Abstract: An automobile fuse (10) for use in extreme temperature conditions such as the engine compartment of an automobile. Fuse (10) is a blade-type fuse with loads (42, 44) on fusible element (40) providing time delay characteristics to match the insulation damage curves of small diameter automobile cable harnesses. The lower portions of terminals (20) and (30) have been selectively plated with silver. The outer housing (50) has been laser etched.

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: A composite time lag fuse having an insulating housing enclosing a time delay fuse and an electrical resistance heater which is located in intimate heat transfer relationship with the time delay fuse. The time delay fuse and electrical resistance heater being connected in a series circuit between a pair of conductive end caps closing the ends of the insulating housing. An overload current flow in the electrical resistance heater resulting in the generation and transfer of heat from the electrical resistance heater to the time delay fuse to cause the time delay fuse to interrupt after a predetermined time delay, an overload current flow in the circuit to be interrupted, which is of a lesser magnitude than would otherwise be interrupted by the time delay fuse. For improved short circuit performance, a short circuit fuse is also enclosed in the insulating housing and is connected in the series circuit.

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: 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.

Abstract: An electrical fuse comprises a fusible ribbon having one or more weak spots along its axial length which is highly resistant to mechanical fatigue caused by cyclic heating and cooling of the fusible ribbon. The weak spot comprises a series of apertures arranged in a curvilinear or angular configuration extending transversely to the axis of the fuse ribbon between the opposite sides thereof. Centers of adjacent apertures of the series are offset from each other with respect to the axis of the fusible ribbon by a distance at least equal to the shortest distance between the geometric center and the peripheral edge of any one of the adjacent apertures such that the cross-sectional area of the weak spot is distributed transversely across the fuse ribbon.

Abstract: An electrical fuse wherein one or more portions of the fuse element are provided with two adjacent parallel weak spots separated by dielectric material or air gap, and arranged such that the direction of current flow in one of the adjacent weak spots is opposite that in the other adjacent weak spot, such that a magnetic field is generated which produces a separating force between the two weak spots. Arcs formed during the fusing of the weak spots are forced apart by the generated magnetic field thus increasing the arcs path lengths which increases arc voltage thereby forcing arc current to zero.

Abstract: A circuit interrupting device responsive to externally generated heat and method of manufacture of such device. The device includes a pair of spaced, coaxially aligned leads each entering a thermally conductive housing from an opposite end. The inserted ends of the coaxially aligned leads are bridged by a conductive member comprising the tail of a conical spring which surrounds one of the leads and is secured at a corresponding end of the housing. The circuit-completing spring tail is secured by fusible material to the inserted ends of each of the spaced-apart leads. In a normal, closed circuit condition, the spring is under tension. Upon heating, the fusible material softens, allowing the spring tail to break away from the inserted ends of the spaced-apart leads, the retracting force of the conical spring, pulling the spring tail from the other one of the leads to open the circuit.

Abstract: A multiple element current limiting fuse has a plurality of tube fuses soldered at opposite ends to a pair of metallic end bells having blade-like terminals for connection to busbars of an external electrical circuit. Fasteners having the general dimensions of the tube fuses are also mounted between the end bells and connectors, such as, studs or rivets are formed on ferrules at opposite ends of the fasteners to mechanically couple the fasteners to the end bells and preserve the spacing between the end bells even when the fuse is subjected to tensile forces and elevated temperatures efficient to soften the solder. The use of a hollow ceramic body and hollow connectors at the ends of the fasteners permits the passage of coolant through the fasteners for cooling the multiple element fuse.

Abstract: A current limiting fuse includes a fusible strip having semi-circular apertures formed therein, centrally disposed between the longitudinal edges of the strip. The diametric edges of the apertures lie transverse to the longitudinal edges of the fusible strip. The curved edges of the apertures are disposed in opposing relationship. Electrical weak spots which are less conductive than the remaining areas of the strip are defined between the semi-circular apertures and the longitudinal edges of the fusible strip. Semi-circular cut-outs may be included along the longitudinal edges of the fusible strip adjacent the centrally disposed semi-circular apertures to define the electrical weak spots between the cut-outs and centrally disposed apertures.

Abstract: A fuse assembly for a miniature plug-in fuse is provided with a pair of parallel spaced-apart conductive legs, each having plug-in members at one end. A fuse link of generally constant cross sectional area, integrally formed with the conductive legs, extends therebetween to form a fuse assembly of substantially planar construction. The fuse link is provided with one or more transverse offsets, each forming a weak spot.

Abstract: A miniature plug-in fuse assembly is provided in which a pair of conductive legs and a fuse link interconnecting them are integrally formed from fusible metal. An insulating casing wholly encloses the fuse link and a portion of the conductive legs, the casing having a hollow body with a cover which does not extend beyond the body in its longer dimension. The cover is secured to the body by a retaining arrangement employing the ends of the conductive legs, which also provides for the insertion of a test current to test the fuse link. Other ends of the legs extend through the body to provide plug-in members. The legs are fastened to the body by protruding lugs on the plug-in members and projecting stops on the portion of the legs in the casing. A method for making the fuse assembly of this invention involves a series of die stamping steps to form the legs and fuse link from a continuous strip of fusible metal and mounting the legs and fuse link in the casing.

Abstract: The dual element fuse of the present invention has at least one fusible element and at least one mass of heat softenable material; and that fusible element will respond to a short circuit to fuse and thereby assure opening of the circuit, whereas that mass of heat softenable material will respond to a long-continued relatively-low potentially-hurtful overcurrent to soften and thereby initiate opening of the circuit. That dual element fuse has a shunt element which shunts the mass of heat softenable material and which will fuse after that mass of heat softenable material has initiated opening of the circuit; and hence that shunt element will minimize arcing as that mass of heat softenable material initiates opening of the circuit.

Abstract: The dual element fuse of the present invention has at least one fusible element and at least one mass of heat softenable material; and that fusible element will respond to a short circuit to fuse and thereby assure opening of the circuit, whereas that mass of heat softenable material will respond to a long-continued relatively-low potentially-hurtful overcurrent to soften and thereby initiate opening of the circuit. That dual element fuse has a shunt element which shunts the mass of heat softenable material and which will fuse after that mass of heat softenable material has initiated opening of the circuit. That shunt element has a current rating which is larger than the current rating of the mass of heat softenable material; and that shunt element has a current-interrupting characteristic which has the same shape as that of the current-interrupting characteristic of the fusible element.

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.

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.