US3259764A

US3259764A - Dishwasher control means

Info

Publication number: US3259764A
Application number: US322375A
Authority: US
Inventors: Norman L Kendt
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1963-11-08
Filing date: 1963-11-08
Publication date: 1966-07-05
Anticipated expiration: 1983-07-05

Description

July 5, 1966 N. L. KENDT DISHWASHER CONTROL MEANS 2 Sheets-Sheet 1 Filed Nov. 8, 1963 Fl G l NORMAN Nrgr H \s ATTORNEY July 5, 1966 N. L.. KENDT 3,259,764

DISHWASHER CONTROL MEANS Filed Nov. 8, 1963 2 Sheets-Sheet 2 C l LS/L; 44 V :a \4

PAUSE muse um P/use Rmss 'INVENTORn NORMAN L.. KEMDT F` G. 3 BY gyn/MLM /L/ ms ATTRNEY Vselector switch closes a pair of electrical contacts.

United States Patent O 3,259,764 DSHWASHER CONTROL MEANS NormanL. Kendt, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Nov. 8, 1963, Ser. No. 322,375 6 Claims. (Cl. 307-141) This invention relates generally to an improved control means for an .automatic dishwasher and, more particularly, to an improved means for providing an automatic rinse and hold operation for an automatic domestic dishwasher.

Many dishwashers being manufacturedtoday are designed to accommodate, at one time, as many as sixteen table settings of dish ware. This does not mean that these dishwashers have been designed specifically for families including sixteen members. On the contrary, these machines have been designed for families having four or five members so that the dishwasher may be used only once a day, after the evening meal, and will accommodate all the dish ware used during the entire day. If the housewife serves all three meals to five members of a household, she will, in effect, have used a total of fifteen place settings for the day. Ideally, the housewife places the dish ware into the dishwasher after each meal and leaves it there until the dish ware for the evening meal has been placed in the dishwasher whereupon the dishwasher is set into operation and all the dish ware used during the day is washed with only one operation of the dishwasher. Such procedure has obvious advantages: savings of water, electricity and detergent and reduction of wear on the dishwasher over the procedure of using the dishwasher after each meal.

In practice it has been discovered that placing the soiled breakfast or lunch dishes into the machine and leaving them there until after the evening meal results in a setting or hardening of the soil on the dish ware such that quite often the dish ware is not as effectively cleaned as when the dishes are washed soon after the meal. Accordingly, various means have been suggested for overcoming this setting of the soil on the dish ware. Perhaps the most practical solution has been the pre-soak or rinse and hold operation wherein the dishwasher is briefly energized to thoroughly rinse the dishes after each meal but the machine is not subjected to a complete washing cycle until the evening meal dishes are placed into the machine. This achieves a satisfactory balance between the aforementioned advantages of operating the dishwash- `er only once a day and the advantages of not allowing the soil to harden on the dish ware. However, many of the means heretofore proposed for achieving a rinse and hold operation have included such undesirable features as a costly second timer control or the retention of vitiated rinse liquids within the dishwasher wash chamber after each rinse and hold operation.

Accordingly, it is an object of this invention to provide an improved control means for achieving a rinse and hold operation in an automatic dishwasher.

Another object of this invention is to provide a control means which will include a rinse and hold operation without necessitating an additional timer control.

A further object of this invention is to provide a rinse and hold operation in a dishwasher which is easily selectable by the operator and which necessitates only an inexpensive modification of the normal control means.

Briefly stated, in accordance with one aspect of the invention, there is provided a control means having a Amanually operated selector switch which when manipulated by the operator pre-conditions the control means. The selector switch includes at least two settings, one representing an entire wash cycle and the other representing a rinse and hold operation. Each setting of the That is, when the selector switch is in one position a first pair 3,259,764 Patented July 5, 1966 ICC of contacts are closed and when the selector switch is in the second position a second pair lof contacts are closed. The first pair of contacts is in electrical series with a first timer-operated switch while the second pair of contacts is in electrical series with a second timer-operated switch. The first timer-operated switch is designed to allow the machine to proceed through an entire wash cycle while the second timer-operated switch is designed to allow the machine to proceed through .a rinse and hold operation only.

In a specific embodiment of this inventi-on, the control means includes a timer motor driving a series of switch operators in the form of cams, each cam opening and closing a switch in predetermined accordance with the configuration of the cam. One cam controls operation of a valve which .admits water t-o the dishwasher. A second cam controls operation of a motor-pump assembly while a third cam controls the function of the motorpump assembly. That is, the third cam determines whether the motor-pump assembly serves to recirculate water for wash and rinse or serves to pump the water from the dishwasher. A fourth cam controls the switch in series with the first pair of contacts in the aforementioned selector switch while a fifth cam controls the switch in series with the second pair of contacts of the selector switch. The switches controlled by the fourth and fifth cams are in parallel with each other and are each in series with the switches controlled by the first, second and third cams. With this arrangement, when the selector switch is set at the rinse and hold position and the timer motor is energized, the fifth cam closes its associated switc-h and thereby provides electrical power to .the switches controlled by the first, second and third cams. The fifth cam is configurated t0 allow the first, second and third cams to control the valve and motor-pump `assembly through the first few steps of .a complete wash cycle whereupon the fifth cam opens its switch and discontinues admission of power to these elements. These first few steps of the complete wash cycle may include a water lill, a wash or rinse step, a drain step, a fill, a wash or rinse and a drain. These first few steps comprise the rinse and hold cycle.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from :the following description taken in connection with the accompanying drawings, in which:

FIGURE l is a front elevational view, partially cut away, of a dishwasher embodying the present invention;

FIGURE 2 is a schematic representation of the electricalcircuitry of the present invention; land FIGURE 3 is a sequence control cam chart illustrating the sequence of operation of the schematically shown switches of FIGURE 2.

Referring now to the drawings, and particularly to FIGURE l, there is illustrated an automatic domestic dishwasher 10 in which the present invention has been incorporated. Dishwasher 10 has a wash chamber 11 which houses

dish supporting racks

12 and 13. An outer cabinet 14 surrounds the wash chamber 11 and is provided with a door 15 so that access to wash chamber 11 and

racks

12 and 13 may be accomplished. Positioned near the bottom of wash chamber 11 is a rotating spray apparatus 16 and la telescoping spray apparatus 17. A motor-pump ssembly 18, supported 'by the bottom wall of wash chamber 11, includes la drive motor 19, a drain pump 20 and a recirculation pump 21. Y

As is well understood in the art, drive motor 19 is of the reversible type wherein in one direction of rotation lrecirculation pump 21 is effectively operated to pump pre-rinse.

,present invention.

wash uids up through

spray apparatus

16 and 17 in a vigorous manner such that an effective wash or rinse action is .applied to the dish ware supported by rack-s 12 and 13. In the other direction of rotation, drive motor 19 effectively operates drain pump 20 to withdraw the wash fluid from wash chamber 11 Ito a conventional Isewer connection (not shown).

An electrical heating means 22 is supported in spaced relationship from the bottom wall of wash chamber 11 and is employed to heat the wash fluid in chamber 11 and to facilitate drying of the dishes supported by racks 12 .and 13 upon completion of the wash operation. A valve 23 is provided to control the admission of water, or other fluids, to the wash chamber 11. A :sequence control means 24, having a manually operable knob 25, is conveniently positioned on the door 15.

The structure thus lfar described is essentially conventional in form and, in fact, may deviate considerably from the specific examples illustrated. In such a conventional machine, the control knob 25 is manipulated to initiate operation of dishwasher 10. Once the knob 25 has been manipulated, the sequence control means 24 is energized and remains energized :throughout the entire wash cycle of the dishwasher and, upon termination of the last step in the operation of the dishwasher, the sequence control means de-energizes itself. A conventional complete wash cycle may include energization of valve 23 to admit a predetermined quantity of water to wash chamber 11 whereupon valve 23 is deenergized and motor-pump assembly 18 is energized in a manner such that recirculation pump 21 `operates to eifect a pre-rinse of the dish ware supported by

racks

12 and 13, After a predetermined period of this action, the motor-pump `assembly 18 is de-energized momentarily and then re-energized in the yreverse direction so that drain pump 20 is caused to drain the water from chamber 11. A second pre-rinse, comprising the same lsteps` just mentioned, may then follow. Usually, upon completion of the second pre-rinse the sequence control means 24 again energizes valve 23 to admit Water to wash chamber 11 as the lirst step in a wash opertioan which comprises essentially the same steps as the prerinse except that the period of activity of recirculation pump 21 and the

spray apparatus

16 and 17 is for a longer time. Also, usually during the early stages of the wash operation, an automatic detergent dispenser (not shown) is energized by the sequence con-trol means 24 to dispense the proper amount of detergent into wash chamber 11 to facili-tate cleaning of the dish ware supported by

racks

12 and 13. The wash operation is followed by a rinse operation which again comprises the same steps as the pre-rinse operation except that again the period of activity of the recirculation pump and the spray apparatus is for a longer time than that of the At the end of the rinse operation the sequence control means 24 energizes heating means 22 for a predetermined length of time to facilitate drying of the dish ware in wash chamber 11. At the completion of the predetermined period of energization of electrical heating means 22, sequence control means 24 deenergizes hea-ting means 22, and also de-energizes itself so that the entire dishwasher is completely shut off.

As mentioned above, the .aforementioned operation is conventional in most present day dishwashers. However, the present invention proposes the addition of a rinse and hold'cycle by means of a relatively inexpensive modification of the sequence control means required to provide the aforementioned conventional oper-ation.

Referring now to FIGURE 2, there is illustrated a schematic representation of the control circuitry of the A pair of power lines L1 and L2 may be connected to a suitable power source (not shown). In power line line L2 there is positioned a master switch 26 which preferably is associated with the latch for door v such that .the control system cannot be energized unless door 15 is properly latched. A

timer motor 27 is electrically connected between power lines L1 and L2 in series with a timer motor switch 28 which is controlled by a cam 29. It is to be understood that cam 29, and subsequent cams to be discussed, Aare driven by timer motor 27 and .are also subject to rotation upon manual rotation of knob 25. This particular arrangement is essentially standard in control means for present day appliances. In series with timer motor switch 28 is a switch 3i) operated by :a cam 31. Also in series with timer motor switch 28, but in parallel with switch 31), is a switch 32 operated by a cam 33.

Also housed Within sequence control means 24 are la heating means switch 34 operated by cam 35, a valve switch 36 operated by a cam 37, a main motor switch 38 operated by a cam 39, and a start winding switch 40 operated by cam 41. When switch 34 is closed heating means 22 is energized, either for the purpose of heating the wash fluid in wash chamber 11 or to facilitate drying of the dish ware supported by racks 12 and 1.3. When :switch 36 is closed, valve.23 is energized and water is .admitted to wash chamber 11. The colsing of switch 38 energizes a main winding 42 of drive motor 19 and `also provides power to start winding switch 40.

As illustrated in FIGURE 2, start winding switch 40 is a single pole double throw switch whereby, depending upon the disposition -of cam 41, power is admitted to one or the other of

start windings

43 and 44 of drive motor 19. As is well known in the motor art, the direction of rotation of motor 19 is dependent upon which of the start windings 43 or 44 is energized. A start winding cut-out switch 45 includes a solenoid 46 in electrical series with main winding 42 of drive motor 19 and mechanically linked to switch 47 which is in electrical series with both start

windings

43 and 44. This arrangement is such that when motor 19 reaches essentially its normal running speeds, the current passing through solenoid 46 causes solenoid 46 to open switch 47 thereby de-energizing whichever start winding had been energized.

With the exception of

switches

30 and 32, the control circuitry just described is essentially conventional and may be modified to some extent without materially aifecting the present invention. For example, the heating means 22 may be removed from the system if so desired and, moreover, a liquid level responsive switch may be installed in series with valve 23 to make the operation of valve 23 further depend upon the level of liquid within wash chamber 11. Also, if desired, a centrifugal type start winding cut-out switch could be ernployed in lieu of start winding cut-out switch 45.

As mentioned earlier, one of the primary objects of this invention is to provide an improved control means to achieve an auto-matic rinse and hold operation. In accordance with this object, there is provided a manually-operated selector switch 48 having individual manuallyoperated switches 49, 50 and 51.

Switches

49, 50 and 51 are controlled by

pushbuttons

52, 53 and 54 respectively as seen in FIGURE l. Referring again to FIG- URE 2, it can be seen that if switch 49 is closed, the operation of the

switches

30 and 32 will have no effect on the operation of heating means 22, valve 23 or motor 19. In `other words, if switch 49 is closed the overall operation of the dishwasher will be controlled primarily by cam 29 and switch 28. It is to be understood that selector switch 48 is preferably of the type whereby the depression of one of the

pushbuttons

52, 53 or 54 automatically resets the remaining two pushbuttons to the open position. In other words, it is preferable to have selector switch 48 arranged so that only one of the

individual switches

49, 50, or 51 may be closed at any given time.

Therefore, if switch 50 is closed it is apparent that the operation of the dishwasher is dependent upon the coniiguration of

cams

29 and 33 which control the operation of

switches

28 and 32 respectively. Similarly, if

switch S1 is closed, the operation of the dishwasher is dependent upon the conguration of

cams

29 and 31 which control the operation of

switches

28 and 30.

Reference to FIGURE 3 will show the periods during which each of the aforementionedrcam operated switches are closed during a complete cycling of the sequence control means 24. For example, it can been seen that timer motor switch 28 is closed throughout the entire cycle while switch 30 is closed for a reasonably short period at the beginning of the cycle and switch 32 does not close until a few minutes after the beginning of the cycle and closes well before the end of the cycle.

Referring now to both FIGURES 2 and 3, it can be seen that the following selection of operations can be achieved. If it is desired to have a complete regular cycle of the dishwasher, pushbutton 52 of selector switch 48 is depressed thereby closing switch 49. Knob 25 is rotated slightly to a pre-indicated position whereby ca-m 29 closes switch 28 to energize timer motor 27.y From this point on, timer motor 274 will drive the sequence control means 24 throughout an entire cycle. Since cam 29 isconfigurated to maintain switch 28 in the closed position throughout the entire cycle, and since switch 49 is closed, power is provided to

switches

34, 36 and 38 for the entire period of operation. Therefore, sequence control means 24 will provide a complete wash cycle comprising the following sequence of steps: brief pumpout, fill, rinse, (with heating means 22 energized for a portion of the rinse), pump out, iill, rinse, pump out, fill, wash (with heating means 22 energized for a portion -of the wash), pump out, fill, rinse, pump out, fill, rinsepump out, and dry (with the heating means 22 energized throughout the entire dry period).

To achieve -a more gentle wash action for such articles as iine china, pushbutton 53 is depressed thereby closing switch 50 of `selector switch 48. As mentioned earlier, it is desirableto have selector switch 48 designed so that the closing of switch 50 opens switches 49 and 51. If selector switch is not so designed, it would be necessary to manually open switches 49 and 51. With switch 50 closed, the operator rotates knob 25 slightly until cam 29 closes switch 28 thereby energizing timer motor 27 which-again will drive sequence control means 24 through an entire cycle. Since switches 49 and 51 are open, electrical power is not provided to

switches

34, 36 and 38 until cam 33 closes switch 32. From FIG- URE 3, it can be seen that switch 32 is not closed until the begining of the operation which constituted the second pre-rinse of the comple-te cycle explained above. Switch 32 remains closed from that point of the aforementioned complete cycle through a reasonably short portion of the dry period of the aforementioned complete wash cycle. This results in an operation of the dishwasher comprising the following sequence of steps: a brief pump out, fill, rinse, pump out, ll, wash (with heating means 22 energized for a portion of the wash), pump out, fill, rinse, pump out, fill, rinse, pump out, and dry.' It should be noted that switch 32 is opened after the heating means 22 has been energized for only a few minutes. When switch 32 opens power is no longer provided at

switches

34, 36 and 38 so that the components controlled by these switches lie dormant. However, since switch 28' remains closed, timer motor 27 remains energized and continues to drive sequence con trol means 24 until switch 28 opens. This -means that sequence control means 24 and knob 2S are returned to the same position as when an entire wash cycle occurs.

From a further review of FIGURES 2 and 3, it can be seen that a rinse and hold cycle is achieved by depressing pushbutton 54 which closes switch 51, and then .rotating knob 25 until cam 29 closes switch 28. Since cam 31 is configurated to immediately close switch 30, power is immediately presented to

switches

34, 36 and 38. Therefore, the machine proceeds through an operation comprising the following steps: a brief pump out, till, rinse (with heating means 22 energized for a portion of the rinse), pump out, lill, rinse and pump out. A-t this point, cam 31 opens switch 30 thereby discontinuing the admission of power to switches 34, 36 and 38. However, as in the ne china operation discussed above, cam 29 continues to maintain switch 28 in a closed position so that the timer motor 27 continues to drive sequence control means 24 until it returns to the same position which would occur if the dishwasher had gone through a complete wash cycle.

Thus, it can be seen that the present invention provides a rinse and hold operation, as well as a series of selectable wash operations, by the employment of a single sequence control means having a single timer motor in cooperation with a manually-operated selector switch.

As will be evident from the foregoing description, certain aspects of the invention are not limited to the particular details of construction of the example illustrated, and it is contemplated that various and other modifications or applications will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modificati-ons and applications as do not depart from the true spirit and scope of the invention.

What I claim as new and `desire to secure by Letters Patent of the United States is:

1. A control means for an automatic dishwasher comprising:

(a) a timer motor,

(b) a first group of cams operated by said timer motor,

(c) a first group of switches operated by said first group of cams,

(d) a second group of cams operated by said timer motor,

(e) a second group of switches operated by said second group of cams, and

(f) a manually operated selector switch in electrical series circuit with said rst group and said second group of switches whereby actuation of said manually operated selector switch will determine which of Said first group of switches will be in operative relationship with said second group of switches,

(g) said first group of switches including one switch operated by a cam configurated to maintain said one switch closed only long enough to allow said second group of switches to conduct the dishwasher through the first several steps of a complete wash cycle whereupon said one switch is opened to thereby terminate the admission of electrical power to said second group of switches.

2. A control means for an automatic dishwasher comprismg:

(a) a timer motor,

(b) a first group of cams operated by said timer motor,

(c) a rst group of switches operated by said first gro-up of cams,

(d) a second group of cams operated by said timer motor,

(e) a second group of switches operated by said second group of cams, and

(f) a manually operated selector switch in electrical series with said first group and said second group of switches whereby actuation of said manually operated selector switch will determine which of said first group of switches will be in operative relationship with said second group of switches,

(g) said first group of switches including one switch operated by a cam configurated to maintain said one switch closed only long enough to allow said second group of switches to conduct the dishwasher through the first several steps of a complete wash cycle whereupon said one switch is opened to thereby terminate the admission of electrical power to said second group of switches,

(h) said first group of switches further including a second switch in electrical series with said timer motor and operated by a cam conligurated to maintain said second switch closed for a period of time equivalent to a complete wash cycle to thereby allow said timer motor to return to the same position irrespective of the setting of saidY manually operated selector switch.

3. In a dishwasher of the' type described, a control means comprising:

(a) a timer motor,

(b) first and second groups of cams 4operated by said timer motor,

(c) first and second groups of switches operated by Isaid first and said second groups of cams respectively,

(d) said second group of switches including:

(aa) a first switch to control a valve,

(bb) a second switch to control a spray apparatus,

(cc) a third switch to control a drain means,

(dd) said first, second and third switches normally operating to control the valve, spray apparatus and drain means in sequential operation to achieve a full wash cycle of the dishwasher,

(e) said first group of switches including a rinse and hold switch in electrical series with all of said first, second and third switches of said second group, and

(f) a manually operated selector switch including one switch in series with said rinse and hold switch and a second switch in parallel with said rinse and hold switch whereby actuation of said selector switch will determine` whether said rinse and hold switch is operatively associated with said second group of switches.

4.y In a dishwasher of the type described, a control means comprising:

(a) a timer motor,

(b) first and second groups of cams operated by said timer motor,

(c) first and second groups of switches operated by said first and said second groups of cams respectively,

(d) said secondgroup of switches including:

(aa) a first switch to control a valve,

(bb) a second switch to control a spray apparatus,

(cc) a third switch to control a drain means,

(e) said first group of switches including:

(aa) a timer switch to control admission of power to said timer motor,

v (bb) a rinse and hold switch in electrical series with all of said first, second and third switches of said second group, and

(f) a manually operated selector switch including one switch in series with said rinse and hold switch and a second switch in parallel with said rinse and hold switch whereby actuation of said selector switch will determine whether said rinse and hold switch is operatively associated with said second group of switches,

(g) said timer switch being controlled by a cam configurated to maintain said timer switch closed for a period' of time equivalent to a complete wash cycle to thereby allow said timer motor to return to the same position irrespective ofthe setting of said manually operated selector switch.

5. A control means for an automatic dishwasher comsaid second timer operated switch and said additional v timer operated switches whereby actuation of said manually operated selector switch will determine whether said first timer operated switch or said second timer operated switch will be in operative relationship With said additional timer operated switches,

(f) said first timer operated switch being closed by said timer motor only long enough to allow said additional timer operated switches to conduct the dishwasher through the first several steps of a complete wash cycle whereupon said first timer operated switch is 4opened to thereby terminate the admission of electrical power to said additional timer operated switches.

6. A control means for an automatic dishwasher comprising:

(a) timer means,

(b) a manually operated selector switch including at least a iirst manually operated switch and a second manually operated switch,

(c) a first timer operated switch in electrical series circuit with said first manually operated switch,

(d) a second timer operated switch in electrical series circuit with said second manually operated switch, and

(e) additional timer operated switches in electrical parallel circuit with each other and in electrical series circuit with both said first timer operated switch and said second timer operated switch,

(f) said first timer operated switch and said second timer operated switch being in electrical parallel circuit with each other,

(g) said first timer operated switch being closed by said timer means only long enough to allow said additional timer operated switches to conduct the dishwasher through the first several steps of a complete wash cycle whereupon said first timer operated switch is opened to thereby terminate the admission of electrical power to said additional timer operated switches.

References Cited by the Examiner UNITED STATES PATENTS ORIS L. RADER, Primary Examiner.

CHARLES A. WILLMUTH, Examiner. 65 R. L. BLEUTGE, W. SHOOP, Assistant Examiners.

Claims

6. A CONTROL MEANS FOR AN AUTOMATIC DISHWASHER COMPRISING: (A) TIMER MEANS, (B) A MANUALLY OPERATED SELECTOR SWITCH INCLUDING AT LEAST A FIRST MANUALLY OPERATED SWITCH AND A SECOND MANUALLY OPERATED SWITCH, (C) A FIRST TIMER OPERATED SWITCH IN ELECTRICAL SERIES CIRCUIT WITH SAID FIRST MANUALLY OPERATED SWITCH, (D) A SECOND TIMER OPERATED SWITCH IN ELECTRICAL SERIES CIRCUIT WITH SAID SECOND MANUALLY OPERATED SWITCH, AND (E) ADDITIONAL TIMER OPERATED SWITCHES IN ELECTRICAL PARALLEL CIRCUIT WITH EACH OTHER AND IN ELECTRICAL SE-