Abstract:
A washing machine including a perforated inner basket and an outer tub is disclosed. The outer tub includes one or more grooves on its inside wall to redirect extracted water from the perforated inner basket downwardly into a collection area for disposal. The groove may be generally vertical or angled along the upper portion of the inner wall of the tub. The groove preferably includes an undercut portion that extends in the same direction as the perforated basket spins.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to an apparatus for washing clothing and other items. More particularly, though not exclusively, the present invention relates to an apparatus for washing clothing that includes a drain-back groove to minimize excess sudsing during the removal of wash water.  
           [0003]    2. Problems in the Art  
           [0004]    Currently, top loading washing machines typically include a perforated basket which holds the clothes or articles being washed and an agitator to mix the clothes and articles in the wash water. At the completion of the wash cycle, the perforated basket is rotated at a high RPM to extract the wash water from the perforated basket and the clothes and articles therein. Because of the spinning nature of the perforated basket, the extraction is known as the spin cycle.  
           [0005]    During the spin cycle water flows out of the holes in the perforated basket and contacts an outer tub. Due to the speed of the perforated basket during the spin cycle, the evacuated water continues to flow in the direction of the spin even after contacting the wall of the outer tub. This delays the water&#39;s arrival at the base of the tub where it is eventually pumped away.  
           [0006]    Often, the evacuated wash water lingers in the upper portions of the tub, eventually accumulating and re-contacting the spinning perforated basket. When this occurs, the result is foam. Eventually, the amount of foam is amplified to the point of suds-locking the washing machine, a condition where the drain pump is no longer able to evacute the suds. During a suds-locking condition, suds may develop to the point where they exert an excessive load on the motor used to drive the spinning basket. To prevent this problem, it is desirable direct the evacuated wash water towards the base of the tub as quickly as possible. This would minimize water build up and any resultant foaming conditions.  
           [0007]    Prior attempts at directing water&#39;s movement in the region between the outer tub and the perforated basket have included U.S. Pat. No. 5,671,617 which issued to Park et al. on Sep. 30, 1997. However, the Park patent uses a series of collars on one of the two interior perforated baskets to recycle water onto the top of the clothes during the wash cycle. Wash water is extracted in a conventional manner and no effort is made to direct the flow of evacuated water during the spin cycle.  
           [0008]    A general objective of the present invention is to provide a washing machine that solves the problems found with the prior art.  
           [0009]    A further objective of the present invention is to provide a washing machine that can affect the flow of water between the perforated basket and the outer tub.  
           [0010]    Another objective of the present invention is to provide a washing machine that efficiently collects wash water during the spin cycle.  
           [0011]    A still further objective of the present invention is to provide a washing machine that minimizes excessive sudsing in the region between the perforated basket and the outer tub.  
         BRIEF SUMMARY OF THE INVENTION  
         [0012]    The foregoing objects may be achieved by the washing machine of the present invention. The present invention generally comprises a cabinet in which a perforated wash basket is mounted in a conventional manner. An agitator, drive motor and drive mechanism are mounted within the cabinet, as is well known, to operate the washing machine.  
           [0013]    Between the perforated wash basket or interior chamber and the cabinet is a tub or outer chamber to collect and contain wash water. The tub has a side wall that includes one or more grooves to direct wash water downward toward a collection area during the spin cycle. Preferably, the groove includes an under-cut portion that prevents collected water from flowing out of the groove.  
           [0014]    During the spin cycle, the motor operates to turn the perforated basket at a high speed. This causes wash water to be extracted from the clothes or articles in the perforated basket. The water flows through the perforations in the basket and out to the tub wall. Because the basket and clothes are spinning at a high rate, the water flows out of the perforated basket and continues to flow in the direction of the spinning basket. When the water contacts the grooves, the flow is redirected to evacuate the water in a more efficient manner thereby minimizing sudsing conditions. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a cross-sectional view of a washing machine.  
         [0016]    [0016]FIG. 2 is a sectional side-view of the interior washing apparatus including a tub of the present invention.  
         [0017]    [0017]FIG. 3 is a sectional side-view of the interior washing apparatus including an alternative tub of the present invention.  
         [0018]    [0018]FIG. 4 is a top sectional view taken generally along line  2 - 2  of FIG. 2.  
         [0019]    [0019]FIG. 4A is an enlarged view of section A of FIG. 4 shown during operational conditions. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    The present invention will be described as it applies to its preferred embodiment. It is not intended that the present invention be limited to the described embodiment. It is intended that the invention cover all modifications and alternatives which may be included within the spirit and scope of the invention.  
         [0021]    Now, referring to the drawings, FIG. 1 illustrates a cross section of a typical washing machine  10 . The washing machine  10  includes a cabinet  12 , a control panel  14 , an access opening  16  and an associated door (not shown). A reversible drive mo tor  18  of conventional construction is mounted within the lower portion of the cabinet  12 .  
         [0022]    The motor  18  is preferably secured to a web  20  by one or more brackets  22 . The motor output shaft  24  extends upwardly through a clutch  26  shown schematically in FIGS. 2 &amp; 4. The clutch  26  is adapted to respond to the rotational direction of the shaft  24  to engage/disengage the hub  28  that is connected to a spherically shaped basket  30 .  
         [0023]    The basket  30  includes a plurality of perforations  32  in the spherical shaped walls for permitting fluid communication between the interior of the basket  30  and the tub  34 . Thus, as fluid is introduced into the basket  30 , the fluid flows through perforations  32  and enters tub  34  also. As is further depicted in FIG. 1, the web  20 , drive motor  18  and the washing assembly are shown suspended from the inside of cabinet  12  by a conventional hung strut suspension system  36  which is of known construction and does not comprise part of the instant invention.  
         [0024]    The washing assembly also includes one or more agitators  38  that operate in a manner as described in U.S. Pat. No. 6,220,063 to Wunderlich on Apr. 24, 2001. During the washing action, rotation of shaft  24  causes clutch  26  to simultaneously disengage hub  28  from shaft  24  and secure hub  28  against rotation. This enables shaft  24  to rotate freely within hub  28  to drive the agitators  38  while also preventing rotation of basket  30 .  
         [0025]    After the washing cycle has completed, the motor  18  is reversed, causing a reverse rotation of shaft  24 . This reverse rotation of shaft  24  causes clutch  26  to couple the shaft  24  to the hub  28 , while simultaneously allowing free rotation of hub  28 , thereby causing the basket  30  to rotate for the spin cycle. During the spin cycle, the washing fluid passes outwardly through perforations  32  and into the tub  34  due to centrifugal force.  
         [0026]    [0026]FIG. 2 shows the tub  34  of the present invention. The tub  34  includes a lower portion  40  and an upper portion  42 . The inner wall of the upper portion  42  includes one or more grooves  44  as is shown in FIG. 4. As shown in FIG. 2, the groove  44  preferably runs along the entire upper portion of the tub  34 , but may be of any length, width or depth as desired.  
         [0027]    The groove  44  also preferably runs in a generally vertical direction, though it may be angled or even spiral around the inside wall of the tub  34  as shown in FIG. 3. Preferably, the tub  34  is made of a plastic material and formed through well known injection molding techniques. Alternatively, the tub  34  may be formed of stainless steel, coated metal, or any other durable material using well-understood techniques.  
         [0028]    Using a mold, the groove  44  is easily formed into a variety of shapes and sizes. The groove  44  preferably includes a front entry portion  46  and an under-cut channel portion  48 . The under-cut channel portion  48  preferably extends away from the front entry portion  46  in the same direction as the direction of spin of the perforated basket  30  during the spin cycle. In order to prevent undue oscillation during the spin cycle, a balancing arrangement of grooves should be used. This means the grooves should be equally spaced along the wall of the upper portion  42  of the tub  34 .  
         [0029]    As is shown in FIG. 4A, during the spin cycle the basket  30  spins to expell water from the interior of the basket  30 , through the perforations  32 , and into the region between the basket  30  and the tub  34 . Because the basket  30  is spinning at a high rate of speed, the water will generally continue to flow in the direction of the spinning basket  30 . As the water flows along the wall of the tub  34 , it eventually comes into contact with the groove  44 . The outwardly flowing water enters the groove  44  through the front entry portion  46 . When the water contacts the under-cut channel portion  48 , the outward rotational flow of the water is redirected into a downward flow as illustrated in FIGS. 2 and 3. Eventually, the water flows into the lower tub portion  40  which terminates in a bottom wall  50  where it is collected and removed through a discharge port (not shown).  
         [0030]    By redirecting the flow of water, the under-cut portion  48  reduces the amount of water spinning around the inside wall of the tub  34 . This helps to minimize sudsing conditions thereby preventing suds lock from occurring.  
         [0031]    While the invention is shown in a washer with a spherical tub and a vertical spin axis, it is envisioned that it could be applied to a conventional vertical axis washer with a cylindrical tub, a conventional drum-style horizontal axis washer, or a washer with any spin-axis angle therebetween.  
         [0032]    A general description of the present invention as well as a preferred embodiment of the present invention has been set forth above. Those skilled in the art to which the present invention pertains will recognize and be able to practice additional variations in the methods and systems described which fall within the teachings of this invention. Accordingly, all such modifications and additions are deemed to be within the scope of the invention which is to be limited only by the claims appended hereto.