Patent Application
20080040871
In the drawings:
Referring now to the figures,
The washing machine 10 of the illustrated embodiment comprises a cabinet 12 that houses a stationary tub 14. A rotatable drum 16 mounted within the tub 14 defines a fabric treatment chamber and includes a plurality of perforations 18, and liquid can flow between the tub 14 and the drum 16 through the perforations 18. The drum 16 further comprises a plurality of baffles 20 disposed on an inner surface of the drum 16 to lift fabric items contained in the drum 16 while the drum 16 rotates, as is well known in the washing machine art. A motor 22 coupled to the drum 16 through a belt 24 rotates the drum 16. Both the tub 14 and the drum 16 can be selectively closed by a door 26.
Washing machines are typically categorized as either a vertical axis washing machine or a horizontal axis washing machine. As used herein, the “vertical axis” washing machine refers to a washing machine comprising a rotatable drum, perforate or imperforate, that holds fabric items and a fabric moving element, such as an agitator, impeller, nutator, and the like, that induces movement of the fabric items to impart mechanical energy to the fabric articles for cleaning action. In some vertical axis washing machines, the drum rotates about a vertical axis generally perpendicular to a surface that supports the washing machine. However, the rotational axis need not be vertical. The drum can rotate about an axis inclined relative to the vertical axis. As used herein, the “horizontal axis” washing machine refers to a washing machine having a rotatable drum, perforated or imperforate, that holds fabric items and washes the fabric items by the fabric items rubbing against one another as the drum rotates. In horizontal axis washing machines, the clothes are lifted by the rotating drum and then fall in response to gravity to form a tumbling action that imparts the mechanical energy to the fabric articles. In some horizontal axis washing machines, the drum rotates about a horizontal axis generally parallel to a surface that supports the washing machine. However, the rotational axis need not be horizontal. The drum can rotate about an axis inclined relative to the horizontal axis. Vertical axis and horizontal axis machines are best differentiated by the manner in which they impart mechanical energy to the fabric articles. In vertical axis machines a clothes mover, such as an agitator, auger, impeller, to name a few, moves within a wash basket to impart mechanical energy directly to the clothes or indirectly through wash liquid in the wash basket. The clothes mover is typically moved in a reciprocating rotational movement. The illustrated exemplary washing machine of
The motor 22 can rotate the drum 16 at various speeds in opposite rotational directions. In particular, the motor 22 can rotate the drum 16 at tumbling speeds wherein the fabric items in the drum 16 rotate with the drum 16 from a lowest location of the drum 16 towards a highest location of the drum 16, but fall back to the lowest location of the drum 16 before reaching the highest location of the drum 16. The rotation of the fabric items with the drum 16 can be facilitated by the baffles 20. Typically, the force applied to the fabric items at the tumbling speeds is less than about 1 G. Alternatively, the motor 22 can rotate the drum 16 at spin speeds wherein the fabric items rotate with the drum 16 without falling. In the washing machine art, the spin speeds can also be referred to as satellizing speeds or sticking speeds. Typically, the force applied to the fabric items at the spin speeds is greater than or about equal to 1 G. As used herein, “tumbling” of the drum 16 refers to rotating the drum at a tumble speed, “spinning” the drum 16 refers to rotating the drum 16 at a spin speed, and “rotating” of the drum 16 refers to rotating the drum 16 at any speed.
The washing machine 10 of
The exemplary washing machine 10 further includes a steam generation system. The steam generation system comprises a steam generator 60 that receives liquid from the water supply 28 through a second supply conduit 62. The inlet valve 34 controls flow of the liquid from the water supply 28 and through the second supply conduit 62 to the steam generator 60. The inlet valve 34 can be positioned in any suitable location between the water supply 28 and the steam generator 60. A steam conduit 66 fluidly couples the steam generator 60 to a steam inlet 68, which introduces steam into the tub 14. The steam inlet 68 can couple with the tub 14 at any suitable location on the tub 14 and is shown as being coupled to a rear wall of the tub 14 in
The washing machine 10 can further include an exhaust conduit that directs steam that leaves the tub 14 externally of the washing machine 10. The exhaust conduit can be configured to exhaust the steam directly to the exterior of the washing machine 10. Alternatively, the exhaust conduit can be configured to direct the steam through a condenser prior to leaving the washing machine 10. Examples of exhaust systems are disclosed in the following patent applications, which are incorporated herein by reference in their entirety: our Docket Number US20050347, titled “Fabric Treating Appliance Utilizing Steam,” our Docket Number US20050348, titled “A Steam Fabric Treatment Appliance with Exhaust,” our Docket Number US20060269, titled “Steam Fabric Treatment Appliance with Anti-Siphoning,” and our Docket Number US20060270, titled “Determining Fabric Temperature in a Fabric Treating Appliance,” all filed concurrently herewith.
The steam generator 60 can be any type of device that converts the liquid to steam. For example, the steam generator 60 can be a tank-type steam generator that stores a volume of liquid and heats the volume of liquid to convert the liquid to steam. Alternatively, the steam generator 60 can be an in-line steam generator that converts the liquid to steam as the liquid flows through the steam generator 60. As another alternative, the steam generator 60 can comprise a heating element located in the sump 38 to heat liquid in the sump 38. The steam generator 60 can produce pressurized or non-pressurized steam.
Exemplary steam generators are disclosed in our Docket Number US20050349, titled “Removal of Scale and Sludge in a Steam Generator of a Fabric Treatment Appliance,” our Docket Number US20050472, Ser. No. 11/450,836, titled “Prevention of Scale and Sludge in a Steam Generator of a Fabric Treatment Appliance,” and our Docket Number US20060227, Ser. No. 11/450,714, titled “Draining Liquid From a Steam Generator of a Fabric Treatment Appliance,” all filed Jun. 9, 2006, in addition to our Docket Number US20050364, titled “Water Supply Control for a Steam Generator of a Fabric Treatment Appliance,” our Docket Number US20060254, titled “Water Supply Control for a Steam Generator of a Fabric Treatment Appliance Using a Weight Sensor,” and our Docket Number US20060255, titled “Water Supply Control for a Steam Generator of a Fabric Treatment Appliance Using a Temperature Sensor,” all filed concurrently herewith, which are incorporated herein by reference in their entirety.
In addition to producing steam, the steam generator 60, whether an in-line steam generator, a tank-type steam generator, or any other type of steam generator, can heat water to a temperature below a steam transformation temperature, whereby the steam generator 60 produces hot water. The hot water can be delivered to the tub 14 and/or drum 16 from the steam generator 60. The hot water can be used alone or can optionally mix with cold water in the tub 14 and/or drum 16. Using the steam generator to produce hot water can be useful when the steam generator 60 couples only with a cold water source of the water supply 28.
The liquid supply and recirculation system and the steam generator system can differ from the configuration shown in
Other alternatives for the liquid supply and recirculation system are disclosed in our Docket Number US20050365, Ser. No. 11/450,636, titled “Method of Operating a Washing Machine Using Steam;” our Docket Number US20060177, Ser. No. 11/450,529, titled “Steam Washing Machine Operation Method Having Dual Speed Spin Pre-Wash;” and our Docket Number US20060178, Ser. No. 11/450,620, titled “Steam Washing Machine Operation Method Having Dry Spin Pre-Wash,” all filed Jun. 9, 2006, which are incorporated herein by reference in their entirety.
The washing machine 10 can further comprise a controller coupled to various working components of the washing machine 10, such as the pump 44, the motor 22, the inlet valve 34, the detergent dispenser 32, and the steam generator 60, to control the operation of the washing machine 10. The controller can receive data from the working components and can provide commands, which can be based on the received data, to the working components to execute a desired operation of the washing machine 10.
The washing machine of
A method of operating the washing machine 10 according to the invention comprises sanitizing a load of fabric items in the fabric treatment chamber, which, as described above, is defined by the drum 16 but can also or alternatively be defined by the tub 14 (e.g., if the washing machine 10 does not include the drum 16). As used herein, “sanitizing” refers to killing, removing, or otherwise rendering innocuous all or a portion of unsanitary microorganisms, such as bacteria, fungi, and viruses, present on the fabric items. The sanitizing process involves heating the fabric items, such as with steam from the steam generator 60, to increase a temperature of the fabric items to a sanitization temperature sufficiently high to sanitize the fabric items. The sanitization temperature can be an empirically determined temperature or can be a temperature set by a sanitization standard. An exemplary range for the sanitization temperature is from about 65° C. to about 70° C. Within this range, it has been determined that an exemplary suitable sanitization temperature is about 70° C.
According to one embodiment of the invention, the sanitization process occurs after the fabric items have been heated to a temperature less than the sanitization temperature as another step in the wash cycle. By conducting the sanitization process after a heating step in the wash cycle, less energy is consumed in the sanitization process because the temperature of the fabric items is already partially raised from the heating step. For example, heating the fabric items from a temperature above ambient temperature to the sanitization temperature requires less energy than heating the same fabric items from ambient temperature to the sanitization temperature.
The heating of the fabric items prior to the sanitization process can occur in any suitable manner, such as by subjecting the fabric items to heated liquid. The heated liquid can be, for example, the liquid associated with a conventional step in a wash process, such as a wash step, where the heated liquid typically comprises water and a wash aid (e.g., detergent), or a rinse step, where the heated liquid typically comprises water. The temperature of the heated liquid is above ambient temperature, and an exemplary range for the temperature of the heated liquid is from about 25° C. to about 60° C. Within this range, an exemplary suitable temperature for the heated liquid is about 40° C. Because the temperature of the heated liquid is above ambient temperature, the heated liquid raises the temperature of the fabric items above ambient temperature.
Exemplary embodiments of the method of operating a washing machine with steam and involving sanitizing the fabric load are illustrated in
As an example, the wash step 102 can include submerging at least a portion of the drum 16 in a liquid comprising water and a wash aid, such as detergent, and rotating the drum 16 through the liquid to wash the fabric items. Alternatively, the wash step 102 can include spraying a liquid, such as the liquid comprising water and the wash aid, onto the fabric load while the drum 16 rotates. For a vertical axis washing machine, the wash step 102 can involve movement of the fabric moving element. Regardless of the type of wash step 102, the wash step 102 in the embodiment shown in
With continued reference to
The exemplary sanitization step 104 initiates with rotating the drum in step 110. According to one embodiment, the rotating of the drum corresponds to rotating the drum at a tumbling speed so that the fabric load tumbles in the drum 16. The drum 16 can rotate in alternating directions or in a single direction. Either after or when the drum 16 begins to rotate, steam is introduced into the tub 14 and/or the drum 16, such as by the steam generator 60, in step 112. The introduction of steam in the step 112 continues until the fabric load reaches a predetermined temperature, which corresponds to the sanitization temperature and can comprise continuously or intermittently introducing the steam. The temperature of the fabric load can be determined in any suitable manner, and an exemplary method of determining the fabric load temperature is described in the above-incorporated patent applications having our Docket Numbers US20050347, entitled Fabric Treating Appliance Utilizing Steam, US20050348 entitled A Steam Fabric Treatment Appliance With Exhaust, US20060269 entitled Fabric Treatment Appliance With Anti-Siphoning, and US20060270 entitled Determining Fabric Temperature In A Fabric Treating Appliance all filed concurrently herewith.
Once the fabric load reaches the predetermined temperature, the temperature of the fabric load is maintained in step 114 for a predetermined time. The temperature can be maintained by continuously or intermittently introducing steam. Alternatively, the maintaining of the temperature can occur without any additional introduction of steam. The predetermined time can be an empirically determined time and is preferably sufficiently long to accomplish a desired sanitization level of the fabric load. The predetermined time can depend on several factors, including fabric type and load size. An exemplary range of suitable predetermined time is from about 5 minutes to about 15 minutes, and within this range, an exemplary suitable predetermined time has been determined to be about 10 minutes.
The drum 16 can continue to rotate during the step 114 of maintaining the predetermining temperature. The rotation of the drum 16 can be continuous, intermittent, in alternating directions, and/or in a single direction. After the predetermined time for maintaining the predetermined temperature expires, the drum rotation can cease immediately or after a period of time in step 116.
Referring back to
Following the rinse step 106, the method 100 continues with the extraction step 108. During the extraction step 108, the drum 16 rotates at a spinning speed to extract excess rinse liquid from the fabric load. The spinning of the drum 16 can occur in any suitable manner, such as according to a spin profile that can include speed ramps and speed plateaus.
As stated above, the sanitization step 104 can be any suitable process that accomplishes sanitization of the fabric items with steam, and an alternative to the exemplary sanitization step 104 of
The exemplary alternative sanitization step 104A initiates with rotating the drum in step 110A, such as at a tumbling speed in one direction or alternating directions. Either after or when the drum 16 begins to rotate, steam is introduced into the tub 14 and/or the drum 16, such as by the steam generator 60, in step 118. The introduction of steam in the step 118 continues for a predetermined time and can comprise continuously or intermittently introducing the steam. The predetermined time can be an empirically determined time and is preferably sufficiently long to accomplish a desired sanitization level of the fabric load. The predetermined time, therefore, inherently includes the fabric items reaching the sanitization temperature and can depend on several factors, including fabric type and load size. An exemplary range of suitable predetermined time is from about 5 minutes to about 15 minutes, and within this range, an exemplary suitable predetermined time has been determined to be about 10 minutes.
The drum 16 can continue to rotate during the step 118 of introducing the steam. The rotation of the drum 16 can be continuous, intermittent, in alternating directions, and/or in a single direction. After the predetermined time for introducing the steam expires, the drum rotation can cease immediately or after a period of time in step 116A.
Alternative examples of the method 100 shown in
Referring particularly to
Referring now to
By performing the sanitization step 104C at the end of the method 100C, the fabric load is heated when the user removes the fabric load from the washing machine 10, thereby providing the user a warm feel at the end of the wash cycle. Alternatively, the warm feel can be provided by simply heating the fabric load with steam at the end of the wash cycle, such as during the extraction step or after the extraction step. When the steam is introduced after the extraction step, the drum 16 can rotate, such as at a tumbling speed, while during the steam introduction.
The exemplary embodiments of the method 100, 100B, 100C have been described as including the wash step 102, 102B, 102C, the rinse step 106, 106B, 106C, and the extraction step 108, 108B, 108C. However, it is within the scope of the invention for the methods 100, 100B, 100C to include only one or a subset of the wash, rinse, and extraction steps. Furthermore, it is contemplated that other steps, such as a pre-wash step, can be included in the methods 100, 100B, 100C. The sanitization step 104, 104A can also be executed as a stand-alone step rather than in the context of a wash cycle. When used as a stand-alone step, the sanitization step 104, 104A can be conducted following input of a user command to begin the sanitization step 104, 104A.
In addition to sanitizing the fabric items with heat, the sanitization step 104, 104A can include introducing a sanitizing agent or chemical into the tub 14 and/or drum 16 to facilitate the sanitization process. The sanitizing agent can be any suitable agent, and examples of the sanitizing agent include, but are not limited to, chlorine, chloramines, chlorine dioxide, alcohols, hydrogen peroxide, ozone, phenol and other phenolics, quaternary ammonium salts, and hypochlorites (e.g., sodium hypochlorite).
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, and the scope of the appended claims should be construed as broadly as the prior art will permit.
