Abstract: A spark gap assembly of a stack of insulating plates which have on one surface thereof a pair of electrodes preassembled and affixed thereto with a defined spark gap therebetween and a piece of ionizing material disposed on and affixed to each of the plates between the pair of electrodes. The plates are stacked with mating surfaces joined together and with a center plate bearing no electrodes that is joined with mating surfaces of each of two symmetrical groups of electrode bearing plates, and an electromagnetic coil is disposed around the periphery of the center plate.

Abstract: A reliable overload protection tube utilizes a meltable sealing material to mount an electrode within a metallic enclosure. The interelectrode gap between the tube electrodes is adjusted to determine the desired tube breakdown voltage. Voltage in excess of breakdown ionizes the tube and conducts the overload current safely to ground. The sealing material upon excess overload current becomes heated and melted allowing the electrodes to move into a short circuit contact to ground.

Abstract: In a vacuum arc discharge device of the rod array type, improved arc diffuseness and enhanced ability to hold off voltage during the recovery period are obtained by tapering the rods, with the maximum diameter occurring near the free ends. A higher threshold current for rod anode spot formation and melting also results.

Abstract: An overvoltage protecting element comprises a hollow cylinder of an insulating material, a pair of electrodes sealed to the opposite ends of the cylinder, and a pair of conductive layers disposed on the inner wall of the cylinder so as to be located opposite to the respective electrodes and each having a projection which extends toward the electrode. The conductive layers are of the band type, and one or more projections are provided on a part thereof. In order to prevent deterioration of insulation resistance by repeated discharge, the conductive layers are provided at positions which are electrically insulated from the two main electrodes.

Abstract: A current limiting spark gap for use in a valve type lightning or surge arrester includes a plurality of identical, mirror-image insulating gap plates assembled together to define arc elongation and cooling chambers between each pair of adjacent gap plates. Conductive electrodes are disposed on opposite sides of each gap plate. Dielectric rods extend through holes formed in the gap plates to vertically and horizontally align the gap plates in a vertical stack and to define and maintain the gap spacing between a pair of electrodes in each arc chamber. The spark gap utilizes only the electrode and arc chamber configurations to cause a follow current arc to move in each arc chamber to increase the length of the arc and to compress the arc against cooling walls and surfaces of the arc chambers. The electrode and arc chamber configurations achieve greater arc elongation and compression, and resultant cooling, to enhance follow current limitation.

Abstract: The hot gases and discharge products are removed from the space between the electrodes of a spark gap switch after the passage of the discharge by a supersonic air flow in the discharge region created by fabricating the ends of the electrodes to form a DeLaval nozzle. The supersonic air flow clears the switch and provides a switch having a very short grace period.

Abstract: A spark gap switch having a central electrode positioned within an annular electrode in a dielectric liquid or saturated vapor flow line, with coaxial or parallel plate electrical connections to said electrodes.

Abstract: Within an arc extinguishing chamber are disposed a pair of main electrodes so as to cause a spark starting gap to be defined therebetween. A single auxiliary electrode is also disposed so as to cause reignition in those interspaces between the auxiliary electrode and the respective main electrodes at positions distant from said spark starting gap. Further, paths for supplying therethrough a heated gas to the reigniting spark gaps when the feet at one side of the arcs between the respective main electrodes and the auxiliary electrode have arrived at the prescribed points of the auxiliary electrode are provided.

Abstract: Spark gap apparatus is provided wherein a wafer of electrical conducting material is affixed to a wafer of electrical insulating material and spaced from a circular array of circular pins of an electron discharge device to provide a spark gap intermediate the wafer of electrical conducting material and certain ones of the circular pins of the electron discharge device.

Abstract: A vacuum interrupter includes a small sized, rigid exciting coil disposed immediately behind at least one main electrode so as to be connected at one end to a current carrying rod and at the other end to the main electrode, and consisting of a plurality of sectoral-shaped unit exciting coils arranged adjacent to each other in a plane substantially parallel to the surface of the main electrode and having the same polarity, in which, when electric currents branched from a main electric current are flowed through the respective unit exciting coils, magnetomotive forces generated due to the electric currents flowing radially of the unit exciting coils are cancelled with respect to each other and only the electric currents flowed through the arcuate sections of the unit exciting coils induce electromotive forces effective to produce magnetic fields in a direction perpendicular to the main electrode.