Patent Application
20100043825
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.
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.
With initial reference to
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
As best illustrated in
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
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
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
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
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
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.
