Spray arm pulsation device of a dish washer

A spray arm of a dish washer having improved washing efficiency by providing the spray arm to pulsate through utilizing the feeding and draining action of washing water, comprises first and second rotation nozzles oppositely formed in each end of the spray arm; a ball moved by washing water fed into the spray arm and the weight of the ball itself, the ball for closing either one of the first and the second nozzles, and a guide member for guiding the ball to move only in one direction.

FIELD OF THE INVENTION 
This invention relates to a spray arm pulsation device of a dish washer, 
more particularly to a spray arm of a dish washer having improved washing 
efficiency by providing the spray arm to pulsate through utilizing the 
feeding and draining action of washing water. 
BACKGROUND OF THE INVENTION 
A spray arm 1a of a conventional dishwasher is, as shown in FIGS. 1 and 2, 
rotatably mounted at the center of a feed water pipe 13 which is installed 
on the bottom 20 of a dish washer. The spray arm 1a has washing nozzles 10 
on upper part thereof for spraying washing water toward dishes, and 
rotation nozzles 11 for generating rotation force by the reaction of 
washing water sprayed therefrom. 
When the feed water is, pressurized by a pump(not shown) and fed through 
the feed water pipe 13, sprayed from the rotation nozzles 11, the spray 
arm 1a is rotated by the reaction of the feed water spray from the 
rotation nozzles 11 only in one direction while washing the dishes by the 
spraying water from the washing nozzles 10. 
In another conventional spray arm 16 as shown in FIGS. 3 and 4, when the 
feed water, pressurized by a pump(not shown), is fed inside of the spray 
arm 1b, ball 6a in the spray arm 1b, moved by water pressure, close 
rotation nozzles 4a and 5a alternatively changing the direction of spray 
resulting in a to change of the direction of rotation of the spray arm. 
However, the conventional spray arm 1a as shown in FIGS. 1 and 2 described 
above has low washing efficiency due to the existence of a dead zone of 
spray developed by the one direction rotation of the spray arm 1a forced 
by water sprayed from the rotation nozzle 11 provided for producing a 
rotation force. 
On the other hand, the conventional spray arm 1b in FIGS. 3 and 4, which 
has ball 6a in the spray arm 1b, resting in the neutral position before 
starting, repeating the action of closing either one of the rotation 
nozzles on feeding of water and returning to the neutral position on stop 
of the feed of water, also has low washing efficiency because the spray 
arm 1b can hardly be expected to rotate reversing periodically, as the 
probability of closing either one of the rotation nozzles 4a and 5a by the 
ball 6a is half and half resulting in the closing of the rotation nozzles 
being irregular, contrary to the required sequential closing of the 
rotation nozzles 4a and 5a by the ball 6a for the periodic reversing of 
the spray arm 1b. 
SUMMARY OF THE INVENTION 
The object of this invention is providing a spray arm of a dish washer 
having improved washing efficiency by widening the range of the spray of 
the washing water by causing the spray arm to pulsate, without supply of 
separate power, through utilizing the pressure of the washing water fed to 
the spray arm. 
This and other objects and the features of this invention can be achieved 
by providing a spray arm pulsation device of a dish washer including first 
and second nozzles formed in opposite direction at the end of the spray 
arm for spraying washing water, a ball for closing either one of the first 
and the second rotation nozzles moved by washing water, and a guide 
member-for guiding the ball to move only in one direction so that the 
nozzle spraying washing water can be changed from the first; to the second 
nozzle to change the direction of rotation of the spray arm.

DETAILED DESCRIPTION OF THE INVENTION 
FIGS. 5 to 7 show a spray arm of a dish washer in accordance with one 
embodiment of this invention including a guide member 2 formed to have a 
two level crossing with a step at each end of guide rails 2a, 2b, 2c and 
2d, and the guide rails 2a, 2b, 2c and 2d each formed to have a slope 
ended with a step between them, provided with guard rails 3 at both sides 
thereof to prevent falling down. 
In the guide member 2, first and second rotation nozzles 4 and 5 used also 
as washing water outlets positioned oppositely are provided at the guide 
rails 3 between the first and the second guide rails 2a and 2b, and the 
third and the fourth guide rails 2c and 2d connected with the spray arm 1, 
and a ball 6 made of glass or plastic is on the guide rail 2a, 2b, 2c and 
2d for closing the first and the second rotation nozzles 4 and 5 
alternatively through moving in one direction along the first, the second, 
the third and the fourth guide rails 2a, 2b, 2c and 2d forced by washing 
water and the weight of the ball itself. A recess 7 for the rest of the 
ball is provided at each entrance of the rotation nozzles 4 and 5. 
The first guide rail 2a is sloped so that a first end is lower than a 
second end, the second guide rail 2b is sloped so that a first end 
connected with the second end of the first guide rail is higher than a 
second end. The first end of the second guide rail is connected with the 
first nozzle. The third rail 2c is sloped so that a first end connected 
with the second end of the second guide rail is lower than a second end, 
and the fourth guide rail 2d is sloped so that a first end connected with 
the second end of the third guide rail is higher than a second end. The 
first end of the fourth guide rail is connected with the second nozzle and 
the second end is connected with the first end of the first guide rail. 
Accordingly, the ball 6 is forced to move by the washing water fed to the 
spray arm 1 from the first guide rail to the second guide rail and from 
the third guide rail to the fourth guide rail, and the ball 6 moves by its 
weight from the second guide rail 2b to the third guide rail and from the 
fourth guide rail to the first guide rail. 
FIGS. 8 and 9 show another embodiment of this invention including, at the 
end of the spray arm 1, a guide member 2' having first, second, third and 
fourth sloped guide surfaces 2'a, 2'b, 2'c and 2'd each separated by 
independent separation room 2'e with steps at the boundaries of the 
surfaces and, on the top and the bottom of each side of the guide member 
2, oppositely positioned first and second rotation nozzles 4' and 5' used 
also as washing water outlets are provided on the second and the fourth 
guide surfaces 2'b and 2'd. 
On one side of the first and the second rotation nozzles 4' and 5' used 
also as washing water outlets in the guide member 2', washing water inlets 
8 and 9 are provided in the first and the third sloped guide surfaces 2'a 
and 2'c for the flow in of the fed washing water, and, on the first, the 
second, the third and the fourth sloped guide surfaces 2'a, 2'b, 2'c and 
2'd of the guide member 2', a ball 6 for alternative closing of the first 
and the second rotation nozzles 4' and 5' through moving in one direction 
along the first, the second, the third and the fourth sloped guide 
surfaces 2'a, 2'b, 2'c and 2'd forced by washing water flowing in through 
the washing water inlets 8 and 9, and by the weight of the ball itself. 
The first sloped guide surface 2'a is sloped so that one side is lower than 
an opposite side. A washing water inlet 8 is in the wall of the one side. 
The third sloped guide surface 2'c is sloped so that one side is lower 
than an opposite side. A washing water inlet 9 is in the wall of the one 
side. The second sloped guide surface 2'b is connected with the first 
rotation nozzle, and has one side which is in contact with the opposite 
side of the first sloped guide surface, and is formed to have a slope 
higher than the third sloped guide surface. The fourth sloped guide 
surface 2'd is connected with the second rotation nozzle, and has one side 
which is in contact with the opposite side of the third sloped guide 
surface, and is formed to have a slope higher than the first sloped guide 
surface. 
The spray arm in accordance with one embodiment of this invention, as shown 
in FIGS. 5 to 7, rotates in a clockwise direction because the ball 6 moves 
along the first sloped guide rail 2a forced by the washing water to close 
the first rotation nozzle 4 which is used also as a washing water outlet, 
this results in the washing water being sprayed through the second 
rotation nozzle 5. The water which is pressurized by a pump (not shown) 
flows into the spray arm 1 through a feed water pipe. Because the ball 6 
has a higher specific weight than water, the ball 6 rests at one end of 
the first guide rail 2a in the guide member 2 mounted in the spray arm 1 
of a dish washer. 
Thereafter, when the feed of washing water to the spray arm 1 is stopped, 
the ball 6, which is closing the first rotation nozzle 4, is unable to 
move toward the first guide rail 2a due to the step 2a' and this moves 
down to the third guide rail 2c through the second sloped guide rail 2b by 
the weight of the ball itself. 
At this time, when washing water is again fed to the spray arm 1, the ball 
6 resting at one end of the third guide rail 2c, is unable to move over 
toward the second guide rail due to the step 2b' of the second guide rail, 
and thus moves along the third guide rail 2c forced by the water feed and 
closes the second rotation nozzle 5 so that the washing water is sprayed 
through the first nozzle 4 to force to rotate the spray arm 1 in 
anti-clock wise direction. 
Then, when the water feed to the spray arm 1 is stopped, the ball 6, as 
shown in FIG. 7, is unable to move toward the third guide rail 2c due to 
the step 2c' at the third guide rail 2c, and thus moves down along the 
fourth sloped guide rail 2d to return to one end of the first guide rail 
2a by the weight of the ball itself, which ball 6, then, when the water 
feed to the spray arm 1 is started again, is unable to move toward the 
fourth rail 2d due to the step 2d' at the fourth guide rail 2d, and thus 
moves up to the first guide rail forced by the water feed. 
Thus, the ball 6 repeats the aforementioned processes, causing the spray 
arm 1 to pulsate. 
In the meantime, as guard rail 3 is formed on both sides of the first, the 
second, the third and the fourth guide rails 2a, 2b, 2c and 2d of the 
guide member 2, the ball 6 is prevented from falling down, and as recesses 
are formed on the bottom of the first and the second, and the third and 
the fourth guide rail 2a, 2b, 2c and 2d at the entrances to the first and 
the second rotation nozzles 4 and 5, the ball 6 can stay stable without 
any movement during the closure of the first and the second rotation 
nozzles 4 and 5. 
On the other hand, when the washing water fed to the spray arm enters into 
the separated room 2'e through the washing water inlets 8 and 9, as shown 
in FIGS, 8 and 9, while the Washing water inlet 8 in the first sloped 
guide surface 2'a in guide member 2' in the spray arm 1 of the dish 
washer, is kept closed by the ball 6, the ball 6 is pushed toward the 
second sloped guide surface 2'b over the step of the first sloped guide 
surface 2'a resulting in the closure of the first rotation nozzle 4' used 
also as a washing water outlet so that the spray arm rotates in clockwise 
direction by the washing water sprayed from the second rotation nozzle 5' 
in the fourth sloped guide surface 2'd of the guide member 2'. When the 
water feed to the spray arm 1 is stopped, the ball 6 is unable to move 
toward the first sloped guide surface 2'a due to the step 2'a' of the 
first sloped guide surface 2'a, and thus moves down to the third sloped 
guide surface 2'c from the second sloped guide surface 2'b due to the 
slope of the second sloped guide surface 2'b by the weight of the ball 
itself. 
When the water is again fed to the spray arm 1 and into the separation room 
2'e through the washing water inlets 8 and 9 in the first and the third 
sloped guide surfaces 2'a and 2'c of the guide member 2' the spray arm 1 
rotates in a counter clockwise direction because the ball 6, which was 
closing the washing water inlet 9 of the third sloped guide surface 2'c, 
closes the second rotation nozzle 5' used also as a washing water outlet 
in the fourth sloped guide surface 2'd because the ball is pushed over the 
step 2'c' of the third sloped guide surface 2'c toward the fourth sloped 
guide surface 2'd by the force of the water feed resulting in the water 
feed being sprayed from the first rotation nozzle 4'. 
When the water feed to the spray arm 1 is stopped, the ball 6, as shown in 
FIG. 9, is unable to move to the sloped third guide surface 2'c due to the 
step 2'c' of the third sloped guide surface 2'c, but moves down to the 
first sloped guide surface 2'a along the fourth sloped guide surface 2'd 
by the weight of the ball itself. Thus, the spray arm 1 pulsates in 
accordance with the aforementioned operation sequence. 
As seen from aforementioned description, this invention can improve the 
washing efficiency of a dish washer by providing a guide member in a spray 
arm including a ball having higher specific gravity than the washing water 
closing the first and the second rotation nozzles alternatively, without 
supply of separate power, moving in one direction forced by the water feed 
to the spray arm and the weight of the ball itself causing the spray arm 
to pulsate to widen the range of the spray of the spray arm. 
Although the invention has been described in conjunction with specific 
embodiments, it is evident that many alternatives and variations will be 
apparent to those skilled in the art in light of the foregoing 
description. Accordingly, the invention is intended to embrace all of the 
alternatives and variations that fall within the spirit and scope of the 
appended claims.