US3744421A - Explosive safe and arming system - Google Patents

Abstract

An explosive safe and arming system for a munition wherein the explosive forms the container. The system includes a first portion having a primer and relatively sensitive charge imbedded within an insensitive explosive charge. The other portion includes a base charge of an insensitive explosive having disposed therein an intermediately sensitive explosive. The two portions are in abutting relation so that in one position the primer is outwardly exposed and the relatively sensitive charge is in-line with base charge. Under these conditions when the primer is ignited its burning will detonate the moderately sensitive charge that in turn will, by its explosive propagation, detonate the intermediate charge thereby creating sufficient energy to initiate the main high explosive container. In the other position the moderately sensitive explosive is out-of-line and can not detonate the insensitive and main charges. Thus, there is provided a safe and arming system which is controlled by the positioning of two separate portions constituting the entire explosive munition.

Description

United States Pact Seeger [111 3,7,421 [4 1 July 10,1973

[ EXPLOSIVE SAFE AND ARMING SYSTEM [75] inventor: Donald E. Seeger, Succasunna, NJ.

[73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: Aug. 9, 1971 [21] Appl. No.: 170,170

52 us. Cl. 102/70 R, 102/76 P .15 N V N .7 V [58] Field of Search 102/70, 22, 24, 27, 102/768l.2, 76 R [56] References Cited UNITED STATES PATENTS 3,618,523 11/1971 Higuera 102/76 R X 2,944,485 7/1960 Ely et al 102/24 R 3,313,236 4/1967 Lohmann 102/76 R X 3,333,541 8/1967 Wagner et al 102/76 R X 3,483,822 12/1969 De Leonardis 102/79 Primary Examiner-Samuel W. Engle Attorney-Harry M. Saragovitz, Edward J. Kelly et a].

[57] ABSTRACT An explosive safe and arming system for a munition wherein the explosive forms the container. The system includes a first portion having a primer and relatively sensitive charge-imbedded within an insensitive explosive charge. The other portion includes a base charge of an insensitive explosive having disposed therein an intermediately sensitive explosive. The two portions are in abutting relation so that in one position the primer is outwardly exposed and the relatively sensitive charge is in-line with base charge. Under these conditions when the primer is ignited its burning will detonate the moderately sensitive charge that in turn will, by its explosive propagation, detonate the intermediate charge thereby creating sufficient energy to initiate the main high explosive container. In the other position the moderately sensitive explosive is out-of-line and can not detonate the insensitive and main charges. Thus, there is provided a safe and arming system which is controlled by the positioning of two separate portions constituting the entire explosive munition.

5 Claims, 6 Drawing Figures PATENIEU JUL 1 mm FIG. 6

INVENTOR DONALD E. SE EGER EXPLOSIVE SAFE AND ARMTNG SYSTEM The invention described herein may be manufactured, used and licensed by or for the Government for govenmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION The present invention relates to the activation of a high explosive and more particularly pertains to an explosive safe and arming system wherein the more sensitive explosives may be selectively removed from, or out-of-line with the less sensitive materials to thus prevent initiation of an explosive wave propagation except when they are armed in an in-line orientation. This system is operative without the need for any external confining container and includes structurally the necessary interrupter.

In the field of explosive safe and arming systems, it has been the general practice to employ mechanical means to either move elements of the explosive train to a position where propagation can not continue to the main charge, or to interpose a barrier or obstruction to interrupt or stop propagation. Relatively large movements and heavy components are necessary in addition to the presence of metallic parts. Previous methods for increasing the lethality of munitions have taken the form of more powerful explosives, altered physical configurations, optimum metal case to explosive ratio and various shaping of the metallic fragments. These parasitic metal parts are normally essential to the accepted safe and arming system to deter or prevent explosive propagation and themselves account for a substantial portion of the total munition weight. Since very little of this weight is explosive the system might be considered parasitic in nature and thus inherently limits the effective area of these devices. The present invention overcomes these deficiencies and fills a present need.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide an explosive munition that has all the advantages of similarly employed prior art devices and has none of the above described disadvantages. To attain this, the present invention provides a unique arrangement of entirely explosive or similar components which includes a first section comprising a linear arrangement of a primer and a sensitive explosive which can be ignited by the burning of the primer both embedded within an insensitive main charge. The second section includes an intermediately sensitive explosive imbedded with a main charge. The two sections are formed or arranged to assume either of two positions with respect to one another. The armed position wherein the primer, the sensitive and the intermediate explosives are in-line and a safe position where they are not in-line whereby in the armed position the entire explosive will be simultaneously detonated due to the ability of the intermediate explosive charges to initiate, to high order detonation, one secondary high explosive and not another which is less sensitive.

An object of the present invention is to provide a simple, direct, reliable and relatively inexpensive munition which may be readily armed and disarmed without the use of the conventional parasitic metal parts of a fuze.

Another object is the provision of a safe and arming system for a high explosive that does not employ any parts or components other than explosives.

A further object is to provide a containerless munition wherein the unique arrangement of explosives permits for a safe and arming system.

Other objects and the many attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a cross-sectional view of the axial initiation embodiment in the safe condition and made in accordance with the principle of the instant invention;

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 in the armed condition;

FIG. 3 is top plan view of another embodiment made in accordance with the principle of this invention employing peripheral initiation in the safe condition;

FIG. 4 is a cross-sectional view taken approximately along line 44 of FIG. 3;

FIG. 5 is a plan view of the embodiment of FIG. 3 in the armed condition; and

FIG. 6 is a cross-sectional view taken approximately along line 66 of FIG. 5.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS In the illustrated embodiment of FIG. I the explosive system 10 includes an upper portion 11 and a lower main charge portion 12 which are in abutting relation. The upper portion ll consists of a primer 13 of a well known material such as NOL No. primer mixture and extends from one face 14 into the body 15 of an insensitive high explosive, as for example, PBX. Disposed below and extending outwardly thereof at face 16 and in alignment therewith is material 17 capable of readily converting the burning energy of the primer to a rela tively weak detonation. One such suitable composition is lead azide. Thus the upper portion consists essentially of an insensitive high explosive body having embedded in serial alignment therethrough from face to face an initiating charge or primer and an intermediate charge both of which are singly or in combination inca pable of detonating the high explosive.

The lower portion 12 in this embodiment includes the body 18 of an insensitive high explosive (PBX) having imbedded in one face 19 thereof and extending inwardly, a relatively insensitive base charge explosive 20 capable of detonating the high explosive and being initiated or activated by the lead azide or intermediate charge 17. This base charge 20 can be fabricated from pure RDX. The two portions are formed so that they can move relative to one another along the interface between surfaces 16 and 19 as by providing a groove or channel in one of the portions. Under this arrangement the portions can assume two relative positions. The first, an unarmed or safe condition (FIG. 1) where, the imbedded explosives of the upper portion 11 are not in-line with the base charge 20 so that even their accidental detonation will not detonate either the base charge or the main charge 15 and 18. In the second or armed condition (see FIG. 2) the primer l3, intermediate charge l7 and the base charge 20 are aligned so that when the primer is initiated its burning activates the lead azide whose detonation initiates the base charge which, thereupon detonates the main charge thus forming an explosive train.

In the alternate embodiment of FIGS. 4-6 the system is again divided into two portions a main charge portion 30 and an initiating portion 31. The main charge member 30 is provided with a central circular recess 32 in face 33 and has embedded therein four mutually orthogonal sections 34 of a base charge whose inner faces 35 form a part of the recess wall. The member 31 is in the form ofa circular disc of a main insensitive high explosive and carried imbedded therein a central core 36 of a primer material and orthogonal, radial and coextensive therewith four extensions 37 of an intermediate charge that extend outwardly to the periphery. This portion is disposed in the recess in a rotatable relation so that it can assume either of two positions with respect to the base charge 34. In the unarmed or safe condition (FIGS. 3 and 4) the intermediate charges (extensions 37) are not in line with any of the base charges 34. Where the rotatable member 31 is turned to a position such that the intermediate charge 37 is aligned with the base charge 34, the munition is in the armed state.

Although the various explosives and primer disclosed hereinabove have provided satisfactory results it has been found that hollow pellets of relatively insensitive explosives (polystyrene bonded RDX) can be loaded with explosive charges normally used in detonators. Therefore, the initiating as well as the intermediate charges can be fabricated with these pellets by adjusting the pellet length and diameter and the charge weight and density so that the resultant explosive can not initiate the insensitive explosive employed as the container, even when the two are in intimate contact.

Where it is desired to activate the base charge, an ex-' plosive such as RDX is loaded into the pellets and placed at the output end of the two component system thus providing a high order of initiation sufficient to detonate or activate the entire explosive system. The successful operation of the invented system is founded on the ability of certain intermediate charges of explosive to initiate, the more sensitive secondary explosives and not another one which is less sensitive when structurally and properly associated. There are presently well known and readily available devices used in munitions and high explosive projectiles which provide the necessary movement between the parts thereof and can be adapted for use in conjunction with the above explosive structure.

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

I claim:

1. A safe and arming high explosive rnunition system comprising:

a first body of an insensitive high explosive having therein a primer and coextensively aligned therewith an intermediate charge capable of being activated by said primer and having an exposed portion thereof facing outwardly of said first body,

a second body of an insensitive high explosive carrying on a surface thereof,

a base charge capable of being activated by said intermediate charge and capable of detonating said insensitive high explosive and having extending thereinto said second body,

whereby said first body can assume one of two abutting positions with respect to said second body wherein said intermediate and base charges are coextensive and another position wherein they are out-of-line.

2. The system according to claim 1 wherein said bodies each have slidable abutting surfaces and said base and intermediate charges have exposed faces on said surfaces.

3. The system according to claim 1 wherein said second body is provided with a circular recess in one face thereof, and wherein said surface is the peripheral wall defining said recess and said first body is a disc rotatably disposed in said recess and said primer and said intermediate charge extending radially therein and said exposed portion being on the peripheral edge of said discv 4. The system according to claim 3 wherein said primer and said intermediate charge form a radial X configuration with said primer central thereof, and

said surface of said base charge comprises mutually orthogonal surfaces.

5. The system according to claim ll wherein said primer is NOL No. primer mixture,

said intermediate charge is lead azide,

said base charge is of RDX explosive and,

said insensitive high explosive is PBX.

Claims (5)

1. A safe and arming high explosive munition system comprising: a first body of an insensitive high explosive having therein a primer and coextensively aligned therewith an intermediate charge capable of being activated by said primer and having an exposed portion thereof facing outwardly of said first body, a second body of an insensitive high explosive carrying on a surface thereof, a base charge capable of being activated by said intermediate charge and capable of detonating said insensitive high explosive and having extending thereinto said second body, whereby said first body can assume one of two abutting positions with respect to said second body wherein said intermediate and base charges are coextensive and another position wherein they are out-of-line.

2. The system according to claim 1 wherein said bodies each have slidable abutting surfaces and said base and intermediate charges have exposed faces on said surfaces.

3. The sysTem according to claim 1 wherein said second body is provided with a circular recess in one face thereof, and wherein said surface is the peripheral wall defining said recess and said first body is a disc rotatably disposed in said recess and said primer and said intermediate charge extending radially therein and said exposed portion being on the peripheral edge of said disc.

4. The system according to claim 3 wherein said primer and said intermediate charge form a radial ''''X'''' configuration with said primer central thereof, and said surface of said base charge comprises mutually orthogonal surfaces.

5. The system according to claim 1 wherein said primer is NOL No. 130 primer mixture, said intermediate charge is lead azide, said base charge is of RDX explosive and, said insensitive high explosive is PBX.

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