Patent US3534730A successfully refreshed from Google Patents.
US3898533A
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Fail-safe surge protective device
Assignee: AT&T Inc
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Filing: 1974-03-11
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Granted: 1975-08-05
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Expires: 1994-03-11
Abstract
Abstract A fail-safe surge protective device includes a housing with electrodes in opposite ends thereof in spaced relation to each other to form a gap. At least one electrode includes a central or discharge portion and an outer or spacing control portion separated therefrom by a groove. The outer portion may include beveled edges. An insulative spacer is disposed between the opposing outer portions of the electrodes and extends outward therefrom to confine discharges to the central portion of the electrodes. The spacer allows the gap spacing between the central portions to be controlled very accurately so that a gap spacing of 3 mils or less to provide a fail-safe protective device can be utilized. The central portions include a coating of carbon thereon. The device can be used either as a gas tube or an air gap protector.
Inventors
- 👤 Jr Frank George Scudner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:55
CPC Classifications
H; H01; H01T; H01T4/00; H01T4/10; H01T4/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
190 words
A surge protective device comprising a housing having first and second ends and a bore extending therethrough, a first electrode disposed in said first end of said housing and extending into said bore, and a second electrode disposed in said second end and extending into said bore in opposing spaced relation to said first electrode, CHARACTERIZED IN THAT: each said first and second electrode includes a discharge portion and a control portion in opposed relation to said discharge portion and said control portion, respectively, of the other of said electrodes to form a gap between said discharge portions, said discharge portion and said control portion are coplanar, and at least one of said electrodes has a depression therein separating said discharge portion and said control portion thereof; and a spacer of insulative material is disposed between said control portions for controlling said gap, said spacer extends over said depression for increasing the distance between said control portions around said spacer to a magnitude substantially greater than the magnitude of said gap whereby discharges between said electrodes are confined to said discharge portions away from said control portions and said spacer.
Claim 2
Dependent Claim
190 words
A surge protective device comprising a housing having first and second ends and a bore extending therethrough, a first electrode disposed in said first end of said housing and extending into said bore, and a second electrode disposed in said second end and extending into said bore in opposing spaced relation to said first electrode, CHARACTERIZED IN THAT: each said first and second electrode includes a discharge portion and a control portion in opposed relation to said discharge portion and said control portion, respectively, of the other of said electrodes to form a gap between said discharge portions, said discharge portion and said control portion are coplanar, and at least one of said electrodes has a depression therein separating said discharge portion and said control portion thereof; and a spacer of insulative material is disposed between said control portions for controlling said gap, said spacer extends over said depression for increasing the distance between said control portions around said spacer to a magnitude substantially greater than the magnitude of said gap whereby discharges between said electrodes are confined to said discharge portions away from said control portions and said spacer.
Claim 3
Dependent Claim
33 words
Apparatus in accordance with claim 1 wherein at least one of said control portions includes beveled edges, said spacer extends outward from said beveled edges to increase said distance between said control portions.
Claim 4
Dependent Claim
71 words
Apparatus in accordance with claim 1 wherein said discharge portion comprises the center of said electrodes, said control portion comprises the outer part of said electrodes about said center, each said electrode includes one said depression separating respective said control portions and discharge portions, said control portions include beveled edges, and said spacer extends outward between said beveled edges for increasing said lengths of said discharge paths between said control portions.
Claim 5
Dependent Claim
198 words
A surge protective device comprising a housing having first and second ends and a bore extending therethrough, a first electrode disposed in said first end of said housing and extending into said bore, and a second electrode disposed in said second end and extending into said bore in opposing spaced relation to said first electrode, CHARACTERIZED IN THAT: each said first and second electrode includes a discharge portion and a control portion in opposed relation to said discharge portion and said control portion, respectively, of the other of said electrodes to form a gap between said discharge portions, each said electrode includes two semicircular depressions therein separating said discharge portion and said control portion thereof, said depressions in one said electrode being rotated 90 degrees with respect to said depressions in the other said electrode; and a spacer of insulative material is disposed between said control portions for controlling said gap, said spacer extends over said depression for increasing the distance between said control portions around said spacer to a magnitude substantially greater than the magnitude of said gap whereby discharges between said electrodes are confined to said discharge portions away from said control portions and said spacer.
Claim 6
Dependent Claim
198 words
A surge protective device comprising a housing having first and second ends and a bore extending therethrough, a first electrode disposed in said first end of said housing and extending into said bore, and a second electrode disposed in said second end and extending into said bore in opposing spaced relation to said first electrode, CHARACTERIZED IN THAT: each said first and second electrode includes a discharge portion and a control portion in opposed relation to said discharge portion and said control portion, respectively, of the other of said electrodes to form a gap between said discharge portions, each said electrode includes two semicircular depressions therein separating said discharge portion and said control portion thereof, said depressions in one said electrode being rotated 90 degrees with respect to said depressions in the other said electrode; and a spacer of insulative material is disposed between said control portions for controlling said gap, said spacer extends over said depression for increasing the distance between said control portions around said spacer to a magnitude substantially greater than the magnitude of said gap whereby discharges between said electrodes are confined to said discharge portions away from said control portions and said spacer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |