Automatic washing machines have existed for many years. Conventional automatic washing machines generally include an external cabinet containing a dual tub arrangement in which an inner perforated tub (wash basket) rotates within an outer tub that remains generally stationary. In addition, conventional washing machines include a central column that can rotate independently and act as an agitator.
In a typical wash cycle, clothing is loaded into the wash basket. The outer tub and nested wash basket are filled with wash liquid to a predetermined level and the central column agitates the wash load within the liquid to cleanse the clothing. Once the wash cycle is complete, wash liquid is drained from the outer tub via a drain outlet provided therein. The wash basket then rotates (spins) at a high rate of speed to force wash liquid absorbed by the wash load out of the load, through the wash basket apertures and into the outer tub, from which it is drained via the drain outlet.
The conventional arrangement of a pair of nested wash tubs, and a central agitator rotatable independently of the wash basket, has been a main stay of the industry for decades, serving relatively well in terms of its washing effectiveness and its reliability. This conventional arrangement is not without its shortcomings, however. For example, the requirement of an inner as well as an outer tub increases materials, manufacturing and assembly costs as compared to the case if only a single tub were required. Additionally, the nesting of one tub within another takes up space within the washer cabinet that could otherwise be used to increase load capacity. Likewise, the requirement for two independently rotatable elements, a central agitator and an inner rotatable tub, increases cost and mechanical complexity as compared to the case if both wash agitation and spin action could be accomplished with just a rotatable tub. Finally, the dual tub arrangement requires additional water usage for a given load size, since the space between the outer stationary tub and the inner wash basket must be filled to the desired water level, yet this volume of water does not substantially contact the wash load or aid in the wash action.
Washing machines have been proposed that employ tub rotation as a means for agitating the wash load during the wash cycle. For instance, U.S. Pat. No. 5,271,251 to Kovich et al. discloses a tub with at least one ramp on the floor of an inner wash basket (nested within a stationary outer basket). The ramp is configured to be used in conjunction with a baffle mounted to a sidewall of the wash basket. It is apparent that the baffles are located at least partially below the standing water line on the inner surface of the tub. The bottom ramps are positioned to guide the wash load upward and outward, toward the sidewall of the tub, into engagement with the baffle surfaces that then cause the load to tumble around the baffle.
U.S. Pat. No. 5,878,602 to Kovich et al. discloses baffles spaced about a cylindrical wall portion. No bottom ramps are used in the '602 patent. Rather, a rotatable wash plate is nested in the tub bottom and includes a pair of diametrically opposed ripples or ridges. The wash plate imparts a vertical motion to the load as the wash plate is oscillated.
In accordance with an aspect of the invention, a washing machine includes a frame and a wash basin assembly rotatably mounted within the frame. The wash basin assembly includes a wash basin container having a bottom and sidewalls extending up from the bottom. A reservoir is arranged at least partially about the sidewalls of the wash basin container. A first plurality of flow channels extends along the sidewalls and is provided in fluid communication with an interior of the wash basin container so as to receive a flow of wash liquid expelled therefrom. The flow channels are configured to expel the wash liquid along the sidewalls and into the reservoir. A reservoir drain is provided for draining wash liquid from the reservoir. The reservoir drain may take the form of a second plurality of flow channels provided to direct the wash liquid from the stabilizing reservoir to a central drain once the wash basin rotation slows and/or stops.
Such an arrangement can advantageously be used to avoid the need for a separate outer splash tub, thus presenting an opportunity to save on washer weight and costs associated with the assembly/manufacturing of the washer. In addition, elimination of an outer tub can make additional space available within the washer housing for increasing the load capacity of the washer without increasing the washer footprint. Further, elimination of an outer tub may reduce the amount of water needed for a given wash load. Additionally, such a single tub arrangement may eliminate the need for a clutch and gearbox which may add mechanical complexity to the washing machine.
In another aspect, an automatic washing machine includes a frame and a wash basin assembly rotatably mounted within the frame. The wash basin assembly includes a wash basin container having a bottom and sidewalls extending up from the bottom. At least one bottom ramp is affixed to and extends upwardly from the wash basin container bottom and presents an upwardly inclined ramp surface. A drive system is provided for selectively rotatably driving the wash basin container, and a controller is provided for controlling the drive system to repeatedly intermittently rotatably drive and brake the wash basin container during a wash cycle of the washer, to thereby cause the wash basin container to alternatively accelerate and decelerate.
At least one sidewall ramp may be affixed to the wash basin container sidewall and present an inwardly inclined ramp surface. The at least one sidewall ramp may be spaced above the top of the at least one bottom ramp.
The acceleration and deceleration causes the at least one bottom ramp to induce a wave wash action on wash liquid within a lower portion of the wash basin container, by liquid flowing over the at least one ramp as the liquid continues to rotate within the wash basin container following an acceleration/deceleration cycle of said wash basin container. The acceleration/deceleration cycle further induces in the wash liquid parabolic water profile formation and collapse actions serving, in conjunction with the at least one sidewall ramp (if provided), to circulate the load so that a portion of the wash load in an upper portion of the wash basin container is circulated to a lower portion of the wash basin container where it can be subjected to the wave wash action induced by the at least one bottom ramp.
Such an arrangement can provide a highly effective and efficient wash action while advantageously eliminating the need for a central agitator and a complex transmission for independently oscillating the central column to agitate the load. An arrangement as described is also well suited to application in a single tub automatic washer configured in accordance with the above-described first aspect of the invention.
In still another aspect, a method of washing a load of laundry using an automatic washing machine includes placing a load of laundry within the wash basin container. The wash basin container is rotatably mounted within a frame. The wash basin container includes a bottom and sidewalls extending up from the bottom. The wash basin container further includes a reservoir arranged at least partially about the sidewalls of the wash basin container to rotate therewith. The method further includes expelling wash liquid to flow from the wash basin upward to the reservoir while the wash basin is being rotated. The method also includes flowing the wash liquid from the reservoir downward to a drain.
Such a method may provide a highly effective and efficient method for washing a load of laundry. The method described minimizes the amount of water necessary to wash the load and also eliminates the need for an outer tub which increases the cost and weight of the washing machine.
This summary is provided to introduce a selection of concepts of the inventive subject matter that are further described below in the detailed description. This summary is not intended to identify essential features or advantages of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Additional features and advantages of various embodiments are further described below.
Aspects of the invention are illustrated by way of example and not by limitation in the accompanying figures in which like reference numerals indicate similar elements and in which:
With reference to
Automatic washing machine 100 also includes a central upstanding column 112 centrally mounted to the bottom of wash basin 108. In contrast to the conventional arrangement, central column 112 is preferably fixedly mounted to the wash basin, rather than being made independently rotatable.
Prior to discussing the structure of automatic washing machine 100 in detail, the basic stages of operation are briefly outlined.
In use, after placing a load of laundry in wash basin 108, along with a suitable type and quantity of laundry detergent, a wash process is initiated by an operator through interaction with control panel 104. The process typically begins with a tub fill cycle, wherein water enters the wash basin 108 via an inlet hose, valve and nozzle (not shown). Water fills the wash basin 108 to a predetermined level, which may be varied, e.g., as a user setting and/or depending upon the size of the wash load. Once the appropriate/set level is reached, the water supply valve is closed and the washer enters a wash cycle comprising a number of sequential stages. In accordance with an aspect of the invention, these stages may take the place of the conventional agitation cycle of a conventional washer having a central independently rotatable agitator column. As will be described in further detail, this wash cycle may include intermittent rotation of the wash basin 108 in one or two directions, i.e., starting and stopping of the rotation of the wash basin 108, to impart, in conjunction with specially configured and placed wash basin-mounted ramps, a highly effective wash action and circulation of the wash load.
Upon completion of the wash cycle, a static drain of the wash liquid from the wash basin 108 is carried out via a central drain pipe 114. Once the free wash liquid (liquid not absorbed into the wash load) pooled within the wash basin 108 is drained, a spin cycle is initiated wherein the wash basin is rotated at a high rate of speed. This rotation of the wash basin 108 forces wash liquid absorbed into the wash load out of the load, and out of the wash basin through the apertures 116 formed in the side of the wash basin 108. This sets the spin drained water on a unique and advantageous drainage path to be described in detail. The wash load may then be subjected to another rinse cycle, in which the water supply valve is again opened to allow fresh water to enter the wash basin 108. The wash basin is again rotated to generate a vigorous rinse action and the static and spin drain cycles outlined above are repeated.
In conventional washing machines, a central auger-like column rotates independent of the wash basin and acts as an agitator to impart a mechanical wash action on the clothes during the wash cycle. In the arrangement shown in
In arrangements of the invention where a central column is present, the shape of the central column 112 may also aid in ensuring a freely moving wash load. For instance, the tapered, generally hourglass shape of the central column 112 can aid in preventing tangling of larger wash load items around the column 112. Large items, such as a bed sheet, may have a tendency to wrap around the column 112 during a wash cycle involving rotation of wash basin 108. The narrow portion 112a of the hourglass shape allows the larger items to wrap around the column 112 and slide toward this narrow portion 112a where it can more easily free itself from the column 112. In addition, positioning the narrow portion 112a of the column 112 beneath the standing water line also aides in preventing and removing tangled wash load items as the wash load is likely to move more freely when submerged in water.
Additional details of washing machine 100 are now described with further reference to the exploded view of
Wash basin 108 is positioned atop a flexible suspension mount as part of the suspended wash group. As is generally known, a suspension mount of the wash group allows movement and forces generated upon rotation of a wash basin with a wash load to be isolated rather than transmitted to the frame and housing of the washer. In the illustrated embodiment, the suspension mount includes a four pronged suspension base plate 101 to which a drive motor 140 and wash basin 108 are mounted. Base plate 101 rests atop a set of four compression spring dampeners 103, one positioned at the tip of each of the prongs of plate 101. The dampeners, which are mounted at the ends of rods 107, provide a buffer serving to isolate the movement and vibration of the wash basin during spinning, and may include on the upper ends of the compression springs respective resilient foam pistons. The composite structure serves to dampen vibrations, as well as larger oscillations. In one arrangement, the foam piston comprises a relatively large cell foam disc serving as a reservoir for lubricating oil, and a smaller celled foam disc provides a low friction contact surface for sliding within a cylindrical sleeve which houses the spring/piston assembly. Rods 107 extend through the spring dampeners 103 and through the suspension base plate 101. Rods 107 extend up to and are attached at the four upper corners of the frame (106 in
In the exemplary arrangement shown in
In the illustrated arrangement, the motor is a brushless DC permanent magnet direct drive motor (BLDC). Use of a BLDC motor allows for improved speed control and braking, which is beneficial in connection with carrying out aspects of the invention. For instance, a BLDC motor may be precisely controlled in its rotational accelerations and decelerations of the wash basin, to thereby allow for better control over the wash action imparted on the wash load. Too much mechanical wash action can damage clothing and break up suspended soils causing them to re-enter the clothing. Better motor control, such as is afforded with a BLDC motor, can provide better control of the intensity of the mechanical wash action corresponding to a selected cycle setting, e.g., when adjusting for delicate loads rather than a typical “normal” wash load.
In another exemplary arrangement, the motor may be a continuous induction-type motor. This type of three-phase motor, used in conjunction with a suitable motor controller, allows the speed of the motor to be controlled, as opposed to the simple on-off control of a conventional induction motor. In addition, as an alternative to a direct drive, a belt drive arrangement may be employed to rotate the wash basin.
Exemplary wash basin 108 is shown with additional detail in
Wash basin 108 further includes a plurality of flow channels 306, 308 arranged around the outer surface of the cylindrical wall 113 of wash basin 108. As shown in
More specifically, the wash liquid in reservoir 302 acts to provide a stabilizing and balancing hydrodynamic weight distribution tending to move the center of mass of wash basin 108, and the contained wash load, toward the center of rotation. In this manner, the stabilizing reservoir may act to provide a sufficient stabilizing force to eliminate the need for a separate conventional stabilizing ring. On the other hand, it may be desirable to use reservoir 302 in conjunction with a conventional stabilizing fluid ring, so as to provide a stabilizing action at the outset and end of the rotation intervals, when reservoir 302 is not filled with a stabilizing volume of the wash liquid.
Flow channels 306 are also arranged about the wash basin 108, and extend vertically downward from reservoir 302 to central drain 114 provided at the center of wash basin 108. In the illustrated exemplary arrangement, the upward and downward flow channels 308, 306 are arranged in an alternating pattern of vertical lines about the cylindrical outer surface of the wash basin 108. The inlets of the downward flow channels 306 are advantageously positioned at the lowest portion of reservoir 302 so as to permit all of the liquid within the reservoir to drain therethrough under the force of gravity, unless retained within the reservoir by counteracting centrifugal forces.
In another illustrative arrangement, shown in
The upward and downward flow channels may be arranged about the circumference of the wash basin in various patterns. For example, there may be two or three consecutive upward flow channels 308 followed by a single downward flow channel 306, and so on. The arrangement shown in
Wash basin 108 and flow channels 306, 308 may be formed using various suitable methods and materials. In one embodiment, wash basin 108 and flow channels 306, 308 are integrally formed of talc filled polypropylene, by injection molding. An integral molding of the wash basin and flow channels as one piece is desirable to maintain the water tight seal of the wash basin 108 and flow channels 306, 308. Fluid-assisted molding techniques, such as water-assisted or gas-assisted injection molding, may facilitate the formation of the elongated flow channels 306 and 308.
During the spin cycle, wash liquid extracted from the wash load is collected in the stabilizing reservoir 302. In one arrangement, the spin cycle includes a slow initial acceleration to allow a portion of the wash liquid to enter the stabilizing reservoir 302 to aid in balancing the load prior to reaching a full-speed spin. Stabilizing reservoir 302 may include a plurality of baffles (460 in
Reservoir 302 is preferably sized sufficiently large to accommodate a substantial portion of the wash liquid typically remaining in the wash basin 108 and wash load after a static drain of the wash liquid (for an expected range of wash load sizes). As one example, reservoir 302 may be sized to accommodate the full amount of wash liquid typically remaining after a static drain. Alternatively, especially in the case of a very large load capacity, reservoir 302 could be sized to accommodate a selected fraction of the anticipated volume of wash liquid remaining after a static drain. In this case, multiple cycles of wash basin spinning and stopping (or slowing) may be carried out to extract and drain substantially the entire amount of extractable liquid in successive portions. For example, reservoir 302 may be sized to accommodate one half of the wash liquid expected to be remaining in a large load after a static drain. In this case, after the static drain, a two-step spin drain process may be implemented in which the wash load is rotated to expel a first portion of the wash liquid in the load and then rotation is temporarily stopped to allow this wash liquid to drain from the reservoir 302 through downward flow channels 306. The temporary pause in the spin drain cycle may be, e.g., approximately 15-30 seconds. The spin drain process is then repeated a second time to remove the remaining extractable wash liquid.
The wash liquid is drained from the reservoir 302 under the force of gravity via the downward flow channels 306 immediately following termination of the spin cycle. As shown, e.g., in
Plate 800 of
The downward flow channels 306 wrap around the curved bottom surface of wash basin 108 and radially converge at a manifold 315 arranged about, and provided in fluid communication with, a central drain 310, as shown in
The flow channels may advantageously be configured such that the size of the flow channels, and/or orifices thereof, increases from upstream to down (from wash basin to sewer), to prevent debris from entering into the flow channels and associated drain paths and subsequently blocking the same.
The flow channel and reservoir arrangement described above advantageously eliminates the need for an outer, stationary splash tub, as used in conventional systems. In the conventional arrangement, the stationary splash tub acts as a reservoir for collecting the wash liquid spun from the wash basin. On the other hand, in accordance with the invention, upward flow channels 308 direct the wash liquid to reservoir 302 as it is spun from the wash basin, thus eliminating the need for an outer, stationary tub. By removing the outer tub from the washing machine, a larger wash basin may be used within a standard sized washing machine cabinet. Further, a single tub arrangement decreases the weight and manufacturing costs associated with providing an outer stationary tub.
Additionally, the single tub arrangement allows for conservation of water by maximizing the amount of water in the wash basin, unlike a conventional arrangement wherein water between the tubs does not aid in wash performance. Also, the single tub arrangement eliminates the need for a clutch and gearbox arrangement as used in conventional systems. The clutch and gearbox not only add to the weight and cost of the washer, but also add mechanical complexity which can lead to the need for additional servicing of the washer throughout its lifespan. Quieter operation is also possible through elimination of the gearbox. Still further, a single tub arrangement as described may also eliminate the need for a mechanical brake, since the start and stop of the spin of the tub can be precisely controlled by the motor (including very high accelerations and decelerations). The ability to rapidly decelerate the tub upon opening the washer lid may also eliminate the need for a lid lock to conform with generally accepted safety practices and governmental or industry regulations.
In conventional washing machines, the central column may rotate or oscillate to act as a wash load agitator for inducing a wash action during the wash cycle, independently of the wash basin rotation. As mentioned, illustrated column 112 does not serve as an agitator for inducing a wash action. Rather, in accordance with another aspect of the invention, a unique wash action and circulation of the laundry load is achieved with an arrangement of wash action ramps and a sequence of tub rotation starts and stops, as will now be described.
One or more wash action ramps 402a may be molded into the bottom of wash basin 400 and have a generally triangular transverse cross-section, as illustrated in
As the wash basin 400 begins to accelerate at the outset of a wash action control sequence, the wash action ramps 402a sweep through the initially static pool of wash liquid to impart a wave wash action on the wash liquid. This action is, by virtue of water shear, generally confined to a lower portion of the wash basin 400. This is the first component of a mechanical wash action and contributes to good mixing of the wash load in the lower half of the wash basin 400. Additional wave wash action occurs when the wash basin 400 decelerates. While the water mass is rotating with the basin, a subsequent deceleration of the wash basin causes the rotating mass of water to sweep over the ramps as they slow down and stop. Overall, the movement of the ramp 402a relative to the water creates a wave turbulence that flexes the wash load to impart an excellent wash action.
As illustrated in
The cross-sectional views of
Although illustrated primarily in conjunction with a single wash basin (tub) embodiment, an arrangement of wash action ramps as described may also be implemented in a washing machine having a conventional dual tub arrangement.
With reference to
With reference to
With reference to
In addition to the sidewall ramp induced circulation and wash action generated upon the wash basin spin deceleration, the parabolic shape of the wash liquid 608 will dramatically collapse, causing mixing of the load. In particular, the collapse of the parabola causes the wash liquid 608 to rush down the sidewall of the wash basin 600 and up, into the center of the wash basin 600, where momentum carries the liquid (and the load) upwardly along the central column. In addition to circulating the load, the collapsing wash liquid 608 causes the wash load 604a, 604b to continue to mix and circulate as the wash liquid 608 rushes down the sidewall and up, into the center of the wash basin 600. In one arrangement, excellent mixing occurs when the parabola is driven as high as possible up the sidewall using rapid acceleration, and a strong forceful collapse of the parabola is precipitated by rapid braking.
Also, at the point of deceleration, the inertia of the wash load 604a, 604b causes the wash liquid and wash load 604a, 604b to continue to rotate longer than the wash basin 600, thereby inducing a wave wash action similar to that induced with the acceleration of wash basin 600. The relative motion of the ramps, the wash liquid and the wash load causes the wash load 604a, 604b to flex and flow over and around the ramps, and wash liquid to flow through the wash load, thereby providing an excellent multi-component wash action. As the size of the load increases, the size of the parabola generally decreases. Thus, with a large load, the sidewall ramps assume a relatively greater role in mixing/circulating of the load.
The wash action illustrated in
In a preferred arrangement, the wash basin 600 is caused to alternately, successively rotate in opposing directions. For instance, the wash basin may rotate counter-clockwise then come to an abrupt stop. The following wash action may begin with the wash basin rotating in a clockwise direction, then coming to an abrupt stop, and so on. The wash cycle may continue in this manner of rotation for the duration of the wash cycle, or a portion thereof. Such spin patterns may be used in conjunction with differing ramp surface profiles to achieve cycle control, as previously described.
The graph of
In one arrangement, each complete cycle may last between 3 and 15 seconds. For example, one cycle may be approximately 9 seconds, allowing for approximately six cycles per minute. An extremely short cycle could comprise an acceleration phase of 1.5 seconds and a braking (deceleration) phase of 1.5 seconds, for a half-cycle time of three seconds (direction would then change and half cycle would repeat). A more typical half-cycle could comprise, sequentially, an acceleration phase of 5 seconds, a pause phase of 2.5 seconds, a braking (deceleration) phase of 5 seconds and another pause phase of 2.5 seconds, providing a half-cycle time of 15 seconds (direction would then change and half-cycle would repeat). For a single tub arrangement, such as the one described, a wash agitation cycle may last, in total, from 10 to 18 minutes. Additional cycles will occur during the rinse portion of the wash process. This rinse cycle time may vary depending on the cycle setting selected, e.g., 4 to 8 minutes. In one example, the rinse cycle is approximately 5 minutes.
Once the sequence of tub accelerations and decelerations comprising the wash cycle is complete, the wash liquid 608 (the “free” water pooled within the wash basin 600) may be drained through a central drain. The washing machine may then enter a spin cycle which dewaters the wash load further. In one example, the wash basin rotates at 700-800 rpm in order to optimize dewatering. In the case of an embodiment as shown in
The invention has been described in terms of particular exemplary embodiments. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure.
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Number | Date | Country |
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745133 | Feb 1956 | GB |
55024016 | Feb 1980 | JP |
Number | Date | Country | |
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20080141466 A1 | Jun 2008 | US |