Title:
Dishwashing machine
United States Patent 2075034


Abstract:
This invention rlates generally to machines such as are characterized by the use of a forcible spray of water or other liquid. It relates particularly to washing machines such as are employed for the washing of dishes, glasses and like articles of tableware. It is a general object of the invention...



Inventors:
Grace, Gordon B.
Lansing, Louis P.
Application Number:
US66491433A
Publication Date:
03/30/1937
Filing Date:
04/07/1933
Assignee:
Lansing
Primary Class:
Other Classes:
134/98.1, 134/139, 134/143
International Classes:
A47L15/06
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Description:

This invention rlates generally to machines such as are characterized by the use of a forcible spray of water or other liquid. It relates particularly to washing machines such as are employed for the washing of dishes, glasses and like articles of tableware.

It is a general object of the invention to devise a dish washing machine which will be a marked improvement over machines which have been developed in the past for this purpose, particularly with respect to the universal effectiveness of the washing action secured, and with respect to capacity and power consumption..

A further object of the invention is to provide a dish washing machine which will have a relatively wide latitude of application, and which, for example, can be used for the washing of tumblers or glasses, as well as for the washing of heavier tableware such as plates.

A further object of the invention is to provide mechanism, useful in machines of the above character, for the pumping and forcible spraying of water or other liquid, and which will be characterized by many features and advantages not inherent in mechanism for this purpose in the prior art. For example, the mechanism disclosed therein for the pumping and spraying of liquid makes possible an adjustment over a substantial range with respect to the quantity of liquid handled, while the velocity of the particles of the spray remains substantially constant.

A further feature of our mechanism is that its rotating part or parts are not apt to be damaged 5 by articles, such as knives and forks, falling upon Sthe same. -Furthermore, cleaning of the mechanism is facilitated because certain parts, including the rotary impeller and its associated bowl structure, can be readily removed.

Another object of the invention is to provide means for controlling a dishwashing machine, whereby the different functions must necessarily follow in proper sequence.

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail in conjunction with the accompanying drawings. The appended claims are to be accorded a range of equivalents consistent with so the state of the prior art.

Referring to the drawings: Fig. 1 is a plan view, lllustrating, a dish washing machine incorporating the present invention, with a part of the cover broken away to expose certain parts to view.

Fig. 2 is a cross-sectional detail taken along the line 2-2 of Fig. 1.

Fig. 3 is a side elevational view, partly in transverse cross-section, except for the pumping and spraying mechanism, and taken particularly along the line 3-3 of Fg. 1.

Fig. 4 is a cross-sectional view taken along the line 4-4 of Fig. 3.

Fig. 5 is a side elevational detail, illustrating a portion of the manual control means for the pumping and spraying mechanism, and for the spraying of rinse water.

Fig. 6 is a cross-sectional detail taken along the line 6-6 of Fig. 1.

Fig. 7 is a cross-sectional detail taken along the line 1-7 of Fig. 9, illustrating the arrangement of a spray nozzle for rinse water.

Fig. 8 is a cross-sectional detail taken along the line 8-8 of Fig. 9.

Fig. 9 is a cross-sectional detail taken along the line 9-9 of Fig. 6.

Fig. 10 is a cross-sectional detail taken along the line 10-10 of Fig. 6.

The particular dish washing machine illustrated in the drawings consists generally of a liquid reservoir or tank 10, carried by a suitable supporting means or stand II. Adapted to overlie reservoir 10 when the machine is operating, there is a cover 12, in the form of an inverted container as will presently be explained. Arranged within the space enclosed by reservoir 10 and the cover 12, above the water in reservoir 10, there is a dish supporting means 13. Arranged below the dish supporting means and within reservoir 10, there is a pumping and spraying mechanism designated generally at 14.

Although the reservoir 10 and its supporting stand II may obviously vary widely in construction, certain of thedetails as illustrated in the drawings will be pointed out, to facilitate a subsequent description of the working parts. As is apparent from Figs. 1 and 3, the reservoir 10 is rectangular in contour, being formed of front and rear vertical walls 16 and 17, side walls 18, and bottom wall 19. The supporting stand for the reservoir includes a pair of legs 21 having their upper ends secured to the forward corners of the reservoir, together with a pair of spaced vertical channels 22 secured to the rear wall 11.

Suitable detail construction for the cover 12 has been illustrated in Fig. 3. In this case the cover has been formed of a cylindrically shaped part 26, made of metal or other suitable material, with an upper part or closure 27 made of glass or like transparent material. A depending annular ridge 28 has been shown formed on the under side of part 27, to more effectively direct water bdck upon top of the dishes, and back into the reservoir 10. In order to more conveniently move the cover 12 from the operating position illustrated in Fig. 3, to an elevated and out-ofthe-way position, the cover has been shown connected with suitable means guided for vertical movements, and suitably counterbalanced. Thus mounted on the rear side of cover 12, there is a stamping or casting 29, which in turn is secured to a pair of spaced depending angle members 31. Extending laterally thru the angle members 31 are the shafts 32 (Fig. 1), and upon the ends of these shafts, rollers 33 are journaled. These rollers are accommodated within the channels 22, and engage the channel flanges, thus guiding the angle members 31 and the cover 12 for vertical movements. To serve as counterbalancing means, we have shown a weight 36 which is connected to the lower shaft 32 thru a cord or bable 37. Cord 37 passes over a pulley 38, whereby when the cover 12 together with the associated angle members 31 is raised, weight 36 is lowered. The counter-balancing effect is preferably such as to enable the cover to be retained either in an elevated out-of-the-way position or in a lowered operating position as shown in Fig. 3.

It is apparent that the relationship of the cover with respect to the reservoir 10 should be such that when the cover is in a lowered operating position there will be no splashing of water from the space thereby enclosed. Likewise, it is desirable to provide means surrounding the upper part of the reservoir to catch refuse. Therefore, the top of reservoir 10 has been shown provided with a cover plate 41 which has an inner annular opening bounded by the annular ring 42. Surrounding ring 42, there is an annular upstanding flange 43, adapted to accommodate the lower edge of cover 12, shown in Fig. 3. The outer edge of plate 41 can be rectangular in contour, similar to the outer contour of reservoir 10, and is shown provided with an upstanding flange 44. Thus, a trough 46 is formed between flanges 43 and 44, to catch refuse (Fig. 3). As shown more clearly in Fig. 2, liquid received by trough 46 may be drained thru a depending tube 47, the lower end of which has been shown accommodated within the upper open end of an overflow pipe 48 within reservoir 10. Overflow pipe 48 leads to a drain pipe 49, communicating thru the bottom wall 19 of reservoir 10.

The dish supporting means 13 can be variously constructed, but, as illustrated, is in the form of a rotatable basket. This basket consists of a bottom 51 of wire screening or like material which will pass a spray of water, and which is secured to the lower edge of an annular wall 52. This basket is adapted to removably rest upon the radial spokes 53 which are secured to the upper end of a rotatable shaft 54. The outer ends of spokes 53 are connected by an annular langed ring 56 which also serves to centrally locate the basket with respect to the center of rotation of shaft 54. - Shaft 54 is removably positioned within a socket 57, which in turn is carried by webs 58, these webs being connected to the removable ring 42. The lower end of socket 57 is shown provided with an anti-friction thrust bearing 59, to engage the lower end of shaft 54.

Removably positioned between certain of the webs 58, we have shown quadrant-shaped, foraminous trays 61, which may catch larger sized solld material removed from the articles being washed. It may be noted at this point that no tray of this character should be positioned immediately above the pumping and spraying mechanism 14, as illustrated in Fig. 1.

The pumping and spraying means 14 can better be understood by reference to Figs. 6, 8, 9, and 10, and is constructed as follows:-The bottom wall 19 of the reservoir 10 is provided with an opening to accommodate a member 66, which can be in the form of a casting. As will be presently explained, this member is preferably constructed to function both as a means for directing flow of water to a rotary impeller and for shrouding the drive shaft for the impeller.

Referring to Fig. 6, member 66 is shown provided with an annular flange 67, underlying a portion of the bottom wall 19, and sealed with respect to this bottom wall by suitable means such as a gasket 68. The curved upper surface 69 of this member 66 serves to direct flow of water inwardly and upwardly towards the impeller, while the upper annular portion 71 serves as a shroud. Mounted upon the curved flow directing surface 69 are a plurality of vanes or fins 72. As is evident from Fig. 9, these vanes are set at an inclination with respect to radii from the- central vertical axis of member 66, to impart swirling movement to water flowing inwardly over surface 69.

Disposed above and surrounding portion 71 of member 66 there is what can be termed a bowl structure 73. The upper portion 74 of structure 73 is bowl-like in shape, that is, it is belled outwardly, while the lower portion 76 is shown substantially cylindrical, to surround the rotary impeller to be presently described. Secured to the lower edge of the portion 76 of the bowl structure, there is a relatively flat annular ring 77 having upwardly turned inner and outer peripheral edge portions 78 and 79. The annular space between ring 77 and the curved surface 69 forms what can be termed an inflow opening 81. The bowl structure is adapted to rest upon bosses 80 which are formed upon the upper side of casting 66. Arranged within the cylindrical portion 76 of the bowl structure, there is a rotary impeller 82. In the detailed construction illustrated, this impeller is formed with a circumferential shroud 83, having a plurality of vanes 84 mounted upon its inner periphery. These vanes are provided with a proper lead, with respect to the direction of rotation, so that they serve to pick up water flowing inwardly thru inflow opening 81, and discharge the same as a sheet of water upon the inner surface of bowl portion 74.

In order to mount the impeller 82 for rotation about a vertical axis, and for driving the same, we have shown an electric motor 86. Lugs 87 serve to secure the frame of this motor to the GO under side of casting 66. One end of the motor shaft 88 is coupled to a shaft extension 89, the upper end of which terminates adjacent the upper end of shroud 71. Mounted upon the upper end of shaft extension 89, by suitable means such as a cap screw 90, there is an Inverted cup-shaped member 91. The lower part of this cup-shaped member 91 surrounds a machined cylindrical surface 92 on shroud portion 71, there being a slight clearance, however, to 70 permit free turning. Removably disposed over the cup-shaped member 91, there is a similarly shaped member 93. This member, however, is formed with a non-circular portion 94, to provide a disengageable driving connection with the 75 head of cap screw 90. The lower edge portion of cup-member 93 is secured to the upper .and inner corners of vanes 84, by suitable means, such as welding. In order to avoid any possible contact of water with the bearings and windings of the electric motor 86, the motor shaft has been shown provided with a dished annular splash plate 96, whereby any water or liquid entering shroud portion 71 is thrown outwardly. Insofar as the pumping and spraying mechanism has been described, it is evident that water flowing thru inflow opening 81 is acted upon by the impeller 82, to impart both rotary and vertical velocity components to the same. The sheet of water thereby delivered upon the inner surface of the bowl-like portion 74, is discharged from the lip 97 in the form of a conical spray, in which the particles tend to twist or progress in the direction of rotation of the impeller. In other words when the particles of water are thrown from the lip 91, they have imparted to them velocity components in an upward or vertical direction, in an outward direction by virtue of removal of restraint afforded by the bowllike portion 7l, and also in a rotary direction tending to cause the particles to progress about the axis of the spray, as they move upwardly and outwardly.

f the water, at the head in which it normally exists in reservoir 10, is permitted to flow directly into the inflow opening 8S, it will be difficult to properly control the capacity of the mechanism between desired limits. In solving this problem we have made it possible to adjust the pumping capacity thru a substantial range, while the velocity imparted to the particles of the spray remains substantially constant. Thus to afford a novel form of throttling means, we provide an open-ended cylinder or throttling member 101, which loosely surrounds the bowl structure 73.

The lower edge of this cylinder is adapted to rest upon the upper surface of casting 66. To afford means for vertically adjusting the position of cylinder 101, we have shown a pair of rods 102 having their upper ends secured to an annular apron 103. This apron is in turn fixed to the upper end of cylinder 10D. Rods 102 slidably extend thru tubular standards 104, to the exterior of the reservoir 10. The lower ends of these standards 104 may be threaded to serve as means for clamping the annular flange 61 to the bottom wall 19 of the reservoir. In order to control the positioning of cylinder 101 through movement of the rods 102, suitable external manually operable means is employed.

Thus referring to Fig. 4, mounted below reservoir 10, there is a suitable rock shaft 106. Levers 101 are secured to shaft .106, and the free ends of these levers are arranged to engage the lower 6o ends of rods 102. Shaft 0I extends to one side of the machine, and :I there journaled in a suitable bracket 10«. (1sg. 5.) An operating lever 109 is pivotally connected to bracket 10I, and extends to the front side..of the machine, where it is provided with a handle or knob III. A suitably slotted lock plate 112 is also provided in conjunction with operating levei 109, whereby this lever can be locked in various adjusted positions. A link I I has its one end pivotally connected to operating lever 109 and its other end connected to a crank 113, which is fixed to shaft 106. Thus when lever 10 is in a neutral position as shown in Fig. 5, cylinder 101 is permitted to contact with the upper surface of casting 66. However upon upward movement of lever 109 from its neutral position, cylinder 101 is elevated, to afford an annular orifice between its lower edge and the upper surface of casting 66, thru which water may flow by gravity.

With respect to the cylinder or throttling member 101, it should be noted that space between this member and the bowl structure 13, which has been indicated by numeral l14 in Fig. 6, is vented to the atmosphere thru apertures 115. It will be noted that these apertures are above the normal level of water within reservoir 10. The advantages to be obtained by venting this space to the atmosphere will be presently explained.

When the cylinder 101 is in its lowered or closed position, there is substantially no spraying of water, since water cannot enter the inflow opening 81. Therefore it is desirable that cylinder 101 remain closed during such times as the cover 12 may be elevated, and that movement of cylinder 101 to an elevated position to effect spraying of water, be permissible only when the cover 12 is in closed or lowered position. To make possible these functions, we provide an interlock mechanism as follows:--Beneath the reservoir 10 (Fig. 4) there is a rod 116. The slidably mounted rear end of this rod terminates in close proximity to one of the vertical angles 3S, while the other end is pivotally connected to a crank 1I7, fixed with respect to rock shaft 106.

When angle members 31 are in their lowermost position, corresponding to closed position of the cover 12, sliding movement of rod 116 which accompanies upward movement of arms 001, is accommodated by an aperture 118 (Fig. 4). However when cover 12, together with the angles 31, is in an elevated position, sliding movement of rod 16 is constrained, so that arms 101 cannot be elevated to open the throttling member 101.

Likewise in the event the throttling member i1 is in open position while the cover 12 is closed, positioning of rod 1!6 in aperture 118 locks the cover in such position.

A novel feature of our pumping mechanism is the provision of means in conjunction with the impeller 82, whereby the water delivered from this impeller is caused to flow thru an automatically variable orifice. Thus overlying the impeller we have shown what can be termed a flap 129. The upper portion 122 of the flap is cupshaped, similar to the formation of members 91 and 93, and a non-circular portion 123 is also provided to form a slidable but driving fit with the portion 94 over which it fits. The lower flange portion 124 of the flap is annular in contour, and is arranged to overlie the vanes of impeller 82. When the flap 121 is in its lowermost position as shown in Fig. 6, a restricted annular orifice 126 for the delivery of water is formed between the outer peripheral edge of flange portion 124, and the upper edge of the impeller 6o shroud 83. As the quantity of water being handled by the mechanism increases, orifice 126 is automatically increased accordingly, by elevation of the flap 121. In other words the peripheral edge of flap portion 124 rides upon the stream 05 of water being discharged from the impeller.

Undesired fluttering of the flap is minimized by a dash pot action, because of its telescopic relationship with member 93. The action Of this flap will be presently explained in greater dptail.

As is apparent from Fig. 1, with the machine utilizing a free rotating basket for supporting the dishes to be washed, the pumping and spraying mechanism 14 previously described, is preferably offset with respect to the axis of the baskept supporting shaft 54. The twisting characterof the spray causes the dish supporting basket to be rotated, by the reaction of the spray of water upon the basket and the articles which may be supported within the same, and the offset relationship makes possible better washing action and a properly regulated speed of rotation without the use of braking means.

Upon the conclusion of a washing cycle, it is desirable to provide a spray of clean water for rinsing. We have also found it desirable to co-ordinate the means utilized for spraying rinse water, with the control for the pumping and spraying mechanism. Thus referring to Fig. 7, we have shown casting 66 provided with a fluid port 13 1, which communicates with the discharge nozzle 132. This nozzle is directed upwardly, and is arranged within the space 114, between the cylinder or throttling member 101, and the bowl structure 73. During normal operation of the pumping mechanism the level of water in space 114 is below the upper end of this nozzle. When water under pressure is introduced thru this nozzle, the stream strikes the outer surface of the belled portion 74 of the bowl structure, and is thereby flattened and caused to discharge as a, sheet of water thru the annular opening 133.

Pipe 134, connected to port 131, leads to an external water pipe 136, and is also connected with an auxiliary spray pipe 135 for directing a jet of water upwardly along one side of the cover 12. Interposed between pipe 134 and pipe 136, there is a control valve 137 of the poppet or plunger type, having an operating stem 138 which is biased toward closed position, and which must be forced downwardly to open the same. Mounted upon the operating lever 109 there is a cam member 139 (Fig. 5), adapted to engage and actuate plunger 138, when lever 109 is moved to its lowermost position. With such an arl rangement, it is obviously impossible to introduce rinse water by way of nozzle 132, except when the throttling member 101 is in closed Sposition. We likewise preferably provide an interlock mechanism, whereby rinse water can only be introduced into the machine when the cover 12 is in closed position. For this purpose there is shown a rod 141, similar to rod 116, below the reservoir 10. The slidably mounted rear end of 50 this rod 141 terminates adjacent to one of the vertical angles 31, while the other end of this rod is connected to a crank 142 mounted upon rock shaft 106. It will be noted that crank 142 is displaced 180 degrees with respect to crank 117. 55 When the cover 12 is closed, the rear end of rod 141 is adapted to be accommodated in aperture 143 provided in the associated angle 31. With such an arrangement it is likewise impossible to lift the cover 12 while rinse water is be60 ing injected, or to introduce rinse water while the cover is elevated.

It is desirable to prevent entrance of foreign material of any considerable size into the pumping mechanism, as for example small articles 05 of table ware being washed or foreign material from the same. For this purpose a screen or strainer 144, which can be cylindrical in shape, is shown surrounding the throttling member 101, and has its lower edge resting upon the bottom 70 wall 19 of the reservoir 10. The upper edge of this screen underlies the apron 103.

Where the machine is being employed continually, it is desirable to provide for the heating of wash water within reservoir 10. For this purNI pose we have shown a suitable heating element in the form of a gas burner 146, beneath the bottom wall 19. A pipe connection 147, controlled by a valve 148, has also been shown for replenishing or replacing the wash water.

Before explaining the mode of operation of the machine, it should be noted that the pumping mechanism has many of its parts readily removable, thus facilitating cleaning of the machine. Thus if it is desired to clean the pumping mechanism, throttling member 101 can first be bodily lifted from the machine. Removal of the throttling member permits removal of the strainer 144. Bowl structure 73 can likewise be lifted from its operating position, without the necessity of removing bolts or like fastening means. The flap 121 can likewise be lifted from its position upon the impeller 82, and then the impeller itself can be removed, to permit cleaning of the upper surfaces of casting 66, or for inspection. Operation of the machine can be outlined as follows:-While the cover 12 is elevated, and operating lever 109 in neutral position, the basket is loaded with articles of tableware, and positioned within the machine as showr in Fig. 3. At this time it is presumed that reservoir 10 contains an ample quantity of wash water, with the upper level of this water somewhat below the level of apron 103. Upon closing the cover 12 the operator lifts .the lever 109. Lifting of this lever causes a lifting of the throttling member 101, to admix water to the inflow opening 81 of the pumping mechanism. Water picked up by the impeller 82 is discharged as a conical spray from the bowl lip 97. This conical spray strikes the articles of tableware in the basket with considerable velocity, and any part of the spray which is not immediately deflected back into the reservoir 10, may be deflected back upon top of the tableware by the cover 12. . Because of the fact that particles of the conical spray progress about its axis, the reaction of the spray upon the basket and upon the articles therein forms a torque tending to rotate the basket and its contents. Because the axis of the spray is offset with respect to the axis of rotation of the basket, the reaction torque is the resultant of two oppositely directed components. Thus the spray particles striking that portion of the basket near its outer periphery tends to rotate the basket in 5o one direction, while the spray particles striking that portion of the basket near its center of rotation tend to rotate the basket in the opposite direction. However since points of impact are at different radii from the axis of rotation of the basket, there is a net resultant torque component to cause rotation. Rotation of the basket in this fashion brings all of the articles of tableware repeatedly into the range of operation of the spray. The speed of rotation is automati- (;0 cally prevented from becoming too rapid, without the use of mechanical braking means, by the oppositely reacting components of the spray particles upon the basket and contents as previously explained. Too rapid rotation of the bas- 65" ket is objectionable not only because of possible displacement or injury to the tableware, but also because poor washing action would result.

The quantity of water handled by the pumping and spraying mechanism is dependent upon 7o the height to which the operating lever 109 is set above its neutral position. Over a substantial range of this adjustment, the velocity of impact of the particles of the spray upon the tableware remains substantially constant, although the quantity of the water sprayed is varied. This characteristic of our machine makes it possible to make adjustments to secure efficient washing of various types of tableware. For example, with plates or like articles, it is desirable to operate the pumping and spraying mechanism 14 at substantially full capacity. However, where the basket is loaded with tumblers, cups or fragile ware, it is desirable to operate at somewhat less than full capacity, for the reason that full capacity operation would react so strongly upon the articles as to cause them to be lifted and displaced, and might not afford opportunity for the water to immediately flow away from interior surfaces being cleaned by impact. However, because of the- characteristic of our machine which has previously been explained, that is that the capacity can be decreased to a substantial degree without a corresponding decrease in the velocity of the sprayed particles, tumblers and cups may be washed efficiently, and fragile articles can be washed without clattering which might cause chippage or breakage. After comSpletion of the washing cycle the operator moves lever 109 downwardly thru neutral position, to the lowest position indicated in Fig. 5. This causes the valve 137 controlling the rinse water to be opened, thus subjecting the articles within the basket to a spray of clean rinse water discharged from nozzles 132 and 135. At this time the basket 13 continues to rotate, by virtue of the momentum attained during the washing cycle.

After the rinsing operation, lever 10S is returned to neutral position, and then cover 12 can be lift3ed to permit removal of the ,washed articles.

With respect to the pumping and spraying mechanism, it has previously been stated that when throttling member 101 is in open or partially open position, it permits an inflow of water to the inflow opening 81 by virtue of the gravity head within reservoir 10. The fact that space 114 immediately within throttling member 101 is vented to the atmosphere, makes it possible for the flow of water beneath throttling member 101 46 to occur in accordance with the laws of flow of liquid thru an orifice under a gravity head, because no suction can be applied to the annular orifice below the throttling member. During normal operation the level of water in space 114 falls to a level in the neighborhood of the lower end of bowl structure 13.

In further explanation of operation of flap 121, the orifice 126 is filled with water throughout substantially the entire range of adjustment of the throttling member 101, except for closed or nearly closed throttle positions. An air space exists within the impeller and below flap 121, and except for closed or nearly closed throttle positions, the flow of water thru orifice 126 functions 6as an air exhausting pump to continuously exhaust or aspirate-air from this space. This evacuated space is in restricted communication with the atmosphere thru the clearance between memSber 91 and cylindrical surface 92, and except for 6full or substantially full open throttle positions, also receives air thru the inflow opening together with the inflowing water. However the exhausting of the air from below flap 121 takes place at such a rate with respect to the flow resistance encountered by inflowing air, that a substantial degree of vacuum is maintained, and the degree of vacuum remains fairly constant for substantially the entire range of adjustment of throttling member 101, excepting of course such adjustments where insufficient water is discharged by the impeller to fill orifice 126.

The flap, and the suction created below it as explained above, has a marked effect upon the capacity of the mechanism. For example, with the flap the capacity of. the pumping mechanism is increased many times compared with the capacity without the. flap. Increasing the rate of inflow of air, as by providing an additional vent aperture in the flap, decreases the pumping capacity for a given setting of the throttling member 101.

The action of the flap 121 also makes possible the use of an impeller which is not provided with an inner restraining wall for the water flow. If an impeller having both inner and outer restraining walls were employed, a high capacity could be secured without the use of a flap, but the desired degree of regulation by adjusting throttling member 101 would not be obtained. With our construction, high capacity is secured with a wide range of regulation, and the absence of an inner restraining wall on the impeller makes for high efficiency and simplification of design. Furthermore our construction permits the use of low water heads in the reservoir 10, with shorter and stiffer motor extension parts, better support of driver members, and a compact simplified assembly formed mainly of loosely fitted sheet metal parts. It is of course possible to make many modifications within the spirit of the invention as disclosed herein. Thus although the use of a rotary basket for supporting the tableware being washed is desirable, it is possible to use other types of supporting means, as will be apparent to one skilled in the art. Likewise while the pumping and spraying mechanism as illustrated gives good results, various modifications can be resorted to, including for example a shaping of the rotary Impeller to depart from the use of a cylindrically shaped shroud.

We claim: 1. In a machine of the character described, a generally upright hollow structure, the lower part of said structure having an intake opening and 45 the upper part of said structure being belled outwardly, in transverse cross-section said structure being annular in contour, an impeller disposed within the lower part of said structure, means serving to mount said impeller for rotation about 50 a generally upright axis, said impeller being formed to impart rotary and vertical velocity components to liquid flowing thru said inflow opening, said impeller being also formed with a peripheral shroud, and a vertically movable mem- 55 ber overlying said impeller, the peripheral edge of said, mei~ber, together with the upper edge of said shroud, serving to define a variable annular orifice.

2. In a machine of the character described, a 60 hollow structure having its lower part formed to afford an Intake opening and having its upper part formed bowl-like, an impeller disposed within the lower part of said structure, means for mounting said impeller for rotation about a gen- 65 erally upright axis, said impeller being formed to impart rotary and vertical velocity components to liquid flowing thru said intake opening and being likewise provided with a shroud about its outer periphery, a vertically movable member over- 70 lying said impeller, the peripheral edge of said member, together with the upper peripheral edge of said shroud, serving to define an orifice of variable area, and means for throttling flow of liquid through said intake opening. 75 3. In a machine of the character described for use in conjunction with a reservoir serving to collect washing water, means disposed within said reservoir for discharging said water in the form of an upwardly-directed conical-shaped spray, said means comprising a stationary bowlshaped structure having a lower intake opening, means adjacent said intake opening for discharging water upwardly along the inner peripheral surface of said structure, and means for throttling flow of water through said intake opening from said reservoir.

4. In a machine of the character described for use in conjunction with a liquid receiving reservoir, a bowl-shaped structure disposed within said reservoir, said structure affording a lower intake opening, means adjacent said intake opening for delivering liquid upwardly along the inner peripheral surface of said structure, and means forming an adjustable orifice for admitting flow of liquid from said reservoir to said intake opening, there being a space between said adjustable orifice and said intake opening which is vented to the atmosphere.

5. In a machine of the character described for use in conjunction with a reservoir for receiving water, a bowl-shaped structure having a lower intake opening, a rotary impeller for delivering liquid upwardly along the inner peripheral surface of said structure, means for throttling flow of water through said opening from said reservoir, and means for maintaining a partially evacuated space within said impeller.

6. In a machine of the character described for use in conjunction with a liquid reservoir, a rotatable shaft extending upwardly through the bottom of said reservoir, a shroud surrounding said shaft and extending upwardly to a level above the level of liquid within said reservoir, said shroud being sealed with respect to the bottom wall of the reservoir, a bowl structure arranged to surround said shroud, the lower part of said bowl structure having an opening for inflow of liquid, an impeller secured to the upper end of said shaft and arranged to surround said shroud within the lower part of said bowl structure, and means for throttling flow of liquid from said reservoir through said intake opening.

7. In a machine of the character described, a generally upright hollow structure, in transverse cross-section said structure being annular in contour, lower part of said structure having an inflow opening and the upper part of said structure being belled outwardly, an impeller disposed within the lower part of said structure and rotatable about a substantially vertical axis, said impeller having an outer annular shroud, and a vertically movable closure member overlying the impeller, said closure member having an annular periphery co-operating with the upper edge of said shroud to form an annular discharge orifice.

8. In a machine of the character described, a stationary and generally upright bowl-shaped structure having a lower intake opening, an impeller disposed within said structure and adjacent said intake opening to impart rotary and upwardly directed velocity components to liquid, and means forming an automatically variable annular orifice for accommodating flow of liquid from said impeller, said last means being within said structure and overlying the impeller.

9. In a machine of the character described, a generally upright hollow structure, in transverse cross section said structure being annular in contour, the lower part of said structure having an inflow opening and the upper part of said structure being belled outwardly, an impeller disposed within the lower part of said structure, means for rotating said impeller about a substantially upright axis, said impeller being formed to impart both rotary and vertical velocity components to liquid flowing into said intake portion, and means overlying said impeller serving to define a variable annular orifice for delivery of liquid from the impeller to the inner peripheral surface of the upper part of said structure, said last means including a member movable in a direction substantially parallel to said axis. 10. In a washing machine, a stationary structure affording a lower intake opening, said structure in transverse cross-section being annular in contour and having its upper portion belled upwardly and outwardly and substantially unobstructed with respect to discharge of liquid therefrom, the lower portion of said structure being of a diameter corresponding generally to the smallest diameter of the belled portion, and a rotary impeller disposed below said belled portion and within the lower portion of said structure for discharging a sheet of liquid upwardly along the inner peripheral surface of said upper belled portion, thereby causing the water to be discharged from the upper edge of said structure as a twisting conical spray.

11. In a machine of the character described, a bowl-shaped structure affording a lower intake opening, a rotary impeller for delivering liquid upwardly along the inner peripheral surface of said structure, and means making use of the aspirating effect of liquid flow from the impeller to said surface for maintaining a partially evacuated space within the region occupied by said impeller. GORDON B. GRACE.

LOUIS P. LANSING.