Patent Publication Number: US-7914625-B2

Title: Sequencing diverter valve system for an appliance

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to the art of valve systems for appliances and, more specifically, to a diverter valve system for selectively supplying washing fluid in an appliance. 
     2. Description of the Related Art 
     Washing appliances, particularly dishwashers, are provided with internal spraying devices for directing streams of washing liquid at objects to be washed. More specifically, a dishwasher includes a washing chamber having a bottom sump in fluid communication with a motor driven pump to supply washing liquid under pressure to a spraying device that directs streams of washing liquid at dishes held in the washing chamber. As is known, the streams of washing liquid generally flow from one or more rotatable wash arms due to the effect of reactions caused by fluid jets coming out of respective pressure nozzles. It is also known to provide a dishwasher with fixed spray nozzle units. 
     Typically, the number of spray arms fed by a pump is limited by available water pressure in the dishwasher system. A drop in pressure within the system may reduce the intensity of the water jets, thus reducing cleaning power. Additionally, effective washing at the corners of a square wash rack is difficult to accomplish with standard spray arm configurations. In one proposed solution set forth in U.S. Patent Application Publication No. 2005/0011544, a dishwasher system allows a user to select particular quadrants of the dishwasher for more intense washing. More specifically, a control selectively operates a valve to block fluid to selected spray arms. Additionally, the speed of the circulating pump motor may be changed, thus altering the exit rate of water jets. However, such a system requires specific controls, and multiple supply lines to respective spray arms. Further, the rate of travel for a particular rotating arm is generally dictated by the pressure of the water jets issuing from the arms. Therefore, increasing the speed of the circulating pump not only increases water jet intensity, but reduces the dwell time, or the time water is impinging on articles in the dishwasher. Conversely, reducing the speed of the circulating pump decreases water jet intensity, but increases dwell time. 
     In any case, there is considered to be a need in the art for a dishwasher system having multiple wash arms for effective cleaning throughout a dishwasher, wherein the system allows for zone washing without sacrificing jet intensity or dwell time. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a washing appliance, such as a dishwasher or clothes washing machine, including a sequencing diverter valve system. In general, the sequencing diverter valve system includes a reduction train and a fluid distribution manifold having a plurality of fluid inlets therein for receiving washing fluid and a plurality of fluid outlets in communication with a plurality of respective spray assemblies, such as rotating spray arms. A fluid responsive rotating drive arm in communication with the fluid distribution manifold has a drive shaft operatively coupled to the reduction train. As the drive arm rotates, a rotational force is transferred to the reduction train by the drive shaft. The drive train includes a gear train, preferably a epicyclical gear train, having an output shaft operatively connected to a rotating sequencing disk to drive the sequencing disk through a plurality of discrete valve positions at a rate of rotation less than the rate of rotation of the drive shaft. As it rotates, the sequencing disk sequentially blocks at least one of the fluid inlets while allowing at least one of the fluid inlets to remain open and transfer washing fluid to an associated spray assembly. The number of spray assemblies that receive washing fluid at any given time is thus dictated by the rotational position of the sequencing disk. In this manner, the sequencing diverter valve system provides increased jet intensity by limiting the number of spray assemblies which operate at one time, without sacrificing dwell time. 
     Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial perspective view of a dishwasher including a sequencing spray arm assembly constructed in accordance with the present invention; 
         FIG. 2  is a perspective view of the sequencing spray arm assembly of  FIG. 1 ; 
         FIG. 3  is a partial cross-sectional side view of the sequencing lower spray arm assembly of  FIG. 2 ; 
         FIG. 4  is a partial cross-sectional perspective view of a sequencing gear train assembly utilized in accordance with the present invention; 
         FIG. 5  is a top partial cross-sectional view of the sequencing gear train assembly of  FIG. 4 ; 
         FIG. 6  is an exploded partial perspective view of the sequencing gear train assembly of  FIG. 4 ; and 
         FIG. 7  is a partial cross-sectional perspective view of an alternative embodiment of the sequencing lower spray arm assembly of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With initial reference to  FIGS. 1 and 2 , a dishwasher constructed in accordance with the present invention as generally indicated at  2 . As shown, dishwasher  2  includes a tub  5  which is preferably molded of plastic so as to include integral bottom, side, and rear walls  8 - 11  respectively, as well as a top wall (not shown). Tub  5  defines a washing chamber  14  within which soiled kitchenware is adapted to be placed upon shiftable upper and lower racks (not shown for drawing clarity), with the kitchenware being cleaned during a washing operation. Tub  5  has attached thereto a pivotally supported door  20  used to seal chamber  14  during the washing operation. In connection with the washing operation, door  20  is preferably provided with a detergent tray assembly  23  within which a consumer can place liquid or particulate washing detergent for dispensing at predetermined portions of the washing operation. Of course, dispensing detergent in this fashion is known in the art such that this arrangement is only being described for the sake of completeness. 
     Disposed within tub  5  is a filtration system generally indicated at  30 . In the preferred embodiment, filtration system  30  includes a central main strainer or filter screen  36  and a secondary strainer  39 . Extending about a substantial portion of filtration system  30 , at a position raised above bottom wall  8 , is a heating element  44 . In a manner known in the art, heating element  44  preferably takes the form of a sheath, electric resistance-type heating element. 
     Dishwasher  2  further includes a fluid distribution system including a circulation pump (not shown) adapted to direct washing fluid from a sump unit (not shown) to a fluid distribution manifold indicated at  53  in a manner known in the art. Fluid distribution manifold  53  supplies washing fluid to a fluid response rotatable drive arm  55  and a conduit  57  leading to at least one upper spray unit (not shown). In a manner known in the art, conduit  57  may supply washing fluid to one or more upper spray assemblies (not shown). Additionally, fluid distribution manifold  53  may be in fluid communication with a spray manifold assembly  59  including a plurality of rotating spray disks  62 . Although the above description of dishwasher  2  was provided for completeness, the present invention is particularly directed to a sequencing diverter valve system  102  for use with a spray assembly such as a sequencing spray arm assembly  100  as will now be described in more detail below. 
     As best seen in  FIG. 2 , sequencing fluid distribution or spray arm assembly  100  includes first, second, third and fourth fluid propelled rotating spray arms  110 - 113  in fluid communication with fluid distribution manifold  53  via respective radially extending and circumferentially spaced elongated carrier arms  120 - 123 . Drive arm  55  is rotatably connected to a central, main support housing  124  of fluid distribution manifold  53  via a hub  125  (depicted in  FIG. 3 ), while carrier arms  120 - 123  are rotatably mounted to fluid distribution manifold  53  at a hub  126  of a lower, fluid chamber defining housing  127 . Rotating spray arms  110 - 113  are independently, rotatably mounted at a distal end of carrier arms  120 - 123  by respective hubs  130 - 133 . In accordance with the invention, this configuration allows for washing fluid distribution throughout washing chamber  14 , including corners which are out of reach of typical spray arms. 
     As best illustrated in  FIG. 3 , carrier arms  120 - 123  are hollow and are in fluid communication with lower housing  127  via fluid outlets  136  in lower housing  127 . A supply line  140  delivers fluid to housing  127  via a recirculating pump (not shown). Carrier arms  120 - 123  also include respective outlets  143  in fluid communication with one of the respective rotating spray arms  110 - 113 . A plurality of nozzles  150  are provided on spray arms  110 - 113  and configured to direct jets of fluid throughout washing chamber  14 . At least one nozzle  150  on each spray arm  110 - 113  directs a jet of fluid in a direction for thrusting the respective spray arm  110 - 113  to rotate, preferably in a common rotational direction. Spray arms  110 - 113  are preferably made of plastic and are relatively short in length, thereby being light compared to typical spray arms, such that less energy is needed to rotate spray arms  110 - 113  during a wash cycle. In one embodiment of the invention, jets of fluid from the at least one nozzle  150  are directed at a relative high acute angle with respect to dishwasher walls  8 - 11 , thereby reducing noise from impinging jets of fluid which would be otherwise directed at a more horizontal or low acute angle to supply a sufficient rotational force to spray arms  110 - 113 . Although depicted as including five nozzles each, spray arms  110 - 113  may be provided with more or fewer nozzles as desired. In the preferred embodiment shown, spray arms  110 - 113  operate on the same plane and are sized such that they can rotate freely without interference within washing chamber  14  while just missing each other, side and rear walls  9 - 11  and door  20 . With this configuration spray arms  110 - 113  provide washing fluid throughout washing chamber  14  so as to provide enhanced spray distribution and better corner washability. 
     In accordance with the present invention, spray arms  110 - 113  are driven in a sequential manner utilizing sequencing diverter valve system  102 . Advantageously, small sequencing spray arms  110 - 113  utilizes less water compared to a single large prior art spray arm, with only one or two of arms  110 - 113  being operated at a given time. Further, by operating only one or two of spray arms  110 - 113  at a time, water pressure in spray arms  110 - 113  is increased, while the fluid flow rate through the system is reduced as compared to a conventional spray arm. 
     Sequencing diverter valve system  102  of the present invention will now be discussed in more detail with reference to  FIGS. 3 and 4 . Sequencing diverter valve system  102  utilizes a reduction train or sequencing gear assembly  160 . In accordance with a novel aspect of the present invention, drive arm  55  is connected to gear assembly  160  housed in fluid distribution manifold  53  by a drive shaft  164 . In use, fluid flows upward through an annular channel  166  in fluid distribution manifold  53  through an upper outlet  167  and into drive arm  55 . Fluid exits drive arm  55  through at least one nozzle  168  adapted to direct jets of fluid in a direction for driving the rotation of drive arm  55  in a common direction to spray arms  110 - 113 , and causing the concurrent rotation of drive shaft  164 . In turn, drive shaft  164  drives an epicyclical gear train  170  of sequencing gear assembly  160 . Gear train  170  includes an output shaft  175  connected to a sequencing valve, shown in the form of a disk  178 , located between fluid supply line  140  and fluid distribution manifold  53 . 
     Sequencing disk  178  includes at least one opening  180  and, in use, acts as a valve to open and close respective inlets  181 - 184  (seen best in  FIG. 6 ) in a bottom wall of lower housing  127 . Each inlet  181 - 184  is in communication with a respective carrier arm  120 - 123 . In other words, sequencing disk  178  is adapted to sequentially block multiple ones of the plurality of respective inlets  181 - 184  to lower housing  127  and thus to sequentially direct fluid through outlets  136  into respective carrier arms  120 - 123  by rotating sequencing disk  178  through a plurality of discrete rotational positions. Therefore, washing liquid from fluid supply line  140  is directed through one or more ports  180  in sequencing disk  178  into lower housing  127 , and through respective outlets  136  into one or more carrier arms  120 - 123 . 
     At this point, it should be understood that the carrier arm or arms that receive washing liquid from fluid supply line  140  depends on the rotational position of sequencing disk  178 . In  FIG. 3 , for example, sequencing disk  178  is in a first rotational position wherein a fluid stream is directed through port  180  into carrier arm  122  of spray arm  112 . In  FIG. 4 , sequencing disk  178  is in a second rotational position wherein a fluid stream is directed through port  180  into carrier arm  123  of spray arm  113 . In this configuration, fluid in spray arm  113  exits nozzles  150  and drives the rotation of spray arm  113 . In accordance with the invention, fluid would next be supplied to adjacent carrier arm  120  when sequencing disk  178  is rotated to a third rotational position (not shown). Washing fluid not directed to one or more carrier arms  120 - 123  is directed through apertures  185  in sequencing disk  178  into channels  166  as secondary fluid streams, and through channels  166  to drive arm  55 , wherein drive arm  55  is powered by washing liquid exiting drive arm  55  through nozzles  168 . 
     Gear train  170  allows for a sufficient dwell time of sequencing disk  178  at each rotational position so as to supply sufficient wash fluid to a particular spray arm  110 - 113  or group of spray arms (e.g.,  110  and  112  depending on the number and relative positions of ports  180  provided in disk  178 ) in a sequential manner. At this point, it should be realized that various different types of gearing reduction driving systems could be employed to establish a desired dwell time based on the rotation of drive arm  55 . In the preferred embodiment shown, gear train  170  is a epicyclical gear train which provides for a rotational ratio of 36 to 1 between drive arm  55  and sequencing disk  178 . That is, for every thirty six rotations of drive arm  55 , gear train  170  will rotate sequencing disk  178  one rotation. However, it should be understood that the dwell time of sequencing disk  178  in each rotational position can be readily altered by altering the gear ratio of gear train  170 . 
     The manner in which gear train  170  connects to sequencing disk  178  and drive arm  55  will now be discussed in more detail with reference to  FIGS. 3 ,  5  and  6 . In general, gear train  170  comprises drive shaft  164 , a stationary epicyclical gear  190 , first and second epicyclical gears  191  and  192 , a gear carrier  193  and an output shaft  194  adapted to extend through a lower housing cover  195 . As depicted in  FIG. 6 , first and second epicyclical gears  191  and  192  include pins (not separately labeled) to engage the respective gear carrier  193  and output shaft  194 . During assembly, a threaded portion  196  of drive shaft  164  extends through an opening in stationary epicyclical gear  190 , an opening in an insert  199  and an opening in main housing  124  to connect to hub  125  of drive arm  55 . A drive lever  202  extending from drive shaft  164  is adapted to abut an upper wall of main housing  124  and operatively engage epicyclical gear  191 . The remaining components of gear train  170  are retained within main housing  124  by lower housing cover  195 . Output shaft  194  extends through a central opening of housing cover  195  and operatively engages sequencing disk  178 . As the rotational force of drive arm  55  is transferred through gear assembly  160  to sequencing disk  178 , sequencing disk  178  is rotated through multiple rotational positions to allow fluid to sequentially enter respective openings  126  in carrier arms  120 - 123 . 
     As should be readily understood from the above description, washing fluid is supplied to sequencing spray arm assembly  100  from below sequencing disk  178 . In an alternative embodiment, a sequencing disk  178 ′ having ports  180 ′ is located below a fluid supply line  140 ′. This alternative spray arm assembly  100 ′ will now be discussed with reference to  FIG. 7 . As in the previous embodiment, a drive arm  55 ′ is operatively connected to a sequencing gear assembly  160 ′ housed in a fluid distribution manifold  53 ′ by a drive shaft  164 ′. However, in this alternative arrangement, a lower housing  127 ′ includes a fluid distribution manifold  300  in communication with additional spray arms (not shown) located below fluid supply line  140 ′ and sequencing disk  178 ′. In the manner discussed above, the rotational force of drive arm  55 ′ is transferred through gear assembly  160 ′ to sequencing disk  178 ′, and sequencing disk  178 ′ is rotated through a sequence of rotational positions to allow fluid to flow through one or more ports  180 ′ in sequencing disk  178 ′. In this embodiment, each port  180 ′ is connected to a respective lower spray arm (not shown) through lower fluid outlets  136 ′. As shown, two ports  180 ′ and, thus, two spray arms (not shown), are supplied with fluid for each rotational position of sequencing disk  178 ′. Washing fluid not directed to lower housing  127 ′ flows into channel  166 ′ defined within a housing  124 ′ as secondary fluid streams, and through channel  166 ′ to drive arm  55 ′, wherein drive arm  55 ′ is powered by washing liquid exiting drive arm  55 ′ and functions to rotate drive shaft  164 ′. 
     Advantageously, the present system provides extended reach of washing fluid into the corners of the dishwasher, resulting in more flexible dish loading options and better corner washability. Additionally, sequencing of the lower arms allows for the potential to reduce the fill amount and to save energy. The reduced flow rate through the small arms results in less fluid noise. Further, the nozzles on the small arm ends may be angled in a more vertical direction, minimizing sound generated by fluid impacting the sides of the dishwasher tub. Pressure increases in each individual small arm, resulting in reduced flow rate and increased pressure over a conventional spray arm. The result is a system having improved wash performance through increased wash intensity and improved coverage. 
     Although described with reference to a preferred embodiment of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, although shown in use with a sequencing spray arm assembly  100 , it should be understood that the sequencing diverter valve system of the present invention may be utilized to sequentially divert washing fluid to any desired combination of fluid outlets, such as spray manifold assembly  59  and an upper spray assembly (not shown) fed by conduit  57 . In addition, the invention is applicable to other washing appliances which would potentially benefit from a sequenced fluid distribution system. Furthermore, although an epicyclical drive train is employed in the preferred embodiment disclosed, other reduction drive mechanisms could also be employed. In general, the invention is only intended to be limited by the scope of the following claims.