Improved washing process for laundry washing machine, and laundry washing machine for actuating such a process

Abstract

 A washing process for a laundry washing machine comprises a step for loading water and detergent into a laundry washing tank (1) of the laundry washing machine. Said water and detergent loading step is preceded by a step for pre-filling the tank with water only; during said water and detergent loading step a basket (2) of the washing machine is maintained in rotation inside said tank (1).

Description

[0001] The present invention refers to an improved washing process for laundry washing machine, and a laundry washing machine for actuating such a process.

[0002] It is known how electric appliance manufacturers have made efforts to make laundry washing machines that afford a modest consumption of energy, water and detergents.

[0003] As far as the containment of detergent consumption is concerned, a source of waste of the same is to be attributed to the fact that, at the moment of loading the detergent, a part of it, not dissolved, deposits in the discharge tube or in the filter of the washing machine; in this zone the detergent cannot be utilized, hence it is wasted.

[0004] There are know on the market washing machines designed to reduce the consumption of detergents, exploiting systems that can be substantially broken down into three categories.

[0005] A first category of said systems includes a pump for the forced recirculation of the washing liquid during the operative cycle of the washing machine.

[0006] A second category provides for the addition of a shut-off valve on the discharge tube of the wash tank.

[0007] A third category provides for the addition of a supplementary tube for the recirculation of the washing liquid, recirculation that is determined by the movement of the basket during washing.

[0008] As can be inferred, all the know systems for saving detergent require an addition of components besides the ones normally provided.

[0009] In view of the state of the technique described, the object of the present invention is to provide a washing method for laundry washing machines that permits to keep down the consumption of detergents without requiring the installation of further components in the machine.

[0010] In accordance with the present invention, such an object has been achieved thanks to a washing process for laundry washing machine, comprising a step for loading water and detergent into a washing tank of the washing machine, characterized in that said water and detergent loading step is preceded by a step for pre-filling the washing tank with water only, and in that during said water and detergent loading step the basket of the washing machine is kept in rotation inside said tank.

[0011] Thanks to the method of the present invention a detergent savings is achieved, due to the fact that in the pre-filling step of (clean) water only the discharge tube is filled, and during the successive water and detergent loading step - given that the basket is kept in rotation, preferably in one direction - the detergent is kept as far away from the discharge tube as possible, so as to present the detergent itself, not yet dissolved in the water, from precipitating into the discharge tube.

[0012] These and other features of the present invention will be rendered more evident by the following detailed description of an embodiment thereof, illustrated as a non-limiting example in the attached drawings, in which:

[0013] Figure 1 is a section view according to a vertical plane of a washing machine in accordance with the invention, during a first operative step of a washing process according to the invention.

[0014] Figure 2 is a section view analogous to the one in Figure 1, but it refers to a second operative step of said washing process.

[0015] In Figure 1 a washing machine is schematically shown in section view according to a vertical plane. The washing machine comprises a washing tank 1, inside which a rotatable basket 2 is lodged, rotated by a motor 3. Tank 1 has an inlet tube 4 with an upper part connected to a detergent dispenser 5, and an outlet tube 6 connected, at one end, with the bottom of the tank 1 and, at the other end, to a discharge pump 7.

[0016] The inside of the detergent dispenser comprises a number of compartments 8A, 8B, 8C separated from each other. To each compartment is associated a respective derivation 9A, 9B, 9C of a clean water supply duct 9. Between each of the derivations 9A, 9B, 9C and the duct 9 is interposed a respective intercepting valve 10A, 10B, 10C individually controlled by a control unit 11, for example composed of a timer normally included in the known washing machines. Timer 11 also controls the activation of motor 3.

[0017] As is visible in the Figures, the first compartment 8A of the detergent dispenser 5 is empty, while in the second compartment 8B the detergent (typically in powder form) is loaded. The third compartment 8C can, for example, contain a softener to be employed during the rinsing step.

[0018] The washing process according to the present invention comprises a first step during which valve 10A associated with the first compartment 8A of the detergent dispenser (the empty one) is opened so as to load a pre-established quantity of clean water, which determines a pre-filling of the discharge duct 6 and also, partially, of tank 1. In this first step, the basket can be left still. The duration of this step depends on the quantity of water that one may want to pre-load into the washing tank.

[0019] In the second step of the washing cycle, valve 10A is shut off and valve 10B associated with the second compartment 8B of dispenser 5 (the one containing powdered detergent) is opened. Moreover, in this step, timer 11 commands the activation of motor 3 to bring about the rotation of the basket 2 (in the example, clockwise). The water coming from derivation 9B of the duct 9 passes into compartment 8B, draws out the detergent and carries it into tank 1 where the water with the detergent can pass into basket 2 through holes normally provided in the walls of the same. In this step, the detergent is not completely dissolved yet. Nevertheless, thanks to the fact that the discharge tube 6 was pre-filled before and that the basket rotates, it is possible to avoid that the particles of detergent still in a solid state can precipitate into the discharge tube 6, where it would remain useless and wasted.

[0020] It is to be pointed out that the quantity of water that is loaded in the pre-filling step of the tank, the position of inlet tube 4, the position of discharge tube 6, and the direction of rotation of the basket during the water loading step (with detergent added) must be determined in such a way that the solid detergent which descends into the tank together with the water remains substantially all inside the tank itself and is not allowed to descend into the dead zones (discharge tube) connected to the tank.

Claims

1. Washing process for a laundry washing machine comprises a step for loading water and detergent into a washing tank (1) of the laundry washing machine, characterized in that said water and detergent loading step is preceded by a step of pre-filling of the wash tank (1) with water only, and that during said water and detergent loading step a basket (2) of the washing machine is kept in rotation inside said tank (1).

2. Process according to claim 1, characterized in that in said loading step, the direction of rotation of the basket (2) is kept constant.

3. Laundry washing machine comprising a washing tank (1), a basket (2) rotatingly lodged in said tank (1), motor means (3) for rotating the basket (2), a first path for feeding water to the tank with drawing out of detergent (9,10B, 9B, 8B, 4), characterized in that the machine comprises a second path for feeding water to the tank without drawing out of detergent (9, 10A, 9A, 8A, 4), valve means (10B, 10A) able to be actuated selectively for putting into operation said first or said second water feeding path, and control means (11) to determine, in a first step of a washing cycle, the activation of said valve means to put into operation said second water feeding path (9, 10A, 9A, 8A, 4) to load a pre-established quantity of water into the tank and, in a second step of the washing cycle, to determine the activation of said first water feeding path (9, 10B, 9B, 8B, 4) to load water mixed with detergent into the tank and, at the same time, to actuated said motor means to rotate the basket.

4. Washing machine according to claim 3, characterized in that said first and second paths comprise respective compartments (8A, 8B) of a detergent dispenser (5) and an inlet tube (4) connected to the dispenser (5) and to the tank (1), a first compartment (8B) being destined for containing detergent, and a second compartment being destined to remain empty.

Drawing