Fuse element and a high voltage current-limiting fuse

Claim 2

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, an insulating core with said fuse element would spirally with a given pitch, an insulating tube spaced around said insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end face thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, and an arc quenching filler surrounding said insulating core within said insulating tube.

Claim 3

A fuse element as claimed in claim 1, wherein the number of said fuse wires is two.

Claim 4

A high voltage current-limiting fuse as claimed in claim 1, said insulating core comprising on its outer surface a plurality of ridges spaced from one another and extending in parallel fashion along the length of the core, whereby the core has a star-shaped cross-section.

Claim 5

A high voltage current-limiting fuse as claimed in claim 1, wherein said skirt portion of the internal electrodes is provided with a plurality of tongues and slits

Claim 6

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twIsted state and including a low melting point alloy portion incorporated therein, a Teflon sleeve spaced around said low melting point alloy portion, an insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end face thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, and an arc quenching filler surrounding said insulating core within said insulating tube.

Claim 7

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twIsted state and including a low melting point alloy portion incorporated therein, a Teflon sleeve spaced around said low melting point alloy portion, an insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end face thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, and an arc quenching filler surrounding said insulating core within said insulating tube.

Claim 8

A high voltage current-limiting fuse as claimed in claim 5, wherein said low melting point alloy portion is formed at least one of a low melting point alloy selected from the group consisting of Au-Si, Ag-Sn and Ag-Pb.

Claim 9

A high voltage current-limiting fuse as claimed in claim 6, wherein said low melting point alloy consisting of Au-Si alloy.

Claim 10

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, which at least the main portion thereof being press rolled under the twisted state, a hollow insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end face thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, an arc quenching filler surrounding said insulating core within said insulating tube, an indicator piece located on the center opening in the outer end face of one of the external electrodes, a resistor wire secured at its one end opposite to said indicator piece to the external electrode and secured at its free end through said hollow insulating core to said indicator piece, and a coiled spring for urging said indicator piece outwards.

Claim 11

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, which at least the main portion thereof being press rolled under the twisted state, a hollow insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end face thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, an arc quenching filler surrounding said insulating core within said insulating tube, an indicator piece located on the center opening in the outer end face of one of the external electrodes, a resistor wire secured at its one end opposite to said indicator piece to the external electrode and secured at its free end through said hollow insulating core to said indicator piece, and a coiled spring for urging said indicator piece outwards.

Claim 12

A high voltage current-limiting fuse as claimed in claim 8, wherein said resistor wire is provided over its intermediate region with a coiled portion and provided at each end thereof with a rectilinear portion.

Claim 13

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state and including a low melting point alloy portion incorporated therein and a Teflon sleeve spaced around said low melting point alloy portion, a hollow insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said hollow insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, an arc quenching filler surrounding said hollow insulating core within said insulating tube, an indicator piece located on the center opening in the outer end face of one of the external electrodes, a resistor wire secured at its one end opposite to said indicator piece to the external electrode and secured at its free end through said hollow insulating core to said indicator piece, and a coiled spring for urging said indicator piece outwards.

Claim 14

A high voltage current-limiting fuse including at least one fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state and including a low melting point alloy portion incorporated therein and a Teflon sleeve spaced around said low melting point alloy portion, a hollow insulating core with said fuse element wound spirally with a given pitch, an insulating tube spaced around said hollow insulating core, a pair of external electrodes closing the ends of said insulating tube and having a center opening at each end thereof, a pair of internal electrodes each provided at one end with a skirt portion for securing said insulating core thereto and provided at another end with a plurality of tongues extending through said center opening of the external electrode and radially folded upon the outer end face of the external electrode for electrically connecting each end of the fuse element to the external electrode, an arc quenching filler surrounding said hollow insulating core within said insulating tube, an indicator piece located on the center opening in the outer end face of one of the external electrodes, a resistor wire secured at its one end opposite to said indicator piece to the external electrode and secured at its free end through said hollow insulating core to said indicator piece, and a coiled spring for urging said indicator piece outwards.

Claim 15

A fuse element comprising two fuse wires twisted together and press rolled in the twisted state, having less width at intersections in which the two fuse wires cross each other, each fuse wire being smaller in thickness at said intersections than in the surrounding area.

Claim 16

A fuse element comprising two fuse wires twisted together and press rolled in the twisted state, having less width at intersections in which the two fuse wires cross each other, each fuse wire being smaller in thickness at said intersections than in the surrounding area.

Claim 17

A fuse element as claimed in claim 11 in which said two twisted fuse wires are of a uniform configuration along the total length thereof.

Claim 18

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, the number of fuse wires being two, said two twisted fuse wires comprise slightly press rolled center and end regions.

Claim 19

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, the number of fuse wires being two, said two twisted fuse wires comprise slightly press rolled center and end regions.

Claim 20

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, wherein said plurality of twisted fuse wires comprise a heavily press rolled center region, and diminishing rolled sections towards each end of the fuse wires.

Claim 21

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, wherein said plurality of twisted fuse wires comprise a heavily press rolled center region, and diminishing rolled sections towards each end of the fuse wires.

Claim 22

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, wherein said plurality of twisted fuse wires comprise slightly press rolled center and end regions.

Claim 23

A fuse element comprising a plurality of fuse wires twisted together, with at least the main portion thereof being press rolled under the twisted state, wherein said plurality of twisted fuse wires comprise slightly press rolled center and end regions.