Abstract: A power supply generating a reaction torque generally simultaneously with its power output is utilized to supply power to fire the railgun. The power supply and the railgun are cooperatively mounted together such that the reaction torque of the power supply upon discharge counteracts the recoil force of the railgun, thereby transferring lateral forces through the compulsator to a position in the power supply which is removed from the position of the coupling between the railgun and the power supply.

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.

Abstract: An electromagnetic launcher system which includes a homopolar generator pulse power supply recovers post-launch rail inductive energy and transfers it to the rotor of the homopolar generator to increase its kinetic energy for use in one or more subsequent launchings.

Abstract: An alternator for repetitive pulsing of an electromagnetic projectile launcher is provided with a stator structure having at least one pair of single layer concentric coil portions which are electrically connected in parallel. A rotating magnetic field induces a voltage in these coil portions without producing circulating currents. The alternator is connected through a switch to a pair of genrally parallel conductive projectile launching rails and a sliding conductive armature between the rails. By causing the switch to conduct at a predetermined phase angle, the voltage across the launching rails can be reduced to zero as the projectile leaves the rails. Where a succession of projectiles is to be fired, the phase angle at which the switch begins to conduct is controlled in order to achieve a substantially constant muzzle velocity for each projectile while minimizing the rail voltage as each projectile exits the rails.

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.

Abstract: An electromagnetic launcher includes a plurality of electrical stages which are energized sequentially in synchrony with the passage of a projectile. Each stage of the launcher includes two or more coils which are arranged coaxially on either closed-loop or straight lines to form gaps between their ends. The projectile has an electrically conductive gap-portion that passes through all the gaps of all the stages in a direction transverse to the axes of the coils. The coils receive an electric current, store magnetic energy, and convert a significant portion of the stored magnetic energy into kinetic energy of the projectile by magnetic reconnection as the gap portion of the projectile moves through the gap. The magnetic polarity of the opposing coils is in the same direction, e.g. N-S-N-S.

Abstract: An electromagnetic projectile launcher has a barrel (10) formed with parallel firing rails (13, 14) and separate supply conductors (18, 19) which are connected to the firing rails to supply firing current to one and receive the firing current from the other. The supply conductors (18, 19) are formed about the bore (11) of the barrel as sectors of a cylinder and are coaxial with one another such that current in adjacent portions of the two supply conductors flow in opposite directions. Very little time varying magnetic field is produced within the bore of the barrel (11) or outside of the supply conductors (18, 19) as a result of firing currents flowing in the supply conductors and in the firing rails. The magnetic field which accelerates a projectile through the bore is provided from a persistent magnet (26), which may be superconducting, formed about the bore in a dipole configuration to provide a constant magnetic field substantially transverse to the path of the projectile through the barrel.

Abstract: An Earth-based, rapid-fire, electromagnetic accelerator system is provided for launching multiple hypervelocity nuclear or non-nuclear independently targetable warheads on ballistic trajectories to targets located anywhere on or above the Earth's surface. The warheads are mounted inside a reinforced launching sabot containing a plurality of coaxial superconducting dipole magnets. The sabot is magnetically accelerated to hypervelocities inside a large-bore vacuum tube by sequentially exciting a series of driving coils mounted coaxially along the tube. The sabots are injected into the tube from pre-evacuated storage canisters thereby eliminating the need for an air-lock. Terminal guidance systems allow the warheads to be fired over intercontinental distances to hit small, preselected targets with nearly perfect accuracy. The launch velocities are sufficiently high to enable warheads to also intercept and destroy orbiting satellites moving in space high above the Earth's surface.

Abstract: An electromagnetic parallel rail launcher with an augmentation winding for post-firing inductive energy recovery. A power supply includes a storage inductor which, in conjunction with the inductance of the augmenting winding, provides the inductive energy storage prior to firing. As the launcher projectile exits, the storage inductor is substantially decoupled from the rail and augmenting winding inductance, so that a high efficiency inductive energy transfer may be accomplished between the rails and augmenting winding.

Abstract: An electrostatic kinetic energy weapon for firing projectiles at speeds up to and in excess of 100 kilometers per second. The weapon having a projectile launcher for launching projectiles using interactive forces acting between charged elements.

Abstract: A rapid-fire electromagnetic projectile launcher. The invention features parallel disks with gaps in their peripheries. A voltage source is applied to the disks to cause current to flow in opposite directions through the disks, generating a strong repulsive force which is utilized to eject a projectile. A rotator is positioned concentric with the disks to control timing of the repulsive action and facilitate projectile reloading.

Abstract: An electromagnetic launcher having spaced-apart rails for launching a projectile includes a plurality of stages connected to the rails for supplying makeup current during a projectile launch. Each stage includes an inductive power supply and an electrically conducting loop physically adjacent the rails for a predetermined length and including a conducting switch, such as a controlled rectifier array. As a projectile launching armature enters the loop area, a countercurrent is built up in the loop and at current zero the switch reverts to a non-conducting condition, thereby causing injection of the inductive current into the rails.

Abstract: A lightweight, portable, electromagnetic railgun. The invention features a conventional railgun coupled to a magnetic flux compression generator (MFCG) section and an injector section. The conventional railgun has two parallel metallic rails (13,15) with a bullet (25) slidably positioned between them. The bullet is rapidly projected between the rails toward a chosen target when a current flows between the rails (and through the bullet). The MFCG section provides a source of high current to the rails. The MFCG section has a piston (73) which moves between two energized bars (51,53). A magnetic field is created by current flowing in a circuit through the piston, (73) the bars (51,53) and the bullet (25). The associated magnetic flux is rapidly compressed as the piston moves between the bars. Compression of the magnetic flux produces a large current pulse which is coupled to the rails (13,15) to propel the bullet (25).

Abstract: A projectile for use in an electromagnetic projectile launcher is provided with a conductive open loop which is mechanically attached to the body of the projectile. Means are provided for electrically connecting the open loop between a pair of generally parallel projectile launching rails when the open loop is in a predetermined angular orientation with respect to the rails. Current flowing in the loop then interacts with magnetic flux produced by current flowing within the rails to place a torque on the loop which can be used to spin-stabilize the projectile or to prevent rotation of the projectile depending upon the particular application.

Abstract: A very low inductance, high current, repetitive opening switch for railguns. A specific embodiment has a circular rotor positioned behind the rails with its rotational axis coaxial with the railgun projectile path defined by the rails. The face of the rotor facing the rails has at least one conducting and at least one insulating region, each symmetric about a diameter of the rotor. A pair of current collectors, or brushes, are positioned against the rotor face so that the rotor, when rotating, will alternately conduct and insulate current between the current collectors as conducting or insulating rotor regions sweep past the brushes, thereby communicating current between the switch and the rails. A specific embodiment of the invention has the conducting region the shape of a diametric strip, or shorting bar, and each current collector substantially the shape of an annular segment. The current collectors are made as a plurality of conductive fingers.

Abstract: A muzzle arc suppressor allowing rapid repetitive refiring of railguns. A varistor or varistors electrically connect the muzzle ends of a railgun. Resistive inserts are placed inside the rails near the muzzle end. When the railgun projectile reaches the resistive inserts, the voltage across the varistor increases to above the varistor breakdown voltage, thereby commutating the railgun current from the projectile to the varistor, and dissipating excess magnetic energy through resistance heating of the varistor. The varistor is preferably made of zinc oxide, which is temperature invariant over a wide temperature range. The varistor may be pre-cooled to increase its energy absorbtion ability. A specific embodiment of the arc suppressor has the zinc oxide varistor conformably shaped to surround the rails. The conformably shaped varistor includes coolant passages.

Abstract: A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Abstract: A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Abstract: A projectile is accelerated through a gun barrel bore by a cartridge containing a high temperature, high pressure plasma jet source. The cartridge has a geometry enabling it to be loaded into a breech bore of the gun. The plasma jet is supplied to the rear of the projectile and is derived by a tube having an interior wall forming a capillary passage. A discharge voltage applied between spaced regions along the capillary passage ionizes a dielectric to form a plasma. First and second ends of the passage are respectively open and blocked to enable and prevent the flow of plasma through them. The blocked end closes the breech bore.

Abstract: An electromagnetic projectile launching system is provided with a passive, conductive loop for energy retention, dissipation or recovery. In a parallel rail launcher, this passive loop is inductively coupled to substantially link magnetic flux produced within the launcher by current flowing in a pair of parallel projectile launching rails. During projectile acceleration, parasitic current flow in the passive inductive loop turn or turns is prevented by a rectifier array. When the projectile exits, post-firing rail inductive energy is inductively and rapidly transferred to the passive inductive loop and is either dissipated there or may be beneficially employed to help accelerate a successive projectile.

Abstract: A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

Abstract: An electromagnetic launcher assembly 10 includes a magnetohydrodynamic power generator 12 for generating electrical energy. The energy is stored in an inductor 26 which is provided with current directing means 30 for selectively routing an electrical charge to activate a rail gun assembly 28 which initiates the firing of a projectile 32 out of the rail gun assembly.

Abstract: A rail gun barrel includes a pair of insulators which are axially prestressed in compression.

Abstract: A rail gun barrel includes gas containment means for limiting the penetration of high pressure gas into interfaces between rails and insulating members. The preferred gas containment means comprises one or more channels formed in one or more of the interfaces. In one embodiment of the invention, the channels simply provide space for expansion of gas. In another embodiment, the channels are partially or totally filled with seal material which prevents gas from escaping radially outward beyond the channels.

Abstract: The electromagnetic projectile launching systems of this invention accelerate projectiles by switching current from a current source to a pair of conductive projectile launching rails such that current flows through the rails and through an armature between the rails to produce an accelerating force on a projectile and the rate of current injection into the rails is controlled so that the initial projectile acceleration occurs at a reduced current level compared to the current used for subsequent projectile acceleration. This reduced current level is provided by initially shorting a resistor connected between one of the rails and the power source or alternatively by inserting a resistor in series with a switch which partially commutates current from the current source to the projectile launching rails. The maximum rail surface temperature during a launch is reduced by controlling the rate of initial current injection.

Abstract: An internally augmented, parallel rail electromagnetic projectile launching system includes a plurality of projectile launching rail pairs wherein the stacked height of the rails adjacent to the launcher bore decreases from the breech end to the muzzle end of the launcher. The launcher rail pairs may be electrically connected in series with each other and in series with an external current source. Alternatively, a separate though not necessarily entirely independent current source may be provided for each pair of rails and switching means may be included to substantially simultaneously connect each current source to its associated rail pair.

Abstract: An armature for use in electromagnetic projectile launchers is provided with a plurality of modular conductive fiber bundles which are arranged in a rectangular array and attached to an insulating armature support structure. The conductive fibers extend across the launcher bore and are sized to provide an interference fit between a pair of generally parallel conductive launcher rails. Each fiber bundle includes a rectangular central sheath and a pair of peripheral rectangular sheets positioned on opposite sides of the central sheath. The axis of each peripheral sheet is positioned at an angle with respect to the axis of the central sheath.

Abstract: An improved electromagnetic induction method and apparatus therefor for simultaneously collapsing and propelling a deformable annular-shaped workpiece of relatively lightweight construction in a direction outwardly of the apparatus and along its axis wherein the apparatus is made up of seven different embodiments for carrying out the method. Each apparatus is generally comprised of a framework. The framework includes at least one pulse coil means; and a power supply circuit is connected to the pulse coil means. Annular-shaped surface portions of various embodiments of the apparatus define part of an aperture or passageway for receiving a workpiece and function to position the workpiece in mutual inductance relation to the coil means.

Abstract: A high DC current switch includes a pair of annular, conductive rails with a pair of brushes mounted for rotary movement therebetween. DC current is conducted by the rails to and from the brushes in directions to electromotively accelerate the brushes into a switching cycle. The rails incorporate a switching gap through which the brushes move. Beyond this switching gap, the rails are split into inner and outer arcuate sections into which current is commutated by the brushes. The directions of commutated current flow to and from the brushes is now such as to decelerate the brushes to a stop.

Abstract: A high-power reversing-counterpulse repetitive-pulse inductive storage and transfer circuit includes an opening switch, a main energy storage coil, a counterpulse capacitor and a small inductor. After counterpulsing the opening switch off, the counterpulse capacitor is recharged by the main energy storage coil before the load pulse is initiated. This gives the counterpulse capacitor sufficient energy for the next counterpulse operation, although the polarity of the capacitor's voltage must be reversed before that can occur. By using a current-zero switch as the counterpulse start switch, the capacitor is disconnected from the circuit (with a full charge) when the load pulse is initiated, preventing the capacitor from depleting its energy store by discharging through the load.

Abstract: A barrel assembly for an electromagnetic rail gun is strong enough to withstand bursting forces generated during firing of the gun and has cooling capacity sufficient to enable the barrel to be fired repeatedly without overheating. The barrel includes a pair of elongated, generally parallel conductive rails having radially outwardly extending fins for structural support and heat transfer.

Abstract: An electromagnetic rail gun system includes an electromagnetic rail gun, a power supply, a cartridge and breech means for holding the cartridge. The gun includes a breech end and a muzzle end and a pair of substantially parallel rails defining a bore for receiving a projectile. The cartridge has releasably held projectile having a nose and a trailing end carrying an armature. The cartridge also includes a casing comprising a pair of electrically conductive casing segments spaced by insulation. The system further comprises interconnection means from the power supply connecting the breech end of the rails in parallel with the casing segments of a cartridge held in the breech means. The cartridge further includes shunt means interconnecting the casing segments for carrying current therebetween, and the armature is in electrically conductive relationship with the casing segments.

Abstract: A rail gun barrel assembly includes barrel components which are radially constrained by a pressure medium contained within a lightweight outer shell.

Abstract: An electromagnetic projectile launcher is provided with a pair of parallel conductive projectile launching rails which are generally T-shaped with a significant current carrying cross section located symmetrically around a horizontal bore center line. Augmenting conductors which may be either series or parallel connected are located adjacent to the projectile launching rails. In favorable embodiments, force augmentation is also achieved by a reduction in launcher rail height from the breech to the muzzle end.

Abstract: A basketball return device comprises a portable unit for positioning on a basketball court in a location generally underneath a basket into which shooting practice is to be conducted. The device includes a base with a ball-return mechanism therein and a vertically extending chute projecting upwardly from the base and terminating in a hoop-like top opening for positioning substantially directly beneath the basket. The ball-return mechanism includes a horizontal ball-collection and dispersion tube mounted in the base for swinging movement about a vertical axis so that the tube may be positioned to direct balls through an open end thereof to a required location on the court. The ball-return mechanism includes a solenoid operated plunger carried at the back of the tube for projecting balls therethrough and the device may include various electrical controls for automatically and semi-automatically operating the ball-return mechanism.

Abstract: Electromagnetic projectile launchers utilize multiple current path armatures in an internally series augmented conductor rail configuration or an internally augmented system connected to multiple power supplies. The current paths include plasmas, conductors or combinations of both. Plasma separation is maintained by trailing insulating plasma dividers extending toward the launcher breech from arc driving faces on a projectile sabot. Arc length and/or plasma volume is reduced by conductive assemblies adjacent to the arc driving faces.

Abstract: An armature for conducting very large DC current between a pair of electrically conductive rails while being driven along the rails under the influence of electromagnetic forces generated by the application of the current includes a plurality of spiraled conductive fibers. These fibers pass through a sleeve and are compacted to a maximum packing density within the sleeve to form a single solidified connection. The brush assembly formed by the sleeve and fibers is mounted on an insulating support structure which is sized to slide between the rails of the electromagnetic launcher.

Abstract: In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

Abstract: An electromagnetic projectile launching system is provided with an electromagnetic launcher portion and a chemically driven launcher portion. The electromagnetic launcher portion includes a pair of generally parallel conductive rails, a source of high current connected to the rails, and means for conducting current between the rails and for propelling a projectile along the rails. The powder driven portion includes a rifled barrel adjacent one end of the conductive rails and axially aligned with the conductive rails, and means for chemically propelling a projectile through the rifled barrel and into the bore of the electromagnetic launcher portion while causing the projectile to spin prior to its entry into the bore.

Abstract: An electromagnetic projectile launcher is provided with a cartridge-type switch for commutating current from a high current source to a pair of generally parallel conductive rails. A conductive cartridge switch in sliding electrical contact with the rails at the breech end includes a pressure chamber and aperture for receiving a projectile. An increase in pressure in the pressure chamber forces the projectile forward while forcing the cartridge rearward. Current is commutated from the cartridge to a conductive armature which subsequently propels a projectile along the conductive rails.

Abstract: A recoilless electromagnetic projectile launcher is provided with a pair of projectile launching conductors, a source of high current, a sliding armature for conducting current between the conductors and propelling a projectile, and a structure which creates a force which is equal but opposite to a recoil force created as the projectile is accelerated. This structure includes a second pair of conductors for accelerating a recoil mass in a direction opposite to the direction of travel of the projectile or, alternatively, an expansion chamber and nozzle for accelerating hot gases resulting from the creation of a plasma armature, in a direction opposite to the direction of travel of the projectile.

Abstract: Electromagnetic projectile launchers utilize multiple current path armatures in an internally series augmented conductor rail configuration or an internally augmented system connected to multiple power supplies. The current paths include plasmas, conductors or combinations of both. Plasma separation is maintained by trailing insulating plasma dividers extending toward the launcher breech from arc driving faces on a projectile sabot. Arc length and/or plasma volume is reduced by conductive assemblies adjacent to the arc driving faces.

Abstract: An electromagnetic projectile launching system utilizes two cylindrical rail configurations. In one configuration, multiple conductive armatures are electromagnetically accelerated along rails which are located on the inner surface of a cylindrical barrel. The second configuration utilizes armatures located between concentric cylindrical rails. Rifling provides for spin stabilization of the projectile.

Abstract: An electromagnetic projectile launcher includes a combination plasma/conductor armature structure which serves to conduct current between a pair of generally parallel conductor rails and to propel a projectile along the rails. A plasma at each end of the conductive element of the armature serves to conduct current between the conductive element and the adjacent conductor rail. A method of launching a projectile in an electromagnetic projectile launcher is provided in which a sliding conductive element conducts current between a pair of generally parallel launching rails until a selected velocity is achieved. At that time, plasmas are generated at each end of the conductive element. These plasmas serve to transfer current between the conductive element and the launcher rails for the remainder of the launch.

Abstract: A high power source of electrical energy, such as a homopolar generator, is connected to a longitudinally extending coaxial structure which forms a gun barrel. Within the gun barrel toward the end to which the power supply is connected is mounted a coaxial projectile, or several projectiles, in engagement with one or more movable conductive elements, that extend between the two longitudinally extending conductors. The homopolar generator is switched to apply on the order of a megajoule of energy to the coaxial structure, and after being delayed for a short interval until the current has built up to a significant level, the conductive element is accelerated with the projectile as a result of the magnetic pressure building up within the coaxial structure. Velocities on the order of 2 kilometers per second with kilogram mass projectiles may be achieved with a gun barrel approximately one meter in length.

Abstract: An armature for electromagnetic launchers is provided with multiple conductive fibers which form a multi-contact interface with the launcher rails. The fibers are attached to an insulating armature support and can extend across the launcher bore or be attached to contact faces of a trailing conductive chevron. Transposition of the fibers reduces electrical skin effect within the armature.

Abstract: An electromagnetic projectile launcher is provided with a magnetic field in the path of the projectile. This field induces currents in conductors within the projectile or interacts with a magnetic projectile to produce a torque which imparts spin stabilization to the projectile. Arcuate conductive rails are brought together to form a cylindrical bore to accommodate the cylindrical projectile necessary for spin stabilization.

Abstract: An electromagnetic projectile launcher having a pair of conductive rails with a breech and a muzzle end and an impedance electrically connected across the conductive rails adjacent the muzzle end of the conductive rails, and a second impedance in the muzzle end of the rails whereby arcs which commutate the current to the first impedance are confined within the muzzle to substantially suppress any external arc as the projectile exits from the launcher.

Abstract: The invention concerns an EM Launcher wherein each projectile has an insuor which, when subjected to a breakdown voltage, allows current conduction through the EM rails and the projectile for acceleration thereof. The insulator thus provides a disposable switch for a rapid fire EM launcher, negating the necessity of electrical (inductor circuit) charging or mechanical (breech) recycling.A key element in the invention is the replacing of a repetitively operated external switch with a plurality of single-shot, disposable switches. Better performance can be obtained from a single-shot switch (i.e., lower inductance, lower on-state voltage drop) because the compromises required of a repetitive switch to enable it to recover its voltage holdoff are not necessary.

Abstract: These electromagnetic guns or launchers comprise a pair of switching rails ith a slidable switching armature associated therewith for commutating a high direct current into a pair of projectile rails which are arranged in tandem with the switching rails and are electrically connected thereto. The kinetic energy of the switching armature is transferred to the projectile armature assembly so that the projectile armature assembly has an initial velocity as the current is commutated to the projectile rails. The projectile armature assembly may be mounted on and carried by the switching armature during its entire travel or the switching armature may bump the projectile armature assembly into the conductive breech region of the projectile rails at the end of its travel.