US3759183A

US3759183A - Multiple option electric detonator

Info

Publication number: US3759183A
Application number: US00209057A
Authority: US
Inventors: M Apstein
Original assignee: United States Department of the Army
Current assignee: United States Department of the Army
Priority date: 1971-12-17
Filing date: 1971-12-17
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

A multiple option detonator comprising an instantaneous electric detonator and a delay electric initiator connected to an electric circuit which provides a means for starting the instantaneous detonator and the delay initiator simultaneously and alternatively. The instantaneous detonator and the delay initiator are juxtaposed in tandem in a single structure. The instantaneous detonator comprises a base charge; a primer charge; and an element of high electrical resistance. The delay initiator comprises a pyrotechnic mixture, a molded insulating plug, and a second element of high electrical resistance. The molded insulating plug has several holes and passageways in it. The holes are filled with a portion of the pyrotechnic mixture. This pyrotechnic mixture is capable of initiating the primer charge in the instantaneous detonator. Another portion of the pyrotechnic delay charge is located behind the insulating plug and is ignitable by the element of high electrical resistance therein. By selectively energizing the proper element either an instantaneous function or a delay function may be achieved. If both bridges are fired simultaneously, the delay provides a backup in case the instantaneous bridge fails.

Description

United States Patent [191 Apstein 1 Sept. 18, 1973 MULTIPLE OPTION ELECTRIC DETONATOR Maurice Apstein, Bethesda, Md.

The United States of America as represented by the Secretary of the Army, Washington, DC.

Dec. 17, 1971 Inventor:

Assignee:

Filed:

Appl. No.:

US. Cl. 102/28 R, 102/70.2 A Int. Cl. F42b 3/16 Field of Search 102/28 R, 46, 70.2 R

[56] References Cited UNITED STATES PATENTS Primary Examiner-Verlin R. Pendegrass Att0rney-Harry M. Saragovitzet al.

[57] ABSTRACT A multiple option detonator comprising an instantaneous electric detonator and a delay electric initiator connected to an electric circuit which provides a means for starting the instantaneous detonator and the delay initiator simultaneously and alternatively. The instantaneous detonator and the delay initiator are juxtaposed in tandem in a single structure. The instantaneous detonator comprises a base charge; a primer charge; and an element of high electrical resistance. The delay initiator comprises a pyrotechnic mixture, a molded insulating plug, and a second element of high electrical resistance. The molded insulating plug has several holes and passageways in it. The holes are filled with a portion of the pyrotechnic mixture. This pyrotechnic mixture is capable of initiating the primer charge in the instantaneous detonator. Another portion of the pyrotechnic delay charge is located behind the insulating plug and is ignitable by the element of high electrical resistance therein. By selectively energizing the proper element either an instantaneous function or a delay function may be achieved. if both bridges are fired simultaneously, the delay provides a backup in case the instantaneous bridge fails.

5 Claims, 4 Drawing Figures a I i i i i i I 1 i z i E PATENTEI] SEN 81975

sum

2 or 2 1 MULTIPLE OPTION ELECTRIC DETONATOR 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 the inventor of any royalty thereon.

BACKGROUND OF THE INVENTION This invention related to pyrotechnic delay electric initiators and instantaneous electric detonators and, more particularly to a combination of a delay initiator and an instantaneous detonator connected to a selecting device which allows a delayed ignition or an instantaneous ignition of a projectile charge, or simultaneously, ignition of a deley electric initiator and an instantaneous electric detonator whereby failure of an instantaneous ignition is backed up by a delayed ignition. Heretofore, there have been several systems designed to provide both delayed ignition and instantaneous ignition of a projectile charge as represented in this invention. However, such systems have been primarily initiated by mechanical means. These mechanical means usually are arranged such that a primer charge is initiated by the impact force of a striker. Such systems are not very useful in proximity type projectiles. Proximity type require detonation before impact upon the target. Consequently, some means other than mechanial actuation of the detonator is required. There are systems which concern themselves primarily with delaying the ignition of a detonator. This is done successfully by the use of a pyrotechnic delaying material. There are other systems which concern themselves with obtaining super quick detonations. Both said systems have as their primary starting means some type of mechanical actuation. Mechanical type actuations are subject to failure. Mechanical type actuating mechanisms for detonators and fuzes are very expensive and more subject to failure than other actuating means which do not require moving parts. Some systems which combine both instantaneous and delay detonation provide some type of mechanical switch or shift in order to select one means or the other. None today are available which electronically select a particular detonating mode. None of the systems available today offer a backup system for the instanteous detonator. Such a system which would back up the initiation of the instanteous detonator would increase successful firings of such detonators tremendously.

Some other systems are available which separate as a complete entity the delay means from the instantaneous detonating means. Such systems usually have the instantaneous detonator disposed in the forward region of a projectile and the delay means disposed in the aft region of a projectile. Such systems are designed to provide a back up for the instantaneous detonating system disposed in the nose in case of nose damage which would prevent instantaneous detonation. However, again such systems depend upon mechanical means in order to initiate the explosive charge within such a projectile.

It is accordingly an object of this invention to provide a detonator, for use in a fuze to be incorporated into a projectile, having both an instantaneous and a delay detonating mode which allows a back up of said instantaneous mode with a pyrotechnic delay means.

It is also an object of this invention to provide a multiple option electric detonator which has both simultaneous and delay detonating modes, which uses the delay detonating mode as a back up for the instantaneous detonating mode, and which provides a circuit means for selecting the detonating mode.

It is another object of this invention to provide a multiple option electric detonator having either an instantaneous or delayed action which may be easily and positivey adjusted electronically to either mode without recourse to mechanical adjustments.

It is a still further object of this invention to provide a multiple option electric detonator having a instantaneous or'delayed action mode which is capble of being initiated or selected by an electronic circuit within the projectile in which the detonator is used.

A still additional object of this invention is to provide a multiple option electric detonator which uses a column of pyrotechnic material to delay the detonation of an explosive charge.

It is yet another further object of this invention to provide a multiple option electric detonator which comprises a separate initiator and detonator assembled in tandem and juxtaposed.

Further objects and the entire scope of the invention will become fully apparent in the following detailed description and in the appended claims.

SUMMARY OF THE INVENTION The multiple option electric detonator comprises essentially an instantaneous electric detonator, a delay electric initiator, and an electric circuit means for starting the instantaneous detonator and the delay initiator simultaneously and alternatively. The detonator is designed primarily for use in a fuze for a projectile and when the detonator is initiated in a simultaneous mode the instantaneous electric detonator and the delay electric initiator are both fired at the same time and a failure of the instantaneous detonator is then backed up by firing of the delay electric initiator. The detonator further comprises an inductive reactance component which provides a high level of reliability for detonation of the projectile whether in the instantaneous mode or the delay mode. When alternative operation of the detonator is desired, another portion of the circuit comprising switches connected with the instantaneous detonator and the delay electric initiator provide for the neutralization of either mode of operation. The delay means comprises primarily a pyrotechnic material which deflagrates and in turn causes ignition of the exposive charge within the detonator.

BRIEF DESCRIPTION OF THE DRAWINGS 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 drawings, in which:

FIG. 1 is a cross-section of a particular embodiment of the multiple option electric detonator.

FIG. 2 shows an emboidment of the invention whereby two detonators are functioned through an inductive means.

FIG. 3 shows a modification of the circuit of the invention.

FIG. 4 shows another modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a metal tube 30 closed at one end and structurally opened at the other end is shown. This metal tube has inserted within its inner space five basic building cylinders. The hollow cylinder nearest the closed end 31 of the tube 30 contains a base charge 55. The metal hollow cylinder 20 holding the base charge fits tightly within the tube 30. On top of cylinder 20 is another metal hollow cylinder 50. This metal cylinder 20 and houses the primer charge 65 with an instantaneous wire bridge 70 immersed therein. Primer charge 65 and base charge 55 comprise the explosive charge for the detonator. On top of cylinder 50 containing the primer charge 65 is a molded insulating plug 40. This molded insulating plug 40 fits tightly on top of the primer charge 65 and metal cylinder 50 and also fits tightly inside of a metal tube 30.

The molded insulating plug 40 has

holes

180 and 181 in it for the passage of

conductive wires

177 and 178 and also larger holes 182 in it in order that they may be filled with a pyrotechnic mixture 35.

On top of molded insulating plug'4i0 is juxtaposed metal cylinder 175 filled with the pyrotechnic mixture 35. Metal cylinder 175 fits tightly within conductive tube 30. There are also holes 190 in metal cylinder 175 which mate and allign with the

holes

180, 181, and 182 in the molded insulating plug 40. The mating of inner holes 190 with hole 182 provides for a burn-through from metal cylinder 175 of the pyrotechnic mixture 35 therein to the pyrotechnic mixture 35 filling the holes in the molded insulating plug 40. The pyrotechnic mixture 35 is compacted into metal cylinder 75. Also, immersed in the pyrotechnic mixture 35 is a delay wire bridge 60.

Inserted into the open end of metal tube 30 is a sealing plug which fits firmly into the end of the conductive tube and is juxtaposed to the pyrotechnic mixture 35. This sealing plug 25 is tightly and peripherally engaged by the conductive tube 30. Four holes are formed in sealing plug 25. These holes provide passageways for conductors.

Conductors

80 and 81 extend through individual holes in the sealing plug 25 and conductor 80 is connected to one termination of the delay wire bridge 60 and conductor 81 is connected to the other termination of the delay wire bridge 60.

Conductors

75 and 76 also extend through the sealing plug 25 and inturn through the pyrotechnic and through holes in the molded insulating plug 44) and then connected to the instantaneous wire bridge 70. Conductor 75 is connected to one termination of the instantaneous wire bridge and conductor 76 is connected to the other termination of the instantaneous wire bridge.

Another production scheme for this prototype is to have

terminations

81 and 76 or 80 and 75 connected and grounded to the metal tube 30. Then, only two wires would have to be extended through plug 25. The case would then serve as the ground return although it is considered as grounded in the specifications recited above.

Referring to FIG. 2, number 1 indicates an electrical feed line of proximity fuze or any electrical detonator exciter means not shown connected to the center-tap 3 of a choke 2. Connected to one termination of the choke 2 is conductor 80 of delay wire bridge 60. Connected to the other termination of the choke 2 is conductor of the instantaneous wire bridge 70. The remaining leads 81 and 76 of the wire bridges are joined in a common return circuit 8 of the exciter means. When a pulse of current is applied to feed-line I, it will divide equally about the center tap 3 and will proportionally flow through detonator 70. If on the other hand detonator 60 is short circuited, twice as much current will pass through the operating detonator 70 causing it to function becaue with detonation 60 shorted the circuit in FIG. 2 becomes an autotransformer with coil 2 serving as the winding.

In the modification shown in FIG. 3, the electrical detonator firing circuit is substantially the same as that shown in FIG. 2 with the exception that the series connected capacitors 9 and 10 have been substituted for the center tapped choke 2. In this modification the feed line 1 is connected to the series connected capacitors 11 in order to provide an equal amount of energy for the detonators.

Another system for insuring detonation of explosive missiles or the like is shown in FIG. 4 wherein the

detonators

60, 70, and 90 are connected across spaced coils 15, 16, and 17, respectively. Positioned in inductive relationship to coils 15 or 16 is a coil or link-up link 18 which is in series with a similar coil or link 19 positioned in inductive relationship between coil 16 and 17. The terminals of the series connected coils comprising link coupling means are connected across the feed line 1 and return circuit 8. In operation, a pulse of current is caused to flow in the link coupling means which in turn induces a current in each of the detonator shunted coils to function the detonators. It is apparent that irrespective of the fact that some detonators or circuits thereof may fail to function, detonation of the explosive missile in which the invention is incorporated may be obtained if but one detonator and circuit remain in operative condition.

To provide for mode selection a means for neutralizing detonator 70 is requisite. For neutralizing either detonator 60 or 70 a shorting switch is connected across each detonator. In FIG. 2 is shown a switching means 98 connected in parallel across delay detonation wire bridge 60. Also, the switching means 99 is connected in parallel across instantaneous detonation wire bridge 70. These twi switching means in combination provide the option of either a delayed or instantaneous function of the multiple option detonator. Closing switch 99 shorts instantaneous wire bridge 70. If switch 98 remains open a pulse through circuit lead will cause delay wire bridge 60 to be activated. On the other hand closing switch 9%, with switch 99 remaining open shorts the delay wire bridge 60, and therefore, a pulse into center tap 3 from feed line 1 will cause instantaneous wire bridge 70 to be activated and thus detonate the multiple option detonator instantaneously. However, if both switch 99 and 98 remain open and feed line 1 sends a pulse into center tap 3 both delay wire bridge 60 and instantaneous wire bridge 70 are activated. In this case an instantaneous activation of the detonator is achieved if wire bridge 70 is properly functioning. In addition, at the instant that instantaneous wire bridge 70 is activated, delay wire bridge 60 is also activated and burning of the pyrotechnic mixture is initiated. This double action provides a backup of the instantaneous detonator 70. Thus, failure of instantaneous wire bridge and detonator 70 is overcome by a delay detonation from delay wire bridge 60 which initiates deflagration of the pyrotechnic mixture 35 by the wire bridge 60.

Furthermore, it is understood that switch 98 across the delay detonation wire bridge 60 is usually not necessary for most military operations and may be eliminated completely in such productions. However, in the development of prototypes it is necessary to check each segment of such a system as this independently. Moreover since such a switch would be included in all phases of testing in many cases, such items are permitted to remain in the final production copy to avoid specification changes which could cause unforeseen problems. Moreover, it is to be understood that an additional solenoid switch in series with the battery may be used to switch the battery into a series connection with the circuit lines 1 and 8.

Switches

98 and 99 may also be activated by solenoids controlled by preset logic circuits.

It is obvious to anyone skilled in this art that many suitable materials of high electrical resistance may be substituted for the wire bridges 60 and 70 defined in these specifications. Among these are mixtures of carbon and other conductive matter commonly known as a conductive mix or carbon mix.

The inventor wishes it to be understood that he does not desire to be limited to the exact detailed construction shown and described, for obvious modifications will occur to a person skilled in the art thereof.

What is claimed is:

1. A multiple option electric proximity fuze detonator comprising:

a. a housing which comprises a shell of electrically conductive material open at one end and closed at the other;

b. an instantaneous electric detonator pressed inside of said housing and comprising an explosive charge and a first element of high electrical resistance in contact with said charge;

c. a delay electric initiator juxtaposed to said electric detonator and peripherally engaged by said shell and sealing said shell at it open end, said initiator being in propagating relationship to said explosive charge, said initiator comprising a pyrotechnic mixture and a second element of high electrical resistance imbedded in said mixture and connected in series with said first element;

d. an inductive reactance component having a center tap and opposite terminals, said series connected elements connected across said terminals;

e. a feed line for receiving a current pulse connected to a point intermediate said elements of high electrical resistance and having a return circuit interconnecting said feed line to said reactance compoennt;

f. means for neutralizing the firing of each of said elements of high electrical resistance and providing for firing of said instantaneous detonator and said delay initiator simultaneously and alternately comprising at least two electrical switches, one connected in parallel with said instantaneous electrical detonator and another connected in parallel with said delay electrical initiator, whereby said switches provide the option of neutralizing said instantaneous electric detonator and said delay electric initiator.

2. The multiple option electric detonator of claim 11 wherein said initiator further comprises a substantially cylindrical insulating plug juxtaposed in tandem to said explosive charge, said plug having at least two holes therein filled with pyrotechnic mixture, said pyrotechnic mixture contacting said explosive charge, whereby one of said filled holes provides a backup for an extinguished burn in the other of said two holes.

3. The multiple option electric detonator of claim 2 wherein siad explosive charge comprises a base charge formed in a metal module and located at the bottom of said housing and a molded primer charge contained in an open ended metal cylinder and placed on top of said base charge such that said primer charge and base charge are in intimate contact, and wherein said first elmeent of high electrical resistance is immersed within said primer charge.

4. The multipe option detonator of claim 3 further comprising another portion of said pyrotechnic mixture contained within a metal cylinder tandemly appositioned to said plug, last said cylinder having at least four holes therein, two of said holes being filled with pyrotechnic mixture, last said pyrotechnic mixture being in intimate contact with the pyrotechnic mixture in the two filled holes of said plug.

5. The multiple option electric detonator of claim 4 wherein said first element of high electrical resistance immersed in said primer charge and said second element of high electrical resistance immersed in said pyrotechnic mixture form a parallel electric connection, said connection providing a backup of said instantaneous detonator.

* III l

Claims

1. A multiple option electric proximity fuze detonator comprising: a. a housing which comprises a shell of electrically conductive material open at one end and closed at the other; b. an instantaneous electric detonator pressed inside of said housing and comprising an explosive charge and a first element of high electrical resistance in contact with said charge; c. a delay electric initiator juxtaposed to said electric detonator and peripherally engaged by said shell and sealing said shell at it open end, said initiator being in propagating relationship to said explosive charge, said initiator comprising a pyrotechnic mixture and a second element of high electrical resistance imbedded in said mixture and connected in series with said first element; d. an inductive reactance component having a center - tap and opposite terminals, said series connected elements connected across said terminals; e. a feed line for receiving a current pulse connected to a point intermediate said elements of high electrical resistance and having a return circuit interconnecting said feed line to said reactance compoennt; f. means for neutralizing the firing of each of said elements of high electrical resistance and providing for firing of said instantaneous detonator and said delay initiator simultaneously and alternately comprising at least two electrical switches, one connected in parallel with said instantaneous electrical detonator and another connected in parallel with said delay electrical initiator, whereby said switches provide the option of neutralizing said instantaneous electric detonator and said delay electric initiator.

2. The multiple option electric detonator of claim 1 wherein said initiator further comprises a substantially cylindrical insulating plug juxtaposed in tandem to said explosive charge, said plug having at least two holes therein filled with pyrotechnic mixture, said pyrotechnic mixture contacting said explosive charge, whereby one of said filled holes provides a backup for an extinguished burn in the other of said two holes.