Abstract: A voltage interrupt device is provided transmits or conducts signals in the RF frequency range but stops all signal transmission when subject to a high energy, low frequency signal such as that generated when the antenna strikes a power line, for example, signals less than or equal to 200 MHz and greater than or equal to 600V.

Abstract: A trip mechanism for a fuse includes a trip unit disposed within an elongated housing of the fuse, and a processor. The trip unit includes a fuse element and an actuator for severing the fuse element. The processor is in electrical communication with the trip unit, and is adapted to monitor electrical current. Responsive to the processor detecting a predetermined prescribed electrical current, the processor is adapted to signal the actuator to sever the fuse element. The processor is programmable to selectively adjust the predetermined prescribed electrical current, thereby enabling the fuse to have a plurality different current ratings.

Abstract: The fuse element retaining device is an L-shaped bracket having a long leg and a short leg. The short leg has a notch and a plurality of vent holes surrounding the notch. At least one clip is provided for mounting the long leg of the L-shaped bracket to a fuse holder barrel. The fuse holder barrel has a top end and a bottom end. When the long leg of the L-shaped bracket is mounted to the fuse holder barrel, the short leg is positioned with the vent holes over the bottom end of the fuse holder barrel. The vent holes are for venting propellant gases during a discharge when a fuse element blows. The notch receives a part of the fuse element from the fuse holder barrel and minimizes projectiles from the fuse element heading towards the ground at very high speeds when the fuse element blows during the discharge.

Abstract: A transfer switch comprising a housing and a strip of metal enclosed in the housing, each end extending through the housing as a first connection. At least one first contact is integral to the metal strip. At least one second contact within the housing extends through the housing wall for a second electrical connection. At least one first section of the metal strip for severing and at least one second section of the metal strip having the properties of a hinge for pivoting. At least one exothermic source in the proximity of the first section that upon ignition severs the metal strip at the first section, and causes at least one segment of the severed metal strip to be propelled about the second section comprising the hinge, whereupon the first electrical contact is propelled to join the second electrical contact.

Abstract: The invention relates to a pyromechanical disconnecting device having a housing (2) in which an electrical conductor (3) is arranged, having a cutting plunger (5) and a cutting chisel (8) made of plastic arranged thereon for severing the electrical conductor (3), and having a pyrotechnic igniter (1) in which a pyrotechnic charge is arranged for driving the cutting plunger (5), the cutting chisel (8) having an edge that slides along a mating edge of the housing (2) or of a component (4) of the housing (2) when the cutting plunger (5) or the cutting chisel (8) is driven and when the electrical conductor (3) is severed. In order to achieve better cutting power, it is proposed that the edge of the cutting chisel (8) and/or the mating edge of the housing (2) or of a component (4) of the housing (2) comprise an inserted structural element (6, 7) having a greater hardness than plastic.

Abstract: A power circuit includes a first low voltage power bus, a second low voltage power bus, a fuse electrically connected between the first low voltage power bus and the second low voltage power bus, and a fuse barrier. The fuse has a non-interrupted state and an interrupted state. The fuse barrier includes a spring having a first end and a second end, a fastener connecting the first end of the spring to one of the first low voltage power bus and the second low voltage power bus, and an insulating barrier. The insulating barrier is disposed from the second end of the spring. The insulating barrier engages a portion of the fuse in the non-interrupted state thereof. The spring drives a portion of the insulating barrier through the fuse in the interrupted state thereof.

Abstract: A fuse assembly is provided having two fusible elements, electrically in parallel with each other, thereby providing the fuse assembly with increased inrush current withstand capacity, a greater range of current ratings and lower temperature rise at higher rated currents.

Abstract: A thermal fuse includes a first electrical contact extending through and engaged in electrical contact with a second contact. A spring is compressed between the first and second contacts. A thermally deformable pin retains the second contact against the compressed spring. The pin is responsive to a high temperature condition such that the pin deforms, thereby allowing the spring to disengage the first and second contacts.

Abstract: Fuses and a subassembly component for fuses. The fuse includes an insulating housing, a short circuit fusible element, and an arc barrier-forming body. The arc barrier-forming body is fitted around, and intimately surrounds a portion of the short-circuit fusible element. The arc barrier-forming body is formed from a silicone rubber sealant which is free flowing at room temperature but upon exposure to air increases in viscosity until it essentially becomes a solid. The arc barrier-forming body provides protection against "burn-back" within the fuse.

Abstract: A time delay fuse that includes a trigger mechanism and fusible element within a cylindrical fuse casing that is closed by end ferrules. The trigger mechanism includes a plunger, a spring, and a cylindrical shell that contains the spring and plunger in a loaded condition. The shell has an end that wraps around an end of the fuse casing and is frictionally contacted by the end ferrule thereover.

Abstract: An electrical interruption device is disclosed in which an overcurrent protective device is provided to interrupt electric current flow on a sustained overcurrent current occurring. The overcurrent protective device is characterized by a plunger which is held in tension against the force of a spring by a low temperature solder, and further in which a sleeve of insulating material, such as silicone, is provided about the plunger. Preferably, the overcurrent protective device includes a housing, with the plunger disposed in the housing and having one end extending therefrom to provide electric communication with the remainder of the electric circuit. The sleeve of insulating material preferably being located about the end of the plunger which extends from the housing. On a predetermined condition causing the solder to melt, the plunger is released and under the force of the spring is moved to a position retracted within the sleeve, interrupting the current flow.

Abstract: A fuse including a tubular casing, first and second blade-shaped terminals extending from respective sides of the casing, a short circuit fusible element attached to the first terminal, a heater attached to the second terminal, and a time delay overcurrent trigger mechanism electrically connecting the fusible element and the heater to each other in series in an electrical path between the blade-shaped terminals, the mechanism being connected to receive heat from the heater and to mechanically interrupt the electrical path when the heater heats up under low overcurrent conditions.

Abstract: An electrical interruption device is disclosed in which a space efficient spiral spring activates current interruption. The spring is characterized by coils which wind continuously about and approach a central axis, with successive coils of the spring having reduced radius to pass axially through the center of an outwardly adjacent coil. The spring may further be made to assume a flat condition with the spring coils lying flat, nesting interposed between adjacent coils. Advantageously, the spiral spring is conical in shape and is tensioned in a reverse loaded configuration wherein the coils of one end of the spring are pulled axially inward, through and past the coils of other end. Preferably the reverse loaded conical spring forms part of a thermally sensitive device which includes a housing having disposed therein a plunger which is in a biased relationship with the spring.

Abstract: A time-delay fuse having a fuse element with a series of weak spots surrounded by a loose sand filler. The fuse element is connected to a trigger mechanism by solder or other meltable alloy. The trigger section provides overload protection and the fuse element provides short circuit protection resulting in a time-delay fuse which can be used in places where there are size restrictions.

Abstract: The improved fuse assembly includes a trigger assembly having an electrically nonconductive barrel for receiving a spring loaded trigger therein and a heater strip disposed along the outer circumferential surface of the barrel with a pair of end flaps. One end flap has a hole therethrough which fits over the end of the trigger adjacent the short circuit element. A second flap fits over the end of the barrel adjacent the end ferrule. The short circuit element, which is electrically and mechanically linked to a ferrule on the opposite end of the tube from the trigger assembly, engages the trigger and heater element in a solder fusing alloy.

Abstract: A time delay fuse including a fusible element for short circuit protection and a spring-loaded plunger partially contained in an enclosure and restrained by a solder mass for time-delayed overcurrent protection, the fusible element including a segment extending along the side of the enclosure in the space between the enclosure and the fuse casing.

Abstract: A time-delay fuse (10) having parallel fusible element (22). The fuse element (22) is connected to a trigger mechanism (30) by solder or other meltable alloy. The trigger section (30) provides overload protection and the parallel fuse element (22) provide short circuit protection resulting in a time-delay fuse which can be used in places where there are size restrictions.

Abstract: A trigger for a dual element time delay fuse includes a paper cap and a heater strip having locating ears thereon.

Abstract: A time delay fuse including a fuse casing, a preassembly including a wall member, a pin passing through a hole through the wall member, solder on one side of the wall member restraining the pin from movement through the hole and electrically connecting a fusible element thereto, a spring engaging the pin and on the other side of the wall member and biasing the spring in a direction away from the solder, and a wire that is electrically connected to the pin, a terminal at an end of the casing making electrical connection to the fusible element, and a terminal at the other end of the casing making electrical connection to the wire.

Abstract: A dual element cylindrical line fuse includes an insulating assembly disposed midway along an insulating tube. A metal eyelet having a barrel with a closed end is disposed through the assembly and retains an electrically conductive coil in place around the insulator assembly. A pair of heater strips extend between the ends of the coil and conductive end caps disposed on the ends of the tube.

Abstract: A current limiting cartridge fuse having a portion of restricted diameter in one end cap, which serves as a rejection feature, is provided with an insulating insert which cooperates with the fuse casing and the one end cap to allow an active portion of a short circuit element to be located in the restricted diameter portion of the end cap.

Abstract: A connecting apparatus for connecting one end of a spring of a time-delay fuse to a hollow body of the fuse and a method for its manufacture is disclosed. The apparatus includes two transverse slots formed in the end of the body. An insert is placed in the slots. A central portion of the insert is disposed in the interior of the hollow body. An opening, such as one or more slots, is provided in the central portion of the insert for attaching one end of a spring to the insert and the body of the fuse. The other end of the spring is adapted to connect to a fusible element of the time-delay fuse. The method of manufacture of the apparatus includes forming transverse slots in the end of a hollow tube, placing the insert in the slots, and attaching one end of the spring to an opening in the insert. An alternative method of manufacture includes molding the hollow tube with an integral transverse member across the end of the tube, the transverse member having an opening in it.

Abstract: The present invention relates generally to a three chamber ferrule type fuse comprising a tube of dielectric material having a tube wall and a bore, providing a unitary sub-assembly comprising a plunger and plunger guide, and two short circuit elements, a coil spring and a ring, having the tube wall staked forming a support for the ring inserting the sub-assembly into said bore of the tube so that one end thereof rests on said ring, having the coil spring under compression, and staking the sub-assembly in place. The construction facilitates assembly by automatic machinery.

Abstract: A heavy-duty, time-delay fuse includes a pair of heat sinks having mutually facing, generally planar contact surfaces normally eutectically soldered to each other. A spring between the heat sinks is operative for urging the contact surfaces apart from each other in a direction generally perpendicular to the planes in which the contact surfaces lie in the event of an overload condition in which an overload electrical current causes a pair of fusible links to generate sufficient heat to melt the eutectically soldered interconnection between the contact surfaces after a predetermined time delay proportional to the amount of heat absorbed and dissipated by the heat sinks.

Abstract: A fuse (12) for protecting a circuit and comprising a tube (14) of insulating material having an inner wall surface (16) and an outer wall surface (18) so as to form a fuse housing. The fuse includes two opposite axial ends (20) and (22), and a first (24) and a second conductive fuse terminal (26) are secured to the tube adjacent each of those opposite axial ends, respectively. Serially-located elements (28) are disposed within the fuse housing and provide electrical continuity between the first fuse terminal and the second fuse terminal. The elements comprise stressed spring means (30) and resistor means (32), with the spring means having a proximate end (40) secured to the fuse adjacent the first fuse terminal and a distal end (41) secured through a meltable junction (34) to the resistor means.

Abstract: A time delay fuse comprises an initially open end insulating housing having conductive terminals at the opposite ends thereof, a current-heatable strip connected to one of said terminals, a thermal mass in heat communication with the current-heatable strip and a coil spring and current shunt strip electrically coupled between the current-heatable strip and the other terminal to complete a circuit between the terminals. A heat meltable solder connection is located between said thermal mass and the coil spring and current shunt strip, the spring and current shunt strip being spring urged away from the thermal mass so that upon the melting of the heat meltable solder connection the coil spring and current shunt strip will be pulled away from the thermal mass to break the physical and electrical connection of the coil spring and current shunt strip with the current-heatable strip.

Abstract: A generally U-shaped connector is included in a current limiting fuse having first and second interior conductor members. The connector is disposed between the first and second conductor members, and completes an electrical circuit therebetween. The first conductor member has a free end which is received between the legs of the U-shaped connector and is secured thereto by a first mass of heat softenable alloy. The second conductor member underlies a leg of the connector, and is secured thereto by a second mass of heat softenable alloy. A hook-like projection struck out of the bight of the U-shaped connector receives a loop end of a spring which biases the connector for circuit-opening movement away from the first conductor member. Upon conducting a small protracted overcurrent, the conductor members and connector are heated to soften the alloy masses, allowing circuit-opening movement of the spring biased connector away from the first conductor member.

Abstract: A slow-blow electrical fuse structure features one or more conducting fuse links for high-current blow-out protection and located in individual chambers filled with arc-quenching filler and in thermal contact with a spring-loaded piston-and-guide structure soldered into an extended position and similarly soldered to one of the fuse links by an extension leading through a chamber-separating insulating partition washer. At overload the heat from the fuse links melts the aforementioned soldered junctions, causing the spring to collapse the piston over the guide, simultaneously withdrawing it from the chamber, thereby breaking the circuit. A similar chamber-defining washer is captively affixed to the opposite end of the piston-and-guide assembly affixed to the optional second fuse link, both partition-forming washers being rotatingly captively secured to the ends of the piston-and-guide assembly by specially configured apertures therein.

Abstract: A dual element, time delay fuse with greater blowing time accuracy and improved operating characteristics wherein any bridging of the circuit opening air gaps by molten alloy is effectively precluded during operation of the fuse, especially operation initiated by small protracted overloads. This is accomplished with a fuse element assembly comprising a series connection of a short circuit member, a central absorber member and a heater element member, the central absorber member held to the short circuit member and heater element member by masses of fusing alloy on each of its ends, which masses of fusing alloy are prevented from combining in fabrication and circuit opening operation by flow restricting apertures located near each end of the absorber member.

Abstract: The electric time-lag fuse involves a substantially T-shaped shorting strip shorting the insulating gap formed between a pair of metal overlays on an insulating strip, and a helical tension spring having a variable diameter affixed with one of the ends thereof to said T-shaped shorting strip, and resting with the other end thereof against the annular surface of a tubular member.

Abstract: A narrow strip of metal-clad material, as used in printed circuitry, is placed inside the casing of a fuse taking the place of the fusible conductor or element. The metal layer is, in part, removed from the strip by etching, or otherwise, leaving a central zone which is completely bare and two axially outer zones where the metal layer is substantially I-shaped. The axially inner ends of this I-shaped metal overlay are conductively interconnected by a spring-biased shorting strip which shorts said completely bare zone. The shorting strip is attached by soft solder to the axially inner ends of the I-shaped overlays and is spring-biased to a circuit interrupting position. The axially outer ends of the I-shaped overlays are connected by blind solder joints to terminal caps mounted on the ends of the casing of the fuse.

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.