US3496868A - Explosive elements - Google Patents

Description

Feb. 24, 1970 A. SILVIA ET AL EXPLOSIVE ELEMENTS Filed May 29, 1.967

INVENTORS 3,496,868 EXPLOSIVE ELEMENTS Denis A. Silvia, Shalimar, Fla., and Richard T. Ramsey, Fredericksburg, Va., assignors to the United States of America as represented by the Secretary of the Navy Filed May 29, 1967, Ser. No. 644,432 Int. Cl. F4211 3/00; F42b 3/00 US. Cl. 102-22 8 Claims ABSTRACT OF THE DISCLOSURE Improved explosive elements capable of performing explosive logic and switching operations consisting of a continuous explosive network suitable for die manufacture. The inherent difiiculty of thin explosive trails in propagating around sharp corners, is utilized in constructing the network.

Cross-reference to related applications This application is an improvement over pending application Ser. No. 468,676, filed June 30, 1965, for Explosive Circuits, by Denis A. Silvia, and is a further improvement over pending application Ser. No. 637,866, filed May 3, 1967 for Explosive Gate, Diode and Switch, by Denis A. Silvia et al. and now Patent No. 3,430,564.

Background of the invention.

The present invention relates generally to improved explosive elements for performing logic operations and, more particularly, to a continuous explosive network utilizing, for its operation, the reluctance of thin explosive trails in propagating around sharp corners.

In the above-mentioned application, Ser. No. 468,676, an explosive destructive cross-over is constructed from a pair of intersecting explosive-filled trails having gaps at the intersection forming a junction or island. Consumption of the explosive in the island, from propagation through a leg of one trail, prevents further propagation therethrough from a leg of the other trail. As an improvement over this explosive circuit, the above-cited Explosive Gate, Diode and Switch was developed in which point contacts between secondary explosive trails are used, in lieu of the gaps, for performing logic operations. While both of these techniques have performed satisfactorily in the laboratory, the use of gaps and mechanical contacts posed problems of reliability and ease of manufacture. The instant invention, therefore, attempts to obviate the difiiculties posed by the prior art, by means of a continuous explosive network thereby replacing the need for mechanical contacts and gaps. Factors of greater control, less weight and complexity, and greater efficiency, of the explosive circuitry, are accordingly achieved.

Summary of the invention The present invention improves upon the reliability, simplicity, and effectiveness of the prior art explosive circuit devices, by utilizing a continuous explosive network of a comparatively thin cross-section. The criticality of the trails gaps and point contacts, in the above-mentioned applications, is obviated when the intersecting trails are made continuous. An explosive destructive cross-over is produced by arranging a pair of trails in intersecting relation whereby one trail terminates in full communication with a constricted or necked-down area of the other trail. Propagation along the constricted trail is prevented at the necked-down area, if the other trail is detonated first. A portion of the constriction is thereby consumed without any hazard in permitting detonation along the constricted trail since the detonation cannot be negotiated around sharp corners. In like manner, an explosive diode is constructed from a single explosive trail having a porate 3,496,868 Patented Feb. 24, I970 tion of its length narrower than its remaining portion. Detonation from the wider end first is incapable of continuing along the narrower portion because of its inherent inability to turn into it. One-way propagation i accordingly allowed only if detonation proceeds first along the narrow section. Also, these two explosive elements easily give rise to the construction of an explosive switch and other explosive circuitry.

It is therefore an object of the present invention to provide an explosive element whereby explosive circuitry is simplified and made easier to manufacture.

Another object of the instant invention is to provide explosive elements which will be considerably sophisticated over existing explosive circuitry at little cost.

A further object of the present invention is to provide improved explosive elements of greater reliability when used for complex decision circuitry.

A still further object of the invention is to provide explosive elements which form a continuous network and perform by simply utilizing a known inherent characteristic whereby explosive gates and diodes may be constructed.

Other objects, advantages and novel features of the present invention will be come apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Brief description of the drawings FIG. 1 illustrates an example of the manner in which the detonation wave leaves a section of explosive undetonated upon turning a corner;

FIG. 2 illustrates the manner in which the detonation cuts itself off when the trail into which the detonation is turning is too narrow;

FIG. 3 illustrates an explosive gate according to the present invention;

FIG. 4 is the same explosive gate as that of FIG. 3 except that detonation is initiated from a different trail;

FIG. 5 is an explosive diode according to the present invention; and

FIG. 6 is the same explosive diode as that of FIG. 5 except that detonation has been initiated differently.

Description of the preferred embodiments In each of the above-mentioned related designs, an explosive circuit of sufiicient workability was produced, but only after extreme caution had been exercised in constructing the critical trail dimensions, gaps, spacings, point contacts, etc. In addition, thicknesses of approximately 0.085 inch were required in order that the detonation be properly negotiated around sharp corners. In the interest of reducing the amount of explosive in the trails for weight-saving purposes, the trail thicknesses are herein reduced to approximately 0.025 inch. With such trail dimensions, however, it was observed that propagation around sharp corners was rendered impossible because the detonation wave left a quantity of undetonated explosive as it turned the corner. It therefore cut itself olf by is failure to negotiate around the corner.

Referring therefore to FIG. 1 of the drawings, there is shown a simple explosive element, preceding the instant design, in which this cutting-off by the detonation wave was observed. FIG. 1 illustrates a plate 10 of inert material with an explosive trail A and an explosive trail B provided thereon. These trails may be constructed by forming a channel or grooves in the plate 10 and filling them with an explosive such as Du Pont EL506C, or by fabricating the trail using the Du Pont sheet explosive. The plates in all the figures of the instant design are so constructed, as are the plates of the two co-pending related applications. In FIG. 1 herein, as well as in the remaining figures, the thickness of each trail is approxi- 3 mately 0.025 inch and the direction of detonation is illustrated by arrows and represented by wave lines. Propagation along trail A in FIG. 1 was found capable of negotiating around the corner to B only when trail B was made significantly wider than trail A. During the course of turning, however, the detonation wave left a quantity of explosive undetonated as at 11. It was further observed that, should the trail width, such as B, be of a dimension substantially equal to A, the detonation would cut itself off. Attention, therefore, is called to FIG. 2 of the drawings in which a plate 20 of inert material is provided with trails A and B thereon. Detonation propagates along trail A and, as it begins to negotiate towards B, a quantity 21 of the explosive fails to detonate. The entire width of the trail B was found to be cut off thereby preventing further propagation. This unique inherent quality of relatively thin layers of sheet explosive trails suggested the construction of the constructive cross-over or gate as clearly shown in FIG. 3 of the drawings. A plate 30 is therein shown provided with a trail A and a trail B-B' thereon. This explosive gate is similar to that gate found in application Ser. No. 637,866 except that the point contact has been completely eliminated. In lieu of the critical point contact, the trail A has simply been necked-down as at 32 and has been allowed to open into the trail B-B' such that complete communication of explosive now exists between the two trails. Trail BB' is constructed with a notch 34 and a constricted portion 33. Also, the explosive width at constriction 33 is less than the minimum thickness for sustained detonation such that detonation will be dying while passing through 33. The length of constriction 33 is also short enough such that sustained detonation is rapidly recovered after passing therethrough. Because the detonation is dying in 33, it is thereby easily stopped by breaking from explosive trail A, which will be hereinafter discussed. Detonation along trail B-B therefore, in either direction, will continue uninterrupted, if detonation along trail A is initiated after B-B'. Because the trails communicate with each other, the detonation has a tendency to propagate towards A. Due to its inherent reluctance to turn sharp corners, however, a portion, as at 3.1, will not be detonated from B-B as propagation passes by trail A. On the other hand, should propagation commence along trail A first, see FIG. 4, the constriction at 33 will be thereby consumed and propagation along trail B-B', will be prohibited, thus forming the explosive destructive cross-over. Tendency of the detonation wave to proceed toward either B or B is impeded because of its inherent inability to turn sharp corners. In addition, the necked-down construction of A, at 32, permits consumption of only a small portion of area 33 and further prevents a turning from A into B or B. Portions 35 of trail B-B' are therefore left undetonated from trail A.

An explosive diode is capable of being easily constructed according to the present design, as on plate 40 in FIG. 5. There, an explosive trail C-D is provided having a narrow portion 42 at which detonation is commenced. Since the portion at D is significantly wider, propagation from C is capable of turning toward D without cutting itself off. Only a quantity at 41 is left undetonated along the trail. Propagation from D toward C, however, FIG. 6, produces a cutting off of the detonation wave, as at 43, since the trail into which the wave is turning is too narrow and negotiation of the turn is inherently impossible.

In accordance with the disclosed explosive elements, the explosive switch can be easily constructed and any form of explosive circuit can be produced without difficulty.

From the above, it can be seen that improved explosive elements have been designed, in the form of continuous networks, for increasing their reliability, efiiciency, and ease of manufacture. More importantly, the inability of the explosive to negotiate around sharp corners is taken advantage of for producing the elementary explosive gate and explosive diode. From an economic standpoint, the invention creates significant cost and weight savings because of the use of a thin explosive trail not heretofore possible. The instant explosive elements are basically simple and therefore manufacture is essentially non-critical. They have a potential application in many explosive advance items and, as in the abovementioned explosive circuit applications, permit an elimination of a large number of safe-arm devices with no reduction in reliability. Particular application of the instant invention are, for example, for warhead escape systems, missile systems, explosive munitions, demolition charges, and the like.

What is claimed is:

1. An improved explosive element for performing logic operations comprising a support plate of inert material having thereon a continuous network of explosive trails including at least a first explosive trail and a second explosive trail in intersecting communication with said first trail, there being a sharp turn in said network at the intersection of said first and second trails, said first trail being sufficiently thin, at least in the area of said intersection, that a detonation front, proceeding first along said second trail is inherently incapable of turning said sharp turn into said first trail.

2. The element of claim 1 wherein said trails intersect to form an L-shaped continuous network.

3. The element of claim 1 wherein said network is made up of shallow, explosive-filled grooves on a surface of said support plate.

4. The element of claim 1 wherein said network is made up of strips of sheet explosive.

5. The element of claim 1 wherein said first trail and said second trail extend in the same direction and are joined by said sharp turn in end-to-end relation, whereby, an explosive diode results, as a detonation front can travel through said network solely in the direction from said first trail to said second trail.

6. The element of claim 1 wherein said first and second trails intersect to form a T-shaped continuous network, said first trail being the top part of the T, whereby an explosive null gate results as a detonation front, proceeding first along said second trail, consumes a portion of said first trail, thereby preventing a detonation front from proceeding through the first trail.

7. The element of claim 1 wherein said second trail, at the juncture of said intersecting trails, is necked-down so as to consume only a minimum portion of said first trail.

8. The element of claim 6 wherein said first trail is relatively wide near both of its ends and thin near its middle.

References Cited UNITED STATES PATENTS 3,095,812 7/1963 Coursen 10227 3,175,491 3/1965 Robertson 10227 3,311,055 3/1967 Stresau et al 102-22 3,368,485 2/1968 Klotz 10227 VER'LIN R 'PENDEGRASS, Primary Examiner

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