US3009470A

US3009470A - Domestic appliance

Info

Publication number: US3009470A
Application number: US685447A
Authority: US
Inventors: Thomas F Zurck
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1957-09-23
Filing date: 1957-09-23
Publication date: 1961-11-21
Anticipated expiration: 1978-11-21

Description

Nov. 21, 1961 Filed Sept. 23, 1957 T. F. ZUREK DOMESTIC APPLIANCE 2 Sheets-Sheet l INVENTOR.

THOMAS F. ZUREK QiLJ/W ATTORNEY Nov. 21, 1961 T. F. ZUREK 73,009,470

DOMESTIC APPLIANCE Filed Sept. 25, 1957 2 Sheets-Sheet 2 INVENTOR. THOMAS F. ZUREK iiM/AM ATTORN EY United States Patent Ofitice 3,009,470 Patented Nov. 21, 1961 3,009,470 DQMESTKC APPLIANCE Thomas F. Zurek, Chicago, 111., assignor to General Electric Company, a corporation of New York Filed Sept. 23, 1957, Ser. No. 685,447 7 Claims. (Cl. 134176) This invention relates to dishwashing apparatus, and, in particular, to an improved means for rotatably mounting a reaction spray device for receipt of a continuous supply of liquid under pressure.

Dishwashers designed especially for domestic use, employ a lower and an upper rack for suitably supporting the dishes and other articles to be washed. It was been found that improved washability results from the employment of two rotating liquid distribution devices, one of which is disposed below the lower rack and the other is arranged intermediate the lower and upper rao'k. By having the lower liquid distributor constructed as a reaction spray device, pursuant to which the reaction of jets issuing from extended arms of the device induce rotation, a very efi'icient Washing action can be obtained. In a form of dishwasher embodying the present invention and manufactured commercially by my assignee herein, the intermediate liquid distributor is automatically mechanically coupled to the lower reaction spray device, whereby it is mechanically rotated by said lower device and, in addition, receives its supply of liquid therefrom. The lower reaction spray device receives a continuous supply of liquid under moderate pressurefor example, approximately eleven pounds per square inchfrom a motor-driven pump which circulates liquid from the dishwasher tub to the conduit supplying the lower reaction spray device.

Domestic dishwashers are sometimes quite carelessly loaded. In spite of precautions taken in the design of the racks, it is possible so to load the racks that a plate or a cooking utensil may project into the path of rotation of the liquid distribution devices. In the said commercial form of dishwasher embodying the present invention, the intermediate liquid distributor is of a flat disk-like construction and is constructed of a relatively light-weight plastic material which has a somewhat yielding surface. Tests have shown that it is not possible to damage even an article of delicate china which may accidentally come into contact with the intermediate distributor. It is most advantageous, however, to make the lower distributor or reaction spray device entirely of metal in order to provide an adequate hub portion from which extend the relatively long tubular arms through which the liquid flows and issues into the tub through the variously disposed apertures. In order to minimize the possibility of damage if one of the tubular members should strike an article of china or the like, the lower reaction spray device is made as light in weight as it is practicable to do, and, in addition, the reaction jets are arranged so that there is actually a very low rotational torque produced thereby. In such an arrangement, there is not enough rotational effort or momentum present in the lowermost device to damage any article which may be in its path of rotation. This lightness and low torque characteristic introduced serious sealing problems at the juncture of the stationary supply conduit and the rotating hub. Even light weight seals of the so-called face type interposed substantial frictional resistance and, in addition, were subject to irregular wear, for during its operation the reaction spray device is per mitted and will experience some gyration about itsvertical axis in view of the turbulent conditions existing within the tub during the operation of the dishwasher.v

The present inventiondispenses with a seal between the hub and the stationary supply conduit. Instead, the

upper end wallof the conduitis machined soiasto be t plane and normal to the vertical axis, whereas the lower portion of the hub is beveled so as to provide an edge from which the wall of the hub extends upwardly and outwardly. The hub is mounted upon a pivot bearing which extends upwardly from the conduit into cooperative relation with a bearing provided in the hub, and the respective bearing elements are sized and disposed so that there is a minute clearance between the edge of the hub and the facing surface of the conduit. The bearing elements are further arranged so that under maximum deflection of the hub during its rotation, there will be no contact of the edge of the hub with the surface of the conduit. A further characteristic of the hub and conduit is that the inside wall of the hub is slightly larger in diameter than the inside wall of the conduit, whereby the edge defining the bottom of the hub is disposed intermediate the inner and outer Walls of the conduit. The effect of this arrangement is that heavier than water food soil, such as coffee grounds, which may have escaped the screened inlet of the circulation pump and thus pass into the hub, will be carried by momentum past the small gap between the hub and the conduit; whereas food soil which is of equal or less specific gravity than water will be carried through the gap between the hub and the conduit. The sharp edge of the hub forms a weir over which the liquid passes with substantial force. The disposition of the edge radially outwardly of the inner wall of the conduit provides sufficient turbulence to continually purge or scour the junction between the hub and the conduit, therefore preventing accumulations of food soil therebetween.

It is, therefore, a principal object of the present invention to provide a low-friction and substantially clog-proof means for rotatably mounting a reaction spray device on a conduit supplying the device with liquid under pressure.

It is another object of the invention to provide a reaction spray device and a supply conduit therefor, arranged to minimize the loss of liquid at the junction therebetween without employing mechanical sealing structures.

It is a further object of the invention to provide a mounting means for a reaction spray device which, although securely maintained against axial displacement with respect to a liquid supply conduit, will operate with minimum friction and escape of liquid.

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

FIG. 1 is a fragmentary front elevational view, partly in section, 'of a dishwashing apparatus embodying the present invention;

FIG. 2 is a fragmentary sectional elevation showing the preferred relationship between the reaction spray device and the supply conduit with the apparatus idle;

FIG. 3 is a view similar to FIGURE 2 but showing the relationship of the elements when the dishwasher is in operation;

FIG. 4 is an enlarged representation of the circled portion of FIG. 3 to schematically show the water action; and

FIG. 5 is a fragmentary elevational view of'the upper liquid distributor.

FIG. 1 shows in fragmentary front elevational section a dishwasher 1 embodying the present invention. The dishwasher comprises a cabinet 2 housing a tub 3 equipped with upper and lower-trackways 4 and 5 which slidably. accommodate the upper and lower racks 6 and 7. It will be understood-that the cabinet is provided with a.

door (not-shown) which is hinged for movement between a substantially vertical closed position and a substantially horizontal openposition. When the door'is in its open positiornthe respective racks may bedrawn forwardly Q with the dishes and other articles (not shown) which are to be washed.

The distribution of the washing liquid throughout the interior of the tub is accomplished by means of an upper liquid distributor 8 which is rotatably supported on a standard 9 fixed to the lower rack 7 so as to be intermediate the upper and lower racks, and a lower distributor 30, later described in detail. The water distribution device S is supplied with washing liquid through the tube 10 which about its lower portion has a support hub 11 of nylon or similar plastic material, shaped (see FIG. 2) to center within opening in the central portion of the lower rack 7. The tube It) terminates in a bell-shaped connection 12 through which the washing liquid enters said tube, as later described.

Heated water is introduced into the tub by way of a solenoid valve 13, the inlet 14 of which is connected to a suitable source of heated water, such as the hot water supply of the building. The discharge tube 15 from valve 13 is arranged to discharge into an inlet fixture 16 which communicates with the tub 3 through the port 17. During washing and rinsing operations, the liquid in the tub is continuously circulated by means of the centrifugal pump 18, driven by motor 19. Pump 18 connects with the tub by way of the inlet fitting 20. The inlet fitting is, of course, equipped with a suitable filter or strainer (not shown) to prevent as much as possible the recirculation of food soil particles which have been removed from the dishes and other articles during the washing operation. As a practical matter, of course, it is virtually impossible to make the filtering device completely effective and some small articles of soil, such as coffee grounds, fragments of cereals, and very small bits of leafyvegetables may find their way through the filtering device and will be redischarged into the tub. The outlet of the pump 18 communicates by way of the

fittings

21 and 22 with a vertical, rigid conduit 23. A pump 25, driven by a suitable electric motor 26, is employed for the discharge of the spent washing or rinsing liquid. The discharge pump communicates with the tub by way of a suitable drainage fitting 27 and discharges through a pipe 23 to a point of connection with the drainage or plumbing waste piping (not shown) of the building.

It will be understood that the operation of the fill-valve 13 and the respective circulation and

drainage pumps

18 and 25 are usually under the control of an automatic timing device (not shown), as is now well-known in the art. The precise time-cycle and the method of control thereof form no part of the present invention, and, therefore, they have been omitted from the present description.

The lower liquid distribution device which embodies the present invention is disposed for rotation relative to the conduit 23. As best appears in FIG. 1, the device 30 comprises a hub 31 from which extend the tubular arms or conduits 32. The arms are plugged at their respective ends, and are provided with

orifices

33 and 34 which operate to direct fan-like sprays or jets of liquid throughout the lower portion of the tub, thereby providing the washing operation for the articles in the lower rack. Certain of the jets-for example, the jets issuing from orifices 34are arranged so as to provide reaction forces which cause the distribution device 30 to rotate. At a pressure of about eleven pounds gage per square inch which the pump 18 supplies to the device 30, the reaction jets will effect a rotation at a speed of approximately 60 rpm. The liquid distribution device 30 is very light in weight. -In the present commercial form, the total weight of the lower distribution device is .54 pound, with approximately 60% thereof represented by the hub 31. This light weight, coupled with the relatively slow speed of rotation so reduces the momentum or rotative effort of the device 30 during its' operation thatthere is no possibility of damage to any article which may project from the lower rack 7 into the path of one of the rotating arms. As previously noted, the low forces of rotation introduced substantial problems as respects the mounting of the device 30 on the conduit 23. No available sealing device was found which would not interpose substantial resistance to rotation; and none was found which was not vulnerable to being clogged by the minute particles of food soil which may be entrained in the washing or rinsing liquid.

There are presently-known reaction spray devices which rotate freely on a liquid supply pipe and are devoid of scaled joints between the pipe and the device. Such prior-art devices, however, are characterized by substantial mass, relatively wide facing surfaces between the hub of the device and the supply pipe, and freedom to rise axially under the pressure of liquid being supplied thereto. In these devices, there is a substantial escape of liquid, which, of course, is non-productive as respects any washing effect. The present invention eliminates completely any sealing device and yet provides construction which reduces the escape of liquid to a minimum and precludes any possibility of jamming or clogging.

As best shown in FIG. 2, the conduit 23 is provided with a spider 35 which supports a pivot bearing 36. The bearing 36 is screw-threadedly affixed to the spider 35, and in order to obtain the desired vertical clearance between the hub 31 and the conduit 23, it is contemplated that shims 37 may be interposed between the bearing 36 and the spider 35. The bearing 36 has a conical end 38 and an enlarged shoulder 40. The hub 31 is formed with a socket 41 which comprises the central portion of an integral hub construction. The socket 41 has a conical seat 42 which rests upon the conical end 38 of the hearing 36.

It will be noted that the open upper end of conduit 23 is formed with a plane surface 43 which is precisely normal to the axis of the pivot bearing 36; and in this connection it will be understood that said bearing 36 and the socket 41 are coaxial with respect to their main structures. The lower rim 44 of the hub 31 is beveled at substantially a 45 degree angle to form a wall which extends upwardly and outwardly from the edge 45. Preferably, the edge is sharp; at least it should be of much less radial width that that of the wall of the conduit 23. Also, the inner wall of the hub at the edge should be radially outward of the inner Wall of the conduit, and I prefer the edge to be spaced outwardly about one'quarter of the thickness of the conduit wall. It is a feature of the construction that the edge 45 is spaced above the wall 43 a minute amount. In the commercial embodiment of the invention, the spacing is of the order of .015 inch. It will be understood that the shim or shims 37 will establish said spacing within relatively close limits. During the operation of the lower water distribution device 30, the very turbulent conditions within the dishwasher tub make it literally impossible for the device 30 to rotate in a precisely horizontal plane. However, it is considered important that the edge 45 not touch the surface 43 and, therefore, the socket 41 is arranged relative to the pivot 36 so that the inner wall of the socket will contact the external wall of the shoulder 40 before the hub 31 has tilted sufiiciently from the vertical to bring the edge 45 into contact with the facing surface 43 of the conduit. In practice, the relationship of the hub 41 to the shoulder 40 is such that the hub of the device 30 is permitted only about a one degree incline from the vertical. This inclination will not permit the edge 45 to touch the conduit or come within the inner area of the conduit.

In contrast to the previously described reaction spray devices which are arranged so that the device may rise or move axially with respect to the conduit, the present invention is adapted to arrangements in which the axial separation of the hub 31 from the conduit 23 is precluded. As shown in FIGS. 2 and 3, the upper end 46 of the hub 31 is open and there is a fiexiblecoupling 47 secured about said open end. The coupling 47 has an opening 48 which is substantially less in diameter than the opening 46 and the coupling 47 is disposed immediately beneath the bell portion 12 of the conduit supplying the upper rotor 8. When liquid under pressure enters the lower distributor 30, a substantial portion of it passes through the hub 31 and impinges upon the overhanging wall portion of the coupling 47. This expands the coupling upwardly, as shown in FIG. 3, and the coupling exerts a substantial pressure against the bottom of the bell 12; in fact, the pressure is such as to raise the conduit 10 relative to the lower rack 7, as clearly indicated in FIG. 3. It will be noted from FIG. 5, that the upper distributor 8 is rotatably engaged with the supporting structure 9 by means of a pivot bearing 48 and a socket 50. There is sufiicient vertical latitude in the bearing and socket relationship to permit the conduit 10 to be lifted before encountering the resistance of the supporting structure 9. Nevertheless, the downward component of forces exerted against the hub 31 maintains the base 42 of the socket 41 firmly on the conical end 38 of the bearing 36. Even under severe operating conditions, therefore, there is no separation of the edge 45 relative to the surface 43 beyond the spacing which is originally provided.

FIG. 4 illustrates somewhat schematically the liquid action at the juncture of the hub 31 and the conduit 23. Because of the very small clearance between these elements, only a minute portion of the liquidwhich is circulating at a rate of 30 gallons per minutecan find its way through the gap. The edge 45 constitutes a sharp weir over which the water escapes with substantial velocity and the location of said edge relative to the inner Wall of the conduit 23 results in a turbulence which continuously scours the adjacent wall areas and prevents the accumulation of food soil thereon. As soon as the liquid and any entrained particles of food soil carried thereby get beyond the edge 45, the outward and upward flare of the wall 44 insures that the food soil will escape from between the facing wall portions. It has been observed that only food soil which is equal to or lighter than water passes through the gap. Particles which are heavier than water, as for example, the illustrated coffe ground G, will project by their own momentum beyond the gap and, therefore, cannot lodge within or in front of the gap. This path of movement of the heavier than water solids is, of course, considerably aided by the fact that no part of the edge will come Within the conduit 23 even at maximum deflection of the hub 31. Ordinarily, the spacing of the edge 45 is outwardly of the inside wall of the conduit 23, with the result that there is a very abrupt corner which the heavier solids cannot negotiate.

Pursuant to the present invention, therefore, there is provided a rotatable connection between a reaction spray device and a supply conduit, in which a small, predetermined, gap is maintained at all times, minimizing friction and loss of liquid. Gelatinous or adhesive soil which may be in suspension in the liquid will not accumulate in the gap, nor will said particles come to rest therein.

While there has been described What is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the scope of the invention.

I claim:

1. For use in dishwashing apparatus having a tub to receive articles to be Washed, means for supplying said tub with a quantity of washing liquid, and pump means to draw said liquid from said tub and return it thereto under moderate pressure: the improvement in apparatus for distributing said liquid among the articles in said tub, comprising a conduit adapted to be fixed Within said tub to receive liquid from said pump, said conduit having an open-ended vertical portion, a water distribution hub member rotatably mounted on said conduit vertical portion to receive liquid directly therefrom, the end wall of said hub facing said conduit being beveled in an upward and outward direction to provide an uninterrupted sharp edge radially outward of the inner wall of said conduit portion, and pivot bearing means interposed between said conduit and said hub for coaxially mounting said hub in predetermined vertical space relation to the discharge end of said conduit while permitting limited gyration of said hub about the axis of rotation; the diameter and spacing of said hub edge relative to said conduit end wall being such that at maximum gyration of said hub there remains a vertical clearance between said edge and said end Wall and no part of said edge is within the area defined by the inner wall of said conduit.

2. For use in dishwashing apparatus having a tub to receive articles to be washed, means for supplying said tub with a quantity of Washing liquid, and pump means to draw said liquid from said tub and return it thereto under moderate pressure: the improvement in apparatus for distributing said liquid among the articles in said tub, comprising a conduit adapted to be fixed within said tub to receive liquid from said pump, said conduit having an open-ended vertical portion, a water distribution hub member rotatably mounted on said conduit vertical portion to receive liquid directly therefrom, the end wall of said hub facing said conduit being leveled in an upward and outward direction to provide an uninterrupted sharp edge radially outward of the inner wall of said conduit portion, pivot bearing means interposed between said conduit and said hub for coaxially mounting said hub .With the edge thereof in predetermined vertical space re lation to the discharge end of said conduit, means for effecting rotation of said hub upon flow of liquid thereinto, and means carried by said hub independent of said pivot bearing means for maintaining said spaced relationship during rotation of said hub.

3. The improvement in liquid distribution apparatus according to claim 2, in which the spacing between the bottom edge of the hub and the end wall of said conduit during rotation of said hub is of the order of 0.015".

4. In a dishwasher having a tub, and a rack removab'ly contained therein for receiving the articles to be washed, a rigid, open-ended conduit extending into said tub from a wall thereof, and means for supplying said conduit with liquid under pressure for discharge into said tub: the improvement comprising a liquid distribution device having a hub portion openly facing said conduit to receive liquid therefrom and tubular members communcating with said hub and extending therefrom, means for freely rotatably mounting said hub portion on said conduit intermediate said conduit and said rack, said means comprising a hearing member secured to and extending axially from said conduit, a bearing member secured to and axially disposed relative to said hub portion, the said bearing members being in interfitting relation and disposing said hub portion in spaced relation to the adjacent end wall surface of said conduit, and resilient means extending from said hub portion and engageable with structure carried by said rack only upon flow of liquid into said hub portion to maintain said. hub and said conduit in the said spacial relationship at all times during flow of liquid into said hub portion.

5. In a dishwasher having a tub and rack means removably contained therein for receiving articles to be washed, a rigid, open-ended conduit extending into said tub intermediate said rack and a wall of said tub, and means for supplying said conduit with liquid under pressure for discharge into said tub: the improvement comprising a liquid distribution device having a hub portion openly facing said conduit to receive liquid therefrom and apertured tubular members communicating with said hub' and extending therefrom, means for freely rotatably mounting said hub portion on said conduit intermediate said conduit and said rack, said means comprising a hearconduit, a bearing member secured to and axially disposed relative to said hub portion, the said bearing members mutually cooperating to dispose said hub portion in spaced relation to the adjacent end wall surface of said conduit, an expansible coupling member openly communicating with said hub portion to receive liquid under pressure therefrom, and a rigid structure carried by said rack means above said coupling member, whereby upon flow of liquid through said hub portion the expansion of said coupling member against said structure maintains said hub and said conduit in the said spaced relationship at all times during flow of liquid into said hub portion.

6. In a dishwasher having a tub and rack means removably contained therein for receiving articles to be washed, a rigid, open-ended conduit extending into said tub intermediate said rack and a wall of said tub, and means for supplying said conduit with liquid under pressure for discharge into said tub: the improvement comprising a liquid distribution device having a hub portion openly facing said conduit to receive liquid therefrom, tubular members communcating with said hub and extending therefrom, said tubular members having apertures arranged to produce reaction jets urging said hub into rotation, bearing structure on said hub portion and said conduit disposing said hub portion rotatably on said conduit in spaced relation to the adjacent end Wall surface of said conduit While permitting said hub portion to gyrate relative to said conduit, an expansible coupling member openly communicating with said hub portion to receive liquid under pressure therefrom, said coupling member having a flexible terminal portion, and a rigid structure carried by said rack means above said coupling member, whereby upon flow of liquid through said hub portion said coupling member expands to bring the said flexible portion thereof against said structure to maintain said hub and said conduit in substantially the said spaced a relationship while permitting gyrations of said hub portion.

7. In a dishwasher having a tub and rack means removably contained therein for receiving articles to be washed, a rigid, open-ended conduit extending into said tub intermediate said rack and a Wall of said tub, and means for supplying said conduit with liquid under pressure for discharge into said tub: the improvement comprising a liquid distribution device having a hub portion openly facing said conduit to receive liquid therefrom and liquid distribution members communicating with said hub and extending therefrom, means for freely rotatably mounting said hub portion on said conduit intermediate said conduit and said rack with said hub portion in spaced relation to the adjacent end wall surface of said conduit, means for effecting rotation of said hub member upon flow of liquid therethrough, an expansible coupling member openly communicating with said hub portion to receive liquid under pressure therefrom, and a rigid structure rotatably mounted within said tub in predetermined spaced relation to said coupling member, whereby upon flow of liquid through said hub portion said coupling member expands against said structure to maintain said hub and said conduit in the said spaced relationship while permitting rotation of said hub portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,577,225 Granger Mar. 16, 1926 1,594,054 Fiego July 27, 1926 1,628,818 Zademach May 17, 1927 1,668,582 Buckner May 8, 1928 2,500,404 Donnelly Mar. 14, 1950 2,681,658 Meeker et a1. June 22, 1954 2,731,296 Grifiith Jan. 17, 1956