US3671798A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for limiting field-emission current
Assignee: National Aeronautics and Space Administration
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Filing: 1970-12-11
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Granted: 1972-06-20
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Expires: 1990-12-11
Abstract
Abstract Self-protected electrodes which inherently limit field-emitted currents to a safe value and also stabilize such currents are disclosed. The electrodes are characterized by a plurality of columnar conductors connected at one end to a common potential source. The electrodes are insulated from one another along their lengths whereby the effective or exposed surfaces thereof are subdivided into a mosaic of conducting patches which are insulated from one another.
Inventors
- 👤 Wayne L Lees
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:58
CPC Classifications
H; H01; H01J; H01J19/00; H01J19/28; H01J19/40; H01J1/00; H01J1/02; H01J1/30; H01J1/304; H01J1/3042
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
146 words
A self-protecting electrode for use in rarified gaseous environments comprising: a plurality of spaced elongated columnar conductors, each of the columnar conductors having first and second ends and having sufficient resistance between the ends to provide a predetermined potential shift in the potential of one end with respect to the other in response to the flow of a predetermined field-emission current through the respective columnar conductors, the distance between any pair of said conductors in a direction perpendicular to their lengths being greater than the length of either conductor in said direction; insulating material for insulating said conductors one from another along their lengths with at least a portion of each conductor extending from its first end being surrounded by said insulating means and inhibited from exposure to the other conductors; and means for electrically connecting the first ends of said conductors to a common point.
Claim 2
Dependent Claim
146 words
A self-protecting electrode for use in rarified gaseous environments comprising: a plurality of spaced elongated columnar conductors, each of the columnar conductors having first and second ends and having sufficient resistance between the ends to provide a predetermined potential shift in the potential of one end with respect to the other in response to the flow of a predetermined field-emission current through the respective columnar conductors, the distance between any pair of said conductors in a direction perpendicular to their lengths being greater than the length of either conductor in said direction; insulating material for insulating said conductors one from another along their lengths with at least a portion of each conductor extending from its first end being surrounded by said insulating means and inhibited from exposure to the other conductors; and means for electrically connecting the first ends of said conductors to a common point.
Claim 3
Dependent Claim
38 words
The electrode of claim 1 wherein said conductors are of substantially equal length, are very long when compared to their cross-sectional area and the second ends of said conductors being of substantially the same cross-sectional shape and area.
Claim 4
Dependent Claim
48 words
The apparatus of claim 2 wherein said insulating material extends the length of said conductors, with only the second ends of said conductors being exposed and each conductor along its entire length being covered by said insulating means to inhibit its exposure along its length to adjacent conductors.
Claim 5
Dependent Claim
123 words
A self-protecting electrode for use in rarified gaseous environments comprising: a plurality of columnar conductors, each of the columnar conductors having first and second ends and having sufficient resistance between the ends to provide a predetermined potential shift in the potential of one end with respect to the other in response to the flow of a predetermined field-emission current through the respective columnar conductors; insulating material for insulating said conductors, one from another along said lengths, said insulating material extending along a portion of said conductors from their first ends, the second ends of the conductors and portions thereof adjacent said second ends extending above the insulating material; and means for electrically connecting the first ends of said conductors to a common point.
Claim 6
Dependent Claim
123 words
A self-protecting electrode for use in rarified gaseous environments comprising: a plurality of columnar conductors, each of the columnar conductors having first and second ends and having sufficient resistance between the ends to provide a predetermined potential shift in the potential of one end with respect to the other in response to the flow of a predetermined field-emission current through the respective columnar conductors; insulating material for insulating said conductors, one from another along said lengths, said insulating material extending along a portion of said conductors from their first ends, the second ends of the conductors and portions thereof adjacent said second ends extending above the insulating material; and means for electrically connecting the first ends of said conductors to a common point.
Claim 7
Dependent Claim
36 words
The apparatus of claim 4 further comprising: a layer of conductive material disposed on the surface of the insulating material through which the conductors extend, said layer of conductive material being electrically isolated from said conductors.
Claim 8
Dependent Claim
118 words
An electrode comprising: a substantially flat electrically conductive base member; a plurality of electrically conductive columnar members, each extending vertically from said base member with a first end in electrical contact with said base member and an opposite second end remote from said base member; and insulating material extending from said base member and surrounding at least a portion of each columnar member from its first end toward its second end, whereby at least a portion of each columnar member is inhibited from exposure to the other columnar members, the distance between any pair of said columnar members in a direction parallel to said base member being greater than the width of either columnar member in said directIon.
Claim 9
Dependent Claim
118 words
An electrode comprising: a substantially flat electrically conductive base member; a plurality of electrically conductive columnar members, each extending vertically from said base member with a first end in electrical contact with said base member and an opposite second end remote from said base member; and insulating material extending from said base member and surrounding at least a portion of each columnar member from its first end toward its second end, whereby at least a portion of each columnar member is inhibited from exposure to the other columnar members, the distance between any pair of said columnar members in a direction parallel to said base member being greater than the width of either columnar member in said directIon.
Claim 10
Dependent Claim
40 words
The electrode of claim 6 wherein said columnar members are of substantially equal length, are very long when compared to their cross-sectional area and the second ends of said columnar members being of substantially the same cross-sectional shape and area.
Claim 11
Dependent Claim
52 words
The apparatus of claim 7 wherein said insulating material extends the entire length of said columnar members, with only the second ends of said columnar members being exposed and each columnar member along its entire length being covered by said insulating material to inhibit its exposure along its length to adjacent members.
Claim 12
Dependent Claim
40 words
The apparatus of claim 7 wherein said insulating material extends along a portion of said columnar members from their first ends, the second ends of the columnar members and portions thereof adjacent said second ends extending above the insulating material.
Claim 13
Dependent Claim
38 words
The apparatus of claim 9 further comprising: a layer of conductive material disposed on the surface of the insulating material through which the columnar members extend, said layer of conductive material being electrically isolated from said columnar members.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |