US3234660A

US3234660A - Dry control apparatus and circuitry for a dry cleaner

Info

Publication number: US3234660A
Application number: US215565A
Authority: US
Inventors: James T Williams; James L Mcconnell
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 1962-08-08
Filing date: 1962-08-08
Publication date: 1966-02-15
Anticipated expiration: 1983-02-15
Also published as: GB1000055A; CH403693A; DE1460348A1; DE1460459A1

Description

1966 J. T. WILLIAMS ETAL 3,234,660

DRY CONTROL APPARATUS AND CIRCUITRY FOR A DRY CLEANER Filed Aug. 8, 1962 3 Sheets-Sheet 1 INYENTORS dam e s 7'. l'Vl/h'dm s dames L M-Uwm e// TORNEYS Feb. 15, 1966 J. T. WILLIAMS ETAL 3,234,660

DRY CONTROL APPARATUS ANDFCIRCUITRY FOR A DRY CLEANER Filed Aug.. 8, 1962 I 3 Sheets-Sheet 2 INVENTORS MIA/07' E S w m X M e mm Odm dames 7. iVM/fams dames A. M-Co/me// mmk mt M A ORNEYS s L m m m E E w T if A? r? 5,4 3

FUNCTION N2 BY-PAS-S I06 T/MEE M736.

ma 115/4 TEE m9 BLOWER CO/VO. PUMP Feb. 15, 1966 J. T. WILLIAMS ETAL 3,234,660

DRY CONTROL APPARATUS AND CIRCUITRY FOR A DRY CLEANER Filed Aug. 8, 1962 3 Sheets-Sheet 5 27 Y X I L J Fig.5 55

I 7 75 7.; gflgo OIIMHV M p mm INVENTORS dame: T 144/001: c/am es LM-Carme United States Patent 3,234,660 DRY CONTROL APPARATUS AND CIRCUITRY FOR A DRY CLEANER James T. Williams, St. Joseph, and James L. McConnell, Stevensville, Mich., assignors to Whirlpool Corporation, St. Joseph, Mich, a corporation of Delaware Filed Aug. 8, 1962, Ser. No. 215,565 Claims. (Cl. 34-45) The present invention relates to an improved apparatus for drying cleaning, and more specifically, to improvements in the field of coin-operated automatic dry cleaning machines.

In a typical coin-operated dry cleaning assembly, the articles to be cleaned are tumbled with a liquid dry cleaning solvent such as perchlorethylene in a washing zone, excess solvent is drained, and then a current of hot air is passed through the articles to vent off solvent. In such systems, solvent recovery is effected by condensing the solvent, filtering and returning the solvent to the Washing zone.

In a typical automatic dry cleaning apparatus, the duration of the wash cycle, the rinse cycle, and the drying cycle are under the control of a master timer mechanism. Such a timer, however, cannot to our knowledge be conveniently modified to take into account variations in the size of the load being cleaned, Thus, it is entirely possible with a small load to have an excessively long drying cycle, with a resultant waste of heat energy and possible adverse effect on the articles themselves. Conversely, with a larger than normal load, the drying cycle may be insufiicient to vent the solvent completely with the result that at the conclusion of the normal timed drying cycle, the clothes may still be damp or may have an objectionable odor of solvent. The retention of solvent in underdried fabrics processed in a publicly operated dry cleaning machine is objectionable from a cost standpoint because of the loss of such solvent and also because the retained solvent in such underdried fabrics, such as rugs and other bulky items, may be offensive or create certain hazards.

It is accordingly an object of the present invention to provide an improved dry cleaning apparatus in which the drying cycle is automatically varied in response to variations in the load being cleaned.

Another object of the present invention is to provide an improved control system for automatically deactivating the timer mechanism employed in automatic dry cleaning assemblies and making the drying interval dependent upon the nature of the clothes load and operation of the vapor condenser incorporated in the dry cleaner.

Still another object of the invention is to provide a mechanism for sensing the rate of flow issuing from the condenser of a dry cleaning apparatus and using this sensing mechanism to control the duration of the drying cycle.

A further object of the invention is to provide a failsafe means for the improved control system.

A still further object of the invention is to provide circuit means for sensing a malfunction in the improved control system during the drying cycle and for automatically completing the dry cycle in the event of a malfunction.

An additional object of the invention is to provide an improved dry control system employing first sequential control means for carrying out a variable time dry cycle and a second sequential control means interconnected by circuitry means to the first sequential control means for overriding the first sequential control means in the case of a malfunction of the dry control system.

Another object of the invention is to provide a dry control system for a dry cleaner which provides for con- ICC tinuous operation of the solvent venting system in the event of a malfunction in the automatic control, thereby substantially eliminating the possibility of recovering solvent-laden clothes in the event of such malfunction.

Still another object of the invention is to provide control circuitry for a drier assembly which compensates by means of overriding circuit elements to eliminate solvent from the articles whenever the load is heavier than normal, or upon the existence of any malfunction which might tend to terminate venting of the solvent prematurely.

Another object is to provide an improved dry cleaning method.

Other objects and features of the present invention will be apparent to those skilled in the art from the following description of the attached sheets of drawings which illustrate a preferred embodiment.

In the drawings:

FIGURE 1 is a somewhat schematic view of the complete dry cleaning assembly;

' FIGURE 2 is a timing chart illustrating the intervals involved in sequence during the operation of the dry cleaning assembly;

FIGURE 3 is a somewhat schematic wiring diagram of the dry control apparatus of the dry cleaning machine;

FIGURE 4 is a plan view of the water separator and float switch assembly employed in the dry control apparatus; and

FIGURE 5 is a cross-sectional view taken substantially along the line VV of FIGURE 4.

As shown on the drawings:

In FIGURE 1, reference numeral 10 diagrammatically indicates generally a casing for receiving the articles to be cleaned and containing a rotatable, perforate drum 11 mounted for rotation on a shaft 12 driven by the motor drive means illustratively shown by numeral -13. An access door 14 is provided to permit introduction of the articles to be cleaned into the interior of the drum 11. The housing 10 is provided with a conically shaped bottom portion 16 Which acts as a sump to collect liquid dry cleaning solvent and discharges it through a line 17 connected thereto. Dry cleaning solvent is fed to the housing 10 by means of a line 18 so that it is injected onto the contents of the drum 11 during the wash cycle. A heater 19 is also located within the housing 10 and serves to heat air entering the drum 11 for drying purposes during the drying cycle.

Solvent vapors are vented from the housing 10 by means of a conduit 21 located at the rear of the housing 10 and feeding a condenser assembly generally indicated at 22 in the drawings. Solvent laden air vented from the housing 10 passes through a lint filter 20 and a condenser 23, normally of the tube and fin type, by the action of a blower generally indicated at numeral 24 in the drawings. The air is then directed through a conduit 26 past the heater 19 back into the housing 10, while the condensed solvent is withdrawn through a line 27 for purposes which will hereinafter be explained more fully.

The unit shown in FIGURE 1 includes a solvent reservoir 28 containing a body of solvent generally indicated at 29. A refrigeration coil 31 is immersed in the solvent body 29 and is cooled by means of a refrigeration unit indicated at 32 in the drawings. Coil 31 and refrigeration unit 32 are coupled as one assembly. This assembly is in an opening in the top 28a of reservoir 28. A submerged pump 33 driven by a motor 34 delivers the cooled solvent from the reservoir 28 through a conduit 36 to a filter 37 Where impurities are removed from the solvent before its return to the system. The discharge from the filter in a discharge line 38 can be passed directly into the inlet line 18 feeding the housing 10 by opening a valve 39 connecting the two lines. A portion of the discharge of the filter 37 can alsobe directed into a conduit 41 controlled by a valve 42 for introduction into the cooling coils contained in the condenser 23. The discharge from the cooling coils is taken through a conduit 43 and returned to the solvent reservoir 28.

The present invention is particularly concerned with a sensing device which is actuated bythe operationof the condenser mechanism to thereby determine the length of the drying cycle. To that end, the liquid .condensate recovered from the :condenser 22 and flowing through line 27 :passes througha waterseparator 47 and then through a drying control mechanism generally indicated by numeral 481m FIGURE 11. .These two assemblies are best illustrated in F'IGU'RES '4..-an'd of the drawings. As seeninthose figures, the condensate in the line 27 is passed to a cylindrical water separator 47 having a threaded bottom portionclosed by means of a cap 51;and sealing gasketi52. The cap 51 may 'be removed to clean the water separator 47. A pair of substantially fiat surfaced dependingrbaffiesa53-and 54 of different lengths extend chordally across'the cylindrical housing of :the separator 47. .Thedischarge from the condenser appearing in line 27 will consist of a mixture of condensed water=and condensed solvent. 'As the condensate builds up intheseparator 47, the bafi les53 and 54 separate the water from the solvent. Since the water is lighter than the solvent, it flows to thetop and is trapped in a chamber56 between theba'flles 53 and 54. During maximum discharge from the condenser, the

water level will be at a line indicated. at '57 in the drawings, and excess water can be continuously withdrawn by an overflow conduit 58 :provided for that purpose. An air vent 59 is also provided'in' the-water separator 47 to prevent excessive pressnre'from buildingup. It will be noted from an inspection ofFIGURES 4 and 5 that the body portion of water separator '47 and-the body portion of the condensate collector 48 are interconnected by a vertical mounting web50 permitting upright installation and that'the internal chambers of these body portions are slightly tapered for easier molding as well as to accommodate free movement of the some what frusto conical fioatf69. i i i The solvent flows under thebafiie '53into a conduit 61 connecting with the condensate sensing 'or dry control mechanism 48. The 'latter'includesa casing 62 having a threaded end portion closed by means of a cap '63 in threaded engagementwith thecasing 62. "The bottom of the cap 63is't'ormed with a metering orifice 64, and the cap presses awsealingr-gasket-66 against a ceramic filtering element 67 located at the -base of the casing "62. 'Condensate' generated by condenser '23 passes from conduit '61 into a chamber-'68 within the dry control mechanism 48 and serves to operate a float 69 contained therein. Whenthe rate of flow o f condensate entering the chamber'6'8 is greater than the rate at which the condensate'is leaving through the metering orifice 64, the floatr69 will rise in the chamber68. The fioat'69 is provided with a switch actuating projection 71 which is aligned with an actuating arrri 72 of a single-pole, double-throw switch '73 having a first lower position and a second upper position." =As'long asthere is sufiicient excess fiow 'wi thin the chamber 68, the switch 73 willbeoperated' to its second upper position and'any additional excess condensate isreturne'd to the reservoir 28 by means of conduit76. When there is insufiicient'flow within the chamber 68,-the fl0at will fall and the switch 73 wi'llreturn to its'first or lower position. The discharge of the metering orifice 64 isalso returned to thereservoir 28 by means of abranch conduit 77.

The electricalcircuitfor controlling operations of the dry cleaning assembly is best illustrated in FIGURES 2 and'3 of the drawings. Referring'first to FIGURE 3, numerals 81 and'82 have been applied 'to the two sides of the line which supplies electrical .power to the series of earns 88 through 94, inclusive.

unit. A door switch 83 is included in the line 81 so that the machine circuitry cannot be energized without the door being closed. The balance of the machine circuitry, apart from a portion of the timing mechanism, has been broadly identified atz-84 since these circuits form no part of the instant invention.

The principal timing control is afforded by a main timer motor86 having a shaft 87 on which are mounted sequentially energized switch contacts controlled by a A manual reset knob 96 isprovided in 'conjunction with the main timer motor 86 for resetting the operations of the timer motor to its zero position 1as.'desired.

.An auxiliary timer motor-.9 8 is also provided, t g with its manual reset means 99. The auxiliary timer motor 98 has a shaft 101 which carries a pair of cams 102 and '103 to operate

switches

114 and 116 in timed sequence, as will be explained in a succeeding portion of thisspecification.

FIGURE 52 illustrates the timing schedule arrangement provided by the various cams operating from the main timer motor 86 and the'auxiliary timer motor '98. A total of 60timer intervals, each one-half minute in duration, is shown for convenience though it should be appreciated. atthe outset-hereof that thetotal elapsed time of this illustrative cycle may exceed thirty minutes.

.At the outsetiof the-timing interval, it will beseen fromFIGURE '2, which is read from left to right, that Switches106 and107, associate'd'with cams-89 and 90, respectively, are closed, thereby applying energizing voltaget-hrough parallel circuits to the switches 1-06 and 1017 across the main timer motor 86. At-the beginning ofthe twenty-sixth timer interval,the heating element 19 and the blower F24 are energized, effectively initiating the drying period,-by timing cams'92 and 93'through their associated

switches

108 and 109 to preheat or warm up the dry cleaning unit during awportion of the extraction period. At the beginning of the twentyeighth timer interval, solvent is conveyed from the reservoir..2'8 byenergizing pump33th-rough' the operation of cam 941and its associated switch 111, therebydelivering solvent through the conduit '36 into thefilter'37,'to conduit 38, pastvalve :42 and .into the condenser :23 to precool the condenser. At the end of twenty-ninthv timer interval, the extraction period .ends, and the drying period: continues.

At the beginning of the pthirty-fourth timerinterval, cam 91 serves to close thejfirst byrpass switch .112 and cam-: is timed tosopen'thesecond bypass switch 107. At the :beginning of the thirty-fifth timer interval, cam 89 operates to. open switch :106. The movement .of switches 112,107 and106,aat.this time, provides .a checking interval to detect 'whethertor'not float 69 is in itsupper position. Normallyin-drying regular fabrics there should be sufiicient amounts of. condensate atthis point of the cycle in thecharnber168, to raise. the float 69- to where. it operates the single-pole, double-throw switch 73 into its upper position .as iseenin'FIGURE 3. Line voltage. is thereby supplied to the timer motor 86 through the switch 73-and the. now closed first'by pass switch 112, connected in parallel shuntingrelationship around switch'106 to continue operation of the timer motor =86. Theswitch 106 remains open for onetimer interval, and at the end of the thirty-fifth timer-interval, the cam 89 operates to reclose switch 106.

Also, at the beginning of the thirty-fifth timer interval, the cam88 operates to close its associated auxiliary timer motor'switch 113 and'thereby apply line voltage across the auxiliary timer motor 98. 1

Switch 73 is responsive to condensate flow which generally decreasesas the over-all condition of dryness of the articles in:drum '11 increases. In a broader form of this invention switch '73 could also be in the form of a thermal responsive element sensitive to the temperature of the fabrics or temperatures of exhaust air from drum 11 and movable from its upper to its lower position during the drying cycle since the temperature of fabrics or exhaust air increases upon attainment of the over-all condition of dryness.

At the beginning of the thirty-seventh timer interval, the cam 91 operates to open the first by pass switch 112 and the cam 90 operates to close the second by pass switch 107. This switching arrangement provides a second checking interval to detect whether the float 69 is in its lower position when cam 89 operates to open main timer motor switch 106 at the end of the fifty-fifth timer interval.

At the beginning of the thirty-ninth timer interval, the auxiliary timer motor 98 moves the cam 102 to a position in which it closes its auxiliary motor by pass switch 114 to provide a by pass or shunt circuit around auxiliary timer motor switch 113. This allows continued energization of auxiliary timer motor 98 after switch 113 is subsequently opened by cam 88 at the beginning of the fortyflfth timer interval.

At the beginning of the fifty-fifth interval, the cam 89 operates to open the main timer motor switch 106. It is at this time that the variation of load size affects the operation of the main timer mechanism 86. With a reasonably light load or moderate load, the articles will be sufficiently dry at this time, and insufiicient condensate will flow into chamber 68 to keep the float 69 in the upper position. The float will fall and the switch '73 will have returned to its first or lower position. Line voltage will thereupon be continued to the timer motor 86 through the lower contact of switch 73 (which is now in the position shown in FIGURE 3) and through the second by pass switch 107 which remains closed. At the beginning of the fifty-sixth timer interval, the cam 89 operates to close the main timer motor switch 106 again and the timer 86 continues to be energized. It is at this time that the heated portion of the dry period ends and the deodorize period begins. At the same time, the heater 19 is de-energized as is the pump 33 which recirculates the condensate. Blower 24, however, remains energized through closed switch 109 to vent to the atmosphere, by means not shown, the last traces of solvent vapor from the articles during the deodon'zing period. The machine cycle is then completed at the end of the sixtieth timer interval at which time cam 90 operates to open the second by pass switch 107, cam 89 operates to open the main motor switch 106 and the blower 24 is de-energized by cam 93 opening blower switch 109.

However, if the articles are still insufficiently dry at the beginning of the fifty-fifth timer interval or if a malfunction occurs such as the float 69 or switch 73 sticking in their upper positions or the orifice 64 in the control chamber 68 plugging with foreign matter, the circuit operates as follows:

In the case of insufiiciently dry articles, the main timer motor 86 will remain de-energized because the rate of flow of condensate is suflicient to keep float '69 in its upper position which in turn keeps switch 73 in its second or upper position. Therefore, since the first by pass switch 112 is open, the operation of the main timer motor 86 will be interrupted and the drying operation will be extended until float 69 falls and thereby re-applies line voltage through the lower contact of switch 73 and the second by pass switch 107 to the main timer motor 86 so that the machine cycle is thereafter completed in exactly the same way as it would have been for lighter loads.

As previously mentioned, the auxiliary timer motor 98 is initially energized at the beginning of the thirty-fifth timer interval. The auxiliary timer motor 98 is preset to operate for thirty minutes or sixty intervals of the timer chart in FIGURE 2. If at the end of the thirty-minute period of the auxiliary timer motor operation the float 69 is still in the upper position where it holds switch 73 in its second or upper position, cam 103 will be operated by the auxiliary timer motor 98 to close its associated switch 116 which closes after thirty minutes of actual timed operation of auxiliary timer motor 98 have elapsed (and therefore not shown in FIGURE 2). However, since the first by pass switch 112 is open, a circuit is not completed to the main timer motor 86, through

switches

116 and 112 and the machine continues to dry until the switch 73 falls to its lower position thereby energizing timer motor 86 through the second by pass switch 107 and the lower contact of float switch 73. This action provides an infinite drying interval so that hard-to-dry articles such as sleeping bags, rugs, blankets and other bulky articles, can be completely dried to a desired dryness before the machine will terminate this drying operation. After the main timer motor 86 has been energized, the drying operation is normally effectively terminated by timer motor 86 continuing to the end of its programmed machine cycle. However, if a malfunction occurs to cause the float 69 to stick in the upper position or to cause the switch 73 to stick in its upper position, the machine will continue to operate until an attendant services the machine.

If a malfunction should occur such as to cause the float '69 or switch 73 to stick in their lower positions or if the condenser 22 fails to produce condensate because of failure of blower 2-4 or pump 33, or if the water separator 47 or float chamber 68 should plug above the float 69 with foreign articles precluding passage of solvent into chamber 68, the following conditions will occur:

At the beginning of the thirty-fourth timer interval, the first by pass switch 112 closes, and the second by pass switch 107 opens. At the beginning of the thirty-fifth timer interval, cam 89 operates to open main timer motor switch 106 and cam 88 operates to close the auxiliary timer motor switch 113 which energizes the auxiliary timer motor 98. Because of the malfunction, a circuit is not made from line 81 through switch 73, switch 112, and through the timer motor 86 as is normally the case. Therefore, the operation of the main timer motor 86 is interrupted and the drying interval is dependent on the thirty-minute operation interval of the auxiliary timer motor 98 which is energized at the beginning of the thirtyfifth timer interval of main timer motor 86. One-half minute before the end of the thirty-minute operation interval of the auxiliary timer motor 98, cam 103 operates to close the auxiliary timer motor interval switch 116 which provides voltage across timer motor 86 through

switches

112 and 116. The main timer motor 86 then operates cam 89 to close the main timer motor switch 106. At the end of the thirty-minute time period of the auxiliary timer motor 98, cam 103 operates to open the auxiliary timer motor interval switch 116 and cam 88 operates to open the auxiliary timer motor switch 113, deenergizing the auxiliary timer motor 98.

Under these conditions, the timer chart of FIGURE 2 is interrupted at the thirty-fifth interval of the main timer motor 86 and actually expanded in length by a thirty-minute interval which is the duration of energization of auxiliary timer motor 98.

After the lapsing of this thirty-minute interval and at the beginning of the thirty-seventh timer interval of main timer motor 86, cam 91 operates to open the first by pass switch 112 and cam operates to close the second by pass switch 107. As can be noted in FIGURE 3, the main timer motor 86 is now energized through the second by pass switch 107 and the lower contact of switch 73 as well as through main timer motor switch 106. At the beginning of the fifty-fifth timer interval, cam 89 operates to open main timer motor switch 106. However, the main timer motor 86 continues to be energized through the second by pass switch 107 and the lower contact of switch 73.

At the beginning of the fifty-sixth timer interval, cam 89 operates to reclose main timer motor switch 106 and permit the timer motor 86 to complete the normal machine cycle.

While we have-illustrated a preferred embodiment of the invention in the accompanying drawings, itshould be evident that various modificationscan be'madeto the described apparatus without departing from the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as'follows:

1. In a dryingapparatus including dryingmeans for effecting the dryingof articles placed insaid drying apparatus, dry controlcircuitry including means, for energizing said drying'meansv during a drying operation,

first sequential control means inisaid circuitry for controlling said drying means throughout .a first fixed time interval,

switch means in saidcircuitry responsive to a'condition of dryness of said articles and operable to termienate said drying operation subsequentto said first fixed time interval, and

second sequential control means in said circuitry to override said switch means and limit the duration of said drying operation in case of a-malfunction of said switch means.

2. In a drying apparatus-including drying means for effecting the drying of articlesplacedinsaid' drying apparatus, dry control circuitry including means for energizing said drying means "duringa drying operation,

first sequential control -means in said' circuitry for controlling said drying means throughout 'a first fixed time interval,

switch means in said circuitry responsive to a condition'of dryness of said articles for extending'said drying operation beyond said first fixed time interval andthereafter terminating said drying operation,

a by-pass switch interconnected in said circuitry 'in parallel with saidswitch means, and

second sequential control means in said circuitry for operatingsaid by-pass switch to limit the duration of said drying operation in the event of a malfunction of said switch means. 3. In a drying apparatus including drying means for effecting the evaporation of'fluids from articles placed in said apparatus and further including condensing means for condensing vapors resulting from said evaporation during a drying operation, the combination comprising,

an electrical circuit for said apparatus including means 'for energizingsaid drying means,

sequential control means in said circuit for controlling saild drying means throughout afirstfixed time interva sensing means responsive to the rate of flow of condensate generated bysaid condensing means, circuit means including a switch actuated by said sensing means between first and'secorid positionsfand means operative between said sequential control means and said switch providing checking intervals for extending said drying operation beyondsaid first fixed time interval when said switch is in said first position and terminating said drying operation when said switch is in said second position.

4. In a drying apparatus including evaporation means for evaporating fluids from articles placed in said app-aratus and condenser means for condensing saidevaporated fluids during a programmed drying operation, a dry control system comprising,

first sequential control means for controlling said evaporation means and said condenser means and for carrying out said programmed drying operation, switch means being movable between first and second positions dependent upon the flow of condensate from said condenser means, said switch means in said first position energizing said first sequential control means,

circuit means including said first sequential control means and said switch means in said first posit-ion,

by-pass circuit means in parallel with said switch means,

and

second sequential control means for energizing said by-pass circuit means to override said switch means to insure the energization of said first sequential control means in the event of a malfunction of said switch means. 5. In a drying apparatus including evaporation means for evaporating fluids from articles placed in said apparatus and condenser means for condensing said evaporated fluids during a programmed drying operation, a dry control system comprising,

first sequential control means for controlling said evaporation means and said condenser means and for carrying out said programmed drying operation,

switch means being movable between first and second positions dependent upon the flow of condensate from said condenser means, said switch means in said first position energizing said firstsequential control means,

circuit means including said first sequential control means and said switch means in said first position,

a bypass switch,

a by-pass circuit in parallel with said switch means and including said by-pass switch, and second sequential control means for actuating said bypass switch to energize said by-pass circuit to override said switch means and'insure the energization of said first sequential control means in the event of a malfunction of said switch means.

6. In a drying apparatus including evaporation means for evaporating fluids from articles placed in said apparatus and condenser means'for condensing said evaporated fluids during a programmed drying operation, a dry control system comprising;

first sequential control means for controlling said evaporation means and said condenser means and for carrying out said programmed drying operation, said first sequential control means providing a first fixed time interval,

switch means having first and second positions as determined by the rate of flow of condensate from said condenser means, said switch means in said first position energizing said first sequential control means after said fixed time interval,

circuit means including said first sequential control means and said switch means in its second position, by-pass circuit means in parallel with said switch means, and second sequential control means for energizing said by-pass circuit means after said fixed time interval to override said switch means and insure energization of said first sequential control means in the event of a malfunction.

7. In a drying apparatus having evaporation means for evaporating fluids from articles placed in said apparatus and condensing means for condensing said evaporated fiuids, a dry control system comprising: first sequential control means providing a first fixed time interval,

firstswitch means controlled by said first sequential control means,

second switch means responsive to the rate of fiow of condensate generated by said condensing means and having a first position when said condensate .flow rate is below a predetermined value and a secondposition when said condensate flow rate is above said predetermined value, a first circuit including said first sequential control means and said second switch means, said first sequential control means being energized through said first switch means during said first fixed time interval during which said second switch means normally moves from its first position to its second position to extend said drying operation beyond said fixed time interval,

and a second sequential control means operatively connected to said first circuit to override said second switch means and to terminate the drying operation during the extended time interval in the event of a malfunction of said second switch means.

8. In a drying apparatus including electrically energized heating means, electrically energized blower means cooperating with said heating means to evaporate dry cleaning solvent from a load, and a timing mechanism arranged to program said apparatus through a timed sequence of drying,

a condenser receiving fluid evaporated from said load,

a water separator receiving the discharge from said condenser and arranged to separate water therefrom,

a dry control mechanism receiving condensed solvent from said Water separator,

dr-a-in means in said mechanism for constantly draining solvent therefrom,

a float in said mechanism,

a switch associated with said float and actuated thereby from a first to a second position when the level of solvent in said mechanism reaches a predetermined level,

and circuit means associated with said timing mechanism to provide checking intervals and being reresponsive to the position of said switch in said second position to continue energization of said blower means and said heating means beyond their normal programmed energization upon malfunctioning of said float in said dry control mechanism.

9. In a dry cleaning apparatus including an electrically energized heater, a blower, and a solvent condenser including a condensate pump for circulating dry cleaning solvent, a control circuit comprising a main timer motor having timing cams thereon to energize said heater, blower, and condensate pump in timed sequence during an operating cycle,

a first cam operated switch actuated by said main timer motor to periodicaly deenergize said main timer motor during an operating cycle,

a second cam operated switch arranged to apply energizing voltage across said main timer motor in one position of said switch during an interval in which said first cam operated switch would otherwise deenergize said main timer motor,

float means responsive to the amount of condensate produced during drying,

a float operated switch in association with said float means and in electrical series relation with said second cam operated switch,

a third cam operated switch actuated by said main timer motor and arranged to energize said main timer motor except for said interval in which said first cam operated switch would deenergize said main timer motor,

an auxiliary time motor,

a fourth cam operated switch actuated by said main timer motor to energize said auxiliary timer motor during said interval in which said first cam operated switch would otherwise deenergize said main timer motor, and

a fifth cam operated switch actuated by said auxiliary timer motor, and in parallel circuit relation to said float operated switch.

10. In a drying apparatus including drying means for effecting the evaporation of fluids from articles placed in said apparatus and further including condensing means for condensing vapors resulting from said evaporation during a drying operation, the combination comprising,

an electrical circuit for said apparatus including means for energizing said drying means,

first sequential control means in said circuit for controlling said drying means throughout a first fixed time interval, and sensing means responsive to the rate of flow of condensate generated by said condensing means for extending said drying operation beyond said first fixed time interval and thereafter terminating said drying operation, a by-pass switch interconnected in said circuit in parallel with said sensing means, and second sequential control means in said circuit for operating said by-pass switch to limit the dura tion of said drying operation.

References Cited by the Examiner UNITED STATES PATENTS 2,019,896 11/1935 Edlich 34-45 2,166,294 7/1939 Hetzer 6818.2 2,911,810 11/1959 Lantz et al. 6820 X 3,002,287 10/1961 Smith 34-45 3,043,125 7/1962 Horecky 6812 3,085,415 4/1963 Gosnell 68--12 3,102,407 9/1963 Stilwell 6824 3,116,625 1/1964 Stewart 6812 WALTER A. SCHEEL, Primary Examiner.

CHARLES A. WILLMUTH, Examiner.

Claims

1. IN A DRYING APPARATUS INCLUDING DRYING MEANS FOR EFFECTING THE DRYING OF ARTICLES PLACED IN SAID DRYING APPARATUS, DRY CONTROL CIRCUITRY INCLUDING MEANS FOR ENERGIZING SAID DRYING MEANS DURING A DRYING OPERATION, FIRST SEQUENTIAL CONTROL MEANS IN SAID CIRCUITRY FOR CONTROLLING SAID DRYING MEANS THROUGHOUT A FIRST FIXED TIME INTERVAL, SWITCH MEANS IN SAID CIRCUITRY RESPONSIVE TO A CONDITION OF DRYNESS OF SAID ARTICLES AND OPERABLE TO TERMINATE SAID DRYING OPERATION SUBSEQUENT TO SAID FIRST FIXED TIME INTERVAL, AND SECOND SEQUENTIAL CONTROL MEANS IN SAID CIRCUITRY TO OVERRIDE SAID SWITCH MEANS AND LIMIT THE DURATION OF SAID DRYING OPERATION IN CASE OF A MALFUNCTION OF SAID SWITCH MEANS.