Abstract: A circuit board with integrated fusing includes an insulating substrate having a circuit trace formed on a surface thereof, the circuit trace including a first circuit trace portion and a second circuit trace portion. A fusible link electrically connects the first circuit trace portion to the second circuit trace portion, the fusible link including a planar surface extending from the first circuit trace portion to the second circuit trace portion. A dielectric reflow encapsulates the fusible link on the planar surface from the first circuit trace portion to the second circuit trace portion.

Abstract: The disclosed concept relates generally to overlay composite fuse elements, materials for their construction that include copper and silver metals, and methods of production and fabrication using metal stamping and ultrasonic welding processes. In certain embodiments, a composite overlay fuse element includes a composite metal material 37 constructed of silver and copper metals, which includes a plurality of strain absorbing bend features 39 constructed of copper metal, and a plurality of arc interrupting weak spot features 43 constructed of a silver metal portion and a copper metal portion. The silver and copper metal portions on each of the plurality of arc interrupting weak spot features 43 are connected by a weld joint surface 45 that is structured to form an overlay of the silver and copper metal portions.

Abstract: A high breaking capacity chip fuse including a bottom insulative layer, a first intermediate insulative layer, a second intermediate insulative layer, and a top insulative layer disposed in a stacked arrangement in the aforementioned order, a fusible element disposed between the first and second intermediate insulative layers and extending between electrically conductive first and second terminals at opposing longitudinal ends of the bottom insulative layer, the first intermediate insulative layer, the second intermediate insulative layer, and the top insulative layer, wherein the first and second intermediate insulative layers are formed of porous ceramic.

Abstract: The present invention provides a substrate surface-mounted fuse that uses a replacement fuse to enable an electric circuit to be electrically connected simply and immediately even when a fuse part melts. A substrate surface-mounted fuse 100 mounted on the surface of a substrate 300 comprises: a housing 110; a fuse part 120 that is disposed in the housing 110; and a terminal part 130 that is coupled to both ends of the fuse part 120 and exposed to the outside of the housing 110, wherein a portion of the terminal part 130 is provided with a fixed section 134 for fixing to the surface of the substrate 300 and is provided with an attachment part 140 enabling attachment of a terminal part 230 of a replacement fuse 200.

Abstract: The object of the invention is a distribution system with an electronic fuse terminal and at least one first series terminal, wherein the electronic fuse terminal and the at least one first series terminal are arranged immediately adjacent to one another on a mounting rail, and wherein the electronic fuse terminal and the at least one first series terminal each have at least one adjacent bridging member, wherein the electronic fuse terminal can be supplied with input voltage, with the electronic fuse terminal making at least one protected first output potential available, and wherein the protected first output potential is forwarded to the first series terminal by means of a first bridging plug to the first series terminal.

Abstract: A fuse element and a method for manufacturing the same are provided whereby the fuse element contains an active response part which is formed by an elongated fuse metal strip having at least four metal sub-strips. At least two of the metal sub-strips are parallel and the sub-strips are defined by two elongated recesses within one or two elongated fuse metal strips. The two recesses are provided in serial alignment along the respective fuse metal strip having leading and trailing parts for electrical connection of each fuse element. The elongated fuse metal strip can be reinforced by an elongated dielectric base layer made of polymer material. Accordingly, performance of such a fuse element can be increased and manufacturing costs can be decreased. The fuse element can be applied to a plurality of capacitor sub-units being integrated in housings and submerged in a cooling and insulating liquid within the housing.

Abstract: A fuse assembly for interrupting fault current in an external DC circuit. The fuse assembly includes 2n fusible conductor elements, where n is an integer, wherein the fusible conductor elements extend along, and are circumferentially around, a longitudinal axis of the fuse assembly. The fusible conductor elements are connected together in series to define fuse elements and the fusible conductor elements are orientated within the fuse assembly such that current flowing along each fusible conductor element is in the opposite direction to current flowing along the fusible conductor element or fusible conductor elements adjacent to it. The fuse assembly further includes a supply terminal connected to an end of the fuse element and connectible to a DC supply, and a load terminal connected to an opposite end of the first fuse element and connectible to an electrical load.

Abstract: A multi-layer fuse and its manufacturing method are provided. The multi-layer fuse comprises a ceramic substrate, back electrodes, front electrodes, fuse wire, protective layers and metal ends, wherein the fuse wire is prepared in multiple layers and the adjacent layers of fuse wire are connected in a head-to-tail style; the two lead-outs of the fuse wire as a whole are respectively connected to the two front electrodes located at the two ends of the substrate, and each layer of the fuse wire is deposited with a protective layer. During manufacturing, all protective layers but the upmost one leaves the tail of each layer of fuse wire uncovered so that the head-to-tail series connection is possible.

Abstract: A chip fuse includes a plurality of parallel fusible link layers disposed between a corresponding plurality of insulating glass layers deposited on a substrate and laminated together. The fusible link layers are interconnected between the glass layers without the need for vias. A first of the plurality of fusible link layers extends beyond a cover disposed over the chip fuse and one of the glass layers to form a first electrical terminal connection. Another of the plurality of the fusible link layers also extends beyond the cover and another of the glass layers to form a second electrical terminal connection.

Abstract: A semiconductor device has a semiconductor substrate and a first electrical fuse and a second electrical fuse, which are provided on the semiconductor substrate. The first electrical fuse has a first upper layer wire and a first lower layer wire formed in different wire layers, and a via for connecting the first upper layer wire to the first lower layer wire. The second electrical fuse has a second upper layer wire and a second lower layer wire formed in different wire layers, and a via for connecting the second upper layer wire to the second lower layer wire. The semiconductor device has a connection portion for connecting the above described first upper layer wire of the first electrical fuse to the second lower layer wire of the second electrical fuse. The connection portion connects the first electrical fuse and the second electrical fuse in series.

Abstract: A semiconductor device includes an electric fuse and first and second large area wirings for applying a voltage to the electric fuse. The electric fuse includes a fuse unit which includes an upper-layer fuse wiring, a lower-layer fuse wiring, and a via connecting the upper-layer fuse wiring and the lower-layer fuse wiring, an upper-layer lead-out wiring which connects the upper-layer fuse wiring and the first large area wiring and has a bent pattern, and a lower-layer lead-out wiring which connects the lower-layer fuse wiring and the second large area wiring and has a bent pattern.

Abstract: The invention includes semiconductor fuse arrangements containing an electrically conductive plate over and in electrical contact with a plurality of electrically conductive links. Each of the links contacts the electrically conductive plate as a separate region relative to the other links, and the region where a link makes contact to the electrically conductive plate is a fuse. The invention also includes methods of forming semiconductor fuse arrangements.

Abstract: A blade fuse includes a first terminal includes an outer edge and an inner edge, the inner edge includes a first portion notched away from the inner edge beneath the first portion; a second terminal includes an outer edge and an inner edge, the inner edge include a second portion notched away from the inner edge beneath the second portion; an element extending from the first portion of the inner edge of the first terminal to the second portion of the inner edge of the second terminal; and a housing covering the element.

Abstract: A fuse assembly includes a main component partially encased in a protective sheath. The main component includes a pair of connectors formed of an electrically conductive material to allow the fuse assembly to be electrically connected into an electric vehicle drive system. A fusible link is electrically connected between the connectors and is preferably encased in the protective sheath. The fusible link reacts to current flowing through the fuse assembly in excess of a predetermined current for a predetermined time, as is well known to those skilled in the art.

Abstract: A blade fuse includes a first terminal includes an outer edge and an inner edge, the inner edge includes a first portion notched away from the inner edge beneath the first portion; a second terminal includes an outer edge and an inner edge, the inner edge include a second portion notched away from the inner edge beneath the second portion; an element extending from the first portion of the inner edge of the first terminal to the second portion of the inner edge of the second terminal; and a housing covering the element.

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: The invention includes semiconductor fuse arrangements containing an electrically conductive plate over and in electrical contact with a plurality of electrically conductive links. Each of the links contacts the electrically conductive plate as a separate region relative to the other links, and the region where a link makes contact to the electrically conductive plate is a fuse. The invention also includes methods of forming semiconductor fuse arrangements.

Abstract: A fuse has a base and multiple wires. The base is an insulator and has a top surface and multiple contact plates. The contact plates are mounted separately on the top surface of the base. The wires are high density conductive alloy including Al 60˜90 wt %, Mg 22˜30 wt %, Si 1˜3 wt % and Cu 1˜3 wt % and connect the contact plates in series. Since the wires are directly heated, response time, sensitivity, power waste and heating resistor damage problems are solved and because the wires are high density conductive alloy that is nearly independent of environmental temperature, the temperature dependency, installation position limitation and leakage current problems are also solved.

Abstract: A temperature protection device is provided, which comprises with a polymeric positive temperature coefficient (PTC) device 1 having a conductive polymer 5 placed between two electrodes 6 and 7, and a metal member 2 bonded to one of the electrodes 7 of the polymeric PTC device, and which, when the ambient temperature exceeds a prescribed temperature, terminates the current-flowing state between the other electrode 6 of the polymeric PTC device 1 and the metal member 2. The conductive polymer 5 expands thermally when the ambient temperature exceeds the prescribed temperature, and a material is selected for the metal member 2 that will melt as a result of the heat generated by the conductive polymer during the thermal expansion.

Abstract: The fuse is used in the medium- and high-voltage sector and has two spaced-apart power supply connections (2, 3) and an active part (1). The active part comprises a fusible, current-carrying fuse element and an arc-extinguishing medium. The fuse element is connected in an electrically conducting manner to the two power supply connections and is arranged on an electrically insulating substrate. It is of a modular construction and has at least two modules (9) connected in series. The arc-extinguishing medium covers the exposed surfaces of the fuse element. The active part is formed in the manner of a sandwich and has two stable moldings (4, 5) and a predominantly planar intermediate layer (6) arranged between the moldings (4, 5). The intermediate layer (6) contains at least the two series-connected modules, whereas a first molding (4) of the two moldings is formed at least by part of the electrically insulating substrate and the second molding (5) is formed at least by part of the arc-extinguishing medium.

Abstract: A Full-Range fuse element assembly includes an insulative former having opposite first and second ends and electrically conducting connectors coupled to ends of the former. A plurality of fuse elements extend between the first connector and the second connector about the insulative former, and each of the fuse elements include a low current interrupting fuse element portion extending from the first connector and a high current limiting fuse element portion extending from the second connector. An insulative sleeve surrounds each of the low current interrupting fuse element portions, and each sleeve includes an end adjacent a respective one of the high current limiting fuse element portions. Each of the low current interrupting fuse element portions includes a weak spot located proximate the second end of a respective one of the sleeves.

Abstract: A fuse cutout for connection to a power source, includes a mounting having upper and lower support members extending from opposing ends of the mounting. A holder member is fixedly attached to the lower support member of the mounting and a pivot member is received in the holder member at a first pivot point. The pivot member is movable between first and second positions. A lever member, movable between non-release and release positions, has unitary first and second portions. The first portion is pivotally coupled to the pivot member. A fuseholder, movable between closed and open positions, has upper and lower ends, the lower end being pivotally coupled to the pivot member at a second pivot point. The first and second positions of the pivot member and each of the closed and open positions of the fuseholder, correspond to each of the non-release and release positions of the lever member.

Abstract: A dual element fuse includes a first conductive fuse coupler portion and an overload fusing assembly coupled to the first conductive fuse coupler portion. The overload fusing assembly includes a barrel having a flange at one end thereof, a trigger received within said barrel and positioned in a pre-operated position by a fusing alloy, and a conductive coil surrounding the barrel predominately in an area adjacent the flange. The conductive coil is connected between the first conductive fuse coupler portion and the flange, thereby concentrating heat generated in the conductive coil toward the flange.

Abstract: A dual element fuse includes a first conductive fuse coupler portion and an overload fusing assembly coupled to the first conductive fuse coupler portion. The overload fusing assembly includes a barrel having a flange at one end thereof, a trigger received within said barrel and positioned in a pre-operated position by a fusing alloy, and a conductive coil surrounding the barrel predominately in an area adjacent the flange. The conductive coil is connected between the first conductive fuse coupler portion and the flange, thereby concentrating heat generated in the conductive coil toward the flange.

Abstract: An electrically conductive fuse element including fusible portions has a hinge portion provided at a middle portion thereof. A resin body is divided into resin body parts so that the resin body parts are provided around the fuse element in such a way as to be separated by the hinge portion. One of the resin body parts is bent from the hinge portion. The fuse element has abutting faces, against which the resin body parts are abutted in a bent state, and engaging means for the resin body parts. A connector housing is provided on the resin body part. Further, a terminal is provided at one of plate portions of the fuse element. Power supply connecting portions and terminal connecting portions are provided in the other plate portion connected to the plate portion through the hinge portion.

Abstract: The fuse is used in the medium- and high-voltage sector and has two spaced-apart power supply connections (2, 3) and an active part (1). The active part comprises a fusible, current-carrying fuse element and an arc-extinguishing medium. The fuse element is connected in an electrically conducting manner to the two power supply connections and is arranged on an electrically insulating substrate. It is of a modular construction and has at least two modules (9) connected in series. The arc-extinguishing medium covers the exposed surfaces of the fuse element. The active part is formed in the manner of a sandwich and has two stable moldings (4, 5) and a predominantly planar intermediate layer (6) arranged between the moldings (4, 5). The intermediate layer (6) contains at least the two series-connected modules, whereas a first molding (4) of the two moldings is formed at least by part of the electrically insulating substrate and the second molding (5) is formed at least by part of the arc-extinguishing medium.

Abstract: A Full-Range fuse element assembly includes an insulative former having opposite first and second ends and electrically conducting connectors coupled to ends of the former. A plurality of fuse elements extend between the first connector and the second connector about the insulative former, and each of the fuse elements include a low current interrupting fuse element portion extending from the first connector and a high current limiting fuse element portion extending from the second connector. An insulative sleeve surrounds each of the low current interrupting fuse element portions, and each sleeve includes an end adjacent a respective one of the high current limiting fuse element portions. Each of the low current interrupting fuse element portions includes a weak spot located proximate the second end of a respective one of the sleeves.

Abstract: A fuse cutout for connection to a power source comprising, a mounting having upper and lower support members extending from opposing ends of the mounting, respectively. A holder member fixedly attached to the lower support of the mounting. A pivot member received in the holder member at a first pivot point, the pivot member being movable between first and second positions. A fuseholder having upper and lower ends, the lower end being pivotally attached to the pivot member at a second pivot point, the fuseholder being movable between closed and open positions corresponding to the first and second positions of the pivot member, respectively. A first biasing member disposed between the pivot member and the lower end of the fuseholder at the second pivot point, biasing the pivot member toward the second position. The pivot member includes a planar cam surface that engages a lower contact of the holder member.

Abstract: A safety structure to prevent a socket from being over-heated in a lamp string, which comprises a separate lamp string made of a pre-determined number of sockets connected in series. The power-supply wire of the lamp string is connected in series with an additional socket to be plugged with a protective bulb. Two copper wires mounted in the glass tube of the protective bulb are fixed in place by means of a positioning bead. The tail ends of the two copper wires are connected with a fuse having a pre-determined power dissipation. In case of the fuse in the protective bulb being over-loaded, the fuse will be burned out automatically so as to prevent the sockets from being over heated to cause a hazard.

Abstract: A non-venting current limiting fuse for mounting in a cutout comprises a high current fuse component and a low current fuse component housed in separate compartments of a housing and connected in series. Interruption of a low current overload results in operation of the low current fuse component only, with the high current component being unaffected. The low current fuse component is removable from the housing such that when a low current overload situation exists, the low current fuse component can be simply removed and replaced without the need for replacement of the more costly high current fuse component.

Abstract: A method of adjusting pre-arcing time-current characteristic for a fuse is performed in a manner that a fusible portion I serving in a dead short-circuit area and a fusible portion II serving in a rare short-circuit area are coupled in series to form a fuse element, and entire pre-arcing time-current characteristic for the fuse is adjusted by combining pre-arcing time-current characteristic of the respective fusible portions I and II. A fuse structure is formed by a fusible portion I serving in a dead short-circuit, and a fusible portion II serving in a rare short-circuit area coupled in series with the fusible portion I serving in a dead short-circuit area. The fusible portion II serving in a rare short-circuit area is formed by material which is different in conductivity and melting point from those of material forming the fusible portion I serving in a dead short-circuit area.

Abstract: A subminiature circuit protector includes a plurality of layers of ceramic material in a laminate structure, each layer bearing a fuse element. The ends of laminate structure are coated with electrically conductive end terminations. The fuse elements of the layers may be connected in parallel, with fuse elements on each layer connecting to both end terminations, or interconnected in series from one end termination to the other. Each of the fuse elements of the individual layers may comprise two or more individual fuse elements connected in series or in parallel. A method for manufacturing the circuit protector in accordance with the invention includes the steps of printing a multiplicity of fuse elements on a plurality of substrates, stacking the substrates to form a laminate structure, cutting the laminate into individual units, and coating the opposite ends of the units with electrically conductive material to form end terminations.

Abstract: A General-Purpose or Full-Range fuse in which one or more integral fuse elements are provided a first part of the length of each element serving as a current limiting device at high fault currents and a second part of the length of each element serving as an expulsion device at lower fault currents. In a preferred embodiment the first fuse part has a plurality of constrictions such as holes or notches disposed along its length and the second part has a single constriction located in a central region thereof, the length of the constriction in the second part exceeding the length of one of the constrictions in the first part.

Abstract: A current limiting fuse with less-inverse time-current characteristics characterized by a tubular housing having electrical terminals at each end, a fusible structure in the housing and interconnected between the terminals, the fusible structure comprising first fusible portions of silver alloy and second fusible portions of tin alloy intermediate the first fusible portions, and an arc-extinguishing filler around the second fusible portion.

Abstract: A fuse link for use in a fast acting current limiting fuse also exhibiting a superior arc quenching capability consisting of a thin copper ribbon placed in series with a thin silver ribbon. The copper section provides a faster heating capability to the fuse while the silver section assures a lower arcing capability. The copper section has a series of apertures along the surface thereof which apertures are semicircular in configuration at the top and bottom of the copper section and separated by a circular aperture in between located in the center of the link. The silver section has top and bottom trapezoidal apertures which are separated by a smaller diameter circular aperture at the center of the link. The copper and silver links are placed in series between fuse terminals and are connected by both a mechanical and electrical connection to afford a reliable bond between the dissimilar metals constituting each of the separate links.

Abstract: A fusible element for a current-limiting fuse comprises a metal ribbon having groups of holes therethrough and therealong. The distance along the ribbon between adjacent holes in a group is less than the distance along between adjacent groups. The lateral width of the ribbon between the hole groups is greater than its laterial width where the holes are located. The ribbon initially melts at the holes and multiple arcs burn back the ribbon at a first rate until the ribbon containing the holes is consumed, following which merger of the arcs occurs. This merger and the greater width of the ribbon between the groups results in burn-back of the ribbon at a second reduced rate. In this way, both 9 kv and 15 kv fault currents may be interrupted without exceeding the spark-over voltage of phase-to-ground arrestors when 9 kv fault currents are interrupted.

Abstract: An electric low-voltage current-limiting fuse completely or substantially complying with the Underwriters Laboratories Inc. Standard Class R fuses. The current carrying part of the fuse comprises a fusible element having serially arranged perforations. This part may be of silver or of copper. The current carrying part of the fuses further comprises tabs of copper bent over the rims of the casing and conductively interconnecting the ends of the fusible element with the terminal caps of the fuse. The fusible element is provided with an M-effect metal to limit the temperature rise of the fusible element and of the casing. The tabs are considerably thicker than the fusible element. If the fusible element is of silver the thickness of the tabs of copper is larger than the thickness required to fully compensate for their higher resistivity.

Abstract: A circuit fuse assembly comprising a plurality of fuse elements which are simultaneously formed using printed circuit or through hole plating techniques and including means for easily substituting a different one of the plural fuse elements when the in-circuit fuse element burns out due to an overload current condition. In the preferred embodiment, the fuse assembly is (a) integrally formed with the printed circuit of the fused electrical apparatus and (b) formed with a common electrical connection such that a single electrical bridge of solder or other means enables substitution of a replacement fuse element. Other embodiments of the present invention provide a restorable printed circuit fuse for use in standard fuse holders, in-line plug connectors, conventional three prong plug connectors, edison bases, and plug-in triple outlets.

Abstract: Electric fuses according to this invention aim to increase the ratio between current-carrying capacity and i.sup.2 .multidot.t values. This means, in other words, to increase the current-limiting action for any given current rating.The fusible element of such fuses comprises an axially inner substantially planar portion of silver having at least one short-circuit neck adapted to initiate circuit interruption when said neck reaches approximately the fusing temperature of silver. The fusible element of such fuses further comprises a pair of non-planar axially outer portions of copper each having a larger width and a larger surface than said axially inner portion. The axially inner portion and the axially outer portions are conductively interconnected.

Abstract: A composite fusible element for electric fuses comprising a pair of spaced drawn wires substantially circular in cross-section, at least one pair of spaced plates of sheet metal in contact with said pair of wires, and electrical bonds conductively connecting each of said pair of wires and one of said pair of plates. The pair of wires is preferably of silver, and the pair of plates is preferably of copper. A fuse according to the invention includes a fusible element as described above.

Abstract: A current-limiting fuse including a fusible element that comprises a relatively long portion of sheet copper and one or two end portions of sheet silver. The portions of sheet silver are each shorter than the portion of sheet copper. The portion of sheet copper is perforated, establishing points of reduced cross-section. The portion or portions of sheet silver are likewise perforated. The points of reduced cross-section established by the perforation, or perforations, in the portion or portions of sheet silver have a considerably smaller cross-section than the points of reduced cross-section in the portion of sheet copper.

Abstract: A fuse for operation with both DC and AC currents is disclosed which consists of a composite fuse link contained in a large insulator housing. Located within the housing are first and second foil sections fabricated from a good conducting material. Each foil section is secured to a right and left terminal with its other end coupled to a central link fabricated from zinc. The central link is contained within a smaller cylinder and is surrounded by air, while the foil sections are surrounded by quartz sand or some other suitable filler material dispersed within the large housing.

Abstract: A fusible element for use in fuse construction wherein the fusible element is made of an elongated, heat-conductive metal or alloy having regions of reduced cross sectional area, including a middle reduced region and two reduced intermediate regions, each of said reduced regions being disposed between two unreduced regions of the fusible element. The dimensions (width and length) of the reduced regions are selected to optimize the performance of the fusible elements.Another embodiment of the invention contemplates a fusible element with a plurality of reduced regions having specified relative dimensions for improved performance characteristics.

Abstract: A current limiting fuse is provided with a number of discrete current limiting elements coupled electrically in parallel between a pair of conductive terminals, and a fused gap assembly in series with each current limiting element whereby full range fault current protection is provided by the fuse. Under the influence of high range fault currents, the current limiting elements operate collectively to quickly clear the fault, while low fault currents are interrupted by fusing of the fused gaps to present a plurality of parallel arc gaps in the elements, which parallel gaps function in turn to sequentially distribute the full fault to each element resulting in successive interruption by the elements and ultimate clearing of the low range fault. In a second form of the invention shiftable contact sets in each element are operably coupled with a low fault current responsive device to create the arc gaps required for sequential operation of the current limiting elements.

Abstract: A fuse element for a cartridge fuse-link comprises a thin metal wire helically wound about a thin flexible core consisting of an electrically and heat insulating filament. Spaced sections of the winding at opposite ends of the fuse element are metallized so as to short-circuit the turns in these sections. The short-circuited sections are electrically interconnected by the active turns of an intermediate section which constitutes the fusible link. The fuse element is disposed in an insulating cartridge with its short-circuited sections connected to conductive end caps on the cartridge.

Abstract: A novel fuse arrangement for electrical and electronic circuits is provided having shorter arcing time and arc-extinguishing time as compared to the prior art fuses. The fuse arrangement described herein comprises a pair of electrodes having contact terminals for connection to the circuit and a support member preferably disposed triangularly relative to the electrodes. In one embodiment, a fusible wire elment is stretched between the electrodes and has its mid portion supported by the support member. The support member is made from a material of large heat capacity and high thermal conductivity to provide a heat dissipating surface for the heat generated in the fusible wire element.

Abstract: An oil immersible current limiting full range fuse including a tubular housing, end caps hermetically sealed to each end of the housing and supporting a full range fuse assembly within said housing, the housing being filled with a granular arc extinguishing filler, the hermetic seal provided between the housing and the end caps is formed by a resilient gasket mounted at each end of the housing and epoxy adhesive provided in the end caps, the adhesive being displaced by the gasket on insertion into the space between the end cap and the outer wall of the housing.A method for testing the hermetic seals for leaks which includes the steps of injecting sulfur hexafluoride into the housing, sealing the housing, confining the fuse in a closed space for a predetermined period of time and testing the atmosphere of the confined space to determine the presence of sulfur hexafluoride.

Abstract: A fusible element for a current limiting fuse includes two silver ribbons, each provided with a plurality of holes spaced apart along the length thereof which define fusible points of reduced cross sectional area, one of these ribbons including a conventional "M" spot consisting of a body of low melting temperature alloy such as tin-lead solder, in intimate contact with the silver ribbon. One end of each of the silver ribbons is joined to a respective end of a centrally disposed tin wire element by a copper interconnecting member. This tin wire central portion of the fusible element has a melt I.sup.2 t which is equal to or greater than that of the silver ribbons in series with it.

Abstract: A relatively low cost dual element fuse link including a meltable solder junction has a pair of thermally insulated, serpentine, fusible elements supported on opposite sides of the junction for increasing the heat transferred to the junction by the elements in response to a given current carried by the link such that the junction will be caused to melt at lower current values thereby providing the link with an increased speed ratio. A pair of cylindrical porcelain insulators disposed along respective serpentine elements present the desired thermal insulation as well as provide structural stability to the elements precluding deformation of their serpentine shape when the fuse link is under tension as in a distribution system cutout. The serpentine shape of the elements presents an increased element length which in turn reduces the temperature gradient along the elements thereby reducing axial conductive heat loss from the ends of the elements remote from the solder junction.

Abstract: A circuit-interrupting device has a stationary current-conducting member, a movable current-conducting member, a connector which accommodates the adjacent ends of the current-conducting members and which normally holds a mass of heat-softenable alloy in engagement with those adjacent ends, an indicator which is connected to the movable current-conducting member and a spring which can simultaneously move the movable current-conducting member, and the indicator to moved positions whenever the circuit-interrupting device opens the circuit. The adjacent ends of the current-conducting members extend into the connector a distance less than one-half of the minimum distance through which the spring will move the indicator.