drum movement is suddenly stopped at 180° from the initial point, i.e. when the clothes are at the top point. As the result of this, the clothes within the drum fall off the peak point downwards and thus the washing performance is improved.

In cotton washing programme, the above mentioned operational process with the oscillating movement of variable amplitudes and stopping the drum at 180° position are used together with the other drum movements and thus the washing performance increases significantly.

Claims

1. A washing method obtaining a high washing performance by means of intermittent drum movements with variable oscillations, for any drum washing machine comprising a tub (4) supported by the body (1) using spring (3) and damper elements (2) and a drum (5) positioned in such a manner that it can perform the rotating movement within the said tub (4) that can rotate around its horizontal shaft axis (7); characterized in that washing performance is improved with various drum movements by increasing or decreasing the drum rotation speed with a desired acceleration that can be variable, and as the result of these movements, by creating the desired velocity differences between water and clothes.

2. A washing method according to claim 1, achieving an excellent washing performance in the said washing machines with drums, by intermittent and variable oscillating drum movements characterized in that the drum movement in said machine is stopped at a desired angle, and desired dropping angles and heights can be obtained at desired rotation speeds.

3. A washing method according to claims 1 and 2 achieving an excellent washing performance in the said washing machines with drums, by intermittent and variable oscillating drum movements characterized in that the drum is rotated with such a revolution that it provides a higher centrifugal acceleration than the gravitational acceleration in order to keep the laundry being washed immobile around the periphery of the drum and the drums is stopped suddenly about 180┬░ after the starting point or in other words when the clothes are at the top (peak) point, so that the clothes fall down from the top point within the drum.

. A washing method according to claims 1 to 3 achieving an excellent washing performance in the said washing machines with drums, by intermittent and variable oscillating drum movements characterized in that performing oscillating movement of variable amplitude and stopping the drum when it is at 180┬░ position are implemented together with other drum movements to increase the washing performance.

5. A washing method according to claim 1 used in the said washing machine with drum, during the wool washing cycle, that improves the washing performance with intermittent and variable oscillating drum movements, characterized in that the dram moves approximately at an angular acceleration of 2 to 4 radians/ sec and 15 to 25 rpm for 1.0 to 1.5 seconds in the clockwise direction and for 1.0 to 1.5 seconds in the counter-clockwise direction and makes oscillating movements of variable angles and frequencies; and meets the requirement that the wool clothes being washed are continuously kept in water by using less water.