Abstract: An antisparking structure, in particular for aircraft, comprises two components made of composite electrically conductive material which overlie each other at least in part and which are assembled together by using an electrically conductive screw having a countersunk head. A conduction-improving arrangement is provided for improving the conduction of electricity between the overlying portions of the two components. Electrical insulation is provided for electrically insulating the screw from the second component, at least in the vicinity of the nut. Thus, when lightning strikes the head of the screw, the lightning current flows between the screw and the first component, and then between the first component and the second component through the conduction-improving arrangement, without there being any arc between the nut and the second component.

Abstract: A lightning strike coating composition for composites. The composite is multilayered and comprises (i) a prepreg containing layer, (ii) a lightweight, highly conductive metallic wire screen or foil layer, and (iii) a sheet of lightweight carrier fabric containing (a) on one side a coating of a highly filled, thermoset resin in which the filler comprises a multimodal combination of filler particles, and (b) optionally, on the other side an adhesive joining it to layer (ii); wherein the layers are bonded to each other.

Abstract: A lightning protection system is disclosed for a seismic data acquisition system having single or multiple geophones positioned at predetermined ground locations over a large area. A surge suppressor is placed across the leads to which the geophones strings are connected. Such surge suppressor preferably comprises a gas discharge arc tube. The base or spike of each geophone is implanted in the ground, A ground lead is connected to the surge suppressor. Electrical energy from a lightning strike affecting the geophones, cables, data acquisition boxes, etc. is dissipated by the surge suppressors through the multiple spikes to the earth thereby to minimize damage resulting from lightning.

Abstract: A lightning surge protector, comprises a current limiting element in a pressure-proof housing. The pressure-proof housing is composed of a conductive material and coupled with an upper electrode member. Also, a self arc-extinguishing LSP comprises a current limiting element and upper and lower electrode members housed and fixed in a conductive pressure-proof housing opened at its lower portion through a suspension structure composed of a suspension rod. The outside and inside of the housing are covered and filled with an insulator, so that, upon occurrence of an internal arc due to a short-circuit fault or the like, the energy due to the arc causes the lower electrode member to break the insulator in the vicinity of an opening portion of the conductive pressure-proof housing so as to electrically connect the conductive pressure-proof housing to a part of the lower electrode member.

Abstract: For protecting electrical installations against electromagnetic interferences and especially against over-voltages as can for instance occur as a consequence of lightning strikes, electrical lines provided between individual electrical apparatus are laid in a flexible hollow tubular member having an electrically conducting surface and at least one separation or division in its longitudinal direction. The hollow member is also provided with an undulated profile. The hollow member can be designed either as divided tubular sections or as cable channels or ducts provided with a covering member.

Abstract: For purposes of protecting electrical installations in airplanes against electromagnetic disturbances and especially against overvoltages as can occur for instance as a consequence of a lightning strike, the electrical lines between the individual electrical devices are laid in flexible profiled tubes consisting of electrically conducting material and are rotatably connected with junction elements arranged on one side. At the same time the tubes are connected by means of these junction elements to charge dissipation points provided at the electrical devices. The lines laid in this manner are arranged in overbraiding of plastic material by way of chafing protection. In another embodiment, the chafing protection is provided by a plastic layer on the inside of the profiled tube. In still another embodiment, the chafing protection is itself a hose fabricated of fiber material.

Abstract: For purposes of protecting electrical installations against electromagnetic disturbances, especially overvoltages, for instance, as a consequence of lightning strikes, wiring lines laid for connecting individual electrical apparatus are surrounded by a shielding, which is formed by a braiding, consisting of electrically conducting material and which is in connection with connector elements arranged at its ends. The connector elements, as well as an additionally provided terminal, branching and attachment elements, comprise, respectively, a transitional part over which the braiding is pulled and on which it is fastened by means of a clamping element. In addition, further sheaths of a plastic braiding are provided between the electrical shielding and the electrical lines.

Abstract: Underwriters Laboratories lists lightning protection components as described in their UL 96, Third Edition Publication. The present invention improves on the basic lightning rod systems. The improvement provides a multiplicity of points extending in all directions from the top of a supporting rod which is designed to fit the conventional lightning rod mounting bases. The points are separated and configured to produce maximum ionization current commensurate and configured to carry an above average lightning strike current flow. The result is a hybrid lightning air terminal and lightning prevention system module named the Spline Ball Terminal (SBT). The SBT partially equalizes the charge differential between the protected site and the cloud thereby preventing many strokes from occurring. If a high energy stroke does enter the protected zone, then the SBT acts like a traditional UL approved lightning rod, but with much greater efficiency.

Abstract: Simple lightning rod systems divert a lightning stroke away from a protected facility. They do nothing to prevent a lightning stroke from occurring. The present invention represents the state of the art improvements in lightning prevention systems. These prevention systems are termed dissipating systems because they neutralize the charge differential between the cloud and the protected facility before the flashover point occurs. The flashover point is seen as lightning. The present dissipative systems leak off the charge differential slowly before the flashover point is reached. The present invention pinpoints the critical design parameters for the optimization of dissipative array systems. The critical design parameters include the number, size and spacing of both the ionizer points and their conductive wires. These Dissipation Array Systems (DAS) provide up to 100% prevention protection from lightning strokes.

Abstract: A lightning protection installation for boats comprising a copper lightning rod mounted on the top of the mast or, in the case of a power boat, mounted on the deck, a copper wire attached to the rod and running downwardly to a point where it is attached to a retractable copper conductor. The copper conductor is retractable through a plastic or fiberglass tube or box molded or inserted in the hull or attached to a centerboard, if available. When the conductor is raised to the passive position, it is protected from the formation of marine growth; and when it is lowered, the conductor provides sufficient wettable electrical conducting grounding surface to conduct the lightning to water ground. Raising the conductor removes the slight drag caused by the grounded conductor.

Abstract: A method for conditioning a composite structure to have an increased sparking current threshold. The method calls for the treatment of the joint in a composite structure by injected currents for predetermined periods of time at a sequence of voltages which are initially less than the present sparking voltage threshold of the structure. The voltage levels can be increased during the treatment to be greater than the sparking voltage threshold of the original structure. If the composite structure contains fasteners, the sparking voltage threshold can be conveniently increased by injecting the current from a timed voltage source through a variety of pairs of the fasteners.

Abstract: A fastener for use with aircraft structures comprising composite materials has improved electrical characteristics designed to reduce damage by lightning strikes. The fastener comprises separate nut and bolt portions and a cage member (4, 1, 6). The nut (4) and the head portion of the bolt 1 both have beveled edges which in use are countersunk in the composite materials to enhance electrical contact between the fastener and aircraft structural members (2, 5). The nut (4) is captively mounted inside the cage member (6) and is moveable, within pre-determined limits, inside the cage (6) so that it may be axially aligned with and the bolt screwed therein, thus compensating for any initial non-aligment of the nut (4) and bolt (1) due to a complex shape of the aircraft structure necessitated by aerodynamic or other considerations.

Abstract: A lightning protective device for a ground based mobile radar antennas of the type which moves round a vertical axis. The device includes: an electrically conductive rod, located near the antenna which is placed outside the transmission and reception sector of the antenna. A first or top end of the rod is higher than the antenna. An electrically insulating rigid support connects the rod and the antenna and transfers rotation of the antenna to the rod, thus keeping the rod outside the transmission and reception sector of the antenna. A fixed electrically conductive circular rail is placed below and around the antenna, and several electrically conductive elements are connected to the rod to the rail, and to the insulating rigid support so as to rotate with the antenna and the rod, and include an electrically conductive skid which rubs against the circular rail, thus providing for an electrical contact between the rotatiing rod and the rail which is connected to ground.

Abstract: A means for conducting an electrical charge from one nonconducting article having a conductive layer thereon to another article across a joint, wherein the means is displaced from the mechanical interface of the joint. This reduces joint stresses from electrical currents.

Abstract: A lightning protected antenna in which at least one metallic antenna and its connected electronic housing is enclosed in a pressurized non-magnetic enclosure. A conductive path for lightning is provided which does not interfere with the radiation pattern of the antenna. The path includes a metal tip on top of the enclosure, and the antenna itself is used as a conductive path for the antenna grounding system.

Abstract: An improved tether having a central strength member comprised of layers of synthetic fibers surrounded by a thin weatherproof plastic barrier. A current carrying metallic braid surrounds the weatherproof barrier and in a portion of the tether is of a higher strength and denser weave copper than in other areas. An outer protective jacket surrounds the metallic braid and one or more windows are formed by removing a short longitudinal section of the outer jacket above an area of the tether which has the high density metallic braid. The weatherproof barrier, at least in the area where windows are formed, is heat sealed to form a seamless barrier. A relatively soft copper wire is wound around the metallic braid in the window area so as to transfer lightning induced currents in the metallic braid of the tether to a grounding system.

Abstract: Lightning protection apparatus for an exterior structural surface includes an electrically insulating protective coating adhered to the exterior surface, and a plurality of conductive particles supported in the coating. The particles are spaced at distances greater than the dimension of the particles in a direction parallel to the surface. The dielectric strength of the coating is thereby weakened by bridging the thickness of the coating with the particles. This enables lightning attachment to occur at a multiplicity of points rather than at one point, thereby reducing interior sparking in an aircraft and minimizing structual damage to the surface of the aircraft.

Abstract: Around an insulating central core (1) is arranged a first conductive component planned to put to earth a lightning installation. This first conductive component is composed of metallic wires (2) spreading parallel to the axis (3) of the whole. An annular coating made of insulating material (4) is arranged around the metallic wires (2) and a second conductive component, constituted by metallic wires (5), is arranged around this intermediate insulating coating (4). Metallic wires of this second component also spread parallel to the axis (3) of the whole and they are joined so as to form a metallic shielding. An outside protecting coating (6), made of insulating material, wraps the set of wires (5) of the second conductive component. This arrangement of metallic wires (2, 5) reduces at least their ohmic resistance and their inductance, which improves the performances of the whole for suppressing of side-flashings.

Abstract: A method for protecting composite structures from electrostatic discharge. This method includes limiting resistive heating in conductivity enhanced layers of composite material to prevent delamination due to pyrolytic reactions. Only sufficient metal is used in external conductivity enhanced layers to cause dielectric breakdown to occur before delamination due to pyrolytic reaction results.

Abstract: A plurality of metal conduits for fuel for hydraulic fluids extend through an aircraft fuel tank made of non-metallic materials such as carbon-epoxy. The conduits are attached to wall portions of the tank at spaced apart locations. The conduits are spaced apart from each other and are each spaced away from such wall portion of the tank. A dielectric insulator such as teflon or polyimide is provided on each conduit.

Abstract: A lightning deterrent device is described which consists of a brush-like conductive structure particularly suited to be mounted on the top of a transmission tower. The device includes a central core formed into an annulus having a diameter sufficient to contain the vertical sides of the tower. The central core mounts a plurality of conductive wires captured therein at their midpoints. Sufficient wires are used to form a brush-like structure. The maximum number of wires is 250 per inch. The wires are preferably 10 inches long and have a diameter of about 0.014 inch. The device has been found to reliably protect against lightning strikes, and in the case of a television transmission tower, increase the signal by over 25 miles.

Abstract: Incorporated in a tensile member by which a hopper or the like is suspended from a ground-supported frame is an electronic load cell which is constructed and arranged to report to a convenient control location a signal which corresponds to the tension in tensile member as a measure of the weight of the material such as sand, crushed stone, cement or ore in the hopper. In order to prevent lightning which may strike the hopper or support frame from travelling along the tensile member and damaging or destroying the load cell, the tensile member is electrically isolated from both the hopper and the support frame by bushed connectors wherein the insulating bushing portion is stressed in compression. These bushed connectors simultaneously provide this electrical shock isolating function and both carry the static load and accommodate mechanical shock produced upon sudden changes in load, as when a load of stone is dumped into or dispensed from the hopper.

Abstract: An elongated, insulative tube of high mechanical strength is equipped with fittings at each end for electrical connection with a high voltage transmission line and a grounded tower. An external spark gap is provided between a first arcing ring mounted in electrical connection with one end fitting and a second arcing ring mounted to the tube intermediate its ends and electrically connected with a contact member disposed within the tube. The portion of the tube interior between the contact member and the other end fitting is packed with a series array of varistor discs. The tube maintains the line in spaced relation with the tower, while the varistor array and spark gap absorb voltage surge differentials between the line and tower.

Abstract: A covered distribution wire is provided with a clamp device having sufficient mass to provide conductor protection against damage from fault current arcs over a section of the conductor where the insulation cover is removed for interconnection or insulator support purposes. The clamp mass is at least a minimum value needed for practicality in usage and otherwise is based on the fault energy to be absorbed from fault arcs in the expected usage.

Abstract: A covered distribution wire is provided with a clamp device having sufficient mass to provide conductor protection against damage from fault current arcs over a section of the conductor where the insulation cover is removed for interconnection or insulator support purposes. The clamp comprises two members which are bolted together to surround the conductor section such that an enlarged disc-like end clamp portion is positioned about the conductor within one and a half centimeters of an end face of the adjacent wire cover. The two members are secured together such that a pair of slots exists between them along opposite sides of the conductor section with splatter barriers located on one end thereof. The slots are tapered with increasing width in the radially outward direction with the minimum width being great enough to avoid weldment and the maximum width being less than that which allows fault arc travel through the slot to the conductor section.

Abstract: An insulated distribution conductor separated from the substation by one or more fuses is protected from arc damage by a clamp device having sufficient mass to absorb the arc energy and thereby prevent burndown and diameter reduction of the conductor at a point where the insulation covering has been removed. The clamp comprises two members which are bolted together to surround the bare section of the conductor and provide additional heat-absorbing mass at the point where the arc tends to dwell, i.e. at the end face of the insulation covering farthest from the power source.

Abstract: A controlled dielectric barrier is created surrounding a fastener to isolate its sparking areas. The barrier is formed by creating a cap to define a desired cavity between the cap and the fastener and then dielectric isolation material is placed in the cavity and held in place by the cap until hardened. The cap may then be removed from the fastener as desired.

Abstract: An aerial power transmission line comprises phase wires suspended from supports and a lightning protection system designed also to convey information in the form of r-f signals and having at least two wires 4 and 5 spaced a certain distance apart and forming an r-f data transmission channel. The wires 4 and 5 of the lightning protection system are suspended from the supports 3 one under the other in a substantially vertical plane.

Abstract: A lightning arrester comprises a non-linear resistor as a lightning arrester element and an insulator holding the non-linear resistor in one body without a gap to prevent deterioration of the non-linear resistor caused by moisture.

Abstract: A d.c. power transmission line comprises two wire-type systems providing for lightning protection of line conductors (2,3). One of the wire-type systems comprises at least two wires (9) in a spaced relation to each other and is located above a line conductor (2) connected to a negative pole (6) of a d.c. power supply (7). A second wire-type system comprises a single wire (11) and is located above a line conductor (3) connected to a positive pole (8) of the d.c. power supply (7).

Abstract: Lightning arresters comprising each non-linear resistor made of a main component of zinc oxide and the other minor component are connected between a steel tower and a power transmission cable supported on the steel tower by an insulator and between the power transmission cables in different phases whereby the lightning resistance of the aerial power transmission system is improved.

Abstract: Construction parts are protected against lightening by a layer which releases a cloud of ionized and ionizable particles to spread the area affected by the lightening flash and to fan out the current path. The layer may include additives which swell when heated to increase the volume and density of the cloud. An electrically and thermal conductive layer or two such layers each having predominantly one of these properties is provided underneath the releasing layer.

Abstract: A system and equipment for the preventative protection of objects located on the surface of the earth from the effects of atmospherics.

Abstract: The invention comprises a braided wire having a shaped clip soldered or otherwise connected to each end. The clip is so formed as to follow the shape of a retainer which is designed to secure a rubber weather seal by means of a cable and groove arrangement.

Abstract: Lightning protection system for roofed buildings having a waste pipe system comprising a series of interconnected waste pipes, a vent stack on the roof of the building, a soil pipe at the building site buried in electrically conductive contact with the ground, a lightning rod with a ball and a space discharge electrode atop the ball, and adapted to be supported by the stack without interfering with the stack's function, the series of interconnected waste pipes being in a building wall between and connecting the vent stack above and the soil pipe below and establishing a grounding circuit including the vent stack, and a bracket carried by the lightning rod and conductively affixed to the vent stack to render the grounding circuit complete to the space discharge electrode.

Abstract: A multilayer cylindrical or rectangular shielding container oriented to pect computer components primarily from magnetic and electromagnetic field disturbances of cloud-to-ground electric lightning strokes is provided. The shielding container is formed of spaced magnetic and nonmagnetic walls. The container preferably is oriented vertically, and leads and cables entering and leaving the container are passed through the top and bottom ends thereof to provide maximum protection from electric fields and from the the predominantly horizontal components of the magnetic field vectors that propagate from such strokes.

Abstract: A process and structure are described for protecting objects from the damaging effects of electrical discharges by employing a coating of a conductive, ablative material such as graphite. Upon occurrence of an intense electrical discharge to this material, it evaporates to dissipate the heat produced by the discharge and protect the structural integrity of the object.

Abstract: A floating cover that is spaced inwardly from the side of an upright tank is electrically grounded to the tank by a plurality of cable loops disposed in substantially vertical planes around the cover and spanning the space between it and the tank side wall. One side of each loop is secured to the side of the cover while the opposite side of the loop engages the side of the tank. The loops are compressed laterally between the cover and the tank side wall to maintain sliding electrical contact with that wall as the cover moves in the tank.