US3728965A

US3728965A - Explosive circuits

Info

Publication number: US3728965A
Application number: US00468676A
Authority: US
Inventors: D Silvia
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1965-06-30
Filing date: 1965-06-30
Publication date: 1973-04-24
Anticipated expiration: 1990-04-24

Abstract

1. An explosive logic device comprising a supporting plate of inert material having formed therein at least one explosive filled groove-like trail interrupted along its length in a plurality of points by strips of inert material disposed at right angles thereto, said trail with said strips forming a pair of legs and a crossover means, said plate having also formed therein an explosive filled groove means terminating at said crossover means with a strip of inert material disposed at right angles to the length of said groove means and at right angles to one of said first-mentioned strips, each of said strips being of a sufficient breadth such that a plane wave caused by initiation of the explosive in one of said legs will be transmitted through its associated strip to the explosive in said crossover which in turn will detonate the explosive in the other of said legs if the explosive in said groove means has not previously been ignited causing a shock wave to be transmitted to said crossover means.

Description

Unite States Patent 91 Silvia 51 Apr. 24, 1973 EXPLOSIVE CIRCUITS Primary Examiner-Verlin R. Pendegrass [75] Inventor: Denis Silvia, King George, Va. y- Rubens and Branning [73] Assignee: The United States of America as EXEMPLARY CLAIM represented by The Secretary of the N 1. An explosive logic device comprising a supporting plate of inert material havin formed therein at least [22] Filed: June 1965 one explosive filled groove-hie trail interrupted along [21] Appl. No.: 468,676 its length in a plurality of points by strips of inert material disposed at right angles thereto, said trail 52 U.S. Cl 102/22, l02/DlG 2 with Said strips forming a pair of legs and a [51] Int. Cl. ..F42c 19/08 means Said plate having also formed therein an [58] Field of Search ..102/22-24, sive fined grow/e means terminating at Said crssver 0 7 70 7 85 DIG. 2 means with a strip of inert material disposed at right angles to the length of said groove means and at right [56 R f r Ci angles to one of said first-mentioned strips, each of said strips being of a sufficient breadth such that a UNITED STATES PATENTS plane wave caused by initiation of the explosive in one 2,774,306 12/1956 MacLeod ..lO2/DlG. 2 of said legs will be transmitted through its associated 3,050,518 5/1962 Coursen r ..l02/22 Strip to the explosive in said crossover which in turn 3,095,812 7/1963 Coursen ....lO2/27 will detonate the explosive in the other of said legs if Aii y the explosive in said groove means has not previously en been ignited causing a shock wave to be transmitted to said crossover means.

5 Claims, 14 Drawing Figures PAIEmEn/mmms 3.728.965

SHEET 2 UP P nib FIG. 40

P Q dob P J O+b FIG 6 P P F/G.

FIG. 7 FIG. 9

PRIMARY EXPLOSIVE EXPLOSIVE CIRCUITS 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 of any royalties thereon or therefor.

The present invention relates to logic switching devices and more particularly to explosive switching devices constructed by placing high explosive in passages formed in inert supporting plates, thereby replacing electrical or mechanical logic devices with explosive logic devices.

It is often desirable to closely control the timing and locale of an explosion or a series of explosions within precise limits, dependent upon a complex series of events. For example, as modern weapons become increasingly sophisticated, detonation of a warhead is dependent upon an increasingly larger and more complexly interrelated set of circumstances external from and internal to the weapon system. Exemplary of the factors which must be considered are: speed of a projectile; elapsed time of flight; atmospheric and weather conditions affecting the flight; and the like.

In the past, electronic and mechanical devices have been utilized to monitor such occurrences. Upon the happening ofa predetermined series of events or sets of series of events, appropriate signals are transmitted to detonate the warhead.

The instant invention provides explosive methods and means for monitoring a series of events, for providing explosive initiation or inhibition of a charge, or for initiating other means upon the occurrence of such events.

It is obvious that the utility of the present invention is not limited to weapons. Any application where an explosion or set of explosions is required would provide utility for the instant invention. Explosive forming and other metal working processes are examples and other environments in which the present invention finds utili- Illustrative of the advantages of explosive networks are the factors that: such circuits are geometrically less complex than their electrical counterparts; and since such devices are self-sustaining and hence amplify directly, no amplification devices are necessary as ancillary equipment.

An object of the present invention is to provide explosive logic circuitry.

Yet another object is the provision of a device for explosively performing logic operations.

A further object is to provide for explosive initiation or inhibition upon the occurrence of a predetermined series ofevents,

Yet a further object is to provide explosive switching circuitry to control an output device.

Other objects, advantages and novel features of the invention will become apparent from the following details description of the invention when considered in conjunction with the accompanying drawings wherein:

FIG. 1 illustrates two explosive trails intersecting at right angles;

FIG. 2a depicts two explosive trails intersecting at right angles with gaps surrounding the intersection;

FIG. 2b shows a schematic notation of the device of FIG. 2a;

FIG. 3a illustrates an explosive NULL gate;

'FIG. 3b depicts a schematic of the device of FIG. 3a;

FIG. 4a illustrates an explosive NEITHER-NOR circuit;

FIG. 4b shows a schematic of the device of FIG. 4a;

FIG. 5 depicts an explosive AND circuit;

FIG. 6 illustrates an OR gate;

FIG. 7 depicts a schematic of an explosive IMPLI- CATION;

FIG. 8 represents the schematic diagram of an explosive BI-IMPLICATION circuit;

FIG. 9 shows the schematic drawing of an explosive EITHER-OR gate;

FIG. 10 represents an alternate embodiment of an OR gate;

FIG. 11 depicts an explosive rectification circuit.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 two

explosive trails

21 and 22 intersection forming legs 23 to 26. These trails are formed by forming channels or grooves in a supporting plate of inert material and filling the channels with a high explosive. Examples of the type of explosive contemplated are Duponts EL506C, desensitized PETN, Tetryl and the like. It has been successfully shown that an impulse or detonating wave traveling along such an appropriately constructed channel or slot will be propagated therealong.

Turning our attention back to FIG. 1, a pulse arriving at any one of the

legs

23 and 26 will be propagated from the intersection along each of the remaining legs. Thus, a pulse or wavefront appearing at leg 23 will travel along this leg, arrive at the intersection and thereafter be propagated along

legs

24, 25 and 26.

Obviously, if a pulse arrives at one of the legs, it will consume the device; that is, the identity of the device would be lost. It is possible, due to the reluctance of a detonating wave to turn sharp corners, that one channel be consumed and the other remain substantially unconsumed. However, this is only a possibility and the configuration shown in FIG. l is an unreliable design to achieve this result.

By forming the plate material, as shown in FIG. 2a, with

legs

23 and 26 and a gap or crossover 27, a plane shock wave striking normal to the gap will be transmitted therethrough. Naturally, the channels and gaps in FIGS. 2a, 3a, 4a and 10 are filled with high explosive material although not shown in the drawings. The gap 27 may be formed as shown or by placing inserts of inert material about the junction. A wave traveling parallel to the gap will not be transmitted. Such a configuration will hereafter be designated a crossover and symbolized schematically as shown in FIG. 2b.

Thus, upon the arrival of the first pulse, the junction will be consumed thereby, preventing the transmission of any later pulse. For example, a pulse arriving on leg 23 will pass through and consume the explosive material in the junction 27 and be further transmitted along the leg 25. Thereafter, pulses occurring upon

legs

24 or 26 will consume the material therein but will not be transmitted through the junction. The use of the crossover is an essential element of the present invention.

FIG. 3a illustrates the use of a consumable junction to effectuate a NULL gate. A wave propagated along leg 26, arriving at the junction 27 prior to a pulse along the trail formed by

legs

23 and 25, consumes the junction 27, thereby prohibiting the passage of a pulse arriving at leg 23 to leg 25. Conversely, a pulse arriving at leg 25 is prevented from propagation along leg 23.

FIG. 3b illustrates the schematic symbology used hereinafter for a NULL gate. The upper case letter A is used to indicate that the gate will be closed, if a pulse along leg 26 arrives at the junction 27 prior to other pulses; for example, a pulse along leg 23. If more than one leg is designated by an upper case letter, they are either simultaneous in arrival at the junction or their time of arrival, one relative to the other, is not significant.

The NEITHER-NOR gate of FIG. 4a is an extension of the NULL gate of FIG. 3. A pulse along leg 23 will propagate through the junction 27 and the junction 28 to leg 25, if neither leg 29 nor leg 26 propagates a pulse at a prior time. The NEITHER-NOR is shown schematically in FIG. 4b.

The logic equation for the NEITHER-NOR function b a 1 b c 1) which is read neither a nor b equal 0. The truth table for this function is in Table I, wherein O and l designate the absence and presence, respectively, of a pulse along its associated leg.

0 b a i, b 0 O I O l O I O 0 l l 0 TABLEI This is easily seen by a comparison of equations l and (2), and truth Tables I and II.

TABLE II Thus, as seen in FIG. 5, the inputs A and B are first nulled in the gates and then Aand Bare presented to the NEITHER-NOR configuration.

The OR function is shown by equation (3) and truth Table III.

a+b=c 3 TABLE 111 It may easily be demonstrated that the OR function is the inverse of the NEITHER-NOR, or:

a+b=a'b 4 This relationship may be proved by substituting equatior i (1) in equation (4) a+b=(a'b) 5 inverting both sides of equation (5) This expression is one of the fundamental relationships of Boolean Algebra, one of DeMorgans Rules, and can be confirmed via Table IV.

Now, a and b are assumed as in the first two columns of the table. Table III indicates the basic OR truths. These truths, inverted, are shown in column 3. The column 4 shows the truths for the NEITHER-NOR function as originally reproduced in TABLE I. Comparing columns 3 and 4, it is seen that they are identical.

Hence, the relationship of equation (4) may be represented by the inversion or nulling of the NEITHER-NOR, thus producing the OR function. This is shown in FIG. 6.

The IMPLICATION function is shown by equation (7) and Table V, simply stated as; ifa than b.

a$ b=c 7 a b a b 0 0 l 0 I 0 1 0 1 l 1 1 TABLEV As seen in Table VI, the IMPLICATION function is the equivalent of the negation of the NEITHER-NOR function with one of the inputs thereto nulled; namely, the a input.

a= b=(a lb) (s) TABLE VI Thus, the IMPLICATION is constructed as shown in FIG. 7. The a input is nulled and a and b are presented to a NEITHER-NOR configuration and thereafter the output of the NEITHER-NOR is nulled.

The truths of the BI-IMPLICATION function are seen in Table VII.

a b a a b (a b) (a b) 0 0 0 l I 0 l O 0 0 l 0 0 O 0 l l l 0 I TABLE VII The BI-IMPLICATION is constructed by presenting the output of an AND gate and the output of a NEITHER-NOR gate to an OR gate. A very, brief notation for this is shown in FIG. 8. The inputs 0 b and a l b are shown coming to a shorthand notation for an OR gate, the circle 31 at the junction of

legs

32 and 33.

The EITHER-OR function is a l b=a b substituting equation (9), we have Thus, as seen in FIG. 9, the EITHER-OR may be devised by presenting (a b) and (a b) to and OR gate. The truths for this function are shown in TABLE VIII.

TABLE VIII To illustrate other ways in which these functions may be devised, the exclusive-OR may also be the negation of the Bl-IM PLICATION.

a l b a b 12 This is seen by comparing the last column of Table VIII with the last column of Table VII.

An additional way of constructing the OR gate is shown in FIG. 10. If either pulse a or b arrive at their respective channels, they will be propagated through the junction. Since they both arrive at right angles, however, no crossover will occur.

A rectification action may be had by using the configuration of FIG. 11. By forming

legs

23 and 25 in the plate such that the distance between them is relatively large, the high explosive therein would be insufficient for detonating waves of sufficient strength from one leg to be transmitted to the other. However, if a primary explosive 35, such as PETN, lead azide or the like, is placed at the termination of one leg, it will be sufficiently sensitive to -pick up" the waves from the other leg. A primary explosive is more sensitive than the high explosive contemplated hereinbefore, but it is no more powerful since there is little difference in the relative power of most explosives. Thus, a pulse will travel from leg 25 to 23 but will not propagate from 23 to 25.

Pulses traveling upon the legs may be timed in many ways: by varying the length or other geometry of the paths, by utilizing explosives with various detonation rates or shock velocities, and by utilizing series ofjunctions. The time for a pulse to propagate across a junction will generally be greater than the time for traversing an equal length of explosive material.

Thus, explosive switching circuits have been fully and completely disclosed.

Ob iously, the devices shown do not have to be restricted to a plane as shown. Three-dimensional circuits may be formed, thereby eliminating crossover problems.

The basic functions illustrated herein are merely shown as examples of various ways of construction. By utilizing equivalent circuits and by simplification of equations, various types of configuration may be used to obtain the functions illustrated.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

2. The device of claim 1 wherein said plate has formed therein a first explosive filled groove-like trail interrupted along its length in two points, wherein said crossover means constitutes a first crossover and wherein said explosive filled groove means constitutes a first explosive filled groove.

I 3. The device of claim ll wherein said plate has formed therein a first explosively filled groove like trail interrupted along its length in two points, wherein said crossover means constitutes a first crossover, and wherein said explosive filled groove means constitutes a first and second explosive filled groove, said first and second grooves terminating at opposite sides of said first crossover.

4. The device of claim 1 wherein said plate has formed therein a first explosive filled groove-like trail interrupted along its length in three points, wherein said crossover means constitutes a first and second crossover and wherein said explosive filled groove means constitutes a first and third explosive filled groove terminating respectively at said first and second crossovers.

5. The device of claim 1 wherein said plate has formed therein a first explosive filled groove-like trail and a second explosive filled groove-like trail spaced from said first trail, each interrupted along its length in three points, wherein said crossover means constitutes a first and second crossover both associated with said between said second and fourth crossovers, and first and third explosive filled grooves terminating, respectively, at said first and second crossovers.

Claims

3. The device of claim 1 wherein said plate has formed therein a first explosively filled groove like trail interrupted along its length in two points, wherein said crossover means constitutes a first crossover, and wherein said explosive filled groove means constitutes a first and second explosive filled groove, said first and second grooves terminating at opposite sides of said first crossover.

5. The device of claim 1 wherein said plate has formed therein a first explosive filled groove-like trail and a second explosive filled groove-like trail spaced from said first trail, each interrupted along its length in three points, wherein said crossover means constitutes a first and second crossover both associated with said first trail and a third and fourth crossover both associated with said second trail, and wherein said explosive filled groove means constitutes a fourth explosive filled groove terminating between said first and third crossovers, a fifth explosive filled groove terminating between said second and fourth crossovers, and first and third explosive filled grooves terminating, respectively, at said first and second crossovers.