High-voltage fuse including insulating mandrel for supporting fusible elements

Claim 2

A high-voltage fuse including a. a tubular casing of electric insulating material; b. a pair of terminal plugs closing the ends of said casing, each of said pair of terminal plugs having a pair of narrow grooves in the axially inner end surface thereof arranged at right angles to each other, and each of said pair of terminal plugs having a circular recess in the axially inner end surface thereof exceeding in depth the depth of said pair of grooves, and one of said pair of plugs having an eccentric internally screw-threaded filling hole normally closed by a plug means; c. a post of electric insulating material arranged in the center of said casing and projecting with each end thereof into said recess in one of said pair of terminal plugs, said post having grooves in the lateral surface thereof extending in a direction longitudinally of said post and being angularly displaced 90*; d. substantially rectangular plates of heat resistant electric insulating material arranged inside said casing each having relatively long edges and relatively short edges and each engaging with a radially inner relatively long edge thereof one of said grooves in said post and each engaging with an axially outer relatively short edge thereof one of said pair of grooves in the axially inner end surfaces of said pair of terminal plugs; e. a fuse link wound helically around the radially outer edges of said plates; and f. a pulverulent arc-quenching filler inside said casing filling the space thereof unoccupied by said post, said plates and said fuse link.

Claim 3

A high-voltage fuse as specified in claim 1 wherein a. said recess in the axially inner end surface of each of said pair of terminal plugs includes an axially inner portion of relatively large diameter and an axially outer portion of relatively small diameter forming a shoulder between said axially inner portion and said axially outer portion, and wherein b. each end of said post projecting into said recess of said pair of terminal plugs is reduced in diameter forming a shoulder between each said end and the center portion of said post, said shoulder on each end of said post abutting against said shoulder in each of said pair of terminal plugs.

Claim 4

A high-voltage fuse as specified in claim 1 wherein the relatively long radially inner edges of said plates are cemented into said grooves of said post.

Claim 5

A high-voltage fuse as specified in claim 1 wherein said relatively long radially inner edges of said plates are bonded to said post and the relatively short axially outer edges of said plates are bonded to said terminal plugs by means of an epoxy resin cement.

Claim 6

A high-voltage fuse including a. a tubular casing of electric insulating material; b. a pair of terminal plugs closing the ends of said casing, said pair of terminal plugs having center recesses in the axially inner end surfaces thereof and a plurality of grooves extending radially outwardly from said center recesses; c. substantially rectangular plates of heat resistant electric insulating material arranged inside said casing, said plates having longitudinal edges arranged parallel to the axis of said casing and said plates having transverse edges conforming to the shape of and projecting into said radially extending grooves in said axially inner end surfaces of said pair of terminal plugs; d. fusible element means wound helically around the radially outer edges of said plates of insulating material anc conductively interconnecting said pair of terminal plugs; e. an insulating post arranged inside of and in coaxial relation to said casing and projecting with the ends thereof into said centEr recesses of said pair of terminal plugs, said post having grooves extending in a direction longitudinally thereof, the axially outer ends of said grooves in said post being substantially coextensive with the radially inner ends of said radially extending grooves in said axially inner end surfaces of said pair of terminal plugs, said grooves extending in a direction longitudianally of said post receiving the radially inner longitudinal edges of said plates of insulating material and said plates of insulating material being affixed at said radially inner longitudinal edges thereof to said post; and f. a pulverulent arc-quenching filler inside said casing embedding said plates of insulating material, said fusible element means and said post.

Claim 7

A high-voltage fuse including a. a tubular casing of electric insulating material; b. a pair of terminal plugs closing the ends of said casing, said pair of terminal plugs having center recesses in the axially inner end surfaces thereof and a plurality of grooves extending radially outwardly from said center recesses; c. substantially rectangular plates of heat resistant electric insulating material arranged inside said casing, said plates having longitudinal edges arranged parallel to the axis of said casing and said plates having transverse edges conforming to the shape of and projecting into said radially extending grooves in said axially inner end surfaces of said pair of terminal plugs; d. fusible element means wound helically around the radially outer edges of said plates of insulating material anc conductively interconnecting said pair of terminal plugs; e. an insulating post arranged inside of and in coaxial relation to said casing and projecting with the ends thereof into said centEr recesses of said pair of terminal plugs, said post having grooves extending in a direction longitudinally thereof, the axially outer ends of said grooves in said post being substantially coextensive with the radially inner ends of said radially extending grooves in said axially inner end surfaces of said pair of terminal plugs, said grooves extending in a direction longitudianally of said post receiving the radially inner longitudinal edges of said plates of insulating material and said plates of insulating material being affixed at said radially inner longitudinal edges thereof to said post; and f. a pulverulent arc-quenching filler inside said casing embedding said plates of insulating material, said fusible element means and said post.

Claim 8

A high-voltage fuse as specified in claim 5 wherein one of said pair of terminal plugs is provided with a pair of eccentric axially extending passageways arranged to opposite sides of said post, the axially inner end of each of said pair of passageways being arranged between said transverse edges of one pair of said plates of insulating material, and the axially outer end of each of said pair of passageways being plugged by one of a pair of plug screws.

Claim 9

A high-voltage fuse as specified in claim 5 wherein said post is formed by a tube of glass-cloth melamine and wherein said plates of insulating material include a ceramic substance.

Claim 10

A high-voltage fuse as specified in claim 5 wherein said post is tubular and filled with a pulverulent arc-quenching filler, wherein one of said center recesses extends to the axially outer surface of one of said pair of terminal plugs, is internally screw-threaded in the axially outer portion therof and receives a screw having a recess in the center therof housing a spring-biased blown fuse indicator, said blown fuse indicator being normally restrained by a restraining wire arranged inside of said tubular post.

Claim 11

A high-voltage fuse including a. a tubular casing of electric insulating material; b. a pair of terminal plugs closing said casing and having narrow grooves in the axially inner end surfaces extending radially outwardly from the centers thereof; c. plates of heat-resistant insulating material having relatively long edges positioned parallel to the axis of said casing and having relatively short edges inserted into said grooves of said pair of terminal plugs; d. fusible element means wound helically around the radially outer edges of said plates and conductively interconnecting said pair of terminal plugs; e. a cylindrical center post of electric insulating material inside said casing arranged in coaxial relation thereto and having ends projecting into said axially inner end surfaces of said pair of plugs, said center post having straight grooves in the outer surface thereof each receiving one of said relatively long edges of said plates; f. cementitious bonds firmly affixing the portions of said plates engaging said grooves in said center post to said center post to support said plates by said center post along the entire length of said plates; and g. a pulverulent arc-quenching filler inside said casing submersing said plates, said fusible element means and said center post.

Claim 12

A high-voltage fuse including a. a tubular casing of electric insulating material; b. a pair of terminal plugs closing said casing and having narrow grooves in the axially inner end surfaces extending radially outwardly from the centers thereof; c. plates of heat-resistant insulating material having relatively long edges positioned parallel to the axis of said casing and having relatively short edges inserted into said grooves of said pair of terminal plugs; d. fusible element means wound helically around the radially outer edges of said plates and conductively interconnecting said pair of terminal plugs; e. a cylindrical center post of electric insulating material inside said casing arranged in coaxial relation thereto and having ends projecting into said axially inner end surfaces of said pair of plugs, said center post having straight grooves in the outer surface thereof each receiving one of said relatively long edges of said plates; f. cementitious bonds firmly affixing the portions of said plates engaging said grooves in said center post to said center post to support said plates by said center post along the entire length of said plates; and g. a pulverulent arc-quenching filler inside said casing submersing said plates, said fusible element means and said center post.