U.S. patent number 3,552,413 [Application Number 04/374,865] was granted by the patent office on 1971-01-05 for feedback divider for fluid amplifier.
This patent grant is currently assigned to N/A. Invention is credited to Ralph G. Barclay, John Gerald Moorehead, Raymond W. Warren.
United States Patent |
3,552,413 |
Warren , et al. |
January 5, 1971 |
FEEDBACK DIVIDER FOR FLUID AMPLIFIER
Abstract
This invention relates to pure fluid amplifiers having dynamic
feedback dividers for providing a feedback which contributes
assistance to the boundary layer lock-on phenomena.
Inventors: |
Warren; Raymond W. (McLean,
VA), Barclay; Ralph G. (Silver Spring, MD), Moorehead;
John Gerald (Silver Spring, MD) |
Assignee: |
N/A (N/A)
|
Family
ID: |
26917105 |
Appl.
No.: |
04/374,865 |
Filed: |
June 12, 1964 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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222748 |
Sep 10, 1962 |
3397713 |
Aug 20, 1968 |
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Current U.S.
Class: |
137/811;
137/835 |
Current CPC
Class: |
F15C
1/08 (20130101); Y10T 137/2104 (20150401); Y10T
137/2234 (20150401) |
Current International
Class: |
F15C
1/08 (20060101); F15C 1/00 (20060101); F15c
001/08 () |
Field of
Search: |
;137/81.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; Samuel
Parent Case Text
This application is a divisional application of copending
application Ser. No. 222,748, filed Sept. 10, 1962, and now U.S.
No. 3,397,713, issued Aug. 20, 1968, entitled Feedback Divider for
Fluid Amplifiers.
Claims
We claim:
1. In a fluid amplifier:
a. a fluid power source for producing a fluid stream;
b. A pair of divergent receiver means;
c. means for directing said power stream toward said receiver
means;
d. divider means for separating said pair of receiver means;
e. said divider means being a solid element having a pair of
divergent sides which form the inner sides of said pair of receiver
means; and having a third side connecting the closer ends of the
divergent sides; and
f. said third side providing a feedback flow to reinforce the
continuance of power stream in one of said receiver means.
2. In a fluid amplifier:
a. a fluid power source for producing a fluid stream;
b. a pair of divergent receiver means;
c. means for directing said power stream toward said receiver
means;
d. divider means for separating said pair of receiver means;
e. said divider means being a solid element having a pair or
receiver means, and having a third side connecting the closer ends
of the divergent sides; and
f. said third side being arcuate in shape.
3. In a fluid amplifier:
a. a fluid power source for producing a fluid stream;
b. a pair of divergent receiver means;
c. means for directing said power stream toward said receiver
means;
d. divider means for separating said pair of receiver means;
e. said divider means being a solid element having a pair of
divergent sides which form the inner sides of said pair of receiver
means, and having a third side connecting the closer ends of the
divergent sides; and
f. said third side being concave in shape with respect to said
power source.
4. A fluid device comprising an inlet for supplying power fluid, a
pair of outlets, a pair of control inlets for directing said power
fluid to a selected outlet, and a vortex chamber all leading from a
common mixing chamber, said vortex chamber being disposed
intermediate said outlets and in alignment with said inlet to
receive power fluid therefrom, said vortex chamber being
dimensioned to create a vortex movement of fluid therein with a
portion of said fluid being directed to said selected outlet to
maintain said fluid at said selected outlet after the application
of fluid from said control inlets has terminated, said control
inlets being disposed at substantially right angles with respect to
said inlet and said vortex chamber, said outlets being angularly
disposed away from said inlet on opposite sides of said vortex
chamber and between said vortex chamber and said control inlets.
Description
The invention described herein may be manufactured and used by or
for the Government of the United States of America for Governmental
purposes without the payment to me of any royalties thereon.
This invention relates to fluid amplifiers and more particularly,
to dynamic feedback dividers in fluid amplifiers.
In previous fluid amplifiers, the dividers which separate the
output channels were substantially wedge shaped with the pointed
edge of the wedge aligned with the power nozzle in such a manner
that the divider would separate the interaction region into two
output channels. If all of the flow from the power stream could not
be contained in one output channel, the divider would separate the
power stream into a majority flow and a minority flow into the
output channels. The favored channel was the channel which had the
majority of the power stream flow. Favoring of one output channel
over the other was a function of the symmetry of the amplifier
elements, the smoothness of the surfaces exposed to the power
stream flow, the divergence of the output channels, the amount of
control provided directly on the stream, boundary layer effects,
loading of the outputs, and the like. Once favored, the power
stream would remain in the favored output channel until a control
signal was provided to switch it to the other channel. This control
signal could originate externally of the amplifier, could be a
portion of the power stream feedback to the interaction chamber
from a location downstream from the divider, or the like.
In some fluid amplifiers, such as bistable devices, it is desired
that the stream remain in one output channel a prescribed length of
time. There are various causes for instability that would prevent
the stream from remaining in a favored channel until switching to
the other channel is desired. One of these causes is encountered
when the amplifier is connected to a load. The resistance in the
system could be such that the output channel would no longer carry
all of the power stream as it would in an unloaded condition. Under
these circumstances, the return of the excess power stream down the
favored channel against the flow of the power stream can cause
perturbations and turbulences that would promote instability. Since
all the fluid does not get out into the load, some of the fluid
leaks around the divider and out through the other channel.
Oscillations as well as other instabilities may result. Further,
the direction of all of the power stream into a favored output
channel and maintaining it there could require an excessive amount
of control signal, and could require that the control signal be
applied for an excessive amount of time.
Accordingly, this invention is directed to improvements in fluid
amplifier dividers which provide: increased stability in a fluid
amplifier; reliability of memory functions; an assist to the
boundary layer lock-on phenomena; the reduction or elimination of
counter flow through the unfavored output channel as well as the
need therefor; momentum in a feedback flow which serves as a
locking control signal; feedback signals which have vector
properties, and feedback signals which operate in the manner of a
servo feedback signal.
It is, therefore, an object of this invention to provide an
improved divider in a fluid-operated device.
A further object of this invention is to provide a divider which
contributes to the stability of a fluid amplifier.
A still further object of this invention is to provide a divider
which enables reliability of memory functions in a fluid
amplifier.
Another object of this invention is to provide a divider which
contributes assistance to the boundary layer lock-on phenomena by
means of feedback.
Still another object of this invention is to provide a divider in a
bistable fluid-operated device which reduces the counterflow in the
output channel not favored by the power stream.
A further object of this invention is to provide a divider which
eliminates the need of counterflow in the output channel not
favored by the power stream in a fluid amplifier so as to enable
the use of the fluid amplifier in outer space or other low-pressure
environments.
A still further object of this invention is to provide a divider in
a fluid amplifier which provides a momentum in a feedback flow
which serves as a control signal.
The FIG. shows one embodiment of this invention.
Briefly, the purposes of this invention are accomplished by the
provision of a divider in a fluid amplifier which feeds back a part
of the power stream in one receiver to reinforce the forces
diverting the power stream into said one receiver. Feedback is
against a blunt or curved end of the divider to provide a pressure
seal over the entrance to the not favored output channel and also
to reinforce the diverting forces on the power stream which direct
it into the favored channel. A vortex is generated which further
enhances the reinforcement and provides a dynamic
characteristic.
The sole FIG. shows a bistable fluid amplifier. One common method
of making the amplifier is a lamanar construction. That is, the
fluid channels are etched or machined in one block such as brass,
then sealed with a flat plate, such as a plexiglass plate, as
shown.
The bistable amplifier shown in FIG. 1 has power jet nozzle,
opposed control nozzles, and a pair of output receiver channels 42
and 43. Separating the receivers 42 and 43 is a divider with a
concave curved surface 41. All of the downstream material of the
divider has been removed to present the surface 42 as the curved
leading edge of the divider between output receivers 42 and 43.
Between the curved surface 41 and the interaction chamber 47, there
is no divider structure. The curved structure 41 is concave when
viewed from the power nozzle. The interaction chamber 47 is bounded
by the divider surface 41, a pair of divergent sidewalls which are
the outer boundaries of output receivers 42 and 43 and the wall
that defines the distance that the control nozzles are set back
from the power nozzle. The power nozzle and the control nozzles are
directed into the interaction chamber 47. As is conventional in the
art, the control nozzles control which receiver channel wall the
power jet latches on to.
In operation, the divider curved edge 41 forms a vortex and directs
the feedback flow down along the unfavored receiver sidewall into
the interaction chamber 47. The flow that is adjacent the divider
41 is directed in a path that approaches the receiver sidewall, and
in the vicinity of the sidewall, turns to travel near the sidewall
in a direction away from the interaction chamber 47 as shown by
flow line 44. A majority of the feedback flow is directed into the
interaction chamber 47 as shown by flow line 44. A majority of the
feedback flow is directed into the interaction chamber where a
vortex 45 is formed by curved flow of the feedback fluid to provide
momentum to the power stream in receiver 42 to further lock the
power stream therein. The remainder of the flow distributes through
the remainder of the interaction chamber 47 in the circular paths
indicated by the remaining arrows 46.
The flow line 44 indicates a pressure area which is a barrier
sufficient to maintain power stream integrity even if the pressure
available exterior to the fluid amplifier is very low. This permits
the amplifier to operate in outer space. The vortex 45 and the
lock-on assist vectors 46 would be maintained in the absence of a
counterpressure down the unfavored receiver 43.
The fluid amplifier in this disclosure is the wall effect
amplifier. The basic bistability comes about because the stream
entrains away fluid and produces a low-pressure separation bubble
on the wall. This is indicated in the drawing by the exposure of
the short bottom end of the sidewall of the favored receiver to
which the power stream is shown not attached. The entrainment and
the bubble provide a low-pressure region which allows the higher
pressure on the opposite side of the power stream to hold the
stream against the favored sidewall. The effectiveness of the
holding of the stream against the sidewall depends on the pressure
differential on the two sides of the stream. The feedback divider
splits off part of the stream and directs it so as to increase the
pushing pressure lock-on. In the embodiment shown, should the
stream move away from the bistable position, more of the stream is
split off and the pushing pressure is increased forcing the stream
back into its bistable position. The action of this restoring
pressure that is generated is similar to the action of a
servoloop.
Fluid amplifiers of the type of which this invention is an
improvement are more adequately disclosed in the copending
application entitled Fluid Amplifier Employing Boundary Layer
Effect, Ser. No. 58,188, filed Oct. 19, 1960 and now U.S. Pat. No.
3,396,619 revised Aug. 13, 1968. by Raymond W. Warren et al. Mr.
Warren is one of the inventors of this application.
So, it is seen that we have provided an improved divider in a fluid
amplifier. The divider improvements of this disclosure contribute
to stability and enable reliability of memory functions in a fluid
amplifier. The counterflow in the not-favored output channel is
reduced or eliminated and operation in outer space is provided. The
lock-on phenomenon is reinforced by the feedback flow and by the
momentum of such flow. The feedback flow has vector properties. The
counterflow around the pointed edge of the divider has been
eliminated and the wandering of the power stream has been used to
provide a pressure proportional to such wandering to reinforce the
power stream in a stable position in the manner of a servoloop.
It will be apparent that the embodiment shown is only exemplary and
that various modifications can be made in construction and
arrangement within the scope of the invention as defined in the
appended claims.
The divider 41 can be concave as shown, blunted as said above,
squared off, or in any shape that will provide the flow pattern
needed to reinforce the lock-on pressure differential and provide
stabiltiy. An example of such a flow pattern is shown by arrows 46
and vortex 45. Dividers shaped like a flat open box, with the open
end directed toward the power stream, will provide a flow pattern
that is equivalent to that provided by a concave divider.
* * * * *