Abstract: Disclosed are various protection devices and associated methods. In some embodiments, a protection device may include a substrate and a fusible element coupled to the substrate, wherein the fusible element may include a first end opposite a second end, and wherein the first and second ends wrap around the substrate. The fusible element may further include a central section comprising a plurality of segments connected end-to-end in a continuous arrangement between the first and second ends, wherein a first set of segments of the plurality of segments extends along a first plane, and wherein a second set of segments of the plurality of segments extends along a second plane, different than the first plane.

Abstract: A high breaking capacity fuse including an electrically insulating fuse body, a fusible element extending through the fuse body, an electrically conductive first terminal connected to a first end of the fusible element, an electrically conductive second terminal connected to a second end of the fusible element, and a first fire extinguishing pad and a second fire extinguishing disposed within the fuse body and sandwiching the fusible element therebetween, each of the first and second fire extinguishing pads formed of a polymeric substrate and a plurality of microcapsules embedded in the polymeric substrate, the plurality of microcapsules filled with an arc-quenching liquid.

Abstract: Provided are approaches for forming a fusible element assembly, wherein an arc suppressant (e.g., silicone) is deposited on a fusible element. The arc suppressant is delivered to the fusible element at a plurality of angles.

Abstract: A fuse includes a fuse element and a fuse body. A portion of the fuse element is housed in a fuse body. The fuse element includes a first terminal and a second terminal disposed outside of the fuse body. The first terminal and the second terminal electrically connects the fuse element to a circuit to be protected and a power source. A first endbell and a second endbell is coupled to the fuse element. A predetermined amount of arc quenching material is disposed within the fuse body. The arc quenching material contacts at least a portion of the fuse element. The predetermined amount of the arc quenching material is less than a total volume size of the fuse tube. The arc quenching material is compacted. A remaining air gap in the fuse tube is filled with a liquid adhesive and cured to a solid state.

Abstract: A printed wiring board includes an insulating resinous substrate having an aperture unit, a first terminal unit and a second terminal unit consisting of a conductor and formed on top of the resinous substrate, and a fuse unit that electrically couples the first terminal unit and the second terminal unit to each other. At least a part of the fuse unit is disposed over the aperture unit, and in addition, is covered by a porous inorganic covering material having insulating properties.

Abstract: A fuse incorporates a fusible element assembly and an auxiliary fusible element assembly in a solid arc extinguishing material configuration. The fusible element assembly has a first operating characteristic and the auxiliary fusible element has a second operating characteristic different than the first operating characteristic.

Abstract: A fuse for a high voltage/high current application, such as a hydro-electric vehicle (“HEV”) application is provided. The fuse employs a variety of arc quenching features to handle a large amount of arcing energy that is generated when such fuse is opened due to a fuse opening event. In one embodiment, an insulative substrate, such as a melamine substrate, is metallized with a fuse element. The fuse element extends to multiple surfaces of the substrate. A fuse opening portion of the element is located so that the arcing energy is forced to travel along multiple insulative planes, increasing an impedance across the opening of the element and decreasing the likelihood of a sustained arc. Also, the substrate and element are disposed in a sealed housing, which is packed in one embodiment with an arc quenching material, such as sand.

Abstract: The present disclosure provides an improved system and method that reduces fulgurites and their effects in a fuse. The fuse element can be at least partially coated with a high temperature elastomeric compound, such as a silicone, that can substantially withstand the heat of the current sufficient to “blow” the fuse and associated arcing, if any, and not allow the local melting of the sand to form the fulgurite. Thus, the elastomeric compound shields the sand from the arcing. The arcing can be suppressed faster by not allowing fulgurites to form near the arc to provide a channel for the arc. The arc can be suppressed quicker with less heat without the channel. In general, if a fulgurite is formed, it is formed near the beginning of the elastomeric coating that is distal from another part of the exposed fuse such that arcing, if any, is reduced.

Abstract: A composite fuse element includes a network or matrix of conductive material that is in contact and interspersed with arc suppressing materials at a particle level. In such a matrix, the conductive (e.g., metal) network and the arc suppressing material particles provides a large contact surface area between these materials. When the conductive network melts or vaporizes, the resulting conductive vapors are adsorbed into the arc suppressing particles in a short time due to the large contact area between conductive and arc suppressing materials and the short diffusion distance that the conductive vapors are required to travel before they are absorbed by the arc suppressing material.

Abstract: A method and an apparatus for protecting an electrical circuit against excessive currents by a fuse assembly. The fuse assembly is configured to interrupt the flow of current through the electrical circuit by increasing dielectric separation between two ends of a fuse element prepared in a form substantially representing a curve. The fuse element is coupled to a pair of conductive endcaps and a dielectric material substantially encloses the fuse element between the endcaps. The method of increasing dielectric separation between two ends of a fuse element includes preparing the fuse element in the form substantially representing the curve, coupling the fuse element between a pair of conductive endcaps, and enclosing the fuse element in a dielectric material which is formed such that a portion of the dielectric material extends into the area bounded by the fuse element and a line intersecting the two ends of the fuse element.

Abstract: The invention is a fusible link-containing structure for an electrical fuse. The structure includes an metallic or other conductive element having a fusible link. The structure further includes at least one arc-quenching tab secured to the metallic element, and that tab may be secured to the metallic element at a position spaced apart from the fusible link. The tab or tabs are secured to the metallic element without rivets or other mechanical fasteners. For example, a lamination process may be used.

Abstract: A high voltage circuit interrupter has a surface modified pulverulent arc-quenching filler composition, with gas-evolving material is bound to the surfaces of the arc-quenching filler by a binder. The pulverulent arc-quenching filler can be selected from the group of silicas and silicates, preferably sand, mica or quartz. The gas-evolving materials can be selected from the group of melamine, cyanuric acid, melamine cyanurate, guanidine, guanidine carbonate, guanidine acetate, 1,3-diphenylguanidine, guanine, urea, urea phosphate, hydantoin, allantoin, and mixtures and derivatives thereof. The device has a generally tubular casing of electrically insulating material, terminal elements closing the opposite ends of the casing, at least one fuse element conductively interconnecting the terminal elements, a core for supporting the fuse element, extending parallel to the longitudinal axis, and a modified pulverulent arc-quenching filler material inside the casing, in close proximity to the fuse element.

Abstract: An overcurrent protection device and a method for the production thereof is provided wherein a fusible link is bonded across a pair of electrodes. A composite layer envelops the fusible link and is formed from a gelatinous composition. The composite layer and the fusible link are further encased within a molded housing. The gelatinous composition includes a nonconductive inorganic powder and a synthetic resin. The inorganic powder has a melting temperature below a fusion temperature of the fusible link. In an embodiment, the inorganic powder includes lead glass powder and alumina powder, and the synthetic resin is a low viscosity silicone resin. The inorganic powder is mixed with the silicone resin in a three to one ratio. Heat treatment dries the composite layer. The composite layer includes air pockets between particles of the inorganic powder elastically bound together by the synthetic resin.

Abstract: A high voltage high power fuse (5) for use in a low pressure environment such as space. The fuse (5) comprises a fuse element (1) which is electrically connected to two conductive pads (2) and surrounded by an elastic medium (3). When the fuse element (1) is vaporized by a current surge, the elastic medium (3) absorbs the energy of the explosion and then snaps back into the space (6) left by the vaporized fuse element (1). This action of the elastic medium (3) effectively quenches any electric arc which may have bridged the gap (6) between the ends of the blown fuse element (1).

Abstract: An improved compact fuse has a fusible metal wire stretched between a pair of metal terminals. The wire and the portion of the terminals to which the wire is connected are enclosed in an envelope made of insulation material. The ends of the terminals protrude outside the envelope. The envelope is filled with silicon cellular resin to cover the wire and create many sectioned spaces that dissipate the thermal energy generated when the wire melts from overcurrent, thereby preventing damage to the envelope. When heated by vaporization of the fusible metal wire, the silicon cellular resin generates byproducts which rapidly extinguish the arc.

Abstract: Arc-quenching coating compositions are provided with effective arc-extinguishing properties and improved track resistance properties, and are relatively easy to apply in liquid form. The coating compositions are used, for example, in high voltage current limiting fuses, expulsion fuses, circuit breakers, circuit interrupters, separable cable connectors, or the like for interrupting circuits. The arc-quenching coating compositions include an arc-quenching gas-evolving material (A) and a film-forming polymer (B) having minimal tracking properties, in which the film-forming polymer (B) acts as a liquid vehicle for the coating composition. The arc-quenching material (A) is preferably selected from the group of guanidine, guanidine carbonate, guanidine acetate, 1,3-diphenylguanidine, guanine, melamine, melamine cyanurate, urea, hydantoin, allantoin and derivatives and mixtures thereof.

Abstract: A ceramic coating for a subminiature fuse includes sodium silicate and silicon dioxide applied over a subminiature fuse wire in slurry form. The coating gives the fuse arc quenching properties.

Abstract: A Class L fuse comprises a pair of conductive elements at the opposite ends of the fuse. A fusible element is secured to and makes electrical contact with each of the conductive elements. A generally cylindrical housing encloses the fusible element. Finally, an insulating, free-flowing arc barrier-forming body or sealant is disposed within the housing. In particular, the arc barrier-forming body or sealant is disposed between a portion of the fusible element and each of the conductive elements.

Abstract: Improved arc-suppressing fuse tubes of the type used in electrical cutouts is provided which includes a fluid epoxy resin matrix core designed, upon experiencing high temperature arcing conditions, to generate sufficient moisture and arc-suppressing gases to safely and efficiently interrupt an arc. The fuse tubes of the invention completely eliminate the use of expensive and difficult to fabricate bone fiber conventionally used in fuse tubes of this type. The preferred fuse tube construction is an integrated, synthetic resin body having an outer tubular shell including an epoxy fiberglass-reinforced synthetic resin matrix, together with an inner tubular arc-suppressing core having an epoxy resin matrix with respective quantities of an organic fiber and an inorganic filler therein. An anhydride curing agent for the epoxy is incorporated at an anhydride to epoxide ratio from about 1.0 to 1.4:1.

Abstract: A ceramic coating for a subminiature fuse includes sodium silicate and silicon dioxide applied over a subminiature fuse wire in slurry form. The coating gives the fuse arc quenching properties.

Abstract: The disclosed full-range fuse provides excellent short-circuit and overload protection using various forms of fuse links, made of copper or copper alloys, or silver, including curtain fuse links, the short-circuit performance being enhanced by solidifying the sand or other granular fill with a binder, notably a silicate or boric acid, the overload interruption being enhanced by boric acid that is distributed throughout the fill.

Abstract: An electrical fuselink having improved surge-resistant characteristics comprises a fuse element (1) disposed in an electrically insulating enclosure (4) having all or part of the air-space within the enclosure filled with a microporous or microcellular insulating material (2) which has low intrinsic thermal conductivity and cavities or cells of a size less than the average inter-molecular collision distance of the gas, normally air, occupying its cavities or cells. The fuse element is connected between electrical leads (3) which project from the enclosure for connecting the fuselink in an electrical circuit.

Abstract: A fuse device comprises a casing, a fuse element accommodated in the casing and an arc-extinguishing agent accommodated in the casing and consisting of a fibrous or powdery non-conductive material.

Abstract: A fillerless electric fuse having a wire-like fusible element is provided with a body of thermoplastic material which cooperates with the fusible element to establish an impermeable barrier within the fuse between the fuse end terminals. The thermoplastic material is preferably a hot melt adhesive introduced into the casing in a fluid state.

Abstract: A high speed high voltage electrical switch opens a current path in which the switch is included. The switch includes first and second normally electrically interconnected contacts which normally carry current in the current path. The contacts are relatively movable along a fixed line of direction. When the contacts move apart, the electrical interconnection therebetween is broken to open the first current path. A piston carried by the second contact defines an enclosed chamber in conjunction with the first contact when the contacts are interconnected. A power cartridge or the like selectively pressurizes the chamber to rapidly drive the contacts apart. The piston enhances the action of the power cartridge by ensuring that pressure increases caused thereby are effected to drive the contacts apart. The piston may be configured to ensure positive sealing engagement with the walls of a cylinder through which the piston and the second contact move following the ignition of the power cartridge.

Abstract: A current limiting fuse construction including a fuse element extending between electrically conductive terminals carries a body of arc-quenching filler material within a hollow casing of electrical insulating material. The filler material includes a first portion of arc quenching aluminum sulfate mixed with calcium sulfate binder, and second portion of arc quenching silica sand arranged in stratified layers, with the aluminum sulfate layer being positioned closest to a weak spot of the fuse element, and the layer of silica sand being positioned closer to an end cap of the fuse casing.

Abstract: A dual element fusible device is provided utilizing a plurality of separate arc quenching fillers disposed in layers within the fuse casing and being effectively separated from one another by an electrically insulative material which is introduced into the casing in a fluid state so that regardless of the configuration of the internal workings of the fuse, it establishes a continuous and impermeable barrier between the respective layers.

Abstract: An electric fuse having a support for the helically wound fusible element or elements. The support includes a plurality of rod-like supports each made of one uniform material. Some of the plurality of rod-like supports consist solely of a non-gas-evolving material, while at least one of the plurality of rod-like supports consists solely of a gas-evolving material.

Abstract: A current limiting fuse construction including a fuse element extending between electroconductive terminals carries a body of arc-quenching filler material within a hollow casing of electric insulating material. The filler material includes loose granular insulating material, such as sand, and larger particles of material uniformly distributed throughout the sand as a resin vaporizable in response to the heat of an arc current. According to a second embodiment a stratified filler comprises uniformly spaced layers alternately occurring between sand and a sand/resin mixture to increase arc voltage.

Abstract: A time-lag fuse is provided which exhibits improved breaking capacity due to its novel construction. It comprises a fuse element which is securely positioned within an insulating cylindrical tube such as a glass cartridge, and a plurality of sintered ceramic bodies (e.g., cylindrical or polygonal) are circumferentially disposed within said tube so as to define a space therewith to achieve the required fusing and time-lag characteristics. The sintered ceramic bodies are arranged so as to define plurality of spaces between adjacent pairs of the ceramic bodies and the insulating tube in order to buffer the pressure created by arcing between the ceramic bodies and the insulating tube during a current overload.

Abstract: A fusible device is provided, of the generally-enclosed type, having an improved granular filler material surrounding, or encompassing the one or more fuse links. Preferably, the granular filler material comprises sand and alumina trihydrate (Al.sub.2 O.sub.3.3H.sub.2 O). Another filler material, which gives roughly half the improvement of the aluminum trihydrate, is aluminum monohydrate (Al.sub.2 O.sub.3.H.sub.2 O) in varying proportions.Of less satisfactory performance, as admixed with the sand, was hydrous alumina silicate (Al.sub.2 O.sub.3.SiO.sub.2.XH.sub.2 O) (unfired lava), and of still less satisfactory performance, is a slight amount of free water physically admixed with sand, although its physical location within the sand is questionable, and such a fuse is of low interrupting reliability.

Abstract: Electric fuses having supports for their fusible element or elements which supports are formed of bundles of glass fibers in form of cords, rovings, or the like glass fiber structures made up of fibers which extend but in longitudinal direction, i.e. do not include fibers which extend in transverse direction. The fibers are under considerable stress in longitudinal direction, so as to form a supporting structure of considerable dimensional stability. The terminal elements of the fuse are preferably in the form of terminal plugs and provided with means to control the stress to which the glass fibers are subjected. The latter may be impregnated with chemical compounds that evolve protective and arc-quenching gases under the heat of electric arcs.

Abstract: A fused high voltage electrical bushing having a housing formed of a ceramic dielectric material, porcelain or glass, and having an axially extending passage, an electric terminal at each end of said passage, a fusible element within said passage interconnecting the terminals, a granular dielectric material completely filling the passage, a conductive layer of material on the inside surface of the passage, and a heat insulating sleeve positioned in the passage between the granular dielectric material and the inside surface of the housing to insulate the housing from the heat of the arc on interruption.

Abstract: A fuse construction has two spaced electrical conductors with inwardly directed conductor ends. A fuse plate member has opposite plate edges secured to said conductor ends. Said fuse plate has an inner insulative sheet with opposite outer conductive sheet faces. One of the sheet faces has an electric current breaking open band adjacent one conductor and the other sheet face has a similar band adjacent the other conductor. A fusible pin passes through a central part of said insulative sheet and said conductive faces and has its pin ends secured to said conductive faces between said open bands so that said bands do not break the electric current passing between said conductors while the pin does not blow but do break said electric current when the pin blows. A method of assembly of said fuse construction is disclosed.