US3528443A

US3528443A - Fluid induction nor gate

Info

Publication number: US3528443A
Application number: US734279A
Authority: US
Inventors: Elmer L Swartz
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1968-06-04
Filing date: 1968-06-04
Publication date: 1970-09-15
Anticipated expiration: 1987-09-15

Description

Sept 15, 1970 E. L. swARTz 3,528,443

l FLUID INDUCTION NOR GATE Filed June 4,l 1968 ELMER L. SWARTZ 7a. 5M Hmmm@ aww ATTORNEYS United States Patent Office 3,528,443 Patented Sept. 15., 1970 U..S. Cl. 13 7-815 4 Claims ABSTRACT OF THE DISCLOSURE A fluid NOR gate whereinthe actuating signal flow does not enter the control channel or Iflow into the main power stream as with most fluid amplifiers. A monostable fluid amplifier of the close wall variety is used with an aspirator located at the end of the active'control channel. When the control signalpasses through the aspirator section it lowers the pressure within the control channel causing the main power stream to switch channels.

RIGHTS4 OF GOVERNMENT This 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 OP THE INVENTION A basic element in the development of uid logic circuits is the element which performs the NOR function. In the design of NOR gates it is important that the devices have a high pressure recovery, high gain, and a constant low input impedance.

In prior systems the control signal used to switch the power stream from its monostable channel to the unstable channel has always consisted of a control signal which flows into the power stream. Because of this factor it is extremely difficult to design such systems for optimum gain and pressure recovery. Difficulties also arise in such a design in maintaining constant low input impedance to the device.

It is therefore an object of this invention to provide a fluid induction NOR gate `which will provide a device with high pressure recovery.

An additional object of the invention is to provide a fluid induction NOR gate which provides a high pressure gain.

Still an additional object of the invention is to provide a NOR fluid induction NOR gate with constant low input impedance.

Yet another object of the invention is to provide a liuid induction NOR gate that has complete decoupling from the control function in the absence of control signals.

SUMMARY OF THE INVENTION A monostable fluid amplifier of the close wall variety is designed with an aspirator located at the end of a control channel. When a signal input passes through the aspirator section it will lower` the pressure in that part of the control channel between the aspirator and interaction chamber before passing out through the aspirator exhaust. The lowered pressure in the control channel will cause the NOR to switch to the unstable output condition. Removal of the control input signal from the aspirator section will cause the NOR to switch back to its stable output condition.

BRIEF DESCRIPTION OF THE DRAWING The specific nature of the invention as |well as other objects, aspects, uses, and advantages thereof will clearly appear from the following description and from the accompanying drawing, in which:

FIG. l illustrates a fluid induction NOR gate in accordance with my invention with no control signal applied.

FIG. 2 illustrates the fluid induction NOR gate of Y FII-G. l with a control input signal applied.

DESCRIPTION `01:" 'ITI-IIE PREFERRED lEMBODIMENTS FIG. 1 shows the fluid induction .NOR gate of my invention in its monostable state with no control signal present. The amplifier 11 has a main amplifier power input 34 which enters the amplifier through channel 35. The left control channel 36 and the mutual control channel 30l are at right angles to the mouth of channel 3K5. The power stream passes through channel 35 and travels upward between the right boundary wall 28 and the left boundary wall 40. The right boundary wall is set back from the main channel at corner 29 while the left boundary wall does not have such a set back at corner 41. Right bleed channel 24 and left bleed channel 43- are positioned in the power stream upstream of the blunt nose splitter 45. The purpose of the blunt nose splitter is to cause the formation of stabilizing vortex 27. The splitter 45 delines the right and

left output channel

26 and 44 which are of equal size.

The mutual control channel 30 has its other end connected to an aspirator section 10. The control signal 18 enters the aspirator section 10 through the control channel 19 and continues therethrough and out the control signal exhaust channel 20. The right control channel 14 is left open.

During operation of the gate with no control signal present, the power signal 34 will enter the amplifier through channel 35 and will attach itself to the left boundary wall 40 due to the smaller setback at corner 41. The power stream will pass out of the amplifier through the left output channel 44 with a stabilizing vortex 27 being formed at the blunt end of the splitter 45 and part of the power stream being bled to the atmosphere through channel 24. This is the stable condition of the ampli-fier.

When` a control signal 18 is applied through channel 19 to the aspirator section 10 and out throughthe controlling signal exhaust channel 20, the effect will be to prevent communication from the mutual control channel 30 to atmosphere. Even very small control signals 18 will cause a low pressure to develop in the mutual control channel 30 and the NOR gate power stream will switch to the right output channel 26 and the left bleed channel 43 as shown in FIG. 2. A vortex 45 will help stabilize this liow. Removing the control signal 18 will again allow the mutual control channel to communicate with atmosphere through right control channel 14 and cause the pressure in channel 30 to rise to that of atmosphere. The main power stream 34 will switch back to its stable condition due to the zero setback existing` at corner 41. This method of switching is called switching by induction since there is no fluid from the control signal 18 flowing through the mutual control channel 30 to cause the switching.

It has been found that using the principle of induction switching allows gains of up to 35 which is much higher than could otherwise be obtained in standard switching units. Also, higher pressure recovery is possible since the bleeds can be made small and the blunt splitter can be brought nearer the input nozzle. In prior devices such optimum design Iwas impossible since the control signal was dumped to atmosphere through the amplifier bleeds and they had to be equal to accommodate large control signals plus Iwhatever portion of the main power stream was to be discarded. In my device,

3 the control signal is dumped directly to atmosphere and adds nothing to the power stream.

In the absence of an input signal there is a complete decoupling between the NOR gate and the device which will eventually supply an input signal. This ideal condition is a result of the aspirator section allowing the NOR gate mutual control to communicate with atmosphere when no controlling signal is present.

=It will be apparent that the embodiments shown are only exemplary and that various modifications can be made in construction and arrangement within the scope of the invention as dened in the appended claims.

l claim as my invention:

1. A liluid induction NOR gate comprising:

(a) a monostable uid amplifier having a power stream therethrough; (b) two control channels positioned adjacent to said power stream;

(c) one of said control channels connected to atmosphere;

(d) the second of said control channels connected to an aspirator section having a control input signal passing therethrough, and causing a low pressure to occur in said control channel which switches the main power stream in the fluid ampliter to its unstable state;

(e) an input signal channel through which the control input signal enters the aspirating section; and

(f) an exhaust channel through which the control input signal leaves said aspirator section without having flowed into said power stream 2. The fluid induction NOIR gate of claim 1 wherein the monostable amplier includes:

(a) a stream splitter positioned on the axis of said power stream and defining a -rst and second output channels;

(b) 4first and second boundary walls located upstream of said stream splitter;

(c) iirst and second bleed channels located between said stream splitter and said boundary walls which are adapted to allow part of the power stream to pass selectively therethrough;

(d) said -rst boundary wall being set back from said power stream a smaller amount than said second boundary wall so that absent a control input signal to said power stream will attach itself to said rst boundary wall and pass through said first output channel.

3. The Huid induction NOR gate of claim 2 wherein said control channels are positioned perpendicular to the direction of liow of said power stream.

`4. The liuid induction NOR gate of claim 3 wherein the upstream end of said stream splitter is blunt to increase stability of the power stream.

References Cited UNITED STATES PATENTS 3,366,131 1/1968 'Swartz l37-81.5 3,417,770 12/1968 Denison 137-81.5

WILLIAM R. CLINE, Primary Examiner