US2543993A

US2543993A - Dishwashing machine

Info

Publication number: US2543993A
Application number: US591644A
Authority: US
Inventors: Stanitz Jacques; Schlobohm Ludwig
Original assignee: Mullins Manufacturing Corp
Current assignee: Mullins Manufacturing Corp
Priority date: 1945-05-03
Filing date: 1945-05-03
Publication date: 1951-03-06
Anticipated expiration: 1968-03-06

Description

March 6, 1951 .1. STANlTZ ETAL 2,543,993

DISHWASHING MACHINE Filed May 3, 1945 6 SheetsSheet 1 twentors March 6, 1951 J. STANITZ EI'AL msamsumc MACHINE 6 Sheets-Sheet 2 Filed May 3, 1945 o o o Zhwentow Jlarzilz&

Jacques Lad igflcklqbolzm %%megfl J. STANITZ El AL DISHWASHING MACHINE March 6, 1951 6 Sheets-Sheet 3 44 16 Filed May 3, 1945 m 9 0 m D n 3 f 2 9 2 M o 6 2, 2 $2 I 5 w M 4 M 2 a v w l j w m 5 2 a 5 a J 5 v a, o a w 5 M In a 2 x l ilmw 11111 w w 5 JS'lan Lu wzyfielzlob olzm VW 7 W March 6, 1951 I s N z r 2,543,993

DISHWASHING MACHINE Filed May 3, 1945 V 6 Sheets-Sheet 4 I mega March 6, 1951 J. STANITZ EIAL 2,543,993

I msmmsnmc mcnm:

Filed May 5, 1945 1 6 Sheets-Sheet 5 4 3 rmentors Jacquw 67am? & BB Ludwig Jalzlabo 1 %M a ornegs March 6, 1951 J. STANITZ ETAL 2,543,993

DISHWASHING MACHINE Filed May 3, 1945 6 Sheets-Sheet 6 3 nventora a Jaagwew Jlanflz & 1; lg i5 69 Bu Ludw Aye/1201 01 atented M. 6, 1951 'DISH'WASHING MACHINE Jacques Stanitz, Warren, and Ludwig Schlobohm, Cleveland Heights, Ohio, assignors to Mullins Manufacturing Corporation, Salem, Ohio, at

corporationof New York Application May 3, 1945, Serial No. 591,644

The invention relates to dishwashing machines and more particularly to a domestic orhousehold'type of dishwasher and to the construction of and the cooperative, relation between elements thereof for obtaining complete and uniform washing of dishes placed in a removable. basket therein.

There are prior art dishwashers in which washing liquid is jetted through holes in an inner tub from a body 'of liquid forced upward between the inner and anouter tub by a rotary impeller at the bottomof the outer tub below the inner tub. The jets strike dishes contained in a basket within the inner tub and may. satisfactorily wash some of, the dishes located adjacent the outer periphery of the basket but the jets do not penetrate to the mass of dishes' within the central portion of the basket except by casual splashing. Moreover, such jets do not providesufliciently forceful liquid sprays to dislodge and completely remove food particlesand the like from the dishes, particularly ifthe dishes have been permitted to stand soiled for any appreciable time. l

There are'othe'rprior artdishwashers in which 10Claims. (or. 134-141) a body of-liquid is forced upward between inner v radially toward the center of the tubs. The cen-' tral convergence of the sheet-like stream forcefully strikes dishes at the top of the centralportion of a basket within the inner tub and'may satisfactorily wash some of the dishes in the central core of the mass of dishes within the basket. However, the mass of dishes, located annularly around the outer periphery of the basket is not washed by the centrally converging overflow stream, except'by occasional splashing.

Holes are sometimes provided in the inner tub of such a dishwasher to provide jets of washing liquid directed against dishesimmediately adjacent the jets'. When such a dishwasher is relatively small, the mass of dishes in the basket has a small diameter and is shallow in depth, and a satisfactory dishwashin 'operation may be carried out. However, the capacity of the basket for such a small washer is very limited and can only accommodate few dishes in performing a washing operation. When the capacity of a dishwasher thus constructed is] increased to accommodate the dishes, say for a dinner for four to six people, the washing action is insufficient to prop- 2 erly wash the annular mass of dishes at and adjacent the periphery of the basket.

There are still other prior art dishwashers in which dishes are placed in a basket in a tub above a relatively large rotary impeller. The spray. agitation or turbulence of washing fluid is very forceful at the bottom of the tub of such a dishwasher and may satisfactorily wash and clean the dishes in a zone at the bottom of the basket. The impeller also acts as a fan and creates a mist-like condition in the remainder of the tub but the mist at the top does not satisfactorily wash and clean the dishes in the upper zone of the basket.

Accordingly, there has existed and continues to exist in the art the problem of providing a do- 'mestic or household dishwasher which will adequately and completely wash and clean a completeload of dishes and at the same time have suiiicient capacity to accommodate the dishes required for a dinner for say six persons.

It is relatively easy to wash and clean certain types of foods from dishes; but other types of food are very difficult to dislodge and remove from soiled dishes particularly when the food particles have dried on the surfaces of dishes.

Thus, dried food particleson dishes ordinarily cannot be dislodged and removed by a stream or jet of water striking the dish in a direction normal to the surface of the dish; but can only be dislodged and washed away by a jet or spray striking the surface of the dish at an acute angle andpreferably as nearly tangentially to the dish surface as is possible.

Moreover, the water jet or spray must strike the dish surface with considerable force, and not by mere splashing, in order to properly dislodge food particles from and clean the dish surfaces. The problem of jetting forceful sprays in the proper direction against every surface of every dish in a large mass ofdishes contained in a basket is complicated because the dishes of necessity, by reason of their various sizes and shapes, must be somewhat haphazardly arranged in the basket and they therefore present dish surfaces located in an infinite number of different positions.

Accordingly it is necessary, in order to properly wash dishes in a dishwasher, to establish conditions whereby dish surfaces extending in an infinite number of directions can each and all be struck throughout their entire surfaces with forceful liquid jets or sprays at an acute angle to each such dish surface.

In other words, provisions must be made for directing forceful sprays against dishes contained in a basket throughout the entire volume of the basket, and at an acute angle to the dish surfaces. irrespective of the dish arrangement within the basket.

Accordingly, it is a primary object of the present invention to provide an improved household or domestic dishwasher construction in which a large number of dishes may be uniformly washed.

Furthermore, it i an object of the present invention to provide a new dishwasher construction in which forceful liquid Jets or sprays may be directed against every surface of every dish of a large number of dishes in the dishwasher wherein the dish surfaces are located in an infinite number of positions.

Likewise, it is an object of the present invention to provide a new dishwasher construction having relatively few parts of simple construction in which forceful spray coverage is obtained over the multi-surfaces of the dish mass.

Also, it is an object of the present invention to provide a new dishwasher construction in which forceful spray coverage is obtained over the multi-surfaces of the dish mass and in which the dish-containing basket may be readily placed into or removed from the dishwasher.

We have discovered that a large number of dishes may be completely and uniformly washed in a dishwasher generally of the overflow type modified by providing a plurality of overflows, one above another, by deflecting the centrally converging sheet jet from at least one and preferably the top overflow at a plurality of zones spaced a substantial distance apart around the periphery of the inner tub, and by rotating the dish-containing basket.

We have further discovered that the basket of a dishwasher may be rotated within the dishwasher tub without any positive driving connection between the basket and the driving means for the liquid impeller.

It is therefore a further object of the present invention to provide a new dishwasher construction in which the dish-containing basket is rotated during operation of the dishwasher without direct driving connection between the basket and dishwasher drive means, thereby eliminating difllculties in supporting the basket within the dishwasher for ready placement and removal.

Likewise, it is an object of the present invention to provide a new dishwasher construction in which the dish-containing basket is rotated by the liquid currents in the dishwasher.

Finally, it is an object of the present invention to incorporate the foregoing desiderata in the construction of a dishwashing machine.

These and other objects and advantages apparent to those skilled in the art from the followin description andclaims may be obtained, the

stated results achieved, and the described difflculties overcome, by the devices, constructions, arrangements, combinations, sub-combinations, parts elements, discoveries and principles which comprise the present invention, the nature of which is set forth in the following general statement, preferred embodiments of which-illustrative of the best modes in which the applicants have contemplated applying the principle-are set forth in the following description and shown in the drawings, and which are particularly and distinctly pointed out and set forth in the appended claims forming part hereof.

The nature of the improvements in dishwashinlr machines of the present invention may be stated in general terms as preferably including in an overflow-type dishwashing machine, an outer container or tub, an inner container or tub, an impeller in the chamber between the inner and outer tub bottoms, means for rotating the impeller to withdraw liquid from the inner tub through perforations in the bottom thereof into the impeller chamber and to then force the liquid outwardly against the side walls of the outer tub and thence upwardly along th annular space between the inner and outer side walls, means forming a plurality of substantially endless annular slit orifices in the inner tub side walls communicating with said annular space,' deflector means for at least one of the slit orifl es at spaced intervals annularly therearound; a d h-containing basket mounted for rotation] about a vertical axis within the inner tub, means associated with said basket for rotating the basket, said means preferably being actuated by rotary liquid currents set up in the bottom of the inner tub by r the impeller means, the impeller drive means ineluding a drive shaft extending through the bottom wall of the outer tub, a sump formed in the outer tub bottomwall around said drive shaft, and drainage means for the dishwasher communicating with said sump.

By way of example, preferred embodiments of the improved dishwashing machine are illustrated in the accompanying drawings forming part hereof, wherein:

Figure 1 is a vertical sectional view taken through a dishwashing machine of the overflow type incorporating the improvements of the present invention;

Fig. 2 is a plan view, with parts broken away and in section, of the improved dishwashing machine illustrated in Fig. 1;

Fig. 3 is a fragmentary perspective view of the upper overflow directing ring of the machine of Fig. 1, illustrating the deflector means thereon;

Fig. 4 is a similar view of the directing ring and deflector means thereon for an intermediate overflow slit orifice of the machine of Fig. 1;

Fig. 5 is a view similar to a portion of Fig. 1 illustrating a dish-containing basket with a load of dishes therein placed in the dishwasher;

Fig. 6 is a view similar to a portion of Fig. l of a modified form of construction;

Figs. '7 and 8 are diagrammatic sectional views illustrating the water or liquid action in the improved washing machine of Fig. 1;

Figs. 9 and 10 are diagrammatic plan views further illustrating the water or liquid action in the machine of Fig. 1;

Fig. 11 is a sectional view taken on the line lll I, Fig. 9;

Fig. 12 is a view similar to a portion of Fig. 1 of a further modified form of construction;

Fig. 13 is a view similar to Fig. 3 of the upper overflow directing ring of the machine of Fig. 12, illustrating the deflector means thereon;

Fig. 14 is a diagrammatic plan view similar to Figs. 9 and 10 illustrating the water or liquid action of the machine illustrated in Fig. 12; and

Fig. 15 is a diagrammatic sectional view taken as on line l5--l5, Fig. 14 similar to Figs. '7 and 8 further illustrating the improved water or liquid action of the machine of Fig. 12.

Similar numerals refer to similar parts throughout various figures of the drawings.

Referring first to the machine of Figs. 1 through 5, an example of improved dishwashing machine comprises an outer tub generally indicated at I ll supported in any desired manner on an under base structure 2 upon which the driving mechanism generally indicated at 3, is mounted. The base 2 may be provided with legs 4 which may rest directly on a floor or may be supported on casters, not shown. Any desired type of drive mechanism may be used including a motor 5 and mechanism for transmitting rotary movement to the impeller drive shaft 6. The drive shaft 6 may be journaled in a lower bearing 1 and extends through a packing gland or stufling box 3 and is journaled in an upper bearing 9 located within the sump l mounted at H centrally of the bottom wall |2 of the outer tub I.

The tub I preferably includes a cylindrical side wall |3 connected by a rounded corner wall H with the bottom wall I2; and the bottom wall I2 is preferably formed to have a shallow conical shape, as shown, so that it drains to the sump III. A drain pipe I5 is connected to the sump l0 and may be suitably connected with the drain pipe of a household plumbing system.

The upper end of the side wall |3 of the tub is provided with an inturned annular directing flange I6 for a'purpose to be later described. The flange I6 is illustrated as comprising a separate ring secured with a gasket I! by suitable means such as bolts or rivets l8 to the outturned flange I!) at the upper end of the tub side wall l3.

Although the dishwasher, as illustrated, only includes a tub assembly and a base for the same, it is understood that the machine may be housed in a suitable cabinet, or housed in association with a kitchen sink. Irrespective of the manner in which the dishwashing machine is supported or housed, a suitable source of hot and cold water, not shown, is intended to be associated therewith.

The interior of the lower portion of the side wall |3 of the outer tub I is provided with a series of annularly spaced vertically extending projections 20 for directing washing fluid upward between the outer tub I and the inner tub composed of a lower tub member 2| and an upper tub member 22 within the outer tub I. These projections may be formed as vertical corrugations in the side walls of the outer tub I or, as shown in Figs. 1 and 2, may be formed by vertically extending angle members 20 secured by any suitable means to the interior of the outer tub I. The projections, either corrugations or the angle members 20, also assist in centering the inner tub within the outer tub.

The lower inner tub member 2| includes a bottom wall 23 provided with a series of perforations 24, a rounded corner wall 25and a cylindrical side wall 26 terminating at an upper edge 21 and formed preferably with a head 28 adjacent the upper edge 21.

A plurality of feet 29 may be secured in any desired manner to the bottom 23 of the lower inner tub member 2|. The feet 23 may be engaged with or secured to the bottom wall l2 of the outer tub I in any desired manner as by engaging the same with or securing them to bosses 29a on the bottom wall l2 of the outer tub I to space the tub bottom wall 23 of the inner tub a fixed distance above the bottom wall l2 of the outer tub I so as to form an impeller compartment generally indicated at 30 in which a rotary impeller 3| is located mounted at 32 onthe upper end of impeller shaft 5. The engagement between the feet 29 and bosses 29a also prevents the inner tub from rotating within the outer tub I, and centers the inner tub within the outer tub I.

The upper section 22 of the inner tub is preferably formed with a cylindrical side wall 33, a lower inturned flange 34, and terminates in an upper free edge with a bead 3i; in the side wall 33 below the upper free edge 35. A plurality of spacer members 31 are secured by any suitable means such as by screws 38 to the inturned flange 34 at the bottom of the upper section 22- of the inner tub. The upper section 22 of the inner tub is thus spaced from the upper edge oi. the lower section 2| of the inner tub and supported thereon by the spacer members 37; and the upper inner tub section 22 is centered within the outer tub I by the projections 20 on the side walls |3 of the outer tub I.

When the inner tub sections 2| and 22 are thus assembled within the outer tub I, an annular channel or chamber 33 is formed around the lower inner tub section 2|, interrupted by the vertically extending inner tub projections 20; and a similar annular chamber 40 is formed around the upper inner tub section 22 communicating with the chamber 39. The chamber 39 likewise communicates with the impeller chamber 30.

Likewise, when the inner tub sections 2| and 22 are assembled within the outer tub. I, as shown, an annular slit orifice 4| is formed between the upper edge 21 of the lower tub section 2|, and the lower face of the inturned flange 34 of the upper tub section 22. The annular slit orifice 4| is interrupted at certain places around its periphery by the spacer members 31 by which the upper tub section 22 is supported on the lower tub section 2|. 1

A similar annular slit orifice 42 is formed between the upper edge 35 of the upper tub section 22 and the'lower surface of the annular inturned flange I6 in the upper end of the outer tub I.

A series of depressions or indentations 43 (Fig. 4) are struck downward in the inturned flange 34 at the bottom of the upper tub section 22, and a similar series of indentations or depressions 44 (Fig. 3) are struck downward at the inner edge of the inturned flange ring I6.

A center post 45 is mounted at 45a on the bottom 24 of the lower inner tub section 2 I; and the post 45 journals the hub 46 of a spider-like platform or turntable 41, a thrust bearing 48 preferably being interposed between the hub 46 and a washer 49 resting on the tub bottom. A dishcontaining basket 50 (Fig. 5) may be placed within the inner tub of the dishwasher and rest upon the turntable 41 after dishes, as illustrated in Fig. 5, have been placed therein for bein washed. Upon completion of a dishwashing operation, the basket 50 may be removed from the dishwasher.

As shown, the turntable 41 includes spider-like flat radial blades 5| for a purpose to be later described. It is understood, however, that the turntable element 41 may be permanentl incorported as a part of the construction of the basket 50, if desired, in which event, the hub member 46 is placed over or removed from the center post 45 in placing the basket 50 in or removing it from the dishwasher.

We have discovered that the shape and arrangement of the blades 3 la of the impeller 3| is important for efficient operation and for most satisfactory water action to be later described. Thus, a four-bladed impeller is indicated in Fig. 2 because the same appearsto be somewhat more eflicient than a three bladed impeller or an impeller having some other number of blades. However, it is understood that the invention is not limited to the use of a four-bladed impeller because a diflerent number of blades gives satisfactory results.

In prior art dishwashers, involved twisted shapes for the impeller blades have been indicated as being important; but we have discovered that for efllcient operation, the blades may be flat in any vertical section, without any curvatur giving a lead at the bottom or top edge of the blades. Furthermore, the blades are each preferably slightly curved, as indicated in Fig. 2, from the impeller hub to the outer ends of the blades 3|a. Finally, the blades are curved concave in the direction of rotation of the impeller 3| as indicated by the arrow in Fig. 2. Tests have shown that an impeller thus constructed and rotated requires less power than when operated in the opposite direction; contrary to the usual mode of operation of curved bladed impellers which are usually rotated with the blades convex in the direction of rotation.

Although the improved impeller construction is desirable because it is inexpensive and efficient in operation, the operation of the improved dishwasher is not dependent upon the use of the specific impeller shown and described. Any form of impeller may be used which will force washing liquid upward between the inner and outertubs and discharge the liquid from the annular slit orifices 4| and 42 with considerable force; and which will also set up a swirling liquid current at the bottom of and within the inner tub in a manner to be later described.

A modified form of construction is illustrated in Fig. 6 in which the inner tub is composed of three sections, rather than two sections, and ineludes a lower section 52, an intermediate section 53 and an upper section 54 constructed in the same manner as the upper and lower inner tub members 2| and 22 of Fig. 1. In the modified construction of Fig. 6, an annular slit orifice 55 is provided between the lower and

intermediate tub sections

52 and 53, a second annular slit orifice 56 is provided between the intermediate and upper

inner tub sections

53 and 54, and a third annular slit orifice 51 is provided at the top oi the inner tub section 54.

The

tub sections

52, 53 and 54 may be assembled within the outer tub in the same manner as described in connection with the construction illustrated in Fig. 1; and projections, such as vertically extending corrugations 58 may be provided in the side walls of the outer tub, similar to the angle members 20, to direct the liquid fiow upward between the inner and outer tubs. Thus, the three channels 59, 60 and around the

inner tub sections

52, 53 and 54, respectively, are interrupted annularly by the vertical corrugations 58.

A series of holes may be placed in the side walls of any one or in all of the inner tub sections as indicated at 62 in the construction illustrated in Figure 1, or these holes may be omitted as shown in Figure 6.

In operating the dishwashing machine, the tubs are filled with hot washing liquid to the approximate liquid level indicated at 63 in Figs. 1 and 5. The washing liquid usually comprises hot water and soap and the like, to which may be added, if desired, a water softening compound or surface tension reducing agent. The soiled dishes to be washed are placed in a dish-containing basket 50, usually removed from the dishwasher, and the same are disposed in the most favorable positions in the basket to be readily impinged from all angles by jetted liquid streams.

As shown in Fig. 5, plates, dishes and the like are preferably placed on edge around the periphery of the basket, cups and glasses may be placed in movable supplementary trays or shelves, and silverware may be disposed in a central compartment. When the term dishes is used herein and in the appended claims, that term is intended to include chinaware, glasses, silverware, pots, pans, and the like.

After the soiled dishes have been thus placed in a most favorable position in the basket 50, the basket is inserted in the dishwasher and placed upon the turntable 41. Thereupon, a cover may be placed upon the dishwasher although the use of a cover is not absolutely essential. The driving mechanism 3 is then started which rotates the impeller 3| in the direction indicated in Fig. 2. Rotation of the impeller 3| forces the washing liquid outward in the impeller chamber 30 and thence upward along

annular chambers

39 and 40 from which the liquid is jetted with considerable force through annular slit orifices 4| and 42 and strikes the soiled dishes contained in the basket 50.

Washing liquid flows into the impeller compartment 30 through bottom openings 24 in the inner tub to the central portion of the impeller 3|. It has been discovered that upon rotation of the impeller 3|, some washing liquid is forced upward thereby through outermost holes 24a (Fig. 2) in the inner tub bottom wall 23 and this liquid tends to swirl within the bottom of the inner tub in the direction of rotation of the impeller. The swirling liquid current strikes the flat radial blades 5| of the turntable 41 and rotates the turntable, thus automatically rotating the basket and dishes contained therein.

When plates and the like are disposed in the basket 50 in the manner illustrated in Fig. 5, the swirling liquid current also strikes the plates and imparts rotary movement to the basket through the plates. Thus, the basket is automatically rotated by means including the swirling liquid current in the bottom of the inner tub set up by the rotary impeller, the force of which is imparted to blades on the basket, or blades on a turntable upon which the basket rests, or to dishes contained within the basket.

Thus, the basket rotates during operation of the dishwasher and the surfaces of the dishes therein have constantly changing positions or 10- cations with respect to the sheet sprays of liquid jetted under considerable force from the annular slit orifices 4| and 42, so that the washing liquid strikes the soiled dish surfaces from every direction with sufiicient force to cleanse the soil and dislodge food particles from the dish surfaces.

The cross-sectional areas of

compartments

39 and 40 and of annular slit orifices 4| and 42 are such that when the proper amount of washing liquid is contained within the dishwasher and the impeller 3| is rotating. continuous sheet-like sprays are jetted continuously under considerable force from the orifices 4| and 42. We have discovered in operating the dishwasher of the present invention that a pressure surge seems to occur in the body of liquid forced upward by the rotary impeller 3| in

annular chambers

39 and 40.

While the reasons for the occurrence of this pressure surge are not clear, a possible explanation for the occurrences thereof is that a constant volume of washing liquid is contained within the dishwasher. As the impeller 3| rotates and forces washing liquid upward along

chambers

39 and 40, pressure is built up therein mo,- mentarily and the pressure head of the remaining liquid in the inner tub is momentarily reduced. As the liquid is jetted through orifices 4| and 42, the pressure in chambers 39 and is momentarily reduced and the water lever in the inner tub momentarily rises. This cycle continues repeated and may account for the repeated pressure surges occurring in the

annular chambers

39 and 40 which cooperatewith the director rings I6 and 34, and the

indentations

44 and 43, respectively therein, to obtain the remarkable and characteristicresulting water action of the dishwasher of the present invention.

If the flanges or director rings I6 and 34 were not provided with the deflector means or

indentations

44 and 43, the annular streams of liquid jetted from the slit orifices 4| and 42 would be substantially flat or slightly dished downward, converging to the center, as indicated diagrammatically by the dot-dash lines 64 in Fig. 7. However, the

deflector indentations

43 and 44 at spaced intervals around the flanges l6 and 34 deflect or contract each jetted liquid sheet spray 65 (Fig. 11) without breaking the continuity of the sheet, to form spaced rounded or trough-like spray portions 66 directed generally radially inward as indicated in Fig. 9. The locations of the bottoms of the trough-like spray portions 66 are indicated diagrammatically in dot-dash lines at 61 in Fig. 7.

We have discovered that if the

deflector indentations

43 and 44 have a substantially sharpcornered, angularly directed, flat shape, as illustrated in Figs. 3 and 4, the wavy trough-like spray formations 66 in the jetted sheet streams 65 have a shape suited to produce the best washing action. .The

indentations

43 and 44 must not be tooclose together. Twelve indentations are shown for the ring it in-Fig. 9 where the ring has an approximate inner diameter of 19 inches. If twenty-four indentations 44 are provided in the ring I6 rather than twelve, there would be twenty-four trough-like formations 66 which would diverge and meet eachother very close to the inner edge of the ring I6 thus substantially destroying the flat sheet stream portions 65 which intervene between the trough-like portions 66 as illustrated in Fig. 9. In other words. the indentations 54 are spaced far enough apart that the diverging trough-like spray portions 66 do not meet each other until they reach the central one-third portion of the dishwashing machine as illustrated in Fig. 9. g

When the pressure surges to a maximum in

chambers

39 and 40 as previously described, a sheet stream 65 is jetted from each annular slit orifice 4| and 42 at approximately the level and in the direction indicated at 84 in Fig. '7; and the unbroken spray or trough portions 66 are directed substantially radially inward as indicated in Fig. 9 and at the a proximate location and level indicated at 6'! in Fig. 7.

However, when the pressure of the liquid in

chambers

39 and 40 drops, as previously .described, the locations of the sheet streams 65 change from those indicated at 64 in Fig. '7 to those indicated at 64a by dot-dash lines, in Fig. 8 with an accompanying drop of the locations of the bottoms of the troughs from the locations indicated at 61 in Fig. 7 to the locations indicated at 67a in Fig. 8. Thus, the characteristic constantlyrepeating pressure surges occurring in operation of the dishwasher result in a constantly repeating raising and lowerming of the sheet stream Jetted from the annular slit orifices 4| and 42 between the locations diagrammatically illustrated in Figs. 7 and 8.

The raising and lowering of the "locations of the jetted sheet streams, and the pressure surges, are also accom'paniedby a change in the directions of the unbroken trough-like spray portions 66 of the sheet streams 65 which switch back and forth between the substantially radial directions thereof shown in Fig. 9 and the deflected locations thereof shown diagrammatically in Fig. 10. Thus, the liquid sheet stream jets 65 and the spray portions 66 thereof, in moving up and down, andthe spray portions 66 in deflecting back and forth in the sheet streams 65 as the sheet streams 66 move upand down, and'the provision of a plurality of sheet streams 65 at a plurality of levels within the dishwasher, results in liquid striking the dishes contained in the basket which is rotating within the dishwasher in an infinite number of directions; and the liquid streams and spray portions traverse the dishes up and down and sideways while the dishes are moving so that every surface of every dish in the entire mass of dishes contained in the basket 5|] is completely and thoroughly washed by the action of washing liquid jetted under considerable force against such surfaces.

The operation of the. dishwashing machine is continued for from say two to six-minutes if the soil on the dishes is not of a character difiicult to remove, or if it has not dried on the dishes for a substantial length of time; and may be continued for a somewhat longer period of time if the soil is of a character difficult to remove. Thereafter, the washing liquid may be drained from the dishwasher through drain pipe l5, and

rinse water may be introduced into the dishwasher and the dishwasher operated for a short period of time to rinse the dishes.

By providing a central drain sump it around the impeller driving shaft 6, complete drainage of the dishwasher is readily obtained and a sump is provided where food particles cansettle so that the washing fluid circulated by the impeller is cleared of such food particles.

The provision of a plurality of overflows for jetting sheet streams of washing liquid against the dishes gives a more complete and uniform coverage of jetted liquid throughout the entire volume of the mass of dishes being washed, than is obtained in a dishwasher having only one top overflow merely converging to the center and which only properly washes the central upper core portion of the mass of dishes. v

The provisions for obtaining a plurality of levels of jetted sheetstreams moving up and down and having spray portions moving sideways, combined with a rotating basket which exposes substantially every part of every dish. to forceful liquid spray action directed thereagainst from constantly changing directions results in complete and uniform washing action upon all dishes contained in the basket never heretofore to our knowledge obtained in any prior art dishwasher.

be provided to supplement the sheet stream jets,

as indicated in Fig. 1, the action thereof is merely cumulative or secondary to the primary and complete washing accomplished by the moving jetted sheet streams striking the moving dishes.

It is understood that the basket can be positively rotated, if desired, but the provision of positive driving connections merely increases the cost of construction and maintenance of the dishwasher; and the necessary rotation of the dishcontaining basket is obtained automatically, without added cost by the liquid currents 'set up in the inner tub by the impeller.

The dishwashing machine shown in Figs. 12 through 15 comprises an outer tub 68, supported in any desired manner, and having any desired type of drive mechanism to transmit rotary movement to the impeller drive shaft 89 journaled in a lower bearing 18 and supported thereon by a collar 1|. The shaft 89 extends through a pack-. ing gland or stuffing box 12, and then through sump 13; and an impeller 14 is mounted at the upper end of the shaft 69.

Inner tub sections

15 and 18 are mounted within the outer tub 68 in the same manner as the inner tub sections of the machine illustrated in Fig. 1, except that the directing projections on the outer tub 88 may take the form of inwardly projecting vertically extending corrugations 11. The sump portion 13 may be shaped to form a drain outlet 18 with which a drain pipe 19 is connected, controlled by a valve 80; and the drain pipe 18 may be suitably connected with the drain pipe of a household plumbing system.

The upper end of the side wall of the outer tub 88 is provided with an annular directing flange 8| and the upper inner tub section 16 is likewise provided with an inturned directing flange 82; and the tub sections when assembled together with their directing flanges 8| and 82 form

annular slit orifices

83 and 84 similar to the annular slit orifices in the machine illustrated in Fig. 1. The inner and outer tubs are spaced so that a compartment 85 is formed therebetween, interrupted by the projections 11, and communicating between the impeller chamber 86 and the

annular slit orifices

83 and 84.

A series of indentations or depressions 81 are struck downward in the upper directing flange 8|, as illustrated in Fig. 13, to form deflector means; and as illustrated in Figs. 12 through 15, six director means 81 are formed with six intervening flats 88. The indentations 81 and flats 88 each preferably have the same circumferential length. Thus, the inner circumference of the directing flange 8| is divided into twelve spaces having approximately equal length, alternating as flats and depressions.

With the proper amount of washing liquid, indicated by the water level 89 in Fig. 12, the machine may be loaded and operated in a manner generally similar to that described for the operation of the dishwashing machine of Fig. 1, to completely, rapidly and satisfactorily wash dishes.

In the operation of the modified form of dishwashing machine illustrated in Figs. 12 through 15, washing liquid flows into the impeller compartment 88 through bottom openings in the inner tub, and some washing liquid is forced upward by the impeller back into the outer periphery of the inner tub and swirls therein in the direction of rotation of the impeller thus rotating the dish-containing basket in a manner previously described. v

Likewise, the impeller 14 forces washing liquid outward in impeller chamber 86, thence upward along compartment from which the liquid is jetted with considerable force through

annular slit orifices

83 and 84. The directing flange 82 for the lower annular slit orifice 84 (Fig. 15) is not provided with any deflector means so that the liquid is jetted from lower orifice 84 in an inwardly directed sheet-like stream converging radially toward the center of the washing machine as indicated at 98.

However, the alternating flats 88 and deflector depressions 81 in the upper directing ring 8| for the upper annular slit orifice 83 produce quite a different, unusual and characteristic water action or patterndllustrated diagrammatically in Figs. 14 and 15. At each flat 88, an unbroken primary sheet stream is jetted from the annular slit orifice 83 generally inward. These primary sheet streams are indicated at 9|, 92, 93, 94, and 96 in Figs. 14 and 15. The sheet stream 9| diverges somewhat from its zone of discharge 9 la from the orifice 83 to present one substantially radial edge 9") and another edge 9|c diverging toward the inner circumference of the directing ring 8| in the direction of rotation of the impeller 14 indicated by the arrow 91. The jetted sheet stream 9| finally forms a falls indicated at 9|d extending somewhat radially of the machine. Each of the other jetted

sheet streams

92, 93, 94, 95 and 96 is similarly formed, directed and located.

Because of loss of pressure head, the inner zone of the sheet stream 9|, and the falls 9|d thereof, are at lower levels than the level of the intermediate zone of the next adjacent primary sheet stream 92; so that the falls 9|d of sheet stream 9| passes below, is located beneath and does not disturb the pattern of the sheet stream 92. Likewise, the falls of sheet stream 92 is below and beneath sheet stream 93; the falls of sheet stream 93 is below and beneath sheet stream 94; the falls of sheet stream 94 is below and beneath sheet stream 95; the falls of sheet stream 95 is below and beneath sheet stream 96; and the falls of sheet stream 96 is below and beneath sheet stream 9|.

At the same time, another series of smaller secondary sheet streams is jetted from the annular slit orifice 83 at the deflector portions 81. the secondary sheet streams being indicated at 98, 99, I89, llll, I02, and H13 in Figs. 14 and 15. Each secondary sheet stream is projected at a greater angle downward from the horizontal than the angle of projection of the primary sheet streams. and forms a smaller water falls, indicated at 980. for secondary sheet stream 98. In this manner, each secondary sheet stream passes below and beneath the primary sheet streams located at either side thereof.

Any surging, described in connection with the operation of the machine of Fig. 1, which may occur in operating the machine of Figs. 12 through 15, seems to have little eifect upon the direction and location of the primary sheet streams, but may cause the secondary sheet streams to switch back and forth beneath the primary sheet streams.

Meanwhile, the dish-containing basket is rotating within the dishwasher in a direction also indicated by the arrow 91 so that the dishes therein pass successively below and are impinged by each of the water falls formed by the primary and secondary sheet streams in constantly changing positions or locations with respect to the liquid; and the considerable force of the sheet streams and the falls thereof, strikes the soiled dish surfaces from substantially every direction.

and completely cleanses the soil and dislodges food particles from the dish surfaces.

At the same time, the washing liquid is jetted 1 from the lower level annular slit orifice 86 in sheet stream 90 toward the mass of dishes contained in the basket so that substantially every surface of every dish in the entire mass of dishes is completely and thoroughly washed by the action of washing liquid jetted with considerable force against substantially all of such surfaces. With the water action and characteristic pattern produced by the alternating flats and depressions on the upper directing ring Bl, it is unnecessary to form a similar water pattern by alternating flats and depressions at the lower annular slit orifice 84, although the directing flange 82 there-.- of may be formed with alternating flats and depressions if desired; or it may be formed with depressions such as shown in Fig. 4.

In its fundamental concept, the improved dishwashing action and results of the present invention are obtained by providing an annular slit orifice construction from which washing liquid is jetted under considerable force in a plurality of definite different sheet streams, each directed in a different direction and at a level avoiding collision, intersection or interference with other sheet streams, so that a multi-directional jetted liquid pattern is maintained striking the surfaces of the dishes being washed from many different directions.

The improved dishwashing action and results are enhanced by rotating the dish-containing basket, while subjecting the dishes to the multidirectional jetted sheet streams, to strike the dish surfaces from an infinite number of directions.

The improved dishwashing, action and results are further enhanced by providing a plurality of vention. the construction and operation of preferred embodiments of the improved dishwashing machine, and the advantageous, new and useful results obtained thereby; the new and useful devices, constructions, arrangements, combinations, sub-combinations, parts and elements, and reasonable mechanical equivalents thereof, obvious to those skilled in the art, are set forth in the appended claims.

We claim:

1. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forcesit upwardly between the inner and outer -tub walls, annular directing flange mean spaced from the top of the inner tub and forming therewith an annular slit orifice from which washing liquid is jetted, and deflector means on the lower surface of the directing flange means at spaced intervals around the directing flange means forming the jetted liquid nto a plurality of non-interfering sheet streams each directed in a different direction.

2. In a dishwashingmachine of the overflowtype wherein rotary impeller means between the bottoms of an inner tub and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, flange means projecting inwardly of the periphery of the inner tub wall and forming with the inner tub wall an annular slit orifice extending around the inner tub at the top thereof from which washing liquid is jetted, and means projecting downward from said flange means within th periphery of the liquid jetting annular orifices, one above another, to enable the capacity of the machine to be inprior art difliculties, solves a complicated problem which has existed in the art, provides for adequate, complete and thorough washing and cleansing of a complete load of dishes of considerable size, provides for jetting washing liquid with considerable force against substantially every surface of every dish of a large volume of dishes from an infinite number of directions, provides for automatically rotating the dish-containing basket without direct driving connection, provides an improved impeller construction, and provides for accomplishing each of the foregoing objects in a simply constructed machine.

In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are utilized for descriptive purposes herein and not for the purpose of limitation and are intended to be broadly construed.

Moreover, the embodiments of th improved construction illustrated and described are by way of example and the scope of the present invention is not limited to the exact details of construction of the various parts.

Having now described the features of the ininner tub wall deflecting the washing liquid jetted from said orifice into multi-directional non-intersecting sheet streams.

3. In a dishwashing machine of the overflowtype-wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, annular directing flange means spaced from the top of the inner tub and projecting inwardly of the periphery of the inner tub wall and forming therewith an annular slit orifice from which washing liquid is jetted, deflector means projecting downward from and at spaced intervals around the directing means forming the jetted liquid into a plurality of non-interfering sheet streams each directed in a different direction, dish-containing basket means within the inner tub, and means for rotating the dish-containing basket means.

4. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, a plurality of inwardly directed annular flanges spaced one above another associated with the inner tub and forming therewith a plurality of annular slit orifices from which washing liquid is jetted, and deflector means at spaced intervals around each flange forming the liquid jetted from each orifice into a plurality of non-interfering sheet streams each directed in a different direction.

5. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, a plurality of inwardly directed annular flanges spaced one above another associated with the inner tub and forming therewith a plurality of annular slit orifices from which washing liquid is jetted, and deflector means at spaced intervals around at least one of the flanges forming the liquid jetted from the adjacent Orifice into mum-directional non-intersecting sheet. streams.

6. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, annular directing flange means spaced from the top of the inner tub and forming therewith an annular slit orifice from which washing liquid is jetted, deflector means at spaced intervals around the directing means dividing the directing means into a plurality of equally spaced alternating flats and deflectors and forming the liquid jetted from said orifice into a series of primary sheet streams flowing from said flats and another series of secondary sheet streams flowing from said deflectors, said primary sheet streams each flowing in a path discharging below the next adjacent primary sheet stream, and said secondary sheet streams each flowing in a path discharging below the primary sheetstreams.

'7. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, annular directing flange means spaced from the top of the inner tub and projecting inward of the periphery of the,

inner tub wall and forming therewith an annular slit orifice from which washing liquid is jetted, and deflector means projecting downward from said annular flange contracting the orifice at spaced intervals annularly therearound.

8. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner tub and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, said inner tub wall having formed therein a first series of annular slit orifices extending around the tub and a second series of annular slit orifices extending around the tub above the first series, annular directing flange means projecting inwardly of said inner tub wall immediately above each series 2,275,411

18 of slit orifices, said orifices each communicatin with the space between the inner and outer tubs, and the washing liquid forced upwardly between the inner and outer tubs being jetted in sheet streams from said orifices. I

9. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner tub and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, annular directing flange means spaced above the top of the inner tub and projecting inwardly of the periphery of the inner tub wall and forming therewith an annular slit orifice. there being a second annular slit orifice formed in the inner tub spaced below the first annular slit orifice and having another associated annular directing flange above said second slit orifice and projecting inwardly of the periphery of the inner tub wall, said orifices each communicating with the space between the inner and outer tubs, and the washing liquid forced upwardly between the inner and outer tubs bein jetted in sheet streams from said orifices.

10. In a dishwashing machine of the overflowtype wherein rotary impeller means between the bottoms of an inner tub and an outer tub draws washing liquid through the perforate bottom of the inner tub and forces it upwardly between the inner and outer tub walls, said inner tub wall having i'ormed therein a first series of annular' slit orifices extending around the tub and a second series of annular slit orifices extending around the tub above the first series, annular directing flange means projecting inwardly of said inner tub wall immediately above each series of slit orifices and having downward depressions therein forming multidirectional sheet streams in the washing liquid forced upwardly between the inner and outer tubs and jetted from said orifices.

JACQUES STANITZ. LUDWIG SCI-ILOBOHM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 516,103 McCausland Mar. 6, 1894 706,473 Low Aug. 5, 1902 858,522 Low July 2, 1907 2,151,354 Osuch Mar. 21, 1939 2,250,314 Rocke July 22, 1941 Ashe Mar. 10, 1942