摘要:
An HRC-fuse as an insulating body surrounding a main fusible conductor and an auxiliary fusible conductor connected to a spring biased impact pin. A conductive cap serving as a terminal for the fusible conductors is arranged on the insulating body and is provided with an outlet opening opposite the impact pin. A tripping hollow pin or sleeve coaxially surrounds at least a part of the impact pin and passes through the outlet opening. A bimetal release pawl is arranged in the one cap parallel to the pin and being electrically connected to the fusible conductors. The pawl engages a rest on the tripping sleeve to counteract a biasing spring. The impact pin and the tripping sleeve are triggered independently one from the other either by a short-circuit current melting the auxiliary conductor, or by an overload which heats up the bimetal release and triggers the sleeve. Both the tripping sleeve and the impact pin act on a load interruptor arranged opposite the outlet opening.
摘要:
An electric fuse includes a tube of insulating material with first and second open ends. Metallic or electrically conducting end caps are placed on each of the first and second ends. A fuse element is mounted with the tube in electrical contact with the end caps. The fuse element includes an elongated body defined by a plurality of heavy portions and a plurality of weak spots. Each weak spot is located between adjacent heavy portions. The weak spots are linear fusible portions integrally connected to adjacent heavy portions and are transverse to an axis extending along the length of the element. Each heavy portion includes first and second ends. A first adjacent heavy portion is connected at a first end of a weak spot and a second adjacent heavy portion is connected to a second end of the weak spot, such that the first ends of adjacent heavy portions are transversely offset from each other.
摘要:
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.
摘要:
Apparatus is provided for automatically interrupting current in an electrical circuit before the first current peak which occurs after an excess current condition develops. The apparatus includes a main conductor in the current path which passes the current under normal operating conditions, and pyrotechnic charge means associated with the conductor at several spaced locations which segments the conductor when it is ignited. The charge means is ignited by a fuse link which senses the current and provides a rapid thermal response to excess current conditions, generating sufficient heat to ignite the charge means within a short period of time. A current limiting fuse element may be connected in parallel with the conductor for operation at higher voltages, if needed, and the entire apparatus, including the resistive sensing means, may be contained in a single housing.
摘要:
An electric fuse, in particular an electric time-lag fuse, comprising a tubular casing, a pair of terminal elements, a granular arc-quenching filler, and a pair of parallel fusible elements inside the casing interconnecting the pair of terminal elements. Each of the pair of fusible elements has a plurality of juxtaposed points of reduced cross-section. Juxtaposed points of reduced cross-section support an M-effect causing overlay thereon. Each of the M-effect causing overlays extends from a pair of juxtaposed points of reduced cross-section in opposite directions longitudinally of said pair of fusible elements. A substantially E-shaped member of a solid gas-evolving material having three arms is associated with said pair of fusible elements. One of said three arms is interposed between said pair of fusible elements at the region thereof where the juxtaposed points of reduced cross-section are located. One of each of the two remaining arms of the substantially E-shaped member is arranged close to said parallel fusible elements and extends at right angles to edges formed by them. The aforementioned three arms are tied together by a fourth arm, at right angles to the aforementioned three arms, so that a substantially E-shaped solid is formed.
摘要:
A fuse comprises a thin metal strip of constant thickness mounted on an insulating support and having relatively wide portions mutually spaced apart and interconnected by a relatively narrow portion constituting a fusible link which overlies a recess or aperture in the support so that the fusible link is spaced apart from the support surface. Preferably, the strip is folded about one end of the support with the fusible link remote from the fold, the relatively wide portions extending around the fold on each side of the support to constitute tab contacts for mating with a receptacle.
摘要:
A current limiting fuse and an expulsion fuse are disposed in side by side relationship on a common supporting structure. One terminal of each fuse are interconnected electrically. The other terminals of each fuse are spaced by a predetermined insulating gap. An external circuit which includes a voltage source and a load to be protected is connected in series circuit relationship with the terminals of the expulsion fuse. The current limiting fuse is only disposed in circuit relationship with the external circuit for current limiting purposes when the expulsion fuse blows because of a relatively high value of fault current. This causes gaseous products to be directed from an internal portion of the expulsion fuse to a region between the unconnected terminals of both fuses. This gas conducts electrical current, thus in effect connecting the current limiting fuse in parallel circuit relationship with the expulsion fuse to commutate the fault current from the expulsion fuse to the current limiting fuse to provide a fault current limiting operation.
摘要:
This current limiting fuse employs auxiliary spark gaps adjacent fusion points of at least one main fuse element for the purpose of reliably melting additional series arc gaps in that main fuse element when the fuse is subjected to a low magnitude overload current.
摘要:
A high-voltage fuse for interrupting both protracted overload currents and major fault currents and operating as a currentlimiting fuse when interrupting major fault currents. The fuse includes one or more fusible elements each operating in the fashion of a composite fusible element including serially connected ribbon sections and a wire section interposed between, and spot-welded to, the ribbon sections. In fuses according to this invention one single stamping, i.e. one single length of sheet silver stock takes the plate of a spot-welded composite of ribbon sections and a wire section. The wire like effect is achieved by providing an oblong hole, or window, in the center region of the ribbon fuse link, resulting in the formation of two wire-like strips of small cross-sectional area to both sides of the oblong hole or window.
摘要:
A high-voltage fuse has ribbon fuse links forming a radially inner core of fuse links and has ribbon fuse links forming a radially outer shell of fuse links. The inner core fuse links are provided with long overload current interrupting neck portions positioned substantially midway between the terminal elements of the fuse. The outer shell fuse links are provided with long overload current interrupting neck portions positioned relatively close to one of the terminal elements of the fuse. The long overload current interrupting neck portions of contiguous outer shell fuse links are arranged in staggered relation.