US2243565A

US2243565A - Washing machine

Info

Publication number: US2243565A
Application number: US72584A
Authority: US
Inventors: Arthur L Kimball; George W Dunham
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1936-04-03
Filing date: 1936-04-03
Publication date: 1941-05-27
Anticipated expiration: 1958-05-27

Description

May 27,1941. A L. KIMBALL x-:rAL

WASHING MACHINE 2 Sheets-Sheet 1 Filed April 5, 1956 I i I o o unam The' Geovge by;l

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May 27, 1941 l A. L KIMBALL r-:rAL l 2,243,565

WASHING MACHINE Filed April 3, 1936 v 2 Sheets-Sheet 2 FgS,

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Inventors:

SHAFT SPEED.

Arthur L. Kimball; Germ-gew Dun ham,

Asupported on a base 2.

Patented May 27, 1941 WASHING MACHINE Arthur L. Kimball, Schenectady, N. Y., and George W. Dunham, Westport, Conn., assignors to General Electric Company, a corporation of New York Application April 3, 1936, serial No. *12,584

1o claims. (o1. 21o-11) The present invention relates to washing machines of the type having a centrifugal extractor for drying the clothes.

In washing machines of this type there may be considerable vibration of the extractor due to unbalanced distribution of the clothes and to gyroscopic action. The vibration due to unbalance may be particularly great when the extractor is being brought up to its normal operating speed. If the machine is rigidly supported on the oor these vibrations will be transmitted to the floor and thereby tion of the oor.

The object of our invention is to provide an improved construction and arrangement in machines `of this type which will decrease the transmission of vibration from the machine to the floor and for a consideration of what we believe to be novel and our invention attention is directed to the accompanying description and the claims appended thereto.

In the accompanying drawings Fig. 1 is a fragmentary sectional elevation of a washing machine embodying our invention; Fig. 2 is an enlarged view of the arrangement for driving the agitator and the rotatable receptacle; Fig. 3 is a sectional view taken on line 3 3 of Fig. 2; Fig. 4 is a sectional elevation of one of the supports for decreasing the transmission of vibration from the machine to the floor; Fig. 5 is a diagrammatic view illustrating the construction and operation of the support shown in Fig. 4; Fig. 6 is a plot showing the frequencies of precession of the receptacle; Fig. 7 is a fragmentary elevation of a machine having a modified 4form of support for decreasing the transmission of vibration to the floor; Fig. 8 is an enlarged view of the spring support; Fig. 9 is an enlarged viewy of the arrangement for damping the-vibrations; and Fig. 10 is an enlarged plan view of the arrangement for damping the vibration.

We have shown our invention applied to the washing machine shown in application Serial cause undesirable vibrawhen the inside of the stationary tub is cleaned. The abutting edges of the tub I and the base 2 are covered by skirt I carried by the tub.

Within the base 2 is supported a driving mechanism for the washing machine which is adapted to effect selective oscillation or rotation of a vertical shaft 8. Any suitable driving mechanism may be used,vfor example the driving mechanism shown in application Serial No. 14,255, filed April 2, 1935. Keyed to the shaft 8 is a brake drum 8 which is connected by means of a suitable un- -versal joint to the lower end of a vertical shaft III .which extends through a sleeve II. The universal joint comprises diametrically opposed pins I2 which are fixed in ears I3 on the upper side of the brake drum. The inner ends of the pins I2 are journalled in bearings I4 clamped between plates I5 whichform the intermediate member of the universal joint. rI'he lower end of the shaft I0 is provided with ldiametrically opposed pins I6 which are spaced between the pins I2 and are likewise journalled in bearings carried between the plates I5 of the universal joint. With this construction the vertical shaft I0 may have a gyratory movement vwith respect to the driving shaft 8. The sleeve II extends above the normal water level in the stationary tub. The upper end of the sleeve is provided with a spherical seat for a self-lubricating bearing I1 which guides the shaft I0. This spherical seat comprises a flared portion I8 of the sleeve and a collar I9 which is secured in the upper end of the sleeve. The spherical seat permits alignment of the bearing I1 lwith the shaft I0 so that the bearing pressurel is uniform regardless of the inclination of the shaft.

The housing for the driving mechanism which y is supported within the base 2 has a hollow post No. 61,635, filed January 3l, 1936. The washing machine comprises a stationary tub I which is The upperend of the tub is partially closed by an annular cover 3 having a flange l which fits within the upper edge of the tub. Between the flange 4 and the tub is a suitable gasket 5. A cover 6 rests on the inner edge of the annular cover 3 and completes the closing of the top of the stationary tub. When clothes are to be inserted or removed from the washing machine only the cover 6 need be removed. The cover 3 is removed 20 which extends through central openings in the top Wall of the base andthe bottom wall of the stationary tub. The post 20 is secured to the bottom wall of the tub and to the base by means of screws 2| which are threaded through a clamping ring 22 into a flange 23 which is integral with the post 20. Suitable gaskets are arranged between the flange 23 and the base and between the base and the bottom wall of the tub. Leakage fromy the bottom of thel tub is prevented by means of a rubber sleeve`f24 which has its lower edge clamped between the ring 22 and the bottom of the tub and which has its upper edge clamped to the vsleeve II above the post 20 by meansr of a clamp 25. Within the post 20 is a resilient mounting for the lower end of the`sleeve II which 'comprises two annuluses 26 of rubber or other resilient material. The lower annulus is arranged between an inwardly extending flange 21 at the lower end of the post and a flange 28 projecting from a sleeve 29 secured to the sleeve Il. The upper annulus is arranged between the upper side of the flange 28 and a washer 30. The inner edge of the upper annulus 26 rests against a sleeve 3| which is fixed to the sleeve Il. The'sleeve 3| is of the same dimensions as the sleeve 29 and is used so that the annuluses 26 may be of the same size. The resilience of the mounting is adjusted by means of a nut 32 which is threaded into the upper end of the post 20. This nut varies the compression of the rubber and thereby varies the stiffness of the mounting. With this mounting, the sleeve Il is resiliently held in a central position and is free to -tilt in all directions in order that the shaft l which is guided in the sleeve may have a gyratory movement.

In the upper part of the stationary tub is a rotatable tub or receptacle 33 for receiving liquid and material to be washed.4 'I'he space between the bottom of the receptacle 33 and the bottom of the stationary tub I is sufficient to provide a storage space for all the liquid which can be placed in the receptacle. At the center of the receptacle is a vertical sleeve 34 which serves as the hub for the receptacle. 'I'he upper end of the sleeve 34 projects above the water level in the receptacle. The lower end of the sleeve 34 fits into an opening in the bottom wall of the receptacle and an opening in a stiffening disk 35, both of which are held in position bey tween a shoulder -and a spun-over portion, as

shown at 36. The lower end of the sleeve 34 is provided with a circular flange 31 which extends over the upper side of the bottom wall of the receptacle. The flange 31 and the stiiening disk 35 are securedfto the bottom wall of the receptacle by means of rivets 38. The lower end of the sleeve 34 is guided by a self-lubricating bearing 39 which is fixed to the vertical shaft I0. 'I'he upper end of the sleeve 34- is guided on the shaft l0 by a self-lubricating sleeve bearing 40 which is pressed within the upper end of the sleeve against an inwardly extending flange 4l (see Fig. 2) formed thereon. The lower end of the sleeve bearing -40 bears on a hardened steel thrust collar .42 which is keyed to the shaft I0. The thrust collar is supported on the shaft by means of a shoulder 43 on the shaft. The weight of the receptacle and the material contained therein is transmitted to the thrust collar 42 by the bearing 40 and through the shoulder 43 to the shaft I0. From the shaft l0 the weight is transmitted through the universal joint and the shaft 8 to a suitable thrustbearing in the driving mechanism which is contained within the base 2.

The shaft Il! projects above the sleeve 34 and the projecting end is provided with splines 44 which fit between complementary splines formed in a bushing 43 which is xed in the upper end of the hub of an agitator 46. Leakage of water through the upper end of the agitator as the water issplashed about is prevented bya. cup

41 which is snapped in place over the upper end of the agitator; 'Ihe splines 44 provide a rigid driving connection for the agitator and at the same time permit the agitator to be easily lifted from the end of the shaft.

During washing, the shaft I0 is oscillated through the driving shaft 8 and thereby causes oscillation of the agitator 46 in the receptacle means of an annular guard ring 48 which is located slightly below the upper edge of the receptacle. During washing, water may be continuously discharged into the top of the recepta,

cle. The excess water will flow through openings 49 in the guard ring over the upper edge of the receptacle, carrying with it the scum which floats on top of the water. The inner edge of the guard ring 48 is provided with a vertical flange 5U having a rounded upper edge 5| which serves as a handle by means of which the receptacle may be lifted from the shaft I0.

l During extracting, the driving connection between the shaft I8 and the receptacle 33 is effected by means of a centrifugal clutch which is carried on the thrust collar 42. This clutch comprises two 'shoes 52 which are held against a squared cam surface 53 of the thrust collar by means of two split rings 54. During washing the agitator 46 is oscillated and the oscillation of the shaft l 0 is at a relatively slow speed ofthe order of magnitude of 60 oscillations per minute, and the split rings 54 are strong enough to hold the shoes 52 against the squared portion 53. For wringing, 'the shafts 8 and I0 are rotated and as soon as the speed of rotation exceeds a few hundred R. P. M, the clutch shoes 52 move outwardly under the action of centrifugal force and touch the inner surface of the sleeve 34 which forms the hub of the receptacle 33. As soon as the-shoes 52 contact the inner surface of the sleeve 34, their rotation is retarded and the squared surface 53 of the collar 42 cooperates with the in ner surface of the shoes 52 and wedges the shoes tightly against the inner surface of the sleeve 34. The pressure between the shoes and the sleeve is proportional to the torque exerted by the shaft I0. 'I'his effects a positivel receptacle causes the clothes -to be washed. During the washing operation, the receptacle 33 may be tilted to one side due to the fact that the clothes are not uniformly distributed in the receptacle. This inclination is permitted by the resilient support for the lower end of the sleeve II and by the universal joint arranged between the driving shaft 3 and the lower end of the shaft I 8. Water is preferably continuously discharged into the top of the receptacle 33 andallowed to flow continuously over the upper edge of the receptacle, thereby floating off the scum which collects on the top of the water. During the washing operation the bearing loss `in 'the bearings 39 and 40 is negligible due to the low speed of oscillation of the shaft Il). y

At the conclusion of the washing operation, the driving mechanism is adjusted so that the shaft 8 is rotated continuously in one direction. As soon as the speed of rotation of the shaft is decreased.

, frequency vibrations due to unbalance.

8 exceeds a few-hundred R. P. M. the clutch shoes 52 move outwardly under the action of centrifugal force and touch the inner surface of the sleeve 34 which forms the hub of the receptacle 33. As soon as the shoes 52 Contact the inner surface of the sleeve 34, their rotation is retarded and the squared surface 53 of the collar 42 cooperates with the inner surface of the shoes 52 and wedges the shoes tightly against the inner surface of the sleeve 34. This effects a positive driving connection between the shaft I and the receptacle which causes the receptacle to be rotated.

Since the clothes may be nonuniformly distributed in the receptacle, the receptacle may be unbalanced. This unbalance will usually consist partially of a static unbalance which is equivalent to a single weight displaced from the axis of rotation of lthe receptacle and partially of dynamic unbalance which is equivalent to the couple produced by vertically spaced weights of. equal size located on opposite sides of and equidistant from the axis of rotation of the receptacle. The static unbalance will tend to cause gyration of the receptacle about its axis so that the receptacle rotates aboutits center of mass. The dynamic unbalance will tend to cause tilting of the receptacle so as to bring the receptacle into a position in which there is no unbalanced couple. The resilient mounting provided for the lower end of the sleeve l0 permits gyration of the receptacle .about its axis so -that the receptacle rotates about its center of mass, neutralizing the eiect of static unbalance.v Since the resilientmounting has some stiffness, the gyration of the receptacle about its axis is not sufficient to permit the receptacle to rotate about its center of mass, but the resilient mounting does permit suilicient gyration of the receptacle so that the vibration due to static unbalance is considerably decreased. Since the sleeve bearings 39 and 40 prevent tilting of the receptacle with respect to the shaft IIJ, the receptacle will cause vibration due to the dynamic unbalance. This tendency of the receptacle to tilt causes heavy bearing pressure on the bearings 39 and 40, but

since there is no relative rotation between the bearing surfaces of these bearings, this pressure causes no bearing loss. Most of the force due to the dynamic unbalance of the receptacle will be transmitted through the universal joint at the lower end of the shaft I0 to the shaft 8. This force is taken by the bearingsin which the shaft 8 rotates. Since the bearings for the shaft 8 are a considerable distance from the receptacle 33, the force on the bearings due to the unbalanced couple is less than it would be at a point nearer the receptacle. This means that the bearingloss due to the unbalanced couple Also, these bearings are located below the stationary tub l and are therefore not 4subjected to the humid atmosphere within the tub and are more easily lubricated. Some of the force due to the dynamic unbalance` or unbalanced couple is transmitted to the sleeve Il. However, since this sleeve is resiliently supported,

these vibrations are cushioned. The cushioning action decreases the bearing pressure on the bearing l1 and thereby decreases the bearing loss. I

During the rotation of the receptacle vibra-l tions are transmitted from the receptacle mounting critical speed. It is desirable that the speed at which this vibration takes place be substantially below the normal operating speed, for example one fifteenth of normal speed, so that the centrifugal forces due to unbalance which are proportional to the square of the speed will be relatively small and the reaction on the bearings will not produce so much friction that the receptacle cannot be driven through the critical speed. In addition to these vibrations there may be gyroscopic vibrations which result in precession of the receptacle. Precession is a rotation of the axis of rotation of the receptacle and may be forward or backward with respect to the direction ofthe shaft rotation. The frequency of precession is of the same order as the mounting critical frequency due to the mounting provided by thevrubber rings 26. As the shaft speedin-` creases above this critical speed the frequency of the forward precession increases slightly and the frequency of the backward precession decreases slightly, both changes being substantially in proportion to the change in speed. Fig. 6 is Y a plot showing the precession frequencies. The gyroscopic vibrations may be of large amplitude. The gyroscopic vibrations occur'y at shaft speeds above the mounting critical speed, Due tothe time required for the gyroscopic vibrations to build up, the gyroscopic vibrations are usually nitude as to cause the receptacle to strike against.

the tub and damage the machine. The-reaction produced on the bearings by the critical vibrations due to the mounting may be sufficiently large to prevent bringing the receptacle vup to its normal operating speed. It is therefore desirable that some means be provided for damping these large amplitude vibrations. should be relatively ineffective for vibration of small amplitudes so that it will not increase the transmission of these vibrations.

A supporting arrangement which will decrease the transmission of the vibrations dueto unbalance at normal running speed and which will damp the larger amplitude vib-rations is shown diagrammatically in Fig. 5. In this figure the machine is shown diagrammatically at 55, and

the floor or other supporting surface is shown a't 56. Between the floor and the machine are arranged supporting springs 51 which are of the i proper stiffness to decrease the transmission to the floor of vibrations due to unbalance at normal running speed. These springs are chosen so that the natural frequency of the machine on the springs does not correspond with any frequency of precession. It is generally preferable to have this natural frequency above the pre- This damping cession frequencies. These springs are arranged .at the outer edge of the machine and are resilient in all directions so that the horizontal and vertical components of vibration are cushioned. In parallel with the springs 51 at the center of the machine is arranged a friction damping means comprising relatively

slidable plates

58 and 59 which are pressed together by a spring 60. The tension of the. spring -60 is varied by means of a screw 6I. The friction plate 59 is provided with a tongue 62 which extends between spaced abutments 63 carriedby the machine. The spacing of the abutments 63 is greater than the thickness of the tongue 62. Due to this lost motion connection, the damping means is elective only for vibrations of large amplitude. During the operation of the machine, the machine has a rocking vibration on the spring 51 which comprises horizontal and vertical components. Since the damping means is arranged at the center of the machine, it is affected by only the vertical component of vibral sistance offered to horizontal vibration will produce a\reaction which will increase the transmission of the vertical vibration. It is also important that the damping means be substantially unaffected by small amplitude vertical vibrations. Another characten'stic of this damping arrangement is that it is not affected by the weight of the machine since the tongue 62 assumes a position which corresponds to the deflection of the springs 51 under the weight of the machine.

Fig. 4 shows a construction utilizing the principles of the construction shown in Fig. 5. In this construction the support for the machine is contained within a plurality of sleeves 64 which are clamped at spaced points to a ring 65 depending from the base 2. Within each sleeve 64 is a spindle 65 which isl slidable in a^ange 66 at the upper end of the sleeve. Between the upper end of the sleeve and a collar 61 threaded on the spindle is arranged a coil spring 68 which provides the resilient support for the machine.

A ilange 66a on the upper end of the spindle holds the spring 68 under initial compression. The upper end of the flange 66 is closed by a dust cover 66h. In the lower'end of the spindle is carried the stem 69 of a suitable caster. With this arrangement the Washing machine is resiliently supported by the spring 68. The arrangement for damping the vibrations of the machine comprises a ring 10 of friction material which has a tight fit within the sleeve 64. The vibrations are transmitted to the ring 10 through the collar 61 and through a llange 1I on sleeve 12 which is threaded on the spindle. The ange 1| and the collar 61 are spaced apart a distance greater than the thickness of the ring 10 so that the damping action of the ring is eiective only for vibrations of large amplitude. The ring 10 is free to assume a position dependent upon the deflection of the spring 68 under the weight of the washing machine. The inner edge of the ring 10 is reenforced by a metal sleeve 13. This sleeve is spaced from the sleeve 12 and provides a space for the flow of air through vents 14 in the collar 61 and a vent 15 in the upper end of the sleeve 64. These vents prevent interference with the action of the support by the compressionv of air within the sleeve 64.

This construction has the disadvantage that the horizontal components of the vibrations tend to productpressures between the spindle 65 and the sleeve 66 and between the collar 61 and the sleeve 64. These pressures tend to increase the transmission of vibration from the machine to the oor.

This objection is overcome by the arrangement shown in Figs. '1 to 10 inclusive. In this arrangement the casters 16 are carried on a supporting ring 11. The weight of the machine is resiliently supported by a plurality of springs 18 which are arranged between spring seats 19a and 19b respectively carried-by brackets 19c and 19d on the base 2 and the ring 11. The springs are short enough so that they provide a stable support forthe machine without requiring guides for preventing tipping of the machine. The

springs 18 are held in the spring seats when the Suitable clearance holes 8| are provided in parts 19a and 19 which permit movement off the base of the machine with respect to the caster supporting ring 11. This means that the horizontal components of vibrations are cushioned by the springs 18. 'I'he arrangement for damping the large amplitude vibrations comprises a plurality of vertical links 82 of friction material arranged between the base 2 and the caster supporting ring 11. As shown in Fig. 9, a strip spring 83 holds the link 82 against the base 2 and provides the damping friction. The lower end of the link 82 is connected to the ring 11 by a pin 84 which extends through an elongated slot 85 in the link. This arrangement provides a lost motion connection which prevents movement of the link 82 with respect to the base 2 by vibrations of small amplitude. The pin and s lot connection also makes the damping action of the links 82 substantially independent of the horizontal components of vibration.

What'we claim as new and desire to secure by4 Letters Patent in the United States is:

1. In combination, a frame, an extractor rotatably carried in the frame, means for resiliently supporting the frame on a base, friction damping means for resisting vibration of the frame relative to the base, said damping means having relatively moving parts and a lost motion connection between the parts, and means for connecting the friction damping means to said frame and said base whereby relative movement of said parts is effected by vibration of the frame relative to the base.

2. In combination, a frame, an extractor rotatably mounted in the frame, means for resiliently supporting the extractor on the frame for gyratory movement relative thereto whereby the extractor may rotate about its center of mass, said supporting means being of such stiffness that the critical speed of the extractor is substantially below its normal running speed, means for resiliently supporting the frame on a base, said supporting means being of such stiffness that the natural frequency of vibration of the frame thereon is outside the frequencies of precession of the extractor, friction damping means for resisting vibration of the frame on effected by vibration of the frame relative to the base.

3. In combination, a frame, an extractor rotatably carried in the frame, said extractor being subject to large amplitude vibrations such as the vibrations at the critical speed and gyroscopic vibrations and being subject to relatively small amplitude vibrations such as the vibrations at the normal ruiming speed due to load unbalance, means for resiliently supporting the frame on a base, friction damping means of the type responsive to said large amplitude vibrations as distinguished from said small amplitude vibrations for resisting vibration of the frame relative to the base, said damping means having relatively moving parts, and means connecting said friction damping means to said frame and said base whereby relative movement of said parts is effected by vibration of the frame relative to the base.

4. In combination, a frame, an extractor rotatably carried in the frame, means for resiliently supporting the frame on a base, said supportn ing means being of such stiffness that the critical vibration occurs substantially below the normal running speed of the extractor, friction damping means for resisting vibration of the frame relative to the base, said damping means having relatively moving parts and a lost motion connection between the parts, and means for connecting the friction damping means to said frame and said base whereby relative movement of said parts is effected by vibration of the frame relative to the base.

5. In a combined clothes washing and drying machine, of the type having a rotatable receptacle in which the clothes are washed and centrifugally dried, a frame, a rotatable receptacle carried by the frame for receiving clothes, means for rotating the receptacle to centrifugally extract liquid from the material contained therein, means for resiliently supporting the frame on a base, friction damping means for resisting vibration of the frame relative to the base, said damping means having relatively moving parts and a lost motion connection between the parts,'and means for connecting the friction damping means to said frame and said base whereby relative movement of said parts is eected by vibration of the frame relative to the base.

6. In a combined clothes washing and drying machine, of the type having a rotatable receptacle in which the clothes are washed and centrifugally dried, a frame, a rotatable receptacle carried by the frame for receiving clothes, means for rotating the receptacle to centrifugally extract liquid from the material contained therein, means for resiliently supporting the receptacle on the frame for gyratory movement relative thereto whereby the receptacle may rotate about its center of mass, said supporting means being of such stiffness that the critical speed of the receptacle is substantially below its normal running speed, means for resiliently supporting the frame on a base, said supporting means being of such stiffness that Ithe natural frequency of vibration of the frame thereon is outside the frel quencies of precession of the receptacle, friction damping means for resisting vibration of the frame on the base, said damping means having relatively movable parts and a lost motion connection between theparts, and means for connecting the friction damping means to said frame and said base whereby relative` movement of said parts is effected by vibration of the frame relative to the base.

7. In a combined clothes washing and drying machine, of the type having a rotatable receptacle in which the clothes are washed and centrifugally dried, a frame, a rotatable receptacle carried by the frame for receiving clothes, means for rotating the receptacle to centrifugally extract liquid from the material contained therein,

said receptacle being subject to large amplitudev vibrations such as the vibrations at the critical speed and gyroscopic vibrations and being subject to relatively small amplitude vibrations such as the vibrations at the normal running speed due to loadunbalance, means for resiliently supporting the frame on a base, friction damping means of thel type responsive to said large amplitude vibrations as distinguished from said small amplitude vibrations for resisting vibration of the frame relative to the base, said damping means having relatively moving parts, and means connecting said friction damping means to said frame and said base whereby relative movement of said parts is effected by vibration of the frame relative to the base. i

8. In a combined clothes washing and drying machine, of the type having a rotatable receptacle in which the clothes are washed and centrifugally dried, a frame, a rotatable receptacle carried by the frame for receiving clothes, means for rotating the receptacle to centrifugally ex-v tract liquid from the material contained therein, means for resiliently supporting the frame on a base, said supporting means being of such stiffness that the critical vibration occurs substantially below the normal running speed of the receptacle, friction damping means for resisting vibration of the frame relative to the base, said damping means having relatively moving parts and a lost motion connection between the parts, and means for connecting the friction damping means to said frame and said base whereby relative movement of said parts is effected by vibra` tion of the frame relative to the base.

9. In combination with a centrifugal extractor, a` support therefor comprising relatively movable parts having resilient means arranged therebemotion connection between said washer and the other of said parts for transmitting the vibration of the centrifugal extractor to said washer.

10. In combination with a centrifugal extractor, a support therefor comprising relatively movable parts having resilient means arranged there'- between, one of said parts being a sleeve and the other of said parts being a spindle slidable in said sleeve, a washer frictionally engaging one of said parts, andmembers carried by one of said parts and spaced apart a distance greater than the thickness of said washer for transmitting vibration from said centrifugal extractor to said Washer.

' ARTHUR L. KIMBALL. GEORGE W. DUNHAM.