A power fuse includes a housing, first and second conductive terminals extending from the housing, and at least one fatigue resistant fuse element assembly connected between the first and second terminals. The fuse element assembly includes at least a first conductive plate and a second conductive plate respectively connecting the first and second conductive terminals, and a plurality of separately provided wire bonded weak spots interconnecting the first conductive plate and the second conductive plate.

A multi layer fuse device includes a substrate and an elongated fuse element, having a pair of contact pads formed therewith at opposed longitudinal ends thereof formed on one surface of the substrate. A pair of passivation layers are provided covering the fuse and contact pads. Windows may be opened through both passivation layers above both of the contact pads, and conductive electrode material is electroplated through the windows to contact the contact pads and to extend partially above a top surface of the passivation layers. Exposed electroplated material may be coated with solderable conductive material or a surface mount termination may be provided. Electroplated material may cover a portion of the fuse surface prior to application of the passivation layers and extend to an end of the substrate so that windows are not required.

A protective element includes a fuse element, a movable member, a concave member, and a press. The fuse member includes, a first end, a second end, and a cut part positioned between the first end and the second end. The fuse element is energized in a first direction from the first end to the second end. The movable member and the concave member are disposed facing each other such that the cut part is interposed therebetween. The press applies a force to the movable member in a pressing direction in which a distance between the movable member and the concave member shortens. At a temperature at or above a softening temperature of the fuse element, the cut part is cut by the force of the press.

Problem To maintain a low internal resistance value and adjust spring characteristics by using a movable contact made of a multilayered material.

Means for Solving Problem A thermosensitive pellet-type thermal fuse includes, in an interior of a cylindrical case having electrical conductivity, a thermosensitive pellet that melts or softens at a temperature, a strong compression spring configured to press the thermosensitive pellet, an insulating cover closing the cylindrical case, a weak compression spring abutting against the insulating cover, a first lead extending through the insulating cover and including an inner end as a fixed contact, a movable contact electrically connecting to the first lead and the cylindrical case, a sealing resin provided surrounding a portion of the first lead and covering an outer end portion of the insulating cover, and sealing an open end portion of the cylindrical case, and a second lead disposed at one end of the cylindrical case. The movable contact includes a conductive base material and a conductive member covering a predetermined surface of the conductive base material. The conductive member is provided to contact portions with the fixed contact and an inner wall surface of the cylindrical case, and is made of a material having a Young’s modulus and a rigidity different from those of the conductive base material.

Problem To maintain a low internal resistance value and adjust spring characteristics by using a movable contact made of a multilayered material.

Means for Solving Problem A thermosensitive pellet-type thermal fuse includes, in an interior of a cylindrical case having electrical conductivity, a thermosensitive pellet that melts or softens at a temperature, a strong compression spring configured to press the thermosensitive pellet, an insulating cover closing the cylindrical case, a weak compression spring abutting against the insulating cover, a first lead extending through the insulating cover and including an inner end as a fixed contact, a movable contact electrically connecting to the first lead and the cylindrical case, a sealing resin provided surrounding a portion of the first lead and covering an outer end portion of the insulating cover, and sealing an open end portion of the cylindrical case, and a second lead disposed at one end of the cylindrical case. The movable contact includes a conductive base material and a conductive member covering a predetermined surface of the conductive base material. The conductive member is provided to contact portions with the fixed contact and an inner wall surface of the cylindrical case, and is made of a material having a Young’s modulus and a rigidity different from those of the conductive base material.

A temperature-sensitive pellet type thermal fuse having a cylindrical metal case (11), a first lead (1) fixedly installed and insulated from the case (11) and a second lead (2) electrically connected to the case (11). A temperature-sensitive pellet (12) is installed by melting inside the case (11) and has a variable height. A moving terminal (16) is elastically coupled by a first spring (17) to the temperature-sensitive pellet (12) and an activating member (15) moves in a height decrease direction of the temperature-sensitive pellet (12) by an elastic repulsive force of a second spring (18). When the temperature-sensitive pellet (12) is melted and thereby is reduced in height, a first moving contact (16b) of the moving terminal (16) is separated from a first contact (1a) of the first lead (1).

A temperature-sensitive pellet type thermal fuse having a cylindrical metal case (11), a first lead (1) fixedly installed and insulated from the case (11) and a second lead (2) electrically connected to the case (11). A temperature-sensitive pellet (12) is installed by melting inside the case (11) and has a variable height. A moving terminal (16) is elastically coupled by a first spring (17) to the temperature-sensitive pellet (12) and an activating member (15) moves in a height decrease direction of the temperature-sensitive pellet (12) by an elastic repulsive force of a second spring (18). When the temperature-sensitive pellet (12) is melted and thereby is reduced in height, a first moving contact (16b) of the moving terminal (16) is separated from a first contact (1a) of the first lead (1).

A temperature-sensitive pellet type thermal fuse having a cylindrical metal case (10) with one end electrically connected to a first lead (L1) and a second lead (L2) installed on the other end via an insulating bushing (50). A temperature-sensitive pellet (30) on a spring (13) is in an inner space (S1) of the case (10). A switch terminal (40) has an upper surface (42) electrically connected to the second lead (L2) by an elastic force of the spring (13). A contact terminal piece (41) extends from the upper surface (42) to contact the inner wall surface (11) of the case 10. An activating member operates when the temperature-sensitive pellet (30) is reduced in height to a predetermined level or less, and releases contact between the contact terminal piece (41) and the case (10) to cut off an electrical connection between the first lead (L1) and the second lead (L2).

A temperature-sensitive pellet type thermal fuse having a cylindrical metal case (10) with one end electrically connected to a first lead (L1) and a second lead (L2) installed on the other end via an insulating bushing (50). A temperature-sensitive pellet (30) on a spring (13) is in an inner space (S1) of the case (10). A switch terminal (40) has an upper surface (42) electrically connected to the second lead (L2) by an elastic force of the spring (13). A contact terminal piece (41) extends from the upper surface (42) to contact the inner wall surface (11) of the case 10. An activating member operates when the temperature-sensitive pellet (30) is reduced in height to a predetermined level or less, and releases contact between the contact terminal piece (41) and the case (10) to cut off an electrical connection between the first lead (L1) and the second lead (L2).

A high breaking capacity chip fuse including a bottom insulative layer, a first intermediate insulative layer, a second intermediate insulative layer, and a top insulative layer disposed in a stacked arrangement in the aforementioned order, a fusible element disposed between the first and second intermediate insulative layers and extending between electrically conductive first and second terminals at opposing longitudinal ends of the bottom insulative layer, the first intermediate insulative layer, the second intermediate insulative layer, and the top insulative layer, wherein the first and second intermediate insulative layers are formed of porous ceramic.