US2960093A

US2960093A - Dishwashing machine

Info

Publication number: US2960093A
Application number: US783369A
Authority: US
Inventors: William J Heerlein
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1958-12-29
Filing date: 1958-12-29
Publication date: 1960-11-15
Anticipated expiration: 1977-11-15

Description

Filed Dec. 29, 1958 INVENTOR WILLJAM :1. uzanuzm EL /Jami ATTORNEY Nov. 15,1960 w. J. HEERLEIN 2,960,093

DISHWASHING MACHINE Filed Dec. 29, 1958 2 Sheets-Sheet 2 F'lGZ INVENTOR.

WILLIAM :r. HEERLEIN HIS ATT RNEY Unite DISHWASHING MACHINE Filed Dec. 29, 1958, Ser. No. 783,369

2 Claims. (Cl. 134-182) This invention relates to dishwashing machines, and more particularly to dishwashers of the type having reversible rotary water circulating and tub draining means effective to perform one function in one direction of rotation and the other function when rotating in the opposite direction.

The general object of the invention is to provide a dishwasher of this type in which the circular flow of water on the bottom of the dishwasher tub is partially interrupted in such a way that both washing action and tub draining action are improved.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Briefly stated, in accordance with one aspect of this invention there is provided a dishwasher including a rotary wash impeller and a drain pump inlet opening centrally located at the bottom of the dishwasher tub, a pump impeller connected for rotation with the wash impeller, and a generally radial vortex interrupting vane mounted on the bottom wall of the tub and positioned so that it directs Water into the pump inlet when the impellers rotate in the pumping direction and also increases the velocity and circulation rate of water circulated in the tub when the impellers rotate in the Washing direction.

For a better understanding of this invention reference may be made to the following description and the accompanying drawing in which:

Fig. 1 is a front elevation view of a dishwasher incorporating the present invention, some of the parts being broken away to show details of construction.

Fig. 2 is a fragmentary cross sectional view taken along the line 22 in Fig. 1.

Fig. 3 is an enlarged fragmentary cross section view taken along the line 33 in Fig. 2. v

Fig. 4 is an enlarged fragmentary cross sectional view taken along the line 44 in Fig. 3.

Referring to Fig. l of the drawing, there is shown a dishwasher having an enclosed washing compartment or tub I of generally rectangular configuration provided with a generally cone-shaped bottom wall 2. An upper rack 3 and a lower rack 4 are mounted in tub 1 and arranged to support dishes or the like during the washing operations. The dishwasher is provided with a water inlet valve 5 adapted to be connected to a water supply system, a water inlet conduit 6, and a fill funnel 7 communicating with the interior of tub 1, these components being mounted on the front wall of the tub and enclosed by a front panel 8. The top access opening of tub 1 is closed by hinged top cover 9 during washing operations, being held in closed position by a latch mechanism 10 which may include an interlock arrangement mechanically associated with a sequence control device or timer generally designated by the numeral 10a. A sheathed heating element 11 mounted on bottom wall 2 is provided to maintates Patent 2,960,093 Patented Nov. 15, 1960 tain wash water temperature and to heat the air in the tub during the drying period.

A drain pump 12 is supported beneath the tub 1, pump 12 having a generally circular inlet opening 13 communicating with the tub, an outlet 14 connected to drain conduit 15, and a housing 16 arranged to support a reversible electric motor 17. It will of course be understood that conduit 15 is adapted to be connected to a plumbing drain system, and that the conduit extends above the maximum static water level in tub 1. Thus water entering the tub is retained therein until discharged by pump 12. Pump 12 is secured to bottom wall 2 of the tub by any suitable means such as a pair of

semi-circular clamps

18 and 19 which cooperate with a flanged portion of the pump housing and an annular flange fixedly secured to tub wall 2. Shaft 20 of motor 17 projects upwardly through pump 12 and supports both a pump impeller 21 and a wash impeller 22 for rotation in both clockwise and counterclockwise directions.

Wash impeller 22 is provided with blades arranged to circulate water radially and upwardly throughout the washing compartment formed by tub I when the impeller rotates in the clockwise direction, as viewed in Fig. 2. Because of the configuration of the impeller blades, however, no water is circulated in the washing compartment when the wash impeller rotates in the counterclockwise direction although some rotary movement of water on the bottom wall 2 occurs under these circumstances. Pump 12 and in particular pump impeller 21 are arranged so that water in tub 1 is rapidly pumped out upon rotation of the two impellers and their common shaft 20 in the counterclockwise direction but that substantially no pumping action takes place when these parts rotate in the clockwise direction. One suitable dishwashing and pumping arrangement of this type is disclosed and claimed in application Serial No. 671,070 filed July 10, 1957, by Russell M. Sasnett et al. and assigned to the assignee of the present application. As disclosed therein, a complete dishwashing cycle includes a number of washing and rinsing steps followed by a drying period. At the beginning of each washing or rinsing step a predetermined quantity of water is admitted to tub 1 whereupon motor 17 is energized so as to rotate shaft 20 and the impellers connected thereto in a clockwise direction and thus circulate water throughout the washing compartment. When the charge of water used during this step is :to be discharged from the tub, motor 17 is reversed so as to drive shaft 2% in the counterclockwise direction thus rendering pump impeller 21 effective to pump water from the tub to discharge line 15. Ittis evident that the total time required for a complete dishwashing cycle depends to a considerable extent on the length of time required to fill and drain the Washing compartment as well as the time actually consumed during washing and rinsing operations. When it is considered that five or six Washing and rinsing steps are often utilized in currently produced dishwashers it will be seen that any appreciable reduction in the time required to completely drain the washing compartment may make a substantial contribution to the shortening of the complete washing cycle.

In accordance with the present invention, a vortex interrupting blade or vane 23 is mounted on bottom wall 2 of the washing compartment formed by tub I so as to partially interrupt the rotary or circular flow or water in the bottom of the tub during washing as well as pumpout operations. Vane 23 includes an upstanding baffle 24 and a horizontal mounting flange portion 25 which may be secured to bottom wall '2 by any suitable means such as screws 26. It will of course be understood that suitable sealing means for preventing leakage of water through the screw openings should be provided.

Vane 23 extends generally radially from pump inlet opening 13 with its radiallyoutermost end angularly displaced clockwise from a radial line passing through its innermost end to an extent such that the vane lies sub stantially along a line tangent to the edge of inlet opening-"1 3.- it has been'found that pump-out time may be minimized by positioning vane 23 inthis manner and that substantial departure from this angle of'in'clination (in either direction) results in an increase in pump-out time. Also, itis desirable that a portion of vane 23 be located directly below the path 'of rotation of wash impeller 22, since this arrangement provides improved washing action, as will be described below.

During'washing operations, when impeller 22 rotates in a clockwise direction, vane 23 performs two useful functions; First, vane 23 serves as a dam to reduce the velocity of the layer of water flowing in a circular pattern on bottom wall 2 and thus increases the relative velocity of the blades of impeller 22 with respect to the water particles with' which it comes into contact as it rotates. Hence, the energy imparted to the water particles by the impeller'is increased, and more vigorous washing'action results. In addition, a wall of water tends to build up along vane 23, and each time one of the blades of impeller 22 passes over the vane the quantity of wa ter thrown upwardly and outwardly by the blade'momen-tarily increases with the result that the-quantity of water thrown up by the bladesfrom this particular point is greater than that thrown up from any other point around the impeller path. It has been found that this increased water charge follows an upwardly inclined spiral path and is concentrated in a region in the upper portion of the washing compartment at a point approximately 180 degrees from vane 23. Thus it will be seen that a zone of maximum washing action may be provided in the upper rack area of the washing compartment and that racks for hard to wash items such as silverware may be located in this area.

While I have shown and described a particular embodiment of my invention, I do not desire the inventionto be limited to the particular construction disclosed, and I intend by the appended claims to cover all modifications within the true spirit and scope of my invention.

What I claim is:

1. A dishwasher comprising a tub including side and bottom walls forming a washing compartment, a wash impeller mounted in said tub adjacent the central portion of said bottom wall for rotation on a vertical axis,

vsaid wash impeller including a blade member arranged to circulate water radially and upwardly throughout said washing compartment when said wash impeller is rotated in a first direction, a pump mounted adjacent the bottom wall of said tub, said bottom wall having a centrally located generally circular opening therein concentric with the axis of said wash impeller and communicating with said pump so as to provide an inlet thereto, a pump impeller in said pump connected for rotation with said wash impeller and arranged to pump water from said tub only when rotating in a second direction opposite to said first direction, means for selectively rotating said impellers in said first and second directions, and a vortex interrupting vane mounted on said bottom wall adjacent said opening, said vane extending generally radially from said opening along a line substantially tangent to the edge thereof, the radially outermost end of said vane being angularly displaced in said first direction with respect to a radial line passing through its innermost end the vane extending upwardly from the bottom of the tub and terminating closely adjacent the path of rotation of the wash impeller, whereby the vane serves as a dam when the wash impeller is rotated in the first direction to reduce the velocity of the water and deflect it into the impeller to provide a charge of water concentrated at a predetermined position in the tub.

2. A dishwasher comprising a tub including side and bottom walls forming awashing compartment, a wash impeller mounted in'said tub adjacent the central portion of said bottom wall for rotation on a vertical axis, said wash impeller including a blade member arranged to circulate water radially and upwardly throughout said washing compartment when said wash'impeller is rotated in a first direction, a pump mounted adjacent the bottom wall of said tub, said' bottom wall having a centrally located generally'circular-opening therein concentric with the axis of said wash impeller and communicating with said pump so as to provide an inlet thereto, a pump impeller in said pump connected for rota-tion with said wash impeller and arranged to pump water from said tub only when rotating in a second direction opposite to said first direction, means for selectively rotating said impellers in said'first and second directions, and a vortex interrupting vane mounted on said bottom wall adjacent said opening, said vane extending generally radially from said opening along a line substantially tangent to the edge thereof, the radially outermost end of said vane being angularly displaced in said first direction with respect to a radial line passing through its innermost end, a portion of said vane underlying the path of rotation of said impeller,

portion of the vane terminating closely adjacent the underside of the path of rotation of the wash impeller, whereby the vane serves as a dam when the Wash impeller is rotated in the first direction to reduce the velocity of the water and deflect it into the impeller to provide a charge of water concentrated at a predetermined posi-' tion in the tub.

References Cited in the file of this patent UNITED STATES PATENTS