Electromagnetic Patents (Class 124/3)
  • Patent number: 5844161
    Abstract: A railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with an insulator material. The insulator material allows the composite insulator to stand off the voltages in a plasma armature even under high radiation flux conditions. Below the conducting material's ablation threshold the amount of ablation produced by the composite insulator is reduced by the reduction of insulator surface area exposed to the radiation. This allows better control of armature growth, mass acceleration by the plasma armature, secondary formation, and other factors normally found to retard projectile acceleration.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: December 1, 1998
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Robert A. Meger
  • Patent number: 5763812
    Abstract: A compact bearing ball, or rail, gun to magnetically accelerate ferro-magnetic BBs is disclosed. The gun comprises a main board containing a channel sized to allow smooth passage of a BB, a straight portion of that channel forming a barrel terminating at an edge of the main board. A plurality of wire coils are disposed perpendicular to the axis of the barrel collinear with that axis. Driver circuitry for inducing in the plurality of wire coils is provided to ensure a synchronized generation of magnetic fields in individual ones of the wire coils to accelerate ferro-magnetic BBs disposed within the channel of the main board through the channel and out of the barrel. In a preferred embodiment, the channel has a loading segment substantially perpendicular to the barrel for aligning ferro-magnetic BBs prior to acceleration through the barrel, along with a magnet at the intersection of the loading segment and the barrel for positioning a BB co-centric with the axis of said barrel prior to acceleration.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: June 9, 1998
    Inventor: Galen Collins
  • Patent number: 5574240
    Abstract: The present invention provides a propellant for electrothermal-chemical guns comprising a dispersion of one or more energetic solids in an energetic liquid phase. The energetic solid is preferably a nitramine such as cyclotrimethylenetrinitramine (RDX) and the energetic liquid component is preferably a homogeneous liquid that is either aqueous or non-aqueous. Aqueous liquid phases suitable for use in the present invention include concentrated solutions containing at least one nitrate salt. Non-aqueous liquid phases suitable for use include those that contain nitrate ester, nitramine, nitro or azido compounds or mixtures thereof.These propellants provide a high level of energy density because of the use of energetic ingredients and the high loading density allowed with a liquid propellant. The presence of a dispersed solid phase within the continuous liquid phase also permits control of the burning behavior of the propellant by variation of the interfacial area between phases.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: November 12, 1996
    Assignee: Hercules Incorporated
    Inventor: Richard V. Cartwright
  • Patent number: 5540134
    Abstract: A superconducting single phase alternator is connected by a circuit breaker across the breech ends of a pair of conductive launching rails. At a predetermined point on the alternator voltage wave a projectile establishes a current path between the rails to initiate a transient, sinusoidal current pulse effective in accelerating the projectile along the rails. A switch is actuated in response to the projectile exiting the muzzle ends of the rails to impose a short circuit across the rails. The circuit breaker disconnects the alternator from the rails as the current pulse goes to zero. The system provides higher launcher efficiency and reduced muzzle flash with minimum barrel length penalty.
    Type: Grant
    Filed: June 2, 1986
    Date of Patent: July 30, 1996
    Assignee: Martin Marietta Corporation
    Inventor: William L. Bird, Jr.
  • Patent number: 5483863
    Abstract: An improved electromagnetic launcher (10; 98; 150) has a barrel (20; 100) formed by at least one pair of bus-bars (30, 32; 102, 104; 156, 158; 184, 184, 188, 190) to transport current longitudinally along the barrel. The barrel includes a bore (36; 108) which is spaced from the bus-bars by a bore structure (34; 106). The bore structure guides an elongated, tapered metal armature (44; 122; 164) through the bore. The current to the armature passes from the bus-bars through an array of deformable contactors (54, 55; 110, 112) disposed near the bore walls and in series with resistors (60, 62, 64, 66; 114, 116, 118, 120). The resistors distribute current and electromagnetic driving force along the armature. A conductive implodable shield (130) confines the bore structure and the bus-bars to impede repulsion of the bus-bars and to compress the magnetic flux between the shield walls and the bus-bars.
    Type: Grant
    Filed: September 13, 1993
    Date of Patent: January 16, 1996
    Assignee: Dyuar Incorporated
    Inventor: Yuri A. Dreizin
  • Patent number: 5458043
    Abstract: A rapid fire electromagnetic launcher system (EML) employs a plurality of capacitor modules which are charged by an equal number of modules of lead acid batteries. The invention comprises the combination of standard automotive lead acid batteries for charging an electrolytic capacitor array which is switched into an Electromagnetic Launcher (EML) by means of silicon controlled rectifiers, and a control circuit for controlling the loading and launching of projectiles at a very rapid rate. The system includes a multishot preinjector and rapid fire controller for operating the system in a safe and reliable manner. The system includes a preaccelerator, magazine and barrel. The combination eliminates the low power density limitation of the batteries, the requirement to repetitively commutate energy out of an inductor, and allows for a modular system than can be expanded to provide higher energy to each projectile in the burst.
    Type: Grant
    Filed: July 28, 1994
    Date of Patent: October 17, 1995
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Daniel B. Jensen, James B. Cornette, Mark W. Heyse, Ronald E. Stearns
  • Patent number: 5454289
    Abstract: Methods and apparatus related to design and construction of lightweight and mobile railgun barrels having high L' (inductance per unit length). The barrels comprise stacked metallic annular laminations in combination with prestressed tension elements to add radial and longitudinal stiffness. Laminations have elongated annular shapes to accommodate a plurality of longitudinal rails within the barrel, and the lamination shape is optimized to contain radial forces (tending to spread the rails) associated with the launching of railgun projectiles. Longitudinal stiffness is obtained from tension elements spirally wound around the barrel at a preferred angle with the barrel longitudinal axis. Radial stiffness is obtained by injecting a settable plastic fluid between barrel laminations and internal (bore) components, the latter being held as a subassembly with a longitudinal shrink tube.
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: October 3, 1995
    Assignee: Board of Regents, The University of Texas System
    Inventors: James L. Bacon, Richard L. Laughlin, John H. Price
  • Patent number: 5435225
    Abstract: A device for electromagnetically accelerating projectiles. The invention features two parallel conducting circular plates, a plurality of electrode connections to both upper and lower plates, a support base, and a projectile magazine. A projectile is spring-loaded into a firing position concentrically located between the parallel plates. A voltage source is applied to the plates to cause current to flow in directions defined by selectable, discrete electrode connections on both upper and lower plates. Repulsive Lorentz forces are generated to eject the projectile in a 360 degree range of fire.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: July 25, 1995
    Inventor: Mohsen Shahinpoor
  • Patent number: 5431083
    Abstract: A segmented electromagnetic launcher, comprising a solid rail (20) and a segmented rail (21), formed from segments (22a to 22z) with number of segments greater than one, isolated from one another. These two rails are positioned parallel to and spaced apart from one another, forming a barrel (3) with breech (4) and muzzle (5) ends for sliding a projectile with armature (23) inside the barrel. Two supply conductors (24a, 24b) are positioned on either side and parallel to the solid rail (20) and isolated from it; side supply conductors (25a to 25z, 26a to 26z) are positioned on either side of the bore of the barrel with the number of side supply conductors two times the number of the segments. Each segment (22k) is connected with two supply conductors (24a, 24b) by two side supply conductors (25k, 26k) in connection points (27a to 27z, 28a to 28z) located at the breech end of each segment.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: July 11, 1995
    Assignee: Lioudmila A. Glouchko
    Inventor: Petr Vassioukevitch
  • Patent number: 5417140
    Abstract: In a two-stage railgun accelerating apparatus, a flying object is initially accelerated by acceleration gas produced by a gas gun. The initially accelerated flying object is led through an introducing pipe to an inlet of a railgun section of the two-stage railgun accelerating apparatus. A position and a velocity of the flying object are detected by a position detector and a velocity detector provided in the introducing pipe. According to the results of detection, both a voltage is applied to the railgun section and the acceleration gas is irradiated just behind the flying object with a laser beam, such that a dielectric breakdown of the gas is effected to generate plasma of good quality for accelerating the flying object.
    Type: Grant
    Filed: November 16, 1993
    Date of Patent: May 23, 1995
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Masanori Onozuka, Yasushi Oda
  • Patent number: 5386759
    Abstract: In a two-stage railgun accelerating apparatus, a flying object is initially accelerated by acceleration gas produced by a gas gun. The initially accelerated flying object is led through an introducing pipe to an inlet of a railgun section of the two-stage railgun accelerating apparatus. A position and a velocity of the flying object are detected by a position detector and a velocity detector provided in the introducing pipe. According to the results of detection, both a voltage is applied to the railgun section and the acceleration gas is irradiated just behind the flying object with a laser beam, such that a dielectric breakdown of the gas is effected to generate plasma of good quality for accelerating the flying object.
    Type: Grant
    Filed: November 16, 1993
    Date of Patent: February 7, 1995
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Masanori Onozuka, Yasushi Oda
  • Patent number: 5385078
    Abstract: Electromagnetic launcher apparatus which includes a set of conductive rails and a projectile having an armature which comprises both primary conductive material and phase changeable conductive material. This conducting, phase change material armature comprises material which when exposed to friction induced heat changes from solid to liquid form during the launching of projectiles along the conductive rails. This conducting, phase change material armature has decreased mass particularly useful for long barrel launches.
    Type: Grant
    Filed: December 15, 1989
    Date of Patent: January 31, 1995
    Assignee: Westinghouse Electric Corporation
    Inventors: Van P. Carey, Minh D. Lee
  • Patent number: 5375504
    Abstract: An electromagnetically energized railgun system in which nesting and segmenting of the primary rails is combined with augmenting rails and crossover bar conductors and an inductorless single power supply arrangement to provide a high efficiency hypervelocity capable railgun improvement over prior railgun arrangements. The disclosed railgun apparatus uses a single power supply or energy source and achieves the desired near zero muzzle energy storage through a combination of inductive and resistive primary rail commutation, power supply pulsing, and augmenting rail inductive energy storage.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: December 27, 1994
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: David P. Bauer
  • Patent number: 5360999
    Abstract: An apparatus and method are provided for controlling the switching characteristics of an explosively actuated switch. The switch comprises a conductor that is only partially severed by explosive forces. A bridge region, the conductive portion of the conductor remaining after the explosion, is then severed by thermal breakdown. Variations in the bridge region enable a user to vary the switching characteristics of the switch.
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: November 1, 1994
    Assignee: Board of Regents, The University of Texas System
    Inventors: Jim L. Upshaw, Jonathan J. Hahne, Richard J. Hayes, Raymond C. Zowarka, Jr., John P. Kajs, Robert L. Sledge, II
  • Patent number: 5331879
    Abstract: An electrothermal firing device (1) including a tube containing a charge chamber (4') in which a first electrode (9) is disposed at the end of the charge chamber (4') adjacent the breechblock (2) and a second electrode (10) is disposed at the end of the charge chamber adjacent the projectile (6). To permit the first electrode (9) adjacent the breechblock to be arranged in the charge chamber without expensive supports, in contrast to such prior art devices, this first electrode (9) is configured as the grounded electrode and the second electrode (10) is configured as the high voltage electrode. Preferably, the two electrodes (9, 10) are arranged in an exchangeable cartouche (18) so that conventional charge chambers employing corresponding loading devices can be retrofitted in a simple manner for use with electrothermal firing devices (1).
    Type: Grant
    Filed: October 1, 1992
    Date of Patent: July 26, 1994
    Assignee: TZN Forschungs-und Entwicklungszentrum Unterluss GmbH
    Inventor: Markus Loffler
  • Patent number: 5297468
    Abstract: A railgun apparatus for accelerating a projectile having a conductive region. The railgun comprises a power supply for providing a current impulse and at least two elongate generally parallel rails. The rails include a first layer comprising a highly conductive material and a second layer comprising a highly resistive layer. The second layer has a resistivity that varies along the length of the rails and is so sized and arranged as to contact the conductive region of the projectile. The power supply is switchably connected to the first layer of the rails. When the current impulse is applied to the rails with the projectile therebetween, the current impulse is spread over the conductive region of the projectile to reduce the velocity skin effect.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: March 29, 1994
    Assignee: Dyuar Incorporated
    Inventor: Yuri A. Dreizin
  • Patent number: 5294850
    Abstract: An electromagnetic accelerator arrangement includes a stationary arrangement including at least one stationary primary coil, and a movable arrangement including at least one moveable secondary coil. The planes of the stationary and the moveable coils are parallel to a direction of movement of the moveable arrangement. The coils of the stationary and the movable arrangements have approximately the same coil width in the direction of movement of the moveable arrangement and transversely thereto, as well as the same coil separation in the direction of movement of the moveable arrangement. The at least one stationary primary coil includes at least two layers between which the at least one secondary coil of the movable component is movably disposed, the distance between the layers being kept small transversely to the direction of movement of the moveable arrangement.
    Type: Grant
    Filed: September 17, 1992
    Date of Patent: March 15, 1994
    Assignee: Rheinmetall GmbH
    Inventors: Herbert Weh, Hardo May, Markus Loffler
  • Patent number: 5285763
    Abstract: A symmetrical railgun is described which consists of at least four rails of electrically conductive material, which extend at the same spacing from and parallel to a predetermined axis of symmetry.
    Type: Grant
    Filed: September 3, 1992
    Date of Patent: February 15, 1994
    Assignee: Igenwert GmbH
    Inventor: Eduard Igenbergs
  • Patent number: 5275083
    Abstract: A single skirt projectile (20) having an insulating skirt (22) at its rear, or a dual trailing skirt projectile (30, 40, 50, 60) having an insulating skirt (32, 42, 52, 62) succeeded by an arc extinguishing skirt (34, 44, 54, 64), is accelerated by a railgun accelerator 10 having a pair of parallel conducting rails (1a, 1b) which are separated by insulating wall spacers (11). The insulating skirt (22, 32, 42, 52, 62) includes a plasma channel (38). The arc extinguishing skirt (34, 44, 54, 64) interrupts the conduction that occurs in the insulating skirt channel (38) by blocking the plasma arc (3) from conducting current from rail to rail (1a, 1b) at the rear of the projectile (30, 40, 50, 60). The arc extinguishing skirt may be comprised of two plates (36a, 36b) which form a horseshoe wherein the plates are parallel to the rails (1a, b); a chisel-shape design; cross-shaped, or it may be a cylindrical (64).
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: January 4, 1994
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Ronald S. Hawke, Allan R. Susoeff
  • Patent number: 5272965
    Abstract: A rail gun for accelerating a projectile therein includes a hollow insulating body forming a gun tube; and two rail assemblies supported in the gun tube and together defining an acceleration channel to accommodate a projectile for being propelled therein by a plasma armature generated by a high intensity current flowing through the rail assemblies and an electric arc connecting the rail assemblies. At least one of the rail assemblies includes a layer of an electrically conducting metal wool mass extending along and bounding the acceleration channel and an insulating substance held in the metal wool mass.
    Type: Grant
    Filed: October 16, 1992
    Date of Patent: December 28, 1993
    Assignee: TZN Forschungs- und Entwicklungszentrum Unterluss GmbH
    Inventor: Markus Loffler
  • Patent number: 5237904
    Abstract: A non-transitioning armature/projectile for launching from a single or multi-turn rail gun including: a nose; a tail; and a current carrying section between the nose and the tail including current channeling means for reducing the current concentration in the tail end of the armature/projectile and distributing the current toward the nose for generally balancing the electrically induced driving force with the inertial force and substantially reducing internal stress in the section.
    Type: Grant
    Filed: January 5, 1988
    Date of Patent: August 24, 1993
    Inventor: Doris Kuhlmann-Wilsdorf
  • Patent number: 5235894
    Abstract: A device for firing projectiles (9) through an electrically heated plasma including a combustion chamber (12) which is provided on the breech side and the muzzle side with an electrode each, between which an arc generating plasma burns. A cartridge (18), which contains a material that decomposes into a low-molecular-weight gas under the effect of the arc, can be introduced into the combustion chamber (12). A current conductor, which connects a breech-side electrode (10) to the muzzle-side electrode (7) extending annularly around the muzzle-side end of the cartridge (18), is arranged in the longitudinal axis of the cartridge (18). The current conductor (20) consists of a plurality of strands (21) which extend radially to the outside from the longitudinal axis toward the annular electrode (7) at least at the muzzle-size end of the cartridge (18).
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: August 17, 1993
    Assignee: Messerschmitt-Bolkow-Blohm GmbH
    Inventors: Felix Nitschke, Thomas Sikora, Hans Leis
  • Patent number: 5231242
    Abstract: The apparatus disclosed herein relates to plasma injection and distribution systems which release high energy plasma into a combustible mass to promote efficient combustion and maximize the muzzle velocity of a projectile. The devices inject plasma streams into a combustible mass in a coherent and directed manner such that pressure peaks and the resultant thermal and dynamic stresses are eliminated. Particularly, strategically positioned outlet orifices and nozzles enable the invasion of a propellant mass by plasma jet streams to create controllable uniform ignition and combustion therein.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: July 27, 1993
    Assignee: FMC Corporation
    Inventors: George S. Chryssomallis, James P. Warren, Dennis Borgwarth
  • Patent number: 5223662
    Abstract: An accelerator is described which comprises an electrothermal accelerator and is preferably of two-stage design, with the first stage consisting of an electrothermal accelerator, in particular an electromagnetically amplified electrothermal accelerator, and with the second stage consisting of a light gas accelerator.
    Type: Grant
    Filed: August 15, 1990
    Date of Patent: June 29, 1993
    Assignee: Igenwert GmbH
    Inventors: Eduard Igenbergs, Martin Rott
  • Patent number: 5217948
    Abstract: The device employs Hybrid Pulsed Transformer principles employing a projectile with an internal pay load. The projectile carries a light weight shorted secondary coil or coils constructed of aluminum and the projectile acts as a moving secondary through a plurality of aligned spaced apart transformer primary coils. The moving secondary coil includes a plurality of surrounding channels containing a liquid, such as water, for cooling. The cooling ability of certain liquids, as for example water, associated with change of state between liquid and gas is employed to cool the coil or coils.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: June 8, 1993
    Assignee: General Dynamics Corporation, Space Systems Division
    Inventors: Eddie M. Leung, Scott D. Peck
  • Patent number: 5197738
    Abstract: A miniature golf course wherein an obstacle is positioned between the tee area and the putting cup hole. The obstacle includes a transparent housing containing a solenoid-controlled plunger which is actuated by a switch responsive to a putted golf ball. When actuated, the plunger propels a golf ball upwardly to a retrieving device which directs the golf ball to the putting surface in a predetermined direction relative to the putting cup hole.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: March 30, 1993
    Inventor: David C. Hartman, Sr.
  • Patent number: 5189244
    Abstract: A method and apparatus for imparting a spin to a projectile fired from a railgun. A projectile which is rotatable within the barrel of the railgun, and which includes a conductive element, is caused to pass through a magnetic field, causing the projectile to rotate. Preferably, the magnetic field will be established by a solenoidal magnet which is coaxial with the path of the projectile.
    Type: Grant
    Filed: August 21, 1989
    Date of Patent: February 23, 1993
    Assignee: Board of Regents, The University of Texas System
    Inventor: William F. Weldon
  • Patent number: 5183956
    Abstract: A device for accelerating a projectile to an extremely high velocity includes a launch tube having electrodes engageable with the projectile assembly for applying a large electrical voltage to it, the projectile assembly includes a pair of travelling electrodes fixed to the rear end of the projectile and engageable with the launch tube electrodes during the travel of the projectile assembly through the launch tube. The travelling electrodes define a spark gap which, under the high voltage applied from the launch tube electrodes, forms a high-temperature, high-pressure plasma arc travelling with the projectile and effective to increase its acceleration.
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: February 2, 1993
    Assignee: State of Israel, Ministry of Defence Rafael-Armamend Development Authority
    Inventor: Gideon Rosenberg
  • Patent number: 5183957
    Abstract: An electromagnetic railgun having a layer of low conductivity material along the rails to interface with the armature as the armature is propelled along the rails. The low conductivity material has been found to permit rapid current penetration between the layer and armature, thereby inhibiting undersirable high current density formation along the trailing edge of the armature. Advantageously, inhibiting the high current density formation permits use of a solid armature at velocities exceeding on kilometer per second. Preferably, the layer is composed of graphite or a graphite/copper mixture. A layer of copper or other high conductivity material is preferably laminated to the low conductivity graphite layer to reduce the overall railgun circuit resistance. In the preferred embodiment, the layer of low conductivity material increases in thickness from the breech to the muzzle to decrease railgun circuit resistance.
    Type: Grant
    Filed: April 13, 1990
    Date of Patent: February 2, 1993
    Assignee: Board of Regents, The University of Texas System
    Inventors: William F. Weldon, Herbert H. Woodson, Glen C. Long
  • Patent number: 5182254
    Abstract: A pair of copper rails on which a projectile is mounted forms an electrometic rail gun. One end of the rails is connected across an electrical coil which resides between a pair of Helmholtz coils made of a high temperature superconducting material. The Helmholtz coils are normally held in a superconducting state and carry large currents without the need of a voltage source. A thermal quencher is provided which is capable of removing the superconducting state by heating the superconducting circuit. When the temperature of the superconducting circuit rises above its critical temperature, the resistance of the wires will increase, causing the current to collapse. This sharp collapse of the current will cause a correspondingly sharp collapse of the magnetic field of the Helmholtz coils, thereby inducing a sharp current pulse in the force coil which produces a high-energy electric power pulse on the rails to launch the projectile. A magnetic quencher may be used in place of the thermal quencher.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: January 26, 1993
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Frank J. Owens
  • Patent number: 5173568
    Abstract: A magnetic gun for the purpose of accelerating a metal clad projectile to high velocities which includes a long dipole magnet extending the length of the gun bore that encloses a plurality of short superconducting dipoles magnets along its length. The short dipoles are superconducting dipoles whose induced current and magnetic field oppose the current and magnetic field of the long dipole. The short dipoles while in a superconducting state prevent the long dipole field from entering the gun bore. When the short dipoles become normal conducting, the current in the short dipoles decay rapidly. When this occurs the field of each of the small dipoles collapse and magnetic flux from the long dipole enters the gun bore at the locaiton of the normal conducting small dipole. This entering flux repels the projectile down the barrel in the direction of least flux, so the projectile is moved to the next short dipole section.
    Type: Grant
    Filed: August 6, 1990
    Date of Patent: December 22, 1992
    Assignee: General Dynamics Corporation, Space Systems Division
    Inventor: Jerome F. Parmer
  • Patent number: 5168118
    Abstract: A method for electromagnetic acceleration of an object involving interaction of magnetic forces between magnetic rings on the object to be accelerated and alternating magnetic fields in a ringing circuit formed in each of a series of linearly arranged doughnut shaped accelerator coils with the frequency of the ringing circuit generated in each coil being adjusted according to velocity of the body being accelerated by adjusting the capacitance in each ringing coil circuit; computation being necessary for each particular application to properly match components to achieve desired velocity.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: December 1, 1992
    Inventor: Jon M. Schroeder
  • Patent number: 5155290
    Abstract: An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 414) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: October 13, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Ronald S. Hawke
  • Patent number: 5155289
    Abstract: High-voltage, solid-state switches that are capable of interrupting current, offer relatively low on-state losses (low forward voltage drop) and provide for high current densities. Low-voltage transistors and silicon-controlled rectifiers are employed to achieve low power losses at high current densities. One embodiment of the present invention relates to a solid-state switch for controlling a source of direct current. The switch includes four switching elements. Each element has a first terminal, a second terminal and a control signal input terminal. The switching elements provide a high resistance to the flow of electrical current in response to a first control signal. A second control signal causes the switching elements to offer a low resistance to the flow of electrical current. The first and second switching elements are connected in series, as are the third and fourth switching elements.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: October 13, 1992
    Assignee: General Atomics
    Inventor: Edward E. Bowles
  • Patent number: 5142962
    Abstract: An electromagnetic railgun accelerator system, for accelerating projectiles (14, 15, 114, 214, 314, 444) by a plasma arc (3), introduces a breakdown inhibiting gas into the railgun chamber (26) behind the accelerating projectile (14). The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF.sub.6. The gas is introduced between the railgun rails (12) after the projectile (14) has passed through inlets (16) in the rails (12) or the projectile (114); by coating the rails (12) or the projectile (15) with a material (28) which releases the gas after the projectile (14 ) passes over it; by fabricating the rails (12) or the projectile (15) or insulators out of a material which releases the gas into the portions of the chamber (26) through which the projectile has travelled. The projectile (214, 314, 414) may have a cavity (232, 332, 432) at its rear to control the release of ablation products (4).
    Type: Grant
    Filed: April 20, 1989
    Date of Patent: September 1, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Ronald S. Hawke
  • Patent number: 5138929
    Abstract: An electromagnetic projectile launcher or railgun capable of withstanding hundreds or thousands of shots. The railgun features a current management system having guard plates which act to reduce peak rail current densities while also maximizing projectile velocity. Guard plates can be used in either square or round bore designs and can be powered by either a single or separate power supply from that of the rails.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: August 18, 1992
    Assignee: Board of Regents, The University of Texas System
    Inventors: William F. Weldon, Joseph H. Beno
  • Patent number: 5133242
    Abstract: An electromagnetic rail accelerator in which a plurality of plasma arc cushions are generated between a plurality of pairs of rails in order to accelerate projectiles. To prevent currents of different intensities from flowing through the individual plasma armatures and, thus subjecting the rails to relatively great wear, the number of rail pairs is made equal to the number of zones in which plasma arc cushions are formed. Preferably, the rail accelerator is composed of a rail arrangement in multiples of three, with the rails being disposed in or on the inner surface of a cylindrical tube of insulating material and with the current flowing in opposite directions in adjacent rails.
    Type: Grant
    Filed: March 21, 1988
    Date of Patent: July 28, 1992
    Assignee: Rheinmetall GmbH
    Inventor: Wolfram Witt
  • Patent number: 5133241
    Abstract: An electromagnetic rail launcher adapted to accelerate a projectile by an electromagnetic force which comprises:a plurality of rail-like electrodes; andan armature being installed so as to shortcircuit the plurality of rail-like electrodes;at least one of said plurality of electrodes being consisted of a first conductive part which contacts with the armature and a second conductive part which is electrically insulated with the first conductive part;said first conductive part being segmented in a plurality of segmented first conductive parts which are insulated with each other, in an acceleration direction of the projectile;each of said plurality of the segmented first conductive parts having at least one hole through which the first conductive part and the second conductive part are bridged by an arc, when a current flows in the second conductive part.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: July 28, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kenichi Koyama, Hideaki Toya
  • Patent number: 5127308
    Abstract: A distributed energy store electromagnetic railgun comprising a plurality of sections, each section having a connector portion and a barrel portion that includes a rail surface. The sections are arranged to form first and second rails. The sections forming each rail are positioned such that their rail surfaces form a substantially continuous barrel surface. The rails are positioned such that their barrel surfaces define a barrel having a longitudinal axis, a breech end, and a muzzle end. For each section, the connector portion is positioned closer than the rail surface to the breech end by greater than the length of an armature, in a direction along the longitudinal axis. Electrical current is provided to each section through its connector portion. Current does not flow through a section until the armature, or a plasma behind an insulating projectile, reaches the rail surface of the section.
    Type: Grant
    Filed: September 17, 1990
    Date of Patent: July 7, 1992
    Assignee: The Boeing Company
    Inventors: Jeffrey G. Thompson, Doris Kuhlmann-Wilsdorf
  • Patent number: 5125321
    Abstract: An electromagnetic cylindrical projectile mass launcher and a method of operation is provided which includes a cylindrical projectile having a conducting armature, a cylindrical barrel in which the armature is received, a plurality of electromagnetic drive coil stages, a plurality of pulse energy sources, and a pulsed power arrangement for generating magnetic pulses forming a pulsed magnetic wave along the length of the launcher barrel. The pulsed magnetic wave provides a propelling force on the projectile along the drive coil. The pulsed magnetic wave of the drive coil stages is advanced along the armature faster than the projectile to thereby generate an induced current wave in the armature. The pulsed generation of the magnetic wave minimizes electromagnetic heating of the projectile and provides for smooth acceleration of the projectile through the barrel of the launcher.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: June 30, 1992
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Maynard Cowan, Jr., Billy W. Duggin, Melvin M. Widner
  • Patent number: 5122506
    Abstract: A process for moving a magnetized object at a velocity in excess of 10 kilometers per second is provided. In this process, a symmetrical chamber which contains alternating portions of superconductive material and electromagnetic coils is provided. A magnetized object is disposed within the chamber and caused to levitate there because of the Meissner effect. The magnetized object is accelerated within the chamber by supplying asynchronous direct current pulses to the coils within the chamber.
    Type: Grant
    Filed: May 11, 1990
    Date of Patent: June 16, 1992
    Assignee: Howard J. Greenwald
    Inventor: Xingwu Wang
  • Patent number: 5105713
    Abstract: The invention is a projectile that is accelerated by electric or magnetic elds through the barrel of a gun. The projectile has an outer layer of composite material, the material having a ceramic constituent and an electrically conductive constituent. The projectile may also have a relatively soft or malleable discarding sabot which is electrically conductive.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: April 21, 1992
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Wayne F. Wirgau
  • Patent number: 5095802
    Abstract: A rail gun assembly (10) having rail electrodes (11, 12) which are of toothed cross-section configuration and an armature (15) which provides an electrical interconnection between the rail electrodes (11,12). The armature (15) is made up of three electrically conductive portions (24,25,26) which are separated by insulators (27,28). The electrically conductive armature portions (24,25,26) are so configured that varying amounts of electrical current pass through them as the armature is operationally accelerated along the gap between the rail electrodes (11,12). Localized overheating of the armature (15) is therefore substantially reduced.
    Type: Grant
    Filed: August 28, 1990
    Date of Patent: March 17, 1992
    Assignee: Rolls-Royce Business Ventures Limited
    Inventor: Graham A. Reynolds
  • Patent number: 5094141
    Abstract: An arrangement for the accelerating of a projectile through the intermediary of a plasma, wherein the plasma is generated by means of an electrical discharging circuit within a metallic tube which has the bottom thereof closed. The one pole of the discharging circuit contacts a first electrode which is formed on the tube rearwardly of the projectile, and in the other pole of the discharging circuit is connected with the casing or jacket of the tube. The projectile, which constitutes the second electrode, forms a current collector which contacts in the casing or jacket of the tube and slides therein during the acceleration of the projectile. The current collector hereby acts in the manner of a sliding contact which, during the acceleration of the projectile, remains in electrical contact with the tube.
    Type: Grant
    Filed: August 22, 1991
    Date of Patent: March 10, 1992
    Assignees: Diehl GmbH & Co., Rheinmetall GmbH
    Inventors: Dieter Zwingel, Klaus Zocha, Markus Loffler
  • Patent number: 5093313
    Abstract: A reusable and regenerative electromagnetic propulsion method and operating system is provided for propelling high mass payloads to orbital velocities which does not require a vacuum environment. The propulsion system comprises a self supporting superconducting dipole coil several kilometers in diamater that is accelerated by magnetic repulsive forces generated by a plurality of giant superconducting field coils mounted in the underground tunnels. The propulsion dipole is mounted inside a circular hypersonic wing-like structure equipped with movable aerodyanmic control surfaces for guidance. The propulsion system can accelerate a payload with any desired launch azimuth by accelerating along a line of magnetic induction generated by the field coils having the desired azimuth angle. The payload is attached to the propulsion system by a plurality of cables.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: March 3, 1992
    Inventor: Michael A. Minovitch
  • Patent number: 5090292
    Abstract: An electrical switch for switching large currents in a low voltage circuit consists of two opposing terminals (32) connected to conducting rails (20) of an electromagnetic projectile launcher (10), each terminal having two conducting arms (32A, 32B) which enclose the breech chamber (114) of the launcher. Conducting contacts (66A, 66B) bridging across the opposing arms of the terminals are rapidly lifted to open the switch when the contacts are exposed to propellant gas pressure exerted on a projectile armature (22) slideable within the chamber. Electromagnetic forces of repulsion, which act upon whichever contact is the latter of the two to lift off the terminals, assist simultaneity of current pathway severance across both arms, thereby suppressing arcing at switch opening.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: February 25, 1992
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Paul Reip, Melton Mowbray
  • Patent number: 5081901
    Abstract: An artillery piece which has a gun barrel made up of a parallel rail electromagnetic launcher bore. Current from a source is injected into the rails to propel a bridging armature and projectile. The velocity of the porjectile is measured as it traverses a certain position within the barrel and the measured velocity is compared with a predetermined desired velocity. The velocity of the projectile is modified (if required) toward the muzzle end of the rails as a result of the comparison.
    Type: Grant
    Filed: June 29, 1987
    Date of Patent: January 21, 1992
    Assignee: Westinghouse Electric Corp.
    Inventors: George A. Kemeny, Daniel W. Deis
  • Patent number: 5078042
    Abstract: A quad armature electromagnetic rail gun uses four conducting rails, in a quadri-pole configuration, with four sliding armatures to propel projectiles. Two of the four conducting rails are positive, and receive one-half of the operating current. The four sliding armatures are slidably disposed between the two positive conducting rails and the two negative conducting rails, and each sliding armature conducts one-quarter of the conducting current therebetween. The quadruple configuration produces a minimum of magnetic interference at the center of the rail gun so that projectiles with electronic components need a minimum of magnetic shielding.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: January 7, 1992
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Daniel B. Jensen
  • Patent number: 5076135
    Abstract: A rail gun barrel has a pair of opposed spaced apart rails separated by a pair of opposed stepped insulator members, which cooperate to define an internal bore. Interior body members surround the bore-defining components and fill the space between those components and an outer surrounding containment tube of varying curvature. A pressure cavity is provided in the interior body members on at least one side of the bore to load the outer containment tube, which because of its varying curvature, translates a circumferentially variable prestress inversely proportional to its curvature and is selected to match the particular loading scenario.
    Type: Grant
    Filed: February 1, 1990
    Date of Patent: December 31, 1991
    Assignee: General Atomics
    Inventors: Thomas W. Hurn, Richard L. Creedon
  • Patent number: 5076136
    Abstract: Electromagnetic launcher apparatus which includes a set of projectile rails and a set of switch rails both lying along a common longitudinal axis. An armature assembly includes at one end thereof a switching armature for conduction of current between the switching rails, and at the other end thereof a projectile armature for conduction of current between the projectile rails. The rail system is supplied with operating current and when a predetermined current level is obtained, the armature assembly separates such that the armatures are propelled in opposite directions. The rearwardly projected switch armature may be intercepted by a stop mechanism while the forwardly projected armature propels a payload such as a projectile.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: December 31, 1991
    Assignee: Westinghouse Electric Corp.
    Inventors: Emmanuel Aivaliotis, Bobby D. McKee