This application is a U.S. National Phase application of PCT International Application No. PCT/EP2018/054395, filed Feb. 22, 2018, which is incorporated by reference herein.

The present invention concerns the field of laundry washing techniques.

In particular, the invention relates to a liquid/water supply system in laundry washing machines that is capable of efficiently supplying liquid/water to laundry received therein.

BACKGROUND ART

Nowadays the use of laundry washing machines, both “simple” laundry washing machines (i.e. laundry washing machines which can only wash and rinse laundry) and laundry washing-drying machines (i.e. laundry washing machines which can also dry laundry), is widespread.

In the present description, therefore, the term “laundry washing machine” will refer to both a simple laundry washing machine and a laundry washing-drying machine.

Laundry washing machines generally comprise an external casing, or cabinet, provided with a washing tub which contains a rotatable perforated washing drum where the laundry is placed. A loading/unloading door ensures access to the washing drum.

Laundry washing machines typically comprise a water supply unit and a treating agents dispenser, preferably having a drawer with compartments, for the introduction of water and washing/rinsing products (i.e. detergent, softener, rinse conditioner, etc.) into the washing tub. A pipe preferably connects the dispenser to the washing tub.

In known preferred embodiments, the water which reaches the washing tub can selectively contain one of the products contained in the compartments of the dispenser, or such water can be clean and in such a case it may preferably reach the washing tub bypassing the compartments of the dispenser.

In alternative known embodiments, a further separate water supply pipe bypassing the dispenser can be provided, which supplies directly clean water into the washing tub.

Known laundry washing machines are also typically provided with recirculation circuits that drain liquid from the bottom region of the washing tub and re-admit it into another region of the washing tub. Preferably, liquid is re-admitted at an upper region of the washing tub and the recirculation circuit is typically provided with a terminal nozzle opportunely arranged so that the recirculated liquid is sprayed over the laundry.

The recirculation circuit is typically provided with a recirculation pump which is opportunely activated to recirculate liquid when necessary during the washing cycle enhancing distribution of the liquid over the laundry through the nozzle.

Numerous efforts and attempts have been made by laundry washing machine manufacturers to find solutions that optimise the distribution of water over the laundry and different shapes for the terminal nozzle have been proposed.

US2014109620A1 discloses a nozzle, or water supply device, having an upper vertical hollow pipe connectable to a water supplying line and a lower horizontal sprayer. Horizontal sprayer has a trapezoidal shape and wash water is sprayed through the frontal opening of the sprayer, having a slit shape, over the laundry.

However, the nozzles of the known art pose some drawbacks.

A drawback of nozzles of the known art is the decreasing of the spraying efficiency when the flow rate of the water through the supplying line varies.

The nozzles and their shapes are typically designed to work properly at a predetermined, or substantially predetermined, flow rate according to the working pump speed. In particular, the water follows a desired path from the sprayer opening to the laundry in order to be uniformly distributed over the laundry.

If the pump speed varies, nevertheless, the uniform distribution is not guaranteed. In particular, if the pump speed increases turbulences are generated at the sprayer opening thus variating the desired optimal water path.

The object of the present invention is therefore to overcome the drawbacks posed by the known techniques.

An object of the present invention is therefore to propose a liquid supply system which guarantees the desired liquid distribution over the laundry at different flow rate conditions.

Another object of the present invention is to propose a liquid supply system enabling the control of the flow direction of the liquid over the laundry as a function of the flow rate assuring the optimal liquid distribution over the laundry in each working condition.

DISCLOSURE OF INVENTION

Applicant has found that by providing a laundry washing machine comprising a washing tub external to a washing drum and a liquid supply line for supplying liquid into said washing tub/drum through a nozzle having an outlet extremity and by providing said nozzle with an obstruction, it is possible to reach the mentioned objects.

In a first aspect thereof the present invention relates, therefore, to a laundry washing machine comprising:a cabinet supporting a washing tub external to a washing drum adapted to receive laundry;a liquid supply line for supplying liquid into said washing tub/drum through an outlet extremity, said liquid supply line being provided at an end thereof with a nozzle comprising said outlet extremity, said nozzle comprising a tubular portion extending along an axis and a sprayer portion comprising said outlet extremity and hydraulically communicating with said tubular portion, wherein said sprayer portion comprises a bent zone which is apt to change the direction of a liquid flowing through said tubular portion towards said outlet extremity, wherein said nozzle comprises an obstruction arranged upstream of said bent zone so that the cross-sectional area of said nozzle first decreases and then increases while proceeding from said tubular portion towards said outlet extremity.

Preferably, the cross-sectional area is the area of the nozzle, where the liquid may flow, in a plane perpendicular to said axis.

According to a preferred embodiment of the invention, the cross-sectional area first monotonically decreases and/or then monotonically increases while proceeding from the tubular portion towards the outlet extremity.

In a preferred embodiment of the invention, the cross-sectional area comprises a smaller area wherein the smaller area is defined at a single point along the axis.

Preferably, the tubular portion comprises a portion that extends rectilinearly along the axis.

According to a preferred embodiment of the invention, the nozzle is arranged so that the axis of the tubular portion and a vertical axis, with the laundry washing machine installed on a horizontal floor, form an angle lower than 30° therebetween, preferably form an angle lower than 10° therebetween, more preferably form an angle equal to 7° therebetween.

In a preferred embodiment of the invention, the bent zone is apt to change a first direction of a liquid flowing in the tubular portion into a second direction of the liquid towards the outlet extremity.

According to a preferred embodiment of the invention, the first and second directions are inclined one to the other with an angle comprised therebetween less than 135°, preferably an angle comprised therebetween equal to 90°.

Preferably, the sprayer portion has a width that expands towards the outlet extremity, more preferably has a trapezoidal shape.

According to a preferred embodiment of the invention, the outlet extremity comprises a lower edge and an upper edge connected therebetween at opposite ends.

In a preferred embodiment of the invention, the distance between the upper edge and the lower edge decreases by proceeding from the center of the outlet extremity towards the opposite ends, the distance being measured in a direction parallel to the axis.

Preferably, the lower edge is rectilinear and/or the upper edge is arcuate.

According to a preferred embodiment of the invention, the liquid supply line comprises a recirculation system for draining liquid from the bottom of the washing tub and to re-admit such liquid into a first region of the washing tub/drum, the recirculation system comprising a recirculation pump and a recirculation duct connected to the nozzle.

In a preferred embodiment of the invention, the recirculation pump is a variable-speed pump.

Preferably, the recirculation pump comprises an inlet connected to the bottom of the washing tub and an outlet connected to the recirculation duct.

According to a preferred embodiment of the invention, the liquid supply line is configured to supply liquid into the washing tub/drum at different flow rates.

In a preferred embodiment of the invention, the nozzle is arranged at a bellows interposed between the cabinet and the washing tub.

Preferably, the bellows comprises a housing apt to receive the nozzle.

