Fuse device

Claim 2

A current-limiting fuse device for interrupting current flow comprising: an expulsion fuse means comprising at least one fusible element for optimumly interrupting current flow in a first current range, said expulsion fuse means having operative portions; and a current-limiting means for optimumly interrupting current flow in a second current range, said current-limiting portion having a hollow interior portion; said expulsion fuse means and said current-limiting means being joined together so that the internal portion of the currentlimiting means can receive at least one of the operative portions of the expulsion fuse means without adversely affecting the voltage withstand capabilities of the currentlimiting means thereby reducing the overall length of the fuse device.

Claim 3

A current-limiting fuse device, as claimed in claim 1, wherein said current-limiting means comprises: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of an electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having an aperture formed through the center thereof; a fuse element connecting said first and second end plates, said fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow thimble mounted to said second end plate through the aperture so that said thimble is positioned within said first hollow housing.

Claim 4

A current-limiting fuse device, as claimed in claim 2, wherein said expulsion fuse portion comprises: a hollow second housing formed of an electrically insulating material mounted at one end to the second end plate around said aperture; an electrical terminal connected to the other end of said second housing, said electrical terminal connected to the second point of the electrical circuit; a movable arcing rod positioned within said second housing; a fusible wire means connected between said arcing rod and said terminal, said fusible wire means formed of a material that will fuse when a second predetermined current level is exceeded; contact means connecting said second end plate and said arcing rod so that a circuit is completed between said first end plate and said terminal; spring means within said second housing for urging said arcing rod towards said hollow thimble so that said arcing rod will be rapidly moved into said hollow thimble within said first housing when said fusible wire means fuse.

Claim 5

A current-limiting fuse device for interrupting current flow between a first and second point of an electrical current comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having an aperture formed through the center thereof; a fuse element connecting said first and second end plates, said fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow thimble mounted to said second end plate through the aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at one end to the second end plate around said aperture; an electrical terminal connected to the other end of said second housing, said electrical terminal connected to the second point of the electrical circuit; a movable arcing rod positioned within said second housing; a fusible wire means connected between said arcing rod and said terminal, said fusible wire means formed oF a material that will fuse when a second predetermined current level is exceeded; contact means connecting said second end plate and said arcing rod so that a circuit is completed between said first end plate and said terminal; spring means within said second housing for urging said arcing rod towards said hollow thimble so that said arcing rod will be rapidly moved into said hollow thimble within said first housing when said fusible wire means fuses.

Claim 6

A current-limiting fuse device for interrupting current flow between a first and second point of an electrical current comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having an aperture formed through the center thereof; a fuse element connecting said first and second end plates, said fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow thimble mounted to said second end plate through the aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at one end to the second end plate around said aperture; an electrical terminal connected to the other end of said second housing, said electrical terminal connected to the second point of the electrical circuit; a movable arcing rod positioned within said second housing; a fusible wire means connected between said arcing rod and said terminal, said fusible wire means formed oF a material that will fuse when a second predetermined current level is exceeded; contact means connecting said second end plate and said arcing rod so that a circuit is completed between said first end plate and said terminal; spring means within said second housing for urging said arcing rod towards said hollow thimble so that said arcing rod will be rapidly moved into said hollow thimble within said first housing when said fusible wire means fuses.

Claim 7

A fuse device, as claimed in claim 4, wherein the first hollow housing is filled with an insulating material.

Claim 8

A fuse device, as claimed in claim 5, wherein said insulating material is quartz sand.

Claim 9

A fuse device, as claimed in claim 4, further comprising an annular liner having a hollow center positioned around said arcing rod in said second housing; said liner formed of a material capable of producing an arc-quenching gas when exposed to an electrical arc.

Claim 10

A fuse device, as claimed in claim 4, wherein said fuse element is an essentially flat ribbon having two opposite flat sides and said fuse element is helically wound so that said flat sides of said fuse element are essentially perpendicular to a center line between said first and second end plates.

Claim 11

A fuse device, as claimed in claim 4, further comprising mounting terminal means attached to said first end plate for mounting said fuse device.

Claim 12

A fuse device, as claimed in claim 4, wherein said fusible wire means comprises a silver wire and a nichrome wire.

Claim 13

A current-limiting fuse device for interrupting current flow between a first and a second point of an electrical circuit comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having an aperture formed at the center thereof; a fuse element connecting said first and second end plates, said fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow thimble mounted to said second end plate through the aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at one end to said second end plate around said aperture; an electrical terminal connected to the other end of said second housing; a movable arcing rod positioned within said second housing; contact means electrically connected to said second end plate and positioned over said aperture, said contact means having openings therethrough communicating with the hollow portion of said thimble; fusible wire means connecting said contact means and said arcing rod, said fusible wire means formed of a material that will fuse when a second predetermined current level is exceeded; muffler means within said hollow thimble for condensing arc gases resulting when said fusible wire means fuses; spring means within said second housing for urging said arcing rod away from said contact means so that said rod will move rapidly away from said contact means when said fusible wire means fuses.

Claim 14

A current-limiting fuse device for interrupting current flow between a first and a second point of an electrical circuit comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having an aperture formed at the center thereof; a fuse element connecting said first and second end plates, said fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow thimble mounted to said second end plate through the aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at one end to said second end plate around said aperture; an electrical terminal connected to the other end of said second housing; a movable arcing rod positioned within said second housing; contact means electrically connected to said second end plate and positioned over said aperture, said contact means having openings therethrough communicating with the hollow portion of said thimble; fusible wire means connecting said contact means and said arcing rod, said fusible wire means formed of a material that will fuse when a second predetermined current level is exceeded; muffler means within said hollow thimble for condensing arc gases resulting when said fusible wire means fuses; spring means within said second housing for urging said arcing rod away from said contact means so that said rod will move rapidly away from said contact means when said fusible wire means fuses.

Claim 15

A fuse device, as claimed in claim 11, wherein said muffler means comprises activated alumina particles.

Claim 16

A fuse device, as claimed in claim 11, wherein said first hollow housing is filled with an insulating material.

Claim 17

A fuse device, as claimed in claim 13, wherein said insulating material is quartz sand.

Claim 18

A fuse device, as claimed in claim 11, wherein said fuse element is an essentially flat ribbon having two opposite flat sides and said fuse element is helically wound so that said flat sides of said fuse element are essentially perpendicular to a center line between said first and second end plates.

Claim 19

A fuse device, as claimed in claim 11, further comprising mounting bracket meAns attached to said first end plate for mounting said fuse device.

Claim 20

A fuse device, as claimed in claim 11, further comprising an annular liner having a hollow center positioned around said arcing rod in said second housing; said liner formed of a material capable of producing an arc-quenching gas when exposed to an electrical arc.

Claim 21

A fuse device, as claimed in claim 11, wherein said fusible wire means comprises a silver wire and a nichrome wire.

Claim 22

A current-limiting fuse device for interrupting current flow between a first and second point of an electrical current comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having a first aperture formed through the center thereof; a first fuse element connecting said first and second end plates, said first fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow first thimble mounted to said second end plate through said first aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at a first end to the second end plate around said aperture; first contact means mounted at the other end of said second housing, said first contact means having openings therethrough; a movable arcing rod positioned within said second housing; a fusible wire means connected between said arcing rod and said first contact means, said fusible wire means formed of a material that will fuse when a second predetermined current level is exceeded; second contact means electrically connecting said second end plate and said arcing rod; spring means within said second housing for urging said arcing rod towards said first hollow thimble so that said arcing rod will be rapidly moved into said first hollow thimble within said first housing when said fusible wire means fuses; a hollow third housing formed of an electrically insulating material; a third conductive end plate sealing one end of said third housing connected to the second point of the electrical circuit; a fourth end plate sealing the other end of said third housing said fourth end plate having a second aperture formed at the center thereof; a second fuse element connecting said third and fourth end plates, said second fuse element formed of a material that will fuse when a third predetermined current level is exceeded; a hollow second thimble mounted to said second end plate through said second aperture so that said thimble is positioned within said third hollow housing; said hollow second housing being mounted at a second end to said fourth end plate around said second aperture; muffler means within said second hollow thimble for condensing arc gases resulting when said fusible wire means fuses.

Claim 23

A current-limiting fuse device for interrupting current flow between a first and second point of an electrical current comprising: a hollow first housing formed of an electrically insulating material; a first conductive end plate sealing one end of said first housing connected to the first point of the electrical circuit; a second end plate sealing the other end of said first housing, said second end plate having a first aperture formed through the center thereof; a first fuse element connecting said first and second end plates, said first fuse element formed of a material that will fuse when a first predetermined current level is exceeded; a hollow first thimble mounted to said second end plate through said first aperture so that said thimble is positioned within said first hollow housing; a hollow second housing formed of an electrically insulating material mounted at a first end to the second end plate around said aperture; first contact means mounted at the other end of said second housing, said first contact means having openings therethrough; a movable arcing rod positioned within said second housing; a fusible wire means connected between said arcing rod and said first contact means, said fusible wire means formed of a material that will fuse when a second predetermined current level is exceeded; second contact means electrically connecting said second end plate and said arcing rod; spring means within said second housing for urging said arcing rod towards said first hollow thimble so that said arcing rod will be rapidly moved into said first hollow thimble within said first housing when said fusible wire means fuses; a hollow third housing formed of an electrically insulating material; a third conductive end plate sealing one end of said third housing connected to the second point of the electrical circuit; a fourth end plate sealing the other end of said third housing said fourth end plate having a second aperture formed at the center thereof; a second fuse element connecting said third and fourth end plates, said second fuse element formed of a material that will fuse when a third predetermined current level is exceeded; a hollow second thimble mounted to said second end plate through said second aperture so that said thimble is positioned within said third hollow housing; said hollow second housing being mounted at a second end to said fourth end plate around said second aperture; muffler means within said second hollow thimble for condensing arc gases resulting when said fusible wire means fuses.