US4833965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic railgun/injector
Assignee: United States Department of the Army
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Filing: 1988-08-05
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Granted: 1989-05-30
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Expires: 2008-08-05
Abstract
Abstract An electromagnetic railgun. The device features two electrically connected parallel rails. One end of each rail may be connected to a D.C. voltage source. At least one of the rails has a hole for closely receiving a metallic projectile. When the projectile is within the hole and the voltage is applied, currents flow through the two rails. Interaction of the currents with the self generated magnetic field causes a repulsive force between the two rails and launches the projectile outward from the rails.
Inventors
- 👤 Jr. Louis J. Jasper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:10
CPC Classifications
F; F41; F41B; F41B6/00; F41B6/006
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
114 words
A device for accelerating a projectile comprising: first and second electrically connected rails spaced a parallel predetermined distance apart, the first of said rails having a gap therethrough dimensioned to closely receive said projectile; means for producing a magnetic field oriented perpendicular to the plane of said rails, said means including a first coil electrically connected to said first rail and a second coil electrically connected to said second rail; and means for applying a voltage across said first and second rails so that presence of said projectile in said gap causes current to flow through said first and second rails and produces acceleration of said projectile from said gap away from said rails.
Claim 2
Independent Claim
114 words
A device for accelerating a projectile comprising: first and second electrically connected rails spaced a parallel predetermined distance apart, the first of said rails having a gap therethrough dimensioned to closely receive said projectile; means for producing a magnetic field oriented perpendicular to the plane of said rails, said means including a first coil electrically connected to said first rail and a second coil electrically connected to said second rail; and means for applying a voltage across said first and second rails so that presence of said projectile in said gap causes current to flow through said first and second rails and produces acceleration of said projectile from said gap away from said rails.
Claim 3
Independent Claim
138 words
A device for accelerating a projectile comprising: first and second electrically connected rails spaced a parallel predetermined distance apart, the first of said rails having a gap therethrough dimensioned to closely receive said projectile, said gap severing said first rail; a rigid conductor electrically connecting said first and second rails; means for producing a magnetic field oriented prependicular to the plane of said rails, said means being positioned above and below said rails, said means including a first coil electrically connected to said first rail and a second coil electrically connected to said second rail; and means for applying a voltage across said first and second rails so that presence of said projectile in said gap causes current flow through said first and second rails and produces acceleration of said projectile from said gap away from said rails.
Claim 4
Independent Claim
138 words
A device for accelerating a projectile comprising: first and second electrically connected rails spaced a parallel predetermined distance apart, the first of said rails having a gap therethrough dimensioned to closely receive said projectile, said gap severing said first rail; a rigid conductor electrically connecting said first and second rails; means for producing a magnetic field oriented prependicular to the plane of said rails, said means being positioned above and below said rails, said means including a first coil electrically connected to said first rail and a second coil electrically connected to said second rail; and means for applying a voltage across said first and second rails so that presence of said projectile in said gap causes current flow through said first and second rails and produces acceleration of said projectile from said gap away from said rails.
Claim 5
Dependent Claim
151 words
An electromagnetic railgun for accelerating a projectile comprising a pair of coextensive parallel conductive rails spaced a predetermined distance apart, means for electrically connecting the rails at one end thereof, one of said rails having a gap therethrough dimensioned to closely receive the projectile, said gap serving to separate said one rail into two sections, a hole in the other rail directly opposite the gap, said hole being slightly larger in size than the projectile, a pair of magnetic means for producing a magnetic field oriented perpendicular to the plane of the rails, said pair of magnetic means being respectively positioned above and below said rails, and means for applying a voltage to said pair of rails so that the presence of said projectile in said gap causes current to flow through the pair of rails so as to produce acceleration of said projectile from said gap away from said rails.
Claim 6
Dependent Claim
151 words
An electromagnetic railgun for accelerating a projectile comprising a pair of coextensive parallel conductive rails spaced a predetermined distance apart, means for electrically connecting the rails at one end thereof, one of said rails having a gap therethrough dimensioned to closely receive the projectile, said gap serving to separate said one rail into two sections, a hole in the other rail directly opposite the gap, said hole being slightly larger in size than the projectile, a pair of magnetic means for producing a magnetic field oriented perpendicular to the plane of the rails, said pair of magnetic means being respectively positioned above and below said rails, and means for applying a voltage to said pair of rails so that the presence of said projectile in said gap causes current to flow through the pair of rails so as to produce acceleration of said projectile from said gap away from said rails.
Claim 7
Dependent Claim
26 words
A railgun as defined in claim 3 wherein the magnetic field produced by said magnetic means augments the magnetic field created by current in the rails.
Claim 8
Dependent Claim
17 words
A railgun as defined in claim 4 wherein said pair of magnetic means comprises coils or solenoids.
Claim 9
Dependent Claim
15 words
A railgun as defined in claim 5 wherein said coils are comprised of superconductive material.
Claim 10
Dependent Claim
15 words
A railgun as defined in claim 6 wherein said rails are comprised of superconductive material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |