US3708120A

US3708120A - Fluidic dishwasher spray system

Info

Publication number: US3708120A
Application number: US00131723A
Authority: US
Inventors: B Camprubi; Tee G Capron
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1971-04-06
Filing date: 1971-04-06
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02

Abstract

In the preferred form this invention teaches a dishwasher including a cavity in which dishes are washed, a plurality of stationary spray nozzle groupings arranged in the washing cavity, and a washing fluid supply system to the nozzle groupings, including at least one fluid logic element arranged to sequentially supply washing fluid to the different nozzle groupings.

Description

United States Paten 1191 Camprubiet al. 1 1

11 1 3,708,120 1 1 Jan.2,1973

1541 FLUIDIC DISHWASHER SPRAY SYSTEM [75] Inventors: Bartholomew Camprubi, lckenham;

Grahame Gerald Capron-Tee, Marlow, both of England [73] Assignee: The Hoover Company, North Canton,0hio

[22] Filed: April 6, 1971 [21]' Appl. No.: 131,723

52 us. (:1. ..239/66, 239/536, 239/563, 134/56 D, 137/815 51 int. c1. ..B05b 13/02 58 Field 61 Search ..239/66, 67, 536, 562, 563, 239/564, 569; 134/191, 176, 179, 56 D, 56 R [56] References Cited UNITED STATES PATENTS 3,620,050 11/1971 Glasgow ..137/8l.5 X 1,889,858 12/1932 Greene et al ..'...239/66 2,596,693 Karlstrom ..134/56 D 3,373,905 3/1968 Laufer ...l37/81.5 X 3,447,752 6/1969 Hardy ...137/81.5 X 3,513,866 5/1970 Boothe et al. ..137/81.5

' FOREIGN PATENTS OR APPLICATIONS 1,052,349 12/1966 Great Britain ..137/81.5 1,920,575 11/1970 Germany ..134/179 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-John J. Love Attorney-Alfred G. Gross and James A. Wanner [57] 1 ABSTRACT In the preferred form this invention teaches a dishwasher including a cavity in which dishes are washed, a plurality of stationary spray nozzle groupings arranged in the washing cavity, and a washing fluid supply system to the nozzle groupings, including at least one fluidlogic element arranged to sequentially supply washing fluid to the different nozzle groupings.

4 Claims, 4 Drawing Figures FLUIDIC DISHWASHER SPRAY SYSTEM This invention relates to washing machines and in particular to a dishwashing machine. This invention is particularly beneficial in providing a sequential fluid discharge operation through a plurality of stationary supply nozzle groupings in the washing chamber of a dishwasher while using a limited amount of washing fluid and utilizing a limited size pump.

This invention is also beneficial in that the water supply system has a minimum wear and maintenance in that relatively few moving parts are utilized to provide a sequential supply of washing fluid to different spray nozzle groupings.

Many dishwashers utilize rotary spray arm systems to provide spray into different zones within a cavity in which the dishes are washed. A disadvantage of these systems is that the spray arms are mounted for rotary or reciprocating movement, therefore requiring many moving parts involved which are susceptible to wear. A rotary spray arm system has the advantage, however, of using a limited power and water supply system in that only a part of the cavity is being supplied with washing fluid at any one time.

Given unlimited power it is possible to eliminate the movement of spray arms by distributing the washing liquid through a plurality of stationary spray nozzles so as to sufficiently provide washing fluid at all zones within the washing cavity. This not only requires considerably more power but also requires a greater supply of washing fluid.

It is possible to reduce the power requirement and washing fluid quantity requirement in a fixed spray system without using a rotary spray arm, but this generally has required the use of a plurality of mechanically or electrically operated valves which again involves moving parts which are expensive and susceptible to malfunction and therefore create maintenance problems.

According to the present invention, a washing machine including a cavity in which dishes are washed is provided with a plurality of stationary spray nozzle groupings, these groupings being provided with a sequential washing fluid supply. The washing fluid supply system includes at least one, and preferably a plurality of fluid logic devices fed from a common source to provide the sequential supply of washing fluid to the different spray nozzle groupings.

The advantage of such a system is that a limited power supply and a limited washing fluid quantity can be utilized in that only a limited number of spray nozzles are in operation at any one time. Furthermore, the water supply system provides this feature using simple inexpensiveelements having no moving parts and thus greatly reduces manufacturing costs and maintenance problems.

Various fluid logic elements may be incorporated. In the preferred form of the invention which is envisioned, a cascade fluid logic system is utilized whereby each spraynozzle grouping has a fluid logic element with Another advantage of the present invention is that the fluid logic elements may be so arranged so as to provide a spray pattern with relatively even fluid distribution throughout different washing zones within the washing cavity. In the alternative, this system may also be arranged so as to provide different spray pressures within the different washing zones within the cavity. This latter feature is provided by the cascading of the fluid logic elements.

Thus, the present invention teaches a washing fluid supply system for a dishwasher and a spray nozzle groupings within the washing cavity utilizing simple, inexpensive elements having no moving parts and yet requiring only a limited power supply and limited supply of washing fluid.

In the drawings:

FIG. 1 is a fragmentary elevational view showing a dishwasher utilizing the washing fluid supply arrangement of the present invention;

FIG. 2 shows a cross-sectional view of the dishwasher taken along the lines 2-2 of FIG. 1, showing a typical spray nozzle arrangement;

FIG. 3 shows an enlarged view of the fluid control system utilized to supply washing fluid to the spray noz zle arrangement of FIG. 2; and

FIG. 4 shows a modification of the fluid supply control-system which may also be used to supply washing fluid to the spray nozzle arrangement of FIG. 2.

In the preferred form, the present invention may be carried out in a dishwashing machine such as that generally shown in FIG. 1. The dishwashing machine has a cabinet 2 which generally defines an internal washing cavity 3 into which dishes and other articles to be washed are placed. These articles can be arranged on racks 4 and 5 located within the washing cavity 3. These racks may be removable through access opening 6 normally closed by a door 7.

As shown in FIGS. 1 and 2, the dishwasher is provided with a sump 8 having a filter 19 which feeds a motor-driven pump 9 which are included in the preferred form to provide a recirculating spray of water for washing articles within the cavity 3. Water may be supplied to the washing cavity by any conventional manner, such as a water supply hose controlled by solenoid valves (not shown).

The dishwashing machine may be provided with a conventional timer and control knob generally indicated by 10 which controls the flll solenoid and pump for timed operation.

As shown in FIG. 2 the floor ll of the washing cavity is provided with four stationary

spray nozzle groupings

12, 13, 14 and 15. Each of these stationary spray nozzle groupingscontain four spray nozzles 18 which are,

generally aimed upwardly into the washing cavity. It is within the intent of the present invention to' utilize fewer or more spray nozzles located solely within the cavity floor or arranged elsewhere within the cavity such as on the sides and top thereof.

Each of these

groupings

12, 13, 14 and 15 contains a separate feed line connected to the spray control unit 16 supplied from a common central source such as the pump 9. A washing fluid under pressure is sequentially fed to the stationary spray nozzle groupings by the spray control unit 16 which contains at least one fluid logic element, such as

elements

20, 30 and4 0.

The spray control unit 16 is shown enlarged in H0. 3. Pressurized washing fluid leaving the pump 9 enters the spray control unit through a conduit 17. Directly fed by the conduit 17 is inlet 21 of the first fluid logic element 20. The fluid logic element 20 is also provided with two

outlets

22 and 23. The first of these outlets 22 feeds the stationary spray nozzle grouping 12 through conduit 24. Also provided is a feedback line 25 interconnecting the conduit 24 with a first control port 26 within the fluid logic element. The fiuid logic element is also provided with a second control port 28 whose purpose will be later explained.

The other outlet 23 of the first fluid logic element 20 is connected by means of conduit 27 to the inlet 31 of the second fluid logic element 30. This fluid logic element 30 is provided with

outlets

32 and 33. The outlet 32 supplies a conduit 34 which feeds the second stationary spray nozzle grouping 13. Also associated with this fluid logic element 30 is a feedback line 35 interconnecting the conduit 34 and a first control port 36 of the fluid logic element 30.

The second outlet 33 feeds a conduit 37 which is connected to the inlet 41 of the third fluid logic element 40.- Again, this fluid logic element 40 has two outlets 42 and 43. The outlet 42 feeds a conduit 44 to supply the stationary spray grouping 14. A feedback line 45 interconnects the conduit 44 with a first control port 46 of the fluid logic element 40. The outlet 43 feeds a conduit 47 associated with spray nozzle grouping 15. Alsoassociated with the outlet 43 and the conduit 47 is a feedback line which is associated with the second control port 28 of the first fluid logic element 20.

It is noted that the spray control unit 16 as above described contains no electrical or mechanical moving parts. However, this control unit can sequentially supply washing fluid to the four stationary spray nozzle groupings 12, l3, l4 and as will now be described.

Washing fluid may be supplied to the cavity 3 through a conventional means not shown. Once a sufficient amount of washing fluid has been supplied the timer 10 may start operation of the motor-driven pump 9 so as to draw the washing fluid from the sump 8 and thus feed conduit 17. Pressurized washing fluid will enter the fluid logic element through inlet 21. The washing fluid will leave the fluid logic element 20 through outlet 22 and conduit 24 to feed the first spray nozzle grouping 12.

Once sufficient pressure has been provided to conduit 24 and also the feedback line 25, the feedback will act at the first control port 26 so as to switch fluid flow from outlet 22 to outlet 23 so as to feed the fluid logic element 30 through conduit 27. The fluid logic element 20 and all the other fluid logic elements herein described are bistable or flip-flop fluid logic elements.

The fluid flow through the second fluid logic element 30 will first feed the fluid spray nozzle grouping 13 through outlet 32 and conduit 34 until sufficient pressure is developed in feedback line 35 and control port 36 so as to switch fluid flow to outlet 33..The outlet33 feeds the third fluid logic element 40 through conduit 37 and inlet 41. v

The fluid flow through the fluid logicelement 40 will feed the stationary spray nozzle grouping l4'through conduit 44 until sufficient pressure is developed in feedback 45 and control port 46'so as to switch the fluid flow through outlet 43 and conduit 47 so as to feed the last stationary spray nozzle grouping 15.

When sufficient pressure has been developed in conduit 47 and therefore feedback line 49, this pressure will act at the fluid control port 28 of the first fluid logic element 20 so as to again provide flow through the outlet 22. The first fluid logic element will provide flow through line 23 until sufficient pressure has been developed at the second control port 28 since the fluid logic elements are bistable.

This process will be continued in a repeated fashion so as to sequentially feed the stationary spray nozzle groupings l2, l3, l4 and 15 until the timer stops the pressurized fluid flow through conduit 17 by de-activating the motor-driven pump 9.

It should be noted that the fluid logic elements as shown in FIG. 3 and above described are cascaded or connected in series relationship. Since there is a certain pressure loss through each fluid logic element, a greater pressure will be provided at the outlets of fluid logic element 20 than is provided at the outlets of fluid logic elements 30. Furthermore, greater pressure will be provided at the outlets of fluid logic element 30 than the outlets of fluid logic element 40. Therefore, the fluid pressure at the spray nozzle groupings 14 and 15 will be less than the pressure at spray nozzle grouping 13 which will be less than the pressure at the spray nozzle grouping 12.

This is provided due to the series relationship of the fluid logic elements and is desirable if the dishwashing machine is designed so as to have higher spray pressures within certain washing zones than the other washing zones. This might be desired if pots and pans are placed in an area above the spray nozzle grouping 12 which could be called a high pressure zone. More fragile articles, such as china, could be placed in an area over the spray nozzle groupings 14 and 15 which could be called a low pressure zone.

A modification of the spray control unit 16 shown in FIG. 3 is shown in FIG. 4 and indicated as spray control unit 16. The spray control unit 16 is also provided with a conduit 17 connected to the pump 9. A first fluid logic element 50 is fed from the conduit 17 through inlet 51. Element 50 has two

outlets

52 and 53 which feed two other fluid logic elements and 70 through

conduits

54 and 55 respectively. Also associated with the fluid logic element 50 are first and

second control ports

56 and 57.

The second fluid logic element has an inlet 61 associated with the conduit 54 of outlet 52 of the first fluid logic element 50. The fluid logic element 60 has

outlets

62 and 63 associated with

conduits

64 and 65 which feed the stationary spray nozzle groupings l2 and 13 respectively.

Also associated with conduit 64 is a feedback line 66 connected to a control port 67 of the second fluid logic element 60. Associated with conduit 65 and connected to the first control port 56 of the first fluid logic element 50 is a feedback line 68.

A third fluid logic element 70 has an inlet 71 in communication with conduit 55 fed by the second outlet 53 of the fluid logic element 50. The fluid logic element 70 has

outlets

72 and 73 which feed

conduits

74 and 75 so as to supply washing fluid to the stationary spray nozzle groupings 14 and 15 respectively. Associated with the conduit 74 and a control port 77 is a feedback line 76. Associated with conduit 75 and the second control port 57 of the fluid logic element 50 is a feedback line 78.

The washing fluid control unit 16' operates along the same general lines as the control unit 16 in that it utilizes no electrical or mechanical moving parts but is able to provide a sequential fluid supply to the stationary spray nozzle groupings. However, in the modification 16 the two

fluid logic elements

60 and 70 associated with the spray nozzle groupings are in parallel relationship with each other and in series relationship with the fluid logic element 50. Again, bistable or flipflop fluid logic elements are utilized to provide the sequential spray pattern. The operation of the spray unit 16' will now be described.

Pressurized washing fluid provided through conduit 17 will enter the fluid logic element 50 through inlet 51 and leave through outlet 52 and conduit 54 to feed the fluid logic element 60 through inlet 61. The washing fluid will then leave the fluid logic element 60 through outlet 62 and conduit 64 to feed the spray nozzle grouping 12 until sufficient pressure is developed in feedback line 66 and control port 67 so as to switch the fluid flow through outlet 62 to outlet 63.

The fluid flow will then leave the fluid logic element 60 through outlet 63 and conduit 65 to provide a washing fluid supply to spray nozzle grouping 13 until sufficient pressure is developed in feedback line 68 and the first control port 56 of the fluid logic element 50. At this point the fluid flow through fluid logic element 50 is switched from outlet 52 to outlet 53 so as to feed the third fluid logic element 70 through conduit 55. The fluid logic element 70, in a similar manner to the element 60, provides fluid supply through outlets 72 and conduits 74 to the spray nozzle grouping 14 until sufficient pressure is developed in feedback 76 and port 77 so as to switch the fluid flow from outlet 72 to outlet 73.

Fluid flow will now be provided through outlet 73 and conduit 75 so as to feed spray nozzle grouping 15 until sufficient pressure is developed in feedback line 78 and the fluid control port 57 of the first fluid logic element 50. At this point the fluid flow through fluid logic element 50 will be switched from outlet 53 to outlet 52, so as to again provide washing fluid to the fluid logic element 60.

This will be continued in a repeated fashion so as to provide sequential switching of the washing fluid to the spray nozzle groupings l2, l3, l4 and 15 until operation of the pump 9 has ceased.

It is noted that in this arrangement that the two

fluid logic elements

60 and 70 which feed the spray nozzle groupings l2, l3, l4 and 15 are in parallel relationship to each other and in series relationship with the fluid logic element 50. Thus, a substantially equal fluid pressure will be provided through the

outlets

62, 63, 72 and 73 so as to provide relatively equal spray pressure at the four stationary supply nozzle groupings.

It is noted that the spray control units 16 and 16' use fluid logic elements and associated feedback lines to provide the sequential control of the washing fluid. The feedback control elements automatically switch the washing fluid from one spray nozzle grouping to another after a predetermined spray period.

If it is desirous to lengthen the predetermined spray period, it may be advantageous to associate a suitable fluid resistance or capacitator delay arrangement known in the fluid logic element art with each of the feedback lines.

As shown in FIG. 2 each of the spray nozzle groupings is provided with four stationary spray nozzles. This is merely shown to indicate one arrangement of the spray nozzles. Spray nozzles could also be located on the sides and top of the washing cavity. Furthermore, if it is desired, only one spray nozzle need be provided for each spray nozzle grouping. If a greater or lesser number of spray nozzle groupings are desired, an appropriate number of fluid logic elements must be provided accordingly.

The foregoing is but the preferred forms of practicing the present invention. The invention is not limited to the particular details or modifications shown and described. It is, therefore, intended that the claims below will cover all modifications which will occur to those skilled in the art and do not depart from the scope and spirit of the invention.

We claim:

1. A washing machine comprising a cabinet defining a cavity for washing articles, a plurality of spray nozzle groupings each having at least one spray nozzle within said cavity, and a washing fluid spray system for sequentially providing a supply of washing fluid to said spray nozzle groupings, said washing fluid supply system comprising a pressurized fluid source, a plurality of fluidic logic elements, a first spray nozzle grouping associated with one of said fluidic logic elements, another spray nozzle grouping associated with another fluidic logic element, and a feedback circuit interconnecting at least two of said fluidic logic elements, whereby said interconnection between said fluidic logic elements causes automatic switching of said fluid supply to said other spray nozzle grouping upon a sufficient rise of fluid pressure in said first fluidic logic element causing control pressure through said feedback circuit.

2. A washing machine comprising a cabinet defining a cavity for washing articles, a plurality of spray nozzle groupings each having at least one spray nozzle within said cavity, and a washing fluid supply system for sequentially providing a supply of washing fluid to said spray nozzle groupings, said washing fluid supply system comprising a pressurized fluid source and a plurality of fluidic logic elements connected in a series relationship, each of said fluidic logic elements having at least one output, and an output of each of said fluidic logic element in said series relationship being in direct fluid flow connection with at least one of said spray nozzle groupings.

3. The washing machine of claim 2 wherein a feedback circuit is provided interconnecting at least two of said fluidic logic elements so as to provide stepped sequential supply of washing fluid to different spray nozzle groupings.

4. The washing machine of claim 2 wherein said cavity defined by said cabinet is provided with a plurality of washing zones, each of said spray nozzle groupings providing a spray pattern in at least one of said washing zones whereby different fluid pressures are provided in different zones.