Feb 24, 2026

US12560418 - Explosive firing train with a single explosive transfer interface

An EFI or LEEFI provides enhanced detonation energy sufficient to directly detonate a main charge to improve the reliability and ease the qualification of an explosive firing train. This is accomplished by forming the EFI's output charge from an explosive material typically used as a booster explosive (e.g., PBXN-5, CH-6 and Composition A5) rather than a primary explosive and making the diameter of the output charge greater than the diameter of the barrel thus increasing the total mass of the output charge. The explosive firing train now requires only a single explosive transfer interface. For use in military grade munitions, the EFI's casing is formed with one or more vent holes radially adjacent the output charge.

Assignee: Raytheon Company
Inventors: Coulton T. Sadler, Eric D. Goertz, Montgomery Carlo, Christopher F. Williams
Filing date: 2024-11-20

explosivesmilitarymunitions

The patent describes an explosive firing train that utilizes an explosive foil initiator (EFI) to enhance detonation reliability by employing a larger output charge that directly detonates a main charge through a single explosive transfer interface. This design aims to improve military-grade munitions by simplifying the detonation process while ensuring effective energy transfer.

Claim 1

1 . An explosive firing train, comprising: an explosive foil initiator (EFI); a main charge; and a single explosive transfer interface on the main charge, wherein the EFI includes a circuit positioned in the bottom of a lower casing with a plurality of leads extending therethrough and a barrel having a through hole and an output charge positioned in an upper casing against and substantially aligned with the barrel through hole, a diameter D oc of the output charge being greater than a diameter D b of the barrel, said output charge having a lower detonation threshold and explosive energy than the main charge; wherein in response to an electric stimulus, the circuit accelerates a flyer plate through the barrel’s through hole to impact and detonate the output charge, which in turn impacts the single explosive transfer interface to detonate the main charge. an explosive foil initiator (EFI); a main charge; and a single explosive transfer interface on the main charge, wherein the EFI includes a circuit positioned in the bottom of a lower casing with a plurality of leads extending therethrough and a barrel having a through hole and an output charge positioned in an upper casing against and substantially aligned with the barrel through hole, a diameter D oc of the output charge being greater than a diameter D b of the barrel, said output charge having a lower detonation threshold and explosive energy than the main charge; wherein in response to an electric stimulus, the circuit accelerates a flyer plate through the barrel’s through hole to impact and detonate the output charge, which in turn impacts the single explosive transfer interface to detonate the main charge.

Google Patents

https://patents.google.com/patent/US12560418

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12560418