US3626965A

US3626965A - Fluidic and/or gate

Info

Publication number: US3626965A
Application number: US1638A
Authority: US
Inventors: Anthony J Healey
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1970-01-09
Filing date: 1970-01-09
Publication date: 1971-12-14
Anticipated expiration: 1988-12-14

Abstract

A fluidic gate having AND and exclusive OR outputs is disclosed in which the switching sensitivity of the gate is selectively determined by simple changes in the interior geometry of the gate.

Description

United States Patent Inventor App]. No.

Filed Patented Assignee Anthony J. Healey State College, Pa.

Jan. 9, 1970 Dec. 14, 1971 Bell Telephone Laboratories, Incorporated Murray Hill, Berkeley Heights, NJ.

FLUlDlC AND/OR GATE 17 Claims, 5 Drawing Figs.

U.S.Cl

lnLCl [50] Field ofSearch l37/8l.5

[56] References Cited UNITED STATES PATENTS 3.285.265 11/1966 Boothe et al 137/815 Primary Examiner-William R. Cline Attorneys-R. J. Guenther and Edwin B. Cave ABSTRACT: A fluidic gate having AND and exclusive OR outputs is disclosed in which the switching sensitivity of the gate is selectively determined by simple changes in the interior geometry of the gate.

PATENTEDUEBHIQR 3,626,965

SHEET 1 OF 3 FIG.

//v VENTOR ANThg NVJ HE AL E V A 7'TOR/VE V PATENIEB 051:1 41971 8,626,965

sum 3 OF 3 noz SWITCHING SENSITIVITY 0 Q I 1 I I.0b L5 b 2.0b 2.5b 3.0b 3.5b 4.0b

OFFSET DISTANCE d r'wmrc AND/R GATE This invention relates to fluidic logic devices and more particularly to fluidic half-adder gates.

BACKGROUND OF THE INVENTION Fluidic half-adder gates may be used to provide the logic functions of AND" and exclusive OR." Such devices have two input ports from which pressurized fluid jets selectively issue. Either jet, appearing alone and exclusively of the other, will be received at a first fluid output. Thus an exclusive OR function is indicated by a fluid flow from the first output. The concurrence of the two jets causes a second fluid output to receive the resultant of the interacting jets. An AND logic function is therefore indicated by fluid flow from this second output.

Such devices are now in general commercial use and were disclosed in such prior patents as US. Pat. No. 3,285,265 issued to W. A. Boothe et al. on Nov. 15, 1966, and US. Pat. No. 3,338,5 l 5, issued to E. M. Dexter on Aug. 29, 1967. However, none of the prior devices provides any method for controlling the switching sensitivity of the device. Switching sensitivity may be defined as the ratio of the pressures in the two inputs at which the pressure in one input is just high enough to switch the jet at the other input from the 0R output to the AND output.

Switching sensitivity is an essential consideration in the selection of components for a fluidic system. If the device is too sensitive, small spurious signals (noise) or impedance mismatches in the system may cause undesired switching of the device. At the other extreme, if the device is too insensitive, it may fail to properly switch in response to low-level input signals.

The optimum switching sensitivity is also a function of the intended application. Obviously if the input jets have relatively high pressure of constant magnitude and the spurious flows are small, an insensitive gate would be much more applicable than if the jets were low pressure, or if the pressure varied widely, or if the signal-to-noise" ratio is low. The system designer must therefore select a device having a switching sensitivity that properly balances the risk of inadvertent switching against the risk of a failure to switch when required.

It is, therefore, an object of my invention to provide simple means for selecting the switching sensitivity of such devices so that a device having the optimum sensitivity may be provided for each application.

SUMMARY OF THE INVENTION In an illustrative embodiment of my invention a wall is provided in the chamber where the two jets interact which helps position the output jets. By locating this wall at a desired and predetermined position relative to the input jets, the desired switching sensitivity may be obtained.

DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a device embodying by invention;

FIG. 2 shows the device of FIG. .1 with the fluid flow path indicated for a first input jet alone;

FIG. 3 shows the device of FIG. 1 with the fluid flow path indicated for a second input jet alone;

FIG. 4 shows the device of FIG. I with the fluid flow path indicated for the two concurrent jets; and

FIG. 5 shows the graphical relationship between the switching sensitivity and the location of the positioning wall.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Fluid logic devices may be constructed from any rigid, nonporous material, including glass, ceramic, plastic and metal. Such devices generally comprise a base, into which the desired passages are impressed or etched, and a cover providing a fluidtight seal which is secured to the base by any of a number of methods, such as adhesives, fasteners, clamps, or the like.

For ease of the illustration, the drawings of FIGS. 1-4 depict a device having a glass cover. This was done to permit the interior of the device to be shown without the confusing presence of cross section lines. This should in no way be interpreted as a limitation on the materials suitable for use in the device, since any rigid, nonporous material is applicable.

The particular device illustrated in FIG. 1 comprises a first fluid input, passage 101, and a second fluid input, passage 102, which connect to independent fluid pressure sources (not shown). These sources provide pressurized fluid selectivity, depending upon system conditions. The inlets I0! and 102 communicate respectively with flow-restricting

nozzles

104 and 105 which are substantially perpendicular to each other. The nozzles act to generate a fluid jet when fluid pressure is present at the respective inlet. The dimensions indicated on the FIGURE will be explained later in detail.

Fluid logic devices of this type usually rely on the Coanda effect, also called the wall attachment phenomenon. This phenomenon results when a fluid jet flows past a wall. The unattached jet traps ambient fluid between the jet and the wall, resulting in a reduction of pressure in the entrainment region. Turbulence increases the entrained flow and the resulting pressure difi'erential across the jet causes the jet to move closer to the wall.

The closer the jet comes to the wall, the greater this force imbalance becomes. Regenerative efl'ects cause the jet to rapidly assume a stable state in which the imbalance forces are minimized. The minimum imbalance state occurs when equilibrium is attained. This occurs when the restraining force exerted by the wall on the jet equals the imbalance force. When this point is reached, the jet has moved so close to the wall, and the forces acting on it have become so strong, that the jet is effectively "attached" to the wall. To break the attachment, equilibrium must be disturbed to such an extent that attachment is broken and a separation of the jet from the wall occurs. Separation occurs at a point and then propagates along the wall until the entire jet is unlocked.

The flow lines in FIG. 2 represent the jet pattern in device 100 when pressurized fluid is present at inlet I01 alone. The exclusive jet issues from nozzle 104 and flows past wall 107. Under the phenomenon just described, the jet attaches itself to wall 107. After flowing past wall 107, the jet is deflected by the curved wall 108. When the jet leaves wall 108, at cusp 109, it has been redirected in a generally downward direction. The jet continues in a relatively straight direction, with the jet diverging slightly, since there is no adjacent wall to which the jet may attach and be supported.

The jet is deflected once again, this time by wall area 112, so that it is received at an output port, receiver 1 14. Fluid flow into conduit 118, whose inlet is receiver 114, is indicative of an exclusive OR" condition, in this case flow from input 101 in the absence of flow from input 102. Any loading effects, or flow resulting from impedance mismatches in the system, which could cause back pressure at receiver 114, is relieved by providing a vent 117 either to the atmosphere or back to the fluid pressure reservoir, depending on the fluid being used.

If pressurized fluid were present at input 102, but not at input 101, the flow pattern of FIG. 3 would be established. The same entrainment wall attachment condition described above will cause the jet from nozzle 105 to attach to wall section 111. The attached jet will then follow wall 1 12 to receiver 114. This is also indicative of the exclusive OR condition since flow is present from input 102 in the absence of flow from input 101. Vent 117 again provides for the release of jet fluid under high load conditions so that the device is maintained at, or near, atmospheric or tank pressure and the integrity of the jet is maintained for all loading conditions.

The resultant jet placement when flow is present at both inputs does not depend upon wall attachment, as previously described. As shown in FIG. 4, if a jet is concurrently present at both nozzles I04 and 105, each will act upon the other. A momentum exchange occurs in which each jet deflects the other from its normal direction. The two deflected jets combine to form a singe resultant jet at an intermediate angle to the original jets.

The curved wall section 108 provides a pocket" in which a circulation is established by the flow of the resultant jet. The circulation creates a higher pressure region near the intersection with wall 107 to hold the resultant jet away from deflecting wall 108 and prevent any deflection towards output 14. At the same time, a lower pressure region is created within the circulation region, which is dependent upon the position of the edge of the jet relative to cusp 109. This phenomenon, known as knife edge attachment," creates a force to position the resultant jet neat the cusp. A second, circulation is created as the resultant jet flows past cusp 109. This circulation, resulting from the knife edge attachment at cusp 109, causes the resultant jet to be guided to receiver 115. The presence of fluid flow through receiver 1 15 into conduit 119 provides the AND logic function and indicates the simultaneous presence of pressurized fluid at

inputs

101 and 102. Vent 117 provides for high load conditions as previously described.

The action of the jets within the device is a function of the relative internal geometry of the device. Since the actual dimensions of the device have relatively little significance, this discussion will be in terms of relative dimensions using the width b of

nozzles

104 and 105 as a unit measure.

The length y of wall 1 11 is normally approximately equal to b. If length y were less than b, the wall surface presented to a v jet from nozzle 105 would be insufficient to provide good attachment characteristics. At the other extreme, if y became too long, the wall 111 would provide a very strong attachment to the jet making it difficult to switch the jet off the wall. This in effect would make the device approach the relatively insensitive device in which a is The consequences of this will be discussed later.

- The radius R of wall 108 normally approximates 2b. If a smaller radius is used, insufficient space is provided for guiding a jet of width b from nozzle 104 and changing is direction. As a result, a highly turbulent condition is created and the jet becomes fragmented. If the radius is increased, less pressure is required for a jet at nozzle 104 to switch a jet from wall 111 towards receiver 115 making the device hypersensitive, as well as making it difficult to obtain a strong attachment to wall 1 12 under the flow condition shown in FIG. 3.

Angle 0 is optimized at approximately 45 if

nozzles

104 and 105 are approximately perpendicular. Since the resultant of two equal and perpendicular jets would travel away at a bisecting angle, receiver 1 15 would most effectively be placed along the bisector. If it were placed to either side of the bisector, only a percentage of the resultant jet would be received and the balance would spill over into vent region 117. Of course, the angle B between

nozzles

104 and 105 could be varies to change the bisector. However, if B were less than 90, the separation between the AND and OR outputs would be decreased, thereby increasing the possibility of a jet causing an unintended effect at the wrong output. If B were greater than 90, the jets would have an undesirable effect on each other caused by the jet being partially directed back through the other orifice.

The length L of wall 112 is nominally 13b. If the length is increased, the dispersion of the jet before it reaches receiver 114 increases and causes loss of pressure recovery. Decreasing the length of wall 112 results in the deflected jet of FIG. 2 being "focused" at a point beyond receiver 114. Once again, a disruption of the regular jet flow occurs and pressure recovery is low.

The effects of the angle a of wall 112 and the length d of wall 107 may be understood by referring to FIG. 5 which shows graphically the relationship between a, d and switching sensitivity P /P Switching sensitivity is the ratio between the pressure in one jet required to switch the other jet from the OR output to the AND output and the pressure in the other jet. Stated in numerical terms, if a jet is issuing from nozzle 104 with a pressure of l0 p.s.i. at input 101, and a jet issuing from nozzle 105 having a pressure of l psi. at input 102 is required to switch the resultant jet from receiver '1 14 to receiver 115, the switching sensitivity of the device is l/lOor 0.10. Pressures below this critical value will deflect the other jet but it will reattach itself to the wall after passing the nozzle.

Highly sensitive devices appear at the bottom of FIG. 5 and relatively insensitive devices appear towards the top. It should also be borne in mind that although the curve for B=20 appears fairly flat, the sensitivity change is from approximately 0.075 to approximately 0.125, which represents a decrease in sensitivity of approximately 67 percent.

The angle a of wall 112 determines how "tightly" the jet from nozzle attaches to wall 112. As 1: decreases, the attachment increases and it becomes more difficult to switch the jet. Therefore, as 41 decreases, a device becomes less sensitive. High values of a result in highly sensitive devices. In this respect, the selection of a value of a by a fluidic system designer is analogous to a rough selection or "coarse adjustment."

The "fine tuning is provided by selecting a value for the length d of wall 107. If wall 107 is very short, or not present at all, the force due to wall attachment exerted on a jet from nozzle 105 by the short wall 107 is minimal. Hence, small variations in the length of wall 107 when d is less than b have little corresponding effect of the switching sensitivity.

lf wall 107 is very long, curved wall 108 becomes so far displaced from

nozzles

104 and 105 that it cannot exert a meaningful influence on the jets. The force that wall 108 exerts on the resultant AND jet is slight, and as a result, variations in the length of wall 107 where d is greater than 4b also have only minimal effect on the switching sensitivity. Thus, it can be seen that only in the approximate range of d greater than b but less than 4b is it possible to make a meaningful selection of the suitable sensitivity.

Using my invention, a fluidics system designer may determine the switching sensitivity he needs for a device in a particular application. Then, by consulting FIG. 5, he may choose the particular value of angle a necessary to yield the approximate sensitivity necessary. He then selects a value of displacement d to yield the specific sensitivity desired. The needed device may then be constructed in accordance with the selected values. Thus, the optimum switching sensitivity may be provided for each device in the system.

Only representative curves for a=0, a=l0 and a=20 are shown in FIG. 5. It should, however, be readily apparent that similar curves, for other values of a, are within the scope of 'the family of curves respectively shown.

Despite the fact that the embodiment describes a passive device, it should also be apparent that the inventive principles are equally applicable to an active device in which either input is continuously present and the active output is determined by the presence or absence of a control jet at the other input.

It should be apparent that my invention could also be applied to fabricate a device having a variable sensitivity. If

walls

107 and 108 were fabricated from a deformable material, or if wall 107 were positioned along an adjustable track, the displacement d could be varied when desired. However, since the optimum switching sensitivity of a device in a particular application does not change, the more usual application of my invention will probably be in selectively fabricating nonadjustable devices.

What is claimed is:

1. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet,

a second aperture adjacent the first aperture for generating a second fluid jet transverse to the axis of the first jet,

an OR receiver positioned to receive the generated first jet in the absence of the second jet,

an AND receiver positioned to receive a resultant jet produced by concurrent generation of the first and second jets, and

a walled chamber in which the concurrently generated first and second jets interact, a first wall of the chamber including an initial section, adjacent the first aperture and having a length exceeding the width of the first aperture, to which the second jet attached itself and a curved section separated from the first aperture by the initial section for redirecting the attached jet to be received at the OR receiver and for positioning the resultant jet to be received by the AND receiver, the curved section being located relative to the first and second apertures in accordance with a predetennined relationship for imparting the desired switching sensitivity to the device.

2. A device in accordance with claim 1 further including a second wall, positioned intermediate the first and second apertures and the R receiver, to which the first jet attaches in the absence of the second jet and to which the redirected second jet attaches in the absence of the first j the second wall being positioned relative to the axis of the first jet in accordance with a second predetermined relationship to impart the desired switching sensitivity to the device.

3. A device in accordance with claim 2 wherein the second predetermined relationship is shown by FIG. in which angle n represents the divergence between the second wall and the axis of the first jet.

4. A device in accordance with claim 1 wherein the predetennined relationship is shown by F IG. 5 in which distance d represents the distance between the curved section means and the first aperture.

5. A device in accordance with claim 5 wherein distance d varies between b and 4b, where b is the width of the first aperture.

6. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet,

an AND receiver positioned to receive the resultant jet produced by the concurrent generation of the first and second jets,

means for redirecting the second jet in the absence of the first jet so that the second jet is received at the OR receiver,

a first wall located between the redirecting means and the first and second apertures to which the second jet attaches in the absence of the first jet, and

a second wall, positioned intennediate the first and second apertures and the OR receiver, to which the first jet attaches in the absence of the second jet and to which the redirected second jet attaches in the absence of the first jet,

the second wall being positioned relative to the axis of the first jet in accordance with a predetermined relationship to impart the desired switching sensitivity to the device.

7. A device in accordance with claim 6 wherein the predetermined relationship is shown by FIG. 5 where angle a represents the divergence between the second wall and the axis of the first jet.

8. A device in accordance with claim 6 wherein the redirecting means is located relative to the first and second aperture in accordance with a second predetermined relationship for imparting the desired switching sensitivity to the device.

9. A device in accordance with claim 8 wherein the second predetermined relationship is shown by FIG. 5 in which distance d represents the length of the first wall and the distance between the redirecting means and the first aperture.

10. A device in accordance with claim 9 wherein distance d varies between b and 4b, where b is the width of the first aperture.

11. A fluidic logic device having a predetermined switching sensitivity comprising a first fluid passage,

a first flow restrictor communication with the first passage for generating a first fluid jet in response to fluid flow in the first passage,

a second fluid passage,

a second flow restrictor communicating with the second passage and adjacent the first restrictor for generating a second fluid jet along an axis transverse to the axis of the first jet in response to fluid flow in the second passage,

a first receiver positioned to receive either jet in the absence of the other jet,

a first fluid conduit communicating with the first receiver for issuing a fluidic signal indicative of an exclusive OR logical function in response to the receipt of a jet by the first receiver,

a second receiver positioned to receive a resultant jet produced by the concurrent generation of the first and second jets,

a second fluid conduit communicating with the second receiver for issuing a fluidic signal indicative of an AND logical function in response to the receipt of a jet by the second receiver, and

a multiwalled chamber communicating with the first and second restrictors and the first and second receivers,

a first wall of the chamber being located so that either jet, in the absence of the other jet, attaches thereto and is delivered to the first receiver,

a second wall of the chamber being located so that the second jet, in the absence of the first jet, is redirected from its normal axis to attach to the first wall and so that the resultant jet is positioned to be received by the second receiver, the second wall including a section adjacent the first restrictor to which the second jet attaches in the absence of the first jet, and

a curved section abutting the section adjacent the first restrictor for both positioning the resultant jet and for redirecting the second jet from its normal axis to another axis in the absence of the first jet,

the location of the first and second walls being in accordance with a predetermined relationship to impart the desired switching sensitivity to the device.

12. A fluidic logic device having a predetermined switching sensitivity comprising a first fluid passage,

a first flow restrictor communicating with the first passage for generating a first fluid jet in response to fluid flow in the first passage,

a second fluid passage,

a second flow restrictor communicating with the second passage and adjacent the first restrictor for generating a second fluid jet, along an axis transverse to the axis of the first jet, in response to fluid flow in the second passage,

a first receiver for receiving either jet in the absence of the other jet,

a first fluid conduit communicating with the first receiver for producing an exclusive OR fluidic logic signal in response to receipt of a jet by the first receiver,

a second receiver for receiving a resultant jet produced by the concurrent generation of the first and second jets,

A second fluid conduit communicating with the second receiver for producing an AND fluidic logic signal in response to receipt of a jet by the second receiver,

a walled chamber communicating with the first and second restrictors and including a first wall section, adjacent the second restrictor and parallel to the axis of the first jet, to which the first jet attaches in the absence of the second jet,

a second wall section, adjacent the first restrictor and parallel to the axis of the second jet, to which the second jet attaches in the absence of the first jet,

a third wall section contiguous to the second section for deflecting the jet attached to the second section away from its normal axis to an altered axis which intersects the normal axis of the first jet,

a cusp contiguous to the third section for positioning the resultant jet to be received at the second receiver, and

a fourth wall section contiguous to the first section to which the altered jet attaches and for delivering to the first receiver both the altered jet and the jet attached to the first wall section, and

a vent passage located between the first and second receiver for relieving fluid pressure in the chamber, and wherein the length of the second wall section, and the resulting location of the third wall section relative to the first and second restrictors, is in accordance with a first predetermined relationship and the angle of divergence between the fourth wall section and the axis of the first jet is in accordance with a second predetermined relationship for imparting a desired and predetennined switching sensitivity to the device.

13. A device in accordance with claim 12 wherein the first and second predetermined relationships are shown by FIG. in which distance d represents the distance between the third'wall section and the first restrictor and angle or represents the divergence between the fourth wall section and the axis of the first jet.

14. A device in accordance with claim 13 wherein distance d varies between b and 4b, where b is the width of the first restrictor.

15. A device in accordance with claim 11 wherein the section adjacent the first restrictor has a length exceeding the width of the first restrictor, the length being determined by the placement of the curved section of the second wall relative to the first restrictor,

the angle of divergence between the first wall and the axis of the first jet determines the placement of the first wall and the predetermined relationship is shown by FIG. 5 where distance d represents the distance between the first restrictor and the curved wall, and angle a represents the divergence between the first wall and the axis of the first jet.

16. A device in accordance with claim 15 wherein distance d varies between b and 4b, where b is the width of the first restrictor.

17. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet,

an AND receiver positioned to receive a resultant jet produced by the concurrent generation of the first and second jets, and

a walled chamber wherein the generated first and second jets interact and which includes a first wall section, adjacent the second aperture, to which the first jet attaches in the absence of the second jet,

a second wall section, adjacent the first aperture, to which the second jet attaches in the absence of the first jet,

a cusp contiguous to the third section for positioning the resultant jet to be received at the AND receiver, and

a fourth wall section contiguous to the first section and at a diverging angle to the axis of the first jet to which the altered jet attaches and for delivering both the altered jet and the jet attached to the first wall section to the OR receiver,

the length of the second wall section, and the resulting location of the third wall section relative to the first and second apertures, is in accordance with a first predetermined relationship and the angle of divergence between the fourth wall section and the axis of the first jet is in accordance with a second predetermined relationship for imparting a desired and predetermined switching sensitivity to the device.

I 1 i i UNITED STATES PATENT OFFICE CERTIFICATE ()F CORRECTION Patent No. 3, 626, 965 Dated December 1 1971 Inventor-(s) Anthony J. Healey It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 58, change "by" to -my- Column 3, line 7, change "1 1" to "11 1"; line 12, change "neat" to "nearline 12, before "circulation" insert -sma11er-; line 37, change "is" to its; lines 51 and 52, change "varies" to -varied Column line 7, change "6" to a; line 24, change "of" to on-; line 34, change "suitable" to switching; line 71, before "concurrent" insert --the. Column 5, line 3, change "attached" to attaches; line 28, delete "means"; line 29, change "5" to t"; line 62, change "aperture to -apertures--. Column 6, line 1, change "communication" to -communicating-; line 59, change "A" to -a. Column 7, line 5, change "receiver" to receivers-.

Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDWJ TRQMJLETQLERJR. ROBERT GOTISCHALK Attesting Officer Commissioner of Patents FORM PO-ZOSO (10-69) USCOMM-DC 60376-P69 u.s. GOVERNMENT PRINTING OFFICE: i969 0-366-334

Claims

1. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet, a second aperture adjacent the first aperture for generating a second fluid jet transverse to the axis of the first jet, an OR receiver positioned to receive the generated first jet in the absence of the second jet, an AND receiver positioned to receive a resultant jet produced by the concurrent generation of the first and second jets, and a walled chamber in which the concurrently generated first and second jets interact, a first wall of the chamber including an initial section, adjacent the first aperture and having a length exceeding the width of the first aperture, to which the second jet attaches itself and a curved section separated from the first aperture by the initial section for redirecting the attached jet to be received at the OR receiver and for positioning the resultant jet to be received by the AND receiver, the curved section being located relative to the first and second apertures in accordance with a predetermined relationship for imparting the desired switching sensitivity to the device.

2. A device in accordance with claim 1 further including a second wall, positioned intermediate the first and second apertures and the OR receiver, to which the first jet attaches in the absence of the second jet and to which the redirected second jet attaches in the absence of the first jet, the second wall being positioned relative to the axis of the first jet in accordance with a second predetermined relationship to impart the desired switching sensitivity to the device.

3. A device in accordance with claim 2 wherein the second predetermined relationship is shown by FIG. 5 in which angle Alpha represents the divergence between the second wall and the axis of the first jet.

4. A device in accordance with claim 1 wherein the predetermined relationship is shown by FIG. 5 in which distance d represents the distance between the curved section means and the first aperture.

5. A device in accordance with claim 4 wherein distance d varies between b and 4b, where b is the width of the first aperture.

6. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet, a second aperture adjacent the first aperture for generating a second fluid jet transverse to the axis of the first jet, an OR receiver positioned to receive the generated first jet in the absence of the second jet, an AND receiver positioned to receive the resultant jet produced by the concurrent generation of the first and second jets, means for redirecting the second jet in the absence of the first jet so that the Second jet is received at the OR receiver, a first wall located between the redirecting means and the first and second apertures to which the second jet attaches in the absence of the first jet, and a second wall, positioned intermediate the first and second apertures and the OR receiver, to which the first jet attaches in the absence of the second jet and to which the redirected second jet attaches in the absence of the first jet, the second wall being positioned relative to the axis of the first jet in accordance with a predetermined relationship to impart the desired switching sensitivity to the device.

7. A device in accordance with claim 6 wherein the predetermined relationship is shown by FIG. 5 where angle Alpha represents the divergence between the second wall and the axis of the first jet.

8. A device in accordance with claim 6 wherein the redirecting means is located relative to the first and second apertures in accordance with a second predetermined relationship for imparting the desired switching sensitivity to the device.

11. A fluidic logic device having a predetermined switching sensitivity comprising a first fluid passage, a first flow restrictor communicating with the first passage for generating a first fluid jet in response to fluid flow in the first passage, a second fluid passage, a second flow restrictor communicating with the second passage and adjacent the first restrictor for generating a second fluid jet along an axis transverse to the axis of the first jet in response to fluid flow in the second passage, a first receiver positioned to receive either jet in the absence of the other jet, a first fluid conduit communicating with the first receiver for issuing a fluidic signal indicative of an exclusive OR logical function in response to the receipt of a jet by the first receiver, a second receiver positioned to receive a resultant jet produced by the concurrent generation of the first and second jets, a second fluid conduit communicating with the second receiver for issuing a fluidic signal indicative of an AND logical function in response to the receipt of a jet by the second receiver, and a multiwalled chamber communicating with the first and second restrictors and the first and second receivers, a first wall of the chamber being located so that either jet, in the absence of the other jet, attaches thereto and is delivered to the first receiver, a second wall of the chamber being located so that the second jet, in the absence of the first jet, is redirected from its normal axis to attach to the first wall and so that the resultant jet is positioned to be received by the second receiver, the second wall including a section adjacent the first restrictor to which the second jet attaches in the absence of the first jet, and a curved section abutting the section adjacent the first restrictor for both positioning the resultant jet and for redirecting the second jet from its normal axis to another axis in the absence of the first jet, the location of the first and second walls being in accordance with a predetermined relationship to impart the desired switching sensitivity to the device.

12. A fluidic logic device having a predetermined switching sensitivity comprising a first fluid passage, a first flow restrictor communicating with the first passage for generating a first fluid jet in response to fluid flow in the first passage, a second fluid passage, a second flow restrictor communicating with the second passage and adjaCent the first restrictor for generating a second fluid jet, along an axis transverse to the axis of the first jet, in response to fluid flow in the second passage, a first receiver for receiving either jet in the absence of the other jet, a first fluid conduit communicating with the first receiver for producing an exclusive OR fluidic logic signal in response to receipt of a jet by the first receiver, a second receiver for receiving a resultant jet produced by the concurrent generation of the first and second jets, A second fluid conduit communicating with the second receiver for producing an AND fluidic logic signal in response to receipt of a jet by the second receiver, a walled chamber communicating with the first and second restrictors and including a first wall section, adjacent the second restrictor and parallel to the axis of the first jet, to which the first jet attaches in the absence of the second jet, a second wall section, adjacent the first restrictor and parallel to the axis of the second jet, to which the second jet attaches in the absence of the first jet, a third wall section contiguous to the second section for deflecting the jet attached to the second section away from its normal axis to an altered axis which intersects the normal axis of the first jet, a cusp contiguous to the third section for positioning the resultant jet to be received at the second receiver, and a fourth wall section contiguous to the first section to which the altered jet attaches and for delivering to the first receiver both the altered jet and the jet attached to the first wall section, and a vent passage located between the first and second receiver for relieving fluid pressure in the chamber, and wherein the length of the second wall section, and the resulting location of the third wall section relative to the first and second restrictors, is in accordance with a first predetermined relationship and the angle of divergence between the fourth wall section and the axis of the first jet is in accordance with a second predetermined relationship for imparting a desired and predetermined switching sensitivity to the device.

13. A device in accordance with claim 12 wherein the first and second predetermined relationships are shown by FIG. 5 in which distance d represents the distance between the third wall section and the first restrictor and angle Alpha represents the divergence between the fourth wall section and the axis of the first jet.

15. A device in accordance with claim 11 wherein the section adjacent the first restrictor has a length exceeding the width of the first restrictor, the length being determined by the placement of the curved section of the second wall relative to the first restrictor, the angle of divergence between the first wall and the axis of the first jet determines the placement of the first wall and the predetermined relationship is shown by FIG. 5 where distance d represents the distance between the first restrictor and the curved wall, and angle Alpha represents the divergence between the first wall and the axis of the first jet.

17. A fluidic logic device having a predetermined switching sensitivity comprising a first aperture for generating a first fluid jet, a second aperture adjacent the first aperture for generating a second fluid jet transverse to the axis of the first jet, an OR receiver positioned to receive the generated first jet in the absence of the second jet, an AND receiver positioned to receive a resultant jet produced by the concurrent generation of the first and second jets, and A walled chamber wherein the generated first and second jets interact and which includes a first wall section, adjacent the second aperture, to which the first jet attaches in the absence of the second jet, a second wall section, adjacent the first aperture, to which the second jet attaches in the absence of the first jet, a third wall section contiguous to the second section for deflecting the jet attached to the second section away from its normal axis to an altered axis which intersects the normal axis of the first jet, a cusp contiguous to the third section for positioning the resultant jet to be received at the AND receiver, and a fourth wall section contiguous to the first section and at a diverging angle to the axis of the first jet to which the altered jet attaches and for delivering both the altered jet and the jet attached to the first wall section to the OR receiver, the length of the second wall section, and the resulting location of the third wall section relative to the first and second apertures, is in accordance with a first predetermined relationship and the angle of divergence between the fourth wall section and the axis of the first jet is in accordance with a second predetermined relationship for imparting a desired and predetermined switching sensitivity to the device.