Explosive firing train with a single explosive transfer interface

Patent metadata

Field	Value
Publication number	US-12560418-B1
Application number	US-202418954077-A
Country	US
Kind code	B1
Filing date	Nov 20, 2024
Priority date	Nov 20, 2024
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

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.

First claim

We claim:

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.

2 . The explosive firing train of claim 1 , wherein plasma from a foil on the circuit drives another thin plastic or metal foil to create the flyer plate.

3 . The explosive firing train of claim 1 , where D oc is at least 2×D b .

4 . The explosive firing train of claim 3 , wherein D b is between 0.5 inches and 1 inch and D oc is between 1 and 3 inches.

5 . The explosive firing train of claim 3 , wherein a diameter Due is between 2.8 and 3 inches.

6 . The explosive firing train of claim 1 , where in the output charge is selected from one of PBXN-5, CH-6 and Composition A5.

7 . The explosive firing train of claim 1 , wherein the output charge is not HNS or RSI-007.

8 . The explosive firing train of claim 1 , wherein the main charge is selected and the output charge is not selected from PBXN-9, LX-14, PBXN-110, PBXN-109 or PBXN-112.

9 . The explosive firing train of claim 1 , wherein the output charge has a detonation threshold of between 1 to 3 Gpa of shock pressure.

10 . The explosive firing train of claim 9 , wherein the output charge when detonated reaches a detonation pressure of between 27 to 38 Gpa and a detonation velocity of between 8,100 to 10,000 m/s.

11 . The explosive firing train of claim 1 , wherein the upper casing includes one or more radial vent holes.

12 . The explosive firing train of claim 1 , wherein only a single output charge resides in the upper casing.

13 . An explosive firing train, comprising:
an explosive foil initiator (EFI); a main charge having a fuze well with an inner diameter of 3 inches; 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 a diameter Duc of the upper casing is between 2.8 and 3.0 inches and D oc >=5*D b 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; wherein said output charge has a detonation threshold of 1 to 3 Gpa of shock pressure and when detonated reaches a detonation pressure of 27 to 38 Gpa and a detonation velocity of 8,100 to 10,000 m/s.

14 . The explosive firing train of claim 13 , wherein plasma from a foil on the circuit drives another thin plastic or metal foil to create the flyer plate.

15 . The explosive firing train of claim 13 , where in the output charge is selected from one of PBXN-5, CH-6 and Composition A5.

16 . The explosive firing train of claim 13 , wherein the output charge is not HNS and RSI-007.

17 . The explosive firing train of claim 13 , wherein the upper casing includes one or more radial vent holes.

18 . The explosive firing train of claim 13 , wherein main charge has a fuze well with an inner diameter of 3 inches, wherein the upper casing has a diameter Duc between 2.8 and less than 3 inches, wherein D oc >=5*D b .

19 . The explosive firing train of claim 13 , wherein the upper casing includes one or more radial vent holes.

20 . The explosive firing train of claim 13 , wherein the main charge is selected and the output charge is not selected from one of PBXN-9, LX-14, PBXN-110, PBXN-109 or PBXN-112.

Assignees

• Raytheon Co

Inventors

• Sadler Coulton T
• Goertz Eric D
• Carlo Montgomery
• Williams Christopher F

Classifications

• F42B3/12 Primary

  Bridge initiators {(F42B3/103, F42B3/11, F42B3/195 take precedence; electric ignitors in propellant charges F42C19/12)} · CPC title

• F42B3/124

  characterised by the configuration or material of the bridge (F42B3/13 takes precedence) · CPC title

• F42C15/40

  wherein the safety or arming action is effected electrically · CPC title

• F42B3/125

  characterised by the configuration of the bridge initiator case (F42B3/11 takes precedence) · CPC title

• F42C11/00

  Electric fuzes ({in combination with other fuzes F42C9/14}; proximity fuzes F42C13/00; {safety or arming effected by electric means F42C15/40; electric contact parts for fuzes F42C19/06}; electric igniters F42C19/12, {F42B3/12 - F42B3/18; optical initiators F42B3/113}) · CPC title