US3593544A

US3593544A - Automatic clothes dryer to heat shrink transfer agent used to clean fabrics

Info

Publication number: US3593544A
Application number: US879034A
Authority: US
Inventors: Billie D Henderson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1969-11-24
Filing date: 1969-11-24
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20

Abstract

An automatic clothes dryer adapted to clean fabrics by tumbling the fabrics therein with a charge of liquid and transfer agent, and then to automatically separate the transfer agent from the fabrics, is provided with a control means to bring the temperature of the air flowing through the dryer drum to a temperature sufficient to heat shrink the soiled, segregated transfer agent, thereby reducing its volume and facilitating its disposal.

Description

United States Patent [72] Inventor Billie D. Henderson Louisville, Ky. [21) Appl. No. 879,034 [22] Filed Nov. 24, 1969 [45] Patented July 20, 1971 [73] Assignee General Electric Company [54] AUTOMATIC CLOTHES DRYER TO HEAT SHRINK TRANSFER AGENT USED TO CLEAN FABRICS 2 Claims, 4 Drawing Figs.

521 US. Cl. 68/12, 68/20, 34/45 [51] Int. Cl D061 33/02, F26d 21/02, F26d 21/06 [50] Field ofSearch 68/20, 12, 19.2; 34/45, 54

[56] References Cited UNITED STATES PATENTS 2,869,247 1/ 1959 Metzger 68/20 X 2,875,526 3/1959 Engel et a1v 68/20 X 3,112,187 11/1963 Stone 68/20X 3,218,730 11/1965 Menk et a1. 34/45 3,242,585 3/1966 Worst v 34/45 3,391,467 7/1968 Miller et a1. 34/45 3,397,461 8/1968 Fogt et a1 34/45 3,409,994 1 111968 Menk 34/45 X Primary ExaminerWil1iam 1. Price Assistant Examiner-Phi1ip R. Coe

AnorneysJames E. Espe, Harry F. Manbeck, Jr., Frank L,

Neuhauser, Oscar B. Waddell and Joseph B. Forman ABSTRACT: An automatic clothes dryer adapted to clean I OFF TEMPERATURE OF F'lRST DIFFERENT \AL TEMPERATURE ON TEMPERAT URE OF FRST THERMOSTAT SECOND THERMOSTAT B THERMOSTAT OFF TEMPERATURE OF SECOND THERM STAT E SEccNn Dl FFERENTtAL TEMPERATURE OF 'T'l ME PATENTED JUL20 :97:

SHEET 1 0F 3 FIGJ INVENTOR. BILLIE D. HENDERSON BY W ms ATTORNEY PATENTEB JUL20 IBTI SHEET 2 BF 2 PAUYSE I CLEANlNG --l FORMING I BLOWER HEATERS OF SECOND SECOND DIFFERENTIAL INVENTOR 0F BILUE D. HENDERSON ms ATTORNEY ET Y mm T T m T MM w mm mm WM m L Fm F E mm i W 2 o i ui D a To AM as H Pi F WT c @T T E w m O M 5 dial mm .rmd m M w A Wm UdDL-(UULEMF AUTOMATIC CLOTHES DRYER TO HEAT SHRINK TRANSFER AGENT USED TO CLEAN FABRICS BACKGROUND OF THE INVENTION This invention relates generally to the dry wash" and dry rinse methods of cleaning and treating fabrics as disclosed respectively in applications filed concurrently herewith Ser. No. 879,315 by W. .l. Ehner and Ser. No. 879,03! by L. Loeb, assigned to the assignee of the instant invention.

The aforementioned Ehner and Loch applications disclose fabric cleaning and treating methods which employ a transfer agent preferably having a large surface area onto which may be transferred a significant quantity of soil to be cleaned from the fabrics. This transfer agent may be tumbled together with the fabrics, as in a domestic automatic dryer, to effect distribution of a treating chemical onto the fabrics and to effect distribution of soil from the areas of concentration on the fabrics and onto the combined surface areas of the transfer agent and the fabrics. The soiled transfer agent may be subsequently separated from the fabrics, whereby the fabrics are cleaned of the soil deposited onto the transfer agent.

In selecting an optimum materialfor use as a transfer agent in the dry wash and dry rinse processes, a number of requirements and desirable attributes must be considered. When the processes are to be performed in an improved automatic clothes dryer, the volume of the transfer agent which may be employed per load of fabrics is limited by the size of the dryer drum and the need for a loose tumbling action of the fabrics therein. Furthermore, the ratio of surface area of the transfer agent to the surface area of the fabrics is preferably as large as possible so that distribution of soil over the combined surface areas of the fabrics and transfer agent will result in a large pereentage of the soil being deposited on the transfer agent. It is also desirable for purposes of automatic separation of the transfer agent from the fabrics, that the transfer agent be sufficiently buoyant to be carried out of the dryer drum by the initiation of airflow through the drum. Such volume, surface area, and buoyancy requirements make it desirable that the transfer agent have a large surface area per unit mass. Furthermore, it is also desirable that the transfer agent be sufficiently inexpensive to permit its disposal after a single use. When the feature of disposability is attained, there is, then, no need for the provision of apparatus or processes designed to purge the transfer agent of the soil and detergent deposited thereon.

In a quest for the materials which best satisfy the aforementioned objectives, a variety of resilient sponge, foam rubber and plastic materials have been investigated. Such materials have been employed in varying shapes from small cubes to large blocks, and from stringlike configurations to solid sheets. However, as previously mentioned, in connection with the performance with the dry wash and dry rinse processes in an automatic clothes dryer, it is also desirable that the transfer agent readily lend itself to automatic separation from the fabrics. Without such automatic separation of transfer agent from the fabrics, it is impossible to perform either the dry wash or dry rinse processes automatically, much less to perform in one complete automatic cycle the desirable sequence of dry wash, dry rinse and then normal fabric drying One material configuration which lends itself to automatic separation is polyethylene foam cubes having" dimensions of /4 inch on each side. Such cubes have been found to be light enough to be picked up and carried out of the rotatable enclosure by airflow, whereafter they may be collected in a lint trap or other trap means.

In an application Ser. No 879,032 filed concurrently herewith by L. A. DePas and assigned to the assignee of the instant invention, a method is disclosed to facilitate disposal of such foam cubes once they are separated from the fabrics and caught in a lint trap or other trap means. According to the method taught by DePas, the soiled, segregated transfer agent is heat shrunk to reduce its volume and to cause at least partial adherence between at least some of the pieces of transfer agent, thereby facilitating its disposal.

It is an object of my invention to provide a machine to efficiently and economically perform the DePas heat-shrinking method of facilitating transfer agent disposal.

SUMMARY OF THE INVENTION Briefly stated, in accordance with one aspect of the present invention, there is provided an automatic fabric-drying machine having an enclosure rotatable about a nonvertical axis to impart a tumbling action to fabrics placed therein. Additionally provided within the dryer are air-heatingmeans adapted to heat a stream of moving air and air-circulating means adapted to circulate a stream of moving air over the heating means and through the enclosure so as, to carry moisture away from the fabrics during rotation of thecnclosure. Means adapted to substantially disable the heating means and air-circulating means are included to permit the cleaning of fabrics within the enclosure without the flow of heated air therethrough by tumbling the fabrics together with a quantity of liquid and transfer agent. A trap means acts to catch the transfer agent blown out of the enclosure when air is circulated therethrough bythe air-circulating means. Additionally, a control means adapted to regulate the heating means so as to bring the temperature of the air flowing through the enclosure to a temperature sufficient to heat shrink the soiled transfer agent deposited in the trap means thereby reducing the volume and causing at least partial adherence between at least some of the pieces of separated transfer agent, facilitating its disposal.

The control means comprises a first thermostat and a second thermostat connected in parallel to control the heating means, wherein the first thermostat has a first temperature differential between the temperatures at which it turns on and off, and the second thermostat has a second temperature differential between the temperatures at which it turns on and off. The second temperature differential is established so as to be smaller than said first temperature differential and so as to lie within the temperaturelange defined by the on and off temperatures of the first thermostat. By this arrangement, the first thermostat is operative to raise the temperature within the enclosure sufficiently high to heat shrink the soiled,

transfer agent, whereafter the first thermostat turns off and the heating means is then controlled by the second thermostat which then maintains a temperature within the enclosure lower than that needed to heat shrink the transfer agent, thereby permitting the transfer agent to solidify.

BRIEF DESCRIPTION OF THE DRAWINGS 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 of the preferred embodiment taken in conjunction with the accompanying drawings, in which:

FIG. I is a side elevational view of a clothes dryer adapted to clean fabrics and incorporating the transfer agent heatshrinking control means of my invention;

FIG. 2 is a schematic electric circuit diagram illustrating a control circuit for the dryer of FIG. I;

FIG. 3 is a sequence cont'rolchart illustrating the positions of the switches in the circuit of FIG. 2 during the sequence of operation of the dryer of FIG. 1; and

FIG. 4 is a temperature sequence chart showing the temperature of the air flowing within the enclosure as controlled by means of my invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with one aspect of my invention, a new and improved apparatus is provided to. facilitate the disposal of transfer agent employed in the "dry wash" and "dry rinse processes of the aforementioned Ehner and Loch applications.

As set out in the Ehner and Loeb applications, the transfer agent may, by various means, be automatically separated from the fabrics at the termination of the dry wash or dry rinse processes. In accordance with the method taught in the aforementioned DePas application, the soiled segregated transfer agent may be heat shrunk to reduce its volume and to cause at least partial adherence between at least some of the pieces of transfer agent, thereby facilitating its disposal. By this method, for example, when V4 inch cubes of polyethylene foam are used as a transfer agent, by raising the temperature of such cubes to 240-250 F., the volume of such cubes can .be reduced at least 4 to l and the cubes solidified into a solid unitary mass without the onset of objectionable odors and without the transfer agent becoming sufficiently liquid to adhere to adjacent metallic surfaces.

In accordance with my invention, as will be discussed in greater detail below, means are provided for performing the DePas heat shrink method in domestic automatic clothes dryers of the type modified to perform the dry wash and dry rinse processes. To better understand the apparatus of my invention, a description of a dryer modified appropriately for the dry wash and dry rinse processes is set out below, following which discussion, the improvement of my invention is discussed in detail.

Referring now to the drawing and initially to FIG. 1 thereof, there is illustrated a domestic automatic clothes dryer l ineluding an appearance and protective outer cabinet 11 having a door or closure 12 to provide access to the interior of the cabinet for loading and unloading fabrics. Provided on the top 13 of cabinet 11 is a control panel 14 which may, in a conventional way, include a suitable manual control 15 connected to a control assembly 16 mounted in the panel 14. By manual setting of control 15, the machine may be caused to start and automatically proceed through a cycle of operation.

Within cabinet 11, there is provided a clothes-tumbling enclosure or drum 17 mounted for rotation on a substantially horizontal axis. Drum 17 is substantially cylindrical in shape, having a center cylindrical wall portion 18, and outer

cylindrical wall portions

19 and 20, located respectively adjacent an annular front wall 21 and a circular rear wall 22 of the drum. On the interior surface of wall portion 18 there are a plurality of clothes-tumbling ribs 23 so that clothes are lifted up when the drum rotates, and then permitted to tumble back down to the bottom of the drum. The front of the drum 17 may be rotatably supported within outer casing 11 by suitable idler wheels, one of which is indicated by numeral 24. These wheels are rotatably secured to the top of the member 25 which extends up from the base 26 of the machine. The wheels 24 are disposed beneath the drum, in contact with portion 19, so as to support the portion 19 on each side to provide a stable support.

The rear end of drum 17 receives its support by means of a stub shaft 27 extending from the center of wall 22. Shaft 27 is secured within a bearing 28 formed in a baffle structure 29 which, in turn, is rigidly secured to the backwall 30 of the cabinet 11 by any suitable means such as welding at a number of points 31. with the arrangement shown the drum may rotate on a horizontal axis, with rollers 24 providing the front support and stub shaft 27 within bearing 28 providing the rear support.

In order to provide for the flow of a stream of drying air through the clothes drum, it is provided with a central aperture or opening 32 defined by the wall 21 and a plurality of perforations 33 in the rear wall 22, the perforations 33 in the present case are formed to extend around the rear wall in an annulus. The opening 32 is in alignment with the opening in cabinet 11 covered by door 12, and thus serves a dual purpose in that it also provides access to drum 17 for loading and unloading fabrics.

As has been stated, baffle structure 29 is rigidly secured to the backwall 30 of cabinet 11. Baffle structure 29 also serves to support heating means 34 which includes two resistancetype

electrical heating elements

35 and 36, appropriately insulated from the baffle member.

Elements

35 and 36 may be annular in shape so as to be generally coextensive with perforations 33 in drum 17. A baffle member 37 is rigidly secured to the rear wall 22 of the drum 17 outside the ring of perforations 33 and within the stationary baffle structure 39, so that an annular air inlet 38 is defined by

baffles

29 and 37. In this manner a passage is formed for air to enter air inlet 38 between the baffles, pass over the heating means 34, and then pass through openings 39 formed in baffle 37 and perforations 33 into the interior ofdrum 17.

The front opening 32 of the drum is substantially closed by means of a stationary bulkhead generally indicated by numeral 40. Bulkhead 40 is made up of a number of adjacent members including the inner surface 41 of the access door 12, a stationary frame 42 formed as a flange on front wall 43 of the cabinet, the inner surface ofan exhaust duct formed by the cooperation of member 44 and the front wall 43 of the cabinet, and an annular flange 45 mounted on the frame 42 of the front wall 43. It will be noted that a suitable clearance'is provided between the inner edge of aperture 32 and the edge of bulkhead 40 so that there is no rubbing between the drum and the bulkhead during rotation of the drum. In order to prevent substantial air leakage through the aperture 32, a suitable ring seal 46 is secured to the flange 45 in sealing relationship with the exterior surface of the drum wall 21. Door 12, whose inner surface forms part of the bulkhead closing the opening, is mounted on cabinet 11 so that when the door is opened fabrics may be inserted into and removed from the drum through the door frame 42. It will be noted that the door includes an outer, flat imperforate section 47 and an inwardly extending hollow section 48, mounted on the flat outer section. Hollow section 48 extends into the door frame 42 when the door is closed, and the door surface 41 which comprises part of the combination bulkhead 40 is actually the inner wall of the hollow section.

The air outlet from the drum is provided by a perforated opening 49 formed in the inner wall 41 of hollow door section 48. The bottom wall section of door 12 and the adjacent wall of door frame 42 are provided with aligned openings 50 and 51, opening 51 providing an entrance to a duct 52 formed by the cooperation of member 44 with front wall 43. A lint trap 53 may be positioned in the exhaust duct 52 within opening 51 and supported by the door frame 42. Duct 52 leads downwardly and communicates with a housing 54. Housing 54 contains a blower 55 driven by motor 56 through clutch 57. The blower draws heated air through the duct 53 and then exhausts it from the cabinet 11 through an appropriate duct (not shown).

In addition to driving the blower, motor 56 constitutes the means for effecting rotation of drum 17. In order to effect this rotation, motor 56 is provided with a shaft 58 having a small pulley 59 fonned at one end thereof. A belt 60 extends around the pulley 59 and also entirely around the wall section 18 of drum 17. The relative circumferences of the pulley 59 and the wall section 18 cause the drum to be driven by the motor at a speed suitable to effect tumbling of fabrics in the drum. In order to effect proper tensioning of the belt 60, a suitable idler assembly 61 is secured to the same support 62 which supports one end of the motor. Thus, air is pulled through the drum and, at the same time, the fabrics within the drum are tumbled. When the air is being heated by

heating elements

35 and 36, the heated air passing through the drum causes vaporization of the moisture from the clothes, the vapor is carried off with the air as it passes out of the machine.

Referring now to FIG. 2, there is shown a schematic electric circuit diagram illustrating a basic or simplified control arrangement for the dryer of FIG. ll. It will be understood that many refinements such as temperature selection means, multiple cycle selection means, and fabric temperature or resistance responsive control means for automatically concluding the operation of the dryer, etc., have not been shown in the circuit of FIG. 2 for the sake of simplicity. As shown, the entire control system of the machine may be energized across a three-wire power supply system which includes

supply conductors

63 and 64 and a neutral conductor 65. For domestic use,

conductors

63 and 64 will normally be connected across a 230 volt power supply, with 1 volts appearing between the neutral line 65 and each of the conductors, and with the neutral line being at ground voltage. Motor 56, connected between

conductors

63 and 65, is a single phase induction motor having a main winding 66 and a start winding 67, both connected at a common end to a conductor 68. Through a conventional door switch 69 (which is closed when door 12 is closed and open when the door is open) conductor 68 is connected to conductor 65.

Start winding 67 is connected in parallel with main winding 66 under the control ofa speed responsive device such as that shown at 70, which is schematically shown as connected to rotor 71 of the motor. The speed responsive device 70 controls a switch 72 which is engageable with either a contact 73 or a contact 74. Switch 72 is engaged with contact 73 when the machine is at rest, and moves into engagement with contact 74 as the motor comes up to speed. It can readily be seen that engagement with contact 73 connects the start winding 67 in parallel with main winding 66, while movement of switch 72 away from this position opens the start winding. Thus, as rotor 71 comes up to speed, the start winding becomes deenergized and the motor then continues to run on the main winding 66 alone.

The starting of the motor is provided by a manually operable switch 75 which may, for instance, in the structure of FIG. 1, be moved to its closed position by depressing manual control 15. Switch 75 connects the motor to supply conductor 63 through contact 76 of a switch 77. The switch'75 is normally biased to the open position as shown in FIG. 2. When control 15 is depressed, assuming

contacts

76 and 77 are closed, energization of the motor 56 is provided and, within less than a second under normal circumstances, the motor comes up to speed so that switch 72 moves from contact 73 to contact 74. As a result of this movement of centrifugally operated switch 72, the main winding 66 of motor 56 continues to be energized by a bypass around switch 75 when control 15 is released thus opening switch 75.

The switch 77 is controlled by a cam 78 which, in turn, is controlled by a timer motor 79 of the shutoff or timing control means. The cam 78 and timer motor 79 also are connected to manual control 15 so that rotation of the manual control causes the cam to rotate and close switch 77. Thereafter, the cam 78 is controlled by the timer motor 79 and, after a predetermined period of operation of the timer motor, the cam is effective to cause switch 77 to be opened for terminating or interrupting the operation of the machine.

An energizing circuit is also completed for heating means 34 through the following circuit. Starting at conductor 63, the circuit proceeds through a switch 80 and through a dryness sensing control means 81 to the heater 34, and then through a conventional safety thermostat 82, and through switches "83 and 84 to conductor 64. Switch 80 is controlled by a cam 85 which, in turn, is controlled by timer motor 79. Switch 83 is controlled by a solenoid 86 and is normally closed when solenoid 86 is not energized. Switch 84 is centrifugally responsive to the speed of rotor 71 and is closed only when motor 56 has come up to speed so that there can be no energization of the heating means 34 except when motor 56 is operating properly. As will be explained in greater detail later, control means 81 is adapted and positioned so as to sense the temperature of the fabrics within the drum 17, or a temperature which varies substantially directly with the clothes temperature and to accordingly regulate heating means 34.

In order to carry out the dry wash or dry rinse processes in the machine of FIG. 1, it is necessary that the means adapted to heat and circulate the air moving through the enclosure be selectively energizable. It is to be understood that during a dry wash or dry rinse cleaning cycle, it is desirable to substantially deenergize both the air-heating and air-circulating means, so as to not blow the carrier about within the rotating enclosure, and also in order to not cause undesired evaporation of the limited amount ofwater used to wet the fabrics.

Therefore, means are provided which are adapted to disable the air-circulating means or blower 55 and the heating means 34 so as to selectively permit the rotation of the drum or enclosure 17 with or withoutthe flow of heated air therethrough. Such means, in the embodiment of FIGS. 1 and 2, comprises solenoid 86 connected on one side to neutral conductor 65, and on the other side through a switch 87 to conductor 63. The switch 87 is controlled by a cam 88 which, in turn, is controlled by timer motor 79. Solenoid 86 operates an armature 89 which, when solenoid 86 is energized, disconnects motor 56 from blower 55 by means of clutch S7, and which simultaneously opens switch 83. Thus, when solenoid 86 is energized, blower S5 and heating means 34 are deenergized.

As may best be seen in FIG. 1, clutch 57 comprises two frictionally

engageable members

90 and 91, member 90 being connected to output shaft 58 of motor 56, and member 91 being connected to blower 55.

Members

90 and 91 are normally held in driving engagement by means of compression spring 92. However, when armature 89 is moved inwardly of solenoid 86 by energization of solenoid'86, lever 93 pivoted at 94 and attached to armature 89 by link 95 operates to move member 90 out of engagement with member 91, thereby disengaging blower 55 from motor 56.

In operation, the machine of FIG. 1 may be programmed to perform the entire cleaning, carrier separation, and drying functions, or separate ones of such functions. Cams 85 and 88 may be so designed such that during the cleaning function, switch 87 is closed causing solenoid 86 to deenergize blower 55 and heating means 34, and during the drying operation, switch 87 is open and switch 80 is closed. By this arrangement, as may be better seen in FIG. 3, the blower 55 is deenergized during cleaning but operates continuously during drying, while the heating means 34 is deenergized during cleaning and selectively energized during drying under the control of sensing means 81. ln order to perform the dry wash or dry rinse processes in the machine of FIG. 1, the fabrics to be cleaned are placed into drum 17 along with a quantity of liquid and transfer agent. In one typical example of the dry wash process, 75 grams of a liquid detergent such as ClNCH, manufactured by Proctor & Gamble, may be employed with 3 pints of water and Vi pound of polyethylene cubes to clean a 3 pound load of cotton fabrics. Control 15 is then moved to initiate operation of the machine in the dry wash mode wherein heating means 34 and blower 55 are deactivated during rotation of drum 17. The fabrics, liquid and transfer agent are thereby tumbled together causing soil from the fabrics to be distributed over the combined surface areas of the fabrics and transfer agent, as previously described. Following this tumbling operation, separation of the transfer agent may be accomplished automatically during the initial portion of the drying operation. By way of illustration, if the transfer agent being used is /4 inch foam cubes, such cubes are sufficiently buoyant to be carried out of drum 17 by the initiation of air circulation therethrough, whereafter such cubes may be caught in lint trap 53 or the like.

ln accordance with my invention, control means 81 will regulate air-heating means 34 so as to bring the temperature of the air flowing through enclosure or drum 17 to a temperature sufficient to heat shrink the soiled transfer agent subsequent to its separation from the fabrics. Although the heatshrinking process may begin before all the transfer agent is separated from the fabrics,ssuch process is substantially carried out with the transfer agent separated from the fabrics. In the preferred embodiment of my invention, control means 81 comprises a first thermostat 96 and a second thermostat 97 connected in parallel to control heating means 34.

As may best be seen in FIG. 4, first thermostat 96 has a differential defined between an on" temperature A and an off" temperature B. Similarly, second thermostat 97 has a differential defined betweenan on" temperature C and an off temperature D. As will be apparent, the differential of the second thermostat 97 is smaller than the differential of the first thermostat 96, and the second differential lies within the temperature range of the first differential.

By this arrangement of control means 81, when the dryer is at room temperature and switch 80 is closed as occurs at the initiation of a drying cycle following a dry wash or dry rinse operation, both

thermostats

96 and 97 will complete the circuit to heating means 34. Simultaneously. as has been previously described, blower S is energized by motor 56 acting through clutch 57, which causes the transfer agent to be carried out of drum l7 and into trap means 53. As heating means 34 increases the temperature of the air circulating through drum 17, the off temperature D of second thermostat 97 will be achieved causing second thermostat 97 to open. However, the circuit supplying energy to heating means 34 through first thermostat 96 will remain operative until the off temperature B of the first thermostat is reached, as is shown in FIG. 4. Temperature B is so selected as to assure the heat shrinkage of the soiled transfer agent which has been caught in trap means 53.

Once the "off" temperature B has been reached, the circuit supplying energy to heating means 34 is opened and the temperature of the air flowing within the drum 17 will drop, as shown in FIG. 4, until on" temperature C of second thermostat 97 is reached. At this time, second thermostat 97 completes the energizing circuit to heating means 34 and the temperature within drum 17 is, from then on, controlled by the second thermostat 97 between temperatures C and D. Toward the termination of the drying cycle, switch 80 may be opened by cam 85 deenergizing heating means 34 and permitting the cooling down of the fabrics within drum 17.

The temperatures A, B, C and D are each selected for differing reasons. Temperatures C and D, representing the normal temperatures at which a domestic dryer is cycled on and off, may respectively be l40 and 150 F. Temperature A may then be 130 F. or lower, such temperature being selected to be at least F. below temperature C to assure that once the first thermostat 96 has turned off heating means 34 will then be exclusively controlled by second thermostat 97 without any further cycling of first thermostat 96. Temperature B, as previously mentioned, is chosen in accordance with the material used as transfer agent, it being realized that temperature B is ideally sufficient to heat shrink and unitize the mass of the transfer agent without entirely melting it. Furthermore, temperature B must not be so high as to ignite the fabrics within drum 17. When polyethylene foam is used as a transfer agent, temperature B may be 240 F. Such a temperature will heat shrink the transfer agent by a ratio of at least 4 to 1 into a unitary mass which may be readily removed from trap means 53 for disposal.

As was previously mentioned, the control means of my invention is particularly adapted for use in automatic clothes dryers wherein it is desirable to provide a means for reducing the volume of the soiled segregated transfer agent following a dry wash or dry rinse operation. From the foregoing description it should now be apparent that the present invention, by providing a control means adapted to regulate the heating of the air flowing through the dryer drum whereby the temperature of such airflow is raised sufficiently high to heat shrink the soiled transfer agent, enables the reduction in volume of the soiled transfer to a unitary mass for ready disposal.

As will be evident from the foregoing description, certainv aspects of the. invention are not limited to the particular details of the examples illustrated, and it is contemplated that other modifications or applications will occur to those skilled in the art. It is, therefore, intended that the appended claims shall cover such modifications 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. In a domestic fabric drying machine wherein it is desirable to clean fabrics by tumbling the fabrics therein with a charge of liquid and transfer agent, wherein the dryer has: an enclosure rotatable about a nonvertical axis to impart a tumbling action to the fabrics; air heating and a circulating means adapted to heat and circulate a stream of air through the enclosureso as to carry moisture away-from the fabrics during rotation of the enclosure; means adapted to selectively energize and deenergize the air heating and circulating means so as to selectively permit the rotation of the enclosure without the flow of heated air therethrough during a drying operation; and

trap means adapted to catch the transfer agent which is blown out of the enclosure when air is circulated therethrough by the circulating means; the improvement comprising:

control means adapted to regulate the air-heating means so as to bring the temperature of the air flowing through the enclosure to a temperature sufficient to heat shrink the soiled transfer agent deposited in the trap means thereby reducing the volume of the transfer agent facilitating its disposal;

said control means comprising a first thermostat and a second thermostat connected in parallel to control the heating means;

said first thermostat having a first temperature differential between the temperatures at which it turns on and off;

said second thermostat having a second temperature differential between the temperatures at which it turns on and off;

said second temperature differential being smaller than said first temperature differential and lying within the temperature range defined by the on and off temperatures of said first thermostat;

whereby said first thermostat is operative to raise the temperature within the enclosure sufficiently high to heat shrink the soiled transfer agent, whereafter the first thermostat turns off and the heating means is then controlled by the second thermostat which thenmaintains a temperature within the enclosure lower than that needed to heat shrink the transfer agent, thereby permitting the transfer agent to solidify.

2. An automatic clothes dryer comprising:

an enclosure rotatable about a nonvertical axis to impart a tumbling action to fabrics placed therein;

air-heating means adapted to heat a stream of moving air;

air-circulating means adapted to circulate a stream of moving air over said heating means and through said enclosure so as to carry moisture away from the fabrics during rotation of said enclosure;

means adapted to disable said heating means and said air circulating means to permit the cleaning of the fabrics within said enclosure without the flow of heated air therethrough by tumbling the fabrics together with a quantity of liquid and transfer agent;

trap means adapted to catch the transfer agent which is blown out of said enclosure when airis circulated therethrough by said air-circulating means; and

control means adapted to regulate said heating means so as to bring the temperature of the air flowing through said enclosure to a temperature sufficient to heat shrink the soiled transfer agent deposited in said trap means thereby reducing the volume of the transfer agent facilitating its disposal;

between the temperatures at which it turns on and off;

said second temperature difierential being smaller than said first temperature differential and lying within the temperature range defined by the on and off temperatures of said first thermostat;

whereby said first thermostat is operative to raise the temperature within the enclosure sufficiently high to heat shrink the soiled transfer agent, whereafter the first thermostat turns off and the heating means is then controlled by the second thermostat which then maintains a temperature within the enclosure lower than that needed to heat shrink the transfer agent, thereby permitting the transfer agent to solidify.

said first thermostat having a first temperature differential

Claims

1. In a domestic fabric drying machine wherein it is desirable to clean fabrics by tumbling the fabrics therein with a charge of liquid and transfer agent, wherein the dryer has: an enclosure rotatable about a nonvertical axis to impart a tumbling action to the fabrics; air heating and a circulating means adapted to heat and circulate a stream of air through the enclosure so as to carry moisture away from the fabrics during rotation of the enclosure; means adapted to selectively energize and deenergize the air heating and circulating means so as to selectively permit the rotation of the enclosure without the flow of heated air therethrough during a drying operation; and trap means adapted to catch the transfer agent which is blown out of the enclosure when air is circulated therethrough by the circulating means; the improvement comprising: control means adapted to regulate the air-heating means so as to bring the temperature of tHe air flowing through the enclosure to a temperature sufficient to heat shrink the soiled transfer agent deposited in the trap means thereby reducing the volume of the transfer agent facilitating its disposal; said control means comprising a first thermostat and a second thermostat connected in parallel to control the heating means; said first thermostat having a first temperature differential between the temperatures at which it turns on and off; said second thermostat having a second temperature differential between the temperatures at which it turns on and off; said second temperature differential being smaller than said first temperature differential and lying within the temperature range defined by the on and off temperatures of said first thermostat; whereby said first thermostat is operative to raise the temperature within the enclosure sufficiently high to heat shrink the soiled transfer agent, whereafter the first thermostat turns off and the heating means is then controlled by the second thermostat which then maintains a temperature within the enclosure lower than that needed to heat shrink the transfer agent, thereby permitting the transfer agent to solidify.

2. An automatic clothes dryer comprising: an enclosure rotatable about a nonvertical axis to impart a tumbling action to fabrics placed therein; air-heating means adapted to heat a stream of moving air; air-circulating means adapted to circulate a stream of moving air over said heating means and through said enclosure so as to carry moisture away from the fabrics during rotation of said enclosure; means adapted to disable said heating means and said air circulating means to permit the cleaning of the fabrics within said enclosure without the flow of heated air therethrough by tumbling the fabrics together with a quantity of liquid and transfer agent; trap means adapted to catch the transfer agent which is blown out of said enclosure when air is circulated therethrough by said air-circulating means; and control means adapted to regulate said heating means so as to bring the temperature of the air flowing through said enclosure to a temperature sufficient to heat shrink the soiled transfer agent deposited in said trap means thereby reducing the volume of the transfer agent facilitating its disposal; said control means comprising a first thermostat and a second thermostat connected in parallel to control the heating means; said first thermostat having a first temperature differential between the temperatures at which it turns on and off; said second thermostat having a second temperature differential between the temperatures at which it turns on and off; said second temperature differential being smaller than said first temperature differential and lying within the temperature range defined by the on and off temperatures of said first thermostat; whereby said first thermostat is operative to raise the temperature within the enclosure sufficiently high to heat shrink the soiled transfer agent, whereafter the first thermostat turns off and the heating means is then controlled by the second thermostat which then maintains a temperature within the enclosure lower than that needed to heat shrink the transfer agent, thereby permitting the transfer agent to solidify.