Patent Application
20150074917
The present subject matter relates generally to washing machine appliances and methods for detecting oversuds conditions therein.
Washing machine appliances generally include a tub for containing wash fluid, e.g., water, detergent, and/or bleach. A basket 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 basket. The basket 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 operation of certain washing machine appliances, a spin cycle is performed to wring wash fluid from the articles within the wash chamber. The spin cycle typically entails rotating the basket at a relatively high rate of speed for a period of time. Typically, and desirably, the tub is generally empty of wash fluid and suds (caused by interaction between water and detergent, etc.). In some cases, however, an oversuds condition can occur, when suds remain in the tub during the spin cycle. If an oversuds condition occurs, the suds can overflow from the washing machine appliance and potentially damage, for example, surrounding floor areas.
Attempts have been made to reduce the risk of oversuds conditions in washing machine appliances. For example, additional water has been added before spin cycles in attempts to reduce suds within the tub and basket. The speed at which the basket rotates during the spin cycle has been reduced. The spin cycle ramp up period has been lengthened. Reductions in recirculation have been made. However, these attempts have not suitably reduced the risk of oversuds conditions occurring.
Accordingly, improved washing machine appliances and methods for detecting oversuds conditions in washing machine appliances are desired. In particular, methods and apparatus that result in improved reductions in the potential for oversuds conditions during spin cycles would be advantageous.
In one embodiment, the present disclosure is directed to a method for detecting an oversuds condition in a washing machine appliance. The washing machine appliance has a tub and a basket rotatably mounted within the tub, the basket defining a chamber for receipt of articles for washing. The method includes measuring a pressure within the tub during a spin cycle, comparing the pressure to a threshold oversuds pressure level, and pausing the spin cycle and enacting an oversuds removal cycle if the pressure exceeds the threshold oversuds pressure level.
In another embodiment, the present disclosure is directed to a washing machine appliance. The washing machine appliance includes a tub and a basket rotatably mounted within the tub, the basket defining a chamber for receipt of articles for washing. The washing machine appliance further includes a valve, a spout configured for directing fluid from the valve into the tub, and a motor in mechanical communication with the basket, the motor configured for selectively rotating the basket within the tub. The washing machine appliance further includes a pressure sensor configured for measuring a pressure within the tub, and a controller in operative communication with the valve, the motor and the pressure sensor. The controller is configured for comparing the pressure measured during a spin cycle to a threshold oversuds pressure level, and pausing the spin cycle and enacting an oversuds removal cycle if the pressure exceeds the threshold oversuds pressure level.
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.
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.
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.
A spout 72 is configured for directing a flow of fluid into tub 64. In particular, spout 72 may be positioned at or adjacent top portion 82 of basket 70. Spout 72 may be in fluid communication with a water supply (not shown) in order to direct fluid (e.g., liquid water) into tub 64 and/or onto articles within chamber 73 of basket 70. A valve 74 regulates the flow of fluid through spout 72. For example, valve 74 can selectively adjust to a closed position in order to terminate or obstruct the flow of fluid through spout 72. A pump assembly 90 (shown schematically in
An agitation element 92, shown as an impeller in
Operation of washing machine appliance 50 is controlled by a processing device or controller 100, that is operatively coupled to the user interface input located on washing machine backsplash 56 (shown in
Controller 100 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 58 and other components of washing machine appliance 50 may be in communication with controller 100 via one or more signal lines or shared communication busses.
In an illustrative embodiment, laundry items are loaded into chamber 73 of basket 70, and washing operation is initiated through operator manipulation of control input selectors 60. Tub 64 is filled with water and mixed with detergent to form a wash fluid. Valve 74 can be opened to initiate a flow of water into tub 64 via spout 72, and tub 64 can be filled to the appropriate level for the amount of articles being washed. Once tub 64 is properly filled with wash fluid, the contents of the basket 70 are agitated with agitation element 92 for cleaning of laundry items in basket 70. More specifically, agitation element 92 is moved back and forth in an oscillatory motion.
After the agitation phase of the wash cycle is completed, tub 64 is drained. Laundry articles can then be rinsed by again adding fluid to tub 64, depending on the particulars of the cleaning cycle selected by a user, agitation element 92 may again provide agitation within basket 70. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a spin cycle, basket 70 is rotated at relatively high speeds.
While described in the context of a specific embodiment of washing machine appliance 50, using the teachings disclosed herein it will be understood that washing machine appliance 50 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.
Referring still to
Further, a deflector 130 may be disposed within and mounted to the tub 64, such as to a sidewall 68 and/or tub bottom 66 thereof. Deflector 130 generally extends inwardly from the sidewall 68 and tub bottom 66 between the tub 64 and basket 70, and deflects and redirects water therein. Inner opening 120 may be defined adjacent to the deflector 130, such that deflector 130 redirects water from the inner opening 120.
As discussed, improved methods and apparatus for detecting, as well as reducing or eliminating, oversuds conditions are desired in the art. The present disclosure is thus further direction to methods for detecting oversuds conditions in washing machine appliances 50. Such methods may advantageously reduce leakages and other issues caused by oversuds conditions by efficiently detecting and facilitating elimination of such conditions. Such methods are additionally unlikely to confuse oversuds conditions with normal washing machine appliance operations, thus increasing the efficiency and reliability of the washing machine appliances. Further, such methods are advantageously robust, and do not require parameter adjustments, when utilized with varying loads, fluid levels, detergent brands and amounts, fluid temperatures and hardnesses, etc.
For example, a method according to the present disclosure may include the step 200 of measuring a pressure 202 within the tub 64 during a spin cycle 204. Such measurement may be taken in exemplary embodiments by pressure sensor 114 and in pressure chamber 110.
During a typical spin cycle, the pressure 202 may generally read as approximately an atmospheric pressure level (gauge) due to the relative lack of fluids, such as wash fluids and suds. However, if an oversuds condition occurs, the pressure 202 may change. An oversuds condition is generally a condition wherein excess fluids, such as wash fluids and suds, are present in a tub. For example, in some embodiments, the existence of a deflector 130 adjacent to the pressure chamber 110 inner opening 120 may create a vacuum within the pressure chamber 110, such as adjacent or in the inner opening 120, during an oversuds condition. This may cause a negative pressure reading relative to the atmospheric pressure level. In other embodiments, the existence of an oversuds condition may cause a positive pressure reading relative to the atmospheric pressure level.
Accordingly, a method according to the present disclosure may further include the step 210 of comparing the pressure 202 to a threshold oversuds pressure level 212. The threshold level 212 may be, for example, a relative positive or negative pressure level which is higher than or lower than the atmospheric pressure level. In some embodiments, for example, a threshold oversuds pressure level 212 may be between approximately 0.2 inches H2O and approximately 3.0 inches H2O above or below the atmospheric pressure level, such as between approximately 0.5 inches H2O and approximately 2.0 inches H2O above or below the atmospheric pressure level, such as in some exemplary embodiments approximately 0.5 inches H2O above or below the atmospheric pressure level.
Further, a method according to the present disclosure may include the step 220 of pausing the spin cycle 204 and enacting an oversuds removal cycle 222 if the pressure 202 exceeds the threshold oversuds pressure level 212. Thus, a determination may be made by, for example controller 100 in communication with pressure sensor 114, that the pressure 202 exceeds a threshold oversuds pressure level 212. Such determining step may be denoted, for example, as step 225. In embodiments wherein a threshold oversuds pressure level 212 is a relatively positive threshold pressure, the pressure 202 exceeds the threshold oversuds pressure level 212 when it is greater than the threshold oversuds pressure level 212. In embodiments wherein a threshold oversuds pressure level 212 is a relatively negative threshold pressure, the pressure 202 exceeds the threshold oversuds pressure level 212 when it is less than the threshold oversuds pressure level 212.
An oversuds removal cycle 222 may generally be a cycle which lessens the amount of suds within the tub 64, thus reducing or eliminating the oversuds condition. For example, in some embodiments, an oversuds removal cycle 222 may include the step 230 of adding a fluid to the tub 64. The fluid may, for example, in exemplary embodiments be a liquid such as water. Valve 74 and spout 72 may be utilized to supply such fluid. An oversuds removal cycle 222 may further include the step 232 of agitating the basket 70. For example, motor 94 may be utilized to spin the basket 70, as discussed above. An oversuds removal cycle 222 may further include the step 234 of draining the fluid from the tub 64. For example, the fluid may be drained through conventional drain apparatus in the tub 64 and appliance 50. Such steps, and the oversuds removal cycle 222 comprised thereof, may serve to dilute the existing suds in the tub 64 and reduce or eliminate the suds, thus reducing or eliminating an oversuds condition.
Details of one suitable oversuds removal cycle 222 may be established in accordance with methods described in U.S. Pat. No. 4,410,329 to Blevins et al. which issued on Oct. 18, 1983, the disclosure of which is incorporated by reference herein.
In some embodiments, a method according to the present disclosure may further include the step 240 of continuing the spin cycle 204 after the oversuds removal cycle 222 has concluded. Thus, normal operation of the appliance may continue after the oversuds condition has been reduced or eliminated.
In some embodiments, a method according to the present disclosure may further include the step 250 of continuing the spin cycle 204 in the pressure 202 does not exceed the threshold oversuds pressure level 212. For example, pressures 202 may be compared to threshold oversuds pressure levels 212 during operation of the appliance 50, and specifically during spin cycles, constantly or intermittently. Thus, a determination may be made by, for example controller 100 in communication with pressure sensor 114, that the pressure 202 does not exceed a threshold oversuds pressure level 212. Such determining step may be denoted, for example, as step 255. If a pressure 202 does not exceed a threshold oversuds pressure level 212, the spin cycle 204 may not pause, and rather may continue as per normal appliance 50 operation.
It should be understood that various method steps as discussed herein may be performed during appliance 50 operation by the controller 100 thereof. Thus, for example, a controller 100 may be configured for comparing the pressure 202 measured during a spin cycle 204 to a threshold oversuds pressure level 212, and pausing the spin cycle 204 and enacting an oversuds removal cycle 222 if the pressure 202 exceeds the threshold oversuds pressure level 212. The controller 100 may further be configured for continuing the spin cycle 202 after the oversuds removal cycle 222 has concluded, and continuing the spin cycle 204 if the pressure 202 does not exceed the threshold oversuds pressure level 212.
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.
