US3840836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current limiting sand fuse
Assignee: Cooper Power Systems LLC
•
Filing: 1972-07-26
•
Granted: 1974-10-08
•
Expires: 1992-07-26
Abstract
Abstract A current limiting fuse having electrical terminals at each end of a tubular housing, a fusible assembly provided within said housing to interconnect the terminals. The fusible assembly including a first fusible element of high current clearing characteristic and a second fusible element of low current clearing characteristic, the first fusible element substantially surrounded by a granular dielectric material, the second fusible element being positioned within an arc extinguishing sleeve formed of a material which is deionizing under the influence of an electrical arc.
Inventors
- 👤 E Link
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:34
CPC Classifications
H; H01; H01H; H01H85/00; H01H85/02; H01H85/38; H01H85/04; H01H85/05; H01H85/055; H01H85/06; H01H85/18; H01H85/42
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
113 words
A current limiting fuse comprising, a housing, an electrical terminal at each end of said housing, a fusible assembly having one end connected to one of said terminals and the other end connected to the other of said terminals and within said housing, said fusible assembly including a first fusible element of high current clearing characteristic, a second fusible element of metallic material of low current clearing characteristic, said first and second elements being connected together to form a series circuit, and an arc extinguishing member being formed of material which is deionizing under the influence of an electrical arc and a granular dielectric material completely filling said housing and surrounding said assembly.
Claim 2
Dependent Claim
113 words
A current limiting fuse comprising, a housing, an electrical terminal at each end of said housing, a fusible assembly having one end connected to one of said terminals and the other end connected to the other of said terminals and within said housing, said fusible assembly including a first fusible element of high current clearing characteristic, a second fusible element of metallic material of low current clearing characteristic, said first and second elements being connected together to form a series circuit, and an arc extinguishing member being formed of material which is deionizing under the influence of an electrical arc and a granular dielectric material completely filling said housing and surrounding said assembly.
Claim 3
Dependent Claim
56 words
The fuse according to claim 1 wherein said arc extinguishing member is in the form of a sleeve having a length substantially equal to tHe length of said second element whereby said second fusible element is insulated from said granular material so that its long time minimum melting current characteristic is less than said first element.
Claim 4
Dependent Claim
14 words
The fuse according to claim 2 wherein said sleeve is formed of silicone rubber.
Claim 5
Dependent Claim
29 words
A fuse according to claim 1 wherein said second fusible element comprises a metallic conductor having a long time minimum melting current characteristic less than said first fusible element.
Claim 6
Dependent Claim
29 words
The fuse according to claim 1 wherein said first fusible element is formed from one of silver and copper wire and said second fusible element is formed from tin.
Claim 7
Dependent Claim
16 words
The fuse according to claim 1 wherein said arc extinguishing sleeve comprises a silicone rubber tube.
Claim 8
Dependent Claim
108 words
A current limiting sand fuse comprising: a hollow casing, a conductive cap at each end of said casing, a fuse assembly positioned in said casing and having one end connected to one of said caps and the other end connected to the other of said caps, said assembly including first means for providing a high current clearing charcteristic, second means for providing a low current clearing characteristic, said first and second means being conducted in series, a granular dielectric material completely filling said casing, and an arc extinguishing sleeve enclosing the full length of said second means for thermally insulating said second means from said granular dielectric material.
Claim 9
Dependent Claim
108 words
A current limiting sand fuse comprising: a hollow casing, a conductive cap at each end of said casing, a fuse assembly positioned in said casing and having one end connected to one of said caps and the other end connected to the other of said caps, said assembly including first means for providing a high current clearing charcteristic, second means for providing a low current clearing characteristic, said first and second means being conducted in series, a granular dielectric material completely filling said casing, and an arc extinguishing sleeve enclosing the full length of said second means for thermally insulating said second means from said granular dielectric material.
Claim 10
Dependent Claim
30 words
The fuse according to claim 7 wherein said first means includes a fusible element formed from one of silver and copper wire and said second means includes a tin element.
Claim 11
Dependent Claim
110 words
A high voltage fuse of the current limiting type, a hollow insulating casing, a conductive cap on each end of said casing, a fusible assembly within said casing and connected at each end to one of said caps, said assembly including, a main fusible element for providing high current clearing characteristics, and a secondary fusible element connected in series with said first element for providing low current clearing characteristics, said secondary element including a low melting point metal wire and a thermally insulating sleeve enclosing the full length of said secondary element, and granular inert refractory arc quenching material within said casing embedding said main fusible element and said sleeve.
Claim 12
Dependent Claim
110 words
A high voltage fuse of the current limiting type, a hollow insulating casing, a conductive cap on each end of said casing, a fusible assembly within said casing and connected at each end to one of said caps, said assembly including, a main fusible element for providing high current clearing characteristics, and a secondary fusible element connected in series with said first element for providing low current clearing characteristics, said secondary element including a low melting point metal wire and a thermally insulating sleeve enclosing the full length of said secondary element, and granular inert refractory arc quenching material within said casing embedding said main fusible element and said sleeve.
Claim 13
Dependent Claim
26 words
The fuse according to claim 9 wherein said secondary fusible element limits the long time temperature rise to a level of not more than 300* C.
Claim 14
Dependent Claim
21 words
The fuse according to claim 10 wherein said metal wire is tin and said insulating sleeve is a silicone rubber tube.
Claim 15
Dependent Claim
40 words
The fuse according to claim 9 wherein said main fusible element includes a silver wire, said secondary fusible element includes a tin wire connected in series with said silver wire and said thermally insulating member comprises a silicone rubber tube.
Claim 16
Dependent Claim
16 words
The fuse according to claim 9 wherein said main fusible element is sealed within said casing.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |