U.S. patent number 3,596,834 [Application Number 04/845,144] was granted by the patent office on 1971-08-03 for self-reversing spray arm assembly for a washing appliance.
This patent grant is currently assigned to General Electric Company. Invention is credited to Donald S. Cushing.
United States Patent |
3,596,834 |
Cushing |
August 3, 1971 |
SELF-REVERSING SPRAY ARM ASSEMBLY FOR A WASHING APPLIANCE
Abstract
A spray arm in an automatic dishwashing machine is caused to
rotate on its axis from the resultant reactive force of a washing
liquid conducted through the body of the spray arm and then
outwardly as a jetstream. The jetstream is discharged from a nozzle
mounted to swivel between two drive positions on the body of the
spray arm. The nozzle is intermittently released so that it will
react to the force of the washing liquid discharged therefrom and
swivel from one of its drive positions to the other and thereby
reverse the direction of rotation of the spray arm.
Inventors: |
Cushing; Donald S. (Louisville,
KY) |
Assignee: |
General Electric Company
(N/A)
|
Family
ID: |
25294519 |
Appl.
No.: |
04/845,144 |
Filed: |
July 28, 1969 |
Current U.S.
Class: |
239/255; 239/227;
239/252; 239/251 |
Current CPC
Class: |
A47L
15/23 (20130101); A47L 15/18 (20130101) |
Current International
Class: |
A47L
15/14 (20060101); A47L 15/23 (20060101); A47L
15/18 (20060101); B05b 003/06 () |
Field of
Search: |
;239/251,255,252,253,227,264 ;134/176,179,180,181 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wood, Jr.; M. Henson
Assistant Examiner: Culp, Jr.; Thomas C.
Claims
I claim:
1. In an automatic article-washing machine having a washing chamber
and means for supplying pressurized washing fluid to said chamber,
an automatically reversing spray arm assembly comprising:
a. a hollow spray arm mounted for rotation and adapted to receive
said pressurized washing fluid therethrough,
b. a nozzle mounted to rotate on said spray arm, on an axis
perpendicular to the longitudinal axis of said spray arm, for
discharging the pressurized washing fluid into the wash chamber and
for rotating said spray arm on said perpendicular axis as a result
of the reactive forces of the fluid discharge therefrom,
c. locking means on said spray arm to maintain said nozzle
alternatively in at least two different fixed positions relative to
said arm, and
d. means for intermittently releasing said locking means whereby
said nozzle is permitted to rotate on said perpendicular axis, as a
result of the reactive force of the washing fluid discharge, from
one fixed position to another relative to said spray arm and
thereby cause said spray arm to reverse its direction of
rotation.
2. A reversing spray arm assembly in an automatic dishwashing
machine comprising:
a. a rotatable spray arm adapted to receive a pressurized
liquid,
b. a rotatable jet nozzle on said spray arm, adapted to receive
pressurized liquid from said spray arm, and continuously discharge
said liquid as it is received, for imparting rotative movement to
said spray arm from the resultant reactive force of liquid
discharge flow therefrom, and
c. said rotatable jet nozzle being adapted to move relative to said
spray arm and thereby change the direction of liquid discharge flow
therefrom and reverse the direction of rotation of said spray arm,
and
d. releasable locking means for engaging and maintaining said
nozzle in a fixed position relative to said spray arm, and means
for intermittently releasing said locking means so that said nozzle
will rotate on its axis in response to the resultant reactive force
of the liquid discharge flow.
3. The invention of claim 2, wherein said spray arm is a
longitudinally elongated structure having an internal liquid
passageway therethrough with discharge apertures spaced apart
therealong for directing respective streams of washing liquid
therefrom, said spray arm is adapted to be oscillated on its
longitudinal axis, and said releasable locking means permits
successive oscillations of said spray arm.
4. The invention of claim 2, wherein said spray arm is a
longitudinally elongated structure adapted for rotation on a
transverse axis.
5. A reversing spray arm assembly in an automatic dishwashing
machine comprising:
a. a rotatable spray arm adapted to receive a pressurized
fluid,
b. a fluid discharge means on said spray arm for imparting rotative
movement to said spray arm from the resultant reactive force of
fluid discharge flow therefrom, and
c. said fluid discharge means being adapted to move relative to
said spray arm and thereby change the direction of fluid discharge
flow therefrom and reverse the direction of rotation of said spray
arm,
d. releasable locking means for releasing and maintaining said
fluid discharge means in a fixed position relative to said spray
arm, and
e. means for intermittently releasing said locking means, including
means adapted to be intermittently electrically energized.
Description
BACKGROUND OF THE INVENTION
In recent years most manufactures of household automatic
dishwashing machines have adopted the general construction of a
cabinet defining an inner washing chamber having a reactive spray
arm rotatably mounted within the chamber. The spray arm is for the
purpose of distributing a recirculating flow of washing liquid on
soiled articles supported within the chamber, and is reactively
driven in rotation by means of the discharge force of recirculated
washing liquid emitted from at least one discharge port or orifice
on the spray arm. Generally, in today's automatic dishwashing
machine, the spray arm is mounted to rotate on a transverse
vertically oriented axis. This is particularly true of the
so-called portable dishwasher that is provided with means for
temporarily coupling it to the kitchen sink faucet and also with
respect to the type of dishwasher designed to be integrated with
the kitchen cabinetry so that its top wall forms a part of the
cabinet counter surface.
The purpose of mounting of the spray arm for rotation is to achieve
an improved pattern of washing liquid distribution in the washing
chamber. A further refinement that has been proposed to assure that
the pressurized washing liquid will contact all of the various
surfaces of the items stored in the supporting racks in the washing
chamber is the provision of means to successively reverse the
direction of rotation of the spray arm during the washing and
rinsing steps of the operational cycle. This reversal of rotation
of the spray arm can be employed both on the aforementioned type of
spray arm that is rotatable on a transverse vertically oriented
axis and also on the type of spray arm that is disposed
longitudinally for rotation or oscillation on a horizontal axis.
The latter type spray arm construction has been suggested
particularly for comparatively small counter top dishwasher
cabinets. It was from the realization of the comparative efficiency
of a reversing spray arm that the need developed for a
comparatively low cost and mechanically simplified means for
effecting the spray arm's sequential reversal.
It is therefore an objective of the present invention to provide a
simplified and reliable means of sequentially reversing a rotating
spray arm in an automatic dishwasher.
It is a further objective of the present invention to provide a
spray arm sequential reversal means that is adaptable in one form
to the type of spray arm that rotates on a transverse vertically
oriented axis, and in another form to the type of spray arm that is
adapted for rotation or oscillation on its horizontal longitudinal
axis.
It is a further objective of the present invention to provide a
simplified means for effecting sequential reversal of a rotatable
spray arm in an automatic dishwasher that may be automatically
controlled by the dishwasher's control means whereby each
successive reversal action will occur after a predetermined time
lapse.
A later version of the present invention is incorporated in the
structure of the invention set forth in an earlier filed copending
application, Ser. No. 799,574 of Lauren W. Guth entitled "Washer
With Self-Reversing Spray Arm Assembly."
SUMMARY OF THE INVENTION
In one form of my invention I provide, for an automatic
article-washing machine having a washing chamber and means for
supplying pressurized washing fluid to the chamber, a spray arm
assembly including a hollow spray arm adapted to rotate on a
transverse axis and to receive pressurized washing fluid through
the hollow body thereof. A rotatable jet nozzle is disposed on the
spray arm near one end thereof for discharging pressurized washing
fluid therefrom and into the washing chamber. The outlet end of the
jet nozzle is oriented such that the reactive force of the fluid
discharge therefrom will impart rotation to the spray arm. A
mechanism is provided in combination with the jet nozzle to lock
the jet nozzle in either of two drive positions on the spray arm
whereby the spray arm will be caused to rotate in one direction or
the other in response to the reactive force of the nozzle's fluid
discharge. The locking means is intermittently released so that the
jet nozzle will react to the force of its fluid discharge and
rotate on the spray arm from its then drive position to its other
drive position. The two drive positions are opposite each other so
that the rotating spray arm will be slowed, halted, and then caused
to move in counter rotation each time the nozzle swivels from one
drive position to the other.
In another form of the invention a spray arm assembly is provided
for an automatic article-washing machine and includes a hollow
elongated spray arm adapted for oscillation on its longitudinal
axis. A jet nozzle is mounted for rotation on the spray arm body
and receives pressurized washing fluid from the spray arm and
ejects it outwardly whereby the spray arm is caused to turn on its
longitudinal axis by the reactive force of the emitted fluid
discharge. A blocking mechanism is provided in combination with the
rotatable jet nozzle to hold the jet nozzle in either of two
oppositely facing operative positions whereby in one operative
position the nozzle is oriented to discharge its jet substantially
at a right angle to the axis of the spray arm and thereby cause the
spray arm to turn in one direction in response to the reactive
force of the jet discharge. The locking mechanism is automatically
released when the spray arm has rotated a predetermined distance on
its axis whereby the jet nozzle then rotates on its own axis
relative to the spray arm to the other drive position. The
aforementioned locking mechanism stops the rotating jet nozzle,
after it has completed substantially a half revolution, at a drive
position whereby its jet flow is directed outwardly in a direction
opposite to that of the first mentioned drive position. The
reactive force of the jet flow then causes the spray arm to reverse
its direction of rotation. The locking mechanism is intermittently
automatically released and repositioned, permitting the rotatable
jet nozzle to swivel between its two operating positions and
thereby impart a continually reversing or oscillatory rotative
motion to the spray arm.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side elevational view of an automatic dishwashing
machine having an oscillating spray arm assembly in accordance with
one form of my invention;
FIG. 2 is a plan view of the lower end of the washing chamber in
horizontal section in the washing machine shown in FIG. 1;
FIG. 3 is a substantially enlarged view of a portion of the spray
arm assembly first shown in FIG. 1, having portions thereof shown
in vertical section;
FIG. 4 is a fragmentary elevational view of a portion of the spray
arm assembly shown in FIG. 1;
FIG. 5 is a front elevational view of an automatic dishwashing
machine having a large section of the cabinet
FIG. 5 is a front elevational view of an automatic dishwashing
machine having a large section of the cabinet front side cut away
to illustrate an alternate form of the spray arm assembly of my
invention;
FIG. 6 is a fragmentary plan view of one end of the spray arm shown
in FIG. 5, here shown substantially enlarged; and
FIG. 7 is an enlarged elevational view of certain related
components of the spray arm assembly first shown in FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is illustrated an automatic dishwashing machine 11
including a cabinet 11 defining therein a washing chamber 12.
Access to the washing chamber 12 is obtained by opening a door 13
pivoted at its lower end and located on the front side of the
cabinet 11. Upper and lower dish-supporting racks 14 are supported
for slidable movement within the washing chamber 12 so that either
may be separately slid outwardly to extend through the cabinet's
front access opening to facilitate loading and unloading of
tableware therein. The lower end of the washing chamber 14 is
defined by a bottom wall or floor portion 15 that separates it from
a lower motor-pump compartment 16. Housed within the compartment 16
is a motor-pump assembly 17 including an electric motor 18 that
powers a pump means 19 for recirculating washing liquid to and from
the washing chamber 12 and for draining washing liquid from the
machine to the household sewage system.
The operational washing cycle of such a machine generally includes
a number of rinsing and washing steps and a final drying step. In a
dishwashing machine such as that shown in FIG. 1, heated water from
the household supply line is directed into the washing chamber 12
by a valve means (not shown). The water accumulates to a
predetermined level on the floor portion 15 and then a timer
control means (not shown) of the machine activates the electric
motor to drive the pump 19 in a recirculation operation. In the
recirculation operation, the accumulated washing liquid is drained
outwardly from the washing chamber 12 by means of a conduit 21
leading to the pump 19 and is then forced upwardly by the pump 19
through a conduit 22 leading to a hollow elongated longitudinally
disposed spray arm 25 located within the lower portion of the
washing chamber 12.
Generally, clean water is introduced into the machine for the wash
step and each rinse step, and detergent is added, by automatic
means (not shown), for the wash step. The term "washing liquid" is
therefore used herein in a generic sense to refer broadly to any
form of cleansing liquid utilized for recirculation in the machine.
The washing liquid is distributed from the spray arm 25 by means of
orifices 25a spaced therealong (FIG. 2) which separate the flow
into a spray pattern over the tableware contained in the racks 14.
The recirculation of the washing liquid from the washing chamber
12, through the pump and then through the spray arm, is continued
for a predetermined length of time after which the electrical
circuit to the motor 18 is automatically interrupted to halt the
pumping action. Thereafter, the motor 18 is automatically
reenergized in a reverse direction whereby the pump 19 pumps the
effluent from the washing chamber 12 and through a drain line 20 to
the household sewage system.
As shown in FIGS. 1 and 2, the bottom wall or floor portion 15 of
the chamber 12 is formed to have a downward depression generally
toward its center so that the accumulated liquid in the washing
chamber 12 will gravitate toward a drain opening 15a leading to the
drainage conduit 21. As shown most clearly in FIG. 3, one end of
the bottom wall 15 is formed with spaced-apart projections 15b
directly beneath one end of the spray arm 25. The upward
projections have a concave trough 15c formed therebetween and
beneath the spray arm end. The spray arm 25 is supported at each
end by suitable pillow blocks 26 to enable it to rotate about its
longitudinal axis as will be hereinafter further described.
In the form of the improved spray arm assembly of my invention
illustrated in FIGS. 3 and 4, the longitudinally elongated spray
arm 25 has a jet nozzle 30 mounted thereon for rotation on an axis
perpendicular to the axis of rotation of the spray arm 25. The jet
nozzle 30 has a tubular body whereby washing liquid can be received
therethrough from the hollow body of the spray arm 25 and ejected
outwardly into the washing chamber 12 of the dishwashing machine
10. The body of the nozzle 30 has a compound curved configuration,
in which the inner nozzle portion 31 extends perpendicularly
outwardly relative to the axis of the spray arm 25. An intermediate
nozzle body portion 33 extends from the outer end of the portion 31
and is disposed perpendicular to the axis of rotation of the jet
nozzle, which is the longitudinal axis of portion 31. An outer end
portion 34 of the nozzle 30 is a comparatively short portion
disposed with its axis perpendicular to the axis of the
intermediate body portion 33.
The jet discharge emitted from the open end of the body portion 34
will exert a reactive force or counterimpedus against the nozzle 30
and urge it to rotate about the axis of the major body portion 31.
The body of the nozzle 30 is preferably of a smooth tubular
construction having a constant diameter therethrough. The inner end
of the nozzle 30 is provided with a radially outwardly extending
annular flange portion 32 which serves to retain it in its mounted
position while permitting it to rotate in the intended manner. An
integral lateral projection or finger 35 extends outwardly from the
major body portion 31 of the nozzle 30 for a purpose hereafter
described.
The nozzle 30 is supported on the spray arm 35 by means of a
supporting member 36 having a curved saddle portion 37 shaped to
conform to the outer configuration of the spray arm 25. A hollow
cylindrical portion or collar 38 extends centrally outwardly from
the salle portion 37 and serves as a supportive socket for the
nozzle 30. The supporting member 36 may be fastened to the spray
arm body by means of rivets 39, and is disposed thereon in a
position whereby the opening through the collar 38 is in alignment
with the opening of similar size through the body of the spray arm
25 for both to accommodate portion 31 of the nozzle 30. It should
be noted that the tubular body portion of the nozzle 30 may be
formed from rigid plastic, with the lower end flange 32 being
formed separately and fixed in the position shown by use of a
suitable bonding agent or by screw threading to the nozzle. This
would be done after the tubular portion of the nozzle 30 has been
placed in its position within the collar 38 of the supporting
member 36.
A nozzle control rod or lever 40 constitutes a part of a locking
mechanism, in combination with the finger 35, that acts to prevent
the nozzle 30 from rotating continuously on its axis when washing
liquid is being received therethrough from the spray arm 25 and
discharged to the washing chamber 12. Lever 40 extends laterally
over the spray arm 25 and is pivotally attached to the side of the
collar 38 by a screw 46 that extends through an opening in an
intermediate lever portion 43 and thence into a threaded socket in
the sidewall of the collar 38. The lever 40 is curved at its
intermediate lever portion 43 and has a pair of upwardly projecting
lugs spaced apart relative to each other whereby a lug 44 is
disposed on one side of the jet nozzle 30, and a similar lug 45 is
disposed on the opposite side of the nozzle 30.
In the operation of the spray arm mechanism shown in FIGS. 1--4,
the lever 40 serves as a trigger or tripping lever for repeatedly
locking and releasing the rotatable nozzle 30. Reference to the
disposition of the components of the spray arm assembly in FIG. 3
shows that the finger 35, laterally jutting from the sidewall of
the nozzle 30, is abutting against lug 45 of the lever end portion
42. With the nozzle end portion 34 oriented to the right as shown
in FIG. 3, washing liquid discharged therefrom will tend to drive
the spray arm about its longitudinal axis in a counterclockwise
direction since the nozzle 30 is prevented from turning on the
spray arm because of the engagement of the finger 35 with the lug
45. As the counterclockwise rotation of the spray arm 25 proceeds,
the outer end of the lever arm portion 41 will be moved downwardly
so that it will strike an upwardly projecting boss 48. The boss 48
is formed in the washing machine's bottom wall 15 on one of the
floor projections 15b. When the lever arm end portion 41 strikes
the boss 48, the lever 40 will stop moving while the
counterclockwise rotation of the spray arm 25 continues, thus
causing a relative pivoting movement of the lever 40 relative to
the spray arm about the screw 46. In a relative sense, the lever 40
will pivot on the screw 46. The lever end portion 42 will move
relative to the nozzle 30 and thereby move the lug 45 out of
engagement with the nozzle finger 35. The nozzle 30 is then free to
rotate on its axis in response to the force of the jet discharge
emitted therefrom. When the nozzle 30 thus turns on its axis
relative to the spray arm 25, the finger 35 will be reengaged by
the lug 44. This will halt the nozzle 30 at its other drive
position wherein the nozzle end 34 will be disposed in a direction
opposite to that shown in FIG. 3. With the nozzle 30 prevented from
turning on its own axis relative to the spray arm 25, the impedus
of the jet discharge from the nozzle 30 is translated through to
the rotatable spray arm 25. The spray arm 25 is thus caused to
rotate in a clockwise direction until the lever end 42 swings
downwardly and contacts the boss 49. The lug 44 is thereby
disengaged from the nozzle finger 35 thus releasing the nozzle 30
for rotation and a complete repetition of the spray arm reversal
action. This reversal action will continue repeatedly, so long as
washing liquid is being pumped outwardly through the spray arm and
thence from the nozzle 30.
An alternate embodiment of my invention involves the utilization of
a rotatable jet nozzle disposed on the end of a spray arm to
reverse the rotation of the spray arm about a transverse spray arm
axis. In FIG. 5 there is illustrated an automatic dishwashing
machine 55 having a cabinet 56 defining an inner washing chamber
57. Access to the washing chamber 57 is obtained by opening a
substantially large front door 58 which is hinged along its lower
edge. With the front access door 58 in the open position, a pair of
upper and lower dish-supporting racks 59, movably mounted within
the washing chamber 57, can be manually pulled outwardly to extend
through the access opening to permit loading and unloading
tableware therein. The washing chamber 57 has a lower bottom wall
or floor portion 60 that separates it from a motor-pump compartment
61. Housed within the compartment 61 is a motor-pump assembly 62
including an electric motor 63 that drives a recirculation and
discharge pump 64. The washing chamber floor portion 60 is provided
with an upwardly humped portion 60a, and a pedestallike conduit 65
extends upwardly therethrough from the pump 68 to provide
recirculated washing liquid to a hollow spray arm 70. The spray arm
70 is rotatably supported on the upper end of the conduit 65 and
has a plurality of spaced-apart orifices 71 in the upper surface
thereof (FIG. 6) for providing a uniform spray pattern over
tableware contained in the racks 59 thereabove.
Just as described with reference to the dishwashing machine
illustrated in FIG. 1, water is directed into he washing chamber 57
by a valve means (not shown). After a timed interval, the
accumulated liquid is drained outwardly from the washing chamber 57
through a collecting sump 66 that carries it downwardly to a
conduit 67 and thence into the pump 64. The motor 63 is
automatically energized to drive the pump 64 and thereby pump the
washing liquid upwardly through the conduit 65, thence into the
spray arm 70, and then to the washing chamber 57 as a cascading
spray. At the end of each rinse or wash step in the operational
cycle of the dishwashing machine, a diverter valve (not shown) in
the housing of the pump 64 is automatically repositioned whereby
the washing liquid is pumped outwardly through a discharge conduit
68 to the household sewage system. The improved spray arm assembly
utilized in the dishwasher machine in FIG. 5 is shown in greater
detail in FIGS. 6 and 7.
FIG. 7 illustrates that an opening 72 is provided in the upper side
of the spray arm 70, adjacent one end of the spray arm, for
mounting a rotatable nozzle 73. The nozzle 73 is illustrated in
FIG. 7 as having a comparatively narrow intermediate neck portion
74 and a lower end annular flange portion 75. The portion of the
jet nozzle 73 that is above the intermediate neck portion 74 is
substantially the same as the configuration of the jet nozzle
described heretofore with reference to the first embodiment shown
in FIGS. 1 through 4, so it is referred to generally after as upper
nozzle portion 76. The jet nozzle 73 is provided with an integral
laterally extending finger 78 that operates cooperatively with a
pivotal plate 80 for locking and releasing nozzle 73 in the
operation of the spray assembly.
The plate 80 has a substantially large opening 81 therein, and
oppositely disposed portions of the plate 80 extend inwardly into
the area of the opening 81 to form shoulders 82 ad 83. The plate 80
is pivotally fastened by means of a rivetlike fastener 84 disposed
at one end of the plate 80, as shown in FIG. 6. FIG. 6 also shows
that the plate 80 is provided with an outward extending finger
portion 85. A vertically oriented stationary post 86 extends
upwardly from the floor portion 60 (FIG. 5) and has a blocklike
head portion 87 located at the upper end thereof, with an arm 88
extended from the head portion 87, for contacting the plate finger
85.
Assuming that when operation of the dishwashing machine shown in
FIG. 5 is initiated, the nozzle 73 is disposed in the drive
position presently shown in FIG. 6, washing liquid discharged from
the nozzle 73 exerts a counterforce thereagainst, and since the jet
nozzle is unable to turn because the finger 78 is in contact with
the shoulder 82, the force is translated through to the spray arm
70 and it is caused to rotate counterclockwise, as viewed from a
position looking downward thereon.
It will be noted with reference to FIG. 6 that counterclockwise
rotation of the spray arm 70 will cause the plate 80 to be pivoted
on its pivot point or fastener because the plate finger 85 will be
displaced by striking the stationary arm 88 extending outwardly
from he post head 87. Such pivotal action applied to the plate 80
will cause the shoulder 82 to move out of the path of the jet
nozzle finger 78, thus releasing the jet nozzle for rotation on its
vertical axis. The jet nozzle will then react to the force of the
jetstream emitted therefrom and rotate clockwise as viewed in FIG.
6, until the finger 78 engages against the shoulder 83. This
engagement will lock the nozzle 73 at is other operative position.
It will be noted that the plate 80 will move or pivot, when the
finger 85 strikes the arm 88, in a short arc limited by finger 83
striking the side of nozzle 73, such that the finger 85 remains in
engagement with the arm 88, thus halting the spray arm rotation.
The finger 78, being in the same horizontal plane as the plate 80,
tracks against the plate edge defining the periphery of the opening
81. Thus, as the nozzle 73 rotates, the nozzle finger 78 tends to
urge the plate back to the position shown in FIG. 6. The nozzle 73,
however, is now positioned to direct its stream in a direction
opposite to that of the drive position shown in FIG. 6, and will
therefore cause the spray arm 70 to rotate in a clockwise
direction. As the spray arm 70 is urged to rotate in a clockwise
direction the plate finger 85 again strikes the fixed arm 88 and
thereby pivots the plate 80 and causes the shoulder 83 to move away
from engagement with the nozzle finger 78. The nozzle 73 is then
free to react to its jet discharge and rotate back to the first
described drive position where the finger 78 again engages the
shoulder 82. The rotation of the spray arm 70 will be continuously
reversed as heretofore described so long as washing liquid is being
pumped through the spray arm 70 and outwardly through the nozzle
73.
Referring now to FIG. 7 it will be seen that the mechanism shown in
FIGS. 5 and 6 can be modified so that the reversal of the rotation
of the spray arm 70 can be automatically timer controlled. In other
words, instead of being reversed at each full revolution, as would
be true with the use of the stationary post 86, the mechanism may
be modified whereby the spray arm 70 can complete a predetermined
number of turns on its axis before the reversal action is
initiated.
FIG. 7 shows that a tubular post 89 may be mounted on the washing
chamber floor portion 60 and be provided with a vertically
reciprocable rod 90 carried within the post 89. The rod 90 has a
lower end that projects through an opening in the floor or bottom
wall 60 and has a laterally extending lower end portion 91 for
connecting it to a drive mechanism mounted beneath the chamber
bottom wall 60. The upper end of the rod 90 is provided with a head
portion thereon that is similar to the head portion 87 shown in
FIG. 6. A rigid arm 93 extends laterally from the head 92 for
engaging the finger 85 projecting outwardly from the pivotal plate
80. An annular flexible seal 95 is disposed within the upper end of
the post 89 for sealing around the rod 90 to prevent washing liquid
from leaking down through the post 89.
The drive mechanism for the rod 90, mounted beneath the chamber
bottom wall 60, includes an arcuate-shaped lever 96 pivotally
mounted at point 97. The lever 96 has an opening 98 provided at one
end thereof for engaging the lower end portion 91 of the rod 90.
The lever 96 is connected at its pivot point 97 through a rigid
bracket 100 extending downwardly from the undersurface of the
chamber bottom wall 60, and a wire spring 101 is provided to urge
the lever 96 normally in a clockwise direction on its pivot point
97, as viewed in FIG. 7, whereby the rod 90 will normally be urged
upwardly in the tubular post 89. A downward extending end 99 of the
lever 96 is interconnected by a rod 102 to a horizontally movable
armature 103 of a stationary solenoid 104.
It can be readily seen that electrical energization of the solenoid
104 retracts the rod 102 and pivots the lever 96 whereby the rod 90
is drawn downwardly. Such downward movement of the rod 90 places
the arm 93 into the path of movement of the finger 85 extended from
the plate 80. Interrupting the current through the solenoid 104
releases the armature 103 so that it moves outwardly and allows the
spring 101 to urge the lever 96 to the position shown in FIG. 7,
thereby raising the rod 90. This moves the arm 93 out of the path
of the finger 85.
Thus, the reversal action of the spray arm mechanism described
herein with reference to FIG. 6 can be automatically timer
controlled whereby the reversal action will take place after a
predetermined time lapse. For example, it may be considered
desirable to have the spray arm 70 rotate on its transverse axis in
one direction for a time interval of 15 seconds and then reverse it
so that it will rotate in the other direction for an interval of 15
seconds. The electrical circuit to the solenoid 104 can be adapted
to be closed by the timer control means (not shown) of the washing
machine whereby the solenoid will be momentarily energized every 15
seconds during each wash and rinsing step of the operational cycle
of the dishwashing machine.
As will be evident from the claims appended hereto, it is not
intended that the invention be limited only to the embodiments
described heretofore or to the particular detailed construction of
the examples illustrated in the accompanying drawings.
* * * * *