U.S. patent number RE38,013 [Application Number 09/566,400] was granted by the patent office on 2003-03-04 for liquid spray systems.
This patent grant is currently assigned to Bowles Fluidics Corporation. Invention is credited to Ronald D. Stouffer.
United States Patent |
RE38,013 |
Stouffer |
March 4, 2003 |
Liquid spray systems
Abstract
A .[.vehicle washer nozzle.]. .Iadd.liquid spray .Iaddend.system
having a source of washer liquid under pressure, a fluidic
oscillator comprising a housing and a fluidic insert having a power
nozzle, an oscillation chamber having an upstream end coupled to
the power nozzle for issuing a jet of .[.washer.]. liquid into the
oscillation chamber and a downstream end having an outlet aperture
for issuing a jet of .[.wash.]. liquid to ambient, and side and top
and bottom walls, an oscillation inducing silhouette in the
oscillation chamber for causing said jet of .[.wash.]. liquid to
rhythmically sweep back and forth between the sidewalls in the
oscillation chamber. Top and bottom walls of the oscillation
chamber first diverge for a predetermined distance in a downstream
direction and then converge towards each other through said outlet
aperture. This enables the deflection angle to be adjusted for
different .[.vehicles.]. .Iadd.uses .Iaddend.and applications by
changes to the fluidic insert without changes to the housing.
Inventors: |
Stouffer; Ronald D. (Silver
Spring, MD) |
Assignee: |
Bowles Fluidics Corporation
(Columbia, MD)
|
Family
ID: |
24553238 |
Appl.
No.: |
09/566,400 |
Filed: |
May 4, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
636765 |
Apr 19, 1996 |
05749525 |
May 12, 1998 |
|
|
Current U.S.
Class: |
239/284.1;
137/835 |
Current CPC
Class: |
B05B
1/08 (20130101); B60S 1/52 (20130101); F15C
1/08 (20130101); F15C 1/22 (20130101); Y10T
137/2234 (20150401) |
Current International
Class: |
B60S
1/46 (20060101); B60S 1/52 (20060101); F15C
1/22 (20060101); F15C 1/00 (20060101); B05B
001/10 (); F15C 001/08 () |
Field of
Search: |
;239/589,589.1,590,284.1,284.2,101,499 ;137/835,826 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Douglas; Lisa Ann
Attorney, Agent or Firm: Zegeer; Jim
Claims
What is claimed is:
1. In a vehicle washer nozzle system having a source of washer
fluid under pressure, a fluidic oscillator having a power nozzle,
an oscillation chamber having an upstream end coupled to said power
nozzle for issuing a jet of washer liquid into said oscillation
chamber and a downstream end having an outlet aperture for issuing
a jet of wash fluid to ambient, and side and top and bottom walls,
an oscillation inducing means in said oscillation chamber for
causing said jet of wash fluid to rhythmically sweep back and forth
between said sidewalls and said oscillation chamber, the
improvement wherein said top and bottom walls first gradually
diverge for predetermined distance in a downstream direction and
then gradually converge towards each other through said outlet
aperture.
2. A vehicle windshield washer system defined in claim 1 wherein
said walls diverge at about a 5.degree. angle and said walls begin
to converge towards each other at a position in advance of said
outlet aperture..Iadd.
3. In a washer nozzle system having a source of washer fluidic
under pressure, a fluidic oscillator having a power nozzle, an
oscillation chamber having an upstream end coupled to said power
nozzle for issuing a jet of wash liquid into said oscillation
chamber and a downstream end having an outlet aperture for issuing
a jet of wash fluid to ambient, and side and top and bottom walls,
an oscillation inducing means in said oscillation chamber for
causing said jet of wash fluid to rhythmically sweep back and forth
between said sidewalls and said oscillation chamber, the
improvement wherein said top and bottom walls first gradually
diverge for predetermined distance in a downstream direction and
then gradually converge towards each other through said outlet
aperture..Iaddend..Iadd.
4. A washer nozzle system defined in claim 3 wherein said walls
diverge at about a 5.degree. angle and said walls begin to converge
towards each other at a position in advance of said outlet
aperture..Iaddend.
Description
BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to fluidic oscillators for use in
vehicle washer systems and more particularly to a fluidic
oscillator for vehicle windshield washer systems in which a
housing, which can be commonly used on different vehicles,
incorporates a fluidic oscillator element, hereinafter termed a
"fluidic insert", which carries a physical silhouette or pattern of
a fluidic oscillator and is adapted to create different deflection
angles. As used herein, the term "deflection angle" means the angle
that the jet of wash liquid makes as it exits the outlet in a plane
orthogonal to the plane of the silhouette, and the term "fan angle"
is the angle made by the jet sweeping back and forth between the
boundaries of the outlet in the plane of the silhouette.
Stouffer U.S. Pat. No. 4,508,267 entitled LIQUID OSCILLATOR DEVICE
and Bray, Jr. U.S. Pat. No. 4,463,904 entitled COLD WEATHER FLUIDIC
FAN SPRAY DEVICES AND METHOD disclose fluidic oscillators which
have proved to be highly successful. They typically comprise a
housing in which a fluidic insert element having a silhouette of a
fluidic oscillator is inserted into the housing. The silhouette of
the fluidic oscillator typically is of the type disclosed in FIGS.
2A and 2B, FIG. 2A being from the aforementioned Stouffer U.S. Pat.
No. 4,508,267 and FIG. 2B being Bray, Jr. U.S. Pat. No. 4,463,904,
it being appreciated that other forms of fluidic oscillators may be
used. This type of fluidic oscillator has a power nozzle PN issuing
a jet of windshield washer liquid JW into an oscillation chamber OC
towards an outlet OL which issues the jet of wash liquid into
ambient where it is oscillated in a fashion so as to cause it to
rhythmically be swept back and forth so as to cause the liquid jet
to break up in droplets of predetermined size configuration or
range so as to impinge on the windshield at a predetermined
position under various driving conditions as disclosed in U.S. Pat.
No. 4,157,161. In the Bray, Jr. patent, the Coanda effect wall
attachment or lock-on cause a dwell at the ends of the sweep which
tends to make the spray heavier at the ends of the sweep than in
the middle. In the Stouffer U.S. Pat. No. 4,508,267, the
configuration of the silhouette is such as to cause the liquid
oscillator issue a swept set fan spray in which the liquid droplets
were relatively uniform throughout the fan spray and the uniform
droplets provide a better cleaning action.
In the manufacture of windshield washer nozzles, it has been found
desirable to provide one housing on different vehicles which
thereby reduces the cost of housing design and the tools. However,
this requires creating different deflection angles in the fluidic
inserts which contains fluidic oscillating element per se.
It has been found desirable to provide variable deflection angles.
In one approach disclosed in FIGS. 2A and 2B, a fluidic oscillator
of the type disclosed in the aforementioned Stouffer U.S. Pat. No.
4,508,267 incorporated a step or bump B at the outlet OL of the
fluidic circuit to create up to about a 6.degree. deflection angle
oscillator. The step appears to deteriorate fluidic functions and
create adverse side effects such as: 1. Inconsistent and unreliable
deflection angles due to the high sensitivity of the flow to the
step height, 2. Reduced fan angles and flow rates because the step
or bump could reduce the throat area, 3. Smaller than normal
droplets caused by the fluid impact on the step or bump, 4. Messy
spray caused by fluid impact on the step or bump, 5. Degraded waves
as a direct result of the destruction of fluid functions made by
the step.
Moreover, the deflection angles of the fluidic washer nozzles can
be adjusted by using the taper at the floor of the fluidic insert
as disclosed in the aforementioned Bray, Jr. U.S. Pat. No.
4,463,904. This eliminates the impact between the fluid and the
step. Therefore, the spray is usually not as messy, and the wave is
usually not degraded until the taper reaches about 10.degree. to
12.degree. when the flow begins to separate from the floor of the
insert. The deflection angles are not as sensitive to the taper as
it is to the step. However, with the use of a large taper, the
spray becomes much thicker, and it makes the reading of the
deflection angle very difficult and inconsistent because it is hard
to find the center of a thick spray.
According to the present invention, the problem discussed above is
solved by the use of a reverse taper at the outlet of the fluidic
insert to adjust the deflection angles of the fluidic wash nozzle.
This reverse type allows one housing to be used for several
different types of vehicles which have different requirements for
deflection angles. It allows the creating of different deflection
angles in the fluidic insert per se rather than designing a housing
and tools for the different deflection angles desired. Thus,
according to the present invention, the windshield washer element
has a housing with a rectangular chamber having formed therein a
silhouette or physical pattern of a fluidic oscillator which may be
of the type disclosed in the above-referenced patents. The fluidic
oscillator silhouette has an oscillation chamber having an upstream
end coupled to the power nozzle for issuing a jet of wash liquid
into the oscillation chamber and a downstream end having an outlet
aperture perforation for issuing wash liquid to ambient. The
oscillation chamber includes means for causing the jet of wash
fluid to rhythmically sweep back and forth between the side walls
and the oscillation chamber and issue in a sweeping rhythmic
fashion and through the outlet. According to the invention, the top
and bottom walls of the oscillation chamber diverge for a
predetermined distance in a downstream direction and then converge
towards each other through the outlet aperture. For different
housings, and different physical applications, the degree of the
taper can be changed to accommodate the deflection angles required
by different vehicles, to thereby reduce the cost of housing design
and the tools.
The invention retains the droplet size without causing a
detrimental increase in smaller droplets which are more adversely
affected by wind and air flow effects over the vehicle. One of the
basic objectives of the fluidic windshield washer nozzle is to have
a fan spray which has a designed or predetermined droplet
distribution through the fan and the present invention retains
desired droplet distribution while providing the uniform droplet
distribution of Stouffer U.S. Pat. No. 4,508,267.
DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the
invention become more apparent when considered with the following
specification and accompanying drawings wherein:
FIG. 1A is a diagrammatic sketch of an automobile windshield washer
system to which the invention has been applied;
FIG. 1B is a diagrammatic sketch of an automobile windshield washer
system wherein there is a dual fan, one for the driver side and one
for the passenger side;
FIG. 1C is a diagrammatic illustration of a "wet arm" windshield
washer system wherein the nozzles are mounted on the arms of the
wiper blades;
FIG. 2A is a top plan view of a silhouette of a power fluidic
oscillator as disclosed in Bray, Jr. U.S. Pat. Nos. 4,463,904 and
4,645,126; and FIG. 2B is a sectional view of the fluidic
oscillator shown in FIG. 2A as inserted in a rectangular
housing;
FIG. 3A is a top silhouette of a fluidic oscillator as disclosed in
Stouffer U.S. Pat. No. 4,508,267; and
FIG. 3B is a section view through a centerline thereof;
FIG. 4A is a silhouette of a fluidic oscillator element having the
bump in the nozzle, outlet aperture;
FIG. 4B is a sectional view thereof through a power nozzle and
outlet aperture;
FIG. 5A is a top plan view of a silhouette of a fluidic oscillator
incorporating the present invention; and
FIG. 5B is a sectional view through lines BB of FIG. 5A.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A, 1B and 1C depict vehicle windshields with different
techniques utilized in the art for mounting the windshield washer
nozzles for applying a fan spray of washer fluid droplets to the
windshield glass surface to be cleaned. It will be appreciated that
while the invention has been illustrated as applied to the
windshield of the vehicle, it can be applied to the tailgate window
glass or to glass headlamp washers, the principal use being for
windshield glass. As shown in FIG. 1, vehicle windshield 10 is
provided with a single fan spray device 11 which issues a fan spray
12 of proper droplet size and sweep frequency. Wash liquid for
spray 12 is provided by pump 13 from reservoir 14 which would
conventionally be under the hood of the vehicle. Windshield wash
liquid 16 is contain ed in reservoir 14. In FIG. 1B, a pair of
fluidic oscillator nozzles 11R and 11L, one for the passenger's
side and one for the driver's side of the vehicle are provided for
issuing fan sprays 12R and 12L from the windshield for the
respective driver and passenger sides of the vehicle. In FIG. 1A, a
fluid oscillator of the type shown in FIG. 2 which is heavy ended,
and this is due principally to Coanda wall attachment effects, so
the sides of the spray are heavier or more concentrated in wash
fluid droplets than the center of the spray so as to provide equal
amounts of wash fluid for distribution on the driver and the
passenger sides.
In the embodiment shown in FIG. 1B, fluidic oscillators of the type
shown in FIG. 3 are preferred since these provide relatively
uniform droplet distributions throughout the fan spray. FIG. 1C
illustrates a "wet arm" embodiment wherein the nozzles are mounted
on the wiper arm while FIG. 1C illustrates the spray as being to
the left of the wiper arm having its position shown, it will be
appreciated that various combinations can be utilized when spraying
either from the left or the right of the wiper arm depending on
design considerations. Either type of fluidic oscillator may be
used in this embodiment.
As described in the above referenced Bray, Jr. U.S. Pat. Nos.
4,463,904 and 4,645,126 and Stouffer U.S. Pat. No. 4,508,267, a
system of vortices is established in the oscillation chamber of the
respective oscillators. Each of the oscillators causes a jet of
wash fluid to be issued through the outlet to ambient, which jet is
oscillated or swept back and forth in a fan angle .beta. and which
varies from about 30.degree. to about 160.degree. as set forth in
Stouffer U.S. Pat. No. 4,508,267.
In the aforementioned Bray, Jr. patents and also in the Stouffer
patent, the upper (roof) or lower walls or both of the fluidic
oscillator have a taper incorporated therein so that the walls
diverge from each other in the direction of the outlet OL so as to
expand the power jet in cold weather, a typical taper or angle
being about 5.degree.. In the aforementioned Bray, Jr. patents, the
taper is within a range of 2.degree. and about 10.degree. with
5.degree. being found to be most acceptable since the taper angle
is a function of the distance between a power nozzle and the fluid
outlet.
In the nozzle construction shown in FIGS. 4A and 4B, a step or bump
30 is provided at the outlet OL of the fluidic circuit to create up
to about 6.degree. deflection angle. However, such a step
deteriorates fluidic function and creates the following undesirable
side affects: 1. Inconsistent and unreliable deflection angles due
to the high sensitivity of the flow to the step height. 2. Reduced
fan angles and slow rates because the step reduces the throat area.
3. Smaller than normal droplets caused by the fluid impact on the
step. 4. Messier spray caused by the fluid impact on the step; and
5. Degraded waves as a direct result of the fluidic functions made
by the step.
The deflection angles of the fluidic oscillator can be adjusted by
using the taper as shown in the Bray, Jr. and Stouffer patents.
This eliminates the impact between the fluid and the step, and
therefore the spray is not as messy and the wave is usually not
degraded until the taper reaches about 10.degree.14 12.degree. when
the flow begins to separate from the floor of the insert. The
deflection angle is not as sensitive to the taper as the step.
However, with the use of a larger taper the spray comes much
thicker making it difficult and inconsistent to find the center of
a thick spray.
THE PRESENT INVENTION
In order to create the required deflection angle without the above
problems, the fluidic oscillator of the present invention solves
this problem by use of a reverse taper at the outlet of the fluidic
insert to adjust the deflection angles of the fluidic washer
nozzles. These are shown in FIGS. 5A and 5B.
The most critical parameter of the reverse taper insert is its
deflection angle, although other performance factors (such as fan
angle, flow rate, spray thickness, wave pattern, fluid droplet size
and spray cleanliness) are important as well. By adding the reverse
taper RT, at angle .phi. the thickness of the spray can be reduced
which makes the deflection angles more consistent and reliable and
as a result, of the thinner spray, fluid is more concentrated in
the middle which aids in the dynamic performance of the fluidic
windshield washer nozzle. Moreover, the reverse taper does not
create as much destruction of the spray as the step at the outlet
of the insert. This makes the spray cleaner and not as degraded as
in the case of the step at the outlet (FIGS. 4A and 4B). In fact,
the droplet sizes are also larger which is good for high speed
testing since the high speed wind affects on small droplets is
significant. In most cases, the throat depth and throat area are
unchanged by adjusting the taper after the reverse taper is added
to the insert. Therefore, the fan angle does not have to be reduced
by the addition of reverse taper.
In a preferred embodiment, the diverging taper from the power
nozzle PW to the point where the converging or reverse taper begin
is about 5.degree. and the reverse taper angles .phi. is about
3.degree.. By making various combinations of changes in this angle
in the fluidic insert, the deflection angle DA can be adjusted
without making any changes in the housing. The length Lr of the
reverse taper can also be adjusted.
While the invention has been described and illustrated with respect
to specific embodiments, it will be clear that various
modifications and adaptations and changes to the invention will be
obvious to those skilled in the art without departing from the true
spirit and scope of the invention as set forth in the appended
claims.
* * * * *