Explosive auto-enhancement device

• US 4,372,214 A
• Filed: 09/08/1980
• Issued: 02/08/1983
• Est. Priority Date: 09/08/1980
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Zimet, Elihu, Toton, Edward T.
• Primary Examiner(s): Bentley, Stephen C.
• Application Number:
  US06/185,076
• Time in Patent Office: 883 Days
• Field of Search: 29/421 M, 89/8, 102/200, 102/209, 102/293, 102/305, 102/475, 102/701, 310/10
• US Class Current: 102/305
• CPC Class Codes: F42B 1/00 Explosive charges characterised by form or shape but not dependent on shape of container
• CPC Class Codes: F42B 3/00 Blasting cartridges, i.e. case and explosive fuse cords, e.g. detonating fuse cords C06C5/00; chemical aspects of detonators, blasting caps or primers C06C7/00
• CPC Class Codes: Y10S 102/701 Charge wave forming

Abstract

An explosive auto-enhancement device for providing higher detonation pressure than can be achieved with conventional explosives by the use of magnetic precompression for enhancing the detonation wave. A cylindrical armature containing an explosive charge is coaxially spaced within a helical field generator winding with a first end of the armature being electrically coupled to the helical winding. A "seed" magnetic field is provided to the helical winding prior to the initiation of the explosive charge. When the explosive charge is initiated, forming a detonation wave, the other end of the cyclindrical armature expands and is coupled to the helical winding, thus completing the electrical circuit between the winding and the armature. As the detonation wave continues through the explosive charge, more of the coils of the helical winding are short circuited which reduces the inductance and results in increased magnetic flux within the winding. A magnetic pressure appears ahead of the detonation wave due to the increased magnetic flux and compresses the undisturbed armature and contained explosive, causing the detonation wave to increase in velocity and pressure. The detonation wave is thus continually accelerated by the generation of magnetic pressure preceeding the detonated explosive wave.

Claims

1. A device for enhancing the detonation wave pressure and detonation wave velocity in an explosive charge, comprising:

elongate means defining an armature and supporting an elongate explosive charge generally coextensive therein, said supporting means being electrically conducting;

means forming a magnetic field surrounding the elongate supporting means, said magnetic field forming means being directly electrically connected to the supporting means at a first end thereof;

said elongate supporting means having its other end disposed in close proximity to the means forming the magnetic field to define a crowbar switch therebetween; and

means at the other end of the elongate supporting means for initiating the explosive charge, the detonation wave of which travels toward the first end;

whereby, upon initial minimal expansion of the elongate supporting means at its other end, the crowbar switch is closed to complete a circuit between the electrically conductive supporting means and means forming the magnetic field so that expansion of the supporting means is opposed by the magnetic field and the explosive charge is precompressed ahead of the detonation wave thus increasing the detonation wave velocity as it travels along the explosive charge.

2. The device as in claim 1 wherein the means forming a magnetic field comprises a helical winding, said support means being positioned in the helical winding.

3. The device as in claim 1 wherein the means forming a magnetic field comprises an outer casing, said support means being positioned in the casing.

4. A device as in claims 2 or 3 wherein the means forming a magnetic field further comprises a source of power forming a seed magnetic field.

5. A device as in claim 1 wherein the explosive charge is further provided with a booster charge.

6. A device for increasing detonation wave pressure and detonation wave velocity in an explosive charge, comprising:

electrically conductive means forming a magnetic field; and

,

an elongate electrically conductive armature supporting the explosive charge longitudinally therein and positioned in the magnetic field, said armature being directly electrically connected at its first end to the means forming the magnetic field;

said armature at its other end being disposed in close proximity to the means forming the magnetic field to define a crowbar switch therebetween;

whereby upon initiation of the explosive charge adjacent the other end of the armature, a detonation wave is formed in the charge to travel toward the first end of the armature and initially expand the armature at its other end to close the crowbar switch in close proximity therewith and complete a circuit between the armature and means forming the magnetic field, and whereby expansion of the armature is opposed by the magnetic field and urged inwardly around the exclusive charge ahead of the detonation wave to precompress it for increasing the detonation wave velocity and detonation wave pressure passing through the charge.

7. A device as in claim 6 wherein the means forming a magnetic field comprises a helical winding.

8. A device as in claim 6 wherein the means forming a magnetic field comprises an outer casing.

9. A device as in claims 7 or 8 wherein the means forming a magnetic field further comprises a source of electrical power forming a seed magnetic field.

10. A device as in claim 6 wherein the explosive charge is provided with a detonator.

11. A device as in claim 10 wherein the explosive charge is further provided with a booster charge.

12. A device for increasing the pressure on an explosive charge for increasing velocity and pressure of a detonation wave passing therethrough comprising:

an electrically conductive tubular member defining an armature and housing an explosive charge therein;

electrically conductive means surrounding the armature for forming a magnetic field thereabout;

said armature electrically connected at its first end directly to one part of the electrically conductive magnetic field forming means;

said armature at its other end disposed in close proximity to another part of the electrically conductive magnetic field forming means to define a crowbar switch therebetween; and

,

means adjacent the other end of the armature for initiating the explosive charge, the detonation wave of which travels toward the first end of the armature and radially expands the armature as it progresses therealong;

said armature other end upon initial expansion closing the crowbar switch to complete an electrical circuit between the armature and the electrically conductive magnetic field forming means;

whereby, upon continued outward expansion of the armature through the magnetic field, the magnetic field is increased which reacts against outward movement of the armature and also reacts against the armature to pressurize it along its undisturbed length ahead of the detonation wave to compress the explosive charge therein for increasing the pressure and velocity of the detonation wave passing therethrough.