US3668458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Explosively actuated ground interrupting device
Assignee: Meidensha Corp
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Filing: 1970-06-03
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Granted: 1972-06-06
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Expires: 1990-06-03
Abstract
Abstract An explosively actuated ground interrupting device for a lightning arrester has an explosive charge which may be detonated by a resistor having a coil-shaped portion which presents a high impedance to transient currents, thereby inhibiting false detonation of the explosive charge.
Inventors
- 👤 Kouhei Irie
- 👤 Misao Kobayashi
- 👤 Masaru Shimamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:09
CPC Classifications
H; H01; H01T; H01T1/00; H01T1/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
61 words
In a device for interrupting a ground connection for a lightning arrester, said device including conductive means defining a discharge gap, a sealed vessel, an elongated resistor mounted in said vessel in parallel circuit with said gap, and a body of heat-sensitive explosive in thermal contact with said resistor, the improvement which comprises a longitudinal portion of said resistor being coil-shaped.
Claim 2
Dependent Claim
61 words
In a device for interrupting a ground connection for a lightning arrester, said device including conductive means defining a discharge gap, a sealed vessel, an elongated resistor mounted in said vessel in parallel circuit with said gap, and a body of heat-sensitive explosive in thermal contact with said resistor, the improvement which comprises a longitudinal portion of said resistor being coil-shaped.
Claim 3
Dependent Claim
28 words
In a device as set forth in claim 1, said resistor having a straight longitudinal portion, said straight portion being in thermal contact with said body of explosive.
Claim 4
Dependent Claim
66 words
In a device as set forth in claim 1, said vessel including a body of insulating material formed with a bore, said resistor and said body of explosive being received in said bore, said conductive means including a substantially cup-shaped member closing one end of said bore in electrical contact with one end of said resistor, a rim portion of said cup-shaped member bounding said gap.
Claim 5
Dependent Claim
36 words
In a device as set forth in claim 3, said conductive means further including a substantially cup-shaped protective cover enveloping said body of insulating material in spaced relation to said rim portion and bounding said gap.
Claim 6
Dependent Claim
75 words
In a device as set forth in claim 1, said vessel including a substantially cylindrical body of insulating material formed with an axial bore therethrough, said resistor and said body of explosive being received in said bore, said conductive means including two substantially cup-shaped members enveloping respective axial ends of said cylindrical body and closing the axial ends of said bore, respective rim portions of said cup-shaped members being spaced to define said gap therebetween.
Claim 7
Dependent Claim
48 words
In a device as set forth in claim 5, said cylindrical body being formed with a recess in the outer circumference thereof, a part of the rim portion of one of said cup-shaped members engaging said recess and thereby axially securing said one member on said cylindrical body.
Claim 8
Dependent Claim
54 words
In a device as set forth in claim 5, said cylindrical body being formed with an annular groove in the outer circumference thereof, said groove being axially coextensive with said gap, and respective parts of said rim portions being received in said groove and thereby axially securing said cup-shaped members on said cylindrical body.
Claim 9
Dependent Claim
42 words
In a device as set forth in claim 3, a terminal formed with an opening therein, the bottom portion of said cup-shaped member being formed with an integral hollow rivet extending through said opening and securing said terminal to said cup-shaped member.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |