Abstract: A plug-in fuse element comprises a one-piece plate-like body of fuse metal which forms parallel terminal blade portions having current-carrying extensions connected by a fuse link portion. For high current rated fuses, the fuse link portion extends between the current-carrying extensions at points much closer to the terminal blade portions than to the outer ends of the current-carrying extensions. An insulating body, preferably forming a housing, is rigidly anchored between the current-carrying extensions. The insulating body is preferably staked to the current-carrying extensions of the plug-in fuse element, there being anchoring apertures provided in the current-carrying extensions for the staking projections produced thereby. The anchoring apertures are located in the current-carrying extensions beyond the point where the fuse link portion joins the current-carrying extensions.

Abstract: An electric fuse having a tubular casing, an arc-quenching filler, a pair of terminal plugs closing the ends of the casing and fusible elements conductively interconnecting said pair of terminal plugs. The thermal duty imposed upon said arc-quenching filler is equalized so that equal amounts of filler are caused to absorb approximately equal amounts of heat. This is achieved by immobilizing the positions of the fusible elements and by giving them such a shape that heat dissipation is substantially equalized. In other words, the position of the fusible elements relative to the casing must be in such a way that they are not displaced when the fuse is filled with pulverulent arc-quenching filler, and the arc path of one of the fusible elements must be separated as much as possible from the arc path of the other fusible element.

Abstract: An improvement in a high voltage, full-range, current limiting fuse of the type which includes a perforated ribbon main fusible element wound about a gas evolving spider within a sand filled enclosure, and having a portion in intimate contact with a body of low melting temperature alloy, and an auxiliary fusible element whose ends are closely spaced from the main element on opposite sides of the alloy body.The portions of the main element in contact with the alloy body, and adjacent the ends of the auxiliary element are relatively long portions having a uniform cross sectional area less than half the cross sectional area of an unperforated remaining portion of the main element, to thereby reduce the time required for the fuse to clear the low magnitude fault current.

Abstract: In a one piece fusible conductor of the type having cutouts for narrowing the path of current so as to form current carrying isthmuses with a hole filled with a solder deposit adjacent each isthmus, the cross section at each isthmus has a definite relation to the cross section of the material between the hole containing the solder deposit and the diamond shaped cutouts.

Abstract: A current limiting fuse is characterized by a self-standing tubular fuse element having a high surface area-to-volume ratio to augment cooling and thus increase the steady-state current rating of the fuse and also having a plurality of axially spaced, generally diamond-shaped perforations each of which extends circumferentially somewhat less than 360.degree., with axially successive perforations displaced 180.degree. apart in a circumferential direction, thereby forming a plurality of axially spaced, ring-shaped portions providing parallel arcuate current paths and with axially extending interconnections between successive pairs of ring-shaped portions disposed on diametrically opposed sides of said tubular element to thereby further increase the length of current path through said fuse element and develop a high arc voltage.

Abstract: A method for making a plug-in fuse assembly like that disclosed and claimed in U.S. Pat. No. 3,909,767, granted Sept. 30, 1975 for Miniature Plug-In Fuse having different desired fuse ratings. The method comprises the steps of providing a strip of fuse metal which is initially preferably provided throughout its length with a continuous longitudinally extending portion of reduced thickness having a fixed thickness dimension and from which fuse link portions of fuse elements are to be stamped. Various selected areas of the strip, those which preferably are not the portions of reduced thickness and from which the terminal portions of the fuses are to be formed, are covered with a non-oxidizable conductive coating, preferably tin plating.

Abstract: A method comprises the steps of providing a blank containing a pair of laterally spaced coplanar terminal forming blade portions which are interconnected by a transverse rigid web, coplanar current carrying extensions thereof and an interconnecting relatively fragile fuse-forming link inserting around the blank a housing made of insulating material with the current carrying extensions of the blank and the interconnecting fuse-forming link preferably within the housing and with the pair of terminal blade portions of the blank and the transverse web on the outside of the housing, securing said blank to the housing so the housing rigidly interconnects and supports the current carrying extensions, and blanking the exposed transverse web interconnecting the terminal blade portions.

Abstract: A high voltage current limiting fuse is taught which has a plurality of radially oriented, notched, pleated fuse ribbons. The fuse ribbons feed through radial slots in spacers at either end of the fuse barrel. A double fold in the fuse ribbon in the region of the slot in each case provides a locking terminal for abutting the fuse ribbon against the spacer. In addition, the double fold arrangement allows the fuse ribbon to be routed conveniently radially over the edge of the spacer and along the side of the fuse barrel, between the fuse barrel and the inside of a ferrule. This secures the end of the fuse element and provides electrical continuity between the fuse element and the ferrule.

Abstract: An electric fuse suitable for motor-starting, i.e. having a considerable time-lag in the range of motor starting currents, and at the same time having a current-limiting action in the high fault current range, characterized by extremely small peak let-through currents and extremely small clearing I.sup.2.multidot. t values. To be more specific, fuses emboyding this invention have considerably smaller maximum peak let-through currents and considerably lower clearing I.sup.2.multidot. t values than Underwriter Laboratories Class RK5 fuses, and meet the maximum acceptable peak let-through current values and clearing I.sup.2.multidot. t values of Underwriter Laboratories Class RK1 fuses. This is achieved by combining specific time-lag means involving a minimum of mass with parallel current paths of greatly increased number and greatly decreased size.

Abstract: An insulating support for fusible elements in ribbon form having points of drastically reduced cross-sectional area which reduces the dimensional stability of the fusible elements to such an extent that they are not capable of supporting themselves. The support consists of a strip of electric insulating material arranged in spaced relation from, and parallel to, the fusible element. The strip has a plurality of arms projecting transversely from the former. Each of said plurality of arms supports the fusible element at a region situated between points of drastically reduced cross-sectional area thereof.

Abstract: An electric fuse having blind metal fusion joints, e.g. solder joints, between the two ferrules and the fusible element, or the fusible elements, thereof. One of these conductive connection joints is situated adjacent the center region of the inner end surface of one of the two ferrules. The other of these conductive connection joints is situated between one of the rims of the casing and the peripheral region of the inner end surface of the other of the two ferrules.

Abstract: A method comprises the steps of providing a blank containing a pair of laterally spaced coplanar terminal forming blade portions which are interconnected by a transverse rigid web, coplanar current carrying extensions thereof and an interconnecting relatively fragile fuse-forming link, inserting around the blank a housing made of insulating material with the current carrying extensions of the blank and the interconnecting fuse-forming link preferably within the housing and with the pair of terminal blade portions of the blank and the transverse web on the outside of the housing, securing said blank to the housing so the housing rigidly interconnects and supports the current carrying extensions, and blanking the exposed transverse web interconnecting the terminal blade portions.

Abstract: The fusible element of an electric fuse has a first electrical path, a second electrical path in parallel relation with the first electrical path, a weak spot in the first electrical path which can respond to a potentially-hurtful overcurrent to fuse and thereby form a first arc in the first electrical path, and a weak spot in the second electrical path longitudinally displaced from the weak spot in the first electrical path which can respond to that overcurrent to fuse and thereby form a first arc in the second electrical path. The weak spots form primary arcs as they fuse; and one important function of those primary arcs is to establish the point at which the rate of rise of the overcurrent starts to diminish, while another important function of those primary arcs is to burn the adjacent portions of the respective electrical conducting paths.

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 high voltage current limiting fuse of the type including a bound silica sand filler has a fusible element provided with evenly spaced perforations along its major length. In the region of the center of the fuse, a segment of the element is provided with additional perforations. At least one of the perforations in the segment has a lead-tin alloy overlay directly adjacent its perimeter which, in conjunction with the additional perforations, lowers the low current clearing level of the fuse.

Abstract: A method is disclosed for making a plug-in fuse assembly like that disclosed and claimed in U.S. Pat. No. 3,909,767, granted Sept. 30, 1975 for Miniature Plug-In Fuse and having different desired fuse ratings. The method comprises the steps of providing a blank of fuse metal which is initially provided throughout its length with a continuous central portion of reduced thickness having a fixed thickness dimension for making fuses of a variety of fuse ratings, and blanking the blank of fuse metal to contain a pair of laterally spaced coplanar terminal forming blade portions which are interconnected by a transverse web of reduced thickness having a fixed thickness dimension, coplanar current carrying extensions thereof and an interconnecting fuse-forming link portion of reduced thickness having a fixed thickness dimension located in a coplanar platelike body of a plug-in fuse element.

Abstract: A method is disclosed for making a plug-in fuse assembly like that disclosed and claimed in U.S. Pat. No. 3,909,767, granted Sept. 30, 1975 for Miniature Plug-In Fuse.

Abstract: An electric fuse having a plurality of fusible elements connected in parallel. The fusible elements extend from the center region of one of the ferrules to the region of the other of the ferrules coextensive with one of the rims of the casing of the fuse. The ends of the fusible elements are conductively connected to the axially inner end surfaces of the ferrules. The plurality of fusible elements is formed by a self-sustained structural unit adapted to be telescoped in one single operation into the casing of the fuse, thus greatly facilitating the assembly of the fuse.

Abstract: An electric fuse has helically wound fusible element means which are supported by a mandrel made up of insulating plates. The latter engage grooves provided in terminal plugs of the fuse. The mandrel-forming plates are locked in position inside said grooves by cooperating abutment means. These abutment means are formed by recesses in the mandrel-forming plates, and by projections formed by displaced portions of the metal of which the plug terminals of the fuse are made, which portions enter into said recesses in said mandrel-forming plates and preclude relative movement of the latter and the plug terminals.

Abstract: An electric fuse has an undulated fusible element provided with a plurality of aligned, spaced perforations. A straight rod preferably of a gas-evolving material extends through said plurality of perforations. The rod increases significantly the dimensional stability of the fusible element structure and contributes at the same time significantly to arc-extinction, if made of a gas-evolving material.

Abstract: A fuse strip used in protecting electrical circuits comprises an elongated strip-shaped body on which a plurality of polygonally-shaped apertures are spaced in the transverse direction. A current-carrying neck portion of uniform width is formed by respective longitudinal parallel sides of each adjacent pair of apertures, and a transverse band of uniform width is formed by two rows of apertures which are spaced in the longitudinal direction, each row of apertures having transverse sides which respectively lie on a common line extending in the transverse direction.

Abstract: A high-voltage fuse having a casing closed at each end thereof by a pair of composite plug terminals. Each of these composite plug terminals is made up of a pair of semi-cylindrical complementary parts. The fuse includes a pair of helically wound fusible element means whose longitudinal axes are parallel to each other and spaced from each other. One of said pair of fusible element means and one pair of semi-cylindrical terminal parts are arranged to one side of a plane of symmetry extending in a direction longitudinally of the casing of the fuse. The other of said pair of fusible element means and another pair of semi-cylindrical terminal parts are arranged to the other side of the aforementioned plane of symmetry.

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.

Abstract: An alloy for use as a fuse element in a high temperature fuse characterized by having a high resistance to corrosion and a melting point at a fixed temperature within a range of 1000.degree. to 1100.degree.C. The alloy consists of copper containing 10-14% aluminum and 0-2.5% of a second constituent which second constituent consists of one or more metals selected from a group consisting of nickel, manganese and iron. The alloy also has desirable hardness and good workability to enable fabrication of the alloy into a fused element.

Abstract: A current-limiting, single-element, dual-function, electric fuse has a fusible element with at least one "weak spot" of very small cross section; and the temperature of that weak spot will exceed eighty percent of the melting temperature of the material of that fusible element when that electric fuse operates at its maximum continuous current carrying capacity. An appreciable amount of the heat, which the weak spot generates in response to a low but potentially-harmful overload, will be conducted to the inner surface of the housing for the electric fuse by the arc-quenching filler; and a substantial percent of that conducted heat will pass to, and be radiated by, the exposed outer surface of that housing.

Abstract: A d-c fuse having a clearing ability ranging from currents close to the minimum fusing current to major fault currents is provided with a wide ribbon fuse link having a matrix-like system of perforations. The fuse link is wrapped around gas-evolving rod means in such a fashion as to form a gap between the longitudinal edges thereof resulting in the formation of currents of arc-quenching gas evolving from said rod means and flowing transversely across said edges of said ribbon fuse link.