US3786838A - Fluid multi-and logical circuit - Google Patents

Abstract

Disclosed herein in a MULTI-AND fluid logic circuit comprising essentially of a conventional fluid amplifier having a power source, first and second control channels and first and second output channels. The amplifier is provided with biasing means which is associated with one of the control channels and means are associated with the other control channel for producing a control signal which is a function of a predetermined number of external signals. More particularly, this last named means comprises a plurality of aspirators, each having an input nozzle and an exhaust nozzle and each connected to an enclosed manifold which in turn is in fluid communication with the second control channel of the fluid amplifier. The operation is such that the simultaneous presence of a fluid signal in all aspirators creates a sufficient pressure change to switch the fluid stream in the fluid amplifier from the first output channel to the second output channel.

Description

United States Patent n 1 Swartz [111 3,786,838 [451 Jan. 22, 1974 FLUID MULTl-AND LOGICAL CIRCUIT [75] Inventor: Elmer L. Swartz, Annandale, Va. [73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: May 22, 1973 '[21 Appl. No.: 362,720

[52] US. Cl 137/814, 137/8 25 ,13:l /3:l,

[51] Int. Cl. F15c 1/14 [58] Field of Search 137/814, 825, 836, 837;

235/201 R, 201 FS, 201 PF, 201 ME [56] References Cited UNITED STATES PATENTS 3,499,459 3/1970 Swartz 137/836 X 3,442,279 5/1969 Swartz 137/836 3,425,431 2/1969 Heskestad 137/836 3,380,655 4/1968 Swartz 235/201 PF 3,324,730 6/1967 Bowles.... 235/201 PF 3,191,611 6/1965 Bauer 235/201 PF X Primary Examiner-Alan Cohan Assistant Examiner-Ira S. Lazarus Attorney, Agent, or Firm-Edward J. Kelly; Herbert Berl; Saul Elbaum [5 7] ABSTRACT Disclosed herein in a MULTI-AND fluid logic circuit comprising essentially of a conventional fluid amplifier having a power source, first and second control channels and first and second output channels. The amplifier is provided with biasing means which is associated with one of the control channels and means are associated with the other control channel for producing a 3 Claims, 3 Drawing Figures 1 FLUID MULTI-AND LOGICAL CIRCUIT RIGHTS OF THE GOVERNMENT The invention described herein may be manufactured, used and licensed by or for the United States Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to MULTl-AND fluid logic devices, and more particularly to a MULTI-AND'fluid logic device utilizing only a single fluid amplifier in combination with a manifold which is associated with a plurality of aspirators.

A fluid AND device is such that it must have a signal present at every input in order to produce an ANDED output signal. In the prior art, a single AND device generally combines two input signals to produce the ANDED output. Such a device usually combines two fluid amplifiers in which the power nozzles of each of the amplifiers consist of the two inputs and in which one output channel from each of the amplifiers is tied together to constitute the ANDED output. If many such signals are to be ANDED, then the outputs of the individual AND units must further be ANDED until there is a single output from the device. Thus, A schematic device for ANDING eight fluid signals would require the use of eight separate AND units which would, in turn, require the use of sixteen fluid amplifiers. In such a circuit arrangement, the output signal would be approximately only six percent of the input signal pressure, assuming all input signals are about equal amplitudes.

It is, therefore, a primary object of this invention to provide a MULTI-AND circuit which does not suffer from any of the aforementioned disadvantages.

Still another object of this invention is to provide a MULTl-AND circuit which utilizes only a single fluid amplifier in its construction.

Another object of this invention is to provide a fluid MULTI-AND circuit in which there can be a wide variation in amplitude of each of the several input signals.

Yet another object of this invention is to provide a circuit which utilizes less space and is far simpler and cheaper to constructthan are prior art devices.

SUMMARY OF THE INVENTION Briefly, in accordance with this invention, a MULTI- AND fluid logic circuit is provided which comprises a fluid amplifier having a power source, first and second output channels and first and second control channels. Biasing means associated with the first control channel is provided for directing the fluid stream into the first output channel in the absence of a more powerful control signal. Means are associated with the second control channel for producing a control signal to switch the fluid stream whenever a predetermined number of external signals to be ANDED are simultaneously provided. This last named means comprises a plurality of aspirators, each having an input nozzle and an exhaust nozzle and each being in fluid communication with an enclosed manifold. The manifold is, in turn, in fluid communication with the second control channel. Upon the simultaneous application of fluid signals in each of the aspirators, a sufficient reduction in pressure occurs in the second control channel such that the power fluid DESCRIPTION OF THE EMBODIMENT The specific nature of the invention as well as other objects and advantages thereof will clearly be apparent from the following description and associated drawings.

FIG. 1 illustrates the fluid flow in the MULTl-AND circuit in the absence of signals applied to the aspirator channels.

FIG. 2 illustrates the fluid flow with all input signals applied.

FIG. 3 illustrates the fluid flow with all but one input signal applied.

Referring now to FIG. 1, amplifier 10 is provided with power input nozzle 11 for issuing a stream of fluid into interaction region 14, whereupon the fluid is diverted to either of output channels 12 or 13. Control channels 15 and 16 are provided in fluid communication with interaction region 14 to provide the appropriate switching area. Bias channel 17 connects fluid from power nozzle 11 to control channel 15 such that under normal flow conditions fluid in power nozzle 11 would be partially diverted into bias channel 17 and would exit to atmosphere by way of control channel 15. This flow of fluid in bias channel 17 would create a low pressure region immediately adjacent the left hand portion of interaction region 14 which would in turn cause the main power fluid to be deflected toward the left and to exit, as shown, through output channel 13.

Control channel 16, which is located at the right hand side of interaction region 14, is in fluid communication with an extended manifold region 50. Manifold 50 is provided with a plurality of aspirator channels 1 through 8 which communicate with a source of power fluid as well as with atmosphere. More particularly, each aspirator is connected to manifold 50 by means of a channel 53 which is in fluid communication with a channel 51. Channel 51 is provided with an input nozzle 54 which may be connected to a source of pressurized fluid and with an exit nozzle 52. The arrangement shown in FIG. 1 assumes that no fluid signals are present near any of the aspirator signal sources 1 through 8. Accordingly, manifold 50 is in fluid communication with atmosphere by means of channel 53 and exit nozzle 52. With this arrangement, the fluid flow in amplifier 10 would be as indicated by the arrow, that is, fluid bias channel 17 would cause the power fluid to exit by way of output channel 13.

Referring now to FIG. 2, this arrangement assumes that each of the aspirator channels 51 is provided with an active source of fluid signal 1 through 8. Each of these said fluid signals causes fluid to enter the aspirator channel and to exit by means of exhaust nozzle 52. As fluid exits from exhaust nozzle 52, suction is created in the region of channel 53. Each of the aspirators contributes a certain amount of suction within the manifold 50 such that the total amount of suction created by the added effect of all eight aspirator channels tends to create a low pressure region immediately to the right hand side of interaction region 14 and within control channel 16. When the low pressure in control channel 16 is such that it overcomes the low pressure within control channel 15, the power fluid is caused to switch from outputs of channel 13 and to exit instead through output channel 12. Thus, upon the application of all eight signals in all eight aspirator channels, an ANDED output signal is achieved in amplifier by the presence of power fluid in output channel 12.

FIG. 3 illustrates the situation in which any one aspirator channel, such as channel 3, is not provided with a signal source. In this illustration, the absence of fluid flow in aspirator channel 3 enables manifold 50 to be in fluid communication with atmosphere. This fluid communication with atmosphere is sufficient to draw in fluid into manifold 50 and to thereby counteract the suction created by each of the other aspirator channels. A single aspirator channel which does not contain a fluid signal will be sufficient to replace enough air into manifold 50 to void the combined suction effects of each of the other aspirators. This is true regardless of how many aspirator channels are provided in communication with the manifold channel. Thus, in the example of FIG. 3, a sufficient amount of low pressure in control channel 16 is not achieved and the power fluid continues to exit through output channel 13 of amplifier 10. It is significant that there can be wide variations in amplitude in each of the eight signal input pressures, sinceit takes only a very small signal to essentially seal off atmospheric pressure from manifold 50;

Referring back to FIG. 1, it should be noted that the bias means for amplifier 10 need not necessarily be in the form of a bias channel 17. Alternatively, the bias means can consist of an additional amplifier 30, having inputchannel 31, control channels 32 and 33, and output channels 34 and 35. Output channel 35 is provided in fluid communication with control channel 15 of amplifier 10 by means of an extended channel portion 36. Upon the application of appropriate control signals through amplifier 30 such that fluid is caused to flow through channels 35 and 36, the reduced pressure region would again be created in control channel 15 which would in turn cause fluid amplifier 10 to be biased left wise as shown. Still additional and alternative types of biasing arrangements can be utilized, such as the NOR type. In this type of biasing arrangement, the amplifier is biased to the left side when no switching signal is present in the right control side. A switching signal in this case means a reduced pressure. In any case, the amplifier 10 should be biased such that output should flow through left output channel 13 when the power jet pressure is initially applied and in the absence of the appropriate number of aspirator signals.

It will thus be apparent that a MULTI-AND device has been illustrated which is capable of producing an ANDED output signal whenever a predetermined num ber of input signals are simultaneously applied. More importantly, the device is such that it requires very little space and is extremely simple and easy to construct. The aspirator signals 1 through 8 need not be of uniform or identical size or pressure since a very small signal is capable of essentially sealing off atmospheric communication with the manifold 50. Additionally, the number of aspirator signals can be readily and easily added or subtracted to the device as desired.

I wish'it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications can be made by a person skilled in the art.

I claim as my invention:

1. A MULTl-AND fluid logic circuit comprising:

a. a fluid amplifier having a power source issuing a fluid stream into an interaction region, first and second output channels for receiving said fluid stream and first and second control channels for directing said fluid stream into said output channels;

b. biasing means associated with said first control channel for directing said fluid stream into said first output channel in the absence of a more powerful control signal;

c. means associated with said second control channel for producing a control signal for switching said fluid stream into said second output channel;

(1. said last named means comprising a plurality of aspirators each having an input nozzle, an exhaust nozzle and a connecting nozzle in communication with an enclosed manifold, said manifold being in fluid communication with said second control channel, whereby the simultaneous presence of a fluid signal in all of said aspirators creates a sufficient pressure reduction to switch said fluid stream from said first output channel to said second output channel.

2. The device of claim 1 wherein said biasing means comprises a bias channel providing fluid communication between said power source and said first control channel, whereby fluid flowing in said bias channel creates a low pressure signal in said first control channel.

3. The device of claim 1 wherein said biasing means comprises a second fluid amplifier having an output channel and fluid communication with said first control channel, whereby fluid flow in said output channel of said second fluid amplifier creates a low pressure signal in said first control channel.

Claims (3)

1. A MULTI-AND fluid logic circuit comprising: a. a fluid amplifier having a power source issuing a fluid stream into an interaction region, first and second output channels for receiving said fluid stream and first and second control channels for directing said fluid stream into said output channels; b. biasing Means associated with said first control channel for directing said fluid stream into said first output channel in the absence of a more powerful control signal; c. means associated with said second control channel for producing a control signal for switching said fluid stream into said second output channel; d. said last named means comprising a plurality of aspirators each having an input nozzle, an exhaust nozzle and a connecting nozzle in communication with an enclosed manifold, said manifold being in fluid communication with said second control channel, whereby the simultaneous presence of a fluid signal in all of said aspirators creates a sufficient pressure reduction to switch said fluid stream from said first output channel to said second output channel.

2. The device of claim 1 wherein said biasing means comprises a bias channel providing fluid communication between said power source and said first control channel, whereby fluid flowing in said bias channel creates a low pressure signal in said first control channel.

3. The device of claim 1 wherein said biasing means comprises a second fluid amplifier having an output channel and fluid communication with said first control channel, whereby fluid flow in said output channel of said second fluid amplifier creates a low pressure signal in said first control channel.

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