US3733572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current limiting fuse
Assignee: Cooper Industries LLC
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Filing: 1970-12-24
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Granted: 1973-05-15
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Expires: 1990-12-24
Abstract
Abstract A current limiting fuse in a tubular casing has sand or highly divided quartz surrounding a fusible element helically wound on a core or spider. The fusible element is connected at its ends to electrical connecting terminals that enable connecting the fuse into the protected circuit. An auxiliary winding is helically wound over a portion of the length of the spider and has gap electrodes connected at each end. The gap electrodes are positioned adjacent the main element and are separated therefrom by a porous fiberglass member. A radially outwardly extending mica barrier is helically wound around the spider to extend between adjacent portions of the fusible element. The barrier is attached to the spider with a heat resistant adhesive, and the auxiliary elements are imbedded in the adhesive along a portion of its length.
Inventors
- 👤 H Mikulecky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:13
CPC Classifications
H; H01; H01H; H01H85/00; H01H85/02; H01H85/38; H01H85/04; H01H85/041; H01H85/042
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
82 words
A high voltage current limiting fuse comprising: a casing, terminal means for connecting the fuse into an electrical circuit, a longitudinally extending spider, a main fusible element connected to the terminal means and helically wound around the spider, a radially outwardly extending barrier helically wound around the spider to form a helical barrier between adjacent portions of the fusible element, and a filler surrounding at least part of the main element selected to provide regions for dissipating arcs formed within the fuse.
Claim 2
Dependent Claim
82 words
A high voltage current limiting fuse comprising: a casing, terminal means for connecting the fuse into an electrical circuit, a longitudinally extending spider, a main fusible element connected to the terminal means and helically wound around the spider, a radially outwardly extending barrier helically wound around the spider to form a helical barrier between adjacent portions of the fusible element, and a filler surrounding at least part of the main element selected to provide regions for dissipating arcs formed within the fuse.
Claim 3
Dependent Claim
19 words
A high voltage current limiting fuse according to claim 1 wherein said barrier comprises a helically wound mica sheet.
Claim 4
Dependent Claim
23 words
A high voltage current limiting fuse according to claim 2 wherein said mica sheet has a thickness of approximately 0.025 to 0.0625 inches.
Claim 5
Dependent Claim
31 words
A high voltage current limiting fuse according to claim 1 wherein said barrier comprises a plurality of mica sheet sections arranged along the helical path and positioned to overlap each other.
Claim 6
Dependent Claim
22 words
A high voltage current limiting fuse according to claim 4 wherein said mica sheet sections comprise a plurality of layers of mica.
Claim 7
Dependent Claim
20 words
A high voltage current limiting fuse according to claim 1 wherein said barrier comprises a plurality of layers of mica.
Claim 8
Dependent Claim
26 words
A high voltage current limiting fuse according to claim 6 wherein said plurality of layers of mica have a thickness of approximately 0.025 to 0.0625 inches.
Claim 9
Dependent Claim
84 words
A high voltage current limiting fuse comprising: a casing, electrical connecting terminals adapted to connect the fuse into an electrical circuit, a spider extending longitudinally within the casing, a main fusible element connected to the electrical connecting terminals and helically wound around the spider, a radially outwardly extending barrier helically wound around the spider and to form a helical barrier between adjacent portions of the fusible element, and a filler within the casing selected to provide regions for dissipating arcs formed within said casing.
Claim 10
Dependent Claim
84 words
A high voltage current limiting fuse comprising: a casing, electrical connecting terminals adapted to connect the fuse into an electrical circuit, a spider extending longitudinally within the casing, a main fusible element connected to the electrical connecting terminals and helically wound around the spider, a radially outwardly extending barrier helically wound around the spider and to form a helical barrier between adjacent portions of the fusible element, and a filler within the casing selected to provide regions for dissipating arcs formed within said casing.
Claim 11
Dependent Claim
23 words
A high voltage current limiting fuse according to claim 8 wherein said barrier is composed of a high temperature resistant, electrically insulating material.
Claim 12
Dependent Claim
29 words
A high voltage current limiting fuse according to claim 9 wherein said barrier comprises a plurality of sections arranged along the helical path and positioned to overlap each other.
Claim 13
Dependent Claim
26 words
A high voltage current limiting fuse according to claim 8 wherein said barrier comprises a mica sheet having a thickness of approximately 0.025 to 0.0625 inches.
Claim 14
Dependent Claim
48 words
A high voltage current limiting fuse according to claim 8 also comprising an auxiliary conductive element helically wound along a portion of the spider and having gap electrodes at each end spaced apart from the main fusible element by a distance selected to provide a selected arc gap.
Claim 15
Dependent Claim
33 words
A high voltage current limiting fuse according to claim 12 also comprising a high temperature resistant, electrical insulating adhesive applied to the barrier and the spider to attach said barrier to said spider.
Claim 16
Dependent Claim
25 words
A high voltage current limiting fuse according to claim 13 wherein said auxiliary element is imbedded in the adhesive along a portion of its length.
Claim 17
Dependent Claim
141 words
A high voltage current limiting fuse comprising: a tubular casing, electrical connecting terminals adapted to connect the fuse in an electricAl circuit, a spider extending longitudinally within the casing, a main fusible element having ends electrically connected to the respective connecting terminals and helically wound around the spider, an auxiliary conductive element helically wound over a portion of said spider and spaced apart from the main fusible element, said element having electrodes at each end spaced apart by a selected amount from said main fusible element to provide an arc gap between said main fusible element and said auxiliary element, a radially outwardly extending barrier helically wound around the spider extending to form a helical barrier between adjacent portions of the main fusible element, and a filler within said tubular casing selected to provide arc energy dissipation areas within the fuse.
Claim 18
Dependent Claim
141 words
A high voltage current limiting fuse comprising: a tubular casing, electrical connecting terminals adapted to connect the fuse in an electricAl circuit, a spider extending longitudinally within the casing, a main fusible element having ends electrically connected to the respective connecting terminals and helically wound around the spider, an auxiliary conductive element helically wound over a portion of said spider and spaced apart from the main fusible element, said element having electrodes at each end spaced apart by a selected amount from said main fusible element to provide an arc gap between said main fusible element and said auxiliary element, a radially outwardly extending barrier helically wound around the spider extending to form a helical barrier between adjacent portions of the main fusible element, and a filler within said tubular casing selected to provide arc energy dissipation areas within the fuse.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |