Stead-field coilgun methods and devices

Patent metadata

Field	Value
Publication number	US-12590779-B2
Application number	US-202418733666-A
Country	US
Kind code	B2
Filing date	Jun 4, 2024
Priority date	Jun 2, 2023
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

A method for operating an electromagnetic coilgun system, the method comprising: an electromagnetic coilgun comprising: a barrel and a longitudinally extended electrical excitation coil; wherein the electrical excitation coil circumferentially surrounds a bore of the barrel, energizing the electrical excitation coil to produce a steady-state magnetic field within and around the bore of the barrel, the steady-state magnetic field extending along a longitudinal axis of the barrel; loading the barrel with a magnetic dipole projectile at a breech end of the barrel, wherein the loaded magnetic dipole projectile is oriented with a first magnetic dipole moment aligned to a magnetic field orientation of the steady state magnetic field; and firing the magnetic dipole projectile by magnetically propelling the magnetic dipole along the longitudinal axis of the bore by a magnetic force produced by the steady-state magnetic field within and around the bore of the barrel.

First claim

What is claimed is:

1 . An electromagnetic coilgun system comprising:
a barrel comprising a longitudinally extended bore, a breech end and a muzzle end; wherein an electrical excitation coil circumferentially surrounds the longitudinally extended bore of the barrel; and a magnetic dipole moment flipper located near a center of the electrical excitation coil, wherein the magnetic dipole moment flipper is configured to reverse a dipole moment of a magnetic dipole projectile traveling from the breech end of the barrel within a steady state magnetic field nearest the breech end of the barrel; wherein the loaded magnetic dipole projectile is oriented in the breech with a first magnetic dipole moment aligned to a magnetic field orientation of the steady state magnetic field.

2 . The system of claim 1 , wherein the magnetic dipole projectile comprises a ferromagnetic material selected the group consisting of: iron, cobalt, nickel, Alnico, ferrite, rare-earth material, and combinations thereof.

3 . The system of claim 1 , wherein a magnetic dipole flip is caused by a curb inside the barrel which applies a torque onto the magnetic dipole projectile to produce a rotation for the flip.

4 . The system of claim 3 , wherein the barrel bore is smooth before a center of the coil and is rifled or partially rifled in a region of the barrel bore after the magnetic dipole flip.

5 . The system of claim 1 , wherein a plurality of electrical excitation coil stages are used for acceleration of the magnetic dipole projectile and are positioned at different longitudinal locations along the barrel, the output of each stage the input to the next stage, except for the last stage, whose output is the muzzle end of the barrel.

6 . The system of claim 5 , wherein a magnetic field of a next stage is opposite to a magnetic field of a previous stage, so that a flipped magnetic dipole projectile emerging from the previous stage has a dipole moment in the same direction as the magnetic field of the next stage to accelerate the magnetic dipole projectile into the electrical excitation coil of the next stage.

7 . The system of claim 5 , wherein a magnetic field of a next stage is aligned to the magnetic field of a previous stages, so that a twice flipped magnetic dipole projectile emerging from the previous stage has its dipole moment in the same direction as the magnetic field of the next stage to accelerate the magnetic dipole projectile into the electrical excitation coil of the next stage.

8 . The system of claim 5 , wherein the barrel bore is smooth everywhere except in an initial section of a first stage of the barrel bore nearest the breech end of the barrel to impart the initial rotation for the instability effect.

9 . The system of claim 1 , wherein the magnetic dipole projectile has three different principal moments of inertia and is magnetized with a dipole moment pointing along its intermediate axis.

10 . The system of claim 1 , wherein the magnetic dipole projectile is in the shape of a rectangular prism of dimensions a, b and c, where a>b>c, and the magnetic dipole projectile is magnetized in a direction of an intermediate principal axis.

11 . The system of claim 10 , wherein an initial rotation around an intermediate axis is brought about by rifling inside the initial section of the barrel, in combination with an acceleration from the magnetic force on the magnetic dipole projection from the electrical excitation coil.

12 . The system of claim 1 , wherein the barrel is slotted along a longitudinal length; and wherein the slots are configured to prevent circular eddy currents by varying the magnetic flux.

13 . The system of claim 1 , wherein the slotted barrel is configured to vent gases laterally from the muzzle of the barrel.

14 . The system of claim 1 , wherein a firing rate is increased by consecutively accelerating a plurality of magnetic dipole projectiles through the barrel.

Assignees

• The United States Of American As Represented By The Secretary Of The Navy
• Us Gov Sec Navy

Inventors

• Kartalov Emil Paskalev
• Catterlin Jeffrey Kyle

Classifications

• F41B6/006

  Rail launchers · CPC title

• F41B6/003 Primary

  using at least one driving coil for accelerating the projectile, e.g. an annular coil · CPC title