Abstract:
A method and apparatus for operating a laundry treating appliance having a tub and a rotatably wash basket, the method comprising draining at least a portion of a wash liquid, accelerating the wash basket, enabling the wash basket to decelerate and supplying a rinse liquid during at least a portion of the deceleration of the wash basket.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Laundry treating appliances, such as clothes washers, typically include a tub in which is mounted a rotatable wash basket which receives laundry for treatment according to a cycle of operation. In a typical wash cycle, the laundry is often treated with a laundry detergent or other wash aid that includes surfactants. These surfactants may mix with liquid on the laundry and in the tub to generate suds. In some cases, the generation of suds may generate a suds lock condition and interfere with the rotation of the wash basket, thereby limiting the speed at which the wash basket may be rotated. 
       BRIEF DESCRIPTION 
       [0002]    A method and apparatus for operating a laundry treating appliance having a tub and a rotatably wash basket, the method comprising draining at least a portion of a wash liquid, accelerating the wash basket, enabling the wash basket to decelerate and supplying a rinse liquid during at least a portion of the deceleration of the wash basket. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a schematic cross-sectional view of a laundry treating appliance according to one embodiment of the invention. 
           [0004]      FIG. 2  is a schematic view of a controller of the laundry treating appliance of  FIG. 1 . 
           [0005]      FIG. 3  is a flow chart illustrating a method for mitigating a suds lock condition according to an embodiment of the invention. 
           [0006]      FIG. 4  is a graphical representation of a wash basket speed profile according to an embodiment of the invention. 
       
    
    
     DESCRIPTION 
       [0007]    Referring now to the figures,  FIG. 1  is a schematic view of an exemplary laundry treating appliance  10  in the form of a washing machine according to one embodiment of the invention. While the laundry treating appliance  10  is illustrated as a vertical axis, top-fill washing machine, the invention may have applicability in other laundry treating appliances, such as a horizontal washing machine, combination laundry treating appliance and dryer, an extractor, a non-aqueous laundry treating appliance, and a tumbling or stationary refreshing/revitalizing machine, for example. 
         [0008]    The washing machine  10  may include a cabinet or housing  12  and an imperforate tub  14  that defines an interior  15  of the washing machine  10 . A sump  16  may be in fluid communication with the interior  15  of the tub  14 . A drum or perforated wash basket  18  may be located within and rotatable relative to the interior  15  of the tub  14  and may define a laundry treating chamber  19  for receiving a laundry load. The wash basket  18  may include a plurality of perforations or apertures (not shown) such that liquid supplied to the wash basket  18  may flow through the perforations to the tub  14 . An agitator or clothes mover  20  may be located within the laundry treating chamber  19  and rotatable relative to and/or with the wash basket  18 . 
         [0009]    The wash basket  18  and/or the clothes mover  20  may be driven by an electrical motor  22 , which may or may not include a gear case, operably connected to the wash basket  18  and/or the clothes mover  20 . The clothes mover  20  may be commonly oscillated or rotated about its axis of rotation during a cycle of operation in order to provide movement to the fabric load contained within the laundry treating chamber  19 . The wash basket  18  may be rotated at high speed to centrifugally extract liquid from the fabric load and to discharge it from the wash basket  18 . The top of the housing  12  may include a selectively openable lid  24  to provide access into the laundry treating chamber  19  through the open top of the wash basket  18 . 
         [0010]    Still referring to  FIG. 1 , a spraying system  30  may be provided to spray liquid, such as water or a combination of water and one or more treating agents into the open top of the wash basket  18  and onto laundry placed within the laundry treating chamber  19 . Non-limiting examples of treating chemistries that may be dispensed by the dispensing system during a cycle of operation include one or more of the following: water, surfactants, enzymes, fragrances, stiffness/sizing agents, wrinkle releasers/reducers, softeners, antistatic or electrostatic agents, stain repellants, water repellants, energy reduction/extraction aids, antibacterial agents, medicinal agents, vitamins, moisturizers, shrinkage inhibitors, and color fidelity agents, and combinations thereof. 
         [0011]    The spraying system  30  may be configured to supply water directly from a household water supply  32  and/or from the tub  14  and spray it onto the laundry through a sprayer  33 . The spraying system  30  may also be configured to recirculate wash water from the tub  14 , including the sump  16 , and spray it onto the laundry. The spraying system  30  can also include additional sprayers and other components to supply liquid to one or more additional locations, such as a portion of the interior  15  between the wash basket  18  and the tub  14 , an exterior surface of the wash basket  18 , an interior surface of the wash basket  18  and an internal surface of the tub  14 . The nature of the spraying system is not germane to the invention, and thus any suitable spraying system may be used with the laundry treating appliance  10 . 
         [0012]    A pump  34  may be housed below the tub  14 . The pump  34  may have an inlet fluidly coupled to the sump  16  and an outlet configured to fluidly couple to either or both a household drain  36  or a recirculation conduit  38 . In this configuration, the pump  34  may be used to drain or recirculate liquid in the sump  16 , which is initially sprayed into the wash basket  18 , flows through the wash basket  18 , and then into the sump  16 . Alternatively, two separate pumps may be used instead of the single pump as previously described. 
         [0013]    As used herein, the term wash liquid refers to a combination of water and one or more treating agents capable of generating suds. The terms rinse liquid and rinse water are interchangeable and refer to water supplied from the household water supply  32  that has not been mixed with a treating agent prior to being applied to the laundry. The terms recirculated liquid and recirculated water refer to water or a combination of water and one or more treating agents that is pumped from the sump  16  and re-applied to the laundry, with or without the addition of additional rinse liquid from the household water supply  32 . 
         [0014]    The washing machine  10  also includes a control system for controlling the operation of the washing machine  10  to implement one or more cycles of operation. The control system may include a controller  60  located within the cabinet  12  and a user interface  62  that is operably coupled with the controller  60 . The user interface  62  may include one or more knobs, dials, switches, displays, touch screens and the like for communicating with the user, such as to receive input and provide output. The user may enter different types of information including, without limitation, cycle selection and cycle parameters, such as cycle options. 
         [0015]    The controller  60  may include the machine controller and any additional controllers provided for controlling any of the components of the washing machine  10 . For example, the controller  60  may include the machine controller and a motor controller. Many known types of controllers may be used for the controller  60 . The specific type of controller is not germane to the invention. It is contemplated that the controller  60  is a microprocessor-based controller that implements control software and sends/receives one or more electrical signals to/from each of the various working components to effect the control software. As an example, proportional control (P), proportional integral control (PI), and proportional derivative control (PD), or a combination thereof, a proportional integral derivative control (PID control), may be used to control the various components. 
         [0016]    As illustrated in  FIG. 2 , the controller  60  may be provided with a memory  70  and a central processing unit (CPU)  72 . The memory  70  may be used for storing the control software that is executed by the CPU  72  in implementing a cycle of operation using the washing machine  10  and any additional software. Examples, without limitation, of cycles of operation include: wash, heavy duty wash, delicate wash, quick wash, pre-wash, refresh, rinse only, and timed wash. A common wash cycle includes a wash phase, a rinse phase, and a spin extraction phase. Other phases for cycles of operation include, but are not limited to, intermediate extraction phases, such as between the wash and rinse phases, and a pre-wash phase preceding the wash phase, and some cycles of operation include only a select one or more of these exemplary phases. 
         [0017]    The memory  70  may also be used to store information, such as a database or table, and to store data received from one or more components of the washing machine  10  that may be communicably coupled with the controller  60 . The database or table may be used to store the various operating parameters for the one or more cycles of operation, including factory default values for the operating parameters and any adjustments to them by the control system or by user input. 
         [0018]    The controller  60  may be operably coupled with one or more components of the washing machine  10  for communicating with and controlling the operation of the component to complete a cycle of operation. For example, the controller  60  may be operably coupled with the motor  22 , the pump  34 , and the spraying system  30  to control the operation of these and other components to implement one or more of the cycles of operation. 
         [0019]    The previously described washing machine  10  may be used to implement one or more embodiments of the invention. The embodiments of the method of the invention may be used to control the operation of the washing machine  10  to minimize the formation of a surfactant foam or suds in the tub  14  to mitigate a suds lock condition. As used herein, mitigating a suds lock condition may include decreasing the formation of suds and/or removing suds from the tub  14  such that a suds lock condition is avoided or the effect of the suds on the tub  14  and wash basket  18  is decreased. 
         [0020]    A typical wash cycle includes a wash phase in which a wash liquid, e.g., a mixture of water and surfactants (and optionally other treating agents), is applied to the laundry, a rinse phase in which the wash liquid is removed from the laundry by rinsing the laundry with rinse liquid, and a spin extraction phase in which at least a portion of the rinse liquid is extracted from the laundry by spinning the laundry at high speeds. A suds lock condition occurs when the wash liquid forms suds and the suds interact with the wash basket  18  and tub  14 , causing excess frictional drag between the wash basket  18  and the tub  14 . The excess frictional drag may inhibit the wash basket  18  from accelerating to a desired wash basket rotation speed, such as a final or spin extraction rotation speed in which the laundry is rotated at high speeds to extract liquid from the laundry. The methods described herein may be used to mitigate a suds lock condition such that the wash basket  18  may be rotated at a desired rotation speed while decreasing or minimizing the frictional drag between the wash basket  18  and the tub  14  effected by the presence of suds in the tub  14 . 
         [0021]    Referring now to  FIG. 3 , a flow chart of a method  100  for mitigating a suds lock condition during a cycle of operation is illustrated. The method  100  may be used during a wash cycle or any other cycle of operation in which wash liquid is or has been applied to the laundry. The method  100  may be implemented as part of a wash or rinse phase of a wash cycle or may be implemented as a separate phase. The sequence of steps depicted for this method is for illustrative purposes only, and is not meant to limit the method in any way as it is understood that the steps may proceed in a different logical order or additional or intervening steps may be included without detracting from the invention. 
         [0022]    The method  100  starts with assuming that a cycle of operation in which a wash liquid is applied to the laundry in the treating chamber  19 , such as a wash cycle, has been implemented. At  102 , the drain pump  34  may be activated to drain at least a portion of any wash liquid that has collected in the sump  16 . The drain pump  34  may be activated at  102  when the wash basket  18  is at or near 0 rpm and may be activated for a predetermined period of time or until a predetermined amount of wash liquid has been drained from the sump  16 . At  104 , the motor  22  can be activated to accelerate the wash basket  18  to rotate at a first predetermined rotation speed. 
         [0023]    At  106 , the wash basket  18  may be decelerated from the first predetermined rotation speed reached at  102 . The wash basket  18  may be passively decelerated by deactivating the motor  22  and allowing the wash basket  18  to simply coast and decelerate. Alternatively, the wash basket  18  may be actively decelerated by activating the motor  22  to brake the wash basket  18  or apply another braking mechanism, and increase the rate of deceleration. The wash basket  18  may be decelerated from the first predetermined rotation speed reached at  102  to a predetermined rotation speed, less than the first, such as 0 rpm, for example. The wash basket  18  may be decelerated from the first predetermined rotation speed after a predetermined amount of time or immediately upon reaching the first predetermined rotation speed. 
         [0024]    At  108 , rinse liquid may be supplied to the tub  14 , such as through the sprayer  33 , for example, during the deceleration of the wash basket  18  at  106 . The rinse liquid may be supplied during the entire deceleration phase from the first predetermined rotation speed or only during a portion of the deceleration phase. For example, rinse liquid may be supplied to the tub  14  when the rotation speed of the wash basket  18  reaches or decreases below a predetermined threshold. In another example, the rinse liquid may be supplied after a predetermined amount of time following the start of the deceleration phase at  106 . 
         [0025]    The rinse liquid may be supplied at  108  either continuously or intermittently. The supplying of the rinse liquid at  108  may end after a predetermined period of time or when the rotation speed of the wash basket  18  reaches or decreases below a predetermined threshold. In one example, the supplying of the rinse liquid at  108  may continue until the wash basket rotation speed reaches 0 rpm. The deceleration phase  106  and rinse liquid supply phase  108  may end concurrently or non-concurrently. 
         [0026]    As used herein, supplying rinse liquid to the tub  14  includes supplying rinse liquid to one or more locations within the area defined by the tub  14 . Supplying rinse liquid to the tub  14  may include supplying rinse liquid to the interior  15  at a space between the tub  14  and the wash basket  18 , an exterior surface of the wash basket  18 , an interior surface of the wash basket  18 , the treating chamber  19 , an internal surface of the tub  14 , and combinations thereof and may include supplying rinse liquid from one or more sprayers, such as the sprayer  33 , for example, or other liquid supply devices provided in the washing machine  10 . 
         [0027]    At  110 , the draining phase  102 , acceleration phase  104 , deceleration phase  106  and rinse liquid supply phase  108  may be repeated one or more times. Each time the acceleration phase  104  is repeated, the wash basket  18  may be accelerated to the same predetermined wash basket rotation speed or a different wash basket rotation speed. In one example, the wash basket  18  may be accelerated to successively higher wash basket rotation speeds each time the acceleration phase  104  is repeated. 
         [0028]    It will be understood that at least some of the rinse liquid supplied to the tub  14  during the rinse liquid supply phase at  108  may collect in the sump  16  and mix with the wash liquid that has also collected in the sump  16 . Thus, when the method  100  is repeated, during the draining phase  102 , it will be understood that draining the wash liquid may also include draining rinse liquid that has mixed with the wash liquid and collected in the sump  16 . 
         [0029]    Draining the wash liquid at  102  and subsequently supplying rinse liquid at  108  dilutes the wash liquid present in the tub  14  and thus reduces the amount of suds that may form and/or disrupt suds that have already formed. If the wash liquid is drained too quickly or too much wash liquid is drained at  102 , suds may form from the agitation of the mixture of water and surfactants in the wash liquid, and a suds lock condition may occur. The rinse liquid may be supplied at  108  while the wash basket  18  is decelerating to gradually dilute the wash liquid and any suds that may have formed while minimizing the formation of additional suds. In this manner, the method  100  may be used to rinse away enough wash liquid, while mitigating a suds lock condition, such that the wash basket  18  may be rotated up to an extraction spin speed in an extraction phase of the wash cycle without generating excessive suds that could lead to a suds lock condition. 
         [0030]    Referring now to  FIG. 4 , an exemplary wash basket speed profile  200  is illustrated. The wash basket speed profile  200  illustrates the speed of the wash basket  18  during implementation of the method  100  of  FIG. 3  in the course of a cycle of operation. The wash basket speed profile  200  may not be indicative of actual data, but is included for the purposes of illustration. 
         [0031]      FIG. 4  illustrates three successive suds-mitigating stages  202 ,  204  and  206 , which may be implemented at a predetermined time period subsequent to a wash cycle in which the laundry is treated with a wash liquid including surfactants. Each of the suds-mitigating stages  202 ,  204  and  206  include a drain phase, an acceleration phase, a deceleration phase, and a rinse liquid supply phase. During the first stage  202 , the drain pump  34  may be activated to drain at least a portion of the wash liquid collected in the sump  16 . Near or at the end of the drain phase, the wash basket  18  may be accelerated to a first predetermined rotation speed  208 , such as 200 rpm, for example, during the acceleration phase. Upon reaching the first predetermined rotation speed  208 , the motor  22  may be turned off and the wash basket  18  may be allowed to coast down to 0 rpm during the deceleration phase. During the deceleration phase, when the wash basket rotation speed decreases to 150 rpm, the spraying system  30  may be activated to supply rinse liquid to the tub  14 . The rinse liquid supply phase may continue during the deceleration phase until the wash basket rotation speed decreases to at or near 0 rpm. 
         [0032]    Following the first stage  202 , the second stage  204  begins with a drain phase and acceleration phase similar to the first stage  202  except that during the acceleration phase, the wash basket  18  is accelerated to a second predetermined rotation speed  210 , which is higher than the first predetermined rotation speed  208 , such as 290 rpm, for example. The wash basket  18  may then be allowed to decelerate and rinse liquid supplied when the wash basket rotation speed decreases to 150 rpm in a manner similar to that described above for the first stage  202 . The third stage  206  is similar to the first and second stages  202  and  204  except that during the acceleration phase, the wash basket  18  is accelerated to a third predetermined rotation speed  212 , higher than the second predetermined rotation speed  210 . Each time the wash liquid is drained from the tub  14  and rinse liquid is supplied, the wash liquid is diluted. Diluting the wash liquid dilutes the amount of surfactant present in the tub  14 , decreasing the amount of suds that may be generated and/or diminishing suds that have already formed. 
         [0033]    The methods described herein may be used to mitigate the formation of a suds lock condition in a washing machine. Excess suds in a washing machine may increase the frictional drag between the wash basket and the tub, which may result in the wash basket not reaching a desired rotational speed or may require additional energy to reach the desired rotation speed, which may increase energy costs during the cycle. During a spin extraction phase, the wash basket is rotated at high speeds to remove liquid from the laundry for subsequent treatment or drying. If the wash basket cannot be rotated at the desired spin extraction speed due to a suds lock condition, it may take longer to extract liquid from the laundry, which may provide an undesirable lengthening of the cycle, or the laundry may maintain more liquid at the end of the cycle, which may be undesirable to the user. The methods described herein may be used to rinse the laundry in such a manner as to mitigate a suds lock condition and decrease the interaction between the tub and the wash basket during rotation of the wash basket. 
         [0034]    To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described. 
         [0035]    While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.