Patent US3679939A successfully refreshed from Google Patents.
US3679939A
Expired / Lapsed
US
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Lightning arrester
Assignee: Mitsubishi Electric Corp
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Filing: 1971-03-01
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Granted: 1972-07-25
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Expires: 1991-03-01
Abstract
Abstract The disclosed gap structure includes two opposed electrodes and a triggering electrode positioned between them to define two gaps with them but not to divide a main electric arc developed between the opposite electrodes. Two impedance elements are connected across the gaps respectively for purpose of voltage division so that, upon applying voltages of the same waveform across the gaps respectively, a ratio of a sparkover voltage across one of the gaps to that across the other gaps ranges from 0.5 to 2.0. This causes the sparkover voltage-to-time characteristic of the gap structure to be flat.
Inventors
- 👤 Tohei Nitta
- 👤 Yoshikazu Shibuya
- 👤 Yukio Fujiwara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:22
CPC Classifications
H; H01; H01T; H01T2/00; H01T2/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
154 words
For use in a lightning arrester device including, an arcextinguishing medium formed of an electrically negative gas, a discharging gap structure comprising, a pair of main discharge electrodes disposed in spaced opposed relationship and a thin triggering electrode coupled to said main discharge electrodes by said arc-extinguishing medium disposed between said main discharge electrodes to define a pair of discharging gaps with said main discharge electrodes, said triggering electrode being located at a position that, upon applying voltages of the same waveform across said discharging gaps respectively, a ratio of a sparkover voltage across one of said discharging gaps to that across the other gap ranges from 0.5 to 2.0, said triggering electrode permits said main discharge electrodes to form a main single electric arc therebetween, and said triggering electrode being of a length so that it does not extend into the path of the axis of minimum spacing between said main discharge electrodes.
Claim 2
Dependent Claim
154 words
For use in a lightning arrester device including, an arcextinguishing medium formed of an electrically negative gas, a discharging gap structure comprising, a pair of main discharge electrodes disposed in spaced opposed relationship and a thin triggering electrode coupled to said main discharge electrodes by said arc-extinguishing medium disposed between said main discharge electrodes to define a pair of discharging gaps with said main discharge electrodes, said triggering electrode being located at a position that, upon applying voltages of the same waveform across said discharging gaps respectively, a ratio of a sparkover voltage across one of said discharging gaps to that across the other gap ranges from 0.5 to 2.0, said triggering electrode permits said main discharge electrodes to form a main single electric arc therebetween, and said triggering electrode being of a length so that it does not extend into the path of the axis of minimum spacing between said main discharge electrodes.
Claim 3
Dependent Claim
97 words
A discharging gap structure as claimed in claim 1, wherein a pair of voltage dividing elements connected in series to each other and across said discharging gaps respectively and have impedances such that a steep wave front voltage is substantially entirely applied across one of said discharging gaps while a slow front wave voltage is divided into a pair of voltage portions as determined by the ratio of the sparkover voltage across said one discharging gap to that across the other gap, and said pair of voltage portions being applied in operation across said discharging gaps respectively.
References Cited (Backward Citations)
US1477303A
Cited
US1477304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |