Note: Descriptions are shown in the official language in which they were submitted.
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In our United States Patent No. 4,135,531 dated January
23, 1979, and relating to a dishwasher operated solely by steam
and hot water, we disclosed a dishwasher in which a steam boiler
is used and hot wash water in the tank underlying the wash/rinse
compartment is entrained by the steam from the boiler and is directed
through wash spray arms against the dishes during the washlng cycle.
No motor or pump is needed for this purpose. Then during the rinse
cycle, ho~ rinse water from the boiler is fed directly to rinse
spray arms in the compartment for rinsing -the dishes and the pressure
within the boiler is sufficient to accomplish this without the need
for a motor driven pump.
An object of our present invention is to deliver cold wash
water into the tank underlying the wash/rinse compartment and use
steam to entrain and heat the cold water Eor delivering the heated
water at about 130 F., mixed with steam and forcing it against the
dishes for washing them. This hot water is returned to the tank by
gravity and is reused during the washing cycle.
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We have found that when the cold wash water is heated andpropelled by the steam it will have a tendency to cling and
flow over the dishes producing a more effective washing
operation than is possible in the standard dishwasher where
the pump propelled wash water has a tendency to strike the
dishes with a force sufficient to cause the water to bounce
off from the dishes. A detergent is fed into the wash
water.
A further object of our present invention is to
deliver cold rinse water into the tank after draining the
wash water therefrom and to steam heat and propel this
heated rinse water through tlle wash/rinse spray arm in the
compartment for rinsing the dishes during the rinse cycle.
A sanitizing agent and a rinse aid are fed into the rlnse
water and this permits the rinse water to sterilize the
dishes at a lower temperature of 120 F., rather than the
usual higher temperature of lB0 F., that would be required
if the sanitizing agent were not used. Also, the use of
the rinse aid in the rinse water will cause a complete
draining of the rinse water from the dishes without leaving
any water stains on the dishes, glasses or silverware.
Brief Description of~the Drawings
Figure I is a front elevation of the dishwasher.
Figure 2 is an enlarged side elevation of the
dishwasher when looking in the direction of the arrows 2-2
of Figure l;
Figure 3 is a transverse vertical section taken
along the line 3-3 of Figure 2~
Figure 4 is a side elevation of the dishwasher
from the opposite side to that of Figure 2 as indicated by
the arrows 4-4 of Figure 1.
~ igure 5 is an enlarged sectional view of the
circled portion 5 in Figure 3, and illustrates the
entraining action of the steam in withdrawing cold wash or
rinse water from the dishwasher tank and delivering it to
the wash/rinse spray arm, this depending upon whether the
dishwasher i5 in its washing or rinsing cycle. Also, the
entraining action created by the steam is su~ficient to
draw a liquid detergent from its container during the wash
cycle and to simultaneously draw a sterilizing agent and
rinse aid from their respective containers during the
rinsing cycle.
Figure 6 is a schematic showing of the entire
dishwasher and includes the timing cams that control the
various functions of the dishwasher during the washing and
rinsing cycles as well as the wiring diagram.
Figure 7 is a graph of the various timing cycles.
Description of the-Preferred Embodiment
In carrying out our invention we show a
dishwasher in Figure 3 that has a wash~rinse compartment A
g
for receiving a rack B of dishes to be washed, rinsed and
sterilized~ The compartment overlies a tank C that is
designed to receive cold wash water for the wash cycle and
to receive cold rinse water for the rinse cycle after the
wash water has been drained from the tank. A vertical
movable door D, see Figure 1, has a handle 1 by means of
which the operator can move the door downwardly into the
tank C, for opening the compartment A so that dish carrying
racks may be placed in the compartment and removed
therefrom.
A steam boiler is shown schematically at E, in
Figure 6 and a steam conveying pipe 2 leads from the boiler
to a steam jet nozzle 3. In Figure 5, we show a vertical
enlarged sectional view of the steam pipe and noæzle. A
cylindrical hollow body 4 is carried by the bottom wall 5
of the tank C, and the hollow body has a pipe 6 connected
thereto that communicates with a wash/rinse spray arm F,
see Figure 3. A water inlet 7 communicates with the hol~low
body 4, as shown in Figure 5 and this water inlet is
positioned just above the bottom wall of the tank C. We
will describe hereinafter how the flow of steam from the
boiler E and moving through the steam pipe 2 and steam jet
3 will create an entraining action in the hollow body 4 and
pipe 6 to entrain fluid from the tank C and cause it to
flow through the water inlet and enter the hollow body 4
and pipe 6 to mix with the steam and be conveyed to and
ejected from the wash/rinse arm F to wash or rinse the
dishes at the proper temperature during the wash and rinse
cycles. We have shown only a lower wash/rinse arm F,
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although there could also be an upper wash/rinse arm~ not
shown; with a pipe, not shown connecting it to the pipe 6
so that both arms would function at the same time~
Referring now to the schematic showing and wiring
diagram in Figure 6, it will be seen that a timer motor is
indicated at G, and this motor rotates a shaft 8. A cam 9
is mounted on the shaft. The timer motor is geared to
rotate the shaft 8 and cam 9 through one complete
revolution in a 90 second time period when the starting
switch 10 in Figure 1 is depressed. We do not wish to be
confined to any precise time interval but we have found
that the dishwasher will effectively washr rinse and
s~erilize the dishes in a time interval of 90 seconds. The
temporary closing of the timer switch will start the motor
G, and rotate the 90 second cam 9 to close a micro switch
11 and th~ motor shaft 8 will also start rotating a
wash/rinse cycle cam 12 to close a second micro switch 13.
When the timer motor circuit is closed, a circuit
will also be closed to a float switch 14 positioned in the
boiler E and if the water level in the boiler is below a
predetermined height the float switch will close a circuit
to a solenoid water valve 15, see Figure 6, that will
permit fresh water to enter the boiler E through the pipe
16 until the proper water level is reached at which point
the float valve will open and permit the solenoid valve t5
to close and stop the flow of water into the boiler. Water
heating elements 17 will heat the water in the boiler to
provide steam that is used during the washing and rinsing
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cycles. A pressure switch 18 is in communicatlon with the
steam boiler and when the proper pressure is reached, the
pressure switch will open and cut off the current to the
heating elements 18. In addition to the pressure switch
18, we make use of a safety switch 19 that will open the
circuit to the heat elements 17 when a predetermined
pressure within the boiler E is reached and the pressure
switch 18 fails to function. As a final precaution against
the steam boiler accidentally blowing up, we provide a
pressure pop-off valve 20 that is in direct communication
with the boiler through the pipe 21 in Figure 6. A
pressure gage 22 is in communication with the boiler E as
well as an air line relief valve 23.
The 90 second cam 9 will keep the micro switch
closed for that period of time and the wash cam 12 will
close the micro switch 13 for a time period of 35 seconds,
see Figure ~. Referring to the timing cycles in Figure 7,
the power ~raph line 24 is shown to be "ON" for the full 90
seconds when the starting switch 10 is closed. The water
fill cam 25 on the motor sha~t 8 is in a position to keep
the micro switch 26 closed and this will close an electric
circuit to a solenoid controlled water valve 27 to open the
valve and permit fresh cold water to flow from a water
supply pipe 2~ into the tank C, as shown in Figure 6. The
graph line 29 in Figure 7 shows that the fill valve cam 25
will keep the micro switch 26 closed for the first 55
seconds during the 90 seconds the dishwasher is operating.
Fresh cold water enters the tank C during this 55 second
period and then the solenoid valve 27 will open for 5
35~
seconds. A predetermined volume of cold rinse water is
delivered into the tank C for rinsing the dishes in the
compartment A.
It will be seen from the detergent graph line 30
that a liquid detergent is fed into the wash water i.n the
tank C, starting at the two second interval when the power
cycle is first turned "ON" and closing at the 5 second
interval on the graph, see Figure 7. In Figure 2, we show
a container H for holding a liquid detergent and a tube 31
extends from the container, see also Figure 6I to a common
tube 32 which communicates with the interior o:E the hollow
body 4, as shown in Figure 5. ~ detergent control cam 33
is mounted on the motor shaft 8 and controls a micro switch
34 that is normally closed in order to keep a detergent
solenoid valve 35 closed except for the 3 second period
shown by the graph line 30 in Figure 7. During the 3
second period when the solenoid valve is open, the steam
flowing through the jet 3 in Figure 5 will create a
sufficient entraininq action in the hollow body 4 to draw
the detergent fluid from the container H, through the
detergent line 31 controlled by the valve 35 and this
detergent will mix with the steam and wash water delivered
to the wash/rinse arm F by the pipe 6. The wash water with
the detergent will strike the dishes for washing them and
then will flow by gravity back into the tank where the wash
water will again be entrained through the water inlet 7 to
the hollow body 4 and again forced by the steam up through
the pipe 6 and out from the wash/rinse arm F, onto the
dishes, This washing detergent operation will continue for
the first 35 seconds of the 90 second wash/rinse allotted
wash cycle.
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At the end of the wash cycle a drain valve
control cam 36, on the motor shaft 8, see Figure 6, will
operate a micro switch 37 to open it and permit a solenoid
controlled drain valve 38 to open and allow the wash water
to drain from the tank C, through a drain pipe 39 leading
to a sewer. The pipe 39 also has an overflow pipe 40 in
the tank C to maintain the wash water at a predetermined
level. ~ drain valve graph line 41 in Figure 7 shows that
the drain valve will remain closed for the first 35 seconds
during the wash cycle and then will open for the next 25
seconds permitting the wash water to drain into the sewer.
Then the drain valve will close for the remainder o]E the 90
second operating time. The drain valve cam 36 has a 25
second low spot to cause the drain valve to operate in the
manner just described.
While the wash cycle of the dishwasher is on the
wash/rinse cam 12 hi~h portion a for the first 35 seconds
of the wash/rinse cycles, the steam line 2 will be open.
The graph line 42 in Figure 7 shows the steam line to be
open during this period of time. The wash/rinse cam 12 not
only controls the wash cycle for 35 seconds, but at the
same time the micro switch 13 in Fiqure 6 will close a
circuit to the solenoid controlled steam va~ve 43 to open
it and permit steam to flow through the pipe 2 and nozzle 3
to entrain wash water from the tank C and heat this water
to about 130 F., and force it out through the wash/rinse
spray arm F to effectively wash the dishes because this
wash water has the liquid detergent mixed with it.
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At the end of the wash cycle the wash/rinse cam
12 has a low portion b which will open the micro switch 13
and close the steam controlled solenoid valve 43. The
steam valve will remain closed for 25 seconds while the
drain valve 38 will be opened during this same period of
time, see the steam valve graph line 42 and the drain valve
graph line 41 in Figure 7. Just before the drain valve
closes, the fill valve 27, see also Figure 6, will be
opened for 5 seconds from the 55 second position to the 60
second position on the timing cycle graphs. Fresh cold
rinse water will flow through the pipe 28 and into the tank
C to flush the tank of its remaining wash water and to
deliver a required volume of Eresh rinse water into the
tank at which time the drain valve 38 will close. The
water fill cam ~5 through the micro switch 26 controls the
opening of the solenoid controlled water valve 27, when the
low portion c of the cam is reached and the valve 27 will
remain open for 5 seconds as also indicated by the graph
line 29 in Figure 7.
At the start of the rinse cycle (at the 60 second
position on the graph line 42, in Figure 7) the steam valve
43 will again be opened and steam will flow through the
pipe 2 from the boiler B and out through the nozzle to
entrain the cold rinse water from the tank C through the
inlet 7 and heat this rinse water to about 120F., and
force it through the wash/rinse spray arm F to rinse the
dishes. At the same time a sanitizing liquid agent valve
44, see Figure 6, and a rinse aid valve 45 will both open
since they are both controlled by a cam 46 in Figure 6, and
the cam has a low portion d which will open a micro switch
47 for only about three seconds, see the graph line 48 in
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the timing cycles chart in Figure 7. The wash/rinse cam 12
not only controls the wash cycle but also the rinse cycle
and the high portion e on the cam will close the micro
switch 13 for 30 seconds, see the graph line 42. During
this 30 second rinse cycle the steam controlled solenoid
valve 43 will be opened and steam will flow through the
pipe 2 and steam nozzle 3 to entrain the rinse water from
the tank C, into the water inlet 7 and hollow body 4 and
pipe 6 to heat the rinse water to about 120F., which is
sufficient to rinse and s~erilize the dishes because the
liquid saniti~ing agent has been fed into the rinse water
from the container J, see Figure 6, and into the common
tube 32 on its way into the hollow body 4 to mix with the
rinse water. The graph line 48 shows that the chlorine
controlled solenoid valve 44 will be opened only for 3
seconds at the start of the rinse cycle. A sufficient
volume of chlorine is fed into the rinse water to
efectively sterilize the dishes even though the water
temperature is about 120F., rather than the 180F. r
required iE no chlorine were used.
At the same time the chlorine solenoid valve 44
is opened for 3 seconds at the start of the rinse cycle a
rinse aid solenoid valve 50 will also be opened, see
Figures 2 and 6. The entraining action of the steam
flowing from the steam nozzle 3 will create a suction in
the hollow body 4 and common pipe 32, see Figure 5, to draw
liquid rinse aid from a tube 51 that is controlled by the
solenoid valve 45 and extends to a container K, in Figure
2, that holds the rinse aid. The graph line 48 in Figure 7
shows that the rinse aid line 51 will be open for 3 seconds
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at the start of the rinse cycle. The cam 46 on the motor
shaft 8 will close the micro switch 47, see Figure 6, and
the rinse aid solenoid valve 45 will close. When the
rinsing~ sterilizing and rinse aid operation is completed
the cam 9 will have completed its 90 second single
revolution and the cam will open the micro switch 11 and
shut of~ the power circuit. The rinse water can remain in
the tank C, and be used as the wash cycle for the next
washing and rinsing cycles when all of the various cycles
will be repea-ted.
The pressure ga~e 22 will indicate the steam
pressure in the boiler E, and will inform the operator when
he can start the dishwasher when the desired steam pressure
is reached. It is best to operate the dishwasher for the
complete 90 second period because the heated rinse water
remaining after the first operation of the machine now
becomes the wash water for the second 90 second operation
of the dishwasher.
When glasses are washed, they are placed in an
inverted position in the dish rack B, as shown in Figure
3. It is wise to flow rinse water over these inverted
glasses to remove any wash water that has detergent mixed
with it. We have shown in the schematic view of Figure 6,
a branch pipe 52 leading from the pipe 28 and c~mmunicating
with an upper spray arm L, mounted in the wash/rinse
compartment A. The opening of the solenoid water valve 27
for the 5 second period at the end of the wash cycle, see
the graph line 29 in Figure ?, will permit rinse water to
enter the tank C. At the same time part of this water will
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f 1QW through the branch pipe 52 and be sprayed from the
upper spray arm L onto the glasses and/or dishes for
removing any detergent wash water from them.
