US2645032A

US2645032A - Control mechanism for clothes driers

Info

Publication number: US2645032A
Application number: US222762A
Authority: US
Inventors: Kemper M Hammell
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1951-04-25
Filing date: 1951-04-25
Publication date: 1953-07-14
Anticipated expiration: 1970-07-14

Description

y 14, 1953 K. M..'HA MMELI,- 6 ,0

CONTROL MECHANISM FOR CLOTHES DRIERS Filed April 25, 1951 2 SheotQShgqtl FIG. 1

2 I00 :5 3g 32 [l6 1g fi so 0 l2 o 3 83 9 FIG. 3 /,\N

POWER ,/92 SOURCE l DRYER HEATER MOTOR IN V EN TOR.

BY Kemper M. Hqmmeli y 4, 1953 K. M. HAMMELL comer. mzcumzsu FOR awn-Iss mamas 2 Shuts-Sheet 2 Filed April 25, 1951 INVENTOR.

Kemper M. Hamme?! Patented July 14, 1953 CONTROL MECHANISM FOR CLOTHES DRIERS Kemper M. Hammell, Harrisburg, Pa., assignor to General Electric Company, a corporation of New York Application April 25, 1951, Serial No. 222,762

11 Claims.

The present invention relates to control mechanisms for clothes driers, and more particularly to such control mechanism of the manually settable type.

A conventional clothes drier comprises a drum for tumbling the clothes, a motor for rotating the drum, an element for heating the clothes, switching mechanism for controlling operation of the motor and energization of the element, timer mechanism operative during a variable time interval for controlling the switching mechanism, and a manual control device for governing the timer mechanism in order selectively to preset the time interval of operation thereof.

In the operation of such a clothes drier, it is apparent that the required time interval of operation of the timer mechanism is dependent both upon the weight of the load of clothes to be dried and upon the condition or state of dryness of the load of clothes that is ultimately desired. Thus the time interval should be increased as the weight of the load of clothes is increased and the time interval should be further increased as the state of dryness of the load of clothes ultimately desired proceeds from a ence between two time intervals that should be set by the control device of the clothes drier to obtain respectively a bone-dry state and a damp-dry state of a given load of clothes is variable depending upon the weight of the given load of clothes, so that it is virtually impossible for the operator to make the necessary calculations and subsequent adjustments of the control device in order to obtain consistent and satisfactory operation of the clothes drier.

Accordingly it is a general object of the present invention to provide in a clothes drier, control mechanism of the manually settable type that may be readily preset in accordance with the weight of the load of clothes to obtain the desired state of dryness of the clothes within a range extending from a damp-dry state to a bone-dry state.

Another object of the invention is to provide control mechanism of the type described that is of simple and economical construction and arrangement and which requires no mental computations on the part of the operator.

Further features of the invention pertain to the particular arrangement of the elements of the control mechanism whereby the above-outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further ob jects and advantages thereof, will best be understood by reference to the following specification, taken in connection with the accompanying drawings, in which Figure 1 is a vertical sectional view of a clothes drier, incorporating control mechanism embodying the present invention,.taken along the line I--I in Fig. 2; Fig. 2 is a vertical sectional View of the clothes drier, taken along the offset line 2-2 in Fig. 1; Fig. 3 is a diagrammatic illustration of the control mechanism incorporated in the clothes drier, shown in Figs. 1 and 2; Fig. 4 is a plan view of a control device forming a part of the control mechanism incorporated in the clothes drier; Fig. 5 is a vertical sectional view of the control device, taken along the line 5-5 in Fig. 4; Fig. 6 is a bottom view, partly broken away, of the control device, shown in Fig. 4 and Fig. 5; Fig. '7 is a plan view of one of the elements incorporated in the control device; Fig. 8 is a plan view of another of the elements incorporated in the control device; and Fig. 9 is a bottom view of a handle carried by the control device.

Referring now to Figs. 1 and 2 of the drawings, there is generally illustrated a conventional clothes drier ID of the household type incorporating control mechanism embodying the features of the present invention. The clothes drier I0 comprises a casing I I having a drying chamber I2 formed therein, a basket or drum [3 arranged within the drying chamber I2 and mounted for rotation about a substantially horizontal axis so as to tumble the contained clothes, a fan or blower I4 for circulating air through the drying chamber I2, and an electric heater I5 for heating the air that is circulated through the drying chamber I2. The casing II includes a front wall I t and a rear wall H, the front wall l6 being provided with an access opening I8 that is normally closed by a suitable hinged door E9. The drum I3 is generally cylindrical in configuration, and the side wall thereof is perforated for the passage of air therethrough, a number of the perforations being indicated at 20. Also a plurality of vanes or baffles 2| extend radially inwardly of the side wall of the drum 3 for tumbling the clothes during rotation of the drum [3. Finally the front of the drum i3 is provided with an access opening 22 which registers with the access opening it formed in the front wall it of the casing H and the rear of the drum i3 is provided with a wall 23 to which there is affixed a shaft 24, the shaft 24 being journalled in a bearing 25 suitably supported by the rear wall ll of the casing i l. The drum i3 is rotated at a relatively low speed, for example, 50 R. P. Iv'., by an electric motor 28. The electric motor 25 is disposed in the lower portion of the casing H and provided withan operating shaft 21 to which there is rigidly secured a pulley 28, the pulley 28 being operatively connected by a flexible belt 29 to a pulley 3U rig idly secured to the shaft 24. The pulleys 28 and 30 and the belt 29 are disposed rearwardly of the. rear wall I! of the casing l i and exteriorly thereof.

Theheating or drying chamber I2 is encourpassed by a generally cylindrical baffle 31 that is provided with an air'inlet opening 32 dispose adjacent to the top thereof, the bottom of the I.

baffle 35 opening into a downwardly extending throat 42 that communicates with an associated passage 33. A lint trap 34 is arranged in the passage 33 and may be in the form of a tray made of wire screen, or the like, so as to effect the accumulation of lint therein from the stream of air discharged from the drying chamber l2 through the passage 33. The lint trap 34 is provided with a handle 35 and is removable through a. suitable opening 36 formed in the lower cen tral portion of the front wall 16 of the casing H. The. cylindrical baffle 3| is also formed to provide a cove ii! in which. the electric heater I is arranged. The electric heater I5 may be of any suitable type and is preferably of the sheathed resistance conductor type so as to effect radiant heating of the drum [3' and the clothes contained. therein, as well as heating of the air that is circulated through the perforations formed in the side wall of the drum 13.

.In the operation of the clothes drier HJ, air from the laundry room is admitted into the casing H through louver openings 39 formed in the lower left-hand portion of the front wall It of the casing H, which air passes upwardly within the casing H and enters the inlet opening 32 into the drying chamber l2. The air thenpasses through the perforated side wall of the drum l3, wherein it is heated by the radiant heat from the electric heater I5, along with the clothes contained in the drum iii. Moisture contained in the clothes is evaporated and carried in the air stream through the passage 33 into a communicating compartment ll! which communicates l4. Finally the blower I4 discharges the damp air back into the laundry room through a discharge conduit ll extending through the righthand side wall of the casing ii. The lint contained in the air that is discharged from the drying chamber 12 through the passage 33 into the compartment All is caught in the lint trap 34 so that it is not blown through the discharge conduit 4! into the laundry room.

In accordance with the present invention, the elecric heater i5 and the electric motor 26 are governed by a control mechanism 59 incorpo rated in the upper right-hand front portion of the casing H and diagrammatically illustrated in Fig. 3. The composite control mechanism directly with the eye of the blower 58 comprises temperature responsive mechanism s: and time responsive mechanism 52. The temperature responsive mechanism 5| includes a frame 53 supporting an expansible bellows 54 that is connected by a capillary tube 55 to a heat responsive bulb 55 that is secured to a portion of the baffle 3i, as illustrated in Fig. l. The bulb iifi closely follows the temperature of the clothes contained in the drum l3 and effects corresponding expansion and contraction of the bellows 54. An arm 51 is pivotally mounted by a pin 58 upon the frame 53 and carries an adjusting screw 59; the inner end of the screw 59 engages the outer end of the bellows 54; and the outer end of the screw 59 is provided with a slot Gil that is accessible through an opening, not shown, provided in the front wall 16 of the casing ll so that the position of the screw 59 with respect to the arm 5'! may be suitably adjusted by employing a screw driver, or the like. The free end of the arm 5'! terminates in a knife edge 51 that is arranged in spaced-apart relation with respect to a cooperating knife edge 62 carried by the frame 53, the opposite-legs of a substantially ii-shaped spring 63 respectively engaging the knife edges 5! and 52. Also the arm 5'1 carries a stop element 64 that coop erates with an associated stop element 65 car ried by the frame 53, the position of the stop element 65 being adjustable with respect to the frame 53 by an arrangement including a threaded shank 66 provided on the stop element 65 a cooperating locknut 51. Further an op rating element 58 is pivotally connected to the arm 5'! adjacent to the free end thereof by a pin 39, which operating element 68 carries two contact bridging members it and H provided with associated contacts.

In view of the foregoing description of the construction and arrangement of the temperature responsive mechanism 5!, it will be understood that when the baflle 3| is cold, the bellows 54 occupies its contracted position causing the arm 5'! to be moved into its cold position disposed away from the base of the frame 51: so that the bridging members 10 and H close the associated contacts. On the other hand, as the baffle 3| is heated, the hydraulic'medium in the bulb 523 operates effecting expansion of the bellows 54, whereby the outer end of the bellows 54 acting upon the inner end of the screw 59 biases the arm 51 toward the base of the frame 53. When the baffle 3! is heated to a given tem perature corresponding to a predetermined temperature of the clothes contained in the drum It, the bellows 5 is sufficiently expanded to effect movement of the arm 5'! over center with respect to the knife edges 5i and $22 so that the arm ill is snapped from its cold position, illustrated Fig. 3, into its hot position; whereby the operating element 68 moves the bridging members it and H to open the associated contacts. By appropriate adjustment of the screw 55, the temperature of the clothes in the drum it at which the bridging members 10 and H are snapped from their closed positions into their open positions may be selectively set within a range, such, for example, as to 200 F. This arrangement of the temperature responsive mechanism 5! prevents overheating of the clothes contained in the drum 13 during operation of the clothes drier It].

The time responsive mechanism 52 comprises a rotatably mounted operating shaft 12 that has rigidly secured thereto two insulating cams l3 and I4 that respectively control two sets of switch springs SI and S2. The set of switch springs SI includes four individual springs providing two pairs of contacts I5 and I6, and the set of switch springs S2 includes two individual springs providing a single pair of contacts IT. The set of switch springs SI is provided with a rider I8 that engages the periphery of the cam I3 and cooperates with a notch I9 formed therein; and the set of switch springs S2 is provided with a rider 80 that engages the periphery of the cam I4 and cooperates with a notch 8| formed therein. The operating shaft I2 has a normal or off position, illustrated in Fig. 3, wherein the riders I8 and 80 respectively enter the notches I9 and 8| respectively operating the sets of switch springs SI and S2 into their open circuit positions. 011 the other hand, when the operating shaft I2 is rotated out of its normal or off position, the riders I8 and 80 respectively ride out of the notches l9 and 8| operating the sets'of switch springs SI and S2 into their closed circuit positions.

A clutch plate 82 is rigidly secured to the inner end of the operating shaft I2; and the outer end of the operating shaft I2 projects through an opening, not shown, provided in the upper righthand portion of the front wall I6 of the casing II. Also the portion noted of the front wall I6 carried a trim plate 83 having an opening therein, i

not shown, through which the outer end of the operating shaft 12 projects. Further a manually settable control device IOU is detachably secured to the extreme outer end of the operating shaft I2 adjacent to the trim plate 83 and arranged to cooperate with an index marker 84 carried by the trim plate 83. Also the time responsive mechanism 52 comprises an electric timer motor 85 of the synchronous type that is provided with an operating shaft 86 that terminates in a gear box 87. The gear box 87 houses reduction gearing and includes a driven shaft 88 that has a clutch plate 89 rigidly secured thereto and frictionally engaging the associated clutch plate 82 secured to the operating shaft I2.

In view of the foregoing description of the construction and arrangement of the time responsive mechanism 52, it will be understood that the operating shaft 72 may be rotated from its off position in the clockwise direction by rotation of the control device I80, whereby operation of the timer motor 85 is initiated to effect further rotation thereof at a timed rate in the clockwise direction until the operating shaft i2 is returned back into its off position, whereby operation of the timer motor 85 is arrested. Thus it will be understood that the operating shaft I2 is rotated one complete revolution in the clockwise direction, the first portion of the revolution being effected by the manual control device Iiiil, and the second portion of the revolution being effected by the timer motor 85 at the time rate, the friction

clutch plates

32 and 89 accommodating rotation of the operating shaft I2 by the manual control device I00 relative to the driven shaft 88 ex tending from the gear box 81. Thus it will be understood that the time interval during which the timer motor 85 is operated is dependent upon the initial setting of the manual control device I00.

Considerin now the circuit connection and arrangement of the clothes drier IE, it is noted that a source of power of the three-wire Edison type is employed including a neutral conductor SI and two

line conductors

92 and 93, the source being 220-volts, single-phase, providing a voltage of 110 volts between the neutral conductor 9| and the line conductor 92 and a voltage of 220' volts between the

line conductors

92 and 93. In the circuit arrangement, the neutral conductor 9| is connected commonly to one terminal of the drier motor 26 and to one terminal of the timer motor 85, the other terminal of the drier motor 26 and the other terminal of the timer motor 85 being commonly connected to one of the contacts II of the set of switch springs S2. The other contact 11 of the set of switch springs S2 is connected to the line conductor 92. The terminals of the electric heater I5 are respectively connected to one of the contacts I5 and to one of the contacts 16 of the set of switch springs SI. The other contact I5 of the set of switch springs SI is connected to one of the contacts associated with the bridging member II; while the other contact I6 of the set of switch springs SI is connected to one of the contacts associated with the bridging member Ill. The other contact associated with the bridging member H is connected to the line conductor 92, and the other contact associated with the bridging member ID is connected to the line conductor 93. In view of the foregoing, it will be appreciated that the drier motor 26 is also of the 110-volts, single-phase type; whereas the electric heater I5 is of the 220-volts, single-phase type.

Considering now the general overall operation of the clothes drier III, when the baflle 3| is cold, the bridging members I0 and TI occupy their closed circuit positions; and when the operating shaft I2 occupies its off position, the sets of switch springs SI and S2 occupy their open circuit positions. In order to initiate operation of the clothes drier ID, the operator rotates the manual control device I00 in the clockwise direction through an appropriae number of degrees, where by the operating shaft I2 is rotated out of its off position, so that the sets of switch springs SI and S2 are operated into their closed circuit positions. More particularly the contacts and I6 of the set of switch springs SI are closed effecting energization of the electric heater I5 across the

line conductors

92 and 93, since the bridging members I0 and II occupy their closed circuit positions; and the contacts T! are closed effecting operation of the drier motor 26 and the timer motor in parallel circuit relation. Thus the drier motor 26 is operated to effect tumbling of the clothes in the drum I3, and the electric heater I5. is energized to effect heating of the clothes in the drum I3. Also the drier motor 26 efiects operation of the blower I4 and the consequent circulation of the air through the drum 53 in the manner previously explained. The timer motor 85 operates to drive the operating shaft 12 further in the clockwise direction and ultimately back into its off position, whereby the sets of switch springs SI and S2 are operated into their open circuit positions. More particularly the set of switch springs SI is operated to effect opening of the contacts 15 and I6 and the consequent de-energization of the electric heater I5; and the set of switch springs S2 is operated to effect opening of the contacts H so as to arrest operation of the drier motor 26 and the timer motor 35. During the course of operation of the clothes drier I0 through the preset time interval, should the temperature of the clothes in the rotating drum E3 become excessive. the temperature responsive mechanism 5| responds opening and subsequently closing the bridging members I0 and II so as to 7. effect de-energization of the electric heater I5 during the time when thetemperature within the drum I3 is excessive.

Referring now to Figs. l to 9, inclusive, of the drawings, the manual control device I essentially comprises a first control member IOI formed of transparent material. Preferably the control member IOI is formed of a suitable molded plastic material and ha a substantiall annular configuration and terminates in a rearwardly directed rim or skirt I02 disposed closely adjacent to the front face of the trim plate The interior surface of the first control member IOI is suitably coated with a layer of paint, or the like, I03 to provide an arcuate-shaped window I04 through the front face thereof so that only the elements of the device I00 disposed directly below the window I0 are visible from the exterior. Also the front iace' of the first control member IOI carries an off legend orindex I05 that cooperates with the index marker 85 that is carried by the trim plate 33. Further a substantially U--shaped handle Hi0, formed of molded plastic, or the like, is rigidly secured to the central. portion of the first control member I0! in bridging relation with respect to the extreme outer end of the operating shaft I2 by an arrangement ineluding two screws I0i and I08. The central portion of the handle I00 terminates in a substantially annular downwardly directed boss I03 having a cavity or hole H0 formed therein that di rectly receives the extreme outer end of the operating shaft 72. The central portion of the boss :09 terminates in a downwardly extendin projection III that carries a spring clip I I2 that cooperates with a flattened portion 72a provided on the extreme outer end of the operating shaft in order detachably to secure the device I00 to the extreme outer end of the operating shaft "I2 while preventing relative rotation therebetween.

A second substantially circular hollow control member I I3 formed of molded plastic, or the like, is arranged between the front face of the first control member Iill and the central portion of the handle I06 in surrounding relation with re spect to the outer end of the operating shaft 12 and rotatably mounted independently of the first control member I0 I. More particularly the outer end of the second control member I i3 is provided with a substantially annular cavity II4 that re ceives the annular boss I09 carried by the central portion of the handle I00; and the inner end of the second control member I I3 is provided with a substantially cylindrical boss I I5 that is received in a substantially annular opening I it formed in the central portion of the front face of the first control member IIlI. The second control member H3 is retained in place by an arrangement including a substantially annular collar II? that is held in place upon the outer end of the shaft I2 by an annular shoulder IIB formed thereon. Thus it will be understood that the second control member H3 is rotatable with respect to the first control member lUI; that also the second control member I I3 is rotated with the first control mem ber I01 as a consequence of rotation of the handle I06 or as a result of rotation of the operating shaft I2 by the timer motor 85.

First and second substantially annular e1ements or dials II9 and I are arranged below the front face of the first control member IOI and within the confines of the skirt I02, the elements H9 and I20 being arranged in stacked or overlapping relation, and the second element I20 being arranged between the front face of the first control member IM and the first element H9. The first element II9 has a substantially centrally disposed opening I2I formed therein that is received upon an inwardly extending boss I22 provided on the second control member II3; which opening I2I is provided with a fiat surface I2Ia engaging a corresponding flat surface I22a provided on the boss I22 to prevent relative rotation between the second control member H3 and the first element II9. Similarly the second element I20 has a substantially centrally disposed opening I23 formed therein that is-received upon the boss I22 provided onthe second control member II3; which opening is substantially annular to accommodate relative rotation of the second control member I13 with respect to the second element I20. In order to accommodate relative rotation between the first element H9 and the second element I20, a substantially annular shim I24 is arranged there between in surrounding relation with respect to the boss I22. The first element II9 has a substantially arcuate slot I25 disposed therein and symmetrically located with respect to the opening I2I, the outer edge of the slot I25 being provided with teeth, indicatedat I26, constituting a rack. Similarly the second element I20 has a substantially arcuate slot, I21 disposed therein and symmetrically located with respect to the opening I23, the outer edge of the slot I21 being provided with teeth, indicated at I28, constituting a rack.

For the purpose of driving the second element I20 from the first element II9, an arrangement is provided that includes first and second gears I29 and I30 that are respectively'disposed in the slots I25 and I2! and that respectively mesh with the racks I29 and I28. More particularly the gears I29 and I30 are rigidly secured together by a pin I3I extending through aligned openings formed therein and are mounted as a unit upon a bearing sleeve I32 carried upon the inner end of the screw I01 adjacent to the head thereof, the bearing sleeve I32 being secured in place by an associated washer I33. The gear I29 is larger in diameter than the gear I30 and consequently has a larger number of teeth, so as to provide a diiferential drive between the first element II 9 and the second element I20 when the second control member H3 is rotated with respect to the first control member IN.

More particularly when the second control member H3 is rotated upon the boss I09 and within the opening II6 with respect to the handle I06 and the first control member IOI, the first element I I9 is rotated therewith as a result of the cooperation between the fiat portion I2Ia provided in the opening I2! and the flat portion I22a provided on the boss I22: whereby rotation of the second control member I I3 through a given angle effects direct rotation of the first element I I9 through the same given angle. This rotation of the first element II9 drives the gear I29 through the cooperation of the rack I26, whereby the gear I29 is rotated a predetermined number of revolutions; and since the gear I30 is directly secured to the gear I29 by the pin I3I, the gear I30 is rotated the same number of revolutions. Specifically the gears I29 and 530 are rotated upon the bearing sleeve I32 that is carried by the screw I01. This rotation of the gear I30 drives the second element I 20 due to the cooperation of the rack I28; whereby the second element I20 is rotated in the same direction as the first element II9 but through a smaller angle as a consequence of-the difference in the number of teeth respectively carried by the gears H and I30.

The first element I I9 carries a bone-dry index dry in the second quadrant thereof, illustrated in Figs l and 8; whereas the second element I20 carries a damp-dry index damp in the first and fourth quadrants thereof, as illustrated in Figs. 4 and '7. Also the outer edge of the second control member H3 carries a weight indicia scale I3 1 extending from the junction between the second and third quadrants thereof around into the first quadrant thereof, as illustrated in Fig. 4; and the outer lower edge of the boss I09 carries an associated load index 135 disposed at the junction between the second and third quadrants thereof The maximum and minimum extremities of the weight scale I 34 respectively carry the indicia max. and min. Further; the second control member H3 is provided with an integral outwardly extending projection I36 that cooperates with two circumferentially spaced-apart shoulders it"! provided in the opening I I0 formed in the firstcontrol member I01 for the purposeof arresting rotation of the second controlmember I I3 when the max. and min. extremities of the weight scale I34 are brought into respective registry with the load index I35. r I

In the arrangement, as illustrated in Fig. i, when the max. extremity of the weight scale I35 registers with the load index I35, the dry index carried by the first element H9 is disposed approximately 110 in the clockwise direction from the damp index carried by the second control element I20. Now as the second control member H3 is rotated in the counterclockwise direction, as viewed in Fig. 4, the min. extremity of the weight scale I34 may be brought into registry with the load index I35; the second control member Iiii being rotatedthrough an angle of approximately 200. Since the first element H9 is rotated directly with the second control member H3, the dry index carried thereby is rotated substantially to the junction between the third and fourth quadrants or approximately through an angle of 200, when the second control member H3 is rotated in the counterclockwise direction approximately through the angle of 200 in order to bring the min. extremity of the scale I34 into registry with the load index I35. Since the second element I20 is rotated at a slower speed than the first element H9 by virtue of the reduction gearing relation between the gears I20 and I30, the second element 120 is rotated only approximately 134 in the counterclockwise direction as the first element H9 is rotated 200 in the counterclockwise direction; whereby the damp index carried by the second element I20 is rotated to a position disposed in the third quadrant approximately 44" below the junction position between the third and fourth quadrants when the min. extremity of the weight scale I34 is rotated into registry with the load index I35. Thus it will be understood that the angular distance between the dry index carried by the first element H9 and the damp index carried by the second element I20 is a maximum and approximately 110 when the max. extremity of the weight scale I34 registers with the load index I35. Moreover the angular distance between the dry" index and the damp index is gradually decreased as the second control member H3 is rotated in the counterclockwise direction, as viewed in Fig. .4; whereby the angular distance between the dry index and the damp index is only approximately 44 when the min. extremity of the weight scale I34 is brought into registry with the load index Hi5.

Considering now in greater detail the empirical factors involved in the design of the clothes drier I0, it is noted that the drum 13 has an eifec tive maximum load handling capacity of approximately 9 lbs. and a minimum effective load handling capacity of approximately 3 lbs., whereby the weight scale IE0 is calibrated between max. at 9 lbs. and min. at 3 lbs. and may be set at any weight of a load of clothes with reference to the load index I35 disposed between 9 lbs. and 3 lbs. Further the timer motor is so constructed and arranged with respect to the gearing in the gear box 8'! that th driven shaft88 is rotated precisely one revolution per hour, and the dry index carried by the first element H9 is disposed only a small angle in the counter clockwise direction from the off index I05 carried by the first control member IOI, so that when the first control member IOI is rotated in the clockwise direction from its off position so that the index marker 84 carried by the trim plate 83 cooperates with the dry index carried by the first element H9, the time interval during which the timer motor 85 must operate in order again to rotate the first control member I0! in the clockwise direction so as again to bring the off index I05 into registry with the index marker 84 is approximately 56 minutes; which time interval of 56 minutes is appropriate to the drying of a maximum of 9 lbs. of clothes to a bone-dry state in the clothes drier H) by virtue of the rating of the electric heater I5, and the setting of the temperature responsive mechanism 5|. In passing it is noted that it is assumed that a given weight of clothes carry the same given weight of water when they are introduced into the clothes drier I0 and carry no measurable weight of water in the bone-dry stater On the other hand, it is assumed that a given weight of clothes carry 40% of the same weight of water when they are in a damp-dry state. Thus when 9 lbs. of clothes are introduced into the clothes drier I0, the total weight is 18 lbs.; and when this load of clothes is dried to a damp-dry state, the total weight is reduced to 12.6 lbs.; and when this load of clothes is dried to a bone-dry state, the total weight is reduced to 9 lbs.

Now it has been discovered that in the clothes drier I0 of the character described that the relationships between the required drying times and the ultimately desired states of dryness are as set forth in the table below:

A B C D E 9 18 56. 5 37. 5 l. 51 7 14 49. O 33. 0 l. 48 6 12 43. 0 29. 5 l. 46 5 10 35. 0 23. 0 l. 52 3 6 25. 0 l7. 0 1. 47

drier IE! to obtain a bone-dry state of clothes so that theycarry no measurable weight of residual ll moisture; the factor D represents the required drying time or" the clothes drier iii to obtain a damp-dry state of the clothes so that they carry 40% by weight of residual moisture; the factor E represents the ratio of the corresponding drying times between the bone-dry state and the I damp-dry state.

From an examination of this table, it will be observed that the approximate ratio between the drying times to obtain a bone-dry state of the different loads of clothes within the range between 9 lbs. and 3 lbs. and the corresponding drying times to obtain a damp-dry state of the different loads of clothes within the range noted is approximately constant and equal to 1.5. Accordingly in the design of the gears 129 and Mt, the ratio between the number of teeth carried by the gear 129 and the number of teeth carried by the gear 138 is approximately 1.5 so that the differential movement between the first and second elements H9 and I20 bears the ratio 1.5.

Accordingly when the second control member H3 is set for 9 lbs., the dry index carried by the first element H9 and the damp index carried by the second element [2t occupies such positions with respect to the first control member llil that when the first control member IBI is rotated t bring the dry index and the damp index into respective registry with the index marker 84 carried by the trim plate 83, the time responsive mechanism 52 is set for the respective time intervals of 56.5 minutes and 37.5 minutes respectively corresponding to the time intervals required by the clothes drier H] to produce a bone-dry state and a damp-dry state of the load of 9 lbs. of clothes. Similarly when the second control member H3 is set for 3 lbs. the dry index and the damp index occupy such positions with respect to the first control member lfll that when the first control member I0] is rotated to bring the dry index and the damp index into respective registry with the index marker .84, the time responsive mechanism 52 is set for the respective time intervals of 25 minutes and 17 minutes respectively corresponding to the time intervals required by the clothes drier It to produce a bone-dry state and a damp-dry state of the load of 3 lbs. of clothes.

In view of the foregoing, it will be understood that in operating the clothes drier 10, it is only necessary for the operator first to set the second control member H3 in accordance with the weight of the load of clothes to be dried, then to rotate the first control member i0! so as to bring the dry index or the damp index into registry with the index marker ii i depending upon whether it is ultimately desired to dry the load of clothes to a bone-dry state or to a dampdry state. Since operation of the clothes drier Ii] proceeds automatically during the preset timeinterval, no further attention is required on the part of the operator and operation of the clothes drier II] will be arrested after it has been oper ated during the preset time-interval. At the conclusion of operation of the clothes drier It), the clothes may be removed therefrom in precisely the preset state of dryness and regardless of the initial weight of the load of clothes within the operating range of the clothes drier l0. Of course, it will be understood that after the second control member I l3 is set in accordance with the weight of the load of clothes to be dried, the first control member It! may be rotated so as to cause the index marker 84 to occupy an intermediate position with respect to the dry index and the 12 damp index, thereby setting a desired state of dryness or the load of clothes somewhere between a bone-dry state and a damp-dry state.

In view of the foregoing, it is apparent that there has been provided a clothes drier incorporating an improved control mechanism so that any given weight of clothes within the operating range thereof may be readily dried precisely to the state of dryness desired.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall withinthe true spirit and scope of the invention.

What is claimed is:

1. Control mechanism fora clothes drierincluding means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first movable control member having an off position and carried by said support and manually settable with respect thereto, a movable element carried by said first control member and bearing a dryindex, a second movable control member carried by said first control member and manually settable with respect thereto, means responsive to setting of said second control member for setting said element withrespect to said first control member, said first and second control members bearing cooperating weight indicia so that said dry-index may be selectively set to a position disposed a variable distance away from the off position of said first control member in accordance with the weight of the clothes to be dried, an index marker carried by said support and cooperating with said dry-index so that said first control member may be initially set a variable distance away from its off position in accordance with the preset position of said dryindex, a timer operative to return said first control member back into its off position during a variable time interval dependent upon the initially set position of said first control member, a switch having open and closed positions for controlling operation of said tumbling means and energization of said heating means, and means responsive to setting of said first control member away from its off position for actuating said switch into its closed position and for initiating operation of said timer and responsive to the return of said first control member back into its ofi position for actuating said switch into its open position and for arresting operation of said timer.

2. Control mechanism for a clothes drier including means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first movable control member having an off position and carried by said support and manually settable with respect thereto, a movable element carried by said first control member and bearing a dryindex, a second movable control member carried by said first control member and manually settable with respect thereto, means responsive to setting of said second control member for setting said element with respect to said first control member, said first and second control members bearing cooperating weight indicia so that said dry-index may be selectively set to a position disposed a variable distance away from the ofi position of said first control member in accordance with the weight of the clothes to be dried, an index marker carried by said support 13 and cooperating with said dry-index so that said first control member may be initially set a variable distance away from its off position in accordance with the preset position of said dryindex, a timer operative to return said first control member back into its off position during a variable time interval dependent upon the initially set position of said first control member, a switch having open and closed positions for controlling an operating circuit for said tumbling means and for controlling an energizing circuit for said heating means and for controlling an operating circuit for said timer, and means responsive to setting of said first control member away from its off position for actuating said switch into its closed position and responsive to the return of said first control member back into its off position for actuating said switch into its open position.

3. Control mechanism for a clothes drier including means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first rotatable control member having an off position and carried by said support and manually settable with respect thereto, a rotatable element carried by said first control member and bearing a dry-index, a second rotatable control member carried by said first control member and manually settable with respect thereto, means responsive to setting of said second control member for setting said element with respect to said first control member, said first and second control members bearing cooperating weight indicia so that said dry-index may be selectively set to a position disposed a variable angular distance away from the off positionof said first control member in accordance with the weight of the clothes to be dried, an index marker carried by said support and cooperating with said dry-index so that said first control member may be initially set in a given direction a variable angular distance away from its oil" position in accordance with the preset position of said dryindex, a timer operative to rotate said first control member further in said given direction until it is rotated through a complete revolution back into its on position during a variable time interval dependent upon the initially set position of said first control member, a switch having open and closed positions for controlling operation of said tumbling means and energization of said heating means, and means responsive to setting of said first control member away from its off position for actuating said switch into -its closed position and for initiating operation of said timer and responsive to the return of said first control member back into its ofi position for actuating said switch into its open position and for arresting operation of said timer.

4. Control mechanism for a clothes drier including means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first movable control member having an off position and carried by said support and manually settable w th respect thereto, a first movable element carried by said first control member and having a bone dryindex, a second movable element carried by said first control member and bearing a dampdry index, a second movable control member carried by said first control member and manually settable with respect thereto, means responsive to setting of said second control member for--setting both of said elements with ,re-

14 spect to saidfirst control member, said first and second control members bearing cooperating weight indicia so that both said bone-dry index and said damp-dry index may be selectively set to positions disposed. variable distances away from the off position of said first control member in accordance with the weight of the clothes to be dried, an index marker carried by said support and commonly cooperating with said bonedry index and said damp-dry index so that said first control member maybe initially set a variable distance away from its off position in accordance With the preset position of said bonedry index or the preset position of said damp-dry index depending respectively upon whether the clothes are to be dried to a bone-dry state or to a damp-dry state, a timer operative to return said first control member back into its off posi tion during a variable time interval dependent upon the initially set position of said first control member, a switch having open and closed positions for controlling operation of said tumbling means and energization of said heating means, and means responsive to setting of said first control member away from its off position for actuating said switch into its closed position and for initiating operation of said timer and responsive to the return of said first control member back into its off position for actuating said switch into its open position and for arresting operation of said timer.

5. Control mechanism for a clothes drier including means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first movable control member having an off position and carried by said support and manually settable with respect thereto, a first movable element carried by said first control member and having a bonedry index, a second movable element carried by said first control member and bearing a dampdry index, a second movable control member carried by said first control member and manually settable with respect thereto, drive means responsive to setting of said second control member for setting both of said elements with respect to said first control member, said first and second control members bearing cooperating Weight indicia so that both said bone-dry index and said damp-dry index may be selectively set to positions disposed variable distances away from the off position of said first control member in accordance with the weight of the clothes to be dried, said drive means being so constructed and arranged that when said second control member is set in respective maximum and minimum weight positions said bone-dry index is set in respective initial and final positions spaced away from the off position of said first control member and said damp-dry index is set in respective initial and final positions spaced away from the oil position of said first control member, wherein the distance between the initial positions of said bone-dry index and said dampdry index is different from the distance between the final positions of said bone-dry index and said damp-dry index, an index marker carried by said support and commonly cooperating with said bone-dry index and said damp-dry index so that said first control member may be initially set a variable distance away from its off position in accordance with the preset position of said bone-dry index or the preset position of said damp-dry index depending respectively upon Whether the clothes are to be dried to a bone-dry state or to a damp-dry state, a timer operative to return said first control member back into its off position during a variabletime interval dependent upon the initially set position or" said first control member, a switch having open and closed positions for controlling operation of said tumbling means and energization oi said heating means, and means responsive to setting of said first control member away from its off position for actuating said switch into its closed position and for initiating operation of said timer and responsive to the return of said first control member back into its off position for actuating said switch into its open position and for arresting operation of said timer.

6. Control mechanism for a clothes drier in cluding means for tumbling the clothes, and means for heating the clothes; said mechanism comprising a stationary support, a first movable control member having an off position and carried by said support and manually settable with respect thereto, a first movable element carried by said first control member and having a bone dry index, a second movable element carried by said first control member and bearing a dampdry index, a second movable control member car-- ried by said first control. member and manually settable with, respect thereto, drive means responsive to setting of said second control themher for setting both of said elements with re s'pect to said first control member, said first and second control members bearing cooperating weight indicia so that both said bone-dry index and said damp-dry index may be selectively set to positions disposed variable distances away from,

the off position of said first control member in accordance with the weight of the clothes to be dried, said drive means being so constructed and arranged that when said second control member is set in respective maximum. and minimum weight positions said bone-dry index is set in re spective initial and final positions spaced away from the off position of said first control member and said damp-dry index is set in respective initial and final positions spaced away from the oil position of said first control member, wherein the distance between the initial positions of said bone-dry index and said damp-dry index is greater than the distance between the finalpositions of said bone-dry index and said damp-dry index, an index marker carried by said support and commonly cooperating with said bone-dry index and said damp-dry index so that said first control member may be initially set a variable distance away from its oil position in. accordance with the preset position of said bone-dry index or the preset position of said damp-dry index depending respectively upon whether the clothes are to be dried to a bone-dry state or to a dampdry state, a timer operative to return said first control member back into its off position during a variable time interval dependent upon the initially set position of said first control member, a switch having open and closed positions for controlling operation of said tumbling means and energization of said heating means, and means responsive to setting of said first control member away from its off position for actuating said switch into its closed position and for initiating operation of said timer and responsive to the return of said first control member back into its ofi position for actuating said switch into open position and for arresting operation of said timer. c

'7. The control mechanism for a clothes drier set forth in claim 6, wherein said drive means includes difiierential gearing establishing a fixed ratio between the movements of said elements.

8. Control mechanism for a clothes drier including means for tumbling the clothes, means for heating the clothes, a timer that is adapted to be selectively set to operate during a variable time interval, and means controlled by operation of said timer for operating said tumbling means and for energizing said heating means; said mechanism comp-rising a first rotatable control member having an off position and carried by said timer and manually settable away from its off position a variable angular distance to set said timer to operate a corresponding variable time interval, a first rotatable element carried by said first control member and bearing a bonedry index, a second rotatable element carried by said first control member and bearing a dampdry index, a second rotatable control member carried by said first control member and manually settable with respect thereto, drive means responsive to setting of said second control member for setting both of said elements with respect to said first control member, said first and second control members bearing cooperating weight indicia so that both said bone-dry index and said damp-dry index may be selectively set to positions disposed variable angular distances away from the off position of said first control member in accordance with the weight of the clothes to be dried, said drive means being so constructed and arranged that when said second control member is set in respective maximum and minimum weight positions said bone-dry index is set in respective initial and final positions angularly spaced away from the oil position of said first control member and said damp-dry index is set in respective initial and final positions angularly spaced away from the off position of said first control member, wherein the angular distance between the initial positions of said bone-dry index and said damp-dry index is greater than the angular distance between the final positions of said bone-dry index and said damp-dry index, and a stationary index marker commonly cooperating with said bone-dry index and said damp-dry index so that said first control member may be initially set a variable angular distance away from its off position in accordance with the preset position of said bone-dry index or the preset position of said damp-dry index depending respectively upon whether the clothes are to be dried to a bone-dry state or to a damp-dry state.

9. The control mechanism for a clothes drier set forth in claim 8, wherein said first control member houses said elements and has a transparent window formed therein through which said bone-dry index and said damp-dry index are visible from the exterior.

10. The control mechanism for a clothes drier set forth in claim 8, wherein saidfirst control member is in the form of a disk housing said elements, and said second control member is in the form of an annular knob mounted upon the front control portion of said first control member.

11. Control mechanism for a clothes drier including means for tumbling the clothes, means for heating the clothes, a timer that is adapted to be selectively set to operate during a variable time interval, and means controlled by operation of said timer for operating said tumbling means and for energizing said heating means; said mechanism comprising a first rotatable control member having an off position and carried by said timer and manually settable away from its off position a variable angular distance to set said timer to operate a corresponding variable time interval, a first rotatable element carried by said first control member and bearing a bonedry index, a second rotatable element carried by said first control member and bearing a dampdry index, a second rotatable control member carried by said first control member and manually settable with respect thereto, drive means responsive to setting of said second control memher for setting both of said elements with respect to said first control member, said first and second control members bearing cooperating weight indicia so that both said bone-dry index and said damp-dry index may be selectively set to positions disposed variable angular distances away from the off position of said first control member in accordance with the weight of the clothes to be dried, said drive means being so constructed and arranged that when said second control member is set in respective maximum and minimum weight positions said bone-dry index is set in respective initial and final positions angularly spaced away from the off position of said first control member and said damp-dry index is set in respective initial and final positions angularly spaced away from the off position of said first control member, wherein the angular distance between the final position of said bone-dry index and the off position of said first control member is greater than the angular distance be- 18 tween the initial position of said bone-dry index and the 011 position of said first control member and the angular distance between the final position of said damp-dry index and the off position of said first control member is greater than the angular distance between the initial position of said damp-dry index and the oil position of said first control member and wherein the angular distance between the initial positions of said bone-dry index and said damp-dry index is greater than the angular distance between the References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,463,934 Allen Mar. 8, 1949 2,467,848 Newell Apr. 19, 1949 2,505,041 Gorsuch Apr. 25, 1950 2,561,348 Dunham July 24, 1951