US3851207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized high intensity sodium vapor lamp
Assignee: General Electric Co
•
Filing: 1972-08-01
•
Granted: 1974-11-26
•
Expires: 1992-08-01
Abstract
Abstract A high intensity sodium vapor arc lamp utilizing a slender tubular envelope of alumina ceramic having self-heating electrodes mounted at opposite ends and containing an excess pool of liquid sodium-mercury amalgam at the cold spot in the lower end. The electrode at the lower end includes a resistive heater portion and lamp current flowing therethrough provides supplementary heat to the amalgam pool varying according to lamp current. In conjunction with the inductive ballast characteristic this stabilizes the cold spot temperature and amalgam vapor pressure, and counters the tendency to arc voltage rise with life. It also reduces the sensitivity of the lamp to radiant energy reflected back from the fixture.
Inventors
- 👤 C Mcvey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:29
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/24; H01J61/28; H01J61/04; H01J61/06; H01J61/073; H01J61/0732
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
101 words
A high intensity sodium vapor stabilized discharge lamp comprising a slender tubular ceramic envelope, closures sealing the ends of said envelope, electrodes in opposite ends of said envelope, a filling of sodium, mercury, and inert gas within said envelope, said lamp containing in operation an excess pool of sodium-mercury amalgam at the lower end, the lower electrode comprising an electron-emissive portion and a resistive heater portion interposed between the emissive portion and the lower closure and through which lamp current flows to reach the emissive portion, said resistive heater portion being supported by the lower closure and supporting the emissive portion.
Claim 2
Dependent Claim
101 words
A high intensity sodium vapor stabilized discharge lamp comprising a slender tubular ceramic envelope, closures sealing the ends of said envelope, electrodes in opposite ends of said envelope, a filling of sodium, mercury, and inert gas within said envelope, said lamp containing in operation an excess pool of sodium-mercury amalgam at the lower end, the lower electrode comprising an electron-emissive portion and a resistive heater portion interposed between the emissive portion and the lower closure and through which lamp current flows to reach the emissive portion, said resistive heater portion being supported by the lower closure and supporting the emissive portion.
Claim 3
Dependent Claim
28 words
A lamp as in claim 1 wherein the emissive portion of the lower electrode is tungsten activated with electron-emissive material, and the resistive heater portion is tungsten wire.
Claim 4
Dependent Claim
36 words
A lamp as in claim 1 wherein the emissive portion of the lower electrode comprises close wound turns of tungsten wire activated with electron-emissive material, and the resistive heater portion comprises spaced turns of tungsten wire.
Claim 5
Dependent Claim
49 words
A lamp as in claim 1 wherein the emissive portion of the lower electrode comprises axially wound close turns of tungsten wire activated with electron-emissive metal oxides coated thereon and lodged in the interstices between turns, and the resistive heater portion comprises axially wound spaced turns of tungsten wire.
Claim 6
Dependent Claim
144 words
A high intensity sodium vapor stabilized discharge lamp comprising a slender tubular ceramic envelope, closures sealing the ends of said envelope, at least one of said closures including a metal exhaust tube sealed at the outer end and projecting inwardly into said envelope, electrodes supported from said closures at opposite ends of said envelope, a filling of sodium, mercury, and inert gas within said envelope, the closure at the lower end of said envelope containing in operation an excess pool of sodium mercury amalgam, the lower electrode comprising an electron-emissive portion and a resistive heater portion interposed between the emissive portion and the lower closure, said resistive heater portion supporting the emissive portion and being attached to and supported by the inwardly projecting metal tube of the lower closure so that lamp current must flow through the resistive portion to reach the emissive portion.
Claim 7
Dependent Claim
144 words
A high intensity sodium vapor stabilized discharge lamp comprising a slender tubular ceramic envelope, closures sealing the ends of said envelope, at least one of said closures including a metal exhaust tube sealed at the outer end and projecting inwardly into said envelope, electrodes supported from said closures at opposite ends of said envelope, a filling of sodium, mercury, and inert gas within said envelope, the closure at the lower end of said envelope containing in operation an excess pool of sodium mercury amalgam, the lower electrode comprising an electron-emissive portion and a resistive heater portion interposed between the emissive portion and the lower closure, said resistive heater portion supporting the emissive portion and being attached to and supported by the inwardly projecting metal tube of the lower closure so that lamp current must flow through the resistive portion to reach the emissive portion.
Claim 8
Dependent Claim
36 words
A lamp as in claim 5 wherein the emissive portion of the lower electrode comprises close wound turns of tungsten wire activated with electron-emissive material, and the resistive heater portion comprises sPaced turns of tungsten wire.
Claim 9
Dependent Claim
49 words
A lamp as in claim 5 wherein the emissive portion of the lower electrode comprises axially wound close turns of tungsten wire activated with electron-emissive metal oxides coated thereon and lodged in the interstices between turns, and the resistive heater portion comprises axially wound spaced turns of tungsten wire.
Claim 10
Dependent Claim
19 words
A lamp as in claim 6 wherein the turns of the emissive portion are wound around a tungsten stud.
Claim 11
Dependent Claim
19 words
A lamp as in claim 7 wherein the turns of the emissive portion are wound around a tungsten stud.
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) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |