US2880521A - Laundry machine including improved heater and condenser arrangement - Google Patents

Description

April 7, 1959 M JR 2,880,521.

W. E. GR LAUNDRY MACHINE INCLUDING IMPROVED HEATER AND CONDENSER ARRANGEMENT Filed Dec. 8, 1955 3 Sheets-Sheet l 38 10a 7 lob INVENTOR.

WALTER E. GRAY, JR.

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HIS ATTORNEY Aprll. 7, 19 w. E. GRAY, JR 2,880,521

7 LAUNDRY MACHINE INCLUDING IMPROVED HEATER AND CONDENSER ARRANGEMENT 7 Filed D00; 8, 1955' 3 Sheets-Sheet 2 'INVENTOR. WALTER E. GRAY, JR.

HIS A T RNEY April 7, 1959 .w. E. GRAY, JR 2,880,521 LAUNDRY MACHINE INCLUDING IMPROVED HEATER AND CONDENSER ARRANGEMENT Filed Dec. 8, 1955 5 Sheets-Sheet 3 FIG. 3 45 I lo 300.

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O O I I J I I75- 0 o INVENTOR. WALTER E- GRAY, JR.

HIS ATTORNEY United States Patent i LAUNDRY MACHINE INCLUDING IMPROVED HEATER AND CONDENSER ARRANGEMENT Walter E. Gray, Jr., Erie, Pa., assignor to General Electric Company, a corporation of New York My invention relates to clothes dryers and combination washer-dryers and more particularly to such machines including a cold wall condenser for condensing the moisture extracted from the clothes.

It is an object of my invention to provide a new and improved arrangement of the heaters and the cold wall condenser within a dryer or a combination washer-dryer so that a particularly elficient drying cycle is produced.

Another object of my invention is to include a thermostat in this heater and condenser arrangement in a manner whereby it accurately senses the temperature of the clothes being dried. v

In carrying out my invention I provide a laundry machine having a clothes basket rotatable about a horizontal axis. The basket is enclosed by 'an impe'rforate tub and drive means are provided for rotating the basket in a predetermined direction ofrotation so that it moves upwardly past one side of the tub and downwardly past the other side. A heater assembly is included for heating the clothes to extract moisture therefrom, and a cold wall condenser is provided for condensing the moisture. By my invention the heater and the condenser are so arranged within the tub that a particularly efficient drying operation is produced. The condenser is disposed on the "side of the tub past which the basket moves upwardly and in particular is disposed below the center line of that side. The heater assembly is also mounted on the same side of the tub but above the center line. Thus the basket and the clothes being tumbled move upwardly first past the condenser and then past the heater assembly. The clothes in the basket are directly exposed to the surface of the condenser and are held in close proximity therewith while they are being lifted by the rotating basket from the bottom portion of the tub, past the condenser, to the horizontal center line of said tub. This action results in an efiicient clothes drying operation with a minimum condenser area being required.

The features of my invention which I believe to be "novel are set forth in particularity in the appended claim. My invention itself, however, both as to its organization and method of operation, may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a rear elevational view "of a combined clothes 'Washing and drying machine embodying my invention in one preferred form thereof, the view being partially broken away and partially in section 'in order to illustrate the details of my "invention;

Fig. 2 is a side elevatio'nal view of the machine of Fig. 1 with the side panel "removed; and p Fig. 3 is a side elevational view of the machine with certain surfaces broken away and with certain surfaces in section to illustrate details.

Referring now to the drawings, I have shown therein a domestic laundry machine .1 comprising a combination "washer and dryer. As described hereinafter, this machine includes an arrangement or a heater assembly and 2,880,521 Patented Apr. 7, 1959 a cold wall condenser which is ettective to produce a par ticularly efiicient clothes drying operation. The machine 1 is of the horizontal axis type, that is, it includes a clothes basket 2 which is rotatable about a generally horizontal axis. The basket 2 includes front and rear walls 3 and 4 and a connecting side or outer wall 5 (see Fig. 3). The outer wall 5 is cylindrical in shape and is provided with a plurality of perforations or holes as shown. The rear wall 4 is reinforced by a suitable plate 6.

The cylindrical basket 2 is mounted within an imperforate tub structure 7 which encloses it on all sides. The tub 7 includes a front wall 8, a rear wall 9 and a connecting side or outer wall 10. In my preferred embodiment the outer wall 10 is generally cylindrical in shape and has the same center as the cylindrical wall 5 of lhe basket 2. The basket is rot'atably supported from the tub structure by a horizontally extending shaft 11 which is mounted in an elongated bearing 12 hung from the rear wall 9 of the tub structure. The shaft 11 supports the basket by means of a hub 13 secured centrally to the basket rear wall 4 and the reinforcing plate 6. The shaft 11 as well as supporting the basket also serves as a means for turning it during the operation of the machine. The tub and the basket are provided respectively with openings 14 and 15 in the front walls thereof which are aligned with a door opening 16 in the front wall of the appearance cabinet 17 which surrounds the tub. A hinged door 18 mounted on the appearance cabinetseals against a gasket 19 around the tub opening 14 to close off the tub during operation of the machine. I

The tub structure 7 and the appearance cabinet 17 are both mounted on a suitable base structure 20 at the base of the machine. The tub specifically is mounted thereon by means of a plurality of brackets or arms 21 which are mounted on upstanding plates 22 fixedly attached to the base. The appearance cabinet may be welded to the base or otherwise suitably attached thereto. In addition to the tub and the appearance cabinet the base 20 also mounts the basket drive means. The drive means comprise a motor 23 and a multi-speed transmission 24 (see Fig. 1). The motor 23 drives the transmission assembly by means of a belt 25 and the transmission assembly in turn drives the basket through a belt 26. The belt 26 specifically turns a basket drive pulley 27 which is mounted on the outer end of the basket drive shaft 11. The direction of rotation of the basket isindicated by the arrow in Fig. 1 so that it moves upwardly past the left hand side 10a of the basket side wall 10 and downwardly past the right hand side 10b. The transmission assemply 24 is shiftable between two different gear ratios so that the basket 2 may be driven at one speed for tumbling clothes and at a second or higher speed for centrifugally extracting water from the clothes. The clothes tumbling speed may, for example, be about 45 revolutions per minute and the centrifugal extraction speed about 200 revolutions per minute. The means whereby the transmission is shifted between the lower and the higher speeds preferably comprises a solenoid operated plunger (not shown).

As mentioned above the machine 1 is a combination washer-dryer, that is, it proceeds through a cycle of operations first washing and damp drying the clothes and then, if desired, completely or fiuff drying .the clothes. The clothes basket is driven at its lower speed both for washing the clothes and for tumbling them during the drying operation. It is driven at its higher speed for ex tracting both wash and rinse water from them by centrifugal extraction. The'machine during its sequence of operation is under the control of a suitable timer operated sequence control 28 (Fig. '1) which energizes and de-energizes the various electrical components of the machine in a predetermined sequence. Since the sequence cons troi forms no part of the present invention, it will not be described herein. However a sequence control and circuit suitable for use in the illustrated machine are described and claimed in my co-pending application S.N. 512,612 filed June 2, 1955 and assigned to the same assignee as the presentinventiom The machine 1 includes a heater assembly for heating the clothes during the drying operation and a cold wall condenser for condensing the moisture extracted from the clothes. The heater assembly and the condenser are arranged in accordance with my invention so that a particularly effective drying operation is produced. Specifically, both these elements are positioned on the side 1011 of the tub past which the basket moves' upwardly. That is, they are positioned on the left hand side 10a of the cylindrical wall 10 .of the tub as viewed in Fig. l.

The heater assembly, which comprises two heating elements 29 and 30, is positioned above the center line of the tub; and the condenser, which comprises a portion of the side wall of the tub itself, is positioned below the center line of the tub. The condenser area of the tub wall is indicated generally at 31 and as described hereinafter it is cooled by flowing cold water over it. With the heater assembly and the condenser disposed in this manner, the side wall 5 of the basket and the clothes in the basket move upwardly first past the condenser and then past the heater assembly. The heater assembly, as shown, extends upwardly along side a of the tub so that its upper end, i.e. heater 30, lies generally atop the tub.

Adjacent the trailing edge-of the heater the clothes fall away from the basket side wall and tumble to' the bottom of the basket.

Theclothes are then carried upwardly again past the condenser, which is exposed to said clothes and is in close proximity therewith while the clothes are moved through the lower quadrant of the tub,.and 'then past the heater assembly repeating the same action.

With this movement of the clothes first past the condenser and then past the heater assembly the clothes are dried quickly and evenly.

The drying action produced is so effective that only a 'limited advantage is obtained by adding additional con denser area on the opposite side 10b of the tub. It has been found that the drying time is not shortened to any appreciable extent when additional condensing area is added on the right side 10b of the side wall of the tub as viewed in Fig. 3. Also, if the condenser on the left hand side 10a of the tub is replaced by a condenser on theright hand side 10b of the tub, the drying time is appreciably lengthened. The positioning of the heater on the same side of the tub above the condenser also results in the minimum drying time. If the heater is moved to any other portion of the tub, the drying time is lengthened or the internal temperature is increased, or both. Naturally, in a clothes drying machine it is desired that the drying time be as short as possible and the internal temperature as low as possible.

In order to sense the condition of the clothes during the drying cycle a thermostat 32 is provided within the machine. The temperature sensing element 32a of this thermostat is preferably associated with the heater assembly and the cold wall condenser in a predetermined manner. Specifically, and as shown, it is disposed on the side wall 10b of the basket past which the basket moves downwardly. Thus, the clothes tumble past the sensing element rather than being carried past it on the side wall of the basket.

It has been found that with this location of the temperature sensing element 32a the temperature sensed by the element closely follows the clothes temperature. That is, the temperature to which the sens'ing element responds rises and falls closely with the clothes temperature. This location of the sensing element, in fact, gives the most accurate results of any easily accessible location within the Some amplification of the slope conditions in the clothes temperature curve occurs, that is, the temperature rise or fall registered by the sensing element is somewhat greater and steeper than the actual rise and fall in the clothes temperature. But this is advantageous for it provides a stronger signal or force for actuation of the thermostat. I

For best results, that is, the most accurate sensing of the clothes temperature, the thermostat sensing element 32a is disposed symmetrically with regard to the center line of the tub side wall. In other words it extends as far above the center line as it does below. Although the positioning of the thermostat in this manner relative to the heater and condenser forms part of the present invention, the mounting of' the thermostat so that it extends circumferentially with respect to the basket is not my invention. Rather, the circumferential mounting and the configuration of the thermostat are described and claimed in the co-pending application of Aidan M. Stone, S.N. 538,893, filed October 6, 1955, and assigned to the same assignee as the present invention. I

To explain in greater detail the operation of the machine 1 during the drying cycle, when the machine proceeds into the drying cycle, the heaters 29 and 30 are energized to heat the clothes and the condenser 31 is activated for condensing the moisture extracted from [the clothes. The heating elements 29 and 30 are positioned closely adjacent the cylindrical wall 5 of the basket 2 so that they radiate heat towards the basket and the clothes therein whenever they are energized. A heat reflector 30a is positioned between the heating elements and-the wall 10 of the tub in order to prevent heat loss to the tub-insofar as possible. This reflector reflects "theradiant heat reaching it from the heating element back-"toward the outer wall of the basket. The heat transfeired to the basket from the heaters is 'passed on to the clothes to cause vapor migration out of the clothes. The heat is transferred from the basket to the clothes both by 'c'om tact of the clothes with the basket and by convection currents within the basket. Since the outer cylindrical shell 5 of the basket is perforated, some of the heatfromthe heating elements also passes directly to the clothes by radiation. In any case the clothes are sufliciently'heated so that the moisture in them is vaporized. The vaporized moisture is then condensed by means of the condenser 31 and is removed from the tub by suitable means described hereinafter.

In the illustrated machine it is contemplated that both the heating elements 29 and 30 will be energized simultaneously during the initial portion of the drying cycle. Thereby the machine temperature is increased and vapor migration is caused out of the clothes. However, since the total heating capacity is not needed to finish the drying after a pre-selected temperature is reached, I prefer to energize only one of the heater sections during the latter portion of the drying operation. For example in a size of the illustrated machine suitable for domestic use having a clothes basket 26 inches in diameter, I provide a heater assembly having a total output of 4000 watts and divide the two heaters so that one has the output of 2800 watts and the other has an output of 1200 watts. In the latter portion of the drying cycle only the 2800 watt heater is energized. This result is preferably effected by a control circuit connected to the thermostat 32. This control circuit, however, forms no part of the present invention and thus is not described herein. One suitable circuit for accomplishing such control is shown in my aforesaid application S.N. 512,612.

In the illustrated embodiment the heater 29, which is mounted nearest the condenser, comprises the 2800 watt heater, and the heater 30, which is mounted further up the side 10b, comprises the 1200 watt heater. The heater 30 may be mounted entirely on the side 10bor", as shown, may be mounted adjacent the top of the basket. It will be understood that I mean to include both arrangements within the statement that the heater assembly is shaves upwardly. In both arrangements the basket Hoes ass med an the side of the tub p st which the tasks:

in ven 'warm past substantiallyall, if riot all or the a sembly. Both heating elements 29 and 30 are preterany of the sheathed type in which a'resi'stah'c'e wire 'inaint'aind in spaced relationship with an outer im ewe sheath by a highly compressed, granulated, heat can'- diictin g, electrically insulating compound such as hag aesium oxide. Such heating elements-are sold under the trade-mark of Calrod and are available commercially. The heating elements may be supported from the wall of the tub by any suitable heat insulating means (not shown). v I I,

n To activate the condenser 31 during "the drying operation cold water is flowed over'its surface therebytofcool th' tub wall to a condensing temperature. In the illustrated machine condenser water is admitted to the tub through a solenoid actuated valve controlled by a solenoid 33. The solenoid 33 is energized by the sequence control 28 during the drying operation so that the valve controlled by it passes water at a slow rate sufficient to condense the moisture extracted from the clothes. The inlet to the condenser water valve is through a suitable water line 34 and the valve discharges through a conduit 35 into a funnel 36. From the funnel 36 the condenser water flows through a line 37 into a trap device 38 which connects the interior of the tub 7 to a vent hose 39 (see Fig. 2). The condenser water flows through the trap 38 into the tub and in doing so it forms a liquid seal therein, whereby steam can not escape from the tub through the vent hose 39 during the drying operation. The arrangement of the trap 38 and in fact the venting system as a whole are not my invention but rather are the copending application of Walter J. Raczynski, S.N. 538,891 filed October 6, 1955 and assigned to the same assignee as the present invention.

The condenser water flowing slowly into the tub through the trap 38 is spread over the side of the tub by an inverted V-shaped bead 40 formed on the tub wall directly below the device 38. The condenser water being so spread out cools a considerable portion of this area of the side wall 10b, whereby there is provided a large cool surface 31 for condensing the moisture extracted from the clothes. The condenser water and the moisture extracted from the clothes are discharged from the tub through a sum 41. A discharge hose 42 leads from the sump to a pump 43 which is connected to the household drain by a flexible conduit 44 (see Fig. 1). The pump 43 is energized continuously during the drying operation to drain the condenser water and the moisture from the machine.

As mentioned above, the thermostat 32 is preferably connected to the sequence control in a manner so that it is effective to control the duration of the drying cycle. Further the thermostat 32 is also preferably connected so that it controls the energization of the heaters throughout the drying cycle. An adjusting knob 45 is provided on the thermostat for varying the length of the drying cycle. The thermostat may be of any suitable hydraulic type and it is actuated from the temperature sensing element 32a by means of a suitable hydraulic line 46. A safety thermostat 47 (Fig. 1) provides overtemperature protection during the drying operation.

Although the present invention is not directed to the washing operation conducted in the machine 1, it will be understood that the machine is provided with suitable water supply means, whereby either hot water or a mixture of hot and cold water may be admitted to the tub 7 for washing and rinsing purposes. The water supply means includes the cold water supply line 34 and a hot water supply line 48 (see Fig. 1). A valve controlled by a solenoid 49 admits hot Water to the tub and a valve controlled by an opposed solenoid 50 admits cold water to the machine. The hot and cold water valves under the control of the solenoids 49 and 50 discharge through a onset conduit 51. from the e i aph 3ft the water passes through a suitable air 'gap intoa ru' n'tii 52. The "tunnel 52 discharges into a line '53 which leads to the sump 41 mounted at the bottom of the tub see Fig. '2). The sump 41, of course, communicates "with the interior of the tub and the inlet water rises "it; the sump into the tub. The break or air gap pro'vr ed funnel 52 makes it impossible for water to be siphoned "from the machine to contaminate the incoming with? sup ly lines. H

In the illustrated machine a pressure sensing'devi'ce 54 (Fig. 1) controls both the water solenoids 49 and 50 To produce the proper water level in the tub during the w ing o erati n. This sensing device is connected to e interior of the tub 7 by a suitable line 155. It will be uh"- dersto'od, of course, that the sensing device 54 eon-nets the water valve solenoids only when suitable circuits are closed by the timer operated sequence control 28. The water level in the tub during the washing operation is such that the lower portion of the basket is covered whereby the basket dips continually into the water as it rotates. For example, in the above mentioned size of the illustrated machine having a clothes basket 26 inches in diameter, the water level in the tub during washing is about 5 inches above the bottom of the basket. At the conclusion of the washing and rinsing operation, the water is discharged from the tub through the sump 41 and the pump 43.

The heating elements 29 and 30 in addition to heating the clothes during the drying cycle are also effective to heat the wash water during the washing cycle. The ar rangement of the heaters to provide this dual function and the manner in which they perform it are, however, not my sole invention but rather are my joint invention with Roger E. Walker. This latter invention is described at length and claimed in our copending application S. N. 542,887 filed October 26, 1955 and assigned to the same assignee as the present invention. As described in that application, when the heaters 29 and 30 are energized during the washing cycle, they heat the water primarily by using the rotating basket as a heat transfer agent. As the basket rotates past the heater, it is heated by direct radiation from the heaters and then as it dips into the wash water at the bottom of the tub it in turn heats the water. Besides the heat transferred through the basket, there is also some heat transferred from the heaters to the water both by reason of the convection currents sent up within the tub by the basket as it rotates and by direct radiation through the perforations of the basket.

Although I have described my invention as embodied in a combination washer-dryer, it will be understood that it can be used with equal advantage in a clothes dryer. My novel arrangement of the condenser and the heater assembly provides equally as good results in clothes dryers as in combination washer-dryers. The arrangement of the condenser and the heater assembly on the same side of the tub wall so that the basket moves upwardly first past the condenser and then past the heater assembly is efiective to provide a particularly efiicient drying operation for a given internal temperature level in both types of machines. As pointed out above, this arrangement provides a minimum drying time with the smallest condenser area being required. Also, as pointed out above, for the most accurate sensing of the clothes temperature, the thermostat should be positioned on the opposite side of the tub so that the basket moves downwardly past it after passing the heaters and before reaching the condenser. The thermostat preferably is arranged symmetrically with regard to the center line of the basket.

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

' drical perforated outer wall, an imperforate tub enclosing said basket, drive means for rotating said basket in a.

' predetermined direction of rotation so that it moves upwardly partone side of said tub and downwardly past the other side of said tub, said one side of said tub being positioned to be relatively close to said basket as saidbasket rotates past it, a heater assembly for heating ..the clothes to extract moisture therefrom a single cold Wall condenser effective throughout the drying operation for condensing the moisture extracted from said clothes, said condenser including an inlet to said tub positionedwapproximately at the center line thereof, said condenser being directly exposed to the interior of the basket anddisposed on said one side of said tub and below the centerlline thereof, the clothes in the basket being held in close proximity to the condenser while said clothes are moved from the base portion of the tub to the horizontal center line of said tub and said heater assembly being mounted within said tub adjacent the upper portion of said one side thereof, whereby said basket moves upwardly first pastsaid condenser and then past said heater assembly.

ReferencesClted'in the file of this patent UNITED STATES PATENTS Smith Sept. 13, 1955 2,720,037 v Erickson Oct. 11, 195 5

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