US2718772A - Sediment ejection - Google Patents

Description

J. C. SHARP ETAL SEDIMENT EJECTION Filed Nov. 7, 1952 sept. 27, 1955 United States Patent O SEDIMENT EJECTION John C. Sharp and Kendall Clark, Glen Ellyn, Ill., as-

signors to General Electric Company, a corporation of New York This invention relates to centrifugal extraction types of washing machines, and in particular to an improved means for accumulating and ejecting heavy dirt and other foreign objects during the centrifuging operation.

In domestic clothes washing machines in which the clothes are washed, rinsed, and centrifugally damp-dried in a single tub or receptable, the wash water and the one or more rinse waters are removed from the tub and to a large measure from the articles being washed, by rotating the tub at a suitable centrifuging speed. In some machines, the tub wall may be perforated over substantially its entire area, in which event the water is thrown radially outward in a multiplicity of ne streams. Alternatively, the tub wall may be imperforate except for openings at/ or adjacent the line of maximum diameter of the tub. In this latter type of machine, it is conventional to have the tub wall increase uniformly upwardly to a zone of maximum diameter near the upper wall thereof, and the water climbs the wall to 4escape through the discharge openings as the tub rotates.

Experience shows that in each of these conventional types, heavy dirt such as sand and similar particles found in childrens clothes, mechanics work clothes, and the like, migrates to the bottom of the tub during the washing operation, but is then trapped by the clothes and held against ejection during the extraction cycle. The perforate tub machines are particularly susceptible to resoi'ling the washed clothes in this manner because the soil 1s strained through the clothing, and the advantage which this type of washing machine tube has overthe imperforate tub type in extracting more water at the same extraction speed is thus offset by inferior washing results.

The present invention provides a washing machine tub of the vertical axis centrifugal extraction type in which improved means are provided for trapping the sedimentary dirt and for discharging it from the tub through external passages, thus avoiding resoiling the clothes by such dirt accumulations. A feature of our invention is that we provide relatively largel perforated tub wall areas which increase the speed and efficiency of the extraction while retaining the desirable features of floating light dirt out of the tub through the upper tub wall openings instead of straining the dirt through the articles of clothing as in the perforated tub types.

It is therefore a main object of our invention to provide a washing machine tub having improved water extraction means.

It is another object of our invention to provide a washing machine tub having means for? improving water extraction from the washed articles while substantially eliminating the resoiling of the articles by providing passages externally of the tub for the discharge of heavy dirt particles.

It is a further object of the invention to provide a centrifugal extraction tub for washing machines and the like having a plurality of vertically extending, relatively wide, outflow channels disposed about the outer wall 'of the tub and communicating with the tub by means of 2,718,772 Patented Sept. 27, 1955 perforated cover plates of relatively large area through which a substantial portion of the water may iiow into the channels for removal from the tub.

It is still another object of the invention to provide a washing machine tub with external sediment ejection passages provided with perforated cover plates which constitute a substantial area of the tub wall and are readily removable to facilitate cleaning the passages from end to end.

Other features and advantages of our invention will be apparent from the following detailed description of a presently preferred embodiment, read in the light of the accompanying drawings in which:

Fig. l shows in vertical section on lines 1-1 of Fig. 2 the tub portion, agitator, and other structure of a washing machine of the centrifugal extraction type;

Fig. Z is a fragmentary plan section taken on lines 2-2 of Fig. l; and

Fig. 3 is a detail, in vertical section on lines 3 3 of Fig. 2, showing the forward edge of a cover plate.

We have considered it necessary to show only the tub and water collector portion of a washing machine, because various types of centrifugal extraction machines are well known and our invention is applicable to any upright axis tub type'. The drive mechanism and arrangement of other extraneous parts are not shown.

The tub 1 is keyed or otherwise aixed to a tubularI shaft 2, journalled in a ixed frame member 3. Said tub is thus rotatably mounted within an encompassing water collector 4, rigidly secured within an outer frame structure (not shown). lt will be noted that the journal member 3 extends through a large coaxial opening 5 in the bottom of the water collector, thus permitting the rotating tub to gyrate about its suspension (not shown) when centrifuging an unbalanced clothes load. A flexible boot 6 seals olf the opening 5 while permitting gyratory movement, as is well known. An agitator 7 is fixed to a shaft 8 journalled within shaft 2. Said shaft is arranged to be oscillated, and shaft 2 rotated, by any conventional drive means (not shown).

The tub wall extends outwardly and upwardly from a central depression or sump 9 and then slopes outwardly in an upward direction to a point of maximum diameter suitably below the top of the agitator post. Adjacent said maximum diameter zone the tub wall has a multiplicity of water outflow openings 10, preferably although not necessarily arranged in a single-row. Mounted on the top wall of the tub is a heavy annular balancing mass 11 defining the opening through which the clothes and the like (not shown) enter the tub. i

As is well known, the tub is filled to an appropriate r level-for example, a normal water line WL-and the articles are washed by the action of the agitator, which mechanically agitates the clothes and sets up powerful currents within the tub which causes the clothes to move and turn over in the body of washing liquid. During the washing period, oatable soil extracted from the clothes gathers at the top of the tub and much of it is sloshed through the openings 10. Sand and other heavy dirt linds its way to the bottom of the tub where much of it gathers in the relatively quiescent pool within the sump 9.

After the washing period the agitator is stopped and` the tub rotated at a speed suicient to extract the freeu water and a large amount of the water entrained within the clothes. The acceleration of the rotating tub during centrifuging causes the water line to assume approximately parabolic curvatures on increasing depth as in` dicated at WL1 and WLZ. Thus, the water climbs the tub wall for discharge through the openings 10 into thewater collector. A pump (not shown) is usually provided to empty the water collector. A usual washing machine.

cycle may include the wash operation and several rinsing operations, at least one of which may be accompanied by agitator action to free the articles of any soap curd, heavy dirt, and the like which may have collected thereon during the previous washing operation.

It has previously been proposed to provide separate escape passages for the heavy sedimentary dirt to reduce the contact of the dir-t with the laundered articles during the centrifuging operations. In Castner U. S. Patent 2,470,140, of May 17, 1949, for example, small diameter tubes are provided on the outside wall of an imperforate tub. Such tubes are subject to clogging with lint and the like and are diflicult to clean.

We provide dirt-ejection passages which have a large ow capacity and arrange said passages with removable cover plates to make it easy for the user to clean the passages. The said cover plates form perforated tub wall areas which increase the efficiency of centrifugal extraction.

In the presently preferred embodiment of our invention, we form the tub 1 with a plurality-for example, two, three, or four-of relatively wide channels 12, each terminating in an open discharge mouth 14 just below the row of water discharge openings 1li. The lowermost end of each channel is in effect a continuation of the bottom wall of the tub at the sump portion thereof; and thus the side Wall 15 dening the sump is periodically interrupted, as best appears in Fig. 2.

The channels form sediment ejection passages when provided with the perforated cover plates 16. As shown in Fig. 2, the cover plates have rearwardly projecting anges 17 which t snugly against the sides of the channels. Said langes may be continuous or interrupted, their primary purpose being to position and support the covers within the channel walls. We prefer to divide the wide channels, and accordingly provide the cover plates with a central rib 18 which reaches to the rear wall of the channel. The cover plates are secured relative to the associated channels in a manner to permit their easy removal by the user for periodic cleaning. Because of the snug seating of the covers within the channels, the securement may be simply accomplished by an eccentric latch member 20 rotatably mounted on a suitable stud 21 passing through the bottom wall of the tub. The latch member is rotatable into or out of engagement with a locking wall 22 projecting from the shoulder 23 of the cover plate. Said locking wall is contigurated to lie along the bottom of the sump portion of the tub and its forward edge is preferably rounded to reduce the obstruction to the outward movement of the sediment. At its upper end the edge of the cover plate abuts the bottom wall of the balance ring 11. lt is not considered necessary to latch or otherwise fasten the upper end of the cover plates.

Over the area from the break of shoulder 23 to substantially the plane of the openings 10, the cover plates are formed with a multiplicity of inow ports 24. These ports are purposely of small diameter'so as to prevent the entry or entrapment of small buttons or the like which may be on a garment being washed. Through the forward shoulder walls, we provide narrow elongated slots 25 also dimensioned to avoid catching buttons or the like during thewashing operation or any later centrifuging steps.

While the articles are being agitated during the Washing and any subsequent agitate-rinse periods, the water currents within the tub and the movement of the articles therein will keep even heavy particles of loose dirt in suspension for some time. A quantity of it will gravitate directly to the central sump portion; other portions may move outwardly and downwardly passing along the inner wall of the tub. Any of the dirt which moves downwardly along the cover plates 16, which are flush with the tub walland. therefore may beconsidered to be a part of the tub wall, may enter the channels 12 directly through the openings 24 and will accumulate in the very gently sloping base portion 26 of the channels.

Assuming an accumulation of heavy dirt particles in the sump 9 and the lower part of the channels at the commencement of a spin operation, centrifugal forces will cause the particles to move outwardly and upwardly. Those already within a channel will move with the water stream upwardly through the channel and will be discharged with the water into the water collector. Dirt which has gathered in the sump will move outwardly through the openings 25 for similar discharge. By making the side Wall 15 of the sump relatively steep and carrying the bell 7.1 of the agitator into rather close proximity to the sump wall, we reduce the return of any dirt particles into the tub at the sump areas between adjacent channels. This dirt should work its way around the sump during the early centrifuging stage when there is still a substantial depth of water above the sump and will eventually be caught by the water streams entering the channel ports 25 to be conveyed thereby into the channels for discharge therefrom.

As centrifuging continues and the water line assumes a shape leaving the sump dry,` the direct inow of Water into the channels through the ports 24 will continue to Convey into the channels any dirt particles which may not have reached the sump. In addition, the perforated cover plate area provides a direct escape for liquid entrained in the particles within the tub rather than requiring the liquid to climb the tub wall to the level of the outilow ports 10. When it is considered that at the later stages of centrifuging the articles become relatively tightly plastered against the tub wall, it is apparent that the articles interfere with the passage of Water to a considerable extent. Our construction, therefore, facilitates the extraction of water while nevertheless permitting to a much greater extent than in the usual perforated tub the flotation of light soil through the openings 1t).

While there has been described what are 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 rnodications as fall within the true spirit and scope of the invention.

We claim:

l. A washing machine of the centrifugal extraction type, comprising a smooth-walled tub adapted to receive washing liquid to a predetermined normal level, said tub being imperforate below said liquid level, means for mounting said tub for rotation about an upwardly extending axis, and an agitator disposed within said tub and having a substantially circular base portion disposed at the bottom of said tub concentric with the axis of rotation thereof; said tub having a substantially circular, shallow sump formed in the bottom wall thereof, said sump being delined by an upstanding outer wall extending about the base of said agitator in close proximity thereto, the bottom portion of said tub then extending outwardly and upwardly from the upper edge of said sump wall and curving upwardly to form a side Wall which extends upwardly and outwardly with gradually increasing diameter to above said normal liquid level; said tub bottom and side walls being formed with a plurality of inwardly facing sediment-ejection channels in symmetric disposition relative to the axis of rotation of said tub, the base wall of each channel comprising an uninterrupted extension of said sump bottom wall and following the contour of the bottom and side wall portions of said tub to terminate in an open end above said normal liquid level; and a cover removably disposed in each said channel, said covers having a forward wall portion effecting substantially a continuation of said sump outer wall, said forward wall portion having at least one opening disposed within the sump for direct communication between said sump and channel, and a plurality of openings disposed throughout the remainder of said cover, whereby said channels and their respective covers provide sluiceways leading outwardly and upwardly from said sump and communieating directly with said sump and with the interior of said tub.

2. A washing machine according to claim 1, in which each said cover has a septum extending the length thereof and reaching substantially to the base of the associated channel to provide a pair of sluiceways, said cover forward wall portion having an opening on each side of said septum.

3. A washing machine according to claim 1, in which the forward wall portion of each said cover has a forwardly projecting lip in surface contact with said sump bottom, and said sump has a locking member rotatable into engagement with said lip to secure the end of said cover releasably against said sump bottom.

References Cited in the le of this patent UNITED STATES PATENTS

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