Firing Device

Abstract

A firing device having an anti-disturbance firing mechanism; a lead short, hunt, or open circuit firing mechanism; and an operator actuated switch firing mechanism, wherein each of said firing mechanisms is capable of causing detonation of a squib. The power supply and the operator actuated arm/disarm and firing switch and ready lamp are included in a control unit remote from the squib housing.

Description

BACKGROUND OF THE INVENTION

In certain mines and land mines in which the firing mechanism is positioned at a remote location from the squib and mine, the enemy has conceived plans and prescribed procedures which compromise the explosive device. Therefore, until now a need has existed for such a device which is uncompromiseable, but disarmable. The present invention fulfills that need.

SUMMARY OF THE INVENTION

The present invention is a remotely actuable, uncompromiseable, but disarmable, firing device. It consists of a remotely located, control unit coupled to a squib and squib detonating circuit located at the explosive device. The control unit includes an arm/disarm switch, an operator actuated firing switch, and a ready lamp. The squib detonating circuit includes a firing capacitor, an anti-disturbance firing mechanism, and a silicon controlled rectifier (SCR) with associated passive components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the present invention; and

FIG. 2 is a schematic diagram of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is shown in block diagram form in FIG. 1 It includes a power supply 14, a remote control unit 10, a squib detonating circuit 12, and a squib 28. The remote control unit 10 comprises an arm/disarm switch 16 coupled to the power supply 14, a ready lamp circuit 18 coupled to switch 16, and an operator actuated firing switch 20 coupled to circuit 18. Remote control unit 10 is coupled through long lead coupler 22 to squib detonating circuit 12. The squib detonating circuit comprises anti-disturbance firing mechanism 24 and firing circuit 26. Squib 28 is coupled to the output of firing circuit 26.

The schematic diagram of the preferred embodiment of the present invention is shown in FIG. 2, wherein like numerals are used to indicate the component composition of the blocks of FIG. 1. Remote control unit 10 taken alone, includes lamp L.sub.1 connected in series with resistor R.sub.1 to the collector, and in parallel with the operator actuated firing switch 20 connected between the lamp and base, of NPN transistor Q.sub.1 ; and the combination coupled in parallel with capacitor C.sub.1 to arm/disarm switch 16. Of course, transistor Q.sub.1 can be replaced with a PNP transistor if the circuit is appropriately modified, as is well known in the art.

Squib detonating circuit 12 comprises anti-disturbance firing mechanism 24 and firing circuit 26. Firing circuit 26, taken alone, includes resistor R.sub.6 coupled to the gate of silicon controlled rectifier (SCR) Q.sub.2, which, in combination with anti-disturbance firing mechanism 24, diode D.sub.1, resistor R.sub.5, and capacitor C.sub.2, is serially connected to the parallel combination of capacitor C.sub.3 and resistor R.sub.7. Squib detonating circuit 12 is coupled to remote control unit 10 by double lead line coupler 22.

While applicant does not wish to be limited to any particular set of circuit constants, the following constant has proven to be useful in the particular circuit shown.

Symbol Components Type or Value 14 Battery 45 volt NEDA 213 C.sub.1 Capacitor 180 microfarads, 50 volt R.sub.1 Resistor 1 Kilohm Q.sub.1 Transistor 2N3904 R.sub.2 Resistor 1 Kilohm R.sub.3 Resistor 10 Kilohm R.sub.5 Resistor 220 Kilohm D.sub.1 Diode 1N916 C.sub.2 Capacitor 2200 Picofarad R.sub.6 Resistor 1 Kilohm Q.sub.2 Silicon controlled 2N885 rectifier R.sub.7 Resistor 470 Kilohm C.sub.3 Capacitor 50 microfarad, 50 volt

For the above indicated components the operation is as follows: When arm/disarm switch 16 is closed current from power supply 14 charges capacitors C.sub.1 and C.sub.3, Lamp L.sub.1 will light if there is a completed circuit, and then, will turn off when the circuit is ready to fire, i.e., when C.sub.3 is sufficiently charged. Squib 28 will then detonate if any of the following occurs: (a) squib detonating circuit 12 is disturbed causing anti-disturbance firing mechanism 24 to close, (b) the long leads connected to coupler 22 are shorted, shunted, or open circuited, or (c) operator actuated firing switch 20 is closed. All of the firing actions caused the voltage difference between points A and B to approach zero, which causes silicon controlled rectifier Q.sub.2 to turn "on" and conduct. Thereby, capacitor C.sub.3 is discharged through silicon controlled rectifier Q.sub.2 and squib 28. As a result, squib 28 is fired.

If the operator wishes to disarm the device he merely opens arm/disarm switch 16. Capacitor C.sub.3 will then discharge through resistor R.sub.7 ; and capacitor C.sub.1 will discharge through R.sub.1 and transistor Q.sub.1, and resistors R.sub.2, R.sub.3 and R.sub.5.

Many modifications and uses of the present invention, including constructing it of miniaturized components and installing it in the cap-well of the mine to be detonated, is contemplated by the inventor and is considered so disclosed.

Claims

What is claimed is:

1. A firing device for detonating a squib or other explosive device wherein the fire control unit is remote from said explosive device, comprising:

a power supply for providing electric power for said device;

an explosive charge;

explosive charge detonating means selectively coupled to said power supply for firing said explosive charge, comprising electrical charge storage means and an anti-disturbance firing mechanism;

fire controlling means remote from said explosive detonating means and said explosive charge for controlling the firing of said explosive charge, comprising an operator actuated firing switch, arming and disarming means coupled to one side of said power supply for arming and disarming said explosive detonating means; a transistor, and a lamp that will light when said arming and disarming means is in the arming mode and be extingished when said electrical charge storage means is sufficiently charged to detonate said explosive charge, wherein one terminal of said lamp is coupled to the first terminal of said transistor, said operator actuated firing switch is coupled between the second terminal of said transistor and the other terminal of said lamp, the junction of said lamp and said operator actuated firing switch is coupled to said arming and disarming means, and the third terminal of said transistor is coupled to the other side of said power supply.

2. The device of claim 1 wherein said fire controlling means is coupled through a coupling means to said detonating means such that after said detonating means is enabled said explosive charge will detonate when said detonating means is moved, when said operator actuated firing switch is closed, when said coupling means is opencircuited, and when said coupling means is short-circuited.

3. The device of claim 2 wherein said detonating means further comprises a silicon controlled rectifier connected in parallel to the combination of of said explosive charge and the parallel combination of a resistor and said storage means.