US2718711A - Laundry drying machine - Google Patents

Description

Sept. 27, CLARK LAUNDRY DRYING MACHINE.

Filed Aug. 29, 1951 j? am A M United States Patent LAUNDRY DRYING MACHINE Kendall Clark, Glen Ellyn, Ill., assignor to General Electric Company, a corporation of New York Application August29, 1951', Serial No. 244,182

6 Claims. (Cl. 34-75) This invention relates to laundry drying machines, and it is' a principal, object of the invention to provide a dryer having improved means for evacuating lint-and-rnoistureladen air from the dryer casing and preventing its escape into the room in which the dryer is located.

The sales of domestic laundry dryers have been so much less than indicated by the large potential market that surveys have been made to determine the nature of the sales resistance. expressed objections to conventional laundry dryers are that they discharge too much heat, too much lint, and too much humidity into the rooms in which they are located. These objections are particularly valid in modern basementless homes which have a utility room-usually off the kitchen-in which the home laundry equipment, is located. During the winter months when the inherent advantages of laundry dryers are most to be realized, the more-thana gallon-of-water evaporated from the usual 8 or 9 pound clothes load and discharged into the room air by the conventional dryer will condense on the. cold, outside walls and window areas of the room with resultantinconvenience and possible damage to the room decoration and structure. During the summer months, the discharge of warm humid air makes the room an unpleasant place in which to work; and in all seasons the escape of lint through the conventional lint trap is an annoyance.

To overcome these difficulties, some manufacturers have recommended that the dryer discharge'into a duct passing through the building. wall or window to discharge.v into the outer air. Such an arrangement is expensive, not always practical, and because the outlet to the duct must be screened against insects, means must be. provided for periodic removal of the screen for cleaning the lint accumulation therefrom. A presently very successful dryer provides for drying the air within the dryer casing by the use of a cold water spray which condenses the moisture out of the air and at the same. time. induces the precipitation of a. large amount of the lint which reaches a sump and is removed as the. Water accumulation in the sump is. pumped to a suitable. drain. Although such a dryer satisfactorily answers the heat, humidity, and lint problems, there are certain structural problems related to the presence of quantities of water within the dryer which require careful attention.

A laundry dryer constructed according to the presentinvention provides adequately for the disposition of lint and prevention. of the. discharge of humid air into. the room without requiring the use of water withinthe. dryer casing or the installation of ducts for conveying thev discharging air to the outside of the building. In a presently preferred embodiment I continually exhaust the humid lint-containing air from the dryer casing by means of a fan or blower, and through a smooth walled flexible hose or the like conduct the air to a spray fitting, which may,

for example, be connected to the cold water faucet of a laundry tub. The spray fitting mixes the discharged air with a spray of cold water. This reduces the air temperature to below its dew point, thus condensing the mois- It has been found that the most frequently- 2,7 18 ,7 l l Patented Sept. 27, 1955 ture and at the same time wetting the lint to be caught on a screen or the like at the tub drain. To insure that no lint will accumulate in the dryer casing, I mount a cleaning brush on the dryer drum and arrange it to sweep the adjacent wall of the casing at every revolution of the drum. The brush is shakenfree of lint at the endof each revolution by novel means.

Important features and objectives of my invention are an improved means for the disposition of. lint-laden humid air discharged from a laundry dryer; and an improved air flow system within the dryer; an improved means for preventing the accumulation of lint in the dryer casing.

In the accompanying drawings, Fig. l is a somewhat schematic front elevation of a dryer installation embodying my invention, the figure being largely in section; Fig; 2 is a side sectional elevation taken along lines 22 of Fig; 1; Fig. 3 is a plan section showing a portion of the air receiving channel; Fig. 4 indicates the manner in which lint is shaken from each-sweeper brush once each revolution; Fig. 5 is a sectional elevation showing a water spray fitting having a solenoid or other automatically operable valve for controlling the water flow; and Fig. 6 is a section. taken through the discharge hose to show the leads from the solenoid running to the dryer through a passage in the wall of the discharge hose.

Referring now to Figs. 1 and 2, a typical domestic laundry dryer comprises a suitable outer housing 1 fabri: cated from sheet metal and appropriately braced and structurally reinforced as. is well understood. By any adequate structures, such as the longitudinally extending members 2, 3 and one or more transverse members 4, a sheet metal casing 5 which may be substantially cylind'rical as shown or of generally volute shape is firmly secured to the outer housing. The several members or other supports may be. welded to the casing and the housing. Rotatably mounted within the casing is a receptacle or basket 6 within which are placed the clothes to be dried.. As schematically shown in Fig. 2, the receptacle is carried by a rear portion of the casing 5; a flanged collar 7 rigidly secured to a rear wall of the casing houses a suitable sleeve bearing 8 which accommodates the shaft 9 to which is affixed the plate 10 fastened to the rear wall of the receptacle. The front receptacle wall may have a concentric neck 11 registering with a door 12 through which the clothes may be loaded into the receptacle. I have indicated a. support for the front end of the receptacle in the form of a felt collar 14 carried. on the. inner face. of a flange projecting fromv the end wall of the casing and encircling the neck 11. These supporting structures may be modified in any suitable way or supplanted by any of the structural means commonly used in domestic clothes. dryer construction; since per se they form no part of the present invention. .The peripheral wall of the receptacle is perforated to provide for air communication between the interior and the space 1-5 between receptacle and casing, and pursuant to conventional practice, the receptacle is provided with a plurality, illustratively three, of tumbling ribs 16. The tumbling and physical displacement of the clothes induce air movement within the receptacle and through the walls thereof.

The casing walls are thermally insulated by a blanket 17 of rock wool or the like suitably secured thereto. An offset 18 at a convenient upper portion of the casing 5 provides a chamber for a heating unit 20 embodying any suitable number and arrangement of electric resistance elements. A reflector 21 may be arranged behind the heating elements and an appropriate screen 22 forms a guard in front of the elements. The rear wall of the offset 18 may be formed with louvers 23 so that air introduced into the housing through the intake louvers 24 thereof will pass through the heating chamber to abstract heat from the resistance elements. It will be observed that the receptacle is arranged to be rotated at a suitable speed--for example, 50 R. P. M.by a motor 25 preferably resiliently mounted on the base 26 of the housing and having any conventional gear reduction unit 27 to drive sheave 28 at an appropriate speed. Through a V- belt 30, or other suitable means, the sheave 28 is arranged to drive the sheave 31 fixed to the end of shaft 9. The final aspect of what may be considered as conventional practice is the use of a suitable time and temperature control switch 32 in an appropriate electrical circuit to establish the operational cycle of the dryer.

In rotating receptacle clothes dryers, two objectives are sought: to reduce the vapor pressure or humidity of the atmosphere within the dryer so as to encourage the evaporation of moisture from the clothes load, and to prevent the lint released from the clothes during the tumbling and fluffing thereof from passing into the air of the room. In the present invention, these objectives are met by continuously withdrawing air from the dryer chamber during at least a selected portion of the drying cycle and condensing out the moisture of the discharging air while simultaneously wetting the lint to prevent it from floating into the room air. In the presently preferred embodiment of my invention disclosed herein, I provide a relatively wide slot 33 extending axially along'casing for substantially the full length thereof; desirably, said slot is at the bottom of the casing, although this is not essential, as will later appear. Welded or otherwise suitably secured to the outer wall of the casing so as to comprehend the full area of the slot is an air receiving channel 34 having a closed end 35 and at its forward or opposite end arranged to be closed by a suitably shaped removable cover 36. Advantageously, the forward end of the channel may be flanged for securement to the front wall of housing 1 by sheet metal screws or other appropriate fastenings (not shown). As best appears in Figs. 1 and 3, channel 34 has an outwardly directed flange 37 and an inwardly directed flange 38 (considered with respect to the cavity of the channel). Flange 37 is in contact with casing 5 throughout its length whereas through the greater part of its length immediately adjacent casing 5 flange 38 is fluted to provide a series of spaced relatively small area air-inflow passages 40 through which air may flow from the housing into the channel. Desirably, the casing 5 is spotwelded to flange 38 at the several peaks formed by the fluting. As Fig. 3 shows, these passages 40 preferably are directed toward one end of the channel. It will, of course, be understood that forwardly of the casing 5 the top of the otherwise open-topped channel is covered, as by a plate 41.

Coupled to the motor for direct drive therefrom is a high velocity fan or blower 42, the intake 43 of which communicates with the air receiving channel 34 preferably adjacent an end thereof. By any suitable means I attach a smooth walled flexible hose or conduit 44 to the discharge 45 of the fan. This hose may be of relatively small diameter-for example 1 /2" I. D.because of the high velocity discharge of the blower. The opposite end of the hose 44 is connected to the intake of an aspirator 46 which is arranged to produce an intimate mixture of the air discharging from the hose and a spray of cold water. The aspirator preferably has a rigid intake fitting 47 adapted by any suitable coupling 48 for attachment to the threaded end of a conventional laundry tub faucet 49. If desired, a solenoid valve 50 may be inserted in fitting 47 and arranged for electrical connection with the time control mechanism 32, whereby at a suitable point in the operational cycle of the dryer the valve may be electrically energized to permit water flow into the aspirator. Alternatively, as shown in Fig. 1, the aspirator may be direct-connected to the faucet 49 and the faucet left open during the entire dryer operation. As also appears in Fig. 1, the discharge from the aspirator flows into the laundry tub 51 and thence through trap 52 to the plumbing waste line. A suitable screen 53 may be placed over the drainage outlet from the tub to collect lint.

A support structure 54 spaces the nozzle 55 at least one inch above inlet port 56 and defines'a plurality of air inflow openings 57 which have a total area several times that of the nozzle. Such construction, as is now well understood, prevents any possibility of siphonage of polluted Water into the fitting 47 in the event of a subatmospheric pressure condition in the domestic water supply piping.

It has previously been noted that substantial amounts of lint become detached from the fabrics being tumbled in the receptacle. Although the continuous operation of the exhaust blower 42 reduces the possibility of lint accumulations within the casing I arrange to sweep the inner walls of the casing during the rotation of the receptacle.

An effective sweeper may be housed within the cavity provided by the tumbling ribs 16. As shown in Figures 2 and 3, each sweeper may comprise an elongated brush 58 having a backbone 60 suitably journaled in openings provided in the respective end walls of the cavity. The backbone may be of any suitable cross section and need not be round so long as its ends may be mounted for limited rotation within the cavity. One or more springs 61 are carried by the brush and engage with the walls of the .tumbling rib to urge the brush into counter-clockwise rotation as viewed in Fig. 1. By selecting a bristle length suitably longer than the maximum transverse dimension of the annular space 15, the brush bears resiliently against the side of the casing to sweep it clean. The sweepings which gather along the leading face of each brush are shaken into the air channel 34 by simple means as best shown in Figures 1 and 4. The slot 33 in the casing is narrower than the maximum width of the channel thus providing the respective walls 62 and 63 separated by a gap so related to the bristle length that as the brush passes the wall 62 the spring elements 61 will cause a substantial portion of the brush length to snap sharply into the upper zone of the channel 34 and to strike the edge of wall 63. As the bristles pass over wall 62 they are fanned out to loosen the lint. This action shakes loose lint from the bristles, and as the drum continues its rotation the edge of wall 63 combs from the brush a large portion of the lint remaining thereon, whereupon the brush resumes its sweep of the casing wall. The lint is, of course, caught by the rapidly moving air stream within the channel and passes through the blower into tube 44. It will be noted that the opening 33 is sufliciently narrow to prevent the respective brushes from being rotated into an inoperative position under the bias of the spring 61. It is obvious, however, that suitable stop pins (not shown) may project from the end walls of the brush receiving cavity to limit counter-clockwise rotation of the brush as desired. It should also be noted that by selection of brush bristles of sufficient resiliency in themselves either or both of the springs 61 may be eliminated. Because of this positive brush action and brush clearing arrangement, the air channel 34 may be positioned almost degrees removed from the Fig. 1 position, if

necessary or desirable to accommodate the various mechanisms within the housing 1.

Although a single brush 58 serves adequately for sweeping the walls of the casing 5 for lint removal, substantial operational advantages accrue from the use of a brush in each of the cavities provided by the ribs 16. As apparent in Fig. 1, for example, the brushes subdivide the space 15 into individual air chambers and insure that air flowing into the space 15 ,through the louvres 23 will flow into the receptacle instead of taking a path of less resistance and flowing directly into the channel 34. When a conventional volute type casing is used, the brushes serve as pump vanes and may advantageously be used to raise the air pressure in a portion of space 15 to drive the warmed air into the receptacle 6 The operation of the dryer will now be summarized. Assuming a. load of wet clothes to have been placed in the dryer and the door 12 closed. and latched, the time switch 32 is manually operated to close a circuit to the heater 20 and motor 25, and in a solenoid equipped water system may also close the current to the solenoid valve. 50 to cause water to flow through the aspirator 46, the faucet valve having previously been manually opened. The necessary electrical circuit. has not been shown because these circuits are known in the art. It will be noted from Figs. 5 and 6 that the solenoid lead wires 64, 65 are advantageously run within a passage 66 provided along the wall of the hose 44. The lead wires may leave the passage 66 through a branch passage such. as the inlet branch 67, Fig. 5, for connection into the control circuit.

The blower reduces the pressure within the channel 34. and the movement of the clothes within the receptacle drives air out through the wall perforations, whence it flows through the opening 33 into the channel. The fabrics are thus tumbled in a drying atmosphere. of warm moving air which accumulates moisture evaporating from them. The direct inflow of air from the housing through the channels 40 insures air movement within the housing itself, keeping it cool and providing a suitable atmosphere for proper motor operation. To be sure of adequate air movement within the housing, I prefer to locate the passages 40 on the opposite side as respects the air intake 24.

During the early stages of the drying cycle the air discharging through the tube 44 has high humidity but is comparatively lint free. As the humid air reaches the aspirator 46 it is chilled below its dew point by the cold water spray within the aspirator, and the condensate passes into the tub 51 and thence to the waste line with the cold. aspirator water. Very little moisture is added to the room air during this operation. As the fabrics become drier they commence to shed lint, which, in the manners above stated, is conveyed by the air stream through the smooth walled conduit 44 to the aspirator 46. The lint becomes saturated and passes into the tub. Ordinarily the quantity of lint is small and it is quite satisfactory to eliminate the strainer 53 to allow the lint to pass directly into the waste line. Shaggy or other materials, which may shed an unusually large amount of lint, may make it desirable to use the strainer 53. It should be noted that the actual water. flow through nozzle 55 is small and that the time necessary to bring the clothes to bone-dry condition is about 60 minutes in the average dryer. Therefore, even in the unlikely circumstance that the strainer 53 became completely clogged with lint before the end of the drying operation, the capacity of the tub would safely accommodate water accumulating therein before the aspirator became submerged.

While there has been described what is at present considered to be the preferred embodiments 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 within the true spirit and scope of the invention.

I claim:

1. A domestic laundry dryer for installation in the laundry room of a residence or the like, comprising a housing provided with air inlet means; a foraminated drying receptacle mounted for rotation therein; a casing substantially enveloping said receptacle; means providing an air inlet passage between said housing and the drying receptacle to provide for air flow into said receptacle from said housing; means for heating said infiowing air; a closed-ended channel supported by said casing and opening along its length into the space between said casing and said receptacle; a blower having its intake connected to said channel to draw air therefrom; means for rotating said receptacle and driving said blower; a relatively small diameter, smooth-walled, flexible conduit for conducting the discharge of said blower to a point of escape into the atmosphere of the laundry room remote from said housing; and means carried by the end of said conduit for connection to a source of cold water to produce a water spray for mixture with the air discharging from said conduit.

2. A domestic laundry dryer for installation in the laundry room of a residence or the like, comprising a housing provided with air inlet means; a foraminated cylindrical drying receptacle mounted for rotation therein; a casing enveloping said receptacle with relatively small clearance with respect to the circumferential wall of said receptacle; means providing a louvered opening in a wall of said casing; means including a plurality of brush elements carried by said receptacle and bearing resiliently against said casing along the length thereof to scrape lint therefrom and to provide air inlet passages between said casing and the drying receptacle to direct air flow into said receptacle from said housing; means for heating said inflowing air; a closed-ended channel supported relative to said casing and communicating along its length directly with the space between said casing and said receptacle and with the housing externally of said casing; a blower having its intake connected to said channel to draw air therefrom; means for rotating said receptacle and driving said blower; relatively small diameter, flexible, conduit means for conducting the discharge of said blower to a point of escape into the outer atmosphere remote from said housing; and means carried by the. end of said conduit means for detachable connection to a source of cold Water to produce a water spray for mixture with the air discharging from said conduit.

3. A domestic laundry dryer for installation in the laundry room of a residence or the like, comprising a housing provided with air inlet means; a. drying receptacle mounted for rotation therein; a thermally insulated casing enveloping said receptacle in spaced relation therewith; means providing a passage between said housing and the drying receptacle to provide for air flow into said receptacle from said housing; means for heating said inflowing air; means for discharging air from said receptacle into the space between said casing and said receptacle; a closed-ended air receiving channel supported by said casing and. opening along its length into the space between said casing and said receptacle to, receive said discharging air said channel having air discharge means; a relatively high-velocity blower disposed within said housing connected to said channel air discharge. means to draw air therefrom; means providing a plurality of air passages from said housing into said channel, said passages being inclined in the direction of said air discharge means; means for rotating said receptacle and driving said blower; a relatively small diameter, flexible, conduit for conducting the discharge from said air receiving channel to a point of escape into the atmosphere of said room remote from said housing; and means carried by the end of said conduit for connection to a source of cold water to produce a water spray for mixture with the air discharging from said conduit.

4. In a laundry drier having a housing provided with air inlet means, a foraminated clothes-receiving receptacle mounted for rotation therein, and a casing enveloping said receptacle with relatively small clearance space with respect to the walls of said receptacle; the improvement in air circulation means within said housing comprising an air receiving channel supported by said casing and opening along its length into the space between said casing and said receptacle for substantially the full length of said receptacle, flexible brush means disposed exteriorly of said receptacle and extending axially therealong for travel about said casing wall, as said receptacle rotates, said brush means having a bristle length materially greater than said clearance space for gathering and periodically depositing into said channel lint which may accumulate within said casing, means for introducing air from said housing into the space defined by said casing and receptacle, means associated with said air receiving channel to provide a plurality of passages for introducing air from said housing into said channel at spaced intervals along a side wall thereof, blower means within said housing, means for rotating said receptacle and driving said blower means, means connecting said air receiving channel to the inlet of said blower, and conduit means for conducting the discharge of said blower from said housing.

5. A laundry drier having a housing provided with air inlet means, a foraminated clothes-receiving receptacle mounted for rotation therein, a motor for rotating said receptacle, a casing enveloping said receptacle to provide an air circulation space between the respective side walls thereof, means providing a cavity extending axially along the peripheral wall of said receptacle, said casing having a closed-ended air receiving channel opening into said space between said receptacle and casing, an elongated lint-removal brush mounted in said receptacle cavity, said brush having means at its end for pivotal securement to said receptacle, the bristles of said brush extending axially of said casing to sweep the adjacent wall thereof with each revolution of said receptacle, spring means biasing said brush to hold the bristles thereof in engagement with said casing wall, the bristle length of said brush being sufficient for the outer end portion thereof to enter said channel, wall means associated with said air receiving channel to comb said brush to remove lint accumulations therefrom for deposit with said channel, and a blower having its intake communicating with said channel and discharging externally of said housing.

6. In a clothes drying machine having a housing, a substantially cylindrical casing fixedly secured therein with its axis inclined from the vertical, a foraminated clothes-receiving receptacle mounted for rotation within said casing, the axis of rotation thereof being parallel to said casing axis, said housing, casing, and receptacle having mutually registering means for loading into said receptacle a quantity of articles to be dried, and said receptacle and easing being dimensionally so related as to provide an air circulation space between their respective side walls, heating means carried by said casing, means for admitting air into said housing and thence over said heating means and into said air circulation space and means for rotating said basket to tumble the clothes therein in a drying atmosphere; the improvement in air circulation and lint removal means comprising a closed-ended air receiving channel fixed relative to said casing and extending substantially the length thereof, said casing having an elongated opening registering with said channel, means defining a passage communicating directly between said opening and said channel, an elongated brush mounted on the exterior of said receptacle and extending substantially the full length thereof, the bristles of said brush being resiliently in engagement with the inner wall of said casing to sweep the casing free of any lint emanating from said receptacle as a result of the tumbling of the clothes therein, wall means defining a leading edge of said elongated casing opening being adapted to engage said bristles to fan the same as the receptacle carries said brush thereacross, wall means defining the opposite edge of said elongated opening adapted to engage the leading face of said bristles to strip the same of any lint carried thereby, a blower mounted in said housing, a conduit extending between said channel and the inlet of said blower whereby lint stripped from said bristles will pass into said blower, means providing a plurality of air inflow passages from said housing into an upper portion of said channel, a discharge conduit leading from said blower to a terminus remote from said housing, and means at said terminus to mix the discharging air with cool water to condense out the moisture content thereof while simultaneously saturating the lint content to prevent the same from flying about in the atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 963,723 Pierce July 5, 1910 973,405 Clark Oct. 18, 1910 1,530,073 Cutter Mar. 17, 1925 1,731,290 Boltz Oct. 15, 1929 1,894,696 Lindeman Jan. 17, 1933 2,092,305 Estes et al. Sept. 7, 1937 2,112,290 Holland Mar. 29, 1938 2,314,748 White Mar. 23, 1943 2,351,198 Friedman June 13, 1944 2,369,366 ONeill Feb. 13, 1945 2,398,880 Broglie Apr. 23, 1946 2,451,692 Pugh Oct. 19, 1948 2,492,046 Johnston Dec. 20, 1949 2,590,295 Constantine Mar. 25, 1952 FOREIGN PATENTS 511,612 Great Britain Aug. 22, 1939

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