US2050625A - Laundry drying apparatus - Google Patents

Description

Aug. 11, 1936. ORR 2,050,625

LAUNDRY DRYING APPARATUS -Filed NOV 7, 1935 2 Sheets-Sheet 1 INVENTOR Carro 1/ f. Dr!- ATTORNEYS Aug. 11; 1936. c, ORR 2,050,625

LAUNDRY DRYING APPARATUS Filed Nov. 7, 1933 2 Sheets-Sheet 2 :1 g H H I INVENTOR 26; D 4 Carrol/[Orr i 7/ 7 M 42, f/u n ATT RNEYS haunted Aug. 11, 1936 PATENT OFFICE EAUNDRY DRYING APPARATUS Carroll E. Orr, East Orange, N. J., assignor to The American Laundry Machinery Company, Cincinnati, Ohio, a corporation of Ohio Application November 7, 1933, Serial No. 697,022

4 Claims.

This invention relates in general to improvements in laundry drying apparatus such as tumbling dryers in which washed clothes or fabrics are subjected first to a drying action by means of a stream of heated air, and then to a cooling action by means of a stream of relatively colder air.

An important object of this invention is to provide an automatically operating apparatus in which the drying period in such a machine is automatically controlled under the action of the humidity of the air stream after passing over the clothes. I

A more specific object of the invention is to 1 provide an apparatus in which the wet clothes or fabrics are subjected to a drying stream of warm or heated air until their moisture content has be'en reduced to a desired value, upon which under control of the humidity of the issuing o drying air the supply of heated air cut on v and the clothes or fabrics are then sub ected, for

a predetermined period, to the action of a relatively colder stream of air.

A still further object of this invention is to provide automatic control means for subjecting the clothes or fabrics to the relatively colder a1r for a predetermined period upon the termination of which a signal is given, indicating that the clothes or fabrics are ready for removal from 30 the machine.

These and many other obJects as will appear from the following disclosure are successfully secured by means of this invention.

This invention resides substantially in the 35 combination, construction, arrangement and relative location of parts, all as will be more fully detailed in the following specification in connection with the attached drawings.

Referring to the drawings, Fig. 1 is a side 0 elevational view of themachine of this invention with parts of the casing broken away to show the interior arrangement of the various elements; Fig. 2 is a left hand elevational view of the same mechanism with a portion of the 45 casing broken away; and Fig. 3 is a simplified wiring diagram of a portion of the control circuit.

The present invention in its broadest aspect is adapted to automatically control the supply 50 of heated and relatively colder air in various types of machines under the control of the humidity of the air stream. More specifically, the invention has been illustrated as applied to a clothes drying machine, particularly of the 66 drying tumbler type in which a rotatable barrel or drum is employed. The machine as described is substantially automatic in operation, requiring only the attendance of an operator in starting and stopping of the machine at the beginning and end of the drying operation. 5

Referring to the drawings, the machine is shown comprising a casing I, having a door 2 horizontally mounted on the side thereof for access to the interior of the casing. A heavy counterweight 5, operating in a protecting cas- 1 ing 6 is connected by means of a chain 3 mounted on roller supports and a bracket 4, to the door 2 to aid in raising and lowering the heavy door. At l is indicated a portion of the tumbling or drying drum which is mounted within the casing and is provided, in accordance with usual practice, with doors through which the materials to be treated may beinserted. This drum is mounted on a rotatable shaft 8 which is journaled in the bearings 9 at the ends of the casing. Keyed to the shaft 8 is a driving gear wheel 9 which meshes with a driving pinion lD driven in turn by the electric motor l5 through the sprocket wheels i l and i2 and the sprocket chain l3. Thus the motor 15 causes the tumbler l to revolve at the desired speed or, in accordance with well known practice, control circuits may be employed to rotate the drum intermittently in opposite directions. The top of casing I, over the drum l is provided with an opening l6, over which is mounted a duct ll which extends across the top of the machine and is connected to the casing of a suction fan Hi. This fan is driven by means of a motor l9. The lower portion of casing l is proxided with a perforated or screened wall 20 on each side thereof.

Referring to Fig. 2, it will be seen that the space below the bottom wall of the casing and defined by the screened side walls 20 is divided into two compartments which extend throughout the length of the machine. These compartments are formed by a baflle wall 23 extending from one end to the other, and a shutter 24 likewise extending co-incidentally with the baffle wall 23. The shutter 24 is mounted upon a shaft 25 suitably journaled and connected either directly with, or through gears, to the torque motor 26. When the shutter is in the full line position shown in Fig. 2, air may enter into the upper portion of the casing around the tumbler drum 1, through the left hand side of the machine. In the left hand compartment thus formed is means for heating the entering air which is shown for purposes of illustration as steam coils 2i provided with the steam supply connections 22. When the shutter 24 is in the dotted line position air can no longer enter the upper portion of the casing over the heating coils, but must enter it through the right hand perforated side of the machine and pass directly thereto without heating. The torque motor 26 is of the usual type which is, as well known, continuously energized in actuated condition. For the first part of the operation the motor 26 is energized so as to hold the shutter 24 in the full line position. When the energization of the torque motor is reversed, the shutter 24 is moved to the dotted line position and held there.

At I is indicated diagrammatically a humidity meter which may assume any one of a number of well known forms. This device is sensitive to the moisture content of air and has its sensitive element mounted within the duct I! so as to be immersed in the air flowing from the drum 1 to the suction fan. Such a meter is calibrated in relative humidity of from 0 to 100 percent. The humidity meter is provided with a fixed and movable contact in accordance with standard practice, so that the movable contact will engage the fixed contact, depending upon the setting of the apparatus, when the moisture content of the air in which the sensitive element is immersed reaches a predetermined value. accordance with this invention, and as diagrammatically illustrated in Fig. 3, this contact controls mechanism whereby the torque motor is reversed in its energization to swing the shutter 24 from full line to dotted line position.

The operation of this apparatus will be better understood by first referring in detail to the diagrammatic circuit arrangement of Fig. 3. At 88 are indicated the wires which are connected to the power source. At 8! is the main control switch which when the machine is to be operated connects wires 80 with wires 82. The circuit as illustrated is a usual three phase alternating current supply circuit. One of the wires 82 is connected by wire 83 to one of the contacts Aux. The other contact is connected by wire 85 through the relay coil 0, wire 86 and normally closed contact D" to wire 84 which returns to one oi the wires 82. Wire 85 is connected by wire 81 through relay coil D, wire 88, contacts HC to wire 84.

The contacts HC represent the contacts of the humidity meter, one of which is fixed and the other of which is movable by the moving element of the meter. The contacts HC are shimted by the normally open contacts C. Wire 88 is also connected by wire 8| through the normally open contacts D, solenoid winding 0 and wire 82 to wire 84. The solenoid coil 0 is shunted by the signal light 88 and the solenoid coil C is shunted by the signal light 83 which is preierably of a different color. The solenoid C is shunted by another relay coil AGA' which is the relay coil of a time delay switch of which a number are well known in the art. One terminal of this coil is connected through wire 84 and the primary 88 of a transformer, contacts AGA and wire 86 to wire 84. The secondary 81 of the transformer is connected to a signal device 88. It will be seen that all this control mechanism is connected across one of the phases of the power supply. At 28 is diagrammatically illustrated the torque motor which may be connected to the power supply source for energization in either direction through the pairs of contacts 0' and C'. The symbols 0 and C on this diagram represent the open and closed position of the shutter 24, that is the full and dotted line positions, Fig. 2. The tumbler motor i5 and the suction fan motor i9 are not shown in Fig. 3, but are connected to the wires 82 so that when switch BI is closed they are both energized. The operation of the apparatus is as follows:

The tumbler drum 8 is first charged with the wet clothes or fabrics to be dried. The drum is then closed, as well as the door 2 on the casing. Main control switch 8i is then closed. This energizes motors i5 and is causing the tumbler drum 1 to revolve and setting the suction fan 68 in operation. Referring to Fig. 3, the contacts HC on the humidity meter will be open. The closing of switch ill will have energized a relay coil R, which closes the contacts marked Am. The current then flows from lower wire 82 through wire 83, contacts Aux wire 85, relay coil 0, as well as lamp 90 and parallel thereto, wire 86, normally closed contacts I)" and wire 86, back to the power supply. The energization of relay coil 0 will cause contacts 0', in the torque motor circuit to close. This energizes the torque motor 26 to hold the shutter in full line position (Fig. 2). The steam supply will be on so that the heating coils 2! will heat the air which flows in through the left hand side of the casing over the heating pipes, up around and through the tumbler drum which is usually perforated in accordance with standard practice, thence to duct l1 and out through the discharge portion of the suction fan i8. Lamp 90 will indicate that this part of the operation is taking place.

As the clothes in the drum give up moisture the air passing through duct i'l will become dryer and dryer with an appropriate efiect on the humidity meter. When the air has reached a dryness which has been predetermined by experience as indicating that the clothes have been sufliciently dried with hot air, the humidity meter will have moved to a position where the contacts HC close. The closing of contacts HC will cause the energization of relay coil D with the current flowing from the power source through wire 83, contacts Aura, wire 85, wire 81, coil D, wire 88, contacts 'HCand wire 84, back to the current source. The energization of relay coil D causes the opening of contacts D" and the closing of contacts D', thus energizing relay coil C with the current flowing from wire 85 through wire 8|, contacts D, relay coil C, wire 92 and back to the current source through wire 84. With the energization of relay coil C, the reversing contacts C are arranged toclose, and at the same time contacts C" are closed. The opening of the normally closed contacts D" at the time that the contacts D' close. deenergizes relay coil 0 and causes the opening of the contacts O'. Substantially simultaneously with the opening of these contacts 0' the contacts C will close (under the control of relay coil C), causing a reversal of the energization of the torque motor 26, so that it will swing the shutter II from full line position to dotted line position. Unheated air is then drawn through the right hand side of the machine around and through the tumbler to duct" and out of the discharge port 01 the suction fan i8. During this action lamp 88 will be extinguished and lamp 93 will be energized, indicating which part of operation is taking place.

At the same time that relay coil C is energizedthecoil AGAotthe time delayrelayisl's Ell accuses energized. At the end of a predetermined pericd, usually about tour minutes, during which the clothes are subjected to the colder air, the contacts AGA' under the action of the coil AGA. will close, thus completing a circuit to the pri mary 95 through wires M and es. The result is that the secondary 91 will he energized and the signal device 98 will be operated. The operator will then open switch M which deenergizes all circuits, including the motors l5 and IS. The clothes will then be ready for withdrawal from the machine, heving been properly dried and cooled so that they may be handled.

The contacts C" controlled by therelay coil.

are merely provided to complete a' shunt eircuit around the contacts HC of thehumidity meter. The purpose of this arrangement is to prevent what might be termed hunting of the apparatus under transient humidity conditions which would he encountered in an apparatus of this type. The contacts K0 are relatively light contacts which do not make a very strong contact, especially when they first come together at the critical time when the humidity is lust passing through the condition for which the machine is set. In order to insure positive action of the in operation. The humidity of the air flowing through duct ll is a most accurate indication of the moisture content of the clothes in the tumbler The humidity of the issuing air;

is s more accurate indication of the condition of the clothes than the temperature oi the air. It has been found, therefore, with the device oi this invention that u very accurate control of the moisture content of the clothes may he had, which is of cardinal importance for emclent ironing operations.

With this machine properly set the clothes may he dried to just the desired degree with greet uniformity in successive hatches.

From the shove description it will be apparent that this invention resides in certain principles of construction and operation which may he cro bodied by those skilled in the art in other physi cal forms, without deperture from the scope oi the invention. I do not, therefore, desire to he strictly limited to the disclosure as given for "purposes oi illustration, hut rather to the scope oi the appended claims,

What I claim is:

i. A drying machine of the type described comprising a chamber for containing materials to he treated, electric motor means for movins: a current of air through said chamber, hot and cold air supply sources adapted to communicate with said chamber, motor operated means mov able into first end second positions for estahlishing communication with said hot and cold air sources respectively, first and second power circults for actuating said last named means into its first and second positions respectively, a device for energizing either oi said power circuits condition oi the air issuing from sold chamber for actueting said device into its second-powerclrcuit-energisins position.

2. In a drying machine having a chamber for treating work and means for circulating a our- 5 rent of air over said work. including a conduit system, a controlmember in said conduit sys tem movable into first and second positions i'or establishing hot and cold air circulating circuits respectively, electrical operating means for said control member having first and second power circuits for moving said control member into its first and second positions respectively, a normolly open switch in each power circuit, a relay for closing each switch,'an energizing circuit for each relay, spoced contacts in each energizing circuit, a reversing relay-adapted alternatively to close the spaced contacts in either one of said energizing circuits and simultaneously to open the spaced contacts in the other of said energiz- 29 ing circuits, said reversing relay being arranged normally to close one pair of said spaced con tacts, a control device responsive to a condition of the air in said conduit system on the discharge side of said chamber, an energizing circult for said reversing relay, a mor-molly open switch in saidlast named circuit, and means actuated by said control device in response to a predetermined air condition for closing said last named switch. 3. A control system for a drying machine as in claim 2 and including a shunt circuit eround said last named switch, normally open contacts in said shunt circuit, and means for electrically closing said last named contacts upon actuation of said control device. e. in a drying machine hsving e chamber for treating work and means for circulating a current of air throush said chemlccr including a conduit system, a control mernher in said conduit system movehle into first and second positions for establishing hot and cold ulr circu lating circuits respectively, electrical operating means ior said control mernloer having first and second newer circuits for moving said control member into its first and second positions re= spectlvely, a normally egocn switch in each grower circuit, first and second'relays for closing the switch in sold first end second newer circuits respectively, an energizing circuit for eschre== lay, cussed contacts in such energizing circuit, a reversing relay adapted elternstively to close the spaced contests hi either one oil id ener gimme? circuits and simultaneously to open the spaced contacts in the other of said energizing circuits, said reversing relay losing arranged nor molly to close the spaced contacts in the ener sizing circuit for said first roles, control olevice responsive to a condition oi the sir in said conduit system on the discharge side oi said so ill ' chamber, an energizing circuit for said revers inc relay, a normally open switch in sold last named circuit, means octuatcd by said control device in response to a predetermined air con, dition for closing sold last switch, es whereby said reversing reley closes the contests in the energizing circuit Ker said second relay, an electricel device, a tlme=deleyed rcloy for. energizing ssid electrical device, end moons for initiating theaction or said time dclsyed relay m l by enersisotion or the circuit for said second relay.

CLL E, ORR.

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