Acceleration of objects to high velocity by electromagnetic forces

Patent metadata

Field	Value
Publication number	US-9581409-B2
Application number	US-201314099933-A
Country	US
Kind code	B2
Filing date	Dec 7, 2013
Priority date	Jul 23, 2008
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

Two exemplary approaches to the acceleration of projectiles are provided. Both approaches can utilize concepts associated with the Inductrack maglev system. Either of them provides an effective means of accelerating multi-kilogram projectiles to velocities of several kilometers per second, using launchers of order 10 meters in length, thus enabling the acceleration of projectiles to high velocities by electromagnetic forces.

First claim

I claim:

1. A apparatus for accelerating a projectile, comprising:
a launcher configured for launching a projectile comprising metallic conductors, wherein said bore comprises a longitudinal axis that is axial with the launch direction of said launcher;
a first set of coils configured for immersing, while said projectile is stationary at a first position within said bore, said metallic conductors in an inducing field of magnetic flux for a first finite period of time, wherein said projectile remains stationary relative to said launcher for the entire duration of said first finite period of time, wherein said inducing field is transverse to said longitudinal axis, wherein flux will be trapped within said metallic conductors for a second finite period of time after said first finite period of time has ended;
means for terminating immersing said metallic conductors in an inducing field of magnetic flux while said projectile is at said first position and is stationary relative to said launcher; and
a second set of coils configured for exposing, while said projectile is at said first location and during said second finite period of time, said projectile to operatively directed currents at 90 degrees to said longitudinal axis to accelerate said projectile down said launcher.

2. The apparatus of claim 1 , wherein said first set of coils is configured for immersing said metallic conductors in an inducing field for a sufficient time to allow said inducing field to soak into said projectile.

3. The apparatus of claim 1 , wherein said operatively directed currents comprise azimuthally directed currents.

4. The apparatus of claim 3 , wherein said means for terminating immersing said metallic conductors separates said projectile from said first set of coils by axially moving at least one of said projectile or said first set of coils.

5. The apparatus of claim 4 , wherein said second set of coils is configured to be pulsed in a sequence along the longitudinal axis of said launcher to produce said azimuthally directed currents, wherein said projectile will be exposed to said azimuthally directed currents flowing as said second set of coils are sequentially pulsed.

6. The apparatus of claim 5 , wherein said second set of coils is configured to provide contact-less guidance along said inner bore.

7. The apparatus of claim 6 , further comprising said projectile, wherein said projectile comprises a cylindrical elongated conductor.

8. The apparatus of claim 6 , further comprising said projectile, wherein said projectile comprises multiple fins.

9. The apparatus of claim 5 , wherein said second set of coils comprises multi-turn conductor coils.

10. The apparatus of claim 5 , wherein said cylindrical elongated conductor is hollow.

11. The apparatus of claim 4 , wherein said first set of coils comprises a first subset of coils and a second subset of coils, wherein said first subset of coils is configured to provide a first component of said inducing field on the outside of said bore and wherein said second subset of coils is configured to provide as second component of said inducing field along the inner surface of said bore, wherein said first component and said second component combine to produce said transverse field.

12. A method for accelerating a projectile, comprising:
placing a projectile at a first position within a bore of a launcher, wherein said projectile comprises metallic conductors, wherein said bore comprises a longitudinal axis that is axial with the launch direction of said launcher;
while said projectile is at said first position and is stationary relative to said launcher, immersing said metallic conductors in an inducing field of magnetic flux for a first finite period of time, wherein said projectile remains stationary relative to said launcher for the entire duration of said first finite period of time, wherein said inducing field is transverse to said longitudinal axis, wherein flux is trapped within said metallic conductors for a second finite period of time after said first finite period of time has ended;
while said projectile is at said first position and is stationary relative to said launcher, terminating the step of immersing said metallic conductors; and
while said projectile is at said first location and during said second finite period of time, exposing said projectile to operatively directed currents at 90 degrees to said longitudinal axis to accelerate said projectile down said launcher.

13. The method of claim 12 , wherein the step of immersing said metallic conductors in an inducing field is continued for a sufficient time to allow said inducing field to soak into said projectile.

14. The method of claim 12 , wherein said operatively directed currents comprise azimuthally directed currents.

15. The method of claim 14 , wherein said launcher comprises a first set of coils for providing said inducing field, wherein the step of terminating the step of immersing said metallic conductors comprises separating said projectile from said first set of coils by axially moving at least one of said projectile or said first set of coils.

16. The method of claim 15 , wherein said launcher comprises a second set of coils configured to be pulsed in a sequence along the longitudinal axis of said launcher to produce said azimuthally directed currents, wherein said projectile is exposed to said azimuthally directed currents flowing as said second set of coils are sequentially pulsed.

17. The method of claim 16 , wherein said second set of coils is configured to provide contact-less guidance along said inner bore.

18. The method of claim 17 , wherein said projectile comprises a cylindrical elongated conductor.

19. The method of claim 17 , wherein said projectile comprises multiple fins.

20. The method of claim 16 , wherein said second set of coils comprises multi-turn conductor coils.

21. The method of claim 16 , wherein said cylindrical elongated conductor is hollow.

22. The method of claim 15 , wherein said first set of coils comprises a first subset of coils and a second subset of coils, wherein said first subset of coils is configured to provide a first component of said inducing field on the outside of said bore and wherein said second subset of coils is configured to provide as second component of said inducing field along the inner surface of said bore, wherein said first component and said second component combine to produce said transverse field.

Assignees

• L Livermore Nat Security Llc

Inventors

• Post Richard F

Classifications

• F41B6/00

  Electromagnetic launchers {; Plasma-actuated launchers (projectiles for electromagnetic or plasma guns F42B6/006)} · CPC title

• F41B6/003 Primary

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