US3160170A

US3160170A - Dishwashing machine and operational cycle therefor

Info

Publication number: US3160170A
Application number: US257508A
Authority: US
Inventors: Kenneth E Sampsel
Original assignee: L T Ind Inc
Current assignee: L T Ind Inc; LT IND Inc
Priority date: 1963-02-11
Filing date: 1963-02-11
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08
Also published as: ES286015A1; CH407440A; BE629473A; GB971357A; FR1353218A; NL289916A

Description

1964 K. E. SAMPSEL 3,160,170

DISHWASHING MACHINE AND OPERATIONAL CYCLE THEREFOR Filed Feb. 11, 1963 s Sheets-Sheet 1 INVENTOR. KENNETH E. SAMPSEL ATTORNEYS K. E. SAMPSEL Dec. 8, 1964 DISHWASHING MACHINE AND OPERATIONAL CYCLE THEREFOR 3 Sheets-Sheet 2 Filed Feb. 11 1963 INVENTOR. KENNETH ESAMPSEL ATTORNEYS Dec. 8, 1964 K. E. SAMPSEL DISHWASHING MACHINE AND OPERATIONAL. CYCLE THEREFOR Filed Feb. 11 1963 3 Sheets-Sheet 3 AVENTOR.

KENNETH E. SAMPJEL FMM M/Zv d ATTORNEYS United States Patent as ll This invention relates to apparatus for washing articles, and more particularly to improvements in automatic dishwashers and the operational cycle therefor.

To efficiently wash dishes and silverware in an automatic dishwasher, it has been found the washing is facilitated by subjecting such articles to a pre-wash of water having a temperature of about 105 degrees F, and then to subject the articles to a main wash period wherein the water is about 140 degrees F, and then to subject the articles to a water rinse and thereafter to apply steam to said articles to form a distilled water rinse and also heat the articles to facilitate drying on completion of the steaming cycle. The dishwasher is connected to a source of water supply which may be a cold water system or from a domestic hot water system. With a domestic hot water system as the supply, the temperature of the water may vary over a wide range and be insulticient for proper washing of the articles in the dishwasher. In order LO provide suitable temperatures to the water for the various cycles of the dishwasher, the present invention contemplates the use of a water heater tank or receptacle located within the dishwasher cabinet with such tank being of small size both for space requirements and to avoid high capacity of the electric heaters in the tank, but still supply water of desired temperature for each portion of the cycle of operation. The invention contemplates the flow of water from the supply through the tank to the washing compartment and the heating of the water as it passes through the tank, and in order to increase the temperature of said water during portions of the cycle, the water flow is interrupted periodically to thereby reduce the average rate of flow through the tank in order that the heater can increase the temperature of the water. According to the present invention, a timer motor determines the length and sequence of the various operations of the dishwasher cycle and a mechanism and an electric circuit to effect a pulsing action or periodic interruption of water how to reduce the average rate of flow through the heater tank whereby the water passing through the tank to the washing compartment is heated to a suitable temperature for the washing of the articles, and after the final water rinse of the articles the water flow through the tank is closed and the water remaining therein is heated to generate steam which is delivered to the washing compartment to steam the articles therein.

The principal objects of the present invention are to provide an improved automatic dishwasher including a casing having a washing compartment in which articles to be washed are supported with a combination of elements in the sequence control whereby a cold water supply may be used and heated to desired temperatures for a pro-wash, a main wash, a rinse and then a steaming cycle for delivery to the washing compartment during the respective cycles; to provide a new combination of elements in a sequence control of an automatic dishwasher having its own water heater tank in which a timer controls the duration and sequence of each operation and mechanism to periodically interrupt the flow of water through the tank to reduce the average rate of water flow whereby the electric water heaters in the tank heat the Water therein to a higher temperature; to provide such a dishwasher with a water level control in the washing compartmcnt and a valve controlled drain for draining all liquid from the washing compartment and control means for shutting off the water flow to the water tank for the heating of water remaining therein into steam which is delivered to the Washing compartment for steaming of the articles therein; and to provide improvements in automatic dishwashing and steaming apparatus and the operation of cycling thereof to efficiently wash dishes and the like that is economical to manufacture, easily maintained and that is positive in operation.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

PEG. 1 is a perspective view of dishwashing apparatus embodying the features of the present invention, with portions broken away to better illustrate the component parts.

FIG. 2 is a transverse sectional view through the dishwashing apparatus taken on the line 22, FIG. 1.

FIG. 3 is a sectional view through a float valve for preventing excessive water level in the washing compartmcnt.

FIG. 4- is an elevational view of a timer cam for effecting opening and closing of a fill valve in the water supply.

FIG. 5 is a wiring diagram of an automatic dishwasher with the essential operating parts diagrammatically shown.

Referring more in detail to the drawings:

1 generally designates an automatic dishwasher which includes a casing 2 having a portion defining a washing compartment 4. The compartment portion of the casing has a bottom wall 5, rear wall 6, top wall 7 and end walls 3 and 9 to form a water-tight compartment having an access opening Ill normally closed by a door 1ft. The bottom wall 5 extends forwardly and downwardly from the lower portion of the rear wall and then forwardly and upwardly terminating in an upstanding flange or wall portion 12 The bottom portion also has a recessed portion 13 substantially on a level with the lowermost portion of the bottom wall to which is connected a drain mechanism lie. The bottom wall 5 forms a sump 15 that extends longitudinally for the length of the Washing compartment, and positioned in said sump and extending longitudinally of the washing compartment is a distributor 16 to move water or washing liquid from the sump and distribute it in relatively high velocity streams or sprays on articles ll? suitably supported on racks 18 or the like arranged in the washing compartment above said distributor.

The drain mechanism it communicates the washing compartment at the sump thereof with a suitable disposal, for example, a sewer or the like, by either gravity flow or by a pump (not shown). The drain mechanism 14 includes an end portion 19 adapted to be connected to a disposal line and also has two conduits 20 and 21 which lead to the washing compartment. The conduit extends through the bottom wall 5 and terminates in an open end 22 adjacent said bottom wall for substantially complete draining of liquid therefrom, said draining being controlled by a valve 23 preferably actuated by a suitable motor 24 such as a solenoid or the like. The conduit 21 extends through the bottom wall and upwardly therefrom and has an open end 25 defining an overflow pipe of suitable height for the maximum desired level of washing liquid in the washing compartment, the open end of the drain pipe or conduit 21 being at a level below the lower edge of the door opening lltl. The conduit 2f connects with the drain end portion 19 downstream of the valve 23 for unrestricted flow to the disposal.

arenas/o The door it is preferably hingedly mounted at its lower edge as by hinged members 26 for outward swinging movement with the edges of the door and the portion of the casing defining the door opening having suitable resilient seal members 27 to provide a substantially watertight seal. However, the lower portion of the door extends downwardly and terminates in a flange 28 inwardly of the flange 12 on the bottom wall to form a vent opening 29 having a resilient cellular material 3% disposed. therein to form a closure as to suds and the like but permit passage of air therethrough.

The casing 2 has an extension beyond the end wall 3 of the washing compartment, said extension having an end wall 31 which cooperates with said wall it and a front wall 32, rear wall 33 and bottom 34 to define a chamber 35. Located in the chamber 35 is a float structure 36 which includes a housing 37 suitably supported on the end wall 8 with an opening 38 communicating the washing compartment below the maximum level of liquid therein with a float chamber 39 in the housing 37. A float lll is arranged in the flat chamber and has an operative connection to stop the water flow to the chamber which, in the illustrated structure, is an upwardly extending shank 41 extending through the top wall of the housing that is connected by an arm 42 with a micro switch 4-3 connected in the electric circuit 44 to interrupt the flow of water to the washing compartment if the water level should become higher than that desired or, in other Words, higher than the open upper end of the drain conduit 21.

An electric motor 45 is arranged in the chamber and is operatively connected with an impeller 46 of the distributor l6. Said impeller is positioned inside of a substantially cylindrical housing d7 having a thin perforated wall with ends terminating to define a longitudinal opening 48 whereby upon rotation of the impeller water is discharged through said opening onto articles in the washing compartment. The housing 47 is oscillated by means of a connecting rod 49 having one end pivotally connected to the housing 47 as at 5% and the other end pivotally connected as at 51 with a crank arm 52 fixed on a shaft 53 driven by a geared motor 54, said motor being arranged in the chamber 35. Rotation of the impeller is such that sheets or streams of wash liquid are directed from the housing 47 through the opening 43 and oscillation of the housing is such that the direction of the stream of water from said housing is changed to traverse the interior of the washing compartment 4 and impinge on dishes or the like in any location in the washing compartment.

A water heating tank or receptacle 55 is mounted in the chamber 35 and, in the illustrated structure, said tank is elongated and horizontally disposed. The tank is connected to a source of water, as, for example, a domestic water supply, by a conduit or pipe 56 which communicates with the lower portion of the tank 55. A water solenoid fill valve 57 is arranged in the water supply pipe for controlling flow therethrough to the tank 55. Steam or water from the tank 55 is delivered through a pipe 5% that communicates with the tank 55 at the upper portion thereof and has a discharge end 59 emptying into a trough-like member 6% that has communication through louvered openings 61 with the upper portion of the washing compartment 4. This arrangement provides a spacing between the discharge end 59 of the pipe 58 and the openings 61 to the washing compartment to provide an air break in the washing compartment water supply whereby no liquid can be siphoned from said washing compartment back into the water system of the house. It is preferred that the bottom of the trough dtl be inclined toward the louvered openings 61 whereby any condensation or liquid collecting in the trough will run back into the washing compartment. The pipes 56 and 53 form a conduit from a water supply to the washing compartment with the receptacle 55 interposed in said flow conduit.

tank 55 preferably has

thermostats

62 and 63 mounted on the respective ends and two heating elements 64 and 65 mounted inside of said tank preferably one above the other in spaced relation, said heating elements being sealed heating units connected into the electric cirsuit 44 to be energized as later described.

In the illustrated sequence control, a timing motor 66 is arranged in the chamber 35 behind the front wall 32. The timing motor es through suitable gearing (not shown) actuates a camshaft 67 which has a control knob 68 mounted thereon at the front of the wall 32. The timer motor 66 rotates the shaft 67 on which cams 69, 7t 71, 72 and 73 are carried, said

cams actuating switches

74, 75, 76, 77 and 78 respectively, for controlling the cycling operations as later described. The electric circuit 4-dincludes leads 79 and 39 connected to a suitable source of electric current, as for example 220 volts, and said lead 79 is connected to the switch 74 whereby upon the cam 69 moving the switch arm 31 to close the switch 74 a conductor 82 is connected in circuit with the lead 79. The lead 8h is connected to the switch 75 and when the cam '7ll actuates the switch arm 33 to close the switch 75, a conductor ti t is electrically connected to the lead 86 The cams 69 and 749 are preferably arranged whereby the switches 74- and 75 are actuated at the same time to make and break the circuits simultaneously. A signal light, for xample a neon light 85, has its terminals connected by conductors as and 37 respectively to the

conductors

82 and 84 to provide a visual signal that the circuit is completed and power is on. A switch 88 is arranged in the conductor 82 and is positioned adjacent the door 11, said switch being biased whereby it is in circuit-opening position when the door Ill is open and is in circuit-making position only when the door 11 is closed.

The timer motor on is connected in circuit by conductors 89 and 9t? connected to the

conductors

82 and 84 respectively, the connection with the conductor 82 being relative to the switch 8% whereby the circuit to the timing motor is interrupted if the door 11 and switch are opened. The solenoid 2 2- of the drain Valve 23 is connected by a conductor 91 to the conductor 84 and by a conductor 9 2 through the switch '76 to the conductor 82 whereby the cam 731 operating the switch 76 controls the drain valve 23. The conductor 532 is connected by a conductor Q3 with one terminal of the heating element 64 with the thermostat 62 arranged in the conductor 82, between the connection of the conductor 92 leading to the drain valve solenoid and the conductor 93 to the heater element 64. Terminals 9d and his" of the heater elements 64 and 65 respectively are connected by a conductor $6 to the conductor The float switch 43 is in the conductor 96 and is normally in closed position, said switch interrupting the circuit only when the water reaches an excessive height in the washing compartment. The other terminal 9 7 of the heating element 65 is connected to a conductor 98 that joins with a conductor that is connected with the

motors

45 and 54, said motors being connected by respective conductors 1% and 1591 to the conductor to complete the circuit. The conductor 93 is also connected to a conductor Th2 that leads to a contact M3 or" the switch 77. The switch arm lltld of said switch is connected by a conductor to the conductor S2. The switch 7'7 is a double switch that has a contact connected by a conductor l d? with a mechanism 108 for controlling adding of water softener into the system near the end of the complete cycle. The connection of the conductors 98 and 99 also is a connection to a conductor 1W9 which has a cycling thermostat therein, said conductor being connected as at Hill to a conductor llllll that connects a contact of the switch 73 with a solenoid of the fill valve 57. The other terminal of the solenoid is connected by a conductor 112 to the conductor between the heating elements and the float switch The switch arm 113 of the switch 78 is connected by a conductor 114 to the conductor 82.

In operation of an apparatus constructed and assembled as described, and with the water pipe 36 connected to a source of water supply, the drain end 19 connected to a disposal, and the leads '79 and dill connected to a suitable source of electric current, the door 11 is opened and dishes or the like articles to be washed are placed in the washing compartment. The door ll is then closed whereby the switch tit; is in circuit-making position. Then the manual control knob 63 is turned to move the cams to the starting position wherein cams 69 and 7% close the switches 74 and 75 to complete the electrical circuit energizing the signal bulb 2:5 and the timing motor 66. The cam 71 also preferably closes the switch as to complete the circuit through the solenoid drain valve 23 to open the drain and the cam 73 closes the switch 78 to energize the solenoid of the fill valve 57 to open sam to start the fiow of water through tSZllCl valve to the tank 55 to fill said tank. Since the washing compartment would be empty, the float switch 43 is in circuio making position and the heater element 64 is energized to heat the water as it moves into the tank 55 and flows therethrough through the pipe 58, trough as and louvered openings as into the Washing compartment. After a short interval and continued movement of the cams on the camshaft 67, the cam 71 causes the switch 76 to open, interrupting the circuit to the drain valve 2 closing the drain whereby washing liquid will collect in the sump of the washing compartment. The cam 7 causes the switch arm M4 to engage the contact 1% so as to energize the heater d5. As an example of water heating, the two heating elements 64 and 65, in normal flow of the water through the tank 55, will cause the waterto be heated to a temperature of approximately 105 degrees F. As this heated water flows into the washing compartment, motors and 5d are energized to actuate the water distributor whereby the water is discharged against the articles in the washing compartment, providing a pro-wash. After such a pro-wash, as for example, four minutes, the cam 71 again moves the switch 76 to close the circuit to the drain valve 23, opening same for quick discharge of the water from the sump of the washing compartment. The cams 72 and 73 also open the switches 77 and 78 to close the fill valve and stop the motors and 54. Then the cams 71, '72 and 73 move the switches 76, 77 and '78 to interrupt the circuit to the drain valve 23 whereby it is closed and open the fill valve and reenergize the motors and 54 and the water again starts to collect in the sump for the main washing cycle.

It is desired to have hotter water for the main washing. To achieve this, a pulsing mechanism is built into the timer and cuts the fill valve oil and on intermittently during the entire main wash period, as for example, at a rate of 7 seconds on, that is the fill valve delivering water to the tank, and 53 seconds off, that is the fill valve being closed. This pulsing action is provided by a portion lid of the cam 73 which opens and closes switch 73 and circuit to the till valve 57 so that the fill valve is closed intermittently thereby permitting the two heating elements 64 and as in the tank to heat the water therein to a higher temperature. When the till valve 57 is closed, no water is flowing from the tank 55 to the washing compartment 4. Then, when the cam 73 'actuates the switch 78 to again complete the circuit to the fill valve 57, water flows to the tank 55 ad a corresponding amount of water flows into the washing compartment d. This intermittent flow with continued heating reduces the average rate of water flow, as for example, to 13 percent of the normal flow rate, and this lower average flow rate allows the water to reach the desired higher temperature, as for example 14-6 degrees F. When the main washing cycle is completed, the earns 71, 72 and 73 actuate their

respective switches

76, 77 and 78 to interrupt the circuit to the fill valve 57,

motors

45 and 54 and heater es and actuator, the drain valve 23 for fast draining of the water from the washing compartment. After a short interval, as for example one minute, to permit such draining, the cams 71, 72 and 73 again actuate the

motors

45 and 54 and open the fill valve 57. This provides for rinse Water to run through the tank 5d and be heated, and this Water is delivered to the washing compartment for rinsing of the dishes. It is preferred that the earns '71, 72 and 73 be arranged whereby the rinse water is drained and the motor stopped and the till valve closed for the draining of the rinse water from the washing compartment, and then close the drain valve and again supply water by opening the fill valve and energizing the motors 55 and 54 to provide another rinse. As many rinses as is de sired can be provided; however, it is preferred that there be three rinses. At the end of the final water rinse cycle, the earns 71, 72 and 73 again actuate their respective switches whereby the solenoid 2d of the drain valve is energized to open the drain for draining of the water from the washing compartment. The cir cuits to the motors 45' and 54 are interrupted to stop the water distributor is in the washing compartment; and the circuit to the fill valve 57 is interrupted to stop flow of water to the tank 55. However, the circuit is still completed to the timing motor and to the heating element which heats the water in the tank 55 generating steam which steam is delivered by the pipe 58 to the washing compartment to steam the dishes or articles therein. The steam entering the washing compartment will condense on the articles, creating a distilled water rinse of said articles. The build-up of steam condensate causes the articles to drip, thus displacing droplets previously left on the articles. These droplets normally contain minerals that would leave Water spots when the articles dry so that the distilled Water rinse removing such droplets eliminates the spots that otherwise would be on the dishes. The steam also heats the dishes so as to facilitate their drying.

if the temperature of the tank 55 should become excessive, as for example if the water in the tank should all be evaporated prior to the end of the complete cycle, in other words before the timing motor moved the cams as and 7t to a position to interrupt the circuit, the safety thermostat 62 would interrupt the circuit to the heater as and thereby prevent damage to the heating element or tank. If the water in the tank 55 during the pulsating heating period reaches a temperature over a predetermined maximum, the cycling thermostat 63 would override the pulsing contact of the timer and open the fill valve 57 for continuous flow of water through the tank 55 until the proper temperature is reestablished. This thermostat, however, is ineffective during the steaming cycle because during that period the cam 73 has caused the switch 7% to open, interrupting the circuit to the fill valve 57. it the drain pipe 21 should become clo ged and water in the washing compartment should reach an excessive level, the float switch 43 opens the circuit to the till valve 537 and also to both of the heating elements 64 and d5; so as to stop the inflow of water until the water recedes to the desired level, and when the proper water level is established the float switch will reestablish fill valve circuit.

When the complete steaming cycle is over, the timing motor 6-5 will have moved to position the cams 69 and wherein they open the switches 74- and 75, interrupting the circuit to the loads 79 and 8'3 respectively, thereby shutting off the entire machine until such time as the manual control 68 is again rotated to start the operation.

It is believed obvious that l have provided an automatic dishwashing machine that will suitably heat the water and generate steam with controls for efiiciently washing, rinsing and steaming dishes in controlled cycles with drain operations for rapidly carrying away the Water whereby any food particles will be carried therewith.

It is to be understood that while I have illustrated and described one form of my invention, it is not to be limited to the specific form or arrangement of parts herein described and shown except insofar as such limitations are included in the claims.

What I claim and desire to secure by Letters Patent is:

1. In an automatic dishwasher of the type described, a cycle control timing mechanism having a timer means, means for energizing a heating means in a receptacle to continuously heat Water as it passes through said receptacle, and means responsive to said timer means periodically opening and closing a valve upstream from the receptacle and reducing the average rate of how of water through the receptacle to a compartment below a normal flow and permitting the energized heating means to effect an increase of the temperature of water delivered to said compartment for a cycle above the temperature efiecte during normal flow.

2. In an automatic dishwasher of the type described, a cycle control timing mechanism having a timer means, means for initiating opening of a valve and energization of a heating means in a receptacle for normal flow of water through said receptacle to a compartment and continuous heating of the water as it passes through said receptacle for a predetermined period, and means responsive to said timer means periodically closing and opening said valve during said predetermined period reducing the average rate of flow of Water through the receptacle to said compartment below said normal how and thereby permitting the energized heating means to effect an increase of the temperature of water delivered to said compartment for a cycle above the temperature effected during said normal flow.

3. In a cycle control timing mechanism as defined in claim 2, means responsive to the temperature of the water in said receptacle and operative in response to temperatures above a predetermined maximum during said cycle to override the periodic valve opening and closing means and hold said valve open for full flow of water through the receptacle until the temperature of the water in the receptacle is lowered at least to the predetermined maximum and said temperature-responsive means becomes inactive returning the control of the valve to the timer periodic means.

4. In an automatic dishwasher of the type described, a cycle control timing mechanism including an electric circuit for regulating the sequence of operation of the dishwasher, electrical means for heating the contents ot a receptacle, timer means including switches connected in an electric circuit and operable to open a valve and energize said electrical heating means for normal flow of water through a receptacle to a compartment and continuous heating of the Water as it passes throu h said receptacle for a predetermined period for a fir t cycle, means responsive to said timer means periodically closing and opening said valve during a second cycle reducing the average rate of flow of water th ough the receptacle to the compartment below said normal flow thereby permitting said energized heating means to effect an increase in the temperature of the water delivered to said compartment above the temperature etlected during said normal flow.

5. In an automatic dishwasher of the type described, a cycle control timing mechanism having timer means operable to open a valve and energize a heating means for normal flow of water through a receptacle to a compartment and the continuous heating of the water as it passes through said receptacle for a predetermined period for a first cycle, means responsive to operation of said timer means periodically closing and opening said valve during a second cycle reducing the average rate of flow or" water through the receptacle to said compartment below said normal flow and thereby permitting the energized heating means to effect an increase of the temperature of the water delivered to said compartment above the temperature effected during said normal flow, and means actuated by said timer means subsequent to said second cycle to close said valve with the heating means energized to convert the water remaining in the receptacle to steam which is delivered to the compartment.

6. In a cycle control timing mechanism as defined in claim 5, means responsive to temperature in the receptacle and operative in response to a predetermined temperature above the boiling point oi water to arrest the operation of said heating means.

7. For use in a dishwasher of the type described, a cycle control timing mechanism comprising, an electric circuit having switches, a timer motor, means driven by the timer motor and actuating said switches in the electric circuit to effect a first cycle, and a second cycle, saic means operated by the timing motor actuating switches in the electric circuit to open a fill valve and to energize a heating means for heating water as it passes through a receptacle for a predetermined period for the first cycle, said means driven by the timing motor having a portion for periodically closing and opening said fill valve to reduce the average rate of flow through the receptacle to a compartment and increase temperature of the Water for the second cycle, and thermostat means in the electric circuit and responsive to a predetermined temperature of water in the receptacle during the second cycle to bypass said periodic portion and open the fill valve for full flow of Water through the receptacle until the water therein is lowered below said predetermined temperature, said means driven by the timing motor actuating the switches to close the fill valve, and open a drain fitting valve to empty the compartment at the end of the second cycle.

8. For use in a dishwasher of the type described, a cycle control timing mechanism comprising, an electric circuit having switches, a timer motor, and means driven by the timer motor and actuating said switches in the electric circuit to effect a first cycle, a second cycle, and a third cycle, said means operated by the timing motor actuating switches in an electric circuit to open a fill valve and to energize a heating means for heating water as it passes through a receptacle for a predetermined period for the first cycle, said means driven by the timing motor having a portion for periodically closing and opening a fill valve to reduce the average rate of flow through said receptacle to a compartment and increase temperature of the water for the second cycle, said means driven by the timing motor actuating the switches to close the fill valve, and open a drain fitting valve to empty the compartment at the end of the second cycle and thereafter maintaining the heating means energized to convert the water remaining in the receptacle to steam which is delivered to the compartment for the third cycle.

9. For use in a dishwasher of the type described, a cycle control timing mechanism comprising, an electric circuit having switches, a timer motor, means driven by the timer motor and actuating said switches in the electric circuit to effect a first cycle, a second cycle, a third cycle and a fourth cycle, said means operated by the timing motor actuating switches in said electric circuit to open a fill valve and to energize a heating means for heating water as it passes through a receptacle to a compartment for a predetermined period for the first cycle and then open a drain fitting to drain the liquid from the compartment and then close the drain fitting and again energize the heating means and opening the fill valve for flow of water through the receptacle for a predetermined period for the second cycle, said means driven by the timing motor having a portion for periodically closing and. opening said fill valve to reduce the average rate of ilow hrough the receptacle to the compartment and increase temperature of the water for the second cycle, and thermostat means in the electric circuit and responsive to a predetermined temperature of water in the receptacle during the second cycle to bypass said periodic portion and open the fill valve for full flow of Water through the receptacle until the temperature of the Water therein is lowered below said predetermined temperature, said means driven by the timing motor actuating the switches to close the fill valve and open a drain fitting valve to empty the compartment at the end of the second cycle and then closing the drain valve opening the fill valve for a predetermined third cycle and thereafter opening the drain valve and closing the fill valve while maintaining the heating means energized to convert the water remaining in the receptacle to steam which is delivered to the compartment for said fourth cycle.

References Cited in the file of this patent UNITED STATES PATENTS Chamberlin et a1 Apr, 2, Clark et al. Sept. 2, Fraiitz Aug. 17, Lyman July 8, Low Apr. 26, Jacobs Dec. 25, James Ian. 8,

Claims

1. IN AN AUTOMATIC DISHWASHER OF THE TYPE DESCRIBED, A CYCLE CONTROL TIMING MECHANISM HAVING A TIMER MEANS, MEANS FOR ENERGIZING A HEATING MEANS IN A RECEPTACLE TO CONTINUOUSLY HEAT WATER AS IT PASSES THROUGH SAID RECEPTACLE, AND MEANS RESPONSIVE TO SAID TIMER MEANS PERIODICALLY OPENING AND CLOSING A VALVE UPSTREAM FROM THE RECEPTACLE AND REDUCING THE AVERAGE RATE OF FLOW OF WATER THROUGH THE RECEPTACLE TO A COMPARTMENT BELOW A NORMAL FLOW AND PERMITTING THE ENERGIZED HEATING MEANS TO EFFECT AN INCREASE OF THE TEMPERATURE OF WATER DELIVERED TO SAID COMPARTMENT FOR A CYCLE ABOVE THE TEMPERATURE EFFECTED DURING NORMAL FLOW.