Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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1 WATER DELIVERY TUBE WIT~ RESERVOIR
2 BACKGROUND OF THE lNv~l.,ION
.
3 1. Fie1d of the Invention
4 The present invention is directed to washers, and more
particularly to washers having a valve for alternating the
6 flow of fluid between two fluid delivery tubes.
7 2. Description of the Related Art
8 In order to efficiently distribute wash fluid, many
9 washers have two spray arms disposed at different heights
within a wash area. Some of these washers direct the wash
11 fluid to the spray arms simultaneously, while other washers
12 direct the wash fluid to the spray arms alternately. If wash
13 fluid is directed to the spray arms alternately, the size of
14 the circulating pump and the wash fluid distribution circuit
can be reduced.
16 One system for alternating the flow of wash fluid to two
17 spray arms is the system disclosed in U.S. Patent No.
18 4,741,353 toi Milocco, incorporated herein by reference. A
19 method for controlling a washing cycle in a washer having a
Milocco system is disclosed in U.S. Patent No. 5,264,043 also
21 to Milocco, incorporated herein by reference. A washer
22 utilizing the Milocco system has upper and lower fluid
23 delivery tubes for respectively supplying wash fluid to the
24 upper and lower spray arms. The upper fluid delivery tube is
connected to the upper spray arm while the lower fluid
26 delivery tube is connected to the lower spray arm.
27 Accorbingly, the upper fluid delivery tube is substantially
28 longer than the lower fluid delivery-tube and, thusl--has a
29 substantially larger interior volume. Wash fluid is pumped
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1 through the upper and lower fluid delivery tubes by a pump
2 having an intake side and a delivery side. The flow of wash
3 fluid from the delivery side of the pump is controlled by a
4 valve. The valve includes a housing having an inlet connected
to the delivery side of the pump and upper and lower outlets
6 respectively connected to the inlets of the upper and lower
7 fluid delivery tubes. A valve closing element within the
8 housing has a stable unblocking position spaced from, but
9 aligned with the upper outlet.
In a first phase of operation, the pump ~irects wash
11 fluid against the closing element, moving the closing element
12 from the stable unblocking position to a first blocking
13 position. The first blocking position closes the upper outlet,
14 directing most of the wash fluid into the lower fluid delivery
tube. A bypass channel, however, allows some of the pumped
16 wash fluid to bypass the closing element and enter the upper
17 fluid delivery tube as well. When the pump is stopped, the
18 bypass wash fluid in the upper fluid delivery tube flows
19 downward and moves the blocking element from the first
blocking position to an unstable unblocking position spaced
21 from, but aligned with the lower fluid delivery tube. A second
22 phase of pump operation is started before the flow of bypass
23 wash fluid stops and the blocking element moves away from the
24 unstable unblocking position. In the second phase of
operation, wash fluid from the pump moves the closing element
26 from the unstable unblocking position to a second blocking
27 position closing the lower outlet, thereby directing the wash
28 fluid into the upper fluid delivery tube.
29 When the pump is stopped, wash fluid flows downward from
the upper fluid delivery tube. However, the pump is not
31 returned to the first phase of operation until after the upper
32 fluid delivery tube is drained. As a result, the closing
33 element will move to the stable unblocking position aligned
34 with the upper outlet. Thus, when the first phase of pump
opera~ion is started again, the closing element will again be
36 moved to the first blocking position, closing the upper outlet
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1 and directing most of the wash fluid into the lower fluid
2 delivery tube.
3 In the foregoing manner, wash fluid is alternately
4 directed to the upper and lower fluid delivery tubes and,
thus, the upper and lower spray arms. As can be appreciated,
6 the timing for the starting and stopping of the pump is
7 critical to the operation of the Milocco system. The timing
8 for starting phase two of the pump operation is especially
9 critical. If phase two of the pump operation is not started
before the wash fluid completely drains from the upper fluid
11 delivery tube, the closing element will move away from the
12 unstable unblocking position and move towards the stable
13 unblocking position. As a result, the closing element will
14 move to the first blocking position rather than the second
blocking position when phase two of the pump operation is
16 finally started, resulting in the blockage of the upper outlet
17 instead of the lower outlet.
i8 In the Milocco system, the amount of time required to
19 drain the upper fluid delivery tube is small. Accordingly, the
pause between phase one and phase two of the pump operation
21 is short. A short pause imposes a tight timing tolerance on
22 a controller for the pump. Inexpensive electro-mechanical
23 controllers often cannot meet the timing tolerance. Therefore,
24 expensive electronic controllers such as a microprocessor-
based programmable controllers are usually used to control a
26 Milocco systlem. For this reason, there is a need in the art
27 for an apparatus that increases the timing tolerance imposed
28 on a controller for a pump in a Milocco system. The present
29 invention is directed to such an apparatus.
' 8UMMARY OF THE lNv~ lON
31 In accordance with the present invention, a fluid
32 delivery tube is provided for use with a washer having a
33 sprayer and a valve with an inlet passage and first and second
34 outlef passages. The fluid delivery tube has an inlet section,
a reservoir section and an outlet section. The inlet section
36 has an inlet opening for communication with the second outlet
,
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1 passage of the valve. The outlet section has an outlet opening
2 for communication with the sprayer. The reservoir section is
3 located between the inlet section and the outlet section and
4 has a cross-sectional area that is greater than the cross-
sectional area of the inlet opening and greater than the
6 cross-sectional area of the outlet opening.
7 Also in accordance with the present invention, a washer
8 is provided having a fluid delivery tube, a hollow spray arm,
9 a pump for pumping fluid and a valve for directing fluid from
the pump. The valve includes a housing and a closing element.
11 The housing has an inlet passage in communication with the
12 pump and first and second outlet passages. The closing element
13 is located within the housing and is movable to a first
14 blocking position that substantially closes the second outlet
passage and is movable to a second blocking position that
16 closes the first outlet passage. The fluid delivery tube has
17 an inlet section, a reservoir section and an outlet section.
18 The inlet section has an inlet opening in communication with
19 the second outlet passage of the valve. The outlet section has
an outlet opening in communication with the interior of the
21 spray arm. The reservoir is located between the inlet section
22 and the outlet section and has a cross-sectional area that is
23 greater than the cross-sectional area of the inlet opening and
24 greater than the cross-sectional area of the outlet opening.
When the closing element is in the second blocking position,
26 the reservoir section conducts fluid from the inl-et section
27 to the'outlet section and thence the spray arm. When the
28 closing element is in the first blocking position, the
29 reservoir section holds fluid.
Also in accordance with the present invention, a washer
31 is provided having lower and upper delivery tubes, lower and
32 upper hollow spray arms for spraying fluid, a pump for pumping
33 fluid to the lower and upper spray arms and a valve. The
34 valve directs fluid from the pump to the lower and upper spray
arms ~o as to alternate fluid flow between the lower and upper
36 spray arms. The valve includes a housing, a closing element
37 and a bypass means. The housing has an inlet passage in
i
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1 communication with the pump and has first and second outlet
2 passages. The closing element within the housing moves in
3 response to a first stoppage of the pump from a blocking
4 position that substantially closes the second outlet passage
to an unstable unblocking position. The closing element is
6 held in the unstable unblocking position by a reverse flow of
7 fluid that enters the second outlet passage. The bypass means
8 allows fluid to exit the second outlet passage when the
9 closing element is in the blocking position.
The lower delivery tube has an inner section with an
11 inner opening in communication with the first outlet passage
12 of the vaive and has an outer section with an outer opening
13 in communication with the interior of the lower spray arm. The
14 upper delivery tube has a reservoir section, an inlet section
and an outlet section. The inlet section has an inlet opening
16 in communication with the second outlet passage of the valve,
17 while the outlet section has an outlet opening in
18 communication with the interior of the upper spray arm. The
19 upper delivery tube retains fluid that passes through thé
bypass means when the closing element is in the blocking
21 position. The upper delivery tube discharges the retained
22 fluid into the second outlet passage of the valve upon the
23 first stoppage of the pump and thereby creates the reverse
24 flow of fluid. The reservoir section provides sufficient
volume for retaining fluid when the closing element is in the
26 blocking position so as to increase the duration of the
27 reverse flow of fluid and therefore the amount of time the
28 closing element is in the unstable unblocking position.
29 ' BRIEF DESCRIPTION OF THE DRAWINGS
The features, aspects, and advantages of the present
31 invention wi~l become better understood with regard to the
32 following description, appended claims, and accompanying
33 drawings where:
34 ~ Fig. 1 shows a schematic view of a washer having a fluid
delivery tube in accordance with the present invention;
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1 Fig. 2 shows the delivery tube of the present invention;
2 and
3 Figs. 3 through 6 are enlarged schematic views
4 illustrating the different operating positions of a valve used
in conjunction with the fluid delivery tube of the present
6 invention.
7 DETATT~n DE8CRIPTION OF THE PREFERRED EMBODIMENT~
8 It should be noted that in the detailed description which
9 follows, identical components have the same reference
numerals, regardless whether they are shown in different
11 embodiments of the present invention. It should also be noted
12 that in order to clearly and concisely disclose the present
13 invention, the drawings may not necessarily be to scale and
14 certain features of the invention may be shown in somewhat
schematic form.
16 Referring now to Fig. 1, there is shown a washer 10, such
17 as a dishwasher, having the apparatus of the present
18 invention. The washer 10 generally includes a wash tub-20, a
19 first or lower spray arm 30, a second or upper spray arm 40,
a first or lower fluid delivery tube 50, a second or upper
2i fluid delivery tube 60, a pump 70 and a controller 80. The
22 wash tub 20 has a lower wash area 22 with a lower rack 24 and
23 an upper wash area 2~ with an upper rack 27. Both the lower
24 and upper racks 24, 27 hold objects to be washed, such as
dishes, silv,erware, glasses and cookware. The lower portion
26 of the wash tub 20 defines a sump 28 for collecting wash
27 fluid. Located in the sump is an inlet to the pump 70. The
28 pump 70 has an impeller 73 driven by a motor 75. An outlet 72
29 from the pump 70 is connected to a valve 100 which distributes
wash fluid to the lower and upper fluid delivery tubes 50,60.
31 The lowèr fluid delivery tube 50 has an inlet section 51
32 with an opening that is in communication with a first outlet
33 passage 150 of the valve 100. The lower fluid delivery tube
34 50 i~ substantially straight and is relatively short in
length. Accordingly, the interior volume of tKe lower fluid
36 delivery tube 50 is relatively small. An opening in an outlet
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1 section 52 of the lower fluid delivery tube 50 is in
2 communication with a central opening in the lower spray arm
3 30, which ig substantially hollow. Disposed along the top
4 surface of the lower spray arm 30 are a plurality of upwardly
S directed openings. Wash fluid delivered to the lower spray arm
6 30 through the lower fluid delivery tube 50 projects through
7 these openings in a series of upwardly directed sprays of wash
8 fluid. These upwardly-directed sprays enter the lower wash
9 area 22 and impinge upon the objects in the lower rack 24,
loosening food particles and other material adhering thereto.
11 The upper fluid delivery tube 60 has an inlet section 61
12 with an inlet opening that is in communication with a second
13 outlet passage 160 of the valve 100. An outlet opening in an
14 outlet section 62 of the upper fluid delivery tube 60 is in
lS communication with a central opening in the upper spray arm
16 40, which is also substantially hollow. Disposed along the
17 bottom surface of the upper spray arm 40 are a plurality of
18 downwardly directed openings. Wash fluid delivered to the
19 upper spray arm 40 through the upper fluid delivery tube 60
projects through these openings in a series of downwardly
21 directed sprays of wash fluid. These downwardly-directed
22 sprays enter the upper wash area 25 and impinge upon the
23 objects in the upper rack 27, loosening food particles and
24 other material adhering thereto.
Referring now to Fig. 2, there is shown a drawing of the
26 upper fluid delivery tube 60. In contrast to the lower fluid
27 delivery tube 50, the upper fluid delivery tube 60 is iong and
28 generally C-shaped. The inlet section 61 of the upper fluid
29 delivery tube 60 has a cylindrical portion that is
horizontally oriented and contains the inlet opening. After
31 the cylindrical portion, the inlet section 61 reduces into a
32 slightly more narrow tubular portion, which extends out
33 horizontally and then curves outward and upward so as to be
34 vertically positioned. After the tubular portion, the inlet
secti~n 61 expands and is joined with a reservoir~section 64,
36 which first extends upward and then curves inward so as to be
37 substantially horizontal. Accordingly, the reservoir section
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1 64 substantially has an inverted L-shape. After extending
2 inward for a distance, the reservoir section 64 is joined with
3 the outlet section 62, which narrows into an elliptical
4 portion. After the elliptical portion, the outlet section 62
expands slightly and turns downward in an end portion where
6 the outlet opening is located. The cross-sectional area of-the
7 reservoir section 64 is substantially greater than the cross-
8 sectionai area of either the inlet opening or the outlet
9 opening. In a preferred embodiment of the present invention,
the cross-sectional area of the reservoir section 64 is at
li- least twice the cross-sectional area of either the inlet
12 opening or the outlet opening.
13 Referring now to Fig.3, the valve 100 is shown as it
14 appears when the pump 70 has been idle for an extended period
of time. The valve 100 generally includes a housing 105 with
16 the second outlet passage 160, the first outlet passaqe 150
17 and an inlet passage 101 connected to the outlet 72 from the
18 pump 70. A bypass channel 110 leads from the inlet passage 101
19 to the outer portion of the second outlet passage 160. The
bypass channel 110 has a cross-sectional area substantially
21 smaller than either the first or second outlet passages
22 150,160.
23 Located within the valve chamber 100 is a spherical
24 closing element 180 resting on a guide 190 that slopes
downward from an upper end 191 located below the first outlet
26 passage 150 to a lower end 193 located below the second outlet
27 passage 160. The closing element 180 is made from a material
28 having a specific gravity greater than the wash fluid.
29 Accordingly, the closing element 180 naturally gravitates
towards the lower end 193. At the lower end 193, the closing
31 element 180 is stable and is not blocking either the second
32 outlet passage 160 or the first outlet passage 150, i.e., the
33 closing element is in a stable unblocking position. In the
34 stable unblocking position, the closing element 180 is aligned
belowlthe second outlet passage 160.
36 The valve 100 operates to alternately direct wash fluid
37 from the pump 70 to the lower and upper delivery tubes 50,60.
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1 The valve loO operates in response to a cycling of the pump
2 70 through four phases: a first phase of operation, a first
3 p~ase of non-operation, a second phase of operation and a
4 second phase of non-operation. The cycling of the pump-70 is
accomplished by the controller 80 (shown in Fig.1), which
6 starts and stops the motor 75. The controller 80 is an
7 electro-mechanical or electronic controller known in the prior
8 art. An example of such an electro-mechanical controller is
g the controller disclosed in assignee's application 08!383,055
which has just recently been allowed.
11 As stated above, the closing element 180 is in the stable
12 unblocking position when the pump 70 has been idle for an
13 extended period of time. When the pump 70 is subsequently
14 started by the controller 80, the pump 70 enters the first
phase of operation. In the first phase of operation, the pump
16 70 directs wash fluid against the closing element 180, moving
17 the closing element 18~ from the stable unblocking position
i8 to a first blocking position shown in Fig.4. In the first
19 blocking position, the closing element 180 is pressed against
the inner portion of the sec~nd outlet passage 160,
21 substantially blocking the flow of wash fluid through the
22 second outlet passage 160. As a result, most of the wash fluid
23 from the pump 70 flows through the first outlet passage 150
24 and the lower fluid delivery tube 50 and enters the lower
spray arm 30. The wash fluid then projects through the
26 upwardly-directed openings in the lower spray arm 30 and
27 enters the lower wash area 22.
28 Although most of the wash fluid flows through the lower
29 fluid delivery tube 50, some of the wash fluid is able to
bypass the closing element 180 and flow through the second
31 outlet passage 160 by travelling through the bypags channel
32 110. This bypass wash fluid enters and passes through the
33 inlet section 61 of the upper fluid delivery tube 60 and
34 proceeds into the reservoir section 64. The bypass wash fluid
conti~ues to enter the upper fluid delivery tube 60 and fill
36 the volume of the reservoir section 64 until the pump 70 is
37 stopped or the hydrostatic pressure exerted by the wash fluid
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1 in the upper fluid delivery tube 60 equals the pressur~'bf the
2 wash fluid entering the upper fluid delivery tube 60. The
3 size of the bypass channel 110 is limited in relation to the
4 capacity of the pump 70 so as to allow the hydrostatic
pressure of the wash fluid -in the upper fluid delivery tube
6 60 to stop the flow of bypass wash fluid before the bypass
7 wash fluid completely fills the upper fluid delivery tube 60
8 and exits through the upper spray arm 40.
9 It should be appreciated that the bypass channel 110 can
be replaced by other arrangements that permit a ~mal'l amount
11 of wash fluid to bypass the closing element 180, enter the
12 upper fluid delivery tube 60 and fill the reservoir section
13 64. For example, the inner portion of the second outlet
14 passage 160 can be made irregular so that the closing element
180 does not completely seal the inner portion when the
16 closing element 180 is in the first blocking position.
17 When the pump 70 is stopped by the controller 80, the
18 pump 70 enters the first phase of non-operation. At the
19 beginning of the first phase of non-operation, the bypass wash
fluid in the upper fluid delivery tube 60 and the wash fluid
21 in the lower fluid delivery tube 50 flow by gravity back into
22 the valve 100. In addition, gravity urges the closing element
23 180 to move away from the first blocking position of Fig.4.
24 The force of gravity on the closing element 180 would, by
itself, move the closing element 180 back to the stable
26 unblocking position. However, the flow of bypass wash'fluid
27 from the upper fluid delivery tube 60 exerts a substantial
28 hydrostatic pressure on the closing element 180 and, instead,
29 moves the closing element 180 to an unstable unblocking
position shown in Fig.5. The flow of wash fluid from the lower
31 fluid delivery tube 50 also exerts a force on the closing
32 element 180,!but this force is small since the amount of wash
33 fluid in the lower delivery tube 50 is negligible.
34 In the unstable unblocking position, the closing element
180 if resting on the upper end 191 of the guide 190 and is
36 spaced from, but aligned with, the first outlet passage 150.
37 This position is unstable because the closing element 180
, . , . ~ . .
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1 would, absent the flow of bypass wash fluid, slide along the
2 guide 190 and return to the stable unblocking position at the
3 lower end 193 of the guide 190. The pump i0, however, is
4 started by the controller 80 before the expiration of a first
period of time, which is the time it takes for the bypass wash
6 fluid to stop flowing from the upper fluid delivery tube 60.
-7 When the pump 70 is again started, the pump enters the second
8 phase of operation.
9 During the second phase of operation, the pump 70 directs
wash fluid against the closing element 180, moving the closing
11 element 180 from the unstable unblocking position shown in
12 Fig. 5 to a second blocking position shown in Fig.6. In the
i3 second blocking position, the closing element 180 is pressed
14 against the inner portion of the first outlet passage 150,
blocking the flow of wash fluid through the first outlet
16 passage 150. As a result, the wash fluid from the pump 70
17 flows through the second outlet passage 160 and into the upper
18 fluid delivery tube 60. The wash fluid exits the upper fluid
19 delivery tube 60 and enters the upper spray arm 40. The wash
fluid then projects through the downwardly-directed openings
21 in the upper spray arm 40 and enters the upper wash aréa 25.
22 During the second phase of operation of the pump 70, the upper
23 fluid delivery tube 60, including the reservoir section 64,
24 fills with wash fluid.
When the pump 70 is stopped by the controller 80, the
26 pump enters the second phase of non-operation. ~t the
27 beginning of the second phase of non-operation, the wash fluid
28 in the upper fluid delivery tube 60 flows by gravity ba~k into
29 the valve 100. In addition, gravity urges the closing element
180 to move away from the second blocking position. Once
31 again, the force of gravity on the closing element 180 would,
32 by itself, mbve the closing element 180 back to the stable
33 unblocking position. However, the closing element 180 is
34 prevented from moving past the unstable unblocking position
by thf hydrostatic pressure exerted by the flow of wash fluid
36 from the upper fluid delivery tube 60. If the pump 70 was
37 started before the flow of wash fluid from the upper fluid
-
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1 delivery tube 60 ceased, the closing element 180 would be
2 moved back to the second blocking position as occurs in the
3 second phase of operation. The duration of the second phase
4 of non-operation, however, is greater than a second period of
time, which is the time it takes for the wash fluid to drain
6 from the upper fluid delivery tube 60 and for the closing
7 element 180 to subsequently move to the stable unblocking
8 position. When the pump 70 is started, the pump 70 returns
9 to the first phase of operation and moves the closing element
180 back to the first blocking position.
11 In the foregoing manner, wash fluid is supplied to the
12 Iower spray arm 30 during the first phase of operation of the
13 pump 70 and wash fluid is supplied to the upper spray arm 40
14 during the second phase of operation of the pump 70. It should
be appreciated, however, that the controller 80 does not have
16 to be programmed to continuously cycle the pump 70 through the
17 four phases so as to continuously alternate the supply of wash
18 fluid to the lower and upper spray arms 30,40. The controller
19 80 can be programmed to alternate the supply of wash fluid to
the lower and upper spray arms 30,40 for a period of time and
21 then supply only one of the spray arms for the remainder of
22 the operation of the washer 10, or the controller 80 can be
23 programmed to only supply wash fluid to the lower spray arm
24 30. The foregoing is accomplished by programming the
controller 80 to stop progressing the pump 70 to subsequent
26 phases. It should be appreciated, however, that wash fluid
27 cannot be supplied only to the upper spray arm 40 because the
28 pump 70 has to progress through the first phase of operation
29 and first phase of non-operation in order to reach the second
phase of operation wherein wash fluid is supplied to the upper
31 spray arm 40.
32 The controller 80 can also be programmed to change the
33 duration wash fluid is supplied to a particular spray arm by
34 changing-the durations of the first and second phases of
opera~ion. The pauses between the changes in supply to the
36 spray arms, i.e., the first and second phases of non-
37 operation, can also be changed, but only to an extent. The
.
12
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1 pause between supplying wash fluid to the lower spray arm 30
2 and supplying wash fluid to the upper spray arm 40, i.e.~, the
3 first phase of non-operation, cannot be greater than the first
4 period of time. However, the first phase of non-operation can
be less than the first period of time. The pause between
6 supplying wash fluid to the upper spray arm 40 and supplying
7 wash fluid to the lower spray arm 30, i.e., the second phase
8 of non-operation, cannot be less than the second period of
9 time. However, the second phase of non-operation can have a
duration greater than the second period of time.
11 The stopping and starting of the pump 70 to switch the
12 flow of wash fluid from the lower spray arm 30 to the upper
13 spray arm 40 is the most stringent operating parameter that
14 has to be met by the controller 80 because the time between
the stopping and the starting of the pump 70 i.e., the first
16 period of time, is short. Accordingly, the first period of
17 time determines the timing tolerance of the controller 80.
18 Since the first period of time is the time it takes for the
19 bypass wash fluid to stop flowing from the upper fluid
delivery tube 60, the first period of time is a function of
21 the volume of the upper fluid delivery tube 60. The volume of
22 the upper fluid delivery tube 60 is significantly greater than
23 the volume of prior art upper fluid delivery tubes because of
24 the reservoir section 64. Accordingly, the time it takes for
bypass wash fluid to stop flowing from the upper fluid
26 delivery tube 60 of the present invention is significantly
27 greater than the time it takes for bypass wash fluid to stop
28 flowing from prior art upper fluid delivery tubes. As a
29 result, the timing tolerance imposed on the controller 80 is
greater than the timing tolerance imposed on the electronic
31 controllers used in prior art Milocco systems. This increase
32 in timing tolerance permits the controller 80 to be a
33 conventional electro-mechanical controller instead of a
'34 sophisticated electronic controller. Of course, a
sophi~ticated electronic controller can also be used in the
36 washer 10, which has the upper fluid delivery tube 60 of the
37 present invention.
13
....
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1 It is to be understood that the description of the
2 preferred embodiments are intended to be only illustrative,
~3 rather than exhaustive, of the present invention. Those of
4 ordinary skill will be able to make certain additions,
deletions, and/or modifications to the embodiments of the
6 disclosed subject matter without departing from the spirit of
7 the invention or its scope, as defined by the appended claims.
14
