Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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).

Abstract: In order to complete a water fill phase, an electromagnetically actuated water fill valve (11) enables water from a supply source to flow into a dishwasher tank, this water being at the same time taken in by a circulation pump (3). Both the valve and the pump are controlled by a timer switch arranged to be energized from a power supply source (4, 5) through a normally open pressure-responsive switch (14) that is arranged to close when the pressure at the delivery side of said circulation pump (3) rises beyond a pre-determined value (P2). At the beginning of the water fill phase, the valve (11) is opened by the timer switch until the latter has been energized for a pre-determined total period of time (T) where T equals the summation of times T1-T6.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A washing machine assembly includes first and second liquid ducts having respective inlets and outlets. The first duct has an interior volume greater than the second duct, and the outlet of the first duct is at a level higher than the outlet of the second duct. A pump pumps liquid to the ducts, and a valve controls the flow of liquid from the pump to the inlets of the first or second ducts. The valve includes a housing having an inlet connected to the delivery side of the pump and first and second outlets connected respectively to the inlets of the first and second ducts. A valve closing element within the housing is movable from a stable first unblocking position spaced from and aligned with the first outlet to a first blocking position closing the first outlet, such that the pumped liquid flows to the second duct. At the same time, a bypass allows some pumped liquid to bypass the closing element into the first duct.

Abstract: 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.

Abstract: A dishwashing machine includes at least one additive distributor for dispensing additive into a wash tub, a first electrically controlled actuator for operating the distributor, a water softener for softening water supplied to the wash tub, a regeneration circuit for regenerating the water softener, a second electrically controlled actuator for operating the regenerating circuit, and a programmer for controlling the operation of the first and second actuators. The first and second actuators are electrically connected in parallel to each other. A single switch is controlled by the programmer for connecting the parallelly connected first and second actuators to a power source for at least one first time period and at least one second time period longer than the first time period. The first and second actuators have response times respectively shorter and longer than the first time period, and the response time of the second actuator is less than the second time period.

Abstract: A dish washing machine includes a wash tank for receipt of dishes to be washed and a hydraulic circuit for receiving water from a water supply source and for supplying water to the wash tank. An electrochemical cell for generating chlorine gas by the electrolysis of a brine solution is connected to the hydraulic circuit. A salt container is connected to the hydraulic circuit by at least one valve and forms brine to be supplied to the electrochemical cell. At least one chlorine gas supply conduit connects the electrochemical cell to the wash tank to thereby supply chlorine gas from the electrochemical cell to the interior of the wash tank.