US3124146A

US3124146A - Rinse

Info

Publication number: US3124146A
Authority: US
Publication date: 1964-03-10
Anticipated expiration: 1981-03-10

Description

March 1964 1-. E. JENKINS ETAL 3,

DRAIN CONTROL SYSTEM FOR A WASHING MACHINE 2 Sheets-Sheet 1 Filed Oct. 29, 1962 INVENTORS THOMAS E. TEMKlNS N A M F F U A K R m w a M b THEJR ATTORNEY Ma h 1964 T. E. JENKINS ETAL 3, 4, 46

DRAIN CONTROL SYSTEM FOR A WASHING MACHINE Filed Oct. 29, 1962- F'lG.3

AUSE PAUSE F'lG.4

INVENTORS THOMAS E. JENKINS B & MELVIN R. KAUF'FMAN THEIR ATTORNEY United States Patent 3,124,146 BRAEN CQNTR'UL SYSTEM FOR A WASHING MACHINE Thorn-as E. .lenlrins and Melvin Kauilinan, Louisville,

Ky, to General Electric Eornpany, a corporation of New York Filed Get. 29, 1962, Ser. No. 233,683 2 (Jlaims. (El. 134-57) This invention relates to control systems for washing machines, and more particularly to an improved arrangement, for use primarily in dishwashers, to prevent occurrence of the undesirable noise which results from op eration of the drain pump after substantially all liquid has been drained out of the machine.

It is an object of our invention to provide a washing machine in which, after a washing operation is provided, the forced drain out operation will be provided only as long as there is need for it.

in one aspect of our invention we provide a washing machine of the type which has an automatic washing cycle. in the usual way, the machine has a tub, washing means for washing articles in the tub, and a drain pump for removing vitiated liquid from the tub together with a drain conduit connected to the pump. Suitable sequence control means are provided for causing operation of the washing means and then operation of the pump, with this sequence being repeated a predetermined number of times until the sequence control means shuts the machine oil. Together with the foregoing, we provide flow responsive means which is effective, when the drain pump operates, to terminate operation of the drain pump when there is no further liquid to be removed by the pump. This is effected, preferably, by having the flow responsive means control a switch in a circuit for causing operation of the drain pump, with the sequence control means giving up control of the drain pump for a predetermined period to the flow responsive means each time after the drain pump has been started.

In the drawings, FIGURE 1 is a side elevational view, with some of the parts broken away to illustrate details, of a dishwasher incorporating our invention;

FEGURE 2 is an enlarged view in cross section showing part of the structure of FIGURE 1;

FKGURE 3 is a schematic electrical wiring diagram illustrating our improved control system in one form thereof; and

FIGURE 4 is a sequence control cam chart illustrating the sequence of operation of the schematically shown switches of FIGURE 3.

Referring now to FTGURE 1, there is shown, for illustrative purposes, a portable automatic dishwasher ll, although our invention will be understood to apply equally well to built-in machines. The dishwasher has a dishwashing compartment 2 formed by a tub 3 with a top opening 4; adapted to be closed by a cover 5 hingedly mounted at the rear of the machine by an assembly 6. The bottom of the tub may have a downwardly sloped portion '7 formin a sump at the center thereof. Tub 3 may have side walls which continue down almost to the base or the floor on which the machine rests so as to form an enclosure or cabinet for the machine. Also, these walls may support casters 8 in any conventional manner so as to make the machine movable.

Within compartment 2 there may be provided a number of dish supporting members such as an upper rack 9 and a lower rack ill which are designed so as to support dishes and other eating and cooking articles. Dishwasher It incorporates suitable washing means which in this case is embodied in a rotatable water ejecting member 11 positioned below rack ill together with a telescoping member 12 positioned at the center of member 11. When under pressure, member 12 rises somewhat and is provided with apertures in its top so as to eject water with substantial force against dishes in the upper rack 9. At the same time, member ii is rotating under the force of the water and is ejecting that water against the dishes in both racks.

Arm l1 and telescoping member 12 form a part of an assembly 13 which further includes a motor 14. The motor 14 operates a pumping assembly 15 which may be of conventional design and which receives its water through an inlet 16 at the very bottom of sump 7. The motor may be of the type which, when rotated in one direction, causes the pumping assembly to force liquid up through members ii and i2, and which when reversed causes the pumping assembly to act as a drain pump and pass the liquid out to drain, such structures being commercially available and well known to those in the art.

In addition, for drying the dishes after they have been cleansed, a suitable electric heating element 17 may be provided in the conventional manner. The heating element 17, as well as the motor lid and a conventional water inlet valve (not shown in FIGURE 1) will normally be under the control of a sequence control assembly (also not physically shown in FIGURE 1). The assembly may be secured within the hollow front wall 18 of the dishwasher, with suitable manually operable members such as 19 extending so as to be readily accessible to an operator for the selection of a sequence of operations of the machine. A suitable sequence of operations: for the machine is described in connection with PIG- URES 3 and 4 herebelow.

It will be understood that all the components described thus far are conventional, and are provided in dishwashers widely available for purchase by the public.

Connected to the outlet 2% of pump 15, and leading to a drain, is a drain conduit 21 to which there is secured an assembly 22. Referring particularly to FEGURE 2, it can be seen that assembly 22 includes a switch 23 having an operating member or button 24 against which is a diaphragm 25 having its surface 26 constitutin a part of the wall of conduit 21. When there is no flow through conduit 21 the button is in its extended position as shown, and the switch 2 3 has a first position for a purpose to be hereinafter discussed. However, when liquid flow occurs through conduit 21 as a result of a drain operation, then the pressure of that flow causes the diaphragm 25 to move so as to depress button and operate the switch 23.

Referring now to FIGURE 3, there is shown a control circuit embodying our invention. It will be understood that, besides the components specifically shown, other electrically controlled components of the machine, such as suitable indicating lights and detergent and rinse agent dispensers, will often be controlled electrically. These other components have been left out of FIGURE 2 only in order to show clearly the invention without confusing additional details which do not form a part thereof.

The circuit is energized through a pair of supply conductors 27 and across a suitable source of power (not shown) such as the conventional volt 60 cycle source generally available. Connected across the

conductors

27 and 28 is the timer motor 29 of the sequence control assembly previously referred to. As shown schematically in FIGURE 3, this sequence control assembly includes the motor 29 in controlling relationship to a plurality of cams 3%, 31, 32, 33 and 34, with the cams 3tl-34 in turn being in controlling relationship to switches 35, 36, 37, 38 and 39. In addition, the assembly will normally include the manual control switches previously referred to by the numeral 19 in FIGURE 1. Switch 35' is in series with motor 29 across the

conductors

27 and 28 so as to permit energization of the motor 29 when it is closed and prevent energization thereof when it is open. Similarly,

the heating element l? is connected across the conductors 27 and 2S series with switch 56, and a solenoid .55 controlling the water valve of the machine is connected across the conductors 27 and E3 in series with the switch 37.

The motor 14- includes a main winding 41 and a pair of start windings 42 and When winding 41 and Winding 4-2 are energized at the same time, the motor rotates in the direction appropriate to cause operation of the washing structures 11 and 12. When windings i1 and 43 are energized at the same time the motor starts to rotate in the direction effective to cause draining of liquid out of tub 3 through conduit 21. In the conventional manner, a start relay 44 may be provided in series with the winding 41, in controlling relationship to a contact 45 in series with both windings 42 and At a relatively high current level, such as that which iiows through the relay 44 when the motor is not rotating, relay 4 E closes switch 4-5. As the motor comes up to speed, the level of energization drops substantially; as a result, relay 44 lets switch 45 move to its normally open position to insure de-energization of whichever of windings 42 and 43 was energized. Thus, the motor 1 may be caused to start in either direction of rotation, as will be explained, and then will continue to run on the winding 41 alone after it comes up to speed.

The direction of rotation is determined by switch 39 which is movable into engagement with either of two contacts 46 and 47 to provide for selection of start windings 42. or 4-3 respectively. Both the start windings, through switch 39, and the main winding are connected through switch 33 so that the entire motor-energizing circuit is connected across

lines

27 and 28 and is controlled by switch 33. In parallel with switch 38, there is provided the how responsive switch 23 which is, as shown, normally open, but which moves to a closed position in response to pressure within drain conduit 21 on diaphragm 25.

Referring now to FIGURE 4, it will be seen that it is intended that a conventional sequence of operations of the machine includes a first rinse which actually is introduction of water and a brief washing operation; this may either be with or without detergent, and is followed by draining of that water. A second similar rinse and drain are then provided, followed by a wash step which is simply a provision of the washing operation for a longer period of time with, preferably, a suitable detergent being injected. This wash is then again followed by drain and then two rinses and drains follow, after which a drying operation may be provided. This is a typical sequence of operations for a dishwasher.

One ditliculty that has been encountered to date is that, with. the draining operation being provided for a predetermined period of time, the water is almost invariably removed from the machine prior to the end of the drain period. This results, with many types of pumping structures, in a noise which may be objectionable to some extent to the operator. It is an important aspect of our invention that operation of the pump after the liquid has been removed is precluded, thereby preventing any possibility that this objectionable noise will exist. In order to achieve this, the timer-operated switch 33, which normally controls motor operation, is caused to open at the end of the first rinse, as can be seen in FIGURE 4, as a result of the surface configuration of cam 33. This causes the motor to be de-energized, and during this de-en-ergization, as shown by the contour of cam 34, switch 39 reverses its position.

As a result, when switch 33 is reclosed the motor is reenergized but in the opposite direction to the direction in which it rotated during rinse. As previously described, the structure is one in which the motor provides operation of the washing means 111 and 12- when it rotates in one direction, but operation of drain pump 15 during rotation in the opposite direction. Thus, because of the moving of switch 39 from engagement with contact 46 to engagement with contact 47, motor 14 starts up in the direction to efi'ect removal of liquid through conduit 21 when switch 38 is reclosed.

Very shortly after the motor starts this operation, switch 33 is again opened by cam 33. However, because of the flow of vitiated liquid through conduit 21, the diaphragm 25 has caused switch 23 to move to the closed position; as a result, motor 14 remains energized without regard to the position of switch 38. This state of atfairs continues until all the liquid in tub 3 has been removed tirough conduit 21 by pump 15. At this point, when there is no further liquid being pumped through the conduit, the pressure on diaphragm 25 is relieved and the switch 23 is opened.

The timed period during which switch 38 is open is designed to insure that the switch remains open for a longer period than pump 15 can possibly take to drain tub This means that switch 23 moves to open position at a time when switch 33 is still caused to be opened by cam 33. As a result, the motor 14 is completely de-energizcd and remains so during the remainder of the first drain period.

Before the end of that drain period, switch 39 is again moved by cam 34 back to its original position, and at the end of the drain period switch 38 is re-closed thereby to give another rinsing operation. At the end of the second rinse, the same thing occurs as before with respect to the drain pump. That is, the timer causes the drain pump to start and then releases its control of it so that the drain pump terminates operation as soon as all the vitiated liquid has been removed through conduit 21, this being done under the control of switch 23. It will be observed that this sequence is followed during each drain operation throughout the cycle. This insures that the objectionable noise which sometimes occurs as a result of the operation of pump 15 without any liquid being passed through it will not be present; thus, this phenomenon, sometimes found objectionable by operators, is removed from the operation of the machine.

It will be seen from the foregoing that our invention provides a control arrangement which insures that operation of the drain pump will continue only so long as there is liquid to be drained, and will stop thereafter, with the machine remaining completely quiescent, except for the operation of the timer, until the next rinse or wash operation, or the drying operation, is reached.

While in accordance with the patent statutes we have described what at present is considered to be the preferred embodiment of our invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and we therefore aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

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

1. A washing machine to provide an automatic washing cycle comprising:

(a) a tub,

(b) washing means arranged to effect washing of aricles in said tub,

(c) a drain pump to remove vitiated liquid from said tub,

(d) a drain conduit connected to said pump,

(e) sequence control means to control operation of said washing means and said pump,

(1) said sequence control means including a first switch to energize said pump and initiate operation thereof,

(g) said first switch being operated by a cam means which maintains said first switch closed at least until said drain conduit is filled with liquid and then opens said first switch for each operation of said pump,

(it) means responsive to liquid flow in said drain conduit including a normally open second switch cllcctive when closed to bypass said first switch,

(i) said means responsive to liquid flow maintaining said second switch closed only as long as there is flow of liquid through said drain conduit.

2. In a dishwasher:

(a) a tub,

(b) washing means to effect washing of articles within said tub,

(c) a drain pump to remove vitiated liquid from said tub,

(d) a drain conduit connected to said pump,

(e) sequence control means to control operation of said washing means and said drain pump and comprising:

(aa) a first switch to energize said drain pump and initiate operation thereof, and

(bb) cam means configurated to close said first switch until said conduit is filled with liquid and then open said first switch for each operation of said drain pump,

(f) flow responsive means positioned in said drain conduit and including a second switch in parallel with said first switch,

(g) said flow responsive means being elfective to maintain said second switch in closed position only as long as there is flow of liquid through said drain conduit.

References Cited in the file of this patent UNITED STATES PATENTS 2,155,868 Pauly et a1. Apr. 25, 1939 2,288,141 Oliver June 30, 1942 2,953,659 Edwards Sept. 20, 1960 3,043,125 Horecky July 10, 1962 3,087,319 Low Apr. 30, 1963

Claims

1. A WASHING MACHINE TO PROVIDE AN AUTOMATIC WASHING CYCLE COMPRISING: (A) A TUB, (B) WASHING MEANS ARRANGED TO EFFECT WASHING OF ARTICLES IN SAID TUB, (C) A DRAIN PUMP TO REMOVE VITIATED LIQUID FROM SAID TUB, (D) A DRAIN CONDUIT CONNECTED TO SAID PUMP, (E) SEQUENCE CONTROL MEANS TO CONTROL OPERATION OF SAID WASHING MEANS AND SAID PUMP, (F) SAID SEQUENCE CONTROL MEANS INCLUDING A FIRST SWITCH TO ENERGIZE SAID PUMP AND INITIATE OPERATION THEREOF, (G) SAID FIRST SWITCH BEING OPERATED BY A CAM MEANS WHICH MAINTAINS SAID FIRST SWITCH CLOSED AT LEAST UNTIL SAID DRAIN CONDUIT IS FILLED WITH LIQUID AND THEN OPENS SAID FIRST SWITCH FOR EACH OPERATION OF SAID PUMP, (H) MEANS RESPONSIVE TO LIQUID FLOW IN SAID DRAIN CONDUIT INCLUDING A NORMALLY OPEN SECOND SWITCH EFFECTIVE WHEN CLOSED TO BYPASS SAID FIRST SWITCH, (I) SAID MEANS RESPONSIVE TO LIQUID FLOW MAINTAINING SAID SECOND SWITCH CLOSED ONLY AS LONG AS THERE IS FLOW OF LIQUID THROUGH SAID DRAIN CONDUIT.