US 3738130 A
An oscillatable tub for a washing machine includes a pair of blades attached eccentrically to and oscillatable with the tub for effecting a washing action. In a preferred embodiment the blades are flexible to enhance the movement of the washing fluid and articles contained therein.
Claims available in
Description (OCR text may contain errors)
nited States Patent 1 1 Smith 1 51 June 12, 1973 OSCILLATABLE TUB FOR WASHING 1,629,762 5 1927 Woodrow 68/174 MACHINE 2,575,691 11 1951 Smith 68/174 x 3,285,040 ll/l966 Bochan 68/134  Inventor: Thomas R. Smith, Newton, Iowa Assignee: The Maytag Company, Newton Primary Examiner-William 1. Price Iowa Assistant Examiner-Philip R. Coe 22 Filed; Man 9, 1972 AttorneyWilliam G. Landwier and Richard L.
. w d i v 21 Appl. No.: 233,155 ar 52 us (:1. 68/154 ABSTRACT lil 26 1;sass;1111'.1111:1111:1 "a /isiflsifivlf oscillmble tub for a washing machine memes a 68} 259/75 pair of blades attached eccentncally to and oscillatable with the tub for effecting a washing action. In a preferred embodiment the blades are flexible to enhance  References Cited th t f th h fl d d t l v UNITED STATES PATENTS taienernjotiileemeeirrill o e was mg m an ar 1c es con 1,629,761 5/1927 Woodrow 68/174 12 Claims, 6 Drawing Figures PATENIED Jum 21m sum 1 er 2 1 OSCILLATABLE TUB FOR WASHING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to washing machines and more particularly to an oscillatable tub for a washing machine having a pair of blades fixed thereto and disposed eccentrically to the tub axis for effecting a washing action within the tub.
2. Description of the Prior Art Prior art has shown oscillatable tubs for washing machines in which at least one blade was fixed to the tube for oscillatory movement therewith to effect a washing action. Initially, the oscillatable tubs were embodied in the non-centrifugally operable washing machines but were later also shown in a centrifugally operable washing machine as in my US. Pat. No. 2,575,691 issued Nov. 20, 1951. The prior art'shows an oscillatable tub having either a single rigid blade or a plurality of equally spaced rigid blades. It is noted that there has been little or no commercial use of the oscillatable tub on a significant scale.
There is a continuing search for an improved washing system for a washing machine that is heightened by the introduction of compact washing machines. An essential consideration in the search is that acceptable levels of washing effectiveness must be maintained. The washing effectiveness can be measured in terms of washability, which is an average degree of cleanness as compared to a standard, and can also be measured in terms of uniformity of cleanness as indicated by the deviation from the means. Uniformity of cleanness is closely related to the turnover and movement of articles within the washing fluid and to tangling of the articles which accompany certain types of agitation.
The commonly used system including a large central agitator cannot effectively be used in compact machines where the washing container must be made smaller while the clothes to be washed therein, except as to total load size, remain a constant. Only by reducing the size, fabric thickness, and construction of the articles being washed could the system now commonly in use be as effectively used in a compact washer construction.
Thus there exists a need for a new washing system for washing machines, and especially for compact units. The system as applied to a compact unit should effectively utilize the entire available space within the washing container to obtain adequate movement of fluid and adequate flexing and movement of articles washed therein.
SUMMARY OF THE INVENTION The instant invention achieves these objects in awashing machine including an oscillatable tub having two blades disposed at one side of the tub and cooperatively operable during tub oscillation for inducing movement of the articles within the washing fluid and effecting an improved washing action.
Operation of the device and further objects and advantages thereof will become evident as the description proceeds and from an examination of the accompanying two pages of drawings.
DESCRIPTION OF THE DRAWINGS The drawings illustrate a preferred embodiment of the invention with similar numerals referring to similar parts throughout the several views, wherein:
FIG. 1 is an overall view of an automatic washer with fragmentary portions removed to show the instant invention embodied therein;
FIG. 2 is a fragmentary section view of an agitating blade as taken generally along lines 2-2 of FIG. ll;
FIG. 3 is a generally horizontal transverse section of the tub comprising a preferred embodiment of the instant invention; and
FIGS. 4 6 are section views similar to FIG. 3 and show alternate placement of blades in the instant invention.
DESCRIPTION OF A PREFERRED EMBODIMENT Referring to FIG. 1, there is shown an automatic washer including a cabinet structure comprising a base frame 10 supported on a plurality of adjustable legs 1 1 and in turn supporting a cabinet sidewall 13 and top cover 14. The top cover 14 includes a hinged door panel 15 normally covering a recessed loading opening and further includes an upwardly extending housing 16 for accommodating various control members such as programming means actuatable by the dial l9.
Mounted within the cabinet structure and effectively supported by the cabinet structure through the base 10 is a tub assembly 20 nutationally mounted on the base frame 10 by an inverted tripod arrangement including tub braces 21 connected at the lower end to a support member 23 positioned on a central dome of the base frame 10. The tub braces 21 are connected at their upper ends to a generally imperforate liquid container or tub 24. The tub braces 21 are also resiliently connected to the base frame 10 by centering springs 25 which resist and effectively limit rotation of the support member 23 relative to the base frame 10 but permit nutational movement of the tub assembly 20 relative to the base frame 10.
The base frame 10 also supports, through a movable motor mount 26, a reversible drive 'motor 29 operable in a bidirectional drive system for selectively effecting an agitating operation or a centrifugal extraction operation. The drive system includes a pulley 30 fixed to the output shaft of the motor 29 and drivingly engaged with a main drive belt 31 which is in turn drivingly engaged with the main drive pulley 33.
The main drive pulley 33 is drivingly connected to either the output agitate shaft 34 through the drive shaft 35 and the gearing of the transmission 36 or to the transmission-housing 39 through the drive shaft 35 and a clutch within the transmission 36 that couples the drive shaft 35 to the transmission housing 39.
The transmission housing 39 includes an upper hub 40 extending upwardly through a central opening in the outer tub. A bearing assembly 43, including a resilient portion 44, is mounted on the transmission hub 40 and engageable with a flange of the outer tub 24. The agitate shaft 34 extends upwardly from and is supported by bearings 46 within the hub 40 for an oscillating operation as driven by the gearing within the transmission 36.
An externally splined hub 49 is fixed to the upper end of the agitate shaft 34 to receive the internally splined hub 50 of a tub support plate 51. A flange portion 53 of the tub support plate 51 mates with the underside of the bottom wall 54 of the fabric basket or perforate inner tub 55 through a gasket member 56. The tub 55 is fixed to the support plate 51 with a plurality of bolts 59. A seal assembly 57 is disposed between the tub support plate 51 and the tub flange 45. The outer tub 55 is effectively imperforate to retain washing fluid received from conventional fluid supply means (not shown).
The inner tub 55 is nested within the outer tub 24 and is selectively oscillatable and centrifugally rotatable within the outer tub 24 by the connection to the drive system through the tub support plate 51. The inner tub 55 is perforated for circulation of washing liquid contained by the outer tub 24 during tub oscillation and for permitting centrifugal extraction. The inner tube 55 is generally aligned with the loading opening in the top cover 14 for permitting the operator to place fabrics within the inner tub 55 and to remove them upon completion of the cycle.
The inner tub 55 defines a washing chamber in which the articles being washed are free to move with an in the washing liquid. Movement of the liquid and articles being washed is induced by at least one agitating blade 60 disposed within the washing chamber and fixed to the inner tub 55 for movement therewith. The inner tub also includes a central dome 58 that extends into the washing chamber to accommodate the tub support plate 51.
The construction and mounting of the inner tub 55 permits the tub to be driven for selectively effecting an agitating or centrifugal extraction operation. Operation of the motor 29 in a first direction effects oscillation of the tub 55 by a drive path including the main drive pulley 33, the drive shaft 35, gearing of the transmission 36, the output shaft 34, and the tub support plate 51. In the opposite motor direction as previously indicated, a clutch arrangement effectively locks the drive shaft 35 to the transmission housing 39 so that the main drive pulley 33 rotates the drive shaft 35, transmission housing 39, and output shaft 34 as a unit. The inner tub 55 is thus rotated at a relatively high speed for centrifugal washing liquid from the inner tub 55 and articles contained therein.
The nutational support of the tub assembly and the selective operation of the drive system for oscillation or centrifugal rotation is more clearly shown and described in the following patents, each of which are assigned to the assignee of the instant invention: Burkland U.S. Pat. No. Re. 25,157; Scott et al. U.S. Pat. No. 2,854,297; and Goodlaxson U.S. Pat. No. 3,013,645.
Referring to FIGS. 1 and 2, the blade 60 is formed in a preferred embodiment of a flexible material such as polypropylene and included a lower, relatively thicker, portion 61 connected to the inner tub 55 along the bottom wall 54 and corner radius 63 with a plurality of screws 62. The blades may be formed with more or less flexibility as desired. The blade could also be formed integrally with the tub if the tub were molded of a suitable material. An upper portion 64 having an edge bead 65 is disposed in a generally vertical plane extending into the washing chamber and is detached from the tub sidewall 66 beginning at point 67 for flexible movement of the upper blade portion 64 relative to the tub 55 during oscillatory movement thereof. The web portion of the blade that is surrounded by the lower portion 61 and the edge bead 65 has a decreasing thickness in the upward direction for gradually increasing the flexibility above the points of attachment to the tub side and bottom walls 66 and 54.
The flexible agitating blades 60 include an upwardly extending portion 64 detached from the tub sidewall 66 for flexible movement during tub agitation. It is believed that the side-to-side movement from a generally vertical plane of the upper blade tip, as generally shown by broken lines 69 and 70 in FIG. 2, tends to enhance the agitation action and further improves the movement of articles within the washing fluid through a fishtail effect.
The fishtail effect is evident at the end of the stroke where the end of the blade 60 is flexed in one direction relative to the normal position of the blade such as indicated by the broken line 70 in FIG. 2 as the blade moves to the left. The tip of the blade 60 moves relatively quickly from the broken line position 70 to the other position 69 as the direction of blade movement is reversed. This fishtailing provides an improved fluid action adjacent the tip and, in addition, the tip of the blade moves in a direction to produce a physical upward nudge to the articles engaging the tip of the blade 60 as the blade assumes full length at the unflexed position.
Furthermore, the flexibility of the agitating blades 60 absorbs the shock produced at the ends of the stroke as especially present with large loads and provides a less severe engagement with the fabrics to avoid unnecessary fabric wear.
The improvement in the washing action achieved by positioning a pair of blades 60 in the washing chamber cooperatively close to one another to produce an accumulative effect on the washing fluid and articles being washed therein is the foundation of the instant invention. In order to be cooperatively close to one another they must, of course, be significantly less than 180 apart, such as a practical maximum of approximately 135 for example, in order to form a channel therebetween. They must also not be too close, with an approximate 45 spacing being an effective minimum.
The channel between the blades accommodates fluid and also accommodates fabrics which are moving with and within the fluid responsive to the pumping forces of the blades 60 and responsive to the centrifugal effect of fluid moving generally outwardly and then upwardly in the space between the blades 60.
The net result of the oscillation of the blades and the back and forth flexing of the blade tip is an upward force on the articles and the washing fluid adjacent the blades so that there is a generally upward circulation of the washing fluid and fabrics at the agitator blades 60 as indicated by the arrows 71 in FIG. 1. The overall circulation pattern in other parts of the tub 55 is dependent upon the number and spacing of the agitating blades 60.
A preferred embodiment as to location of blades is shown in FIG. 3. In this embodiment the two blades 60 are spaced approximately degrees apart. With this spacing the blades function cooperatively to achieve outstanding turnover of the articles being washed. The upward movement induced at each of the agitating blades 60 and in the space therebetween is cumulative portion of the body of liquid, and then down the other 'side, generally opposite the blades, and across the lower portion of the body of liquid to complete the cycle.
The tub construction with two blades 60 as a cooperative pair positioned asymmetrically within the tub, or eccentrically relative to the axis, is specially advantageous in compact washing machines. The eccentric positioning of the blades 60 leaves the major portion of the washing chamber in tub 55 for better fabric movement and turnover. To place an agitator in the center of a compact tub would leave little space for movement of fabrics.
The feature of flexible agitating blades fixed to the tub for oscillation therewith is also disclosed and is claimed in a copending application entitled Oscillatable Tub with Flexible Blade filed on an even date with this application by Thomas R. Smith and assigned to the assignee of the instant invention.
In a specific construction of the preferred embodiment of FIGS. 1, 2 and 3 the following structural and operating details were present:
'tub (55) inside diameter inches height 14 inches (to water line) lower corner radius 2 inches blade (60) 2 blades spaced 90 apart material polypropylene thickness 0.156 inches at the edge bead and at the base of the flexible portion and tapering to 0.080 inches for an inner portion at the top thickness of lower portion 61 0.437 inches height 5 inches width 1-9/ 16 inches at top to 2-3/4 inches at base of flexible portion to 4-3/16 at connection to tub drive stroke 204 degrees speed S4 strokes/minute Alternate embodiments of blade position in accordance with the instant invention are shown in FIGS. 4, 5 and 6. In FIG. 4 the blades 60 are generally parallel to each other and to a radial line 79 of tub 75 that is intermediate the two blades. FIG. 5 shows a pair of relatively closer spaced blades in tub 76 on radial lines approximately 45 apart. FIG. 6, on the other hand, shows blades in a tub 77 spaced approximately 120 apart. Operational tests on washing machines embodying these alternate constructions resulted in satisfactorily good washability.
It is thus clear that the oscillatable tub of the instant invention including a pair of blades fixed to and rotatable with the tub and disposed within the tub at cooperatively close positions on generally one side of the tub axis represents an improved construction for a washing machine. The construction provides agitating means especially effective in compact washing machines.
In the drawings and specification, there has been set forth a preferred embodiment of the invention and, although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in form and the proportion of parts as well as the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as defined in the following claims.
1. In a washing machine, the combination comprismg: supporting structure means; a tub defining a washing chamber for containing fabrics and supported by said supporting structure means for oscillation about a generally vertical axis; a pair of blades within said washing chamber and attached to said tub at spaced-apart positions disposed radially outwardly from said axis, said blades being cooperatively positioned as a pair eccentrically to said axis; means forproviding washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein.
2. In a washing machine as defined in claim I wherein said pair of blades are angularly spaced apart.
3. In a washing machine as defined in claim 2 wherein said pair of angularly spaced-apart blades are positioned on radial lines of said tub.
4. In a washing machine as defined in claim 1 wherein said pair of blades are generally parallel to each other.
5. In a washing machine as defined in claim 4 wherein said parallel blades are also generally parallel to a radial line of said tub intermediate said blades.
6. In a washing machine as defined in claim 1 wherein said blades are formed of a flexible material and constructed and disposed within said tub so that a portion of the blade is movable relative to the tub during oscillation thereof.
7. In a washing machine as defined in claim 1 wherein said pair of blades is disposed in a lower portion of said washing chamber and each blade includes a lower edge fixed to said tub and further includes an upper portion flexibly movable relative to said tub during oscillation thereof.
8. In a washing machine as defined in claim 1 wherein said blades are connected to said tub at a position adjacent to a peripheral sidewall of said tub and are formed of a flexible material for movement of at least a portion of said blade relative to said tub during oscillation thereof.
9. In a washing machine, the combination comprising: supporting structure means; a tub defining a washing chamber for containing fabrics and supported by said supporting structure means for oscillation about a generally vertical axis; a pair of blades within said washing chamber and attached to said tub on angularly spaced-apart generally radial lines at positions spaced from said axis, the angular spacing of said blades not exceeding approximately 135 degrees whereby said blades as a cooperative pair are eccentrically disposed relative to said axis; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein.
10. In a washing machine as defined in claim 9 wherein said blades are spaced apart approximately degrees.
11. In awashing machine as defined in claim 9 wherein said blades are formed of a flexible material and each includes a portion detached from the sidewall of said tub for flexible movement relative to said tub during oscillation thereof.
12. In a washing machine, the combination comprismg: supporting'structure means; a tub defining a washing chamber for containing fabrics and supported by said 8 blades as a pair are eccentrically disposed relative to said axis; means for providing washing fluid to said tub; and means for oscillating said tub to effect the washing of fabrics therein.