US3541814A - Extraction system for washing machine - Google Patents

Description

Nov. 24, 1970 J. BOCHAN 3,541,814

EXTRACTION SYSTEM FOR WASHING MACHINE Filed May 8. 1968 INVENTOR. JOHN ,socHAN HIS ATTORNEY United States Patent Ofice Patented Nov. 24, 1970 3,541,814 EXTRACTION SYSTEM FOR WASHING MACHINE John Bochan, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed May 8, 1968, Ser. No. 727,571 Int. Cl. D06f 31/00 US. Cl. 68-4 7 Claims ABSTRACT OF THE DISCLOSURE A washing machine adapted to wash two loads of fabrics simultaneously in separate solutions without liquid interchange therebetween includes a chamber with a first or outer, perforated tub mounted in the chamber to receive liquid and fabrics to be washed in that liquid. A movably mounted agitator extends upwardly in the first tub and the machine includes drive means for effecting a washing motion of the agitator and rotation of the agitator and tub together for centrifugal extraction operation. A second, substantially imperforate tube, to receive liquid and fabrics to be washed in that liquid is mounted on the agitator for movement therewith. A number of return bent, generally vertical conduits are provided with inlets connected to the upper portion of the inner tub and outlets disposed adjacent the upper portion of the outer tub to prevent splashing of liquid from the inner tub during agitation and to allow discharge of liquid from the second tub during centrifugal extraction. The first tub includes a number of openings therein for dis charge of liquid from the second tub during centrifugal extraction and includes a pair of spaced walls for guiding the liquid from the second tub over the top of the first tub so that the liquid from both tubs is received in the chamber during centrifugal extraction. The machine also includes a pump effective during centrifugal extraction to exhaust liquid from the chamber.

BACKGROUND OF THE INVENTION This invention relates to fabric Washing machines, and more particularly, to such a machine which is adapted to wash two separate loads of fabrics concurrently without intermingling the liquid used in the washing process. One shortcoming of presently available fabric washing machines is that the user cannot concurrently wash items which are incompatible; for instance, white garments and colored garments which may run, or fuzzy garments and other garments which might pick up lint released from the fuzzy garments. Thus, for what should be an average wash load, the user may have to divide the fabrics into two or more separate loads in order to wash all of the items, even though the total size of the load does not exceed the capacity of the washing machine. Prior art patents relating to washing machines for pro Viding concurrent washing operations propose very complicated systems for keeping the liquids separate. One area of such excess complexity is the system for centrifugally extracting the liquid from the fabrics without having the liquid from either of the fabric containers impinge upon any of the fabrics in the other container.

An object of this invention is to provide a new and improved washing machine for concurrently washing two loads of fabrics.

Another object of the present invention is to provide such a machine wherein the liquid for washing each load is maintained away from the other load.

Still another object of this invention is to provide such an improved machine having a simple, inexpensive and yet effective liquid extraction system.

SUMMARY OF THE INVENTION By one form of the invention there is provided, in a vertical axis washing machine, a chamber with a first, outer, open top tub movably mounted in the chamber to receive liquid and fabrics to be Washed in the liquid. A movably mounted agitator extends upwardly in the first tub. A second, substantially imperforate tub to receive liquid and fabrics to be washed in that liquid is mounted on the agitator for movement therewith. Drive means is provided for effecting a washing motion of the agitator and for rotating the tubs and agitator together for centrifugal extraction of liquid from the fabrics. The first tub defines openings therein for the discharge of liquid into the chamber during centrifugal extraction and means is provided defining paths for the discharge of the liquid of the second tub over the top of the first tub and into the chamber during centrifugal extraction. A pump is provided and is effective during periods of centrifugal extraction to exhaust the liquid from the chamber.

BRIEF DESCRIPTION OF THE DRAWING The single figure of the drawing is a somewhat schematic, partial side elevational view of a clothes washing machine incorporating one embodiment of the present invention, the view being partly broken away and partially in section to illustrate details.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown therein an agitator type clothes washing machine 1 having an outer, open top tub or receptable 2 to receive liquid and fabrics to be washed in that liquid. The tub 2 includes a lower wall 3 and a generally cylindrical, upwardly extending side wall 4, the walls 3 and 4 being provided with a number of spaced perforations or openings 5. The tub 2 is positioned within an'outer imperforate casing 6 which defines an undivided chamber 7 with the tub 2 mounted within the chamber so that when liquid is added to the tub 2 it will flow into the chamber 7 and fill .the chamber and tub to the same level. The top of the tub may be provided with a balance ring 8 to help steady the tub when it is rotated at high speed.

The casing 6 is rigidly mounted within an appearance cabinet 9 which includes a cover 10 hingedly mounted in the top portion 11 of the cabinet for providing access through an opening 12 to the tub 2. A gasket 13 may be provided as to form a seal between the top of the casing 6 and the portion 11 of the cabinet, thereby to prevent escape of moisture and moist air into the cabinet around the casing.

There is a movably mounted agitator 14 extending upwardly within the center of the tub 2. In the present case the agitator is shown as including a center post 15 and a plurality of outwardly extending vanes 16 and 17 which extend partially along the center post and are joined at their lower ends by an outwardly flared skirt 18. In the particular agitator illustrated the vanes 16 extend further up the center post than do the vanes 17; however, this is for illustrative purposes only and the vanes may take any desired shape.

The tub 2 and agitator 14 are rotatably mounted. The tub 2 is mounted on a flange 19 of a rotatable hub 20 and the agitator 14 is mounted on a shaft (not shown) which extends upwardly through the hub 20 and through the center post 15 and is secured to the agitator so as to drive it. During a typical cycle of operation the agitator is caused to oscillate about its axis, that is, in a horizontal plane Within the tub 2, to cause a washing action of the fabrics in the machine. Then the agitator and tub are rotated together at high speed for centrifugal extraction of liquid from the fabrics in the machine. This sequence of operation is repeated the desired number of times for a complete cycle and normally is provided at least twice to give a Washing step and a rinsing step.

The tub 2 and agitator 14 may be driven through any suitable means. By way of example I have shown them as driven from a reversible motor 21 through a system including a suitable load limiting clutch 22 mounted on the motor shaft. A belt 23 transmits power from the clutch 22 to a transmission assembl 24 through a pulley 25. Thus, depending upon the direction of motor rotation, the pulley 25 and transmission 24 are driven in opposite directions. The transmission 24 is so arranged that it supports and drives both the agitator drive shaft and the basket mounting hub 20. When the motor 21 is rotated in one direction the transmission causes agitator 14 to oscillate in a substantially horizontal plane within the tub 2. Conversely, when the motor 21 is driven in the opposite direction the transmission rotates the tub 2 and agitator 14 together at high speed for centrifugal liquid extraction. While the specific type of transmission mechanism used does not form part of the invention, reference is made to Pat. 2,844,225 issued to James R. Hubbard et al. on July 22, 1958 and owned by General Electric Company, assignee of the present invention. That patent discloses in detail the structural characteristics of a transmission suitable for use in the illustrated machine.

In addition to operating the transmission 24 as described, the motor 21 also provides a direct drive through a flexible coupling 26 to a pump structure generally indicated at 27, which may include two separate pump units 28 and 29, both operated in the same direction simultaneously by the motor 21. Pump 28 has an inlet which is connected by a conduit 30 to an opening 31 formed in the lower most point of easing 6. Pump 28 also has an outlet which is connected by a conduit 32 to a suitable drain (not shown). The pump 29 has an inlet connected by a conduit 33 to the interior of chamber 7 at the lower portion of the chamber and an outlet connected by a conduit 34 to a nozzle 35. The pump structure is formed so that, in the spin direction of motor rotation, pump 28 will draw liquid in from the chamber 7 through the opening 31 and conduit 30 and then discharge it through conduit 32 to drain. In the other direction of motor rotation, pump 29 will draw in liquid through the conduit 33 and discharge it through the conduit 34 and nozzle 35. Each of the pumps is substantially inoperative in the direction of rotation in which it is not used. The particular form of the pump structure 27 is not significant; rather structure 27 is representative of any structure capable of passing liquid selectively out through one outlet or another, whether by use of one pump with suitable valving, a combination structure or two pumps.

As will be explained hereinafter, it may be desirable that rotation of tub 2 and agitator 14 for centrifugal extraction of liquid from fabrics within the machine be delayed a sufiicient period of time during each extraction step for the pump 28 to lower the level of liquid within the chamber 7 at least to below the bottom wall 3 of the tub 2. Applicants Pat. 3,131,797 issued on May 5, 1964, and assigned to General Electric Company, assignee of of the present invention; and Pat. 3,197,982 issued on Aug. 3, 1965 to Joseph C. Worst, and assigned to General Electric Company, assignee of the present invention, both disclose details of the structural characteristics of clutches which will provide a suitable delay in the high speed rotation of tub 2 and agitator 14 so that the pump 28 can lower the level of liquid in the chamber 7.

The motor 21, clutch 22, transmission 24, tub 2 and agitator 14 form a suspended washing and centrifuging system which is supported by the stationary structure of the machine so as to permit isolation of vibrations from the stationary structure. While any suitable structure may be used, one such structure includes a bracket member 36 with the transmission 24 mounted on the top thereof and the motor 21 mounted on the underside thereof. A suitable counterweight 37 may also be mounted to the underside of the bracket 36 to help balance the loading of the bracket. The bracket member in turn is secured to a pair of upwardly extending rigid members 38, and each of the two upwardly extending members 38 is con nected to a cable (not shown) supported from the top of the machine. While only a portion of the suspension system is shown, such a vibration isolation system is fully described and claimed in applicants Pat. 2,987,190 issued on June 6, 1961 and assigned to the General Electric Company, assignee of the present invention.

In order to accommodate the movement which occurs between the tub 2 and the casing 6 without any danger of leakage between them, the stationary casing 6 is joined to the upper part of transmission 24 by a flexible boot member 39. Boot 39 may be of any suitable configuration, many of which are known in the art, to permit relative motion of the parts to which it is joined without leakage therebetween.

Hot and cold water may be supplied through conduits 40 and 41, which are adapted to be connected respectively to sources of hot and cold water (not shown). Conduits 40 and 41 extend into a conventional mixing valve structure 42 having solenoids 43 and 44. Energization of solenoid 43 permits passage of hot water through the valve to an inlet hose 45, energization of solenoid 44 permits passage of cold water through the valve, and energization of both solenoids permits mixing of hot and cold water in the valve and passage of warm water into the hose 45. The inlet hose 45 is connected to a discharge horn 46 which is positioned to discharge into the tub 2 so that when one or both of the solenoids 43 and 44 are energized, the water passes into the tub 2 and chamber 7. The level to which the water rises in the tub 2 and chamber 7 may be controlled by any suitable liquid level sensing means (not shown) many of which are known in the art.

As thus far described, the machine is capable of pro viding the usual washing operation in which fabrics are placed in the tub 2 and are washed and rinsed, with the washing and rinsing water being centrifugally extracted from the fabrics and expelled from the machine by the pump 28. In order to be able to wash two loads simultaneously without intermixing the washing and rinsing liquid inside the tub 2 so that noncompatible fabrics may be Washed simultaneously, there is provided a second or inner, substantially imperforate, open top tub 47 to receive liquid and fabrics to be washed in that liquid.

The tub 47 includes an inner wall 48 which is channeled as indicated at 49 along its radially inner portion and curves outwardly at the bottom so as to fit closely around the agitator 14 and be driven thereby as the agitator is oscillated and rotated during a sequence of operation of the machine. The tub 47 also includes a generally cylindrical outer wall 50 which extends upwardly and defines an open top 51 by means of an inwardly facing annular flange 52 which extends around the top of the wall 50. The outer wall 50 may have extending therefrom a number of small vanes 53 which aid in providing a suitable washing motion in the liquid and fabrics in the outer tub 2 when the inner tub 47 is in the machine. The diameter of the inner tub 47 is made substantially less than the diameter of the outer tub 2 so that each tub may have a suitable volume separate from the other to receive liquid and fabrics to be washed in the liquid. In the machine illustrated the inner tub 47 does not completely cover the vanes 16 and 17 of the agitator 14 so that their lower tips may assist in causing a suitable washing motion in the outer tube.

The upper portion of the wall 50 generally slants inwardly as indicated at 54 and this inwardly slanting portion is provided with a number of recesses 55 which continue in a move vertical fashion and are spaced circum ferentially around the wall 50. Each of these recesses terminates in an upwardly extending pipe 56. The upper end of each pipe 56 is joined to a return bent, generally vertically extending tube 57 of stifliy resilient material so that each pipe and tub together form a conduit 58. Each con duit has an inlet 59 in the upper portion of inner tub 47 and an outlet 60 which opens outwardly above the top of the tub 47. For ease in construction, pipes 56 and tubes 57 can be formed integrally with both being a part of the material forming the inner tub 47. However, on many occasions the inner tub 47 will be removed from the machine and stored separately so that the machine may be used to wash large loads of compatible fabrics. By making tubes 57 separately and of a stiflly resilient material, the likelihood of damaging the free standing portion of the conduits will be much reduced.

The water inlet horn 46 and recirculation nozzle 35 both are formed and positioned so that the streams of liquid discharged therefrom flow in paths which bring them into register with the open upper end 51 of the inner tub 47. There is provided a suitable cover structure 61 which fits within the opening 51 and allows a stream of water from horn 46 to flow into the tub 47 until it is full and then directs the stream into the tub 2 and chamber 7 so that the same inlet mechanism normally used in washing machines may be used in a machine for simultaneously washing two loads. The cover structure also functions to direct the stream of recirculated liquid from nozzle 35 back into tub 2 without any of it flowing into the tub 47, so that a normal recirculation type filtering system may be used in a machine which will simultaneously wash two loads.

The cover structure includes a cup like center portion 62. which fits over the top of agitator post 15 and includes an annular inner wall 63 extending downwardly around the agitator center post and into the upper end of the tube 47. The cover structure also includes a series of vertically spaced, generally horizontally extending walls. The upper of these walls 64 extends radially outwardly from the annular wall 63. An intermediate wall 65 is spaced slightly below the upper wall and with its outer periphery beyond the outer edge or periphery of the upper Wall 64. This outer periphery of the middle wall 65 includes a downwardly extending flange 66 and a short horizontally extending flange 67. The flanges 66 and 67 fit in liquid tight relationship to a gasket 68. The gasket in turn is mounted in liquid tight relationship to flange 52 on the upper end of the tub 47 so that the outer edge of the cover structure is mounted in liquid tight relationship to the upper edge of the tub 47. From the flanges 66 and 67, the wall 65 extends inwardly in a generally horizontal fashion and terminates in a short, upwardly extending flange 65a, which is spaced slightly outwardly of the inner wall 63. A lower wall 69 extends outwardly from the inner Wall 63 and is formed at its radially outer edge with a short, downwardly extending flange 70. The flange 70 is spaced slightly inwardly of the flange 66. The intermediate wall 65 is maintained in its vertically spaced relationship with walls 64 and 69 by circumferentially spaced webs 71 which extend therebetween. As indicated by the drawing, the cover structure 61 can be formed from a number of separate elements which are firmly joined together to make a unitary structure.

Thus, a labyrinth passage is formed in and extending through the covering structure. This passage extends between the upper wall 64 and intermediate wall 65, over the flange 65a and then between it and the inner wall 63, then outwardly between the intermediate wall 64 and lower wall 69, and finally downwardly between the flanges 66 and 70. When the cover structure 61 is mounted over the agitator 14 and in the inner tub 47, at least the lower portion of this passage is positioned within the tub 47 and well below the upper limit of the outlet conduits 58. With such an arrangement, the inlet water flowing from the horn 46 will impinge upon the cover structure 61. This water initially flows through the labyrinth passage into the tub 47. This flow continues until the liquid in the inner tub 47 rises to the level of the labyrinth passage. When this occurs, no further flow through the passage is possible and the inlet water is directed outwardly over the cover structure to flow into the outer tub 2 and chamber 7 to fill these to the desired level, at which time the inlet water flow will be terminated.

Similarly, since inner tub 47 will be full during periods of agitation, the stream of recirculated liquid being emitted from the nozzle 35 onto the cover will be directed outwardly over the cover structure 61 and back into the tub 2 and chamber 7 without any of its entering the inner tub 47, due to the seal formed by the full labyrinth passage. The webs or vanes 71 act as pumps to insure that none of the liquid leaks through the labyrinth into tub 47. As stated above, the tops of the return bent conduits 58 are well above the labyrinth passage and thus well above the level of liquid in tub 47. This effectively prevents the movement of the inner tub during agitation from causing any of the light to be emitted from the tub through conduits 58.

In order to filter lint and other foreign matter from the recirculated stream of liquid the cover structure may also include a pan like filter having a generally horizontal lower wall 72 and an upwardly extending side wall 73. The lower wall 72 is spaced above the upper wall 64 and is formed with a plurality of openings 74 so that liquid entering the filter will flow through the openings 74 in the filter and fall onto the upper wall 64.

In order to wash two loads of incompatible fabrics simultaneously it is also necessary to insure during centrifugal extraction periods of operation that none of the liquid used in washing the fabrics in the inner tub impinges upon the fabrics in the outer tub. To this end, and as an important part of this invention there are provided the conduits 58 and an associated structure around the upper end of the tub 2. A first wall 75 extends inwardly and downwardly from the top edge of the first tub 2 and underlies the outlet ends 60 of the conduits 58. The liquid exiting from the conduits 58 during centrifugal extraction will strike the wall 75 and be guided up to the top of the tub 2. The inner end of the wall 75 is formed with an upturned flange 76 which is positioned inwardly of the outlets 60 so that any liquid dropping from the conduits 58 at the end of the extraction operation or spraying out during centrifugal extraction operation will be caught 'by the flange 76 and prevented from dropping into the outer tub 2.

A second wall 77 extends around and is spaced above the top edge of the tub 2. The wall 77 is supported above the tub 2 by some suitable means such as circumferentially spaced, small posts 78 which extend from the top of the tub 2 and engage the wall 77. The wall 77 includes a first portion 79 which extends inwardly and downwardly into the tub 2 parallel to and spaced from the wall 75 and terminates outwardly of the ends of the tubes 57. The Wall 77 also includes a second portion 80 which extends outwardly and downwardly outside the tub 2. Thus the liquid exiting from the conduits 58 and directed upwardly by the wall 75 will be directed over the top of the tub 2 by the wall portion 79 and outwardly and downwardly into undivided chamber 7 away from the tub 2 by the wall portion 80.

For a typical cycle of operation for washing two loads simultaneously the inner tub 47 will be placed within the outer tub 2 around the agitator 14. One type of fabrics will be placed within the outer tub 2 and another type of fabrics will be placed in the inner tub 47. For instance, white and color fast items would be placed in the tub 2 and items which tend to fade would be placed in the tub 47. Then the cover member 63 is placed over the agitator center post and into the top of the tub 47. The controls for the machine will be set to cause the machine to automatically proceed through a cycle of operation. Many such suitable controls are lznown in the art and do not form a part of this invention, therefore, none have been described in detail herein.

First valve 42 is energized so that water of a selected temperature fiows in through the inlet hose 45 and horn 46 to impinge upon the cover member 63. Initially, this stream of water flows through a labyrinth passage into the inner tub 47 until it is filled. Thereafter the stream of inlet water is directed outwardly over the cover structure 61 into the outer tub 2. Since the outer tub is provided with perforations over its side and bottom walls, this liquid also flows outwardly into chamber 7 and fills the tub 2 and chamber 7 with liquid.

When they have filled to a suitable level, the water supply is interrupted and the motor 21 is started in a first direction to cause oscillation of the agitator while tub 2 is held stationary. The inner tub 47 moves with the agitator 14 so that the channels 49 in the inner wall of the inner tub cause the liquid and fabrics in the inner tub to be agitated while the vanes 53 and tips of the vanes 16 and 17 cause the liquid and fabrics in the outer tub to be agitated. At the same time, pump 29 draws liquid out of chamber 7 through the conduit 33 and discharges it through the conduit 34 and nozzle 35 so that it is projected into the filter pan. From the filter pan it passes through the openings 74 and onto the upper wall 64. Since the labyrinth passage is blocked by the body of liquid in the inner tub 47, this recirculated liquid is directed outwardly and back into the outer tub 2.

At the conclusion of the agitation period of operation the motor is stopped and then restarted in the other direction to cause the tubs and agitator to be rotated together at high speed for centrifugal extraction of liquid from both of the loads. The liquid in the outer tub is expelled through the openings into the chamber 7 from whence it is exhausted by the pump 28 through the open- 1ng 31 and conduit and then discharged to drain through the conduit 32. The liquid in the inner tub 47 is caused to flow upwardly and then outwardly through the recesses and conduits 58. From the conduit outlets this liquid flows up and over the wall and under the wall 77. It is directed by the wall portion downwardly and outwardly to be received in the chamber 7 away from the tub 2 so that it does not impinge on the fabrics in the tub 2.

of the type illustrated, wherein the tub 2 is provided with openings over much of its surface. With such an outer tub construction, if vitiated liquid from the inner tub is expelled into the chamber 7 before the standing level of liquid in the chamber is reduced to a point below the Outer tub, it will mix with this standing liquid and may contaminate the fabrics in the outer tu-b.

Some machines use a substantially imperforate outer tub, with only a few openings positioned adjacent the upper edge of the outer tub. With such a construction clutch 22 would not necessarily be of the type to provide this drain down operation.

The steps of operation of filling, agitation and centrifugal extraction are repeated at suitable number of times for a complete cycle of operation and are normally provided at least twice, the first time with detergent in the two tubs to provide a wash step and the second time with clear water to provide a rinse step.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a vertical axis washing machine:

(a) means defining an undivided chamber;

(b) an outer, open top tub movably mounted in said chamber to receive liquid and fabrics to be washed in that liquid;

(c) an inner, substantially imperforate tub disposed within said outer tub to receive liquid and fabrics to be washed in that liquid;

(d) drive means for effecting a washing action in said tubs, and for rotating said tubs for centrifugal extraction of liquid from the fabrics;

(e) said outer tub defining openings therein for the discharge of liquid from said outer tub into said chamber during centrifugal extraction;

(f) means defining paths for the discharge of liquid from said inner tub into said chamber without entry into said outer tub during centrifugal extraction; and

(g) drain means connected at the lower portion of said chamber and effective during periods of centrifugal extraction to exhaust liquid from said chamher.

2. The invention as set forth in claim 1 wherein said outer tub includes a bottom wall and an upwardly extending side wall, said side wall having a plurality of spaced openings therein so that when liquid is introduced into said outer tub it will fill said chamber to substantially the same level as said first tub; said drain means being effective prior to each centrifugal extraction operation to reduce the level of liquid in said chamber to below said bottom wall.

3. In a vertical axis washing machine;

(a) means defining a chamber;

(b) an outer, open top tub movably mounted in said chamber to receive liquid and fabrics to be washed in that liquid;

(c) an inner, substantially imperforate tub disposed within said outer tub to receive liquid and fabrics to be washed in that liquid;

(d) drive means for effecting a washing action in said tubs and for rotating said tubs for centrifugal extraction of liquid from the fabrics;

(e) said outer tub defining openings therein for the discharge of liquid from said outer tub into said chamber during centrifugal extraction;

(f) a plurality of return bent, generally vertically to the upper portion of said inner tub and their outlets disposed adjacent the upper portion of said outer tub to prevent splashing of liquid from said inner tub during agitation and to allow discharge of liquid from said inner tub over the top of said outer tub during centrifugal extraction;

(h) drain means effective during periods of centrifugal extraction to exhaust liquid from said chamber.

4. The invention as set forth in claim 3 wherein a wall extending generally inwardly from the top of said outer tub, the inner edge of said wall having an upturned lip disposed inwardly of and below the outlets of said conduits to prevent any liquid dropping from said conduits into said outer tub.

5. The invention as set forth in claim 3 wherein a wall is disposed around and spaced above the top of said outer tub, said Wall extending downwardly outside said outer tub for guiding liquid discharged from said inner tub into said chamber away from said outer tub.

6. The invention as set forth in claim 3 wherein the outlets of said conduits are below the top of said outer tub; a first wall extends inwardly and downwardly from the top of said outer tub to underlie said conduit outlets for guiding liquid from said conduits to the top of said outer tub, an upturned flange being formed at the inner edge of said first wall to prevent liquid dropping into said outer tub; and a second wall extends around and spaced above the top of said outer tub, said second wall including a first portion spaced above said first wall and a second portion extending downwardly outside said outer tub for guiding liquid from said conduit outlets into said chamber away from said outer tub.

7. The invention as set forth in claim 6 wherein said 9 10 outer tub includes a bottom wall and an upwardly extend- References Cited ing side wall, said side wall having a plurality of spaced UNITED STATES PATENTS openings therein so that when liquid is introduced into said outer tub it will fill said chamber to substantially the 314,688 6/1967 Hubbard same level as said' outer tub; said drain means being effective prior to each centrifugal extraction operation to 5 reduce the level of liquid in said chamber to below said U.S. Cl. X.R. bottom wall. 68--23.7, 27

WILLIAM 1. PRICE, Primary Examiner

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