Patent Publication Number: US-6658902-B2

Title: Dynamic balancer for an automatic washer

Description:
This application is a continuation of application Ser. No. 09/541,310 filed on Apr. 3, 2000 now U.S. Pat. No. 6,550,292. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to washing machines, and more particularly, to a combination dynamic balancer for a wash basket of a vertical axis washing machine. 
     It is common to spin a wash basket of a washing machine at high speed to extract washing fluid from the laundered articles within the basket. Invariably, the wet articles within the basket are not evenly distributed and create an unbalanced condition during the high speed spinning cycles of the machine. The unbalanced condition creates a rotating wash basket mass that does not correspond to the rotational axis of the wash basket and the washing machine. This generates unwanted stress on the components of the machine, excessive noise, severe vibration of the wash basket, and often movement of the machine. The loads created by the out of balance condition as well as the severe vibration can also create excessive wear and damage to the components of the washing machine. 
     It is therefore imperative that the wash basket including the wet articles therein be balanced to avoid these unwanted results. However, this is difficult because the out of balance condition varies from load to load and from machine to machine depending on the size of the machine, the quantity and weight of the articles being laundered and the variable positioning of the articles within the basket from load to load. The out of balance condition also varies for each load as the amount of water extracted from the articles within the basket changes during the period of each spin cycle. Therefore, it is imperative that any balancing mechanisms utilized in conjunction with the washing machine to correct these out of balance conditions be dynamic in nature. 
     One type of commonly used balancing device is known as a liquid balancing ring attached to the top of the basket. A typical liquid balancer ring includes an annular chamber that is partly filled, typically just over half full, with a fluid. This relatively simple balancer ring permits the fluid within the annular chamber to collect unevenly within the ring to offset an unbalanced condition of the wash basket. U.S. Pat. No. 5,345,792 discloses multiple liquid balancing rings. 
     Another type of balancer is known as a ball balancer and is typically utilized on horizontal axis washing machines. A ball balancer has a hollow annular chamber in a balancing ring wherein a plurality of steel balls are held within the chamber. These balls roll through a viscous fluid also held within the chamber. The annular chamber is completely filled with fluid once the steel balls are placed in the chamber. The rolling balls can distribute unevenly within the chamber to offset an unbalanced condition in the wash basket. The viscous fluid tempers movement of the balls within the chamber. U.S. Pat. Nos. 5,593,281 and 5,802,885 discloses a ball balancing ring. 
     Another type of balancing device utilized on horizontal axis automatic washing machines is a combination ball and liquid balancer. This type of device includes an annular ring that is divided into two hollow annular chambers that are essentially concentric or stacked upon one another. One of the chambers houses a ball balancer as described above and the other chamber houses a liquid balancer also as described above. This type of device functions wherein the balls can shift to a position opposite the unbalance condition or heavy side of the wash basket for small unbalances. If the balancing balls are completely shifted and the wash basket still spins with some vibration, the liquid balancing portion of the combined device further reduces the unbalance condition by shifting liquid to collect opposite the out of balance condition or heavy side of the wash basket. This combination ball and liquid balancer therefore simply extends the range of unbalance that a normal ball balancing device could handle. The combined liquid and ball balancer described above also provides somewhat of an improvement for wash basket stability during start up and also when a wash basket is spinning at high speeds and is empty. One example of a combination balancer is disclosed in WO99/10583. 
     The above balancing devices have their limitations. They can only cover limited ranges of out of balance conditions for vertical axis washing machines. Additionally, the ball balancer has typically not been used on vertical axis washing machines. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a balancing device for a vertical axis washing machine. Another object of the present invention is to provide a balancing device for automatic washing machines that provides an increased range of unbalance coverage over prior balancing devices. A further object of the present invention is to provide a balancing device that produces such increased range without increasing the cost of the balancing device. A still further object of the present invention is to provide a balancing device for automatic washing machines that has three separate balancing elements or characteristics producing a triple balancing device. 
     To achieve these and other objects, features and advantages of the present invention, a balancing device in one embodiment is constructed as an annular ring divided into two separate hollow annular chambers. A first chamber has a first fluid held therein that only partly fills the first chamber. The second chamber is disposed adjacent the first chamber and has a plurality of objects held therein that are movable within the second chamber. A second fluid is also held in the second chamber and, in combination with the objects, only partly fills the second chamber. 
     In one embodiment, the first fluid is water. In another embodiment, the first fluid is salt water. In one embodiment, the first fluid fills about one-half of the first chamber. 
     In one embodiment, the second chamber is stacked on top of the first chamber and is co-axial therewith. In another embodiment, the first chamber is at least partly defined in a first annular material ring and the second chamber is at least partly defined in a second annular material ring. In one embodiment, the second annular ring is stacked on top of the first annular ring and is attached thereto. In one embodiment, a third annular ring is disposed between the first and second annular ring and separates the first and second chambers. 
     In one embodiment, the dynamic balancer device includes a third injection molded ring of material defining a race. The race is attached to a second upper injection molded annular ring defining an inverted annular channel wherein the second chamber is defined between the race and the upper ring. A first lower injection molded ring of material that defines an annular channel is attached to the combined race and upper ring and defines the first chamber between the lower ring and the race. In one embodiment, each of these injection molded compartments is adhered to one another by heat welding, sonic welding, spin welding, or hot plate welding. 
     In one embodiment, the upper ring includes a pair of opposed depending walls and the race includes a pair of opposed edges that are attached to the depending walls of the upper ring. The lower ring includes a pair of upstanding and opposed walls. The lower ring is connected to the combined upper ring and race so that the attachment joints between the race and upper ring are received in the first chamber between the upstanding walls of the lower ring. 
     In one embodiment, the plurality of objects are each capable of rolling within the second chamber. In one embodiment, the objects are spherical balls. In another embodiment, the balls are steel balls. 
     In one embodiment, the second fluid has a higher viscosity than the first fluid. In one embodiment, the second fluid is an oil. In one embodiment, the oil is a ten weight oil. In one embodiment, the second fluid and the solid bodies, in combination, fill about one-half of the second chamber. 
     In another embodiment of the invention, an automatic washer includes an imperforate tub and a perforate wash basket disposed within the tub. The wash basket is rotatable about a generally vertical axis and has an annular top edge defining an opening. A rotary dynamic balancer is associated with the top edge of the wash basket and includes an annular hollow first chamber. A first fluid is held in the first chamber and only partly fills the chamber. An annular hollow second chamber is disposed adjacent to the first chamber and includes a plurality of solid bodies disposed therein. The solid bodies are movable within the second chamber. A second fluid is held within the second chamber and, in combination with the solid bodies, only partly fills the second chamber. 
    
    
     These and other objects, features and advantages of the present invention will become apparent upon reviewing the written description and the accompanying drawings. The foregoing and other objects of the invention are attained by a dynamic balancer that provides three separate balancing functions. The first function is provided by the first fluid held within the first chamber. The fluid itself will collect within the first chamber opposite an out of balance or heavy side of a rotating object. The second balancing function is provided by the objects held within the second chamber. The objects will roll or slide within the second chamber and collect opposite an out of balance or heavy side of a rotating object. The third balancing function is provided by the viscous fluid within the second chamber since it does not fill the remaining volume of the second chamber. The viscous or second fluid will also flow and collect within the second chamber opposite an out of balance or heavy side of a rotating object. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a general perspective view of an automatic washer partially cut away to illustrate various interior components. 
     FIG. 2 is a side sectional view of the automatic washer of FIG.  1 . 
     FIG. 3 is a top view of a balancing device constructed in accordance with one embodiment of the present invention. 
     FIG. 4 is a cross section taken along line IV—IV of FIG.  3  and illustrating the internal components and construction of the balancer of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, FIGS. 1 and 2 illustrate an automatic washer construction for which the balancing device of the invention is useful. The automatic washer  20  generally refers to a washing machine having a pre-settable control for operating a washer through a pre-selected wash cycle program including automatic washing, rinsing and drying operations. During at least the drying operation, the washing machine  20  operates at relatively high rotational speeds in order to extract water from articles such as clothing that have been washed by the machine. This portion of a wash cycle is commonly known as the spin cycle. 
     The washing machine  20  includes a frame  22  carrying vertical panels  24 , forming sides  24   a , a top  24   b , a front  24   c , and a back  24   d  of a cabinet  25 . A hinged lid  26  is provided in the usual manner for access to the interior or treatment zone  27  of the washing machine  20 . The washer  20  also includes a console  28  having a timer dial  30  or other timing mechanism and a temperature selector  32  as well as a cycle selector  33  and other selectors as desired. 
     Internally, the exemplary washing machine also includes an imperforate tub  34  within which a wash basket  36  is received. The wash basket  36  is perforated including a number of holes  35  permitting fluid to pass between the wash basket interior and the tub. A pump  38  is provided below the tub  34 . The wash basket  36  defines an open top wash chamber and has an upstanding sidewall  37 . Baffles may be provided on the interior of the sidewall  37  or on an upstanding axial projection for agitating the water and articles within the wash basket during a wash cycle as is commonly known. A motor  100  is operatively connected to the wash basket  36  through a transmission  102  to rotate the wash basket  36  relative to the stationary tub  34 . All of the components within the cabinet  25  are supported by struts  39 . 
     Water is supplied to the imperforate tub  34  by hot and cold water supply inlets  40  and  42 . A hot water valve  44  and a cold water valve  46  are connected to a manifold conduit  48 . The manifold conduit  48  is interconnected to a plurality of wash additive dispensers  50 ,  52  and  54  disposed around a top opening  56  above the tub  34 , just below the lid  26 . As shown in FIG. 1, the dispensers are accessible when the hinged lid  26  is opened. Dispensers  50  and  52  can be used for dispensing additives such as bleach or fabric softeners and dispenser  54  can be used to dispense detergent, either liquid or granular, into the wash load at an appropriate time during the automatic wash cycle. Each of the dispensers  50 ,  52  and  54  is typically supplied with liquid, generally fresh water, through separate dedicated conduits (not shown). Each of the conduits can be connected to a fluid source in a conventional manner, such as through respective solenoid operated valves (also not shown), which contain built-in flow devices to control flow rate, connecting each conduit to the manifold conduit  48 . 
     Disposed at the bottom of the tub  34  is a sump portion  72  for receiving wash liquid supplied into the tub through the wash additive dispensers  50 ,  52  and  54 . A pressure sensor (not shown) is disposed in the sump  72  for controlling the quantity of wash liquid added to the wash tub  34 . The pump  38  is fluidly interconnected with the sump  72  and is operable for drawing wash liquid from the sump  72  and moving the liquid through a recirculation line  74  having a first portion  74   a  and a second portion  74   b . A two-way drain valve  76  is provided in the recirculation line  74  for alternately directing wash liquid flow to a drain line  77  or to the second portion  74   b  of the recirculation line  74 . 
     A nozzle  78  is fluidly connected with a recirculation line  74 . The nozzle  78  extends beyond the top opening  56  of the tub  34  and is positioned above the wash basket  36  such that wash liquid flowing through the recirculation line  74  is sprayed into the basket  36  and on to clothes disposed in the basket below the nozzle  78 . Wash liquid can therefore be recirculated over clothing disposed in the wash basket  36 . 
     The above described general description of a washing machine  20  is provided for illustration only. As will be evident to those skilled in the art, the general construction of the machine  20  can vary considerably without departing from the spirit and scope of the present invention. The present invention is directed to a balancing device for the washing machine  20  as is described below. 
     The cross section of FIG. 2 generally illustrates a balancer device  100  carried at a top edge  102  of the wash basket  36 . The top opening  56  of the wash tub  34  is disposed adjacent the top edge  102  of the wash basket  36  providing access directly into the wash basket. 
     The dynamic balancer  100  is received within the opening of the top edge  102  of the wash basket  36 . The contour of the top edge  102  of the wash basket  36  is conformed to receive the balancer device  100  therein and to provide a ledge or step  104  on which the device  100  can rest. FIG. 3 illustrates a top view of the balancer device  100  illustrating that the device is an annular ring to be received within the top edge  102  of the basket  36 . The balancer  100  can include a plurality of clips  106  for securely holding the balancer to the wash basket  36 . 
     FIG. 4 illustrates a cross section of the annular ring balancer device  100  in one embodiment. The device  100  includes generally a lower continuous annular chamber  110  and an upper continuous annular chamber  112 . In the preferred embodiment, the chambers  110  and  112  are arranged coaxially and stacked on top of one another at essentially the same radius relative to a center longitudinal axis A of the wash basket  36 . However, the chambers could be arranged on the basket differently, either at different radii and/or spaced apart vertically or horizontally, and not adjacent to one another as shown in the illustrated preferred embodiment, all departing from the invention disclosed herein. 
     In the present embodiment, the lower or first chamber  110  has a cross sectional area which when extended around the entire circumference of the chamber defines a first chamber volume. A first fluid  114  having a first fluid volume that is less than the volume of the chamber  110  partly fills the chamber. In the present embodiment, the first fluid  114  is water and is preferably salt water. The first fluid  114  and chamber  110  define a fluid type balancer. 
     The lower or first chamber  110  is defined by a first annular ring of material  115  having an inner annular wall  116  disposed generally parallel relative to the vertical axis A connected at a bottom end to a bottom wall  118 . The bottom wall is upwardly tapered relative to the inner wall  116  moving outward from the center or vertical axis A of the device  100 . Together, the inner wall  116  and bottom wall  118  define a trough or channel  120  therein. 
     The outer edge of the bottom wall  118  includes a pair of spaced apart and upwardly extending annular flanges  122  defining a groove  124  therebetween. The upper end of the inner wall  116  defines an annular tongue  126  extending upward therefrom. An inwardly directed flange  128  extends from the wall  116  just below the tongue  126 . Each of the walls, grooves and flanges extends around the circumference of the device  100 . 
     An upper annular material ring  130  of the balancer device  100  interconnects with the lower annular ring  115 . The upper ring  130  includes a top wall  132  that transitions via a curved section  133  into a downwardly depending annular inner wall  134 . The outer edge of the top wall  132  further from the axis A also includes a downwardly extending outer wall  136  spaced radially outwardly from the inner wall  134 . The combination of the outer wall  136 , top wall  132  and inner wall  134  define an inverted annular channel  140  therebetween. 
     The inverted annular channel  140  and the trough or channel  120  are divided or separated by an annular third ring of material  142 . The third annular ring  142  is disposed generally horizontal between the inner and outer walls of the upper and lower material rings  115  and  130 , respectively. The annular ring  142  therefore generally separates the balancer device  100  into the two chambers  110  and  112 . The particular construction of the three annular material rings  115 ,  130  and  142  of the device in the present embodiment of the invention provides additional benefits described in greater detail below. 
     The inner wall  134  of the upper material ring  130  defines a pair of adjacent annular grooves  144  and  146  extending upward. The first groove  144  is disposed radially inward from the second groove  146  relative to the axis A of the balancer device  100 . The second groove  146  is disposed closer to the chamber  112  as a result. The first groove  144  is defined between a pair of depending annular flanges  148  and  150  which depend downward from a step  152  extending radially inward from the inner wall  134  of the upper material ring  130 . The second groove  146  is formed between the annular flange  150  and a distal end  154  of the inner wall  134  and is therefore disposed between the step  152  and the radial inner wall  134 . 
     The rear wall  136  of the material ring  130  includes a thick section  156  extending radially outward therefrom. An annular leg  158  depends from the thickened section  156  and terminates at an annular tongue  160 . The tongue  160  has a lesser thickness than the leg  158  and therefore defines a pair of shoulders or steps  162  between the tongue and the leg. A groove  164  is also formed between the outer wall  136  and the leg  158  of the thickened section  156 . 
     The horizontally disposed annular ring  142  includes an inner radial edge having a tongue  166  projecting upward therefrom and an outer radial edge having a tongue  168  projecting upward therefrom. The material ring  142  also includes a recessed channel or race  170  formed therein. The purpose of the race  170  is described in greater detail below. Again, each of the grooves, flanges, tongues, channel and walls is annular in construction extending around the circumference of the device. 
     The balancer device  100  is assembled by generally connecting the three annular material rings  115 ,  130  and  142  to one another. The material ring  142  is placed below and adjacent the material ring  130  so that the tongue  166  aligns with the groove  146  and the tongue  168  aligns with the groove  164 . The tongues are received in the grooves and the materials adhere to one another by a suitable welding process in a manner described in greater detail below. The lower material ring  115  is then placed adjacent the assembled upper ring  130  and horizontally disposed third ring  142 . The tongue  160  of the leg  158  is received in the groove  124  of the bottom wall  118  of the lower ring  115 . The tongue  126  of the inner radial wall  116  of the ring  115  is received in the groove  144  of the step  152  of the upper material ring  130 . The tongues and grooves of these two components are again adhered to one another by a suitable welding process described in more detail below. 
     Upon assembly, the chamber  110  is defined by the inner wall  116  and bottom wall  118  of the lower or first ring  115  as well as the bottom surface of the interior horizontal ring  142  and the depending leg  158  of the upper or second ring  130 . The upper chamber  112  is defined by the top wall  132 , inner wall  134  and outer wall  136  of the upper ring  130  as well as the top surface of the interior or third ring  142 . 
     Each of the annular rings  115 ,  130  and  142  is preferably made from an injection molded plastic material but could be made from virtually any suitable material including plastics, composites, metals, alloys, or the like. In the present embodiment, the injection molded components are welded to one another at the joints created by the tongues and grooves described above. The welding process can be a hot plate or heat welding process, a spin welding process, a sonic welding process or the like. The welding process must at least create a sealed material joint between each assembled tongue and groove of the device  100  so that the joints don&#39;t leak. Adhesives may alternatively be used to adhere the components to one another. If the materials selected are not suitable for plastic welding processes, the components must simply be adhered relative to one another in order to create a fluid tight seal at each joint. 
     As noted above, a first fluid  114  such as water or salt water is disposed within the lower or first chamber  110 . The first fluid  114  partly fills the chamber and is free to flow around the annular chamber. A plurality of baffles  180  can be formed in the trough or channel  120  of the lower or first ring  115  wherein the baffles extend upward generally perpendicular to the bottom wall  118 . The plurality of baffles  180  serve to stabilize the flow of fluid within the chamber  110  and yet permit the fluid  114  to flow within the chamber as necessary to perform the intended balancing function of the balancer device  100 . 
     A second fluid  182  is disposed within the second chamber  112  and preferably has a higher viscosity than the first fluid  114 . In one embodiment, the second fluid  182  is an oil. In another preferred embodiment, the oil is a 10 weight (10W) oil. Also disposed within the upper chamber  112  are a plurality of weighted spherical balls  184 . In one embodiment, the balls  184  are comprised of steel. The composition of the second fluid  182  and the material composition and construction of the balls  184  can vary considerably within the scope of the present invention. In addition, the balls  184  can be replaced by a plurality of other objects that add mass to the balancer device  100 . For example, the balls  184  can be replaced by disks, cylinders, or other such weighted sliding or rolling elements that are free to travel along the circumference of the chamber  112 . In the present embodiment, the race  170  of the interior material ring  142  is provided for precisely guiding the balls  184  along the chamber  112  at a particular radius from the center axis A of the device. The second fluid, balls and second chamber generally define a ball balancer. 
     The second fluid  182  composition can be virtually any fluid providing a desired viscosity that will not damage the balls, the material of the annular rings  142  and  130 , or the construction of the joints securing the two components together. The type of fluid such as the oil noted above can vary considerably within the scope of the present invention as will be evident to those skilled in the art. The volume of the second fluid  182  is less than the remaining volume of the second chamber  112  after adding the balls  184 . 
     In use, the balancer device  100  produces three separate balancing elements or characteristics. One balancing element or characteristic produced by the balancer device  100  of the invention is provided by the plurality of sliding or rolling elements or steel balls  184 . The balls will roll within the chamber  112  and collect at a higher concentration or density opposite a small out of balance or heavy condition within the wash basket  36 . The balls  184  are inhibited from freely rolling within the chamber  112  by the second fluid  182 . The higher viscosity of the second fluid controls movement of the balls  184 . Therefore, for minor or small out of balance conditions of the wash basket  36 , the balls  184  and second fluid  182  will provide an initial balance correction. If the ball movement within the second chamber  112  is sufficient to correct the out of balance, the balls will essentially distribute as needed throughout the chamber  112  and remain as positioned once the minor out of balance condition is corrected. If a larger out of balance condition occurs wherein the balls  180  cannot sufficiently correct the condition, the balls will remain positioned within the chamber  112  as collected with greater density opposite the out of balance condition, but will not completely balance the basket  36 . 
     Another balancing characteristic is therefore provided by the first chamber  110  and the first fluid  114 . As the wash basket  36  spins, the larger out of balance condition will cause the wash basket to waiver from the center axis A of rotation of the basket. The out of balance condition will cause the first fluid  114  within the chamber  110  to flow and distribute at a higher volume within one portion of the chamber. The fluid will also gather in greater volume opposite the out of balance condition or heavy condition of a wash load held within the basket  36 . The first fluid  114 , combined with the balls  184  often provide sufficient offset to correct the out of balance condition. 
     There are instances however where significant out of the balance conditions occur that cannot be corrected by the movement of the weighted steel balls  184  and the flow of the first fluid  114 . With that in mind, the third characteristic or element of the balancer device  100  is provided by the quantity of the second fluid  182  within the chamber  112 . By only partly filling the chamber  112  with the second fluid  182  after addition of the balls  184 , the second fluid can also flow relatively freely within the upper or second chamber  112 . If the first fluid  114  and the balls  184  cannot correct an out of balance condition, the second fluid  182  will therefore flow within the second chamber  112  and gather at a higher volume opposite the out of balance condition providing further balance correction for the device  100  of the invention. 
     In a preferred embodiment, the volume of the first fluid  114  is about one-half the volume of the first chamber  110 . The volume of the second fluid  182  in a preferred embodiment is about one-half that of the remaining volume of the second chamber  112  after inclusion of the balls  184  or other weighted elements within the chamber. These volumes can vary within the scope of the present invention as well wherein the volumes noted above are provided merely as one preferred embodiment. 
     Similarly, the construction of the balancer device  100  including the three annular material rings  115 ,  130  and  142  can also vary considerably and yet fall within the scope of the present invention. In the described embodiment, the first chamber  110  is disposed directly below the second chamber  112 . In one alternative embodiment, the second chamber  112  can be disposed below the first chamber  110 . In another alternative embodiment, one of the chambers can be disposed radially inward or outward relative to the other of the chambers and relative to the center axis A of the device  100 . 
     The particular construction of the attachment joints for each of the rings  115 ,  130  and  142  can also vary considerably and yet remain within the scope of the invention. However, the described embodiment provides a significant advantage over many other possible embodiments in that the second fluid  182  such as oil disposed within the second chamber  112  will not enter the wash basket  36  if a leak occurs at one of the joints that seal the second chamber. In a described embodiment, the tongue  168  and groove  164  forming one joint of the second chamber  112  is disposed radially inward of the annular leg  158  and therefore generally within the first chamber  110 . Similarly, the tongue  166  and the groove  146  defining the other joint of the second chamber  112  is disposed radially outward from the inner wall  116  of the lower chamber  110  and therefore is also generally disposed within the first chamber. If a leak occurred at either joint of the second chamber  112 , any oil or fluid  182  escaping from the second chamber would only escape into the first chamber  110  and not into the wash basket  36 . Therefore, the risk of the second fluid  182  escaping into the wash basket is significantly reduced. The construction and orientation of the components defining the two chambers can vary from the described embodiment and yet still provide this leak preventing benefit. 
     As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.