US2604497A

US2604497A - Washing machine control circuit

Info

Publication number: US2604497A
Authority: US
Inventors: Harold E Morrison
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 1946-04-26
Filing date: 1946-04-26
Publication date: 1952-07-22
Anticipated expiration: 1969-07-22

Description

July 22, 1952 H. E. MORRISON WASHING MACHINE CONTROL CIRCUIT 2 SHEETS-SHEET 1 Filed April 26, 1946 fiYI EHZEF HamZaE MOP/Z3072 by 75%;. W E7575 July 22, 1952 v I 'H E. MORRISON,

' WASHING MACHINE CONTROL CIRCUIT 2 SHEETS-5HEET 2 Filed April 26, 1946 INVENTOR. jFh roZa E fifow-z'san Patented July 172, 1952 WASHING MACHINE CONTROL CIRCUIT Harold E. Morrison, St. Joseph, Mich, asslgnor to Whirlpool Corporation, a corporation of New York Application April 26, 1946, Serial No. 665,280

3 Claims. 1

This invention relates to a washing machine control circuit and more particularly to control circuits of automatic washing machines having a'storage pump associated therewith for returning suds water previously used to the washing machine tub.

One of the principal features and objects of the present invention is to provide a control circuit for an automatic washing machine which includes the main washing machine motor, a timer motor, and a storage or suds pump motor, and in which the timer motor is always energized either in series with the main washing machine-motor or in series with the suds pump motor.

A further object of the present invention is to provide a novel energization circuit for the timer motor of an automatic laundry machine.

Another object of the present invention is to provide a novel energization and control for a pump motor associated with an automatic washing machine.

Still another object of the present invention is to provide novel safety means for substantially eliminating the possibility of burning out the pump motor of a laundry machine.

Still another and further object of the present invention is to provide a novel control circuit for an automatic washing machine in which means is provided for manually selecting the liquid level in the washing machine tub when desired.

The novel features which I believe to be characteristic of my invention are set forth with particularity. in the appended claims. My invention itself, however, both as to its organization, manher of construction and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of a novel control circuit embodying the novel features and characteristics of the present invention;

Figure 2 is a diagrammatic representation of the washing machine and storage tub; and

Figure 3 is a schedule setting forth the sequential operation of the device.

The washing machine l0, which is diagrammatically illustrated as embodying the novel features of the invention, includes a main washing machine motor H which is preferably a split phase induction motor and is of such a size as to oscillate an agitator l2 in a clothes basket 13 of the washing machine l0. Fresh water admission to the tub 14 m which the as awi l a d the 2 clothes basket l3 are disposed is under the control of a solenoid l5 and a solenoid l6, which when energized opens suitable valves arranged to admit water to tub H at two different predetermined elevated temperatures, or a mixture thereof. Since the structure of the fresh water valve admission mechanism forms no partof the present invention, it has only diagrammatically been referred to. Any suitable conventional structure may be used such, for example, .as that illustrated in the Breckenridge Patent No. 2,296,266, entitled Liquid Mixing Device," issued September 22, 1942. j

The agitator I2 is arranged to be operated about a vertical axis and is controlled by a solenoid which, when energized, mechanically connects the agitator with the drive mechanism from the main motor H, such, for example, as in the manner described in the copending application of Peter Eduard Geldhof and Luther Ringer, Serial No. 491,618, filed June 21, 1943, now Patent No. 2,521,158, entitled Automatic Washing, Rinsing and Drying Machine, and assigned to the same assignee as th present invention. Thus for operation of the agitator l2 both the agitator control solenoid I1 and the main motor H must be energized.

The basket I3 is arranged to be rotated at a relatively high speed by the motor II about a vertical axis coincident with the axis of oscillation of the agitator [2. This operation is effected by energlzation of a solenoid 35 which connects the basket IS with the drive mechanism from the motor H, such, for example, as in the manner described in the copending application of Peter Eduard Geldhof and Luther Ringer, Serial No. 491,618, filed June 21, 1943, entitled Automatic Washing,Rinsing and Drying Machine, and assigned to the same assignee as the present invention. 4

The washing machine [0 is also equipped with a pump l8 which is always in open communication with the tub M. The discharge side [9 of the pump I8 is connected to a hose 20 which leads through a two-way valve 2| and a hose 22m 2. suds pump 3i and to a discharge nozzle 23, the suds pump 3| being disposed in a. storage compartment 28 and the discharge nozzle being disposed over a drain compartment 29 having a drain 24 in the bottom thereof. These compartments or

chambers

28 and 29 may conveniently be a set of ordinary household wash tubs 21 with the drain in the compartment 28 stopped up to form a storage compartment. I This arrangement ,QI the pump "and two-way'valve is only diagrammatically illustrated since the structural features and arrangement per se are described and claimed in the copending application of Peter Eduard Geldhof, Luther Ringer, and myself, Serial No. 630,032, filed November 21, 1945, now Patent No. 2,562,610, entitled Self-Priming Pumping System, and assigned to the same assignee as the present invention.

Attention is called to the fact that the elevation of the two-way valve or the elevation of the high point of the hose 22 of the nozzle 23 is such that it is higher than the maximum desired water level of the tub I4. Thus, while the intake side of the pump I8 is in open communication with the sump 26 in the bottom of .thetub I4,'the water nopending application of PeterEduard Geldhof and Luther Ringer. SerialNo. 619,192, filed-September 28, 1945. now Patent ,No. 2,540,72 i,entitledfControl Mechanism forWashing Machine,

nndnssigned to.:the.same.cassignee as the present invention. Thus'operationof the pump I8 depends upon two conditions'being filled; namely, motor II must be running and solenoid 'IImust :be deenergized.

The intake 32 of .the snclsipump 3I is adjacent thebottom of .the; storagezcompartment 2 8. The suds pump 3i is:driv.en-by the motor-3.0 and israrrangedtopump suds water back from the stor g compartment: 2 8. through the hose 22, the twoway'valVe'ZI, the'hose zo-and'the'pump. 1- and hose- 25, to the tub I4 of thewashing machine TIL? While the complete cycle. of operation will be discussed in detail when the detail operation of the control: circuit of Figure lis described, itmay 'besaid at this time-that ingeneral he clothes are placed in the basket I 3*within the tub 14, and washed therein. After the washing the suds water is pumped by thepump I8 to the storage compartment, the two-way valvetl being energized 'so'that the valve member thereof placesrthe hose connection 22 in communication iv ith the hose 20. The baskel'rlt is then rotated at hig'h speed to extract'waterriitom the clothes. The :tu'b I4 is then filled with .:fresh water and theclothes are rinsed. Afterrinsing. the fresh wateris discharged by the pump I8- through the two-way valve; 2I, through the discharge nozzle 23 oversthe drain tub 29., the-two-way valve 2| being deenergized during this stage so that the valve member 33 is in its dotted line position, as shownin Figure 2.- The basket is thenrotated ngain'atihigh. speed to extract water from the clothes. When a new batch of clothes-isto be washedrthe Isuds. water, which has been stored in the; storage compar m nt-2 is p p back into 'the tub I4-by the suds pump 3| driven by themotorfifl. 1

.I'Thelwashing machine II) has three motors which are associated therewith; namely,' the mainwashing machine-motor I I, which is a split phas induction motor; thesuds pump or storage :pumpniotor- 30, which is a. small series commutator motor; and synchronous motor 34, which 'isrthetimer motorfor controlling the sequential operation "of the automatic washing machine.

These three motors, I I, and 34, are very different in their impedance characteristics, and as will presently be pointed out, advantage is taken of the fact that the impedance of the synchronous motor 34 is relatively high as compared with the impedance of either the induction motor II or the series commutator motor 30. Thus, if an E. F. is impressedacross the synchronous motor 34 and theinduction'motor II, with these two motors in series, the synchronous motor 34 will be driven, but the induction motor II will not be driven due to the relatively low voltage drop across the induction motor as compared with the synchronous motor. The fact that the induction motor I I is not running will not affect the operation of the synchronous motor 34. Similarly, if the synchronous timer motor 34 is connected in series with the storage pump or suds pump motor 30 and an E. M. F. is impressed across the two of them while in series, the timer motor will run but the suds pump or storage pump motor 38 will not run. Furthermore, due to the very low impedance of the series motor, there will not be any excessive heating of this motor even though it stands idle and the current to the synchronous flows therethrough.

One of the principal features-of the present invention is to provide a novel automatic control circuit wherein safety-means is providedto prevent overheating and burning out of the suds pump motor and particularly wherein the sequential timer control mechanism will creep over into the next operationstage if ther is an insufficient supply of sudsy water in the storage compartment to raise the upper float of the washing machine, and which will bring in additional fresh water to make up the deficiency.

Referring now-particularly to Figure 1 of the drawings, the automatic sequential operation of the Washing-machine I0 is under the control of a plurality of cam operated switches 36- to 42, which are arranged to be actuated by a plural ity of cam disks 43 to 49 respectivelmall mounted on a cam shaft50 driven by the synchronous timer motor 34. Switches 3'! and 39v to 42- have single stationary contacts'iiI and 53 to 56 associated therewith respectively. Switch '36 has a lower contact 51 and an:upper'contact 58, while switch 38 has a lower contact 52 and an upper contact 95. In this connectionit will be noted that the

cam disks

43 and 45 not only have notches or depressed portions in the peripheral surface thereof; but also have raised portions 58 and 94 respectively, which are arranged to raise the switches 36 and'38'into engagement with the upper contacts 58 and 35.

The cam shaft 59 is also provided with a bridging contact 60'which closes across the gap between the contacts GI and E2. Theshaft 58 is axially movable so as to disengage th bridging contact 60 from the stationary contacts 60 and (H to open the entlrecontrol circuit. The

shaft 50 is provided with acontrol knob 63 which enables the shaft 50 to be axially moved to position the bridging contact into and out ofengagement with the stationary contcats El and 52', and is also arrangedto advance the cams in a counter-clockwise direction as viewed in- Figure 1 of the drawing, which is the direction of normal rotation of the cam shaft 50 by the synchronous motor 34.

Energy is supplied to the control circuit through a pair of

power supply conductors

64 and 65 which are connected to the terminal block 66. The power supply conductor 65 is connected to switch 35.

the stationary contact 5|. The return circuit to the power supply conductor G4 is through the conductor 61, which, for purposes of this discussion, may be considered as the grounded side of the control circuit. Two float operated switches, 65 and 69, are provided for the washing machine 10. The float operated switch 68 is the upper fluid level control and the float operated switch 69 is the lower fluid level control. These two switches 68 and 69 are diagrammatically represented as being actuated by the upper fluid level float I0 and the lower fluid level float H. The lower level float H is positioned so as to b in its lowermost position only when the tub I4 is substantially empty. The float switches 68 and 59 are provided with upper contacts '12 and 13 respectively and with

lower contacts

14 and 15 respectively. The movable contact arm 68 of the upper float 1c is connected to the power supply conductor 55 through a switch 76, conductor Ti, bus 18, bridging contact 60 and conductor 79.

The hot and mix fluid control solenoids l5 and i6 are connected through a pair of manually operable switches 80 and BI respectively, which are actuated by a pair of

cams

82 and 83 mounted on a, control shaft 84 which may be turned by the knob 35. I'he cam 82 is provided with a pair of notches 86 and 81, while the cam 83 is provided with a pair of

notches

88 and 89. 31 and 88 are angularly aligned and for that reason it will be apparent that when the control shaft 84 is in one position only switch is closed; while in asecond position switches 88 and 8| are closed; and while still further and in a third position only switch 8| is closed. It will thus be apparent that water may be supplied to the tub M at ony one of three different temperatures as selected by the control knob 85.

Switch 80 is connected to the stationar contact 52 associated with the cam disk 45, while switch ill is connected to stationary contact 54 associated. with the cam disk 4'1.

It will thus be seen that the hot and warm fluid solenoids l5 and 55 are under the control of the cam switches 38 and Mi. Warm fluid solenoid I5 is also under the control of the cam switch 35, for the lower end of the solenoid i6 is directly connected to the

stationaryfcontacts

51 and 58 associated with the The agitator and pump control solenoid is connected to the stationary contact El and is under the control of the switch 31. The lower end of the extractor solenoid 35 is directly connected to the lower contact 55 of the low level float switch 68. The movable float switch 69 is connected to the stationary contact 55 of the cam switch 4! and also to the midpoint 90 between. the main motor I9 and the synchronous motor 34. The lower side of the two-way valve solenoid '2! is connected to the stationary contact 53 or the cam switch 38 and also to contact -65 of switch 38.

The lower side of the suds motor 30 is connected through a conductor 9| to the timer motor 'parison thereof with the schedule as illustrated in Figure 3 will show that the cam shaft 5!! has just passed the suds pump stage of the operation of the complete cycle and is at the point where additional water will be introduced into the tub if the suds water has not raised the liquidilevel to a height sufiicient to raise the top float Hi. It

.is not deemed necessary to illustrate the cams in The notches all of their diflerent relative positions during the successive stages of the cycle of operation, for the following description of the operation will be sufficientto understand the operation of the control circuit.

Assume that the cam shaft 50 has been rotated to a point where the cam switch 42 has just dropped into the cam recess 93 so as to close the switch 42 against the contact 58 and that the cam shaft 50 has been moved axially so as to close the bridging contact 60 across the contacts 6i and 62. With the cam shaft 50 in this particular position, the elevated portion 94 of the cam 45 has come into engagement with a depending engaging portion of the switch 38 and raised the switch 38 into engagement with an upper contact 95 which is connected to the lower side of the two-way valve 2| through conductor 5 B3. The cam 44 has also caused the cam switch 31 to close against the stationar contact 5|; the remaining cam switches 36, 39, 49 and 4| being open.

The manual switch I6 is normally in the full line position as shown in Figure 1 of the drawlugs, and is only moved to its dotted line position in a manner hereinafter to be described to eliminate the operation of the top float and control the water height inthe tub. Let it-also be assumed thatthe control knob is in the position as shown in Figure 1 of the drawings so that switches 89 and 8| are both closed.

Thus in thi initial position of the elements of the control circuit 5| the suds pump 38 is energized from the conductor 65 through conductor l9, bridging contact fill, conductors "l8 and i, switch it, float switch 58, lower contact 14 of the upper float switch 68, conductor cam switch 42 and conductor 92, to one side of the ends motor 31' The other side of the suds motor 39 is connected to the return conductor 61 to the other supply conductor 64. The two-way valve 2! is also energized through the upper contact 55 of the cam switch 38, the power therefor being obtained from conductor 65 through conductor T9, bridging contact 50, conductors J8 and ii, switch '56, float switch 68, lower contact 14, conductor 96, bus 91, cam switch 38, upper contact 95 and conductor N19 to the lower side of the two-way valve 2|. 7

The other side of the two-way valveZl is connected to the return conductor 61. The energization of the two-way valve 2i is of course necessary to place the hose connection 22 from the pump 37% into connection with the hose 2%) which is the return path for the suds water.

after the top float T9 raises to close the float switch 63 against the upper contact i2. That means that the agitator does not start to oscil late until after the desired water level has been reached within the tub M. When the top float it rises to close the float switch68 against the upper contact l2 the agitator control solenoid I! is energized from the supply conductor 65, the conductor 19, bridging contact Gil, conductors iii and Ti, switch Hi, top float switch 53, contact 72, conductor 98, lower float switch 69, upper contact 13 of lower float switch 69, conductor 99, cam switch 37 and conductor I88, to the lower side of the agitatorcontrol solenoid The other side of the solenoid l"! is connected to return conductor. 61.

This means that while the cam switches are still closed in the. manner above describe the ends pump. and the two-way valve. H are. energized to. pump water back: into h t b. and that. after the: waterlevelin. the. tub has reached the desired height, the agitator is placed into operation. Since; the two -wey valve ZI, and the suds pump motor 30 are both enersi ed h oue the top float switch while it is in its lower position it will be apparent that as the top float switch 68 moves ofi of; the lower contact 1 4, the two-way valve 2 I and the suds pump motor 30 are deenerg-izedg It will be observed that during the time that the suds pump motor; is being energized through the cam switch 42, the synchronous timer motor 34 is connected in series with the split phase induction motor [I across the line. More par-. ticularly, it has already been pointed out that the conductor 92, during this stage of the operation, is inconnection with the supply conductor 65. Since the upper side of the synchronous timer motor is connected to the com ductor 552 through the conductor 9|, it will be apparent that the synchronous motor is connected in series between the conductors 92 and 61 which are in turn connected to the power supply conductors 55- and 64. This causes operation of the synchronous motor 34-to rotate the cam shaft 50. It will be, remembered that the synchronous motor 34 has a relatively high impedance as compared with the split phase induction motor II so that during this stage of the operation the induction motor II does not have a suflicient voltage impressed thereacross to cause operation thereof.

At the time when the top float switch 60 is raised from its lower position to its upper position the induction motor II is energized from supply conductor 65, conductor I9, bridging contact 60, conductors l8 and TI, switch It, float switch 68, top contact I2, and conductors 90, III and I to the upper side of the motor II. The lower side of the motor II is.connected to the return conductor 61. c

It will be observed that if some additional connection is not provided for the timer motor 3-4, its operation would cease at this point. It will be noted, however, that at this time the synchronous motor is connected in series with the suds pump motor across the line. The power connection, from the supply conductor 65 up to the point 90 has been traced. From here it passes through the synchronous motor 34, conductor SI and suds pump motor 30 to the return conductor '61. It will thus. be observed that the timer motor continues to rotate the cam shaft 50 although it is now being energized serially with the suds pump motor 30 rather than with the induction motor II. Since the relative impedance of the timer motor 34 is very high with respect to the commutator motor 30, the commutator motor 30 does not have a sufficient voltage impressed thereacross to cause operation thereof.

From the above it will be apparent that irrespective of whether there is suincient water stored in the storage compartment 28, the timer motor will continue to operate to advance the cam shaft 50 out of the first stage or cycle of operation of the washing machine I0. The second stage in the cycle of operation is the stage reached when the cam switches are in the position as shown in Figure 1 of the drawings. At this time the two-way valve 2I and the suds pump motor 30 have been deenergized, but the agitator cam switch 31 is still in engagement 8v with th st t a y ta w ch n nected to the agitator control solenoid I'I through the conductor I08.

At this point in the cycle of operation earn switch 38 has dropped into engagement with the lower stationary contact 52 which is connected, in turn, to the switch associated with the hot fluid inlet solenoid I5. Cam switch 40 has simie larly dropped into engagement with the station? ary contact 54 which is connected to the switch BI associated with the mixed fluid inlet control solenoid I6. Since power to the cam switches 38 and 40 is obtained through the top float switch 68 being in engagement with the lower contact I4, it will be apparent that if the suds water returned from the storage compartment 20 has not been sufiicient to raise the top float I0, then the solenoids I5 and I6 are energized through the cam switches 38 and 40 to introduce addi; tional water to the tub. This introduction of additional water continue until the top float I0 is raised.

Whether or not one or the other, or both, of the solenoids I5 and I6 are energized, will, of course, depend upon the relative position of the control knob which determines the temperature of the water being introduced into the tub.

After the top float I0 has been raised, either by the addition of fresh water under the control of solenoids I5 and I6, or by admission of sumcient suds water in the original instance, the agitator continues to operate for the length 01' time determined for the washing cycle. As shown by the cam, this will continue until the cam 44 has been rotated sufficiently to separate the cam switch 31 from the stationary contact 5 I. At this same time the cam switch 39 falls into engagement with the stationary contact 53 to energize the two-way valve 2| from the bottom bus 18 through conductor I09. At this point in the operation the cam switch 38 is returned to an intermediate position which is out of engagement with both of its stationary contacts. The cam switch, at this time, has also been lifted out of engagement with its associated contact 54. Also, we find that cam witch II has now dropped into engagement with its associated stationary contact 55.

By virtue of the fact that the cam switch H has closed against the stationary contact 55, the main motor II is directly energized from supply conductor 65 through conductor I9, bridging contact 50, bus 18, cam switch 4| and conductor I00 on one side and through conductor 61 to supply conductor 64 on the other side.

As has previously been pointed out, when the agitator solenoid I1 is deenergized and the motor II is in operation, the pump I8 is placed into operation to pump water from the pump I4 through the hose 20 in the two-Way valve II to the storage compartment 28. As the water level in the tub falls the top float switch drops to its lower position against stationary contact 14. After substantially all of the water has been pumped from the tub I4 so that the bottom float II causes the float switch 69 to close against the stationary contact I5, the extractor solenoid 35 is energized. This energization is from the supply conductor 65, conductor 19, bridging contact 60, bus 18, cam switch 4i, contact 55, conductor IOI, lower float switch 69, contact 75. and conductor I02 to one side of the solenoid 35. The other side of the solenoid 3'5 is connected to the return conductor 61. Upon energization of the solenoid 35 the basket I3 is rotated at high speed by the motorIL, Duringthis period the synchronous motor 34 continues to rotate through its series connection with the pump motor 30'.

While the basket I3 is rotated at high speed, the cut out portion I03 of the cam disk 43 moves under the cam follower I04 of the cam switch, 36. The cam switch 36 does not immediately; fall, however, against the lower stationary contact 51, for it is held in place by the small cam I05. This small cam I05 is a disk having a flattened portion I thereon, and the cam I is rotated by the synchronous motor 34.

During the time that the cut out portion I03 is under the cam follower I04, the flattened portion I00 rotates into a position opposite the tail I01 of the cam switch 36 and permits the cam switch 36 to close. This is for a spray rinse operation, for it introduces water into the basket while the basket is rotating at high speed. The introduction of water is only momentary.

It will be observed that all of the time that the agitator solenoid 35 is energized and the main motor I0 is energized, the pump is operating to continually pump water out of the bottom of the tub I4.

After the end of the first extractor period the cam switch 4i opens by virtue of the high point I08 on the cam disk 48. At this time the high point 59 on the cam disk 43 also raises the cam switch 36 to close it against the upper contact 58. Furthermore, at this time, the cam switch 31 closes again to connect the agitator solenoid I1 to the conductor I08 which is energized only through both float switches 68 and 69 in their upper positions.

At this point in the cycle of operation the timer motor 34 is not energized and hence water under the control of the solenoid I5 is introduced into the tub. This continues until both of the floats I0 and 'II are raised. At this time the agitator control I I is energized, as is also the timer motor 34, the latter being energized through the top float switch 68 and conductors IM and I00 in series with the suds pump motor 30. This is the deep rinse stage of the cycle of operation of the automatic washing machine I0. At the end of this stage in the cycle of operation the agitator I1 is deenergized and the main motor I I is again energized through the cam switch 4|. It will be noted that at this time, however, the two-Way valve 2| is not energized. Thus the water which is pumped from the hub I4 now is discharged into the drain compartment 29 where it fiows by gravity out through the drain pipe 24. The timer motor 24 is energized during this stage through the cam switch 4| and in series with the suds pump motor 30.

After all of the water has been pumped out so that the lower float switch 69 closes against the lower stationary contact '15, the extractor is energized through the cam switch 4| and the float switch 69. At the end of this operation the cams move to a position where all of the cam switches are open, and in this position no power is supplied to any of the motors II, 39 or 34, nor to any of the control apparatus, and the cycle of operation is complete.

If only a few items are to be laundered in the tub I4, it is desirable to arrange the control circuits so that a full tub of water is not required, but which will enable the other automatic portions of the cycle of operation to be carried forward. This is accomplished by the switch 15. When the operator of the machine has observed that the liquid level has reached a accent? 10' sufiicient. height to satisfactorily launder .the few items desired, the manually operated switch 16 is thrown from its full line position to its dotted line position as shown in Figure 1 of the drawings. This has the same efiect'as though the to'p' fioat switch 58' had moved to its upper position against the stationary contact I2. Otherwise the circuit is the same.

It will be observed that the provision of the upper contact oncam switch 30 andthe energization of the two-way valve -2I therethrough instead of through its separate cam switch 39 provides an antisyphoning arrangement for the time when the suds motor 30 is deenergized. The reason is that the two-way valve 2I is deenergized at the same time the suds motor 30 is deenergized.

From the above description it will be observed that one of the peculiar and novel characteristics of the present invention lies in the manner in which the timer motor is energized serially either through the main washing machine motor or through the storage pump motor. The many other and further features of the novel control circuit and control mechanism are apparent from the foregoing description, and as will be obvious to those skilled in the art, provides an extremely simple and eflicient control mechanism for a complicated and detailed cycle of operation of an automatic washing machine.

The schedule of cyclic steps in the operation of the automatic washing machine is exemplified by the diagram shown in Figure 3 of the drawings, and with the aid of this diagram the ready understanding of the operation of the control mechanism will be greatly enhanced.

While I have shown a certain particular embodiment of my invention, it will, of course, be understood that I do not wish to be limited thereto, since many modifications may be made, and I contemplate, by the appended claims, to cover all such modifications as fall within the true spirit and scope of my invention.

I claim as my invention:

1. A control circuit for a machine having a pair of motors which are selectively and automatically operated one at a time, sequence switch control means, a timer motor for driving said sequence switch control means, said timer motor having an impedance of many times the impedance of either of said motors of said pair, means for energizing one of said motors of said pair while said timer motor is energized serially through the other of said motors of said pair.

2. A control circuit for a machine having a first motor and a second motor which are selectively and automatically operated one at a time, sequence switch control means, a timer motor driving said sequence switch control means, said timer motor having an impedance of many times the impedance of either of said first two motors, means for energizing said first motor while said timer motor is energized serially through said second motor, and means for energizing said second motor while said timer motor is energized serially through said first motor.

3. A control circuit particularly adapted to control the sequential operation of a washing machine having a drive motor of a low impedance for carrying out certain operations of the machine, sequence switch control means, a timer motor for driving said sequence switch control means, said timer motor having an impedance many times the impedance of said drive motor, means including said sequence switch control 11 12. means energizing said drive motor in series with i said tinier motor to stop .said drive motor ,while said timer motor continues to operate and ener- Number Name t s ing said drive motor i parallel with Said 2,029,335 Oberhofiken et a1. EebA, 1936 timer motor 150 operate said low impedance drive 5 2,225,407 B s t Dec. 17, 1950 motor with said high impedance timer motor. "23915 1 g 'dfi a 25 1 45 HAROLD O S {2,395,591 Staples 'et a1. Feb. 26, 1946 21425;788 Edwards Aug. 19, 1947 FER NG I ED '2; 144,s45 Geldhof et a1. J'u1y s, 1948 The following references are of record in the 10 2 98, 88 Gl d hof et :1. J Feb. 28 119 50 gne" g: isms paten