WASHING MACHINE APPLIANCE AND A METHOD FOR OPERATING THE SAME

Abstract

A washing machine appliance and a method for operating a washing machine appliance are provided. The method includes steps to determine the absorptivity of the articles received in the washing machine appliance for washing.

Description

FIELD OF THE INVENTION

The present subject matter relates generally to washing machine appliances and methods for operating washing machine appliances.

BACKGROUND OF THE INVENTION

Washing machine appliances generally include a tub for containing wash fluid, e.g., water, detergent, fabric softener, and/or bleach, during operation of such washing machine appliances. A drum is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During operation of such washing machine appliances, wash fluid is directed into the tub and onto articles within the wash chamber of the drum. The drum can rotate at various speeds to agitate articles within the wash chamber in the wash fluid, to wring wash fluid from articles within the wash chamber, etc.

During operating of certain washing machine appliances, a volume of water is directed into the tub to form wash fluid and/or rinse articles within the wash chamber of the drum. The volume of water can vary depending upon a variety of factors. Large loads can require a large volume of water relative to small loads that can require a small volume of water. Likewise, loads containing absorptive fabrics, such as cotton, can require a large volume of water relative to similarly sized loads containing certain synthetic fabrics, such as polyester or nylon.

To operate efficiently, the volume of water directed into the tub preferably corresponds or correlates to a size of a load of articles within the wash chamber of the drum and/or a load type of articles within the wash chamber of the drum. Thus, to properly wash large loads or loads of highly absorptive articles, large volumes of water are preferably directed into the washing machine's tub. Conversely, to properly wash small loads or loads of poorly absorptive articles, small volumes of water are preferably directed into the washing machine's tub. Directing an improper volume of water into the drum can waste valuable water and/or energy and can also hinder proper cleaning of articles within the wash chamber of the drum. However, accurately determining the type of a load of articles within the wash chamber of the drum can be difficult.

Accordingly, a method for operating a washing machine appliance to determine the type of a load of articles within a wash chamber of a drum of the washing machine appliance would be useful. In addition, a washing machine appliance with features for determining the type of a load of articles within a wash chamber of a drum of the washing machine appliance would be beneficial.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a washing machine appliance and a method for operating a washing machine appliance. The method includes steps to determine the absorptivity of the articles received in the washing machine appliance for washing. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In a first exemplary embodiment, a method for operating a washing machine appliance is provided. The washing machine appliance has a wash basket positioned within a tub, and the wash basket is configured to receive a load of articles for washing. The method includes the steps of estimating a mass of articles within the wash basket; determining a height h_load of the load of articles; directing liquid to the wash basket through a fluid additive dispenser and a spray nozzle of the washing machine appliance for a portion of a predetermined time interval t_int; dispensing liquid to the wash basket through only the spray nozzle for a remaining portion of the predetermined time interval t_int; counting a time t_absp to fill the tub with a volume of liquid to a predetermined height h_pre; and establishing an absorptivity of the articles in the load.

In a second exemplary embodiment, a washing machine appliance is provided. The washing machine appliance includes a tub; a wash basket positioned within the tub, and the wash basket configured to receive articles for washing; a plurality of valves configured for directing a flow of water to the tub; a fluid additive dispenser; a spray nozzle; and a controller in operative communication with the plurality of valves. The controller is configured for estimating a mass of articles within the wash basket; determining a height h_load of the load of articles; directing liquid to the wash basket through the fluid additive dispenser and the spray nozzle for a portion of a predetermined time interval t_int; dispensing liquid to the wash basket through only the spray nozzle for a remaining portion of the predetermined time interval t_int; counting a time t_absp to fill the tub with a volume of liquid to a predetermined height h_pre; and establishing an absorptivity of the articles in the load.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 illustrates an exemplary embodiment of a washing machine appliance of the present invention with a door shown in a closed position.

FIG. 2 illustrates the exemplary embodiment of a washing machine shown in FIG. 1 except with the door shown in an open position.

FIG. 3 is a front, perspective view of an exemplary embodiment of a fluid dispenser of the present invention.

FIG. 4 is a cross-sectional view of the exemplary embodiment of a fluid dispenser shown in FIG. 3.

FIG. 5 is a front view of the exemplary embodiment of a fluid dispenser shown in FIG. 3 except with the dispenser drawer removed.

FIG. 6 illustrates a method of operating a washing machine appliance according to an exemplary embodiment of the present subject matter.

FIG. 7 illustrates an exemplary plot of volume-liquid level absorption correlations for various load types of articles within a wash chamber of a washing machine appliance and an estimated mass of articles within the wash chamber.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIGS. 1 and 2 illustrate an exemplary embodiment of a vertical axis washing machine appliance 100. In FIG. 1, a lid or door 130 is shown in a closed position. In FIG. 2, door 130 is shown in an open position. While described in the context of a specific embodiment of vertical axis washing machine appliance 100, using the teachings disclosed herein it will be understood that vertical axis washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., horizontal axis washing machines.

Washing machine appliance 100 has a cabinet 102 that extends between a top 103 and a bottom 104 along a vertical direction V. A wash basket 120 (FIG. 2) is rotatably mounted within cabinet 102. A motor (not shown) is in mechanical communication with wash basket 120 to selectively rotate wash basket 120 (e.g., during an agitation or a rinse cycle of washing machine appliance 100). Wash basket 120 is received within a wash tub or wash chamber 121 (FIG. 2) and is configured for receipt of articles for washing. The wash tub 121 holds wash and rinse fluids for agitation in wash basket 120 within wash tub 121. An agitator or impeller (not shown) extends into wash basket 120 and is also in mechanical communication with the motor. The impeller assists agitation of articles disposed within wash basket 120 during operation of washing machine appliance 100.

Cabinet 102 of washing machine appliance 100 has a top panel 140. Top panel 140 defines an opening 105 (FIG. 2) that permits user access to wash basket 120 of wash tub 121. Door 130, rotatably mounted to top panel 140, permits selective access to opening 105; in particular, door 130 selectively rotates between the closed position shown in FIG. 1 and the open position shown in FIG. 2. In the closed position, door 130 inhibits access to wash basket 120. Conversely, in the open position, a user can access wash basket 120. A window 136 in door 130 permits viewing of wash basket 120 when door 130 is in the closed position, e.g., during operation of washing machine appliance 100. Door 130 also includes a handle 132 that, e.g., a user may pull and/or lift when opening and closing door 130. Further, although door 130 is illustrated as mounted to top panel 140, alternatively, door 130 may be mounted to cabinet 102 or any outer suitable support.

A control panel 110 with at least one input selector 112 (FIG. 1) extends from top panel 140. Control panel 110 and input selector 112 collectively form a user interface input for operator selection of machine cycles and features. A display 114 of control panel 110 indicates selected features, operation mode, a countdown timer, and/or other items of interest to appliance users regarding operation.

Operation of washing machine appliance 100 is controlled by a controller or processing device 108 (FIG. 1) that is operatively coupled to control panel 110 for user manipulation to select washing machine cycles and features. In response to user manipulation of control panel 110, controller 108 operates the various components of washing machine appliance 100 to execute selected machine cycles and features.

Controller 108 may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 100 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. Control panel 110 and other components of washing machine appliance 100 may be in communication with controller 108 via one or more signal lines or shared communication busses.

Top panel 140 includes at least one fluid additive dispenser 200 (FIG. 2) for receipt of one or more fluid additives, e.g., detergent, fabric softener, and/or bleach. While only one fluid dispenser will be described herein, it will be understood that multiple fluid dispensers may be used in alternative embodiments of the invention. Fluid additive dispenser 200 is positioned near wash tub 121; in FIG. 2, dispenser 200 is depicted at a vertical position above wash tub 121 near back panel 106 of cabinet 102, but dispenser 200 could be positioned in other locations as well. Fluid additive dispenser 200 is described in greater detail below.

In an illustrative embodiment, laundry items are loaded into wash basket 120 through opening 105, and washing operation is initiated through operator manipulation of input selectors 112. Wash basket 120 is filled with water and detergent and/or other fluid additives from e.g., dispenser 200, to form wash and rinse fluids. One or more valves can be controlled by washing machine appliance 100 to provide for filling wash basket 120 to the appropriate level for the amount of articles being washed and/or rinsed. By way of example for a wash mode, once wash basket 120 is properly filled with fluid, the contents of wash basket 120 can be agitated (e.g., with an impeller as discussed previously) for washing of laundry items in wash basket 120.

After the agitation phase of the wash cycle is completed, wash basket 120 can be drained. Laundry articles can then be rinsed by again adding fluid to wash basket 120 depending on the specifics of the cleaning cycle selected by a user. The impeller may again provide agitation within wash basket 120. One or more spin cycles also may be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle to wring wash fluid from the articles being washed. During a spin cycle, wash basket 120 is rotated at relatively high speeds. After articles disposed in wash basket 120 are cleaned and/or washed, the user can remove the articles from wash basket 120, e.g., by reaching into wash basket 120 through opening 105.

While described in the context of a specific embodiment of washing machine appliance 100, using the teachings disclosed herein it will be understood that washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations (such as horizontal-axis washing machine appliances), different appearances, and/or different features may also be utilized with the present subject matter as well.

FIG. 3 illustrates an exemplary embodiment of fluid additive dispenser 200. As shown, dispenser 200 includes housing 202 and dispenser drawer 220. Dispenser drawer 220 slides into and out of housing 202 along a sliding direction S.

FIG. 4 is a cross-sectional view of the exemplary embodiment of a fluid additive dispenser 200 shown in FIG. 3. As illustrated, housing 202 has an upper surface 204, lower surface 206, and opposing side surfaces 208. Dispenser drawer 220 includes a foot 228 on either side that slides along the sliding direction S on a ledge 209 defined by lower surface 206 of dispenser housing 202. A ledge 209 is defined adjacent each opposing side surface 208. Further, dispenser drawer 220 defines a groove portion 230 that slides over water channel 210 formed in lower surface 206 of housing 202.

Additionally, dispenser drawer 220 includes compartments 222, 224 for the receipt of fluid additives such as fabric softener, detergent, bleach, and the like. Compartments 222, 224 may be configured to receive a dispenser cup, such as the removable dispenser cup 226 disposed in compartment 224 as illustrated in FIG. 4. Moreover, dispenser drawer 220 defines a gap 232 between compartments 222, 224. In alternative embodiments, dispenser drawer 220 may be configured with one, two, or three or more compartments, and for drawers having more than one compartment, a gap may or may not be defined between adjacent compartments. In still other embodiments, more than one compartment of dispenser drawer 220 may be configured to receive a dispenser cup for the receipt of a fluid additive.

As shown in FIGS. 4 and 5, valves 216, 217, 218, 219 are located near housing 202 to control the flow of hot and cold water into fluid additive dispenser 200 to convey water or a mixture of water and fluid additives to wash basket 120. A given valve may control the flow of hot or cold water into dispenser drawer 220 or water channel 210. For example, in the exemplary embodiment illustrated in FIGS. 4 and 5, valve 216 provides a flow of cold water to housing 202 that is used to flush compartment 222 of dispenser drawer 220. Similarly, valve 218 provides a flow of cold water and valve 219 provides a flow of hot water to housing 202 used to flush compartment 224 of dispenser drawer 220. Valve 217 provides a flow of cold water through water channel 210 to a spray nozzle 214 (FIG. 5), which provides a spray of water into wash basket 120. In alternative embodiments, valve 217 could provide water to a compartment of dispenser drawer 220. In still other embodiments, fewer or more than four valves could supply water to dispenser drawer 220 to flush one or more fluid additives from one or more compartments of the drawer.

Whether hot or cold water is supplied to a given compartment of dispenser drawer 220 may depend on the wash cycle selected by a user of washing machine appliance 100. Alternatively, one or more compartments of dispenser drawer 220 may be designated to receive a particular fluid additive, and whether hot or cold water is supplied to a given compartment may depend on the compartment's designated fluid additive.

Additionally, each compartment 222, 224 defines an outlet (not shown) for the flow of a mixture of water and fluid additive from the compartment to the wash basket 120. The mixture of water and fluid additive may flow from housing 202 directly to wash basket 120, e.g., through an opening between dispenser drawer 220 and lower surface 206, or the mixture may be conveyed to wash basket 120 through, e.g., pipes, tubes, or the like. As shown by arrows F in FIG. 5, the outlets defined in dispenser drawer 220 may be configured such that water or a mixture of water and a fluid additive flows from dispenser drawer 220, along lower surface 206 of housing 202, and spills over into wash basket 120. As described above, the mixture of water and fluid additive flows to wash basket 120 to form a wash and/or rinse fluid for cleaning laundry articles contained in wash basket 120. Further, water may be provided through spray nozzle 214 to wash basket 120 to form a wash and/or rinse fluid. Additionally, as described in detail below, water may be directed to wash basket 120 through dispenser drawer 220 and/or spray nozzle 214 at the beginning of a wash cycle to determine the absorptivity of the load of articles to be washed.

As shown in FIG. 4, a plate 240 is disposed in housing 202 below upper surface 204 such that a gap is defined between plate 240 and upper surface 204 along the vertical direction V. Plate 240 defines a plurality of apertures 242 for the flow-through of water introduced into housing 202 from valves 216, 218, 219 to compartments 222, 224. The plurality of apertures control the flow of water into each compartment 222, 224, creating a shower-like flow into each compartment rather than allowing a deluge of water in one area of the compartment, which could hinder the complete flushing of the fluid additive from the compartment. The flow of water into the compartment through apertures 242 flushes the fluid additive contained in the respective compartment 222, 224 from the compartment through its outlet, providing the mixture of water and the fluid additive to wash basket 120.

FIG. 6 illustrates a method 300 of operating a washing machine appliance according to an exemplary embodiment of the present subject matter. Method 300 can be used to operate any suitable washing machine appliance, such as washing machine appliance 100 (FIG. 1). Method 300 may be programmed into and implemented by controller 108 (FIG. 1) of washing machine appliance 100.

Utilizing method 300, controller 108 can establish an absorptivity of a load of articles within wash basket 120, which can be used to determine the load type of the articles in wash basket 120. As used herein, the term “load type” corresponds to a composition or fabric type of articles, e.g., within wash basket 120. As an example, if articles within wash basket 120 have a relatively high absorptivity, the load type of such articles is a high absorption load type. Cotton articles can have a relatively high absorptivity such that a load of cotton articles is a high absorption load type. Conversely, if articles within wash basket 120 have a relatively low absorptivity, the load type of such articles is a low absorption load type. Synthetic articles, such as nylon or polyester articles, can have a relatively low absorptivity such that a load of synthetic articles is a low absorption load type. If a mixed or blended load of articles is disposed within wash basket 120, the load type of such articles is a mixed or blended absorption load type. By accurately determining the load type, controller 108 can provide an optimal amount of liquid to wash basket 120 to sufficiently wash and/or rinse the load of articles while also conserving water.

As will be easily understood, the accuracy of the established absorptivity determines the accuracy of the load type determination. The accuracy in establishing the absorptivity of the load of articles may be improved by covering the articles with liquid as evenly as possible when determining the absorptivity of the articles. As described more fully below, method 300 includes steps for providing liquid to the load of articles in a manner that substantially uniformly covers the articles.

As shown in FIG. 6, method 300 includes step 310 of estimating the mass of the load of articles in wash basket 120. In one embodiment, controller 108 may estimate the mass of the load based upon the inertia of the articles, which is determined by first rotating wash basket 120 with a motor (not shown), e.g., controller 108 can activate the motor to rotate basket 120. Further, controller 108 can operate the motor such that basket 120 rotates at a predetermined frequency or angular velocity. The predetermined frequency or angular velocity can be any suitable frequency or angular velocity. For example, the predetermined frequency or angular velocity may be about one hundred and twenty revolutions per minute.

Next, controller 108 can utilize the motor to adjust an angular velocity of basket 120. As an example, controller 108 can deactivate the motor, e.g., by shorting the windings of the motor using any suitable mechanism or method, to adjust the angular velocity of basket 70. Then, controller 108 can determine an angular acceleration or first derivative of the angular velocity of basket 120, or a jerk or a second derivative of the angular velocity of basket 120, e.g., based at least in part the adjustment of the angular velocity of basket 120. Based upon the first and/or second derivative of the angular velocity of basket 120, controller 108 can estimate an inertial mass of articles within wash basket 120. As an example, the magnitude of the first and/or second derivative of the angular velocity of basket 120 can be inversely proportional to the mass of articles within wash basket 120. Thus, controller 108 can correlate the magnitude of the first and/or second derivative of the angular velocity of basket 120 to the mass of articles within wash basket 120 at step 310. Controller 108 may also establish a tolerance range for the mass of articles within wash basket 120 to correspond, e.g., to the error or uncertainty of the estimate of the mass of articles within wash basket 120.

Method 300 also includes step 312 of determining the height h_load of the load of articles. The height h_load may be determined based on the mass of the load estimated at step 310, i.e., for a given estimated mass of the load of articles, controller 108 may correlate the mass to a height h_load. In certain embodiments, the height h_load may correspond to the distance from the fluid additive dispenser 200 to the load of articles, such that a small size load that is further from dispenser 200 has a larger height h_load. For example, controller 108 may correlate a load with an estimated mass of approximately three pounds to a height h_load of about 16 inches. That is, for the exemplary embodiment illustrated in FIG. 2, where dispenser 200 is positioned above wash tub 121, such a load would be at a vertical distance of 16 inches below dispenser 200. As a further example, a load with an estimated mass of approximately 12 pounds may correlate to a height h_load of about 10.5 inches, and a load with an estimated mass of approximately 18.7 pounds may correlate to a height h_load of about five inches. It should be understood that the height h_load may have other values, depending on the mass of the load of articles estimated at step 310, and that the height h_load is an estimated height of the load of articles and not an exact measurement. Additionally, other methods of determining the height h_load of the load of articles may be used.

At step 314, a volume of liquid is provided to wash basket 120 until a level of liquid within wash tub 121 reaches a predetermined height h_pre. In certain embodiments, height h_pre may be about 1.5 inches. In other embodiments, height h_pre may be in the range of approximately one to four inches. Other values for height h_pre may also be used.

The liquid is provided to wash basket 120 by allocating a flow of liquid through dispenser drawer 220 and spray nozzle 214 for a portion of a time interval and allocating a flow of liquid through only spray nozzle 214 for the remaining portion of the time interval. In particular, controller 108 opens one or all of valves 216, 218, 219 to direct water to dispenser drawer 220, and controller 108 opens valve 217 to direct water to spray nozzle 214. Liquid is directed to wash basket 120 through both dispenser drawer 220 and spray nozzle 214 for a portion of a predetermined time interval t_int. For the remaining portion of time interval t_int, controller 108 dispenses water through only spray nozzle 214. In one embodiment, time interval t_int may be about five seconds. In alternative embodiments, time interval t_int may be in the range of about ten to about thirty seconds, or t_int may be any other suitable time interval.

FIG. 7 illustrates an exemplary plot of the correlation between load height and the portion of the time interval t_int that liquid should be directed through the combination of dispenser drawer 220 and spray nozzle 214 and dispensed through only spray nozzle 214. At step 314 of the exemplary method of FIG. 6, controller 108 can provide the plurality of load height-time allocation correlations. For example, the plurality of load height-time allocation correlations can be established experimentally and may be stored in the memory of controller 108 during production of washing machine appliance 100. Each correlation of the plurality of load height-time allocation correlations corresponds to a respective manner of providing liquid to wash basket 120 to fill wash tub 121 to the predetermined height h_pre. In the exemplary embodiment shown in FIG. 7, the plurality of load height-time allocation correlations includes a combination dispenser drawer/spray nozzle load height-time allocation correlation and a spray nozzle load height-time allocation correlation.

According to the exemplary embodiment illustrated in FIG. 7, for a load height h_load that is about 16 inches below dispenser 200, i.e., a relatively small load, liquid is directed through the combination of the dispenser drawer 220 and spray nozzle 214 for 14% of time interval t_int, and liquid is dispensed through only spray nozzle 214 for the remaining 86% of time interval t_int. For a load height h_load that is about 10.5 inches below dispenser 200, i.e., a relatively medium load, liquid is directed through the combination of the dispenser drawer 220 and spray nozzle 214 for 25% of time interval t_int, and liquid is dispensed through only spray nozzle 214 for the remaining 75% of time interval t_int. For a load height h_load that is about five inches below dispenser 200, i.e., a relatively large load, liquid is directed through the combination of the dispenser drawer 220 and spray nozzle 214 for 34% of time interval t_int, and liquid is dispensed through only spray nozzle 214 for the remaining 66% of time interval t_int. Additionally, using the curves illustrated in FIG. 7, the time allocated to directing liquid through the combination of dispenser drawer 220 and spray nozzle 214 and dispensing water through only spray nozzle 214 may be determined for any other load height h_load.

Also at step 314, the time t_absp to reach the predetermined height h_pre is counted. Further, method 300 includes step 316 of determining whether the level of liquid in wash tub 121 has reached the predetermined height h_pre. If the liquid level has not reached height h_pre, the method may return to step 314 and repeat steps 314 and 316. If, at step 316, the liquid level has reached height h_pre, the method proceeds to step 318 to establish the absorptivity of the articles in the load. Additionally, controller 108 may close valve 217 to terminate the flow of liquid into wash tub 121 through spray nozzle 214. Thus, in one embodiment, the time t_absp to reach height h_pre may be counted from when valve 217 is opened to when valve 217 is closed. The time t_absp to fill wash tub 121 with a volume of liquid until the liquid level reaches the height h_pre may be counted in other ways as well. Further, it will be understood that the predetermined time interval t_int is less than or equal to the time t_absp to fill wash tub 121 with a volume of liquid.

As stated, at step 318, the absorptivity of the articles in the load of articles in wash basket 120 is established. In one exemplary embodiment, controller 108 can calculate the volume of liquid within wash tub 121, e.g., based on time t and a flow rate of liquid through valve 217 when liquid is being dispensed through only spray nozzle 214. That is, for the exemplary embodiment of dispenser 200 shown in FIGS. 3, 4, and 5, the flow rate of liquid through valve 217 when liquid is being dispensed through only spray nozzle 214 is the total flow rate of liquid available to valves 216, 217, 218, 219. Thus, the volume of liquid within wash tub 121 may be determined based on this total flow rate and time t_absp.

Then, the volume of liquid directed and dispensed to reach height h_pre and the estimated mass from step 310 can be used to establish the absorptivity of the articles. As an example, for a given mass of articles, if the articles within wash basket 120 have a relatively high absorptivity, a relatively large volume of liquid can be required to fill wash tub 121 to height h_pre. Conversely, for a load with an identical mass as the above example, a relatively small volume of liquid can be required to fill wash tub 121 to height h_pre if the articles have a relatively low absorptivity. If a blended load of articles with an identical mass is disposed within wash basket 120, a volume of liquid between the relatively large volume of liquid and the relatively small volume of liquid can be required to fill wash tub 121 to height h_pre. Correlations between mass and volume may be determined experimentally and stored in controller 108. These correlations may then be used at step 318 to establish the absorptivity of the load of articles within wash basket 120.

Based on the absorptivity established through method 300, controller 108 can direct a first volume of water into wash tub 121 of washing machine appliance 100 during a wash cycle of washing machine appliance 100 if at step 318 the load of articles is determined to have a high absorptivity. Moreover, controller 108 can direct a second volume of water into wash tub 121 of washing machine appliance 100 during the wash cycle of washing machine appliance 100 if at step 318 the load of articles is determined to have a medium absorptivity. Further, controller 108 can direct a third volume of water into wash tub 121 of washing machine appliance 100 during the wash cycle of washing machine appliance 100 if at step 318 the load of articles is determined to have a low absorptivity. The first, second, and third volumes are different. In particular, the first volume may be greater than the second volume. In such a manner, controller 108 can direct less water into wash tub 121 if the load type of articles within wash basket 120 is the blended load type, i.e., a blend of cotton and synthetic articles, which has an absorptivity between the absorptivity of a load of cotton articles and a load of synthetic articles. Further, controller 108 can ensure that sufficient water is directed into wash tub 121 if the load type of articles within wash basket 120 is the cotton load type, which has a high absorptivity. Similarly, the second volume may be greater than the third volume. In such a manner, controller 108 can direct less water into wash tub 121 if the load type of articles within wash basket 120 is the synthetic load type, which has a low absorptivity. Thus, by accurately establishing the absorptivity of the articles in the load, water can be conserved by providing only the amount sufficient to wash and rinse the articles in wash basket 120.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A method for operating a washing machine appliance, the washing machine appliance having a wash basket positioned within a tub, the wash basket configured to receive a load of articles for washing, the method comprising the steps of:

estimating a mass of articles within the wash basket;

determining a height hload of the load of articles;

directing liquid to the wash basket through a fluid additive dispenser and a spray nozzle of the washing machine appliance for a portion of a predetermined time interval tint;

dispensing liquid to the wash basket through only the spray nozzle for a remaining portion of the predetermined time interval tint;

counting a time tabsp to fill the tub with a volume of liquid to a predetermined height hpre; and

establishing an absorptivity of the articles in the load.

2. The method of claim 1, further comprising the step of:

selecting the portion of the predetermined time interval tint based at least in part on the height hload of the load of articles.

3. The method of claim 1, further comprising the steps of:

repeating the steps of directing and dispensing until the tub is filled to the predetermined height hpre.

4. The method of claim 1, wherein the absorptivity of the articles in the load is established at least in part using the time tabsp to fill the tub to the predetermined height hpre.

5. The method of claim 1, wherein height hload of the load of articles is determined at least in part using the mass of articles from the step of estimating.

6. The method of claim 1, wherein the step of directing comprises opening one or more valves of the washing machine appliance to provide a flow of water to the fluid additive dispenser and the spray nozzle.

7. The method of claim 1, wherein the step of dispensing comprises opening one or more valves of the washing machine appliance to provide a flow of water to the spray nozzle.

8. The method of claim 1, wherein the predetermined time interval tint is less than or equal to the time tabsp to fill the tub with the volume of liquid.

9. A washing machine appliance, comprising:

a tub;

a wash basket positioned within the tub, the wash basket configured to receive articles for washing;

a plurality of valves configured for directing a flow of water to the tub;

a fluid additive dispenser;

a spray nozzle; and

a controller in operative communication with the plurality of valves, the controller configured for estimating a mass of articles within the wash basket; determining a height hload of the load of articles; directing liquid to the wash basket through the fluid additive dispenser and the spray nozzle for a portion of a predetermined time interval tint; dispensing liquid to the wash basket through only the spray nozzle for a remaining portion of the predetermined time interval tint; counting a time tabsp to fill the tub with a volume of liquid to a predetermined height hpre; and establishing an absorptivity of the articles in the load.

10. The washing machine appliance of claim 9, wherein the controller is further configured for selecting the portion of the predetermined time interval tint based at least in part on the height hload of the load of articles.

11. The washing machine appliance of claim 9, wherein the controller is further configured for repeating the steps of directing and dispensing until the tub is filled to the predetermined height hpre.

12. The washing machine appliance of claim 9, wherein the absorptivity of the articles in the load is established at least in part using the time tabsp to fill the tub to the predetermined height hpre.

13. The washing machine appliance of claim 9, wherein height hload of the load of articles is determined at least in part using the mass of articles from the step of estimating.

14. The washing machine appliance of claim 9, wherein the controller operates one or more of the plurality of valves to provide water to the fluid additive dispenser and the spray nozzle for directing and dispensing liquid to the wash basket.

15. The washing machine appliance of claim 9, wherein the predetermined time interval tint is less than or equal to the time tabsp to fill the tub with the volume of liquid.

16. The washing machine appliance of claim 9, wherein the fluid additive dispenser further comprises a dispenser drawer defining one or more compartments for the receipt of fluid additives.

17. The washing machine appliance of claim 16, wherein the spray nozzle is positioned adjacent the dispenser drawer.

18. The washing machine appliance of claim 9, wherein the predetermined height hpre is based at least in part on the height hload of the load of articles.

19. The washing machine appliance of claim 9, wherein the spray nozzle is in fluid communication with a supply of cold water.