US2678814A - Clothes drier and electrical control thereof - Google Patents

Description

May 18, 1954 P. E, GELDHOF ET AL 2,673,814

CLOTHES DRIER AND ELECTRICAL CONTROL THEREOF Original Filedflct. 22, 1949 4 Sheets-Sheet l lmn ll W I??? FEE 1-1 ZE T5 Pei-Gr Eduard G l Harald E. Morrison 231:7 Eff-1 75 y 18, 1954 P. E. GELDHOF ETAL CLOTHES DRIER AND ELECTRICAL CONTROL THEREOF 4 Sheets-Sheet 2 Original Filed 001.. 22, 1949 Eire-1112227115- Peer Eduard Geld/z of Hawk! 5. Morrison y 13, 1954 P, E. GELDHOF' arm. 2,678,814

CLOTHES DRIER AND ELECTRICAL CONTROL THEREOF Original Filed Oct. 22, 1949 4 Sheets-Sheet 3 Pei-er Eduard Geld/70v" [:Ezrola E. Morrison 4 Sheets-Sheet 4 III-IVE 17 Z22? r 5 Peter Eduard Geld/ 0f Harald E .Morrison P. E. GELDHOF ET AL CLOTHES DRIER AND ELECTRICAL CONTROL THEREOF w bm n? 3 EW i A ewmx as I $5 s u x ms GIQWWQGNW Q u mm.- b

May 18, 1954 Original Filed Oct. 22 1949 Patented May 18, 1954 CLOTHES DRIER AND ELECTRICAL CONTROL THEREOF Peter Eduard Geldhof Mic Benton Harbor, Corporation, St. of New York and Harold h., assignors Joseph, Mich., a corporation E. Morrison, to Whirlpool Original application October 22, 1949, Serial No. 123,018. Divided and this application January 31, 1951, Serial No. 208,708

5 Claims. (01. 263-33) 1 This invention relates to improvements in Figure 6 is a schematic wiring diagram a clothes driers and controls therefor, and more particularly, relates to improvements in electrical controls controlling the operation of household clothes driers or the type where the clothes are tumbled in a rotating drum through which heated air from a gas burner is circulated.

A principal object of our invention is to provide a new and improved form of clothes drier and control therefor arranged with a view toward utmost simplicity in control and safety in operation.

A further object of our invention is to provide a novel and efficient form or clothes drier and control therefor so arranged that when the temperature rises above a predetermined maximum within the clothes drum, the heat will automatically be turned off without interrupting rotation of the drier drum.

Still another object of our invention is to provide a new and improved circuit for a clothes drier, controlled by a door-operated switch and a timer switch and so arranged that the door operated switch and timer switch are energized to initiate the drying operation when the door is closed, and the timer switch continues to the end of its time cycle irrespective of whether heat may be turned off within the drier due to excessive temperatures, to continue the rotation of the drier drum to the end of the drying cycle to cool and prevent burning of the clothes therein.

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

Figure 1 is a view in side elevation of a drier constructed in accordance with our invention with certain parts broken away, and certain other parts shown in transverse section;

Figure 2 is a longitudinal sectional view taken through one of the control valves for supplying gas to the burner;

Figure 3 is a longitudinal sectional view taken through another of the valves and showing the by-pass connection to the pilot;

Figure 4 is an end view of the pilot used in a drier of the present invention;

Figure 5 is a schematic wiring diagram oi! a control circuit for the drier and burner valves; and

gas to a main gas burner modified form of control circuit.

This application is a division of application, Serial No. 123,018, filed on October 22, 1949, now Patent No. 2,635,354, and entitled Gas Heated Drier."

The gas burner and pilot of our invention is herein shown as being operative to supply heat to a clothes-drying drum I0 of a household type clothes drier as shown and described in our parent application. The drier itself, therefore, need only oe described generally herein.

As herein shown, the drier drum I0 is rotatably mounted within a casing I I on a bulkhead I2 confronting the rear wall thereof and confining the circulation of air to pass into and out of said drum in a manner clearly shown and described in our parent application, Serial No. 123,018, previously mentioned.

The drier drum is rotatably driven by means of an electric motor 85, diagrammatically illustrated in Figure 5. The air may be heated for circulation into and out of the drum through the rear wall thereof by means of a gas burner I05 extending within a combustion chamber 98 connected with a flanged opening 06 in the bulkhead I2, by means of a duct extending vertically from said combustion chamber and communicat- 'mg with said flanged opening.

Referring now in particular to Figures 2, 3 and 5 of the drawings illustrating the gas burner and control circuits therefor, a pipe I34 leading from a gas supply main is connected to deliver gas to a first gas valve [35 which, in turn, delivers supply valve I36 through valve I36, upon being through a bleeder tube a pipe I381). The gas opened, also supplies gas I52 to a pilot burner I31.

The gas burner I05 may be of well known construction and is supplied with gas from the main burner valve 136, suitably connected thereto. The bleeder line I52 leads from the main burner valve I36 and is connected at its free end with the pilot i3l disposed adjacent the end of the main burner valve I05 to supply a gas flame for lgniting the gas passing through said main burner valve. The pilot flame may be ignited by a glow coil I39 energized by the secondary or a transformer I38. The glow coil I39 is positioned adjacent the pilot I31 to ignite said pilot.

The gas supply and the ignition oi the gas is under the control of an especially designed electrical circuit equipped with suitable safety devices to assure safe and efiicient operation of the drier. This control, as may be seen best from an inspection of Figure 5, includes a warp switch I18 having metallic contact elements HI and I12 which will deenergize the control circuit to the gas valve I35 and to the glow or ignition coil I39 in the event that the pilot does not ignite.

The control includes a flame-detecting switch I60 in the main gas valve I36, as shown in Figure 3, and which, in its cold position indicates the absence of a pilot name by engaging contact I6I, and in its hot" position indicates the presence of a pilot flame by engaging the contact element I62. A thermostat I13 is provided to turn the main gas burner on and on during normal op eration and thereby control the temperature within the clothes-drying drum I0. A safety thermostatic switch I15 is provided for emergency purposes and is arranged to open at a substantially higher temperature than that of thermostat I13. This safety thermostatic switch I15 may be located on the housing adjacent the hot air supply duct 35.

Provision is also made for lightin the interior of the clothes drum when the door is opened, which is herein shown as being an electric light I3I connected in series with a door switch 6| erated by opening and closing of the drier door (not shown) The particular manner in which the various elements are electrically connected will now be described. Electrical energy is derived from a suitable source of power through conductors I16 and I11. In one side of the line, the door switch BI is connected. This door switch 6| includes a movable contact element I18 and two stationary contacts I closing of the door, as described in our parent application, Serial No. 123,018, of which this application is a division.

When the door is in its closed position, the movable contact element I18 engages the stationary contact I19, and when the door is in its open position, the movable contact I18 engages the stationary contact I80.

Suitable ignition means is provided for the primary of which is energized through the warp switch I10, the flame-detecting switch I60, and a pair of timer-controlled switches I8I and I32. The switches [III and I62 are closed upon setting a timer motor I83 to its time-setting position and will termined periods of t1me, switch I82 being arranged to stay closed for a longer period of time than switch I8I.

It will thus be seen from an inspection of Figure that with the closure of the timer switches I3I and I82 and the door switch 6| so that its movable contact element I18 engages its lower contact I19, current flows through the transformer I38, the glow coil I33, the solenoid I40 of the gas valve I35, through warp switch contact elements In and I12 to the other side of the line. also flows through the heatil'lg element I 84 to the other side of the line. The heatin element I84 has a metal sheath I84a which absorbs heat providing a time delay to the action of the element I12.

It will also be observed from an inspection of Figure 5 that the closure of the door switch BI 19 and I80 actuated upon opening and to its lower position energizes the main drive motor through timer switch I 32, while the timer motor likewise is energized through a parallel circuit around the main motor 85. It will further be seen that the main gas valve I36 cannot be energized until the pilot flame has heated up the temperature-sensitive bulb or responsive element I51 which actuates the switch I06 against a, spring I58 to its hot position, namely, with its movable contact element I 60 positioned against stationary contact I62. At this time, the solenoid I63 of the main gas valve I 36 is energized and the full supply of gas is supplied to the main burner I05. It will be noted that the drum tempcrature-responsive thermostat I13 is in series with the energizati-on circuit of the main gas valve I36.

It will also be apparent that in the event the temperature rises above a predetermined maximum within the clothes drum I0, the solenoid I63 becomes deenergized and the main gas valve closes.

The pilot is, of course, still burning so that upon dropping of the temperature within the drum, the thermostatic switch I13 upon reclosing will again open the main gas valve. It is to be noted, however, that if, for any reason, the pilot has gone out, the switch I60 will return immediately to its position against contact IfiI and prevent reopening of the main gas valve even though the thermostatic switch I13 closes.

Timer switches I8I and I62 are so arranged that timer switch IBI opens a. predetermined period of time before the opening of timer switch I82, thus assuring a running of the machine without heat, for a predetermined time after the heat is shut oil. After this additional period of time has elapsed, contact I82 opens, thus deenergizing both main motor 82 and timer motor I83.

Certain additional safety switches are provided in the circuit for reasons which will be apparent to those skilled in the art. In the event the flame-detecting switch I60 on the gas burner valve does not move from its cold to its hot" position due to failure of current to the glow coil I39, defective glow coil, or failure of gas supply, the warp switch element I10 will open to shut 01? current to the gas valves I35 and I36 and the transformer I383. The warp switch may be of any conventional construction and is diagram- When the warp switch is open, the motor 85 will continue to run after the defect has been corrected.

As previously pointed out, the safety switch I15 operates at a higher temperature than the thermostat I13. It thus eliminates danger to the clothes which might be caused by the failure of the thermostat; I23, for upon opening of the safety switch I15, the main gas burner valve I36 will be closed, the. pilot valve I35 will be closed, and the transformer I36 and warp switch I10 will be deencrcized The light to illuminate the interior of the drum to facilitate inserting and removing clothes is operated through the door switch 6! when the movable contact element H8 thereof is in its upper position against stationary contact Hill. This condition results from the opening of the door.

The thermostat H3 is an adjustable one to facilitate a control of the heating temperature within the drum. In order that the opening and closin temperature of the thermostat H3 may be adjusted, a control knob i1 is provided on the outer side of the cabinet.

In Figure 6, a schematic diagram of a modified control circuit is illustrated. In this circuit, the elements are exactly the same as in Figure 5 and will be designated by the same reference numerals plus an aflix a.

In this circuit, a switch 25a is connected in the conductor llfia to deenergize the entire drier circuit, and the pilot valve solenoid Mild is connected to the conductor IIBa at the outer side of the switch 25a, so that it is always energized as long as the switch 250. is closed so that the pilot I3! is continuously supplied with gas even though the washing cycle is completed. Then, after one drying cycle is completed, another can be started immediately without waiting for the transformer 138a to heat the glow coil i39a for starting the pilot burner which would subsequently actuate the hot-cold switch liifla.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

We claim as our invention:

1. A gas-heated clothes drier comprising a cabinet having a rotatable clothes drum journaled therein and a door afiording access to said drum, an electric motor mechanically connected to said drum to rotate the same, a main gas burner having a gas supply line connected thereto, a first solenoid-operated valve in said supply line, a second solenoid-operated valve in said supply line between said first valve and said burner, a pilot burner connected to said supply line between said first and second valves, a door switch, a timer having one switch closing upon the setting of the timer to initiate the drying operation and another switch which closes upon initiation of a cycle of operation and which opens after the elapse of a predetermined period of time, an electric energlzation circuit, a flame switch actuatable by the presenc of a flame in said pilot burner, a first stationary contact engaged by said flame switch when no flame is present in said pilot burner, a second stationary contact engaged by said flame switch when a flame is present in said pilot burner, an adjustable thermostatic switch, said first valve being electrically connected to said circuit through said first stationary contact of said ilame switch and said timer switch, and said second valve being electrically connected to said circuit through said thermostatic switch, said second stationary contact of said flame switch and, said second switch of said timer switch and said door switch, said drum-rotating motor being connected to said circuit through said first switch of said timer switch and said door switch, and said first switch of said timer switch remainin closed after opening of said second switch, to continue rotation of said motor when the flame is out.

2. A clothes drier comprising a cabinet, 9, rotatable drum within said cabinet, said cabinet having a door opposite one end of said drum, an electric motor connected to drive said drum, electrically controlled heating means operated by said motor, means for circulating heated air through said drum, a door switch movable to a closed position by closure of said door, a timer having two switches closing at diiierent time intervals, said electrically controlled heating means being energized through said second switch and said motor being energized through said door switch through said first switch, said first switch closing prior to said second switch, and said switches opening in a reverse order, whereby said motor and drum continue to rotate after the heat is turned off.

3. A clothes drier comprising a cabinet, a rotatable drum within said cabinet, said cabinet having a door opposite one end of said drum, an electric motor connected to drive said drum, a timer having two switches, one of which closes upon settin of the timing cycle and the other of which closes in a time delayed interval upon the initiation or a cycle of operation and which opens after the elapse of a predetermined period of time, electrically controlled heating means, means driven by said motor for circulating heated air through said drum, a door switch movable to a closed position by closure of said door, said electrically controlled heating means being energized through said second switch of said timer and said door switch, and said drum-rotating motor being energized through said first switch of said timer and through said door switch.

4. In a clothes drier, a cabinet having a door affording access to the interior thereof and a drier drum rotatably journaled therein having a clothes-receiving opening confronting said door, a motor within said cabinet for driving said drum and circulating heated air therethrough, electrically controlled means for heating the air in said drum, and means operable upon closing of said door, for energizing said motor and said electrically controlled means, comprising a door switch having a contact connected to energize said motor upon closing of the door, a timer having one switch in series with said motor and said door switch and closing upon setting of the timer to it cycle of operation, and having another switch in series with said electrically controlled means for heating the air, and a timer motor in parallel with said first motor and energized upon the setting of said timer, to close said second switch after a predetermined time interval, to energize said electrically controlled means for heating the air, and opening prior to the opening of said first switch of said timer, to maintain said motor in operation after the heating means has been shut off, until opening of said door switch.

5. In a clothes drier, a cabinet having a door for access to the interior thereof, a drier drum rotatably mounted within said cabinet and having a clothes-receiving opening confronting said door, a motor within said cabinet for driving said drum and circulating heated air through said drum, electrically controlled means for heating the air in said drum, an energizing circuit operable upon the closing of the door for energizing said motor, said electrically controlled means comprising a door switch having a contact connected; to energize said motor upon closing of the door, a, timer having one switch in series with said motor and closin on setting of said timer, to initiate the drying cycle and having another switch in series with said electrically controlled mean for heating the air in said drum, a timer motor in parallel with said motor and energized 75 upon the setting of said timer to close said one 7 mhotsntcennmt ammnturmnfleaermingcircmt thmughsald dear switch, Mather moatafleakly operated switch in wins with said second switch at said timer and opening when tha heat vmlfinsaid driardmm reaches a pre- W was. whereby said mater win m mammal drier drumwhen theheatts Medofl.

kemrgncescited-inthefileei hbpaknt STATES mum Name Date Carroll June 2 192 Number 8 Name Date Klein Apr. 1%,. 1.945 Broglie- Apr. 2 I946 Mintner et a1. Feb. 21. 1 9 Moore May 2, 195,0 Kauflman II Apr. 10', tfil Strobe! Aug. 21, 1951- Weber et a1 Aul. 21. 19%

Wagner Mar. 25, 1952

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