Patent Abstract:
In a household washer which contains a tub with a cylindrical wall suspended by means of suspension rods, the tub also is comprised of ears with petals by which the tub is held in one extreme by suspension rods, at least one cylindrical reinforcement which surrounds the cylindrical wall, at least one pair of lobes in a substantially upper area of the tub, and additionally preferably one spout for over-flow in a substantially upper area of the tub.

Full Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority from Mexican application Serial No. MX/a/2009/013992 filed Dec. 17, 2009, which is incorporated herein by reference in its entirety. 
       FIELD OF INVENTION 
       [0002]    The present invention falls under the washer category, in particular that of top loading washers and even more specifically; it applies to washers which has a metal cabinet, from which four fastened suspension rods hang each having a lower extremity comprised of a shock absorber; these are inserted into an equal number of disposable ears in the tub intended specifically for this purpose which in turn support the tub and additionally act as a good suspension system for the vibrations which are generated during the washing, rinsing and centrifuge motions. The tub holds in its interior a perforated basket, which itself contains an agitator in concentric form: the shaft of said agitator is mechanically connected to an electric motor which is suspended in the lower portion of the tub. 
       BACKGROUND 
       [0003]    The tub not only holds the weight of the water and the articles to be washed, but also supports the static and dynamic charges which are generated with the washing or centrifuge motions, some of which can be large enough to deform the shape of the tub, knowing that these are generally manufactured by thermoplastic injections, the most popular being polypropylene. So, for example, when the basket is turning at a high speed in order to achieve centrifuge it is very common that the weight of articles to be washed in the basket cause an imbalance of the system, which cause the basket to not only have a rotational movement but also a translational one within the tub, even causing possible scraping against the tub&#39;s internal wall, not a desired effect of the design. If this occurs in addition to the deformation caused in the tub&#39;s mouth, the gap between the basket and the tub is greatly reduced. 
         [0004]    This is why it is necessary to design a tub for a top loading washer which is highly rigid, not discounting the difficulty of manufacture, using thermoplastics like polyethylene or polypropylene, which help absorb, distribute and transmit the different forces and efforts created by the varying washing and centrifuge cycles. 
         [0005]    Various efforts in this area have taken place with said objectives in mind, such as Paul Gregory Hall&#39;s AU2006235808 patent application which deals with a bombing system which is fastened to the lower portion of the tub;  FIG. 2  shows a cross section of the lower portion of the tub where the reinforcements of the inferior external part of the tub can be seen, where a pancake type motor is grasped emphasizing the bomb&#39;s assembly, the part of particular interest in this tub being the use of lobes in the tub&#39;s superior part which are aligned with the reinforcement of the support ears. 
         [0006]    Jonathan David Hartwood&#39;s et al EP 1 783 264 A2 published patent application which presumably shows in  FIG. 2 , the same tub as Hall&#39;s, where there appear a pair of lobes aligned with the ear reinforcements, wherein said lobes were presumably designed to create more space for the basket inside the tub, given their number, as it only is comprised of two lobes which do not significantly increase the area&#39;s rigidity in the tub&#39;s mouth, allowing a larger space to the basket as well as to the tub&#39;s cover which can house a grid, window or passage in the precise additional area created by the lobes intended to transport chemicals deeper into the tub to be mixed with greater ease. 
         [0007]    Even so, though the tubs shown in both documents at a simple glance appear to have strong reinforcements at the ears making them better able to hold heavy loads, no concern seems to be given to avoiding the deformation neither to the tub&#39;s mouth nor to the tub&#39;s cylindrical wall with an end result of attaining a more rigid tub which supports, absorbs, cushions and transmits the forces generated inside the basket while washing or centrifuge motions take place. 
         [0008]    Given the above discussion, the need to develop a tub with higher rigidity yet using the traditional manufacturing materials, thereby reducing cost becomes apparent. The tub also allows for larger baskets to be held due to lesser deformities and thus transmits more efficiently the efforts to the suspension rods with shock absorbers, and also avoids the scraping between the tub and the basket during centrifuge, where larger baskets allow for larger washing loads as well as water and detergent (mixes water with chemicals or additives), allowing for larger washing loads in an equal volume sized cabinet, this being the purpose of this invention. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0009]    Derived from the experience of designing and manufacturing washers it is noted that the tub, far from being solely an object which contains water and detergent, has structural functions as well. It supports the basket&#39;s assembly which is aligned with the tub in its symmetrical axis, as well as to the transmission or reduction box which can be fitted to the agitator; it also supports the electric motor, hoses, overflow ducts etc. This entire group afore mentioned plus the suspension rods are known as the sub-washer. The tub itself hangs from four suspension rods whose lower area has a shock absorber mechanism, whereas the higher section of said suspension rods are attached to the upper corners of the cabinet which statically and kinematically support the sub-washer. The lower area of the suspension rods are fastened to the tub by means of ears lodged in the shock absorbers, this system allows the tub at least three degrees of freedom, because if it were a rigid assembly, the washer would tend to “walk” or jump, not being capable of softening the vibrations emerging from its own operation, such as those being created from the agitation of the wash load itself or the centrifuge stages. 
         [0010]    This is why the tub is comprised of a robust system of reinforced ears with veins which run along its length as well as the tub&#39;s circumference. 
         [0011]    Another characteristic of the tub discussed in the present invention, are reinforcements running like a belt on the external periphery of the tub&#39;s cylindrical wall, which discourage possible deformations to said tub, and knowing that water&#39;s own weight exerts a force on said wall, coupled with certain washing conditions which require hot water for proper stain removal or to activate chemicals or detergents mixed in the wash, said temperatures can reach near 60° C., which can cause a considerable re-softening in the equatorial area of the tub&#39;s cylindrical wall inflating it to a balloon shape, not a desirable deformation because when this happens, the tub&#39;s mouth itself tends to deform inwardly reducing the gap or area between the basket and the tub, which in turn creates friction due to scraping between these two parts during the agitation and specially centrifuge motions which leads to wear out and possible permanent damage as a hole can be formed on the cylindrical wall where the repeated and prolonged scraping take place. 
         [0012]    Another characteristic to be outlined, are the higher petal lobes located in the tub&#39;s mouth which allow the tub&#39;s mouth higher rigidity avoiding deformities to the tub&#39;s mouth caused by the basket&#39;s rotations, widening the gap between the tub and the basket precisely in the area where the basket&#39;s nodding occurs considerably avoiding the friction due to scraping between the tub and the basket. To help avoid deformities to the tub&#39;s circular wall between the lobes and over the reinforcement belt, reinforcements are placed in arc form. These reinforcements allow for the distribution of forces created by the dynamic and hydrostatic charges allowing for a better transmission of these to the shock absorbers of the suspension rods. 
         [0013]    Yet another aspect of the present invention is found in the tub&#39;s bottom crafted as a truncated cone which allows drainage and guides the washing mixture unto the lower area, followed by an inclined plane which then guides the washing mixture towards a trough, where the valves or the pumps are fed. 
         [0014]    On the opposite side of the tub&#39;s bottom, that is, the deep exterior, a reinforcement of a series of ribs is found which allow for extraordinary rigidity using minimum material. In this way, the elements herein described coupled with others to be detailed later, constitute the present invention creating a robust top loading washing machine with exceptional structural rigidity which allows for withstanding of high temperatures of washing mixtures without causing major deformities, high work effort, a reduced gap between the tub and the basket which allows for significant water conservation while being able to use a smaller volume tub, among other attributes. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]    These and other characteristics, aspects and advantages of the present invention will be better understood upon reading the following detailed description referencing the accompanying drawings in which: 
           [0016]      FIG. 1  is an isometric cross-section of a sub-washer. 
           [0017]      FIG. 1   a  is an isometric representation of the tub with suspension rods, a drainage duct and a spraying hose. 
           [0018]      FIG. 2  is an isometric representation of the tub with suspension rods, an overflow duct, a spraying hose and an exploded drainage system. 
           [0019]      FIG. 3  is an upper view of the tub. 
           [0020]      FIG. 4  is a lateral cross view of the tub. 
           [0021]      FIG. 5  is an inferior isometric view of the tub. 
           [0022]      FIG. 6  is a detailed view of the lower part of the tub, specifically that of the ear. 
           [0023]      FIG. 7  is a lateral view of the tub. 
           [0024]      FIG. 8  is a detailed cross section of the tub&#39;s ear. 
           [0025]      FIG. 9  is an upper isometric view of the tub. 
           [0026]      FIG. 10  is a detailed cross-section of the overflow drain. 
           [0027]      FIG. 11  is a detailed view of the assembly of the drainage duct unto the overflow drain. 
           [0028]      FIG. 12  is a detailed isometric view of the tub&#39;s mouth. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    The washing machine being described in the present invention, illustrated in  FIG. 1 , is a top loading machine or vertical axis, and possesses a cabinet from which four suspension rods  12  are attached, said suspension rods  12  support the tub&#39;s weight  11  with the additional accessories to said cabinet, said suspension rods in addition of supporting static charges, mitigate the dynamic charge through shock absorbers present in its lower part, which help dissipate the vibrations caused by the washing motions. 
         [0030]    Thus the tub  11  is hung from the suspension rods  12  by means of ears  35  placed in the lower portion of said tub  11 . The remaining peripheral equipment is mounted on said tub  11 , such as the motor  21 , in a preferred embodiment, a planetary gear for reduction  24 , which, in an alternative embodiment of the present invention, can be omitted thereby adjusting the pulley relationship  22 ; in this form, the pulley  22  with the largest diameter will be adjusted over the internal shaft  25  which will receive energy proceeding from the electric motor  21  thanks to the arrangement of pulleys  22  and band. In a preferred embodiment the shaft  25  on its upper part shall be coupled to a planetary gear for reduction  24  with the purpose of reducing angular speed, thereby accomplishing greater torque the exiting shaft from the planetary gear for reduction which reintegrates into one shaft  25 , on whose upper part the agitator is placed  13 . In an alternative embodiment the internal shaft  25  has a pulley with the largest diameter coupled to its lower part  22  and on its upper part is coupled to the agitator  13 . The interior of the hollow shaft  26  houses the internal shaft  25 . Said hollow shaft  26  is mechanically coupled to a clutch  28 , which can make both shafts  25 ,  26  rotate together or independently, and also said hollow shaft  26  is mechanically coupled to the basket&#39;s center called the “hub”  32 , so that when shafts  25 ,  26  are clutched and rotating together, the hollow shaft  26  shall transmit energy to the basket  10  so that it turns along with the agitator  13 . 
         [0031]    The basket  10  is crowned with a balance hoop  27  which counteracts the unbalancing caused by the shifting of the wash load inside the basket  10 . In a preferred embodiment, the tub  11  on its upper part is joined to a covered tub which houses a grill  19  and a spray deflector  18 . The cabinet itself is covered with the main cover  30  which covers the washer&#39;s upper part  20 , said main cover  30  serves as a support to the crest (not shown) wherein the electric components such as the controls  40 , the interrupting or relief drivers, the pressure switch  41  etc are housed as well as the washer&#39;s cover or lid  29  through which the items to be washed shall be loaded. 
         [0032]    As can be seen in  FIGS. 3 ,  4  the tub&#39;s bottom  11  which is crafted in its center by a truncated cone  49  which allows the liquid or washing mixture to slide to a lower area aided by the force of gravity, this lower zone is formed by a ring with a β pendant whose lowest point coincides with the entrance to the trough  46 , wherein the liquid or washing mixture is collected to be extracted by a bomb  15  whether it be for drainage or whether the liquid or washing mixture be transported to the spraying system.  FIG. 5  shows the tub&#39;s lower side  11  and it is here that the series of reinforced ribs which have been implemented can be seen. It should be highlighted that a series of diametrical ribs  53  have been traced in cross shape. That is to say, they emerge from the sides of the ears  35 , as can be seen in  FIG. 6 , and cross diametrically at the opposite ear  35 , discontinuing the ribs as they pass through the center, the remaining being the radial ribs  52 . In a preferred embodiment to the present invention, another set of diametric ribs  53  emanate from the tub&#39;s center  11  towards the periphery of the tub&#39;s bottom  42 , said diametric ribs  53  are preferably traced precisely in the middle of the diametric ribs which go from ear  35  to ear  35 . This intricate rib arrangement gives the bottom of the tub  42  greater rigidity with a minimum amount of material used. Using this intricate rib arrangement ensures the placement of sufficient material in the precise area where the forces require strength. 
         [0033]    The ears  35  can be seen in  FIGS. 1   a ,  5 ,  6 ,  7 ,  8 . It should be noted that said ears  35  are formed by a pair of petals  54  which wrap the shock absorbers from the suspension rod  12  as can be seen in  FIG. 1   a . Said petals have the end result of distributing the final dynamic forces, that is, the forces which are generated when the washer is in a wash, centrifuge or rinse mode. In this way, said dynamic forces are not transmitted in their full capacity to the suspension rods&#39;  12  shock absorbers, but rather, are diluted into the tub&#39;s body  11 . 
         [0034]    That is, the suspension rod&#39;s  12  shock absorber makes contact on a horizontal plane which protrudes from the ear  35 . The lower side of said plane has a spherical surface which has an opening which can be coupled in a swivel form to the upper side of the suspension rod&#39;s shock absorber  12 . Said aperture allows the suspension rod access through said horizontal plane of the ear  35  allowing it enough space to allow for angular movement on the vertical axis, this being one degree of freedom: a second and third degree of freedom are obtained on the horizontal axis, allowing the tub  11  a limited translational movement. 
         [0035]    In this way, this system ensures restricted amplitude of movement with 3 degrees of freedom, not allowing movement in the 3 remaining degrees of freedom. However, if the horizontal plane protruding from the ear  35  could be formed as a cantilevered beam (see  FIG. 8 ) this would create a strong lever arm on the tub&#39;s  11  cylindrical wall  34  and create large forces on the tub&#39;s bottom  42 . In a best case scenario, this can cause deformities to said tub&#39;s parts  11 , which once said applied forces cease being applied, will return to its original shape. In another case, said deformities can be permanent or cause premature fatigue on said parts of the tub  11 . With the intent of reinforcing said protrusion from the ears  35  on the horizontal plane a pair of petals  54  are added to the ear which help distribute the dynamic forces over a greater area on the tub&#39;s  11  cylindrical wall  34 . 
         [0036]    The mentioned petals possess an alternative embodiment from the present invention with reinforcement ribs  36 . The distinct shape of these ears  35  allow a better way to transmit the forces concentrated there unto a larger area of the tub&#39;s  11  cylindrical wall  34  and also restrain them to some degree from reaching the deepest part of the tub  42 , lessening the lever&#39;s effect on said deepest part  42 . As can be seen from the previous discussion as well as from the figures, this design can transmit to a great degree the forces on the tub  11  and dissipate them unto the tub&#39;s body transmitting these forces to a lesser degree on the suspension  12 . The ears&#39; robust design  3  is more difficult to deform, thereby increasing the tub&#39;s life, lessening fatigue and additionally increasing the tub&#39;s total rigidity  11 . 
         [0037]    Another facet of the present tub&#39;s  11  invention, making reference to  FIGS. 1   a ,  2 ,  5 ,  7 ,  8  is based on the arch shaped reinforcements  39  which can be directed on the external side of the tub&#39;s  11  cylindrical wall  34 . Said arch&#39;s base is precisely on the side of the ear  35 , which itself serves as reinforcement to the ear  35 . It should also be noted that the lower part of the arch  39  presents a greater radial height, this helps increase moment of inertia in the lower part, which in turn helps the rigidity of the tub&#39;s lower part as well as aids in the distributing of forces over a greater area. Thus, when the arch&#39;s curvature increases in height over the tub&#39;s  11  cylindrical wall  34 , radial height decreases, understanding that the upper portion of the tub  11  does not require high rigidity, therefore being able to economize material with this design, as well as allowing for coherent distribution of dynamic and static forces. The arch as can be discerned, can be formed in different curvatures and configurations, the preferred curvature shall depend on the particular design of each tub, depending on variations of the ear&#39;s  35  design, the presence or lack of belts or cylindrical reinforcements  37 , and in case of the actual configuration of these, on the design of the mold itself, are among other factors which can alter the shape or curvature of the arch  39 , which is built with the best possible shape to ensure the best distribution of forces on the tub&#39;s  11  cylindrical wall  34 . 
         [0038]    Now turning attention to the belts or cylindrical reinforcements  37  shown in  FIGS. 1   a ,  2 ,  5 ,  6 ,  7 ,  8  it can be seen that said belt or cylindrical reinforcements  37  can be developed preferably in the tub&#39;s lower part  11  surrounding the cylindrical wall  34 . The reinforcements  37  are ribs in rectangular or trapezoidal transverse sections, which protrude in radial shape from the cylindrical wall&#39;s  34  exterior surface. This allows for a greater moment of inertia giving the mid to lower area of the cylindrical wall  34  excellent rigidity which decreases the deformations caused to this area of the tub  11  and also allows for more efficient distribution of dynamic and static forces to which said tub  11  is subjected to. 
         [0039]    The lobes  38  shown in  FIGS. 1   a ,  3 ,  4 ,  5 ,  9 ,  10 ,  11  in addition to giving rigidity to the tub&#39;s  11  mouth  47 , confer a greater action radius to the basket  10 , since it is precisely in this area where the gap or space between the tub  11  and the basket  10  is decreased when the basket spins, this is due to the basket&#39;s  10  head movement which has its greatest translation movement on the horizontal plane at this point, taking into account that said basket  10  is fastened in its lower or deepest part to the hollow shaft  26 . So that when a considerable shift in the wash load causes imbalance within the basket  10 , the translational movement of the basket&#39;s  10  upper part is exacerbated and can indeed scrape the tub&#39;s  11  mouth  47  causing the tub  11  harm such as perforations to the cylindrical wall&#39;s  34  higher interior surface or in the best of scenarios, loss of energy due to friction caused by the surface contact between the tub  11  and the basket  10 . Thereby the lobes increase the space within which the basket  10  in case of being subjected to translational movement due to its imbalance, avoid to a great degree the scraping problem and as has been mentioned before, increase to a great degree the rigidity of the tub&#39;s  11  mouth  47 , which in a common tub  11  or one which does not possess said lobes  38  nor the arch  39 , due to the weight or static and kinematic forces which are transmitted to the tub  11  originating from the basket  10  when it is loaded with articles to be washed submerged in the washing mixture coupled to the lever arms which are generated in supporting the tub  11  to the suspension rods through the ears  35 , cause the tub&#39;s  11  mouth to lose its cylindrical shape tending to collapse inwardly or along the tub&#39;s  11  own symmetrical axis. In this way, said lobes  38  help avoid the inconveniences mentioned above. 
         [0040]    The tub&#39;s  11  mouth  47  has an interesting spout  48 , which has the function of draining the washing mixture or liquid contained in the tub  11 , which for whatever reason is found in excess guaranteeing a maximum level of washing mixture or liquid within the tub  11 . This spout acquires particular relevance since it avoids, should the operator overfill the system with water or in case the pressure switch  41  or the full capacity valve  45  or electronic control  40  malfunction and cause the overfilling of water above the tub&#39;s  11  maximum water capacity and the washer  20  can then carry out the washing and rinsing functions. Said liquid or washing mixture excess has to be drained because otherwise the liquid or washing mixture can overflow from the tub  11  over its upper part with the liquid or washing mixture sliding in fountain form over the exterior surface of the tub&#39;s  11  cylindrical wall  34 , possibly causing the pumps or motors among other electrical devices to become wet when the overflow of liquid or washing mixture moistens the floor where the washer  20  is placed causing this flow of events to create a dangerous situation, which in a worst possible outcome, could lead to the operator&#39;s electrocution since the liquid or washing mixture previously mentioned, has a high water content and water is an electric conductor. In order to avoid such a dangerous situation, the spout  48 , has been designed as shown in  FIGS. 1   a ,  10 ,  11 , as coupled via a ring, clasp or another securing mechanism to a sleeve  55 , which itself is a tube preferably made from a polyethylene extruded with low density, similar to a plastic bag with no bottom. Said sleeve  55  transports the excess liquid or washing mixture to the washer&#39;s  20  lower part. 
         [0041]    Having fully described the present invention, it is found to attain a high degree of inventive activity, its industrial application undeniable, warning at the same time that a technician with knowledge in the area can discern alternative modalities which shall be included within the reach and spirit of the following claims.

Technology Classification (CPC): 3