US3293769A - Adjustable cool-down control for dryer cycle - Google Patents

Description

Dec. 27, 1966 w. GRAHAM 3,293,769

ADJUSTABLE COOL'DOWN CONTROL FOR DRYER CYCLE Filed June 18, 1964 l NVENTOR.

Dcgle W Graham A TTOR E YS Uited States Patent OfiFice 3,293,769 Patented Dec. 27, 1866 3,293,769 ADJUSTABLE CGGLDGWN CGNTRGL FGR DRYER KIYCLE Dale W. Graham, Benton. Harbor, Mich, assigncr to This invention relates to improvements in clothes dryers and more particularly relates to a control system for a clothes dryer wherein a cool down period compatible with the size and type of load being dried may be preselected.

The invention specifically relates to a clothes dryer and sequential controlling mechanism therefor, in which the programming of one or more of the sequential operations of a fabric treatment cycle, such as the cooldown period or heat-01f period, may be adjusted or modified with respect to the duration of another operation of the treatment cycle or heat-on period.

The control mechanism includes a timer mechanism incorporating a motor driven shaft having at least one cam thereon regulating the heating of the air stream supplied to the dryer drum and the termination of the fabric treatment cycle and having modifying cam means associated therewith which may be so arranged as to vary the length of an operation in the cycle of fabric treatment by manual positioning of the modifying cam.

In the disclosed embodiment of the invention, the modifying cam is adapted to provide a cool-down time of a clothes drying apparatus in which the heat is turned off and the blower and tumbling drum continue to operate, although it should be understood that the principles of the present invention may also be applied toward modifying the heat-on time as well as the cool-down time.

A principal object of the present invention is to provide a clothes dryer and control therefor operable to selectively provide an operation in the fabric treatment cycle of a clothes dryer in addition to the heating operation, the length of time of which may readily be varied.

Another object of the invention is to provide an improved form of control means for controlling the cycle of operation of a clothes dryer in which a cool-down time of the treatment cycle may be provided and selected in accordance with the size of load and material to be dried.

Another object of the invention is to provide a sequential controller particularly adapted to control the treatment cycle of a domestic clothes dryer including a cam driven by a timer motor and positionable to control the heat-on time of drying and .a second cam rotatable therewith and adjustable relative thereto to modify the contour of the control cam and thereby provide cooldown time of the clothes dryer which may readily be adjusted.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawing wherein:

FIGURE 1 is a diagrammatic view of a domestic clothes dryer looking at the dryer from the back thereof with certain parts of the back cover broken away;

FIGURE 2 is a top plan view of the timer shaft and cams of a timer for domestic clothes dryer showing the control cams in horizontal section;

FIGURE 3 is an end view of the dial knob shown in FIGURE 2 and showing the control means for varying the cool-down time of the dryer; and

FIGURE 4 is a diagrammatic view illustrating the timer and modifying cams and the control circuit to the heater and dryer drum motor.

In the embodiment of the invention illustrated in the drawings, I have shown in FIGURE 1, in general diagrammatic form, a clothes dryer 10 having a control therefor of a type suitable for carrying out my invention. The clothes dryer 10 generally includes a tumbler drum 11 rotatably journalled in acabinet 12 for the clothes dryer. The tumbler drum 11 is driven from amotor 15, to tumble clothe-s therein, through a conventional form ofbelt drive 16. Aheater duct 17 extends vertically along aback plate 19, extending along the back of the dryer drum 11 and communicating with air at atmospheric pressure at the front of thecabinet 12 through aduct 29. Theheater duct 17 has communication with the dryer drum through a port 21.

A suitable heater 23 (FIGURE 4), diagrammatically shown as being an electric heater, is mounted within theheater duct 17 to heat the air discharged into the dryer drum and thereby effect the drying of clothes in the drum. While theheater 23 is shown as being an electric heater, it need not be an electric heater, but may be a gas heater controlled by electrically energizable gas valves. Air is drawn into theduct 20, theheater duct 17, through the dryer drum by ablower 24 driven from themotor 15 through abelt drive 25 and having communication with the back of the dryer drum through theplate 19. Spent air drawn through the dryer drum by theblower 24, and tumbling clothes therein, is discharged to the atmosphere through a port opening 26.

A sequential controller or timer generally indicated byreference character 27 is provided at the back of thecabinet 12 and includes adial knob 29, pinned or otherwise secured to atimer shaft 30, suit-ably journalled in acasing 31 for the timer and driven from atimer motor 32 in a suitable manner. The timer motor may be a conventional form of electrically enengizable timer motor having reduction gearing in the housing for the timer motor for driving thetimer shaft 30 for substantially one complete revolution, in the time required to dry a normal heavy load of goods in the tumbling drum 11. The timer motor and the drive to the timer shaft 13, therefore, need not herein be shown or described further.

A cycle control ortimer cam 33 is pinned or otherwise secured to thetimer shaft 30 for rotation therewith. Said cycle control ortimer cam 33 has a raisedperipheral cam surface 35 which extends for a greater portion of the circumference of the cam and alow portion 38 of the cam which connects opposite ends of thehigh portion 35 together. Thehigh portion 35 determines the heating period of theheater 23, which may be a resistor type of electrically energizable heater, while thelow portion 38 determines a plurality of off positions.

As shown in FIGURE 4, a resilient switch arm 37 has acam follower 36 and acontact 42 on the end thereof engage-able with acontact 43 on aresilient switch arm 44. Engagement of thecontact 42 with thecontact 43 will complete an energizing circuit to thetiming motor 32 and thedrive motor 15. Theswitch arm 44 also has acontact 45 on the opposite side thereof from thecontact 43 for engaging acontact 46 on aresilient switch arm 47. Engagement of thecontact 45 with the contact 4-6, effected by the riding of thefollower 36 on the raisedcam surface 35, will complete an energizing circuit to theheater 23, to supply the heat in theheater duct 17 necessary to dry articles of clothing and the like in the tumbling drum 11, in a predetermined period of time, depending upon the type and weight of the articles to be dried.

Acycle modifying cam 50 is rotatably mounted on theshaft 30 adjacent thecam 33 and has aplane face 54 3 frictionally engaged with aplane face 34 of thecam 33, biased by aspring 51 encircling theshaft 31 As diagrammatically shown in FIGURE 2, thespring 51 is interposed between acollar 52, pinned or otherwise secured to the shaft 39, and ahub 53 extending from thecycle modifying cam 50. The cycle modifying cam, therefore, normally rotates with thecam 33, but may be moved with respect to thecam 33, when it is desired to change or modify the contour of thecam 33 to give a predetermined effective profile of the combined cams.

As diagrammatically shown in FIGURES 2 and 3, anarm 55 extends radially outwardly of thehu 53 and is suitably secured thereto. Anarm portion 56 extends axially of the outer end portion of thearm 55 over thedial knob 29 on theshaft 36. Thearm 56 has an inwardly extending indexing end orpointer 59 terminating in a point and cooperating with indicia 66 to an outerinclined face 61 of thedial knob 29. The indicia 6d are in registry with thelow portion 38 of thecam 33 and correspond to the time of a cool-down period attained by movement of a raisedcam face 62 of thecam 50 to mask saidlow portion 38. As for example, when thepointer 59 is in registry with thenumeral 12, the dryer drum will rotate for a cool-down period of 12 minutes with the heat off.

Thecycle modifying cam 50, as shown in FIGURE 4, ha a raisedcam face 62, extending for a portion of the circumference thereof and terminating into a reduceddiameter face 63 of the same diameter as the reduceddiameter face 38 of thecycle control cam 33.

The rise of thecam face 62, when engaged by thefollower 36, is sufiicient to engage thecontact 42 with thecontact 43 and maintain a circuit to themotor 15 and thetimer 32. When thefollower 36 rides along a reduceddiameter face 63 of thecam 50, and along theface 38 of thecycle control cam 33, thecontact 42 will be moved out of engagement with thecontact 43 and thedrive motor 15 andtimer motor 32 will be deenergized and the dryer will stop. Thus cam faces 38 and 63 provide a plurality of off positions, determined by selection of the duration of the cool-down period.

It will be noted from FIGURES 2 and 3 that thecycle modifying cam 50 is positioned by operation of thearm 55. By moving said arm in a counterclockwise direction, the cool-down period is increased. Thecams 33 and 50 are rotated together in a clockwise direction by the timer to carry out a sequential treatment cycle.

It may further be seen from FIGURES 3 and 4 that the cycle modifying cam can be adjusted to vary the cool-down period from zero to 12 minutes and that when positioning the cycle modifying cam to select the cooldown period, thecam 33 may be held from rotation by holding thedial knob 29, while thecam 50 is rotated by grasping thepointer 59 and moving said pointer in registry with a desired cool-down period indicated on thedial knob 29, it being understood that thedial knob 29 is turned in a clockwise direction to select the length of a drying cycle in accordance with the type of goods to be dried.

The cycle modifying cam shown in the drawings is of a configuration which varies the cool-down period, leaving the heat-on period constant, and thus varies the total cycle time within the limits of the cool down period. The cycle modifying cam, however, may be of a configuration which varies the heat-on period, leaving the total cycle time constant. In the latter case, the cycle control cam may be provided with the combined cam contour shown in FIGURE 4 and the cycle modifying cam provided with a peripheral raised portion equal to the diameter of raisedportion 35 shown in FIGURES 2 and 4. The cycle modifying cam may then be positioned in such a manner as to increase the heat-on portion of the treatment cycle while simultaneously decreasing the cool down portion of the cycle.

While I have herein shown and described exemplary forms in which the invention may be embodied, it may readily be understood that various variations and modifications in the invention may be attained without departing from the spirit and scope of the novel concepts thereof.

The embodiments of the invention in which an eX- clusive property or privilege is claimed are defined as follows:

1.. In a control for a clothes dryer having a drying chamber,

motor-driven means for tumbling clothes in the drying chamber and for translating air thereover and a heater for heating the air,

the combination of a rotatable sequence timer manually movable from an inactive position to selective active positions and controlling operation of the heater and the motor driven means,

a multiple parts cam rotatable with said timer,

and said multiple parts together with one another forming a single cam profile having a peripheral cam high portion, a peripheral cam raised portion, and a peripheral cam low portion,

and multiple switch means actuatingly operated by said cam profile and engaging a corresponding multiple of cam followers disposed in operative register with high portion, said raised portion, and said low portion to ope-rate the dryer automatically under the control of said rotatable sequence timer through a drying cycle including (1) a heat-on period, and (2) a cool-down period and an (3) off position,

said heat-on period and said cool-down period corresponding to said high and raised portions on said cam profile,

and adjustment means to selectively modify the heaton period and the cool-down period by selectively adjusting said multiple parts of said cam to modify the profile of the cam by changing the effective circumferential lenth of said com high portion and said cam raised portion.

2. In a clothes dryer having a tumbling drum, a main motor for rotatably driving said drum to tumble goods therein for drying, a heater, and means for drawing heated air through said tumbling drum, the improvement comprising:

a timer controlling the sequential operation of said dryer through a fabric treatment cycle and including a timer motor for driving said timer,

circuit means including an energizing circuit for said main motor,

said timer motor and said heater,

a timer cam rotatably driven by said timer motor and switch means operated by said timer cam for controlling said circuit means,

said timer oam having a high operating said switch means to energize said main motor, said heater and said timer motor,

and having a low portion accommodating the opening of said switch means and the deenergization of said main motor,

said timer motor and said heater,

and second cam means having clutching engagement with said timer cam and driven thereby and having a cam surface adjustably modifying the low portion of said timer cam to deenergize said heater and maintain said main motor and said timer motor in operation to provide a cool-down portion of said fabric treatment cycle,

said switch means including at least three switch arms,

a follower on one switch arm engaging said timer cam and operated thereby to complete said energizing circuit through said three switch arms during rotation of said timer cam as said follower rides on the high portion thereof and operable to break said energizing circuit between said switch arms as said follower rides on the low portion of said timer cam,

and wherein said second cam has a rise spaced radially inwardly of the high cam surface of said timer cam and radially outwardly of the low cam surface of said timer cam and engaged by said follower to maintain said energizing circuit between two of said switch arms and to deenergize the third of said switch arms, to eifect deene-rgization of said heater and the continued operation of said main motor and said timer motor for a cool-down portion of said fabric treatment cycle,

and manually operable means for selectively adjusting the position of said second ca m with respect to said timer cam and the duration of said cool-down portion.

3. In a dryer as defined in claim 2 and further characterized by said second cam being rotatably adjustable with respect to the cam in a direction opposite to the direction of rotation of said cam to control the sequential operation of the dryer,

References Cited by the Examiner UNITED STATES PATENTS Kriechbavm 34-45 X Kostelich 3445 Uilman 74568 Cook 20038 X Hendry 200-38 X Genbavffe 3445X 20 FREDERICK L. MATTESON, JR., Primary Examiner.

D. A. TAMBURRO, Assislant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3, 293, 769 December 27, 1966 Dale W. Graham It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4,line 26, before "high" insert said line 40, for "lenth" read length same line 40, for "com" readcam line 56, after "high" insert portion Signed and sealed this 24th day of October 1967,

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissioner of Patents

Claims (1)

1. IN A CONTROL FOR A CLOTHES DRYER HAVING A DRYING CHAMBER, MOTOR-DRIVEN MEANS FOR TUMBLING CLOTHES IN THE DRYING CHAMBER AND FOR TRANSLATING AIR THEREOVER AND A HEATER FOR HEATING THE AIR, THE COMBINATION OF A ROTATABLE SEQUENCE TIMER MANUALLY MOVABLE FROM AN INACTIVE POSITION TO SELECTIVE ACTIVE POSITIONS AND CONTROLLING OPERATION OF THE HEATER AND THE MOTOR DRIVEN MEANS, A MULTIPLE PARTS CAM ROTATABLE WITH SAID TIMER, AND SAID MULTIPLE PARTS TOGETHER WITH ONE ANOTHER FORMING A SINGLE CAM PROFILE HAVING A PERIPHERAL CAM HIGH PORTION, A PERIPHERAL RAISED PORTION, AND A PERIPHERAL CAM LOW PORTION, AND MULTIPLE SWITCH MEANS ACTUATINGLY OPERATED BY SAID CAM PROFILE AND ENGAGING A CORRESPONDING MULTIPLE OF CAM FOLLOWERS DISPOSED IN OPERATIVE REGISTER WITH HIGH PORTION, SAID RAISED PORTION, AND SAID LOW PORTION TO OPERATE THE DRYER AUTOMATICALLY UNDER THE CONTROL OF SAID ROTATABLE SEQUENCE TIMER THROUGH A DRYING CYCLE INCLUDING (1) A HEAT-ON PERIOD, AND (2) A COOL-DOWN PERIOD AND AN (3) OFF POSITION, SAID HEAT-ON PERIOD AND SAID COOL-DOWN PERIOD CORRESPONDING TO SAID HIGH AND RAISED PORTIONS ON SAID CAM PROFILE, AND ADJUSTMENT MEANS TO SELECTIVELY MODIFY THE HEATON PERIOD AND THE COOL-DOWN PERIOD BY SELECTIVELY ADJUSTING SAID MULITPLE PARTS OF SAID CAM TO MODIFY THE PROFILE OF THE CAM BY CHANGING THE EFFECTIVE CIRCUMFERENTIAL LENTH OF SAID COM HIGH PORTION AND SAID CAM RAISED PORTION.

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