US3426780A

US3426780A - Pure fluid push-pull summing amplifier of the impact type

Info

Publication number: US3426780A
Authority: US
Inventors: Samuel A Gray
Original assignee: Bell Aerospace Corp
Current assignee: HR TEXTRON Inc A CORP OF DE; Bell Aerospace Corp
Priority date: 1966-09-16
Filing date: 1966-09-16
Publication date: 1969-02-11
Anticipated expiration: 1986-02-11

Description

Feb. 11, 1969 s. A. GRAY 3,426,780

PURE FLUID PUSH-PULL SUMMING AMPLIFIER OF THE IMPACT TYPE Filed Sept. 16, 1966 SAMUEL ,4. GQAY ILL ii INVENTOR FE G. 3 fiwflaw 5x40249 40 ATTORNEYS- United States Patent 3,426,780 PURE FLUID PUSH-PULL SUMMING AMPLIFIER OF THE IMPACT TYPE Samuel A. Gray, Sun Valley, Calif., assignor to Bell Aerospace Corporation, a corporation of Delaware Continuation-impart of application Ser. No. 562,338, July 1, 1966. This application Sept. 16, 1966, Ser. No. 579,973 US. Cl. 137-815 12 Claims Int. Cl. FlSc 1/14 ABSTRACT OF THE DISCLOSURE Disclosed is a fluidic amplifier which utilizes the impact type proportional amplifier principle, both direct and transverse, to provide a push-pull output signal which is proportional to the difference between the momentum flux of the impacting input streams.

This invention relates generally to pure fluid amplifiers and more particularly to a push-pull proportional summing amplifier which utilizes the impact technique.

This application is a continuation in part of United States patent application, Ser. No. 562,338, now abandoned, filed July 1, 1966 by Samuel A. Gray for Pure Fluid Push-Pull Summing Amplifier of the Impact Type.

Pure fluid amplifier type devices have become rather well known in the past few years. In such devices there are no moving parts other than the fluid (i.e. the gas or liquid which flows therethrough) and therefore there is nothing in the device to wear out. The devices themselves can be manufactured of any material which is desired including plastic, metal and ceramic. Therefore, temperature is not a limiting factor as is the case in many active devices utilized for amplification. As a result of the foregoing, fluid amplifiers have potential for wide application in various fields, primarily as a result of their high reliability, their temperature insensitivity, their shock resistance and their ease of fabrication. Fluid amplifiers as presently recognized in the prior art may be operated as pneumatic devices employing a compressible fluid such as gas or air, or as hydraulic devices utilizing an incompressible fluid such as water or oil. The pure fluid amplifiers at present fall into two basic types. These types are either of the on-off logic type or of the proportional amplifier type device. The present invention is directed specifically to the proportional fluid amplifier.

Various pure fluid devices and particularly of the proportional amplifier types are well known in the prior art, for example, such as the stream interaction amplifier, the double-leg elbow amplifier, the vortex amplifier, and the impact modulator. Such devices, among others, are described and illustrated in Machine Design, June 24, 1965 issue, pages 154 through 180. The present invention more specifically utilizes the techniques and principles employed in the impact modular type amplifier.

In the impact modulator type proportional amplifier a pair of collinear power input tubes are arranged to cause axially opposing jets of fluid to impact. Such impact causes the production of a radial jet, the position of which is determined by the relative strength of the two impacting jets. The relative strength of the two jets may be varied by directly changing the pressure of the impacting jets or by introducing another jet transversely to the axis of the impacting jets. In either event the sensed pressure in the output chamber changes according to the position taken by the radial jet. All presently known impact modulator type amplifiers are single ended. Thus to interface with any push-pull type device requires two such amplifiers properly interconnected to provide the necessary output signals.

Accordingly, it is an object of the present invention to provide a push-pull fluid amplifier having no moving parts.

It is another object of the present invention to provide a fluid amplifier which is simple, rugged and easy to manufacture.

It is a further object of the present invention to provide a novel fluid amplifier utilizing the impact technique to produce a push-pull output signal.

It is still a further object of the present invention to provide a novel fluid amplifier using the impact technique which provides an improved gain, a higher sensitivity, and a greater efficiency.

Additional objects and advantages of the present invention both as to its operation and organization will become apparent from a consideration of the following description taken in conjunction with the accompanying drawing which is presented by way of example only and is not intended as a limitation upon the scope of the claims appended hereto and in which:

FIGURE 1 is a perspective view of a device constructed in accordance with the present invention;

FIGURE 2 is a schematic representation of a pushpull amplifier in accordance with the present invention, when the signals applied thereto are equal;

FIGURES 3 and 4 illustrate the device shown in FIG- URE 2 with the input signals applied thereto having different relative magnitudes; and

FIGURE 5 is a schematic representation of an alternative embodiment of a push-pull amplifier in accordance with the present invention.

A pure fluid push-pull summing amplifier in accordance with the present invention includes a pair of axially aligned input nozzles arranged to have fluid emanate therefrom in such a manner so as to impact along a predetermined axis in such a manner as to form a radial jet. There is arranged with at least one of the nozzles input signal means which cooperate so as to cause the position of the radial jet to change in accordance with the applied input signal. A receiving chamber surrounds the area where the fluid emanating from the nozzles impact and includes a pair of output openings which are spaced oppositely from the point of impact so as to produce equal signals at the output openings when there is no input signal applied by way of the input signal means. The two output openings in the receiving chamber are effectively isolated by exhaust means.

Referring now to the drawing and more particularly to FIGURE 1 there is illustrated a push-pull amplifier in accordance with the present invention. As is therein shown, the amplifier 10 includes a housing 11 having a pair of input tubes 12 and 13 connected thereto and aligned axially along the axis a-b. Sources of fluid (not shown) are connected to tubes 12-13 to provide fluid flow into housing 11. Also connected to the housing 11 is a pair of input signal means such as the tubes 14 and 15. Input signals are applied to these tubes from sources thereof (not shown) to affect the flow of fluid through the tubes 12 and 13. A pair of

output tubes

16 and 17 are also connected to the housing and sense, in a pushpull manner, any variation in the signals applied to the input signal tubes 14 and 15. An exhaust tube 18 is connected to the housing 11 and cooperates to dump any fluid not flowing through the

output tubes

16 and 17 and thereby isolates the output tubes. Further exhaust tubes 3 8' 3'9' are connected to the housing 11 and function to provide isolation between the input and output signals.

A better understanding of the apparatus in accordance with the present invention will be had by reference to FIGURES 2 through 4 which will now be considered in some detail. As is shown in FIGURE 2 the input tube 12 terminates in a nozzle 21 having an orifice 22. The input tube 13 terminates in a nozzle 23 having an orifice 24. The orifice 22 of the nozzle 21 is disposed at the output orifice of an input signal receiving chamber A while the orifice 24 of the nozzle 23 is disposed at the output orifice of an input signal receiving chamber B. It should be noted that the output orifices of the chambers A and B are arranged concentrically with the output orifices of the

nozzles

21 and 23 respectively and thereby form a second pair of nozzles.

The remainder of the housing 11 is utilized as a receiving chamber C. The receiving chamber C is divided into

output signal chambers

31 and 32 and isolating

exhaust chambers

33, 38 and 39. The output signal chamber 31 is separated from the exhaust chamber 38 by a wall member 26 having an aperture 27 therein while the output signal chamber 32 is separated from the exhaust chamber 39 by a wall member 28 having an aperture 29 therein. The output signal chamber 31 is further separated from the exhaust chamber 33 by a wall member 34 having an aperture 35 therein while the exhaust chamber 33 is separated from the output chamber 32 by a wall member 36 having an aperture 37 therein. The

exhaust chambers

38 and 39 are vented to atmosphere by ports 38' and 39' respectively. It can be seen by reference particularly to FIGURE 2, that the two

output tubes

16 and 17 are effectively isolated one from the other by the two walls 34 and 36 and the exhaust chamber 33 and from the input signal receiving chambers by the

exhaust chambers

38 and 39.

As is illustrated in FIGURE 2, in the absence of input signals applied to the input signal tubes 14 and 15, the fluid power jets applied to the tubes 12 and 13 pass inwardly into the housing 11 as is illustrated by the arrows 20-30 and meet in the exhaust chamber 33 and impact therein. At the point of impact a radial jet or cone 40 is formed as is illustrated. Assuming that the power jets 20 and 30 are equal in their characteristics, the radial jet 40 would be located at the exact center of the exhaust chamber 33. Under these circumstances the output signals experienced in the

output chambers

31 and 32 and appearing at the

output tubes

16 and 17 would be identical as is indicated by the

arrows

41 and 42 and there would be no differential therebetween. This being the case there would be effectively zero output signal from the push pull amplifier of the present invention. In the event that some difference did exist, as a result of manufacturing or operational tolerances for example, between the output signals 41 and 42, under normal operating conditions and in the absence of input signals at the input tubes 14 and 15, either the signal 20 or the signal 30 would be adjusted so as to cause the output signals at'

output tubes

16 and 17 to be substantially equal. Input signal information may be applied to input signal tubes 14 and or either of them or alternatively the power jets and applied to tubes 12 and 13 may be changed by way of introducing a variation in the signal if such is desired. Typically however, inputsignals will be applied to the input signal receiving chambers A and B by applying them to the input tubes 14 and .15.

By reference now to FIGURE 3 it is illustrated schematically what occurs upon the application of an input signal to the input tube 14. Under these circumstances an input signal is now experienced in the input signal receiving Chamber A which signal causes fluid flow to be directed through the orifice from Chamber A surrounding the nozzle 21. This fluid flow forms a pressure surrounding the jet 20 emanating from the nozzle orifice 22. Under these circumstances the diameter of the jet 20 is slightly constricted thus increasing the momentum flux thereof. Since no change has been imparted to the input power jet 30, the balance point between the jets 20 and 30 is caused to move toward the right as is illustrated at in FIGURES 3. Such movement of the balance point occurs since the momentum flux of the input jet 20 plus the momentum flux of the input signal applied to the input signal receiving Chamber A is greater than the momentum flux of the input jet 30. As a result of the movement of the radial jet 40 toward the right the output signal emanating from the output tube 17 is larger as is illustrated at 42' than is the output signal from the tube 16 as is illustrated at 41. Thus there is a difference between the output signals 41' and 42' and the difference therebetween is the output signal from the push-pull amplifier in accordance with the present invention.

If an input signal is applied to the input tube 15 as is illustrated in FIGURE 4, then exactly the reverse of that which was described with respect to FIGURE 3 occurs. That is, the momentum flux of the input jet 30 is increased relative to the momentum flux of the input jet 20 thus causing the radial jet 40 to move toward the left and to thereby increase the output signal 41 as compared to the output signal 42" as is shown. It should, of course, be understood that although the radial jet 40 is shown completely in

output chambers

31 and 32 in FIGURES 3 and 4, respectively, it may occupy any position within the receiving chamber C which may be dictated by the relative dicerence between the momentum flux of the input streams 20 and 30 as afliected by input signals applied to the input signal receiving chambers A and B. It should also be understood that in each case any flow which does not appear at the

output tubes

16 and 17 would of course be exhausted through the exhaust tubes 18, 38' and 39' to atmosphere or to a fluid sump as the case may require.

As will be recognized by those skilled in the art, the fonegoing description of a push-pull amplifier in accordance with the present invention utilizes the principles and techniques of the direct impact type proportional amplifier. It should also be understood that without departing from the spirit or scope of the present invention the techniques and principles of the transverse impact proportional amplifier may also be utilized. Such an embodiment in accordance with the present invention is illustrated in FIGURE 5 to which reference is hereby made. As is therein illustrated the power jet 50 is applied through a nozzle 51 into an input signal receiving chamber 52. An input signal may be applied through an input nozzle or tube 53 as is illustrated by the arrow 54 so as to be in a transverse impact relationship with the input signal 50 applied through the nozzle 51. Also an input power jet 60 may be applied through a nozzle 61 into an input signal receiving chamber 62. An input signal may be applied through the input nozzle or tube 63 as is illustrated by the arrow 64 so as to be in a transverse impact relationship with the power jet 60. Under these conditions the axial position of the power jets 50 and 60 may be changed as a result of the transverse impact of the signals 54 and 64 therewith in the input receiving chambers 52 and 62. The axial position of the power jets 50 and 60 being thus changed affects the momentum flux of these power jets and thus causes the radial jet 70 to move within the receiving chamber in accordance with the relative strength of the momentum flux of the power jets 50 and 60 as above described. As the radial jet 70 positions itself in accordance with the relative momentum fluxes of the power jets 50 and 60 the output signals 71, 72 appearing at the output tubes 68 and 69 also change. The system again is arranged in such a manner that under those circumstances wherein there is no input signals 54 and 64 the power jets 50 and 60 being equal in characteristics, the radial jet 70 is positioned in such a manner that the output signals 71 and 72 are substantially equal thus presenting no differential signal therebetween. In a system of the type illustrated in FIGURE 5, the two input signal receiving chambers 52 and 62 are exhausted as is illustrated at 55 and 65 respectively.

It should again be understood that the input signals 54 and 64 may be applied separately or simultaneously and have any particular magnitude which is desired for the particular application under consideration. As was above indicated under these circumstances the radial jet 70 positions itself in accordance with the difference between the momentum fluxes of the two jets 50-60 as aflected by these input signals.

There has thus been disclosed and described two embodiments of a proportional push-pull summing amplifier utilizing the impact principles and techniques of the prior art. Although a detailed description and illustration has been given such is to be taken by way of explanation and illustration only and is not to be taken as a limitation upon the scope of the present invention as defined in the appended claims.

What is claimed is:

1. Pure fluid push-pull summing amplifier comprising:

(A) first and second axially aligned spaced apart input orifices arranged to cause fluid emanating therefrom to impact along the axis of said orifices and form a radial jet;

(B) first input signal means cooperatively arranged to vary the characteristics of fluid emanating from said first orifice to change the position of said radial jet proportional to variations imparted to said fluid;

(C) a receiving chamber surrounding the area where fluid emanating from said orifices impacts;

(D) first and second output openings communicating with said receiving chamber,

( 1) said output openings being spaced oppositely from the point of impact on said axis to produce substantially equal signals at said openings in the absence of an input signal at said first input signal means; and

(E) exhaust means connected to effectively isolate said output openings from each other.

2. Pure fluid amplifier as defined in claim 1 which further includes second input signal means cooperatively arranged to vary the characteristics of fluid emanating from said second nozzle.

3. Pure fluid amplifier as defined in claim 2 in which said exhaust means includes first, second and third exhaust chambers eflectively isolating said first and second output openings from each other and from said first and second input signal means respectively.

4. Pure fluid amplifier as defined in claim 3 wherein said first and second input signal means is arranged not to change flow direction of fluid emanating from said nozzles.

5. Pure fluid amplifier as defined in claim 3 wherein said first and second orifices are defined by first and second input nozzles and said first and second input signal means include fluid flow directing means connected to receive signal fluid and direct it into contact with said fluid emanating from said first and second nozzles.

6. Pure fluid amplifier as defined in claim 5 wherein said first and second input signal fluid flow directing means are second and third orifices surrounding said first and second nozzles respectively.

7. Pure fluid amplifier as defined in claim 5 wherein said first and second input signal means is a pair of nozzles each having an axis disposed transversely of the axis of said first and second input orifices.

8. Pure fluid amplifier as defined in claim 5 wherein said first and second output openings are spaced approximafely equal distances in opposite directions from the center of said receiving chamber.

9. Pure fluid amplifier as defined in claim 8 wherein said receiving chamber includes first and second output chambers, said first and second output openings being in communication With said first and second output chambers respectively, and said first exhaust chamber is disposed between said first and second output chambers.

10. Pure fluid amplifier as defined in claim 9 which further includes a first input signal receiving chamber having said first nozzle orifice disposed therein and said first input signal means including an opening communicating with said first input signal receiving chamber, and a second input signal receiving chamber having said second noZZle orifice disposed therein and said second input signals means includes anopening communicating with said second input signal receiving chamber.

11. Pure fluid amplifier as defined in claim 10 which includes a housing and in which said input signal receiving chambers, said output chambers and said exhaust chambers are defined by substantially parallel spaced apart wall members disposed in said housing, each wall member defining an aperture therein, said apertures being aligned and axially disposed along the axis of said nozzles.

12. Pure fluid amplifier as defined in claim 11 wherein the aperture in said wall members defining said first and second input signal receiving chambers each defines effectively a nozzle orifice concentrically disposed with respect to said first and second input nozzle orifices respectively.

References Cited UNITED STATES PATENTS 3,272,215 9/1966 Buornsen et al 137-81.5

3,279,489 10/1966 Buornsen et a1 13781.5

3,285,263 11/1966 Buornsen et al 137-815 3,323,532 6/1967 Campagnuolo 137-815 M. CARY NELSON, Primary Examiner.

WILLIAM R. CLINE, Assistant Examiner.