A surge protection device with a high breaking capacity includes a housing with at least two lead-out electrodes, and a voltage limiting device and a thermal tripping mechanism that are installed in the housing. The voltage limiting device includes a voltage limiter, a first electrode and a second electrode that are positioned and installed in an insulating cover. The thermal tripping mechanism includes a fixed assembly, a movable assembly and a thermal trigger device. The fixed assembly and the movable assembly form a plurality of displacement switches arranged in series. The thermal trigger device is disposed in linkage with the movable assembly and includes a metal trigger sheet, a fusible alloy and an energy storage member. One end of the metal trigger sheet is fixed on the movable assembly, and the other end of the metal trigger sheet is fixed on the second electrode through welding by the fusible alloy.

Provided is a temperature-sensitive pellet-type thermal fuse having excellent reliability including an insulation property after having operated. The fuse includes, in a tubular case with high electrical conductivity and high thermal conductivity, at least a temperature-sensitive pellet being capable of melting and softening at a specific temperature, a strong compression spring pressing the temperature-sensitive pellet, an insulating lid body closing an end portion of an opening of the tubular case, a weak compression spring being in contact with the insulating lid body, a first lead having an inner end penetrating the insulating lid body as a stationary contact, and a movable contact electrically connected to the first lead and the tubular case, and further includes a second lead disposed at an end of the tubular case.

A surge protection device has at least one disconnecting device (34), at least one actuating device (36), an indicating device (40), and a shaft (38) mounted for rotation between at least a first position and a second position, the at least one actuating device (36) being variable between a first position and a second position. The shaft (38), the indicating device (40) and the actuating device (36) are formed in such a way and the actuating device (36), when in the first position, is fastened to the at least one disconnecting device (34) so as to be preloaded such that when the disconnecting device (34) is triggered, the actuating device (36) is released and triggers the indicating device (40) by means of the shaft (38). Further, a modular surge protection system is described.

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).

The present disclosure provides a high-temperature thermal pellet composition that maintains structural rigidity up to a transition temperature of about 240° C. The composition comprises at least one organic compound (e.g., triptycene or 1-aminoanthroquinone). The pellet can be disposed in a housing of a thermally-actuated, current cutoff device, such as a high-temperature thermal cutoff device (HTTCO). Also provided are material systems, which include the pellet composition and a high-temperature seal that provides substantial sealing up to at least the transition temperature. Methods of making such high-temperature pellet compositions and incorporating them into a thermally-actuated, current cutoff device are also provided.

A temperature-sensitive pellet type thermal fuse having a metal case (10); a first lead wire (L1) on an open end of the metal case (10) and insulated from the metal case (10); a second lead wire (L2) electrically connected to the bottom wall (12) of the metal case (10); a temperature-sensitive pellet (30) installed inside the case (10); a movable terminal (60) being in contact with the second lead wire (L2) and a fixed terminal (40) when below a fuse cutoff operation temperature, and being in contact with the metal case (10) but separated from the second lead wire (L2) when above the fuse cutoff operation temperature; the movable terminal (60) having a movable contact element (50) slidably contacting with the inner wall of a through hole (41) of the fixed terminal (40) to electrically connect to the fixed terminal (40).

A surge protection device with a high breaking capacity includes a housing with at least two lead-out electrodes, and a voltage limiting device and a thermal tripping mechanism that are installed in the housing. The voltage limiting device includes a voltage limiter, a first electrode and a second electrode that are positioned and installed in an insulating cover. The thermal tripping mechanism includes a fixed assembly, a movable assembly and a thermal trigger device. The fixed assembly and the movable assembly form a plurality of displacement switches arranged in series. The thermal trigger device is disposed in linkage with the movable assembly and includes a metal trigger sheet, a fusible alloy and an energy storage member. One end of the metal trigger sheet is fixed on the movable assembly, and the other end of the metal trigger sheet is fixed on the second electrode through welding by the fusible alloy.

A temperature-sensitive pellet type thermal fuse is disclosed. The thermal fuse comprises a metal case (10); a first lead wire (L1) fixedly installed on an open end of the case (10) to be insulated from the case (10) by an insulating bushing (20); a second lead wire (L2) electrically connected to the bottom wall (12) of the case (10); a temperature-sensitive pellet (12) installed inside the case (10); a movable terminal (60) being in contact with the fixed contact point (L2a) of the second lead wire (L2) and with the fixed terminal (40) below a fuse cutoff operation temperature, and being in contact with the case (10) but separated from the fixed contact point (L2a) of the second lead wire (L2) above the fuse cutoff operation temperature; a fixed terminal (40) having a through hole (41) with an inner wall, and being fixed on an inner wall (11) of the case; and the movable terminal (60) having a movable contact element (50) slidably contacting with the inner wall of the through hole (41) of the fixed terminal (40) to electrically connect to the fixed terminal (40).

A surge protection device has at least one disconnecting device (34), at least one actuating device (36), an indicating device (40), and a shaft (38) mounted for rotation between at least a first position and a second position, the at least one actuating device (36) being variable between a first position and a second position. The shaft (38), the indicating device (40) and the actuating device (36) are formed in such a way and the actuating device (36), when in the first position, is fastened to the at least one disconnecting device (34) so as to be preloaded such that when the disconnecting device (34) is triggered, the actuating device (36) is released and triggers the indicating device (40) by means of the shaft (38). Further, a modular surge protection system is described.