Zanussi Elettrodomestici S.p.a.

Industrie Zanussi S.p.a.

Electrolux Zanussi Elettrodomestici S.p.a.

Claudio Milocco

Giovanni Centis

Gianluca Tassotti

Gianni Santarossa

Ugo Favret

Giuseppe Bianchi

Daniele Favaro

Mario Filippetti

Mario Battel

Alessandro Cantu'

Antonio Martegani

Rosa Sist

Dishwashing machine including a washing tank (1) provided with an upper aperture (6) and a lower aperture (7) that are interconnected through a conduit (8) extending outside the tank. During drying, the vapor in the tank is caused to circulate along a closed-loop flow-path defined by the tank and the conduit (8), thereby reducing to a minimum the effect of thermal stratification of the vapor in the tank and, as a result, favoring a homogeneous drying effect of the washload items.

Washload drying arrangement of dishwashing machines

A dishwashing machine having a reservoir (6) communicating with the washing tank (1) through a lower aperture (7) connected to the delivery side of a drain pump (3). The reservoir (6) comprises an upper aperture (9) capable of communicating with the outside ambient through a valve (10) which is controlled by the program sequence control switch (13) of the machine so as to open during a pre-determined water discharge phase to enable the reservoir (6) to be filled by the water being let out from the tank (1); to temporarily close so as to prevent said reservoir (6) from emptying after said water discharge phase; and to finally open again so as to enable the water stored in the reservoir (6) to flow back into the washing tank (1), through the lower aperture (7) and the pump (3), to be used during said subsequent phase of the washing process.

Washing machine with a multi-function water reservoir

A dishwashing machine includes a water circulating circuit with rotating spray arms 6, 7 arranged in a washing tub 3 and supplied with water by a pump provided to recirculate water collecting in a sump 5. The water is heated by a resistance-type electric heating element 11 arranged in a casing 10. Through the surface of the casing, the heating element is in a heat exchange relationship with both the interior of the washing tub and the water collecting in said sump. The casing 10 is provided in the water circulation circuit of the dishwashing machine in a parallel arrangement with respect to the spray arms 6, 7, with an inlet 12 connected to the delivery side 14 of the pump 8, and with an outlet 13 communicating with the interior of the washing tub 3.

Dishwashing machine with electric heating means

A method for controlling the amount of water filled in a dishwashing machine through a normally closed valve (18) to carry out a duty cycle of the machine in which the water is sprayed onto the washload items by a circulation pump (10) driven by an electric motor (11). The water is put under pressure by the pump in an intermittent manner with an alternate sequence of pre-set operating periods (T) and pauses (S) during which the motor rotating speed is at its highest value (V.sub.1) and lowest value (V.sub.0), respectively. The valve (18) is opened in at least one subsequent pause (S) following a preceding period (T) in which the pressure of the water in correspondence of the pump (10) decreases below a pre-determined threshold value (P.sub.2).

Method for controlling the amount of water filled in a dishwashing

A dishwashing machine includes a water circulation circuit provided with at least one rotating spray arm (6, 7) arranged in a washing tank (3). Water collecting in a sump (5) on the bottom (4) of the tank is supplied to the spray arm through a circulation pump (8). The water is heated up by an electric resistive heating element (11) housed in a casing (10) that is a part of the water circulation circuit (9). The casing (10) is arranged within the washing tank (3) in such a manner that the heating element (11) is in a heat-exchange relationship with the interior of the washing tank and the water collecting in the sump (5) through a surface of the casing.

The operational process includes a step in which water is let into a collecting sump (5) up to a static level (L) . The water is then sprayed onto the washload through appropriate spray means (8, 13) that are supplied by a pump (7) having a suction mouth (11) whose top portion is situated at a level (H). The water is sprayed in an intermittent manner through a sequence of alternating spray periods (T) and pause periods (Tp) during which the pressure of the water downstream of the pump (7) is at its maximum (P1) and at its minimum (Pm), respectively. Each spray period (T) has a duration that is equal to the time needed for the water in the sump (5) to sink from the static level (L) to the level (H) of the pump suction mouth (11). Each pause period (Tp) has a duration that is equal to the time needed for the water in the sump (5) to rise again from the level (H) up to or nearly up to the static level (L).

Operational process for a dishwashing machine

Drive system for a water pump unit (7, 8) driven by the shaft of a reversible motor (4) through a partition wall, about said shaft (5) being mounted a first sealing ring (14) fixed to said wall (13), and a second sealing ring (15) rotatably driven by the shaft and forming a rotatable water-tight sealing arrangement (6) with the first ring (14). The system includes control device (19, 22) capable of normally actuating the motor according to a preset program, and devices (19, 20, 26) to make the motor temporarily oscillate at a predetermined frequency (f), with a sequence of rotations in alternate directions, in case the two sealing rings (14, 15) are sticked together. The oscillation of the rotatable unit associated with the rotor (5) causes the two sealing rings to mutually separate.

Drive system for a water pump with rotatable sealing arrangement

A dishwasher whose drying system works by condensation, having a washtub (3) in heat-exchange contact with a duct (8) that may be closed by a non-return valve and having a fan (14) suitable for causing a flow of cooling air to circulate. The dishwasher also includes a circulation pump (4) and a discharge pump (5), whose rotors are connected to the driveshaft (6) of a reversible motor (7), to pump water to their corresponding force ducts when the shaft is rotating in one direction or the other, respectively. The valve plug (15) is pneumatically switchable by the fan (14) between a closed position and an open position of the duct (8) when the shaft (6) rotates in one direction or the other, so that the flow of air circulates only when the discharge pump (5) is operating.

Dishwasher with drying by condensation

The present invention relates to a method of controlling an automatic dishwasher having a tub, a lower spray arm and an upper spray arm disposed in the tub, a water circulating system including a pump for selectively supplying the spray arms with water, and a heater having a heating element in the tub. The method establishes at least an operative cycle in which the spray arms are supplied alternately with water to spray the crockery. The operative cycle includes a first phase (t1-t2) in which only the lower spray arm is supplied with water, and a second phase (t3-t4) in which only the upper spray arm is supplied with water. The heating element is only energized when the lower spray arm is being supplied with water.

Method of controlling a washing cycle in an automatic dishwasher

A washing process for an automatic dishwashing machine, includes the steps of feeding a predetermined volume of water into the wash tub of the machine, adding a predetermined amount of detergent to the water to form a washing solution, heating the so formed washing solution, and subjecting the articles to be washed to the chemical and a mechanical action of the washing solution. After having reached a predetermined temperature, the washing solution is partially discharged and is replenished with a corresponding quantity of water. The detergent is added in two steps, respectively, before and after the partial discharge of the washing solution.

Washing process for an automatic dishwashing machine

In a reversible motor pumping system of a dishwasher, the reversible electrical motor has a drag shaft on which are mounted the impellers of a circulation pump and a discharge pump. The discharge pump is provided in a hydraulic discharge circuit so as to force fluid from the dishwasher after having washed the objects in the dishwasher. The discharge pump includes a lateral wall defining a chamber of a substantially circular section in which the impeller of the discharge pump is housed. An aspiration inlet is open to the chamber and communicates with the interior of the dishwasher while a delivery outlet is open to the chamber at a location spaced from the aspiration inlet such that a portion of the lateral wall defining the chamber extends between the aspiration inlet and the discharge outlet. This portion of the lateral wall constitutes a tooth of the discharge pump having a reduced inner diameter. At least one air intake is open to the chamber at the tooth of the discharge pump. Thus, the reduced pressure at the tooth of the discharge pump inhibits water being forced through the discharge circuit from flowing back through the air intake and into the bottom of the dishwasher. Therefore, problems which would otherwise occur in such a case are alleviated.

Dishwasher with reversible motor pumping system

A method is provided for regenerating a mass of active resin contained in a water softening device connected in the water filling circuit of a washing machine. The water softener device has an internal volume which is equal to the sum of the volume of the mass of resin plus a free volume, and is selectively supplied with both fresh water and brine through respective valves controlled by a program control device. The water softening device is supplied with a volume of brine during a first period of time, and is subsequently supplied with a complementary volume of water during a second period of time. The sum of the volume of brine, which is selected according to the hardness of the supply water, and the complementary volume of water is equal to the free volume of the water softening device.

Method for regenerating water softener in a washing machine

A dishwashing machine includes a recirculating pump having a casing, an inlet communicating with a sump of a washing tub, an outlet communicating with a spray arm located above the sump, and an impeller rotatable within the casing in a recirculating direction during a washing phase of operation of the machine and rotatable in a direction opposite to the recirculating direction during a drain phase of operation of the machine. A recirculating filter is positioned between the spray arm and the sump. To ensure that all water collected in the sump adjacent the inlet of the recirculating pump is discharged during the drain phase of operation of the machine, a conduit has a first end connected to the interior of the casing of the recirculating pump and a second end positioned adjacent the recirculating filter. A passage through the conduit has a cross section that is calibrated to achieve, upon the impeller of the recirculating pump rotating in the opposite direction thereof, discharge of water collected in the sump adjacent the inlet of the recirculating pump as a water jet from the second end of the passage. Such water jet passes through and cleans the recirculating filter and is directed toward the intake of a drain pump of the machine.

Washing machine including improved apparatus for cleaning a

A pump unit, particularly for use in a dishwasher, includes first and second pumps having respective impellers and a motor drive shaft fixed to the two impellers for alternately rotating the impellers in a first direction, during which only the first pump delivers a liquid, and an opposite second direction during which only the second pump delivers a liquid. The first pump is a peripheral outflow pump, and the second pump is a centrifugal pump the impeller of which includes blades oriented forwardly with respect to the second direction of rotation.

Impeller construction for centrifugal pump of two-pump pump unit

A washing machine includes a tub having a water collecting well, a water suply conduit provided with a controllable valve for supplying water to the well during at least one water supply phase of the operation of the washing machine, and a circulation pump for circulating water collected in the well during at least a latter portion of the supply phase. A control system automatically controls operation of the valve and thereby the supply of water to establish a minimum water level within the well required for optimum operation of the circulation pump. The control system includes a control chamber and an overflow wall having a predetermined overflow level and communicating the well with the control chamber, such that when the level of water in the well reaches the overflow level the water overflows the overflow wall into the control chamber. A calibrated flow opening communicates the intake of the circulation pump with the control chamber, such that operation of the circulation pump draws water from the control chamber through the flow opening. A pressure switch is operatively connected to the valve and is responsive to the pressure within the control chamber to close the valve when the rate of water overflowing the overflow wall into the control chamber is at least equal to the rate of water flowing from the control chamber through the flow opening.

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Pordenone, Italy

Claudio Milocco