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: 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 blown fuse indicator is supported by a socket separate from the casing of the fuse whose blowing the indicator is supposed to indicate. The indicator includes an indicating pin of relatively large size under the bias of a relatively powerful helical spring. The pin is biased in a direction at right angles to the longitudinal axis of the fuse, or of its casing, respectively. Normally the pin is restrained by a latch projecting into a recess in the lateral wall of the pin. The latch is spring biased in the pinrestraining position thereof. When the bias of the latch is overcome by an external force, the pin moves to the indicating position thereof.

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 for elevated circuit voltages having a fusible element that is substantially in the shape of a helix and is, in essence, supported only by the pulverulent arc-quenching filler of the fuse, i.e. which is supported without resort to a mandrel of electric insulating material around which the fusible element is wound. The casing of the fuse is sealed to preclude the escape of hot arc products by circular disks of asbestos fibers and by ferrules mounted on the ends of the casing. Plug terminals performing that sealing function are dispensed with. The steps involved in assembling the fuse are described in detail.

Abstract: A fuse for elevated circuit voltages is provided with first fusible element means having a relatively low resistance and wound substantially helically around a mandrel formed of insulating plates. The fuse is provided with a spring-biased blown fuse responsive device for indicating whether or not the fuse has blown, or for tripping a switching device with relatively movable contacts, e.g. a disconnect. The blown fuse responsive device is under the control of a second fusible element means which has a relatively high resistance. Said second fusible element means includes a plurality of spaced sections forming therebetween a voltage-responsive break-down spark gap. The mandrel for supporting the first fusible element has a perforation immediately adjacent the end thereof at which the blown fuse responsive device is arranged. Two contiguous sections of the second fusible element are spaced from each other and form a voltage responsive break-down spark gap.

Abstract: A high-voltage fuse having a pair of axially spaced paper labels at the relatively cool ends thereof remote from the plateau-like high temperature zone formed by the fuse when carrying current.

Abstract: A fuse having a composite casing. It includes a radially inner tubular portion that is circular in cross-section, of uniform wall thickness, and houses the fusible element means and a body of pulverulent arc-quenching filler. The casing structure further includes a plurality of angularly displaced rods of an electric insulating material having substantially the same length as the tubular portion of uniform wall thickness of the casing arranged parallel to the axis of said tubular portion, in abutting relation to the outer surface thereof, and adhesively affixed to said outer surface. A pair of spaced external terminal plates closes the tubular portion of the casing and is provided with fasteners having shanks projecting into the end surfaces of said plurality of rods.

Abstract: An electric fuse having a casing which has a substantially prismatic outer surface rounded at the longitudinal edges thereof. The casing is a multiply glass cloth laminate including thermosetting resin and is formed by pultrusion.

Abstract: An electric fuse has a casing of synthetic-resin-glass-cloth laminate which includes but three re-inforcement plies, namely an outermost ply of woven glass fiber cloth forming an overlap extending in a direction longitudinally of said casing, and innermost ply formed by spaced rovings of glass fibers extending in a direction longitudinally of said casing, and an intermediate ply formed by a mat of substantially non-uniformly oriented glass fibers, said overlap of said outermost ply and said rovings penetrating into said intermediate ply to such an extent that the outer surface and the inner surface of said casing are substantially smooth substantially cylindrical coaxial surfaces.

Abstract: An electric fuse has a casing of synthetic-resin-glass-cloth laminate which includes a plurality of re-inforcement plies - of woven glass fiber cloth - to the exclusion of any non-woven mat material. There are along the wall of the casing cyclically alternating regions of relatively large and relatively small glass-to-resin content, which allows to impart substantially the same wall thickness to the entire perimeter of the casing.

Abstract: An electric fuse comprises a fusible element, arc-quenching means surrounding said fusible element, a casing of synthetic-resin-glass-cloth laminate housing said fusible element and said arc-quenching means, and a pair of terminal elements arranged at the ends of said casing and conductively interconnected by said fusible element. Said casing includes a plurality of plies, at least an outermost ply and an innermost ply, both formed by woven glass fiber fabric and at least one intermediate ply formed by a glass fiber mat having non-uniformly oriented fibers. The outermost ply and the innermost ply each form an overlap extending substantially in a direction longitudinally of said casing. Both overlaps are angularly displaced. The casing further includes a thermosetting resin integrating said outermost ply, said innermost ply and said intermediate ply into a laminate.

Abstract: An electric fuse adapted to form multibreaks at the occurrence of small protracted overload currents includes a first fusible element having a relatively small resistance which supports at a predetermined point thereof means for causing formation of a break at the occurrence of small protracted overloads. The fuse includes a second fusible element having a relatively high resistance shunted across said predetermined point of said first fusible element and has ends adapted to initiate arcing at small current intensities at points thereof located immediately adjacent said first fusible element. Blocks of metal are arranged in spaced relation from said first fusible element in the zone of arcing established by fusion of said ends of said second fusible element to increase the contamination of said zone by products of arcing resulting from vaporization of said blocks.A rod member of electric insulating material is arranged parallel to, but spaced from, the axis of the casing of the fuse.

Abstract: A fuse for elevated circuit voltages, e.g. 4-34 kv, has a tubular insulating casing closed on both ends thereof by means of plug terminals. The latter are provided with blind bores of which each receives one end of a fusible element, a spring means for clamping said end of said fusible element against the lateral wall of said blind bore, and a solder joint conductively interconnecting said end of said fusible element and one of said plug terminals.

Abstract: Electric fuses having a helically wound fusible element are provided with simple, cost-effective sheet metal means performing the dual function of supporting insulating plates which, in turn, support the helically wound fusible element, and of establishing conductive connections between the ends of the helically wound fusible element and a pair of ferrules by which the casing of the fuse is closed.

Abstract: A miniature fuse for small current ratings and small voltage ratings has a casing of porous cellulosic material, a pulverulent non-fulgurite-forming arc-quenching filler, a fusible element of low fusing point metal having ends bent upon the outer surface of the casing and squashed by the pressure of terminal caps press-fitted on the casing, and bodies of a cured synthetic resin imparting dimensional stability to the ends of the casing, firmly affixing the terminal caps to the casing, and resulting in the formation of a conductively stable mechanical connection between the fusible element and the terminal caps.

Abstract: A method for assembling fuses having casings closed by plug terminals conductively interconnected by helically wound fusible elements. The fusible elements are wound around squirrel-cage-like structures involving extremely thin and extremely stiff metal rods. These rods are withdrawn from the fusible elements and drawn out of the casings of the fuses at such time when the pulverulent arc-quenching filler filled into the casings provides sufficient support for the fusible elements so that the support thereof previously provided by the aforementioned metal rods can safely be dispensed with. The small diameter of the rods minimizes the voids initially formed by their removal which, in turn, minimizes the tendency of the fusible elements to be somewhat displaced incident to removal of their temporary metallic supporting rods.

Abstract: A fuse for elevated circuit voltages is provided with an arrangement or array of gas-evolving beads intended to improve the performance of the fuse under major fault current conditions. The fusible element is wound around a space in the shape of a four-sided prism, each full turn including four quarter sections. The fusible element supports a plurality of beads of a gas-evolving material that are positioned on all four sides of said space and substantially equally distributed among the four sides thereof. Said beads are mounted periodically on said quarter sections of said fusible element in such a way that bead-bearing quarter sections of said fusible element alternate with equal numbers of non-bead-bearing quarter sections thereof.