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: A fuse that includes an insulative housing made from two housing pieces made of thermoplastic material, terminals extending through slots in the ends of the housing, and a fusible element having ends connected to both of the terminals.

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: A fuse having a rated current for protecting electric or electronic circuitry comprises a body having a blow chamber. A fusible element is contained within the body and extends through the blow chamber. A contact is disposed on the body electrically connected to the fusible element for making an electrical connection between the fuse and the circuitry. The blow chamber is sealed around the fusible element so that thermal energy in the fusible element can increase within the blow chamber for causing the element to open when an elevated current is applied to the element. The blow chamber is sufficiently sealed around the element for retaining a pressure created therewithin by vaporization of a portion of the element; that pressure is sufficient to cause an arc produced by fusion of the element to extinguish. The body is of sufficient strength to contain the pressure within the blow chamber for allowing the fuse to fail gracefully.

Abstract: The disclosed electrical fuse has a fuse link in a filling of sand and a binder that imparts high thermal conductivity to the filler. The binder is a shiny coating on the grains of sand extending from grain to grain. It is an amorphous coating. The exemplary binder is boric oxide, B.sub.2 O.sub.3.

Abstract: A continuous hollow compartment open at both opposite ends thereof is arranged within an electrically insulating housing. Tubular portions of end contacts extend into ends of the hollow compartment and are completely covered at their inner surfaces by an arc-inhibiting screen. Flat portions of the end contacts form clamping locations and solder pins. The ends of a fuse wire and the ends of the screen are clamped at the clamping locations. The solder pins form a respective wave solder region and a reflow solder region. During manufacture of the safety fuse element, the tubular-shaped end contacts are inserted into the ends of the hollow compartment of the housing. Then there is drawn-in the screen and the fuse wire and the flattenable portions of the end contacts are flattened to form the flat portions, so that there are clamped at the clamping locations the ends of the fuse wire and the ends of the screen. Now the flat portions are bent to form the solder pins.

Abstract: An electrical component, particularly a fuse for a surface-mount component, is formed by sputtering an aluminum conductor onto a square tube, sleeving the tube into an outer tube, filling the assembly with a room-temperature vulcanizing silicone sealant, cutting the assembly into segments, and metallizing the ends of each segment. In one embodiment, the sleeved tubes are mechanically separated from the surrounding silicone. In another embodiment, the silicone-coated tubes are mechanically separated from the outer tubes. In another embodiment fuses are made by sputtering the conductors onto a thin glass substrate, covering a link portion of the conductors with silicone adhesive, and dicing the substrate.

Abstract: A hermetic terminal assembly for a housing including a fuse-like area positioned in the outer pin segment of a terminal pin extending in sealed relation through the body member of the terminal assembly which body member can be sealed to a housing wall, the fuse-like area in the outer pin segment being covered with a thermally decomposable coating which in the event of decomposition includes an arc suppressant. A pin guard and lead wire end connection securing device is provided to protect the outer pin segment and to secure the lead wire end connection thereto.

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: A subminiature fuse is disclosed comprising two terminals (20, 30), two substrates (80, 90), a fusible conductor (140), an insulating coating (180), and a unitary housing (170). The unitary housing is protected from the interrupt arc by the substrates (80, 90) and the housing (170) is sealed to provide increased mechanical strength, thus reducing the risk of a catastrophic failure of the fuse. The upper portion of the fuse terminals are shaped into finger like projections (70) adaptable to mechanically holding the fusible conductor (140) and a substrate (80), thus facilitating the manufacturing process. In one embodiment the fusible conductor and adjacent portions of the terminals and substrates are coated with a insulating coating or adhesive (180). The insulating coating (180) conducts heat away from the fusible conductor (140) during normal operation. To further protect the housing in the event of a short circuit interruption, a substrate (90) is placed between the housing and the fusible conductor.

Abstract: A fuse body encloses a fuse element of a current-limiting fuse wherein the fuse body is formed from an inexpensive material and provided with a shield between the inner surface of the fuse body and the fuse element. Thus, when the fuse element melts and arcs during interruption, the fuse body is protected from the hot gaseous arc products by the protective shield thereby preventing burning of the fuse body. The protective shield can be a spray coating such a ceramic spray coating applied to the inner surface of the fuse tube, a glass coating, or ceramic paper. The fuse body can be made from glass filament wound epoxy material.

Abstract: An electrical fuse including a fuse casing having a tubular wall including multiple-filament reinforcing yarns that have been braided in the tubular shape of the wall and a synthetic resin bonding the yarns together and impregnating the yarns, a pair of terminals secured to the ends of the fuse casing, and a fusible element inside the casing and connected to the terminals.

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 microfuse (10) with a ceramic chip (12), thick film pads (14), fusible wire (16), attached to pads (14) without solder or flux, in an insulating enclosure or fuse tube (40). Ferrules (42) are attached to metallized areas (14) with solder (44). Performance and manufacturing of fuse (10) is improved by utilizing a wire bonding technique to improve the quality of the manufacturing process and increase the reliability of the fuse, and to reduce manufacturing cost.

Abstract: A sub-miniature fuse having a fusible conductor which will fuse under an over-current condition within a pressure-tight chamber. A metal surface is positioned near the fusible conductor within the chamber and is formed and positioned relative to the fusible conductor so that during the switching off of the fuse, any arc created between the fused ends jumps over to the metal surface. Thus, at least one secondary arc is created which burns against the metal surface as a shunt line. By melting a part of the metal surface, sufficient heat is absorbed that the secondary arc is quenched.

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: A fuse for an alternating current power circuit. The fuse comprises an input terminal (4), a first contact (5) electrically connected to the input terminal, an output terminal (9) and a second contact (8) electrically connected to the output terminal. A fusible element (11) electrically connects the first and second contacts and completes a normal electrical path between the input and output terminals. An arcing contact (6) is positioned in relation to the first contact (5) so as to form a potential arc path between the first contact and the arcing contact, along which path an arc will become established after the fusible element breaks in response to fault current. The arcing contact (6) is electrically connected to a third terminal (41) and is electrically isolated from the output terminal (9).

Abstract: A microfuse (10) with a ceramic chip (12), thick film pads (14), fusible wire (16), attached to pads (14) without solder or flux, ceramic coating (18) and plastic body (20). External lead (24) configuration can be axial, radial or surface mount. The method of manufacturing the fuse (10) is improved by utilizing a wire bonding technique in order to improve the quality of the manufacturing process and increase the reliability in performance of the fuse and reduce manufacturing cost.

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 for an alternating current power circuit in the medium voltage (3.3 kV to 38 kV) range. The fuse comprises a sealed chamber and a first electrode (41) is mounted within the chamber, the first electrode having a substantially circular periphery (42) and being electrically connected to a first terminal (3) to which a first conductor may be connected. A second electrode (35) is arranged with a conductive surface internally of the chamber, the conductive surface being spaced from the first electrode. A coil (10) is connected in an electrical path between the second electrode (35) and a second terminal (18) to which a second conductor may be connected. An additional electrical contact (44) is mounted within the chamber and in direct electrical connection with the second terminal, and a fusible element (43) directly electrically connects the first electrode (41) and the additional electrical contact (44). An electronegative halogenated medium fills free space within the chamber.

Abstract: A core assembly having a flexible insulating material core and a spirally wound inner fuse wire engages with one or more elongate bodies of the flexible insulating material to sandwich and compress the inner fuse wire therebetween. An arc burning between the blown ends of the inner fuse wire will be blocked and quenched by the core and body insulating materials expanding or moving into the space where the arc subsists and is burning away a portion of the inner fuse wire. An outer fuse wire, an outer wrapper of shrinkable tubing or twisting together the core assembly and the elongated body or bodies retains the core assembly and insulating body or bodies engaged along their length and forms a fuse wire assembly.

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 fuse (12) comprising a tube of insulating material having an inner (16) and an outer wall surface (18) and forming a fuse housing (14). The fuse includes a pair of conductive fuse terminals (24, 26) secured at opposite axial ends (20, 22) of the tube. A fuse element (23) is axially disposed within and extends between the ends of the fuse housing, and its ends are electrically and physically directly connected with the adjacent fuse terminal. A plug of initially solid, arc-quenching material (32) at preferably only at one end of the fuse housing occupies only a limited axial extent thereat and evaporates under fuse blowing conditions to fill the housing with an arc-quenching vapor.

Abstract: A fuse cartridge for example of the cylindrical type comprising an insulating cylindrical body ending in two conducting end pieces and a fuse element connected electrically to the end pieces, further comprising two pistons housed in the body which are movable in translation in opposite directions to each other and collect the gases released by the electric arc at the time of its appearance, so that the pressure of the gases exerts on each piston a force which causes it to move towards a position in which the arc is totally sheared.

Abstract: A high voltage circuit interrupter characterized by a tubular insulating casing that encloses a tube of boric acid forming an elongated bore. The bore includes bore portions of smaller and larger diameter. An elongated conductor is disposed in the bore and forms a clearance space therewith. Fusible means extend between the enlarged conductor and a fuse terminal. Upon fusion of the fusible means the larger end portion of the conductor is retracted into the smaller bore portion while maintaining a clearance space therewith, so that a minimal clearance space between the smaller bore portion and the enlarged end portion of the conductor provides adequately high water vapor pressure to extinguish an electric arc generated by fusion of the fusible means.

Abstract: The fuse comprises an elongated support formed at least partially from ferrite, magnetized in the direction of its thickness and on which is disposed, between two terminals, a metal wire (9) capable of being destroyed by melting. The fuse comprises for example two ferrite strips (5 and 6) assembled together and spaced apart by means of two insulating-material bars (7 and 8), a silver wire (9) being disposed between the two strips. When the wire melts, the molten metal and the electric arc are driven laterally in accordance with the LAPLACE law.

Abstract: An overload fuse with a fusible conductor and quenching baffles is curved preferably forming a partial annulus, and several quenching baffles are disposed perpendicular to the fusible conductor. Due to its flat design, this fuse has only a small volume and at the same time a large switching capacity because the partial arcs formed between the quenching baffles are driven radially outward by the dynamic forces and are lengthened accordingly.

Abstract: A miniature fuse has a housing consisting of a plastics base (1), a plastics cap (2), and two conductors which pass through the base and are bridged across inside the cap by a fusible conductor (3). The interior of the fuse housing is fully or partially lined with a ceramic-based lining (5) to protect the plastics against thermal decomposition and to promote condensation of the fusible conductor which may be evaporated, upon blowing of the fuse, to reduce internal pressure in the housing and hence avoid separation of the cap from the base and exposure of conductive parts.

Abstract: This current-limiting fuse comprises a fusible element having a predetermined location at which an arc will be initiated when prolonged overcurrents of relatively low value have persisted for a predetermined duration. For increasing the arc voltage developed by said arc, an electrical insulating member is disposed about the fusible element in a position where at least a portion of the arc will burn within the insulating member and cause vapors to be evolved from the material of the insulating member. The insulating member is of a material that evolves substantially no vapors or gases at the temperatures reached by the insulating material prior to arc-initiation during prolonged overcurrents of up to one hour in duration. This material is a baked material, a major portion of which is hydrated aluminum silicate including water of hydration that is released only at temperatures in excess of those attained by the insulating material during prolonged overcurrents as long as one hour.

Abstract: A drywell fuse holder and a loadbreak fuse assembly, the holder including an arc-extinguishing sleeve located adjacent to the inner contact sleeve, the loadbreak fuse assembly including a non-expulsion fuse having electrical interface assemblies at each end spaced apart a distance less than the distance the inlet to the contact sleeves in the fuse holder, the interface assemblies including a spacer ring to center the fuse assembly in the holder and protect the garter spring contact and an arcing washer to transfer the arc from the garter spring; and an arc-extinguishing follower on the fuse assembly which is pulled through the arc-extinguishing sleeve to extinguish the arc.

Abstract: A fuse having a high cycling ability combined with a high arc-extinguishing ability due to the presence of a gas-evolving material. The fuse includes a pair of fusible elements having end portions and intermediate portions arranged between the end portions and converging in opposite directions, so as to form a pair of wedge-like structures. The pair of fusible elements is composed of planar portions and portions where these planar portions meet. The fusible element has points of minimized cross-section which are spaced from any bent in the fusible element. The improvement comprises a rectangular plate of gas-evolving material inserted into the gap, or space, defined by the pair of parallel fusible elements. The terminal elements of the fuse and its casing form abutments for the plate of gas-evolving material in longitudinal and in transverse direction so that no additional means are required for maintaining the gas-evolving plate in position relative to the pair of fusible elements of the fuse.

Abstract: An improved fuse tube for a high voltage fuse contact used to interrupt low and high fault currents. The fuse tube has an arc-extinguishing bore into which a fuse link is insertable. The fuse link includes an arc-extinguishing sheath surrounding a pair of separable terminals and a fusible element normally between the terminals. An arc established and elongated between the separating terminals after the fusible element melts and decomposes the bore, the sheath, or both to rapidly evolve large amounts of arc-extinguishing gases which are exhausted from an open end of the bore. A conductive chamber in the bore is electrically connected with one of the terminals and surrounds a portion of the sheath and the terminals. A mild taper is formed in the bore so that its larger end is at the open bore end. The chamber permits the fuse link to be positioned deep within the bore so that low fuse current interruption is not compromised.

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: A non gas evolving insulating support of generally star shaped X-sect for supporting the turns of a helically wound fusible element is provided with gas evolving means affixed thereto in proximity with but spaced from the fusible element.

Abstract: A lead weight or other mass is crimped to the contact button assembly of the arcing rod of a high-voltage alternating-current power fuse thereby increasing the mass of the arcing rod without increasing the diameter of the rod. The increased mass of the arcing rod decreases the velocity with which the arcing rod moves upon fusing of the fusible member thereby decreasing the rate of elongation of the arc drawn between the end of the arcing rod and the stationary ferrule at the other end of the fuse. Under high current conditions, the shorter arc length drawn in the fuse reduces the pressure of the arc-extinguishing gas generated by the arc, thereby reducing the risk that an economically constructed fuse will burst in those situations when the arc is not interrupted at the first current zero. This result is accomplished without adversely affecting operation of the fuse and interruption of the arc at low current levels.

Abstract: An electric fuse has rod supports for the helically wound fusible element which are of a laminate of glass cloth and a synthetic resin. This is a material which is slightly gas evolving. The rods have inserts of a material which is highly gas evolving, and they provide a substantial spacing between the path of the fusible element--and the arc path--and the surface of the rod supports for it. The limited gas evolving capacity of the rods combined with the large gas evolving capacity of the inserts and combined with the spacing between the arc path and the surface of the rods allows proper operation of the fuse in the absence of any ceramic insulators or ceramic supports for the fusible element.

Abstract: An electric fuse having a gas evolving substance to generate arc-quenching blasts of gas when arcing inside the fuse occurs. Fuses of this type are known. However, fuses according to present fuses are far simpler to manufacture than prior art fuses of this description. They comprise a block of gas evolving material shorter than the diameter of the casing of the fuse arranged substantially transversely to and between a pair of fusible elements, the pair of fusible elements hugging a portion of the periphery of the block so as to position the block loosely at a predetermined point between the terminal elements.

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: An improved circuit interrupting device extinguishes an arc by directing a dielectric fluid at the arc as it is elongated. Elongation is effected by relative movement apart of a pair of contacts between which the arc is established. A reservoir contains a piston which defines a first volume and a second volume. The fluid is held under pressure in the second volume. The reservoir directs the fluid in the second volume at the arc from a port normally closed by a diaphragm. One contact is normally mechanically attached to the diaphragm and is adjacent the other contact which is on the reservoir. Sudden expansion of the first volume, such as by the ignition of a power cartridge, forcefully moves the reservoir relative to the piston and away from the one contact. The seal is torn or cut open to permit the pressurized fluid to flow from the port simultaneously with the piston forcing the fluid from the second volume and the movement apart of the contacts.

Abstract: Deterioration of the electrical contacts of variable load flashers provided for intermittently energizing vehicle signal lamps is inhibited by the provision of a coiled length of a current conductor having a suitable inductance value connecting the flasher contacts with at least one output terminal. In the case of a two-terminal flasher, the conductor extends to the single output terminal from a junction at the flasher contacts and in such a flasher for use in a signal lamp circuit having a relatively high current load, the coiled length is wound about a heat conductive core member connected to the single output terminal and has an inductance value of about 5.8 to 6 microhenrys. In two terminal flashers for use in signal lamp circuits having a lower current load, the coiled length may have an air core and an inductance value of about 2 to 2.2 microhenrys.

Abstract: A current limiting fuse is disclosed wherein at least one fuse element is positioned within and extends from a sealed electrically insulating glass member substantially filled with dielectric liquid. The glass member is positioned within an outer casing having electrical terminals and filled with granular material. The fuse element extends to the electrical terminals. The narrow space filled substantially with dielectric liquid defines the arc constrictor while the outer casing defines the plasma cooler space.

Abstract: An arc interrupter for heavy surge currents in power systems is provided in hich a self-biasing, spring helix conductor is fixed between two frangible and/or fusible elements which are in turn integrally fastened to the edges of respective eddy-current rings canted to effect a horn gap for magnetic blow-out of any ensuing arc in the area of the helix. The helix generates magnetic forces in addition to its spring force to break the fusible and/or frangible elements in response to predetermined surge currents and will then drop out of the gap between the eddy-current rings by gravity action. The circuit is thus broken and any ensuing arc is extinguished.

Abstract: An electrical loadbreak fuse and canister assembly with arc quenching means operative upon withdrawal of the fuse from the canister or upon insertion of the fuse in the canister under either load or fault conditions. The canister, formed of a glass filled polyester tube, is designed to extend within the enclosure for an electrical device to be protected by the assembly, and is provided with a flange at the outer end for mounting on the enclosure. A fixed loadbreak contact at the inner end of the canister is enclosed within a non-conductive sleeve having a collar formed there around. The inner end of the fuse is provided with a loadbreak contact probe having a non-conductive tip and with a non-conductive disc mounted between the fuse and the contact probe. Both the sleeve and collar, and the disc serve to defuse and cool ionized gases generated by arcing between the loadbreak contacts within the canister.

Abstract: An electric protective device capable of handling both short-circuit currents and minor overload currents of impermissible duration. The device for interrupting small overload currents of impermissible duration includes a cylinder, a plunger inside said cylinder, a spring biasing said plunger, heater means, a solder joint conductively connected to said heater means and said plunger, and a body of material evolving gases under the heat of an arc surrounding said solder joint, adjacent portions of said plunger and adjacent portions of said heater means.The process of manufacturing this device is preferably performed in two steps, namely arranging adjacent the solder joint of the device a sleeve-shaped body of melamine and an inorganic filler in a highly viscous putty-like form, and thereafter allowing said body to harden completely.