"A LAUNDERING METHOD PROVIDING LOW LEVEL OF VIBRATION OF THE CLOTHES BARREL BASKET OF THE CLOTHES WASHING MACHINE DURING THE CENTRIFUGATION STAGE, AND A CLOTHES WASHING MACHINE PRACTICALLY FREE OF VIBRATION DURING THE CENTRIFUGATION STAGE"

Field of the Invention

The present invention is related to a method of laundering clothes that provides a low level of vibration of the clothes barrel basket of the clothes washing machine during the centrifugation stage, and a clothes washing machine practically free of vibration during the centrifugation stage. The novelty of the invention resides in the fact that there is provided, prior to the centrifugation stage, a step of redistribution of the clothes within the clothes barrel basket of the clothes washing machine whereby the occurrence of vibration during the centrifugation stage can be minimized.

Prior Art

In order to extract the largest possible amount of water from the clothes after the same have been washed and rinsed in the clothes washing machine, and further in order to reduce the drying time of the clothes, the clothes barrel basket spins at high speeds during the centrifugation stage.

However, a poor distribution of the clothes within the barrel basket may cause a significant amount of imbalance, resulting in excessive vibration and undesired noise.

Until the advent of the present invention, no prior art document or equipment taught the performance of a step prior to the centrifugation stage, directed at the redistribution of the clothes within the clothes barrel basket, in order to improve the balance thereof, and to consequently minimize the effects of vibration and noise.

Summary of the Invention

The present invention refers to a clothes laundering method that provides a low level of vibration of the clothes barrel basket of the clothes washing machine during the centrifugation/extraction stage. The method comprises the performance, prior to the centrifugation stage, of a step of redistribution of the clothes within the clothes barrel basket of the clothes washing machine in order to minimize the vibration of the clothes barrel basket during the centrifugation stage.

The present invention also refers to a clothes washing machine that is practically free of vibration during the centrifugation/extraction stage, characterized by the fact of comprising programming means to provide, prior to the centrifugation/extraction stage, a step of redistribution of the clothes within the clothes barrel basket of the clothes washing machine towards the bottom of the clothes barrel basket.

Such redistribution of clothes is preferably achieved by means of fast and cyclic mechanical actions of the agitator and/or of the clothes barrel basket itself, applied to the clothes lying within the clothes barrel basket. Such cyclic motions are performed by inverting the direction of rotation of the

agitator and/or of the clothes barrel basket at certain time intervals.

Brief Description of the Figures

Figure 1 is a cross section view of a clothes washing machine.

Figures 2A and 2B show different distributions of the clothes within a clothes barrel basket of a clothes washing machine.

Figures 3 A and 3B depict the results of vibration tests conducted in respect of clothes washing machines during the centrifugation/extraction stage.

The first figure corresponds to a machine that did not use the method according to the present invention, and the second figure corresponds to a machine in which the method according to the present invention was implemented.

Detailed Description of the Invention

The method according to the present invention is preferably implemented in a clothes washing machine 1 wherein the loading of the clothes barrel basket 2 is performed through the top part 3, as shown in Figure 1.

The clothes washing machines of top-loading type known in the art are usually provided with a device known as agitator 4 which acts inside the clothes barrel basket 2 in order to apply a mechanical action to the clothes 5.

The clothes laundering method using the currently known clothes washers comprises at least the steps of washing, rinsing and centrifugation of the clothes.

During the clothes washing stage, the agitator 4 acts mechanically on the clothes, in combination with the chemical action provided by the cleaning products and the water, to perform the cleaning of the clothes.

After the clothes washing step, there follows a rinsing step for purposes of withdrawal of the dirty water from the clothes barrel basket. In that stage, usually after the water is drained from the clothes barrel basket, there occurs a first centrifugation for removal of dirt residues and soap from the clothes, which will be removed from the clothes barrel basket by means of a new intake of clean water and draining of dirty water. In this step, the agitator usually performs a mechanical action on the clothes to aid the removal of dirt and soap from the clothes.

The programs implemented by the clothes washing machines allow the rinsing step to be repeated two or more times.

After the rinsing stage, there occurs the centrifugation/extraction, which is intended to withdraw the water impregnated in the clothes located in the clothes barrel basket. The centrifugation consists in spinning the clothes barrel basket 2 at the fastest possible angular velocity to allow the water to separate from the clothes. In this manner, the clothes containing a lesser amount of water will dry faster, both in a forced drying machine and outdoors.

However, the high speed of the clothes barrel basket combined with the load imbalance caused by irregular distribution of the weight of the clothes within the same might cause it to reach the natural resonance frequency of the

equipment, resulting in strong vibration of the clothes washing machine. In some cases, depending on the surface whereon the equipment is installed, the machine may even be subject to displacement due to vibration.

It was surprisingly noted that the compaction of the clothes 5 towards the bottom 6 of the clothes barrel basket 2 causes the distance between the center of gravity CG of the set of clothes 5 in relation to the bottom 6 of the clothes barrel basket 2 to be minimized. Therefore, the load moment of the set of clothes in relation to the bottom of the clothes barrel basket is minimized, and thereby the frequency of natural resonance of the clothes washing machine is not easily reached.

Figures 2A and 2B show the distribution arrangement of clothes in a clothes barrel basket, respectively before and after implementation of the clothes redistribution step of the present invention.

The compaction of the clothes towards the bottom of the clothes barrel basket reduces the quantity and intensity of the mechanical impacts of the washing mechanism against the housing. The washing mechanism is comprised by the equipment components located within a clothes washing machine that are in charge of performing the clothes washing operation, such as the clothes barrel basket.

Such results are shown in Figures 3 A and 3B. Figure 3 A shows a clothes distribution arrangement with a center of gravity at a greater distance from the bottom of the basket than that which is shown in Figure 3B.

In the graphs shown, the vertical axis refers to the impacts of the clothes barrel basket against the housing of the clothes washing machine. The vertical axis unit is the acceleration in m/s2, since in the tests having been conducted there were placed two sensors, offset by 90 degrees, that measured the acceleration of the clothes barrel basket in relation to the housing of the clothes washing machine. The horizontal axis refers to the time, measured in seconds, elapsed during the centrifugation/extraction operation.

It may be noted that, in Figure 3 A, the intensity of the impacts is much greater that that which is shown in the graph of Figure 3B.

Upon there having been ascertained by means of tests that the distribution arrangement of the clothes nearest the bottom of the clothes barrel basket is essential to minimize the vibrations that take place therein, there was created a simple and effective manner of achieving the said compaction of the clothes, which consists in the addition of a step preceding the centrifugation/extraction stage and intended to redistribute the clothes 5 within the clothes barrel basket 2.

In the preferred embodiment of the present invention, such clothes redistribution step is realized by the mechanical action of the agitator 4 and/or the basket 2 on the clothes 5. Such mechanical action is preferably carried out in cyclic and rapid movements in order to achieve a better accommodation of the clothes.

During the clothes redistribution step, the agitator 4 may act on the

clothes both by itself and together with the movement of the basket 2, or alternating therewith. That is, the agitator and the basket may be actuated independently from one another.

The agitator 4 and the clothes barrel basket 2 are normally driven by a driving assembly 6, which comprises a driving device 7, a basket driving shaft 8, an agitator driving shaft 9 and a connecting means 10 that interconnects the driving device 7 with the shafts 8, 9. Such connecting means may consist, for example, in a belt. Usually, the basket 2 and the agitator 4 are driven by the same driving device 7. However, the basket shaft 8 may be uncoupled whenever it is intended that only the agitator should rotate.

However, the method according to the present invention also applies to washing machines wherein the basket and agitator driving mechanisms are independent from one another.

Therefore, the method of the present invention, intended for laundering clothes with a low level of vibration of the clothes barrel basket of the clothes washing machine during the centrifugation/extraction stage, is characterized by comprising, prior to the centrifugation stage, a step of redistribution of the clothes within the clothes barrel basket of the clothes machine, in order to minimize the vibration of the clothes barrel basket during the centrifugation/extraction stage, where such redistribution of the clothes within the clothes barrel basket of the clothes washing machine is preferably provided by the mechanical action of the agitator and/or of the basket, which is characterized by rapid and cyclic movements applied to the clothes.

The method according to the present invention may be implemented in a clothes washing machine by means of an alteration in the programming of the washing machine.

Although the invention was described based on a specific embodiment, there may be introduced modifications therein by technicians skilled in the art without departing from the spirit and the scope of the basic inventive concept.