US2728481A - Clothes drier - Google Patents

Description

Dec. 27, 1955 CLOTHES DRIER Original Filed Feb. 3, 1951 J. H. ROBINSON ETAL 3 Sheets-Sheet l Inventors John HRobinson;

Paul L Paulseh 1955 J. H. ROBINSON ETAL 2,728,481

CLOTHES DRIER Original Filed Feb. 3, 1951 3 Sheets-Sheet 2 Inventovs John H. Robinson,

Paul L. Paulsen, 5 Their Airborneg.

Dec. 27, 1955 J. H. ROBINSON EIAL 2,728,481

CLOTHES DRIER Original Filed Feb. 3, 1951 3 Sheets-Sheet 3 Inventors JohnH. Robinson, Paul L. Paulsen,

T heir Attorne 5.

CLOTHES DRIER John H. Robinson, Buechel, and Paul L. Paulsen, Lyndon,

Ky., assignors to General Electric Company, a corporation of New York Original application February 3, 1951, Serial No. 2119,280. Divided and this application June 19, 1953, Serial No. 362,732

3 Claims. (Cl. 220-4) Our invention relates to a clothes drier of the tumbler type, and in particular to a drier adapted for domestic use.

This application is a division of our copending application Serial No. 209,280, filed February 3, 1951, now Patent No. 2,707,837, issued May 10, 1955, and assigned to the General Electric Co., assignee of this application.

We have directed our invention primarily to the objective of providing a clothes drier having a simplified construction capable of eflicient performance over a long life span, arranged for easy servicing by mechanically unskilled persons.

..More specifically, the objects of our invention include the provision 6f an air distribution system which improves heat transfer by forced convection and conduction and minimizes the accumulation of lint in diflicultly accessible areas within the drier; a simplified heater chamber construction which provides a tumbler shaft supporting structure of substantial rigidity; and an improved construction which facilitates manufacturingof. an improved machine at a lower cost.

. In a presently preferred embodiment of our invention we mount a foraminated tumbler within a heated,'insulated chamber for rotation-on a non-vertical axis. At a lower corner of the chamber there is provided an air duct extending the full length thereof; by suitable fan means we develop within the duct an air pressure somewhat above that of the chamber atmosphere. This air is substantially at room temperature andidischarges into the heater chamber as sheets or curtains of air, one of which flows about the tumbler counter to the direction of rotation thereof, while another conforms generally to the direction of rotation, impinging angularly against the bottom of the tumbler.

.In accordance with one of the features of this invention, we provide a simplified and improved construction in which end panels for the heater chamber are secured to a base. The sides and roof are formed by a single wrap-around sheet of material with V-shaped marginal flanges to receive edges of .the end panels when drawn into position and anchored to the base. The wraparound sheet carries an insulation blanket which is held in place by the same anchoring means extending into the base. By this arrangement, the Walls defining the heating chamber also define in effect a large hollow structural beam for aiding in support ofthe. drier. drum in cantilever fashion.

Other features and advantages of ouninvention will be better understood from the, following detailed .description of the presently preferred embodiment as'illustrated in the accompanying drawings, in which .Fig. -l is a front elevation of one form of. drierembodying our invention, certain casing portions having beenbroken away to reveal underlying structure; Fig. 2'is.a rear 'elevation of the drier, certain portions being broken away; Fig. 3 is a side sectional elevation of the drir. of Fig.1 on line 3-3 ofFig. 1; Fig.4 is a detail in sectional elevation showing a method ofconstructirig the heater cha n;

ttes atentO her and securing the insulation thereto; and Fig. 5 is a corner construction detail showing a method of insulation securement and application of the top wall portion of the outer housing.

Referring to the drawings, the general structure of a drier embodying our invention comprises an outer'housing 1 having conventional unitary wall panels arranged in wrap-around fashion on a suitably reinforced footprovided base 2. The rear panel 3 is attached to side wall flanges and to the base 2 by removable fastenings to provide for easy access to the drive mechanism, later described. A cylindrical sleeve 4 extends inwardly from the rectangular recessed front housing wall portion 5 within which a door 6 seats when closed. The dooris preferably gasketed by a resilient strip 7 which compresses against the front wall panel when the door'is latched in closed position by conventional means (not shown). The gasket prevents the escape of lint during the operation of the drier. We prefer to hinge the door by concealed hinges 8. As usual, the door may have a transparent window 9 through which the interior of the drier is visible. The front panel overhangs the base as shown best in Fig. 3 to provide toe space, and the lower front casing portion therefore conveniently comprises an angle strip 10, hereinafter called a toe-board panel, to the projecting portion of which the bottom edge of the front casingwall is fastened.

Integration of the five'sides of the housing above the base is accomplished in'a manner which provides a simple, rigid assembly. As presently constituted, the upper edge portions of the front and side walls of the housing are inwardly flanged to support the similarly flanged front and side edges of the top panel 11. Tablike extensions 12 of the top panel front flange act as base 2. For the cylindrical tumbler type of drier presently.

exemplifying our invention, we employ eccentrically horseshoe-shaped front and rear panels 16, 17, flanged at their lower ends to befastened to the base wall structure 2 as seen in Fig. 3. Each panel is appropriately apertured to accommodate various operating components; for example, the forward wall 16 has a projecting flangedended cylindrical aperture 18 which secures to the front outer casing panel about the sleeve 4, with respect to which the aperture is concentric. We prefer to gasket the connection between the-respective front panels of the heater casing and outer casing. About the front and rear panels, 16, 17, we wrap a metal sheet 19, the forward and rear edges of which are flanged to overlap the peripheries of said panels in a socket-like arrangement shown best in Fig. 5. necessary mechanically to secure the sheet 19 to the front and rear panels. A convenient manner of afiixing the sheet 19 to the base 2 is shown in Fig. 4. The lower side edges 20 of the sheet are shaped to providea -resilient bead which rests upon a base wall portion 21 0th.

set to the required angularity. Machine screws 22 passing through aligned apertures in the beads 20 into tapped holes in base wall 21. draw the sheet 19 securely into position.

The resilience of the beads 20 affords a yieldability whieh compensates forminor irregularities of alignment;' the reaction of the beads also provides a lock-nut, effect Such arrangement makes itllll-x which holds the screws 22 against loosening. We insulate the heater chamber with conventional materials such as glass W011 pads or batts. The insulation adjacent sheet 19 is conveniently held in place by straps 24 which are clamped against the respective base offsets 21 by the beads and screws 22. Front and rear wall insulation is held in place by tabs 25 extending from sheet 19 over the front and rear panels 16, 17, as illustrated clearly by Figs. 3 and 5.

Heater 26 is an integrated assembly, preferably embodying a channel-like frame 27 from which project a suitable number of insulators 23 on which the resistance wire 30 is convoluted over an area which extends substantially the whole length of the heater chamber. A reflecting sheet may be fixed back of the heater coil, and we guard against direct contact of lint with the coils by providing a guard screen 32 (Fig. 3), the mesh of which is sufficiently large to pass radiant heat in substantial quantity. The heater assembly is passed through an opening 33 in rear panel 17 of the heater chamber and is supported on members secured to panel 17 and to front panel 16 by screws engaging the several brackets 34a. At the rear panel 17 the insulation blanket is suitably arranged to provide a space for a binding post plate 35 of insulating material which carries the heater coil connection terminals 36.

Panel 17 is set sufficiently forward of outer housing panel 3 to provide a relatively deep rear compartment which accommodates the tumbler drive mechanism and serves as an air admission chamber communicating by way of the louvres 38 with the outer atmosphere. Tumbler 40, which illustratively is of the horizontal axis cylindrical type, has imperforate front and rear walls 41, 42 and a foraminated peripheral Wall 43. The front wall has a short neck 44 which extends in concentric overlapping relationship with the collar 4.

It will be noted that tumbler is supported only at its rear end. Accordingly, We impart rigidity by inwardly dishing a relatively large central area of rear wall 42 and secure the center of said wall portion by rivets or the like to the flanged end of an enlarged head portion of tumbler shaft 45. We also provide a dished reinforcement plate 46 riveted to rear wall 42 and secured to the drive shaft in spaced relation with respect to said wall 42.

Ribs 47 (only one shown in Fig. 3) supplement the usual plurality of conventional triangular tumbling ribs 48 in tumbling and flufling the clothes as the cylinder is rotated. The tumbler support structure comprises a rigid relatively wide channel 50 bolted through base 2 to a heavy plate 51 (see Fig. 2) and preferably riveted through its web to heater chamber panel 17. A stiffening angle member 52 is affixed to the upper end of channel 50 as shown in Fig. 2 and extends transversely across the rear panel 17 to which it also is secured. The ends of the angle member 52 extend to, or slightly beyond the marginal edges of the heater chamber side wall panel. Thus, the forward thrust of the channel 50 occasioned by the weight of the tumbler and its contents is opposed by the very substantial resistance to distortion of the heater chamber which acts as a large box girder firmly affixed to the base 2.

The shaft and tumbler supporting means comprises a relatively heavy sleeve 53 which rests within a centering notch 54 (Fig. 2) provided in the upper end of channel 50 and within the similarly notched rear wall 55 of a bracket 56 fixed to the side flanges of the channel and projecting rearwardly therefrom. The web of the channel and the said rear wall 55 provide relatively widely spaced support points. A saddle clamp 57 secures the sleeve in position. Within the sleeve we provide suitable bearings 58, 60 (Fig. 3) preferably of the oil impre nated type, within which shaft 45 rotates.

Drive motor 61 may be mounted on base 2 with a conventional resilient bearing cradle as shown. Reduction 4 from the 1725 R. P. M. motor speed to the 50 R. P. tumbler speed may conveniently be accomplished by belt drive through an idler sheave system in which the idler 62 is belt connected to drive sheave 63 on the motor shaft and is in turn connected through its associated sheave 64 to sheave 65 fixed to shaft 45. tension we support sheave 62 on an idler bar 66 passing through openings of suitable dimension in angle member 52 and a second angle member 67 secured to rear panel 17 below the level of shaft 45 and at one side of channel 56, as clearly appears in Fig. 2. The openings are sized relative to bar 66 and aligned with respect to each other in such fashion that under the bias of the spring 68 the bar is urged downwardly and to the left of Fig. 2 and has a limited freedom of lateral plane rotation relative to the respective sheaves. Such single unit belt tensioners are well known in the art and we make no claim thereto.

The air distribution system includes a plenum or pressure chamber from which air flows into the heater chamber, and a lint trap through which it is exhausted. The plenum chamber, as seen in Fig. 1, comprises the base 2 and lower portion of the heater chamber side wall sheet 19 in association with a side wall plate 70 and a roof plate 71, each of the latter plates extending the full length of the heater chamber for securement to the end wall panels thereof. As appears in Figs. 2 and 3, the motor 61 is mounted in the plenum chamber and its shaft carries the fan 72 which operates in the plane of an opening 73 formed in the rear wall panel 17. The fan draws air through louvres 38 into the plenum chamber from which it discharges under pressure through two relatively narrow slots 74, 75, which are substantially parallel to the tumbler axis. Each air discharge is sheetlike. Slot 74 directs air upwardly to follow the side wall sheet 19 of the heater chamber in a direction counter to the rotation of a tumbler whereas the air discharging from 75 impinges against the bottom of the tumbler in the direction of tumbler rotation. These air slots are conveniently formed by spacing the edges of the plate 71 with respect to the side wall plate 70 and the side wall sheet 19, and, therefore, extend the full width of the heater chamber. The upwardly traveling air sheet or curtain envelops the heater unit 26 and abstracts heat therefrom and incidentally serves to cool the side wall and roof portions of the heater chamber reducing the insulation requirements thereof. In the domestic type clothes drier exemplified herein, the heater coil is rated at approximately 4400 watts. The metal channel-like housing for the coils absorbs a substantial amount of heat which is transferred to the air flowing thereabout. The turbulence created by the relatively rough peripheral wall of the tumbler improves heat transfer from the air to the tumbler wall and the pump-like etfect of the motion of the clothes within the tumbler produces an interchange of the external heated air and the humid air volume which builds up within the tumbler. The tumbler and contents also benefit by the substantial amount of radiant heat of the heat coils reflected toward the tumbler by the reflector plate 31.

As is well known, laundry which is taken from a domestic washing machine after having been damp-dried by centrifuging or run through a wringer has a moisture content which may be equal to or more than the dry weight of the clothes according to the efliciency of the damp-drying devices. Assuming a conventional nine pound washer load, it is apparent that the clothes when w For maintenance of belt ticles of laundry during the tumbling thereof. The .air stream discharging through slot 75, being cool and flowing about the lower left quadrant of the tumbler as viewed in Fig. 2, reduces the temperature of air discharging from the tumbler. During the later portion of the drying operation, such a temperature reduction is very desirable, particularly when the drier discharges into the room in which it is located.

The discharge from the heater chamber is through a suitable lint trapping device, as described in greater detail in our above-cited copending application Serial Number 209,280, new Patent No. 2,707,837. As shown herein by Figs. 1 and 3, moist air exhausts through the toe-board panel which is provided with a relatively long eccentrically disposed opening snugly to receive the lint trap, which preferably is a drawer-like structure including a base panel from which sides 77 extend upwardly, and an upwardly-sloping mouth structure 78. We provide a lint trap screen 82 suitably arranged in a frame 83. Itis intended that the user periodically remove the lint trap to brush or otherwise clean the accumulation of lint on the screen. However, in consideration of the possibility that this may not be done we provide a port 88 (Fig. 3) in the respective walls 77 so as to insure the discharge of air from the heater chamber even in the circumstance that the lint trap screen is substantially blocked by a lint accumulation. The rear heater chamber panel 17 is provided with an opening over which a cover plate 97 is removably applied. It will be observed from a comparison of Figs. 1 and 2 that the opening in panel 17 is of substantially less width than the opening in the toe board 10 necessary to accommodate the lint drawer. The purpose of this is to utilize conventional air duct sizes, for example, approximately 3 /2 in. deep by 10 in. wide in the ductwork for the rear discharge trap arrangement. The rear edge walls of the drawer however also fit snugly against the panel 17. The rear casing panel 3 has an opening provided with a removable cover plate 98, said opening and cover plate being slightly larger than the opening and cover plate 97 of the panel 17 as best appears in Fig. 2. When a rear discharge system is to be utilized the respective cover plates 97 and 98 are removed and a duct section sufficient to extend suitably beyond the rear casing 3 is inserted through the rear casing opening and is secured to the chamber wall 17 by screws or equivalent passing through the inwardly directed flanges of the extension. The size of the duct extension is such that the mechanic may easily reach through it to complete the fastening. Further duct extensions may be aflixed by conventional slip fit elements, not shown.

In all tumbler driers of which we have knowledge, some lint will accumulate within the heater chamber; not all of the lint remains suspended in the air stream discharging through the lint trap. We appreciate that this will also be true in a drier constructed according to our invention as above described. However, we effectively minimize the accumulation of lint in ditficultly accessible portions of the chamber by the relationship of the plenum chamber and the direction of air discharged therefrom to the tumbler and its direction of rotation, as well as by the horseshoe slope of the casing defined by the wall panels 16 and 17 and the enclosing sheet 19, which shape makes it possible to avoid having narrow lint trapping passages between the casing and the lower portion of the tumbler 40. The disposition of the air slots 74 and 75 creates a small quiet air zone immediately above and in the right of the plenum chamber roof panel 71 as viewed in Fig. 2. The air curtain from 74 follows up along the wall 19 until loss of momentum causes it to diffuse around the heater assembly, and the force of discharge through slot 75 reduces turbulence which might produce back-flow over the panel 71. The slope of roof panel 71 toward the tumbler and the direction of rotation of the tumbler establishes a condition in which the tumbler acts as an airpumpwhich prqduces a; relatively gentle ain flow through the throat formed by the convergence of the tumbler and the roof panel. .The diffusing curtain from slot 74 maintains a sufficient turbulence about the upper portion of the tumbler and the heating unit to preclude lint from settling thereon. Lintwhich may be carried through the lower portion of the tumbler by the mechanical action of the clothes movement therein will be mechanically transported into the quiet zone area where some of it will deposit on the roof panel 71. Eventually the air movement induced by the tumbler sweeps the lint into the air flow discharging from 75 and it will be carried by said air flowtoward the lint trap. The air' discharge .from orifice 75 sweeps the bottom portion of the tumbler and removes lint which may have adhered thereto; The air movement through the orifices 74 and 75 provides a discharge pattern which minimizes lint accumulation in diflicultlyaccessible portions of the heater, chamber. Accordingly, the chamber. may easily be cleaned with conventional vacuum cleaner accessory tools.

A suitable drier control is provided as described in detail by our copending application Serial No. 209,280, now Patent No. 2,707,837, referred to above. For clarity, these details have been omitted from this application, and we have shown only a thermostat control 107 and an on-ofi and drying period control knob 106 (Fig. 1).

As best shown in Fig. 3 the temperature sensitive bulb 108 for thermostat 107 is located suitably within the heater chamber to sense an average temperature therein. The location shown in Fig. 3 may not actually be that selected for the bulb; some experimentation may be required to determine the most advantageous standardization of bulb location. It will be understood that the thermostat is the type which closes its circuit when the bulb temperature is below the setting point. A protective fuse (not shown) may be concealed beneath the toe board ledge behind a swingable cap 116, pivotally affixed to the toe board ledge and secured by a thumb nut 117, see Fig. 1. It will be understood that the rear of cap 116 is open and that when the cap is on home position, the rear. wall of the toe board completes the fuse head enclosure. For illumination of the interior of the heater chamber and the tumbler, we provide an incandescent lamp 118 socketed within the plenum chamber behind a removable window 120. An ozone producing lamp 121 similarly within the plenum chamber tends to give the air within the chamber a fresh outdoor odor which is to some extent imparted to the clothes.

While we have shown a particular embodiment of our invention, it will be understood, of course, that we do not wish to be limited thereto since many modifications may be made; and we, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In a drier for fabrics and the like, a heater chamber comprising a base, end-wall forming panels secured to and extending from said base in mutual alignment, side and roof-forming means including a resilient metallic sheet wrapped over peripheral edges of said panels and having marginal flanges providing a pocket having a substantially V-shaped contour within which said edges of the respective front and rear wall panels are disposed,

- and means for drawing said sheet about said end panels to confine the edges thereof snugly within said pocket, said means including a substantially semi-cylindrical edge portion integral with said sheet at the other marginal edge portions thereof andfastening means extending chordally through said semi-cylindrical edge portions to compress the same against said base.

2. In a drier for fabrics and the like, a heater chamber comprising a base, end-wall forming panels secured to and extending from said base in mutual alignment, side and roof-forming means including a resilient metallic sheet wrapped over peripheral edges of said panels and having marginal flanges providing a pocket having a substantially V-shaped contour within which said edges of the respective front and rear wall panels are disposed, means for drawing said sheet about said end panels to confine the edges thereof snugly within said pocket, including a bottom edge portion of semi-cylindrical configuration at each side of said sheet extending between the front and rear panels and fastening means passing through said semi-cylindrical edge portions into said base, a Wall of insulation material disposed about said sheet, and securement means for said insulation wall comprising strap means extending continuously about said sheet and secured beneath each of the said bottom semi-cylindrical edge portions.

3. In a drier for fabrics and the like, a heater chamber comprising a base, end-wall forming panels secured to and extending from said base in mutual alignment, side and roof-forming means including a resilient metallic sheet wrapped over peripheral edges of said panels and having marginal flanges providing a pocket having a substantially V-shaped contour within which said edges of the respective front and rear wall panels are disposed, and means for drawing said sheet about said end panels to confine the edges thereof snugly within said pocket, said means including a springable edge portion formed on each side of said sheet extending between the front and rear panels and fastening means passing through said springable portions into said base.

References Cited in the file of this patent UNITED STATES PATENTS 1,066,215 Murray July 1, 1913 1,943,255 Booth Jan. 9, 1934 2,046,810 Cannon July 7, 1936 2,271,260 Horsley Jan. 27, 1942 2,540,955 Moore Feb. 6, 1951 2,644,245 Hammell et al. July 7, 1953

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