Apparatus for spraying washing fluid

A spray assembly for a dishwasher includes a fluid pump and a spray tower. The spray tower includes a lower stationary member and an upper rotatable member and includes a fluid cavity therein. The rotatable member has at least one spray opening adjacent its upper end. A spray nozzle directs a stream of washing fluid upwardly into the spray tower and moves the stream of washing fluid in a circular pattern. The stream of water engages the upper rotatable member of the spray tower and the upper rotatable member rotates in response thereto. One form of the invention uses a deflecting surface on the rotatable member for causing rotational movement of the rotatable member and for causing precession of the rotatable member. Another modification of the present invention utilizes a pair of intermeshing gears for causing precession of the rotatable member.

BACKGROUND OF THE INVENTION 
This invention relates to a method and apparatus for spraying washing 
fluid. 
Many present dishwashers include a lower wash arm that rotates about a 
vertical axis. These dishwashers also usually include an upper or second 
level spray mechanism to provide a spray both upward and radially outward 
onto the articles within the dishwasher. 
Some prior art dishwashers utilize a fixed tower which extends upwardly 
from the lower wash arm and which directs washing fluid from the lower 
wash arm upwardly to a spray head at the top of the tower. One deficiency 
of this type of spray head is that the sprays usually travel in regular 
patterns, and therefore strike the same locations within the dishwasher 
during each rotation of the spray head. 
Therefore a primary object of the present invention is the provision of an 
improved method and apparatus for spraying washing fluid within a 
dishwasher. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which causes a spray head 
or diverter at the top of a vertical tower to rotate and create a rotating 
spray pattern within the dishwasher. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid within a dishwasher from 
the top of a tower in a pattern which is controlled, but which is random 
and contacts many different locations within the dishwasher. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which includes a rotating 
spray head or deflector at the top of a tower for providing a random spray 
pattern during the time that the spray head rotates. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which includes a spray 
head at the top of a tower which rotates at a different speed from the 
lower wash arm at the bottom of the tower. 
A further object of the present invention is to provide a spray head which 
will increase the dwell time of the spray pattern from the spray head in 
any area of the wash chamber. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which rotates a spray head 
at the top of a tower in a direction opposite from the direction of 
rotation of the spray arm. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which directs a rotating 
column of water up through the interior of a tower to a deflector spray 
head mounted at the top of the tower. 
A further object of the present invention is the provision of an improved 
method and apparatus for spraying washing fluid which is economical to 
manufacture, durable in use and efficient in operation. 
SUMMARY OF THE INVENTION 
The foregoing objects may be achieved by a spray assembly which includes a 
fluid pump and a spray tower having a lower stationary member and an upper 
rotatable member mounted for rotation about a first rotational axis with 
respect to the stationary member. The stationary member includes a fluid 
cavity therein and the rotatable member includes a spray opening in 
communication with the fluid cavity of the stationary member for receiving 
fluid therefrom and for directing the fluid outwardly away from the spray 
tower. A spray nozzle is connected to the fluid pump for receiving 
pressurized washing fluid therefrom and for directing a stream of the 
washing fluid into the fluid cavity of the stationary member and outwardly 
through the spray opening of the rotatable member. The spray nozzle is 
rotatable about a nozzle axis for moving the stream of washing fluid in a 
pattern which extends circumferentially around the first rotational axis 
of the rotatable member. 
In one modification of the invention the rotatable member includes a 
deflecting surface for receiving the stream of fluid and for causing 
rotation of the rotatable member about its first rotational axis in 
response to receiving the stream of fluid. In one species of this 
modification the position of the spray nozzle, the direction of the first 
rotational axis of the rotatable member, and the shape of the deflecting 
surface on the rotatable member are chosen so as to cause movement of the 
rotatable member in the same rotational direction as that of the spray 
nozzle. In another species of this modification the rotatable member 
rotates in the same direction and at the same speed as the rotation of the 
spray nozzle in response to engagement of the stream of washing fluid with 
the deflecting surface of the rotatable member. 
In another modification of the present invention a gear mechanism interacts 
with the rotation of the nozzle so as to cause rotation of the rotatable 
member in the opposite direction with respect to rotation of the spray 
nozzle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIGS. 1 and 2, a dishwasher 10 includes a dishwasher door 12 
which opens into a washing compartment 14 formed by a tub 16. In the 
bottom of tub 16 is a pump 18 which is connected to and provides washing 
fluid to a wash arm assembly 20. A lower rack 22 includes a spray tower 
24, which when rack 22 is inserted into the dishwasher 10 registers above 
the vertical rotational axis of the wash arm assembly 20. Also included 
within the washing compartment 14 above the top of spray tower 24 is an 
upper rack 26. 
The structure of wash arm assembly 20 is shown in FIG. 4 in cross-section. 
A wash arm manifold 28 encloses a cylindrical cavity 30 for receiving 
pressurized washing fluid from pump 18. A plurality of radial ports 32 
extend radially outwardly from cavity 30 for introducing pressurized fluid 
from cavity 30 into spray arm cavities 36 which are within filter spray 
arms 34. Filter spray arms 34 are rotatably mounted within the housing of 
pump 18 and are adapted to deliver washing fluid to backwash the filter 
within the pump in conventional fashion. Filter spray arms 34 are 
connected to a central filter spray hub 38 which is keyed to and rotates 
with the wash arm manifold 28. 
Wash arm manifold 28 includes adjacent its upper end an upwardly facing 
shoulder 40. Extending upwardly from shoulder 40 is a threaded shank 42 
having a plurality of radially extending vanes 44 centrally mounted 
therein. At the center of the radial vanes 44 is a central sleeve 46 which 
rotates about the shank 52 of an axle bolt 48. Threaded over the upper end 
of axle bolt 48 is a cap 50 and extending downwardly therefrom is the 
shank 52 about which the wash arm manifold 28 rotates. At the lower end of 
shank 52 is a nut 54 integrally formed as part of axle bolt 48. Axle bolt 
48 continues downwardly from nut 54 and is threadably contained within a 
shaft 56 which supports the wash arm manifold 28. 
Wash arm assembly 20 also includes a wash arm 58 having a pair of opposed 
wash arm cavities 60. Wash arm 58 includes a central opening 62. 
As best shown in FIG. 10, spray nozzle 64 includes an angled spout 66 
having an angled spray port 68 therein. Nozzle 64 also includes an annular 
flange 70 and a depending finger 72 extending downwardly from the annular 
flange 70. Spray nozzle 64 rests upon the upper edges of radial vanes 44, 
and depending finger 72 protrudes downwardly between the radial vanes 44. 
A wash arm cap 74 includes a top flange 76 and a depending sleeve or 
cylinder 78. Within sleeve 78 is a cap cavity 80, and a plurality of ports 
82 provide communication from cap cavity 80 into the wash arm cavities 60. 
Sleeve 78 of wash arm cap 74 includes threads 84 which threadably engage 
threaded shank 42 of wash arm manifold 28. Wash arm cap 74 includes a jump 
up opening 86 through which the angled spout 66 of spray nozzle 64 can 
jump upwardly. The annular flange 70 of spray nozzle 64 prevents the spray 
nozzle 64 from passing completely through and provides an annular seal 
around the jump up opening 86. The depending finger 72 of spray nozzle 64 
causes the spray nozzle 64 to drop freely downwardly to its lower position 
shown in FIG. 4 from its elevated position shown in FIG. 5 without 
becoming lodged or misaligned within the interior of the cap cavity 80. 
The operation of wash arm 58 commences when pump 18 is activated to 
introduce washing fluid under pressure into the cylindrical cavity 30 of 
wash arm manifold 28. This fluid engages the annular flange 70 of spray 
nozzle 64 and forces it to jump upwardly from its lower position shown in 
FIG. 4 to its elevated position shown in FIG. 5. At the same time washing 
fluid passes under pressure from the cap cavity 80 through the ports 82 
into the wash arm cavities 60. Wash arm 58 is provided with a plurality of 
jet spray openings (not shown) which permit the spraying of washing fluid 
from wash arm cavities 60 onto articles being cleaned. 
Pressurized washing fluid also passes through angled spray port 68 in the 
direction shown by arrows 87 in FIG. 5. 
Spray tower 24 includes a base flange 88 which is adapted to fit beneath 
the cross members of lower rack 22 in such a manner as to secure the spray 
tower 24 in a stationary position registered above spray nozzle 64. Tower 
24 also includes an upstanding tower tube 90 having an elongated 
upstanding tube cavity 92 which is lined with a plurality of upstanding 
ribs 94. At the upper end of tower tube 90 are a plurality of radially 
extending vanes 96 which are connected at their inner ends by a central 
section 98. A bolt 100 has a lower threaded end 102 which is threaded 
within central section 98. Immediately above central section 98 on bolt 
100 is a nut 104 and extending upwardly therefrom is a shank 106. 
The upper ends of the upstanding ribs 94 and the vanes 96 are spaced 
somewhat below the uppermost end of the spray tower 24. An annular ring 97 
is formed at the upper ends of the ribs 94 and vanes 96 and extends just 
slightly radially into the inside diameter of the tube cavity 92 at that 
level. As washing fluid moves along the ribs 94 and toward the spray head 
108, the washing fluid will encounter a portion of the annular ring 97 and 
will be directed slightly toward the center line of spray tower 24 just 
prior to contact with the deflector subsurfaces 116. It has been found 
that redirecting the spray with the annular ring 97 enhances the shape of 
the washing fluid stream as it flows off the subsurfaces 116 providing a 
more active washing fluid stream for contact with the items being washed. 
As further shown in FIGS. 3, 4 and 5, spray tower 24 includes a pair of 
forwardly facing apertures 95. These apertures 95 specifically direct a 
pair of fluid jets forwardly through the handle opening of the silverware 
basket 99 to enhance the cleaning of utensil portions that extend upwardly 
above the top edge of the silverware basket 99. 
A rotatable member is formed by a diverter or spray head 108 which includes 
a bottom wall 110 having a swivel opening 112 therein. Extending around 
the circumference of diverter 108 is a deflector surface 114 which is 
comprised of a plurality of deflector subsurfaces 116 (FIG. 6) which 
extend radially outwardly from the swivel opening 112. Each of the 
deflector surfaces 116 has a cross-sectional shape which is in the form of 
an inverted U, but each of the deflector subsurfaces 116 is slightly 
different in shape from the others so as to deflect a spray pattern which 
is slightly different from the spray pattern created by the other 
deflector surfaces. A vertical port 118 extends vertically through 
diverter 108 adjacent the outer periphery thereof and is in registered 
alignment with a vertical port 122 of a diverter cap 120 which is 
detachably secured over the top of diverter 108. The aligned vertical 
ports 118 and 122 provide a washing fluid stream directly to preselected 
areas in the upper rack 26. A cap nut 124 is threaded over the upper end 
of bolt 100, and exposes a length of shank 106. 
An important feature of the present invention is the fact that the swivel 
opening 112 is slightly larger than the diameter of shank 106 as is 
illustrated most clearly in FIGS. 7 and 8. This permits the diverter 108 
to tilt with respect to its mounting on shank 106 in the manner shown in 
FIGS. 7 and 8. While in the preferred embodiment, the tilt angle of the 
diverter 108 is about 7.degree. from vertical, the present invention is 
not to be limited to this specific angle. Swivel opening 112 also permits 
the diverter 108 to rotate with respect to shank 106. The third type of 
movement permitted is illustrated by the initial lowered position of 
diverter 108 shown in FIG. 4 and the elevated position of diverter 108 
shown in FIGS. 5, 7 and 8. 
The operation of the wash arm 58 and the spray nozzle 64 have been 
described above. This results in a stream of washing fluid exiting from 
the angled spray port 68 of spray nozzle 64 at an angle of inclination 
similar to that shown by arrows 87 in FIG. 5. The column of water strikes 
the interior surface of tower tube 90 and is directed upwardly by the ribs 
94 which extend upwardly generally parallel to one another within the 
interior surface of tube cavity 92. 
When the column of water exits the top of spray tower 24 it engages a 
portion of the deflector subsurfaces 116 and causes the diverter 108 to 
move from its lowered position shown in FIG. 4 to its elevated tilted 
position shown in FIG. 5. As indicated by the arrows 89 the column of 
water is diverted radially outward by the subsurfaces 116 in a direction 
which extends upward and radially away from the spray tower 24. 
Because wash arm 58 is rotating and consequently spray nozzle 64 is also 
rotating, the column of water represented by arrows 87 moves around the 
interior circular surface of spray tower 24 in a circular pattern which 
surrounds and is spaced radially outwardly from the vertical central axis 
of spray tower 24. This circular movement also causes the spray column to 
move around the circular deflector surface 114 so that it engages the 
different subsurfaces 116. This causes the tilting axis of the diverter 
108 to rotate in a cone shaped pattern. Also, the circular movement of the 
spray column cooperates with the subsurfaces 116 to cause the diverter to 
precess in a rotational direction which is the same as the direction of 
circular movement of the fluid column within spray tower 24. As used 
herein, the term "precession" refers to the above described complex motion 
executed by the rotating diverter 108 when subjected to a torque tending 
to change its axis of rotation marked by a conical locus of the axis. This 
results in the diverter 108 rotating in the same direction as the 
rotational direction of wash arm 58. Diverter 108 also rotates at a 
velocity which is slower than the rotational velocity of the wash arm 58 
providing a lengthened dwell time of the deflected stream or spray pattern 
upon articles placed in upper rack 26 for cleaning. 
Furthermore, partially because each of the subsurfaces 116 has a slightly 
different contour, the spray pattern created and designated by the arrows 
89 is random. Thus, if a glass for example is positioned in upper rack 26, 
the spray pattern strikes the glass at a randomly different spot and for 
an extended period each time the column of water rotates around the 
interior of spray tower 24. This random action is caused by the many 
unique contours of the subsurfaces 116 and by the fact that the diverter 
108 has a conical locus of motion and a velocity which is different from 
the rotational velocity of the spray column within spray tower 24 caused 
by the rotation of wash arm 58 and spray nozzle 64. The term precession as 
used herein refers to the complex motion executed by the rotating diverter 
108 being subjected to a torque tending to change its axis of rotation (as 
a result of the column of washing fluid) marked for constant speed of 
rotation and constant magnitude of the applied torque by a conical locus 
of the rotational diverter axis of the diverter 108. 
In summary, as the spray nozzle 64 rotates with the wash arm 58, a stream 
of fluid identified by numeral 87 impinges on the inner diameter of spray 
tower 24 and into the spaces between ribs 94 so that the stream of fluid 
87 rotates at the same rotational velocity as the wash arm 58. Toward the 
top of the spray tower 24, the stream of fluid 87 contacts the annular 
ring 97 and is deflected slightly inward as shown in FIG. 8a. The stream 
of fluid 87 continues upward and contacts the deflecting subsurfaces 116 
moving the diverter 108 upward while tilting it on the shank 106. As the 
stream of fluid 87 rotates and contacts the deflecting subsurfaces 116, 
the stream of fluid identified by numeral 89 leaving the subsurfaces 116 
is characterized by a substantially circumferential component provided by 
rotation of the diverter 108 as well as a constantly changing vertical 
component provided by the various deflecting subsurfaces 116 and the tilt 
caused by precession of diverter 108 as the stream of fluid at 87 rotates 
around the inner diameter of the spray tower 24. Thus, as the diverter 108 
precesses about its rotational axis at a speed much slower than the speed 
of the wash arm 58, the vertical component of the spray of fluid at 89 
leaving the subsurfaces 116 will be slightly different at any given 
location around the diameter of the spray tower 24 each time the stream of 
fluid indicated by numeral 87 rotates past that location. In other words, 
the fluid spray pattern from this system is constantly changing and random 
in nature so that a given area in the washing compartment 14 will not be 
subjected to a regular or repeating spray pattern. 
Referring to FIGS. 11-14 a modified form of the present invention is 
designated generally by the numeral 126. As best shown in FIG. 12, wash 
arm 128 is mounted for rotation much in the same fashion as the wash arm 
58 shown in FIGS. 1-10. Wash arm 128 includes a threaded boss 130. 
Threaded over boss 130 is an eccentric member 132 having a threaded base 
134 threadably engaging boss 130 and having an upwardly extending nozzle 
136. Nozzle 136 is eccentrically located with respect to the rotational 
axis of wash arm 128, but is adapted to rotate in unison with wash arm 128 
about the rotational axis of wash arm 128. This causes the bottom of the 
vertical central axis of nozzle 136 to move in a circular pattern around 
the rotational axis of wash arm 128. 
Slideably fitted over the outside of nozzle 136 is a bearing sleeve 138 
which also rotatably fits within the lower end of a bottom section 142 of 
a telescoping tower 140. Bottom section 142 includes a fluid chamber 144 
for receiving pressurized fluid from the upper end of nozzle 136. The 
lower end of bottom section 142 includes a planetary gear 146 extending 
around its outer circumference. Gear 146 has a plurality of gear teeth 148 
on its outer circumference. 
The upper end of bottom section 142 includes an opening 150 through which 
an upper section 152 is telescoped. Upper section 152 includes a plurality 
of intermediate spray openings 154, a radial spray opening 156 adjacent 
the top thereof and a top spray opening 158 along the top edge thereof. 
Upper section 152 also includes a bottom flange 160 which engages the 
margins of upper opening 150 so as to limit the upward telescoping 
movement of upper section 152 with respect to lower section 142. 
A stationary tower housing 162 includes a top opening 164 through which the 
upper section 152 of telescoping tower 140 protrudes. The lower portion of 
stationary tower housing 162 includes a ring gear 166 having a plurality 
of inwardly protruding ring gear teeth 168. 
In operation, the rotation of wash arm 128 causes the nozzle 136 to rotate 
in a concentric fashion about the rotational axis of wash arm 128. 
Referring to FIG. 13, the slightly misaligned lower end of bottom section 
142 illustrates the eccentric off-center position of the vertical 
longitudinal axis of the telescoping tower 140. As the nozzle 136 moves in 
this circular pattern, it causes the planetary gear 146 to rotate around 
the ring gear teeth 168 of ring gear 166. This causes the telescoping 
tower 140 to tilt and precess due to the motion between the planetary gear 
146 and the ring gear 166. That is, rotation of the nozzle 136 in a 
clockwise direction as designated by the arrow 170 in FIG. 13 causes the 
planetary gear 146 to rotate in a counter-clockwise direction at a much 
slower speed as indicated by the arrow 172. The rotation of planetary gear 
148 in a direction opposite from the rotational direction of wash arm 128 
also causes the telescoping tower 140 to rotate in the opposite direction 
from the wash arm 128 thereby creating a random spray pattern which is 
opposite to the rotating spray pattern caused by the wash arm 128. As the 
tilted assembly comprising the bottom section 142 and the tower section 
140 precesses due to the gear reduction between the planetary gear 146 and 
the ring gear 166, the spray pattern generated by openings 154, 156 and 
158 will rise and fall as the assembly rotates in a direction opposite to 
and at a much slower rate than the rotation of wash arm 128. 
Referring to FIG. 15, a modified form of diverter 108 is shown at 174. 
Diverter 174 is held in place by means of a nut or cap 176 on the top of 
shank 106. Diverter 174 includes a housing 178 having a bottom wall 180 
with a central opening 182 therein which surrounds and slides vertically 
upon shank 106. Central opening 182 is slightly longer than the swivel 
opening 112 of diverter 108 so that it does not permit the diverter 174 to 
tilt on shank 106. However, the central opening 182 does permit the 
diverter 174 to slide vertically upward and downward and rotate on shank 
106. 
Diverter 174 includes a deflector surface 184 which is comprised of a 
plurality of deflector subsurfaces 186. Each of the deflector subsurfaces 
186 is slightly different from the others so that each of them creates a 
slightly different spray pattern. A pair of helical deflector rotation 
surfaces 188, 190 are adapted to receive the column of water passing 
upward through the tower and because of their helical configuration they 
impart a rotational movement to the diverter 174. Thus as diverter 174 is 
struck by the rising column of water within the tower it moves upwardly to 
its upper most position on shaft 106 and begins rotating in unison with 
the circular pattern of the moving column of water within the spray tower 
24. This diverter 174 does not precess as does the diverter 108, and it 
rotates in the same direction and in unison with the wash arm 20 below. A 
cap 192 is provided over the top of diverter 174. 
In the drawings and specification there has been set forth a preferred 
embodiment of the invention, and although specific terms are employed, 
these are used in a generic and descriptive sense only and not for 
purposes of limitation. Changes in the form and the proportion of parts as 
well as in the substitution of equivalents are contemplated as 
circumstances may suggest or render expedient without departing from the 
spirit or scope of the invention as further defined in the following 
claims.