Patent Publication Number: US-6662600-B1

Title: Foamed cleaning liquid dispensing system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Reference is hereby made to the following related applications: U.S. application Ser. No. 10/026,411, filed Dec. 21, 2001, still pending, and entitled “APPARATUS AND METHOD OF USE FOR CLEANING A HARD FLOOR SURFACE UTILIZING AN AERATED CLEANING LIQUID”, which in turn claims priority to U.S. Provisional Application Ser. No. 60/308,773, filed Jul. 30, 2001, still pending, and entitled “APPARATUS AND METHOD OF USE FOR CLEANING A HARD FLOOR SURFACE UTILIZING AN AERATED CLEANING LIQUID”; U.S. application Ser. No. 10/143,582, filed May 9, 2002, still pending, and entitled “CLEANING LIQUID DISPENSING SYSTEM FOR A HARD FLOOR SURFACE CLEANER”; U.S. application Ser. No. 10/152,537, filed May 21, 2002, still pending, and entitled “CHEMICAL DISPENSER FOR A HARD FLOOR SURFACE CLEANER”; and U.S. application Ser. No. 10/152,549, filed May 21, 2002 still pending, and entitled “CLEANER CARTRIDGE.” All of the above-referenced applications are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to washing machines and, more particularly, to a foamed cleaning solution dispensing system for use in washing machines. 
     BACKGROUND OF THE INVENTION 
     There are generally two categories of washing machines that are used for the purpose of washing laundry articles such as clothes. A first category is a vertical axis washing machine that allows for top-loading of laundry articles into a washing chamber that includes an agitator that rotates about a vertical axis. The agitator generates a vortex flow within the washing chamber and causes the laundry articles to undergo a vigorous frictional movement against each other and the agitator to provide the desired cleaning action. A second category of laundry machine is a horizontal axis laundry machine that allows for front-loading of laundry articles into the washing chamber and includes a rotary drum that rotates about a horizontal axis and is partially submerged in the cleaning liquid of the washing chamber. With this type of washing machine, the laundry articles contained in the rotary drum are rubbed against each other as the drum rotates. 
     The above-described washing machines typically include a detergent container that is adapted to contain a quantity of powder or liquid detergent product that when mixed with water forms the cleaning liquid that is used to wash the laundry articles. The detergent container is in fluid communication with the washing chamber of the washing machine. A flow of water is sent through the detergent container during the wash cycle of a selected washing sequence to thereby flush out and convey into the washing chamber a quantity of the detergent that further mixes with water in the washing chamber to form the cleaning liquid. Different detergent products and/or fabric softeners can be added to the detergent container at different phases or cycles of an ongoing washing sequence to have them introduced into the washing chamber. 
     It has been estimated that 35 billion loads of laundry are washed in the United States each year. As a result, an enormous amount of energy is consumed by washing machines to clean laundry. Additionally, pollutants in the form of detergents and chemical agents that are used during the washing of the laundry can potentially harm the environment. Accordingly, concerns exist not only to the enormous amount of energy that is consumed by washing machines, but the potential harm that detergents and other chemicals used during the washing process may have on the environment. 
     The energy used by a washing machine to wash a load of laundry is directly related to the duration of the wash and rinse cycles. The duration of the rinse cycles are related to the amount of detergent or chemicals that are used. In general, the more detergent used during a wash cycle, the longer the rinse cycle must be in order to extract the detergent from the laundry articles and, hence, the more energy that must be used by the washing machine. Furthermore, the more detergent used during a wash cycle, the more pollutant byproducts that are generated. Accordingly, both the energy used by the washing machine and the pollutant byproducts produced thereby can be reduced by reducing the amount of detergent that is used during the wash cycle. 
     To that end, efforts are directed to increase the cleaning efficiency of washing machines to not only reduce the amount of energy that is used during wash and rinse cycles but, possibly, the amount of detergent that is used as well. One method of accomplishing this is through the introduction of air bubbles into the washing chamber during the wash cycle. The air bubbles are used to improve the cleaning efficiency of the cleaning liquid by attracting dirt particles to their surfaces. The air bubbles along with the clinging dirt particles are then removed from the washing chamber. Although air bubbles can be generated during the washing cycle as a result of the movement of the clothes within the washing liquid, more efficient cleaning can result through the injection of air bubbles into the washing chamber by a bubble generating component. Such bubble generating components are typically positioned at a base of the washing chamber and produce air bubbles that travel through the cleaning liquid that is stored therein. 
     There exists a never-ending demand for improvements to washing machines to increase their cleaning efficiency while reducing their energy consumption and their production of environmentally harmful byproducts. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a foamed cleaning liquid dispensing system for use in a washing machine that improves the cleaning efficiency of the cleaning liquid, reduces washing machine energy consumption and chemical waste. The foamed cleaning liquid dispensing system generally includes a cleaning liquid dispenser and a foaming device. The cleaning liquid dispenser includes an output flow of cleaning liquid, which is received by the foaming device. The foaming device includes an input flow of air and a mixing member in which the flows of air and cleaning liquid are combined to form an output flow of foamed cleaning liquid that is directed to a washing chamber of the washing machine. The foamed cleaning liquid provides a significant improvement to the cleaning efficiencies of the cleaning liquid, which allows for less cleaning agent or chemical to be used for a given wash cycle. As a result, the foamed cleaning liquid dispersing system of the present invention reduces washing machine energy consumption and chemical waste. 
    
    
     These and other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram of a washing machine that includes a foamed cleaning liquid dispensing system in accordance with various embodiments of the invention. 
     FIG. 2 is a simplified diagram of a foamed cleaning liquid dispensing system in accordance with various embodiments of the invention. 
     FIG. 3 is a schematic diagram of a flow restriction member in accordance with an embodiment of the invention. 
     FIG. 4 is a simplified cross-sectional view of a nozzle that forms a foaming device in accordance with an embodiment of the invention. 
     FIG. 5 is a schematic diagram of a system for dispensing one or more supplies of cleaning liquid in accordance with various embodiments of the invention. 
     FIGS. 6-8 are schematic diagrams of chemical dispensers in accordance with various embodiments of the invention. 
     FIG. 9 is a cross-sectional view of a flow restriction member in accordance with an embodiment of the invention. 
     FIG. 10 is a simplified cross-sectional view of a cleaner cartridge in accordance with an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed to a foamed cleaning liquid dispensing system  100  for use in a washing machine, such as washing machine  102  as shown in the schematic diagram of FIG.  1 . System  100  is generally adapted to dispense a foamed cleaning liquid for use during wash cycles to clean laundry articles. The foamed cleaning liquid produced by system  100  enhances the cleaning process performed by the washing machine as compared to the prior art through better activation of the surfactant (surface-active material) of the cleaning liquid so that it works more quickly and efficiently by forming stable, or quasi-stable, dispersions with soils so that they are readily removed from the laundry articles. The foaming of the cleaning liquid not only allows for less cleaning agent to be used, but also allows for complete dispersion of the cleaning agent into the water at low temperatures. This provides advantages over the prior art, which typically requires the water to be heated in order to ensure that the cleaning agent properly goes into the solution to form the cleaning liquid. As a result, energy is conserved by foamed cleaning liquid dispensing system  100  of the present invention by not only allowing for shorter rinse cycles due the use of less cleaning agent, but also by allowing the wash cycle to be performed at lower temperatures. Thus, washing machine  102  utilizing system  100  can perform cleaning operations with less chemicals for improved cleaning efficiency, lower energy consumption, and less chemical waste, than would be possible using conventional washing machine cleaning liquid dispensing systems. 
     In addition to foamed cleaning liquid dispensing system  100 , washing machine  102  also includes several conventional components, such as a controller  104 , a supply of water  106 , a washing chamber  108 , a washing device  110  contained in washing chamber  108 , and a motor  112  that drives washing device  110 . Controller  104  controls the operation of washing machine  102  including motor  112  and other components of washing machine  102 , such as water flow control valve  114 , to perform various washing cycles to clean laundry articles that are contained within washing chamber  108 . Washing machine  102  can also include sensors (not shown), such as temperature and water level sensors, that controller  104  can use during washing operations. 
     Washing machine  102  can be any type of washing machine including a vertical axis washing machine or a horizontal axis washing machine. The vertical axis washing machine allows for top-loading of laundry articles into washing chamber  108  and includes washing device  110  in the form of an agitator. The agitator is driven by motor  112  to generate a vortex flow within washing chamber  108  that causes the laundry articles to undergo a vigorous frictional movement against each other and the agitator to provide the desired cleaning action. The horizontal axis laundry machine that allows for front-loading of laundry articles into washing chamber  108 . In accordance with this type of laundry machine, washing device  110  is typically a rotary drum that rotates about a horizontal axis and is partially submerged in the cleaning solution that is contained in washing chamber  108 . With this type of washing machine, the laundry articles contained in the rotary drum are rubbed against each other as the rotary drum rotates. 
     An example of a typical wash sequence includes a wash cycle followed by one or more rinse cycles. After loading the laundry articles into washing chamber  108 , the wash cycle begins by adding hot, warm or cold water to washing chamber  108  from water supply  106  by actuation of valve  114  by controller  104 . Additionally, as will be discussed in greater detail below, controller  104  or a separate controller controls the operation of foamed cleaning liquid dispensing system  100  to dispense a predetermined quantity of foamed cleaning liquid into washing chamber  108 , as indicated by arrow  116 . Next, controller  104  causes motor  112  to drive washing device  108  and commence the washing of articles contained in washing chamber  108 . The washing cycle ends after a predetermined period of time, and one or more rinse cycles are performed after washing chamber  108  is drained. Each rinse cycle begins by adding hot, warm or cold water from supply  106  to washing chamber  108 . Additionally, a rinse agent or fabric softener can be added by foamed cleaning liquid dispensing system  100  in accordance with one embodiment of the invention. During the rinse cycle, washing device  110  is again driven by motor  112  to agitate the laundry articles within the water. Finally, the soiled water is typically extracted from the laundry articles by rotating the laundry articles within washing chamber  108  and draining the extracted liquid to waste. 
     Foamed cleaning liquid dispensing system  100  generally includes a cleaning liquid dispenser  120  and a foaming device  122 . Cleaning liquid dispenser  120  includes an output flow of cleaning liquid  124  that is received by foaming device  122 . Foaming device  122  includes an input flow of air  126  and a mixing member  128  that combines the cleaning liquid flow  124  with the air flow  126  to thereby generate the flow of foamed cleaning liquid  116  that is directed into washing chamber  108 . 
     One embodiment of cleaning liquid dispenser  120  includes a supply of cleaning liquid  130 , conduit  132 , and a cleaning liquid flow control device  134 . Conduit  132  is in fluid communication with cleaning liquid supply  130  and foaming device  122 . Cleaning liquid flow control device  134  is positioned in line with conduit  132  and is adapted to control the output flow of cleaning liquid  124  which is provided to fluid mixing member  128 . 
     FIG. 2 is a simplified diagram of a foamed cleaning liquid dispensing system  100  including a cleaning liquid dispenser  120  and foaming device  122  in accordance with various embodiments of the invention. In accordance with one embodiment, cleaning liquid flow control device  134  includes a pump  140  in line with the conduit  132 , which is fluidically coupled to the cleaning liquid supply  130 . Pump  140  is adapted to drive the cleaning liquid flow  124  through conduit  132  in a controlled manner. 
     Pump  140  includes an outlet  144 , through which cleaning liquid flow  124  is driven, that is maintained at a high pressure. In accordance with one embodiment, the pressure at outlet  144  is held substantially constant at approximately 40 pounds per square inch (psi). Pump  140  can be a diaphragm pump, such as diaphragm pump model number 8006-543-250 manufactured by Shur Flow of Garden Grove, Calif., or other suitable pump. 
     Cleaning liquid flow control device  134  can further include a controller  146  having a control signal  148  that is electrically coupled to pump  140 , which drives output flow  124  of cleaning liquid in response to the control signal. Accordingly, control signal  148  can cause pump  140  to increase or decrease the pressure at output  144  to thereby increase or decrease the flow rate of output flow  124  of cleaning liquid, respectively. Pump  140  can be powered using conventional means or from control signal  148 . Controller  146  can be either separate or integrated with controller  104  of washing machine  102 , shown in FIG.  1 . 
     In accordance with another embodiment of the invention, cleaning liquid flow control device  134  further includes a flow restriction member  150  in line with conduit  132  and pump  140 . Flow restriction member  150  is configured to generate a pressure drop in conduit  132  to thereby restrict the flow rate of the cleaning liquid flow  124  therethrough. Accordingly, flow restriction member  150  includes an upstream high pressure side  152  and a downstream low pressure side  154 . Multiple flow restriction members  150  can be employed to provide the desired pressure drop in conduit  132  that results in desired volume flow rate of cleaning liquid flow  124 . In accordance with one embodiment, the output flow  124  of cleaning liquid is preferably limited by flow restriction member  150  to approximately 2.0 gallons per minute (GPM). 
     In accordance with one embodiment, flow restriction member  150  is a metering orifice or orifice plate  156 , shown in FIG.  3 . Orifice plate  156  includes an orifice  158  and is installed in conduit  132 , the inner diameter of which is indicated by dashed line  160 , such that cleaning liquid flow  124  is forced to flow through orifice  158 . This produces the pressure drop as described above and restricts the cleaning liquid flow  124  to the desired flow rate for a given pressure at outlet  144  of pump  140 . In accordance with a preferred embodiment, orifice  158  of orifice plate  156  has a diameter D of approximately 0.3 inches to provide the desired output flow of 2.0 GPM when the pressure of outlet  144  of pump  140  is at 40 psi. One example of a suitable metering orifice or orifice plate  156  is part number CP 4916-40 manufactured by Spraying Systems Company of Wheaton, Ill. Other orifice plates or metering orifice configurations are possible as well, such as by providing multiple orifices in the plate  156  or other flow restriction configurations. 
     Foaming device  122  may include a variety of foam generation devices including, but not limited to, pressurized air and/or pressurized liquid systems, agitation systems, etc. In accordance with one embodiment, foaming device  122  includes an air system  162  that includes an air pump  164  that generates air flow  126 , a check valve  166 , and associated fluid conduit sections  168  and  170 , as shown in FIG.  2 . Suitable types of air pumps  164  include piston, diaphragm or rotary vane pumps. One preferred air pump  164  is a piston pump model number 22D1180-206-1002 manufactured by Gast Manufacturing, Inc. of Benton Harbor, Mich. Check valve  166  is provided to prevent the back flow of cleaning liquid into air pump  164 . Check valves can also be positioned in line with cleaning liquid dispensing system  120  to prevent the back flow of fluid therethrough. 
     Mixing member  128  preferably includes a first mixing element  172  that receives air flow  126  from air system  162  via conduit section  170  and pressurized cleaning liquid from cleaning liquid dispensing system  120  via conduit section  174 . First mixing element  172  is a Y-coupling having a pair of inlet, ports  176  and  178  and an outlet port  179 . The cleaning liquid flow  124  and the air flow  126  are combined in first mixing element  172  to form a flow of aerated cleaning liquid  180 , which is discharged through outlet port  179  into conduit section  181 . First mixing element  172  can be alternatively configured, but should include at least a pair of inlet ports for receiving the cleaning liquid flow  124  and the air flow  126  and an outlet port for discharging the mixture. Furthermore, although first mixing element  172  is described as a passive mixing element, it may also include active mixing devices, such as an energized impeller. 
     In accordance with one embodiment, a valve  182  is provided in line with conduit section  181  to control the aerated cleaning liquid flow  180  therethrough. Valve . 182  is preferably an electric solenoid valve, under control of controller  146 , that is operable between an open position in which the aerated cleaning liquid flow  180  is permitted to flow through first mixing element  172 , and a closed position in which the aerated cleaning liquid flow  180  is blocked. Alternative valves may be used to control the flow of fluid within the system  100 , such as a variable output valve or other suitable component. 
     The aerated cleaning liquid flow  180  can be dispensed directly into washing chamber  108  as a form of foamed cleaning liquid flow  116  through, for example, a nozzle that can provide additional foaming action to increase the foam in flow  116 . An example of such a nozzle will be discussed in greater detail below. 
     In accordance with another embodiment of the invention, fluid mixing member  128  further includes a foam generating member  184  that enhances the mixing of air and cleaning liquid and the generation of the foamed cleaning liquid  116 . Foam generating member  184  can be a passive element including a rigid housing  186  having an inlet port  188  and an outlet port  190  as shown in FIG.  2 . Inlet port  188  receives the aerated cleaning liquid flow  180  through conduit section  192 . A diffusion medium  194  is contained in housing  186  and is adapted to increase foam generation by providing a shearing action, air entrainment, or a combination of both, to the aerated cleaning liquid flow  180 . In accordance with a preferred embodiment, diffusion medium  194  includes a plurality of SCOTCH BRITE® brand copper pads, manufactured by Minnesota Mining and Manufacturing Company of St. Paul, Minn. Alternative diffusion media may also be practicable including, but not limited to, glass beads, foams, and other porous substrates. 
     The length and diameter of housing  186  of foaming member  184  as well as the structure of diffusion medium  194 , are sized to maintain the operating pressure of system  100  at a desired level. For example, using a coarser diffusion medium  194  allows for easier passage of the aerated cleaning liquid flow  180  and the foamed cleaning liquid flow  116  through housing  186 . However, such a coarser diffusion medium  194  also results in larger foam bubbles in the foamed cleaning liquid flow  116 . However, by using a sufficiently long housing  186  with an appropriate diffusion medium  194 , large foam bubbles formed near inlet  188  will break down into more desirable smaller micro-bubbles preferably of approximately 0.002 inches in diameter, prior to reaching outlet  190 . As an example, housing  186  of the illustrated foaming member  184  is preferably approximately 9 inches long and has an inner diameter of approximately 2 inches. 
     The output flow of foamed cleaning liquid  116  is discharged from foaming member  184  at outlet port  190  and is directed toward washing chamber  108  via conduit section  196 . Foaming member  184  may be provided at an incline relative to the ground surface so that inlet port  188  is at a slightly lower elevation than outlet port  190 . This arrangement reduces the amount of foamed cleaning liquid  116  that is delivered to washing chamber  108  after valve  182  has been closed. Alternatively, valve  182  can be located downstream of outlet port  190  and closer to washing chamber  108  to provide further control over the amount of foamed cleaning liquid  116  that is dispensed into washing chamber  108 . 
     FIG. 4 is a schematic diagram of another embodiment of foaming device  122 . Here, foaming device  122  takes the form of a nozzle  200 . Nozzle  200  includes an inlet  202  that receives the cleaning liquid flow  124  from cleaning liquid dispensing system  120 . The flow  124  is directed through a constricted throat portion  204  having a convergent upstream end  206  and a divergent downstream end  208 . Nozzle  200  also includes radial ports  212  extending from throat  204  through which air flow  126  is provided in response to the vacuum generated within throat  204  by the cleaning liquid flow  124 . In accordance with this embodiment of foaming device  122 , mixing member  128  generally corresponds to constricted throat portion  204  and mixing chamber  214  in which the aerated cleaning liquid is formed. The aerated cleaning liquid is finally dispensed as the foamed cleaning liquid flow  116  into washing chamber  108  through nozzle tip  210 . One example of a suitable nozzle  200  is the Foam Cannon, part number HP 344030, distributed by Higher Power Supplies, Inc. 
     In operation, the triggering of a wash cycle by controller  104  of washing machine  102  causes controller  146  of system  100  to drive air pump  160  of air system  162  and pump  140  of cleaning liquid dispenser  120  for the embodiment depicted in FIG.  2 . Additionally, if necessary, controller  146  opens valve  182 . Pressurized air flow  126  is then directed through conduit section  168 , check valve  166  and conduit section  170  to mixing element  172 . Additionally, cleaning liquid dispensing system  120  delivers cleaning liquid flow  124  through pump  140 , conduit section  132 , flow restriction member  142  (if installed), and conduit section  174 , to inlet port  178  of mixing element  172 . The air flow  126  and cleaning liquid flow  124  are combined in mixing element  172  and discharged as aerated cleaning liquid flow  180  through outlet  179  and into conduit section  181 . The aerated cleaning liquid flow  180  can either be dispensed into washing chamber  108  or directed to a foam generating or foaming member  184  where it is received at inlet port  188 . Foaming member  184  provides additional foaming action to the aerated cleaning liquid flow  180  through interaction a diffusion medium  194  contained in housing  186 . The foamed cleaning liquid flow  116  can then be dispensed through outlet  190  of foaming member  184  and is directed to washing chamber  108  via conduit section  196  for use during the wash cycle. 
     In accordance with the nozzle embodiment of foaming device  122 , the triggering of a wash cycle by controller  104  of washing machine  102  causes controller  146  of system  100  to drive the cleaning liquid flow  124  into inlet  202  and through throat  204 . In response to the cleaning liquid flow  124 , air flow  126  enters radial ports  212  and is combined with cleaning liquid flow  124  to form aerated cleaning liquid in mixing chamber  214 . Finally, the aerated cleaning liquid or foamed cleaning liquid  116  is dispensed through nozzle tip  210  and into washing chamber  108 . 
     Cleaning liquid  130  is preferably a mixture of a primary cleaning liquid component and a detergent or cleaning agent. The supply of cleaning liquid  130  can be stored in a container of washing machine  102  and fed to cleaning liquid flow control device  134  through conduit  132 , as shown in FIG.  1 . The primary cleaning liquid component is preferably water that is received from water supply  106  or from another source. The cleaning agent preferably includes an anionic surfactant, a nonionic surfactant, a cationic surfactant, or a combination thereof. A particularly preferred surfactant is DeTeric CP-Na-38 manufactured by DeForest Enterprises, Inc., of Boca Raton, Fla. A particularly preferred surfactant concentration of the cleaning liquid is approximately 0.1% of the primary cleaning liquid component. Alternative cleaning liquids may include one or more surfactants, builders, solvents, or other components. 
     In accordance with an alternative embodiment, the supply of cleaning liquid  130  is generated as a combination of separate supplies of cleaning agent  220  and primary cleaning liquid component  222 , as illustrated in the schematic diagram of FIG.  5 . Cleaning agent supply  200  is preferably in concentrated form and is a component of a chemical dispenser  224 . Chemical dispenser  224  also includes a cleaning agent flow control device  226 , which is fluidically coupled to supply  220  and provides a flow  228  of cleaning agent at a predetermined volume flow rate, preferably 0.1% of the primary cleaning liquid component to a fluid mixing member  230 . As mentioned above, the supply  222  of primary cleaning liquid component is preferably provided from water supply  106  (FIG.  1 ), but could be provided by another source. Fluid mixing member  230  combines the cleaning agent flow  228  from flow control device  226  and a flow of primary cleaning liquid component  232  from supply  222  to form the cleaning liquid supply  130  in the form of a cleaning liquid flow  234 , which is provided to cleaning liquid flow control device  134 . 
     FIGS. 6-8 illustrate various embodiments of chemical dispenser  224  that can be used to inject cleaning agent flow  228  into flow  232  of primary cleaning liquid component to form the supply of cleaning liquid  130  for foamed cleaning liquid dispensing system  100  in accordance with various embodiments of the invention. Fluid mixing member  230  can be positioned either upstream or downstream of cleaning liquid flow control device  134 , such as pump  140  shown in FIG.  2 . It should be understood that the cleaning liquid supply  130  depicted in FIG. 2 could comprise only the primary cleaning liquid component where chemical dispenser  224  injects the cleaning agent flow  228  either upstream or downstream of cleaning liquid flow control device  134 . Cleaning liquid flow control device  134  still substantially controls the flow rate of cleaning liquid flow  124  since the volume flow rate of cleaning agent flow  228  is small in comparison to the flow  232  of the primary cleaning liquid component. 
     Fluid mixing member  230  can be a T-coupling having inlets  236  and  238  that respectively receive the flows  228  and  232  of cleaning agent and primary cleaning liquid component, as shown in FIG.  6 . The flow of cleaning liquid  124  is then provided at an outlet  240 . Other types of fluid mixing components can be used as well to perform the function of fluid mixing member  230 . 
     One embodiment of flow control device  226  includes a pump  242  that receives cleaning agent from cleaning agent supply  220  and drives the flow  228  of cleaning agent through conduit  244  to fluid mixing member  230  as shown in FIG.  6 . The cleaning agent flow  228  is preferably generated substantially independently of the volume of cleaning agent in supply  220 . A check valve (not shown) can be installed in line with conduit section  132  upstream of fluid mixing member  230  to prevent the back flow of cleaning agent therethrough. Pump  242  is preferably a solenoid pump, such as pump number ET200BRHP sold through Farmington Engineering of Madison, Conn., and manufactured by CEME. Another suitable pump is the SV 653 metering pump manufactured by Valcor Scientific. Other types of pumps can also be used for pump  230 . 
     A controller  246  controls the operations of pump  242  through a control signal  248 . Controller  246  can be incorporated into washing machine controller  104  (FIG. 1) or controller  146  (FIG.  2 ). An example of a suitable controller is part number QRS2211C (either 24 V or 36 V) sold by Infitec Inc. of Syracuse, N.Y. In accordance with one embodiment, signal  248  is a pulsed signal that provides power relative to ground (not shown.) and controls the duration over which pump  242  drives the flow  228  of cleaning agent through conduit section  244 . For example, control signal  248  can turn pump  242  on for 0.1 seconds and off for 2.75 seconds to produce the desired low volume output flow  228  of cleaning agent. 
     In accordance with another embodiment of the invention, flow control device  226  includes a flow restriction member  250  having an upstream high pressure inlet  252  and a low pressure outlet  254 , as shown in FIG.  7 . Inlet  252  of flow restriction member  250  is fluidically coupled to supply of cleaning agent  220  through conduit section  256 . Outlet  254  is fluidically coupled to inlet  236  of fluid mixing member  230 . Fluid mixing member  230  is positioned upstream of cleaning liquid flow control device  134  and receives the flow of primary cleaning liquid  232  at inlet  238 . A vacuum generating component  258 , such as the metering orifice or orifice plate shown in FIG. 3, in combination with pump  140  (FIG.  2 ), can be provided in line with the flow of primary cleaning liquid component  232  to produce a low pressure region, preferably at approximately −1.0 psi, adjacent outlet  254  of flow restriction member  250 . This vacuum produces a pressure gradient from the inlet  252  to the outlet  254  of flow restriction member  250  that results in a substantially constant flow  228  of cleaning agent through flow restriction member  250 . 
     One embodiment of flow restriction member  250  includes a labyrinthine fluid flow path to provide the desired flow restriction. The labyrinthine path is preferably formed by one or more drip irrigators  260 , such as those shown in FIG.  9 . One such preferred drip irrigator  260  that can be used to form flow restriction member  250  is described in U.S. Pat. No. 5,031,837 and available as part no. R108C manufactured by Raindrip of Woodland Hills, Calif. Preferably three drip irrigators  260  are coupled together with tubing sections  262  and  264 . A surround  266  covers drip irrigators  260  and tubing sections  262  and  264 . Outlet  254  of flow restriction member  250  couples to inlet  236  of fluid mixing member  230  or to a section of tubing (not shown) that is coupled to inlet  236  of fluid mixing member  230 . Inlet  252  of flow restriction member  250  is coupled to conduit section  256  (FIG. 7) for fluid communication with supply  220  of cleaning agent. Other suitable drip irrigators or similar flow restriction devices can also be used to form the desired labyrinthine path of this embodiment of flow restriction member  250 . 
     In accordance with another embodiment of the invention, cleaning agent flow control device  226  of chemical dispenser  224  includes both the pump  242  and flow restriction member  250 , as shown in FIG.  8 . Pump  242  and flow restriction member  250  are placed in line with the supply of cleaning agent  220  and fluid mixing member  230 . Pump  242  drives the flow of cleaning agent  228  through flow restriction member  250  in response to a control signal  248  from controller  246 . A check valve  270  can be placed in line with flow  232  to prevent back flow to the primary cleaning liquid supply  222 . Thus, pump  242  generates the desired pressure at inlet  252  of flow restriction member  250  that is higher than that at outlet  254  or at fluid mixing member  230  to drive the cleaning agent flow  228  therethrough at a substantially constant flow rate. 
     Foamed cleaning liquid dispensing system  100  can also be configured to use multiple chemical dispensers  224 , as illustrated in FIG. 5, each of which is configured to dispense a respective cleaning agent or chemical for mixing with a flow of primary cleaning liquid component to form the desired cleaning liquid. Thus, for example, two cleaning agent dispensers  224 A and  224 B can be provided to respectfully dispense flows  228 A and  228 B of cleaning agents  220 A and  220 B using flow control devices  226 A and  226 B. The flows  228 A and  228 B are provided to fluid mixing member  230  for mixing with flow  232  of the primary cleaning liquid component. Additional chemical dispensers  224  adapted to dispense other cleaning agents or chemicals can also be added. This arrangement allows foamed cleaning liquid dispensing system  100  to dispense a different type of cleaning agent or other chemical as desired for the particular washing operation being performed by washing machine  102 . For example, cleaning agent  220 A can be a detergent for use during a wash cycle and cleaning agent  220 B can be a fabric softener for use during a rinse cycle. In accordance with this embodiment, fluid mixing member  230  can be configured to selectively mix one or more of the cleaning agents with output flow  232  of the primary cleaning liquid component. Fluid mixing member  230  can include a single multi-way valve or other suitable component to accomplish selective mixing of a flow of cleaning agent  228  and the flow  232  of primary cleaning liquid component to form the desired cleaning liquid flow  234 . 
     Cleaning agent supply  220  is preferably contained in a disposable container or cleaner cartridge. In accordance with one embodiment, cleaner cartridge  272  generally includes a container  274  having an interior cavity  276  and conduit  278 , as shown in FIG.  10 . Conduit  278  includes a first end  280  that is fluidically coupled to flow control device  226  of cleaning agent dispenser  224 . Container  274  is preferably a collapsible bag that is completely sealed except where connected to conduit  278 . Thus, container  274  shrinks as the cleaning agent stored therein is depleted. In accordance with this embodiment, container  274  can be formed of vinyl or other suitable material. Alternatively container  274  can take the form of a rigid container, such as a box, that includes a vent for replacing dispensed cleaning agent with air. Container  274  can be transparent or translucent to allow the cleaning agent contained therein to be viewed. Alternatively, container  274  can be formed of a material that prevents the exposure of the cleaning agent contained therein from light. 
     First end  280  of conduit  278  is preferably attached to container  274  such that it is flush with the inside of outlet  284 . A seal  286  is formed between first end  280  and container  274  at outlet  284  to prevent cleaning agent from escaping at that junction. In accordance with one embodiment, seal  286  includes an annular neck  288  surrounding first end  280  and adjoining container  274 . A weld  290  can be formed between annular neck  288  and first end  280  and container  274  to further seal the junction. Other methods for sealing the junction of first end  280  and container  274  can also be used. 
     Conduit  278  can also include a flow control member  292 , such as that depicted in FIG. 6, mounted to second end  282  to prevent the flow of cleaning agent therethrough when disconnected from flow control device  226 . Flow control member  292  preferably includes a connector (quick-disconnect coupling) that includes a shut-off valve that is actuated when disconnected to seal container  274  and prevent the outflow of cleaning agent therefrom. A cooperating connector  294  is preferably attached to a section of conduit  244  and cooperates with connector/flow control member  292  to facilitate the quick-connection of cleaner cartridge  272  to cleaning agent flow control device  226 . One suitable arrangement for connector/flow control member  292  and the cooperating connector  294  are coupling insert PLCD2200612 and coupling body PLCD1700412 manufactured by Colder Products Company of St. Paul, Minn. Other types of flow-control members  292  can also be installed at second end  282  of conduit  278  to seal interior cavity  276  of container  274  such as a valve, a metering device, a clamp, a membrane, a cap, or other suitable control member. 
     In accordance with one embodiment of the invention, cleaner cartridge  272  includes a housing  296 , shown in FIG. 6, that encloses container  274 . Housing  296  provides protection and support to container  274 , which is particularly useful when container  274  is in the form of a collapsible bag. Housing  296  is preferably made from a single piece of rigid or semi-rigid material, such as plastic, cardboard and/or metal that is folded to form a box in which container  274  is contained. In accordance with a preferred embodiment, housing  296  is formed of corrugated plastic or cardboard. 
     In operation, cleaner cartridge  272  is provided and a supply of cleaning agent is stored in interior cavity  276  of container  274 . Next, second end  282  of conduit  278  is coupled to cleaning agent flow control device  226  and cartridge  272  is installed in a cartridge receiver mounted to washing machine  102 . Cleaning agent flow control device  226  can then receive the supply of cleaning agent through conduit  278  and provide a controlled output flow  228  of cleaning agent, as discussed above. 
     Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, the foamed cleaning liquid dispensing system of the present invention may be used with other washing machines, such as dish washing machines, car washing machines, and other types of washing machines in which improved cleaning efficiency, lower energy consumption, and reduced waste is desired. Furthermore, it should be understood that the particular configuration of the various components of the present invention can be rearranged and still provide the desired function while remaining within the scope of the present invention.