US3689995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric fuses
Assignee: Laur Knudsen Nordisk Elektricitets Selskab AS
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Filing: 1970-08-17
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Granted: 1972-09-12
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Expires: 1990-08-17
Abstract
Abstract An electric fuse comprises a metal ribbon provided with indentations or openings to form zones of narrowed cross-section serving as fuse elements, the adjacent portions of the ribbon serving as heat sinks and cooling surfaces. According to the invention, one or more insulating stiffening members is/are attached to the ribbon to improve mechanical strength in the weakened zones without affecting arc formation. In a preferred method of manufacturing, the final formation of the fuse elements takes place after the stiffening member has been attached.
Inventors
- 👤 Karl Lerstrup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:58
CPC Classifications
H; H01; H01H; H01H85/00; H01H85/02; H01H85/04; H01H85/05; H01H85/055; H01H85/08; H01H85/10; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49107
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A method of making a fuse element strip for a sand-filled fuse, comprising the steps of: punching a row of spaced holes longitudinally along a metal ribbon wherein the spacing of said holes provides sufficient mechanical strength of said metal ribbon for subsequent processing; attaching at least one insulating strip having a width less than the transverse dimension of said holes to at least one surface of said metal ribBon with the edges of said insulating strip spaced from the outer transverse portions of the edges of said holes; and punching additional material portions from said metal ribbon to form narrow necked fuse element portions spaced from said insulating strip.
Claim 2
Independent Claim
110 words
A method of making a fuse element strip for a sand-filled fuse, comprising the steps of: punching a row of spaced holes longitudinally along a metal ribbon wherein the spacing of said holes provides sufficient mechanical strength of said metal ribbon for subsequent processing; attaching at least one insulating strip having a width less than the transverse dimension of said holes to at least one surface of said metal ribBon with the edges of said insulating strip spaced from the outer transverse portions of the edges of said holes; and punching additional material portions from said metal ribbon to form narrow necked fuse element portions spaced from said insulating strip.
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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |