US2000720A - Impeller - Google Patents

Description

f lg This invention relates"'to"jimpe11er`s,` more 'pary vticiiiariy to rotafyifiuid tcirculating impeners for yandy1f; has' for iis-object the y'provision pr an mi- 1 AVai well-known-type l'of dishwasher, n and :other lutensils to be washed aresupportedin f' suitable i@peri-workytmys or bsketsgjsported cleanse the dishes andkiitensiis placed-'within the, f f .,Ilgisshown; 'I'his-lowerfra'ckandfalsothe upperrv Y racks: v i

firai'tofis-thataisfacnmad y will 'Water to over substantially th sani rack as does theietheifbla p ranged tio "iinpelthe wateriipwardlyand circumfso area than has been possible Heijtoforel g l f `f "For a 'Amore' completepnderstand panyiifigjcirawingv inwhichFg: 1v isY a; fragmentary with this invention and rig 61s @pian view or@ therim'peller shownlin Fig; 15.15@ i '1' L Referring` morel particularly oEigs,`

washing chamberonvatsli Thevat is provided l opening" I2 .is provided 1in this bottom wall.' )The `openingel2,1'communicateslwch adrain conduit m` 1 Suitable reinovab1e-zopen-work',dish supporting l trays for racksil are provided` in the "lower-j: and 15 upper portions of the Vati-I0;on1ythe ;1ower; rack `The fiinpeller I5 israrrangedyto engageracks supnnied `abbi/,ef thje fimpelle; A Suitable clensing-rfluidrsych vas vedge 32 of the impeller.

through the trays. As shown, the impeller l5 comprises two blades v25 and 25 mounted upon a hub 21. 'I'he motor shaft IBa is provided with a square-shaped projection 28 which is received in a square-shaped aperture naxprovidedfor it in the hub. 'I'he hub is thus keyed'fto rotate with the shaft. The impeller is secured to the shaft by means of a suitable screw 29.

Each of the blades 25 and 26 is provided with a front fluid engaging face 30 that is curved downwardly and forwardly from its'upper` edge 3| to its lower edge 32 in the `direction of rota#y tion oi the impeller with gradually diminishing radii, -as clearly shown in Fig. 3; it being understood that the impeller will be rotated ina counterclockwisedirection, as viewed in Fig.. 2. More-f over, each front face 30, as shown in 1"ig.'2, has

` a transverse curvature forwardly in the direction of rotation of the impeller from the hub 2l to the outer vertical edge of the face, the-curvature having gradually diminishingfradii from the hub to the outer face,- and theradii becoming gradually shorter from the upper edge 3i .to the lower The impeller `is thus somewhat wider at the ltop than it is at the -bot tom. y

The impeller blade' 26 however is somewhat shorter than is the other blade 25. As shown in Fig.4, the height of the blade 26 is approximately equal to three-quarters of that of the blade 25.

Otherwise the blade25has substantially identically the same shape and form as has the correspending lower portion of the blade 25.

In the operation ofthe machine, whena washing fluid has been supplied-to and allowed to accumulatevin the lower portion-of the vat and the motor I6 has'been energized'to lrotate the impeller, the blades 25 andl 25 will engage the washing fluid to deflect lt'upwardly from the blades. The blades by virtue of their curvature fromv their vlower to their upper edges gradually increase the vertical deflection given the uid as it travels up the blades. Y Themomentum imparted to the the blades where it slides off of the blades. `At

and'circumferential velocity` so that-its trajectory upthrough the racks` assumes roughlyja this point the fluid has considerable upward vconical form.' The blades'of'- course arer 'continuously picking up` the washing fluid which gravitates to the bottom of the vat andcontinually impelling it upwardly `inthe manner previously described.

However in view of the fact that the blade V26 is somewhatshorter than the blade V25, but has the same shape and formas the corresponding lower part of the blade 25, the fluid which travels up the blade 26-will not be deflected upwardly in thevvertical direction to the same extent thatl the fluid is deflected upwardly by the blade 25. In other words, the blade 28 will not function t'o'deflect the fluidupwardly through as great an angle as does the blade'25.

The action of the two blades is clearly illus# trated in Fig. 4, In this figure, it will be observed that the fluid stream 35 that issues from the top edge 3i of the blade 25 has more nearly' a vertical trajectory than has the fluid stream 35 which issues from the top 3l vol' the shorter blade 25. The blade 25 thereforecauses the fluid to travel upwardly and circumferentially through the vat within a second body of uid which also moves upwardly and circumferentially through the vat ,radii of the blade 42.

from the blade however are not distinct bodies, but overlap considerably and of course are more or less deflected by the dishes and utensils placed within `the lower rack. The two masses however do cover a considerablyv greater rack area than would be possible if both bladeswere of the same shape and size, as hasbeen the practice heretofore.

.prises a hub 40 carryingv two blades 4| and l2 arranged symmetrically 'on thehub. The blade 4I, as shown,vis somewhat shorter than the blade 42. These twoblades have in general the same shape and formation as have the blades 2l and 25 of Figs. 1 to 4. In thisvcase however-the transverse radii of the short blade 4l are somewhat greater than the corresponding transverse y 'I'his curvature is clearly shown in the plan view of the ,impeller shown .in Fig.,6. By reason of lthis arrangement the shorter blade 4| `spreads the fluid over a wider path than does the corresponding shorter blade 26 of Figs. 1-4. The taller blade 42, as before, functions to hurl the fluid more directly upward in the vat.

- The shorter blade 4| picks up a little more fluid than does the taller blade 42, but releases it more quickly,` whilel the taller blade holds a slightly less amount of water for a somewhat greater period of time. This actiontends yto Ymaintain a balanced load on the impeller.

As a matter of fact,`in either form of the invention there is practically noincreased vibra- 28. These two masses of huid' tion in a dishwashingmachinewhen using the impellers arranged in accordance with this invention. A

' While we have shown'parti'cular embodiments of our invention, it will be understood of course that we do not wish to be limited thereto since 'many modifications may be made, and we therefore contemplate by the appended claims to cover any such modifications as fall within. the true spirit and scope of our invention.

What we claim as new and desire'to secure by Letters Patent of the `United States is:

1. In a dishwashlng machine provided with a vat and a dish-supporting rack within saidrvat.

a rotary fluid circulating impeller adapted to be operated within said vat below said rack comprlsing va hub, a pair of blades on said hub, each having a fluid engaging face curving downwardly and forwardly from its upper to its lower edge in the direction of 'rotation of the impeller with gradually diminishingl radii so that each blade when it engages washing fluid in said vat deflects said fluid .upwardly within said vat, the blades vgradually increasing the vertical deflection of said fluid as the fluid flows up the blades, the lower edges4 of said fluid engaging faces lying in subj stantially the same Vplane and the upper edge of the fluid engagin'gface of one of said blades being materially below the `upper `edge of the ,other so that fluid is Vdeflected upwardly by said one blade through a smaller vertical angle than the fluid deflected by the other blade.

2. In a dishwashing machine provided with a vat and a dish-supporting. rack` within said vat, 7s

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