Dishwashing machine

Aug. 14, 1962

3,049,136

Η. E. VAN SCOYK

DISHWASHING MACHINE Filed Sept. 21, I960

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His Attorney

United States Patent Office „ 3,049,136

Patented Aug. 14, 1962

£.

washing liquid before it enters the pump and is redistributed over the surface of the dishes.

The water distribution system for the dishwashing chamber 12 includes a spray tube 32 rotatably mounted 5 within the chamber on a support bracket 34 and receiving water or washing liquid from a supply conduit 36 at the rear of the dishwasher. Disposed between the supply conduit 36 and the outlet of the pump 26 is a diverter valve 40 which is adapted by way of solenoid operation to direct 10 water either to the supply conduit 36 or drain 42 leading to any suitable sanitary sewer. Water for the distribution system is supplied by way of a water valve 44 which may be periodically energized in accordance with a sequential dishwasher timer shown generally at 46.

For heating water within the sump 24 and for selectively drying the dishes, an annular tubular sheathed heating element 48 is supported by terminal end portions on a wall of the sump and suspended within an upper portion of the sump so that it may be selectively inundated by water 20 supplied to the sump by the valve 44.

A dishwashing cycle suitable for use with the teachings of this invention will include the sequential timer 46 which will selectively operate the water valve 44, the motor 28 and the diverter valve 40. More particularly, a 25 dishwashing cycle may include a first period of washing wherein water is supplied to the sump 24 by the supply valve 44. After the sump 24 is filled to the desired level, the motor 28 is energized to direct water to the supply conduit 36 and the spray tube 32 which will rotate in 30 response to a swirl of water within the spray tube. Of course, a detergent of any suitable kind may be placed manually or mechanically within the dishwashing chamber 12 prior to the start of the dishwashing cycle. After the washing fluid of water and detergent is circulated 35 about the dishwashing chamber 12 for a predetermined period of time, the diverter valve 40 is actuated along with the pump motor 28 to direct the soiled wash water to drain. Then the diverter valve 40 is positioned to close the drain and the water supply valve 44 energized to 40 again refill the sump 24 with rinse water. This clear rinse water will be pumped to the spray tube 32 and will impinge over the surfaces of the dishes, thereby flushing the soiled washing liquid from the surface of the dishes. One or more rinsing operations may be provided in ac⁴⁵ cordance with conventional design procedures.

. Subsequent to the spray rinse distribution operation, the diverter valve. 40 is again actuated along with the pump motor 28 to direct the used rinse water to the drain line 42. Throughout the .various washing and spray rinse portions of the dishwashing cycle, the heater 48 may be energized intermittently in order to maintain the temperature of the water within the sump 24 at a desired level.

After the last spray rinse and after the water is drained from the sump 24, the heater 48 may be energized con^5o tinuously to dry the dishes as the last portion of the dishwashing cycle. In prior art dishwashers which have been installed in hard water areas, the droplets remaining on the dishes at the conclusion of the final rinse evaporate from the heat of the heating means 48 and leave an unθθ sightly mineral residue or hard water spot. It is to the elimination of this problem that the present invention is directed.

To facilitate, an improved dishwashing result, a steam bathing cycle is interposed between the final rinse spray 65 portion of the cycle and the dish drying portion of the cycle. For this reason a steam generator baffle 50 is adapted to be removably positioned on top of the heating element 48. The steam generator baffle 50 is so configured to form an annulus or ring-shaped, open center 70 saucer. This baffle 50 includes an upturned radially inner flange 52 and a radially outer slightly upwardly sloping outer flange 54. Between the flanges 52 and 54, and in3,049,136 DISHWASHING MACHINE

Howard E. Van Scoyk, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware

Filed Sept. 21, 1960, Ser. No. 57,500 12 Claims. (Cl. 134—95)

This invention relates to a domestic appliance and more particularly to a device for preventing the formation of hard water spots on dishes which have been washed in an automatic dishwasher.

In. certain localities of the country, the water supplied to dishwashing apparatus contains minerals and other foreign matter. This hard water presents a particular problem when used in conventional automatic dishwashers in that such water leaves spots on the dishes and other utensils when the dishwashing cycle is completed. These spots occur when droplets of water containing such foreign matter are evaporated during the drying portion of a dishwashing cycle.

Accordingly, it is an object of this invention to eliminate the formation of hard water spots on dishes or the like washed in an automatic dishwasher.

It is also an object of this invention to provide a steam bathing operation between the final rinse’and the drying period of a dishwashing cycle.

. A more specific object of this invention is the provision of an annular, saucer-shaped baffle resting in intimate contact with a dishwasher heating element for catching liquid during the washing and rinsing portions of a dishwashing cycle and subsequently vaporizing said liquid in a steam bathing operation, said baffle and said heating element cooperating after said steam bathing operation to create thermal drafts within the dishwasher which aid in drying.

Another object of this invention is to provide in a steam bathing apparatus for a dishwasher an annular baffle removably seated on a heating element and having a radially inner trough terminating outwardly in a gently sloping flange for flushing the trough and dissipating the heat of the heating element.

. Further objects and advantages of the present invention will.be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a schematic side sectional view of a dishwasher suitable for use with this invention;

FIGURE 2 is a fragmentary plan view taken along line 2—2 in FIGURE 1;

FIGURE 3 is a fragmentary sectional view taken along line 3—3 in FIGURE 2;

FIGURE 4 is an enlarged detail of the baffle section 4 seen in FIGURE 3; and

FIGURE 5 is a fragmentary perspective of another embodiment of this invention.

In accordance with this invention and with reference to FIGURE 1, a conventional domestic dishwasher 10 is illustrated. . The dishwasher 10 is comprised of a casing forming a. dishwashing chamber 12 in which are supported in any suitable fashion a pair of support baskets 14 and 16 for supporting dishes or the like during a dishwashing cycle. The dishwashing chamber 12 has a front opening 18 which is closed by a horizontally pivotally hinged door 20. The bottom of the dishwashing chamber 12 is closed by a bottom wall 22 in a portion of which is a water retaining generally conical sump 24. The sump 24 opens at its bottom end into the inlet of a pump 26 driven by a motor 28. Any suitable strainer 30 may be positioned over the inlet to the pump 26 for filtering the

3,049,136 heating element 48 rather than a porcelain surface. More particularly, the baffle 62 is comprised of a radially outer porcelain covered slightly conical sheet metal ring 64 which has a plurality of notches 66 and tabs 67 about its radially inner edge. A preformed annulus 68 of stainless steel is formed with a radially outer flange 70, a radially inner flange 72 and a trough 74 formed at the juncture of the flanges 70 and 72. The heighth of the flange or collar 72 will be determined in accordance with that necessary to produce the desired chimney effect. It may, of course, extend above the outer edge of flange 64. ,

The tabs 67 of the outer ring 64 overlap portions of the outer flange 70· of the stainless steel portion 68. Thus the adjacent annular ring portions 64 and 68 are joined by fastening means such as screws 76. Interposed between the head of the screw and the porcelain coated flange 64 is a washer 78 of felt or other suitable resilient material. Note that the assembly of the stain20 less steel ring 68 to the porcelain coated ring 64 leaves an opening 80 through which water will overflow from the trough 74. With this design, the inner flange 72 of the stainless steel portion may extend upwardly to the necessary distance required for proper chimney effect 25 action in the dishwashing chamber. The amount , of water retained in the trough 74 for the steam generation cycle will be determined by the heighth of the overflow opening 80. For more or less steam, the length and slope of the inner ring flange 70 may be adjusted to 30 facilitate the retention of more or less water in the annular trough.

It should now be seen that an improved steam generating device has been provided for a dishwasher which will facilitate proper temperature distribution within the 35 dishwashing chamber, shield the dishes from direct radiation, add to the life of the heating element, and produce a toroidal-shaped air flow in the dishwashing chamber to speed the drying process.

While the embodiments of the present invention as 40 herein disclosed, constitute preferred forms, it is to be understood that other forms might be adopted.