US3116123A

US3116123A - Clothes conditioning machine

Info

Publication number: US3116123A
Application number: US128758A
Authority: US
Inventors: Russell M Sasnett
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1961-08-02
Filing date: 1961-08-02
Publication date: 1963-12-31
Anticipated expiration: 1980-12-31

Description

Dec. 31, 1963 R. M. SASNETT 3,116,123

CLOTHES CONDITIONING MACHINE Filed Aug. 2, 1961 3 Sheets-Sheet l FIGJ I21. INVENTOR.

RUSSELL M. SASNETT BYMPM H\S ATT RN Y R. M. SASNETT 3,116,123

CLOTHES CONDITIONING MACHINE 3 Sheets-Sheet 2 INVENTOR. RUSSELL M. SASNETT BY QJ P W HIS ATTORNEY F'IG.2.

Dec. 31, 1963 Filed Aug. 2, 1961 Dec. 31, 1963 R. M. SASNETT CLOTHES CONDITIONING MACHINE 3 Sheets-Sheet 3 Filed Aug. .2, 1961 F'IG.3

T m Y T s a m N W R M m A a m m H Y B United States Patent 3,116,123 CLQTHEEBB CQNDITIGNENG MACHINE Russell M. Sasnett, Louisville, Ky, assignor to General Electric Company, a corporation of New York Filed Aug. 2, 1961, Ser. No. 128,758 Claims. (6!. 3445) This invention relates to domestic clothes drying ma chines, and more particularly to an electrical control system used in such machines.

For maximum utility and saleability, a domestic clothes dryer should not only be capable of fully drying a load of clothes to a condition suitable for immediate use, but also should be capable of providing what is generally known as a de-wrinkling cycle for wash and wear type clothes. In this latter type of cycle, the wrinkles in the wash and Wear type fabric may be removed by elevating the dryer temperature to a point where the synthetic material assumes some degree of plasticity so that the wrinkles are eliminated, the clothes thereafter being cooled and removed from the machine before wrinkles can reset themselves in the clothes. Various control systems for achieving these two cycles have been devised, and several are presently in machines which are commercially available. All of these machines do have the feature in common that the control system for the machine necessarily includes a sequence control assembly having an electrically driven motor of some kind which times the opening and closing of certain switches during a cycle of operation. A very common structure for achieving this goal is the provision of a synchronous motor which, through a gear train, operates a bank of cams controlling diiferent switches so that the switches open and close at the proper time during cycles of operation to provide the desired effect. The sequence control assembly usually constitutes by far the most expensive component of the dryer control system. It is, consequently, most desirable to eliminate this costly item without at the same time losing the ability to provide the functions and cycles described above.

It is therefore an object of my invention to provide a clothes dryer having an electrical control system wherein, without the conventionally present sequence control assembly, the machine may provide either a complete automatic drying cycle, or a de-wrinkle cycle.

It is a further object of my invention to provide such an electrical control system in a drying machine wherein the automatic drying cycle is of the type wherein the dryness of the clothes is measured by the clothes temperature, and air at a substantially constant temperature is continually introduced into contact with the clothes in order to evaporate the moisture therein.

In carrying out my invention in one form thereof, I provide a clothes drying machine which has the conventional clothes container with an air inlet and an air outlet. The air inlet is connected to inlet duct means which has a heater positioned therein so that, when air is circulated through the duct means into the container, the air is heated in order to evaporate moisture in the clothes with in the container. In order to circulate the air, appropriate means may be provided: in the conventional manner, this usually includes an electric induction-type motor which operates a speed responsive device. The speed responsive device controls a switch which moves to closed position as the motor comes up to speed for a purpose explained herebelow.

The temperature of the air coming into the container is maintained relatively constant so that the temperature of the clothes may provide a reliable indication as to their degree of dryness. In order to sense the temperature of the clothes, I provide control thermostatic means posialiens Patented Dec. 31, 1963 tioned to be responsive to their temperature and arranged to trip at a predetermined high temperature which indicates that the clothes are dry. In addition to this thermostatic means, as an important feature of my invention, I provide an auxiliary thermostat which is also positioned to respond to the temperature of clothes in the container, but to do so more slowly than the control thermostat.

My system includes two manually operable switches: the first is movable between open and closed positions, and the third is movable between first and second closed positions.

The motor providing circulation of the air may be energized through either one of two circuits. The first of these circuits includes the control thermostat in its untripped position, the auxiliary thermostat, and the motor. The second motor circuit includes the control thermostat in its tripped position, the first manually operated switch, and the motor. For the heater, there are three diflierent energizing circuits which may be provided. The first includes the control thermostat in its untripped position, the second manual switch in its first position, the heater, and the speed responsive switch means. The second heater circuit includes the control thermostat in its tripped position, the first manual switch, the auxiliary thermostat in its untripped position, the second manual switch in its first position, the heater, and the speed responsive switch means. The third circuit includes the second manual switch in its second position, the heater, and the speed responsive switch.

In combination with the foregoing structure I provide a manual switch control which is operable to first and second stations; in its first station, the control causes the first manual switch to be opened and the second manual switch to be in its second manual position; in its second station, the control means causes the first manual switch to be closed and the second manual switch to be in its first position.

With this arrangement, movement of the control to its first station provides an automatic drying cycle, while in its second station the arrangement described above provides a de-wrinkle heating cycle followed by a cool down.

The automatic cycle is provided because, with the motor energizing circuit including the control thermostat in its first position, tripping of the control thermostat will open the motor circuit, and this in turn, by the speed responsive switch, will open the heater circuit to de-energize the machine. However, when the control means is in its second (or de-wrinkle) position with the first manual switch closed and the second manual switch in its first position, both the motor and the heater continue to be energized after the control thermostat trips. Energization of the heater ceases after an additional period when the auxiliary thermostat trips, and energizing of the motor ceases when the control thermostat cools enough to move back to its initial position as a result of the de-energization of the heater.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. My invention, however, both as to or anization and method of operation together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings.

In the drawings,

FIGURE 1 is a side elevational view of a clothes dryer incorporating my improved dryer control arrangement, the view being partly broken away and partly sectionalized in order to illustrate details;

FIGURE 2 is a hoirzontal sectional view of the dryer,

with certain surfaces broken away and partly sectionalized to illustrate further details; and

FIGURE 3 is a schematic illustration of my improved control system as used in the control of the drying machine of FIGURES l and 2.

Referring now to FIGURES l and 2, I have shown therein a domestic clothes dryer 1 including a clothes tumbling container or drum 2 provided with a suitable outer casing or cabinet 3 which completely encloses the drum on all sides. The drum is mounted for rotation within cabinet 3 on a substantially horizontal axis, and is generally cylindrical in shape, having a first outer Wall portion 4 second and third outer wall portions 5 and 6 located respectively adjacent the ends of the drum, a back wall 7, and a front wall 8. Outer wall portions 4, 5 and 6 are imperforate over their entire length, so that the entire outer shell of the basket is imperforate; on the interior surface of central portion 4 there is provided a plurality of clothes tumbling ribs 9.

The front of drum 2 is rotatably supported within the outer casing 3 by means of a pair of idler roller wheels 10 and 11 which are rotatably secured to the top of an upwardly extending member 12 secured at its bottom to the base 12a of the machine (FIGURE 1). Rollers 1t) and 11 are disposed beneath the drum in contact with portion 6 thereof. The rear end of the drum receives its support from a roller wheel 13 which is positioned beneath portion 5 of the drum in supporting and frictionally driving engagement therewith.

Roller 13 is secured on a shaft 14 supported in bearings 15. Shaft 14 is secured to a pulley 16 which is driven from a belt 17 in turn powered by a pulley 18 mounted on the end of the shaft 19 of an induction-type electric motor 2t). The motor, pulleys, and roller 13 are so proportioned to drum 2 and to each other that drum 2 is rotated by roller 13 at the appropriate speed to provide tumbling action for articles of clothing placed therein.

In order that a stream of drying air be introduced into and passed through the clothes drum, the drum is provided with a central aperture 21 in its front wall 3 and with a plurality of perforations 22 extending in an annulus around back wall 7. Rigidly secured to the rear wall 23 of easing 3 by any desired means such as, for instance, welding at suitable points 24, is a bafile member 25 which has secured thereto heating means such as an electric heater 26, appropriately insulated from the bafile member.

Heating elements 26 may be annular in shape so as to be generally coextensive with perforations 22 in drum 2. The bafile member 27 is rigidly secured to the back wall 7 of the drum outside the ring of perforations 22 and within the stationary baffle 25 so that an annular air inlet 28 is, in effect, formed by the

baffles

25 and 27. Baffle 27 is further provided with an annular series of openings 29. In this manner, a passage is formed for air to enter annular opening 28 between the baffles, pass over the heating elements 26, and through openings 29 and perforations 22 into the interior of drum 2.

In addition -to the air guiding function, the

baffles

25 and 27

help rollers

10, 11, and 13 to support the drum 2. Secured to the central portion 30 of bafile 27 is a bracket 31 to which in turn is secured a stub shaft member 32 substantially co-axially positioned relative to drum 2. The central portion of baffie 25 has a slot-like opening 34 formed therein. The slot is suitably formed (as is more fully described in copending application Serial No. 789,- 869, filed January 29, 1959, by William F. Simpson and assigned to the same assignee as this invention) so as to permit stub shaft 32 a limited amount of movement in the vertical direction but virtually no movement in the horizontal direction. Thus, the slight vertical motions of the drum which result from the tumbling of the clothes can be accommodated while at the same time undesirable horizontal motion is 'aflirmatively prevented by engagement of stub shaft 32 in slot 34.

The front opening 21 of the drum is substantially closed by means of a stationary bulkhead generally indicated by the numeral 35. Bulkhead 35 is made up of a number of adjacent members including the inner surface 36 of an access door 37 mounted on the dryer cabinet, stationary frame 38 for the door, the inner surface 39 of an exhaust duct 46, and an annular flange 41 mounted on the frarne 38 and on the duct wall. It will be noted that a suitable clearance is provided between the inner edge of the drum opening 21 and the edge of bulkhead 35 so that there is no rubbing between the drum and the bulkhead during rotation of the drum. In order to prevent any substantial air leakage through opening 21 between the interior and the exterior of the drum a suitable ring seal 42, preferably formed of felt-like material, is secured to flange 41 in sealing relationship with the exterior surface Clf drum Wall 8.

Front opening 21, in addition to serving as part of the air flow path through the drum, also serves as a means whereby clothes may be loaded and unloaded from the drum. The door 37, whose inner surface forms part of the bulkhead closing the opening, is mounted on cabinet 3; when the door is opened, clothes may be inserted into or removed from the drum through the door frame 38. It will be noted that the door includes an outer fiat imperforate section 43 and an inwardly extending hollow section 44 mounted on the flat outer section. Hollow section 4-4 extends into the door frame 38 when the door is closed, and the door surface 36 which comprises part of the combination bulkhead 35 is actually the inner wall of the hollow section.

The air outlet from the basket is provided by a perforated opening 45 formed in the inner wall 36 of hollow door section 44. The bottom wall section of door 44 and the adjacent wall of door frame 38 are provided with aligned

openings

46 and 47, opening 47 providing the entrance to duct 40. As shown, a lint trap 48, which may comprise a fine mesh bag, is preferably positioned in exhaust duct 40 at opening 47, the bag being supported by the door. Duct 40 leads to suitable air moving means which may, as shown, comprise a centrifugal blower 49 mounted on the motor shaft and thus driven directly by motor 24 The outlet of blower 49 communicates with an outlet duct 56 (FIGURE 2) which extends to an opening 51 in the back 23 of cabinet 3.

During operation of motor 20, the rotation of blower 49 causes air to be drawn into cabinet 3 through a suitable opening 52 (FIGURE 1) provided at the front of the machine, through annular opening 28, over heaters 26, through openings 29 and perforations 22 into drum 2, across the drum, through perforated opening 45 and aligned

openings

46 and 47 into duct 40, and then through the blower 49, outlet duct 50, and opening 51 back into the atmosphere.

The operation of dryer 1 is controlled by a new and improved control system as shown in the circuit diagram of FIGURE 3. As shown there, the entire control system of the machine may be energized across a three wire power supply system which includes

supply conductors

53 and 54 and a neutral conductor 45. For domestic use, the

conductors

53 and 54 will normally be connected across a 220 volt power supply, with volts appearing between the neutral line 55 and each of the conductors.

As an important component of my control circuit, I provide a switch assembly 56 whose structure will be explained at this time, but whose cooperative relationship with the remainder of the electrical components will be described further below. Assembly '56 is schematically shown as including a group of

conductors

57, 58, 59, 60, 61 and 62 which are respectively connected to

terminals

63, 64, 65, 66, 67, and 68. Six movable contact members 69, 70, 7-1, 72, 73, and 74 are respectively movable along the conductors.

Arms '69 through 74 are movable as a unit by a manually operable slide member 75 so that the arms may be positioned, as shown, so that there is no contact made at all, or else may be moved to any one of three operating positions: auto dry, fluff, or dewrinkle. Under auto dry, contact is made by arm 79 with conductor 58, arm 72 with conductor 66, and arm 73 with conductor 61, the other arms not making contact with their associated conductors. Under fluff, arms 71), 71 and 73 respectively engage contacts on

conductors

58, 59, and 61, the other conductors not being engaged by their contact arms. And under dc-wrinkle, arms 69, 72, and 74 respectively engage conductors 57, 60 and 62, the other conductors not being engaged.

It can be seen that arm 69 and conductor 57 in effect represent a switch movable between open and closed positions, and that the same is true of arm 79 and conductor 58. Arms 71 and 72, together with

conductors

59 and 64 represent a switch movable to either one of two closed positions, and the same is true of arms 73 and 74 and conductors 61 and 62.

There are a total of three thermostats associated with my improved control circuit. First, in order to control the inlet temperature of the air entering drum 2 and cause it to be a constant value regardless of the temperature of the ambient air being used for the drying operation, I provide a thermostat 76. Thermostat 76 is connected directly in series with the heaters 26 and is positioned in the inlet duct between bafiles and 27, as shown in FIGURE 2, so as to sense the temperature of incoming air. By providing a relatively small differential between the trip and reset temperatures in the design of thermostat 76, the temperature of the air coming into drum 2 after it has contacted the heaters 26 may be controlled within fairly accurate limits. For instance, if the thermostat has high and low limits of, respectively, 235 F. and 220 F., the temperature of the air will be kept within these limits and for all practical purposes may be considered to be substantially constant, thereby providing a datum line so that a specific clothes temperature may be taken as indicating dryness of the clothes.

In order to sense this clothes temperature, I provide a second thermostat 77 (preferably of the type includ ing a bimetal as the temperature-sensitive element), generally known as a control thermostat, which normally connects a pair of

conductors

78 and 79, but which, when tripped, connects conductor 79 to a conductor fill. Conductor 73 in turn is joined to a conductor 81 which engages terminals 68 and to a conductor 82 which, through a conductor 83, engages the contact arm 76'. The conductor 84) engages the contact arm 69. It will be understood that the thermostat 77 is positioned so as to sense the temperature of clothes within the container 2. One position for thermostat 77 which has been found to be effective in achieving this goal is, as shown in FIGURE 1, directly below door 37 on the wall 39 of duct 4t} so that as the clothes tumble they actually contact the thermostat 77 and, in addition, the air passing from the rear of the container through the front thereof passes closely adjacent the thermostat.

A third auxiliary thermostat, provided in accordance with my invention, is shown by the numeral 84. As can be seen in FIGURE 1, thermostat 84 (which preferably is also formed with a bimetal temperature-sensing element) is positioned closely adjacent thermostat '77 and is therefore subject to the same temperature influences. In addition, it is designed to trip open at the same temperature. Thermostat 84 does, however, have more thermal mass than thermostat 77 so that it requires a longer period of time to react to temperature and, therefore, to open. In other words, although the two thermostats respond to substantially the same temperature, thermostat 77 will normally open prior to thermostat 84 because it has less thermal mass and 6 therefore responds more quickly to the temperatures it senses.

Turning now to the motor 2%) and its construction, it includes, in the usual manner, a main winding -85 and a start winding 86, both connected at a common end to conductor 55. At the other end, a speed responsive switch '37 connects the start winding 86 in parallel with the main winding 85 and in series with a normally open manually operated start switch 88 to the other side of the line 53. Thus, when switch 88 is pushed closed, a motor starting circuit may be completed across

lines

53 and 55, with the windings S5 and 86 in parallel with each other. As the rotor 89 of motor 20 comes up to speed, it causes a centrifugal mechanism 90 to move switch arm 87 for engagement with contact 91 into engagement with a second contact 92. This has the dual function of dis-connecting the start winding from the circuit so that it is no longer energizcd across the source of power, and of providing an energizing circuit for the main winding 85 so that it will continue to run when the start switch 88 is released since, because of its bias, switch 38 will then return to the open position. Thus, switch arm 87 in combination with contact 91 represents a first switch means which opens as motor 20 comes up to speed, and the same switch arm in combination with contact 92 represents a second switch means which closes as the motor comes up to speed.

Either one of two energizing circuits for the main winding 85 is completed by the movement of the switch arm 87. The first, starting with conductor 55, proceeds through the main winding 85, the switch arm 87, contact 92, a conductor 93, the thermostat 84, conductor 32, conductor 78, the thermostat 77 and conductor 79 to conductor 53. The other energizing circuit for the main winding 85, starting at conductor 55, is identical from its beginning through conductor 93; then the second energizing circuit for the motor proceeds through the terminal 63, the conductor 57 and the switch arm 69 to conductor 80, and thence through the thermostat 77 in its tripped position to the conductor 79 and conductor 53. It will be seen that the first circuit is dependent on the untripped condition of thermostat 77, while the second is dependent both on the tripped condition of thermostat 77 and on closure of arm 69 with conductor 57.

The centrifugal mechanism 90 of motor 20 also controls another speed responsive switch 94, moving it to closed position as the motor comes up to speed and otherwise causing it to be in its open position. Switch '94- is in series with the heaters 26, thereby insuring that the heaters cannot operate unless the motor is running and causing air to be circulated through the container. With the structure thus far described, three separate energizing circuits may be provided for the heaters 26 depending upon the position of the various manually operated switches and of the thermostats. A first circuit which is provided when assembly 56 is in the auto dry position is as follows: starting with conductor 53, through a conductor 95 to terminal 67, then through contact arm 73 to a jumper conductor 96,

. through arm 72, conductor 60, and terminal 66 to a pair of conductors 97 and 98; then through the heaters 26 themselves, the thermostat 76 and the speed responsive switch 94 to conductor 54. In the de-wrinkle position, a circuit for the heaters 26 is initially provided as follows: starting with conductor 53, through conductor 79 and thermostat 77 in its untripped position, conductor 78, conductor 81, terminal 68, conductor 62, contact arm 74, jumper 96, contact arm 72, and then in the same manner as before through the heaters.

It will be seen that when the thermostat 77 trips, this circuit can no longer be provided. Instead, a third energizing circuit for the heaters is provided as follows during a de-wrinlde cycle; starting with conductor 53, through conductor 79 to thermostat 77, then through conductor 80 to contact arm 69, through conductor 57 to terminal 63, then through a conductor 99 and thermostat 84, then through conduct-or 82 and conductor S1, and then through the switch assembly 56 and the heater 26 in the same manner described in connection with the second heater energizing circuit.

Completing the description of the system of FIGURE 3, additional elements to those described hereabove are required in order to provide a iiufr" cycle without the provision of a timer of the oonventionai type. In order to effect adequate timing for a fluff cycle, I provide a conductor 100 connected to conductor 55 which leads to a biasing resistance heater 1811 positioned physically adjacent thermostat 77 so as to effect a heating action thereon when energized. Conventionally, the biasing heater 19d may be provided within the same casing and form an integral part of the thermostat 77. The resistance heater 101 is connected through a conductor 2 to terminal 65. Thus, during a fluff cycle, an energizing circuit for the resistance heater element lill is completed as follows: starting at conductor 55, the circuit proceeds through conductor 100, the resistance heater 1G1}, conductor Hi2, terminal 65, conductor 59, contact arm 71, jumper 96, contact arm 73-, conductor 61, terminal 67, and conductor 95 to conductor 53. It will be understood that none of the three energizing circuits described in connection with the heaters 26 are completed when the manual assembly 56 is in the fluff position. Therefore, without any heating of the clothes at all, the thermostat 77 is gradually heated by biasing heater 161 until it trips. The design may be such that this is caused to occur after a period of tumbling on the order to ten minutes, thereby providing the desired fluif action. Conductor lilo may include a switch 162a operated by mechanism 9t) so that opening of the biasing heater circuit is ensured except when motor 20 is running.

The system of FIGURE 3 includes a switch 193, not previously mentioned, which is connected at one end through a conductor 10 4- to conductor 97, and at its other end to a contact 105 which engages a variable resistor 106. Resistor 16 6' in turn is connected to resistor 101. When assembly 56 has been moved by manual member 75 to the auto dry position, and manual switch 103 has been closed, there is, in addition to the other circuits completed in connection with the auto dry position, a circuit for the biasing heater which is provided as follows: starting at conductor 55, through conductor ltlii to element 101, then through resistor 10 6 and contact 165 to switch 163, conductor 1G4, conductor 97, terminal 66, conductor 66, contact arm '72, jumper 9-6, contact arm 73, conductor 61, terminal 67, and conductor 95 to conductor 53. Thus, with the switch lit? closed there is energization of the resistance heater 191 when motor 20 i is operating. However the degree of heating provided by the biasing heater 101 is not as great as during the fluff cycle because there is, in series with the element 101, an additional resistance 106. Therefore, with proper calibration of resistance 106, a conventional automatic drying cycle may be provided with the single exception that the final trip is provided before the clothes are properly dry and while they are still in the condition generally known as damp-dry. By this means, a damp-dry cycle may be provided when so desired by the simple expedient of closing manual switch 10-3 at the same time the automatic drying cycle is selected.

Describing now the operation of my improved drying machine, let it be assumed that an automatic drying cycle is desired and therefore the assembly 56 has been positioned by slide 75 so that the contact arms 69 through 74 are ail directly under the auto dry inscription. With assembly 56 set in this manner, it is then merely necessary to push on button 88 and the motor will start operation through its starting circuit and then continue operation through the energizing circuit which includes both thermostat 84 and thermostat 77. In addition, the heaters are energized through assembly 56 by the first energizing circuit described. These circuits continue to be completed until such time as the thermos-tat 77 trips, thereby indicating a dry condition ot the clothes in container 2. The tripping of thermostat 77 opens all energizing circuits for the motor 28 inasmuch as the second motor energizing circuit is dependent upon the switch arm 69, and this switch arm is not closed in the automatic dry position. As a result, the motor slows down to a stop and as it does so, switch 94 opens to de-energize the heater so that the machine is completely de-energized with the clothes having been automatically brought to a dry condition.

When a de-wrinkling operation is desired, slide 75 is moved so that the switch arms 69' to 74 are positioned directly under the dc-wrinkle inscription with, consequently, switch arms 69, 72 and 74 engaging their respective conductors 57, 6t), and 62. As before, as a result of this amrangement, when start switch 3 8 is closed and the motor 20 is started, an energizing circuit for the motor is provided in the same manner as before. In addition, the second energizing circuit described in connection with the heaters is provided so that the air entering the container is heated to start to raise the temperature of the clothes. When the appropriate temperature for effecting de-wrinlding is reached thermostat 77 trips. However because switch arm 79 engages conductor 57 and thermostat 84 is closed, the motor is still energized through the second circuit described in connection therewith, and the heaters are still energized through the third circuit described in connection therewith. The temperature at this point ceases to rise, primarily because of the stabilizing etiect of thermostat 76 on the temperature of the incoming air. With the temperature at about the F. level, the slower thermostat 84 trips open after a few minutes of continued operation, and this causes the heater energization to be interrupted without, however, interrupting the motor circuit being used. As a result, the temperature in the dryer starts to cool down, with the clothes still being tum-bled and with air still being blown over them. When the temperature reaches a sufficiently low level, the thermostat 77 moves back to its untrippecl position and this interrupts the second motor energizing circuit without, however, re-establishing the first motor energizing circuit because thermostat 84 is now open. As a result, no enengizing circuit for the motor is provided and the motor comes to a stop to terminate the cycle. It can thus be seen that for a de-wrinkling operation, a high temperature operation is provided by the relationship of the

thermostat

77 and 8 4, and that this relationship further provides a cool-down subsequent to the heating.

Briefly completing the description of the various operations of which my machine is capable, for a fluff operation the slide 75 is moved so that the switch arms are under the inscription fluff. As described above, this causes the main heater 26 to be de-energ-ized by preventing any of the energizing circuits therefor from being completed, while at the same time providing a complete energizing circuit for biasing heater 18 1 so that the biasing heater heats the thermostat 77 until eventually it trips thereby to cause de-energiztion of the motor energizing circuit.

If damp-dry is desired, the automatic dry cycle previously described is selected, and the switch 103 is closed. This not only provides the automatic drying cycle described, but also provides an energizing circuit for the biasing heater 101 which includes resistor 106 so as to cause the biasing effect to be relatively small. This causes termination of the cycle before the clothes are completely dry so that the clothes may be taken out of the machine in a damp-dry condition.

The switch made up of arm '79 and conductor 58 is connected directly across thermostat 84. This switch is provided to ensure that, if thermostat 84 should accidentally trip before thermostat 77 during an automatic drying cycle, it will have no effect. This may happen in practice, despite the greater thermal mass of thermostat 8-4, because the relatively large loads normally subjected to automatic drying cause the temperature rise to be very gradual. It will be noted that arm 70 engages contact 53 to bridge across thermostat 84 in auto dry and fluff, and is open during dc-wrinkle.

It can be seen from the foregoing that my invention provides a machine wherein all the various cycles normally desired are provided without the need for a sequence control assembly.

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

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

1. A clothes drying machine comprising: a clothes container having an air inlet and an air outlet; inlet duct means connected to said air inlet; means for circulating air through said duct means into said container and through said outlet including an electric induction-type motor including a speed responsive device; an air heater positioned in said duct means; means for maintaining the temperature of air entering said container substantially constant; first thermostatic means positioned to be responsive to the temperature of clothes in said container, said first thermostatic means being arranged to trip at a predetermined high temperature indicating that the clothes are dry and to reset at a lower temperature; second thermostatic means positioned to respond to the temperature of clothes in said container more slowly than said first thermostatic means and being arranged to trip at substantially the same clothes temperature; switch means controlled by said speed responsive device and movable from open to closed position as said motor comes up to speed; a first manually operable switch movable to open and closed positions; a second manually operable switch movable to first and second closed positions; manual means for starting said motor; means bypassing said motor starting means during motor operation; a first motor energizing circuit including said first and second thermostatic means in their untripped positions, said motor, and said bypassing means in series, and said manual means being in series with said motor and in parallel with the remainder of said first motor energizing circuit; a second motor energizing circuit including said first thermostatic means in its tripped position, said first manually operable switch, said motor and said bypassing means in series, and said manual means being in series with said motor and in parallel with the remainder of said second motor energizing circuit; a first heater energizing circuit including said first thermostatic means in its untripped position, said second manually operable switch in its first position, said heater, and said speed responsive switch means; a second heater energizing circuit including said first thermostatic means in its tripped position, said first manually operable switch, said second thermostatic means in its untripped position, said second manually operable switch in its first position, said heater, and said speed responsive switch means; a third heater energizing circuit including said second manually operable switch in its second position, said heater, and said speed responsive switch means; and a manual switch control means operable to first and second stations, said first station causing said first manually operable switch to be opened and said second manually operable switch to be in its second position, said second position causing first manually operable switch to be closed and said second manually operable switch to be in its first position.

2. The apparatus defined in claim 1 wherein said means 'for maintaining the temperature of air entering said container substantially constant comprises third thermostatic means positioned to sense the temperature of air after it has been heated and prior to its being affected by clothes in said container, said third thermostatic means being arranged to turn said heater on and off in response to predetermined low and high temperatures thereby to maintain the temperature of air entering said container within a predetermined range.

3. The apparatus defined in claim 1 including a third manually operable switch connected across said second thermostatic means, said third manually operable switch being movable to open position when said first manually operable switch is closed and to closed position when said first manually operable switch is open.

4. The apparatus defined in claim 1 wherein both said thermostatic means are in the form of bimetallic elements positioned adjacent the air outlet of said container, said second thermostatic means having agreater thermal mass than said first thermostatic means for slowing down its response to the temperature of clothes in said container relative to the response of said first thermostatic means.

5. A clothes drying machine comprising: a clothes conltainer having an air inlet and an air outlet; inlet duct means connected to said air inlet; means for circulating air through said duct means into said container and through said outlet including an electric induction-type motor having a main Winding, a start winding connected in parallel with said main winding, and first speed responsive switch means for opening the connection of said start winding as said motor comes up to speed; an air heater positioned in said duct means; first thermostatic means positioned to sense the temperature of air after it has been heated and prior to its being affected by clothes in said container, said first thermostatic means being arranged to turn said heater on and otf in response to predetermined loW and high air temperatures thereby to maintain the temperature of air entering said container within a predetermined range; second thermostatic means positioned to be responsive to the temperature of clothes in said container, said second thermostatic means being arranged to trip at a predetermined high temperature indicating that the clothes are dry and to reset at a lower temperature; third thermostatic means positioned to respond to the temperature of clothes in said container more slowly than said second thermostatic mean and being arranged to trip at substantially the same clothes temperature; second speed responsive switch means moved to closed position as said motor comes up to speed; a first manually operable switch movable to open and closed positions; a second manually operable switch movable to closed position and biased to return to open position; a third manually operable switch movable to first and second closed positions; a first motor energizing circuit including said second and third thermostatic means in their untripped positions, said motor and said first speed responsive switch in series with each other, and said second manually operable switch in parallel with said first speed responsive switch; a second motor energizing circuit including said second thermostatic means in its tripped position, said first manually operable switch, said motor, and said first speed responsive switch means in series with each other, and said second manually operable switch in parallel with said first speed responsive switch means; a first heater energizing circuit including said second thermostatic means in its untripped position, said third manually operable switch in its first position, said heater, and said second speed responsive switch means; a second heater energizing circuit including said second thermostatic means in its tripped position, said first manually operable switch, said third thermostatic means in its untripped position,

11 r. 12 said third manually operable switch in its first position, posit-ion causing said first manually operable switch to be said heater, and said second speed responsive switch closed and said third manually operable switch to be in means; a third heater energizing circuit including said its first position.

third manually operable switch in its second position, said References Cited in the file f th's t t heater, and said second speed responsive switch means; 5 O 1 pa an and manual switch control means operable to first and UNITED STATES PATENTS second stations, said first station causing said first manual- 2,743,532 Steward May 1, 1956 1y operable switch to be open and said third manually 2,807,889 Dunke'lman Oct. 1, 1957 operable switch to be in its second position, said second 2,882,610 Hughes Apr. 21, 1959

Claims

1. A CLOTHES DRYING MACHINE COMPRISING: A CLOTHES CONTAINER HAVING AN AIR INLET AND AN AIR OUTLET; INLET DUCT MEANS CONNECTED TO SAID AIR INLET; MEANS FOR CIRCULATING AIR THROUGH SAID DUCT MEANS INTO SAID CONTAINER AND THROUGH SAID OUTLET INCLUDING AN ELECTRIC INDUCTION-TYPE MOTOR INCLUDING A SPEED RESPONSIVE DEVICE; AN AIR HEATER POSITIONED IN SAID DUCT MEANS; MEANS FOR MAINTAINING THE TEMPERATURE OF AIR ENTERING SAID CONTAINER SUBSTANTIALLY CONSTANT; FIRST THERMOSTATIC MEANS POSITONED TO BE RESPONSIVE TO THE TEMPERATURE OF CLOTHES IN SAID CONTAINER, SAID FIRST THERMOSTATIC MEANS BEING ARRANGED TO TRIP AT A PREDETERMINING HIGH TEMPERATURE INDICATING THAT THE CLOTHES ARE DRY AND TO RESET AT A LOWER TEMPERATURE; SECOND THERMOSTATIC MEANS POSITIONED TO RESPOND TO THE TEMPERATURE OF CLOTHES IN SAID CONTAINER MORE SLOWLY THAN SAID FIRST THERMOSTATIC MEANS AND BEING ARRAGNED TO TRIP AT SUBSTANTIALLY THE SAME CLOTHES TEMPERATURE; SWITCH MEANS CONTROLLED BY SAID SPEED RESPONSIVE DEVICE AND MOVABLE FROM OPEN TO CLOSED POSITION AS SAID MOTOR COMES UP TO SPEED; A FIRST MANUALLY OPERABLE SWITCH MOVABLE TO OPEN AND CLOSED POSITIONS; A SECOND MANUALLY OPERABLE SWITCH MOVABLE TO FIRST AND SECOND CLOSED POSITIONS; MANUAL MEANS FOR STARTING SAID MOTOR; MEANS BYPASSING SAID MOTOR STARTING MEANS DURING MOTOR OPERATION; A FIRST MOTOR ENERGIZING CIRCUIT INCLUDING SAID FIRST AND SECOND THERMOSTATIC MEANS IN THEIR UNTRIPPED POSITIONS, SAID MOTOR, AND SAID BYPASSING MEANS IN SERIES, AND SAID MANUAL MEANS BEING IN SERIES WITH SAID MOTOR AND IN PARALLEL WITH THE REAMINDER OF SAID FIRST MOTOR ENERGIZING CIRCUIT; A SECOND MOTOR ENERGIZING CIRCUIT INCLUDING SAID FIRST THERMOSTATIC MEANS IN ITS TRIPPED POSITION, SAID FIRST MANUALLY OPERABLE SWITCH, SAID MOTOR AND SAID BYPASSING MEANS IN SERIES, AND SAID MANUAL MEANS BEING INSERIES WITH SAID MOTOR AND IN PARALLEL WITH THE REMAINDER OF SAID SECOND MOTOR ENERGIZING CIRCUIT; A FIRST HEATER ENERGIZING CIRCUIT INCLUDING SAID FIRST THERMOSTATIC MEANS IN ITS UNTRIPPED POSITION, SAID SECOND MANUALLY OPERABLE SWITCH IN ITS FIRST POSITION, SAID HEATER, AND SAID SPEED RESPONSIVE SWITCH MEANS; A SECOND HEATER ENERGIZING CIRCUIT INCLUDING SAID FIRST THERMOSTATIC MEANS IN ITS TRIPPED POSITION, SAID FIRST MANUALLY OPERABLE SWITCH, SAID SECOND THERMOSTATIC MEANS IN ITS UNTRIPPED POSITION, SAID SECOND MANUALLY OPERABLE SWITCH IN ITS POSITION, SAID HEATER, AND SAID SPEED RESPONSIVE SWITCH MEANS; A THIRD HEATER ENERGIZING CIRCUIT INCLUDING SAID SECOND MANUALLY OPERABLE SWITCH IN ITS SECOND POSITION, SAID HEATER, AND SAID SPEED RESPONSIVE SWITCH MEANS; AND A MANUAL SWITCH CONTROLS MEANS OPERABLE TO FIRST AND SECOND STATIONS, SAID FIRST STATION CAUSING SAID FIRST MANUALLY OPERBLE SWITCH TO BE IN ITS SECOND SAID SECOND MANUALLY OPERABLE SWITCH TO BE IN ITS SECOND POSITION, SAID SECOND POSTION CAUSING FIRST MANUALLY OPERABLE SWITCH TO BE CLOSED AND SAID SECOND MANUALLY OPERABLE SWITCH TO BE IN ITS FIRST POSITION.