US2406226A

US2406226A - Washing machine

Info

Publication number: US2406226A
Application number: US450131A
Authority: US
Inventors: Arthur L Kimball
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1942-07-08
Filing date: 1942-07-08
Publication date: 1946-08-20
Anticipated expiration: 1963-08-20

Description

Aug., 20, 1946.

A, l.. mMBALL WASHING MACHINE Filed July s, 1942 Figz.

3 SheAets-Sheetl Argh@ 1.-. Kimball;

His Attorney.

Aug. 20, 1946. A. L. KIMBALL ,2,406,226 'WASHING MACHINE AFilad July s, 1942 zangers-sheet *.2

Arthur* L. Kimball v by .Mwycf [His- Attorneg.

Aug'. 2 0, 1946. l A. l..v KIMBLL WASHING MACHINE Filed July 8, 1942 Patented Aug. 20, 1946 OFFICE WASHING MACHINE Arthur L. Kimball,

Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application July 8, 1942, Serial No.' 450,131

vThe present invention relates to washing machines of the type having a spinner basket in which the clothes are centrifugally dried.

During centrifugal drying there-are unbalanced forces resulting from non-uniform distribution of clothes in the spinner basket, from gyration of the driving mechanism and from precession of the spinner basket. Y

The object of my invention is to provide an improved construction andv arrangement in which objectionable vibration resulting from these unbalanced forces is kept at a minimum, and, for a consideration of what I believe novel and my invention, attention is directed to the following description and the claims appended thereto. A In. the drawings, Fig. 1 is a sectional elevation of a washing machine embodying my invention; Fig.` 2 iszan enlarged sectional elevation of the support for thespinner'basket; Fig. 3 is a sectional view on line 3-3 of Fig. rl; Fig. 4 is a sectional view on line 4-4 of Fig. 2;V Fig. 5-is a sectional view taken on line 5-5 of Fig. 2; Fig. 6 is asectional elevation of the driving mechanism; Fig. 7 is a sectional View on line 1-1 of Fig. 6; and Fig. :Sis a sectional View taken on line 8-8 of Fig. 6.

Referring to the drawings, there is shown a washing machine having an outer casing I in the upper part of which is a spinner basket or clothes receptacle 2 having outwardly flaring fluted side walls 3 provided with centrifugal dischargeopenings 4 at the region of maximum diameter. The

spinner basket is made of .relatively thinsheet metal, which may be porcelain enameled steel, and is'removably supported in a combined carrier and balance ring having relatively heavy side walls 5 surrounding the spinner basket and spaced radialtarms 6 extending `beneath the bottom of the spinner basket and connecting the side walls 5 with a hub .1.v The carrier sidewalls 5, as shown more clearly in Fig. 3, loosely surround the side walls. of the spinner basket. Possible rattling due to this looseness is prevented by rubber bushings *.8 bolted tothe carrier side walls and having flexible projections 9 which fit in the` flutes in the side Wallsof the spinner basket. The spinner basket is secured to the rcarrierfby means of a nut I0 threaded on a sleeve I I fixed to the carrier hub, the basketbeing clamped between the nut I0 and a shoulder I2 on the sleeve II.y The carrier hub 1 loosely surrounds a sleeve I3 which at its upper end,as shown` in Fig. '5, has inwardly extending projections .1I-4 provided with axial grooves I5 by means of which the sleeve issplined on a tubular Ashaft I 6 and with ing with precession and 6 Claims. (Cl. 210-71) a circumferentialgroove I1 receiving a snap ring I 8 for engaging a shoulder I 9 on the tubular shaft l6so as to support the sleeve I3. The projections I 4 are spaced apart so as to provide drain passages 20. At the lower end the sleeve I3 has The arms 25 are connected to a flexible steel ring 26 which atintermediate points is connected tov the carrier arms 6. The connections to the arms 6 and 25 `are made through bolts 21 having bushings 28' which clamp ofthe bolts. The clamping surfaces are chamfered, as shown at 29, so as to prevent localized stresses in the ring. The connection between the bolts 21 andthe carrier arms 6 is complicated by the fact that the carrier arms have a stiffening rib 30 directly .above the desirable vposition for the bolts. The connectionis accordingly made through projections 3| on bushings 28 (Fig. 4) which are riveted at 32 to the under side of thecarrier arms, and the carrier arms are provided with. holes 33 through which a wrench may be inserted'totighten the bolts.

The above described construction provides a support .for the spinner basket which permits' a universal tilting of' the spinner basket relative to the driving shaft I 6. This tilting tends to neutralizeany .unbalanecd couple or dynamic unbalance which would otherwise transmit objectionable vibration to. the driving shaft. 'I'he spinner basket is also resiliently supported for axialmovement with respect to the shaft to cushion axialv forces which, as hereinafter explained, arise while thespinner basket is rotatunbalanced distribution of the clothes.

Animportant feature of this universal connection is its relatively low friction which results from the use of a material of low internal friction'forthe .ring 26 and from the design of the connections to the ring so as to minimize the friction.. The lowfriction is important in preventing forward precession. or shaft whip which is 4excitedby friction in the rotating parts.

. Low friction `means low exciting force.

the ring against the heads 5 between anoutwardly extending Ilan-ge, |08 ,at the lower end ofthe supportingfmember-v|03 and a; ring |09 clamped betweenA a flange IIIJ at -theyupper edge ofthesupporting ring 13 anda ,flange III at the lower end. of a supporting ring H2. The,rub.ber vring |01 isrconned between lthe supporting ring 13, the'supporting member I04,.and a ange H3 at the inner end of the ring; |09. Rotation of the rubber ring |01 relativeto the support |04 and the ring |019 is pre,- vented by tabsA ||4 struckoutof parts I 09and |08 and fitting in notchesA in the rubber ring. The rubber ring point `at which its modulus. ofelasticityincreases. This means that upon tilting of the spinner bas,- ketfrom a ,central position the restoring force due to the rubber ring increases at a continually increasing rate. Also, since, the pressure onthe brake shoes |05 is dueto the weight of the spinner vbasket and gear ca sing. and the compressive forces in the `rubber ring, the `pressure on the brake shoes increases as the spinner basket tilts away; fom its central position. y This means that theI friction damping eiect of the brake shoes |05 increases as the spinner basket moves from its central position.

The spinner basket and its driving mechanism are all supported from the bottom wall of the outer casing by -a flange II5 on the ring ||2 which is clamped between a ring ||3a and the bottom wall of the outer casing. The upper end |01 is rinitially compressed to a of the driving mechanism projects through a clearance opening IIS in the bottom wall of the outer` casing which is sealed by a rubber sleeve .|I1 having its upper end xed tothe tubeV 93 by a clamp ||8 and having its lower end clamped between a ring IIS and the upper side of the bottom wall of the outer casing. Y

Duringwashing, the brake shoe 69 is applied, holding the gear housing 41 vstationaryand causing oscillation of the agitator 34. During centrifugal extracting, the brake shoe 60 is released and-the motor 5| is reversed to couple the housing to the pulley 54 through the overrunning clutch Blf-9 I.

j During centrifugal extracting, the clothes will :be non-uniformly.- distributed causing an unbalance which can be divided into a static unbalance (equivalent to a weight shifting the center of gravityof the lbasket transverse to its axis of rotation) and a dynamic unbalance (equivalent to `a couple tending to tilt the basket about an axis perpendicular to the axis of rotation).

Static unbalance during spinning is neutralized bythe gyratory support provided by the rubber ring I 01 which permits tilting of the spinner shaft IB about the center of the gear casing to bring the center of gravity of the spinner basket directly above the center of the gear casing. In this positionthe spinner basket rotates about its center of gravity.'v From one aspect, the rubber ring |01 can be considered as resiliently supportingA the shaft, gear casing and basket for gyratory movement. While the spinner basket is rotating about its center of gravity.. the upper end of the agitator hub, which` is at the geometric center of the basket, describes a circle about the center of gravity having a radius equal to the l displacement of the center of gravity due to static unbalance. The motion of the spinner basket can be divided into two components, rotation on its geometric axis andfgyration about an axis passing through the center of gravity of the spinner, basket and through the center of the gear casing. (the spinnershaft I 6 and the gear casancedcouple.

.ing `also rotate on and gyrate. about, these axes).

. lDynamic, unbalance is neutralized.` by the` tiltable support, of the spinnerbasket provided :by

the; rinf,r 26,. The basket tilts relative to the shaft IBto a position in which there. isnounba-lr- Of Ycourse ,thejstatic and dynamic unbalances are not perfectly neutralized bythe tiltable sup- |01 and 26. Thefstif- Dynamic and static unbalance, cause vibrations of shaft frequency which are iof greatest magni-V tude at the critical speeds, thepspeeds at which the shaft speed is resonant with one ofthe natural frequencies of. vibration of thefrotating system (the basket, shaft, gear c'asing,etc.). In the present machine there are two critical speeds to be considered, the rst critical `speed infwhich the basket and other parts supported. by the ru-b- .ber ring |01 vibrate as a unit, on the ring and the second critical speed in which the basket would tendv to tilt or vibrate v`relative to thefupper end of the shaft I6. vThe first critical speed is dueV to the rubber ring |01 and Vcan be called a mounting" critical speed. The second critical speed, in which thereis ilexure between the shaft and the basket, can bev called a shaftf critical speed. Y

`It has been observed, and these observations have been checked --by theoretical computations, that the second critical speed vexistsonly when the moment of inertia of the basket aboutthe axis of'rotation is less thanr the moment ofy inertiaof the basket aboutuan axis at right angles tothe axisof rotation and through its center of gravity. The second critical speed, beinghigher than the rst critical speed, is objectionabledue to the higher centrifugal forces which makeit more diilicult to bring the spinner basket.; up through the second critical speed. This second criticalspeed has beeneliminated in the present construction by making the moment of ,inertia o f the basket about its axis of rotationgreater than the moment of inertia of the basket about an axis at right angles to its axis of rotation and through its 4center of gravity.

The rubber ring |01 is preferably proportionl ,d sov that the first critical speedv is substantially belowthe normal extractingspeed.V In the-pres;- ent machine the critical speed due tothe ,rubber ring |01 (the natural frequency of vibration of the basket, shafts, gear casing, etc., on the rubber ring) is of the order of, R. P. M., whilegthe v extracting speed is 1200 R. P. M. Itis of ccnsiderable advantage to have the natural frequency due to the rubber ring |01 `(the firstV critical speed) low so that the centrifugal forces due to the unbalance, which vary` as the square ofthe speed, will be small. If the critical speedishigh they centrifugal forces which vary as the square of the speed will be correspondingly higher and the friction forces on the bearings may be sufficient to keep the basket from coming up to speed.-

VVAnother feature in the present construction which assists in bringing the the critical speed is the friction damping vprovided by the brake` shoes |05which frictionally resist tilting of the axis of rotation and accordingly limit the amplitude of the vibration atthe critical speed. This'limitation on the amplitude at the critical speed keeps thenspinner basket in a more` nearly centralposition in which. it, can be more easily accelerated.. f .f At speeds abovev thjeilr'st criticalfs'pe'e @there basket up vthroughV encens@ y aregyrcfscopic svibrati'ons Ilmonmjrascpreeession. v

vibrationsconsistfor:eitneraiorvvardror a Y Thacilsivardarotationoi-the basket aboutfitslaxisiof andbackwardrprecession. f'Du'ring 11a-recession lthe ti'onalilyf resist tilting Lof .the '1 axis` fof rotation of tth'febasket. Forwardfprece'ssion, which is due `to Viric'ti: inthe rotating system, isi 'kept to a Lnlin- 4imum'iby:makin'g 'the ring `Z-G'Iof'a .'rnaterial having ilw nternalfrictiomsuchas spring steel, andlby .desi'gningkthe connectionsfto the ring Iso to to "eirectively' cushion `this,` axial Kforce and upre- Iventtrinsmissiontothe door. 1 'i l The above :described construction producesi-a fcrnpact arrangement Vofith'e the resilientT `support, and 'the `friction damper.

The 'driving :mechanism is f spherical'housing concentric vwith the :friction iminimiz'efriction.. has been Ademonstrated by adding'ifriction'intthe supporting ring"126'that for-` fward-preces'sion may be excited `to a value diiiie f `fcuf'ltiito control by the brake shoes P05.

The resilient" support for tilting 'of the basket ue'latiie =to 4thevs'haft is designed for-a minimum of friction while ithe'resili'ent support for g'yfrafitibnzof 'the shaft is Adesigned Vto have friction damping providedlin the present construction by rthebrakeis'hoe's i105. The friction in the resilient' support for the basket is low compared tothe friction lthe resilient support for the shaft. i;

relationbetween the `friction 'in the respecvftivefsupports is animpor-tant factor in the deisign'.' Y

- Forward precession 4is also decreased by de- @signing fthe friction damper so v :dampr-ifn'g increases asr the basket tilts 'from the vertical; 'In Ythe present construction thi-sffrictinnampingcharacteristic is obtainedby initially :compressing 'the rubber ring `|01 to a point 'at which'l its modulus of elasticity increases. This means that the pressure on itandfaccordingly the f-fr'i'ctional resistance Lor Y camping) is a -minimum when the masker is in 'the vertical position. By 'ltests Vin which the friction ydamper was replaced by a damper in which fthe friction damping was a `minimum when the axis' of rotation of the lbasket was-tilted from thewefrtical, it hasfbeen found that the basket tended to assume vthe pos'itionof minimum -da-mp'f ingand' that objectionablewf'orward pre'cessi'on builtup. For a minimum of `'forward precession it isf-important that fthe friction damping vdoes not, increase toward the :cer-rter. l f

vlllfien fthereis beth preces'sion and unbalance, 'thereeis anaXa-l force off haft frequencytending 'tel-move the basket up and I'downalongthe axis fof rotation. F11-'his axial iorcelarise's when 'the shaft frequency gyration of the spinner basket about itsfaxis of rotation is superimposed ilpor thelovv 'frequency rotation or prec'essfion ofthe aixis'fof' rotation. ThisY results Iin af-variable displacement sha-ift frequencyof 4the spinner 1basket r'o'm'fth'e Vpos'tion -of perfect balance. Fromanother aspect-fthe angularity 4of the rlshaft varies fat shait freque'ricy.` f lSincel either `the the' basket Von the ringzsiisif thecrcer (5f-20o 'that its lTfr-10131011 Iovif the normal extactinglspeed 'of120'0 R; P." M.

fdamper and lwith the brake for controlling Vthe drivingfmechanism.f ISince the driving 'finecha- -nismbccupiesa 'minimum of, space, it. can'be made :relatively ISlight and. accordinglywill h niininmmy of inertia reaction on the' bearingsfsivli .and during theextracting operation lwheniit is .forcedtofgyratewith'the basket. The reaction -due' to the iforiced :gyration ofthe gear .casing lis -furtherdecreased by 'the fact that the casing 4.is

Vspherical#and rotates :atfthe same `speed` as the basket. .In 'perfect 'sphere `4while rotating can :be tilted about l"any axis without producing VIan'ylrefaction. In the present lgear 'casingfthe inertia reactionfdue :toiits `forcedgyration `is .due to ilthe deviation of '.th'e gear i casing ffro'm fa. theoretically perfectly'balanced sphere. L 'Ifhisdeviation can be ikept toria minimum by counterweights lsuch as the Jo'ossi) .and .the "counterweight Y88.

What I claim as new and desire to `'secure-by Letters'-Patentof Ythe UnitedStates is: f

'1. In Aa laundry machine, a 'spiner'lbasketg fa vertical drive shaft forV the basket, a Aiieiri'ble member of a material havingallowinternalfriction ihaving spaced points alternatelycbnneeted to the `shaft and Vbasket for Y resilientlysupporting the vbasket for tilting and axial movemntfwith respect tothe shaft, means resil-i'ntlylsupporting and friction Idarn-ping means acti-ng throught-'said part Yforv frictionally vresisting gyration lofA the shaft, Y Y 1 =2. YIn a laundry machine, a spinner basket, fa

'vertical v'dr'ive Ishaft for `the basket; meansresili- 1 ently supporting the basketfor tilting and axial movement relative to the shaft, means resiliently supportingjthe shaft for gyratory movement,sa'ii shaft supportingmeans 'being proportioned so that the critical speed vdu'e to such means isbe- -l'wthe normal speedof the Vbasket `during en@ v`trifugaldrying,a part in whichthe vshaftisjournaled, and friction 'damping' `means acting through said part for frictionally resisting'gyration of the sha-ft. y

comprising Ya rotatable frame, a driving shaft ljourna'led in ysaid framejmeans jfor Vselectively holding 'the frame "stationaryv or vcouplingr vthe 'drivings'haftto 'thefrarna aspinn'er basket, 'shaft means for connecting the frame vto `the spinner basket, Ameans comprising, a flexible '-m'etalri'n'g having 'a minimum of internal friction'connected to the basket and tthe shaft means supporting the basket for tilting relative to-said shaft means',

a. tub surrounding the spinner basket, la stationary' member.; means connected lto said `mernb'ejrin cluding a sleeve `in which 'the shaftv means is journaled for supporting the 'shaft means, spin-V ner 'basket and frame'on said stationary member to permit 'gyratory movement relative to the tub; and friction daml'ng ,meansI between lsai'd 1as't means .and the stationary member for friction; ally resistingfthfegyratory movement; j, .A 1n 'a Washing machine, a spinner1ba'sket; a support 'having an upwardly presented spherical 'contained "Witln a Y 3'. vfin a washing machin-e, ldriving lrnecl'rarisni friction surface, a vertical sleeve having its lower end depending around and seated on said surface whereby tilting of the sleeve is frictionally resisted, spring means holding the lower end of said sleeve against said spherical surface, said spring means having a modulus increasing with the deflection of the sleeve from the central position, and a shaft journaled in said sleeve rotatably supporting the spinner basket.

5. In a Washing machine, a driving mechanism comprising a rotatable frame, a driving shaft journaled in said frame, means for selectively holding the frame stationary or coupling the driving shaft to the frame, a spinner basket, shaft means for connecting the frame to the spinner basket, a joint connecting the basket to the shaft means comprising flexible arms of a material having a low internal friction, a tubsurrounding the spinner basket, a stationary member, means connected to said member including a sleeve in which the shaft means is journaled for supporting the shaft means, spinner basket and frame on said stationary member to permit gyratory movement relative to the tub, and friction damping means between said last means and the stationary member for frictionally resisting the gyratory movement.

6.`In a Washing machine, driving mechanism comprising a rotatable frame, a driving shaft journaled in said frame, means for selectively holding the frame stationary or allowing it to be coupled to the driving shaft, a spinner basket, shaft means for connecting the frame to `the spinner basket, flexible metal spring means having lovv internal friction connected at spaced points to said basket and said shaft means and extending radially from said shaft means, Whereby the basket is supported for tilting and axial movement relative to said shaft means, a tub surrounding the spinner basket, a stationary member, means connected to said member including a sleeve in which the shaft means is journaled for supporting the shaft means, spinner basket and frame on said stationary member to permit gyratory movement relative to the tub, and friction damping means between said last means and the stationary member for frictionally resisting the gyratorymovement.

ARTHUR L. KIMBALL.